The IEEE Compliant Lead Task Force

The leads of leadless chip carrier packages need to be yielding or compliant so that stresses on the solder Joints are minimal. These stresses are caused both by differences in the thermal expansions of the package and the material but also by board flexing. A special task force of the IEEE has determined that there are major differences between packages from different vendors, and that the differences are relevant. Guidelines are furnished to enable the systems engineer to estimate probable useful life for board assemblies of surface-mounted "J" leaded packages.