Electrical Circuit Module and Method of Manufacture.

摘要

1,181,621. Semi-conductor devices. BECKMAN INSTRUMENTS Inc. 27 May, 1968 [7 June, 1967], No. 25168/68. Heading H1K. [Also in Division C1] A semi-conductor device is attached at an electrode surface to a conductive track on an insulating substrate bearing other circuit components by means of a cermet consisting of finely-divided metal particles distributed in a glassy matrix. The substrate may be of glass, alumina, beryllia, steatite or insulated metal and the finely divided particles of gold, silver, palladium, platinum, ruthenium, rhodium, iridium or alloys thereof. For mounting germanium or silicon devices a glass with a softening temperature below 450‹ C., such as a high lead or bismuth oxide-cadmium oxide glass is used, and to ensure good conduction the metal should constitute more than 60% by weight of the cermet. In one embodiment, a transistor with aluminium emitter and base electrodes and a gold collector is mounted collector down on a platform of corresponding shape, or an area only one edge of which is covered by the conductive track, by applying the cermet in an organic binder by brushing, stencilling, or silk screening, mounting the device on the wet cermet and heating first at 70-80‹ C. to remove the binder, and then at 400‹ C. in a reducing atmosphere to sinter or fuse the glass. A suitable method of forming the cermet is to moisten glass particles with a noble metal resinate, calcine to deposit the metal on the particles and then grind to a suitable mesh size and add the organic binder.