Substrate having high electrical connection reliability of a penetrating via connected to wirings and a method for manufacturing the same

Abstract

A disclosed substrate is composed of a base member having a through-hole, a penetrating via provided in the through-hole, and a wiring connected to the penetrating via. The penetrating via includes a penetrating part having two ends on both sides of the base member, which is provided in the through-hole, a first protrusion protruding from the base member, which is formed on a first end of the penetrating part so as to be connected to the wiring, and a second protrusion protruding from the base member, which is formed on a second end of the penetrating part. The first protrusion and second protrusion are wider than a diameter of the through-hole.

1 . A substrate comprising: 
 a base member having a through-hole;    a penetrating via provided in said through-hole, wherein    said penetrating via includes 
 a penetrating part provided in said through-hole, said penetrating part having a first end and a second end;  
 a first protrusion protruding from said base member, said first protrusion being connected to the first end of said penetrating part; and  
 a second protrusion protruding from said base member, said second protrusion being connected to the second end of said penetrating part, wherein  
   said first protrusion and second protrusion are wider than a diameter of said through-hole.    
   
   
       2 . The substrate as claimed in  claim 1 , wherein 
 a diffusion protecting layer is formed on said first protrusion and on said second protrusion.    
   
   
       3 . A substrate comprising: 
 a base member having a through-hole;    a penetrating via provided in said through-hole; and    a first wiring and a second wiring connected to said penetrating via, wherein    said penetrating via includes 
 a penetrating part provided in said through-hole having a first end and a second end; and  
 a protrusion to be connected to said first wiring, being connected to the first end of said penetrating part and another protrusion to be connected to said second wiring, being connected to the second end of said penetrating part, wherein  
 said protrusion is wider than a diameter of said through-hole.  
   
   
   
       4 . The substrate as claimed in  claim 3 , wherein one of said first wiring and said second wiring has an external connection terminal; and a diffusion protecting layer is formed on said external connection terminal.  
   
   
       5 . A method for manufacturing a substrate comprising a base member having a through-hole; and a penetrating via formed in said through-hole in said base member, wherein said penetrating via includes; a penetrating part provided in said through-hole, said penetrating part having a first end and a second end; a first protrusion protruding from said base member, said first protrusion being connected to the first end of said penetrating part; and a second protrusion protruding from said base member, said second protrusion being connected to the second end of said penetrating part, wherein said first protrusion and second protrusion are wider than a diameter of said through-hole, 
 said method comprising the step of forming said penetrating via.    
   
   
       6 . The method for manufacturing the substrate as claimed in  claim 5 , wherein the step of forming said penetrating via further includes the steps of: 
 attaching a metal foil on a support board by an adhesive;    forming a first resist layer on said metal foil;    disposing said base member having said through-hole on said first resist layer;    removing said first resist layer exposed from said through-hole by a developer so as to expose said metal foil and to form a space being wider than a diameter of said through-hole;    forming a second resist layer having a first open part being wider than the diameter of said through-hole so as to expose the through-hole in said base member; and    forming a conductive metal layer according to an electrolytic plating method so as to fill the space, the through-hole and the first open part.    
   
   
       7 . The method for manufacturing the substrate as claimed in  claim 6 , further comprising the step of hardening said first resist layer according to a thermal treatment after the step of forming said space.  
   
   
       8 . The method for manufacturing the substrate as claimed in  claim 6 , further comprising the step of forming a first diffusion protecting layer on said metal foil exposed in said space according to an electrolytic plating method after the step of forming said second resist layer.  
   
   
       9 . The method for manufacturing the substrate as claimed in  claim 6 , further including a wiring forming step forming a wiring so as to be connected to said first protrusion, said wiring forming step comprising: 
 removing said second resist layer;    forming an insulating layer having a second open part exposing said first protrusion on said base member; and    forming a seed layer on said insulating layer where said wiring is formed; wherein    said insulating layer comprises a resin containing palladium particles therein.    
   
   
       10 . The method for manufacturing the substrate as claimed in  claim 9 , wherein said wiring has an external connection terminal, said method further comprising the step of forming a second diffusion protecting layer on said external connection terminal according to the electrolytic plating method after the step of forming said wiring.  
   
   
       11 . The method for manufacturing the substrate as claimed in  claim 10 , further comprising the steps of: 
 disposing a heat-resistant protecting member so as to cover at least said wiring and said second diffusion protecting layer after the step of forming said second diffusion protecting layer; and    removing said adhesive and said support board from said base member according to a thermal treatment after the step of forming said protecting member.    
   
   
       12 . The method for manufacturing the substrate as claimed in  claim 11 , further comprising the steps of: 
 removing said first resist layer; and    removing said protecting member after the step of removing said first resist layer.    
   
   
       13 . The method for manufacturing the substrate as claimed in  claim 8 , wherein the step of forming said first diffusion protecting layer is performed immediately after the step of disposing said metal foil.