Method of manufacturing a metal-ceramic circuit board

Abstract

A metal-ceramic circuit board is characterized by being constituted by bonding on a base plate of aluminum or aluminum alloy at least one of ceramic substrate boards having a conductive metal member for an electronic circuit. A method of manufacturing a metal-ceramic circuit board is characterized by comprising the steps of melting aluminum or aluminum alloy in a vacuum or inert gas atmosphere to form a molten metal, contacting one surface of a ceramic substrate board directly with the molten metal in a vacuum or inert gas atmosphere, cooling the molten metal and the ceramic substrate board to form a base plate of aluminum or aluminum alloy, which is bonded directly on the ceramic substrate board without forming any oxidizing film therebetween and bonding a conductive metal member for an electronic circuit on the ceramic substrate board by using a brazing material. The base plate has a proof stress not higher than 320 (MPa) and a thickness not smaller than 1 mm.

1 . A method of manufacturing a metal-ceramic circuit board characterized by comprising the steps of melting aluminum or aluminum alloy in a vacuum or inert gas atmosphere to from a molten metal, contacting one surface of a ceramic substrate board directly with said molten metal in a vacuum or inert gas atmosphere, cooling said molten metal and said ceramic substrate board to form a base plate of aluminum or aluminum alloy, which is bonded directly on said one surface of the ceramic substrate board, and bonding a conductive metal member for an electronic circuit on the other surface of said ceramic substrate board by using a brazing material.  
   
   
       2 . A method of manufacturing a metal-ceramic circuit board characterized by comprising the steps of melting aluminum or aluminum alloy in a vacuum or inert gas atmosphere to from a molten metal, contacting one surface of a ceramic substrate board directly with said molten metal in a vacuum or inert gas atmosphere, cooling said molten metal and said ceramic substrate board to form a base plate of aluminum or aluminum alloy, which is bonded directly on said one surface of the ceramic substrate board, and bonding a conductive metal member for an electronic circuit on the other surface of said ceramic substrate board.  
   
   
       3 . The method of manufacturing the metal-ceramic circuit board according to  claim 1 , wherein said ceramic substrate board is made of a material selected from alumina, aluminum nitride and silicon nitride.  
   
   
       4 . The method of manufacturing the metal-ceramic circuit board according to  claim 2 , wherein said ceramic substrate board is made of a material selected from alumina, aluminum nitride and silicon nitride.  
   
   
       5 . The method of manufacturing the metal-ceramic circuit board according to  claim 1 , wherein said conductive metal member contains at least one metal selected from copper, copper alloy, aluminum, and aluminum alloy.  
   
   
       6 . The method of manufacturing the metal-ceramic circuit board according to  claim 2 , wherein said conductive metal member contains at least one metal selected from copper, copper alloy, aluminum, and aluminum alloy.  
   
   
       7 . A method of manufacturing a power module characterized by comprising the steps of melting aluminum or aluminum alloy in a vacuum or inert gas atmosphere to form a molten metal, contacting one surface of a ceramic substrate board directly with said molten metal in a vacuum or inert gas atmosphere, cooling said molten metal and said ceramic substrate board to form a base plate of aluminum or aluminum alloy, which is bonded directly on said one surface of the ceramic substrate board, forming a metal layer of desired pattern on the other surface of said ceramic substrate board, and fixing a semiconductor tip on said metal layer.