| 摘要 |
1,167,729. Moulding circuit board base. TEXAS INSTRUMENTS Inc. 8 Dec., 1966 [23 Dec., 1965], No. 54944/66. Heading B5A. [Also in Divisions H1 and H2] In a method of making a circuit board, a plurality of contacts 9, Fig. 6, are formed on a temporary carrier 1 as by photo-etching a sheet of weldable metal such as " Kovar " (Registered Trade Mark) or nickel; the bared ends of insulated wires 13 are welded to contacts 9 to interconnect the latter into a required circuit pattern; and a base 15 is moulded around the contacts 9, completely embedding the wires 13, e.g. in fibre-filled epoxy resin. The circuit board is now removed from the temporary support 1; a plastics parting layer 5 to which the metal sheet is originally stuck may be provided to facilitate this. Holes 11 may be provided in selected contacts 9, and registering holes 17 may be formed in the base 15. To produce a double-sided circuit board, a carrier 23, Fig. 9, comprising sections 25, 27, hinged together at 31 is employed. Contacts 9 interconnected by wires 13 are formed on both sections 25, 27 (Fig. 8, not shown), parting layer 5 being omitted, and a sheet 29 of fibreglass is interposed between the contacts on the two sections when the latter are closed together, as in Fig. 9. The space between sections 25, 27 is filled with a plastics moulding material; subsequently carrier 23 is removed. In use, component leads are welded to the exposed faces of contacts 9; in addition, preformed terminal devices (41, 51, Fig. 11, not shown), may be moulded into the base (49), each terminal device comprising a body member (43, 53) having spaced tubular conductors (45, 55) extending through it. Each tubular conductor has an integral tab (47, 57) at one end thereof, to which insulated wires (50) may be welded before the moulding operation. Instead of single conductors, twisted of parallel pairs or conductors may be used to similate transmission line characteristics; and a foil, screen, mesh or sprayed ground plane may be provided on the circuit board. |
