Flexible interconnect cable with high frequency electrical transmission line

• US 6,797,891 B1
• Filed: 03/26/2002
• Issued: 09/28/2004
• Est. Priority Date: 03/18/2002
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Applied Micro Circuits Corporation (MACOM Technology Solutions Holdings, Inc.)
• Inventors: Smith, Jeffrey Thomas, Blair, James Leroy, Schreiber, Oswin M.
• Primary Examiner(s): Zarneke, David A.
• Assistant Examiner(s): NORRIS, JEREMY C
• Application Number:
  US10/107,667
• Time in Patent Office: 917 Days
• Field of Search: 174/268, 174/110.R, 174/117.F
• US Class Current: 174/268
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16237 the bump connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/4985 Flexible insulating substrates H01L23/49572 and H01L23/49855 take precedence
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/15173 in a single layer of the multilayer substrate
• CPC Class Codes: H01L 2924/15174 in different layers of the multilayer substrate
• CPC Class Codes: H05K 1/0219 Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 1/147 at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit H05K1/148 takes precedence
• CPC Class Codes: H05K 2201/0715 provided by an outer layer of PCB
• CPC Class Codes: H05K 2201/09236 Parallel layout
• CPC Class Codes: H05K 2201/10734 Ball grid array [BGA]; Bump grid array
• CPC Class Codes: H05K 3/222 Completing of printed circuits by adding non-printed jumper connections printed jumper connections H05K3/4685
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits

Abstract

A high speed flexible interconnect cable includes a number of conductive layers and a number of dielectric layers. Conductive signal traces, located on the conductive layers, combine with the dielectric layers to form one or more high speed electrical transmission line structures. The transmission line structure may be realized as a grounded coplanar waveguide structure, a microstrip structure, a stripline structure, or the like. The cable can be coupled to destination components using a variety of connection techniques, e.g., direct bonding to a circuit substrate, direct soldering to a flip chip, mechanical attachment to a component, or integration with a circuit substrate. The cable can also be terminated with any number of known or standardized connector packages, e.g., SMA, GPPO, or V connectors.

Claims

1. An electronic assembly comprising:

an electrical interconnect cable comprising;

a flexible dielectric layer; and

a flexible conductive layer coupled to said flexible dielectric layer, said flexible conductive layer comprising a number of conductive traces of a high-frequency electrical transmission line structure, each of said conductive traces terminating at an exposed conductive pad;

a component carrier substrate having a number of conductive substrate pads located thereon, each of said conductive substrate pads corresponding to one of said exposed conductive pads; and

a compression connector configured to hold said electrical interconnect cable against said component carrier substrate to form a compression connection between said exposed conductive pads and said conductive substrate pads.

2. An electronic assembly according to claim 1, wherein said flexible dielectric layer and said flexible conductive layer are configured such that the minimum bend radius of said electrical interconnect cable is approximately three times the thickness of said electrical interconnect cable.

3. An electronic assembly according to claim 1, further comprising an insulating jacket surrounding said flexible dielectric layer and said flexible conductive layer over at least a portion of the length of said electrical interconnect cable.

4. An electronic assembly according to claim 1, wherein said number of conductive traces form a coplanar waveguide transmission line structure.

5. An electronic assembly according to claim 1, further comprising a flexible conductive ground layer coupled to said flexible dielectric layer such that said flexible dielectric layer resides between said flexible conductive layer and said flexible conductive ground layer.

6. An electronic assembly according to claim 5, wherein said number of conductive traces and said flexible conductive ground layer form a grounded coplanar waveguide transmission line structure.

7. An electronic assembly according to claim 5, wherein said number of conductive traces and said flexible conductive ground layer form a microstrip transmission line structure.

8. An electronic assembly according to claim 5, wherein said number of conductive traces and said flexible conductive ground layer form a stripline transmission line structure.

9. An electronic assembly according to claim 5, wherein said number of conductive traces and said flexible conductive ground layer form an edge coupled stripline transmission line structure.

10. An electronic assembly according to claim 5, wherein said number of conductive traces and said flexible conductive ground layer form a broadside coupled stripline transmission line structure.

11. An electronic assembly according to claim 1, further comprising a stiffening element coupled to said flexible dielectric layer proximate a terminating end of said electrical interconnect cable, said stiffening element including a plurality of dielectric layers providing structural rigidity to said terminating end of said electrical interconnect cable.

12. An electronic assembly according to claim 1, wherein each of said conductive traces terminates at an exposed conductive pad located proximate a terminating end of said electrical interconnect cable.

13. An electronic assembly according to claim 12, wherein each of said exposed conductive pads is shaped to match a corresponding conductive pad formed on a component carrier substrate.

14. An electronic assembly according to claim 13, wherein said compression connector holds exposed conductive pads at said terminating end of said electrical interconnect cable against said corresponding conductive pads on said component carrier substrate.

15. An electronic assembly according to claim 13, wherein said compression connector forms a compression connection between exposed conductive pads at said terminating end of said electrical interconnect cable and said corresponding conductive pads on said component carrier substrate.

16. An electronic assembly according to claim 13, wherein said exposed conductive pads are configured to facilitate electrical bonding to said corresponding conductive pads on said component carrier substrate.

17. An electronic assembly according to claim 12, wherein each of said exposed conductive pads is configured to facilitate electrical bonding to a corresponding solder ball formed on an electronic device.

18. An electronic assembly according to claim 1, wherein said compression connector creates a compressive force for holding said flexible dielectric cable against said component carrier substrate by means of a device selected from the group consisting of springs, clips, tension elements, screws, fasteners, hinges, and sliding elements.

19. An electronic assembly according to claim 1, further including at least one keyway on the electrical interconnect cable, and at least one keyway on the component carrier substrate for engaging with the at least one keyway on the electrical interconnect cable.

20. An electronic assembly according to claim 19, further including at least one key way on the compressive connector for engaging with a keyway on the electrical interconnect cable.