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US 6,280,851 B1Granted
Multilayer product for printed circuit boards
AssigneeSentrex Company, Inc.
InventorsMelvin Pasternack, Jurgen Matthes
Life of this patent
Estimating the term…
Abstract
Copper foil used in printed circuit boards is protected from contamination both prior to laying up the circuit board components and during processing by a multilayer protective film structure having a silicone adhesive disposed on one entire surface and a silicone release composition on the other entire surface.
Claims19
A protected copper foil laminate comprising a copper foil layer having a first side and a second side,
- wherein the first side is covered by a dielectric layer of an epoxy resin-impregnated woven glass fiber body and the second side is covered by a multi-layer protective film,
- wherein the multi-layer protective film has (i) an outer surface consisting of a silicone polymer release composition which prevents adhesion of the film to the copper at high temperature and pressure laminating conditions, and (ii) an inner surface adjacent the copper foil layer, said inner surface having disposed uniformly thereon a solution of a pressure sensitive polysilicone polymer in an organic solvent from which the organic solvent is removed, and
- wherein after exposure of the copper foil laminate to a temperature of at least 300° F. and a pressure of at least 300 psi, no pressure sensitive silicone polymer transfers to the copper foil layer.
A copper foil laminate consisting of:
- (A) a clean copper foil sheet having a first side and a second side;
- (B) a dielectric layer of an epoxy resin-impregnated woven glass fiber body covering the first side of the clean copper foil sheet;
- and
- (C) a protective deep matte polyester film laminated to the second side of the copper foil sheet, said film having a smooth side and a rough side and having a uniform release coating on the entire smooth side and a uniform pressure sensitive silicone adhesive on the entire rough side, said silicone adhesive being in adhesive contact with the copper foil sheet,
- wherein no adhesive transfers to the copper foil sheet after exposure of the laminate to a temperature of at least 300° F. and a pressure of at least 300 psi.
2 more elements
Dependencies are inferred from the claim text.