Patent ID: 7020961
Filing Date: 2006-04-04
Classification: H01L,H05K,Y10T

Abstract:
1. A method for manufacturing a bump-attached wiring circuit board in which bumps are formed on a wiring circuit, comprising the steps of: (a) laminating a protective film over the bump formation side of a metal foil having a thickness equal to the sum of the thickness of the wiring circuit and the height of the bumps to be formed on the wiring circuit, and forming a wiring circuit formation etching mask on the wiring circuit formation side of the metal foil; (b) forming a wiring circuit in a predetermined thickness by half-etching the metal foil from the side with the wiring circuit formation etching mask; (c) removing the wiring circuit formation etching mask, and then providing a cover coat layer to the wiring circuit; (d) removing the protective film provided to the bump formation side of the metal foil, and then forming a bump formation etching mask on this bump formation side; (e) forming bumps of a predetermined height by half-etching the metal foil from the bump formation etching mask side; (f) removing the bump formation etching mask, and then forming a metal thin film layer composed of a different metal from that of the metal foil; (g) forming a polyimide precursor layer over the metal thin film layer so as to bury the bumps; and (h) etching back the polyimide precursor layer and forming an insulating layer in a predetermined thickness by imidation.