Ceramic copper circuit board and semiconductor device based on the same
According to one embodiment, a ceramic copper circuit board a ceramic substrate, a copper circuit board provided at one surface of the ceramic substrate. A ratio of a thickness of the copper circuit board to a thickness of the ceramic substrate is 1.25 or more. A number of grain boundaries is not less than 5 and not more than 250 along every 10-mm straight line drawn in a front surface of the copper circuit board.
1. A ceramic copper circuit board, comprising:
a ceramic substrate; and
a copper circuit board provided at one surface of the ceramic substrate,
a ratio of a thickness of the copper circuit board to a thickness of the ceramic substrate being 1.25 or more,
a number of grain boundaries being not less than 5 and not more than 250 along every 10-mm straight line drawn in a front surface of the copper circuit board,
wherein a warp amount of the ceramic substrate is less than 0.1 mm.
2. The ceramic copper circuit board according to claim 1 , wherein the number of grain boundaries is not less than 20 and not more than 150 along every 10-mm straight line drawn in the front surface of the copper circuit board.
3. The ceramic copper circuit board according to claim 1 , wherein the number of grain boundaries is not less than 80 and not more than 150 along every 10-mm straight line drawn in the front surface of the copper circuit board.
4. The ceramic copper circuit board according to claim 1 , wherein
an arithmetic average roughness Ra of the front surface of the copper circuit board is 0.4 μm or less,
a ten-point average roughness Rzjis of the front surface is 4 μm or less, and
a maximum height Rz of the front surface is 5 μm or less.
5. The ceramic copper circuit board according to claim 1 , wherein
an arithmetic average roughness Ra of the front surface of the copper circuit board is not less than 0.1 μm and not more than 0.4 μm,
a ten-point average roughness Rzjis of the front surface is not less than 1.5 μm and not more than 4 μm, and
a maximum height Rz of the front surface is not less than 1 μm and not more than 5 μm.
6. The ceramic copper circuit board according to claim 4 , wherein a skewness Rsk of a roughness curve of the front surface of the copper circuit board is less than 0.
7. The ceramic copper circuit board according to claim 1 , wherein the ceramic substrate is one of an aluminum oxide substrate, an aluminum nitride substrate, or a silicon nitride substrate.
8. The ceramic copper circuit board according to claim 1 , further comprising a bonding layer provided between the ceramic substrate and the copper circuit board,
the bonding layer including Ag and Ti.
9. The ceramic copper circuit board according to claim 8 , wherein when the copper circuit board is uniformly trisected in a thickness direction, a proportion of a surface area where Ag exists in a region of the copper circuit board on the bonding layer side is not less than 20% and not more than 80%.
10. The ceramic copper circuit board according to claim 1 , wherein the thickness of the copper circuit board is 0.6 mm or more.
11. The ceramic copper circuit board according to claim 1 , further comprising a copper plate provided at another surface of the ceramic substrate,
a through-hole being provided in the ceramic substrate,
the copper circuit board and the copper plate conducting via the through-hole.
12. The ceramic copper circuit board according to claim 11 , wherein the number of grain boundaries is not less than 5 and not more than 250 along every 10-mm straight line drawn in a front surface of the copper plate.
13. A semiconductor device, comprising:
the ceramic copper circuit board according to claim 1 ; and
a semiconductor element mounted to the copper circuit board via a bonding layer.
14. The semiconductor device according to claim 13 , further comprising wire bonding or a metal terminal bonded to the copper circuit board.
15. The ceramic copper circuit board according to claim 1 , wherein
the number of grain boundaries is not less than 20 and not more than 150 along every 10-mm straight line drawn in the front surface of the copper circuit board,
an arithmetic average roughness Ra of the front surface of the copper circuit board is 0.4 μm or less,
a ten-point average roughness Rzjis of the front surface is 4 μm or less, and
a maximum height Rz of the front surface is 5 μm or less.
16. The ceramic copper circuit board according to claim 1 , wherein
the number of grain boundaries is not less than 20 and not more than 150 along every 10-mm straight line drawn in the front surface of the copper circuit board,
an arithmetic average roughness Ra of the front surface of the copper circuit board is 0.4 μm or less,
a ten-point average roughness Rzjis of the front surface is 4 μm or less,
a maximum height Rz of the front surface is 5 μm or less, and
the thickness of the copper circuit board is 0.6 mm or more.
17. The ceramic copper circuit board according to claim 1 , wherein
the number of grain boundaries is not less than 20 and not more than 150 along every 10-mm straight line drawn in the front surface of the copper circuit board,
an arithmetic average roughness Ra of the front surface of the copper circuit board is 0.4 μm or less,
a ten-point average roughness Rzjis of the front surface is 4 μm or less,
a maximum height Rz of the front surface is 5 μm or less,
the thickness of the copper circuit board is 0.6 mm or more, and
the ceramic substrate is a silicon nitride substrate.
18. The ceramic copper circuit board according to claim 1 , further comprising a bonding layer provided between the ceramic substrate and the copper circuit board, the bonding layer including Ag and Ti, wherein
the number of grain boundaries is not less than 20 and not more than 150 along every 10-mm straight line drawn in the front surface of the copper circuit board,
an arithmetic average roughness Ra of the front surface of the copper circuit board is 0.4 μm or less,
a ten-point average roughness Rzjis of the front surface is 4 μm or less,
a maximum height Rz of the front surface is 5 μm or less, and
the thickness of the copper circuit board is 0.6 mm or more.
19. The ceramic copper circuit board according to claim 1 , further comprising a bonding layer provided between the ceramic substrate and the copper circuit board, the bonding layer including Ag and Ti, wherein
the number of grain boundaries is not less than 20 and not more than 150 along every 10-mm straight line drawn in the front surface of the copper circuit board,
an arithmetic average roughness Ra of the front surface of the copper circuit board is 0.4 μm or less,
a ten-point average roughness Rzjis of the front surface is 4 μm or less,
a maximum height Rz of the front surface is 5 μm or less,
the thickness of the copper circuit board is 0.6 mm or more, and
the ceramic substrate is a silicon nitride substrate.