After high temperature reflow soldering,the printed circuit board(PCB)substrate will shrink in different degrees,lowering the graphic accuracy.It is difficult to meet the standard of controlling the accuracy within ±0.050 mm before and after assembling components.By studying the variation law of graphic accuracy of PCB after reflow soldering at high temperature,it is found that the variation of PCB graphic accuracy is the largest after the first reflow soldering,and the variation after the second reflow soldering is smaller.According to this characteristic of PCB substrate,we introduce reflow soldering equipment in the traditional PCB process,before the PCB is handed over to the customer in the PCB factory.After one reflow soldering,the performance of PCB graphic accuracy before and after the client reflow soldering is obviously improved,the graphic accuracy of PCB before and after the assembly of components is controlled within 0.050 mm,which can meet the requirements.
reflow soldering equipmentgraphic accuracytrapezoidal accuracy of graphics
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维普
