WO2016011780A1

WO2016011780A1 - Mems microphone and top-port mems microphone

Info

Publication number: WO2016011780A1
Application number: PCT/CN2014/095523
Authority: WO
Inventors: 万景明
Original assignee: 山东共达电声股份有限公司
Priority date: 2014-07-25
Filing date: 2014-12-30
Publication date: 2016-01-28

Abstract

An MEMS microphone comprises a circuit board, a package structure enclosed by a housing, and a sound hole. An MEMS chip and an integrated circuit ASIC chip are disposed in the package structure. The sound hole is formed in the housing. The inner cavity of the MEMS chip is in communication with the sound hole to form a front cavity of the MEMS microphone. The sound hole is formed in the housing, a bonding pad on the circuit board and the sound hole in the housing are disposed on two ends of the MEMS microphone respectively, and therefore, no soldering point exists near the sound hole, and no rosin and other impurities enter a sound cavity through the sound hole (12) during reflow soldering. The inner cavity of the MEMS chip is in communication with the sound hole to form the front cavity of the MEMS microphone, the front cavity occupies only a small part of the volume; back cavities are formed in the space between the outer side of the MEMS and the circuit board and the space between the outer side of the MEMS and the housing, the back cavities are large in volume, and therefore, the sensitivity and the signal-to-noise ratio of the MEMS microphone can be improved. A top-port MEMS microphone.

Description

MEMS microphone, forward sound MEMS microphone

This application claims the priority of the following five Chinese patent applications, the entire contents of which are hereby incorporated by reference in each of

1. Chinese patent application filed on July 25, 2014, Chinese Patent Office, application number 2014103564244.1, invention titled “a new type of MEMS MIC and its production process”;

2. Chinese patent application filed on October 22, 2014, the Chinese Patent Office, application number 201410565898.7, and the invention name is “a MEMS microphone”;

3. Submitted to the Chinese Patent Office on September 29, 2014, the application number is 201420566661.6, and the Chinese patent application titled “a MEMS microphone”;

4. Submitted to the Chinese Patent Office on September 29, 2014, the application number is 201420566745.X, and the Chinese patent application titled “a MEMS microphone”;

5. Submitted to the Chinese Patent Office on September 29, 2014, the application number is 201420566741.1, and the Chinese patent application titled “A Forward Sound MEMS Microphone”;

Technical field

The present application relates to the field of speaker equipment technology, and more particularly to a MEMS microphone and a forward sound MEMS microphone.

Background technique

Micro-Electro-Mechanical System (MEMS) microphones are microphones based on MEMS technology.

The structure of the MEMS microphone in the prior art is generally as shown in FIG. 1, and mainly includes: a circuit board 1', a MEMS chip 2', an integrated circuit ASIC chip 5', and a casing 8'; wherein the MEMS chip 2' adopts a bottom The glue 3' is bonded to the circuit board 1', and the integrated circuit ASIC 5' is fixed on the circuit board 1' by using a bottom glue 6'. The outer casing 8' is made of solder paste or glue. 'fixed on the circuit board 1', the MEMS chip 2' and the integrated circuit ASIC chip 5' and the circuit board 1' are connected by a gold wire 4', wherein "V rear" is a rear sound cavity, The "V front" is a front sound chamber, 12' is a sound hole, and 10' is a pad, wherein the pad 10' and the sound hole 12' are disposed on the same side of the circuit board 1', and the a sound hole 12' is disposed on the MEMS chip Corresponding position of the 2' sound chamber.

The applicant has found through research that since the pad 10' and the sound hole 12' in the comparative document 1 are disposed on the same side of the circuit board 1', it is easy to cause the rosin to pass through during the reflow process of the product. Hole 12' enters the front chamber and causes product failure.

Therefore, how to solve the problem that the MEMS microphone in the prior art causes product failure due to entering the rosin before the front sound chamber V during the reflow process becomes one of the technical problems to be solved by those skilled in the art.

Summary of the invention

In view of this, the present application provides a MEMS microphone for solving the problem that in the prior art, in the process of reflowing a MEMS microphone, it is easy to cause impurities such as rosin to enter the front sound chamber and cause product failure, and at the same time, Improve the sensitivity and signal-to-noise ratio of the forward sound products.

In order to achieve the above objectives, the proposed scheme is as follows:

The present invention provides a MEMS microphone comprising a package structure surrounded by a circuit board and a casing, and a sound hole, the package structure is internally provided with a MEMS chip and an integrated circuit ASIC chip, the sound hole is disposed on the outer casing; the MEMS chip An inner cavity is in communication with the sound hole to form a front cavity of the MEMS microphone.

Based on the above scheme, the present invention has the following technical effects:

1. Since the sound hole is disposed on the outer casing, the sound holes on the circuit board pad and the outer casing are respectively disposed at the two ends of the MEMS microphone, and there is no solder joint near the sound hole, so no rosin and other impurities pass through the sound hole during reflow soldering. 12 enter the sound chamber.

Second, the inner cavity of the MEMS chip communicates with the sound hole to form the front cavity of the MEMS microphone. Thus, the front cavity occupies only a small portion of the volume, and the space between the MEMS outer side and the circuit board and the outer casing forms a back cavity (ie, the rear sound cavity described in the background art), that is, most of the entire MEMS microphone cavity is used as The back cavity of the MEMS has a large volume of the back cavity, and the volume of the back cavity can increase the sensitivity and signal-to-noise ratio of the MEMS microphone. Therefore, the invention ensures the sensitivity and the reliability of the MEMS microphone under the premise of achieving the first technical effect described above. Noise ratio.

Optionally, an open end of the inner cavity of the MEMS chip is disposed opposite to the sound hole, and the MEMS chip directly fits on an inner wall of the outer casing.

Or connected to the inner wall of the outer casing by a connecting member for the sound hole to communicate with the sealing of the front cavity of the MEMS microphone.

Optionally, an open end of the MEMS chip is disposed toward the circuit board, and a channel is disposed inside the package structure to communicate the sound hole and the MEMS inner cavity, and form the front cavity.

Optionally, the MEMS microphone comprises a pallet fixed on the circuit board, and the bracket is provided with two through holes;

The MEMS chip is fixed on the pallet, and an inner cavity of the MEMS chip is opposite to a through hole of the pallet;

The MEMS microphone further includes a sealing ring fixed between the outer casing and the pallet, a top end of the sealing ring is fixed on an inner wall of the outer casing, and a bottom end is fixed on the pallet. The other through hole of the pallet is opposite to the inner cavity of the sealing ring, and the bracket communicates with the inner cavity of the MEMS chip and the inner cavity of the sealing ring;

The sound hole is opened on the outer casing corresponding to the inner cavity of the sealing ring, and the inner cavity of the sealing ring, the two through holes and the passage between the two through holes form the passage.

Optionally, the circuit board is provided with a first groove and a second groove;

The MEMS microphone further includes a seal ring fixed between the outer casing and the circuit board, the first recess being opposite to an inner cavity of the MEMS chip, the second recess and the The sealing ring is opposite to the port, and the sound hole is opened on the outer casing corresponding to the other port of the sealing ring, the inner cavity of the sealing ring, the first groove and the second groove, and The passage between the two forms the channel.

Optionally, a lead structure for turning on the circuit board is further included; the MEMS chip is electrically connected to the circuit board through the lead structure.

Optionally, there is no connection wire between the MEMS chip and the ASIC chip.

Optionally, the MEMS chip and the ASIC chip both turn on the circuit board through the lead structure.

In order to solve the above problems, the present invention also adopts the following technical solutions: a novel MEMS MIC includes a circuit board, a circuit board is bonded with a casing, a MEMS chip is disposed between the outer casing and the circuit board, and the MEMS chip has a side of the cavity. Bonded to the inner wall of the outer casing, and the other side is connected to the circuit board through the pad, and the sound hole is opened on the outer casing corresponding to the cavity of the MEMS chip, An ASIC chip is connected to the side of the MEMS chip on the circuit board. With the above technical solution, the intermediate board and the cover plate are replaced by a one-piece housing, and the MEMS chip is directly connected to the circuit board through the pad, and the MEMS chip and the ASIC chip are no longer connected by the gold wire, and the pad height is almost negligible. Except for the overall height of the MEMS MIC, it can be reduced in size and light weight. The sound hole corresponds to the cavity of the MEMS chip. The cavity of the MEMS chip is the front cavity, and the other cavity is the back cavity and back cavity. Larger, forward-looking MEMS MICs enable high signal-to-noise ratios.

The following are further improvements of the invention:

The ASIC chip is bonded to the circuit board through the bottom of the ASIC, and the ASIC chip and the circuit board are connected by a gold wire, thereby saving the bonding, sealing and curing processes, and the process is simpler.

Further improvement:

The ASIC chip is packaged with ASIC sealant, and the ASIC sealant makes the ASIC chip more secure.

Further improvement:

The ASIC chip is mounted on the board. The process of bonding, sealing and curing is saved, and the process is simpler.

Further improvement:

The bottom of the ASIC chip is filled with a filling glue, and the setting of the filling glue can make the ASIC chip fixed more firmly.

A new MEMS MIC production process that includes the following steps:

a. The MEMS chip is bonded to the outer casing by the bottom of the MEMS chip, and after curing, the pad is implanted on the MEMS chip;

b. Connect the ASIC chip to the terminal block;

d. Draw solder paste on the wiring board and bond the wiring board to the outer casing;

e. Ultrasonic welding of MEMS chips, SMT, to form MEMS MIC.

The above technical solution saves the bonding, sealing and curing processes, and the process is simpler.

The following are further improvements of the invention:

In step b, the ASIC chip is bonded to the wiring board by using an ASIC bottom glue, and the ASIC chip and the wiring board are connected by a gold wire.

Further improvement:

After the ASIC chip and the wiring board are connected by a gold wire, the ASIC sealing glue is sealed on the upper part of the ASIC chip.

Further improvement:

In step b, the ASIC chip is directly mounted on the wiring board.

Further improvement:

The bottom of the ASIC chip is filled with a filler, and the filling of the adhesive makes the ASIC chip more secure.

The invention adopts the above technical solution, and the height of the pad is almost negligible on the MEMS chip, so the overall height of the MEMS microphone is reduced, so that a microphone with a smaller and lighter quality can be produced; the back of the MEMS microphone The cavity is a cavity outside the MEMS chip inside the microphone casing, and has a larger volume, so that a higher signal-to-noise ratio than a conventional structure product can be achieved; the invention directly connects the MEMS chip to the circuit board through the pad, and is no longer The MEMS chip is connected to the ASIC chip by a gold wire, and the ASIC chip is directly mounted or bonded on the circuit board, thereby saving the bonding, sealing and curing processes, and the process is simpler; the setting of the filling glue can make the ASIC chip more firmly fixed. .

The invention provides a MEMS microphone for solving the problem that in the prior art, in the process of reflowing a MEMS microphone, it is easy to cause impurities such as rosin to enter the front sound chamber and cause product failure, and improve the sensitivity of the forward sound product. Signal to noise ratio.

In order to achieve the above objectives, the proposed scheme is as follows:

A MEMS microphone includes a package structure surrounded by a circuit board and an outer casing, and a sound hole. The package structure is internally provided with a MEMS chip and an integrated circuit ASIC chip fixed on the circuit board, and the sound hole is disposed on the outer casing. ;

The open end of the inner cavity of the MEMS chip faces one side of the sound hole;

A sealed channel is disposed between the sound hole and the open end of the lumen of the MEMS chip.

Preferably, in the MEMS microphone, an isolation layer is disposed in the sealing channel; and at least one through hole is disposed on the isolation layer.

Preferably, in the above MEMS microphone, the sound hole is disposed at an upper end of the outer casing;

The MEMS chip is disposed directly below the sound hole with an open end of the inner cavity facing upward.

Preferably, in the above MEMS microphone, the sound hole is disposed on a sidewall of the outer casing;

The open end of the inner cavity of the MEMS chip faces the sound hole.

Preferably, in the above MEMS microphone, the isolation layer is a thin plate or a combined thin plate.

Preferably, in the above MEMS microphone, the MEMS chip is soldered on the circuit board, including but not limited to a solder ball, or a solder paste connection.

Preferably, in the above MEMS microphone, the isolation layer is provided with a plurality of isolation holes arranged regularly.

Preferably, in the above MEMS microphone, the edge position of the surface of the isolation layer is connected to the inside of the casing through a glue.

Preferably, in the above MEMS microphone, the isolation layer is a glass flake or a metal foil.

Preferably, in the above MEMS microphone, the isolation layer is composed of a plurality of sub-isolation layers having the same structure.

It can be seen from the above technical solution that the sound hole of the MEMS microphone disclosed in the present application is disposed on the casing, thereby ensuring that the cavity of the MEMS chip does not enter impurities during the reflow process, and the MEMS chip is inverted. The post-cavity of the MEMS MIC of the advancing sound is enlarged, and the MEMS MIC product of the advancing sound is solved because the back cavity is too small, which leads to the disadvantage of low sensitivity and signal-to-noise ratio, and effectively improves the sensitivity and signal noise of the forward sound product. ratio.

The invention also provides a MEMS microphone, which can prevent impurities such as rosin from entering the front sound chamber and causing product failure, and reduce the use of metal wires, relatively increase the volume of the back cavity, and can generate a relatively high signal to noise ratio. The MEMS microphone includes: The MEMS chip and the ASIC chip are built in between the housing and the cavity formed by the circuit board, the ASIC chip is fixed on the circuit board, the metal wire connects the ASIC chip and the circuit board, and the MEMS chip is fixed in the On the inner wall of the top end of the casing, a cavity is formed between the outer side of the MEMS chip and the outer casing and the circuit board; a sound hole is formed on the casing opposite to the inner side of the MEMS chip, and the sound hole and the sound hole are Forming a front cavity between the inner sides of the MEMS chip; a guiding member is fixed between the MEMS chip and the circuit board, and at least two conductive pillars are disposed in the guiding component, and one end of the conductive pillar is fixed at the The other end of the pad of the MEMS chip is fixed on a pad of the circuit board, and the conductive post realizes conduction between the MEMS chip and the circuit board.

Preferably, the outer casing and the circuit board are sealed by a sealant to form a cavity.

Preferably, the ASIC chip is covered with a sealant for packaging.

Preferably, the bottom of the MEMS chip and the outer casing are bonded by a fixing glue, and the bottom of the ASIC chip and the circuit board are soldered to the circuit board by fixing glue or solder paste.

Preferably, the guiding member is a non-seal member having a slit at least one side wall.

Preferably, the cross section of the connecting member is n-shaped.

Preferably, the top end of the guiding member is bonded to the MEMS chip by a fixing glue, and the bottom portion and the circuit board are soldered to the circuit board by fixing glue or solder paste.

Additionally, preferably, the conductive post is a metal piece embedded inside the lead.

It can be seen from the above description and practice that the MEMS microphone provided by the present invention has a MEMS chip fixed on the outer casing, a sound hole disposed on a corresponding outer casing of the MEMS chip, and a front cavity formed between the inner side of the MEMS chip and the outer casing, and the MEMS A cavity is formed between the outer side of the chip and the outer casing and the circuit board, and the volume of the back cavity is significantly increased relative to the volume of the MEMS microphone in the prior art, so the signal-to-noise ratio is increased to form a MEMS microphone having a high signal-to-noise ratio; Second, a guiding member is arranged in a sealed space formed by the outer casing and the circuit board, and a conductive column is arranged inside the guiding member, and a conductive column is arranged inside the guiding member, and the conductive column can be a metal member or a plated member, and one end of the conductive column is fixed. On the MEMS chip, one end is fixed on the circuit board, which acts as a conductive connection between the MEMS chip and the circuit board, replacing the metal wire originally connected between the MEMS chip and the ASIC chip, thereby avoiding improper connection between the metal wires. The resulting short circuit, the position and shape of the connecting member is also relatively flexible, and the connecting member is a non-seal member having a slit at least one side wall.

The invention also provides a forward sound MEMS microphone, which can prevent impurities such as rosin from entering the front sound chamber and causing product failure, and the back cavity volume is relatively increased, and can generate a relatively high signal to noise ratio, and the forward sound MEMS microphone comprises: MEMS The chip and the ASIC chip are built in a cavity formed by the outer casing and the circuit board, the metal wire is connected to the MEMS chip and the ASIC chip, and the MEMS chip is fixed on the inner wall of the top end of the outer casing, and the outer side of the MEMS chip is Forming a back cavity between the outer casing and the circuit board; the sound hole is formed on the casing opposite to the inner side of the MEMS chip, and the sound hole and the inner side of the MEMS chip form a front cavity; the connecting piece The top end is fixed on the outer casing, the bottom end is provided with a pad and is fixed on the circuit board, and the connecting member realizes the MEMS chip, the ASIC chip and the circuit board through the metal wire Conduction between.

Preferably, the ASIC chip is fixed to the inner wall of the top end of the casing.

Preferably, the guiding member is located on the same side of the MEMS chip and the ASIC chip.

Preferably, the ASIC chip is fixed on the circuit board.

Preferably, the lead is located between the MEMS chip and the ASIC chip.

Preferably, the top end of the connecting member is bonded to the outer casing by a fixing glue, and the bottom pad is soldered or fixed to the circuit board.

Preferably, the bottom of the MEMS chip and the outer casing are bonded by a fixing glue, and the bottom of the ASIC chip is bonded to the outer casing or the circuit board by a fixing glue.

Preferably, the bottom of the guiding body is stepped, the top end of the guiding member is bonded to the outer casing by a fixing glue, and the bottom pad is soldered or fixed to the circuit board.

Additionally, preferably, the ASIC chip is fixed to the lead body.

As can be seen from the above description and practice, the present invention provides a forward-sounding MEMS microphone. First, the MEMS chip is fixed on the outer casing, and the sound hole is disposed on the corresponding outer casing of the MEMS chip, and the front cavity is formed between the inner side of the MEMS chip and the outer casing. The outer cavity of the MEMS chip forms a back cavity between the outer casing and the circuit board, and the volume of the back cavity is significantly increased compared with the volume of the forward-looking MEMS microphone in the prior art, so the signal-to-noise ratio is improved to form a high signal-to-noise ratio. a MEMS microphone; secondly, a guiding member is disposed in a sealed space formed by the outer casing and the circuit board, and one end of the connecting member is fixed on the outer casing, and one end is fixed on the circuit board to serve as a support and between the chip and the circuit board. The function of the conductive connection; the conductive member is used for conducting the MEMS chip, the ASIC chip and the circuit board, so that the relative positions of the MEMS chip and the ASIC chip can be flexibly set, in particular, the position of the ASIC chip can be set on the outer casing and the circuit On the board and the connecting member, in order to match the conduction connection of the two, the position and shape of the connecting member are relatively flexible, and can be disposed on the same side of the MEMS chip, the ASIC chip, or both. Room.

The invention also provides a MEMS microphone, which can prevent impurities such as rosin from entering the front sound chamber and causing product failure, and the back cavity volume is relatively increased, and can generate a relatively high signal to noise ratio, including: the MEMS chip and the ASIC chip are built in Between the outer casing and the cavity formed by the circuit board, the ASIC chip is fixed on the circuit board, the metal wire connects the ASIC chip and the circuit board, and the pallet is fixed on the circuit board, the pallet Two through holes are provided; the MEMS chip is fixed on the pallet, and an inner wall of the MEMS chip is opposite to a through hole of the pallet, The MEMS chip and the ASIC chip are connected by a metal wire; a sealing ring is fixed between the outer casing and the pallet, a top end of the sealing ring is fixed on an inner wall of the outer casing, and a bottom end is fixed on the pallet The other through hole of the pallet is opposite to the inside of the sealing ring, the pallet is connected to the MEMS chip and the sealing ring; the sound hole is opened on the outer casing opposite to the inner wall of the sealing ring, The cavity formed by the sealing ring, the pallet and the inner side of the MEMS chip is a front cavity; the cavity formed by the outer side of the MEMS chip, the outer casing and the circuit board is Back cavity.

Preferably, the tray is provided with two through holes, one of the through holes is located below the sealing ring and opposite to the sound hole, and the other of the through holes is located under the MEMS chip, and The inner sides of the MEMS chip are opposed to each other, and the bottoms of the two through holes communicate with each other, and the pallet communicates with the MEMS chip and the sealing ring.

Preferably, the tray is provided with two through holes, one of the through holes is located below the sealing ring and opposite to the sound hole, and the other of the through holes is located under the MEMS chip, and The inner side of the MEMS chip is opposite to each other, and the circuit board below the two through holes is provided with a groove connecting the two through holes, and the groove communicates with the two through holes of the tray to the MEMS Chip and the seal ring.

Preferably, the groove includes a first groove and a second groove, the first groove and the second groove respectively opposite the two through holes of the tray, and the first groove and The bottoms of the second grooves communicate with each other, and the first grooves and the second grooves communicate with the two through holes of the tray to the MEMS chip and the sealing ring.

Preferably, the edge of the pallet is sealed to the circuit board by a sealant.

Preferably, the outer casing and the circuit board are sealed by a sealant or a solder paste to form a cavity.

Preferably, the ASIC chip is covered with a sealant for packaging.

Preferably, the bottom of the MEMS chip and the pallet are bonded by a fixing glue, and the bottom of the ASIC chip is bonded to the circuit board by a fixing glue.

In addition, preferably, the top end of the sealing ring is bonded to the inner side of the outer casing by a fixing glue, and the bottom end is bonded to the supporting plate by a fixing glue or a solder paste.

It can be seen from the above description and practice that the MEMS microphone provided by the present invention has a fixed plate on the circuit board, a MEMS chip and a sealing ring fixed above the pallet, and the through hole of the pallet can be realized. The MEMS chip is connected to the sealing ring. The inside of the sealing ring is opposite to the sound hole. The cavity formed by the sealing ring, the supporting plate and the inside of the MEMS chip is the front cavity, and the outer surface of the MEMS chip is formed by the outer casing and the circuit board. The volume of the back cavity is significantly larger than that of the MEMS microphone in the prior art, so the signal-to-noise ratio will be relatively increased to form a MEMS microphone with a high signal-to-noise ratio; second, the MEMS chip and the seal The connection between the rings is various, and can be realized by the communication between the two through holes on the pallet, and the two through holes are respectively connected with the MEMS chip and the sealing ring, so that communication can be realized; The groove on the circuit board is realized, the two through holes may not communicate with each other, but the two through holes are respectively communicated with the groove, and are respectively connected with the MEMS chip and the sealing ring, so that communication can be realized; The first groove and the second groove connected to the bottom of the plate are disposed, and the two through holes may not communicate with each other, but the first groove and the second groove are respectively communicated with the two through holes, and respectively connected to the MEMS chip with The seal ring communication, therefore, communication can be achieved, but also increase the strength of the circuit.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can obtain other drawings according to the provided drawings without any creative work.

1 is a structural diagram of a MEMS microphone in the prior art;

2 is a structural diagram of a MEMS microphone according to a first embodiment of the present invention;

3 is a structural diagram of a MEMS microphone according to a second embodiment of the present invention;

4 is a structural diagram of a MEMS microphone according to a third embodiment of the present invention;

FIG. 5 is a structural diagram of a MEMS microphone according to a fourth embodiment of the present invention; FIG.

6 is a schematic view of a connecting member of the MEMS microphone shown in FIG. 5;

FIG. 7 is a structural diagram of a MEMS microphone according to a fifth embodiment of the present invention; FIG.

FIG. 8 is a structural diagram of a MEMS microphone according to a sixth embodiment of the present invention; FIG.

FIG. 9 is a structural diagram of a MEMS microphone according to a seventh embodiment of the present invention; FIG.

10 is a structural diagram of a MEMS microphone according to an eighth embodiment of the present invention;

11 is a structural diagram of a MEMS microphone according to a ninth embodiment of the present invention;

12 is a structural diagram of a MEMS microphone according to a tenth embodiment of the present invention;

FIG. 13 is a structural diagram of a MEMS microphone according to an eleventh embodiment of the present invention; FIG.

Figure 14 is a schematic view of the pallet of the MEMS microphone shown in Figure 13;

Figure 15 is a cross-sectional view of the pallet shown in Figure 14;

16 is a structural diagram of a MEMS microphone according to a twelfth embodiment of the present invention;

Figure 17 is a cross-sectional view of the pallet shown in Figure 16;

FIG. 18 is a structural diagram of a MEMS microphone according to a thirteenth embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In order to solve the problem in the prior art that impurities such as rosin easily enter the front sound chamber through the sound hole during the reflow process, the present application designs a MEMS microphone capable of effectively preventing impurities such as rosin from entering the front or back cavity of the MEMS microphone.

Please refer to FIG. 2. FIG. 2 is a structural diagram of a MEMS microphone according to a first embodiment of the present invention.

The MEMS microphone (or the full abbreviation MEMS MIC) provided by the present invention, including the circuit board 1 (known to those skilled in the art, the circuit board 1 referred to herein as a circuit board, a wiring board, etc.) and the outer casing 8 are enclosed. The package structure (forming the inner cavity of the MEMS microphone) and the sound hole 12, inside the package structure are provided with MEMS chip 2 (or MEMS DIE sensor, MEMS chip) and integrated circuit ASIC chip 5 (or ASIC chip). Different from the prior art, the present invention places the sound hole 12 on the outer casing 8; and the inner cavity of the MEMS chip 2 communicates with the sound hole 12 to form a front cavity of the MEMS microphone.

1. Since the sound hole 12 is disposed on the outer casing 8, the pad on the circuit board 1 and the sound hole 12 on the outer casing 8 are respectively disposed at both ends of the MEMS microphone, and there is no solder joint near the sound hole 12, so there is no reflow soldering. Impurities such as rosin enter the sound chamber through the sound hole 12.

2. The inner cavity of the MEMS chip 2 communicates with the sound hole 12 to form a front cavity of the MEMS microphone. in this way, The front cavity occupies only a small portion of the volume, and the space between the outer side of the MEMS chip 2 and the circuit board 1 and the outer casing 8 forms a back cavity (ie, the rear sound cavity described in the background art), that is, most of the entire MEMS microphone cavity. As the back cavity of the MEMS microphone, the back cavity is bulky, and the back cavity is large, which can improve the sensitivity and signal-to-noise ratio of the MEMS microphone. Therefore, the invention ensures the MEMS microphone under the premise of achieving the above first technical effect. Sensitivity and signal to noise ratio.

Further, in order to satisfy that the MEMS chip cavity can communicate with the sound hole 12 to form a front cavity, the open end of the inner cavity of the MEMS chip 2 can be disposed opposite to the sound hole 12, that is, the open end corresponds to the position of the sound hole 12. Compared with the prior art, the MEMS chip 2 at this time is equivalent to the reverse setting, so that the inner cavity of the MEMS chip 2 and the sound hole 12 are connected in a smart and simple manner to form a front cavity.

There are several ways to implement the reverse solution, as follows:

Referring to FIG. 2, the MEMS microphone includes a circuit board 1. The circuit board 1 is bonded with a casing 8 through a solder paste 9. The inner wall of the casing 8 is bonded with the MEMS chip 2 through the MEMS bottom glue 3, and the MEMS chip 2 is bonded. One side has a cavity (ie, the inner cavity of the MEMS chip 2), and one side of the MEMS chip 2 having a cavity is bonded to the inner wall of the outer case 8, and the side of the MEMS chip 2 adjacent to the circuit board 1 passes through the pad 10 and the circuit. The board 1 is connected, and a sound hole 12 is defined in the outer casing 8 at a position corresponding to the cavity of the MEMS chip 2, and the ASIC chip is bonded to the MEMS chip 2 on the side of the MEMS chip 2 by the ASIC bottom glue 6 5. The ASIC chip 5 and the circuit board 1 are connected by a gold wire 4, and the ASIC chip 5 is packaged with an ASIC sealant 7.

With the above technical solution, the MEMS chip 2 is directly connected to the circuit board 1 through the pad 10, and the MEMS chip 2 is no longer connected with the ASIC chip 5 by the gold wire, and the pad height is almost negligible, so that the overall height of the MEMS microphone It will be reduced, can be miniaturized and light in weight; the sound hole corresponds to the cavity on the MEMS chip, the cavity of the MEMS chip becomes the front cavity, the other cavity is the back cavity, the back cavity is large, and the forward sound MEMS MIC Can achieve high signal to noise ratio.

Correspondingly, the embodiment further provides a production process of the MEMS microphone, comprising the following steps:

a, the MEMS chip 2 is bonded to the outer casing 8 with the MEMS chip bottom glue 3, after curing, the pad 10 is implanted on the MEMS chip 2;

b, the ASIC chip 5 is bonded to the circuit board 1 with the ASIC bottom glue 6, and cured;

c, the ASIC chip 5 is connected to the circuit board 1 by the gold wire 4, and the ASIC sealant 7 is sealed on the upper part of the ASIC chip 5;

d. Draw a solder paste 9 on the circuit board 1 to bond the circuit board 1 and the outer casing 8 together;

e, ultrasonic welding MEMS chip 2, SMT (Surface Mount Technology surface mount technology), forming a MEMS microphone.

The MEMS chip 2 is directly connected to the circuit board 1 through the pad 10 by using the above process, and the MEMS chip 2 is not connected to the ASIC chip 5 by the gold wire, and the ASIC chip 5 is directly mounted or bonded on the circuit board 1. The process of bonding, sealing and curing is saved, and the process is simpler.

Please refer to FIG. 3. FIG. 3 is a structural diagram of a MEMS microphone according to a second embodiment of the present invention. The difference from the first embodiment is that the ASIC chip 5 is directly mounted on the circuit board 1, that is, on the ASIC chip 5. There is a pad, which can be directly bonded to the pad of the circuit board 1 with solder paste or silver paste to achieve conduction, and the bottom of the ASIC chip 5 is filled with a filling glue, and the ASIC chip 5 and the circuit board 1 need not be passed through the gold wire 4 The connection does not require the ASIC sealant 7 to be sealed on the upper portion of the ASIC chip 5. Compared with the structure of the MEMS microphone in Embodiment 1, the structure is simpler, and a high signal-to-noise ratio advancing microphone can also be fabricated; the setting of the filling glue can make the ASIC chip 5 more firmly fixed, so it can be understood that the direct mounting is not filled. Glue is also feasible.

Correspondingly, the second embodiment also provides a production process of a novel MEMS microphone, which is different from the above-described production process embodiment in that the ASIC chip 5 is directly mounted on the circuit board 1 in step b, The bottom of the ASIC chip 5 is filled with a filling paste, and step c is omitted. The process is simpler than the production process embodiment described above.

It should be noted that the first and second embodiments specifically show the conduction manner of the MEMS chip 2 and the ASIC chip 5 and the circuit board 1. In fact, in addition to the above manner, other conduction modes may be provided. For example, the MEMS chip 2 can be connected to the ASIC chip 5 by wires as described in the background art. Of course, direct conduction through the pad 10 can save space and be more reliable than the line connection. In addition to this, the conduction mode with the circuit board 1 is also involved in the following embodiments, and can be understood by reference.

For the solution of the MEMS chip, please refer to FIG. 4. FIG. 4 is a structural diagram of a MEMS microphone according to a third embodiment of the present invention. The MEMS microphone in this embodiment includes:

a circuit board 1, a package structure surrounded by the case 3, a MEMS chip 6 (or MEMS DIE sensor), a sound hole 5, and an integrated circuit ASIC chip 13, the case 3, the MEMS chip 6 And the integrated circuit ASIC chip 13 is fixed on the circuit board 1, the MEMS chip 6 and the integrated circuit ASIC chip 13 are disposed between the outer casing 3 and the circuit board 1; wherein the sound hole 5 is disposed in the outer casing 3 on;

The open end of the inner cavity of the MEMS chip 6 faces one side of the sound hole 5 (ie, corresponds to the sound hole position, and the two are oppositely disposed);

A sealed passage is disposed between the sound hole 5 and the open end of the inner cavity of the MEMS chip 6.

Referring to the MEMS microphone structure of the present application, the sound hole 5 of the MEMS microphone in the above embodiment of the present application is disposed on the housing, thereby ensuring that the cavity of the MEMS chip 6 does not enter during the reflow process. Impurities, and the sound hole 5 is connected to the sound cavity of the MEMS chip 6 by a sealed channel, such that the sound cavity of the MEMS chip 6 is the back cavity, the sound cavity between the outer casing 3 and the circuit board 1 is back The cavity makes the back cavity larger, effectively improving the sensitivity and signal-to-noise ratio of the forward sound product.

It can be understood that, as shown in the embodiments of FIGS. 2 and 3, the inner cavity of the MEMS chip can be directly attached to the inner wall of the outer casing, such as by adhesive bonding or direct mounting. It can also be attached to the inner wall of the housing by a connector to enable the sound hole to be in sealing communication with the front cavity of the MEMS microphone, such as the sealed channel shown in this embodiment. The connector is arranged such that there is a distance between the MEMS chip and the sound hole to avoid sound damage to the diaphragm of the MEMS chip.

In FIG. 4, reference numeral 2 is a pad, and the integrated circuit ASIC chip 13 is connected to the circuit board 1 through a wire 16, and is fixed on the circuit board 1 by a glue or solder ball 14. The outer casing 3 is fixed by the glue 4 On the

circuit board

1, 15 is a protective layer coated on the surface of the integrated circuit ASIC chip 13. The cavity 17 inside the outer casing 3 serves as a back cavity of the MEMS microphone, and the inner cavity 12 of the MEMS chip 6 serves as The front cavity of the MEMS microphone.

It can be understood that the top of the inner cavity opening of the MEMS chip 6 is provided with an isolation layer 10, and the isolation layer 10 is provided with an isolation hole 8 for isolating impurities such as rosin generated during reflow soldering. The spacer layer 10 may be pasted with the top of the MEMS chip 6 by a glue 9 coated on the edge of the lower surface of the spacer layer 10. The technical solution in this embodiment is provided with an isolation layer structure 10 due to the open end of the cavity 12 in the MEMS chip 6, and the isolation layer 10 is provided with an isolation hole 8 for isolating impurities such as rosin. Impurities such as rosin produced during the reflow process cannot enter the cavity 12, so no impurities such as rosin enter. The cavity 12 causes a problem of product failure, and since the volume of the back cavity 17 in the technical solution in the present embodiment is large, it is possible to maintain high sensitivity.

It should be noted that the arrangement of the MEMS chip 6 and the isolation layer 10 and the sound hole 5 in FIG. 4 is only a specific expression form in the above embodiment, only for the reader to intuitively understand the overall technical solution of the present application. The applicant uses the structural form in FIG. 4 to introduce the technical solution in this embodiment.

It should be noted that, in the above embodiment of the present application, the MEMS chip 6 is soldered to the circuit board 1, including but not limited to a solder ball, or a solder paste connection.

It should be noted that the MEMS chip 6 and the sound hole 5 can be disposed in the manner shown in FIG. 4, that is, the bottom end of the MEMS chip 6 is fixed on the circuit board 1 by using a solder ball 7. The integrated circuit ASIC chip 13 is fixed on the circuit board 1 by solder balls 14. The sound hole 5 is disposed on the outer casing 3 and directly above the isolation layer 10, and the isolation layer 10 and the outer casing 3 The glue 11 is fixed between the edges of the upper surface of the separation layer 10, and the space between the top of the separation layer 10 and the outer casing 3 is isolated from the back cavity 17. Alternatively, the sound hole 5 may be disposed on a sidewall of the outer casing 3, and an open end of the inner cavity of the MEMS chip faces the sound hole.

The external sound enters the outer casing 3 through the sound hole 5 and enters the front cavity 12 through the isolation hole 8 on the isolation layer 10 to be transmitted to the diaphragm of the MEMS chip 6, causing the vibration of the diaphragm and converting the external sound signal into an electrical signal. The acoustic-electrical conversion is realized. The electrical signal is connected to the circuit board 1 through the solder ball 7 between the MEMS chip 6 and the circuit board 1, and is connected to the integrated circuit ASIC chip 13 through the internal circuit of the circuit board 1.

It can be understood that during the product experiment, the user can finely adjust the volume of the back cavity 17 by changing the thickness of the isolation layer 10 and the glue 9, to test the thickness of the isolation layer 10. The MEMS microphone has higher sensitivity. After the experiment is finished, the thickness of the isolation layer 10 can be selected as the thickness of the isolation layer when the sensitivity of the MEMS microphone is the highest in the laboratory. For example, the thickness of the glue 9 can be increased by the user. The thickness of the isolation layer 10 is reduced such that the volume of the back cavity 17 is increased.

It can be understood that the number of the isolation holes 8 on the isolation layer 10 and the size of the aperture of the isolation holes 8 can directly affect the sensitivity of the MEMS microphone, and since the isolation holes 8 are used for isolation An impurity such as rosin generated during the reflow process, the body of the isolation hole 8 The amount of the isolation holes 8 on the isolation layer 10 may be multiple, which may be evenly distributed, and the isolation layer 10 may be a network. An orifice-like structure, the mesh can be regarded as the isolation hole 8.

It can be understood that the material of the isolation layer 10 can be set according to user requirements. For example, the isolation layer 10 can be a metal piece or a glass piece or the like.

It can be understood that, in order to facilitate the experiment, the thickness of the isolation layer 10 is affected by the sensitivity of the MEMS microphone, the isolation layer 10 is a thin plate or a combined thin plate, and the specific isolation layer 10 may be composed of multiple structures. The sub-isolation layer is composed, and the user can adjust the thickness of the isolation layer 10 by increasing or decreasing the number of the sub-isolation layers during the experiment.

It can be understood that, in order to further reduce the probability of impurities such as rosin entering the front cavity 12 during reflow soldering, a layer of mesh cover may be disposed at the sound hole 5 of the MEMS microphone of the present application for further preventing impurities such as rosin from entering.

For the solution of the MEMS chip, please refer to FIG. 5-6. FIG. 5 is a structural diagram of a MEMS microphone according to a fourth embodiment of the present invention. 6 is a schematic view of a connecting member of the MEMS microphone shown in FIG. 5.

As shown in FIGS. 5 and 6, the MEMS microphone includes a circuit board 1, a MEMS chip 2, an ASIC chip 3, a metal wire 4, a sound hole 5, a case 6, a connecting member 7, and a fixing glue 8.

The MEMS chip 2 and the ASIC chip 3 are built in between the outer casing 6 and the cavity formed by the circuit board 1. Preferably, the outer casing 6 and the circuit board 1 are sealed by a sealant 9 to form a cavity. In the present embodiment, the MEMS chip 2 is fixed to the casing 6, and the ASIC chip 3 is fixed to the circuit board 1. Preferably, the bottom of the MEMS chip 2 is bonded to the outer casing 6 by a fixing glue 8, and the bottom of the ASIC chip 3 is bonded to the circuit board 1 by a fixing glue 8. The metal wire 4 connects the ASIC chip 3 and the circuit board 1, and electrically connects the ASIC chip 3 to the circuit board 1. In the present embodiment, the ASIC chip 3 and the circuit board 1 are connected by a metal wire 4. Preferably, the ASIC chip 3 is covered with a sealant 9 for packaging.

The MEMS chip 2 is fixed on the inner wall of the top end of the outer casing 6, and the bottom of the MEMS chip 2 is bonded to the outer casing 6 through the fixing glue 8. The space between the outer side of the MEMS chip 2 and the outer casing 6 and the circuit board 1 is called the back cavity 10.

The sound hole 5 is opened on the casing 6 facing the inside of the MEMS chip 2, the sound hole 5 is opposite to the space inside the MEMS chip 2, and the space between the sound hole 5 and the inner side of the MEMS chip 2 is called the front. Cavity 20.

In the sealed space formed by the outer casing 6 and the circuit board 1, the connecting member 7 is fixed between the MEMS chip 2 and the circuit board 1. Preferably, the top end of the connecting member 7 is bonded to the MEMS chip 2 by the fixing glue 8, and the bottom portion is bonded to the circuit board 1 by the fixing glue 8, and the solder paste may be directly soldered on the circuit board 1. Preferably, the guiding member 7 is a non-seal member having a slit at least one side wall, and the inside of the guiding member 7 also belongs to a portion of the back chamber 10, thereby avoiding affecting the volume of the back chamber 10. At least two or more conductive pillars 71 are disposed in the guiding member 7. One end of the conductive pillar 71 is fixed on the pad of the MEMS chip 2, the other end is fixed on the pad of the circuit board 1, and the conductive pillar 71 realizes the MEMS. Conduction between the chip 2 and the circuit board 1.

As shown in Fig. 6, the connecting member 7 includes two opposite parallel side walls, and the top ends of the two side walls are provided with a connecting plate. Preferably, the connecting member 7 has an n-shaped cross section. Three conductive pillars 71 are disposed in the guiding member 7, and the conductive pillars 71 can achieve conduction between the MEMS chip 2 and the circuit board 1. The MEMS chip 2 no longer needs to connect the ASIC chip 3 through the metal wire 4, and then connects the circuit board 1 to achieve the conduction function. Further, preferably, the conductive post 71 is a metal member embedded in the inside of the connecting member 7, and may be an electroplated member. It can be understood that the conductive pillars 71 are not limited to three, two or more.

In this embodiment, the bottom of the MEMS chip 2 is bonded to the outer casing 6 through the fixing glue 8, and the bottom of the ASIC chip 3 is bonded to the circuit board 1 through the fixing glue 8, and the metal wire 4 is between the ASIC chip 3 and the circuit board 1. The ASIC chip 3 is covered with a sealant 9, and a conductive member 7 is disposed between the MEMS chip 2 and the circuit board 1. The conductive member 71 is provided with three conductive pillars 71. The top end of the conductive pillar 71 and the MEMS chip 2 are connected. The pad is fixed, and the bottom end is fixed to the pad of the circuit board 1, thereby achieving a conductive connection between the MEMS chip 2 and the circuit board 1. The space between the outer side of the MEMS chip 2 and the outer casing 6, the circuit board 1 is referred to as the back cavity 10, and the space between the sound hole 5 and the inner side of the MEMS chip 2 is referred to as the front cavity 20, apparently, due to the arrangement of the guide members 7. The volume of the back chamber 10 is relatively increased.

Please refer to FIG. 7. FIG. 7 is a structural diagram of a MEMS microphone according to a fifth embodiment of the present invention. The main difference between the MEMS microphone shown in FIG. 7 and the MEMS microphone shown in FIG. 5 is that, in FIG. 7, the ASIC chip 3 is directly soldered on the circuit board 1 instead of being bonded to the circuit board 1 by the fixing glue 8. on. Thus, the conduction between the ASIC chip 3 and the circuit board 1 no longer requires a metal wire, thereby avoiding a short circuit caused by improper connection between the metal wires. The relative positions of the back chamber 10 and the front chamber 20 are unchanged, so that the volume of the back chamber 10 of the MEMS microphone is also relatively increased.

The MEMS microphone provided by the above fourth and fifth embodiments, wherein the MEMS chip is fixed on the outer casing 6, and the sound hole 5 is disposed on the corresponding outer casing 6 on the inner side of the MEMS chip 2, and the upper surface of the circuit board 1 and the outer casing 6 are The sound holes 5 are respectively disposed at both ends of the MEMS microphone, and there is no solder joint near the sound hole 5. Therefore, no impurities such as rosin enter the sound cavity through the sound hole 5 during reflow soldering; moreover, between the inner side of the MEMS chip 2 and the outer casing 6 The front cavity is formed, and the back cavity 10 is formed between the outer side of the MEMS chip 2 and the outer casing 6 and the circuit board 1. The volume of the back cavity 10 is significantly increased relative to the volume of the MEMS microphone in the prior art, so the signal-to-noise ratio will be increased to form a MEMS microphone having a high signal-to-noise ratio; secondly, a guiding member 7 is disposed in a sealed space formed by the outer casing 6 and the circuit board 1, and the conductive member 71 is disposed inside the guiding member 7, and the conductive post 71 may be a metal member or The electroplating member has one end fixed on the MEMS chip 2 and one end fixed on the circuit board 1 to serve as a conductive connection between the MEMS chip 2 and the circuit board 1, instead of being connected to the MEMS chip 2 and the ASIC chip. Metal wire between 3 to avoid improper connection between metal wires The resulting short circuit, the position and shape of the connecting member 7 is also relatively flexible, and it is preferable that the connecting member 7 is a non-seal member in which at least one side wall is provided with a slit.

For a solution of the MEMS chip, please refer to FIG. 8. FIG. 8 is a structural diagram of a MEMS microphone according to a sixth embodiment of the present invention. As shown in FIG. 8, the progressive MEMS microphone includes a circuit board 1, a MEMS chip 2, an ASIC chip 3, a metal wire 4, a sound hole 5, a casing 6, a connecting member 7, and a fixing glue 8.

The MEMS chip 2 and the ASIC chip 3 are built in between the outer casing 6 and the cavity formed by the circuit board 1. Preferably, the outer casing 6 and the circuit board 1 are sealed by a sealant 9 to form a cavity. In the present embodiment, both the MEMS chip 2 and the ASIC chip 3 are fixed to the outer casing 6. Preferably, the bottom of the MEMS chip 2 is bonded to the outer casing 6 by a fixing glue 8, and the bottom of the ASIC chip 3 is bonded to the outer casing 6 by a fixing glue 8. The MEMS chip 2 and the ASIC chip 3 are connected by a metal wire 4. In the present embodiment, the MEMS chip 2 and the ASIC chip 3 are connected by a metal wire 4.

The sound hole 5 is opened on the casing facing the inside of the MEMS chip 2, the sound hole 5 is opposed to the space inside the MEMS chip 2, and the space between the sound hole 5 and the inside of the MEMS chip 2 is referred to as the front cavity 20.

In the sealed space formed by the outer casing 6 and the circuit board 1, the top end of the connecting member 7 is fixed on the outer casing 6, and the bottom end is provided with a pad 71, and is fixedly bonded to the circuit board 1 by the fixing glue 8, and can also pass The soldering or fixing glue 8 is adhered to the circuit board 1, which can play a supporting role and simultaneously initiate the conduction. The lead member 7 realizes conduction between the MEMS chip 2, the ASIC chip 3, and the circuit board 1 through the metal wire 4. The ASIC chip 3 on the side close to the lead member 7 and the lead member 7 are connected by a metal wire 4. If the metal wire 4 is connected on the side away from the lead member 7 and close to the side of the MEMS chip, a short circuit phenomenon easily occurs.

In this embodiment, the bottom of the MEMS chip 2 is bonded to the outer casing 6 by a fixing glue 8, and the bottom of the ASIC chip 3 is bonded to the outer casing 6 by a fixing glue 8, and the MEMS chip 2 and the ASIC chip 3 are connected by a metal wire 4, and the ASIC is connected. The chip 3 is covered with a sealant 9 for packaging, and the connecting member 7 is located on the same side of the MEMS chip 2 and the ASIC chip 3. As shown in FIG. 8, the connecting member 7 is located on the left side of the two, from left to right. The lead piece 7, the ASIC chip 3, and the MEMS chip 2 are in turn. The top end of the connecting member 7 is bonded to the outer casing 6 by a fixing glue 8, and the bottom end of the pad 71 is connected to the ASIC chip 2 via a metal wire 4, and the pad 71 is bonded to the circuit board 1 by a fixing glue 8.

Please refer to FIG. 9. FIG. 9 is a structural diagram of a MEMS microphone according to a seventh embodiment of the present invention. The main difference between the progressive MEMS microphone shown in FIG. 9 and the progressive MEMS microphone shown in FIG. 8 is that, in FIG. 9, the bottom of the MEMS chip 2 is bonded to the outer casing 6 by the fixing glue 8, and the bottom of the ASIC chip 3 is fixed. The glue 8 is adhered to the circuit board 1, and a guiding member 7 is disposed between the MEMS chip 2 and the ASIC chip 3. The top end of the guiding member 7 is bonded to the outer casing 6 through the fixing glue 8, and the bottom end of the pad 71 passes through the fixing glue. 8 is bonded to the circuit board 1. The metal wires 4 are respectively protruded on both sides of the pad 71, and the metal wires 4 at one end are connected to the MEMS chip 2, and the metal wires 4 at one end are connected to the ASIC chip 3.

Please refer to FIG. 10 again. FIG. 10 is a structural diagram of a MEMS microphone according to an eighth embodiment of the present invention. The main difference between the progressive MEMS microphone shown in FIG. 10 and the progressive MEMS microphone shown in FIG. 8 is that, in FIG. 10, in the sealed space formed by the outer casing 6 and the circuit board 1, the bottom of the connecting member 7 is a step. The stepped upper portion of the ASIC chip 2 and the connecting member 7, that is, the protruding portion, is connected by the metal wire 4; the stepped lower portion of the connecting member 7, that is, the recessed portion, and the bottom end is connected to the pad 71. The upper end of the connecting member 7 is fixed on the outer casing 6, and the bottom end is provided with a pad 71, and is fixedly bonded to the circuit board 1 by the fixing glue 8 In the above, it can also be bonded to the circuit board 1 by soldering or fixing glue 8, which can play a supporting role and simultaneously initiate the conduction. The lead member 7 realizes conduction between the MEMS chip 2, the ASIC chip 3, and the circuit board 1 through the metal wire 4. The metal wire 4 between the ASIC chip 3 and the lead member 7 has a gold wire arc height. Due to the stepped design, the stepped portion provides space for the line arc height to prevent the line arc from being short-circuited with the circuit board 1.

Please refer to FIG. 11. FIG. 11 is a structural diagram of a MEMS microphone according to a ninth embodiment of the present invention. The main difference between the progressive MEMS microphone shown in FIG. 11 and the progressive MEMS microphone shown in FIG. 8 is that, in FIG. 11, in the sealed space formed by the outer casing 6 and the circuit board 1, the bottom of the MEMS chip 2 passes through the fixing glue 8 Bonded on the outer casing 6, the bottom of the ASIC chip 3 is bonded to the circuit board 1 by a fixing glue 8, the MEMS chip 3 is located above the ASIC chip 3, and the guiding member 7 is located on the same side of the MEMS chip 2 and the ASIC chip 3, The top end of the connecting piece 7 is fixed on the outer casing 6, and the bottom end is provided with a pad 71, and is fixedly bonded to the circuit board 1 by the fixing glue 8, and can also be bonded to the circuit board 1 by soldering or fixing glue 8. Play a supporting role and initiate conduction. The bottom of the connecting member 7 is stepped, and the stepped upper portion of the MEMS chip 2 and the connecting member 7, that is, the protruding portion, is connected by the metal wire 4; the stepped lower portion of the guiding member 7, that is, the recessed portion The bottom end is connected to the pad 71 and bonded to the circuit board 1 by the fixing glue 8. A metal wire 4 is protruded from the pad 71 to realize conduction between one end of the ASIC chip 3 and the pad 71 of the connecting member 7. The other end of the ASIC chip 3 is extended by a metal wire 4 connected to the circuit board 1. The lead member 7 realizes conduction between the MEMS chip 2, the ASIC chip 3, and the circuit board 1 through the metal wire 4. 11, the MEMS chip 2 and the ASIC chip 3 are disposed opposite each other, and the lead members 7 are located on the left side of both.

Please refer to FIG. 12, which is a structural diagram of a MEMS microphone according to a tenth embodiment of the present invention. The main difference between the progressive MEMS microphone shown in FIG. 12 and the progressive MEMS microphone shown in FIG. 8 is that, in FIG. 12, in the sealed space formed by the outer casing 6 and the circuit board 1, the connecting member 7 is L-shaped. One side of one side is used for fixed bonding with the outer casing 6 through the fixing glue 8, and the other side is for providing adhesion, and the ASIC chip 3 is fixedly bonded to the connecting member 7 by the fixing glue 8; the MEMS chip 2 and the ASIC The chip 3 is connected by a metal wire 4, and the ASIC chip 3 is covered with a sealant 9 for packaging, of course, without sealing; the bottom of the other side is stepped; the ASIC chip 3 and the connecting member 7 are stepped. The upper part, the protruding part, passes through the metal wire 4 Connecting; the stepped lower portion of the connecting member 7, that is, the recessed portion, the bottom end is connected to the pad 71, and is adhered to the circuit board 1 by the fixing glue 8, and the top end of the guiding member 7 is fixed on the outer casing 6. The bottom end is provided with a pad 71, and is fixedly bonded to the circuit board 1 by the fixing glue 8, and can also be bonded to the circuit board 1 by soldering or fixing glue 8, which can play a supporting role and simultaneously initiate the conduction function. . The lead member 7 realizes conduction between the MEMS chip 2, the ASIC chip 3, and the circuit board 1 through the metal wire 4.

According to the forward sound MEMS microphone provided by the sixth to tenth embodiments, the MEMS chip 2 is fixed on the outer casing, the sound hole is disposed on the corresponding outer casing 6 on the inner side of the MEMS chip 2, and the pad and the outer casing 6 on the circuit board 1 are provided. The upper sound holes 5 are respectively disposed at both ends of the MEMS microphone, and there is no solder joint near the sound hole 5. Therefore, no impurities such as rosin enter the sound cavity through the sound hole 5 during reflow soldering; moreover, the inside of the MEMS chip 2 and the outer casing 6 The front cavity is formed, and the back cavity 10 is formed between the outer side of the MEMS chip 2 and the outer casing 6 and the circuit board 1. The volume of the back cavity 10 is significantly increased relative to the volume of the forward-looking MEMS microphone in the prior art, so the signal-to-noise ratio will be The MEMS microphone having a high signal-to-noise ratio is formed. Secondly, a guiding member 7 is disposed in a sealed space formed by the outer casing 6 and the circuit board 1. The connecting member 7 is fixed at one end to the outer casing 6, and one end is fixed to the circuit board. 1 , plays the role of support and the function of the conductive connection between the chip and the circuit board 1; the connecting member 7 is used for the conduction of the MEMS chip 2, the ASIC chip 3 and the circuit board 1, thereby, the MEMS chip 2, the ASIC The relative position of the chip 3 can be flexibly set, especially the ASIC chip 3 The arrangement can be disposed on the outer casing 6, on the circuit board 1 and on the connecting member 7. In order to cooperate with the conductive connection of the two, the position and shape of the guiding member 7 are relatively flexible, and can be disposed on the MEMS chip 2 and the ASIC chip 3. On the same side or between the two.

The above embodiments provide a solution in which the MEMS chip is reversely formed to directly form a front cavity with a sound hole provided on the outer casing, and a MEMS chip is provided according to the prior art (the inner cavity port faces the circuit board). A solution is realized in which the inner cavity communicates with the sound hole to form a front cavity.

In the above embodiment, in order to ensure that the sound hole can be disposed on the outer casing and the back cavity can have a large volume, the arrangement of the inner cavity of the MEMS chip toward the sound hole is adopted, which is equivalent to the reverse MEMS chip compared with the prior art. In the following embodiments, the MEMS chip is still facing the circuit board, but it can also satisfy that the sound hole is disposed in the outer casing and the back cavity is large.

Please refer to FIG. 13-15. FIG. 13 is a MEMS microphone according to an eleventh embodiment of the present invention. FIG. 14 is a schematic view of the pallet of the MEMS microphone shown in FIG. 13; and FIG. 15 is a cross-sectional view of the pallet shown in FIG. As shown in FIGS. 13, 14, and 15, the MEMS microphone includes a circuit board 1, a MEMS chip 2, an ASIC chip 3, a metal wire 4, a sound hole 5, a casing 6, a pallet 7, and a seal 10.

The MEMS chip 2 and the ASIC chip 3 are built in between the outer casing 6 and the cavity formed by the circuit board 1. Preferably, the outer casing 6 and the circuit board 1 are sealed by a sealant 9 or a solder paste to form a cavity. The ASIC chip 3 is fixed on the circuit board 1. Preferably, the bottom of the ASIC chip 3 is bonded to the circuit board 1 by a fixing glue 8. The metal wire 4 connects the ASIC chip 3 and the circuit board 1, and electrically connects the ASIC chip 3 to the circuit board 1. In the present embodiment, the ASIC chip 3 and the circuit board 1 are connected by a metal wire 4. Preferably, the ASIC chip 3 is covered with a sealant 9 for packaging.

The pallet 7 is fixed on the circuit board 1, and the bracket 7 is provided with two through holes 71; as shown in Fig. 14 and Fig. 15, in the embodiment, the pallet 7 is a flat plate, and the two on the pallet 7 The through holes 71 are spaced apart, but the bottoms of the two through holes 71 are in communication with each other, the plate 7 is sealed with the circuit board 1, and the edge of the plate 7 is adhesively sealed to the circuit board 1 by the sealant 9 to avoid The communication between the through holes 71 is hindered.

The MEMS chip 2 is fixed on the pallet 7, and preferably, the bottom of the MEMS chip 2 is bonded to the pallet 7 by a fixing glue 8. The inner wall of the MEMS chip 2 is opposed to one through hole 71 of the pallet 7, and the MEMS chip 2 and the ASIC chip 3 are connected by a metal wire 4.

The sealing ring 10 is fixed between the outer casing 6 and the pallet 7. The top end of the sealing ring 10 is fixed on the inner wall of the outer casing 6, and the bottom end is fixed on the pallet 7. Preferably, the top end of the sealing ring 10 and the inner side of the outer casing 6 pass the fixing rubber 8 Bonding, the bottom end and the pallet 7 are bonded by a fixing glue 8 or a solder paste. The other through hole 71 of the pallet 7 is opposed to the inside of the seal ring 6, one through hole 71 of the pallet 7 is in communication with the MEMS chip 2, and the other through hole 71 is in communication with the seal ring 10, and the through holes 71 are also connected to each other. Therefore, the pallet 7 connects the MEMS chip 2 and the seal ring 10.

The sound hole 5 is formed on the outer casing 6 opposite to the inner wall of the sealing ring 10. The cavity formed by the inner side of the sealing ring 10, the supporting plate 7 and the MEMS chip 2 is the front cavity 20; the outer side of the MEMS chip 2, the outer casing The cavity formed by the circuit board 1 and the circuit board 1 is the back cavity 30.

In the present embodiment, the pallet 7 is a flat plate, and the pallet 7 is provided with two through holes 71 spaced apart. One through hole 71 is located below the sealing ring 10 and opposite to the sound hole 5, and the other through hole 71 is located. Below the MEMS chip 2, and opposite to the inside of the MEMS chip 2, the bottoms of the two through holes 71 communicate with each other to form a communicating cavity, and the pallet 7 communicates with the MEMS chip 2 and the sealing ring 10; the sound hole 5 is opened in On the outer casing 6 facing the inner wall of the sealing ring 10, the cavity formed by the sealing ring 10, the supporting plate 7 and the inner side of the MEMS chip 2 opposite to the sound hole 5 is the front cavity 20; the outer side of the MEMS chip 2, the outer casing 6 and the circuit board 1 The cavity formed is the back cavity 30, and the volume of the back cavity 30 is relatively increased, so that the signal-to-noise ratio is relatively increased.

16-17, FIG. 16 is a structural view of a MEMS microphone according to a twelfth embodiment of the present invention; and FIG. 17 is a cross-sectional view of the pallet shown in FIG. 16. The main difference between the MEMS microphone shown in FIG. 16 and the MEMS microphone shown in FIG. 13 is that the structure of the pallet 7 and the circuit board 1 are different. As shown in Fig. 17, the pallet 7 is a flat plate, and the two through holes 71 on the pallet 7 are spaced apart, and the bottoms of the two through holes 71 are not connected to each other, but penetrate the pallet 7. However, the circuit board 1 is provided with recesses 11 which respectively communicate with the two through holes 71 of the pallet 7, and the through holes 71 communicate with each other through the recesses 11. Moreover, the two through holes 71 are respectively in communication with the MEMS chip 2 and the seal ring 10, so that the groove 11 and the two through holes 71 of the pallet 7 communicate with the MEMS chip 2 and the seal ring 10; and the sound hole 5 is opened in the seal ring 10, the outer casing 6 facing the inner wall, the cavity formed by the sealing ring 10, the supporting plate 7 and the inner side of the MEMS chip 2 opposite to the sound hole 5 is the front cavity 20; the outer side of the MEMS chip 2, the outer casing 6 and the circuit board 1 The cavity is the back cavity 30, and the volume of the back cavity 30 is relatively increased, so that the signal to noise ratio is relatively increased.

Please refer to FIG. 18. FIG. 18 is a structural diagram of a MEMS microphone according to a thirteenth embodiment of the present invention. The main difference between the MEMS microphone shown in FIG. 18 and the MEMS microphone shown in FIG. 17 is that the structure of the circuit board 1 of the two is different, and the structure contributes to an increase in the strength of the circuit board. As shown in Fig. 18, the pallet 7 is a flat plate, and the two through holes 71 on the pallet 7 are spaced apart, and the bottoms of the two through holes 71 are not connected to each other, but penetrate the pallet 7. However, the circuit board 1 is provided with a recess 11 which includes a first recess 111 and a second recess 112, and the bottoms of the first recess 111 and the second recess 112 communicate with each other to form a communication. The cavity, the first groove 111 and the second groove 112 are respectively opposite to the two through holes 71 on the pallet 7, and the two through holes 71 of the pallet 7 respectively communicate with the MEMS chip 2 and the sealing ring 10; A groove 111, a second groove 112 and the two through holes 71 of the pallet 7 communicate with the MEMS chip 2 and the seal ring 10. And the sound hole 5 is opened on the outer casing 6 opposite to the inner wall of the sealing ring 10, and the sound hole 5 is opposed by the sealing ring 10, the pallet 7 and The cavity formed on the inner side of the MEMS chip 2 is the front cavity 20; the cavity formed by the outer side of the MEMS chip 2, the outer casing 6 and the circuit board 1 is the back cavity 30, and the volume of the back cavity 30 is relatively increased, so that the signal-to-noise ratio is relatively increased. It can be understood that, at this time, it is also possible to not provide the pallet 7, one port of the sealing ring 10 is connected to the sound hole 5, and the other port is opposite to the second groove 112, and the MEMS chip 2 is connected to the first groove 111. The second recess 112, which in turn is connected to the sound hole 5 through the seal ring 10, forms a front cavity.

According to the MEMS microphone provided in the eleventh to thirteenth embodiments, one of the boards 1 is fixed to the pallet 7, the MEMS chip 2 and the sealing ring 10 are fixed above the pallet 7, and the through hole 71 of the pallet 7 can realize the MEMS The chip 2 and the sealing ring 10 are in communication, and the inside of the sealing ring 10 is opposite to the sound hole 5, and the cavity formed by the sealing ring 10, the supporting plate 7 and the inside of the MEMS chip 2 opposite to the sound hole 5 is the front cavity 20, and the MEMS chip 2 The cavity formed by the outer side and the outer casing 6 and the circuit board 1 is the back cavity 30. The volume of the back cavity 30 is significantly increased relative to the volume of the MEMS microphone in the prior art, so the signal-to-noise ratio will be relatively increased to form a high signal noise. Second, the MEMS chip 2 and the sealing ring 10 are connected in various ways, which can be realized by the communication between the two through holes 71 on the pallet 7, and the two through holes 71 are respectively associated with the MEMS chip. 2 is connected to the sealing ring 10, so that communication can be realized; or the groove 11 on the circuit board 1 below the through hole 71 can be realized, and the two through holes 71 can be disconnected, but the two through holes 71 are respectively The grooves 11 are in communication and are respectively connected to the MEMS chip 2 and the sealing ring 10, so that The first groove 111 and the second groove 112 connected to each other are disposed on the circuit board 1. The two through holes 71 may not communicate with each other, but the first groove 111 and the second groove 112 respectively It communicates with the two through holes 71 and communicates with the MEMS chip 2 and the seal ring 10, respectively, so that communication can be achieved and the strength of the circuit board 1 can be increased.

It can be seen from the eleventh to thirteenth embodiments that when the open end of the MEMS chip 2 is disposed toward the circuit board 1, since the inner cavity of the MEMS chip 2 needs to communicate with the sound hole 5 to form the front cavity, at this time, the outer casing 6 is required. A channel is formed inside the package structure formed with the circuit board 1 to connect the inner cavity of the MEMS chip 2 and the sound hole 5. The above three embodiments give a specific channel arrangement. The passage is a passage between the inner cavity of the seal ring 10, the two through holes 71, and the two through holes 71, and may also be a passage between the inner cavity of the seal ring 10 and the first groove 111 and the second groove 112.

It can be understood that the manner of setting the channel is not limited thereto. For example, the MEMS chip 2 can be supported on the circuit board 1 by using the conductive pillars 71 as shown in FIGS. 5 and 7, and the circuit board 1 is disposed between the circuit board 1 and the circuit board 1. If there is a certain space, the channel may be a sealed elbow, one end of the sealing elbow is connected to the sound hole 5, and one end is connected to the open end of the MEMS chip through the space under the MEMS chip 2.

For the above various embodiments, the MEMS chip 2 can be electrically connected to the circuit board 1 and there is no wire connection between the MEMS chip 2 and the ASIC chip 3. For example, FIG. 2 and FIG. 3 realize conduction with the circuit board 1 through the pad 10; FIG. 4 realizes conduction with the circuit board 1 by solder balls 7; and FIGS. 5 and 7 have conductive pillars 71 provided at the bottom of the MEMS chip 2. The conductive member 7 is electrically connected to the circuit board 1; and the conductive member 71 is electrically connected to the circuit board 1 through a connecting member 7 that is electrically connected to the circuit board 1. The guiding members 7 and the like shown in FIG. 8-12 are all a guiding structure, that is, the MEMS chip can be electrically connected to the circuit board through the guiding structure, and the ASIC chip is connected by wires according to the prior art. In the way of reconnecting the circuit board, it is obvious that the lead structure makes the conduction mode of the MEMS chip and the circuit board more flexible and is not limited by the ASIC chip.

Further, when the lead structure is provided, the MEMS chip can be directly electrically connected to the circuit board 1 through the lead structure, and the ASIC chip 3 is not required to be connected by a line, so that the internal line arrangement can be simplified. As shown in Figures 2, 3, 5, 7, and 9. There may be other ways to achieve direct conduction between the MEMS chip 2 and the circuit board 1. For example, in FIG. 3, the ASIC chip 3 is turned on by attaching a contact contact, and the ASIC chip 2 and the MEMS chip 3 may also be connected to the same. The contacts are simultaneously turned on with the circuit board 1, and the structure is more simplified.

When the lead structure is set, the MEMS chip and the ASIC chip can also conduct the circuit board through the lead structure, so that the MEMS chip and the ASIC chip are relatively flexible in setting positions, and the pad on the circuit board is easy to set.

It can be understood that, in each of the above embodiments, the ASIC chip 3, the MEMS chip 2, and the circuit board 1 have different conduction modes, and can be mutually transferred according to the specific structure. For example, the conduction mode of the conductive post 71 in FIG. 5 can be applied to FIGS. 2, 3, and 8-12 (of course, in the several embodiments, the lead member 7 is already provided), and FIG. 13-18 (required) The embodiment in which the size of the pallet 7 is appropriately set to reserve the position where the conductive post 71 is disposed) is used. On the contrary, the conduction modes of the above embodiments can also be applied to the embodiments of FIGS. 5 and 7. It can be understood that the manner of conducting between the ASIC chip 3, the MEMS chip 2 and the circuit board 1 is not limited to the manners provided in the embodiments of the present invention, and any manner in which the three can be turned on can be applied to the above embodiments. in.

The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is It is to be understood that those skilled in the art are susceptible to variations and substitutions within the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

A MEMS microphone includes a package structure surrounded by a circuit board and a casing, and a sound hole, the package structure is internally provided with a MEMS chip and an integrated circuit ASIC chip, wherein the sound hole is disposed on the outer casing; the MEMS A chip cavity is in communication with the sound hole to form a front cavity of the MEMS microphone.
The MEMS microphone according to claim 1, wherein an open end of the inner cavity of the MEMS chip is disposed opposite to the sound hole, and the MEMS chip directly fits on an inner wall of the outer casing.

Or the MEMS chip is connected to the inner wall of the outer casing by a connector for the sound hole to communicate with the sealing of the front cavity of the MEMS microphone.
The MEMS microphone according to claim 1, wherein an open end of the MEMS chip is disposed toward the circuit board, and a channel is disposed inside the package structure to communicate the sound hole and the MEMS cavity And forming the front cavity.
The MEMS microphone of claim 3 wherein:

The MEMS microphone includes a pallet fixed on the circuit board, and the bracket is provided with two through holes;

The MEMS chip is fixed on the pallet, and an inner cavity of the MEMS chip is opposite to a through hole of the pallet;

The MEMS microphone further includes a sealing ring fixed between the outer casing and the pallet, a top end of the sealing ring is fixed on an inner wall of the outer casing, and a bottom end is fixed on the pallet. The other through hole of the pallet is opposite to the inner cavity of the sealing ring, and the bracket communicates with the inner cavity of the MEMS chip and the inner cavity of the sealing ring;

The sound hole is opened on the outer casing corresponding to the inner cavity of the sealing ring, and the inner cavity of the sealing ring, the two through holes and the passage between the two through holes form the passage.
The MEMS microphone according to claim 3, wherein the circuit board is provided with a first groove and a second groove;

The MEMS microphone further includes a seal ring fixed between the outer casing and the circuit board, the first recess being opposite to an inner cavity of the MEMS chip, the second recess and the The sealing ring is opposite to the port, and the sound hole is opened at the other port of the sealing ring. On the outer casing, the inner cavity of the seal ring, the first groove and the second groove, and a passage therebetween form the passage.
The MEMS microphone according to any one of claims 1 to 5, further comprising a conductive structure that turns on the circuit board; the MEMS chip is electrically connected to the circuit board through the conductive structure.
The MEMS microphone of claim 6 wherein there is no connection wire between the MEMS chip and the ASIC chip.
The MEMS microphone of claim 6 wherein said MEMS chip and said ASIC chip both conduct said circuit board through said lead structure.
A MEMS microphone includes a circuit board (1), a circuit board (1) is bonded with a casing (8), and a MEMS chip (2) is disposed between the casing (8) and the circuit board (1), and is characterized in that: The MEMS chip (2) has one side of the cavity bonded to the inner wall of the outer casing (8), and the other side is connected to the circuit board (1) through the pad (10), and the outer casing (8) is attached to the MEMS chip ( 2) A sound hole (12) is opened at a corresponding position of the cavity, and an ASIC chip (5) is connected to the circuit board (1) at a position on one side of the MEMS chip (2).
A MEMS microphone includes a package structure surrounded by a circuit board and a casing, and a sound hole. The package structure is internally provided with a MEMS chip and an integrated circuit ASIC chip fixed on the circuit board, wherein:

The sound hole is disposed on the outer casing;

The open end of the inner cavity of the MEMS chip faces one side of the sound hole;

A sealed channel is disposed between the sound hole and the open end of the lumen of the MEMS chip.
The MEMS microphone of claim 10 wherein:

An isolation layer is disposed in the sealing channel; at least one through hole is disposed on the isolation layer.
The MEMS microphone of claim 11 wherein:

The sound hole is disposed at an upper end of the outer casing;

The MEMS chip is disposed directly below the sound hole with an open end of the inner cavity facing upward.
A MEMS microphone according to claim 11 or 12, wherein:

The sound hole is disposed on a sidewall of the outer casing;

The open end of the inner cavity of the MEMS chip faces the sound hole.
A MEMS microphone comprising: a MEMS chip and an ASIC chip, which are built in between a housing and a cavity formed by a circuit board, the ASIC chip is fixed on the circuit board, and the metal wire is connected to the ASIC chip and the a circuit board, characterized in that

The MEMS chip is fixed on an inner wall of the top end of the outer casing, and a rear cavity is formed between the outer side of the MEMS chip and the outer casing and the circuit board;

a sound hole is formed on the housing opposite to the inner side of the MEMS chip, and a sound cavity is formed between the sound hole and the inner side of the MEMS chip;

A guiding member is fixed between the MEMS chip and the circuit board, and at least two conductive pillars are disposed in the guiding member, and one end of the conductive pillar is fixed on a pad of the MEMS chip, and the other end is fixed On the pads of the circuit board, the conductive posts enable conduction between the MEMS chip and the circuit board.
A MEMS microphone according to claim 14, wherein said connecting member is a non-seal member having a slit at least one side wall.
The MEMS microphone of claim 14 wherein said lead member has an n-shaped cross section.
A forward sound MEMS microphone comprising: a MEMS chip and an ASIC chip, which are built in between a housing and a cavity formed by a circuit board, the metal wire connecting the MEMS chip and the ASIC chip, wherein

The MEMS chip is fixed on an inner wall of the top end of the outer casing, and a rear cavity is formed between the outer side of the MEMS chip and the outer casing and the circuit board;

a sound hole is formed on the housing opposite to the inner side of the MEMS chip, and a sound cavity is formed between the sound hole and the inner side of the MEMS chip;

a top end of the guiding member is fixed on the outer casing, a bottom end is provided with a pad and is fixed on the circuit board, and the connecting member realizes the MEMS chip, the ASIC chip and the metal through the metal wire Conduction between boards.
The progressive MEMS microphone of claim 17 wherein said ASIC chip is attached to an inner wall of said top end of said housing.
The progressive MEMS microphone of claim 18 wherein said lead is located on the same side of said MEMS chip and ASIC chip.
The progressive MEMS microphone of claim 17 wherein said ASIC chip is attached to said circuit board.
The progressive MEMS microphone of claim 19 wherein said lead is located between said MEMS chip and an ASIC chip.
The progressive MEMS microphone according to claim 17 or 19 or 21, wherein the top end of the connecting member is bonded to the outer casing by a fixing glue, and the bottom end is bonded by the pad solder or the fixing glue. On the circuit board.
The progressive MEMS microphone according to claim 17 or 19, wherein the bottom of the connecting body is stepped, the top end of the connecting member is bonded to the outer casing by a fixing glue, and the bottom end is passed through. A pad solder or a fixing paste is bonded to the circuit board.
The progressive MEMS microphone of claim 23 wherein said ASIC chip is attached to said lead body.
A MEMS microphone comprising: a MEMS chip and an ASIC chip, which are built in between a housing and a cavity formed by a circuit board, the ASIC chip is fixed on the circuit board, and the metal wire is connected to the ASIC chip and the a circuit board, characterized in that

The pallet is fixed on the circuit board, and the pallet is provided with two through holes;

The MEMS chip is fixed on the pallet, an inner wall of the MEMS chip is opposite to a through hole of the pallet, and the MEMS chip and the ASIC chip are connected by a metal wire;

a sealing ring is fixed between the outer casing and the pallet, a top end of the sealing ring is fixed on an inner wall of the outer casing, a bottom end is fixed on the pallet, and another through hole of the pallet is The inside of the sealing ring is opposite, the pallet is connected to the MEMS chip and the sealing ring;

a sound hole is formed on the outer casing opposite to the inner wall of the sealing ring, and the cavity formed by the sealing ring, the pallet and the inner side of the MEMS chip is a front cavity; The cavity formed by the outside of the MEMS chip, the outer casing and the circuit board is a back cavity.
A MEMS microphone according to claim 25, wherein said pallet is provided with two through holes, one of said through holes being located below said seal ring and opposite said sound hole, the other said pass A hole is located under the MEMS chip and opposite to an inner side of the MEMS chip, and bottoms of the two through holes communicate with each other, and the carrier communicates with the MEMS chip and the sealing ring.
A MEMS microphone according to claim 25, wherein said pallet is provided with two through holes, one of said through holes being located below said seal ring and opposite said sound hole, the other said pass a hole is located under the MEMS chip, and opposite to the inner side of the MEMS chip, the circuit board below the two through holes is provided with a groove connecting the two through holes, the groove and the Two through holes of the pallet communicate with the MEMS chip and the seal ring.
The MEMS microphone according to claim 27, wherein said groove comprises a first groove and a second groove, said first groove and said second groove respectively communicating with said tray The holes are opposite, and the first groove and the bottom of the second groove communicate with each other, and the first groove and the second groove communicate with the two through holes of the tray to connect the MEMS chip And the seal ring.