Paddle Card With Improved Performance

• US 20140202751A1
• Filed: 01/18/2013
• Published: 07/24/2014
• Est. Priority Date: 01/18/2013
• Status: Active Grant

• Current Assignee: Molex LLC (KOCH Industries Incorporated)
• Original Assignee: Molex Incorporated (KOCH Industries Incorporated)
• Inventors: BUGG, Mark Alan
• Granted Patent: US 9,049,787 B2
• Time in Patent Office: Days
• US Class Current: 174/261
• CPC Class Codes: H01R 12/57 surface mounting terminals
• CPC Class Codes: H01R 12/62 connecting to rigid printed circuits or like structures
• CPC Class Codes: H01R 12/775 Ground or shield arrangements
• CPC Class Codes: H01R 13/6474 by variation of conductive properties, e.g. by dimension variations
• CPC Class Codes: H01R 13/65912 for shielded multiconductor cable coaxial cables with one conductor surrounded by shield H01R9/05; flat shielded cables H01R12/594
• CPC Class Codes: H05K 1/0216 Reduction of cross-talk, noise or electromagnetic interference grounding H05K1/0215
• CPC Class Codes: H05K 1/0296 Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295 H05K1/11 takes precedence; lay-out adapted to mounted component configuration H05K1/18
• CPC Class Codes: H05K 1/111 Pads for surface mounting, e.g. lay-out
• CPC Class Codes: H05K 1/112 directly combined with via connections
• CPC Class Codes: H05K 1/117 Pads along the edge of rigid circuit boards, e.g. for pluggable connectors
• CPC Class Codes: H05K 2201/09218 Conductive traces
• CPC Class Codes: H05K 2201/09381 Shape of non-curved single flat metallic pad, land or exposed part thereof; Shape of electrode of leadless component
• CPC Class Codes: H05K 2201/09418 Special orientation of pads, lands or terminals of component, e.g. radial or polygonal orientation
• CPC Class Codes: H05K 2201/09727 Varying width along a single conductor; Conductors or pads having different widths
• CPC Class Codes: H05K 2201/10356 Cables
• CPC Class Codes: H05K 3/3405 Edge mounted components, e.g. terminals

Abstract

A paddle card construction disclosed for use in connecting electronic devices together. The paddle card takes the form of a circuit board that has a plurality of conductive contact pads arranged thereon in pairs. The contact pads of each pair are spaced apart from each other to provide a pair of points to which cable wire free ends may be terminated, such as by soldering. The spacing of the pads apart from each other in effect reduces to amount of capacitance in the cable wire termination area on the circuit board, thereby reducing the impedance and insertion loss in that area at high frequencies. The contact pads of each pair may be further interconnected together by a thin, conductive trace that extends lengthwise between the contact pads.

Claims

1. An improved cable assembly, comprising:

a cable, the cable including a plurality of signal-transmitting wires, pairs of the signal-transmitting wires being arranged in the cable, each signal-transmitting wire including a conductor surrounded by an insulative covering, each conductor extending forwardly past a leading edge of the insulative covering to define a free end of each signal-transmitting wire;

a circuit board having opposite leading and trailing edges, the circuit board including a first portion to which the free ends are terminated and a second portion extending forwardly from and spaced apart from the first portion, the first portion including a plurality of contact pads disposed on a surface thereof, the contact pads being arranged in pairs of contact pads associated with each free end, the contact pads of each contact pad pair being aligned with each other so that a leading edge of the forwardmost contact pad and a trailing edge of the rearmost contact pad define a predetermined length, L, therebetween, the contact pads being separated from each other by an intervening spacing, the cumulative length of the contact pads being between about 0.5 L to 0.8 L; and

a housing enclosing at least a portion of the circuit board.

2. The cable assembly of claim 1, wherein each contact pad pair includes a thin, conductive trace interconnecting the pads of each contact pad pair together.

3. The cable assembly of claim 1, wherein one of the free ends is terminated to one of the pairs of contact pads.

4. The cable assembly of claim 3, wherein at least one pad of the pairs of contact pads encompasses a via extending into the circuit board.

5. The cable assembly of claim 4, wherein each pad of each pair of contact pads encompasses a via extending into the circuit board.

6. The cable assembly of claim 1, wherein the pairs of contact pads are spaced widthwise apart from each other by a first predetermined spacing, and the circuit board further includes conductive transmission traces extending from the forwardmost contact pads in a direction toward the first portion, the transmission traces being separated by a second spacing which is less than the first spacing.

7. The cable assembly of claim 6, wherein the transmission traces converge toward each other until separated by the second spacing.

8. The cable assembly of claim 1, wherein the contact pads have a length of about 0.8 mm, and the intervening spacing between the contact pads has a length of about 1.0 mm.

9. The cable assembly of claim 1, wherein the intervening spacing is between about 0.2 L to about 0.4 L.

10. The cable assembly of claim 1, wherein each interconnecting trace is generally centered between the pair of contact pads it connects together.

11. The cable assembly of claim 1, wherein each interconnecting trace has a width of about 25% to about 40% of a width of the contact pads.

12. A circuit board for use in a high speed cable connector, the circuit board having improved impedance characteristics, comprising:

a circuit board having opposite leading and trailing edges, the circuit board including a first portion proximate to the trailing end defining a termination area in wires of an associated cable are terminated, and a second portion extending forwardly from and spaced apart from the first portion and ending proximate to the second portion, the second portion including a plurality of contacts disposed thereon and configured to mate with an opposing connector, the first portion including a plurality of termination contact pads disposed on a surface thereof, the termination contact pads being arranged in pairs of contact pads, the contact pads of each pair of termination contact pads being arranged on the circuit board so that a leading edge of the forwardmost pad of the contact pad pair and a trailing edge of the rearmost pad of the contact pad pair are separated by a predetermined termination length, L, for a single one of the cable wires, and the contact pads being separated from each other by an intervening spacing, and the cumulative length of the contact pads is between about 0.5 L to 0.8 L.

13. The circuit board of claim 12, wherein each contact pad has a square configuration.

14. The circuit board of claim 12, wherein each contact pad pairs include a thin, conductive trace interconnecting the pads of each contact pad pair together such that the contact pad pairs have a dogbone-like configuration when viewed from the top.

15. The circuit board of claim 14, wherein the interconnecting conductive trace is generally centered between the contact pads it interconnects and at least one of the contact pads includes a via extending into the circuit board.

16. The circuit board of claim 14, wherein the interconnecting conductive trace has a width between about 25% and about 40% of the width of one of the contact pads.

17. The circuit board of claim 12, wherein the pairs of contact pads are spaced apart widthwise by a first spacing and conductive traces extending forwardly from the forwardmost contact pads are separated by a second widthwise spacing, less than the first spacing.

18. The circuit board of claim 12, wherein each contact pad has a length of about 0.8 mm and the intervening spacing has a length of about 1.0 mm.

19. The circuit board of claim 12, wherein the intervening spacing between the contact pads has a length of between about 0.2 L to about 0.4 L.