Temperature compensation for silicon MEMS resonator
AssigneeRobert Bosch GmbH
InventorsMarkus Lutz, Aaron Partridge
Life of this patent
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Abstract
Thermally induced frequency variations in a micromechanical resonator are actively or passively mitigated by application of a compensating stiffness, or a compressive/tensile strain. Various composition materials may be selected according to their thermal expansion coefficient and used to form resonator components on a substrate. When exposed to temperature variations, the relative expansion of these composition materials creates a compensating stiffness, or a compressive/tensile strain.
Claims24
1-31. (canceled)
A microelectromechanical resonator, comprising:
- a substrate;
- an oscillating beam formed from a plurality of materials, wherein the oscillating beam includes:
- (i) an inner-core comprising a first material having a first coefficient of thermal expansion, and
- (ii) an outer-layer, disposed around the inner-core, comprising a second material having a second coefficient of thermal expansion, wherein the second thermal expansion coefficient is different from the first thermal expansion coefficient;
- and
- an anchor, disposed on the substrate and coupled to the oscillating beam, to, at least in part, support the oscillating beam above the substrate.
A microelectromechanical resonator, comprising:
- a substrate;
- an oscillating beam formed from a plurality of materials, wherein the oscillating beam includes:
- (i) a first inner-core comprising a first material having a first coefficient of thermal expansion,
- (ii) a second inner-core, disposed on and around the first inner-core, comprising a second material having a second coefficient of thermal expansion, and
- (iii) an outer-layer, disposed on and around the second inner-core, comprising a third material having a third coefficient of thermal expansion, wherein at least two of the first, second and third thermal expansion coefficients are different;
- and
- an anchor, disposed on the substrate and coupled to the oscillating beam, to, at least in part, support the oscillating beam above the substrate.
A micromechanical resonator, comprising:
- a substrate;
- an oscillating beam formed from a plurality of materials which, in combination, provide a first thermal expansion coefficient, wherein the oscillating beam includes:
- (i) a first inner-core comprising a first material having a first coefficient of thermal expansion, and
- (ii) an outer-layer, disposed around the inner-core, comprising a second material having a second coefficient of thermal expansion, wherein the second thermal expansion coefficient is different from the first thermal expansion coefficient;
- and
- an anchor, disposed on the substrate and coupled to the oscillating beam, to, at least in part, support the oscillating beam above the substrate, wherein the anchor is formed from at least one material which provides a thermal expansion coefficient which is different from the second thermal expansion coefficient.
Dependencies are inferred from the claim text.