Preparation method of copper foam

Patent metadata

Field	Value
Publication number	US-12409492-B2
Application number	US-202217922979-A
Country	US
Kind code	B2
Filing date	Jul 20, 2022
Priority date	Jun 30, 2022
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A preparation method of copper foam includes coating copper paste on a release film to form a coating sheet with a thickness of 50-200 μm on the release film, peeling off the release film to obtain a copper foam preform after drying the release film with the coating sheet, and performing a glue discharging process on the copper foam preform and sintering the copper foam preform to obtain the copper foam having a thickness of 30-120 μm and having a porosity of 50-80%. The thickness of the copper foam is reduced, which ensures a balance between the porosity and a structural strength of the copper foam, so the copper foam has a good water absorption performance, and a heat dissipation performance of the copper foam is effectively improved.

First claim

What is claimed is:

1. A preparation method of copper foam, comprising:
coating copper paste on a release film to form a coating sheet on the release film;
peeling off the release film to obtain a copper foam preform after drying the release film with the coating sheet; and
sequentially performing a glue discharging process on the copper foam preform and sintering the copper foam preform to obtain the copper foam;
wherein a thickness of the coating sheet range from 50-200 μm; a thickness of the copper foam ranges from 30-120 μm; a porosity of the copper foam is 50-80%;
wherein a viscosity of the copper paste ranges from 10000-35000 cps; the copper paste comprises copper powder, a binder, a pore forming agent, a solvent, a tackifier, a dispersant, a leveling agent, and an antioxidant.

2. The preparation method of the copper foam according to claim 1 , wherein an average particle size of the copper powder is 0.5-10 μm, and a median particle size of the copper powder is 3 μm.

3. The preparation method of the copper foam according to claim 1 , wherein during a process of sintering the copper foam preform, a sintering temperature range from 650-1050° C., sintering time ranges from 0.5-24 h, and a sintering atmosphere is ammonia gas.

4. The preparation method of the copper foam according to claim 1 , wherein during the glue discharging process, a glue discharging temperature ranges from 350-450° C. and a glue discharging atmosphere is nitrogen.

5. The preparation method of the copper foam according to claim 1 , wherein the release film is selected from one of polyethyleneterephthalat (PET), polyethylene (PE), and o-phenylphenol (OPP); a thickness of the release film ranges from 75-120 μm.

6. The preparation method of the copper foam according to claim 1 , wherein the binder comprises one or more of polyvinyl alcohol (PVA), epoxy resin, acrylic resin, phenolic resin, modified phenolic resin, hydroxymethyl cellulose, and ethyl cellulose; the copper paste comprises 0.1-30 wt % of the binder;
wherein the pore forming agent comprises one or more of ammonium chloride, urea, ammonium sulfate, citric acid, and benzoic acid; the copper paste comprises 5-50 wt % of the pore forming agent.

7. The preparation method of the copper foam according to claim 1 , wherein the solvent comprises one or more of ethanol, propanol, isopropanol, acetone, toluene, xylene, terpineol, triethanolamine, isophorone, divalent ester, and water; the copper paste comprises 1-70 wt % of the solvent;
wherein the tackifier comprises one or more of natural rubber, styrene-butadiene rubber, neoprene, C5-type petroleum resin, and C9-type petroleum resin; the copper paste comprises 0.01-5 wt % of the tackifier.

8. The preparation method of the copper foam according to claim 1 , wherein the dispersant comprises one or more of methyl amyl alcohol, cellulose derivatives, polyacrylamide, and fatty acid polyethylene glycol ester; the copper paste comprises 0.01-5 wt % of the dispersant.

9. The preparation method of the copper foam according to claim 1 , wherein the leveling agent comprises one or more of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium tetradecylsulfonate, sodium cetylsulfonate, lecithin, triethanolamine, KH550, polyethylene glycol, and triethanolamine; the copper paste comprises 0.01-10 wt % of the leveling agent;
wherein the antioxidant comprises one or more of citric acid, phytic acid, vitamins, oxalic acid, ascorbic acid, and glucose; the copper paste comprises 0.01-10 wt % of the antioxidant.

Assignees

• Aac Tech Nanjing Co Ltd

Inventors

• Zhang Bo
• Huang Guochuang

Classifications

• B22F2304/058

  Particle size above 300 nm up to 1 micrometer · CPC title

• B22F2301/10

  Copper · CPC title

• B22F2003/1131

  Foaming in a liquid suspension and decomposition · CPC title

• B22F3/1021

  Removal of binder or filler (removal of binder from ceramics C04B35/638) · CPC title

• C22C1/08

  Alloys with open or closed pores · CPC title