封装工艺介绍.ppt

Click to edit master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Page,*,Confidential,Package process introduction,Presenter:GanJun Luo,2019/08/15,Purpose and Outline,Purpose:,Share package process introduction,Out line:,The purpose of chip packagingProcess flow,Page,2,The purpose of chip packaging,Page,3,The purpose of chip packaging:,The IC dies on the wafer are,separated,for die attach,connect external pins by wire bonding,then do molding to,protect electronic packaging devices from environmental pollution(moisture,temperature,pollutants,etc.);,protect the chip from mechanical impact;provide structural support;provide electrical insulation support.It is easily connected to the PCB board.,Process flow,Page,4,Wafer Saw,Die Attach,Wafer Mount,Wafer Grinding,Epoxy Cure,Pre-Molding plasma,P,ost,M,old,C,ure,Plating,Trim/Form,Test,De-junk,Laser Marking,Before,After,Laser Marking,Laser Marking,Pre-WB plasma,Wire Bond,FOL(Front of Line),EOL(End of Line),Molding,De-flash,Packing,Page,5,Wafer Grinding,Purpose:,Make the wafer to suitable thickness for the package,Machine,Disco(DFG8540),Material,UV Tape,Control,DI Wafer Resistivity,Vacuum Pressure,Check,Wafer Roughness,Wafer Warpage,Wafer Thickness,Visual Inspection,Page,6,Wafer Mount,Purpose:,Combine the wafer with D,icing,tape,onto the frame,for,die,sawing,Page,7,Wafer Saw,Purpose:,Make the wafer to unit can pick up by die bonder,Machine,Disco(DFD4360/DAD3350),Material,Saw Blade,Control,DI,Water,Resistivity(+CO2),Sawing/Cleaning Parameter,Check,Kerf Chipping Width,Visual Inspection,Page,8,Wafer Saw,Wafer Saw Technology,Technology,Advantages or Characteristics,Range of application,BD(Blade Dicing),使用微细金刚石颗粒构成的磨轮刀片，以每分钟,3,万转到,4,万转的高转速切割晶圆，同时,承载着晶圆的工作台以一定的速度沿刀片与晶圆接触点的切线方向呈直线运动,切割晶圆产生的硅屑被去离子水,(Dl water),冲走。,切割速度慢，生产效率低，随着晶片的厚度越薄，切割的难度也就越大，背面崩裂现象就会有加重的趋势。,一般硅晶片,Laser full cutting,将激光能量于极短的时间内集中在微小区域，使固体升华、蒸发的全切割加工,切割速度快，生产效率高，对于薄片可以有效减少背面崩裂现象，切割槽宽度小，与刀片相比切割槽损失少，所以可以减小芯片间的间隔,Thin wafer,；背面附金属膜的硅晶片如：,GaP(,磷化镓,),晶片等,Laser Groove+BD,先在切割道内切开用激光,2,条细槽,(,开槽,),，然后再使用磨轮刀片在,2,条细槽的中间区域实施全切割,采用了非发热加工方式即短脉冲激光切割技术，来去除切割道上的,Low-k,膜及铜等金属布线，所以能够在开槽加工过程中最大限度地排除因发热所产生的影响，能够提高生产效率，减少崩裂、分层,(,薄膜剥离,),等不良因素造成的加工质量问题。,Low-k wafer,SD(Stealth Dicing),隐形切割是将激光聚光于工件内部，在工件内部形成改质层，通过扩展胶膜等方法将工件分割成芯片的切割方法,由于工件内部改质，因此可以抑制加工屑的产生。适用于抗污垢性能差的工件；适用于抗负荷能力差的工件（,MEMS,等），且采用干式加工工艺，无需清洗；可以减小切割道,宽度，,因此有助于减小芯片间隔,Ultra-thin wafer(Flash Memory,Memory Controller),Process difference between BD and SD:SDBG:,Refer to www.disco.co.jp/cn_s,Page,9,Wafer Saw,Quality Control,切偏,正崩,划片宽度量测,Page,10,Die Attach,Purpose:,Pick up the die and attach it on the lead frame by epoxy,Pick up tool:247X479mil,Machine,ESEC/ASM,MaterialEpoxy/Leadframe,Control,Bonding Parameter,Collect/Needle Height,Check,Epoxy Thickness/Die Tilt,Bonding Position/Die Shear,Visual Inspection,Collect,Needle,Page,11,Die Attach,Die attach,method,Eutectic,Epoxy,soft solder,DAF,装片工艺,粘结方式,技术要点,技术优缺点,共晶（,Eutectic,）,金属共晶化合物；扩散,芯片背面镀金，镀银基岛，轨道气保护加热,导热电性能好，但,CTE,失配严重，在焊接中易产生热应力，芯片易开裂，一般只用于小芯片装片,导电胶（,Epoxy,）,环氧树脂（填充银）化学结合,芯片不需要预处理，粘结后固化出来或热压结合,工艺通用性强，适用于导电热性要求不高的器件，因为其导热电性能比共晶、铅锡银装片差，吸潮易形成空洞，开裂。,软焊料（,Soft Solder),铅锡银焊料合金反应,芯片背面,镀银,或金或镍，镀银基岛更优，轨道气保护加热,导热电性能好，但工艺复杂，焊料易氧化，一般用于大电流大功率器件,玻璃胶（,DAF,）,绝缘玻璃胶物理结合,上胶加热至玻璃熔融温度,成本低，适用于超薄芯片叠封，焊线前需要洗,plasma,去除有机成分,Page,12,Die Attach,粘着剂的工艺流程,Page,13,Die Attach,Quality Control,Die Shear,Epoxy Thickness&Fillet Height,空洞不良：,焊料装片单个空洞面积大于,3%,芯片面积，累计空洞面积大于,8%,芯片面积,Solder paste,装片单个空洞面积大于,5%,芯片面积，累计空洞面积大于,10%,芯片面积,出水不良：,芯片周围任意一边无胶溢出,芯片位置不良,：,芯片水平方向旋转角度,5,造成无法正常球焊（特殊工艺须按规定）,芯片位置不良,：,-,软焊料或,Solder paste,装片，芯片倾斜两端高低差距,38um,不）导电胶装片，芯片倾斜两端高低差距,25um,Page,14,Epoxy cure,Purpose:,Solidify the epoxy after D/A,Oven,Inside,Machine,C sun,Material,N/A,Control,Cure,Parameter,Nitrogen gas flow,Check,Die Shear,Page,15,Wire Bonding,Purpose:,Use ultrasonic,force,temp,time to c,onnect the bond pad with lead frame by gold/copper/,Silver/Aluminium wire.,Ball Bonding,Wedge Bonding,Machine,KNS/ASM,Material,Wire/Capilary,Control,Bonding Parameter,Heat Block Temp,Check,WBP/WBS,Ball Size/Crater,Visual Inspection,Page,16,Wire Bonding,The difference between,Ball Bonding,and,Wedge Bonding,球焊,Ball Bonding,和键合,Wedge Bonding,的区别,1,、,在一定温度下，在超声发生器作用下，通过焊能头使电能转变为机械振动，带动金球、铜球与铝层产生塑型形变，形成良好的牢度。,(,在形成球时需要用氢氮混合气体避免铜线氧化）,2,、键合又叫锲形焊，是因为它的压点象锲形,(,三棱镜,),。在常温下，铝丝通过换能头及劈刀的机械振动，与铝层粘合在一起。它的优点是不会产生化合物。,Page,17,W,ire Bonding,Quality Control,Ball Shear,Wire Pull,弧度不良：,焊丝与芯片，引线框及其他焊丝的最短距离,2,倍焊丝直径,球形不良：,球,径大小不良，,2,倍焊丝直径或,4,倍 焊丝直径；特殊情况（压区尺寸小于常规 情况）下，球径焊区单边边长的,70%,或焊区单边边长为不良,；,球厚度不良,:,压扁变形,球厚度,70%,焊线直径为不良,二焊点不良：,第二焊点根部有撕裂或隐裂现象,Cratering Test,IMC Check,Page,18,Molding,Purpose:,Seal the product with EMC to prevent die,gold wire from being damaged,contaminated and oxygenic.,Machine,TOWA/ASM,Material,Compound,Control,Mold,Temp;Clamp pressure,Transfer pressure/time;Cure time,Check,Body Thickness/Wire Curvature,Void/Delamination,Visual Inspection,EMC,为黑色块状，低温存储，使用前需先回温。其特性在高温下先处于熔融状态，然后会逐渐硬化，最终成型,Page,19,Molding,Quality Control,弧度不良：焊线冲歪率大于,20%,碰线不良：线与线的距离小于,2,倍线径、断线、接触芯片或外引脚,孔洞,缺角,内部气泡,上下错位,溢胶,C-SAM,检查,Page,20,Post Mold Cure,Purpose:,To let EMC react completely so that products can be protected more effectively.,Oven,Machine,C-Sun,Material,NA,Control,Cure temp.,Cure time,Check,Profile,后固化目的：提高材料的交联密度；缓释制造应力。,后固化温度：通常在,175,度左右（接近,Tg,温度，分子链相对松弛；催化剂的活性较高。）,后固化时间：,4-8H,，通常恒温,6H,（后固化烘箱温度均匀性；后固化烘箱的升温速度。）,Page,21,Laser Marking,Purpose:,Provide a permanent identification on product body,.,Machine,Laser machine,Material,NA,Control,Laser power,Check,Laser depth,Visual inspection,Page,22,De-junk,Purpose:,Remove the dam-bar of leadframe,Before,After,Laser Marking,Laser Markng,Dam-bar,Page,23,De-flash,Purpose:,Remove,the residue of EMC around the package body and lead,毛刺飞边是指封装过程中塑封料树脂溢出，贴带毛边，引线毛刺等飞边毛刺现象,Laser Marking,Laser Marking,高压水去飞边,电解高压水去飞边,浸酸软化,废胶残留图片,控制项目：软化时间，软化液温度；电解电流，电解液浓度；高压水压力，传送速度,手工检验，超标溢料手工去除,Page,24,P,lating,Purpose:,To plating Sn on the lead which will mount on board pad.,利用金属和化学的方法，在框架表面镀上一层镀层，以防止外界环境的影响,(,潮湿和热），并使元器件在,PCB,板上容易焊接及提高导电性。,Laser Marking,Laser Marking,load,unload,Plating line,After,Before,load,unload,Plating line,Machine,SYM-SSP-2000,Material,Tin,Control,Component,Temp,of plating bath;Planting current;Planting time;DI water resister,Check,Visual inspection;Plating thickness;Solderability,Page,25,P,lating,Baking after plating(,电镀退火）,:,目的：让无铅电镀后的产品在高温下烘烤一段时间，以便消除电镀层潜在的锡须生长（,Whisker Growth,）的问题。,条件：,150+/-5C;2Hrs,Laser Marking,Laser Marking,load,unload,unload,Plating line,电镀两种类型：,Pb,Free,：无铅电镀，锡（,Tin,）的纯度,99.95%,符合,Rohs,的要求；,Tin-Lead,：铅锡合金。,Tin,占,85%,，,Lead,占,15%,，由于不符合,Rohs,，目前基本被淘汰。,晶须（,Whisker,），是指锡在长时间的潮湿环境和温度变化的环境下生长出的一种须状晶体，可能导致产品引脚的短路。,Page,26,Planting,Quality Control,外观检查,Solderability test,镀层厚度量测,Preconditioning:Steam aging 93+3/-5,8 hrs,Solder dip:SnAgCu 245,5,5,0.5s,solder coverage,95%,Page,27,Trim Form,Purpose:,Remove the tie-bar and lead-frame and form products to units from stripsfill them into tubes and then pass to next process.,Laser Marking,Laser Marking,load,unload,Plating line,load,unload,Plating line,Saw work area,unload,Working area,unload,Laser marking,Trimming,Forming,Page,28,Trim Form,Quality Control,毛刺,脚偏,漏底材,长短脚,脚弯,异物附着,外观检查,外形尺寸量测,连筋,压伤,共面性不良：同一产品不同管脚站立高度大于,0.1mm,Page,29,Packing,Purpose:,Protect the product in the circulation process,convenient storage and transportation,Laser Marking,Laser Marking,load,unload,Plating line,load,unload,Plating line,Saw work area,unload,Working area,unload,Bulk,AMMO,Tube,Tape and Reel,Tray,Thank You!,Page,30,