Vertical microcoaxial interconnects
In one embodiment, a vertical microcoaxial interconnect includes a dielectric substrate having a top side and a bottom side, an inner conductor extending through the substrate from its top side to its bottom side, an outer conductor that extends through the substrate from its top side to its bottom side, the outer conductor surrounding the inner conductor, a signal line extending to the inner conductor without contacting the outer conductor, and a ground line extending to the outer conductor without contacting the inner conductor or the signal line.
1. A vertical microcoaxial interconnect comprising:
a dielectric substrate having a top side and a bottom side;
an inner conductor extending through the substrate from its top side to its bottom side;
an outer conductor that extends through the substrate from its top side to its bottom side, the outer conductor comprising first and second generally C-shaped lateral portions whose ends are separated by opposed gaps and that concentrically encircle the inner connector;
a bridge that crosses one of the gaps to join two ends of the C-shaped lateral portions;
a first signal line formed on the top side of the substrate and extending to the inner conductor without contacting the outer conductor or the bridge;
a second signal line formed on the bottom side of the substrate and extending to the inner conductor without contacting the outer conductor or the bridge; and
a ground line extending to the outer conductor without contacting the inner conductor or the signal line.
2. The interconnect of claim 1 , wherein the inner conductor is rod-shaped and has a generally circular cross-section.
3. The interconnect of claim 2 , wherein the inner conductor has a diameter of approximately 50 to 150 microns.
4. The interconnect of claim 1 , further comprising a second bridge that crosses the other gap to join two other ends of the C-shaped lateral portions.
5. The interconnect of claim 4 , wherein the first bridge is provided on the top side of the substrate and the second bridge is provided on the bottom side of the substrate.
6. The interconnect of claim 1 , wherein the dielectric substrate is made of high-resistivity silicon.
7. The interconnect of claim 1 , wherein the dielectric substrate is approximately 250 to 350 microns thick.
8. The interconnect of claim 1 , wherein the gaps are approximately 100 to 120 microns wide.
9. The interconnect of claim 1 , wherein the first and second lateral portions lie within an outline of a generally circular ring having an inner diameter of approximately 250 to 350 μm and an outer diameter of approximately 500 to 650 μm.
10. The interconnect of claim 1 , wherein the signal line and the ground line are formed on the top side of the substrate and wherein the interconnect further comprises a further signal line and a further ground line formed on the bottom side of the substrate, wherein the further signal line extends to the inner conductor and the further ground line extends to the outer conductor.
11. A vertical microcoaxial interconnect comprising:
a dielectric substrate having a top side and a bottom side;
a rod-shaped inner conductor extending through the substrate from its top side to its bottom side, the inner conductor having a generally circular cross-section;
an outer conductor that extends through the substrate from its top side to its bottom side, the outer conductor having first and second C-shaped lateral portions whose ends are separated by opposed gaps, the lateral portions lying within an outline of a generally circular ring and concentrically encircling the inner conductor;
a first bridge that crosses one of the gaps to join two ends of the C-shaped lateral portions;
a second bridge that crosses the other gap to join two other ends of the C-shaped lateral portions;
a first signal line provided on the top side of the substrate and extending to the inner conductor without contacting the outer conductor;
first and second ground lines provided on the top side of the substrate and extending to respective lateral portions of the outer conductor without contacting the inner conductor or the signal line and not being in direct physical contact with the first and second bridges;
a second signal line provided on the bottom side of the substrate and extending to the inner conductor without contacting the outer conductor; and
third and fourth ground lines provided on the bottom side of the substrate and extending to respective lateral portions of the outer conductor without contacting the inner conductor or the signal line and not being in direct physical contact with the first and second bridges.
12. The interconnect of claim 11 , wherein the dielectric substrate is approximately 250 to 350 microns thick.
13. The interconnect of claim 11 , wherein the inner conductor has a diameter of approximately 50 to 150 microns.
14. The interconnect of claim 11 , wherein the gaps are approximately 100 to 120 microns wide.
15. The interconnect of claim 11 , wherein the outer conductor defines an inner diameter of approximately 250 to 350 μm and an outer diameter of approximately 500 to 650 μm.