SMT solder paste deposit inspection based on 3D PMP and 2D image features fusion

Abstract

Defects inspection for solder paste deposit in PCB SMT assembly can depress final fault rate and save rework cost. The solder paste deposit inspection needs both 2D analysis and 3D volume measurement. Conventional methods suffered slow speed and low reliability. This paper proposed inspecting by grating projection phase shifting profilometry 3D scale fusion with 2D image features, which help phase measuring and unwrapping as well as shadows processing. Experimental results show that the approach is fast, accurate and reliable.