Electrically conductive adhesive agent, joined body, and joint

Patent metadata

Field	Value
Publication number	US-10650939-B2
Application number	US-201414910406-A
Country	US
Kind code	B2
Filing date	Apr 15, 2014
Priority date	Aug 6, 2013
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

This invention has an object to provide an electrically conductive adhesive agent which enables a thermosetting resin to cure in a short time. It contains electrically conductive metallic powder including Sn, the thermosetting resin; an acid-anhydride-based hardening agent and an organic acid. The electrically conductive metallic powder and the organic acid are reacted during a heating process to produce an organic acid metal salt which is used as hardening accelerator. It enables thermosetting resin to cure in a short time, for example, a time equivalent to a time that is required for the general reflow process.

First claim

The invention claimed is:

1. A method of forming a joint, comprising:
heating an electrically conductive adhesive agent,
wherein the electrically conductive adhesive agent comprises an electrically conductive metallic powder including Sn, a thermosetting resin, an acid-anhydride-based hardening agent, and an organic acid,
wherein the electrically conductive metallic powder contains Sn of 85 weight % or more based on 100 weight % of the electrically conductive metallic powder,
wherein the electrically conductive adhesive agent contains 88 through 90 weight % of the electrically conductive metallic powder based on 100 weight % of the electrically conductive adhesive agent,
wherein the electrically conductive adhesive agent is heated at a temperature of 150 degrees C. or more and less than a melting point of the electrically conductive metallic powder to cause the electrically conductive metallic powder and the organic acid to react and to produce a hardening accelerator comprised of an organic acid metal salt,
wherein, prior to heating, the electrically conductive adhesive agent does not include a hardening accelerator, and
wherein the joint is formed without melting the electrically conductive metallic powder.

2. The method according to claim 1 , wherein the electrically conductive metallic powder further includes at least one of:
Ag, Bi, Cu, Au, Ni, Sb or Pd; or
an alloy consisting of any combination of Sn, Ag, Bi, Cu, Au, Ni, Sb and Pd.

3. The method according to claim 1 , wherein the thermosetting resin is an epoxy resin having an aliphatic skeleton, wherein the epoxy resin has flexibility.

4. The method according to claim 1 , wherein the acid-anhydride-based hardening agent is selected from the group consisting of: acetic acid anhydride, propionic anhydride, succinic anhydride, and maleic anhydride.

5. The method according to claim 1 , wherein the electrically conductive adhesive agent contains 2 through 6 weight % of the organic acid.

6. The method according to claim 1 , wherein a volume resistivity of the electrically conductive adhesive agent in the joint is less than 1*10 −3 Ωcm.

Assignees

• Senju Metal Industry Co

Inventors

• Mizowaki Toshio
• Takagi Yoshinori

Classifications

• H05K3/321

  by conductive adhesives · CPC title

• C08K2201/001

  Conductive additives · CPC title

• B23K35/262

  Sn as the principal constituent · CPC title

• C09J163/00

  Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins · CPC title

• H01B1/22 Primary

  the conductive material comprising metals or alloys · CPC title