Base material for the production of printed circuits and process for the preparation of the base material
AssigneeDynamit Nobel Aktiengesellschaft
InventorsSiegfried Kopnick, Dirk Huthwelker, Arnold Franz, Lothar Jacob
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Abstract
A base material for the production of printed circuits according to the additive method includes a laminate base made up of laminated-together core sheets impregnated with hardenable resin, and a cover layer made up of a substrate sheet preimpregnated with phenolic resol resin and provided with an adhesive layer of an elastomeric polymer. The preimpregnated substrate sheet is also provided with a further resin impregnation containing a self-crosslinking copolymer of acrylic monomers and up to 30% by weight of a hardenable phenolic resol resin.
Claims5
A base material for the production of printed circuits according to the additive method which comprises a laminate base made up of laminated-together core sheets impregnated with hardenable resin, and a cover layer made up of a substrate sheet preimpregnated with phenolic resol resin and provided with an adhesive layer of an elastomeric polymer, said preimpregnated substrate sheet being provided with a further resin impregnation containing a self-crosslinking copolymer of acrylic monomers and up to 30% by weight of a hardenable phenolic resol resin.
A process for the preparation of a base material for forming printed circuits which comprises impregnating a plurality of core sheets with a hardenable resin solution, drying the resin impregnated core sheets at temperatures of 100.degree.-140.degree. C. to effect prepolymerization of the resin, then preimpregnating a substrate sheet constituting a cover layer with a phenolic resol resin, coating this cover layer with a rubber adhesive and then drying the cover layer, pressing the thus-layered sheets, with the use of pressure and at temperatures of 130.degree.-170.degree. C., together to bond the sheets under hardening of the resin and of the adhesive, the preimpregnated, predried substrate sheet serving as the cover layer being impregnated with a further hardenable resin material containing a self-crosslinking copolymer on the basis of acrylic derivatives and up to 30 parts by weight of a hardenable phenolic resol resin, and being dried at a temperature of between 110.degree. and 180.degree. C., whereafter the adhesive is applied preferably in a layer thickness of 30-50.mu. and dried at temperatures of 130.degree.-150.degree. C.
Dependencies are inferred from the claim text.