CN215453273U

CN215453273U - Microphone assembly and electronic equipment

Info

Publication number: CN215453273U
Application number: CN202122112713.5U
Authority: CN
Inventors: 孙恺; 荣根兰; 孟燕子; 胡维
Original assignee: Memsensing Microsystems Suzhou China Co Ltd
Current assignee: Memsensing Microsystems Suzhou China Co Ltd
Priority date: 2021-09-02
Filing date: 2021-09-02
Publication date: 2022-01-07
Anticipated expiration: 2031-09-02

Abstract

The utility model provides a microphone assembly and electronic equipment, and belongs to the technical field of microphones. The stress release structure arranged on the vibrating diaphragm can well release the stress of the vibrating diaphragm and improve the sensitivity of the microphone.

Description

Microphone assembly and electronic equipment

Technical Field

The utility model relates to the technical field of microphones, in particular to a microphone assembly and electronic equipment.

Background

A microphone is a pressure sensor that finally converts a sound pressure signal into an electrical signal, and a small microphone manufactured by using a Micro Electro Mechanical System (MEMS) technology is called a Micro-Electro-Mechanical System (MEMS) microphone or a Micro microphone. A MEMS microphone chip generally includes a substrate, a backplate, and a diaphragm. The backplate and vibrating diaphragm are parallel and the interval sets up, and both constitute two plate electrodes of plate capacitor, and the vibrating diaphragm is used for vibrating under the effect of sound wave, leads to the relative distance between backplate and the vibrating diaphragm to change to make plate capacitor's capacitance value change, the change of capacitance value is changed into the signal of telecommunication through peripheral circuit.

The diaphragm structure of the existing MEMS microphone chip is generally two types: the first is a flat membrane and the second is a membrane with corrugations around the membrane. Under the condition that the size of the current chip is smaller, the first flat-laid film cannot release stress, and the requirement on the manufacturing process of the diaphragm is higher. The second type of the corrugated structure, however, cannot release stress well because of its shallow corrugation depth.

SUMMERY OF THE UTILITY MODEL

The utility model provides a microphone assembly and electronic equipment, which are used for solving the problem that the sensitivity of a microphone is reduced because the stress of a diaphragm cannot be well released in the prior art.

In a first aspect, the present invention provides a microphone assembly, where the microphone assembly includes a substrate, a diaphragm, a first backplate, and a second backplate, the substrate has a back cavity penetrating through the substrate in a thickness direction, and a first support body for supporting the first backplate is disposed on one side of the substrate, a second support body for supporting the diaphragm is disposed on one side of the first backplate away from the back cavity, a third support body for supporting the second backplate is disposed on one side of the diaphragm away from the back cavity, at least one through hole is disposed on each of the first backplate and the second backplate, and the through holes on the first backplate and the second backplate are in one-to-one correspondence in position;

the vibrating diaphragm is provided with at least one bulge part with a preset shape, and the bulge part is used for releasing the stress of the vibrating diaphragm.

In one embodiment of the utility model, each of the protrusions protrudes in a direction towards the back cavity or in a direction away from the back cavity.

In one embodiment of the utility model, the first support body is positioned at the edge of the substrate to support the first back plate, so that the first back plate is suspended above the back cavity.

In an embodiment of the utility model, the second supporting body is located at an edge of the first backplate to support the diaphragm, so that the diaphragm is suspended above the first backplate, and the first backplate and the diaphragm form a first variable capacitor.

In an embodiment of the utility model, the third supporting body is located at an edge of the diaphragm to support the second backplate, so that the second backplate is suspended above the diaphragm, and the second backplate and the diaphragm form a second variable capacitor.

In one embodiment of the utility model, each of the bosses has a through hole on the first and second back plates corresponding thereto in position and/or size.

In one embodiment of the present invention, the predetermined shape is a circle, or a polygon, or a cross.

In one embodiment of the present invention, the width of each of the protrusions is 5-50um, and the protrusion height of each of the protrusions is 0.5-5 um.

In an embodiment of the present invention, the at least one protrusion is arranged in a staggered manner, or in a cross-shaped manner, or in a linear manner along an X-axis or Y-axis direction within a diameter range of the diaphragm.

In one embodiment of the present invention, at least one additional annular protrusion is further provided at the edge of the diaphragm, the additional annular protrusion is in a continuous annular shape or an interrupted annular shape, and the additional annular protrusion protrudes toward the back cavity or away from the back cavity.

In an embodiment of the present invention, the first support, the second support, and the third support are made of silicon oxide, the first back plate and the second back plate are made of a composite material of silicon nitride and polysilicon, and the diaphragm is made of polysilicon.

In an embodiment of the present invention, the center positions of the first back plate and the second back plate are connected to the center position of the diaphragm to form a center connection structure, and a relief hole for balancing internal and external air pressures is provided on the center connection structure of the diaphragm or at the edge of the diaphragm.

In a second aspect, the present invention further provides a microphone assembly, where the microphone assembly includes a substrate, a first diaphragm, a second diaphragm, and a back plate, the substrate has a back cavity penetrating in a thickness direction of the substrate, and a first support body for supporting the first diaphragm is disposed on one side of the substrate, a second support body for supporting the back plate is disposed on one side of the first diaphragm, which is away from the back cavity, a third support body for supporting the second diaphragm is disposed on one side of the back plate, which is away from the back cavity, and the back plate is provided with at least one through hole;

the first diaphragm and/or the second diaphragm are/is provided with at least one bulge part with a preset shape, and the bulge part is used for releasing the stress of the diaphragms.

In one embodiment of the present invention, the first support is located at an edge of the substrate to support the first diaphragm, so that the first diaphragm is suspended above the back cavity.

In an embodiment of the utility model, the second supporting body is located at an edge of the first diaphragm to support the back plate, so that the back plate is suspended above the first diaphragm, and the back plate and the first diaphragm form a first variable capacitor.

In an embodiment of the utility model, the third supporting body is located at an edge of the back plate to support the second diaphragm, so that the second diaphragm is suspended above the back plate, and the back plate and the second diaphragm form a second variable capacitor.

In one embodiment of the utility model, each of the bosses has a through hole on the back plate corresponding in position and/or size thereto.

In an embodiment of the present invention, the at least one protrusion is arranged in a staggered manner, or in a cross-shaped manner, or in a linear manner along an X-axis or Y-axis direction within a diameter range of the corresponding first diaphragm and/or second diaphragm.

In one embodiment of the present invention, at least one additional annular protrusion is further provided at an edge of the first diaphragm and/or the second diaphragm, the additional annular protrusion is in a continuous annular shape or an interrupted annular shape, and the additional annular protrusion protrudes toward the back cavity or protrudes away from the back cavity.

In an embodiment of the present invention, the first support, the second support, and the third support are made of silicon oxide, the back plate is made of a composite material of silicon nitride and polysilicon, and the first diaphragm and the second diaphragm are made of polysilicon.

In one embodiment of the present invention, the center positions of the first diaphragm and the second diaphragm are connected to the center position of the backplate to form a center connection structure, and a relief hole for balancing the internal and external air pressures is provided on the center connection structure or at the edge of the second diaphragm.

In a third aspect, the present invention further provides a microphone assembly, where the microphone assembly includes a substrate, a first structure, and a second structure, the substrate has a back cavity penetrating in a thickness direction of the substrate, a first support for supporting the first structure is provided on one side of the substrate, and a second support for supporting the second structure is provided on one side of the first structure away from the back cavity;

wherein the first structure is a diaphragm and the second structure is a backplate; or the first structure is a back plate and the second structure is a diaphragm;

the back plate is provided with at least one through hole, and the edge of the diaphragm is provided with at least one annular bulge part for releasing the stress of the diaphragm.

In one embodiment of the utility model, the annular protrusion is in a continuous ring shape or an interrupted ring shape, and the annular protrusion protrudes towards the back cavity or away from the back cavity.

In one embodiment of the present invention, the first support is located at an edge of the substrate to support the diaphragm, so that the diaphragm is suspended above the back cavity.

In an embodiment of the utility model, the second supporting body is located at an edge of the diaphragm to support the back plate, so that the back plate is suspended above the diaphragm, and the back plate and the diaphragm form a variable capacitor.

In one embodiment of the present invention, at least one additional protrusion having a predetermined shape is further disposed within an annular region defined by the annular protrusion of the diaphragm.

In one embodiment of the utility model, each of the additional protrusions has a through hole on the back plate corresponding in position and/or size thereto.

In one embodiment of the utility model, the at least one additional raised portion is raised in a direction towards the back cavity or in a direction away from the back cavity.

In one embodiment of the present invention, each of the additional protrusions has a width of 5-50um, and a protrusion height of 0.5-5 um.

In an embodiment of the present invention, the additional protrusions are distributed in a staggered manner within a diameter range of the diaphragm, or distributed in a cross-shaped manner, or distributed in a linear manner in an X-axis or Y-axis direction.

In an embodiment of the present invention, the first support and the second support are made of silicon oxide, the back plate is made of a composite material of silicon nitride and polysilicon, and the diaphragm is made of polysilicon.

In a fourth aspect, the present invention also provides an electronic device comprising a microphone assembly as defined in any of the above.

According to the microphone assembly and the electronic equipment, the vibrating diaphragm is provided with the bulge part with the preset shape positioned on the vibrating diaphragm or the annular bulge part positioned on the edge of the vibrating diaphragm, so that the stress of the vibrating diaphragm can be well released, and the sensitivity of the microphone is improved.

Further, set up the shape bellying of predetermineeing that is located on the vibrating diaphragm and the annular bellying that is located the vibrating diaphragm edge on the vibrating diaphragm simultaneously, can balance the stress around vibrating diaphragm middle part and the vibrating diaphragm for stress can not concentrate on middle part or around, under the combined action of two kinds of bellyings, the release effect of stress is better, improves the sensitivity of microphone greatly.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other structures can be obtained according to the drawings without creative efforts.

Fig. 1(a) is a schematic cross-sectional view of a microphone assembly having a dual-layer backplate and a single-layer diaphragm according to the present invention;

FIG. 1(b) is a perspective view of the microphone assembly shown in FIG. 1 (a);

FIG. 2 is a second schematic cross-sectional view of a microphone assembly having a dual-layer backplate and a single-layer diaphragm according to the present invention;

fig. 3(a) is a third schematic cross-sectional view of a microphone assembly having a dual-layer backplate and a single-layer diaphragm according to the present invention;

fig. 3(b) is a perspective view of the microphone assembly shown in fig. 3 (a);

fig. 4(a) to 4(c) are schematic views of a convex portion on a diaphragm provided by the present invention;

fig. 5(a) is a schematic cross-sectional view of a microphone assembly having a single-layer backplate and a double-layer diaphragm according to the present invention;

fig. 5(b) is a perspective view of the microphone assembly shown in fig. 5 (a);

FIG. 6 is a second schematic cross-sectional view of a microphone assembly having a single-layer backplate and a dual-layer diaphragm according to the present invention;

FIG. 7 is a third schematic cross-sectional view of a microphone assembly having a single-layer backplate and a dual-layer diaphragm according to the present invention;

FIG. 8 is a fourth schematic cross-sectional view of a microphone assembly having a single-layer backplate and a dual-layer diaphragm according to the present invention;

FIG. 9 is a fifth cross-sectional view of a microphone assembly having a single-layer backplate and a dual-layer diaphragm according to the present invention;

FIG. 10 is a sixth schematic sectional view of a microphone assembly having a single-layer backplate and a dual-layer diaphragm according to the present invention;

fig. 11(a) is a schematic cross-sectional view of a microphone assembly having a single-layer backplate and a single-layer diaphragm according to the present invention;

fig. 11(b) is a perspective view of the microphone assembly shown in fig. 11 (a).

Reference numerals:

101: a substrate; 102: a first support plate; 103: a second support plate;

104: a third support plate; 105: a back cavity; 106: a first back plate;

107: vibrating diaphragm; 108: a second back plate; 109: a through hole;

110: a boss portion; 111: an air release hole; 112: a first oscillating acoustic cavity;

113: a second oscillating acoustic cavity; 114: an annular boss; 115: a first diaphragm;

116: a second diaphragm; 117: an elastic beam; 118: a back plate;

119: the acoustic cavity is oscillated.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," and the like in the description and in the claims, and in the drawings described above, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.

The working principle of MEMS microphones is to measure the capacitance between the diaphragm and the back plate. The air pressure change brought by the sound wave can cause the diaphragm to displace, and the air can pass through the through hole on the back plate, so that the position of the back plate can not be changed. During the movement of the diaphragm, the distance between the diaphragm and the backplate changes, which eventually results in a change in capacitance between the diaphragm and the backplate, and this change in electrical signal can be recorded and analyzed.

The utility model provides a microphone assembly and electronic equipment, which are used for solving the problem that the sensitivity of a microphone is reduced because the stress of a vibrating diaphragm cannot be well released in the prior art.

The microphone assembly and the electronic apparatus of the present invention will be described below with reference to fig. 1 to 11 (b).

The microphone component is a core component of an MEMS (micro-electromechanical systems) microphone, and can be applied to electronic equipment with a sound acquisition function, such as a smart phone, a tablet personal computer, a recording pen, a hearing aid, vehicle-mounted equipment and the like. The utility model is not limited to the above application scenarios.

The signal-to-noise ratio is a key performance index of the MEMS microphone, and the electric signal is increased by arranging a single-layer diaphragm of the double-layer backboard and a double-layer diaphragm of the single-layer backboard so as to improve the signal-to-noise ratio.

The first embodiment is as follows:

fig. 1(a) is a schematic cross-sectional view of a microphone assembly having a dual-layer backplate and a single-layer diaphragm according to the present invention, and fig. 1(b) is a perspective view of the microphone assembly shown in fig. 1(a), as shown in fig. 1(a) and fig. 1(b), the microphone assembly includes a substrate 101, a diaphragm 107, a first backplate 106, and a second backplate 108.

Exemplarily, the substrate 101 has a back cavity 105 penetrating in a thickness direction thereof, a first support 102 for supporting the first back plate 106 is disposed on one side of the substrate 101, a second support 103 for supporting the diaphragm 107 is disposed on one side of the first back plate 106 away from the back cavity 105, a third support 104 for supporting the second back plate 108 is disposed on one side of the diaphragm 107 away from the back cavity 105, at least one through hole 109 is disposed on each of the first back plate 106 and the second back plate 108, and the through holes 109 on the first back plate 106 and the second back plate 108 are in one-to-one correspondence in position.

Both the sound pressure load during normal operation and the blowing load during abnormal operation are applied to the diaphragm 107 through the back chamber 105. The first support 102 is supported between the first backplate 106 and the substrate 101, and is used for electrically isolating the first backplate 106 from the substrate 101 and providing support for the first backplate 106. The second support 103 is supported between the first back plate 106 and the diaphragm 107, and is configured to electrically isolate the first back plate 106 from the diaphragm 107, so that the first back plate 106 and the diaphragm 107 are disposed opposite to each other and spaced apart from each other, and a second oscillation acoustic cavity 113 for the diaphragm 107 to vibrate is formed between the first back plate 106 and the diaphragm 107. The third supporting body 104 is supported between the diaphragm 107 and the second backplate 108, and is used for electrically isolating the diaphragm 107 from the second backplate 108, so that the diaphragm 107 and the second backplate 108 are arranged oppositely and at an interval, and a first oscillation acoustic cavity 112 for the diaphragm 107 to vibrate is formed between the diaphragm 107 and the second backplate 108.

Illustratively, the first support 102 is located at an edge of the substrate 101 to support the first back plate 106, such that the first back plate 106 is suspended above the back cavity 105. The second supporting body 103 is located at an edge of the first back plate 106 to support the diaphragm 107, so that the diaphragm 107 is suspended above the first back plate 106, and the first back plate 106 and the diaphragm 107 form a first variable capacitor. The third supporting body 104 is located at an edge of the diaphragm 107 to support the second back plate 108, so that the second back plate 108 is suspended above the diaphragm 107, and the second back plate 108 and the diaphragm 107 form a second variable capacitor.

Through the first variable capacitor and the second variable capacitor, the output electric signal can be increased, so that the signal-to-noise ratio of the microphone is improved.

Illustratively, each of the bosses 110 of the diaphragm 107 has a through hole 109 on the first back plate 106 and the second back plate 108 corresponding thereto in position and/or size.

By providing through holes 109 in the first back plate 106 and the second back plate 108, squeeze film damping can be reduced. This is because, when the microphone is small in size, the gaps between the first backplate 106 and the diaphragm 107 and between the second backplate 108 and the diaphragm 107 generate squeeze film damping, which limits the frequency response bandwidth of the microphone, and therefore, at least one through hole 109 needs to be provided in the first backplate 106 and the second backplate 108 to reduce the squeeze film damping.

Illustratively, the diaphragm 107 is provided with at least one protrusion 110 having a predetermined shape for releasing stress of the diaphragm. Each projection 110 projects in a direction toward the back cavity 105 or in a direction away from the back cavity 105 (e.g., the projections 110 shown in fig. 1(a) and 1(b) project in a direction away from the back cavity 105).

Illustratively, the predetermined shape is a circle, or a polygon, or a cross, as shown in fig. 4(a) to 4 (c). The convex portion 110 of the diaphragm 107 shown in fig. 4(a) is circular, the convex portion 109 of the diaphragm 107 shown in fig. 4(b) is hexagonal, and the convex portion 110 of the diaphragm 107 shown in fig. 4(c) is cross-shaped. Fig. 4(a) shows that the boundary connecting line of the convex portion 110 of the diaphragm 107 is a straight line (temporarily not shown), whereas fig. 4(b) and 4(c) show that the boundary connecting line of the convex portion 110 of the diaphragm 107 is a curved line (temporarily not shown) instead of a straight line. Therefore, the stress releasing effect of the diaphragm of fig. 4(b) and 4(c) may be better than that of fig. 4 (a). However, the projection of the present invention is not limited to the above shape.

Illustratively, the at least one protrusion 110 is disposed in a staggered arrangement (as shown in fig. 4 (b)), a cross arrangement (as shown in fig. 4 (c)), or a linear arrangement in the X-axis or Y-axis direction (as shown in fig. 4 (a)) within the diameter of the diaphragm 107.

Illustratively, in order to avoid the over-size of the protrusions 110 from decreasing the structural reliability of the diaphragm 107, and also avoid the over-size of the protrusions 110 from decreasing the stress release effect of the diaphragm, the width of each protrusion 110 is set to be 5-50um, and the protrusion height of each protrusion 110 is set to be 0.5-5 um.

Illustratively, the boundary of each protrusion 110 is arcuately shaped, which facilitates further stress relief of the diaphragm 105.

Illustratively, in order to ensure the stress release effect, the center position of the diaphragm 107 is connected to the center positions of the first back plate 106 and the second back plate 108 at the same time to form a center connection point, and the center connection point is formed to ensure that the circumferential stress of the diaphragm 107 is consistent during the processing or use process.

Illustratively, a release hole 111 for balancing the internal and external air pressures is provided on the center connection structure of the diaphragm 107 or at the edge of the diaphragm 107 to reduce the air pressure impact received during the vibration of the diaphragm 107, so that the diaphragm 107 is vibrated, and the high-pressure air flow generated in the first and second vibration

acoustic chambers

112 and 113 is partially discharged to the external space through the release hole 111, thereby effectively balancing the internal and external air pressures, improving the acoustic effect, and preventing the damage caused by the uneven vibration due to the pressure difference between the two sides of the diaphragm 107 during the vibration.

One air release hole 111 may be provided at the center of the diaphragm 107, or several air release holes may be provided around the center, and the position of the air release hole 111 may also be provided at the protrusion 110 of the diaphragm 107. The number, size and position of the air release holes 111 are not limited in the present invention.

Illustratively, at least one additional annular raised part 114 (shown in fig. 3(a) and 3 (b)) is further provided at the edge of the diaphragm 107, the annular raised part 114 is in a continuous annular shape or an interrupted annular shape, and the annular raised part 114 is raised towards the back cavity 105 or is raised towards the direction away from the back cavity 105. The provision of the annular convex portion 114 can further relieve the stress of the diaphragm 107.

Illustratively, the first support 102, the second support 103, and the third support 104 are made of silicon oxide, the first back plate 106 and the second back plate 108 are made of a composite material of silicon nitride and polysilicon, and the diaphragm 107 is made of polysilicon, because silicon nitride has high hardness, the first back plate 106 and the second back plate 108 are used as fixed electrodes and are not easily deformed, thereby improving the reliability of the microphone.

Example two:

fig. 2 is a second cross-sectional view of a microphone assembly with a dual-layer backplate and a single-layer diaphragm according to the present invention, as shown in fig. 2. Fig. 2 differs from fig. 1(a) in that: the bulge 110 of the diaphragm 107 in fig. 2 is convex towards the back cavity 105, whereas the bulge 110 of the diaphragm 107 in fig. 1(a) is convex away from the back cavity 105. The microphone assembly shown in fig. 2 can be described with reference to fig. 1(a) and 1(b), and will not be described herein again.

Example three:

fig. 3(a) is a third schematic cross-sectional view of a microphone assembly with a dual-layer backplate and a single-layer diaphragm according to the present invention, fig. 3(b) is a perspective view of the microphone assembly shown in fig. 3(a), and as shown in fig. 3(a) and fig. 3(b), the technical solutions shown in fig. 3(a) and fig. 3(b) are different from the technical solutions shown in fig. 1(a) and fig. 1 (b): fig. 3(a) and 3(b) show the technical solutions shown in fig. 1(a) and 1(b), and two additional annular protrusions 114 are added to the diaphragm 107. The additional annular protrusion 107 may have a continuous annular shape or an interrupted annular shape, and the additional annular protrusion 107 may protrude toward the back cavity 105 or protrude away from the back cavity 105. The number of the annular protrusions 114 is not limited in the present invention. Other aspects of the microphone assembly shown in fig. 3(a) and 3(b) can be described with reference to fig. 1(a) and 1(b), and are not described again here.

Example four:

fig. 5 is one of cross-sectional schematic views of a microphone assembly having a single-layer backplate and a double-layer diaphragm according to the present invention, and fig. 5(b) is a perspective view of the microphone assembly shown in fig. 5(a), as shown in fig. 5(a) and 5(b), the microphone assembly includes a substrate 101, a first diaphragm 115, a backplate 118, and a second diaphragm 116.

Exemplarily, the substrate 101 has a back cavity 105 penetrating in a thickness direction thereof, and a first support 102 for supporting the first diaphragm 115 is disposed on one side of the substrate 101, a second support 103 for supporting the back plate 118 is disposed on one side of the first diaphragm 115 far from the back cavity 105, a third support for supporting the second diaphragm 116 is disposed on one side of the back plate 118 far from the back cavity 105, and at least one through hole is disposed on the back plate 118;

in the first diaphragm 115 and/or the second diaphragm 116 provided in the embodiment of the present invention, at least one protrusion having a preset shape is provided thereon for releasing stress of the diaphragms (for example, fig. 5(a) and 5(b) show that the first diaphragm 115 is provided with at least one protrusion 110 having a preset shape, and the second diaphragm 116 is flat and is not provided with a protrusion 110).

Each of the convex portions 110 provided in the embodiments of the present invention is convex toward the back cavity 105 or convex away from the back cavity 105 (for example, the first diaphragm 115 shown in fig. 5(a) and 5(b) is convex toward the back cavity 105).

Both the sound pressure load during normal operation and the blowing load during abnormal operation are applied to the first diaphragm 115 and the second diaphragm 116 through the back chamber 105. The first supporting body 102 is supported between the first diaphragm 115 and the substrate 101, and is used for electrically isolating the first diaphragm 115 from the substrate 101 and providing a support for the first diaphragm 115. The second support 103 is supported between the first diaphragm 115 and the back plate 118, and is configured to electrically isolate the first diaphragm 115 from the back plate 118, such that the first diaphragm 115 and the back plate 118 are disposed opposite to each other and spaced apart from each other, and a second oscillating acoustic cavity 113 for the first diaphragm 115 to vibrate is formed between the first diaphragm 115 and the back plate 118. The third supporting body 104 is supported between the back plate 118 and the second diaphragm 116, and is configured to electrically isolate the back plate 118 from the second diaphragm 116, such that the back plate 118 and the second diaphragm 116 are disposed opposite to each other and spaced apart from each other, and a first oscillating acoustic cavity 112 for the second diaphragm 116 to vibrate is formed between the back plate 118 and the second diaphragm 116.

Illustratively, the first support 102 is located at an edge of the substrate 101 to support the first diaphragm 115, such that the first diaphragm 115 is suspended above the back cavity 105. The second supporting body 103 is located at an edge of the first diaphragm 115 to support the back plate 118, so that the back plate 118 is suspended above the first diaphragm 115, and the back plate 118 and the first diaphragm 115 form a first variable capacitor. The third supporting body 104 is located at an edge of the back plate 118 to support the second diaphragm 116, so that the second diaphragm 116 is suspended above the back plate 118, and the back plate 118 and the second diaphragm 116 form a second variable capacitor.

The first variable capacitor and the second variable capacitor can increase the output electric signal to improve the signal-to-noise ratio of the microphone.

Illustratively, each of the bosses 110 of the first diaphragm 115 has a through hole 109 on the back plate 118 corresponding in position and/or size thereto.

By providing through holes 109 in the back plate 118, squeeze film damping can be reduced. This is because, when the microphone is small in size, the gaps between the first diaphragm 115 and the back plate 118 and between the back plate 118 and the second diaphragm 116 generate squeeze film damping, which limits the frequency response bandwidth of the microphone, and therefore, at least one through hole 109 needs to be provided in the back plate 118 to reduce the squeeze film damping.

Illustratively, the first diaphragm 115 is provided with at least one protrusion 110 having a predetermined shape for releasing stress of the diaphragm. Each projection 110 projects in a direction toward the back cavity 105 or in a direction away from the back cavity 105 (e.g., the projections 110 shown in fig. 5(a) and 5(b) project in a direction toward the back cavity 105).

Illustratively, the predetermined shape is a circle, or a polygon, or a cross, as shown in fig. 4(a) to 4 (c). However, the projection of the present invention is not limited to the above shape.

Illustratively, the at least one protrusion 110 is arranged in a staggered manner within the diameter of the first diaphragm 115 (as shown in fig. 4 (b)), or in a cross-shaped manner (as shown in fig. 4 (c)), or in a linear manner along the X-axis or Y-axis direction (as shown in fig. 4 (a)).

Illustratively, the width of each of the protrusions 110 of the first diaphragm 115 is 5-50um, and the protrusion height of each of the protrusions 110 is 0.5 um-5 um.

Illustratively, the boundary of each of the protrusions 110 is in an arc-shaped configuration, which facilitates further stress relief of the first diaphragm 115.

Illustratively, in order to ensure the stress release effect, the center positions of the first diaphragm 115 and the second diaphragm 116 are simultaneously connected to the center position of the back plate 118 to form a center connection structure, and the center connection structure is formed to ensure that the circumferential stresses of the first diaphragm 115 and the second diaphragm 116 are consistent during the processing or use.

Illustratively, a gas release hole 111 for balancing internal and external gas pressures is provided on a center connection structure of the first diaphragm 115 and the second diaphragm 116 or at edges of the first diaphragm 115 and the second diaphragm 116, so as to reduce the gas pressure impact received during the vibration process of the first diaphragm 115 and the second diaphragm 116, so that a high-pressure airflow part generated in the first vibration acoustic cavity 112 and the second vibration acoustic cavity 113 is discharged to an external space through the gas release hole 111 during the vibration process of the first diaphragm 115 and the second diaphragm 116, thereby effectively balancing the internal and external gas pressures, improving the acoustic effect, and preventing the damage problem caused by the non-uniform vibration due to the pressure difference between two sides of the first diaphragm 115 and the second diaphragm 116 during the vibration process.

The air release hole 111 may be disposed at the center of the first diaphragm 115 and the second diaphragm 116, or may be disposed at the periphery of the center, and the position of the air release hole 111 may also be disposed at the protruding portion 110 of the first diaphragm 115 and the second diaphragm 116. The number, size and position of the air release holes 111 are not limited in the present invention.

In addition, an elastic beam 117 for fixing the second diaphragm 116 is further provided on the second diaphragm 116.

For example, at least one additional annular protrusion 114 (as shown in fig. 3(a) and 3 (b)) may be further disposed at an edge of the first diaphragm 115 and/or the second diaphragm 116, where the annular protrusion 114 has a continuous annular shape or an interrupted annular shape, and the annular protrusion 114 protrudes toward the back cavity 105 or protrudes away from the back cavity 105. The provision of the annular convex portion 114 may further relieve stress of the first diaphragm 115 and/or the second diaphragm 116.

Illustratively, the first support 102, the second support 103, and the third support 104 are made of silicon oxide, the back plate 118 is made of a composite material of silicon nitride and polysilicon, and the first diaphragm 115 and the second diaphragm 116 are made of polysilicon, so that the back plate 118 is used as a fixed electrode and is not easily deformed due to the higher hardness of silicon nitride, thereby improving the reliability of the microphone.

Example five:

fig. 6 is a second cross-sectional view of a microphone assembly with a single-layer backplate and a double-layer diaphragm according to the present invention, as shown in fig. 6. The difference between the scheme shown in fig. 6 and the scheme shown in fig. 5(a) is that: the bulge portion 110 of the first diaphragm 115 in the solution shown in fig. 6 is bulged in a direction away from the back cavity 105, whereas the bulge portion 110 of the first diaphragm 115 in the solution shown in fig. 5(a) is bulged in a direction toward the back cavity 105. Other aspects of the microphone assembly shown in fig. 6 can be described with reference to fig. 5(a) and 5(b), and are not described herein again.

Fig. 7 is a third schematic cross-sectional view of a microphone assembly with a single-layer backplate and a double-layer diaphragm according to the present invention, as shown in fig. 7. The solution shown in fig. 7 differs from the solution shown in fig. 6 in that: the second diaphragm 116 of the solution shown in fig. 6 is flat and is not provided with a bulge 110, whereas the second diaphragm 116 of the solution shown in fig. 7 is provided with a bulge 110, the bulge 110 of which bulges away from the back cavity 105. Other aspects of the microphone assembly shown in fig. 7 can be described with reference to fig. 5(a) and 5(b), and are not described herein again.

Example six:

fig. 8 is a fourth schematic cross-sectional view of a microphone assembly with a single-layer backplate and a double-layer diaphragm according to the present invention, as shown in fig. 8. The solution shown in fig. 8 differs from the solution shown in fig. 7 in that: the bulge portion 110 of the first diaphragm 115 in the solution shown in fig. 7 is bulged in a direction away from the back cavity 105, whereas the bulge portion 110 of the first diaphragm 115 in the solution shown in fig. 8 is bulged in a direction towards the back cavity 105. Other aspects of the microphone assembly shown in fig. 8 can be described with reference to fig. 5(a) and 5(b), and are not described herein again.

Example seven:

fig. 9 is a fifth cross-sectional view of a microphone assembly with a single-layer backplate and a double-layer diaphragm according to the present invention, as shown in fig. 9. The solution shown in fig. 9 differs from the solution shown in fig. 8 in that: the bulge 110 of the second diaphragm 116 in the version shown in fig. 8 bulges in a direction away from the back cavity 105, whereas the bulge 110 of the second diaphragm 116 in the version shown in fig. 9 bulges in a direction towards the back cavity 105. Other aspects of the microphone assembly shown in fig. 9 can be described with reference to fig. 5(a) and 5(b), and are not described herein again.

Example eight:

fig. 10 is a sixth schematic cross-sectional view of a microphone assembly with a single-layer backplate and a double-layer diaphragm according to the present invention, as shown in fig. 10, the difference between the solution shown in fig. 10 and the solution shown in fig. 9 is: the bulge portion 110 of the first diaphragm 115 in the solution shown in fig. 9 bulges in a direction towards the back cavity 105, whereas the bulge portion 110 of the first diaphragm 115 in the solution shown in fig. 10 bulges in a direction away from the back cavity 105. Other aspects of the microphone assembly shown in fig. 10 can be described with reference to fig. 5(a) and 5(b), and are not described herein again.

Example nine:

fig. 11(a) is one of schematic cross-sectional views of a microphone assembly having a single-layer backplate and a single-layer diaphragm according to the present invention, and fig. 11(b) is a perspective view of the solution shown in fig. 11(a), as shown in fig. 11(a) and fig. 11(b), the microphone assembly includes a substrate 101, a backplate 118, and a diaphragm 107.

Illustratively, the substrate 101 has a back cavity 105 penetrating in a thickness direction thereof, and a first support 102 for supporting the diaphragm 107 is provided on one side of the substrate 101, a second support 103 for supporting a back plate 118 is provided on a side of the diaphragm 107 away from the back cavity 105, and at least one through hole 109 is provided on the back plate 118. Wherein, at least one annular bulge 114 is arranged on the edge of the diaphragm 107 for releasing the stress of the diaphragm 107.

Illustratively, the annular protrusion 114 is in a continuous ring shape or an interrupted ring shape, and the annular protrusion 114 protrudes toward the back cavity 105 or away from the back cavity 105 (for example, the annular protrusion 114 shown in fig. 11(a) protrudes toward the back cavity 105).

Illustratively, both the sound pressure load during normal operation and the blow load during abnormal operation are applied to the diaphragm 107 through the back chamber 105. The first support 102 is supported between the backplate 118 and the substrate 101, and is used for electrically isolating the backplate 118 from the substrate 101 and providing support for the backplate 118. The second support 103 is supported between the back plate 118 and the diaphragm 107, and is configured to electrically isolate the back plate 118 from the diaphragm 107, such that the back plate 118 and the diaphragm 107 are disposed opposite to each other at an interval, and an oscillating acoustic cavity 119 for the diaphragm 107 to vibrate is formed between the back plate 118 and the diaphragm 107.

Illustratively, the first support 102 is located at an edge of the substrate 101 to support the diaphragm 107, so that the diaphragm 107 is suspended above the back cavity 105. The second support 103 is located at an edge of the diaphragm 107 to support the back plate 118, so that the back plate 118 is suspended above the diaphragm 107, and the back plate 118 and the diaphragm 107 form a variable capacitor.

Illustratively, at least one bulge 110 having a preset shape is further disposed in the annular region defined by the annular bulge 114 of the diaphragm 107, and the at least one bulge 110 is bulged toward the back cavity 105 or is bulged away from the back cavity 105 (for example, the bulge 110 of the diaphragm 107 shown in fig. 11(a) and 11(a) is bulged toward the back cavity 105).

Illustratively, the predetermined shape is a circle, or a polygon, or a cross, as shown in fig. 4(a) to 4 (c). The convex portion 110 of the diaphragm 107 shown in fig. 4(a) is circular, the convex portion 110 of the diaphragm 107 shown in fig. 4(b) is hexagonal, and the convex portion 110 of the diaphragm 107 shown in fig. 4(c) is cross-shaped.

Illustratively, in order to avoid the over-size of the protruding portion 110 and reduce the structural reliability of the diaphragm 107, and also avoid the over-size of the protruding portion 110 and reduce the stress release effect of the diaphragm, the width of each protruding portion 110 is 5-50um, and the protruding height of each protruding portion 110 is set to be 0.5-5 um.

Illustratively, each boss 110 of the diaphragm 107 has a through hole 109 on the back plate 118 corresponding in position and/or size thereto.

Illustratively, the boundary of each protrusion 110 is arcuately shaped, which facilitates further stress relief of the diaphragm 107.

Illustratively, a release hole 111 for balancing the internal and external air pressures is provided on the center connection structure of the diaphragm 107 or at the edge of the diaphragm 107, so as to reduce the air pressure impact received during the vibration of the diaphragm 107, so that the diaphragm 107 is in the vibration process, and the high-pressure air flow generated in the vibration acoustic cavity 119 is partially discharged to the external space through the release hole 111, thereby effectively balancing the internal and external air pressures, improving the acoustic effect, and preventing the damage caused by the uneven vibration due to the pressure difference between the two sides of the diaphragm 107 during the vibration process.

Illustratively, the first support 102 and the second support 103 are made of silicon oxide, the back plate 118 is made of a composite material of silicon nitride and polysilicon, and the diaphragm 107 is made of polysilicon, so that the back plate 118 is used as a fixed electrode and is not easily deformed due to the higher hardness of silicon nitride, thereby improving the reliability of the microphone.

It should be noted that the microphone assembly with a single-layer backplate and a single-layer diaphragm disclosed in the present invention is not limited to the structure with the diaphragm above and the backplate below as shown in fig. 11(a), and also includes embodiments with the backplate above and the diaphragm below; the bulge is not limited to bulge towards the back cavity, and the bulge also comprises an embodiment of bulge towards the back cavity; and the annular convex part is not limited to be convex towards the back cavity, and also comprises the embodiment of convex towards the back cavity.

The utility model also provides electronic equipment which comprises any one of the microphone assemblies.

In summary, the stress release structure provided on the diaphragm according to the utility model can release the stress of the diaphragm well, and improve the sensitivity of the microphone.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A microphone assembly is characterized by comprising a substrate, a vibrating diaphragm, a first back plate and a second back plate, wherein the substrate is provided with a back cavity which is communicated in the thickness direction of the substrate, a first supporting body used for supporting the first back plate is arranged on one side of the substrate, a second supporting body used for supporting the vibrating diaphragm is arranged on one side, away from the back cavity, of the first back plate, a third supporting body used for supporting the second back plate is arranged on one side, away from the back cavity, of the vibrating diaphragm, at least one through hole is formed in each of the first back plate and the second back plate, and the through holes in the first back plate and the second back plate are in one-to-one correspondence in position;

wherein, be provided with at least one bulge with preset shape on the vibrating diaphragm.

2. The microphone assembly of claim 1, wherein each of the protrusions protrudes toward the back cavity or protrudes away from the back cavity.

3. The microphone assembly of claim 1, wherein the first support is located at an edge of the substrate to support the first backplate such that the first backplate is suspended above the back cavity.

4. The microphone assembly of claim 2, wherein the second supporting body is located at an edge of the first backplate to support the diaphragm, so that the diaphragm is suspended above the first backplate, and the first backplate and the diaphragm form a first variable capacitor.

5. The microphone assembly of claim 4, wherein the third supporting body is located at an edge of the diaphragm to support the second backplate, so that the second backplate is suspended above the diaphragm, and the second backplate and the diaphragm form a second variable capacitor.

6. The microphone assembly of any one of claims 1-5, wherein each of the bosses has a through-hole on the first and second back plates corresponding in position and/or size thereto.

7. The microphone assembly of claim 6, wherein the predetermined shape is a circle, or a polygon, or a cross.

8. The microphone assembly of claim 7, wherein the width of each of the protrusions is 5-50um, and the protrusion height of each of the protrusions is 0.5-5 um.

9. The microphone assembly of claim 8, wherein the at least one protrusion is disposed in a staggered arrangement, a cross arrangement, or a linear arrangement along an X-axis or Y-axis within a diameter of the diaphragm.

10. The microphone assembly as claimed in claim 1, wherein at least one additional annular protrusion is further provided at the edge of the diaphragm, the additional annular protrusion is in a continuous annular shape or an interrupted annular shape, and the additional annular protrusion protrudes toward the back cavity or away from the back cavity.

11. The microphone assembly of claim 1, wherein the first support, the second support, and the third support are made of silicon oxide, and the diaphragm is made of polysilicon.

12. The microphone assembly of claim 1, wherein the center positions of the first and second back plates are connected to the center position of the diaphragm to form a center connection structure, and a relief hole for balancing air pressures inside and outside is provided on the center connection structure of the diaphragm or at the edge of the diaphragm.

13. A microphone assembly is characterized by comprising a substrate, a first vibrating diaphragm, a second vibrating diaphragm and a back plate, wherein the substrate is provided with a back cavity which is communicated in the thickness direction of the substrate, a first supporting body used for supporting the first vibrating diaphragm is arranged on one side of the substrate, a second supporting body used for supporting the back plate is arranged on one side, far away from the back cavity, of the first vibrating diaphragm, a third supporting body used for supporting the second vibrating diaphragm is arranged on one side, far away from the back cavity, of the back plate, and at least one through hole is formed in the back plate;

the first diaphragm and/or the second diaphragm are/is provided with at least one bulge part with a preset shape.

14. The microphone assembly of claim 13, wherein each of the protrusions protrudes toward the back cavity or protrudes away from the back cavity.

15. The microphone assembly of claim 14, wherein the first support is located at an edge of the substrate to support the first diaphragm such that the first diaphragm is suspended above the back cavity.

16. The microphone assembly of claim 15, wherein the second support is located at an edge of the first diaphragm to support the back plate, such that the back plate is suspended above the first diaphragm, and the back plate and the first diaphragm form a first variable capacitor.

17. The microphone assembly of claim 16, wherein the third supporting body is located at an edge of the back plate to support the second diaphragm, so that the second diaphragm is suspended above the back plate, and the back plate and the second diaphragm form a second variable capacitor.

18. A microphone assembly according to any of claims 13-17, wherein each boss has a through hole in the backplate corresponding in position and/or size to it.

19. The microphone assembly of claim 18, wherein the predetermined shape is a circle, or a polygon, or a cross.

20. The microphone assembly of claim 19 wherein each of the protrusions has a width of 5-50um and a protrusion height of 0.5-5 um.

21. The microphone assembly of claim 20, wherein the at least one protrusion is disposed in a staggered arrangement, a cross arrangement, or a linear arrangement along an X-axis or Y-axis within a diameter of the corresponding first diaphragm and/or the second diaphragm.

22. The microphone assembly of claim 13, wherein at least one additional annular protrusion is further provided at an edge of the first diaphragm and/or the second diaphragm, the additional annular protrusion is in a continuous annular shape or an interrupted annular shape, and the additional annular protrusion protrudes toward the back cavity or away from the back cavity.

23. The microphone assembly of claim 13, wherein the material of the first support, the second support, and the third support is silicon oxide, and the material of the first diaphragm and the second diaphragm is polysilicon.

24. The microphone assembly of claim 13, wherein the center positions of the first diaphragm and the second diaphragm are connected to the center position of the back plate to form a center connection structure, and a relief hole for balancing the internal and external air pressures is provided on the center connection structure or at the edge of the second diaphragm.

25. A microphone component is characterized by comprising a substrate, a first structure and a second structure, wherein the substrate is provided with a back cavity which is communicated in the thickness direction of the substrate, a first supporting body used for supporting the first structure is arranged on one side of the substrate, a second supporting body used for supporting the second structure is arranged on one side of the first structure far away from the back cavity,

the back plate is provided with at least one through hole, and the edge of the diaphragm is provided with at least one annular bulge.

26. The microphone assembly of claim 25, wherein the annular protrusion is in the shape of a continuous ring or an interrupted ring, and wherein the annular protrusion protrudes toward the back cavity or away from the back cavity.

27. The microphone assembly of claim 26, wherein the first support is located at an edge of the substrate to support the diaphragm such that the diaphragm is suspended above the back cavity.

28. The microphone assembly of claim 27, wherein the second support is located at an edge of the diaphragm to support the backplate such that the backplate is suspended above the diaphragm, the backplate and the diaphragm forming a variable capacitance.

29. A microphone assembly as claimed in any one of claims 25 to 28, wherein at least one additional raised portion of a predetermined shape is provided within the annular region defined by the annular raised portion of the diaphragm.

30. A microphone assembly according to claim 29 wherein each additional boss has a through hole in the backplate corresponding in position and/or size to it.

31. The microphone assembly of claim 30, wherein the predetermined shape is a circle, or a polygon, or a cross.

32. The microphone assembly of claim 31, wherein the at least one additional raised portion is raised toward the back cavity or raised away from the back cavity.

33. The microphone assembly of claim 32 wherein each of the additional protrusions has a width of 5-50um and a protrusion height of 0.5-5 um.

34. The microphone assembly of claim 33 wherein the additional protrusions are arranged in a staggered arrangement, or in a cross-shaped arrangement, or in a linear arrangement along the X-axis or Y-axis within the diameter of the diaphragm.

35. The microphone assembly of claim 25, wherein the first and second supports are made of silicon oxide and the diaphragm is made of polysilicon.

36. An electronic device comprising a microphone assembly as claimed in any one of claims 1-35.