High power, double-sided thin film filter
A high power thin film filter is disclosed includes a substrate having a substrate thickness in a Z-direction between a first surface and a second surface. A thin film capacitor may be formed over the first surface. A thin film inductor may be spaced apart from the thin film capacitor by at least the thickness of the substrate. A via may be formed in the substrate that electrically connects the thin film capacitor and the thin film inductor. The via may include a polymeric composition.
1. A high power thin film filter comprising:
a substrate having a first surface and a second surface opposite the first surface in a Z-direction;
a thin film capacitor formed over the first surface;
a thin film inductor spaced apart from the thin film capacitor by at least the substrate in the Z-direction; and
a via formed in the substrate and electrically connecting the thin film capacitor and the thin film inductor, the via comprising a polymeric composition.
2. The filter of claim 1 , wherein the via comprises a conductive layer formed over an inner surface of the substrate, the conductive layer extending through the substrate from the first surface to the second surface of the substrate.
3. The filter of claim 1 , wherein the via has a via width in an X-Y plane that is perpendicular to the Z-direction, and the substrate has a substrate thickness in the Z-direction, and a ratio of the substrate thickness to the via width is less than about 7.
4. The filter of claim 1 , wherein a substrate thickness of the substrate in the Z-direction is greater than about 300 microns.
5. The filter of claim 1 , wherein the via width is greater than about 100 microns.
6. The filter of claim 1 , wherein the polymeric composition comprises an epoxy.
7. The filter of claim 1 , wherein the polymeric composition comprises alumina particles.
8. The filter of claim 1 , wherein the polymeric composition comprises conductive particles.
9. The filter of claim 1 , wherein the substrate comprises sapphire.
10. The filter of claim 1 , wherein the thin film inductor comprises a conductive layer having a width in an X-Y plane that is perpendicular to the Z-direction, the width of the conductive layer being greater than about 40 microns.
11. The filter of claim 1 , wherein the thin film inductor comprises a conductive layer having a thickness in the Z-direction that is greater than about 10 microns.
12. The filter of claim 1 , wherein the thin film inductor comprises a conductive layer forming a coil having a single loop diameter that is greater than about 200 microns.
13. The filter of claim 1 , further comprising a plurality of contact pads exposed along a bottom surface of the filter for mounting the filter to a mounting surface.
14. The filter of claim 1 , wherein the filter has a power capacity that is greater than about 15 W.
15. The filter of claim 1 , wherein the filter has an area power capacity that is greater than about 0.6 W/mm 2 .
16. The filter of claim 1 , wherein the filter has a length and a width, and wherein the length is greater than the width, and wherein the length is less than about 14 mm.
17. The filter of claim 1 , further comprising a dielectric layer arranged over the first surface of the substrate, the dielectric layer having a first surface and a second surface, the second surface of the dielectric layer facing the first surface of the substrate, and wherein the thin film capacitor comprises a first electrode formed over the first surface of the substrate and a second electrode formed over the first surface of the dielectric layer.
18. The filter of claim 17 , further comprising a dielectric layer arranged over the second surface of the substrate, the dielectric layer having a first surface and a second surface, the second surface of the dielectric layer facing the second surface of the substrate, and wherein the thin film inductor comprises a first conductive layer formed over the first surface of the substrate, a second conductive layer formed over the second surface of the dielectric layer, and a via connecting the first conductive layer with the second conductive layer.
19. The filter of claim 1 , wherein the thin film inductor is formed over the second surface of the substrate.
20. A high power thin film filter comprising:
a substrate having a first surface and a second surface opposite the first surface in a Z-direction; and
a thin film capacitor formed over the first surface; and
a thin film inductor spaced apart from the thin film capacitor by at least the substrate;
wherein the high power thin film filter has an area power capacity that is greater than about 0.5 W/mm 2 .
21. The filter of claim 20 , wherein the filter has a power capacity that is greater than about 15 W.
22. The filter of claim 20 , wherein the filter has an area power capacity that is greater than about 0.5 W/mm 2 .
23. A method for forming a high power thin film filter, the method comprising:
providing a substrate having a first surface and a second surface opposite the first surface in a Z-direction;
depositing a thin film capacitor over the first surface;
depositing a thin film inductor that is spaced apart from the thin film capacitor by at least the substrate; and
forming a via in the substrate electrically connecting the thin film capacitor and the thin film inductor, the via comprising a polymeric composition.