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 - 6 . (canceled) 
   
   
       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;   providing conductive layers on both sides of the insulating substrate, respectively; and   forming an alloy of the component materials of the conductive material with the component materials of the conductive layers;   wherein each of the conductive layers has particles containing metal to be alloyed with the conductive material.   
   
   
       8 . The method according to  claim 7 ,
 wherein the conductive layers contain copper,   wherein the component materials of the conductive material are metal, and   wherein the conductive materials include particles 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.   
   
   
       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 layers contain copper,   wherein the conductive material contains copper and metal which can be alloyed with copper, and   wherein forming an alloy comprises forming an alloy containing at least a portion 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.   
   
   
       18 . The method according to  claim 7 ,
 wherein each of the conductive layers has a surface facing each of the both sides of the insulating layer, the surface of each of the conductive layers has a first portion facing the insulating layer and a second portion facing the conductive material,   said method further comprises providing the conductive layers with the particles on the surface of each of the conductive layers, and   wherein said providing the conductive layers on both sides of the insulating substrate, respectively comprises providing the conductive layers on both sides of the insulating substrate, respectively, such that the particles are provided between the insulating layer and the second first portion of the surface of each of the conductive layers.