Effect of resin content on PCB warpage and anti-shock performance of BGA solder joint

Abstract

In this paper, the relationship between resin content and the PCB warpage and anti-shock performance of lead-free solder joint was investigated. In order to measure the warpage of PCB during reflow progress, thermal shadow Moire method had been used. Thermal shadow Moire was an optical noncontact method to measure warpage using a Moire fringe pattern resulting from the geometric, interference between a flat reference grating and the projected shadow of the grating on warped test object. The shock test was performed on the mounted PCBA samples, which the same BGA was soldered to PCBs with various resin content, and the dye test was performed to inspect the crack of solder joint. It was found that the resin content had little effect on PCB warpage during the reflow progress, while had a significant influence on the shock performance of solder joint. The higher resin content was benefit to improve the anti-shock strength of solder joint. This conclusion provides reference for the substrate design of PCB.