Surface-mount electronics meet the military's high reliability needs

Surface-mount electronics, as opposed to through-hole mounted electronics, will be dominant board assembly technique in the U.S. for at least the next ten years for weight and space saving and for high reliability. New pin-out and packaging standards have been developed, to the benefit of both military and industrial and commercial users. Reliability rather than standards is, however, the major issue, and design, material selection and manufacturing techniques at the board-component interface determine how well any producer's equipment stands up to demanding applications and environments. Problems of matching thermal coefficients of expansion are dwindling as new chip technologies reduce semiconductor power dissipation drastically. The special soldering methods needed, preparation of the circuit board, and the increasingly widespread use of metal-core circuit boards are treated.