Electronic device

• US 6,693,801 B2
• Filed: 12/31/2002
• Issued: 02/17/2004
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Original Assignee: Kanji Otsuka
• Inventors: Otsuka, Kanji
• Primary Examiner(s): Tokar, Michael
• Assistant Examiner(s): Tan, Vibol
• Application Number:
  US10/331,767
• Publication Number:
  US 20030090291A1
• Time in Patent Office: 413 Days
• Field of Search: 361/684, 361/686, 361/737, 361/762, 361/763, 361/766, 361/793, 361/768
• US Class Current: 361/763
• CPC Class Codes: H01L 23/50 for integrated circuit devices, e.g. power bus, number of leadsH01L23/482 - H01L23/498 take precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H05K 1/0216 Reduction of cross-talk, noise or electromagnetic interference grounding H05K1/0215
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence

Abstract

An electronic device includes a wiring board, and at least one pair of signal lines that is provided on the wiring board in parallel and has an equal length. A chip is mounted on the wiring board and includes at least one differential driver which outputs complementary digital transmit signals to said at least one of lines. A pair of power system lines is provided to supply first and second power supply voltages to the above-mentioned at least one differential driver. The power system lines are parallel to each other and have an equal length.

Claims

1. An electronic apparatus comprising

a wiring board having first and second surfaces;

a CPU mounted on a chip mounting area provided on a central position of the first surface of the wiring board; and

memories mounted on at least one of the first and second surfaces of the wiring board; and

first, second, third and fourth groups of respective parallel signal lines having an equal length,

the first, second, third and fourth groups respectively extending on the first surface from sides of the chip mounting area in four orthogonal directions, penetrating through the wiring board and extending on the second surface toward a center thereof,

wherein the memories located at an equal distance from connections between terminals of the CPU and the first through fourth groups of signal lines along the four orthogonal distances are of an identical type and are connected to corresponding groups of signal lines.

2. The electronic apparatus as claimed in claim 1, wherein the first through fourth groups of signal lines respectively include pairs of signal lines over which complementary digital transmit signals are transferred.

3. The electronic apparatus as claimed in claim 1, further comprising a pair of parallel power system lines having an equal length, first and second power supply voltages being supplied to the CPU and the memories via the pair of parallel power system lines.

4. An electronic apparatus comprising

first and second wiring boards respectively having first and second surfaces;

a CPU mounted on a chip mounting area provided on a central position of the first surface of the first wiring board;

memories mounted on at least one of the first and second surfaces of the wiring board; and

first, second, third and fourth groups of respective parallel signal lines having an equal length,

the first, second, third and fourth groups respectively extending on the first surface from sides of the chip mounting area in four orthogonal directions and extending on the second surface toward a center thereof,

wherein the memories located at an equal distance from connections between terminals of the CPU and the first through fourth groups of signal lines along the four orthogonal distances are of an identical type and are connected to corresponding groups of signal lines.

5. The electronic apparatus as claimed in claim 4, wherein the first through fourth groups of signal lines respectively include pairs of signal lines over which complementary digital transmit signals are transferred.

6. The electronic apparatus as claimed in claim 4, further comprising a pair of parallel power system lines having an equal length, first and second power supply voltages being supplied to the CPU and the memories via the pair of parallel power system lines.

7. An electronic apparatus comprising

first and second semiconductor substrates respectively having first and second surfaces;

a CPU mounted on a chip mounting area provided on a central position of the first surface of the first semiconductor substrate;

memories mounted on at least one of the first and second surfaces of the semiconductor substrate; and

first, second, third and fourth groups of respective parallel signal lines having an equal length,

the first, second, third and fourth groups respectively extending on the first surface from sides of the chip mounting area in four orthogonal directions and extending on the second surface toward a center thereof,

wherein the memories located at an equal distance from connections between terminals of the CPU and the first through fourth groups of signal lines along the four orthogonal distances are of an identical type and are connected to corresponding groups of signal lines.

8. The electronic apparatus as claimed in claim 7, wherein the first through fourth groups of signal lines respectively include pairs of signal lines over which complementary digital transmit signals are transferred.

9. The electronic apparatus as claimed in claim 7, further comprising a pair of parallel power system lines having an equal length, first and second power supply voltages being supplied to the CPU and the memories via the pair of parallel power system lines.