SMT生产中常见问题与对策演示幻灯片.ppt

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,SMT生产中常见问题与解决对策,太安（深圳）有限公司,SMT技术服务中心,1,目 录,锡珠,碑立,桥接,虚焊,焊点上锡不足,焊点锡量过多,焊膏坍塌,焊点暗淡,残留物明显且颜色深,SMT常用术语,表面组装术语,2,锡 珠,分析原因,锡膏不良,-,已经氧化,锡膏有水份,锡膏量较多,加热速度过快,元件放置压力太大,PCB,板受潮、,解决方法,增强锡膏活性,降低环境湿度,减小钢网开孔、增大刮刀压力,调整温度曲线,减小贴片压力,烘烤,PCB,板,3,元件直立,分析原因,加热速度过快或热风不均匀,锡膏的合金成份,元件可焊性差,-,氧化,贴片精度,基板的材料和厚度,焊盘间距离太大,印刷不规范,PAD,设计大小不一致,解决对策,调整温度曲线,-,温度、速度,采用含银或铋的合金焊膏,采用活性强的焊膏,调整贴片精度,焊盘的热容量差异大,选料正确,调整印刷准确度,通知,PCB,供应商改善,4,桥 接,分析原因,锡膏冷坍塌,钢网反面残留有锡膏,升温速度过快,焊盘上的锡膏量较多,网板质量不好或变形,擦网材料的选择,解决方法,增加锡膏的金属含量或黏度,常清洁钢网,调整温度曲线,-,温度、速度,减小网板开孔、增大刮刀压力,采用激光切割网板,选用专业的擦拭纸,5,虚 焊,分析原因,印刷时产生膏量不足,焊锡熔化升过元件引角,焊盘有阻焊物或污物,解决对策,减小锡膏黏度、调整刮刀压力,调整温度曲线,重新检查,PCB,板,6,焊点上锡不足,分析原因,钢网的质量差,焊膏量不够,模板与印制板虚位,回流时间短,刮刀速度快，网板太厚,解决对策,采用激光切割的摸板,选用金属刮刀，降低压力,采用接触式印刷,加长回流时间,降低刮刀速度，减小网板厚度,7,焊膏量过多,分析原因,网板开孔太大,锡膏黏度小,网板太厚,解决对策,减小网板开孔,调整锡膏黏度,减小网板厚度,8,焊膏坍塌,分析原因,焊膏黏度太低,环境温度太高,搅拌时间长,贴片压力大,解决对策,调整锡膏黏度,控制环境温度,缩短搅拌时间,调整贴片压力,9,锡点暗淡,整个回流过程中的,温度偏高,2.,回流时间不足，,SOLDER,PASTE,没有完全融化，,助焊剂挥发太快,锡粉氧化严重,10,SMT常用术语,表面张力-Interfacial tension,弯液面 -Meniscus,固化温度-Curing Temperature,固化时间-Curing Time,熔蚀-Erosion,腐蚀性-Corrosion,可溶性-Solubility,焊剂活性-Flux Activatiy,稀释剂-Diluent,焊料粉末-Solder Powder,卤化物含量-Halide Content,金属(粉末)百公含量-Percentage of Metal,11,SMT常用术语,焊膏分层-Paste Separating,贮存寿命-Shelf Life,工作寿命-Woring Life、Service Life,防氧化油-Anti-oxidtion Oil,塌落-Slump,免清洗焊膏-No-clean Solder Paste,丝网印刷-Screen Printing,刮板-Squeegee,丝网印刷机-Screen Printing,漏版印刷-Stencil Printing,金属漏版-Metal Stencil Stencil,滴涂器-Dispenser,12,SMT常用术语,针板转移式滴涂-Pin Transfer Dispensing,注射式滴涂-Syringe Dispensing,挂珠-Stringing,电烙铁-Iron,热风嘴-Hot Air Reflowig Noozle,吸铡器-Tin Extractor,吸锡带-Soldering Wick,焊后检验-Post-Soldering Inspection,目视检验-Visual Inspection,机器检验-Machine Inspection,焊点质量-Soldering Joint Quality,焊点缺陷-Soldering Joint Defect,13,SMT常用术语,错焊-Solder Wrong,漏焊-Solder Skips,虚焊-Pseudo Soldering,冷焊-Cold Soldering,桥焊-Solder Bridge,脱焊-Open Soldering,焊点剥离-Solder-Off,不润湿焊点-Solder Nonwetting,锡珠-Soldering Balls,拉尖-Icicle/Solder Projection,孔洞-Void,焊料爬越-Solder Wicking,14,SMT常用术语,过热焊点-Overheated Solder Connection,不饱和焊点-In Sufficient Solder Connection,过量焊点-Excess Solder Connection,助焊剂剩余-Flux Residue,焊料裂纹-Solder Crazeing,焊角翘离-Fillet-Lifting、Lift-Off,15,表面组装术语(一),一般术语,表面组装元器件Surface mounted components/devices(SMC/SMD),表面组装技术Surface mount technology(SMT),表面组装组件Surface mounted assemblys(SMA),再流焊Reflow soldering,波峰焊wave soldering,组装密度Assembly density,16,表面组装术语(一),元器件术语,焊端Terminations,矩形片状元件Rectangular chip component,圆柱形表面组装元器件Metal electrode face(ME1F)component;cylindrical devices,小外形封装Small outline package(SOP),小外形晶体管Small outline transistor(SOT),小外形二极管Small outline diode(SOD),小外形集成电路Small outline integrated circuit(SOIC),收缩型小外形封装Shrink small outline package(SSOP),芯片载体Chip carrier,塑封有引线芯片载体Plastic leaded chip carriers(PLCC),17,表面组装术语(一),元器件术语,四边扁平封装器件Quad flat pack(QFP),无引线陶瓷芯片载体Leadless ceramic chip carrier(LCCC),微型塑封有引线芯片载体Miniature plastic leaded chip carrier,有引线陶瓷芯片载体Leaded ceramic chip carrier(LDCC),C型四边封装器件C-hip quad pack;C-hip carrier,带状封装Tapepak packages,引线Lead,引脚Lead foot;lead,翼形引线Gull wing lead,J形引线J-lead,I型引线I-lead,18,表面组装术语(一),元器件术语,引脚间距Lead pitch,细间距Fine pitch,细间距器件Fine pitch devices(FPD),引脚共面性Lead coplanarity,19,表面组装术语(一),工艺、设备及材料术语,膏状焊料 sold paste;cream solder,焊料粉末 solder powder,触变性 thixotropy,流变调节剂 rheolobic modifiers,金属（粉末）百分含量 percentage of metal,焊膏工作寿命 paste working life,焊膏贮存寿命 paste shelf life,塌落 slump,焊膏分层 paste separating,免清洗焊膏 no-clean solder paste,低温焊膏 low temperature paste,20,表面组装术语(一),工艺、设备及材料术语,贴装胶 adhesives,固化 curing,丝网印刷 screen printing,网版 screen printing plate,刮板 squeegee,丝网印刷板 screen printer,漏版印刷 stencil printing,金属漏版 metal stencil:Stencil,柔性金属漏版 flexible stencil,印刷间隙 snap-off-distance,滴涂 dispensing,21,表面组装术语(一),工艺、设备及材料术语,滴涂器 dispenser,针板转移式滴涂 pin transfer dispensing,注射式滴涂 syringe dispensing,挂珠stringing,干燥 drying:prebaking,贴装 pick and place,贴装机 placement equipment;pickplace equipment;chip mounter;mounter,贴装头 placement head,吸嘴 nozzle,定心爪 centering jaw,22,表面组装术语(一),工艺、设备及材料术语,定心台 centering unit,供料器 feeders,带式供料器 tape feeder,杆式供料器 stick feeder,盘式供料器 tray feeder,刮刀 Squeegee,模板 Stencil,23,表面组装术语(一),工艺、设备及材料术语,锡膏 Solder Paste,点胶 Epoxy Glue,锡条 Solder Bar,锡线 Solder Wire,助焊剂 Flux,清洁剂 Cleaning Agent,稀释剂 Thinner,24,