Shielded probe for testing a device under test
View Patent ↗A probe measurement system for measuring the electrical characteristics of integrated circuits or other microelectronic devices at high frequencies. The probe measurement system preferably includes a probe having a conductive path extending between the first and second surfaces of a membrane and a probe contact electrically connected to the conductive path.
1. A probe comprising:
(a) a flexible membrane;
(b) an elongate conductor suitable to be electrically interconnected to a test signal supported by a first side of said membrane;
(c) a conductive member suitable to be electrically interconnected to a ground signal supported by a second side of said membrane wherein said conductive member is under a majority of the length of said elongate conductor;
(d) a conductive path between said first side of said membrane and said second side of said membrane in a manner free from an air gap between the conductive path and the end of said membrane for at least a majority of the thickness of said membrane and said electrically connected to the elongate conductor and free from electrical interconnection with said conductive member; and
(e) a contact electrically interconnected to said conductive path for testing a device under test.
2. The probe of claim 1 wherein said elongate conductor is electrically interconnected to a central conductor of a coaxial cable.
3. The probe of claim 2 wherein said conductive member is electrically connected to a conductor surrounding said central conductor of said coaxial cable.
4. The probe of claim 3 wherein said membrane is supported by said coaxial cable.
5. The probe of claim 4 wherein said membrane is supported by a shelf of said coaxial cable.
6. The probe of claim 1 wherein said conductive member is substantially planar.
7. The probe of claim 1 further comprising a second conductive member suitable for electrical interconnection to a ground signal, said second conductive member supported on a side of said elongate conductor opposite said membrane.
8. The probe of claim 7 wherein a dielectric separates said second conductive member and said elongate conductor.
9. The probe of claim 1 wherein said membrane has a dielectric constant less than 7.
10. The probe of claim 1 wherein said membrane has a dielectric constant less than 5.
11. The probe of claim 1 wherein said membrane has a dielectric constant less than 4.
12. The probe of claim 1 wherein said membrane has a dielectric constant less than 2.
13. The probe of claim 1 wherein said ground signal is zero volts.
14. The probe of claim 1 wherein said conductive member covers greater than 50% of said second side of said membrane.
15. The probe of claim 1 wherein said conductive member covers greater than 60% of said second side of said membrane.
16. The probe of claim 1 wherein said conductive member covers greater than 70% of said second side of said membrane.
17. The probe of claim 1 wherein said conductive member covers greater than 80% of said second side of said membrane.
18. The probe of claim 1 wherein said conductive member covers greater than 90% of said second side of said membrane.
19. The probe of claim 1 wherein said conductive member, said elongate conductor, and said membrane collectively form a microstrip transmission structure.
20. The probe of claim 1 wherein said conductive path is a via through said membrane.
21. The probe of claim 1 wherein said conductive member laterally surrounds at least 50% of said contact.
22. The probe of claim 1 wherein said conductive member laterally surrounds at least 75% of said contact.
23. The probe of claim 1 wherein said conductive member laterally surrounds at least 100% of said contact.
24. The probe of claim 1 wherein said contact is in the form of a bump.
25. The probe of claim 1 wherein said membrane has a thickness less than 40 microns.
26. The probe of claim 1 wherein said membrane has a thickness less than 30 microns.
27. The probe of claim 1 wherein said membrane has a thickness less than 20 microns.
28. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 10 times the distance between said elongate conductor and said shield member.
29. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 7 times the distance between said elongate conductor and said shield member.
30. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 5 times the distance between said elongate conductor and said shield member.
31. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 4 times the distance between said elongate conductor and said shield member.
32. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 2 times the distance between said elongate conductor and said shield member.
33. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 10 times the distance between said elongate conductor and said shield member.
34. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 7 times the distance between said elongate conductor and said shield member.
35. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 5 times the distance between said elongate conductor and said shield member.
36. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 4 times the distance between said elongate conductor and said shield member.
37. The probe of claim 1 further comprising a conductive shield member arranged proximate said elongate conductor on a side of said elongate conductor opposite of said conductive member and suitable to be electrically interconnected to a ground signal, wherein a distance between said elongate conductor and said conductive member is less than 2 times the distance between said elongate conductor and said shield member.
38. A probe comprising:
(a) a non-rigid membrane supporting an elongate conductor on a first side of said membrane and a conductive member supported by a second side of said membrane wherein said conductive member is under a majority of the length of said elongate conductor;
(b) a conductive path between said first side of said membrane and said second side of said membrane in a region within the periphery of said membrane for at least a majority of the thickness of said membrane said conductive path electrically connected to said elongate conductor and free from electrical interconnection with said conductive member; and
(c) a contact electrically interconnected to said conductive path for testing a device under test.
39. The probe of claim 38 wherein said elongate conductor is electrically interconnected to a central conductor of a coaxial cable.
40. The probe of claim 39 wherein said conductive member is electrically connected to a conductor surrounding said central conductor of said coaxial cable.
41. The probe of claim 38 wherein said dielectric membrane has a dielectric constant less than 7.
42. The probe of claim 38 wherein said dielectric membrane has a dielectric constant less than 5.
43. The probe of claim 38 wherein said dielectric membrane has a dielectric constant less than 4.
44. The probe of claim 38 wherein said dielectric membrane has a dielectric constant less than 2.
45. The probe of claim 38 wherein said conductive member covers greater than 50% of said second side of said membrane.
46. The probe of claim 38 wherein said conductive member covers greater than 60% of said second side of said membrane.
47. The probe of claim 38 wherein said conductive member covers greater than 70% of said second side of said membrane.
48. The probe of claim 38 wherein said conductive member covers greater than 80% of said second side of said membrane.
49. The probe of claim 38 wherein said conductive member covers greater than 90% of said second side of said membrane.
50. The probe of claim 38 wherein said conductive member, said elongate conductor, and said membrane collectively form a microstrip transmission structure.
51. The probe of claim 38 wherein said membrane has a thickness less than 40 microns.
52. The probe of claim 38 wherein said membrane has a thickness less than 20 microns.
53. The probe of claim 38 wherein said membrane has a thickness less than 10 microns.