Printed wiring board and method for manufacturing the same

Abstract

A printed wiring board includes a support plate, a laminate formed on the support plate and including first conductor pads on a first surface side of the laminate and second conductor pads on a second surface side of the laminate, and a solder resist layer interposed between the support plate and the laminate and having openings formed such that the openings are exposing the first conductor pads respectively. The laminate includes a resin insulating layer and has a first surface on the first surface side and a second surface on the second surface side on the opposite side with respect to the first surface of the laminate, the second conductor pads are embedded in the second surface of the laminate such that the second conductor pads have surfaces exposed from the second surface of the laminate respectively.

1 . A printed wiring board, comprising:
 a support plate;   a laminate formed on the support plate and comprising a plurality of first conductor pads on a first surface side of the laminate and a plurality of second conductor pads on a second surface side of the laminate; and   a solder resist layer interposed between the support plate and the laminate and having a plurality of openings formed such that the openings are exposing the first conductor pads respectively,   wherein the laminate includes a resin insulating layer and has a first surface on the first surface side and a second surface on the second surface side on an opposite side with respect to the first surface of the laminate, the plurality of second conductor pads is embedded in the second surface of the laminate such that the second conductor pads have surfaces exposed from the second surface of the laminate respectively.   
     
     
         2 . A printed wiring board according to  claim 1 , wherein the laminate includes a via conductor structure penetrating from the first surface to the second surface of the laminate such that the via conductor structure comprises at least one via conductor formed in the resin insulating layer and tapering from the first surface side toward the second surface side of the laminate. 
     
     
         3 . A printed wiring board according to  claim 1 , wherein the plurality of first conductor pads is formed on the first surface of the laminate. 
     
     
         4 . A printed wiring board according to  claim 1 , wherein the second surface of the laminate is not covered with a solder resist layer. 
     
     
         5 . A printed wiring board according to  claim 1 , further comprising:
 an electronic component connected to the plurality of second conductor pads such that the electronic component is mounted on the second surface side of the laminate.   
     
     
         6 . A printed wiring board according to  claim 1 , wherein the plurality of second conductor pads is formed such that each of the second conductor pads comprises a dissimilar metal layer comprising mutually different metal layers. 
     
     
         7 . A printed wiring board according to  claim 6 , wherein the dissimilar metal layer comprises a copper plating layer and a corrosion resistant plating layer formed on the copper plating layer. 
     
     
         8 . A printed wiring board according to  claim 1 , wherein the plurality of second conductor pads is formed such that the surfaces of the second conductor pads are protruding from the second surface of the laminate. 
     
     
         9 . A printed wiring board according to  claim 1 , wherein the plurality of second conductor pads is formed such that the surfaces of the second conductor pads have a height in a range of 2 μm to 10 μm from the second surface of the laminate. 
     
     
         10 . A printed wiring board according to  claim 1 , wherein the plurality of second conductor pads is formed on a center side of the second surface of the laminate, and the laminate includes a plurality of third conductor pads formed on the second surface side of the laminate such that the third conductor pads are positioned on an outer peripheral side than the plurality of second conductor pads, embedded in the second surface of the laminate and have surfaces exposed from the second surface of the laminate respectively. 
     
     
         11 . A printed wiring board according to  claim 10 , wherein the plurality of second conductor pads is formed such that the plurality of second conductor pads has a pitch that is smaller than a pitch of the plurality of third conductor pads. 
     
     
         12 . A printed wiring board according to  claim 10 , wherein the plurality of third conductor pads is formed such that each of the third conductor pads comprises a dissimilar metal layer comprising mutually different metal layers. 
     
     
         13 . A printed wiring board according to  claim 12 , wherein the dissimilar metal layer of each of the third conductor pads comprises a copper plating layer and a corrosion resistant plating layer formed on the copper plating layer. 
     
     
         14 . A printed wiring board according to  claim 10 , further comprising:
 a plurality of conductor posts formed on the second surface side of the laminate such that the conductor posts are formed on the third conductor pads respectively.   
     
     
         15 . A printed wiring board according to  claim 14 , wherein the conductor posts comprise metal film layer portions formed in contact with the third conductor pads and plating layer portions formed on the metal film layer portions respectively. 
     
     
         16 . A printed wiring board according to  claim 15 , wherein the plurality of conductor posts has a height in a range of 50 μm to 200 μm. 
     
     
         17 . A printed wiring board according to  claim 14 , wherein the plurality of conductor posts is formed such that the plurality of conductor posts has a diameter that is greater than a diameter of the plurality of third conductor pads. 
     
     
         18 . A printed wiring board according to  claim 14 , wherein the laminate includes a via conductor structure penetrating from the first surface to the second surface of the laminate such that the via conductor structure, one of the conductor posts and one of the first conductor pads are formed in overlapping positions and that the via conductor structure is connecting the one of the conductor posts and the one of the first conductor pads. 
     
     
         19 . A method for manufacturing a printed wiring board, comprising:
 preparing a base plate having a metal film on a surface of the base plate;   forming, on the metal film, a conductor layer comprising a plurality of conductor pads;   laminating, on the conductor layer, at least one set of a resin insulating layer and a conductor layer, such that a laminate comprising the conductor layers and resin insulating layer is formed to have a first surface and a second surface on a metal film side on an opposite side with respect to the first surface;   forming a solder resist layer on the first surface of the laminate;   adhering a support plate on a first surface side of the laminate such that the solder resist layer is interposed between the laminate and the support plate;   removing the base plate from the laminate; and   removing the metal film from the laminate such that the conductor pads have surfaces exposed on the second surface of the laminate.   
     
     
         20 . A method for manufacturing a printed wiring board according to  claim 19 , further comprising:
 connecting an electronic component to the plurality of conductor pads such that the electronic component is mounted on a second surface side of the laminate prior to the removing of the base plate.