Manufacturing method of circuit board

Abstract

A manufacturing method of a circuit board is provided. In the manufacturing method, an electrically insulating layer and at least one electrically insulating material are formed on a plane of a thermally conductive plate, and a metal pattern layer located on the electrically insulating layer is formed. The electrically insulating layer partially covers the plane, and the electrically insulating material covers the plane where is not covered by the electrically insulating layer. The electrically insulating material touches the thermally conductive plate. A thermal conductivity of the electrically insulating material is larger than that of the electrically insulating layer.

What is claimed is: 
     
         1 . A manufacturing method of a circuit board, comprising:
 forming an electrically insulating layer and at least one electrically insulating material on a plane of a thermally conductive plate, wherein the electrically insulating layer partially covers the plane, the electrically insulating material covers the plane where is not covered by the electrically insulating layer and touches the thermally conductive plate, and a thermal conductivity of the electrically insulating material is larger than that of the electrically insulating layer; and   forming a metal pattern layer located on the electrically insulating layer.   
     
     
         2 . The manufacturing method of a circuit board according to  claim 1 , wherein the electrically insulating layer and the electrically insulating material are formed by laminating or printing. 
     
     
         3 . The manufacturing method of a circuit board according to  claim 1 , wherein the method of forming the electrically insulating layer and the electrically insulating material comprises:
 laminating a prepreg with at least one opening in the plane; and   laminating a thermal pad on the plane, wherein the thermal pad is located in the opening.   
     
     
         4 . The manufacturing method of a circuit board according to  claim 1 , wherein the method of forming the electrically insulating layer and the electrically insulating material comprises applying two coatings to the plane. 
     
     
         5 . The manufacturing method of a circuit board according to  claim 1 , wherein the electrically insulating layer and the electrically insulating material are formed on a metal foil, and both the electrically insulating layer and the electrically insulating material touch the metal foil. 
     
     
         6 . The manufacturing method of a circuit board according to  claim 5  wherein the method of forming the metal pattern layer comprises:
 laminating the metal foil on the plane, wherein the electrically insulating layer and the electrically insulating material are located between the metal foil and the plane; and 
 removing a part of the metal foil after laminating the metal foil. 
 
     
     
         7 . The manufacturing method of a circuit board according to  claim 1 , wherein the method of forming the metal pattern layer comprises electroless plating and electroplating. 
     
     
         8 . The manufacturing method of a circuit board according to  claim 1 , wherein the method of forming the metal pattern layer comprises:
 laminating a metal foil on the electrically insulating layer and the electrically insulating material; and   removing a part of the metal foil after laminating the metal foil.