Heat-dissipating circuit board, heat-dissipating member, and production method for heat-dissipating circuit board

1. A heat-dissipating circuit board comprising a metal material that is provided to be adjacent to one surface of an insulating layer and a conductive metal layer that is provided on the other surface of the insulating layer, wherein

a material of the metal material is copper or a copper alloy or aluminum or an aluminum alloy, and the metal material has a sheet shape with a thickness of 0.2 mm or more and 20 mm or less, and

the insulating layer is a metal oxide layer that is represented by a compositional formula: AlxOyTz,

(where Al represents an aluminum atom, O represents an oxygen atom, T represents one atom or a plurality of atoms other than Al and O; x, y, and z denote a mass ratio, x+y+z=100, x is 30 or more and 60 or less, y is 40 or more and 70 or less, and z is 0 or more and 10 or less), and

has a thickness of 0.2 μm or more and 30 μm or less, a volume resistivity of 1000 GΩ·cm or more, and a porosity of 10% or less.

2. The heat-dissipating circuit board according to claim 1 , wherein a surface roughness (Ra1) of the metal material on an insulating layer side is 1.0 μm or less, and a surface roughness (Ra2) of the insulating layer on a conductive metal layer side is 0.3 μm or less.

3. The heat-dissipating circuit board according to claim 1 , wherein a content of carbon atoms in the metal oxide layer is 0.1% by mass or more and 5% by mass or less.

4. A heat-dissipating member obtained by bonding the metal material in the heat-dissipating circuit board according to claim 1 to a heat sink with an adhesive or grease.

5. A production method for the heat-dissipating circuit board according to claim 1 , wherein the insulating layer is formed by reacting a coating liquid containing a salt or complex of aluminum on the metal material for film formation.

6. The production method for a heat-dissipating circuit board according to claim 5 , wherein the film formation method is a method in which mist or droplets obtained by atomizing the coating liquid or forming the coating liquid into droplets are conveyed with a carrier gas, and then the mist or droplets are reacted on the metal material in a temperature atmosphere of 230° C. or more and 450° C. or less.

7. The production method for a heat-dissipating circuit board according to claim 5 , wherein the coating liquid contains an aluminum complex at 0.2% by mass or more and 20% by mass or less.

8. The heat-dissipating circuit board according to claim 2 , wherein a content of carbon atoms in the metal oxide layer is 0.1% by mass or more and 5% by mass or less.

9. A heat-dissipating member obtained by bonding the metal material in the heat-dissipating circuit board according to claim 2 to a heat sink with an adhesive or grease.

10. A production method for the heat-dissipating circuit board according to claim 2 , wherein the insulating layer is formed by reacting a coating liquid containing a salt or complex of aluminum on the metal material for film formation.

11. The production method for a heat-dissipating circuit board according to claim 10 , wherein the film formation method is a method in which mist or droplets obtained by atomizing the coating liquid or forming the coating liquid into droplets are conveyed with a carrier gas, and then the mist or droplets are reacted on the metal material in a temperature atmosphere of 230° C. or more and 450° C. or less.

12. The production method for a heat-dissipating circuit board according to claim 10 , wherein the coating liquid contains an aluminum complex at 0.2% by mass or more and 20% by mass or less.