Power module and power module with heat sink

• US 7,019,975 B2
• Filed: 08/09/2001
• Issued: 03/28/2006
• Est. Priority Date: 08/09/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Materials Corporation
• Original Assignee: Mitsubishi Materials Corporation
• Inventors: Nagatomo, Yoshiyuki, Nagase, Toshiyuki, Shimamura, Shoichi
• Primary Examiner(s): Chérvinsky, Boris
• Application Number:
  US10/343,857
• Publication Number:
  US 20040022029A1
• Time in Patent Office: 1,692 Days
• Field of Search: 361/699, 361/704, 361/705, 361707-711, 361/713, 361/715, 361717-719, 165/80.3, 165/80.4, 165/185, 174/252, 174/256, 174/258, 257/706, 257712-714, 428/901, 428/209, 428/210
• US Class Current: 361/704
• CPC Class Codes: C04B 2237/407 Copper
• CPC Class Codes: H01L 2224/2612 Auxiliary members for layer connectors, e.g. spacers
• CPC Class Codes: H01L 23/3735 Laminates or multilayers, e.g. direct bond copper ceramic substrates
• CPC Class Codes: H01L 23/3736 Metallic materials H01L23/3732, H01L23/3733, H01L23/3735, H01L23/3737, H01L23/3738 take precedence
• CPC Class Codes: H01L 24/32 of an individual 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01025 Manganese [Mn]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01032 Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01058 Cerium [Ce]
• CPC Class Codes: H01L 2924/0132 Binary Alloys
• CPC Class Codes: H01L 2924/15787 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/351 Thermal stress
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 3/0058 : Laminating printed circuit boards onto other substrates, e.g. metallic substrates H05K1/0281 takes precedence
• CPC Class Codes: Y10T 428/12007 : Component of composite having metal continuous phase interengaged with nonmetal continuous phase

Abstract

The present invention relates to a power module in which an insulated circuit board is fixed to one main surface of a heat discharge plate. It is an object thereof to provide a power module in which the heat discharge characteristics are improved without any marked warping being generated, and that has an extended heat cycle longevity.

In the power module 10 of the present invention, a square insulated circuit board 12 is fixed to one main surface of a heat discharge plate 11. The heat discharge plate 11 is formed of an Al based alloy plate having a thickness A of 3 to 10 mm, and the insulated circuit board 12 having a side B of 30 mm or less in length is brazed directly onto the heat discharge plate 11. It is-preferable that the brazing material used is one or two or more brazing materials selected from Al—Si, Al—Ge, Al—Cu, Al—Mg, and Al—Mn based brazing materials. It is also preferable that the insulated circuit board 12 is formed by a ceramic substrate 12a and Al plates 12b and 12c that are bonded to both surfaces thereof, and that the Al plate 12b has a purity of 99.98 or greater percent by weight.

Claims

1. A power module in which one or two or more square insulated circuit boards are fixed to one main surface of a heat discharge plate, wherein

the heat discharge plate is an Al alloy plate having a thickness of 3 to 10 mm, and

the insulated circuit board has a side with a length of 30 mm or less and is brazed directly onto the heat discharge plate.

2. The power module according to claim 1, wherein the brazing material used is one or two or more brazing materials selected from Al—

Si, Al—

Ge, Al—

Cu, Al—

Mg, and Al—

Mn based brazing materials.

3. The power module according to claim 1 or 2, wherein the insulated circuit board is provided with a ceramic substrate formed of Si₃N₄, AlN, or Al₂O₃ and with first and second Al plates that are bonded to both surfaces of the ceramic substrate, and the first or second Al plate that is brazed to the heat discharge plate has a purity of 99.98 or greater percent by weight.

4. The power module according to claim 1 or 2, wherein the insulated circuit board is provided with a ceramic substrate formed of Si₃N₄, AlN, or Al₂O₃ and with an Al plate that is bonded to one surface of the ceramic substrate, and another surface of the ceramic substrate is brazed directly onto the heat discharge plate.

5. The power module in which another main surface of the heat discharge plate of the power module according to any of claim 1 or 2 is joined to a water cooled or air cooled heat sink formed of an Al based alloy.

6. The power module according to claim 5, wherein the heat sink is provided with a heat sink main body in which is formed a coolant passage and with a lid body that is joined to the heat sink main body so as to cover and seal the coolant passage, and the heat discharge plate of the power module is structured so as to be able to also function as the lid body.

7. A power module in which one or two or more square insulated circuit boards are fixed to one main surface of a heat discharge plate, wherein

the insulated circuit board is provided with a ceramic substrate formed of Si₃N₄, AlN, or Al₂O₃ and with first and second Al plates that are bonded to both of the ceramic substrate,

the first Al plate of the insulated circuit board is brazed using one or two or more brazing materials selected from Al—

Si, Al—

Ge, Al—

Cu, Al—

Mg, and Al—

Mn based brazing materials directly to the heat discharge plate alloy plate, and

the average values of component contents of Si, Cu, Mn, and Ge measured by performing 5 point quantitative analysis using an EPMA in an area within the first Al plate at a position 0.2 mm away from the heat discharge plate on the first Al plate side are within the following ranges;

0.05 percent by weight≦

Si≦

3.0 percent by weight when the brazing material is Al—

Si based;

0.05 percent by weight≦

Cu≦

2.0 percent by weight when the brazing material is Al—

Cu based;

0.05 percent by weight≦

Mg≦

2.0 percent by weight when the brazing material is Al—

Mg based;

0.05 percent by weight≦

Mn≦

1.0 percent by weight when the brazing material is Al—

Mn based; and

0.05 percent by weight≦

Ge≦

3.0 percent by weight when the brazing material is Al—

Ge based.

8. The power module according to claim 7, wherein the heat discharge plate is an Al based alloy plate having a thickness of 3 to 10 mm, and the insulated circuit board has a side with a length of 30 mm or less.

9. A power module in which one or two or more square insulated circuit boards are fixed to one main surface of a heat discharge plate, wherein the insulated circuit board is provided with a ceramic substrate formed of Si₃N₄, AlN, or Al₂O₃ and with first and second Al plates that are bonded to both surfaces of the ceramic substrate,

the first Al plate of the insulated circuit board is brazed using one or two or more brazing materials selected from Al—

Si, Al—

Ge, Al—

Cu, Al—

Mg, and Al—

Mn based brazing materials, directly to the heat discharge plate formed by an Al based alloy plate, and

a layer formed by the brazing material is not visible at a portion where the heat discharge plate is bonded to the first Al plate even when a scanning electron microscope image of a magnification of 1000 times or more is used.