Circuit board and method of manufacturing the same

Abstract

A circuit board is manufactured by filling a via-hole formed in an insulating substrate with conductive material, disposing conductive layers on both sides of the insulating substrate, and forming alloy of component material of the conductive material with component material of the conductive layers. In the circuit board, therefore, the conductive material filled in the via-hole formed in the insulating substrate is securely connected electrically as well as mechanically to the conductive layers on both sides of the insulating substrate with high reliability.

1 . A circuit board comprising: 
 an insulating substrate having a via-hole formed therein;    a conductive material filled in said via-hole;    conductive layers on both sides of said insulating substrate, respectively;    first alloy containing component material of said conductive material and component material of said conductive layers; and    second alloy contained in said conductive material.    
     
     
         2 . The circuit board according to  claim 1 , 
 wherein at least one of said conductive layers and said conductive material contains copper, and    wherein said first alloy contains copper.    
     
     
         3 . The circuit board according to  claim 1 , 
 wherein said conductive layers contain copper, and    wherein said first alloy contain said copper in said conductive layers.    
     
     
         4 . The circuit board according to  claim 1 , 
 wherein said conductive material contains copper, and    wherein said first alloy contains said copper in said conductive material.    
     
     
         5 . The circuit board according to  claim 4 , wherein said conductive material contains 50 wt % or less of copper.  
     
     
         6 . A circuit board comprising: 
 an insulating substrate having a via-hole formed therein;    a conductive material filled in said via-hole, said conductive material containing alloy; and    conductive layers on both sides of said insulating substrate, respectively.    
     
     
         7 . A method of manufacturing a circuit board comprising the steps of: 
 filling a via-hole formed in an insulating substrate with a conductive material;    disposing conductive layers on both sides of the insulating substrate, respectively; and    forming alloy of component material of the conductive material with component material of the conductive layers.    
     
     
         8 . The method according to  claim 7 , 
 wherein the conductive layers contain copper,    wherein the component material of the conductive material is metal, and    wherein the conductive material includes a particle containing the metal.    
     
     
         9 . The method according to  claim 8 , wherein the metal has a lower melting point than copper.  
     
     
         10 . The method according to  claim 7 , 
 wherein the conductive material contains copper, and    wherein the conductive layers each includes a particle containing metal to be alloyed with copper placed on a surface of the conductive layers.    
     
     
         11 . The method according to  claim 10 , wherein the metal has a lower melting point than copper.  
     
     
         12 . The method according to  claim 7 , 
 wherein the conductive material contains copper,    wherein the conductive material contains copper and metal which can be alloyed with copper, and    wherein said step of forming the alloy of the component material of the conductive material with the component material of the conductive layers comprises the step of forming the alloy containing at least a part of the copper.    
     
     
         13 . The method according to  claim 12 , wherein the metal has a lower melting point than copper.  
     
     
         14 . The method according to  claim 7 , 
 wherein said step of disposing the conductive layers comprises the step of pressing the conductive layers onto the insulating substrate, and    wherein said step of forming the alloy of the component material of the conductive material with the component material of the conductive layers comprises the step of compressing the conductive material simultaneously to said step of pressing the conductive layers.    
     
     
         15 . The method according to  claim 7 , 
 wherein said step of disposing the conductive layers comprises the step of heat-pressing the conductive layers onto the insulating substrate, and    wherein said step of forming the alloy of the component material of the conductive material with the component material of the conductive layers comprises the step of compressing and heating the conductive material simultaneously to said step of heat-pressing the conductive layers.    
     
     
         16 . The method according to  claim 15 , 
 wherein the component material of the conductive layers contains copper, and    wherein the component material of the conductive material contains metal having a melting point lower than a temperature in said step of heat-pressing the conductive layers.    
     
     
         17 . The method according to  claim 15 , 
 wherein the component material of the conductive layers contains copper, and    wherein the component material of the conductive material contains one of tin, zinc, silver, palladium, indium, and bismuth.