Temporary planar electrical contact device and method using vertically-compressible nanotube contact structures
View Patent ↗A wafer-scale probe card for temporary electrical contact to a sample wafer or other device, for burn-in and test. The card includes a plurality of directly metallized single-walled or multi-walled nanotubes contacting a pre-arranged electrical contact pattern on the probe card substrate. The nanotubes are arranged into bundles for forming electrical contacts between areas of the device under test and the probe card. The bundles are compressible along their length to allow a compressive force to be used for contacting the probe card substrate to the device under test. A strengthening material may be disposed around and/or infiltrate the bundles. The nanotubes forming the bundles may be patterned to provide a pre-determined bundle profile. Tips of the bundles may be metallized with a conductive material to form a conformal coating on the bundles; or metallized with a conductive material to form a continuous, single contact surface.
1. A probe card comprising:
a substrate comprising an electrically conductive pattern on a surface thereof;
bundles of joined nanotubes, each said bundle disposed on said conductive pattern and extending from said surface of said substrate; and
an elastic material disposed in spaces between said bundles,
wherein said elastic material is a distinct and different material than said nanotubes,
each of said bundles is part of an electrically conductive element coupled at one end to said conductive pattern and extending from said one end away from said surface to an opposite end.
2. The probe card of claim 1 , wherein said nanotubes comprise carbon nanotubes.
3. The probe card of claim 1 , wherein said nanotubes comprise germanium-nano-tubes.
4. The probe card of claim 1 , wherein said elastic material comprises an elastomer.
5. The probe card of claim 1 , wherein said elastic material is disposed on said surface of said substrate.
6. The probe card of claim 1 , wherein said elastic material fills space between each of said bundles.
7. The probe card of claim 1 , wherein said bundles are embedded in said elastic material.
8. The probe card of claim 1 , wherein said nanotubes comprise single-walled-nano-tubes.
9. The probe card of claim 1 , wherein said nanotubes comprise double-walled-nano-tubes.
10. The probe card of claim 1 , wherein said spaces between said bundles in which said elastic material is disposed are external to each of said bundles.
11. A probe card comprising:
a substrate comprising an electrically conductive pattern on a surface thereof;
bundles of joined nanotubes, each said bundle disposed on said conductive pattern and extending from said surface of said substrate; and
an elastic material disposed in spaces between said bundles, wherein:
each of said bundles is part of an electrically conductive probe comprising a base end and a contact end,
said base end of said probe is coupled to said conductive pattern, and
said probe extends from said base end away from said surface of said substrate to said contact end.
12. The probe card of claim 11 , wherein said contact end comprises metallization of a first end of said bundle.
13. The probe card of claim 12 , wherein said first end of said bundle comprises a surface comprising a confluence of ends of said nanotubes of said bundle.
14. The probe card of claim 12 , wherein said base end comprises metallization of a second end of said bundle opposite said first end.
15. The probe card of claim 14 , wherein said second end of said bundle comprises a surface comprising a confluence of ends of said nanotubes of said bundle.
16. The probe card of claim 11 , wherein said contact end comprises a cap-shaped tip coupled to a first end of said bundle.
17. The probe card of claim 11 , wherein each of said bundles buckles under a compressive load on said contact end of said probe of which said bundle is a part.
18. The probe card of claim 11 , wherein said probes are partially embedded in said elastic material with said contact ends of said probes extending from an outer surface of said elastic material.
19. The probe card of claim 11 , wherein said elastic material is disposed on said surface of said substrate.
20. The probe card of claim 11 , wherein said elastic material fills space between each of said bundles.
21. The probe card of claim 11 , wherein said elastic material comprises an elastomer.
22. The probe card of claim 11 , wherein said probe extends vertically from said base end away from said surface of said substrate to said contact end.
23. The probe card of claim 11 further comprising electrically conductive probes, wherein:
each said probe comprises a base end coupled to said conductive pattern and a contact end disposed away from said substrate,
each said probe is spaced apart from every other one of said probes,
each said probe comprises one or more of said bundles, and
said elastic material is disposed between said probes.