不同电镀面积计算方法探讨

Discussion about the different calculating method of plating area

电镀铜流程是印制板制造过程中非常重要的一步,孔壁镀铜厚度是影响板件可靠性的重要因素之一,PCB制造厂家和客户都十分重视孔铜的控制。在电镀生产过程中,电流密度和电镀面积是决定孔铜厚度的两个关键参数,通过这两个参数,可以利用法拉第定律来理论计算电镀铜层的厚度。但在实际运用过程中,对于全板电镀使用拼板面积(板件尺寸长×宽)做为电镀面积,而对于图形电镀使用外层线路图形面积(拼板面积减去干膜覆盖面积)做为电镀面积,往往出现实际孔铜厚度与理论计算相差甚远,这是因为没有考虑到板件上孔对电镀面积的影响。板件厚度和孔数量对实际电镀面积影响很大,本文讨论了三种电镀面积的计算方法,确定了最合适的电镀面积计算方法,并在实际生产过程中进行验证。

Copper plating progress is a very important step in PCB manufacturing process and copper thickness of hole is one of important factor about the reliability.Both PCB manufacturer and customer take care of the copper thickness.In electroplating progress,current density and plating area are key parameters of the copper thickness,through these two parameter,we can theoretically calculate the copper thickness by Faraday Law.In actually production progress,panel area（dimensions of board length multiply width） is calculated as plating area in panel plating progress;outer pattern area（panel area subtract dry film cover area） is calculated as plating area in pattern plating progress,which don＇t consider the effect of hole area,as result,the actual copper thicknesses are very different from theory results.Board thickness and hole quantity play an important role for the actual plating area.This article discusses three calculating methods of plating area,ascertains a prime method,proved by the actually producing progress.