Stretchable interconnects using stress gradient films

• US 20020094701A1
• Filed: 11/29/2000
• Published: 07/18/2002
• Est. Priority Date: 11/29/2000
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Reich, James, Fork, David, Biegelsen, David Kalman
• Granted Patent: US 6,743,982 B2
• Time in Patent Office: Days
• US Class Current: 439/32
• CPC Class Codes: B25J 13/084 Tactile sensors in general G01L5/16, G01L5/22
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: H01L 23/5387 Flexible insulating substrates H01L23/5388 takes precedence
• CPC Class Codes: H01L 24/01 Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
• CPC Class Codes: H01L 25/0655 the devices being arranged next to each other
• 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 2924/14 Integrated circuits
• CPC Class Codes: H05K 3/4092 Integral conductive tabs, i.e. conductive parts partly detached from the substrate

Abstract

A stretchable interconnect for electrically connecting electronic devices comprises a photolithographically patterned conductor extending between two of said devices for electrically coupling a contact of one device to a contact of another device. The stretchable interconnect preferably comprises a coiled conductor. The coiled conductor is formed of a metal or alloy having a stress gradient extending through a thickness of said conductor. A sensor array employs the stretchable interconnects to connect contacts of one electronic device to another electronic device. The sensor array can be employed in a flexible or stretchable sensing skin of a robot as well as other applications. The stretchable interconnects can be formed by a photolithographic process on the same substrate which supports the electronic devices. The interconnects become stretchable when the supporting substrate is removed from the interconnect. Preferably coils which are formed are di-helic.

Claims

1. A stretchable interconnect for electrically connecting electronic devices which are supported for movement relative to one another, comprising:

a photolithographically patterned stretchable conductor extending between two of said devices for electrically coupling a contact of one device to a contact of another device, said conductor being comprised of a conductive material.

2. The stretchable interconnect as in claim 1 wherein said interconnect comprises a coiled conductor which as patterned has a stress gradient extending through at least a portion of the thickness of said conductor

3. The stretchable interconnect as in claim 1 wherein as photolithographically patterned said interconnect comprises at least one “

V”

shaped section.

4. The stretchable interconnect as in claim 3 wherein said interconnect comprises a plurality of “

V”

shaped sections.

5. The stretchable interconnect as in claim 2 wherein as photolithographically patterned and prior to coiling said interconnect comprises at least one “

V”

shaped section, which when unsupported forms said coil.

6. The stretchable interconnect as in claim 5 wherein said interconnect comprises a plurality of “

V”

shaped sections, which when unsupported forms said coil.

7. The stretchable interconnect as in claim 2 wherein said coiled conductor is di-helic.

8. A sensor array comprising at least two electronic devices which are supported for movement relative to one another and at least one stretchable interconnect for connecting said electronic devices, said interconnect comprising:

a photolithographically patterned stretchable conductor extending between said devices for electrically coupling a contact of one device to a contact of another device, said conductor being formed of a conductive material.

9. The sensor array as in claim 8 wherein said interconnect comprises a coiled conductor which as patterned has a stress gradient extending through at least a portion of the thickness of said conductor

10. The sensor array as in claim 8 wherein as photolithographically patterned said interconnect comprises at least one “

V”

shaped section.

11. The sensor array as in claim 10 wherein said interconnect comprises a plurality of “

V”

shaped sections.

12. The sensor array as in claim 9 wherein as photolithographically patterned and prior to coiling said interconnect comprises at least one “

V”

shaped section, which when unsupported, forms said coil.

13. The sensor array as in claim 12 wherein said interconnect comprises a plurality of “

V”

shaped sections, which when unsupported form said coil.

14. The sensor array as in claim 9 wherein said coiled conductor is di-helic.

15. The sensor array as in claim 9 which comprises a tactile sensing array.

16. The sensor array as in claim 15 which comprises a tactile sensing portion of a robot.

17. The sensor array as in claim 16 wherein said sensor array is arranged in a flexible and stretchable skin of said robot.

18. The sensor array as in claim 9 which includes a plurality of said stretchable interconnects.

20. The process as in claim 19 wherein said interconnect conductor is formed with a stress gradient extending through at least a portion of the thickness of said conductor so that upon removal of said substrate from support of said interconnect conductor will cause said interconnect conductor to form a stretchable coil.

21. The process as in claim 20 wherein said interconnect comprises a coiled conductor which as patterned has a stress gradient extending through at least a portion of the thickness of said conductor

22. The sensor array as in claim 19 wherein as photolithographically patterned said interconnect comprises at least one “

V”

shaped section.

23. The sensor array as in claim 22 wherein said interconnect comprises a plurality of “

V”

shaped sections.

24. The process as in claim 20 wherein as photolithographically patterned and prior to substrate removal said interconnect conductor comprises at least one “

V”

shaped section, which when unsupported forms said coil.

25. The process as in claim 24 wherein said photolithographically patterned interconnect comprises a plurality of “

V”

shaped sections, which when unsupported forms said coil.

26. The process as in claim 20 wherein said interconnect conductor when unsupported is di-helic.

27. The process of claim 20 which comprises making a sensor array having at least two electronic devices and including a plurality of stretchable interconnect conductors connecting adjacent electronic devices.

28. The process as in claim 27 further comprising mounting said sensor array to a flexible and stretchable skin material.

29. The process as in claim 28 wherein said sensor array comprises a tactile sensing array.

30. The process as in claim 29 further comprising mounting said sensor array to a tactile sensing portion of a robot.

19. A process for making a stretchable interconnect for electrically connecting electronic devices which are supported for movement relative to one another, comprising:

forming said devices supported by a substrate, said devices being spaced apart from each other in said substrate;

depositing an interconnect conductor supported by said substrate for electrically coupling a contact of one device to a contact of another device,

photolithographically patterning said interconnect conductor with a pattern which upon removal of said substrate from support of said interconnect conductor will cause said interconnect conductor to form a stretchable interconnect.