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Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,11/7/2009,#,按一下以編輯母片標題樣式,D,esign,F,or,M,anufacturing,生產方式,零件正確選擇,板子大小尺寸,光學點的需求,標示及識別說明資料,吃錫的考慮,零件方向,零件空間距離,銅泊,錫墊,孔徑大小,治具孔,維修重工,測試點,折板與連板的考量,線路與導通孔,測試著想而設計,導入工業標準,偏 移,Pad 設計不良易造成偏移(往吸熱較多處),Component space,For wave soldering components,must be spaced sufficiently far apart to avoid bridging.This is less important for reflow soldering but sufficient space must be allowed to enable rework should it be required.,Component space,Free,Area,Test Pad,5.00mm,Fixture,0.5mm Min,Depanelization,Defects can still occur much further away from the board edge if the board is large and flexible or if components are perpendicular to stress gradients.Components need to be isolated from connectors,mounting holes,pots,etc.to minimize damage from those sources of deflection.,NG,NG,Component Orientation,Dip Flow,OK,NG,減少 Short,Dip Flow,增加拖錫點將錫留在特定位置，減少短路,避免造成短路,盡量將,PAD,與大銅箔隔離，避免受熱不均,Change to,1.5 mm,採用短腳作業，,避免引腳間短路,IC Alignment,在四邊的,PAD,加大，利用熔錫時的內聚力作位置校正,板彎,(1)PCB,设计不合理，元件分布不均会造成,PCB,热应力过大，外形较大的连接器和插座也会影响,PCB,的膨胀和收缩，乃至出现永久性的扭曲。,(2),双面,PCB,，若一面的铜箔保留过大,(,如地线,),，而另一面铜箔过少，会造成两面收缩不均匀而出现变形。合理设计,PCB,，双面的钢箔面积应均衡，在没有电路的地方布满钢层，并以网络形式出现，以增加,PCB,的刚度，在贴片前对,PCB,进行预热，其条件是,105,4h,；调整夹具或夹持距离，保证,PCB,受热膨胀的空间；焊接工艺温度尽可能调低；已经出现轻度扭曲时，可以放在定位夹具中，升温复位，以释放应力，一般会取得满意的效果。,避免板彎,Add dummy circuit,Too many empty area,1.,利用治具挾持,2.,增,加空銅箔達到熱均勻,3.,減少,V-Cut,，以機器切板,Fillet Lifting,How to avoid:,Use silver-rich alloys.Silver contents of 3.5%are recommended.,Process Qualification,Void,How voids are formed:,Voids are the result of solder shrinkage during solidification.,Poor wetting can case voids.,Outgassing in the plated through holes during soldering may produce holes,in the solder.,Sources of gas are moisture in the laminate and incomplete curing of the laminate.,Incomplete outgassing can be caused by gas from flux chemistry of the solder paste,or the flux for wave soldering.,Improper amount of solder,Process Qualification,Stencil,CHIP,元件，按,1,：,1,开口,P=0.5mm,，,IC&QFP,，开口宽,0.25mm,P=0.635mm,，,IC&QFP,，开口宽,0.35mm,P,0.635mm,，,IC&QFP,，开口宽为,55%PITCH,P=0.8mm,，,BGA,，开,0.45mm,的圆。,P=1.27mm,，,BGA,，开,0.7mm,的圆。,Lead Free Stencil Hole,Lead Stencil Hole,露銅,1.,可,三方,往外延伸,0.10.2 mm,或,鋼板開孔總面積約加大,1015%,2.,將,PAD,形狀一致化,Solder Paste,Pad,Pad Unity,
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