Electronic Assembly Misprint Cleaning Innovations
Assemblers surveyed report that cleaning misprinted circuit assemblies is a production gap that has not been adequately addressed. Traditionally, the industry has used stencil cleaning agents and equipment to address this rework need. One of the benefits of cleaning misprinted assemblies with the stencil cleaning process is the ability to collect and filter wet solder paste. The major short coming of cleaning misprints within stencil cleaning processes is the inability to remove B-side reflow flux residues from both the surface and under bottom termination components.
The purpose of this research is to test and validate new cleaning equipment innovations that allow for misprints to be cleaned from electronic assembly batch and inline production cleaning equipment. Cleaning misprints within production spray-in-air cleaning equipment has been looked down upon due to wet solder paste accumulating within the wash tank. Free solder spheres that are picked up by the pump can be wedged and deposited onto production assemblies. Recent cleaning equipment innovations have been developed to trap, collect and filter wet paste removed from misprints. Designed experiments will be run to test the robustness of the process and validate cleaning of both wet solder paste and reflowed flux residues.