CN111711901B

CN111711901B - MEMS sensor chip

Info

Publication number: CN111711901B
Application number: CN202010839498.6A
Authority: CN
Inventors: 何宪龙; 詹竣凯; 罗松成; 李承勲
Original assignee: Gettop Acoustic Co Ltd
Current assignee: Gettop Acoustic Co Ltd
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2020-12-22
Anticipated expiration: 2040-08-19
Also published as: CN111711901A

Abstract

The invention provides an MEMS sensor chip, which comprises a substrate, a back plate and a diaphragm, wherein the back plate and the diaphragm are arranged on the substrate, the diaphragm is fixed on one side of the substrate, the back plate covers one side of the diaphragm, which is far away from the substrate, the diaphragm comprises a sensing part and a peripheral part, which surrounds the periphery of the sensing part, a plurality of slots are arranged between the peripheral part and the sensing part, an isolating part is arranged inside the slot, which is close to the sensing part, and the isolating part protrudes from the diaphragm towards the substrate or protrudes from the substrate towards the diaphragm so as to increase the damping of vibration passing through the slots.

Description

MEMS sensor chip

Technical Field

The invention relates to the technical field of Micro-Electro-Mechanical systems (MEMS), in particular to a MEMS sensor chip.

Background

As a typical MEMS sensor, a MEMS microphone is an energy converter that converts an acoustic signal into an electrical signal, and in recent years, with the rapid development of portable electronic devices, the MEMS microphone has been widely used in the portable electronic devices.

The main technical indexes of the MEMS microphone include sensitivity, frequency response, directivity characteristics, output impedance, dynamic range, signal-to-noise ratio, etc., wherein the frequency response is an important index reflecting frequency distortion in the process of sound-to-electricity conversion of the MEMS microphone. The frequency response is that when the MEMS microphone receives sounds of different frequencies, the output signal is amplified or attenuated with the change of the frequency. The optimal frequency response curve is a horizontal line representing the characteristics of the output signal that truly represents the original sound, but this ideal situation is difficult to achieve. When the output frequency of the MEMS microphone is lower than a certain frequency, i.e. a low frequency, the frequency response curve is significantly reduced, which may affect the acoustoelectric conversion performance of the microphone, as shown in fig. 1.

In order to timely release pressure and improve mechanical sensitivity of an existing MEMS diaphragm, a plurality of through hole-groove structures are designed on the diaphragm. The low-frequency drop of the frequency response curve is mainly caused by an open area, namely a hole groove structure, formed on the MEMS diaphragm, and the more the open area is, the larger the amplitude of the low-frequency drop of the frequency response curve is. Therefore, how to improve the low frequency drop of the frequency response curve of the MEMS microphone is one of the research directions of those skilled in the art.

Disclosure of Invention

In view of this, the present invention provides an MEMS sensor chip capable of effectively improving the low frequency sag of the frequency response curve.

In an embodiment, the isolation extends from the membrane to a surface of the substrate facing the membrane or from the substrate to a surface of the membrane facing away from the substrate.

In one embodiment, the substrate has a back chamber, the diaphragm covers the back chamber, and the isolation portion is disposed on the sensing portion and offset from the corresponding slot of the back chamber.

In one embodiment, the outer edge of the partition is evenly spaced from the inner edge of the slot.

In one embodiment, the open groove includes a plurality of outer grooves and a plurality of inner grooves, the plurality of outer grooves are arranged at the inner edge of the peripheral portion, the plurality of inner grooves are arranged at the outer edge of the sensing portion, a first connecting arm is formed between two adjacent outer grooves, a second connecting arm is formed between two adjacent inner grooves, an annular connecting arm is formed between the plurality of outer grooves and the plurality of inner grooves, the annular connecting arm is connected with the peripheral portion through the first connecting arm, and is connected with the sensing portion through the second connecting arm.

In one embodiment, at least one of the first connecting arm and the second connecting arm is provided with a rib structure which is convexly arranged on one side of the first connecting arm and/or the second connecting arm facing the substrate to block the vibration from passing through the inner groove or the outer groove.

In one embodiment, each of the inner grooves forms an inner concave section corresponding to the first connecting arm, and the reinforcing rib structure is located inside the corresponding inner concave section.

In one embodiment, each of the inner slots has a plurality of segments connected in series, at least one segment is located on a different circumference from the rest of the segments, each of the partitions forms a plurality of partitions corresponding to each of the segments, and each of the partitions is correspondingly disposed in a segment of one of the inner slots.

The invention also provides an MEMS sensor chip, which comprises a substrate, a back plate and a diaphragm, wherein the back plate and the diaphragm are arranged on the substrate, the substrate is provided with a back chamber, the diaphragm is fixed on one side of the substrate and covers the back chamber, the back plate covers one side of the diaphragm, which is far away from the substrate, an air gap is formed between the back plate and the diaphragm, the diaphragm comprises a sensing part and a peripheral part, which surrounds the periphery of the sensing part, a plurality of open grooves are formed between the peripheral part and the sensing part, a plurality of closed-loop isolation grooves are formed between the sensing part and the open grooves, the part in the isolation grooves extends towards the substrate direction to form an isolation part, and the isolation part is used for preventing the vibration entering the air gap from entering the back chamber from the open grooves or preventing the vibration entering the back chamber from entering the air gap from the open grooves.

In one embodiment, the plurality of slots include a plurality of outer slots and a plurality of inner slots, the plurality of inner slots are annularly arranged at the outer edge of the sensing part, and the isolation slots are located inside the inner slots and form uniform intervals with the inner slots.

In summary, the present invention provides a MEMS sensor chip, wherein a plurality of spacers are provided on one side of the diaphragm facing the substrate or one side of the substrate facing the diaphragm, for example, the spacers may be provided between the sensing portion and the inner tank, for example, inside the spacer, between the outer tank and the inner tank, or inside the inner tank, or both between the sensing portion and the inner tank and between the outer tank and the inner tank, or both between the sensing portion and the inner tank and inside the inner tank, or both between the outer tank and the inner tank and inside the inner tank. The isolator may be adjacent to or attached to the substrate to block low frequency sag in the frequency response curve caused by vibration leaking from the diaphragm inner and/or outer slots into the back chamber or from the diaphragm inner and/or outer slots into the air gap.

Furthermore, a reinforcing rib structure is arranged on one side face, facing the substrate, of the diaphragm, and the reinforcing rib structure can reduce the cross-sectional area of a leakage channel formed by a gap between the diaphragm and the substrate, so that the damping effect is further increased, and the low-frequency effect is improved.

Drawings

Fig. 1 is a schematic diagram showing a change of a low-frequency drop of a frequency response curve of a MEMS sensor chip.

Fig. 2 is a cross-sectional view of a MEMS sensor chip of the present invention.

FIG. 3 is a schematic structural diagram of a MEMS diaphragm of the present invention in one embodiment.

FIG. 4 is a schematic structural diagram of a MEMS diaphragm of the present invention in another embodiment.

Fig. 5 is an enlarged schematic view of the arrowed bead structures of fig. 3.

Fig. 6 is an enlarged view of a portion of the fishbone rib structure of fig. 3.

Fig. 7 is an enlarged view of a portion of the fishbone rib structure of fig. 4.

Detailed Description

Before the embodiments are described in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in other forms of implementation. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," "having," and the like, herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. In particular, when "a certain element" is described, the present invention is not limited to the number of the element being one, and may include a plurality of the elements.

The MEMS sensor chip of the invention can be applied to a micro-electromechanical device, such as a micro-electromechanical microphone. Fig. 2 is a cross-sectional view of a MEMS sensor chip of the present invention. The MEMS sensor chip comprises a back plate 10, a membrane 12 and a substrate 14, wherein the back plate 10 and the membrane 12 are installed on the substrate 14. The membrane 12 is, for example, a MEMS membrane, the substrate 14 is, for example, a silicon substrate 14, and the silicon substrate 14 has a back chamber 16. The diaphragm 12 is fixed on one side of the substrate 14 and covers the back chamber 16, for example, the diaphragm 12 is fixed on one side of the silicon substrate 14 through a fixing support point, the back plate 10 covers one side of the diaphragm 12 far away from the silicon substrate 14 and forms an air gap 13 between the back plate 10 and the diaphragm 12, for example, the bottom of the outer edge of the back plate 10 is connected and fixed to the top edges of the silicon substrate 14 and the diaphragm 12 through a connecting column 18a and a connecting column 18b respectively, the diaphragm 12 is supported and fixed above the silicon substrate 14 through a fixing column 20, and electrodes are arranged on the diaphragm 12 and the back plate 10 so as to form a capacitor between the two.

More specifically, the back chamber 16 is formed in a central position of the silicon substrate 14, and is formed by, for example, etching through the silicon substrate 14. On the back plate 10, a plurality of sound holes 22 for passing signals, such as sound vibration/sound wave, are formed in a manner of penetrating from the upper surface to the lower surface, as shown in fig. 2, the sound holes 22 are uniformly arranged in the middle area of the back plate 10 at intervals, and the back chamber 16 faces the center of the back plate 10. The diaphragm 12 includes a sensing portion 24 and a peripheral portion 26 surrounding the periphery of the sensing portion 24, and the back chamber 16 faces a central location of the sensing portion 24. The sensing portion 24 is used for sensing external pressure, for example, sensing sound pressure, when the micro-electromechanical microphone is applied, the sensing portion 24 moves relative to the back plate 10 when being subjected to the sound pressure, so that the capacitance between the sensing portion 24 and the back plate 10 changes, and a corresponding electrical signal is generated.

The connection column 18a is connected between the bottom surface of the back plate 10 and the top surface of the silicon substrate 14, the connection column 18b is connected between the bottom surface of the back plate 10 and the top surface of the peripheral portion 26, the fixing column 20 is connected between the bottom surface of the peripheral portion 26 and the top surface of the silicon substrate 14 for supporting and fixing the peripheral portion 26, and the peripheral portion 26 is used for connecting and supporting the sensing portion 24. The acoustic vibration acts on the sensing part 24 through the acoustic hole 22 so that the sensing part 24 moves relative to the back plate 10, the capacitance between the back plate 10 and the diaphragm 12 changes, and the acoustic vibration is converted into an electrical signal through the capacitance change.

A plurality of slots are disposed between the peripheral portion 26 and the sensing portion 24, and in this embodiment, the plurality of slots include a plurality of outer slots 32 and a plurality of inner slots 34. The slots and the gap formed between the diaphragm 12 and the silicon substrate 14 together form a leakage path through which part of the acoustic vibrations enter the back chamber 16, causing loss of the acoustic signal. Particularly, when the sound frequency is low, the generated sound pressure is low, the acting force of the diaphragm 12 receiving the sound pressure impact is low, the sound sensing sensitivity is low, and due to the design of the groove in the diaphragm 12, part of the sound pressure can leak from the groove, so that the frequency response curve drops at low frequency, and the low-frequency sound is distorted. To solve this problem, in the present invention, the spacers 28 are provided between the sensing part 24 and the inner grooves 34 and/or between the outer grooves 32 and the inner grooves 34, and the spacers 28 may be provided in plurality for blocking vibration from entering the back chamber 16 through the outer grooves 32 and/or the inner grooves 34 or entering the air gap 13 through the outer grooves 32 and/or the inner grooves 34. It should be noted that there are two sources of vibration, one is from the back chamber 16 to the diaphragm 12, and the vibration exits the back chamber 16 through the slot of the diaphragm 12 to the air gap 13 and then through the back plate 10; the other is from the back plate 10 to the diaphragm 12, and the vibration passes through the back plate 10 to the air gap 13 and enters the back chamber 16 through the slot of the diaphragm 12. Whether the vibration propagates from the back chamber 16 towards the diaphragm 12 or from the backplate 10 towards the diaphragm 12, it must pass through the slots and the leakage path formed between the diaphragm 12 and the silicon substrate 14. The present invention can effectively block the leakage path or reduce the cross-sectional area of the leakage path by providing the isolation part 28 in the leakage path, that is, increase the damping of the leakage of the vibration from the inner groove 34 and the outer groove 32, and has the effect of preventing the leakage of the sound pressure. Here, the vibration refers to a vibration wave formed by the air being subjected to sound pressure or other pressure.

From another perspective, the isolation portion 28, the diaphragm 12, the silicon substrate 14 and the fixing posts 20 together enclose a sealed chamber, and the outer slots 32 and the inner slots 34 are communicated with the sealed chamber. When the sound vibration propagates from the back plate 10 to the diaphragm 12, the sound vibration entering the sealed chamber from the outer grooves 32 and the inner grooves 34 increases the pressure in the sealed chamber, so that the sound vibration is difficult to enter the sealed chamber and directly acts on the sensing portion 24 of the diaphragm 12, thereby greatly improving the low-frequency drop of the frequency response curve. When the acoustic vibrations propagate from the back chamber 16 in the direction of the diaphragm 12, no or only a very small amount of acoustic vibrations enter the closed chamber and leak out of the plurality of slots due to the blocking action of the partition 28 blocking the acoustic vibrations from entering the closed chamber.

In some embodiments, not shown, a spacer may also be provided inside the slot proximate to the sensing portion 24, such as inside the inner groove 34, which may protrude from the diaphragm 12 toward the silicon substrate 14 or from the silicon substrate 14 toward the diaphragm 12 for increasing damping of vibrations through the slot. The isolation may extend from the membrane 12 to a surface of the silicon substrate 14 facing the membrane 12, or from the silicon substrate 14 to a surface of the membrane 12 facing away from the silicon substrate 14. The spacer may be disposed on the sensing portion 24 offset from a corresponding slot in the back chamber 16, i.e., within the inner groove 34.

The present invention will be described below by way of example in which the spacer 28 is provided between the sensor 24 and the plurality of inner grooves 34.

In the illustrated embodiment, the sensing portion 24 is provided with a plurality of closed-loop isolation grooves 30 in a region away from the back chamber 16, and a portion of the isolation grooves 30 extends vertically toward the silicon substrate 14 to form a plurality of isolation portions 28, such as isolation walls, for example. The isolation portion 28 may extend to the surface of the silicon substrate 14 facing the membrane 12, i.e. the isolation portion 28 is fixedly connected between the membrane 12 and the silicon substrate 14. On one hand, the isolation groove 30 can release pressure in time, and the mechanical sensitivity of the diaphragm 12 is improved; on the other hand, the design of surrounding the isolator 28 with the isolation groove 30 can isolate the isolator 28 from the diaphragm 12 so that the placement of the isolator 28 does not affect the sound pressure sensing motion of the sensing portion 24 of the diaphragm 12.

A plurality of isolation slots 30 are arranged in a ring at the outer edge of the sensing portion 24. Specifically, referring to fig. 3 and 4, the outer slots 32 are annular and spaced apart from each other at the inner edge of the peripheral portion 26, the outer slots 32 together define an outer circle, the inner slots 34 are annular and spaced apart from each other at the outer edge of the sensing portion 24, and the inner slots 34 together define an inner circle. In the illustrated embodiment, the outer and inner circles are concentric, the sensing portion 24 is circular, and the peripheral portion 26 is also circular. In other embodiments, the diaphragm 12 may take on other shapes. Annular connecting arms 36 are formed between the outer slots 32 and the inner slots 34, the peripheral portion 26 is connected to the sensing portion 24 by the annular connecting arms 36, and the annular connecting arms 36 separate the peripheral portion 26 from the sensing portion 24. The width of the annular connecting arm 36 can be determined according to actual design requirements, and the outer groove 32 and the inner groove 34 can disperse stress, so that stress concentration on the membrane 12 is reduced.

The annular connecting arms 36 may have a uniform radial width or may have a varying radial width. In the embodiment shown in fig. 3, the annular connecting arms 36 have a varying radial width, for example, increasing their radial width in areas of greater stress to increase their rigidity. In the embodiment shown, the inner groove 34 is inwardly inclined near its ends to form inclined segments, i.e. the inner groove 34 comprises inclined segments in addition to circular arc segments, the radial width of the annular connecting arm 36 at the respective inclined segments being larger than the radial width at the respective circular arc segments. In the embodiment shown in fig. 4, the annular connecting arms 36 have a uniform radial width.

The number of the outer grooves 32 and the inner grooves 34 may be set to be plural according to specific design requirements and practical use conditions. The number of outer slots 32 and inner slots 34 may be the same or different. In the embodiment shown in fig. 3 and 4, the number of the two is the same, and the two are four.

It should be noted that the number of the outer slots 32 may be odd or even, and the number of the inner slots 34 may be odd or even. In this embodiment, both are even numbers. Further, the number of the outer grooves 32 is preferably six or less. Still further, four are preferable.

The four outer slots 32 are evenly spaced circumferentially, and each outer slot 32 is identical in shape and configuration. The four inner grooves 34 are evenly spaced circumferentially, and each inner groove 34 is identical in shape and configuration. The following description will be given only to the shape and structure of one outer tank 32 and one inner tank 34 of each embodiment.

The ends of the outer grooves 32 are each provided with a first bend 38, in the embodiment shown in fig. 3 the first bend 38 extends towards the inner side of the membrane 12; in the embodiment shown in fig. 4, the first bend 38 extends towards the outside of the membrane 12. The ends of the plurality of inner grooves 34 are provided with second bends 40, in the embodiment shown in fig. 3, the second bends 40 extend towards the inner side of the membrane 12; in the embodiment shown in fig. 4, the second bend 40 extends towards the inner side of the membrane 12. The first bent portion 38 and the second bent portion 40 are disposed in a mutually staggered manner in the circumferential direction of the membrane 12, and the disposition of the first bent portion 38 and the second bent portion 40 can facilitate the release of the residual stress of the membrane 12, so as to reduce the residual stress of the membrane 12.

It should be noted that the outer side and the inner side are relative to the central portion of the entire membrane 12, the outer side being a direction away from the central portion, and the inner side being a direction toward the central portion. In this embodiment, the outer slots 32 together define an outer circle, the inner slots 34 together define an inner circle, the outer circle and the inner circle are concentric, and the peripheral portion 26 and the sensing portion 24 are both circular, so that the center of the circle is also the center of the peripheral portion 26 and the sensing portion 24, or the center of the circle of the diaphragm 12, and the centers of the circles are the same. The center of the diaphragm 12 can also be understood as the center of the circle.

Preferably, the first and second

bent portions

38, 40 may comprise a curved segment, a straight segment, or a combination of a curved segment and a straight segment. That is, the ends of the outer groove 32 and the inner groove 34 may extend inward in a curved shape, may extend inward in a linear shape, may extend inward in a curved shape first and then in a linear shape, or may extend inward in a linear shape first and then in a curved shape. In the illustrated embodiment, each outer slot 32 is provided with a first bend 38 at each end. To further reduce stress concentration, the end of the first bent portion 38 may be a circular arc-shaped end. The second bent portion 40 is formed at both ends of each inner groove 34. In order to reduce the stress concentration, the end of the second bent portion 40 may be a circular arc-shaped end.

In some embodiments, as shown in fig. 3, the first bending portion 38 at the end of the outer slot 32 extends toward the inner side, and the first bending portion 38 is a combination of an arc-shaped segment and a straight-line segment, i.e., the first bending portion 38 is first curved and rounded and then extends linearly toward the inner side. The second bent portion 40 at the end of the inner groove 34 extends towards the inner side, and the second bent portion 40 is also a combination of an arc section and a straight section, i.e. the second bent portion 40 is first curved and smoothly transited and then linearly extends towards the inner side.

In other embodiments, as shown in fig. 4, the first bending portion 38 at the end of the outer slot 32 extends outward, and the first bending portion 38 is a combination of an arc-shaped segment and a straight-line segment, i.e., the first bending portion 38 first forms a curved smooth transition and then forms a straight line extending outward. The second bent portion 40 at the end of the inner groove 34 extends toward the inner side, and the second bent portion 40 is an arc-shaped segment extending toward the inner side in a half-bracket shape. For an inner groove 34, the two second bent portions 40 at the two ends of the inner groove 34 can be regarded as forming a complete round bracket. For two adjacent inner slots 34, the two adjacent second bent portions 40 of the two adjacent inner slots 34 can be regarded as two opposite semicircular brackets.

As shown in fig. 3, each inner groove 34 is recessed inwardly at a portion corresponding to the end of two adjacent outer grooves 32. Each outer groove 32 includes at least one first circular arc segment 32a, each inner groove 34 includes two second circular arc segments 34a, an inner concave segment 34b and two inclined segments 34c, the inner concave segment 34b is connected between the two second circular arc segments 34a and located at the middle position of the inner groove 34, and the inclined segments 34c extend obliquely relative to the second circular arc segments 34a toward the inner side of the sensing portion 24 to increase the radial width of the annular connecting arm 36 at this position, thereby increasing the mechanical strength thereof. The concave section 34b extends toward the inner side of the sensing portion 24 relative to the second circular arc section 34a, and the first circular arc section 32a and the second circular arc section 34a are concentric. The end of each first bending portion 38 extends into the region 42 enclosed by the inner concave section 34b of the corresponding inner groove 34. It should be understood that the region 42 formed by the concave section 34b belongs to a portion of the annular connecting arm 36, that is, the portion of the annular connecting arm 36 corresponding to the concave section 34b extends toward the inner side of the sensing portion 24.

The plurality of isolation grooves 30 are disposed inside the plurality of inner grooves 34, and each isolation groove 30 corresponds to one inner groove 34. When the inner groove 34 has a plurality of segments connected in series and at least one segment is located on a different circumference from the remaining segments, each of the partition grooves 30 and the partition parts 28 forms a plurality of partition groove parts and partition separating parts corresponding to each of the segment parts, each of which corresponds to a segment part of one of the inner grooves 34. In this embodiment, the middle portion of the inner groove 34 is recessed inwardly to form an inner concave section 34b, so that each inner groove 34 is divided into three segments, including a segment formed by the inner concave section 34b and two segments formed by the two second arc sections 34 a. Therefore, each of the separation grooves 30 and the separation portions 28 is also divided into three sub-groove portions and three sub-separation portions, including the sub-groove portion 30b and the separation portion 28b provided corresponding to the inner concave section 34b, and the two sub-groove portions 30a and the two sub-separation portions 28a provided corresponding to the two second circular arc sections 34a, respectively.

In some embodiments, the outer edges of the partitions 28 are spaced a uniform distance from the inner edges of the partition slots 30, and the outer edges of the partition slots 30 are spaced a uniform distance from the inner edges of the inner slots 34. Correspondingly, the outer edges of the separating

portions

28a and 28b have a uniform spacing distance from the inner edges of the corresponding

sub-groove portions

30a and 30b, respectively, and the outer edges of the

sub-groove portions

30a and 30b have a uniform spacing distance from the inner edges of the corresponding inner groove 34 positions, respectively. That is, the partition portion 28 varies in the radial direction with the variation in the radial direction of the partition groove 30, and the partition groove 30 varies in the radial direction with the variation in the radial direction of the inner groove 34. In other embodiments, the spacing distance between the isolation portions 28 and the isolation grooves 30 may be non-uniformly arranged, and the spacing distance between the isolation grooves 30 and the inner groove 34 may be non-uniformly arranged.

When the partitions are provided inside the inner tank 34, the outer edges of the partitions may be uniformly spaced from the outer edges of the corresponding inner tank 34.

As shown in fig. 4, each inner groove 34 has a continuous arc segment, so that an arc isolation groove 30 is correspondingly disposed inside each inner groove 34, and an arc isolation portion 28 is disposed inside each isolation groove 30. In the illustrated embodiment, the isolation groove 30 is located on one side of the bracket formed by the two second bending portions 40 close to the arc segment.

In some embodiments, to further enhance the barrier against leakage of vibrations through the sound holes 22 from the leakage path, a rib structure may also be provided on the side of the membrane 12 facing the substrate 14.

Specifically, a first connecting arm 44 is formed between the ends of two adjacent outer slots 32, and a second connecting arm 46 is formed between the ends of two adjacent inner slots 34. The first connecting arm 44 extends outwardly from the outer edge of the annular connecting arm 36, the second connecting arm 46 extends inwardly from the inner edge of the annular connecting arm 36, and the first and second connecting

arms

44, 46 are offset from each other in the circumferential direction of the annular connecting arm 36. Thus, the peripheral portion 26 is connected to the sensing portion 24 by the first connecting arm 44, the annular connecting arm 36 and the second connecting arm 46. The stiffener structure is provided at least one of the first and second connecting

arms

44, 46. In the embodiment shown in fig. 3, the stiffener structure is provided at all of the first connecting arms 44 and the second connecting arms 46, please refer to fig. 5 and 6 simultaneously. In the embodiment shown in fig. 4, the rib structures are provided at all of the second connecting arms 46, please refer to fig. 7 at the same time.

The reinforcing rib structure can be arranged in an arrow shape or a fishbone shape. When the rib structure is arrow-shaped, the rib structure 48 includes a first rib bar 50 and side ribs 52 connected to both sides of one end of the first rib bar 50, and the first rib bar 50 is located inside the side ribs 52. The two side ribs 52 are V-shaped and form the head of the arrowhead shaped rib structure 48 and are symmetrical about the first rib shaft 50.

When the strengthening rib structure is the fishbone form, strengthening rib structure 54 includes main muscle 56 and a plurality of side muscle that are located 56 both sides of main muscle, and the relative muscle pole 56 slope of a plurality of side muscle, more specifically, a plurality of side muscle respectively with main muscle 56 between be the contained angle, the contained angle is greater than 0 degree less than or equal to 90 degrees. Preferably, the side ribs have the same inclination direction, i.e. the side ribs on the same side are parallel to each other. The side rib connected to one end portion of the main rib 56 is referred to as a main side rib 58a constituting the head portion of the fishbone-shaped rib structure 54, the remaining side ribs are referred to as auxiliary side ribs 58b, and the arm length of the main side rib 58a is larger than that of the auxiliary side ribs 58 b. In the illustrated embodiment, the fishbone-shaped rib structure 54 includes three secondary side ribs 58b, one of the secondary side ribs 58b is disposed adjacent to the primary side rib 58a, and the three secondary side ribs 58b are spaced apart at the same distance and are greater than the spacing between the secondary side rib 58b and the primary side rib 58 a.

In the embodiment shown in fig. 3, arrow-like bead structures 48 are provided at all first connecting arms 44 projecting from the bottom surface, with the arrows pointing to the outside of the membrane 12. A fishbone-shaped rib structure 54 is provided at all second connecting arms 46 projecting from the bottom surface with the head directed towards the inside of the membrane 12.

In the embodiment shown in fig. 4, a fishbone-like stiffener structure 54 is provided protruding from the bottom surface at all second connecting arms 46, with the head pointing towards the inside of the membrane 12.

The rib width of the fish bone shaped rib structure 54 of fig. 4 is greater than the rib width of the fish bone shaped rib structure 54 of fig. 3.

It should be noted that the above described positioning of the stiffener structure at the first and/or second connecting

arms

44, 46 may involve a number of situations, for example, the stiffener structure being positioned entirely within the connecting arm, or the stiffener structure being partially within the connecting arm and partially extending beyond the connecting arm.

In the illustrated embodiment, the side ribs are all linear. It will be appreciated that in other embodiments, the side ribs may also be curved.

Since the rib structure is provided protruding from the bottom surface of the diaphragm 12, the leakage path can be narrowed, thereby increasing the leakage damping. It will also be appreciated that in other embodiments the rib structure may be designed in other shapes as long as it acts as a barrier to acoustic vibrations passing through the leakage path.

When the partition portion is provided inside the inner groove 34, a rib structure may be provided on at least one of the first connecting arm 44 and the second connecting arm 46, and the rib structure may be provided protruding on a side of the first connecting arm 44 and/or the second connecting arm 46 facing the silicon substrate 14 to block the vibration from passing through the inner groove 34 or the outer groove 32. Each inner groove 34 may define a concave section corresponding to the first connecting arm 44, and the rib structure may be located inside the corresponding concave section. Each inner groove 34 may have a plurality of segments connected in series, at least one segment and the rest of the segments are located on different circumferences, each partition forms a plurality of partitions corresponding to each segment, and each partition corresponds to a segment of one inner groove 34.

In the embodiment shown in fig. 3 and 4, the plurality of outer grooves 32, the plurality of inner grooves 34, the plurality of isolation grooves 30, the isolation portion 28, and the stiffener structure are all symmetrically designed, for example, both symmetrically about at least one diametrical direction of the sensing portion 24, i.e., the diaphragm 12 is entirely symmetrical about at least one diametrical direction of the sensing portion 24. In the embodiment shown, the membrane 12 as a whole is symmetrical, for example, with respect to the diameter direction of the connecting line between the two opposite first connecting arms 44 or the two opposite second connecting arms 46.

In some embodiments, the plurality of outer grooves 32, the plurality of inner grooves 34, the plurality of spacer grooves 30, the spacers 28, and the rib structures may also be provided in an asymmetric design.

In other embodiments, not shown, spacers may also be provided between outer slots 32 and inner slots 34, or between sensing portion 24 and inner slots 34 and between outer slots 32 and inner slots 34, and the spacers may be provided in plurality. That is, multiple spacers may be provided between sensing portion 24 and inner slots 34 and/or between outer slots 32 and inner slots 34. When the spacers are disposed between the outer grooves 32 and the inner grooves 34, the spacers may be disposed near the outer grooves 32 or the inner grooves 34, and similarly, the spacers may be disposed around the spacers on the diaphragm 12 to be separated independently, and the specific arrangement may refer to the above-mentioned embodiment.

The concepts described herein may be embodied in other forms without departing from the spirit or characteristics thereof. The particular embodiments disclosed should be considered illustrative rather than limiting. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. Any changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. An MEMS sensor chip comprises a substrate, a back plate and a membrane, wherein the back plate and the membrane are installed on the substrate, the membrane is fixed on one side of the substrate, the back plate covers one side of the membrane far away from the substrate, the membrane comprises a sensing part and a peripheral part surrounding the periphery of the sensing part, and the MEMS sensor chip is characterized in that a plurality of slots are arranged between the peripheral part and the sensing part and comprise a plurality of outer slots and a plurality of inner slots, the outer slots are arranged on the inner edge of the peripheral part, the inner slots are arranged on the outer edge of the sensing part, a first connecting arm is formed between every two adjacent outer slots, a second connecting arm is formed between every two adjacent inner slots, an annular connecting arm is formed between the outer slots and the inner slots, the annular connecting arm is connected with the periphery part through the first connecting arm and is connected with the sensing part through the second connecting arm, an isolator is disposed within the slot proximate the sensing portion, the isolator projecting from the diaphragm toward the substrate or projecting from the substrate toward the diaphragm for increasing damping of vibrations through the slot.

2. The MEMS sensor chip of claim 1, wherein the isolation portion extends from the membrane to a surface of the substrate facing the membrane or from the substrate to a surface of the membrane facing away from the substrate.

3. The MEMS sensor chip of claim 1, wherein the substrate has a back chamber, the diaphragm covers the back chamber, and the isolation portion is disposed on the sensing portion offset from the back chamber in the corresponding slot.

4. The MEMS sensor chip of claim 1, wherein an outer edge of the spacer is evenly spaced from an inner edge of the slot.

5. The MEMS sensor chip of claim 1, wherein at least one of the first and second connecting arms is provided with a rib structure protrusively provided on a side of the first and/or second connecting arm facing the substrate to block vibration from passing through the inner or outer groove.

6. The MEMS sensor chip of claim 5, wherein each of the inner grooves forms an inner concave section at a location corresponding to the first connecting arm, and the rib structure is located inside the corresponding inner concave section.

7. The MEMS sensor chip of claim 1, wherein each of the inner grooves has a plurality of segments connected in series, and at least one segment is located on a different circumference from the remaining segments, each of the partitions forming a plurality of partitions corresponding to each of the segments, each of the partitions being disposed within a segment of one of the inner grooves.

8. The utility model provides a MEMS sensor chip, includes the base plate, install in back of the body plate and diaphragm on the base plate, the base plate has back of the body room, the diaphragm is fixed in one side of base plate and cover back of the body room, back of the body plate cover in keeping away from of diaphragm one side of base plate and form the air gap between back of the body plate and the diaphragm, the diaphragm includes sensing portion and centers on sensing portion outlying peripheral portion, a serial communication port, peripheral portion with be equipped with a plurality of flutings between the sensing portion, sensing portion with be equipped with a plurality of isolation grooves that are closed loop between the fluting, the part orientation in the isolation groove the base plate direction extends and forms isolation portion, isolation portion is used for the separation to get into the vibration of air gap is followed the fluting gets into back of the body room or get into the vibration of back of the body room is.

9. The MEMS sensor chip of claim 8, wherein the plurality of slots comprises a plurality of outer slots and a plurality of inner slots, the plurality of inner slots being annularly arranged at an outer edge of the sensing portion, the isolation slots being located inside the inner slots and forming uniform spacing with the inner slots.