The study of plastic package cracking induced by the moisture/solder reflow process

Abstract

The relationship between the size of plastic internal cracks and the extent of plastic delamination was investigated by using scanning acoustic tomography and visual cross-sectional inspection. Plastic internal cracks grow larger as plastic delamination spreads during consecutive moisture/solder reflow process stress tests. The effect of die pad size on plastic package cracking induced by the moisture/solder reflow process was studied. It was found that the extent of package cracking decreased with longer die pads due to the venting effect of the support pin. A package design that demonstrates good performance with respect to package cracks is presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>