Electro ceramic components
View Patent ↗An array apparatus has a micromachined SOI structure, such as a MEMS array, mounted directly on a class of insulative substrate, such as low temperature co-fired ceramic or a thermal-coefficient of expansion matched glass, in which is embedded electrostatic electrodes disposed in alignment with the individual MEMS elements, where the electrostatic electrodes are configured for substantial fanout. In a specific embodiment in order to compensate for differences in thermal-expansion characteristics between SOI and ceramic, a flexible mounting is effected by means of posts, bridges and/or mechanical elements which allow uneven expansion in x and y while maintaining z-axis stability. Methods according to the invention include fabrication steps wherein electrodes are fabricated to a post-fired ceramic substrate and coupled via traces through the ceramic substrate to driver modules.
1. An array apparatus comprising:
a micromachined structure having a plurality of actuatable elements;
an insulative substrate; and
electrostatic electrodes embedded in said insulative substrate and disposed in alignment with individual ones of said actuatable elements on a reverse side of said insulative substrate, said electrostatic electrodes coupled via traces through said insulative substrate.
2. The apparatus of claim 1 further having a driver module mounted to a reverse side of said insulative substrate and said micromachined structure being mounted directly on an obverse side of the insulative substrate.
3. An array apparatus comprising:
a micromachined structure having a plurality of actuatable elements;
an insulative substrate; and
electrostatic electrodes embedded in said insulative substrate and disposed in alignment with individual ones of said actuatable elements on a reverse side of said insulative substrate, said micromachined structure and said insulative substrate having mismatched thermal-expansion characteristics, further including a flexible mounting and bias means which allow uneven expansion in x and y while maintaining z-axis stability.
4. The apparatus according to claim 3 wherein said micromachined structure is a silicon on insulator (SOI) and said insulative structure is a low-temperature co-fired ceramic (LTCC).
5. The apparatus according to claim 4 wherein said LTCC comprises a plurality of ceramic layers with electrical resistors buried between said layers and further including a driver module mounted on an obverse side of said insulative substrate and a heat extraction means juxtaposed to said driver module for drawing heat away from said insulative substrate.
6. The apparatus according to claim 3 wherein said flexible mounting and bias means further include bridge means between posts, said bridge means slidably confronting a reverse side of the micromachined structure.
7. The apparatus according to claim 3 wherein said insulative structure is a glass.
8. The apparatus according to claim 3 wherein current-limiting resistances are imbedded in the insulative structure in circuit paths between said electrodes and said driver module.
9. The apparatus according to claim 3 wherein the flexible mounting and bias means comprise posts of metal pins mounted to the insulative layer and each has a fixed cap confronting an reverse restraining surface of said micromachined structure, and a elastomeric element between juxtaposed obverse surfaces of said micromachined structure and said insulative structure.
10. The apparatus according to claim 3 wherein said micromachined structure is a MEMS array.
11. An array apparatus comprising:
a micromachined structure having a plurality of actuatable elements;
an insulative substrate; and
electrostatic electrodes embedded in said insulative substrate and disposed in alignment with individual ones of said actuatable elements on a reverse side of said insulative substrate, said electrostatic electrodes coupled via traces through said insulative substrate, further including a flexible mounting and bias means which allow uneven expansion in x and y while maintaining z-axis stability.
12. The apparatus of claim 1 further having a driver module mounted to a reverse side of said insulative substrate and said micromachined structure being mounted directly on an obverse side of the insulative substrate.