Copper-ceramic composite

Patent metadata

Field	Value
Publication number	US-11021406-B2
Application number	US-201716078676-A
Country	US
Kind code	B2
Filing date	Feb 16, 2017
Priority date	Feb 26, 2016
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

The invention relates to a copper-ceramic composite comprising: a ceramic substrate; and a copper or copper alloy coating on the ceramic substrate, the copper or copper alloy having grain sizes of 10 μm to 300 μm.

First claim

The invention claimed is:

1. A copper-ceramic composite comprising:
a ceramic substrate,
a coating which is present on the ceramic substrate and is composed of copper or a copper alloy,
wherein the copper or the copper alloy has
grain sizes in the range from 10 μm to 300 μm;
a grain size number distribution having a d 95 in the range from 140 μm to 250 μm; and
an average grain shape factor R a (Cu) of greater than or equal to 0.60, wherein the average grain shape factor R a (Cu) is obtained from the arithmetic mean of the shape factors R K of the individual grains, the shape factor R K of each individual grain being d K,ortho /d K,max , wherein d K,max is the maximum grain diameter and d K,ortho is the grain diameter running perpendicular to d K,max , determined on half the length of d K,max , and

wherein the coating composed of copper or a copper alloy is applied by means of a DCB process to the ceramic substrate.

2. The copper-ceramic composite of claim 1 , wherein the copper or the copper alloy has a number distribution of the grain sizes having a median d 50 in the range from 55 μm to 115 μm.

3. The copper-ceramic composite of claim 1 , wherein the d 95 is in the range from 140 μm to 230 μm.

4. The copper-ceramic composite of claim 1 , wherein the grain size number distribution of the copper or the copper alloy has a d 5 of greater than or equal to 15 μm.

5. The copper-ceramic composite of claim 1 , wherein the grain sizes of the copper or of the copper alloy are in the range from 15 μm to 250 μm.

6. The copper-ceramic composite of claim 1 , wherein the coating composed of copper or a copper alloy has a thickness D Cu and the grain size number distribution of the copper or the copper alloy has a median d 50 value, the ratio of the D Cu to the median d 50 value being in the range from 0.05 to 0.40, wherein the thickness D Cu and the median d 50 value have the same unit of measure for determination of the ratio of the D Cu to the median d 50 value.

7. 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.

8. The copper-ceramic composite of claim 1 , wherein the ceramic substrate contains an oxide, a nitride, a carbide or a mixture or composite of at least two of these materials.

9. The copper-ceramic composite of claim 1 , wherein the ceramic substrate contains at least 65% by weight of Al 2 O 3 .

10. 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.

11. A module containing at least one copper-ceramic composite according to claim 1 and one or more bond wires.

12. The copper-ceramic composite of claim 4 , wherein the d 5 is in the range from 15 μm to 80 μm.

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

14. 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.

15. The copper-ceramic composite of claim 1 , wherein the average grain shape factor R a (Cu) of the copper or the copper alloy is greater than or equal to 0.60 and less than or equal to 1.0.

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

17. The copper-ceramic composite of claim 9 , wherein the Al 2 O 3 is in the form of grains, the grains having
grain sizes in the range from 0.01 μm to 25 μm; and
a grain size number distribution having a d 95 in the range from 4.0 μm to 15.0 μm.

18. The copper-ceramic composite of claim 9 , wherein the Al 2 O 3 grains have an average grain shape factor R a (Al 2 O 3 ) of greater than or equal to 0.40, wherein the average grain shape factor R a (Al 2 O 3 ) is obtained from the arithmetic mean of the shape factors R K of the individual grains, the shape factor R K of each individual grain being d K,ortho /d K,max , wherein d K,max is the maximum grain diameter and d K,ortho is the grain diameter running perpendicular to d K,max , determined on half the length of d K,max .

Assignees

• Heraeus Deutschland Gmbh & Co Kg

Inventors

• Herbst Kai
• Muschelknautz Christian

Classifications

• C04B2235/782

  Grain size distributions · CPC title

• C04B2237/343

  Alumina or aluminates · CPC title

• C04B2235/78

  Grain sizes and shapes, product microstructures, e.g. acicular grains, equiaxed grains, platelet-structures · CPC title

• C04B2237/704

  of one or more of the ceramic layers or articles · CPC title

• C04B37/021 Primary

  in a direct manner, e.g. direct copper bonding [DCB] · CPC title