Vibration device, speaker unit, and method for manufacturing vibration device
A vibration device includes a substrate, a first drive source, a second drive source, and a membrane. The membrane includes a main portion extending in an in-plane direction, and a damper protruding in a direction perpendicular to a plane of the membrane. The main portion includes a first region disposed on the first drive source, a second region disposed on the second drive source, and a third region disposed between the first region and the second region. The damper includes a first portion connecting the first region and the third region, and a second portion connecting the second region and the third region.
1 . A vibration device comprising:
a substrate;
a first drive source disposed on the substrate and configured to vibrate the substrate;
a second drive source disposed on the substrate and being away from the first drive source on the substrate, the second drive source being configured to vibrate the substrate; and
a membrane disposed on the first drive source and the second drive source and extending from the first drive source toward the second drive source, the membrane including
a main portion extending in an in-plane direction, and
a damper protruding in a direction perpendicular to a plane of the membrane,
wherein the main portion includes
a first region disposed on the first drive source,
a second region disposed on the second drive source, and
a third region disposed between the first region and the second region, and
wherein the damper includes
a first portion connecting the first region and the third region, and
a second portion connecting the second region and the third region.
2 . The vibration device according to claim 1 , wherein each of the first portion and second portion includes a first end and a second end,
wherein the damper includes
a third portion connecting the first portion and the second portion at respective first ends, and
a fourth portion connecting the first portion and the second portion at respective second ends, and
wherein the damper has a closed shape in which the first portion, the second portion, the third portion, and the fourth portion are joined end to end.
3 . The vibration device according to claim 2 , wherein the substrate includes a frame and an opening formed inside the frame, and
wherein the closed shape of the damper is defined along an edge of the opening.
4 . The vibration device according to claim 1 , wherein the damper has a parabolic cross-sectional shape that protrudes in the direction perpendicular to the plane.
5 . A speaker unit comprising:
a vibration device including
a substrate,
a first drive source disposed on the substrate and configured to vibrate the substrate,
a second drive source disposed on the substrate and being away from the first drive source on the substrate, the second drive source being configured to vibrate the substrate, and
a membrane disposed on the first drive source and the second drive source and extending from the first drive source toward the second drive source, the membrane including
a main portion extending in an in-plane direction, and
a damper protruding in a direction perpendicular to a plane of the membrane,
wherein the main portion includes
a first region disposed on the first drive source,
a second region disposed on the second drive source, and
a third region disposed between the first region and the second region, and
wherein the damper includes
a first portion connecting the first region and the third region, and
a second portion connecting the second region and the third region.
6 . A method for manufacturing a vibration device, the method comprising:
forming a first drive source and a second drive source at spaced apart positions on a substrate;
forming a photoresist film on the substrate, the first drive source, and the second drive source;
exposing the photoresist film under a condition in which a photomask is disposed at a predetermined distance from the photoresist film, and forming a photosensitive portion, a first non-photosensitive portion, and a second non-photosensitive portion in the photoresist film, each of the first non-photosensitive portion and the second non-photosensitive portion having a protruding shape;
removing the photosensitive portion of the photoresist film;
forming a membrane in a region including the first non-photosensitive portion and the second non-photosensitive portion, the region being exposed by removing the photosensitive portion, and forming a damper that protrudes to correspond to protruding shapes of the first non-photosensitive portion and the second non-photosensitive portion; and
removing the first non-photosensitive portion and the second non-photosensitive portion.
7 . The method for manufacturing a vibration device according to claim 6 , further comprising:
heating the first non-photosensitive portion and the second non-photosensitive portion, after removing the photosensitive portion.