Scalable wideband probes, fixtures, and sockets for high speed IC testing and interconnects
View Patent ↗We introduce a new Periodic micro coaxial transmission line (PMTL) that is capable of sustaining a TEM propagation mode up to THz band. The PMTL can be manufactured using current photolithographic processes. This transmission line can be embedded in microscopic layers that allow many new applications. We further use the embedded PMTL to develop a modular, scaleable and fully automated Universal Test Fixture for testing chips in various stages of development mainly for digital IC chips that can be utilized in production lines with pick and place of chips on tape to test every chip before insertion into circuits. The PMTL can also provide Confined Field Interconnects between various elements on semiconductor wafers to reduce parasitic and radiation losses and practically eliminating cross talk, thus, increasing the speed of digital IC's. The PMTL is also used to develop a Universal Test Socket, and a Hand Probe.
1. A micro coaxial transmission line comprising:
an outer conductor comprising:
a first conducting strip extending substantially along a first axis;
a second conducting strip extending substantially parallel to said first axis; and
a plurality of conductive members, each of said members electrically connecting said first conducting strip to said second conducting strip, said conductive members arranged along said first and second conducting strips;
an inner conductor substantially between the first and second conducting strips of the outer conductor, and extending substantially parallel to said first axis; and
a dielectric located between and extending roughly parallel to the inner conductor and the outer conductor, said dielectric extending roughly parallel to the first axis,
wherein the dielectric comprises dielectric material with a plurality of cavities therein, said cavities being separated from one another by dielectric material and spaced periodically along the extent of the dielectric in a direction roughly parallel to the first axis.
2. The periodic micro coaxial transmission line of claim 1 , wherein said conductive members comprise plated-through holes.
3. The periodic micro coaxial transmission line of claim 1 , wherein said inner conductor comprises:
a first inner conducting strip;
a second inner conducting strip substantially parallel to said first conducting strip; and
a plurality of inner conductive members electrically connecting said first inner conducting strip to said second inner conducting strip, said inner conductive members arranged along said first and second inner conducting strips.
4. The periodic micro coaxial transmission line of claim 3 , wherein said inner conductive members comprise plated-through holes.
5. The periodic micro coaxial transmission line of claim 1 , wherein said first and second conducting strips and said conductive members comprise a cage enclosing said inner conductor.
6. The periodic micro coaxial transmission line of claim 1 , wherein said conductive members are arranged in two rows substantially along first and second edges of said first conducting strip and said second conducting strip.
7. The periodic micro coaxial transmission line of claim 1 , wherein said cavities are filled with a low-loss dielectric.
8. The periodic micro coaxial transmission line of claim 7 , wherein said low-loss dielectric comprises air.
9. The periodic micro coaxial transmission line of claim 7 , wherein said low-loss dielectric comprises a gas.
10. The periodic micro coaxial transmission line of claim 7 , wherein said low-loss dielectric comprises a foam.
11. The periodic micro coaxial transmission line of claim 1 , wherein said at least one inner conductor comprises a single conductive strip.
12. The periodic micro coaxial transmission line of claim 1 , wherein said cavities comprise one or more pockets of vacuum or low pressure gas.
13. The periodic micro coaxial transmission line of claim 1 , comprising two or more inner conductors, wherein said inner conductors form one or more signaling pair units.
14. The periodic micro coaxial transmission line of claim 1 , wherein said outer conductor further comprises at least two dielectric layers each comprising a channel extending along the first axis, wherein the channel comprises metalized walls, and wherein said metalized walls substantially shield said inner conductor.
15. The periodic micro coaxial transmission line of claim 1 , wherein the pattern of cavities are formed by evenly spaced holes.
16. The periodic micro coaxial transmission line of claim 1 , wherein the pattern of cavities repeats periodically.
17. The periodic micro coaxial transmission line of claim 1 , wherein the dielectric comprises a plurality of dielectric layers.
18. The periodic micro coaxial transmission line of claim 1 , wherein the plurality of cavities are located above and below the inner conductor.
19. The periodic micro coaxial transmission line of claim 1 , wherein the plurality of cavities are located beside the inner conductor.