Conductive adhesive for screen printing, joined body of inorganic material, and method for producing same

Patent metadata

Field	Value
Publication number	US-10285280-B2
Application number	US-201214434024-A
Country	US
Kind code	B2
Filing date	Dec 21, 2012
Priority date	Oct 31, 2012
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

The present invention relates to a conductive adhesive for screen printing containing metal colloid particles (A) containing metal nanoparticles (A1) and a protective colloid (A2) containing an organic compound having a carboxyl group and a polymer dispersant having a carboxyl group, a viscosity modifier (B) having an amide bond and/or a urea bond, and a dispersion solvent (C).

First claim

The invention claimed is:

1. A conductive adhesive for screen printing, comprising:
metal colloid particles (A) containing metal nanoparticles (A1) and a protective colloid (A2) containing an organic compound having a carboxyl group and a polymer dispersant having a carboxyl group;
a viscosity modifier (B) having a urea-modified polyamide skeleton; and
a dispersion solvent (C),
wherein the dispersion solvent (C) has a boiling point under atmospheric pressure of 220° C. or higher and plural hydroxyl groups per molecule,
the viscosity modifier (B) has a polyoxy-C 2-4 -alkylene group and/or an alkyl group, and
the viscosity modifier (B) is a compound represented by the formula (1):
R 1 -A-U-R 2 -U-A-R 1 ,

where R 1 is a hydroxy (poly)C 2-4 -alkoxy group or an alkyl group; A is a urea-modified polyamide group; U is a urea group; and R 2 is a (poly)oxy-C 2-4 -alkylene group or an alkylene group.

2. The conductive adhesive for screen printing according to claim 1 , wherein a proportion of the viscosity modifier (B) is from 1 to 4 parts by mass based on 100 parts by mass of the metal nanoparticles (A1).

3. The conductive adhesive for screen printing according to claim 1 , wherein a proportion of the protective colloid (A2) is from 1 to 3 parts by mass based on 100 parts by mass of the metal nanoparticles (A1).

4. A production method of a joined body of inorganic materials, comprising:
subjecting the conductive adhesive for screen printing of claim 1 to screen printing on a joining surface of a first inorganic material;
installing a joining surface of a second inorganic material on the conductive adhesive printed on the joining surface of the first inorganic material; and
sandwiching the conductive adhesive by both of the first and the second inorganic materials, and then heating at 100° C. or higher to sinter the conductive adhesive to form a sintered film between the first and the second inorganic materials,
wherein the sintered film has a thickness from 1 to 50 μm.

5. The production method according to claim 4 , wherein the joining surface of at least one of the first and second inorganic materials contains a noble metal.

6. The conductive adhesive for screen printing according to claim 1 , wherein the urea-modified polyamide skeleton accounts for 10 to 80% by mass of the viscosity modifier (B).

7. The conductive adhesive for screen printing according to claim 1 , wherein a number-average molecular weight of the viscosity modifier (B) is from 50,000 to 150,000.

Assignees

• Mitsuboshi Belting Ltd

Inventors

• Iseda Taisuke
• Kawahara Kazutomo
• Iwamoto Masahiro

Classifications

• B22F1/107

  containing organic material comprising solvents, e.g. for slip casting · CPC title

• B22F1/0545

  Dispersions or suspensions of nanosized particles · CPC title

• B22F1/103

  containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent · CPC title

• H05K2203/1131

  Sintering, i.e. fusing of metal particles to achieve or improve electrical conductivity · CPC title

• Y10T156/10

  Methods of surface bonding and/or assembly therefor · CPC title