Walter A Heinrich

US Patent:

40643573, Dec 20, 1977

Filed:

Dec 2, 1975

Appl. No.:

5/636986

Inventors:

Herbert Dixon - West Andover MA
Walter Heinrich - Derry NH
Gilbert Morris - Amherst NH

Assignee:

Teledyne Electro-Mechanisms - Nashua NH

International Classification:

H05K 100

US Classification:

174 685

Abstract:

A method of making and electrically interconnecting layers of printed circuitry involves the steps of: (1) coating an insulator on both sides with an adhesive; (2) punching holes through the insulator at points where interconnections are to be made; (3) laminating conductor planes to both sides of the insulator by means of the adhesive; (4) forming printed circuit patterns on the conductors such that a proper conductor geometry is created at the points where the interconnections are to be made; (5) applying pre-punched, adhesive-coated cover layers of insulation over the exposed printed circuits, except in the area of the interconnections; and (6) applying solder to the conductor pattern. Since the geometry at the interconnections is carefully controlled a solder bridge is formed, which connects the two conductor patterns during step (6) by the flow of solder into the interconnection area, past the upper conductor, to the lower conductor. Alternatively, solder can be deposited between the conductor planes at the interconnection points during the formation of the laminate.