Micro electro-mechanical system sensor
Provided is a micro electro-mechanical system (MEMS) sensor including a substrate including a first cavity, a first frame including a second cavity at least partially overlapping the first cavity, at least a portion of the first frame being spaced apart from the substrate, a plurality of resonators, each of the plurality of resonators including a first end connected to the first frame and a second end extending into the second cavity, and a second frame including a first region connected to the first frame and a second region spaced apart from the first frame and connected to the substrate.
1 . A micro electro-mechanical system (MEMS) sensor comprising:
a substrate including a first cavity;
a first frame including a second cavity at least partially overlapping the first cavity in a first direction, at least a portion of the first frame being spaced apart from the substrate;
a plurality of resonators, each of the plurality of resonators comprising a first end connected to the first frame and a second end extending into the second cavity; and
a second frame comprising a first region connected to the first frame and a second region spaced apart from the first frame in a second direction perpendicular to the first direction and a third direction perpendicular to the first direction and the second direction, the second frame being connected to the substrate,
wherein a width of the first region in the third direction is greater than or equal to a width, in the third direction, of a portion of the second region and a width, in the second direction, of a remaining portion of the second region.
2 . The MEMS sensor of claim 1 , wherein the second frame is provided adjacent to an outer circumferential surface of the first frame.
3 . The MEMS sensor of claim 1 , wherein the first frame and the second frame have a monolithic structure.
4 . The MEMS sensor of claim 1 , wherein the first frame and the second frame comprise silicon.
5 . The MEMS sensor of claim 1 , wherein the first region extends in the second direction and the portion of the second region extends in the second direction and the remaining portion of the second region extends in the third direction, and
wherein a length, in the second direction, of the first region is less than a length, in the second direction, of the portion of the second region and a length, in the third direction, of the remaining portion of the second region.
6 . The MEMS sensor of claim 1 , wherein the width, in the third direction, of the first region is equal to a sum of the width, in the third direction, of the second region and a gap between the second region and the first frame in the third direction.
7 . The MEMS sensor of claim 1 , wherein a gap between the second region of the second frame and the first frame in the third direction is constant.
8 . The MEMS sensor of claim 1 , wherein, based on the second frame having a rectangular shape, a gap between the second region of the second frame and the first frame is greater than or equal to a value d1 and less than or equal to 4 times of the value d1, where d1 satisfies:
d
1
=
L
2
2
*
L
1
2
6
*
E
peri
*
(
L
2
2
*
I
1
,
x
+
L
1
2
*
I
2
,
x
)
S
+
L
2
3
*
L
1
3
12
*
E
peri
*
(
L
2
3
*
I
1
,
x
+
L
1
3
*
I
2
,
x
)
F
I
i
,
x
=
w
i
3
t
peri
12
,
i
=
1
,
2
where, F is a force applied to the second frame in the first direction, S is shear stress of the second frame, L i (where i=1 or 2) is a length of the first direction side of the second frame, I i , x (where i=1 or 2) is a moment of inertia of the second frame, E peri is a strength of the second frame, and W i (where i=1 or 2) is a width of the second frame.
9 . The MEMS sensor of claim 1 , wherein a partial region of the second frame is connected to the substrate.
10 . The MEMS sensor of claim 9 , wherein the second region of the second frame is connected to the substrate.
11 . The MEMS sensor of claim 1 , wherein the first region of the second frame is a partial region of the first frame.
12 . The MEMS sensor of claim 1 , wherein a ratio of a length of the second frame to a width of the second frame is greater than or equal to 8 and less than or equal to 200.
13 . The MEMS sensor of claim 1 , wherein a ratio of a length of the second frame to a thickness of the second frame is 1.2 to 15.
14 . The MEMS sensor of claim 1 , wherein a thickness of the second frame is greater than a thickness of the first frame.
15 . The MEMS sensor of claim 1 , wherein a shape of an outer circumferential surface of the second frame is one of a polygon, a circle, and an oval.
16 . The MEMS sensor of claim 1 , wherein a shape of an inner circumferential surface of the second frame is different from the shape of an outer circumferential surface of the second frame.
17 . The MEMS sensor of claim 1 , wherein the substrate comprises a printed circuit board configured to receive electrical signals from the plurality of resonators.
18 . The MEMS sensor of claim 1 , further comprising a cover configured to protect the plurality of resonators from the outside.
19 . The MEMS sensor of claim 18 , wherein an end of the cover is connected to the substrate.
20 . The MEMS sensor of claim 18 , further comprising a spacer that comprises a first end in contact with the cover and a second end in contact with the second frame,
wherein the cover is connected to the second frame through the spacer.
21 . The MEMS sensor of claim 1 , wherein the plurality of resonators comprise:
a first group of resonators fixed to a first side of the first frame; and
a second group of resonators fixed to a second side of the first frame opposite to the first side.
22 . A micro electro-mechanical system (MEMS) sensor comprising:
a substrate including a first cavity;
a first frame including a second cavity at least partially overlapping the first cavity in a first direction, at least a portion of the first frame being spaced apart from the substrate;
a plurality of resonators, each of the plurality of resonators comprising a first end connected to the first frame and a second end extending into the second cavity; and
a second frame provided adjacent to the first frame, the second frame comprising:
a first region connected to the first frame and partially spaced apart from the substrate; and
a second region spaced apart from the first frame in a second direction perpendicular to the first direction and a third direction perpendicular to the first direction and the second direction, the second frame being connected to the substrate,
wherein a width of the first region in the third direction is greater than or equal to a width, in the third direction, of a portion of the second region and a width, in the second direction, of a a remaining portion of the second region.