Status of Microminiaturization

The status of microminiaturization is summarized under the following three headings: 1) assembly of pretested conventional or specially designed component parts, 2) printing or vapor deposition of multicomponent assemblies on fiat insulating substrates, and 3) preparation of complete circuits from a solid block of semiconductor material. Under the first heading, assembly of parts in three-dimensional (3-D) soldered structures, in 3-D welded structures, in imitation 2-D-type structures, and in structures of disciplined geometry is briefly described. The latter structures now include not only the Micro-module but also new pelletized parts. Under the second heading, the original 2-D thin-film type of construction is briefly summarized and then the evolution of this system into experimental circuits containing all thin-film passive parts is shown. The logical next step, preparation of circuits conraining thin-film active as well as passive parts, is in even earlier stages of research. Under the third heading, new developments in integrated and functional circuits are presented. The trend of current work points to the conclusion that equipment available commercially in the next decade will probably take the form of hybrid structures comprising both individually fabricated parts, and single-process parts arrays, all mounted or processed onto an insulating substrate.