Via fill composition and filling

PURPOSE: To obtain a composition which is used for filling vias of a circuit carrier and the like and causes little shrinkage when cured, without a solder being wicked into vias or through holes, by incorporating a large amount of a conductive powder into an epoxy or cyanate binder composition. CONSTITUTION: The fill composition consists of (A) about 35 to about 95 wt.%, preferably about 60 to about 92 wt.%, of conductive powder and (B) about 5 to about 65 wt.%, preferably about 8 to about 40 wt.%, of a binder, where the component B comprises (C) about 25 to about 100 wt.% of an alicyclic epoxy resin, a novolack epoxy resin and/or a cyanate ester resin, (D) 0 to about 75 wt.% of a curing agent (about 25 to about 75 wt.% when the resin is an alicyclic epoxy resin) and (E) a catalyst in an amount sufficient to accelerate the curing of the resin. When this fill composition is filled into the vias and through holes of a circuit carrier and cured, the shrinkage percentage is less than about 0.8%. COPYRIGHT: (C)1995,JPO