Method of manufacturing a metal-ceramic circuit board

• US 20060242826A1
• Filed: 06/20/2006
• Published: 11/02/2006
• Est. Priority Date: 09/04/2000
• Status: Active Grant

• Current Assignee: DOWA Metaltech Co., Ltd. (DOWA Holdings Company Limited)
• Original Assignee: Dowa Mining Company Limited
• Inventors: Osanai, Hideyo, Furo, Masahiro
• Granted Patent: US 7,487,585 B2
• Time in Patent Office: Days
• US Class Current: 29/831
• CPC Class Codes: B32B 2311/12 Copper
• CPC Class Codes: B32B 2311/24 Aluminium
• CPC Class Codes: C04B 2237/121 based on aluminium
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/124 based on copper
• CPC Class Codes: C04B 2237/125 based on noble metals, e.g. silver
• CPC Class Codes: C04B 2237/16 Silicon interlayers
• CPC Class Codes: C04B 2237/368 Silicon nitride
• CPC Class Codes: C04B 2237/402 Aluminium
• CPC Class Codes: C04B 2237/407 Copper
• CPC Class Codes: C04B 37/026 consisting of metals or metal salts
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/83424 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/83444 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/83455 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 23/142 Metallic substrates having insulating layers
• CPC Class Codes: H01L 23/3735 Laminates or multilayers, e.g. direct bond copper ceramic substrates
• CPC Class Codes: H01L 24/83 using a layer connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H05K 1/0306 : Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/053 : the metal substrate being covered by an inorganic insulating layer
• CPC Class Codes: H05K 2203/128 : Molten metals, e.g. casting thereof, or melting by heating and excluding molten solder spraying droplets of molten metal H05K2203/1344
• CPC Class Codes: H05K 3/0061 : onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/101 : by casting or moulding of conductive material
• CPC Class Codes: H05K 3/38 : Improvement of the adhesion between the insulating substrate and the metal
• CPC Class Codes: Y10T 29/49124 : On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49147 : Assembling terminal to base
• CPC Class Codes: Y10T 29/49149 : by metal fusion bonding
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49222 : forming array of contacts or terminals

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.

Claims

1. A method of manufacturing a metal-ceramic circuit board characterized by comprising the steps of:

bonding a conductive metal member for an electric circuit on a first surface of the ceramic substrate board;

placing a quantity of aluminum or an aluminum alloy in a furnace;

placing said ceramic substrate board being bonded said conductive metal member for the electric circuit in an inside bottom portion of the furnace;

creating an inert gas atmosphere inside the furnace;

melting the aluminum or aluminum alloy to form a molten metal;

dispensing the motel metal via narrow conduit onto said ceramic substrate board and in direct contact with a second surface of said ceramic substrate board; and

cooling said motel metal and said ceramic substrate board being bonded said conductive metal member for the electric circuit to form a base plate of aluminum of aluminum alloy, which is bonded directly on the second surface of the ceramic substrate board.

2. The method of manufacturing the metal-ceramic circuit board according to claim 1, wherein said conductive metal member for the electric circuit is bonded on the first surface of the ceramic substrate board by using a brazing material.

3. The method of manufacturing the metal-ceramic circuit board according to claim 1, wherein said conductive metal member for the electric circuit is bonded on the first surface of the ceramic substrate board directly.

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 3, wherein said ceramic substrate board is made of a material selected from alumina, aluminum nitride and silicon nitride.

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. The method of manufacturing the metal-ceramic circuit board according to claim 3, wherein said conductive metal member contains at least one metal selected from copper, copper alloy, aluminum, and aluminum alloy.