CN218041696U

CN218041696U - Microphone structure and electronic equipment

Info

Publication number: CN218041696U
Application number: CN202222061515.5U
Authority: CN
Inventors: 沈晓燕
Original assignee: Suzhou Debei Electronics Co ltd
Current assignee: Suzhou Debei Electronics Co ltd
Priority date: 2022-08-05
Filing date: 2022-08-05
Publication date: 2022-12-13
Anticipated expiration: 2032-08-05

Abstract

The utility model provides a microphone structure and electronic equipment, wherein, the microphone structure includes base plate, casing and sound electric conversion structure, the casing with the base plate fixed connection is in order to form the cavity, sound electric conversion structure with the base plate towards one side fixed connection of casing and be located in the cavity; the substrate faces one side of the shell and is provided with a concave structure, the bottom of the concave structure is provided with at least one protruding portion, one end of each protruding portion is fixedly connected with the bottom of the concave structure, the other end of each protruding portion faces the cavity, each protruding portion is coated with a bonding agent, and the sound-electricity conversion structure is fixedly connected with the substrate through the bonding agents. The utility model provides a microphone structure and electronic equipment can increase the thickness of the bonding agent of subsides dress between sound-electricity conversion structure and the base plate has promoted the reliability of microphone product.

Description

Microphone structure and electronic equipment

Technical Field

The utility model relates to a microphone technical field, more specifically the utility model relates to a microphone structure and electronic equipment that says so.

Background

A microphone is a pressure sensor that finally converts a sound pressure signal into an electrical signal, and a small microphone manufactured using a Micro Electro Mechanical System (MEMS) technology is called a Micro-Electro-Mechanical System (MEMS) microphone or a Micro microphone. MEMS microphone chips generally include a substrate, a diaphragm, and a backplate. The vibrating diaphragm and the back plate are important parts in an MEMS microphone chip, the vibrating diaphragm and the back plate are arranged in parallel and at intervals, the vibrating diaphragm and the back plate form two electrode plates of the flat capacitor, the vibrating diaphragm is used for vibrating under the action of sound waves, and the relative distance between the back plate and the vibrating diaphragm is changed, so that the capacitance value of the flat capacitor is changed, the change of the capacitance value is converted into an electric signal through a peripheral circuit, and the conversion of sound and electricity is realized.

In practical microphone applications, the MEMS microphone chip is sensitive to the stress, and is generally improved by increasing the thickness of the mounting glue in the practical packaging process. However, due to the structural and application limitations of the MEMS microphone sensor, the excessively high glue thickness requires a correspondingly higher product height, which makes the product at a disadvantage in competition.

Accordingly, there is a need for improvements in the art.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least, provide a microphone structure and electronic equipment.

The purpose of the utility model is realized by adopting the following technical scheme:

according to an aspect of the present invention, a microphone structure is provided, the microphone structure includes a substrate, a housing and an acoustic-electric conversion structure, the housing and the substrate are fixedly connected to form a cavity, the acoustic-electric conversion structure is fixedly connected to a side of the substrate facing the housing and located in the cavity; wherein, the base plate towards one side of casing is provided with sunk structure, sunk structure's bottom is equipped with at least one bellying, the one end of bellying with sunk structure's bottom fixed connection, the other end orientation the cavity, and every the cladding has the binder on the bellying, the acoustoelectric conversion structure passes through the binder with base plate fixed connection.

Further, the height of the convex part is smaller than the depth of the concave structure.

Further, the acoustic-electric conversion structure comprises a substrate and an acoustic wave sensing component arranged on the substrate, and a back cavity penetrating through the substrate in the thickness direction is arranged on the substrate; and the projection of the convex part is at least partially overlapped with the projection of the substrate along the direction perpendicular to the plane of the base plate.

Furthermore, the bottom of the concave structure is provided with a plurality of convex parts which are arranged in an array mode, and the projection of the plurality of convex parts surrounds the projection of the back cavity along the direction perpendicular to the plane of the substrate.

Further, the protruding part is columnar, and the cross section of the protruding part is circular or polygonal.

Further, the substrate includes a substrate layer, a metal layer, and a solder resist layer, and the metal layer and the solder resist layer do not cover the bottom of the recess structure.

Optionally, along a direction perpendicular to a plane on which the substrate is located, a projection of the recessed structure is rectangular.

Optionally, the bottom of the recessed structure is provided with four of the convex portions, and the four convex portions are respectively located at four corners of the recessed structure.

Further, the housing or the substrate is provided with an acoustic hole, and the acoustic hole conducts the acoustic wave from the outside to the acoustic wave receiving region of the acoustic-electric conversion structure.

Furthermore, the microphone structure further comprises a signal processing circuit located in the cavity, and the signal processing circuit is electrically connected with the acoustic-electric conversion structure through a first conductive path and is electrically connected with the substrate through a second conductive path.

According to another aspect of the present invention, there is also provided an electronic device, which includes the microphone structure according to any of the above embodiments.

The utility model provides a microphone structure and electronic equipment aim at passing through the base plate orientation one side of cavity is provided with sunk structure, and sunk structure's bottom is equipped with at least one bellying, the one end of bellying with sunk structure's bottom fixed connection, other end orientation the cavity, then every the cladding has the binder on the bellying to the thickness of bed hedgehopping binder, the bottom and the binder contact of sound-electricity conversion structure to realize after the binder solidification with fixed between the base plate. The thickness of the adhesive attached between the acoustic-electric conversion structure and the substrate is ensured, so that the reliability of the microphone structure is enhanced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other embodiments based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of a microphone structure according to an embodiment of the present invention;

FIG. 2 is an enlarged schematic view of the structure at A in FIG. 1;

fig. 3 is a schematic diagram of another microphone structure provided by the embodiment of the present invention;

FIG. 4 is a schematic top view of the structure corresponding to FIGS. 1 and 3;

FIG. 5 is a schematic top view of the substrate of FIG. 1;

fig. 6 is a schematic top view of the substrate shown in fig. 3.

Detailed Description

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following preferred embodiments are described in detail with reference to the accompanying drawings.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The embodiment of the utility model provides a microphone structure is the core component of MEMS microphone, can be applied to the electronic equipment who has the sound collection function for example smart mobile phone, panel computer, recording pen, audiphone, mobile unit etc.. The embodiment of the utility model provides a be not limited to above-mentioned application scene.

Example one

Fig. 1 is a schematic diagram of a microphone structure according to an embodiment of the present invention, and fig. 2 is an enlarged schematic diagram of a position a in fig. 1.

Referring to fig. 1-2, an embodiment of the present invention provides a microphone structure, which includes a substrate 2, a casing 1, and an acoustic-electric conversion structure 3, where the casing 1 is fixedly connected to the substrate 2 to form a cavity, and the acoustic-electric conversion structure 3 is fixedly connected to one side of the substrate 2 facing the casing 1 and located in the cavity; wherein, base plate 2 face one side of casing 1 is provided with sunk structure 9, sunk structure 9's bottom is equipped with at least one bellying 5, the one end of bellying 5 with sunk structure 9's bottom fixed connection, the other end orientation the cavity, and every the cladding has binder 6 on the bellying 5, acoustoelectric conversion structure 3 passes through binder 6 with base plate 2 fixed connection.

Specifically, the acousto-electric conversion structure 3 includes a MEMS chip for acousto-electric conversion.

Exemplarily, in the embodiment of the present invention, the substrate 2 is a PCB (Printed Circuit Board) Board. The PCB is a support for electronic components (e.g., MEMS devices and AEIC devices) and a carrier for electrical interconnection of electronic components, and for example, a copper-clad PCB substrate is used as a connecting wire. The substrate 2 is designed based on multilayer wiring copper as a wiring board for connecting leads, and may include, for example, a base material layer, a metal layer, and a solder resist layer.

In a common technology, after the MEMS chip is manufactured, the bottom surface of the substrate of the MEMS chip is soldered to the PCB substrate to electrically connect with a signal processing circuit on the PCB substrate, but in the soldering process, the PCB substrate may deform due to heating, and the deformation on the PCB substrate may be transmitted to the MEMS chip, so that a sensitive film on the MEMS chip may generate stress concentration to cause unnecessary deformation, and the detection sensitivity of the MEMS chip may be decreased.

In order to reduce the stress caused by PCB deformation caused by welding between the bottom surface of the substrate of the MEMS chip and the PCB, in another common technology, glue is coated on the periphery of the bottom surface of the substrate of the MEMS chip and then the MEMS chip is fixed with the PCB. And an excessively high glue thickness requires a correspondingly higher product thickness.

Adopt the technical scheme provided by the utility model, aim at through the base plate orientation one side of cavity is provided with sunk structure, and sunk structure's bottom is equipped with at least one bellying, the one end of bellying with sunk structure's bottom fixed connection, the other end orientation the cavity, then every the cladding has the binder on the bellying to the thickness of bed hedgehopping binder, the bottom and the adhesive contact of acoustoelectric conversion structure to realize after the adhesive solidification with fixed between the base plate. Not only guaranteed the thickness of the adhesive that pastes between acoustoelectric conversion structure and the base plate, compare in the mode that glue and PCB fixed is scribbled around the substrate bottom surface of MEMS chip among the common technology moreover, can reduce the area of contact of the support MEMS chip that corresponds on the PCB board, specifically, support by the substrate bottom surface of MEMS chip and change into local bellying (point) and support to can avoid the sensitive membrane of MEMS chip that the deformation of PCB board brought to receive stress concentration's problem, moreover, every the cladding has the binder on the bellying, with the thickness of bed hedgehopping binder, also strengthened the reliability of microphone structure to a certain extent.

The housing 1 is a metal housing fixed on the substrate 2 to form a cavity 2 for shielding external electromagnetic field interference.

Further, the height h1 of the protruding portion 5 is smaller than the depth h2 of the recessed structure 9. That is, the top of the protrusion 5 is lower than the plane of the substrate 2 facing the housing 1. Therefore, the height of the adhesive and the height of the protruding part are the total bonding height, the using amount of the adhesive is reduced to a certain extent, and the adhesive is prevented from overflowing to the inside of the MEMS chip.

Illustratively, the protruding portion 5 may be formed on the basis of some layers on the substrate 2, for example, by forming a part of a metal layer on the substrate 2 or by stacking a part of a metal layer and a part of a solder resist layer on the substrate 2, which eliminates the need for fixing the protruding portion 5 and the bottom of the recessed structure 9 by other adhesives for fixing, thereby reducing the difficulty of the manufacturing process.

Further, the acoustic-electric conversion structure 3 includes a substrate and an acoustic wave sensing component disposed on the substrate, and a back cavity penetrating through the substrate in a thickness direction is disposed on the substrate; wherein, along the direction perpendicular to the plane of the base plate 2, the projection of the convex part 5 and the projection of the substrate at least partially overlap. The bottom of the substrate of the acoustic-electric conversion structure 3 can be suspended by the protrusion 5 and the adhesive 6. And the height between the acoustic-electric conversion structure 3 and the substrate 2 is increased, so that the volume of a back cavity can be increased to a certain extent, and the performance of a microphone product is improved.

Specifically, the sound wave sensing assembly comprises a vibrating diaphragm and a back plate, wherein the vibrating diaphragm is used for vibrating under the action of sound waves to cause the relative distance between the back plate and the vibrating diaphragm to change, so that the capacitance value of the flat capacitor changes, and the change of the capacitance value is converted into an electric signal through a peripheral circuit to realize sound-electricity conversion.

Further, the bottom of the concave structure 9 is provided with a plurality of the convex portions 5 arranged in an array manner, and along a direction perpendicular to the plane of the substrate 2, the projection of the plurality of the convex portions 5 surrounds the projection of the back cavity. That is, a plurality of the protrusions 5 are arranged in a ring shape below the position corresponding to the substrate.

Further, the substrate 2 is provided with a sound hole 7, and the sound hole 7 conducts sound waves from the outside to a sound wave receiving region of the acoustic-electric conversion structure 3.

Fig. 3 is a schematic view of another microphone structure according to an embodiment of the present invention, fig. 4 is a schematic view of a top structure corresponding to fig. 1 and 3, and fig. 5 is a schematic view of a top structure of the substrate in fig. 1.

Fig. 3 differs from fig. 1 in that fig. 1 is a microphone structure for bottom-entry tones, and fig. 3 is a microphone structure for top-entry tones.

Illustratively, as shown in fig. 3, in a further embodiment of the present invention, an opening 8 is provided on the housing 1, and the opening 8 is used as a sound hole of a microphone structure of a top-entering sound to conduct sound waves from the outside to a sound wave receiving area of the acoustic-electric conversion structure 3.

Specifically, as shown in fig. 4 and 5, the boss 5 is columnar, and the cross-sectional shape of the boss 5 is circular or polygonal. It should be understood that the circular or polygonal central symmetrical shape is relatively uniform in force at each position, and therefore, the cross section of the protruding portion 5 is preferably circular or polygonal central symmetrical shape.

The substrate 2 includes a base material layer, a metal layer, and a solder resist layer, and the metal layer and the solder resist layer do not cover the bottom of the recess structure 9 except for the region where the projection 5 is located. For example, the bottom of the substrate 2 may be etched by etching to form the protrusions 5 having a certain height. Specifically, the corresponding film layer on the substrate 2 may be etched according to the required height of the protruding portion 5, as long as the height h1 of the protruding portion 5 is lower than the depth h2 of the recessed structure 9.

As shown in fig. 4, the projection of the recessed structure 9 is rectangular in a direction perpendicular to the plane of the substrate 2. The projection of the adhesive 6 overlaps with the projection of the substrate, and the adhesive 6 is completely accommodated in the recessed structure 9 and does not overflow to the surface of the base plate 2 facing the shell, so that the adhesive can be prevented from polluting the surface of the base plate 2.

Preferably, as shown in fig. 5 and 6, four protrusions 5 are provided at the bottom of the recessed structure 9, and the four protrusions 5 are respectively located at four corners of the recessed structure 9, so that the acoustic-electric conversion structure 3 can be uniformly supported, and the problem of the decrease in adhesion or the decrease in sensing sensitivity of the acoustic-electric conversion structure 3 due to uneven support can be prevented.

Further, in the above embodiment, the microphone structure further includes a signal processing circuit 4 located in the cavity, and the signal processing circuit 4 is electrically connected to the acoustic-electric conversion structure 3 through a first conductive path and is electrically connected to the substrate 2 through a second conductive path.

Specifically, the signal processing Circuit 4 is an ASIC (Application Specific Integrated Circuit) chip for signal amplification. The first conductive path and the second conductive path are, for example, gold wires, respectively. Adopt the technical scheme provided by the utility model, because the part of sound electricity transform structure 3 is located in sunk structure 9, the event has reduced sound electricity transform structure 3 with difference in height between signal processing circuit 4, the event still is favorable to reducing to a certain extent and connects sound electricity transform structure 3 with the line arc height of gold thread between the signal processing circuit 4. The reliability of the microphone structure is further improved.

The utility model also provides an electronic equipment, electronic equipment includes as above any kind of microphone structure. The microphone structure can be applied to various electronic devices, such as smart phones, tablet computers, recording pens, hearing aids, vehicle-mounted devices and the like.

Therefore, adopt the embodiment of the utility model provides a microphone structure and electronic equipment can increase the thickness of the bonding agent of subsides dress between acoustoelectric conversion structure and the base plate, consequently, reduce the volume that has still increased the back of the body chamber of acoustoelectric conversion structure simultaneously at the acoustoelectric conversion structure encapsulation reliability that has improved the microphone product, are favorable to the reliability of microphone product and the promotion of sensitivity.

Furthermore, in a limited space, the height of the adhesive is ensured, and the arc height of the gold wire is not influenced.

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

Claims

1. A microphone structure is characterized by comprising a substrate, a shell and an acoustoelectric conversion structure, wherein the shell and the substrate are fixedly connected to form a cavity, and the acoustoelectric conversion structure is fixedly connected with one side, facing the shell, of the substrate and is positioned in the cavity;

the substrate faces one side of the shell and is provided with a concave structure, the bottom of the concave structure is provided with at least one protruding portion, one end of each protruding portion is fixedly connected with the bottom of the concave structure, the other end of each protruding portion faces the cavity, each protruding portion is coated with a bonding agent, and the sound-electricity conversion structure is fixedly connected with the substrate through the bonding agents.

2. The microphone structure of claim 1 wherein the height of the raised portion is less than the depth of the recessed structure.

3. Microphone structure according to claim 1,

the acoustic-electric conversion structure comprises a substrate and an acoustic wave sensing assembly arranged on the substrate, and a back cavity penetrating through the substrate in the thickness direction is arranged on the substrate;

and the projection of the convex part is at least partially overlapped with the projection of the substrate along the direction perpendicular to the plane of the base plate.

4. Microphone structure according to claim 3,

the bottom of the concave structure is provided with a plurality of convex parts which are arranged in an array mode, and the projection of the plurality of convex parts surrounds the projection of the back cavity along the direction perpendicular to the plane where the substrate is located.

5. The microphone structure according to claim 4, wherein the protrusion is cylindrical, and a cross-section of the protrusion has a circular or polygonal shape.

6. Microphone structure according to claim 1,

the substrate includes a substrate layer, a metal layer, and a solder resist layer, and the metal layer and the solder resist layer do not cover the bottom of the recess structure.

7. Microphone structure according to claim 6,

along the direction perpendicular to the plane of base plate place, the projection of sunk structure is the rectangle.

8. Microphone structure as claimed in claim 7,

the bottom of the concave structure is provided with four convex parts, and the four convex parts are respectively positioned at four corners of the concave structure.

9. Microphone structure according to one of claims 1 to 8,

the shell or the substrate is provided with a sound hole, and the sound hole conducts sound waves from the outside to a sound wave receiving area of the sound-electricity conversion structure.

10. The microphone structure of claim 9 further comprising a signal processing circuit within the cavity, the signal processing circuit electrically connected to the acousto-electric conversion structure through a first conductive via and electrically connected to the substrate through a second conductive via.

11. An electronic device, characterized in that the electronic device comprises a microphone structure according to any of claims 1-10.