GB1136753A - Improvements relating to electrical connecting arrangements - Google Patents

Abstract

1,136,753. Electric couplings. ENGLISH ELECTRIC COMPUTERS Ltd. 4 Oct., 1966 [26 Oct., 1965], No. 14906/68. Heading H2E. [Also in Division H1] A printed circuit board assembly comprises a plurality of metal sheets each having an insulating layer on opposite surfaces thereof and a plurality of conductors on each insulating layer, the sheets being mounted together in spaced relation, and connecting means being provided between conductors on different sheets. The sheets may be made of, or coated with, A1, Mg, Ti, Be, Zr, or alloys thereof, a surface of which is oxidized, by anodization or otherwise, to form the insulating layers; alternatively, the latter may be formed by spraying or evaporating insulating material on to the metal sheets. The conductors may be of Au, Cu or A1 and may be deposited by electroless or electrolytic plating, vacuum or vapour phase deposition, spraying, silk screening, or lithography, followed as necessary by etching or electron beam scribing. Plated through holes are used to interconnect conductors on opposite surfaces of a sheet, the hole walls being coated first with insulation unless a conductive connection to the sheet is required; such conductive connection may also be provided by omitting or removing the insulating layer from selected areas of the sheet surface before depositing the conductors. Double-sided printed circuit boards of the invention are stacked, Fig. 5, not shown, adjacent boards 15, 16 having registering stand-off portions 17, 18, 20, 21 which are bonded or riveted together to provide a space 19 between the boards. Conductors on adjacent boards are interconnected where required by metal plugs 23 soldered or upset in position in registering through holes in boards; such plugs may also be used to connect the boards mechanically. Fig. 4, not shown, depicts adjacent boards held together in spaced relation by rivets which are secured in registering holes in the boards and then welded together. An edge of a circuit board may be serrated to form projections 9, Fig. 2, which are completely covered by the insulating layer and carry conductive contacts to form plug-portions of a coupling arrangement; the serrations may be omitted. Alternatively, Fig. 3, the edge of the board at which connections are to be made is bent through a rightangle, plated through holes 10 being provided in the bent-up portion which are engaged by plug pins 11. The boards may be cooled, as by water flowing through channels in or on the metal sheets.