Patent ID: 8535546
Filing Date: 2013-09-17
Classification: H01L,H05K,Y10T

Abstract:
1. A method of manufacturing a multilayer wiring substrate having a laminate structure which has a first main surface and a second main surface and in which a plurality of resin insulation layers made primarily of the same resin insulation material, and a plurality of conductor layers are laminated alternately, wherein a solder resist layer is provided on at least one of the first main surface and the second main surface of the laminate structure, the solder resist layer has a plurality of openings for exposing external connection terminals, and the plurality of conductor layers are connected with one another by via conductors formed in the plurality of resin insulation layers such that their diameters increase toward the first main surface side or the second main surface side, the method comprising: a solder resist layer formation step of providing a base member having a copper foil separably laminated thereon, and applying a photosensitive resin insulation material on the copper foil to thereby form the solder resist layer; an opening formation step of forming the plurality of openings in the solder resist layer through exposure and development; a conductor portion formation step of forming a metal conductor portion of copper in each of the plurality of openings of the solder resist layer; a dissimilar metal layer formation step of forming a dissimilar metal layer over a surface of the metal conductor portion and an entire surface of the solder resist layer by a physical film formation process, the dissimilar metal layer being formed of at least one metal which is lower in etching rate than copper; a terminal and wiring formation step, performed after the dissimilar metal layer formation step, of performing copper electroplating to thereby form the external connection terminals on the dissimilar metal layer at positions corresponding to the plurality of openings such that each of the external connection terminals has a diameter greater than that of a corresponding opening, and forming a wiring pattern on the dissimilar metal layer at a position different from positions of the external connection terminals; a build-up step of alternately laminating the plurality of resin insulation layers and the plurality of conductor layers on the solder resist layer having the external connection terminals and the wiring pattern formed thereon, to thereby form the laminate structure; a base member removal step, performed after the build-up step, of removing the base member to thereby expose the copper foil; and a terminal exposure step of exposing surfaces of the external connection terminals from the plurality of openings by removing the exposed copper foil and the metal conductor portion through etching.