Coaxial structure for transmission of signals in test equipment

Patent metadata

Field	Value
Publication number	US-10451652-B2
Application number	US-201414332757-A
Country	US
Kind code	B2
Filing date	Jul 16, 2014
Priority date	Jul 16, 2014
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

An example system includes a circuit board having electrical elements; a wafer having contacts; and an interconnect to route signals between the electrical elements and the contacts. The interconnect includes multiple layers, each of which includes a flexible circuit. The flexible circuit includes a conductive trace disposed thereon. The interconnect also includes shielding between adjacent layers of the multiple layers. The shielding is electrically connected to ground.

First claim

What is claimed is:

1. A system comprising:
a circuit board comprising electrical elements;
a wafer comprising contacts; and
an interconnect to route signals between the electrical elements and the contacts, the interconnect comprising multiple layers, each of the multiple layers comprising a flexible circuit, the flexible circuit comprising a conductive trace disposed thereon, the interconnect further comprising shielding between adjacent layers of the multiple layers, the shielding being electrically connected to ground, the shielding and the multiple layers comprising part of a coaxial transmission structure that extends through an entirety of the interconnect and through the circuit board to connect to the electrical elements;
wherein the shielding comprises multiple layers of shielding arranged within the interconnect so that each conductive trace is between two layers of shielding, each of the two layers of shielding having a cut-away portion adjacent to a corresponding conductive trace.

2. The system of claim 1 , wherein the flexible circuit comprises a dielectric, an end of the conductive trace extending beyond the dielectric; and
wherein the interconnect comprises a second dielectric, the end of the conductive trace bending around the second dielectric, the end of the conductive trace comprising an electrical contact.

3. The system of claim 1 , wherein the shielding for each conductive trace comprises a conductive layer above the conductive trace and a conductive layer below the conductive trace, each of the conductive layer above the conductive trace and the conductive layer below the conductive trace being arranged so that at least part of the conductive trace is between cut-away portions of different conductive layers.

4. The system of claim 1 , wherein a cut-away portion of each of the two layers is arranged relative to the conductive trace so that there is air between the conductive trace and each of the two layers of shielding.

5. The system of claim 1 , wherein at least some conductive traces in the interconnect comprise curved or serpentine portions configured to achieve substantially matching electrical path lengths and time-of-flight, impedances, and signal attenuation between different conductive traces in the interconnect.

6. The system of claim 1 , wherein the electrical elements are arranged at a first pitch and the contacts are arranged at a second pitch; and
wherein the interconnect is configured to translate between the first pitch and the second pitch.

7. The system of claim 1 , wherein the circuit board further comprises:
electronics associated with each of the electrical elements, wherein electronics associated with a corresponding electrical element are for supporting operation of the corresponding electrical element.

8. The system of claim 1 , wherein each of the electrical elements comprises part of a radio frequency (RF) probe card.

9. The system of claim 1 , wherein the electrical elements comprise electrical cables that terminate on the circuit board.

10. The system of claim 1 , wherein the contacts are arranged in parallel rows on the wafer; and
wherein the system further comprises:
a tester to make electrical contact between the interconnect and a subset of the contacts.

11. The system of claim 1 , further comprising:
an interposer between the interconnect and the circuit board, the interposer comprising a part of an electrical pathway between the electrical elements and the contacts.

12. The system of claim 11 , further comprising:
contacts on the interposer that are electrically-conductive and mechanically-compliant, the contacts to provide a mechanically-compliant electrical connection between the interposer and the corresponding contacts on the interconnect.

13. The system of claim 1 , further comprising:
pins between the interconnect and the wafer, the pins for providing at least part of an electrical pathway between the contacts and the interconnect; and
an interface board, the interface board being at least part of the electrical pathway containing the contacts and the interconnect, the interface board comprising electronic components in the electrical pathway.

14. The system of claim 13 , wherein the electronic components are passive electronic components.

15. The system of claim 14 , wherein the electronic components comprise at least one of capacitors, baluns or switches.

16. The system of claim 13 , wherein the electronic components comprise active electronic components.

17. A system comprising:
a circuit board comprising electrical elements;
a wafer comprising contacts; and
an interconnect to route signals between the electrical elements and the contacts, the interconnect comprising multiple layers, each of the multiple layers comprising a conductor surrounded by a dielectric, the interconnect further comprising shielding between adjacent layers of the multiple layers, the shielding being electrically connected to ground, the shielding and the multiple layers comprising part of a coaxial transmission structure that extends through an entirety of the interconnect and through the circuit board to connect to the electrical elements;
wherein the shielding comprises multiple layers of shielding arranged within the interconnect so that each conductor is between two layers of shielding, each of the two-layers of shielding having a cut-away portion adjacent to a conductor.

18. The system of claim 17 , wherein an end of the conductor extends beyond the dielectric; and
wherein the interconnect comprises a second dielectric, the end of the conductor bending around the second dielectric, the end of the conductor comprising an electrical contact.

19. The system of claim 17 , wherein the shielding for each conductor comprises a conductive layer above the conductor and a conductive layer below the conductor, each of the conductive layer above the conductor and the conductive layer below the conductor being arranged so that at least part of the conductor is between cut-away portions of different conductive layers.

20. The system of claim 17 , wherein a cut-away portion of each of the two layers is arranged relative to the conductor so that there is air between the conductor and each of the two layers of shielding.

21. The system of claim 17 , wherein at least some conductors in the interconnect comprise curved or serpentine portions configured to achieve substantially matching electrical path lengths and time-of-flight, impedances, and signal attenuation between different conductors in the interconnect.

22. The system of claim 17 , wherein the electrical elements are arranged at a first pitch and the contacts are arranged at a second pitch; and
wherein the interconnect is configured to translate between the first pitch and the second pitch.

23. The system of claim 17 , further comprising:
an interposer between the interconnect and the circuit board, the interposer comprising a part of an electrical pathway between the electrical elements and the contacts.

24. The system of claim 17 , further comprising:
contacts on the interposer that are electrically-conductive and mechanically-compliant, the contacts to provide a mechanically-compliant electrical connection between the interposer and the corresponding contacts on the interconnect.

25. The system of claim 17 , wherein the circuit board further comprises:
electronics associated with each of the electric

Assignees

• Teradyne Inc

Inventors

• Sinsheimer Roger Allen
• Lewinnek David Walter
• Valiente Luis Antonio

Classifications

• G01R1/07357

  with flexible bodies, e.g. buckling beams · CPC title

• G01R1/0491 Primary

  for testing integrated circuits on wafers, e.g. wafer-level test cartridge · CPC title

• G01R1/18

  Screening arrangements against electric or magnetic fields, e.g. against earth's field · CPC title

• G01R1/20

  Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments · CPC title

• G01R1/07378

  using an intermediate adapter, e.g. space transformers (G01R1/07371 takes precedence) · CPC title