回流焊设备在高图形精度PCB流程中的应用

Application of reflow soldering equipment in the process of printed circuit board with high graphic accuracy

印制电路板(PCB)基板在经过高温回流焊后均会发生不同程度的图形精度收缩变化。PCB的图形精度很难满足在装配元件前后管控±0.050 mm的标准。通过研究PCB在回流焊高温后图形精度的变化规律,发现PCB的图形精度在第一次回流焊后变化量最大,第二次回流焊后的变化量较小。根据PCB基板的这个特性,在传统的PCB流程中导入回流焊设备,在把PCB交给客户之前,先将PCB在工厂内完成一次过回流焊处理。结果表明,PCB的图形精度在客户端回流焊前后的表现明显得到改善,在装配元件前后图形精度可管控在±0.050 mm以内,达到了PCB的要求。

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.