Flexible wiring board and use thereof

Patent metadata

Field	Value
Publication number	US-2016295686-A1
Application number	US-201615077203-A
Country	US
Kind code	A1
Filing date	Mar 22, 2016
Priority date	Mar 30, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

Provided is a flexible wiring board having high durability. The present invention provides a flexible wiring board including a flexible substrate and a conductive film formed on the flexible substrate. The conductive film contains a conductive powder and a curd product of a heat curable resin. The conductive film has pencil hardness of at least 2H, based on a pencil scratch hardness test in accordance with JIS K5600 5-4 (1999). The conductive film has adhesiveness of at least 95/100 by a 100 squares cross-cut test in accordance with JIS K5400 (1990).

First claim

1 . A flexible wiring board comprising: a flexible substrate; and a conductive film formed on the flexible substrate, wherein
the conductive film contains a conductive powder and a cured product of a heat curable resin and has following characteristics: (1) pencil hardness of at least 2H, based on a pencil scratch hardness test in accordance with JIS K5600 5-4 (1999); (2) adhesiveness of at least 95/100 by a 100 squares cross-cut test in accordance with JIS K5400 (1990).

2 . The flexible wiring board according to claim 1 , wherein the conductive film has adhesiveness of at least 99/100 by the 100 squares cross-cut test.

3 . The flexible wiring board according to claim 1 , wherein
a volume resistivity (heat-drying conditions: 130° C., 30 minutes) of the conductive film is 100 μΩ·cm or less.

4 . The flexible wiring board according to claim 1 , wherein
the heat curable resin comprises (a) an epoxy resin, as a first heat curable resin.

5 . The flexible wiring board according to claim 4 , wherein
(a) the epoxy resin comprises: (a1) a polyfunctional epoxy resin having two or more epoxy groups; (a2) a monofunctional epoxy resin having one epoxy group; and (a3) a flexible epoxy resin having a structure of three or more consecutive secondary carbons.

6 . The flexible wiring board according to claim 4 , wherein
the heat curable resin comprises (b) an epoxy group-containing acrylic resin having one or more epoxy groups, as a second heat curable resin.

7 . The flexible wiring board according to claim 1 , wherein
an average aspect ratio of the conductive powder is 1.0 to 1.5.

8 . The flexible wiring board according to claim 1 , wherein
an average particle diameter of the conductive powder, based on a laser diffraction-light scattering method, is 0.5 to 3 μm.

9 . The flexible wiring board according to claim 1 , wherein
the conductive powder does not comprise squamous conductive particles.

10 . A portable electronic equipment comprising the flexible wiring board according to claim 1 .

Assignees

• Noritake Co Ltd

Inventors

• Fukaya Shuhei
• Kakizoe Hirohito
• Baba Tatsuya
• Sugiura Terusada
• Yoshino Yasushi

Classifications

• C08L2203/20

  use in electrical or conductive gadgets · CPC title

• C08L63/00

  Compositions of epoxy resins; Compositions of derivatives of epoxy resins · CPC title

• C08L33/068

  containing glycidyl groups · CPC title

• H05K1/095 Primary

  for polymer thick films, i.e. having a permanent organic polymeric binder · CPC title

• C08K2003/0806

  Silver · CPC title