硅片切割工艺讲义.ppt

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 Saw7、Cleaning Station的介绍,1、车间流程的介绍,Building 1 Layout,2、SQUARER的介绍,3、Cropping Saw,BAND SAW,Slice usable length of brick by cropping top&bottomUsable 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 TableTable moves at set speed to slice the brick,Maximum performance will come from proper band alignment,tensioning and band speed.,Maximum performance will come from proper band alignment,tensioning and band speed.,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,high-strength 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 in 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.,SPECIFICATIONS,Band Specifications:Diamond coated steel blade.Length:240,Width:1,Thickness:0.020,Grit:80/100 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,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.,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,BRICK PREPARATION,Prepare bricks in such a way that usable in wire saw and Wafers are acceptable in Cell Line.,BAND SAW,SURFACE GRINDER,CHAMFER GRINDER,BRICK PREPARATION,Lift and glue Ingot on gluing plate(Activity),Hoist&Glueing plate(Equip),Load Ingot into Square Cut ingot into Brick Ingot into Slab(Activity),Squarer(Equip),Load gluing plate onto Squarer Cart(Activity)Fork lift and Squarer cart,Measure Resistivity and Lifetime tester of sample bricks(Activity)Resistivity station and Life time tester(Equip),Unload Bricks using squarer cart and transport the bricks to Brick cleaning Booth(Activity).Squarer cart,Fork Lift,Water gun(Equip),Side Slabs to blaster for recycling,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),Top portion of Bricks To SCRAP,Bricks on Cart,Bottom portion of bricks to blaster for recycling,Bricks on Cart,Bricks On Cart,Angle&Size Correction For Square(Activity).It may not be required,if the size of brick is as per spec Surface Grinder-I(Equip),SHAPING,Diamond Grinding Wheel and Utilities as in the Chart,Chamfering(To eliminate the Sharp Edges(Activity)Chamfer Grinder(Equip),Bricks on Cart,Bricks On Cart,4、SURFACE GRINDER,Grind the surfaces to match the specification of 156 x 156 mm cross section Uses Diamond coated Grinding Wheel3 AXIS MachineBrick is mounted on Special a chuck.Special Diamond coated grinding Wheel grinds the surface,WHY DIAMOND GRINDING WHEEL?,High Productivity-Higher Material Removal Rates Improve Quality Less Damage to work pieceLonger Wheel LifeAbove brought down Grinding Cost.,PRINCIPLE,Chuck with Brick moves,BACK&FORTH in X axis at Constant speedChuck 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,X,Y,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”)x H(5”)x J(8”)x U(1”)x X(1/4”).(Standard#14A1),5、Gluing Brick,6、WIRE SAW,Wire ManagementWebWindersTensionTran scanner/TravelWire SafetyTable ManagementSlurry ManagementTemperature MgmtMachine Safety,7、WAFER CLEANING,WAFER CLEANING HAS TWO STAGEPre-CleaningBeam,which contains sliced wafer is transferred to Pre cleaning station,where the 90%of slurry is cleaned.It is crucial step on Wafer surface qualityCleaningCleaned with Alkaline Detergent&Ultrasonic for micro cleaning.,WAFER CLEANING,Wafers are cleaned with Alkaline Detergent:VALTON SP2200Detergent heated and Ultrasonic vibration is provided for better micro cleaning,Advantage of Ultrasonic cleaning,Ultrasonic cleaning of wafer removes particles down to 0.05 m 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.,Wafer cleaning,*Wafer cleaning Movie,