HEAT SINK, ELECTRONIC DEVICE, METHOD OF MANUFACTURING HEAT SINK, AND METHOD OF MANUFACTURING ELECTRONIC DEVICE

Abstract

A heat sink includes a base portion formed of insulating diamond, and a plurality of pressure contacting members formed of the insulating diamond and arranged on the base portion

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic cross section of an electronic device including a heat sink according to a first embodiment of the invention;

FIG. 2 is a view showing a relationship between the crystal grain size and the heat conductivity of polycrystalline diamond in the heat sink according to the first embodiment;

FIG. 3 is a cross section of a main portion showing the pressure contacting state between a device body and a self-supported insulating diamond substrate, for explaining a comparative example of the electronic device according to the first embodiment;

FIG. 4 is a cross section of a main portion showing the pressure contacting state between a device body and a heat sink of the electronic device according to the first embodiment;

FIG. 5 is a graph showing a relationship between the pressure contacting load and the amount of contact in the electronic device according to the first embodiment;

FIG. 6 is a cross section of a main portion showing another pressure contacting state between a device body and a heat sink of the electronic device according to the first embodiment;

FIG. 7 is a cross section showing a first process for explaining a method of manufacturing the heat sink and the electronic device according to the first embodiment;

FIG. 8 is a cross section showing a second process;

FIG. 9 is a cross section showing a third process;

FIG. 10 is a cross section showing a fourth process;

FIG. 11 is a cross section showing a fifth process;

FIG. 12 is a cross section showing a sixth process;

FIG. 13 is a perspective view of a main portion showing a state after anodization of a porous coat film in the process of manufacturing the heat sink shown in FIG. 8;

FIG. 14 is a schematic cross section of a heat sink provided in an electronic device according to a second embodiment of the present invention;

FIG. 15 is a cross section showing a first process for explaining a method of manufacturing the heat sink and the electronic device according to the second embodiment;

FIG. 16 is a cross section showing a second process;

FIG. 17 is a cross section showing a third process;

FIG. 18 is a cross section showing a fourth process;

FIG. 19 is a cross section showing a fifth process;

FIG. 20 is a cross section showing a sixth process;

FIG. 21 is a cross section showing a seventh process;

FIG. 22 is a schematic cross section of an electronic device including the heat sink according to the second embodiment;

FIG. 23 is a schematic cross section of a heat sink provided in an electronic device according to a third embodiment of the present invention;

FIG. 24 is a cross section showing a first process for explaining a method of manufacturing the heat sink and the electronic device according to the third embodiment;

FIG. 25 is a cross section showing a second process;

FIG. 26 is a cross section showing a third process;

FIG. 27 is a cross section showing a fourth process;

FIG. 28 is a cross section showing a fifth process;

FIG. 29 is a cross section showing a sixth process; and

FIG. 30 is a schematic cross section of the electronic device having the heat sink according to the third embodiment of the invention.

Claims

1. A heat sink comprising: a base portion formed of insulating diamond; anda plurality of pressure contacting members formed of the insulating diamond and arranged on the base portion.

2. The heat sink of claim 1, wherein the insulating diamond is formed of polycrystalline diamond.

3. The heat sink of claim 2, wherein the polycrystalline diamond has a grain size in units of micrometers.

4. The heat sink of claim 1, further comprising: a fixing base member provided on a second surface of the base portion opposite to a first surface on which the pressure contacting members are arranged, the fixing base member having a slot for allowing the base portion to warp.

5. An electronic device comprising: a substrate that a device is formed having heat generation portions in a first region and having non heat generation portions in a second region which is different from the first region; anda heat sink having a base portion formed of insulating diamond and a plurality of first pressure contacting members which are pressure contacted onto the heat generation portions of the substrate and a plurality of second pressure contacting members which are pressure contacted onto the non heat generation portions of the substrate, the first pressure contacting members and the second pressure contacting members being formed of the insulating diamond and arranged on the base portion.

6. The electronic device of claim 5, wherein the first pressure contacting members and the second pressure contacting members of the heat sink are pressure contacted onto the heat generation portions and the non heat generation portions, respectively, in a buckled state.

7. The electronic device of claim 5, wherein the substrate is a semiconductor substrate, andthe heat generation portions are regions in which a circuit including an element is disposed and the non heat generation portions are regions in which the element is not disposed.

8. The electronic device of claim 5, wherein the first pressure contacting members and the second pressure contacting members are disposed so as to be spaced from each other.

9. The electronic device of claim 5, further comprising; a fixing base member provided on a second surface of the base portion opposite to a first surface on which the first pressure contacting members and the second pressure contacting members are arranged, the fixing base member having a slot for allowing the base portion to warp.

10. The electronic device of claim 5, wherein the plurality of first pressure contacting members of the heat sink have a height which is different from a height of the plurality of second pressure contacting members.

11. The electronic device of claim 5, wherein the heat sink diffuses heat generated in the heat generation portions in the non heat generation portions, through each of the plurality of first pressure contacting members, the base portion, and the second pressure contacting members.

12. A method of manufacturing a heat sink, the method comprising: forming a porous coat film on a surface of an insulating diamond substrate;forming a large number of holes connecting from a top surface of the porous coat film through a rear surface thereof which is opposite to the top surface;burying a mask inside the holes of the porous coat film;selectively removing the porous coat film; andetching a portion of the insulating diamond substrate in the thickness direction from a top surface of the insulating diamond substrate toward a rear surface thereof which is opposite to the top surface, with the mask being used as an etching mask, to form a plurality of pressure contacting members.

13. The method of manufacturing a heat sink of claim 12, wherein formation of the large number of holes is performed by anodization.

14. A method of manufacturing an electronic device, the method comprising: producing a substrate that a device is formed having heat generation portions in a first region and having non heat generation portions in a second region which is different from the first region;producing a heat sink by forming a porous coat film on a surface of an insulating diamond substrate, forming a large number of holes connecting from a top surface of the porous coat film through a rear surface thereof which is opposite to the top surface, burying a mask inside the holes of the porous coat film, selectively removing the porous coat film, and etching a portion of the insulating diamond substrate in the thickness direction from a top surface of the insulating diamond substrate toward a rear surface thereof which is opposite to the top surface, with the mask being used as an etching mask, to form a plurality of pressure contacting members; andpressure contacting the pressure contacting members of the heat sink onto each of the heat generation portions and the non heat generation portions of the substrate.

15. A method of manufacturing an electronic device, the method comprising: producing a substrate that a device is formed having heat generation portions in a first region and having non heat generation portions in a second region which is different from the first region;producing a heat sink by estimating a step shape of the surface of the substrate on which the heat generation portions and the non heat generation portions are disposed, etching a surface of an insulating diamond substrate such that the surface of the insulating diamond substrate corresponds to the step shape of the surface of the substrate, forming a porous coat film on the surface of the diamond substrate which is etched, forming a large number of holes connecting from a top surface of the porous coat film through a rear surface thereof which is opposite to the top surface, burying a mask inside the holes of the porous coat film, selectively removing the porous coat film, and etching a portion of the insulating diamond substrate in the thickness direction from a top surface of the insulating diamond substrate toward a rear surface thereof which is opposite to the top surface, with the mask being used as an etching mask, to form a plurality of pressure contacting members; andpressure contacting the pressure contacting members of the heat sink onto each of the heat generation portions and the non heat generation portions of the substrate.