Abstract:

This paper addresses the challenge of optimizing process parameters when assembling surface mount components that have thermal adhesive under them. The goal is to consistently produce reliable solder joints The influence of key parameters such as adhesive volume, component alignment, and solder paste volume and location, are explored through design of experiments. Experimental data shows the importance of tighter process controls in stencil design, solder paste printing, adhesive dispensing, parts placement, and at reflow. Each step of the classic surface mount process becomes more demanding in the presence of cured thermal adhesives because of the inability of the component to self align or settle vertically during the solder reflow. This can result in starved solder joints leading to costly rework and reduced life expectancy.