Recent advances in the design of surface mount interconnects have satisfied the long-time concern of achieving adequate solder joints between the leads and the board. The ability of solder joints to withstand the effects of repeated insertion and withdrawal is determined by the quality of both the interconnect design and the manufacturing process.

The contacts must be designed to achieve an optimal balance between a low withdrawal force and a normal force adequate to assure acceptable contact resistance. The solder tails must be designed to maximize the strength of the solder fillet when attached to solder pads of various size. The most critical manufacturing tolerance is the coplanarity of the solder tails, which must be precisely controlled to avoid introducing weak solder joints into the system.