Patent ID: 9693458
Date: 2017-06-27
CPC Classifications: H01L,H05K

Claim:
1. A method for manufacturing a printed wiring board, comprising: forming a resin insulation layer on an interlayer resin insulation layer such that the resin insulation layer has a plurality of first opening portions exposing a plurality of conductive circuits formed in a central portion of the interlayer resin insulation layer and a plurality of second opening portions exposing a plurality of conductive circuits formed in a peripheral portion of the interlayer resin insulation layer; forming a plurality of solder bumps in the plurality of first opening portions such that the plurality of solder bumps is formed on the plurality of conductive circuits in the central portion of the interlayer resin insulation layer, respectively; forming a plating resist over the solder bumps and the resin insulation layer such that the plating resist has a plurality of resist opening portions having diameters greater than diameters of the plurality of second opening portions and exposing the plurality of second opening portions; forming a seed layer on the plating resist such that the seed layer is formed on the plating resist, in the resist opening portions and on the conductive circuits exposed through the second opening portions; applying electrolytic plating on the plating resist such that an electrolytic plating material fills the resist opening portions and forms an electrolytic plated film on the plating resist via the seed layer and a plurality of metal posts in the resist opening portions, respectively; etching the electrolytic plating material such that the electrolytic plated film on the plating resist is removed and a plurality of recess portions is formed on surfaces of the metal posts in the resist opening portions, respectively; applying surface-treatment on the recess portions formed on the surfaces of the metal posts prior to removing of the plating resist; and removing the plating resist, wherein the surface-treatment comprises forming a plurality of Ni/Pd/Au films on the recess portions of the metal posts, respectively, or forming a plurality of Ni/Au films on the recess portions of the metal posts, respectively.