CN212936203U

CN212936203U - MEMS microphone

Info

Publication number: CN212936203U
Application number: CN202022382461.3U
Authority: CN
Inventors: 袁兆斌; 穆洪峰
Original assignee: Qingdao Goertek Intelligent Sensor Co Ltd
Current assignee: Qingdao Goertek Intelligent Sensor Co Ltd
Priority date: 2020-10-22
Filing date: 2020-10-22
Publication date: 2021-04-09
Anticipated expiration: 2030-10-22

Abstract

The utility model discloses a MEMS microphone, the MEMS microphone includes the casing, the casing includes base plate and closing cap of shroud on the base plate; the outer periphery of the substrate is provided with an annular boss protruding out of the inner surface of the substrate; the periphery wall of closing cap is provided with the overlap joint groove, the closing cap passes through the overlap joint groove overlap joint be in on the annular boss, and with annular boss is connected fixedly. The utility model discloses a MEMS microphone can reduce the condition emergence that the fused welding material trickled or splashed the internals of MEMS microphone among the assembling process to improve MEMS microphone's product quality.

Description

MEMS microphone

Technical Field

The utility model relates to a microphone technical field, in particular to MEMS microphone.

Background

A MEMS (micro electro mechanical system) microphone is a microphone manufactured based on MEMS technology, and can be applied to electronic equipment as an acoustic-electric conversion device. The housing of a conventional MEMS microphone is generally composed of a substrate and a cover that covers over the substrate. However, the substrate of the MEMS microphone is usually a flat plate, and during the process of mounting the cap on the substrate, the high-temperature molten solder material may flow or splash along the surface of the substrate laterally to the inside of the housing and contact the internal components of the MEMS microphone (such as the chip or the gold wire connecting the chip), which may damage the internal components of the MEMS microphone, thereby reducing the product quality of the MEMS microphone.

SUMMERY OF THE UTILITY MODEL

The main objective of the present invention is to provide a MEMS microphone, which aims to reduce the occurrence of the condition that the melted welding material flows or splashes to the inner member of the MEMS microphone during the assembling process, so as to improve the product quality of the MEMS microphone.

In order to achieve the above object, the present invention provides a MEMS microphone, which includes a housing, the housing includes a substrate and a cover covering the substrate; the outer periphery of the substrate is provided with an annular boss protruding out of the inner surface of the substrate; the periphery wall of closing cap is provided with the overlap joint groove, the closing cap passes through the overlap joint groove overlap joint be in on the annular boss, and with annular boss is connected fixedly.

Optionally, the annular boss has a top surface and an inner circumferential surface located at one side of the top surface; the lapping groove is provided with a first lapping surface and a second lapping surface which is arranged at a right angle with the first lapping surface; the first overlapping surface is matched with the top surface of the annular boss, and the second overlapping surface is matched with the inner circumferential surface of the annular boss.

Optionally, the top surface of the annular boss is provided with a welding material so as to be fixedly connected with the first overlapping surface through the welding material.

Optionally, the closure has a top panel and a skirt extending downwardly from a periphery of the top panel, the skirt having a peripheral wall at a lower end thereof configured to form the overlapping groove.

Optionally, the coaming is provided with an annular portion on one side of the overlapping groove, the outer side surface of the annular portion forms a second overlapping surface of the overlapping groove, and the lower end surface of the annular portion is opposite to the inner surface of the substrate and is arranged at an interval.

Optionally, a distance between a lower end surface of the annular portion and the inner surface of the substrate ranges from 10 μm to 50 μm.

Optionally, a thickness of the substrate is greater than or equal to twice a height of the annular boss protruding from the inner surface of the substrate.

Optionally, the height of the annular boss protruding from the inner surface of the substrate ranges from 40 μm to 100 μm.

Optionally, the housing is provided with a sound inlet hole at the cover; alternatively, the housing is provided with a sound inlet hole in the substrate.

Optionally, the MEMS microphone further comprises a MEMS chip mounted on an inner surface of the substrate.

Optionally, the MEMS microphone further includes an ASIC chip, the ASIC chip is mounted on an inner surface of the substrate, and the MEMS chip is electrically connected to the MEMS chip.

The technical scheme of the utility model, set up annular boss through the periphery at the base plate, and be provided with the overlap joint groove at the periphery wall of closing cap, this closing cap is through the cooperation of this overlap joint groove with the annular boss overlap joint of base plate, thereby make the closing cap be difficult for following the interior surface of base plate to its circumference translation, realize the prepositioning to the closing cap, the condition that can effectively reduce the closing cap dislocation like this appears, very big local continuation carries out welded fastening to closing cap and base plate, improve the goodness rate of MEMS microphone assembly.

Drawings

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

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

FIG. 2 is P in FIG. 1₁An enlarged view of (a);

FIG. 3 is a schematic view of the substrate and cover assembly of the MEMS microphone of FIG. 1;

FIG. 4 is P in FIG. 3₂An enlarged view of (a);

FIG. 5 is P in FIG. 3₃An enlarged view of (a).

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Shell body	123a	First overlapping surface
110	Substrate	123b	Second overlapping surface
				111	Annular boss	124	Annular portion
111a	The top surface	101	Sound inlet hole
				111b	Inner peripheral surface	102	Packaging chamber
120	Sealing cover	200	MEMS chip
				121	Top board	300	ASIC chip
122	Boarding board	400	Welding material
				123	Overlapping groove

The purpose of the present invention is to provide a novel and improved method and apparatus for operating a computer.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that, if directional indications (such as upper, lower, left, right, front and rear … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides an embodiment of MEMS microphone, the condition that the fused welding material trickled or splashed the internals of MEMS microphone can be reduced in the MEMS microphone among the assembling process takes place to improve the product quality of MEMS microphone. It should be noted that the MEMS microphone may be applied to electronic devices such as a mobile phone, a tablet, a notebook computer, and a sensor.

Referring to fig. 1 to 3, in an embodiment of the MEMS microphone of the present invention, the MEMS microphone includes a housing 100; the casing 100 includes a substrate 110 and a cover 120 covering the substrate 110, wherein an annular boss 111 protruding from an inner surface of the substrate 110 is disposed at a periphery of the substrate 110; the outer peripheral wall of the cover 120 is provided with a lap groove 123, and the cover 120 is lapped on the annular boss 111 through the lap groove 123 and is fixedly connected with the annular boss 111.

Specifically, the substrate 110 of the housing 100 is a PCB board, on which a circuit is integrated; the cover 120 of the housing 100 is made of a metal material, and the cover 120 covers the substrate 110 to enclose the substrate 110 to form a package cavity 102, where the package cavity 102 is used for mounting the MEMS chip 200 and the ASIC chip 300. Here, the sound inlet hole 101 may be provided in the substrate 110, or the sound inlet hole 101 may be provided in the cover 120. In the present embodiment, the sound inlet hole 101 is provided on the substrate 110.

For the annular boss 111, the annular boss 111 surrounds the substrate 110 for a whole circle, and the annular boss 111 can be integrally formed with the substrate 110; or in other embodiments, the annular boss 111 may be a separate structure that is separately formed and mounted on the substrate 110. Accordingly, the overlapping groove 123 of the cover 120 is surrounded along the outer circumferential wall of the cover 120 by one full turn to correspond to the annular projection 111 of the base 110.

Since the overlapping groove 123 of the cover 120 is matched with the annular boss 111 of the substrate 110 to form the concave-convex embedded structure, when the concave-convex embedded positions of the cover 120 and the substrate 110 are welded, the high-temperature molten welding material 400 is not easy to penetrate the concave-convex embedded structure, and further is not easy to laterally flow or splash into the housing 100, and is not easy to contact with internal components of the MEMS microphone (such as the MEMS chip, the ASIC chip, and gold wires connecting the chips).

When the cover 120 is mounted on the substrate 110, the overlapping groove 123 of the cover 120 may be firstly overlapped on the annular boss 111 of the substrate 110 to limit the cover 120 inside the annular boss 111 of the substrate 110, and the cover 120 is not easy to translate along the inner surface of the substrate 110 to the circumferential direction thereof, so as to realize the pre-positioning of the cover 120; then, weld the lapped position of closing cap 120 and base plate 110 and fix, because closing cap 120 has been prepositioned, so be difficult for taking place the activity at welding in-process closing cap 120 to can greatly make things convenient for operating personnel to weld, the assembly of closing cap 120 and base plate 110 is accomplished to quick accurate, and then the condition that effectively reduces closing cap 120 dislocation appears.

The technical scheme of the utility model, through the periphery at base plate 110 set up annular boss 111, and be provided with overlap joint groove 123 at the periphery wall of closing cap 120, make closing cap 120 can overlap joint groove 123 and base plate 110's annular boss 111 and put the cooperation and form unsmooth gomphosis structure, therefore, when welding the unsmooth gomphosis position of closing cap 120 and base plate 110, this unsmooth gomphosis structure of difficult infiltration of high temperature melting's welding material 400, and then difficult side direction trickles or splashes the inside to casing 100, just also difficult internal member (like the MEMS chip, ASIC chip and the gold thread etc. of connecting these some chips of the chip of contact) to the MEMS microphone.

Referring to fig. 3 to 5, for the annular projection 111 of the substrate 110, the annular projection 111 may be configured as a first step or a second step. In this embodiment, the annular projection 111 is provided as a step, and the overlapping groove 123 should be adapted to the shape of the annular projection 111. Alternatively, the annular boss 111 has a top surface 111a and an inner peripheral surface 111b on one side of the top surface 111 a; accordingly, the overlapping groove 123 has a first overlapping surface 123a and a second overlapping surface 123b disposed at right angles to the first overlapping surface 123 a; wherein the first overlapping surface 123a is engaged with the top surface 111a of the annular boss 111, and the second overlapping surface 123b is engaged with the inner circumferential surface 111b of the annular boss 111.

Regarding the manner of fixing the cover 120 and the annular protrusion 111, a solder material 400 (e.g., solder paste) may be optionally disposed on the top surface 111a of the annular protrusion 111 to be soldered to the first overlapping surface 123a of the overlapping groove 123 via the solder material 400. During the soldering process, a soldering material 400 is added to the top surface 111a of the annular boss 111 of the substrate 110; then, the lap groove 123 of the cover 120 is lapped on the annular boss 111 of the base plate 110 from top to bottom, and as the welding material is heated and melted, the first lap surface 123a of the lap groove 123 is pressed down onto the top surface 111a of the annular boss 111, so that the first lap surface 123a is in large-area sealing connection with the top surface 111a of the annular boss 111, and the air tightness is improved.

In the above-mentioned welding process, the second overlapping surface 123b is kept attached to the side surface of the step, so that the gap between the second overlapping surface 123b and the side surface of the step is very small or even zero, and the welding material 400 melted at high temperature during the welding process is not easy to leak or splash into the inside of the housing 100 from between the second overlapping surface 123b and the side surface of the step, and thus is not easy to damage the internal components (such as the MEMS chip 200 and the ASIC chip 300) of the housing 100.

Referring to fig. 3 to 5, according to any of the above embodiments, the cover 120 includes a top plate 121 and a surrounding plate 122 extending downward from the periphery of the top plate 121, and the surrounding plate 122 forms a lap joint groove 123 at the outer periphery of the lower end thereof. The shroud 122 is sealingly attached to the annular boss 111 of the base plate 110 by the overlapping groove 123, thereby forming the enclosure 102 between the cover 120 and the inside of the base plate 110.

Further, the shroud 122 is formed with an annular portion 124 on one side of the overlapping groove 123, an outer side surface of the annular portion 124 forms a second overlapping surface 123b of the overlapping groove 123, and a lower end surface of the annular portion 124 faces the inner surface of the base plate 110. It is considered that if the lower end surface of the annular portion 124 contacts the inner surface of the base plate 110, the volume of the welding material 400 decreases after the welding material 400 is melted at a high temperature during the process of welding the cap 120, the cap 120 presses down on the annular boss 111, and the lower end surface of the annular portion 124 moves down to contact and abut against the inner surface of the base plate 110, so that the cap 120 cannot be pressed down, and it is difficult to ensure the airtightness of the connection between the first overlapping surface 123a of the overlapping groove 123 and the top surface 111a of the annular boss 111.

To solve the above technical problem, optionally, the lower end surface of the annular portion 124 is opposite to and spaced apart from the inner surface of the substrate 110. That is, the lower end surface of the annular portion 124 is suspended above the inner surface of the substrate 110, so that a space is reserved between the lower end surface of the annular portion 124 and the inner surface of the substrate 110, thereby preventing the lower end surface of the annular portion 124 from contacting and abutting against the inner surface of the substrate 110, and further pressing the overlapping groove 123 of the cover 120 onto the welding material 400 on the annular boss 111 in the process of welding the cover 120.

As shown in fig. 2, D in fig. 2 represents a distance between the lower end surface of the annular portion 124 and the inner surface of the substrate 110. The size of the distance can be reasonably designed according to the size of the MEMS microphone. Alternatively, the distance between the lower end surface of the annular portion 124 and the inner surface of the substrate 110 may be in a range from 10 μm to 50 μm, and may specifically be, but is not limited to: 20 μm, 30 μm, 40 μm, 50 μm, and the like. If the pitch is less than 10 μm, the first pitch is too small, and the ring portion 124 easily abuts against the inner surface of the substrate 110 to make it difficult to press the cap 120 against the soldering material 400. If the distance is larger than 50 μm, the distance is too large, and the distance occupies a larger longitudinal space, so that the overall volume of the MEMS microphone is increased, and the MEMS microphone is not beneficial to micro-design. Therefore, the pitch is preferably kept in the range of 10 μm to 50 μm.

As shown in FIG. 4, H in FIG. 4₁Expressed as the thickness, H, of the substrate 110₂Indicated as the height of the annular boss 111 protruding from the inner surface of the base plate 110. Alternatively, the thickness of the base plate 110 is greater than or equal to twice the height of the annular boss 111 protruding from the inner surface of the base plate 110. That is, H₁≥2*H₂. This ensures that the substrate 110 has a strong strength, and prevents the substrate 110 from being broken at a portion thereof located inside the annular projection 111.

Further, it is considered herein that if the height of the annular boss 111 is too small, the shroud 122 of the cover 120 is easily displaced against the restraining force of the annular boss 111, so that the positioning effect of the cover 120 is not good; if the height of the annular boss 111 is too large, the longitudinal space of the substrate 110 is correspondingly increased, and the overall volume of the MEMS microphone is increased, which is not beneficial to the MEMS microphone micro-design.

In view of this, research and analysis have shown that when the height of the annular protrusion 111 protruding from the inner surface of the substrate 110 is in the range of 40 μm to 100 μm, the annular protrusion 111 has a better limiting effect on the cap 120, and the cap 120 is limited inside the annular protrusion 111 and is not easily displaced; and, the vertical space occupied by the substrate 110 at this time is small. Therefore, the height of the annular protrusion 111 protruding from the inner surface of the substrate 110 may be in the range of 40 μm to 100 μm. Specific examples include, but are not limited to: 45 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 95 μm, and the like. Of course, the height of the annular protrusion 111 protruding from the inner surface of the substrate 110 may be selected from a range of 40 μm to 60 μm.

Referring to fig. 1, according to any of the above embodiments, the MEMS microphone further includes a MEMS chip 200 and an ASIC chip 300; the MEMS chip 200 and the ASIC chip 300 are both mounted on the inner surface of the substrate 110; the ASIC chip 300 is electrically connected to the MEMS chip 200. The MEMS chip 200 is used for sensing sound and processing the sound into an electrical signal, and the ASIC chip 300 is used for receiving and processing the electrical signal transmitted by the MEMS chip 200.

Since the cover 120 of the housing 100 is in lap fit with the annular boss 111 of the substrate 110 through the lap groove 123, in the process of soldering and connecting the cover 120 and the substrate 110, the solder melted at high temperature is not easy to splash onto the MEMS chip 200 and the ASIC chip 300 beyond the soldering position of the cover 120 and the substrate 110, and thus the MEMS chip 200, the ASIC chip 300 or the gold wires connected to these chips are not easy to be damaged, and the MEMS chip 200 and the ASIC chip 300 are protected.

The above only is the preferred embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structure changes made by the contents of the specification and the drawings under the inventive concept of the present invention, or the direct/indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A MEMS microphone, comprising:

the shell comprises a substrate and a sealing cover covering the substrate; wherein the content of the first and second substances,

the outer periphery of the substrate is provided with an annular boss protruding out of the inner surface of the substrate;

the periphery wall of closing cap is provided with the overlap joint groove, the closing cap passes through the overlap joint groove overlap joint be in on the annular boss, and with annular boss is connected fixedly.

2. The MEMS microphone of claim 1, wherein the annular boss has a top surface and an inner circumferential surface on one side of the top surface; the lapping groove is provided with a first lapping surface and a second lapping surface which is arranged at a right angle with the first lapping surface; the first overlapping surface is matched with the top surface of the annular boss, and the second overlapping surface is matched with the inner circumferential surface of the annular boss.

3. The MEMS microphone of claim 2, wherein a top surface of the annular boss is provided with a welding material to be connected and fixed with the first land by the welding material.

4. The MEMS microphone of claim 2, wherein the cap has a top plate and a skirt extending downward from a periphery of the top plate, the skirt having a peripheral wall at a lower end thereof configured to form the lap joint groove.

5. The MEMS microphone according to claim 4, wherein the surrounding plate is formed with a ring portion at one side of the lap groove, an outer side surface of the ring portion forms a second lap surface of the lap groove, and a lower end surface of the ring portion is opposed to and spaced apart from an inner surface of the substrate.

6. The MEMS microphone of claim 5, wherein a distance between a lower end surface of the annular portion and an inner surface of the substrate is in a range of 10 μm to 50 μm.

7. The MEMS microphone of any one of claims 1 to 6, wherein a thickness of the substrate is greater than or equal to twice a height of the annular boss that projects from an inner surface of the substrate.

8. The MEMS microphone of claim 7, wherein the height of the annular boss protruding from the inner surface of the substrate is in a range of 40 μm to 100 μm.

9. The MEMS microphone of any one of claims 1 to 6, wherein the housing is provided with a sound inlet hole at the cover; alternatively, the housing is provided with a sound inlet hole in the substrate.

10. The MEMS microphone of any one of claims 1 to 6, further comprising a MEMS chip and an ASIC chip; the MEMS chip and the ASIC chip are both arranged on the inner surface of the substrate, and the MEMS chip is electrically connected with the MEMS chip.