Stress Analysis of Partially Yielded Soldered Joint for Surface Mount Connectors

A closed-form solution is derived for deformation of Partially yielded L-shaped joints commonly seen in surface mount connectors. The solder layer is modeled by one-dimensional elastic/ plastic foundation. The solution agrees well with a published result of an elastic problem as a special case and with a finite element analysis in an elastic/plastic case. This analysis provides a few useful conclusions in the design of soldering leads. They are 1) the soldering lead (but not the vertical portion) should be thick to distribute the load in a larger area, and 2) peel stress may be reduced by appropriately including a moment to counteract the effect Of vertical force.