SMT锡膏印刷培训课件

1、Design. Build. Ship. Service.锡膏印刷培训Document Title : Lean Hand BookDocument No : GBE-KPO-2-033-00Doc. Revision : 02Document Date : March 26, 2008Business Excellence第1页，共34页。2022/8/202TechnologyScreen printer/丝网印刷机Solder Paste Printing丝网印刷丝印机Chip贴片机多功能贴片机多功能贴片机Chip贴片机回流炉第2页，共34页。2022/8/203TechnologyDe

2、scribing the Stencil Printing Process丝网印刷工艺概述第3页，共34页。2022/8/204Technology15mm min Dia. Paste/最小直径15mm的锡膏体Zero Print Gap零印刷间隙Metal sheet/金属平板Open aperture/开孔Basic Stencil Printing Process/基本丝网印刷工艺第4页，共34页。2022/8/205TechnologyControlled Print Speed控制印刷速度Even Squeegee Pressure以及刮刀压力Basic Stencil Print

3、ing Process, cont. /基本丝网印刷工艺（续）Paste Rolling锡膏滚动第5页，共34页。2022/8/206TechnologyBoard is lowered under controlled Separation Speed在“分离速度”控制下，板被分离下来Basic Stencil Printing Process, cont. /基本丝网印刷工艺（续）第6页，共34页。20-Aug-227TechnologySTENCIL钢网第7页，共34页。20-Aug-228TechnologyEffect of stencil丝网的影响效果With a good ste

4、ncil优良的丝网Excellent results极好的结果Few failures很少的故障Predictable yields可预知的合格率With a bad stencil不良的丝网Lots of stencil wiping需要大量的擦拭Lots of bridges and insufficient disposition产生许多的桥连和少锡Stencil Design Guideline: IPC 7525丝网设计指导文件：IPC7525第8页，共34页。20-Aug-229TechnologyStencils Considerations 丝网的关键因素Stencil Thi

5、ckness丝网的厚度Stencil Material丝网的材质Stepped or uniformed thickness stencil阶梯式的或者同一厚度的丝网Stencil Material Coefficient of Friction丝网材质的摩擦系数Stencil Surface Roughness丝网的表面粗糙度Stencil Hardness/Tensile Strength丝网的硬度、抗拉强度Framing Tension边框的张力Mounting Material原料的装配Partial or Full部分的和全部的Aperture Size孔径尺寸Aperture Sh

6、ape & Wall开口外形和内侧的形状Aperture Arrangement开口排列Aperture Aspect Ratio开口的纵横比例Area Ratio面积比Aperture Tolerance开口大小的公差Aperture Gasketing开口的涂层Aperture Location Tolerance开口的位置公差Thickness Tolerance厚度公差第9页，共34页。20-Aug-2210TechnologyStencil Type丝网的类型Full Stencil全平面丝网Partial Stencil (stencil with mesh border)局部的丝

7、网Polyester mesh (tension 22-30 Newtons per square cm)聚酯型网孔（表面张力在22-30N/cm2之间)Stainless steel mesh (tension 30-40 Newton per square cm)不锈钢网孔（表面张力在30-40N/cm2之间）Frameless stencil 无框的丝网MicroMount from DEKDEK公司的微小贴装丝网TECFOIL from TECFOILTECFOIL公司的TECFOIL技术SMart frame from SMTSMT小巧的外框第10页，共34页。20-Aug-2211

8、TechnologyStencil Fabrication Methods 丝网的制作方法Chemical etch化学腐蚀Single side etch单个侧面腐蚀Dual side etch双行侧面腐蚀Etch and electro-polish蚀刻和电抛光Laser cut激光切割Straight laser 直接光刻Laser and polish 光刻并抛光Electroform 电铸成型 Stencils are manufactured by three main methods:制造丝网的主要三种方法第11页，共34页。20-Aug-2212TechnologyWall c

9、haracteristicChemical Etch 化学腐蚀孔内壁的特性第12页，共34页。20-Aug-2213TechnologyCleaning of stencilWhenever printing is completed, Clean the stencil with low lint paper soaked in IPA.任何时候,只要印刷结束，就要用浸有IPA的无尘纸擦净丝网Use brush to clear paste in stencil aperture if necessary.如果需要，用刷子清理丝网开孔第13页，共34页。20-Aug-2214Technolo

10、gyStencil Handling丝网的使用Handle the stencil with extreme care. Any dents, crack or damages will result in poor print quality. 移动丝网时，要万分小心任何破边，破碎，或损坏都将导致糟糕的印刷质量Always hold the stencil by the aluminum frame and do not drop any object on the stencil or foil.保持丝网在铝框中永远处于绷紧状态，并且严禁把东西放在丝网上Do not set stencil

11、 down on surface that will damage the foil surface.不要把丝网底部平放其它物体上，那样会损坏金属的表面第14页，共34页。2022/8/2015TechnologyThe Perfect Print/完美的印刷Clean edges/清洁的边缘Flat on top/顶部平坦Height = Stencil Thickness 高度=钢网厚度Good Alignment/很好地对位No Flux Bleed .无助焊剂溢出第15页，共34页。2022/8/2016TechnologyPaste Print Defect: Bridging/锡膏

12、印刷缺陷：桥联第16页，共34页。2022/8/2017TechnologyPaste Print Defect: Excess Print Height/锡膏印刷缺陷：高度偏高第17页，共34页。2022/8/2018TechnologyPaste Print Defect: Scooping/锡膏印刷缺陷：塌陷第18页，共34页。2022/8/2019TechnologyIncomplete Print/不完全印刷（少锡）第19页，共34页。2022/8/2020TechnologyPaste Print Defect: Misalignment/锡膏印刷缺陷：偏位第20页，共34页。20

13、22/8/2021TechnologyTailing/锡膏拉尖Acceptable/可接受 (Solder smear or slump 10%)锡量减少10%)锡量减少10%Solder Paste Print Quality/锡膏印刷质量第21页，共34页。2022/8/2022TechnologyPaste Clogging锡膏堵塞Acceptable/可接受(paste deposit 90%)焊盘锡量超过90%Reject/拒收(paste deposit 90%)焊盘锡量超过90%Solder Paste Print Quality /锡膏印刷质量第22页，共34页。2022/8/

14、2023TechnologySmearing and Slumping/锡膏塌陷Acceptable/可接受(Solder smear or slump 10%)塌陷大于10%Solder Paste Print Quality第23页，共34页。2022/8/2024TechnologyMajor contributor to defects/缺陷的主要分布Source: MPMs A users guide to more Precise SMT printing第24页，共34页。2022/8/2025TechnologyHardware/硬件Software/软件Environment

15、/环境Squeegees/刮刀Print Speed/印刷速度Temperature/温度Paste/锡膏Humidity/湿度Stencil/钢网Pressure/压力Tooling/surport pinPrint Gap/印刷间隙Board/印刷线路板Separation Speed/分离速度Factors Affecting the Print/影响印刷的因素第25页，共34页。2022/8/2026TechnologySqueegee/刮刀第26页，共34页。2022/8/2027TechnologySqueegee Type/刮刀类型Diamond edgeTrailing edg

16、eD cut第27页，共34页。2022/8/2028TechnologySqueegee Material/刮刀材料Polyurethane/聚亚安酯Composite/合成物2 part polyurethaneEpoxy/环氧树脂Metal/金属Plain Steel/平钢Polished/被抛光RolledLubricated surfaceTeflonPermalex第28页，共34页。2022/8/2029TechnologySqueegee/刮刀Hardness/硬度 : 30 to 90 durometer (Shore A) with 60 to 90 durometer m

17、ost used, metal.Attack Angle/接触角度 : 45 to 75 degreesPressure/压力Parallelism/平行度第29页，共34页。2022/8/2030TechnologyScan pic of rubber and metal squeegee , paste, cyberoptics橡胶和金属刮刀，锡膏，影像Scavenging第30页，共34页。2022/8/2031TechnologyPrint Parameters/印刷参数Print Speed/印刷速度Squeegee Pressure/刮刀压力Separation Speed/分离速度Print Gap/印刷间隙Under Screen Clean Rate/钢网底板清洗频率Paste Dispense/加锡膏Environment/环境第31页，共34页。2022/8/2032TechnologyTriangulation method/三角方法