水晶工作原理介绍

Confidential
(1)
DIP 49U XTAL
Blank cleaning Base plating Auto mount
Annealing
Freq. adjustment
Curing
Sealing
Aging
F.Q.C.
O.Q.C.
X’TAL Process
SMD X’TAL
Blank cleaning
来自百度文库(2)
Surface Treatment & Etching
AVG. size um # # 500 800 25 14 11.5 6.5 4.0 2.7 Roughness um 6 3 2.5 1.1 0.8 0.5 Inter-Crack um 22 10 8 3.5 2.6 1.3 Inter-Crack Roughness
------+++++
Si +4
X
----Si +4
O -2
O -2
O -2 + + + + + O -2
O -2
------When a electric field applied , the induced electric filed is generated and force the Oxygen atom move outward .
14.318 MHz 0.116 mm
20.000MHz 0.083 mm
26.973 MHz 0.062 mm
35.328 MHz 0.047 mm
Laping & Etching
Laping Machinism
Confidential
(1)
Laping & Etching
Confidential
Parameters of Effective Circuit
Confidential
(1)
C0：Static ( Shunt ) Capacitance：
一般 C0< 5.5pF 以下 一般 C0< 3.5pF 以下 ( Dip 49U ) ( SMD 7.0*5.0 ) 2
C0=0.02 ‧ del ‧
Characteristics of Crystal Unit
Structure & Process Effective Circuit of Crystal Unit Parameter of Effective Circuit Measureing the Crystal Parameters
Why is AT-Cut
Low Frequency CT +380 DT -520 ET +660 FT -570
Confidential
(2)
High Frequency AT +35015’ BT -490
Why is AT-Cut
Confidential
(3)
各種切割角度 / 溫度 之關係
Why is AT-Cut
AT
Confidential
(4)
切割角度 / 溫度 之關係
Frequency vs. Thickness
AT-Cut Crystal F ( MHz) = 1670 T
( um )
Confidential
or
F ( kHz) =
1670 T
( mm )
Frequency Thickness
Confidential
Introduction of Quartz Crystal
Content
Characteristic of Quartz Material Characteristics of Crystal Units Choose the Right Crystal Unit
Confidential
# 1000 # 2000 # 3000 # 4000
# 6000
# 10000
2.0
0.60
0.3
0.08
0.8
0.05
Note : The roughness and inter-crack data are dependet on the quartz material and the type of abbresive .
MECHANICAL AXIS OPTICAL AXIS
Quartz Material
Confidential
(2)
Quartz Material
Confidential
(3)
SYNTHETIC QUARTZ CRYSTAL
AUTOCLAVE HYDROTHERMAL METHOD RAW MATERIAL： Silica HIGH PRESSURE： HIGH TEMPERATURE： ~400 ℃ HIGH TEMP. STABILITY ： ± 0.2 ℃ LONG GROWTH TIME： 1 ~ 6 Month HIGH PURITY： Infra-Red Absorption (IRA)： 3585 CM-1
Confidential
Structure of X’TAL – Dip Type
Confidential
Structure of X’TAL – SMD Type
Confidential
Metal Lid
Coated Electrode
Quartz Blank Ceramic Base
XTAL Process
Parameters of Effective Circuit
Lm：Dynamic Inductance
由 Mechanical Mass 決定大小
Confidential
(3)
L1=
1 = 2C Ws 1
1 2fsC1
低頻時，晶片較厚，WAFER較大…數HENRIES 高頻時，晶片較薄，BLANK較小…數mH
振盪原理
Confidential
R ~ 200K ~ 1M
R ~ 200K ~ 1M
14.318 MHz
Cg
Cd
Cg
Cd
Principle of Oscillation
振盪原理
Ohm
(1)
Confidential
Gain Curve of Osc Circuit
Freq . Fund. 3 rd. 5 th. 7 th.
Why is AT-Cut
振動模式
長度彎曲振動 伸縮振動 輪廓振動 厚度振動
Confidential
(1)
Length-width flexure Extensional flexure Face shear flexure Thickness shear flexure
基 本 波：Fundamental 3 倍 頻：3rd overtone 5 倍 頻：5th overtone
PiezoElectricity
Confidential
(1)
Y
-Si
+4
++
Si +4
X
Si +4
O -2
O -2
O -2
++
O -2
O -2
--
O -2
The SiO2 is always in the static state of electric neutrial .
The positive electric-field is induced when the mechanic force pull the Oxygen atom out of original position .
材料成份： 二氧化矽
Confidential
(1)
SiO2
TRIGONAL-DIGONAL CLASS：32
材料組成： 正六方晶系 材料特性：
熔點 α-β相變點 硬度 密度 壓電特性 光雙折性
1,750℃ 537℃ ~7.2莫氏硬度 2,648Kg/M3 Y軸： 機械軸 Z軸： 光學軸
@1atm @1atm @25 ℃ @25 ℃
++++++
When a electric field applied , the induced electric filed is generated and force the Oxygen atom move closer .
- - - -O -
-2
The SiO2 is always in the static state of electric neutrial .
Parameters of Effective Circuit
Confidential
(2)
Cm：dynamic capacitance
C1=0.1‧Kc‧del ‧
2
fs n3
f=Resonance Freqency del：Electrode Diameter n：Ordinal Number of Harmonics(1,3,5,7,..) kc：Correction Constant kc=1…fundamental oscillation kc=0.85…3rd over tone kc=0.75…5rd over tone
Characteristics of Quartz Material
Quartz Material Piezo Electricity Why is AT-Cut Frequency vs. Thickness Lapping & Etching
Confidential
Quartz Material
Parameters of Effective Circuit
Confidential
(4)
R1：Dynamic Resistance…….(Rr)
R=P L A
相關原因：
(1) 音響學上的損失 晶片表面平行度 大氣R1 > N2R1 > 真空中R1 (2) 石英晶片表面清潔度 晶片表面與鍍膜層附著性 (3) 電極面之設計 (4) 石英原料材質 石英晶片表面處理
The negative electric-field is induced when the mechanic force push the Oxygen atom toward center position .
PiezoElectricity
Confidential
(2)
Y
Si +4
++++++
，A↑，R↓
Measuring the Crystal Parameters
Oscillation Method Pi NetWork Method
Calculation Method Measurement Method Physical Load Method
Confidential
Choose the Right Crystal
fs n
The shunt capacitance include the capacitance of XTAL and stray cap. of paste , metal cap …… inside the package . Mounting system的改變 或 base 長度/材質 不同 C0 值會變化 0.2 pF~1 pF 之間. C0小 → 起振電壓低，但CI較困難製造.
Effective Circuit of XTAL
等效電路
Confidential
Co : Shunt Capacitance
Cm : Motional Capacitance
Lm : Motional Inductance Rr : Motional Resistance
Note : “ Motional “ means the Frequency Dependency .
Principle of Oscillation
振盪原理
Ohm
(2)
Confidential
Gain Curve of Osc Circuit
Freq . Fund. 3 rd. 5 th. 7 th.
Principle of Oscillation
振盪原理
Ohm
(3)
Confidential
Confidential
(2)
Alignment Curing
Base Plating Blank auto mount Aging Gross leak test Taping
Freq. adjustment Annealing Final Test Laser marking
Auto seam welding Fine leak test F.Q.C.
Principle of Oscillation Characteristics of Load Capacitance Pullability & Trim & Q-value Read the Testing Data Setting the Specification
Confidential
Principle of Oscillation