Copper/ceramic composite
The invention relates to a copper/ceramic composite comprising—a ceramic substrate which contains aluminum oxide, —a coating which lies on the ceramic substrate and which is made of copper or a copper alloy, wherein the copper or the copper alloy has a particle size number distribution with a median value d 50 , an arithmetic mean value d arith , and a symmetry value S(Cu)=d 50 /d arith ; the aluminum oxide has a particle size number distribution with a median value d 50 , an arithmetic mean value d arith , and a symmetry value S(Al 2 O 3 )=d 50 /d arith ; and S(Al 2 O 3 ) and S(Cu) satisfy the following condition: 0.7≤S(Al 2 O 3 )/S(Cu)≤1.4.
1. A copper-ceramic composite comprising:
a ceramic substrate containing aluminum oxide, and
a coating composed of copper or a copper alloy present on the ceramic substrate, wherein
the copper or the copper alloy has a number distribution of the grain sizes having a median d 50 , an arithmetic mean d arith and a symmetry value S(Cu)=d 50 /d arith ,
the aluminum oxide has a number distribution of the grain sizes having a median d 50 , an arithmetic mean d arith , and a symmetry value S(Al 2 O 3 )=d 50 /d arith ,
and S(Al 2 O 3 ) and S(Cu) satisfy the following condition:
0.7≤S(Al 2 O 3 )/S(Cu)≤1.4.
2. The copper-ceramic composite of claim 1 , wherein the copper or the copper alloy has grain sizes in the range from 10 μm to 300 μm.
3. The copper-ceramic composite of claim 1 , wherein the aluminum oxide has grain sizes in the range from 0.01 μm to 25 μm.
4. The copper-ceramic composite of claim 1 , wherein S(Al 2 O 3 ) and S(Cu) satisfy the following condition:
0.74≤S(Al 2 O 3 )/S(Cu)≤1.35.
5. The copper-ceramic composite of claim 1 , wherein the ceramic substrate contains the aluminum oxide in an amount of at least 65% by weight.
6. The copper-ceramic composite of claim 1 , wherein the coating composed of copper or a copper alloy is applied by a Direct Copper Bonding (DCB) process to the ceramic substrate.
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 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/or the ceramic substrate has a thickness in the range of 0.2-1.2 mm over at least 70% of its area.
9. A module containing at least one copper-ceramic composite according to claim 1 and one or more bond wires.
10. The copper-ceramic composite of claim 1 , wherein the copper or the copper alloy has grain sizes in the range from 15 μm to 250 μm.
11. The copper-ceramic composite of claim 1 , wherein the copper or the copper alloy has grain sizes in the range from 20 μm to 210 μm.
12. The copper-ceramic composite of claim 1 , wherein the aluminum oxide has grain sizes in the range from 0.3 μm to 23 μm.
13. The copper-ceramic composite of claim 1 , wherein the aluminum oxide has grain sizes in the range from 0.5 μm to 20 μm.
14. The copper-ceramic composite of claim 1 , wherein S(Al 2 O 3 ) and S(Cu) satisfy the following condition:
0.80≤S(Al 2 O 3 )/S(Cu)≤1.25.