Abstract: Shrinking of partially cured or B-staged resin coated fabric, also known as prepreg, during C-staging or full curing is reduced by cutting at least a plurality of the warp of the fabric in at least one location before C-staging. Prepreg is useful in the computer industry in the manufacture of printed circuit boards.

Abstract: A method of making a high density dimensionally stable encapsulated circuit board. A curable adhesive is utilized to bond insulated wires to a substrate, the dimensional stability of which is maintained by a sheet of relatively thick copper foil. Since the adhesive is cured and since the copper foil returns to the same dimensions when thermally, mechanically or chemically cycled, the entire composite is dimensionally stable.At each location where a connection is to be made to a wire, the wire has a non-linear geometrical portion. The increased dimensional stability plus non-linear shaped portion of the wires allows connections to be made to the board utilizing a very small drill. The result is a high density stable circuit board.

Abstract: A high density dimensionally stable encapsulated circuit board and a method of making such a board is described. A curable adhesive is utilized to bond insulated wires to a substrate, the dimensional stability of which is maintained by a sheet of relatively thick copper foil. Since the adhesive is cured and since the copper foil returns to the same dimensions when thermally, mechanically or chemically cycled, the entire composite is dimensionally stable.At each location where a connection is to be made to a wire, the wire has a non-linear geometrical portion. The increased dimensional stability plus non-linear shaped portion of the wires allows connections to be made to the board utilizing a very small drill. The result is a high density stable circuit board.

Abstract: A system for cleaning a thru hole on a substantially planar electrical board. The electrical board has two major surfaces, upper and lower. A first gas and liquid transmission device is connected to the board to introduce etching gas and liquid into the thru hole. The device is adapted to surround the thru hole and seal the periphery thereof on one surface of the board. A second gas and liquid transmission device is connected to the board to remove the etching gas and liquid from the thru hole. This second device is adapted to surround the thru hole and seal the periphery thereof on the other surface of the board. A vacuum system is used to force gas and liquid to move through the thru hole from the first transmission device to the second transmission device, thereby etching and/or cleaning material from the thru hole.