CN213847007U - Micro-electro-mechanical microphone packaging structure and micro-electro-mechanical system microphone - Google Patents

Abstract

The utility model discloses a micro-electromechanical system microphone packaging structure and micromotor system microphone. The micro-electromechanical microphone packaging structure comprises: a substrate base plate; the cross section of the bonding layer on a plane parallel to the substrate base plate is in an annular closed graph; the micro-electro-mechanical microphone chip comprises a micro-electro-mechanical microphone unit and a supporting part for supporting the micro-electro-mechanical microphone unit, wherein the supporting part is provided with a cavity structure and is positioned on the surface of one side, far away from the substrate, of the bonding layer; the projection of the bonding layer on the substrate base plate surrounds the projection of the cavity structure on the substrate base plate, and the ratio of the overlapping area of the projection of the bonding layer on the substrate base plate and the projection of the cavity structure on the substrate base plate to the projection area of the cavity structure on the substrate base plate is greater than or equal to 0% and less than or equal to 50%. The utility model provides a technical scheme has improved the stability of the acoustoelectric conversion performance of micro-electromechanical microphone chip.

Description

Micro-electro-mechanical microphone packaging structure and micro-electro-mechanical system microphone

Technical Field

The embodiment of the utility model provides a relate to semiconductor technology field, especially relate to a micro-electromechanical system microphone packaging structure and micromotor microphone.

Background

With the development of wireless communication, more and more mobile phone users are worldwide. People have higher and higher requirements on call quality. Micro Electro Mechanical System (MEMS) microphone packaging structures are more widely used at present.

The existing micro-electromechanical microphone packaging structure comprises a substrate, an adhesive layer and a micro-electromechanical microphone chip, but the projection of the adhesive layer on the substrate usually has most of cavity structures arranged in the micro-electromechanical microphone chip in the projection of the substrate, and the deformation of a vibrating diaphragm is affected due to the difference of sound wave transmission distances, so that the stability of the sound-electricity conversion performance of the micro-electromechanical microphone chip is not high.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the present invention provides a micro electro mechanical system microphone and a package structure thereof, which improves the stability of the acoustic-electric conversion performance of the micro electro mechanical system microphone chip.

In a first aspect, an embodiment of the present invention provides a micro-electromechanical microphone packaging structure, including:

a substrate base plate;

the cross section of the bonding layer on a plane parallel to the substrate base plate is in an annular closed graph;

the micro-electromechanical microphone chip comprises a micro-electromechanical microphone unit and a supporting part for supporting the micro-electromechanical microphone unit, wherein the supporting part is provided with a cavity structure and is positioned on the surface of one side of the bonding layer, which is far away from the substrate;

the projection of the bonding layer on the substrate base plate surrounds the projection of the cavity structure on the substrate base plate, and the ratio of the overlapping area of the projection of the bonding layer on the substrate base plate and the projection of the cavity structure on the substrate base plate to the projection area of the cavity structure on the substrate base plate is greater than or equal to 0% and less than or equal to 50%.

Optionally, a ratio of an area of the bonding layer overlapping with the projection of the cavity structure on the substrate base plate to the projection of the cavity structure on the substrate base plate is equal to 0%.

Optionally, the inner edge of the cross-sectional shape of the bonding layer parallel to the plane of the substrate base plate is surrounded by a wave-shaped curve.

Optionally, the cross-sectional shape of the bonding layer in a plane parallel to the substrate base plate is defined by a plurality of circles.

Optionally, an annular groove is formed in the substrate base plate, and the bonding layer is at least partially located in the annular groove;

the projection of the annular groove on the substrate base plate and the projection of the cavity structure on the substrate base plate are not overlapped, and the projection of the annular groove on the substrate base plate surrounds the projection of the cavity structure on the substrate base plate.

Optionally, the depth of the annular groove is greater than or equal to 15 micrometers and less than or equal to 30 micrometers.

Optionally, the depth at the corner of the annular groove is greater than the depth at the non-corner.

Optionally, the substrate further comprises a support ring, wherein the support ring is positioned between the bonding layer and the substrate base plate;

the projection of the support ring on the substrate base plate and the projection of the cavity structure on the substrate base plate are not overlapped, and the projection of the support ring on the substrate base plate surrounds the projection of the cavity structure on the substrate base plate.

Optionally, the surface of the support ring close to one side of the cavity structure is provided with a groove pattern or a protrusion pattern.

Optionally, the base substrate includes a printed circuit board.

In a second aspect, an embodiment of the present invention further provides a mems microphone, including any of the mems microphone package structures of the first aspect;

the micro-electro-mechanical microphone packaging structure further comprises an application-specific integrated circuit chip, and the application-specific integrated circuit chip is electrically connected with the micro-electro-mechanical microphone chip included in the micro-electro-mechanical microphone packaging structure.

The technical scheme provided by this embodiment controls the ratio of the overlapping area of the projection of the bonding layer on the substrate base plate and the projection of the cavity structure on the substrate base plate to the projection area of the cavity structure on the substrate base plate to be greater than or equal to 0% and less than or equal to 50%, reduces the overlapping area of the projection of the bonding layer on the substrate base plate and the projection of the cavity structure on the substrate base plate, and ensures that most of the sound waves are transmitted at the same distance in the cavity structure, so that the deformation of the diaphragm caused by the difference of the transmission distances in the transmission process of the sound waves in the cavity structure is not affected, and avoids the technical problem that the deformation of the bonding layer on the substrate base plate in the prior art usually causes most of the cavity structure arranged at the supporting portion in the projection of the substrate base plate, and the acoustic-to-electrical conversion performance of the micro-electro-mechanical microphone chip is affected due to the difference of the transmission distances of the sound waves, and the stability of the sound-electricity conversion performance of the micro-electromechanical microphone chip is improved. In addition, in the prior art, the adhesive layer is formed by continuously extruding the adhesive, and for the uncontrollable uniformity and continuity of the adhesive extruded each time, the cross-sectional shape of the adhesive layer in a plane parallel to the substrate may be not in a ring-shaped closed pattern, which results in poor sealing performance between the mems microphone chip and the substrate. According to the technical scheme, the point-shaped bonding objects are formed by adopting piezoelectric glue spraying, pneumatic extrusion, glue dipping and the like, no interval exists between the adjacent point-shaped bonding objects, so that the bonding layer is in an annular closed graph in the cross section parallel to the plane where the substrate base plate is located, and good sealing performance between the micro-electro-mechanical microphone chip and the substrate base plate is guaranteed.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

fig. 1 is a schematic structural diagram of a mems microphone package structure in the prior art;

fig. 2 is a schematic structural diagram of a mems microphone package structure according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention;

fig. 7 is a further micro-electromechanical microphone package structure according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a micro-motor system microphone according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

As described in the background art, the projection of the bonding layer of the existing mems microphone package structure on the substrate usually has a portion located in the projection of the cavity structure of the mems microphone chip on the substrate, which results in low stability of the acoustic-electrical conversion performance of the mems microphone chip. Fig. 1 is a schematic structural diagram of a mems microphone package structure in the prior art. Wherein FIG. 1a is a top view of a base substrate 10 and an adhesive layer 20; FIG. 1b is a top view of the entire MEMS microphone package structure; FIG. 1c is a cross-sectional view taken along line A1-A2 of FIG. 1 b. Referring to fig. 1, for this reason, the mems microphone unit 31 included in the mems microphone chip 30 includes a diaphragm 310 and a backplate 311, the diaphragm 310 and the backplate 311 form a capacitor structure, when the diaphragm 310 senses an external audio sound pressure signal, a distance between the diaphragm 310 and the backplate 311 changes, a capacitance capacity of the capacitor structure formed by the diaphragm 310 and the backplate 311 changes, and correspondingly, voltage values of the diaphragm 310 and the backplate 311 change, wherein the substrate 10 is provided with a through hole 10A for sound wave transmission. In the prior art, the adhesive layer 20 is generally formed by continuously extruding a linear adhesive, and the content of the adhesive is large for each extrusion. The projection of the adhesive layer 20 formed by curing the adhesive on the substrate base plate 10 usually has a part of the cavity structure 32A arranged on the support part 32 in the projection of the substrate base plate 10, resulting in that the distance of transmission of the sound wave in the cavity structure 32A is different, two transmission distances of the first distance L1 and the second distance L2 exist, since the ratio of the area of the overlap of the projection of the adhesive layer 20 on the base substrate 10 and the projection of the cavity structure 32A on the base substrate 10 to the area of the projection of the cavity structure 32A on the base substrate 10 is too large, typically more than 50%, and further, the deformation of the diaphragm 310 is affected by the difference of the transmission distance, which affects the distance between the diaphragm 310 and the backplate 311, causes the change of the capacitance capacity of the capacitance structure formed by the diaphragm 310 and the backplate 311, and the change of the voltage value of the diaphragm 310 and the backplate 311, thereby causing the technical problem that the stability of the sound-electricity conversion performance of the micro-electromechanical microphone chip 30 is not high.

To the above technical problem, the embodiment of the utility model provides a following technical scheme:

fig. 2 is a schematic structural diagram of a mems microphone package structure according to an embodiment of the present invention. Wherein fig. 2a is a top view of the base substrate 10 and the adhesive layer 20; FIG. 2b is a top view of the entire MEMS microphone package structure; FIG. 2c is a cross-sectional view taken along line A1-A2 of FIG. 2 b. Referring to fig. 2, the mems microphone package structure includes: a base substrate 10; the cross section of the bonding layer 20 in a plane parallel to the substrate base plate 10 is in an annular closed graph shape; the micro-electromechanical microphone chip 30 comprises a micro-electromechanical microphone unit 31 and a supporting part 32 for supporting the micro-electromechanical microphone unit 31, wherein the supporting part 32 is provided with a cavity structure 32A, and the supporting part 32 is located on the surface of the bonding layer 20 far away from one side of the substrate base plate 10; the projection of the bonding layer 20 on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10, and the ratio of the overlapping area of the projection of the bonding layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 to the projection area of the cavity structure 32A on the substrate base plate 10 is greater than or equal to 0% and less than or equal to 50%.

It can be known that, the micro-electromechanical microphone chip 30 includes the micro-electromechanical microphone unit 31 and the supporting portion 32, the micro-electromechanical microphone unit 31 includes the vibrating diaphragm 310 and the backplate 311, the vibrating diaphragm 310 and the backplate 311 constitute a capacitance structure, after the vibrating diaphragm 310 senses an external audio sound pressure signal, a distance between the vibrating diaphragm 310 and the backplate 311 changes, a capacitance capacity of the capacitance structure formed by the vibrating diaphragm 310 and the backplate 311 changes, and correspondingly, voltage values of the vibrating diaphragm 310 and the backplate 311 change, so that the micro-electromechanical microphone chip 30 converts the sound signal into an electrical signal, wherein the substrate 10 is provided with a through hole 10A for sound wave transmission.

In this embodiment, a plurality of dot-shaped adhesives are formed one at a time by using a piezoelectric glue spraying, pneumatic extrusion, glue dipping, or the like, or a plurality of dot-shaped adhesives are formed at a time, and the adhesive layer 20 is formed after the adhesives are cured. Although the projection of the bonding layer 20 formed by curing the bonding material on the substrate base plate 10 may have a part of the transmission distance of the cavity structure 32A arranged on the support portion 32 in the projection of the substrate base plate 10, which is different from the transmission distance of the sound wave in the cavity structure 32A, and there are two transmission distances of the first distance L1 and the second distance L2, the content of the dot-shaped bonding material in the embodiment is easy to control, so that the ratio of the overlapping area of the projection of the bonding layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 to the projection area of the cavity structure 32A on the substrate base plate 10 can be precisely controlled to be greater than or equal to 0% and less than or equal to 50%, the overlapping area of the projection of the bonding layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 is reduced to ensure that the distance of the most of the sound wave transmitted in the cavity structure 32A is the second transmission distance L2, therefore, the deformation of the diaphragm 310 caused by the difference of the transmission distance in the transmission process of the sound wave in the cavity structure 32A is not affected, and the technical problem that the sound-electricity conversion performance of the micro-electromechanical microphone chip is affected due to the fact that the most part of the cavity structure 32A arranged on the supporting portion 32 is usually exposed in the projection of the substrate 10 by the bonding layer 20 in the projection of the substrate 10 in the prior art and the deformation of the diaphragm 310 is affected by the difference of the transmission distance of the sound wave is avoided, thereby improving the stability of the sound-electricity conversion performance of the micro-electromechanical microphone chip. In addition, in the prior art, the adhesive layer 20 is formed by continuously extruding the adhesive, and for the uncontrollable uniformity and continuity of the adhesive extruded each time, the cross-sectional shape of the adhesive layer 20 in a plane parallel to the substrate 10 may be not in a ring-shaped closed pattern, which results in poor sealing performance between the mems microphone chip 30 and the substrate 10. According to the technical scheme in the embodiment, the point-shaped bonding objects are formed by adopting piezoelectric glue spraying, pneumatic extrusion, glue dipping and the like, no interval exists between the adjacent point-shaped bonding objects, so that the cross section of the bonding layer 20 in a plane parallel to the substrate base plate 10 is in an annular closed pattern, and good sealing performance between the micro-electromechanical microphone chip 30 and the substrate base plate 10 is guaranteed.

On the basis of the above technical solution, the base substrate 10 includes a printed circuit board. The printed circuit board with low price is used as the substrate base plate 10, the cost of the formed micro-electromechanical microphone packaging structure is low, and other external chips electrically connected with the micro-electromechanical microphone chip 30 can be conveniently placed.

Fig. 3 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention. Wherein fig. 3a is a top view of the base substrate 10 and the adhesive layer 20; FIG. 3b is a top view of the entire MEMS microphone package structure; FIG. 3c is a cross-sectional view taken along line A1-A2 of FIG. 3 b. Alternatively, referring to fig. 3, the ratio of the area of the projection of the adhesive layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 to the area of the projection of the cavity structure 32A on the substrate base plate 10 is equal to 0%, i.e., the projection of the adhesive layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 do not overlap.

Because the content of the point-shaped bonding objects is easy to control, the projection of the bonding layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 can be accurately controlled to have no overlap, to ensure that the distance that the sound waves travel in the cavity structure 32A are both the second travel distance L2, therefore, the deformation of the diaphragm 310 caused by the difference of the transmission distance in the transmission process of the sound wave in the cavity structure 32A is not affected, and the technical problem that the sound-electricity conversion performance of the micro-electromechanical microphone chip is affected due to the fact that the most part of the cavity structure 32A arranged on the supporting portion 32 is usually exposed in the projection of the substrate 10 by the bonding layer 20 in the projection of the substrate 10 in the prior art and the deformation of the diaphragm 310 is affected by the difference of the transmission distance of the sound wave is avoided, thereby improving the stability of the sound-electricity conversion performance of the micro-electromechanical microphone chip.

The cross-sectional shape of the adhesive layer 20 in a plane parallel to the base substrate 10 will be described in detail. Fig. 4 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention. Wherein fig. 4a is a top view of the base substrate 10 and the adhesive layer 20; FIG. 4b is a top view of the entire MEMS microphone package structure; FIG. 4c is a cross-sectional view taken along line A1-A2 of FIG. 4 b. On the basis of the above technical solution, referring to fig. 4, in the structure of the mems microphone package structure, the inner edge of the cross-sectional shape of the bonding layer 20 parallel to the plane of the substrate 10 is defined by a wave-shaped curve.

In particular, since the present embodiment adopts the piezoelectric glue spraying, pneumatic extrusion, glue dipping and other manners to form the point-shaped bonding object, by controlling the distance between the adjacent dot-shaped adhesives, the adhesive layer 20 formed after curing of the plurality of dot-shaped adhesives is surrounded by a wave-shaped curve at the inner edge of the cross-sectional shape parallel to the plane of the substrate board 10, and in the case where the width is large as compared with the line-shaped adhesives, the effect of reducing the content of the formed point-shaped bonding objects of the bonding layer 20 is achieved, the ratio of the overlapping area of the projection of the bonding layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 to the projection area of the cavity structure 32A on the substrate base plate 10 is accurately controlled, further, it is ensured that the deformation of the diaphragm 310 caused by the difference of the transmission distances is not affected during the transmission of the sound waves in the cavity structure 32A, and the stability of the sound-electricity conversion performance of the micro-electro-mechanical microphone chip is improved. In this embodiment, the ratio of the area of the overlapping projection of the adhesive layer 20 on the substrate 10 and the projection of the cavity structure 32A on the substrate 10 to the area of the projection of the cavity structure 32A on the substrate 10 is equal to 0%.

Fig. 5 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention. Wherein fig. 5a is a top view of the base substrate 10 and the adhesive layer 20; FIG. 5b is a top view of the entire MEMS microphone package structure; FIG. 5c is a cross-sectional view taken along line A1-A2 of FIG. 5 b. On the basis of the above technical solution, referring to fig. 5, the cross-sectional shape of the adhesive layer 20 in a plane parallel to the substrate base plate 10 is defined by a plurality of circles. When the dot-shaped bonding objects are formed, the distance between the dot-shaped bonding objects is properly increased, so that the adjacent dot-shaped bonding objects are in contact, the cross section of the bonding layer 20 formed after the plurality of dot-shaped bonding objects are cured and parallel to the plane of the substrate base plate 10 is defined by a plurality of circles, the effect of further reducing the content of the bonding objects forming the bonding layer 20 is achieved, the ratio of the overlapping area of the projection of the bonding layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 to the projection area of the cavity structure 32A on the substrate base plate 10 is accurately controlled, the condition that the deformation of the diaphragm 310 is influenced due to the difference of transmission distances in the transmission process of the sound waves in the cavity structure 32A is further ensured, and the stability of the sound-electricity conversion performance of the micro-electro-mechanical microphone chip is improved. In this embodiment, the ratio of the area of the overlapping projection of the adhesive layer 20 on the substrate 10 and the projection of the cavity structure 32A on the substrate 10 to the area of the projection of the cavity structure 32A on the substrate 10 is equal to 0%.

In order to further limit the content of the bonding layer 20 in contact with the mems microphone chip 30, the embodiment of the present invention further provides the following technical solutions:

fig. 6 is a schematic structural diagram of another mems microphone package structure according to an embodiment of the present invention. Wherein fig. 6a is a top view of the base substrate 10 and the adhesive layer 20; FIG. 6b is a top view of the entire MEMS microphone package structure; FIG. 6c is a cross-sectional view taken along line A1-A2 of FIG. 6 b; FIG. 6d is a cross-sectional view taken along line B1-B2 of FIG. 6B. On the basis of the above technical solution, referring to fig. 6, in the micro-electromechanical microphone packaging structure, an annular groove 10B is formed on a substrate 10, and at least a part of an adhesive layer 20 is located in the annular groove 10B; the projection of the annular groove 10B on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 do not overlap, and the projection of the annular groove 10B on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10.

It should be noted that the adhesive layer 20 is at least partially located in the annular groove 10B, i.e., part of the adhesive layer 20 is located in the annular groove 10B or the entire adhesive layer 20 is located in the annular groove 10B.

On the basis that the projection of the adhesive layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 are not overlapped, and the projection of the adhesive layer 20 on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10, when part of the adhesive layer 20 is positioned in the annular groove 10B, the height of the adhesive layer 20 is higher than the depth of the annular groove 10B, so that the surface of the supporting part 32 far away from the micro-electromechanical microphone unit 31 can be ensured to be completely contacted with the adhesive layer 20, and further, the micro-electromechanical microphone chip 30 and the substrate base plate 10 are ensured to have good sealing performance. Since the content of the dot-shaped adhesive in this embodiment is easy to control, the overlapping area between the projection of the adhesive layer 20 on the substrate 10 and the projection of the cavity structure 32A on the substrate 10 can be precisely controlled, so as to ensure that the deformation of the diaphragm 310 caused by the difference of the transmission distances during the transmission of the acoustic wave in the cavity structure 32A is not affected.

When all the bonding layers 20 are located in the annular groove 10B, the height of the bonding layers 20 is equal to the depth of the annular groove 10B, and the surface of the supporting portion 32 away from the micro-electromechanical microphone unit 31 is just completely contacted with the bonding layers 20, so that on the basis of ensuring good sealing performance between the micro-electromechanical microphone chip 30 and the substrate base plate 10, the consumption of bonding materials is reduced, and further the cost of the micro-electromechanical microphone packaging structure is reduced.

Specifically, in the technical scheme, the adhesive layer 20 is limited in the annular groove 10B, the projection of the annular groove 10B on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 are not overlapped, and the projection of the annular groove 10B on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10, and because the content of the point-shaped adhesive substance is easily controlled in the embodiment, the overlapping area of the projection of the adhesive layer 20 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 can be accurately controlled, so that the deformation of the diaphragm 310 caused by the difference of transmission distances in the transmission process of the sound wave in the cavity structure 32A is not affected, and the stability of the sound-electricity conversion performance of the micro-electromechanical microphone chip is further improved.

The depth range of the annular groove 10B is further described below. On the basis of the technical scheme, the depth of the annular groove 10B is greater than or equal to 15 micrometers and less than or equal to 30 micrometers.

Specifically, the depth of the annular groove 10B is too small to be less than 15 μm, and is insufficient to place the adhesive, resulting in the adhesive overflowing from the annular groove 10B. The depth of the annular groove 10B is too great to be larger than 30 microns, resulting in the substrate base plate 10 being too mechanically weak to support the microelectromechanical microphone chip 30 and the adhesive layer 20.

Since the amount of the adhesive at the corners of the annular groove 10B is relatively large, the adhesive easily overflows from the annular groove 10B. To solve the above technical problem, an embodiment of the present invention provides the following technical solution, referring to fig. 6c and 6d, the depth of the corner of the annular groove 10B is greater than the depth of the non-corner.

Specifically, because the amount of the adhesive formed at the corner of the annular groove 10B is relatively large due to the structural characteristics of the corner of the annular groove 10B, and the adhesive easily overflows from the annular groove 10B, in this embodiment, the depth of the corner of the annular groove 10B is greater than the depth of the corner, so that all the adhesive can be placed in the annular groove 10B to avoid the adhesive from entering the cavity structure 32A, so that the projection of the adhesive layer 20 on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10, and it can be ensured that the distance of transmission of the sound wave in the cavity structure 32A is the second transmission distance L2, therefore, the deformation of the diaphragm 310 caused by the difference of the transmission distances during the transmission of the sound wave in the cavity structure 32A is not affected, and it is avoided that the projection of the adhesive layer 20 on the substrate base plate 10 in the prior art usually has the projection of the cavity structure 32A on the substrate base plate 10 located at most of the supporting portion 32, the deformation of the diaphragm 310 is affected by the difference of the transmission distance of the sound wave, which results in the technical problem that the acoustoelectric conversion performance of the micro-electromechanical microphone chip is affected, and further improves the stability of the acoustoelectric conversion performance of the micro-electromechanical microphone chip.

The embodiment of the utility model provides a micro-electromechanical microphone packaging structure is still provided. Fig. 7 is a further micro-electromechanical microphone package structure according to an embodiment of the present invention. Wherein fig. 7a is a top view of the base substrate 10 and the adhesive layer 20; FIG. 7b is a top view of the entire MEMS microphone package structure; FIG. 7c is a cross-sectional view taken along line A1-A2 of FIG. 7 b; FIG. 7d is a schematic surface view of one of the support rings 40 of FIG. 7b adjacent to the cavity structure 32A; figure 7e is a schematic surface view of an alternative support ring 40 of figure 7b adjacent to the cavity structure 32A. On the basis of the above technical solution, referring to fig. 7, the mems microphone package structure further includes a support ring 40, where the support ring 40 is located between the bonding layer 20 and the substrate 10; the projection of the support ring 40 on the substrate base 10 and the projection of the cavity structure 32A on the substrate base 10 do not overlap, and the projection of the support ring 40 on the substrate base 10 surrounds the projection of the cavity structure 32A on the substrate base 10.

Specifically, as long as it is ensured that the projection of the support ring 40 on the substrate base plate 10 and the projection of the cavity structure 32A on the substrate base plate 10 do not overlap, the projection of the support ring 40 on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10, and the excess adhesive can extend to the side surface of the support ring 40 to avoid the adhesive from entering into the cavity structure 32A, so that the projection of the adhesive layer 20 on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10, it can be ensured that the transmission distances of the sound wave in the cavity structure 32A are both the second transmission distance L2, so that the deformation of the diaphragm 310 caused by the difference of the transmission distances during the transmission of the sound wave in the cavity structure 32A is not affected, and it is avoided that the projection of the adhesive layer 20 on the substrate base plate 10 in the prior art usually has most of the projection of the cavity structure 32A on the substrate base plate 10, the deformation of the diaphragm 310 is affected by the difference of the transmission distance of the sound wave, which results in the technical problem that the acoustoelectric conversion performance of the micro-electromechanical microphone chip is affected, and further improves the stability of the acoustoelectric conversion performance of the micro-electromechanical microphone chip.

In order to extend the excess adhesive to the side of the support ring 40, but not to the surface of the substrate base plate 10, the following technical solutions are provided in the present embodiment:

referring to fig. 7, the surface of the support ring 40 adjacent to the side of the cavity structure 32A is provided with a groove pattern 40A or a protrusion pattern 40B.

Specifically, the groove pattern 40A or the protrusion pattern 40B may be disposed as an extra adhesive to ensure that the extra adhesive may extend to the side of the support ring 40 and may not further extend to the surface of the substrate base plate 10, thereby preventing the adhesive from entering into the cavity structure 32A, realizing that the projection of the adhesive layer 20 on the substrate base plate 10 surrounds the projection of the cavity structure 32A on the substrate base plate 10, and ensuring that the transmission distance of the sound wave in the cavity structure 32A is the second transmission distance L2, so that the deformation of the diaphragm 310 caused by the difference of the transmission distances during the transmission process of the sound wave in the cavity structure 32A is not affected, and avoiding that the most of the projection of the adhesive layer 20 on the substrate base plate 10 is located in the projection of the cavity structure 32A disposed on the support portion 32 on the substrate base plate 10 in the prior art, and the deformation of the diaphragm 310 is affected by the difference of the transmission distances of the sound wave, the technical problem that the sound-electricity conversion performance of the micro-electro-mechanical microphone chip is influenced is caused, and the stability of the sound-electricity conversion performance of the micro-electro-mechanical microphone chip is improved.

Fig. 8 is a schematic structural diagram of a micro-motor system microphone according to an embodiment of the present invention. Referring to fig. 8, the mems microphone includes a mems microphone package structure composed of a substrate 10, an adhesive layer 20, and a mems microphone chip 30 in the above technical solution; also included is an application specific integrated circuit chip 50, with electrical connections between the application specific integrated circuit chip 50 and the microelectromechanical microphone chip 30.

The application specific integrated circuit chip 50 is electrically connected with the micro-electromechanical microphone chip 30, and is used for processing and outputting the voltage signal converted from the sound signal by the micro-electromechanical microphone chip 30.

This embodiment of the utility model provides a little electromechanical system microphone includes that above-mentioned technical scheme is arbitrary micro electromechanical system microphone packaging structure, consequently the embodiment of the utility model provides a little electromechanical system microphone also has the beneficial effect that describes in the above-mentioned embodiment, and here is no longer repeated.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. MEMS microphone packaging structure, its characterized in that includes:

a substrate base plate;

the cross section of the bonding layer on a plane parallel to the substrate base plate is in an annular closed graph;

the micro-electromechanical microphone chip comprises a micro-electromechanical microphone unit and a supporting part for supporting the micro-electromechanical microphone unit, wherein the supporting part is provided with a cavity structure and is positioned on the surface of one side of the bonding layer, which is far away from the substrate;

the projection of the bonding layer on the substrate base plate surrounds the projection of the cavity structure on the substrate base plate, and the ratio of the overlapping area of the projection of the bonding layer on the substrate base plate and the projection of the cavity structure on the substrate base plate to the projection area of the cavity structure on the substrate base plate is greater than or equal to 0% and less than or equal to 50%.

2. The microelectromechanical microphone package structure of claim 1, characterized in that a ratio of an area of overlap of a projection of the adhesive layer on the substrate base and a projection of the cavity structure on the substrate base to a projected area of the cavity structure on the substrate base is equal to 0%.

3. The microelectromechanical microphone package structure of claim 1, wherein the bonding layer is defined by a wave-shaped curve at an inner edge of a cross-sectional shape parallel to a plane of the substrate base.

4. The microelectromechanical microphone package structure of claim 3, characterized in that the cross-sectional shape of the bonding layer in a plane parallel to the substrate base is defined by a plurality of circles.

5. The microelectromechanical microphone package structure of claim 1, characterized in that the substrate has an annular groove disposed thereon, the bonding layer being at least partially disposed in the annular groove;

the projection of the annular groove on the substrate base plate and the projection of the cavity structure on the substrate base plate are not overlapped, and the projection of the annular groove on the substrate base plate surrounds the projection of the cavity structure on the substrate base plate.

6. The microelectromechanical microphone package structure of claim 5, characterized in that the depth of the annular groove is greater than or equal to 15 microns and less than or equal to 30 microns.

7. The microelectromechanical microphone package structure of claim 5, wherein a depth at a corner of the annular recess is greater than a depth at a non-corner.

8. The microelectromechanical microphone package structure of claim 1, further comprising a support ring positioned between the bonding layer and the substrate;

the projection of the support ring on the substrate base plate and the projection of the cavity structure on the substrate base plate are not overlapped, and the projection of the support ring on the substrate base plate surrounds the projection of the cavity structure on the substrate base plate.

9. The mems microphone package structure of claim 8, wherein a surface of the support ring on a side thereof adjacent to the cavity structure is provided with a groove pattern or a protrusion pattern.

10. A mems microphone comprising the mems microphone package of any one of claims 1-9;

the micro-electro-mechanical microphone packaging structure further comprises an application-specific integrated circuit chip, and the application-specific integrated circuit chip is electrically connected with the micro-electro-mechanical microphone chip included in the micro-electro-mechanical microphone packaging structure.

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