Designs of MEMS
来自ST的MEMS麦克风使用指南,含参数计算
February 2017DocID025704 Rev 2 1/20 AN4426 Application note Tutorial for MEMS microphonesIntroductionThis application note serves as a tutorial for MEMS microphones, providing general characteristics of these devices, both acoustic and mechanical, as well as summarizing the portfolio available from ST. MEMS microphones target all audio applications where small size, high sound quality, reliability and affordability are key requirements.ST's MEMS microphones are designed, developed and manufactured within ST, creating an industry-unique, vertically integrated supply chain. Both analog and digital-input, top and bottom-port solutions are available.Our best-in-class AOP and SNR make ST’s MEMS microphones suitable for applications that require a very high dynamic range, improving the audio experience in any environment. Matching very tightsensitivity allows optimizing beamforming and noise cancelling algorithms for multi-microphone arrays. Low power consumption allows extending battery life.Contents AN4426 Contents1Mechanical specifications, construction details (4)2Acoustic parameters (11)2.1Sensitivity (11)2.2Directionality (11)2.3SNR (12)2.4Dynamic range and acoustic overload point (12)2.5Equivalent input noise (13)2.6Frequency response (15)2.7Total harmonic distortion (16)2.8PSRR and PSR (16)3MEMS microphone portfolio (17)4Revision history (19)2/20 DocID025704 Rev 2AN4426 List of figures List of figuresFigure 1: MEMS microphone inside package (4)Figure 2: MEMS transducer mechanical specifications (4)Figure 3: Capacitance change principle (5)Figure 4: 4 x 5 package (5)Figure 5: 3 x 4 metal cap package - bottom port (6)Figure 6: 3 x 4 package - top port (6)Figure 7: 2 x 3 package - bottom port (7)Figure 8: Faraday cage in ST’s MEMS microphones (7)Figure 9: RF immunity simulation (8)Figure 10: EMC test setup (8)Figure 11: RF test disturbance signal with sinusoidal pattern (9)Figure 12: RF immunity test results - MP34DT04 (9)Figure 13: RF test disturbance signal @ 217 Hz burst pattern (10)Figure 14: RF immunity of analog differential microphones (10)Figure 15: Omnidirectional microphone (11)Figure 16: A-weighted filter response (12)Figure 17: Acoustic and electrical relationship - analog (13)Figure 18: Acoustic and electrical relationship - digital (14)Figure 19: MP45DT02-M frequency response (15)Figure 20: MEMS microphone portfolio (17)Figure 21: MEMS microphone notation (17)DocID025704 Rev 2 3/201 Mechanical specifications, construction detailsA microphone is a dual-die device consisting of two components, the integrated circuit andthe sensor, which are housed in a package using techniques that are proprietary to ST.ASICintegratedThe sensor uses MEMS technology (Micro-Electrical-Mechanical Systems) and it isbasically a silicon capacitor. The capacitor consists of two silicon plates/surfaces. Oneplate is fixed while the other one is movable (respectively, the green plate and the grey oneshown in the following figure). The fixed surface is covered by an electrode to make itconductive and is full of acoustic holes which allow sound to pass through. The movableplate is able to move since it is bonded at only one side of its structure. A ventilation hole,allows the air compressed in the back chamber to flow out and consequently allows themembrane to move back. The chamber allows the membrane to move inside but also, incombination with the chamber created by the package will affect the acoustic performanceof the microphones in terms of frequency response and SNR.Figure 2: MEMS transducer mechanical specificationsSo basically the microphone MEMS sensor is a variable capacitor where the transductionprinciple is the coupled capacitance change between a fixed plate (back plate) and amovable plate (membrane) caused by the incoming wave of the sound.4/20 DocID025704 Rev 2Figure 3: Capacitance change principleThe integrated circuit converts the change of the polarized MEMS capacitance into a digital (PDM modulated) or analog output according to the microphone type. Finally the MEMS microphone is housed in a package with the sound inlet placed in the top or in the bottom part of the package, hence the top-port or bottom-port nomenclature of the package. ST manufactures microphones using industry-wide techniques, but also has developed innovative packaging to achieve improved performance of the microphones. Packaging techniques will be discussed in further detail.The 4x5 package is widely used to house the digital microphone MP45DT02-M. It is a common packaging technique in a top-port configuration where the ASIC is placed under the sound inlet with glue on top (glob top) in order to protect the circuit from light and the MEMS sensor is placed beside the integrated circuit. The two silicon components are fixed to the substrate and the pads of the device are on the bottom side. The resonant chambers are identified depending on the position of each chamber with respect to the membrane and the incoming sound. In this case, considering the incoming direction of the sound, the front chamber is created by the package and the chamber inside the MEMS, behind the MEMS membrane, is the back chamber. This configuration allows protecting the MEMS from dust and particles falling into the package but results in a low SNR and frequency response with a peak in the audio band.Figure 4: 4 x 5 packageThe 3x4 package is used in ST to produce both the bottom and the top-port digital microphones, MP34DB02 and MP34DT01-M, MP34DT04/-C1, and MP34DT05. Considering the bottom configuration first, this structure is depicted in the following figure. The ASIC and the MEMS sensor are fixed to the substrate and the pads of the device are on bottom side as well. The sound inlet is obtained by drilling the substrate according to the position of the MEMS sensor. The package encloses all the components. In this configuration the front chamber is the cavity of the MEMS sensor and the package creates the back chamber. This design optimizes the acoustic performance of the microphone in terms of SNR and also allows obtaining a flat response across the entire audio band. The drawback of this solution is represented by the assembly of this microphone. Usually theDocID025704 Rev 2 5/20bottom-port microphones are soldered on the PCB. The thickness of the board modifies thevolume of the front chamber, degrading the flat response of this type of microphone (referto AN4427, “Gasket design for optimal acoustic performance in MEMS microphones” fordetails). In order to minimize the artifacts caused by this environment, a flex cable isrecommended to be used. Additionally, the bottom-port microphones have a ringed metalpad around the hole. A very careful soldering process is required to avoid dust or solderingpaste from entering in the sound port, damaging the MEMS membrane.Figure 5: 3 x 4 metal cap package - bottom portThe 3x4 top-port configuration is basically a mirrored bottom-port microphone. The ASICand the sensor are placed close to each other, the sensor is still under the sound inlet butthese two components are attached to the top of the structure, in other words, the ASICand MEMS are fixed to the package lid, not to the substrate. The pads are on the substrateand thus on the bottom side of the microphone. This configuration, covered by ST patents,allows optimizing all the benefits of the bottom-port microphone in terms of acousticperformance (i.e. maximized SNR and flat band) and all the benefits related to the top-portconfiguration during the assembly process.Figure 6: 3 x 4 package - top port6/20 DocID025704 Rev 2A smaller package, 2.5 x 3.35 mm, has been introduced in ST's product portfolio (for simplicity referred to as 2x3, see Figure 7: "2 x 3 package - bottom port"). This package is a bottom-port configuration with the same internal construction as the 3 x 4 bottom-port package and it is used for the analog differential microphones MP23AB01DM/DH and analog single-ended microphone MP23AB02B. As a result of the 2x3 bottom-port package and differential output configuration, the MP23AB01DH is the best microphone provided by ST in terms of SNR and AOP.Figure 7: 2 x 3 package - bottom portMEMS microphones housed in a plastic package are protected from radiated disturbances by embedding in the plastic package a metal shield which serves as a Faraday cage. The model in the following figure shows how the Faraday cage is implemented in ST’s plastic packages.Figure 8: Faraday cage in ST’s MEMS microphonesThe next figure shows the simulation of an electric field in open space. By applying an electric field source outside the microphone package, the Faraday cage is able to considerably attenuate the field inside the microphone structure. The temperature grade of the E field is an easy way to plot the results.DocID025704 Rev 2 7/20Figure 9: RF immunity simulationIn addition to the simulation, ST has a dedicated test to evaluate immunity, “Microphonedurability to EMC disturbances”.Microphones are subjected to RF disturbances using a proper jig with the following setup.Basically the test consists of placing the microphone under an antenna radiating adisturbance signal of 1 kHz AM modulated in the range [0.8, 3] GHz. The RF amplitudediffers depending on the frequency range according to the following criteria:•+33 dBm in the range [0.8, 2.4]•+17 dBm in the range [2.4, 3.0]8/20 DocID025704 Rev 2Figure 11: RF test disturbance signal with sinusoidal patternThe carrier of the disturbance is 1 kHz since it is an audio signal. Hence, the RF immunity of the microphone is evaluated by measuring the residual of the carrier at the output of the microphone. The next figure shows the result of the peak at 1 kHz measured when applying the RF disturbance on top of an MP34DT04.In parallel with the sinusoidal pattern, another 217 Hz burst pattern used to test the RF immunity is shown in the following figure.•The RF amplitude (power): +33 dBm•Carrier frequency: 700 MHz ~ 2.5 GHz•GSM burst frequency: 217 Hz pattern (see below)DocID025704 Rev 2 9/20Figure 13: RF test disturbance signal @ 217 Hz burst patternFigure 14: RF immunity of analog differential microphones10/20 DocID025704 Rev 2AN4426Acoustic parametersDocID025704 Rev 211/202Acoustic parameters2.1SensitivityThe sensitivity is the electrical signal at the microphone output to a given acoustic pressure as input. The reference of acoustic pressure is 1 Pa or 94 dBSPL @ 1 kHz. The sound pressure level, expressed in decibel, dBSPL=20*Log(P/Po) where Po = 20 µPa is the threshold of hearing. 20*Log(1Pa/20µPa) = 94 dBSPL • For analog microphones the sensitivity is expressed in mV RMS /Pa or dBV/Pa •For digital microphones the sensitivity is expressed in dBFSdBV ≠ dBFS. It is not correct to compare different units. As given in the above equations, dBV is in reference to 1V RMS instead of dBFS where the reference is the digital full scale.2.2 DirectionalityThe directionality indicates the variation of the sensitivity response with respect to thedirection of the arrival of the sound. MEMS microphones from ST are omnidirectional which means that there is no sensitivity change to every different position of the source of thesound in space. The directionality can be indicated in a Cartesian axis as sensitivity drift vs. angle or in a polar diagram showing the sensitivity pattern response in space.The following figure depicts the directionality in these two reference systems.Figure 15: Omnidirectional microphoneAcoustic parametersAN442612/20DocID025704 Rev 22.3 SNRThe signal-to-noise ratio specifies the ratio between a given reference signal to the amount of residual noise at the microphone output. The reference signal is the standard signal at the microphone output when the sound pressure is 1Pa @ 1 kHz (microphone sensitivity). The noise signal (residual noise) is the microphone electrical output at silence.This parameter includes both the noise of the MEMS element and the ASIC. Concerning this sum, the main contribution to noise is given by the MEMS sensor, the integrated circuit contribution can be considered negligible. Typically, the noise level is measured in an anechoic environment and A-weighting the acquisition. The A-weighted filter corresponds to the human ear frequency response.Figure 16: A-weighted filter response2.4 Dynamic range and acoustic overload pointThe dynamic range is the difference between the minimum and maximum signal that the microphone is able to generate as output. • The minimum signal is the smallest audio signal that the microphone can generate distinctly from noise. In other words, the minimum signal is equivalent to the residual noise.•The maximum audio signal is that which the microphone can generate withoutdistortion. It is also called acoustic overload point (AOP). Actually, the specification allows up to 10% in terms of distortion at the acoustic overload point.AN4426 Acoustic parameters2.5 Equivalent input noiseA microphone is a sound-to-electricity transducer which means that any output signalcorresponds to a specific sound as input. The equivalent input noise (EIN) is the acousticlevel, expressed in dBSPL, corresponding to the residual noise as output.For example, a digital microphone with a sensitivity of -26 dBFS and a 63 dB as SNR:Residual noise = -26 - 63 = -89 dBFS this sum transposed in the acoustic domain is:EIN = 94 - 63= 31 dBSPLThe following figures summarize the relationship between the acoustic and electricdomains related to each of the parameters listed above. Figure 17: "Acoustic and electricalrelationship - analog" and Figure 18: "Acoustic and electrical relationship - digital" illustratethis for analog and digital microphones, respectively.Figure 17: Acoustic and electrical relationship - analogDocID025704 Rev 2 13/20Acoustic parametersAN442614/20DocID025704 Rev 29030-90-3094dBSPL AOPS N R =63d B-26dBFSD y n a m i c R a n g e =89d BSensitivity EIN Residual noiseAN4426 Acoustic parameters 2.6 Frequency responseThe frequency response of a microphone in terms of magnitude indicates the sensitivityvariation across the audio band. This parameter also describes the deviation of the outputsignal from the reference 0 dB. Typically, the reference for this measurement is exactly thesensitivity of the microphone @ 0 dB = 94 dBSPL @ 1 kHz. The frequency response of amicrophone can vary across the audio frequency band depending on three parameters: theventilation hole, the front chamber geometry, and back chamber geometry. The ventilationhole and the back chamber geometry have an impact on the behavior at low frequencieswhile the behavior at high frequencies depends on the geometry of the front chamber only.Behavior at high frequencies can be a resonance peak caused by the Helmholtz effect.This resonance is the phenomenon of air resonance in a cavity. As a matter of fact, itdepends on the dimension of the front chamber of the microphone, representing the soundcavity in which the air resonates. A microphone with a flat frequency response is suitablewhen natural sound and high intelligibility of the system is required. The following figureshows the response of the MP45DT02-M. It shows a roll-off at low frequencies and a peakaround 18 kHz caused by the large front chamber of this microphone.Figure 19: MP45DT02-M frequency responseThe frequency response of a microphone in terms of phase indicates the phase distortionintroduced by the microphone. In other words, the delay between the sound wave movingthe microphone membrane and the electrical signal at the microphone output results in thatthis parameter includes both the distortion due to the membrane and the ASIC.DocID025704 Rev 2 15/20Acoustic parametersAN442616/20DocID025704 Rev 22.7 Total harmonic distortionTHD is the measurement of the distortion affecting the electrical output signal of themicrophone given an undistorted acoustic signal as input. THD+N is expressed as a ratio of the integer in a specified band of the power of the harmonics plus the power of noise and the power of the undistorted signal (fundamental). Equation 1TTTTTT +NN (%)=∑PPPPPPPPPP (TTHHPPHHPPHHHH HH HH )+PPPPPPPPPP (NNPPHH HH PP )NN nn−1PPPPPPPPPP (FFFFHHFFHHHHPPHHFFHHFF )Typically ST indicates the THD+N measured in the (50 Hz - 4 kHz) band for a given undistorted signal 1 kHz @ 100 dBSPL.2.8 PSRR and PSRPSRR indicates the capability of the ASIC to reject noise added to the supply voltage. To evaluate this parameter, a tone of V IN = 100 mVpk-pk @ 217 Hz (GSM switching frequency in phone applications) is added to the power supply and then the amplitude of the output is measured. The added noise can be either a square wave or sinusoidal wave. Typically the square wave is preferred since it is the worst case.PSRR is the ratio of the residual noise amplitude at the microphone output (V OUT @ 217 Hz) to the added spurious signal on the supply voltage. It is typically expressed in dB as given in the equation below: Equation 2PPPPPPPP =20 xx log �(VV OOOOOO @217TTHH )(VV IINN @217TTHH )�The capability of the integrated circuit to reject noise added to the supply voltage can also be expressed with another parameter that is the PSR. Basically it is simply a measurement of the output when noise of 100 mVpk-pk @ 217 Hz is superposed to the supply voltage. Consequently expressed in dB as given in the equation below: Equation 3 PPPPPP =20 xx log[VV OOOOOO @217TTHH ]To evaluate either the PSRR or PSR, proper sealing of the sound inlet or measurements performed in an anechoic chamber are recommended to avoid mixing the superimposed noise with that of the noise floor of the output. Finally, in the microphone datasheets PSR is commonly given instead of PSRR.AN4426 MEMS microphone portfolio3 MEMS microphone portfolioFigure 20: MEMS microphone portfolioST’s portfolio includes digital and analog microphones. The commercial products arenamed using the notation depicted in the following figure.Figure 21: MEMS microphone notationDocID025704 Rev 2 17/20MEMS microphone portfolio AN442618/20DocID025704 Rev 2The following table provides a complete overview of the microphones offered by ST. Additionally it serves as a summary for selecting the appropriate microphone among the ST portfolio as the features of both digital and analog microphones are given.Table 1: Features of MEMS microphonesParameter MP45DT02-M MP34DB02 MP34DT01-M MP34DT04 MP34DT04-C1 MP34DT05 MP23AB02B MP23AB01DM MP23AB01DH Sensitivity -26 dBFS -26 dBFS -26 dBFS -26 dBFS -26 dBFS -26 dBFS -38 dBV -38 dBV -38 dBV Directivity OmnidirectionalOmnidirectional OmnidirectionalOmnidirectionalOmnidirectionalOmnidirectionalOmnidirectionalOmnidirectionalOmnidirectionalSNR 61 dB 62.5 dB 61 dB 64 dB 64 dB 64 dB 64 dB 64 dB 65 dB AOP 120 dBSPL 120 dBSPL 120 dBSPL 120 dBSPL 120 dBSPL 122 dBSPL 125 dBSPL 130 dBSPL 135 dBSPL EIN 33 dB 31.5 dB 33 dB 30 dB 30 dB 30 dB 30 dB 30 dB 29 dB THD+N <5% @ 115 dBSPL <5% @ 115 dBSPL <2% @ 115 dBSPL <5% @ 115 dBSPL <5% @ 115 dBSPL <6% @ 120 dBSPL <2% @ 120 dBSPL <10% @ 130 dBSPL <5% @ 130 dBSPL PSR -70 dB -86 dB -70 dB -70 dB -70 dB -72 dB -70 dB -85 dB -100 dB Max. current consumption 650 µA 650 µA 600 µA 700 µA 700 µA 650 µA 220 µA 250 µA 250 µA Package dimensions 3.76x4.76x1.25mm3x4x1mm 3x4x1.06mm 3x4x1.095mm 3x4x1.095mm 3x4x1mm 2.5x3.35x0.98mm 2.5x3.35x0.98mm 2.5x3.35x0.98mm Port location Top port Bottom port Top port Top port Top port Top port Bottom port Bottom port Bottom port Operating temperature-30°C<T<+85°C-40°C<T<+85°C-40°C<T<+85°C-40°C<T<+85°C-40°C<T<+85°C-40°C<T<+85°C-40°C<T<+85°C-40°C<T<+85°C-40°C<T<+85°CAN4426Revision historyDocID025704 Rev 219/204 Revision historyTable 2: Document revision historyDate RevisionChanges09-Jan-20141Initial release14-Feb-2017 2Updated part numbers throughout documentUpdated "Introduction" and Section 1: "Mechanical specifications, construction details"Updated Figure 5: "3 x 4 metal cap package - bottom port", Figure 20: "MEMS microphone portfolio", Figure 21: "MEMS microphone notation"Added Figure 7: "2 x 3 package - bottom port",Figure 13: "RF test disturbance signal @ 217 Hz burst pattern", Figure 14: "RF immunity of analog differential microphones" Updated Table 1: "Features of MEMS microphones"AN4426IMPORTANT NOTICE – PLEASE READ CAREFULLYSTMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement.Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers’ products.No license, express or implied, to any intellectual property right is granted by ST herein.Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product.ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners.Information in this document supersedes and replaces information previously supplied in any prior versions of this document.© 2017 STMicroelectronics – All rights reserved20/20 DocID025704 Rev 2。
MEMS原理解读
什么是MEMS？
• MEMS是英文Micro Electro Mechanical systems的缩写，即微 电子机械系统。微电子机械系统(MEMS)技术是建立在微米/纳 米技术（micro/nanotechnology）基础上的21世纪前沿技术， 是指对微米/纳米材料进行设计、加工、制造、测量和控制的技 术。它可将机械构件、光学系统、驱动部件、电控系统集成为一 个整体单元的微型系统。这种 微电子机械系统不仅能够采集、 处理与发送信息或指令，还能够按照所获取的信息自主地或根据 外部的指令采取行动。它用微电子技术和微加工技术(包括硅体 微加工、硅表面微加工、LIGA和晶片键合等技术)相结合的制造 工艺，制造出各种性能优异、价格低廉、微型化的传感器、执行 器、驱动器和微系统。 微电子机械系统（MEMS）是近年来发 展起来的一种新型多学科交叉的技术，该技术将对未来人类生活 产生革命性的影响。它涉及机械、电子、化学、物理、光学、生 物、材料等多学科。
Materials for MEMS Manufacturing
• Silicon • Polymers [ˈpɔlimə] • Metals
MEMS Basic Processes
• This chart is not complete:
Basic Process
Deposition
Patterning
MEMS description
• MEMS technology can be implemented using a number of different materials and manufacturing techniques; the choice of which will depend on the device being created and the market sector in which it has to operate.
MEMS微系统 复习红宝书(北理)
20.BGA : Ball Grid Array 球状矩阵排列
21.SHM:Structural Health Monitoring 结构健康监测
22.ICT:Information and Communications Technologies 信息与通信技术
23.MtM More than Moore 超越摩尔定律
24.FEA:Finite Element Analysis 有限元分析
25.SEM:Scanning Electron Microscope 扫描电子显微镜
12.ITRS International technology Roadmap for Semiconductor 国际半导体技术规
划
.
27.DARPA :Defence Advanced Research Projects Agency of theDepartment of
成，它们各具不同的能带隙。这些材料可以是 GaAs 之类的化合物，也可以是 Si-Ge 之类的半导体合金。按异质结中两种材料导带和价带的对准情况可以把异 质结分为Ⅰ型异质结和Ⅱ型异质结两种。 12.微加工：以微小切除量获得很高精度的尺寸和形状的加工。 13.引线键合：引线键合（Wire Bonding）是一种使用细金属线，利用热、压力、 超声波能量为使金属引线与基板焊盘紧密焊合，实现芯片与基板间的电气互连和 芯片间的信息互通。 14. 倒装芯片：倒装芯片（Flip chip）是一种无引脚结构，一般含有电路单元。 设 计用于通过适当数量的位于其面上的锡球（导电性粘合剂所覆盖），在电气上和 机械上连接于电路。 15.热声焊：热声焊是一种固态键合技术，为热压结合与超音波结合的混合方法。 它可完成电路片与芯片、腔体之间的电连接。 16.各向异性粘接:用各向异性导电胶（主要使用单一或双重成分的环氧树脂）完 成对电路基板与倒装芯片之间的互连。 17.柔性印刷电路:即 FPC，是以聚脂薄膜或聚酰亚胺为基材制成的一种具有高度 可靠性,绝佳曲挠性的印刷电路。通过在可弯曲的轻薄塑料片上，嵌入电路设计， 使在窄小和有限空间中堆嵌大量精密元件，从而形成可弯曲的挠性电路。 18.高深宽比：垂直于加工表面的高度与其加工表面上所具有的特征尺寸的比值 大。 19. 盲孔： 定义 1.位于印刷线路板的顶层和底层表面，具有一定深度，用于表层线路和下面 的内层线路的连接，孔的深度通常不超过一定的比率（孔径）。
What is MEMS Technology
What is MEMS Technology?Micro-Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through microfabrication technology. While the electronics are fabricated using integrated circuit (IC) process sequences (e.g., CMOS, Bipolar, or BICMOS processes), the micromechanical components are fabricated using compatible "micromachining" processes that selectively etch away parts of the silicon wafer or add new structural layers to form the mechanical and electromechanical devices.MEMS promises to revolutionize nearly every product category by bringing together silicon-based microelectronics with micromachining technology, making possible the realization of complete systems-on-a-chip. MEMS is an enabling technology allowing the development of smart products, augmenting the computational ability of microelectronics with the perception and control capabilities of microsensors and microactuators and expanding the space of possible designs and applications.MEMS ApplicationsMicroelectronic integrated circuits can be thought of as the "brains" of a system and MEMS augments this decision-making capability with "eyes" and "arms", to allow microsystems to sense and control the environment. Sensors gather information from the environment through measuring mechanical, thermal, biological, chemical, optical, and magnetic phenomena. The electronics then process the information derived from the sensors and through some decision making capability direct the actuators to respond by moving, positioning, regulating, pumping, and filtering, thereby controlling the environment for some desired outcome or purpose. Because MEMS devices are manufactured using batch fabrication techniques similar to those used for integrated circuits, unprecedented levels of functionality, reliability, and sophistication can be placed on a small silicon chip at a relatively low cost.There are numerous possible applications for MEMS. As a breakthrough technology, allowing unparalleled synergy between previously unrelated fields such as biology and microelectronics,many new MEMS applications will emerge, expanding beyond that which is currently identified or known. Here are a few applications of current interest:BiotechnologyMEMS technology is enabling new discoveries in science and engineering such as the Polymerase Chain Reaction (PCR) microsystems for DNA amplification and identification, micromachined Scanning Tunneling Microscopes (STMs), biochips for detection of hazardous chemical and biological agents, and microsystems for high-throughput drug screening and selection.CommunicationsHigh frequency circuits will benefit considerably from the advent of the RF-MEMS technology. Electrical components such as inductors and tunable capacitors can be improved significantly compared to their integrated counterparts if they are made using MEMS technology. With the integration of such components, the performance of communication circuits will improve, while the total circuit area, power consumption and cost will be reduced. In addition, the mechanical switch, as developed by several research groups, is a key component with huge potential in various microwave circuits. The demonstrated samples of mechanical switches have quality factors much higher than anything previously available.Reliability and packaging of RF-MEMS components seem to be the two critical issues that need to be solved before they receive wider acceptance by the market.AccelerometersMEMS accelerometers are quickly replacing conventional accelerometers for crash air-bag deployment systems in automobiles. The conventional approach uses several bulky accelerometers made of discrete components mounted in the front of the car with separate electronics near the air-bag; this approach costs over $50 per automobile. MEMS technology has made it possible to integrate the accelerometer and electronics onto a single silicon chip at a cost between $5 to $10. These MEMS accelerometers are much smaller, more functional, lighter, more reliable, and are produced for a fraction of the cost of the conventional macroscale accelerometer elements.Fabricating MEMSMEMS devices are extremely small -- for example, MEMS has made possible electrically-driven motors smaller than the diameter of a human hair (right) -- but MEMS technology is not primarily about size.MEMS is also not about making things out of silicon, even though silicon possesses excellent materials properties, which make it an attractive choice for many high-performance mechanical applications; for example, the strength-to-weight ratio for silicon is higher than many other engineering materials which allows very high-bandwidth mechanical devices to be realized. Instead, the deep insight of MEMS is as a new manufacturing technology, a way of making complex electromechanical systems using batch fabrication techniques similar to those used for integrated circuits, and uniting these electromechanical elements together with electronics. Advantages of MEMS ManufacturingFirst, MEMS is an extremely diverse technology that could significantly affect every category of commercial and military product. MEMS are already used for tasks ranging from in-dwelling blood pressure monitoring to active suspension systems for automobiles. The nature of MEMS technology and its diversity of useful applications make it potentially a far more pervasive technology than even integrated circuit microchips.Second, MEMS blurs the distinction between complex mechanical systems and integrated circuit electronics. Historically, sensors and actuators are the most costly and unreliable part of a macroscale sensor-actuator-electronics system. MEMS technology allows these complex electromechanical systems to be manufactured using batch fabrication techniques, decreasing the cost and increasing the reliability of the sensors and actuators to equal those of integrated circuits. Yet, even though the performance of MEMS devices and systems is expected to be superior to macroscale components and systems, the price is predicted to be much lower.Current ChallengesMEMS technology is currently used in low- or medium-volume applications.Some of the obstacles preventing its wider adoption are:Limited OptionsMost companies who wish to explore the potential of MEMS technology have very limited options for prototyping or manufacturing devices, and have no capability or expertise in microfabrication technology. Few companies will build their own fabrication facilities because of the high cost. A mechanism giving smaller organizations responsive and affordable access to MEMS fabrication is essential.PackagingThe packaging of MEMS devices and systems needs to improve considerably from its current primitive state. MEMS packaging is more challenging than IC packaging due to the diversity of MEMS devices and the requirement that many of these devices be in contact with their environment. Currently almost all MEMS development efforts must develop a new and specialized package for each new device. Most companies find that packaging is the single most expensive and time consuming task in their overall MEMS product development program. As for the components themselves, numerical modeling and simulation tools for MEMS packaging are virtually non-existent. Approaches which allow designers to select from a catalog of existing standardized packages for a new MEMS device without compromising performance would be beneficial.Fabrication Knowledge RequiredCurrently the designer of a MEMS device requires a high level of fabrication knowledge in order to create a successful design. Often the development of even the most mundane MEMS device requires a dedicated research effort to find a suitable process sequence for fabricating it. MEMS device design needs to be separated from the complexities of the process sequence.How the MEMS Exchange Can HelpThe MEMS Exchange provides services that can help with some of these problems.∙We make a diverse catalog of processing capabilities available to our users, so our users can experiment with different fabrication technologies. We also have a number of novel processes that are difficult to obtain from other fabrication services.∙Our users don't have to build their own fabrication facilities, and∙Our web-based interface lets users assemble process sequences and submit them for review by the MEMS Exchange's engineers and fabrication sites.。
微型电声元器件产业链
微型电声元器件产业链英文回答：The Micro-Electro-Acoustic Component (MEMS) industry chain is a complex and highly specialized ecosystem that involves a wide range of players, from raw materialsuppliers to device manufacturers to end-user applications. The industry is characterized by its rapid innovation cycle, driven by the continuous advancements in materials science, fabrication techniques, and device packaging.The MEMS industry chain can be broadly divided into the following stages:Raw material suppliers: These companies provide the basic materials used in the fabrication of MEMS devices, such as wafers, substrates, and thin films.Foundries: Foundries are specialized manufacturersthat produce MEMS devices based on customer designs. Theytypically offer a range of fabrication technologies, suchas photolithography, etching, and deposition.Device manufacturers: Device manufacturers integrate MEMS devices into larger systems and products. They may design their own MEMS devices or source them from foundries.End-user applications: MEMS devices are used in a wide variety of end-user applications, including consumer electronics, automotive, medical devices, and industrial automation.The MEMS industry chain is a global one, with major players located in North America, Europe, and Asia. The industry is highly competitive, with a number of large,well-established companies competing for market share. However, there are also a number of smaller, specialized companies that are focused on niche markets.The MEMS industry is expected to continue to growrapidly in the coming years. This growth will be driven by the increasing demand for MEMS devices in a wide range ofapplications. The industry is also expected to benefit from the development of new fabrication technologies that will enable the production of more complex and sophisticated MEMS devices.中文回答：微型电声元器件（MEMS）产业链是一个复杂且高度专业化的生态系统，涉及广泛的参与者，从原材料供应商到器件制造商再到最终用户应用。
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基于MEMS的人体运动信息采集系统
摘要摘要近年来，随着大众对体育运动的关注逐渐增加，对健康生活意识不断增强，智能运动设备迎来了最好的发展机会，同时借助MEMS传感器技术的发展，基于MEMS的人体运动信息采集系统具有很重要的应用价值。
该系统可以实现对人体运动状态及身体信息等的实时监测，对于可能发生的运动损伤等问题及时预警，将该系统应用在竞技运动项目中，能够详细记录运动员的训练数据，辅助运动员制定合理的训练计划，提升运动员比赛成绩。
因此，基于MEMS的人体运动信息采集系统及其进一步应用具有重要意义。
本论文首先根据基于MEMS的人体运动信息采集系统的主要应用，对该系统所需的MEMS传感器进行建模分析，为确保其测量精度，给出标定方法，并针对MEMS传感器测量精度易受温度影响的特点，对其进行温度补偿。
进一步给出一种多传感器同步测试方法，提高MEMS传感器的标定、温度补偿及测试效率。
然后，本论文针对基于MEMS的人体运动信息采集系统在实际应用中的需求，根据三种MEMS传感器的特性设计姿态估计算法，实现由传感器测量数据到姿态数据的转换，并对算法的性能进行分析及改进，进一步实现全角度姿态估计算法。
对比了四种UWB定位算法，从中选择TDOA算法，并对其进行详细分析以及仿真验证，确保UWB定位算法的定位精度。
接下来，本论文完成了整个基于MEMS的人体运动信息采集系统的硬件设计，先给出了该系统的整体设计方案，并在此基础上对该系统采用模块化设计，分别设计了姿态测量单元、UWB定位单元以及数据存储及通信单元，其中姿态测量单元由根据实际使用中的不同需求，设计了微小型姿态测量单元和多功能姿态测量单元，而数据存储及通信单元为了保证数据存储及传输的可靠性，分别设计了数据离线存储单元及蓝牙远程通信单元。
该系统采用模块化设计，使得该系统具有更为方便的扩展与升级能力，具有较好的适用性及可靠性。
最后，本论文对基于MEMS的人体运动信息采集系统的性能进行了测试，主要完成了对其姿态测量单元静态及动态姿态估计精度、UWB定位精度的测试，然后利用该系统对常见的头部运动进行采集验证其信息采集能力，并在以羽毛球为背景的应用环境中对该系统的整体性能进行测试，验证其具备运动信息采集能力，可以与神经网络等智能算法相配合，完成更为具体的人体运动信息分析功能。
纹理物体缺陷的视觉检测算法研究--优秀毕业论文
摘 要
在竞争激烈的工业自动化生产过程中，机器视觉对产品质量的把关起着举足 轻重的作用，机器视觉在缺陷检测技术方面的应用也逐渐普遍起来。与常规的检 测技术相比，自动化的视觉检测系统更加经济、快捷、高效与 安全。纹理物体在 工业生产中广泛存在，像用于半导体装配和封装底板和发光二极管，现代 化电子 系统中的印制电路板，以及纺织行业中的布匹和织物等都可认为是含有纹理特征 的物体。本论文主要致力于纹理物体的缺陷检测技术研究，为纹理物体的自动化 检测提供高效而可靠的检测算法。 纹理是描述图像内容的重要特征，纹理分析也已经被成功的应用与纹理分割 和纹理分类当中。本研究提出了一种基于纹理分析技术和参考比较方式的缺陷检 测算法。这种算法能容忍物体变形引起的图像配准误差，对纹理的影响也具有鲁 棒性。本算法旨在为检测出的缺陷区域提供丰富而重要的物理意义，如缺陷区域 的大小、形状、亮度对比度及空间分布等。同时，在参考图像可行的情况下，本 算法可用于同质纹理物体和非同质纹理物体的检测，对非纹理物体 的检测也可取 得不错的效果。 在整个检测过程中，我们采用了可调控金字塔的纹理分析和重构技术。与传 统的小波纹理分析技术不同，我们在小波域中加入处理物体变形和纹理影响的容 忍度控制算法，来实现容忍物体变形和对纹理影响鲁棒的目的。最后可调控金字 塔的重构保证了缺陷区域物理意义恢复的准确性。实验阶段，我们检测了一系列 具有实际应用价值的图像。实验结果表明 本文提出的纹理物体缺陷检测算法具有 高效性和易于实现性。 关键字: 缺陷检测；纹理；物体变形；可调控金字塔；重构
Keywords: defect detection, texture, object distortion, steerable pyramid, reconstruction
II
MEMS加速度计二阶非线性补偿方法研究
MEMS加速度计二阶非线性补偿方法研究王一焕;李杰;刘一鸣;兰洋;李文豪【摘要】Aiming at the problem that because of fixing error of the 3-axis accelerometer installed in the micro inertial measurement unit(MIMU)will enlarged in harsh cone movement situation,this paper puts forward a calibration-compensation method which is based on multi-position static rotation of the 3-axis position speed turntable.according to the establishment of the angle error compensation model to design the completed experiment process of calibration,and finally,calculating calibration factor matrix and accelerometer's zero voltage accurately based on the method of nonlinear fitting data processing.according to the calibration experiment and error calculation contrast,this error of calibration method is one order of magnitude smaller than the previous one,improving the output accuracy of the accelerometer effectively,having significant engineering application meaning.%微惯性集成测量组合(MIMU)中的惯性传感器,陀螺仪和加速度计的标定补偿研究大多集中在安装误差角补偿和一阶线性常数的计算上,对二阶非线性系数的测量、计算研究的不多不深.通过分析含二次非线性系数的加速度计输出模型,提出一种补偿二次非线性系数的方法,并进行了完善的理论分析和试验.最终通过计算能有效补偿MIMU的输出精度,为后续的导航信息解算奠定了基础,具有重要的工程应用价值.【期刊名称】《传感技术学报》【年(卷),期】2017(030)003【总页数】7页(P418-424)【关键词】MIMU;标定;二阶非线性系数;误差补偿【作者】王一焕;李杰;刘一鸣;兰洋;李文豪【作者单位】中北大学电子测试技术重点实验室,太原 030051;中北大学电子测试技术重点实验室,太原 030051;中北大学电子测试技术重点实验室,太原 030051;中北大学电子测试技术重点实验室,太原 030051;中北大学电子测试技术重点实验室,太原 030051【正文语种】中文【中图分类】V241.62某型高速旋转弹在飞行过程中,轴向旋转角速率极大,角加速度变化极为剧烈。
mems技术的基础流程
mems技术的基础流程英文回答：Microelectromechanical Systems (MEMS) Fabrication Process Flow.1. Substrate Preparation: A silicon wafer is cleanedand oxidized to form a thin layer of silicon dioxide (SiO2).2. Patterning: A photoresist (PR) layer is spun ontothe substrate and exposed to UV light through a mask. The exposed PR is developed, creating a pattern of exposed SiO2.3. Etching: The exposed SiO2 is etched using a reactive ion etch (RIE) or wet etch, creating a recessed region inthe silicon wafer.4. Thin Film Deposition: A thin film of material, such as metal, polymer, or ceramic, is deposited conformallyover the substrate using techniques like physical vapordeposition (PVD) or chemical vapor deposition (CVD).5. Patterning and Release: A second PR layer is spun onto the substrate and patterned using photolithography. The PR is then used as a mask for etching the sacrificial layer underneath the thin film, releasing the MEMS structure.6. Bonding: The MEMS structure is bonded to another substrate or device using anodic bonding, thermal bonding, or adhesive bonding.7. Packaging: The MEMS device is packaged to protect it from the environment and provide electrical connections.中文回答：微机电系统 (MEMS) 制造工艺流程。
MEMS设计中的尺度效应
更一般的固体热导率的形式为
QqAkAT x
由式可知，对于固体介观和微观的热传导，其尺度
规律为
Q(l2)l(1)(l1)
从这个尺度规律中可看出，尺度的减小将导致固体 中整个热流量的减小。
第二种尺度规律涉及微系统的现象行为尺度，考 虑到系统的尺寸和材料特性。
微系统设计中常涉及的物理量：
体积：体积与器件的质量和重量有关 表面积：表面特性与流体力学中的压力和浮力有
关,与对流热传导中固体热吸收和耗散有关。
在一个尺度减小的过程中，同等地减小一个物体的 体积和表面积是不可能实现的。
下图是一个实心长方体的例子。a>b>c，体积V=abc， 表面积S=2×(ac+bc+ab)。如果l 代表一个固体的线 性因次，
例题
如图所示，如果平行板的长L和宽W都减小10倍， 求一对平行板电极产生的静电力的减小。
解：
当平板电极没充电时保持间隙为d。因此，由静电 力分量的表达式，可得出各自的静电力分量：
法向力分量Fd∝l2 沿宽度方向的力分量FW∝l2 沿长度方向的力分量FL∝l2 即，静电力在三个方向上减小(10)2=100倍
例题4-2
当MEMS器件减小10倍时，计算加速度a，时间 t和驱动能源的相应变化。
解： 已知重量 ： W∝ l 3
意味表4.1中的三阶。从表格中可得：
1）加速度没有减小(l0)
2）完成运动的时间减小(l)0.5=(10)0.5=3.16
3 ） 功 率 密 度 将 减 小 (l)0.5=3.16 。 功 耗 的 减 小 为 P=3.16V0。由于器件的体积减小10倍，在尺寸 缩小后功耗将减小P=3.16/10=0.3倍。
在微观领域在微观领域与特征尺寸的高次方成比例的与特征尺寸的高次方成比例的惯性力电磁力等的作用相对减小惯性力电磁力等的作用相对减小而与特而与特征尺寸的低次方成比例的弹性力表面张征尺寸的低次方成比例的弹性力表面张力和静电力的作用显著力和静电力的作用显著表面积与体积之比表面积与体积之比增大增大因而微机械中常常采用静电力作为驱因而微机械中常常采用静电力作为驱动力
智能家居 外文翻译 外文文献 英文文献
Increasing an individual’s quality of life via their intelligent home The hypothesis of this project is: can an individual’s quality of life be increased by integrating “intelligent technology” into their home environment. This hypothesis is very broad, and hence the researchers will investigate it with regard to various, potentially over-lapping, sub-sections of the population. In particular, the project will focus on sub-sections with health-care needs, because it is believed that these sub-sections will receive the greatest benefit from this enhanced approach to housing. Two research questions flow from this hypothesis: what are the health-care issues that could be improved via “intelligent housing”, and what are the technological issues needing to be sol ved to allow “intelligent housing” to be constructed? While a small number of initiatives exist, outside Canada, which claim to investigate this area, none has the global vision of this area. Work tends to be in small areas with only a limited idea of how the individual pieces contribute towards a greater goal. This project has a very strong sense of what it is trying to attempt, and believes that without this global direction the other initiatives will fail to address the large important issues described within various parts of this proposal, and that with the correct global direction the sum of the parts will produce much greater rewards than the individual components. This new field has many parallels with the field of business process engineering, where many products fail due to only considering a sub-set of the issues, typically the technology subset. Successful projects and implementations only started flow when people started to realize that a holistic approach was essential. This holistic requirement also applies to the field of “smart housing”; if we genuinely want it to have benefit to the community rather than just technological interest. Having said this, much of the work outlined below is extremely important and contains a great deal of novelty within their individual topics.Health-Care and Supportive housing：To date, there has been little coordinated research on how “smart house” technologies can assist frail seniors in remaining at home, and/or reduce the costs experienced by their informal caregivers. Thus, the purpose of the proposed research is to determine the usefulness of a variety of residential technologies in helping seniors maintain their independence and in helping caregivers sustain their caringactivities.The overall design of the research is to focus on two groups of seniors. The first is seniors who are being discharged from an acute care setting with the potential for reduced ability to remain independent. An example is seniors who have had hip replacement surgery. This group may benefit from technologies that would help them become adapted to their reduced mobility. The second is seniors who have a chronic health problem such as dementia and who are receiving assistance from an informal caregiver living at a distance. Informal caregivers living at a distance from the cared-for senior are at high risk of caregiver burnout. Monitoring the cared-for senior for health and safety is one of the important tasks done by such caregivers. Devices such as floor sensors (to determine whether the senior has fallen) and access controls to ensure safety from intruders or to indicate elopement by a senior with dementia could reduce caregiver time spent commuting to monitor the senior.For both samples, trials would consist of extended periods of residence within the ‘smart house’. Samples of seniors being discharged from acute care would be recruited from acute care hospitals. Samples of seniors being cared for by informal caregivers at a distance could be recruited through dementia diagnosis clinics or through request from caregivers for respite.Limited amounts of clinical and health service research has been conducted upon seniors (with complex health problems) in controlled environments such as that represented by the “smart house”. For exa mple, it is known that night vision of the aged is poor but there is very little information regarding the optimum level of lighting after wakening or for night activities. Falling is a major issue for older persons; and it results in injuries, disabilities and additional health care costs. For those with dementing illnesses, safety is the key issue during performance of the activities of daily living (ADL). It is vital for us to be able to monitor where patients would fall during ADL. Patients and caregivers activities would be monitored and data will be collected in the following conditions.Projects would concentrate on sub-populations, with a view to collecting scientific data about their conditions and the impact of technology upon their life styles. For example:Persons with stable chronic disability following a stroke and their caregivers: to research optimum models, types and location of various sensors for such patients (these patients may have neglect, hemiplegia, aphasia and judgment problems); to research pattern of movements during the ambulation, use of wheel chairs or canes on various type of floor material; to research caregivers support through e-health technology; to monitor frequencies and location of the falls; to evaluate the value of smart appliances for stroke patients and caregivers; to evaluate information and communication technology set up for Tele-homecare; to evaluate technology interface for Tele-homecare staff and clients; to evaluate the most effective way of lighting the various part of the house; to modify or develop new technology to enhance comfort and convenience of stroke patients and caregivers; to evaluate the value of surveillance systems in assisting caregivers.Persons with Alzheimer’s disease and their caregivers: to evaluate the effect of smart house (unfamiliar environment) on their ability to conduct self-care with and without prompting; to evaluate their ability to use unfamiliar equipment in the smart house; to evaluate and monitor persons with Alzheimer’s diseas e movement pattern; to evaluate and monitor falls or wandering; to evaluate the type and model of sensors to monitor patients; to evaluate the effect of wall color for patients and care givers; to evaluate the value of proper lighting.Technology - Ubiquitous Computing：The ubiquitous computing infrastructure is viewed as the backbone of the “intelligence” within the house. In common with all ubiquitous computing systems, the primary components with this system will be: the array of sensors, the communication infrastructure and the software control (based upon software agents) infrastructure. Again, it is considered essential that this topic is investigated holistically.Sensor design: The focus of research here will be development of (micro)-sensors and sensor arrays using smart materials, e.g. piezoelectric materials, magneto strictive materials and shape memory alloys (SMAs). In particular, SMAs are a class of smart materials that are attractive candidates for sensing and actuating applications primarily because of their extraordinarily high work output/volume ratiocompared to other smart materials. SMAs undergo a solid-solid phase transformation when subjected to an appropriate regime of mechanical and thermal load, resulting in a macroscopic change in dimensions and shape; this change is recoverable by reversing the thermo mechanical loading and is known as a one-way shape memory effect. Due to this material feature, SMAs can be used as both a sensor and an actuator.A very recent development is an effort to incorporate SMAs in micro-electromechanical systems (MEMS) so that these materials can be used as integral parts of micro-sensors and actuators.MEMS are an area of activity where some of the technology is mature enough for possible commercial applications to emerge. Some examples are micro-chemical analyzers, humidity and pressure sensors, MEMS for flow control, synthetic jet actuators and optical MEMS (for the next generation internet). Incorporating SMAs in MEMS is a relatively new effort in the research community; to the best of our knowledge, only one group (Prof. Greg Carman, Mechanical Engineering, University of California, Los Angeles) has successfully demonstrated the dynamic properties of SMA-based MEMS. Here, the focus will be to harness the sensing and actuation capabilities of smart materials to design and fabricate useful and economically viable micro-sensors and actuators.Communications: Construction and use of an “intelligent house” offers extensive opportunities to analyze and verify the operation of wireless and wired home-based communication services. While some of these are already widely explored, many of the issues have received little or no attention. It is proposed to investigate the following issues:Measurement of channel statistics in a residential environment: knowledge of the indoor wireless channel statistics is critical for enabling the design of efficient transmitters and receivers, as well as determining appropriate levels of signal power, data transfer rates, modulation techniques, and error control codes for the wireless links. Interference, channel distortion, and spectral limitations that arises as a result of equipment for the disabled (wheelchairs, IV stands, monitoring equipment, etc.) is of particular interest.Design, analysis, and verification of enhanced antennas for indoor wirelesscommunications. Indoor wireless communications present the need for compact and rugged antennas. New antenna designs, optimized for desired data rates, frequency of operation, and spatial requirements, could be considered.Verification and analysis of operation of indoor wireless networks: wireless networking standards for home automation have recently been commercialized. Integration of one or more of these systems into the smart house would provide the opportunity to verify the operation of these systems, examine their limitations, and determine whether the standards are over-designed to meet typical requirements.Determination of effective communications wiring plans for “smart homes.”: there exist performance/cost tradeoffs regarding wired and wireless infrastructure. Measurement and analysis of various wireless network configurations will allow for determination of appropriate network designs.Consideration of coordinating indoor communication systems with larger-scale communication systems: indoor wireless networks are local to the vicinity of the residence. There exist broader-scale networks, such as the cellular telephone network, fixed wireless networks, and satellite-based communication networks. The viability and usefulness of compatibility between these services for the purposes of health-care monitoring, the tracking of dementia patients, etc needs to be considered.Software Agents and their Engineering: An embedded-agent can be considered the equivalent of supplying a friendly expert with a product. Embedded-agents for Intelligent Buildings pose a number of challenges both at the level of the design methodology as well as the resulting detailed implementation. Projects in this area will include：Architectures for large-scale agent systems for human inhabited environment: successful deployment of agent technology in residential/extended care environments requires the design of new architectures for these systems. A suitable architecture should be simple and flexible to provide efficient agent operation in real time. At the same time, it should be hierarchical and rigid to allow enforcement of rules and restrictions ensuring safety of the inhabitants of the building system. These contradictory requirements have to be resolved by designing a new architecture that will be shared by all agents in the system.Robust Decision and Control Structures for Learning Agents: to achieve life-long learning abilities, the agents need to be equipped with powerful mechanisms for learning and adaptation. Isolated use of some traditional learning systems is not possible due to high-expected lifespan of these agents. We intend to develop hybrid learning systems combining several learning and representation techniques in an emergent fashion. Such systems will apply different approaches based on their own maturity and on the amount of change necessary to adapt to a new situation or learn new behaviors. To cope with high levels of non-determinism (from such sources as interaction with unpredictable human users), robust behaviors will be designed and implemented capable of dealing with different types of uncertainty (e.g. probabilistic and fuzzy uncertainty) using advanced techniques for sensory and data fusion, and inference mechanisms based on techniques of computational intelligence.Automatic modeling of real-world objects, including individual householders: The problems here are: “the locating and extracting” of information essential for representation of personality and habits of an individual; development of systems that “follow and adopt to” individual’s mood and behavior. The solutions, based on data mining and evolutionary techniques, will utilize: (1) clustering methods, classification tress and association discovery techniques for the classification and partition of important relationships among different attributes for various features belonging to an individual, this is an essential element in finding behavioral patterns of an individual; and (2) neuro-fuzzy and rule-based systems with learning and adaptation capabilities used to develop models of an individual’s characteristics, this is essential for estimation and prediction of potential activities and forward planning.Investigation of framework characteristics for ubiquitous computing: Consider distributed and internet-based systems, which perhaps have the most in common with ubiquitous computing, here again, the largest impact is not from specific software engineering processe s, but is from available software frameworks or ‘toolkits’, which allow the rapid construction and deployment of many of the systems in these areas. Hence, it is proposed that the construction of the ubiquitous computing infrastructure for the “smart house” should also be utilized as a software engineering study. Researchers would start by visiting the few genuine ubiquitous computing systems inexistence today, to try to build up an initial picture of the functionality of the framework. (This approach has obviously parallels with the approach of Gamma, Helm, Johnson and Vlissides deployed for their groundbreaking work on “design patterns”. Unfortunately, in comparison to their work, the sample size here will be extremely small, and hence, additional work will be required to produce reliable answers.) This initial framework will subsequently be used as the basis of the smart house’s software system. Undoubtedly, this initial framework will substantially evolve during the construction of the system, as the requirements of ubiquitous computing environment unfold. It is believed that such close involvement in the construction of a system is a necessary component in producing a truly useful and reliable artifact. By the end of the construction phase, it is expected to produce a stable framework, which can demonstrate that a large number of essential characteristics (or patterns) have been found for ubiquitous computing.Validation and Verification (V&V) issues for ubiquitous computing: it is hoped that the house will provide a test-bed for investigating validation and verification (V&V) issues for ubiquitous computing. The house will be used as an assessment vehicle to determine which, if any, V&V techniques, tools or approaches are useful within this environment. Further, it is planned to make this trial facility available to researchers worldwide to increase the use of this vehicle. In the long-term, it is expected that the facilities offered by this infrastructure will evolve into an internationally recognized “benchmarking” site for V&V activities in ubiquitous computing.Other technological areas：The project also plans to investigate a number of additional areas, such as lighting systems, security systems, heating, ventilation and air conditioning, etc. For example, with regard to energy efficiency, the project currently anticipates undertaking two studies:The Determination of the effectiveness of insulating shutters: Exterior insulating shutters over time are not effective because of sealing problems. Interior shutters are superior and could be used to help reduce heat losses. However, their movement and positioning needs appropriate control to prevent window breakage due to thermalshock. The initiation of an opening or closing cycle would be based on measured exterior light levels; current internal heating levels; current and expected use of the house by the current inhabitants, etc.A comparison of energy generation alternatives: The energy use patterns can easily be monitored by instrumenting each appliance. Natural gas and electricity are natural choices for the main energy supply. The conversion of the chemical energy in the fuel to heat space and warm water can be done by conventional means or by use of a total energy system such as a V olvo Penta system. With this system, the fuel is used to power a small internal combustion engine, which in turn drives a generator for electrical energy production. Waste heat from the coolant and the exhaust are used to heat water for domestic use and space heating. Excess electricity is fed back into the power grid or stored in batteries. At a future date, it is planned to substitute a fuel cell for the total energy system allowing for a direct comparison of the performance of two advanced systems.Intelligent architecture: user interface design to elicit knowledge modelsMuch of the difficulty in architectural design is in integrating and making explicit the knowledge of the many converging disciplines (engineering, sociology, ergonomic sand psychology, to name a few), the building requirements from many view points, and to model the complex system interactions. The many roles of the architect simply compound this. This paper describes a system currently under development—a 3Ddesign medium and intelligent analysis tool, to help elicit and make explicit these requirements. The building model is used to encapsulate information throughout the building lifecycle, from inception and master planning to construction and ‘lived-in’ use. From the tight relationship between m aterial behaviour of the model, function analysis and visual feedback, the aim is to help in the resolution of functional needs, so that the building meets not only the aims of the architect, but the needs of the inhabitants, users and environment.The Problem of Designing the Built Environment：It is often said that architecture is the mother of the arts since it embodies all the techniques of painting: line, colour, texture and tone, as well as those of sculpture: shape, volume, light and shadow, and the changing relative position of the viewer, andadds to these the way that people inhabit and move through its space to produce—at its best—a spectacle reminiscent of choreography or theatre. As with all the arts, architecture is subject to personal critical taste and yet architecture is also a public art, in that people are constrained to use it. In this it goes beyond the other arts and is called on to function, to modify the climate, provide shelter, and to subdivide and structure space into a pattern that somehow fits the needs of social groups or organizations and cultures. Whilst architecture may be commissioned in part as a cultural or aesthetic expression, it is almost always required to fulfill a comprehensive programme of social and environmental needs.This requirement to function gives rise to three related problems that characterize the design and use of the built environment. The first depends on the difference between explicit knowledge—that of which we are at least conscious and may even have a scientific or principled understanding—and implicit knowledge, which, like knowing your mother tongue, can be applied without thinking. The functional programmes buildings are required to fulfill are largely social, and are based on implicit rather than explicit bodies of knowledge. The knowledge we exploit when we use the built environment is almost entirely applied unconsciously. We don’t have to think about buildings or cities to use them; in fact, when we become aware of it the built environment is often held to have failed. Think of the need for yellow lines to help people find their way around the Barbican complex in the City of London, or the calls from tenants to ‘string up the architects’ when housing estates turn out to be social disasters.The second is a problem of complexity. The problem is that buildings need to function in so many different ways. They are spatial and social, they function in terms of thermal environment, light and acoustics, they use energy and affect people’s health, they need to be constructed and are made of physical components that can degrade and need to be maintained. On top of all this they have an aesthetic and cultural role, as well as being financial investments and playing an important role in the economy. Almost all of these factors are interactive—decisions taken for structural reasons have impacts on environment or cost—but are often relatively independent in terms of the domains ofknowledge that need to be applied. This gives rise to a complex design problem in which everything knocks on to everything else, and in which no single person has a grasp of all the domains of knowledge required for its resolution. Even when the knowledge that needs to be applied is relatively explicit—as for instance in structural calculations, or thoseconcerning thermal performance—the complex interactive nature of buildings creates a situation in which it is only through a team approach that design can be carried out, with all that this entails for problems of information transfer and breakdowns in understanding.The third is the problem of ‘briefing’. It is a characteristic of building projects that buildings tend not to be something that people buy ‘off-the-shelf’. Often the functional programme is not even explicit at the outset. One might characterise the process that actually takes place by saying that the design and the brief ‘co-evolve’. As a project moves from inception to full sp ecification both the requirements and the design become more and more concrete through an iterative process in which design of the physical form and the requirements that it is expected to fulfill both develop at once. Feasible designs are evaluated according to what they provide, and designers try to develop a design that matches the client’s requirements. Eventually, it is to be hoped, the two meet with the textual description of what is required and the physical description of the building that will provide it more or less tying together as the brief becomes a part of the contractual documentation that theclient signs up to.These three problems compound themselves in a number of ways. Since many of the core objectives of a client organization rest on implicit knowledge—the need for a building to foster communication and innovation amongst its workers for instance—it is all too easy for them to be lost to sight against the more explicitly stated requirements such as those concerned with cost, environmental performance or statutory regulations. The result is that some of the more important aspects of the functional programme can lose out to less important but better understood issues. This can be compounded by the approach that designers take in order to control themcomplexity of projects. All too often the temptation is to wait until the general layout of a building is ‘fixed’ before calling in the domain experts. The result is that functional design has to resort to retrofitting to resolve problems caused by the strategic plan.The Intelligent Architecture project is investigating the use of a single unified digital model of the building to help resolve these problems by bringing greater intelligence to bear at the earliest ‘form generating’ phase of the design process when the client’s requirements are still being specified and when both physical design and client expectations are most easily modified. The aim is to help narrow the gap between what clients hope to obtain and what they eventually receive from a building project.The strategy is simple. By capturing representations of the building as a physical and spatial system, and using these to bring domain knowledge to bear on a design at its earliest stages, it is hoped that some of the main conflicts that lead to sub- optimal designs can be avoided. By linking between textual schedules of requirements and the physical/spatial model it is intended to ease the reconciliation of the brief and the design, and help the two to co-evolve. By making available some of the latest ‘intelligent’ techniques for modelling spatial systems in the built environment, it is hoped to help put more of the implicit knowledge on an equal footing with explicit knowledge, and by using graphical feedback about functional outcomes where explicit knowledge exists, to bring these within the realm of intuitive application by designers.The Workbench：In order to do this, Intelligent Architecture has developed Pangea. Pangea has been designed as a general-purpose environment for intelligent 3D modelling—it does not pre-suppose a particular way of working, a particular design solution, or even a particular application domain. Several features make this possible.Worlds can be constructed from 3D and 2D primitives (including blocks, spheres, irregular prisms and deformable surfaces), which can represent real-world physical objects, or encapsulate some kind of abstract behaviour. The 3D editor provides a direct and simple interface for manipulating objects—to position, reshape, rotate andrework. All objects, both physical and abstract, have an internal state (defined by attributes), and behaviour, rules and constraints (in terms of a high-level-language ‘script’). Attributes can be added dynamically, making it possible for objects to change in nature, in response to new knowledge about them, or to a changing environment. Scripts are triggered by events, so that objects can respond and interact, as in the built environment, molecular systems, or fabric falling into folds on an irregular surface.Dynamic linking allows Pangea’s functionality to be extended to include standard ‘off-the-peg’ software tools —spreadsheets, statistical analysis applications, graphing packages and domain-specific analysis software, such as finite element analysis for air- flow modelling. The ‘intelligent toolkit’ includes neural networks [Koho89] [Wass89], genetic algorithms [Gold89] [Holl75] and other stochastic search techniques [KiDe95], together with a rule- based and fuzzy logic system [Zade84]. The intelligent tools are objects, just like the normal 3D primitives: they have 3D presence and can interact with other 3D objects. A natural consequence of this design is easy ‘hybridisability’ of techniques, widely considered as vital to the success of intelligent techniques in solving realistically complex problems [GoKh95]. This infrastructure of primitive forms, intelligent techniques and high-level language makes it possible to build applications to deal with a broad range of problems, from the generation of architectural form, spatial optimisation, object recognition and clustering, and inducing rules and patterns from raw data.Embedding Intelligence：Many consider that there is an inevitable trade-off between computers as a pure design medium, and computers with intelligence, ‘as a thinking machine’ [Rich94]. We propose here that it is possible to provide both these types of support, and allow the user to choose how best to use each, or not, according to the situation.It is essential that the creative role of the architect is preserved as he or she uses the work bench, that the architect as artist may draw manipulate the world as seen through the workbench as freely as they would when using a sheet of paper. Much of。
Personal Statement
Personal StatementProgram: Mechanical EngineeringI was born into a poor family in a remote mountainous village in Shandong Province. The untimely death of my uncle, who was very close to me, because of illness and poverty shocked me to such an extent that I once decided to drop out of the school and to help support the family. But my parents did not allow me to do so. Illiterate as they were, they nonetheless understood that "Education is the key," and were anxious to put this key in my pocket, in spite of all their difficulties. With the growth of age, I now have a much clearer sense of purpose for my life, which is not just to help one family, but to lift many more out of poverty and ignorance.I remember that I proved to be a fast learner as early as at elementary school. For instance, I was the only one student in the entire school who could solve linear equations with two variables. At high school, my favorite subjects of learning were Mathematics, Physics, and Chemistry. Every year, I participated in national or provincial contests in Mathematics, Physics, and Chemistry for high school students, and won either a first or a second prize. With this kind of training, I gradually developed a confidence in my ability to compete effectively in any academic circumstance. In 1996, I entered the famed T singhua University as a student majoring in Precision Instruments and Mechanics, with scores at the National University Entrance Examinations ranking the first in the region and the fifth in the province.In T singhua University I found the gateway to the beautiful garden of Mechanics. What I saw in its Micron and Nanotechnology Center, such as electric generators only a few microns large, and various laser devices in precision measurement, carried me away completely. When I learned that in near the future, Nano-electronics could produce pocket-sized giant computers, and make fragile porcelain ware exceedingly robust, and, especially, that Nanotechnology will play a central role in the development of Information T echnologies, more than Computer does, my mind was made up to pursue a career in this exciting area, for the rest of my life.During my undergraduate years, I built a solid foundation in the Basics of Precision Measurement, Material Science, Precision Equipment Engineering, and other related areas, earning excellent academic records. In addition, I made concentrated effort in developing a strong ability in lab research, especially during my undergraduate senior studies and during my Master's Program. I once designed a piezoelectrically driven micro-jet, following the idea of the spray mechanism of the ink jet printer with certain micro-mechanical processing. On the basis of this research, I invented a new model of micro-jet for lung treatment. During the several months of lab research and the writing of my graduation thesis "Experimental Research on Micro-jets," I learned a great deal about power electronics, microelectromechanic systems, silicon processing, and engineering mechanics, and significantly enriched my lab experience through dozens of lab testing projects in precision measurement, in areas such as the sugar thickness sensor, designs of precision mechanics, the appliances of microcomputer, the applications of multimedia technologies, and the use of the single-chip computer. Besides lab research, I also did part-time work with three companies, involved in the research and development of products of micro-mechanic systems, database, and the GIS. With these work experiences, I developed an ability to conduct research work incorporal environments, and also attained a keen insight into the practical and commercial sides of micro-mechanics. I applied my knowledge of MEMS to the preparation process of the micro-flow sensor produced by the company. For this project I looked up a large amount of technical literature, which also involved much translation for those who could not read in English. My English improved considerably, after many hours spent in the library reading IEEE publications. In this environment, I remain a fast learner, because I have learned how to learn, not just what to learn. I in fact learned some of the computer programming software, such as Visual Basic, Visual C++, and Delphi, on my own.It was also during the lab experiments that I no tice that most of the key equipments I used in the lab were foreign imports. Since the manuals that came with them often did not cover all the technical details of their internal structures, it made them rather difficult to operate. With this experience I began to realize that China is still way behind Western countries in the development of precision engineering. I wish to pursue a higher degree abroad, with a focus on MEMS, and especially on micro-mechanical systems. T o my great surprise, I found that Ari zona State University has a highly advanced graduate program in Mechanical Engineering, which will meet my needs perfectly. I have visited the web page of the university several times, and have some contact with Professor Ampere T seng, whose research areas seem very attractive to me. Professor T seng has in fact encouraged me to apply to its graduate program.There remain some problems in the lab experimentation that cannot be solved with all the knowledge I presently have. For instance, how can we produce orifices smaller than those already produced with more refined precision technology so that we can observe their dynamic characteristics? T o realize this, all the technical details of the system have to be taken into consideration. The system not only consists of the objects to be processed and the processing devices, but also consists of the working environment, mechanical and environmental control, training of the operating personnel, specifics of operation, and the fundamental understanding of the entire process. All those procedures must be properly handled in order to ensure the successful production of the smallest orifices possible, with perfect accuracy under the help of the most sophisticated precision instruments. I look forward to finding answers to this and many other problems during my graduate study at ASU.In my future program at your prestigious graduate school, I intend to concentrate on the following areas of study: (1) MEMS; (2) CAD/CAM/CIMS; (3) Micro-Mechanical System;(4) Micro-Flow; and (5) System Control. In accordance with this, I would like to divide my studies into three distinctive stages. First, I will continue with my studies of the foundational courses in MEMS to construct a firmer theoretical basis to expand the related knowledge in electro-mechanical integration. In the second stage, I plan to undertake some research projects that can demonstrate leading technology and creativity, especially in the field of MEMS technology and its application, so that I may develop myself into a specialist in this field. Finally, since the 21st Century is bound to be a century of nanotechnology and since China's accession into WTO has created many technical challenges and opportunities, I believe that nanotechnology, especially MEMS, will become the prevalent technology in the new millennium. This will be a rare opportunity for the maturation and the development of nanotechnology and its products. By that time I can contribute my professional expertise to this important process as a leading scientist in China.Recommendation LetterDear Colleagues:I am the dean of School of Science, Northern Jiaotong University and a member of ASPE (American Society for Precision Engineering). As Mr. Manuel Yin's teacher, I am glad to write this letter to support his application for admission into your university.In December 1999, Mr. Y in was assigned to do experiments on the dynamic characteristics of micro-jet in our school. I was attracted by his diligence and seriousness at the first sight of him. For three months, he stayed in the lab almost day and night and participated in every test. His logic reasoning and talents for experiments impressed all of us.Before the experiment was carried out, he designed several plans. After comparing them, he chose the best one. In the regular reports, he summarized the precedent work, analyzed the problems they were facing and raised his solutions. His work helped to improve performance of the micro-jet .Mr. Yin's talent in language and ability of solving problems are worth mentioning, too. Since our equipment was imported from other countries, most of the operation instructions hadn't been translated into Chinese by that time. Mr. Yin translated these English materials in his spare time. Because of his familiarity with the materials and his solid foundation of engineering, he solved a lot of problems in the operation of the equipment. For his excellent performance, he was praised by the teachers.Mr. Y in is an active young man. He was enthusiastic about mechanical designing competitions, extra-curriculum activities and lectures on the latest development in the mechanical engineering field. All these helped him to advance in his study.Having been to UNCC(University of North Carolina at Charlotte) as a visiting sc holar, I know that compared with the development of precision mechanics technology in the US, we still have a long way to go. I take great pleasure in supporting this promising young man to study in your university. His sound foundation, serious scientific attitude and practicality give me confidence that he will finish his study successfully. I will be very grateful if you can give due consideration to his application for admission into your university and grant him financial assistance.Sincerely yours,Dean of School of Science, Northern Jiaotong UniversityMember of International Society for Optical EngineeringMember of American Society for Precision EngineeringProfessor and Director of PhD, Northern JiaotongUniversi。
MEMS sensor 微传感器原理
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其中变量分别为电容(F)、真空介电常数(8.854x10-14F/cm)、相对介电 常数、极板重叠面积(cm2)和极板间距(cm)。当有多层介质时
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C=
ε 0ε r A
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-------电容传感器结构相对简单和宜于加工。可以通过改变d、ε或A 来实现非线性(比如用d)和线性(比如用A)的位置-电容转换。 ------电容传感器的最大优点是其温度系数低(只要极间材料是温度系 数低的介电质，比如空气或者真空)。根据文献，空气介电常数的温 度常数在1atm20℃时约为2ppm/ ℃(干燥), 到7ppm/ ℃(最潮湿)。但 是空气介电常数对于气压很敏感，约为100ppm/atm。如果极板间是 压力恒定的空气(或真空)，起支配作用的影响是结构热变形不平衡 (通常也很小)。 -------另外一个优点是测量是非接触的。
半导体材料，特别是Ge和Si，作为机械量-电学量转换器利用起源于 1957年。在此以前C.S.Smith发表了Ge和Si的压阻系数比其它材料高的结 果。F.P.Burns用两块Si薄片制成了声音传感器，W.P.Mason等人几乎在 同时发表了更实用化的同种器件。二者是压阻传感的开始。 这之后，随着半导体材料加工技术的快速发展，材料变得更容易获得。 1960年左右丰田理研开发出了十分实用的半导体应变传感器，同 时,W.P.Wason等人制作了细长的Si传感器，可以贴在弹性体上作为载荷计 使用。1961和1962年的Instrument Society of America大会上半导体应 变传感器相关的报告很多。在此基础上，MicroSystem、Baidwin-LimaHamiton、和Kulite-Bytrex公司都先后推出了半导体应变计商品。另外 一些工业化生产的微传感器产品，包括在石英上制作的霍尔效应（Hall Effect）探头、加速度计、力传感器以及化学传感器等等。 可以用微系统技术开发的微型传感器种类很多，本课程无法全部介绍。 所以我们只能从基本的传感原理讨论入手，然后从一些典型微传感器结构 来看这些原理是如何应用的。
芯片推力方法与MEMS芯片固化工艺的研究
Research and Innovation of Die Shear Methodand Curing Process for MEMS Chip CuringZHENG Zhi-rong,CHEN Xue-feng,DONG Hua,HU Nai-ren,ZHU Tian-yiSuzhou Good-Ark Electronic Co.,Ltd.Abstract:The general process of die shear for MEMS （micro electro mechanical system chip ）die bonding is intro-duced.The problems in the process of chip solidification are suggested.Experiments are carried out for the process and materials which are argued,the method of mathematical statistics is used for analysis.The material and structure of MEMS die bonding are researched,the problems in the implementation process of die shear are found out,and the optimization method of MEMS die shear is implemented.Finally,the feasibility of the die shear method in the process is verified by mathematical statistics.The method meets the requirements of mass production.Keywords:Assembly;MEMS;Die shear芯片推力方法与MEMS 芯片固化工艺的研究郑志荣，陈学峰，董华，胡乃仁，朱天意苏州固鍀电子股份有限公司摘要：介绍了封装推力与MEMS （微电子机械系统芯片）固化的通用工艺，提出了芯片固化中遇到的问题。
MEMS设计技术
PPT学习交流
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•1.5.2 微制造技术
•（1）硅基MEMS技术
• 以硅为基础的微机械加工工艺往往归纳为两大类，即 表面微加工技术(Surface Micromachining)和体微加工技术 (Bulk Micromachining)。
• 表面微加工技术是把MEMS的“机械”(运动或传感)部分 制作在沉积于硅晶体的表面膜上，然后使其局部与硅体部 分分离，呈现可运动的机构。
• MEMS Pro为工程设计中普通MEMS设计者和MEMS专家 提供考虑MEMS和IC混合作用的、在Windows操作系统下的设 计环境。MEMS Pro 是一个用户化的易于使用的平台，还可 以根据某个厂家的制造工艺进行工艺处理定义。MEMS Pro有 两个版本帮助你迅速可靠地占领MEMS相关产品的市场。
• 6. IntelliMask ( Construat mask )—— 建立掩膜
• 7. Mechanical ( Mechanical and thermal analysis)—— 机械和热 分析
• 8. MEMaterial ( Simulate and model MEMS materials) —— MEMS材料的模型和模拟
MEMSApplicationsofCMP（CMP的MEMS应用）
MEMS Applications of CMPEdward HwangSponsored by UC SMARTAbstract— In order to keep pace with tight designs for MEMS, CMP hasstarted to be adopted. In this report, some MEMS devices fabricated withCMP are shown, and some possible areas in which CMP can makecontribution to are suggested.Keywords: CMP, MEMS, SUMMiT, and multi-level structures.1. IntroductionLike IC devices, multi-level structures have been widely used in the MEMS devices.Micro engines, pressure sensors, micromechanical fluid pumps, micro mirrors, and micro lenses are good examples of these structures. Since these devices include moving parts within the multi-level structures, planarity issues have attracted attention for a long time.In order to address these planarity issues, CMP has emerged as a solution. For example,the Sandia Ultra-planar, Multi-level MEMS Technology (SUMMiT™) fabrication process, one of the big MEMS foundries, employs the multi-layer polycrystalline silicon surface micromachining process. This process polishes the silicon dioxide sacrificial layers every time before depositing another polycrystalline silicon layer. The reason being is that intrusion of upper polycrystalline levels into gaps, left between lower polycrystalline silicon levels, complicates the design and limits layout flexibility, in addition to causing undesirable areas of stress concentration. The intrusions are inevitable without the help of CMP, but these problems are completely overcomed by the use ofCMP in fabrication. One typical example is shown in Figure 1. Figure 2 also shows theFigure 1. Micro-engine without CMP (left) and with CMP (right).Figure 2. Micromechanical fluidic pump fabricated using with CMP.benefit of adopting CMP in the fabrication of a micromechanical fluid pump. The planar top surface of the pump chamber indicates that there is no protrusion of the top polycrystalline silicon into the enclosed pump mechanism. Other examples are the optical MEMS devices - micro mirrors, micro lenses – and field emission devices. As the operating wavelength gets smaller, the flatness requirement for lenses is stringent. Researchers at Case Western have used to improve the optical quality of mirrored surfaces produced on polycrystalline silicon, suface-micromachined devices, by reducing the roughness of the polycrystalline silicon. Improved performance of a lateral field emission device using CMP is also reported.2. DiscussionThere is no major difference between polishing MEMS devices and IC devices, because the same materials are used and the same machine can be used. The only and interesting difference between MEMS and IC from the CMP perspective is the involved step height. While the step height for IC is at most 1.0 µm, the step height for MEMS can be as large as 5 µm. The large step height associated with MEMS devices might present a challenge, since it will affect, especially at earlier times in the processing, a lot of factors such as pad deformation, slurry flow, uniformity, etc.3. OutlookAt this point, the CMP process used in MEMS is not as critical as it is in IC. It seems that there is not much benefit from using the CMP process in multi-level structure MEMS devices. However, the time will come when people will revise the processes in order to accommodate shrinking device sizes. In order to seize the moment, experiments on larger step heights (~5 um) and step height evolution versus time under various process conditions need to be conducted.The first area that can possibly benefit the best from CMP is the optical MEMS area, which is emerging nowadays. The surface of a micro-mirror or micro-lens used in optical MEMS requires flatness as well as nano-scale surface finish. The importance of the surface will become more evident as the wavelength of a light source gets smaller and smaller. CMP will be the method of choice that people will look for, since CMP has successfully solved very similar problems in IC.Overall process steps for the SUMMiT-V process1. Start with a Si substrate2. Grow 0.6um of oxide thermally3. CVD 0.8um of Si3N44. Dry-etch Si3N4 (thru)5. Etch thermal oxide6. CVD 0.3um of polySi (the layer called Poly0)7. Dry-etch Poly08. CVD SacOx1 and CMP to leave 2um of SacOx1 from poly09. Do a Dimple1 Cut (dry-etch, 1.5um)10. Dry-etch SacOx1 Cut (2um)11. CVD 1um of Poly112. Pinjoint Cut (dry-etch)13. Pinjoint Undercut (dry-etch oxide)14. Pinjoint undercut (wet-etch oxide)15. Dry-etch Poly1 (1 um)16. CVD SacOx2 and CMP to leave 0.3um17. Dry-etch SacOx2 (0.3um)18. CVD 1.5um of Poly219. Dry-etch Poly2 (up to 2.5um)20. CVD SacOx3 and CMP to leave 1.6um21. Dimple3 Cut (dry-etch)22. Dimple3 backfill, CVD23. SacOx3 dry etch (0.4 um)24. CVD Poly3 and CMP to leave 2.2um25. Dry-etch Poly3 (2.2um)26. CVD SacOx4 and CMP to leave 1.8um27. Dry-etch Dimple4 Cut28. Dimple4 backfill, CVD29. Dry-etch SacOx4 (1.8um)30. CVD 2.2um of Poly431. Dry-etch Poly4 (2.2um)32. CVD 0.4 um of Aluminum33. MMetal wet etch (thru Al)34. RELEASE structure.。
Digilent PmodMIC3 MEMS麦克风参考手册说明书
1300 Henley CourtPullman, WA 99163509.334.6306PmodMIC3™ Reference ManualRevised April 12, 2016This manual applies to the PmodMIC3 rev. AOverviewFeatures include:∙MEMS Microphone module with digitalinterface∙Transform audio inputs with 12-bit A/Dconverter∙Adjust incoming volume with on-boardpotentiometer∙up to 1 MSPS of data∙Small PCB size for flexible designs 1.1 in × 0.8in (2.8 cm × 2.0 cm)∙6-pin Pmod port with SPI interface∙Follows Digilent Pmod Interface SpecificationType 2The PmodMIC3.1 Functional DescriptionThe PmodMIC3 is designed to digitally report to the host board whenever it detects any external noise. By sending a 12-bit digital value representative of frequency and volume of the noise, this number can be processed by the system board and have the received sound accurately reproduced through a speaker. The on-board potentiometer can be used to modify the gain from the microphone into the ADC.2 Interfacing with the PmodThe PmodMIC3 communicates with the host board via the SPI protocol. The 12 bits of digital data are sent to the system board in 16 clock cycles with the most significant bit first. For the ADC7476, each bit is shifted out on each falling edge of the serial clock line after the chip select line is brought low with the first four bits as leading zeroes and the remaining 12 bits representing the 12 bits of data. The datasheet for the ADC7476recommends that for faster microcontrollers or DSPs, the serial clock line is first brought to a high state before being brought low after the fall of the chip select line to ensure that the first bit is valid. More information about this can be found in the PmodMIC3User Guide.Pin Signal Description1 SS Chip select2 NC Not connected3 MISO Master-in slave-out4 SCK Serial clock5 GND Power supply ground6 VCC Power supply (3.3V/5V)Table 1. Pinout table diagram.The PmodMIC3 is capable of converting up to 1 MSa per second of 12-bit data, making it an ideal Pmod to use in conjunction with the PmodI2S for an audio development application.Any external power applied to the PmodMIC3 must be within 3V and 5.5V to ensure that the on-board chips operate correctly; however, it is recommended that Pmod is operated at 3.3V.A sample timing diagram taken from the ADCS7476 datasheet representing the data that will be received by the system board from the Pmod is shown in FIg. 1.Figure 1. Timing diagram.3 Physical DimensionsThe pins on the pin header are spaced 100 mil apart. The PCB is 1.1 inches long on the sides parallel to the pins on the pin header, and 0.8 inches long on the sides perpendicular to the pin header.。
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Fe We
Lateral motion
independent on y
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Principle of Electrostatic Actuator
Dielectric slab
Conductor slab
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Electrostatic Actuation
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Operation principles and materials properties
Examples:
Electrostatic capacitor
Solenoid inductor Shape Memory Alloy Thermoelectric effect Piezoelectric effect Thermal expansion and thermoresistive
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Piezoelectric Actuator
Piezo. Mat.
Piezo. Mat.
Piezoelectric stack actuator
Piezoelectric bimorph actuator
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Inchworm stepping motors
B l
0
: permeability : susceptibility
Fm
Magnetic restoring force
dWm 1 n 2 I 2 A0 dy 2
23
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Theory of Shape Memory Alloys (SMA)
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Magnetic Force
Translational motion Fm
dy
Fm Wm
1 2 1 2 2 Wm LI n AlI n=N/L 2 2 1 2 2 dWm n I A[ (l dy) 0dy] 2
0 (1 )
Disadvantage: small capacitance (generally 1...3 pF) => measurement circuit has to be integrated on the chip or specially designed to null the stray capacitance
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Energy Transformation
Thermal Thermal expansion, T-dependent phase transformation, … Thermoelectric, Joule heating, thermal resistive,…
Movement along a rod by 3 piezoelements “Unlimited” movement Good resolution Maximum speed 2 mm/s Drawbacks - Expensive - Small lateral load
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Multi-stage module
Fiber optics cooling modules
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Thermoelectric Sensor
Thermal sensors IR detectors
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Thermoelectric accelerometer
Physical, chemical and biological models, material properties, scaling effect,…
Analysis and modeling of devices and systems Packaging and integration
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Electrostatic Forces
Capacitance: C=Q/V=orA/d 0= 8.854x10-12 F/m r: dielectric constant Stored energy V V 1 2 We Vdq CVdV CV 0 0 2
L
N 2 A
l
dI 1 2 Wm (emf )dq L( )dq LI 0 dt 2 1 N 2 B2 B2 Wm ( ) ( Al ) 2 ( Al ) 2 2 l (N / l) 2
I
Stored energy density:
B2 1 Wm ' H B 2 2
Reversible thermal-mechanical transformation of the atomic structure of the metal at certain temperatures Austenite form = high temperature shape - Alloy above transformation temperature - Alloy returns to a desired shape (after deformation at martensite form) and generates force/stress and a displacement Martensite form = low temperature form - Alloy below transformation temperature - Remains in austenite form position if there is no external stress - Alloy can be deformed with an external stress
Poly-Si heating wire suspended across a cavity Heat transfer by natural convection Al/poly-Si thermopiles measure changes of thermal profile caused by acceleration
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Thermal Actuators
pad Poly wire pit
Poly wire
A
A’
beam
Metal 1
beam
Thermally driven cantilever beam Thermal expansion mismatch induced actuation Thermal resistive heating (poly wire) to change the temperature of the beam Electrical → Thermal → Mechanical
8
Piezoresistive AFM
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Electromagnetic Actuator
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Thermoelectric Coolers
Laser cooling modules Telcom cooling module
Байду номын сангаас
1 A 2 1 We 0 r V ( Ad ) E 2 2 d 2
Stored energy density 1 2 1 We ' E D E 2 2
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Electrostatic Force
Perpendicular motion
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Capacitive Pressure Sensor
Measures average deflection
The change of capacitance is not linear with respect to deformation or pressure (but the relationship is reproducible)
Mechanical
Electrical
Piezoelectric, piezoresistive,…
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Thermal Actuators
Thermal energy transformed into mechanical movement Once applying a current, the narrow beam will be heated up more and expand more due to higher resistance and current density. Once stopping current input, the structure will come back to original position
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Solenoid inductor
dI d emf L N dt dt
Ampere’s law
H dl NI