Reinforcing member for flexible printed wiring board, flexible printed wiring board, and shield printed wiring board

Patent metadata

Field	Value
Publication number	US-9736924-B2
Application number	US-201414770118-A
Country	US
Kind code	B2
Filing date	Feb 25, 2014
Priority date	Feb 26, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A reinforcing member for a flexible printed wiring board that maintains an electromagnetic wave shielding effect and a ground effect of the printed wiring board over a long period of time. A reinforcing member is disposed opposite a predetermined part of a ground wiring pattern and includes one surface opposing and in electrical conduction with the predetermined part of the ground wiring pattern. The other surface is in electrical conduction with an external ground member which is at a ground potential, the one surface and the other surface opposing each other. The reinforcing member includes a base made of conductive metal and a surface layer formed on a surface of a base to constitute at least a part of the other surface, the surface layer has higher conductivity and corrosion resistance than the base made of metal, and the surface layer is 0.004 to 0.2 μm thick.

First claim

The invention claimed is:

1. A reinforcing member for a printed wiring board, which is disposed opposite to a predetermined part of a ground wiring pattern of the printed wiring board, the reinforcing member comprising:
a conductive metal base;
a first surface layer formed on a first side of the conductive metal base and opposing and in electrical conduction with the predetermined part of the ground wiring pattern via a conductive composition layer;
a second surface layer formed on a second side of the conductive metal base and in electrical conduction with an external ground member which is at a ground potential, wherein,
the first side and the second side are on opposite sides of the conductive metal base,
the second surface layer has higher conductivity and corrosion resistance than the metal base, and
the second surface layer is 0.004 to 0.2 μm thick.

2. The reinforcing member according to claim 1 , wherein, the first and second surface layers are formed of alloy which is made of noble metal or mainly made of noble metal.

3. The reinforcing member according to claim 2 , wherein, the noble metal is gold or palladium.

4. The reinforcing member according to claim 1 , wherein, the conductive metal base is formed of stainless steel.

5. The reinforcing member according to claim 1 , further comprising a conductive composition layer which is provided on the first surface side of the conductive metal base.

6. The reinforcing member according to claim 1 , wherein, at least one of the first and second surface layers comprise an assembly of lines and/or dots.

7. A flexible printed wiring board comprising:
a base member;
a ground wiring pattern formed on the base member; and
the reinforcing member according to claim 1 , which is disposed opposite to a predetermined part of the ground wiring pattern.

Assignees

• Tatsuta Electric Wire & Cable Co Ltd

Inventors

• Watanabe Masahiro
• Tajima Hiroshi

Classifications

• H05K1/09

  Use of materials for the {conductive, e.g. } metallic pattern · CPC title

• H05K1/189

  characterised by the use of flexible or folded printed circuits · CPC title

• H05K2201/2009

  Reinforced areas, e.g. for a specific part of a flexible printed circuit · CPC title

• H05K1/0218 Primary

  by printed shielding conductors, ground planes or power plane (H05K1/0236 takes precedence) · CPC title

• H05K2201/0715

  provided by an outer layer of PCB · CPC title