Shielded probe for testing a device under test
View Patent ↗A probe for measuring the electrical characteristics of integrated circuits or other microelectronic devices at high frequencies may include a dielectric substrate that supports a signal path interconnecting test instrumentation and a probe tip and a ground path that shields both the signal oath and the probe tip.
1. A probe comprising:
(a) a dielectric substrate supporting an elongate conductor on said substrate and a conductive member supported on said substrate;
(b) a contact electrically interconnected to said elongate conductor for testing a device under test;
(c) wherein said elongate conductor and said conductive member form a controlled impedance structure;
(d) a flexible structure interconnected with said dielectric substrate, and a pre-loading mechanism that pre-loads said flexible structure with a force when said contact is free from being engaged with said device under test in such a manner that when force is applied to said probe it has a non-linear vertical deformation profile versus force applied.
2. The probe of claim 1 further comprising a conductive path between said first side of said substrate and said second side of said substrate.
3. The probe of claim 1 wherein said controlled impedance structure is a microstrip.
4. The probe of claim 1 wherein said flexible structure is a co-axial cable.
5. The probe of claim 1 herein said substrate has a thickness of less than 40 microns with a dielectric constant of less than 7.
6. The probe of claim 1 wherein said conductive path is in a region within the periphery of said substrate for at least a majority of the thickness of said substrate.
7. The probe of claim 1 wherein an elongate conductor is electrically interconnected to a central conductor of a coaxial cable.
8. The probe of claim 1 wherein said conductive member is electrically connected to a conductor surrounding said central conductor of said coaxial cable.
9. The probe of claim 1 herein said substrate has a thickness of less than 40 microns with a dielectric constant of less than 7.
10. A probe comprising:
(a) a dielectric substrate supporting an elongate conductor;
(b) a probing element electrically interconnected to said elongate conductor for testing a device under test; and
(c) a flexible structure interconnected with said dielectric substrate, and a pre-loading mechanism that pre-loads said flexible structure with a force when said contact is free from being engaged with said device under test in such a manner that when force is applied to said probe it has a non-linear vertical deformation profile versus force applied.
11. The probe of claim 10 wherein said elongate conductor forms part of a controlled impedance structure.
12. The probe of claim 11 wherein a tensioned state is released when sufficient pressure is exerted between said probing element and said device under test.
13. The probe of claim 11 herein said substrate has a thickness of less than 40 microns with a dielectric constant of less than 7.
14. The probe of claim 11 wherein said elongate conductor is electrically interconnected to a central conductor of a coaxial cable.
15. The probe of claim 10 wherein a tensioned state is released when sufficient pressure is exerted between said probing element and said device under test.
16. The probe of claim 10 herein said substrate has a thickness of less than 40 microns with a dielectric constant of less than 7.
17. The probe of claim 10 wherein said elongate conductor is electrically interconnected to a central conductor of a coaxial cable.