| 摘要 |
1457809 Printed circuit component assemblies RCA CORPORATION 26 March 1974 [28 March 1973] 13381/74 Heading H1R A printed circuit comprises an insulant board 2 of e.g. fibreglass-epoxy to which is laminated and riveted a sheet metal e.g. sheet or aluminium board 6 having a laminar portion 8 and periphery 10 upturned into mounting flange 24 with an opening 12 therein exposing an area 14 of the insulant board. The latter is perforated at 6 for the lead wires of e.g. resistors, capacitors, transistors or transformers and at 8 to receive sockets of plug in modules or circuit boards. The underside 20 has a network of printed conductors 22 to which the leads are soldered, and metallized ground plane and screen areas 23. The upper side may have conductors 25 interconnecting the holes 16 and may be insulatedly located on metal board 6. The latter is also upset into a metal screen 26 adjacent the opening 12, and may have standoffs 28 mounting e.g. power transistors for cooling. Openings 30 surround perforations 16 to prevent shortcircuiting of the leads. Other standoffs 32 for heat generating units may be formed adjacent the edges of the metal board for heat generating components with an adjacent upset shield 34. In a modification (Figs. 4, 5 not shown) the metal board may cover a laterally disposed portion of the insulant board with upset shield flanges also serving to mount heat generating components on brackets. Lead openings may be provided and slots e.g. for canned electrolytic capacitors may be provided in the insulant board. A rectangular opening through the superimposed insulant and metal boards may have adjacent upset metal flanges to mount and ventilate high dissipation resistors. A modified mount for heat dissipating components comprises (Fig. 6 not shown) a Z shaped upset of the metal board, the horizontal leg of which supports a resistor with leads extending downwardly to engage apertures of the insulant board. |
