# US 2021/0242385 A1 · Method of producing heat dissipation substrate and method of producing composite substrate

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- Number: US 2021/0242385 A1
- Document ID: US20210242385A1
- Status: Published application
- Kind: A1
- Application number: 17/161,305
- Filed: 2021-01-28
- Published: 2021-08-05
- Earliest claimed: 2020-01-31
- Assignees: Nichia Corporation
- Applicants: Nichia Corporation
- Inventors: Shoichi YAMADA; Takeshi KIHARA; Masatsugu ICHIKAWA
- Web page: https://patentgrep.com/patent/US20210242385A1

## CPC

- C22C 26/00: Alloys containing diamond {or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes}
- H10H 20/8581: {characterised by their material}
- B22F 3/105: by using electric current {other than for infrared radiant energy}, laser radiation or plasma (B22F3/11 takes precedence){; by ultrasonic bonding (B22F3/115 takes precedence)}
- B22F 3/12: Both compacting and sintering (by forging B22F3/17)
- B22F 7/06: of composite workpieces or articles from parts, e.g. to form tipped tools {(B22F7/002 takes precedence)}
- H10W 40/254: {Diamond}
- H10W 40/258: {Metallic materials (H10W40/254, H10W40/257, H10W40/255, H10W40/251, H10W40/253 take precedence)}
- H10W 70/02: of conductive package substrates serving as an interconnection, e.g. of metal plates (manufacture or treatment of leadframes H10W70/04)
- B22F 2202/06: Use of electric fields
- B22F 2301/10: Copper
- B22F 2302/406: Diamond
- B22F 2304/10: Micron size particles, i.e. above 1 micrometer up to 500 micrometer
- F28F 2255/06: composite, e.g. polymers with fillers or fibres
- H10H 20/8583: {not being in contact with the bodies}
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16)

## Abstract

A method of producing a heat dissipation substrate, the method including: providing a composite material containing diamond and a metal; performing a treatment on a surface of the composite material to reduce a thickness of the composite material, the treatment forming a processed surface of the composite material; and subsequently, performing pulsed electric current sintering with a pressure of less than 50 MP applied to the composite material, to heat the composite material.

## Claims

### Claim 1

A method of producing a heat dissipation substrate, the method comprising:
providing a composite material containing diamond and a metal;
performing a treatment on a surface of the composite material to reduce a thickness of the composite material, the treatment forming a processed surface of the composite material; and
subsequently, performing pulsed electric current sintering with a pressure of less than 50 MP applied to the composite material, to heat the composite material.

### Claim 2 (depends on 1)

The method according to claim 1, wherein:
the pulsed electric current sintering is performed with a metal powder or metal plate placed in contact with the processed surface of the composite material, to form a metal layer bonded to the processed surface.

### Claim 3 (depends on 2)

The method according to claim 2, wherein:
the metal layer has a thickness of 50 μm or greater and 500 μm or less.

### Claim 4 (depends on 1)

The method according to claim 1, wherein:
the pulsed electric current sintering is performed without placing a metal powder or metal plate in contact with the processed surface of the composite material.

### Claim 5 (depends on 1)

The method according to claim 1, wherein:
the step of providing the composite material comprises:
preparing a mixed powder of diamond particles and copper powder particles; and
producing the composite material from the mixed powder by pulsed electric current sintering with a pressure of 5 MPa or greater and 100 MPa or less applied to the mixed powder, and the mixed powder maintained at a temperature equal to or higher than 500° C. and lower than 800° C.

### Claim 6 (depends on 5)

The method according to claim 5, wherein:
an amount of metals other than copper in the mixed powder is 1% or less in mass fraction.

### Claim 7 (depends on 5)

The method according to claim 5, wherein:
a mass fraction of the copper powder particles in the mixed powder is 60% or greater and 85% or less, and
a mass fraction of the diamond particles in the mixed powder is 15% or greater and 40% or less.

### Claim 8 (depends on 5)

The method according to claim 5, wherein:
the diamond particles in the mixed powder have an average particle size of 200 μm or greater and 400 μm or less.

### Claim 9 (depends on 5)

The method according to claim 5, wherein:
the diamond particles in the mixed powder include particles having an average particle size of 200 μm or greater and 400 μm or less, and particles having an average particle size of 40 μm or greater and 80 μm or less.

### Claim 10 (depends on 5)

The method according to claim 5, wherein:
in the step of producing the composite material, a pressure of 5 MPa or greater and 50 MPa or less is applied.

### Claim 11 (depends on 10)

The method according to claim 10, wherein:
the step of producing the composite material comprises repeatedly applying a first pressure and a second pressure higher than the first pressure with the composite material maintained at the temperature.

### Claim 12 (depends on 5)

The method according to claim 5, wherein:
the copper powder particles have an average particle size of 3 μm or greater and 10 μm or less.

### Claim 13

A method of producing a composite substrate, comprising:
providing a composite material comprising diamond and a metal, the composite material having been subjected to a treatment to reduce a thickness of the composite material; and
subsequently, performing pulsed electric current sintering with a pressure of less than 50 MP applied to the composite material, to heat the composite material.