PURPOSE: To reduce buckling of a metal foil laminated over a resin plate when a hole is drilled in the resin plate.

CONSTITUTION: A thermoplastic resin plate 2 containing an inorganic filler is used as a patch plate for drilling hole in a stack of metal foil covered resin plates (copper foil covered epoxy resin laminated plates). Further, the drilling is made so as to the tip end of a drill 4 enters into the thermoplastic resin plate 1. The thermoplastic resin plate is polypropylene (resin/filler (weight part) = 100/20 to 400), high density polyethylene (100/10 to 400), ABS resin (100/10 to 250), polyethylene terephthalate (100/10 to 250) or the like.