| 摘要 |
1,221,968. Printed circuit assemblies. INTERNATIONAL BUSINESS MACHINES CORP. 17 April, 1968 [8 May, 1967], No. 18052/68. Heading H1R. [Also in Division H2] Electrical connection between two electrically conductive coatings 46, 48, Fig. 3, on a dielectric base 47 is produced by providing in one coating conical members 53 which project through holes in the base 47 and corresponding conical members in the second coating which fit over the first said members. Such connections are produced by depositing a conducting layer (72), Fig. 2b (not shown), of e.g. copper, on a steel former (70) having raised conical projections (71), and then assembling a prepunched dielectric layer (73), e.g. of epoxy or silicone glass, a further conducting layer (74), e.g. of copper, provided with conical members (76), on the deposited conducting layer. The various layers are then laminated together by heat and pressure and thereafter removed from the former. To ensure good electrical connections, solder may be provided between the mating surfaces of the projections. The copper layer (72) may be deposited on the former by vapour deposition, sputtering, electroless or electroplating or spraying. The prepunched conical members (76) in the copper layer (73) are open so they leave the end of the conical members of layer (72) exposed. After removal from the former circuit patterns are produced in one or both copper layers, e.g. by photoresist and photo etching methods, and the upper layer (73) covered by a protective dielectric coating 45. To prevent oxidation of the surfaces of the connectors these may be coated with precious metal 44 or with solder. A stack of printed cards, strip line connectors, modules, all provided with the above type of connectors may be assembled together, Figs. 1, 3, the projection on one layer being located in the corresponding depression in the next layer. The whole assembly may be held together by air pressure bags, through which cooling liquid may flow, or alternatively the layers may be soldered together, where a solder layer is provided in place of the precious metal layer 51, Fig. 3. In a modification where connection between the two conducting layers of one laminate is not required, Fig. 5 (not shown), a relatively small conical member (64) is formed in the first conducting layer (60) and a hole, corresponding to that in the dielectric layer (61) in the second conducting layer (62). A protective dielectric coating (62) being provided as before. |
