Printed wiring board

Patent metadata

Field	Value
Publication number	US-9549460-B2
Application number	US-201514717456-A
Country	US
Kind code	B2
Filing date	May 20, 2015
Priority date	May 21, 2014
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

To suppress occurrence of a difference in transmission time due to a difference in length between signal lines, there is provided a printed wiring board having: an insulating substrate ( 10 ); a first signal line (L 31 A) that constitutes differential signal lines formed on the insulating substrate ( 10 ) and includes a curved portion; a second signal line (L 31 B) provided along the first signal line (L 31 A) and side by side inside the curved portion; and a ground layer ( 30 ) formed for the first signal line (L 31 A) and the second signal line (L 31 B) via an insulating material ( 10 ). The ground layer ( 30 ) includes a first ground layer (G 31 A) corresponding to a first region (D 1 ) and a second ground layer (G 31 B) corresponding to a second region (D 2 ). The first region (D 1 ) is defined based on the first signal line (L 31 A) and has a first predetermined width (W 31 A). The second region (D 2 ) is defined based on the second signal line (L 31 B) and has a second predetermined width (W 31 B). The first ground layer (G 31 A) has a remaining ratio lower than a remaining ratio of the second ground layer (G 31 B).

First claim

What is claimed is:

1. A printed wiring board comprising:
an insulating substrate;
a first signal line that constitutes differential signal lines formed on the insulating substrate and includes a curved portion;
a second signal line provided along the first signal line and side by side inside the curved portion; and
a ground layer formed for the first signal line and the second signal line via an insulating material, the ground layer including a first ground layer corresponding to a first region and a second ground layer corresponding to a second region, the first region being defined based on a position of the first signal line and having a first predetermined width, the second region being defined based on a position of the second signal line and having a second predetermined width,
the first ground layer having a remaining ratio lower than a remaining ratio of the second ground layer,
the first predetermined width of the first region being three times or more of a circuit width of the first signal line, the second predetermined width of the second region being three times or more of a circuit width of the second signal line.

2. The printed wiring board according to claim 1 , wherein the circuit width of the first signal line is larger than the circuit width of the second signal line.

3. The printed wiring board according to claim 1 , wherein the first predetermined width of the first region is larger than the second predetermined width of the second region.

4. The printed wiring board according to claim 1 , wherein each of the first ground layer and the second ground layer has a mesh structure in which a plurality of partial region are discretely removed so that a remaining region constitutes the mesh structure.

Assignees

• Fujikura Ltd
• Fujikura Ltd

Inventors

• Watanabe Hirohito
• Ogawa Taiji

Classifications

• H05K1/0393

  Flexible materials (H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups) · CPC title

• H05K2201/09681

  Mesh conductors, e.g. as a ground plane · CPC title

• H05K2201/09727

  Varying width along a single conductor; Conductors or pads having different widths · CPC title

• H05K1/0237

  High frequency adaptations (H05K1/0216 takes precedence) · CPC title

• H05K1/0216 Primary

  Reduction of cross-talk, noise or electromagnetic interference (grounding H05K1/0215) · CPC title