Copper-ceramic composite

Patent metadata

Field	Value
Publication number	US-11584696-B2
Application number	US-201716078662-A
Country	US
Kind code	B2
Filing date	Feb 16, 2017
Priority date	Feb 26, 2016
Publication date	Feb 21, 2023
Grant date	Feb 21, 2023

Abstract

A copper-ceramic composite: includes a ceramic substrate containing alumina and a copper or copper alloy coating on the ceramic substrate. The alumina has a mean grain shape factor Ra(Al2O3), defined as the arithmetic mean of the shape factors R of the alumina grains, of at least 0.4.

First claim

The invention claimed is:

1. A copper-ceramic composite comprising:
a ceramic substrate containing grains of aluminum oxide, and
a coating composed of copper or a copper alloy present on the ceramic substrate, wherein the grains of the aluminum oxide each have a maximum grain diameter d K,max , a grain diameter d K,ortho running perpendicular to d K,max , determined on half the length of d K,max , and a shape factor R K =d K,ortho /d K,max and the aluminum oxide has an average grain shape factor R a (Al 2 O 3 ), determined as arithmetic mean of the shape factors R K of the grains, of at least 0.8,
wherein the coating composed of copper or a copper alloy is applied to the ceramic substrate by a direct copper bonding (DCB) process, the DCB process comprising:
oxidizing a copper foil to form a copper oxide layer on the copper foil;
laying the copper foil with the copper oxide layer on the ceramic substrate;
heating the ceramic substrate and copper foil with the copper oxide layer to a temperature ranging from 1025° C. to 1083° C.; and
cooling the heated ceramic substrate and copper foil with the copper oxide layer to room temperature.

2. The copper-ceramic composite of claim 1 , wherein the grains of aluminum oxide range from a d min of ≥0.01 μm to a d max of ≤25 μm.

3. The copper-ceramic composites of claim 1 , wherein the ceramic substrate contains at least 65% by weight of the grains of aluminum oxide.

4. The copper-ceramic composite of claim 1 , wherein the coating composed of copper or a copper alloy at least partly has structuring to form electrical contact areas.

5. The copper-ceramic composite of claim 1 , wherein the coating composed of copper or a copper alloy has a thickness in the range of 0.2-1.2 mm over at least 70% of its area; and the ceramic substrate has a thickness in the range of 0.2-1.2 mm over at least 70% of its area.

6. A module containing at least one copper-ceramic composite according to claim 1 and one or more bond wire(s).

7. The copper-ceramic composite of claim 1 , wherein the grains of aluminum oxide range from a d min of ≥0.3 μm to a d max of ≤23 μm.

8. The copper-ceramic composite of claim 1 , wherein the grains of aluminum oxide range from a d min of ≥0.5 μm to a d max of ≤20 μm.

9. The copper-ceramic composite of claim 1 , wherein the coating composed of copper or a copper alloy has a thickness in the range of 0.2-1.2 mm over at least 70% of its area.

10. The copper-ceramic composite of claim 1 , wherein the ceramic substrate has a thickness in the range of 0.2-1.2 mm over at least 70% of its area.

11. The copper-ceramic composite of claim 1 , further comprising copper-aluminum spinels between the ceramic substrate and the coating.

12. The copper ceramic composite of claim 1 , wherein the ceramic substrate and copper foil with the copper oxide layer are heated to a temperature ranging from 1065° C. to 1083° C.

Assignees

• Heraeus Deutschland Gmbh & Co Kg

Inventors

• Herbst Kai
• Muschelknautz Christian

Classifications

• H10W70/692

  Ceramics or glasses · CPC title

• H10W40/255

  having a laminate or multilayered structure, e.g. direct bond copper [DBC] ceramic substrates · CPC title

• C04B41/88 Primary

  Metals · CPC title

• C04B2235/788

  Aspect ratio of the grains · CPC title

• C04B35/111 Primary

  Fine ceramics · CPC title