| 摘要 |
1,211,412. Semi-conductor devices; circuit assemblies. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 24 Jan., 1968 [27 Jan., 1967], No. 3678/68. Headings H1K and H1R. A support for one or more transistors or monolithic integrated circuits comprises an insulating substrate with projections constituted by conductive layers electroplated to a thickness exceeding that of the transistors or circuits which are to be mounted between the projections with their supply conductors electrically connected to them. The supports can be made in multiple from a borosilicate glass or enamelled ceramic plate by first vapour depositing through a metal mask to form a repeating pattern of conductive tracks 35, 36, 37 (Fig. 6) consisting of 1-2Á thick aluminiumchromium with a 200 A‹ overlayer of chromium. Then the entire surface is coated by vapour deposition with copper which is thickened by electroplating either before or after provision of a photo-resist mask exposing only the sites of the projections. The copper on the unmasked areas is then electroplated with a 2-3Á layer of gold. After removing the photo-resist the plate is etched in nitric acid to remove the copper save where it is protected by the gold. After ultrasonically soldering the terminals of transistors 34 to the conductive tracks and coating with resin the plate is sawn up into single units. In another method the conductive tracks are made by depositing goldcoated chromium overall and then patterning by etching with aqua regia through a photoresist mask. If desired, a plurality of transistors and associated circuit elements are attached to each unit of the support with the projections attached to the terminals of the elementary circuits thus formed. The supports are intended for soldering in an inverted position on hybrid circuit boards. |
