Critical Component Requirements for Vapor Phase Soldering Leadless Components on Circuit Board Assemblies for Military Electronics

Leadless components have an established assembly technology and a good history of reliable performance in hybrid applications. However, their attachment to printed circuit boards with vapor phase soldering is a relatively recent technology. Some critical component requirements are discussed which are necessary to ensure cost effective processing yields and reliable field performance. New specification requirements are proposed for leadless component terminations, for solderability of printed circuit board pads and component terminations, and for limits on precious metal dissolution into solder joints.