Conductive paste and method for producing conductive film using same

Patent metadata

Field	Value
Publication number	US-9732236-B2
Application number	US-201415103440-A
Country	US
Kind code	B2
Filing date	Dec 5, 2014
Priority date	Dec 10, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

After there is prepared a conductive paste which contains fine copper particles having an average particle diameter of 1 to 100 nm, each of the fine copper particles being coated with an azole compound, coarse copper particles having an average particle diameter of 0.3 to 20 μm, a glycol solvent, such as ethylene glycol, and at least one of a polyvinylpyrrolidone (PVP) resin and a polyvinyl butyral (PVB) resin and wherein the total amount of the fine copper particles and the coarse copper particles is 50 to 90% by weight, the weight ratio of the fine copper particles to the coarse copper particles being in the range of from 1:9 to 5:5, the conductive paste thus prepared is applied on a substrate by screen printing to be preliminary-fired by vacuum drying, and then, fired with light irradiation by irradiating with light having a wavelength of 200 to 800 nm at a pulse period of 500 to 2000 μs and a pulse voltage of 1600 to 3800 V to form a conductive film on the substrate.

First claim

The invention claimed is:

1. A conductive paste comprising:
fine copper particles having an average particle diameter of 1 to 100 nm, each of the fine copper particles being coated with an azole compound;
coarse copper particles having an average particle diameter of 0.3 to 20 μm;
a glycol solvent; and
at least one of a polyvinylpyrrolidone resin and a polyvinyl butyral resin.

2. A conductive paste as set forth in claim 1 , wherein a total amount of said fine copper particles and said coarse copper particles in said conductive paste is 50 to 90% by weight.

3. A conductive paste as set forth in claim 1 , wherein a weight ratio of said fine copper particles to said coarse copper particles in said conductive paste is in the range of from 1:9 to 5:5.

4. A conductive paste as set forth in claim 1 , wherein said azole compound is benzotriazole.

5. A conductive paste as set forth in claim 1 , wherein said glycol solvent is ethylene glycol.

6. A conductive paste as set forth in claim 1 , which further comprises a dispersing agent.

7. A conductive paste as set forth in claim 1 , wherein said conductive paste contains the polyvinylpyrrolidone resin, and an amount of said polyvinylpyrrolidone resin in said conductive paste is 3 to 9% by weight with respect to the total amount of said fine copper particles and said coarse copper particles.

8. A conductive paste as set forth in claim 1 , wherein said conductive paste contains the polyvinyl butyral resin, and an amount of said polyvinyl butyral resin in said conductive paste is 3 to 6% by weight with respect to the total amount of said fine copper particles and said coarse copper particles.

Assignees

• Dowa Electronics Materials Co Ltd

Inventors

• Kaneda Shuji
• Fujita Hidefumi
• Itoh Daisuke

Classifications

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B22F1/054

  Nanosized particles · CPC title

• H05K1/097

  Inks comprising nanoparticles and specially adapted for being sintered at low temperature (H05K1/095 takes precedence) · CPC title

• C09D5/24 Primary

  Electrically-conducting paints {(conductive materials H01B1/00)} · CPC title

• C09D139/06

  Homopolymers or copolymers of N-vinyl-pyrrolidones · CPC title