Miniature microphone of FBAR structure on diaphragm

A microphone and diaphragm technology, applied in electrostatic transducer microphones and other directions, can solve the problems of piezoelectric materials being easily affected by external temperature and measurement errors, and achieve improved temperature stability, high operating frequency, and good manufacturability. Effect

CN104837099AInactive Publication Date: 2015-08-12INST OF ELECTRONICS ENG CHINA ACAD OF ENG PHYSICS
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2015-08-12
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a miniature microphone of a FBAR structure on a diaphragm. The miniature microphone comprises a substrate, a detection element, and a composite elastic supporting layer. The substrate is disposed on the lower part of the composite elastic supporting layer, the detection element is disposed on the upper part of the composite elastic supporting layer, and the composite elastic supporting layer is used to support the detection element. The substrate comprises a Si substrate and a cavity. The Si substrate is in the shape of a cuboid, and the middle part of the Si substrate is provided with a trumpet-shaped through hole. The smaller end of the aperture of the through hole is disposed on the upper surface of the Si substrate, and the upper surface of the Si substrate is tightly attached to the lower surface of the composite elastic supporting layer, and the cavity can be formed between the through hole and the composite elastic supporting layer. The part of the composite elastic supporting layer corresponding to the top surface of the cavity is the elastic diaphragm, which is used to form the vibration diaphragm, and the top surface and the side surface of the cavity can be used to form the acoustic wave reflection interfaces. The detection element comprises a FBAR, a lead, and a pad, and the FBAR is connected with the pad by the lead. The miniature microphone is advantageous in that the manufacturability is good, the temperature stability is high, the intermodal cross coupling is small, and the mechanical strength is high.
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Description

technical field

[0001] The invention belongs to the field of micro-electro-mechanical system devices, and in particular relates to a micro-microphone with an FBAR (film bulk acoustic-wave resonators) structure on a diaphragm. The micro-microphone with this structure has high rigidity, small cross-coupling, High sensitivity and good linearity. technical background

[0002] The micro-microphone is one of the most important MEMS sensors. At present, it mainly uses electret, capacitor, piezoelectric and other detection principles. The meter outputs a weak analog signal, which is easily affected by factors such as ambient temperature and parasitic capacitance, which is easy to cause the device to be reliable. Issues such as performance and stability.

[0003] Thin-film bulk acoustic wave resonators (FBAR, thin-film bulk acoustic wave resonators) are a new type of miniature electroacoustic resonator, which has the characteristics of high sensitivity, high operating frequency and ...

Examples

Embodiment Construction

[0031] The present invention is described in detail below in conjunction with accompanying drawing:

[0032] like Figure 1(a)-1(d) and figure 2 Shown are respectively the top view structure schematic diagram and the side view structure schematic diagram in the present invention.

[0033] The micro microphone of the FBAR structure on the diaphragm comprises a base, a detection element 2 and a composite elastic support layer 14, the base is located below the composite elastic support layer 14, and the detection element 2 is located above the composite elastic support layer 14, and the composite elastic support layer 14 is used for Support the detection element 2; the base includes a Si base 3 and a cavity 5, the shape of the Si base 3 is a cuboid, and a trumpet-shaped through hole is arranged in the middle of the Si base 3, and the end of the through hole with a smaller diameter is located on the Si base 3, the upper surface of the Si base 3 is close to the lower surface of ...