Process for producing copper-clad base materials
AssigneeHuls Troisdorf Aktiengesellschaft
InventorsHelmut Fasbender, Burkhard Voss
Life of this patent
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Abstract
In a process known per se for producing base materials copper-clad on at least one side, in which a winding core carrying a copper foil is wound with a reinforcing fiber, the laid fibers are impregnated with a solvent-free resin and the resin is cured fully to reach the C-stage, it is proposed to use, as the resin, a solvent-free epoxy-isocyanurate resin having a viscosity at processing temperature of less than 1000 mPa.s and an NCO content of more than 20%.
Claims16
In a process for producing base materials copper-clad on at least one side, comprising:
- (a) winding reinforcing fibers on a winding core carrying a copper foil,
- (b) impregnating the resultant wound fibers with a solvent-free resin, and
- (c) curing the resin fully, the improvement comprising employing as the resin a solvent-free epoxy-isocyanurate resin having a viscosity at processing temperature of less than 1000 mPa.s and an NCO content of more than 20%.
In a process for producing multilayers, comprising compacting a plurality of base materials with interposed prepegs with application of pressure and heat, the improvement comprising producing said base materials by a process comprising winding reinforcing fiber on a winding core carrying a copper foil, impregnating the resultant wound fibers with a solvent-free epoxy-isocyanurate resin having a viscosity at processing temperature of less than 1000 mPa.s and an NCO content of more than 20% and wherein the resin for said prepegs is an epoxy-isocyanurate resin in the A state or B-stage, which is solid at room temperature and has an NCO content of less than 17%.
A circuit board having a copper foil surface reinforced by glass fibers impregnated with an epoxy-isocyanurate resin having an NCO content of more than 20%.
A multilayer comprising a plurality of layers having a copper foil surface reinforced by glass fibers impregnated with an epoxy-isocyanurate resin having an NCO content of more than 20% , said layers being joined by an epoxy-isocyanurate resin prepeg having an NCO content of less than 17%.
Dependencies are inferred from the claim text.