EFFECT OF STENCIL ALIGNMENT ON THE SOLDER BEADING IN SMT PROCESS

摘要

Large balls of solder are used to be formed at the side of low standoff components during Printed Circuit Board (PCB) assembly in Surface Mount Technology (SMT). This phenomenon is known as solder beading and negatively affects the soldering quality and production yield of PCBs. It is shown that the alignment of stencil with the contact lands in the printing process is a major concern and a proper printing is effective on reducing the solder beading.