Study on High Density Fine pitch PCBA Cleaning Process Optimization Based on Ceramic Board and Flexible Plate

This paper present the industrial case study on quality improvement of the post reflow cleaning process in an assembly industry. Ceramic carrier boards are widely used in industrial fields due to their good thermal conductivity, strength and insulation. In order to reduce the terminal volume, flexible plates are also widely used. For the high quality industry application, a number of manufacturing related issues needed to be addressed. Of all Potential defects, the PCBA pollution is most critical defect which will affect the long term reliability. The ceramic board and FPC was assembly with Sn96.5Ag3Cu0.5 solder paste an orthogonal experimental design was conducted to understand the relationship among the washing temperature, washing solution and the cleanness level. From the experiment we got the optimal post-reflow process conditions for achieving highest quality cleaning status, which meet the requirements of IPC standard.