Wiring board and method for manufacturing the same

Abstract

A wiring board having an insulation layer, and a buildup structure formed on the insulation layer and including insulation layers. The insulation layer and the buildup structure form a board structure in which a cavity portion having an opening on a surface of the buildup structure on the opposite side of the insulation layer is formed. The cavity portion is extending through one or more of the insulation layers in the buildup structure and has a groove portion formed on the bottom surface of the cavity portion along a wall surface of the cavity portion. The board structure composed of the insulation layer and the buildup structure has a pad formed on the bottom surface of the cavity portion in a position farther from the wall surface of the cavity portion than the groove portion.

1 - 12 . (canceled) 
     
     
         13 . A method for manufacturing a wiring board, comprising:
 preparing an insulation layer having a conductive layer comprising a pad formed on a surface of the insulation layer;   covering the pad with a mask layer which is separable from the insulation layer and is substantially corresponding to a bottom surface of a cavity portion;   forming on the insulation layer, the conductive layer and the mask layer a buildup structure comprising a plurality of insulation layers;   irradiating laser on a surface of the buildup structure on an opposite side of the insulation layer substantially along a shape of the mask layer such that the laser forms a separable portion including the mask layer in the buildup structure and a groove portion in the insulation layer substantially along the shape of the mask layer; and   removing the separable portion formed in the buildup structure such that the cavity portion having the groove portion on the surface of the insulation layer is formed and the pad is exposed on the bottom surface of the cavity portion in a position farther from the wall surface of the cavity portion than the groove portion.   
     
     
         14 . The method for manufacturing a wiring board according to  claim 13 , wherein the conductive layer includes a conductive pattern electrically connected to the pad, and the groove portion is crossing a portion of the conductive pattern. 
     
     
         15 . The method for manufacturing a wiring board according to  claim 14 , wherein the laser is set to an intensity which is sufficiently low such that the groove portion is formed intermittently. 
     
     
         16 . The method for manufacturing a wiring board according to  claim 14 , wherein the buildup structure comprises a laminated structure in which the plurality of insulation layers are laminated, and the cavity portion of the board structure is formed in the laminated structure. 
     
     
         17 . The method for manufacturing a wiring board according to  claim 14 , wherein the insulation layer of the board structure is a rigid substrate having a core material, and the groove portion of the cavity portion is formed in the rigid substrate. 
     
     
         18 . A method for manufacturing a wiring board, comprising:
 forming a board structure comprising an insulation layer, a buildup structure formed on the insulation layer and a pad formed in the board structure, the buildup structure comprising a plurality of insulation layers; and   forming a cavity portion in the board structure such that the cavity portion has an opening on a surface of the buildup structure on an opposite side of the insulation layer, the cavity portion is extending through at least one of the insulation layers in the buildup structure, the cavity portion has a groove portion formed on a bottom surface of the cavity portion along a wall surface of the cavity portion, and the pad formed in the board structure is exposed on the bottom surface of the cavity portion in a position farther from the wall surface of the cavity portion than the groove portion,   wherein the forming of the board structure comprises covering the pad with a separable mask layer which is substantially corresponding to the bottom surface of the cavity portion, and the forming of the cavity portion in the board structure comprises irradiating laser on the surface of the buildup structure substantially along a shape of the separable mask layer such that the laser forms a separable portion including the separable mask layer in the buildup structure and a groove portion in the bottom surface of the cavity portion substantially along the shape of the mask layer and removing the separable portion formed in the buildup structure such that the cavity portion having the groove portion is formed and the pad is exposed in the cavity portion formed in the board structure.   
     
     
         19 . The method for manufacturing a wiring board according to  claim 18 , wherein the conductive layer includes a conductive pattern electrically connected to the pad, and the groove portion is crossing a portion of the conductive pattern. 
     
     
         20 . The method for manufacturing a wiring board according to  claim 18 , wherein the laser is set to an intensity which is sufficiently low such that the groove portion is formed intermittently. 
     
     
         21 . The method for manufacturing a wiring board according to  claim 13 , wherein the groove portion is formed such that the groove portion surrounds a partial region on the bottom surface of the cavity portion along the wall surface of the cavity portion, and the pad is positioned in the partial region on the bottom surface of the cavity portion. 
     
     
         22 . The method for manufacturing a wiring board according to  claim 13 , further comprising forming a solder resist on a portion of the bottom surface of the cavity portion where the groove portion is not formed such that the solder resist has an opening exposing the pad. 
     
     
         23 . The method for manufacturing a wiring board according to  claim 13 , wherein the pad has an anticorrosion layer forming a surface of the pad. 
     
     
         24 . The method for manufacturing a wiring board according to  claim 23 , further comprising forming a solder structure on the anticorrosion layer of the pad. 
     
     
         25 . The method for manufacturing a wiring board according to  claim 23 , further comprising forming a plurality of pads on the surface of the buildup structure outside the cavity portion, wherein the pads on the surface of the buildup structure have anticorrosion layers on surfaces of the pads, and the anticorrosion layer on the pad inside the cavity portion comprises a same anticorrosion material as the anticorrosion layers on the pads on the surface of the buildup structure. 
     
     
         26 . The method for manufacturing a wiring board according to  claim 18 , wherein the groove portion is formed such that the groove portion surrounds a partial region on the bottom surface of the cavity portion along the wall surface of the cavity portion, and the pad is positioned in the partial region on the bottom surface of the cavity portion. 
     
     
         27 . The method for manufacturing a wiring board according to  claim 18 , further comprising forming a solder resist on a portion of the bottom surface of the cavity portion where the groove portion is not formed such that the solder resist has an opening exposing the pad. 
     
     
         28 . The method for manufacturing a wiring board according to  claim 18 , wherein the pad has an anticorrosion layer forming a surface of the pad. 
     
     
         29 . The method for manufacturing a wiring board according to  claim 28 , further comprising forming a solder structure on the anticorrosion layer of the pad. 
     
     
         30 . The method for manufacturing a wiring board according to  claim 28 , further comprising forming a plurality of pads on the surface of the buildup structure outside the cavity portion, wherein the pads on the surface of the buildup structure have anticorrosion layers on surfaces of the pads, and the anticorrosion layer on the pad inside the cavity portion comprises a same anticorrosion material as the anticorrosion layers on the pads on the surface of the buildup structure. 
     
     
         31 . The method for manufacturing a wiring board according to  claim 18 , wherein the buildup structure comprises a laminated structure in which the plurality of insulation layers are laminated, and the cavity portion of the board structure is formed in the laminated structure. 
     
     
         32 . The method for manufacturing a wiring board according to  claim 18 , wherein one of the insulation layers in the buildup structure has a surface portion forming the bottom surface of the cavity portion, and the groove portion of the cavity portion is formed in the one of the insulation layers in the buildup structure such that the groove portion of the cavity portion does not penetrate through the one of the insulation layers in the buildup structure.