硅片切割工艺讲义

4、SURFACE GRINDER
WHY DIAMOND GRINDING WHEEL?
High Productivity - Higher Material Removal Rates Improve Quality – Less Damage to work piece Longer Wheel Life Above brought down Grinding Cost.
硅片切割工艺讲义
制造二部 林青云 2006年3月
主要内容
1、车间流程的介绍 2、Squarer的介绍 3、Cropping Saw的介绍 4、Grinder的介绍 5、gluing Brick 的介绍 6、Wire Saw 7、Cleaning Station的介绍
1、车间流程的介绍
Building 1 Layout
Bottom portion of bricks to blaster for recycling
Bricks On Cart Diamond Grinding Wheel and Utilities as in the Chart Angle & Size Correction [For Square] (Activity). It may not be required, if the size of brick is as per spec Surface Grinder - I (Equip) Bricks on Cart
7、WAFER CLEANING
WAFER CLEANING HAS TWO STAGE
Pre-Cleaning
Beam, which contains sliced wafer is transferred to Pre cleaning station, where the 90% of slurry is cleaned.. It is crucial step on Wafer surface quality
SPECIFICATIONS
1. Band Specifications: Diamond coated steel blade . Length : 240", Width : 1", Thickness: 0.020", Grit : 80/100 2. Cutting Specifications: • • • • Feed rate: 0.5” to 1” per minute Feed pressure: 100 PSI (1Bar=14.5PSI) Blade tension: 22000 PSI Belt Speed : 3500 ~4000 FPM
BRICK PREPARATION
BAND SAW SURFACE GRINDER
Prepare bricks in such a way that usable in wire saw and Wafers are acceptable in Cell Line.
CHAMFER GRINDER
Lift and glue Ingot on gluing plate (Activity), Hoist & Glueing plate (Equip) Load gluing plate onto Squarer Cart (Activity) Fork lift and Squarer cart
Silicon: Product is cut using water as the coolant (Some prefer to condition the water to minimize contamination of the silicon metal). Thin-band saws (consisting of an endless, highstrength steel band with an electroplated diamond cutting edge) is capable of cutting large-diameter silicon ingots and other large diameter materials accurately and efficiently and can be manufactured in different sizes. Cutting rates are relatively slow, approximately 2-4 in² per minute. Proper grit size selection is important to minimize chipping of the workpiece. Smaller grit size, such as 80/100 mesh, will slow cutting rates but improve surface finish.
PRINCIPLE
Chuck with Brick moves, BACK & FORTH in X axis at Constant speed Chuck also advances in Z direction at Every BACK or FORTH Limits. At the end of each Z Limit(Front Or Back), Grinding Wheel moves downward at configured distance. Number of step in Y axis(Grinding wheel) and Step Length is configured
Some time Brick Sizes may be higher than 125 x 125(Man or Machine error). Hence, surfaces needs to be grinded to required 125 x 125 mm. SURFACE GRINDER (GT Supplied) helps in Surface Grinding and to get right size bricks. As silicon is brittle and sharp edges are prone to cracks while Handling. CHAMFERING(GT Supplied) grind edges to avoid cracks during Brick & Wafer handling
Measure Resistivity and Lifetime tester of sample bricks (Activity) Resistivity station and Life time tester (Equip) Bricks on Cart Brick Top Cropping [Length of Brick adjusted depending on the Ingot Life time] (Activity) Cropping Saw I & II (Equip) Bricks on Cart Brick Bottom Cropping [Length of Brick adjusted depending on the Ingot Life time] (Activity) Cropping Saw –III & IV (Equip) Bricks on Cart Top portion of Bricks To SCRAP
BRICK PREPARATION
Ingot is sliced into 16 pieces of 156x 156 x 220 mm size bricks.
Top & Bottom of Ingot has contaminations and has less Life time and hence to be cropped. BAND SAW(GT Supplied) Crops Top & Bottom.
5、Gluing Brick
6、WIRE SAW
Wire Management Web Winders Tension Tran scanner/Travel
Wire Safety
Байду номын сангаас
Table Management Slurry Management Temperature Mgmt Machine Safety
Y X
GRINDING WHEEL SPEC.
14A1 Diamond grinding wheel(Model # SDC 230 N100 B6)
Type : Nickel & Copper coated Diamond Grid Size : US MESH # 230( Micron size: 62 micron) Grade : Medium Concentration : 100 Bond : Resinoid. Size:D (14”) x T (1 ½”) x H(5”) x J(8”) x U(1”) x X(1/4”). (Standard # 14A1)
Side Slabs to blaster for recycling
Load Ingot into Square Cut ingot into Brick Ingot into Slab(Activity), Squarer (Equip) Unload Bricks using squarer cart and transport the bricks to Brick cleaning Booth (Activity) . Squarer cart, Fork Lift, Water gun (Equip)
2、SQUARER的介绍
3、Cropping Saw
BAND SAW
Slice usable length of brick by cropping top & bottom Usable length of brick is determined by the Life time tester. Special diamond coated blade is used for cropping Blade rotates at constant speed. Mount the Brick Suitably on the Table Table moves at set speed to slice the brick
Advantage of Ultrasonic cleaning
Ultrasonic cleaning of wafer removes particles down to 0.05 µm in size. Wafer is immersed in a heated liquid medium of DI water plus a surfactant, agitated using 40 KHz and 25 KHz sound waves for a few minutes, rinsed with clean DI water, and then dried. In aqueous cleaning, mechanical energy is used to remove particles through agitation; in ultrasonic cleaning, this agitation is caused by cavitations. Ultrasonic cavitations produces more energy to remove particles than does low pressure spray cleaning. Cavitations refers to the generation, growth, and subsequent violent collapse of vapor bubbles. The collapse of bubbles produces shock waves which scrub particles from that surface. Choosing 40 kHz frequency generators; the higher the frequency, the more gentle the ultrasonic cleaning action. Unlike the 25 kHz used in industrial cleaning, the higher frequency (40 kHz) “softens” cavitations – To avoid etching.
Chamfering [(To eliminate the Sharp Edges] (Activity) Chamfer Grinder (Equip)
Bricks On Cart
Grind the surfaces to match the specification of 156 x 156 mm cross section Uses Diamond coated Grinding Wheel 3 AXIS Machine Brick is mounted on Special a chuck. Special Diamond coated grinding Wheel grinds the surface
Cleaning
Cleaned with Alkaline Detergent & Ultrasonic for micro cleaning.
WAFER CLEANING
Wafers are cleaned with Alkaline Detergent : VALTON SP2200 Detergent heated and Ultrasonic vibration is provided for better micro cleaning