Patent ID: 6265767
Filing Date: 2001-07-24
Classification: H01L,H05K

Abstract:
A method of producing a metal sheet for a metal-sheet-inserted double-side metal-foil-clad laminate for a semiconductor plastic package, the metal-sheet-inserted double-side metal-foil-clad laminate being a printed wiring board to which at least one semiconductor chip is to be fixed and being obtained by placing prepregs of a thermosetting resin composition in a semi-cured state, resin sheets of said thermosetting resin composition, metal foils with said thermosetting resin composition or a layer of said thermosetting resin composition on front and reverse surfaces of a metal sheet having a plurality of metal protrusions having the form of a frustum of a cone and a clearance hole or a slit hole in which a through hole for conduction between the front and reverse surfaces, placing metal foil or foils thereon and laminate-forming the resultant set under heat and pressure,the method comprising placing a solder for forming the protrusions having the form of a frustum of a cone on part of one surface of a metal sheet as a raw material, placing an etching resist for forming the clearance hole or the slit hole by etching on the other surface of the metal sheet, and simultaneously forming the protrusions having the form of a frustum of a cone and the clearance hole or the slit hole in an etching step of blowing an alkaline etching liquid having a lower pressure to a surface where the protrusions having the form of a frustum of a cone are to be formed and blowing an alkaline etching liquid having a higher pressure to the other surface, to form a printed wiring board having a specially shaped metal sheet inserted therein.