Electrocompatibility Aspects of Microelectronics

This paper considers the effects (relative to conventional design) of microminiaturization on the mutual compatibility among various portions of systems. It discusses the major factors involved, such as power levels, sizes of radiators and pick-ups, spacings among them and function trends toward solid-state switching and greater use of digital operations. From these, compatibility relationships are developed, and the relative severity of the compatibility problem is estimated. Problems of corrective measures to enhance electrocompatibility are discussed, such as common use of heat paths as electromagnetic shields, filters utilizing effective or apparent inductance from semiconductor functions, and shielding effectiveness of flat cables and microminiature connectors. The treatment of material in the paper is not intended to be exhaustive but to high-light the major problem areas and to stimulate further thought. Conclusions are that RF susceptibility to magnetic fields is reduced, but susceptibility to electric fields is increased with respect to conventional construction. The larger parasitic parameters of the Semiconductor Integrated Circuits (SCIC) approach will degrade electro-compatibility. An anticipated trend toward digitized circuits will also degrade electrocompatibility. The inflexibility in modification of microcircuits requires that electro-compatibility be considered in very early stages of design. Filtering techniques are presently unsatisfactory due to lack of adequate inductance elements.