Acoustic converter and microphone

Abstract

To alleviate stress concentration during collision between the thin film and the backplate, thereby suppressing damage to both the thin film and the backplate. [Solution] The acoustic converter 100 comprises a substrate 10 having a cavity 11, a thin film 20 arranged to cover the cavity 11, and a back plate 30 facing the thin film 20 in the thickness direction of the substrate 10 and positioned on the opposite side of the substrate 10 from the thin film, with a plurality of holes 31 formed therein. The plurality of holes 31 form a plurality of rows aligned in the X direction when viewed in the Z direction. The back plate 30 has a main plate 32 with a plurality of holes 31 formed therein and facing the thin film 20, and a protruding portion 60 that protrudes from the main plate 32 toward the thin film 20. The protruding portion 60 extends in the Y direction, and the length of the protruding portion 60 in the longitudinal direction is greater than or equal to the diameter of the plurality of holes 31.

Claims

1. A substrate having a cavity, A thin film arranged to cover the cavity, The substrate comprises a back plate that faces the thin film in the thickness direction of the substrate, is positioned on the opposite side of the substrate from the thin film, and has a plurality of holes formed on it, The aforementioned plurality of holes are When viewed in the thickness direction of the substrate, a plurality of rows are formed that are aligned in the first direction, The aforementioned backplate is The aforementioned plurality of holes are formed in the main body plate facing the thin film, It has a protruding portion that extends from the main body plate toward the thin film, The aforementioned protrusion is Extending in the first direction, or in a second direction intersecting the first direction, An acoustic converter in which the length of the protrusion in the longitudinal direction is greater than or equal to the diameter of the plurality of holes.

2. The acoustic conversion device according to claim 1, wherein the plurality of protrusions are arranged apart in a direction intersecting the longitudinal direction of the protrusions.

3. The acoustic conversion device according to claim 1 or 2, wherein the plurality of holes are arranged in a grid pattern when viewed in the thickness direction of the substrate.

4. The aforementioned protrusion is A first projection extending in the first direction, The acoustic conversion device according to claim 1 or 2, further comprising a second projection extending in the second direction.

5. The end of the second projection is connected to the end of the first projection, The sound conversion device according to claim 4, wherein the protruding portion is formed in a spiral shape when viewed in the thickness direction of the substrate.

6. The end of the second projection is connected to the end of the first projection, The acoustic conversion device according to claim 4, wherein the protruding portion is formed to form a polygon when viewed in the thickness direction of the substrate.

7. The sound conversion device described in claim 1 or 2, A microphone comprising a circuit section that outputs the signal output from the aforementioned sound converter to the outside.

8. A housing having an opening and housing the sound conversion device, The enclosure further comprises a bottom plate that closes the opening of the enclosure, The housing or the bottom plate has through holes that penetrate in the thickness direction of the substrate and communicate with the cavity. Inside the aforementioned housing, The first space is the space between the thin film and the housing or the bottom plate in which the through hole is formed, The microphone according to claim 7, wherein a second space is formed between the thin film and the housing or bottom plate in which the through hole is not formed.

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