Semiconductor devices with back-side coils for wireless signal and power coupling
A semiconductor device includes a substrate, a plurality of circuit elements on a front side of the substrate, and a first substantially spiral-shaped conductor on a back side of the substrate is provided. The device further includes a first through-substrate via (TSV) electrically connecting a first end of the substantially spiral-shaped conductor to a first one of the plurality of circuit elements, and a second TSV electrically connecting a second end of the substantially spiral-shaped conductor to a second one of the plurality of circuit elements. The device may be a package further including a second die having a front side on which is disposed a second substantially spiral-shaped conductor. The front side of the second die is disposed facing the back side of the substrate, such that the first and second substantially spiral-shaped conductors are configured to wirelessly communicate.
1. A semiconductor device, comprising:
a silicon substrate;
a first insulating layer on a front side of the silicon substrate;
a second insulating layer on a back side of the silicon substrate;
a plurality of circuit elements in the first insulating layer on the front side of the silicon substrate;
a first substantially spiral-shaped conductor in the second insulating layer on the back side of the silicon substrate;
a first through-substrate via (TSV) extending through the silicon substrate between the first insulating layer and the second insulating layer and electrically connecting a first end of the substantially spiral-shaped conductor to a first one of the plurality of circuit elements;
a second TSV extending through the silicon substrate between the first insulating layer and the second insulating layer electrically connecting a second end of the substantially spiral-shaped conductor to a second one of the plurality of circuit elements; and
a second substantially spiral-shaped conductor in the first insulating layer on the front side of the silicon substrate, coaxially aligned with the first substantially spiral-shaped conductor, and electrically connected to the first substantially spiral-shaped conductor by the first and second TSVs.
2. The semiconductor device of claim 1 , wherein the first substantially spiral-shaped conductor is configured to be wirelessly coupled to another substantially spiral-shaped conductor in another semiconductor device.
3. The semiconductor device of claim 1 , wherein the first TSV is coaxially aligned with the first and second substantially spiral-shaped conductors.
4. The semiconductor device of claim 1 , wherein the first TSV and the second TSV are disposed proximate to but not coaxially aligned with the first substantially spiral-shaped conductor.
5. The semiconductor device of claim 1 , wherein the first insulating layer covers the first substantially spiral-shaped conductor.
6. The semiconductor device of claim 1 , wherein the silicon substrate is between about 10 and 100 μm thick.
7. The semiconductor device of claim 1 , wherein each of the first and second TSV is between about 2 and 50 μm in diameter.
8. The semiconductor device of claim 1 , wherein the first and second substantially spiral-shaped conductors each spans an area of between about 80 and 600 μm across.