CN110784813A - MEMS microphone and production process thereof - Google Patents

Abstract

The invention relates to the field of microphones, in particular to an MEMS microphone and a production process thereof, which comprises a PCB substrate and a positioning plate, wherein the positioning plate is provided with fixing grooves for uniformly fixing a shell, the shell is fixed in the fixing grooves, tin paste is printed on the bottom end surface of the shell through a silk screen, a PCB is fixed on the PCB substrate at a position corresponding to the fixing grooves, an ASIC chip and an MEMS chip are fixed on the PCB, the ASIC chip is connected with the MEMS chip and the PCB at the corresponding position through a bonding wire, and the shell is mutually bonded and fixed with the PCB at the corresponding position on the PCB substrate through the corresponding tin paste on the shell. The process of drawing the tin cream has been replaced through the process of full-page printing tin cream, can promote the operating efficiency who draws the tin cream process by a wide margin, and simultaneously, backward flow soldering tin process places the PCB board in the below, and the shell is placed in the top to place the shell and place the tool and put into the backward flow stove together, can prevent effectively that the shell from floating high, increase the welding firmness.

Description

MEMS microphone and production process thereof

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of microphones, in particular to an MEMS (micro-electromechanical systems) microphone and a production process thereof.

[ background of the invention ]

MEMS is a Micro-Electro mechanical System (Micro-Electro mechanical System), which refers to a sensor device with a size of several millimeters or less, and the internal structure of the sensor device is generally in the micrometer or nanometer level, and the sensor device is an independent intelligent System. Briefly, the MEMS is a silicon-based sensor formed by miniaturizing mechanical components of a conventional sensor, fixing a device on a silicon wafer (wafer) by a three-dimensional stacking technique, for example, a three-dimensional through-silicon via (TSV) technique, and finally cutting and assembling the device in a specially-customized packaging form according to different application occasions. The MEMS has the advantages of miniaturization and high integration degree which cannot be achieved by the common sensor simultaneously due to the cost advantage brought by the IC silicon chip processing batch production which cannot be achieved by the common sensor.

The chip can not print solder paste on the PCB surface after being pasted, the traditional MEMS microphone process is characterized in that the shell and the PCB are connected by a dispenser and the shell is pasted and packaged after the solder paste is drawn on a bonding pad on the outer ring of the PCB, the efficiency of the whole process is low, and the bottleneck for restricting the production energy of the MEMS microphone is also realized, so that the realization of rapidly welding the shell and the PCB plate has important significance for actual production.

The invention is provided for overcoming the defects of the prior art.

[ summary of the invention ]

The present invention is directed to overcoming the above-mentioned disadvantages of the prior art, and provides an MEMS microphone and a manufacturing process thereof, in which a plurality of housings are fixed, solder paste is printed on an end surface of the housing by a screen printing, and the solder paste is melted after the housings and a PCB are fixed to each other, thereby encapsulating the housings and the PCB.

The invention can be realized by the following technical scheme:

the invention discloses an MEMS microphone, which comprises a PCB substrate and a positioning plate, wherein the positioning plate is provided with fixing grooves for uniformly fixing a shell, the shell is fixed in each fixing groove, the bottom end surface of the shell is printed with solder paste through a silk screen, the PCB is fixed on the PCB substrate at a position corresponding to the fixing grooves, an ASIC chip and an MEMS chip are fixed on the PCB, the ASIC chip is connected with the MEMS chip and the PCB at a corresponding position through a bonding wire, and the shell is mutually bonded and fixed with the PCB at the corresponding position on the PCB substrate through the solder paste corresponding to the shell. The process of drawing the tin cream has been replaced through the process of full-page printing tin cream, can promote the operating efficiency who draws the tin cream process by a wide margin, and simultaneously, backward flow soldering tin process places the PCB board in the below, and the shell is placed in the top to place the shell and place the tool and put into the backward flow stove together, can prevent effectively that the shell from floating high, increase the welding firmness.

A production process of an MEMS microphone comprises the following steps

a. Attaching the ASIC chip on a corresponding PCB on the PCB substrate by using an adhesive, and curing by baking;

b. the MEMS chip is attached to a corresponding PCB on the PCB substrate through an adhesive, and the bottom of the MEMS chip is completely sealed through the adhesive;

c. the MEMS chip, the ASIC chip and the PCB are electrically connected by using a bonding wire in a lead bonding mode;

d. uniformly placing the shell in a fixing groove on the positioning plate in an inverted manner;

f. uniformly coating solder paste on the end face of the bottom of the shell by a screen printing technology;

g. fixing the PCB substrate and the positioning plate with each other, fixing the corresponding shell and the corresponding PCB, and uniformly distributing solder paste at the contact position of the shell and the PCB;

h. placing the fixed PCB substrate and the positioning plate in a hot air tin soldering machine, uniformly blowing hot air to the contact position of the shell and the PCB by the hot air tin soldering machine, and then melting the solder paste, wherein the PCB is completely fixed with the corresponding shell;

i. and taking down the PCB with the shell fixed on the PCB substrate.

Compared with the prior art, the invention has the following advantages:

1. the process of drawing the solder paste is replaced by the process of printing the solder paste in a full-page manner, and the operating efficiency of the process of drawing the solder paste can be greatly improved.

2. The PCB is placed below in the reflow soldering process, the shell is placed above, the shell is placed in the reflow furnace together with the jig, the shell can be effectively prevented from floating, and welding firmness is increased.

[ description of the drawings ]

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings, in which:

FIG. 1 is a schematic diagram of a PCB substrate structure;

FIG. 2 is a schematic view of an assembly structure of a PCB substrate, an ASIC chip and an MEMS chip;

FIG. 3 is a schematic diagram of a positioning plate structure according to the present invention;

FIG. 4 is a schematic view of the housing structure of the present invention;

FIG. 5 is a schematic view of the housing structure of the present invention;

FIG. 6 is a schematic view of an assembly structure of the positioning plate and the housing of the present invention;

FIG. 7 is a schematic structural view of the present invention;

in the figure: 1. a PCB substrate; 2. a PCB board; 3. an ASIC chip; 4. an MEMS chip; 5. a bonding wire; 6. positioning a plate; 7. fixing grooves; 8. a housing;

[ detailed description ] embodiments

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings:

as shown in fig. 1 to 7, the invention discloses an MEMS microphone, which comprises a PCB substrate 1 and a positioning plate 6, wherein the positioning plate 6 is provided with fixing grooves 7 uniformly provided with fixing housings 8, the fixing grooves 7 are all fixed with the housings 8, the bottom end surfaces of the housings 8 are all printed with solder paste through silk screens, the PCB substrate 1 is fixed with a PCB plate 2 at a position corresponding to the fixing grooves 7, the PCB plate 2 is fixed with an ASIC chip 3 and an MEMS chip 4, the ASIC chip 3 is connected with the MEMS chip 4 and the PCB plate 2 at a corresponding position through a bonding wire 5, and the housing 8 is mutually bonded and fixed with the PCB plate 2 at a corresponding position on the PCB substrate 1 through the solder paste corresponding to the housing 8. The technology through full-page printing tin cream has replaced the technology of drawing tin cream, can promote the operating efficiency who draws tin cream technology by a wide margin, and simultaneously, backward flow soldering tin process places PCB board 2 in the below, and shell 8 is placed in the top to place the tool with shell 8 and put into the backward flow stove together, can prevent effectively that shell 8 from floating high, increase the welding firmness, the shadow part is the tin cream position in figure 4.

A production process of an MEMS microphone comprises the following steps

a. The ASIC chip 3 is attached to the corresponding PCB 2 on the PCB substrate 1 by using an adhesive and is cured by baking;

b. the MEMS chip 4 is attached to the corresponding PCB 2 on the PCB substrate 1 through an adhesive, and the bottom of the MEMS chip 4 is completely sealed through the adhesive;

c. the MEMS chip 4, the ASIC chip 3 and the PCB 2 are electrically connected by using a bonding wire 5 in a lead bonding mode;

d. the shell 8 is evenly placed in the fixing groove 7 on the positioning plate 6;

f. uniformly coating solder paste on the end face of the bottom of the shell 8 by a screen printing technology;

g. mutually fixing the PCB substrate 1 and the positioning plate 6, fixing the corresponding shell 8 and the corresponding PCB 2, and uniformly distributing solder paste at the contact position of the shell 8 and the PCB 2;

h. placing the fixed PCB substrate 1 and the positioning plate 6 in a hot air tin soldering machine, uniformly blowing hot air to the contact position of the shell 8 and the PCB 2 through the hot air tin soldering machine, and then melting the solder paste, wherein the PCB 2 and the corresponding shell 8 are completely fixed;

i. the PCB 2 with the housing 8 fixed thereto is removed from the PCB substrate 1.

The above description is only a preferred embodiment of the present invention, and it should be noted that a person skilled in the art can make various changes, modifications, substitutions and alterations to the embodiments without departing from the technical principles of the present invention, and such changes, modifications, substitutions and alterations should also be regarded as the protection scope of the present invention.

Claims (2)

1. A MEMS microphone, characterized by: including PCB base plate and locating plate, be equipped with the fixed slot that evenly is equipped with fixed shell on the locating plate, all be fixed with the shell in the fixed slot, all there is tin cream through the silk screen printing on the shell bottom terminal surface, it all is fixed with the PCB board all to correspond the position with aforementioned fixed slot on the PCB base plate, be fixed with ASIC chip and MEMS chip on the PCB board, the aforementioned MEMS chip of ASIC chip and the PCB board that corresponds the position are connected through the bonding wire to the ASIC chip, the shell passes through the tin cream that corresponds on the shell and the PCB base plate PCB board that corresponds the position and bonds fixedly each other.

2. A production process of an MEMS microphone is characterized in that: comprises the following steps

a. Attaching the ASIC chip on a corresponding PCB on the PCB substrate by using an adhesive, and curing by baking;

b. the MEMS chip is attached to a corresponding PCB on the PCB substrate through an adhesive, and the bottom of the MEMS chip is completely sealed through the adhesive;

c. the MEMS chip, the ASIC chip and the PCB are electrically connected by using a bonding wire in a lead bonding mode;

d. uniformly placing the shell in a fixing groove on the positioning plate in an inverted manner;

f. uniformly coating solder paste on the end face of the bottom of the shell by a screen printing technology;

g. fixing the PCB substrate and the positioning plate with each other, fixing the corresponding shell and the corresponding PCB, and uniformly distributing solder paste at the contact position of the shell and the PCB;

h. placing the fixed PCB substrate and the positioning plate in a hot air tin soldering machine, uniformly blowing hot air to the contact position of the shell and the PCB by the hot air tin soldering machine, and then melting the solder paste, wherein the PCB is completely fixed with the corresponding shell;

i. and taking down the PCB with the shell fixed on the PCB substrate.

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