Back to results
US 11,115,756 B2Granted
MEMS microphone and method of manufacturing the same
AssigneeDB HiTek Co., Ltd.
InventorsHyeok In Kwon, Jong Won Sun
Life of this patent
Estimating the term…
Abstract
A MEMS microphone includes a first dummy pad elevating a circumferential portion of an intermediate insulation layer adjacent to a second pad electrode, a second dummy pad elevating a first circumferential portion of an upper insulation layer adjacent to the second pad electrode, and a third dummy pad elevating a second circumferential portion of the upper insulation layer adjacent to the first pad electrode. Thus the first circumferential portion of the upper insulation layer is elevated relative to an upper surface of the second pad electrode, and the second circumferential portion of the upper insulation layer is elevated relative to an upper surface of the first pad electrode.
Claims14
A MEMS microphone comprising:
- a substrate presenting a vibration area, a supporting area surrounding the vibration area, and a peripheral area surrounding the supporting area, the substrate defining a cavity formed in the vibration area;
- a diaphragm being disposed over the substrate to cover the cavity, the diaphragm being spaced apart from the substrate and configured to generate a displacement thereof in response to an applied acoustic pressure;
- an upper back plate being disposed over the diaphragm in the vibration area, the upper back plate being spaced apart from the diaphragm to form an air gap between the diaphragm and the upper back plate, and the upper back plate defining a plurality of acoustic holes therein;
- a diaphragm pad disposed in the peripheral area and in electrical contact with the diaphragm;
- a back plate pad disposed in the peripheral area and in electrical contact with the back plate;
- an upper insulation layer covering the back plate and mechanically coupled to the back plate to space the back plate apart from the diaphragm;
- a lower insulation layer disposed on an upper surface of the substrate and supporting the diaphragm pad;
- an intermediate insulation layer disposed between the lower insulation layer and the upper insulation layer and supporting the back plate pad;
- a first pad electrode penetrating through the upper insulation layer and the intermediate insulation layer and disposed on the diaphragm pad;
- a second pad electrode penetrating through the upper insulation layer and disposed on the back plate pad;
- a first dummy pad interposed between the lower insulation layer and the intermediate insulation layer, wherein the first dummy pad is arranged to elevate a circumferential portion of the intermediate insulation layer adjacent to the second pad electrode relative to a another portion of the intermediate insulation layer such that a first circumferential portion of the upper insulation layer corresponding to the circumferential portion of the intermediate insulation layer, is elevated relative to an upper surface of the second pad electrode;
- a second dummy pad interposed between the intermediate insulation layer and the upper insulation layer to surround the back plate pad, wherein the second dummy pad is arranged to elevate the first circumferential portion of the upper insulation layer corresponding to the first dummy pad relative to another portion of the upper insulation layer such that the first circumferential portion of the upper insulation layer is elevated relative to the upper surface of the second pad electrode;
- and
- a third dummy pad interposed between the intermediate insulation layer and the upper insulation layer, wherein the third dummy pad is arranged to elevate a second circumferential portion of the upper insulation layer adjacent to the first pad electrode relative to another portion of the upper insulation layer such that the second circumferential portion of the upper insulation layer is elevated relative to an upper surface of the first pad electrode.
11 more elements
A method of manufacturing a MEMS microphone, comprising:
- forming a lower insulation layer on a substrate being divided into a vibration area, a supporting area surrounding the vibration area, and a peripheral area surrounding the supporting area;
- forming a diaphragm on the lower insulation layer in the vibration area, a diaphragm pad in electrical contact with the diaphragm on the lower insulation layer in the peripheral area, and a first dummy pad on the lower insulation layer in the peripheral area;
- forming an intermediate insulation layer on the lower insulation layer to cover the diaphragm, the diaphragm pad, and the first dummy pad;
- forming a back plate facing the diaphragm on the intermediate insulation layer in the vibration area, a back plate pad in electrical contact with the back plate on the intermediate insulation layer in the peripheral area, a second dummy pad on the intermediate insulation layer in the peripheral area, and a third dummy pad on the intermediate insulation layer in the peripheral area;
- forming an upper insulation layer holding the back plate to be spaced from the diaphragm on the intermediate insulation layer to cover the back plate, the back plate pad, the second dummy pad, and the third dummy pad;
- forming a first pad electrode penetrating through the upper insulation layer on the diaphragm pad and the intermediate insulation layer;
- and
- forming a second pad electrode penetrating through the upper insulation layer on the back plate pad,
- wherein the first dummy pad is arranged to elevate a circumferential portion of the intermediate insulation layer adjacent to the second pad electrode relative to a another portion of the intermediate insulation layer such that a first circumferential portion of the upper insulation layer corresponding to the circumferential portion of the intermediate insulation layer, is elevated relative to an upper surface of the second pad electrode,
- wherein the second dummy pad is arranged to elevate the first circumferential portion of the upper insulation layer corresponding to the first dummy pad relative to another portion of the upper insulation layer such that the first circumferential portion of the upper insulation layer is elevated relative to the upper surface of the second pad electrode, and
- wherein the third dummy pad is arranged to elevate a second circumferential portion of the upper insulation layer adjacent to the first pad electrode relative to another portion of the upper insulation layer such that the second circumferential portion of the upper insulation layer is elevated relative to an upper surface of the first pad electrode.
8 more elements
Dependencies are inferred from the claim text.