CIRCUIT BOARD WITH SIGNAL ROUTING LAYER HAVING UNIFORM IMPEDANCE

• US 20140262441A1
• Filed: 08/30/2013
• Published: 09/18/2014
• Est. Priority Date: 03/13/2013
• Status: Abandoned Application

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: WU, KAI-WEN
• Application Number:
  US14/014,401
• Publication Number:
  US 20140262441A1
• Time in Patent Office: Days
• US Class Current: 174/250
• CPC Class Codes: H05K 1/024 Dielectric details, e.g. changing the dielectric material around a transmission line
• CPC Class Codes: H05K 1/0253 Impedance adaptations of transmission lines by special lay-out of power planes, e.g. providing openings H05K1/0251 takes precedence
• CPC Class Codes: H05K 1/117 Pads along the edge of rigid circuit boards, e.g. for pluggable connectors
• CPC Class Codes: H05K 2201/0191 wherein the thickness of the dielectric plays an important role
• CPC Class Codes: H05K 2201/09736 Varying thickness of a single conductor; Conductors in the same plane having different thicknesses
• CPC Class Codes: H05K 2201/09972 Partitioned, e.g. portions of a PCB dedicated to different functions; Boundary lines therefore; Portions of a PCB being processed separately or differently

Abstract

A circuit board includes a dielectric layer and a signal routing layer on the dielectric layer. The signal routing layer includes connector traces, chip traces, and signal traces connecting the two. A width of the signal traces is greater than a width of the chip traces, which is less than a width of the connector traces. The dielectric layer includes trace areas of different depths for each type of trace to achieve a uniform impedance throughout all traces.

Claims

1. A circuit board, comprising:

a signal routing layer comprising a plurality of connector traces, a plurality of chip traces, and a plurality of signal traces, each of the signal traces directly connecting to a respective one of the chip traces to a respective one of the connector traces, a width of the signal traces being greater than a width of the chip traces, while the width of the signal traces being less than a width of the connector traces;

a dielectric layer supporting the signal routing layer, the dielectric layer comprising a signal trace area carrying the signal traces, a chip trace area carrying the chip traces, and a connector trace area carrying the connector traces;

wherein a depth of the signal trace area is less than a depth of the connector trace area, while the depth of the signal trace area is greater than a depth of the chip trace area, so as to achieve an uniform impedance throughout all traces.

2. The circuit board of the claim 1, wherein the signal traces, the chip traces, and the connector traces are made of the same material, and have substantially the same depth.

3. The circuit board of claim 1, wherein a width of the signal traces is greater than a width of the chip traces, while the width of the signal traces is less than the width of the connector traces.

4. The circuit board of the claim 1, wherein the dielectric layer is made of fiberglass mixed with resin.

5. The circuit board of the claim 4, wherein the chip trace area of the dielectric layer comprises ceramic powder.

6. The circuit board of the claim 1, comprising a ground layer, wherein the ground layer is located on the dielectric layer.

7. The circuit board of the claim 1, wherein each of the signal traces is a single strip.

8. The circuit board of the claim 7, wherein each of the chip traces is a single strip.

9. The circuit board of the claim 8, wherein each of the connector traces is a single strip.