CN112830448B

CN112830448B - Microphone packaging technology and microphone packaging structure

Info

Publication number: CN112830448B
Application number: CN202110073228.3A
Authority: CN
Inventors: 贲锋; 孟凡亮; 花飞
Original assignee: Weifang Goertek Microelectronics Co Ltd
Current assignee: Weifang Goertek Microelectronics Co Ltd
Priority date: 2021-01-19
Filing date: 2021-01-19
Publication date: 2023-12-26
Anticipated expiration: 2041-01-19
Also published as: CN112830448A

Abstract

The invention discloses a microphone packaging process and a microphone packaging structure, wherein the microphone packaging process comprises the following steps: forming a through hole by punching on the film; attaching the mounting film to an MEMS chip so that the through hole corresponds to a sound hole of the MEMS chip; attaching the MEMS chip to a substrate; attaching an ASIC chip to the substrate; and arranging the packaging shell on the substrate, and enclosing the packaging shell with the substrate to form a containing cavity, so that the ASIC chip and the MEMS chip are contained in the containing cavity. The invention aims to provide the microphone packaging process which can conveniently monitor the adhesive layer and effectively avoid glue overflow, and the microphone packaging process can effectively improve the acoustic performance of the microphone packaging structure.

Description

Microphone packaging technology and microphone packaging structure

Technical Field

The invention relates to the technical field of microphone packaging, in particular to a microphone packaging process and a microphone packaging structure applying the microphone packaging process.

Background

In the related art, the bonding process of the MEMS chip and the PCB in the microphone structure is usually that the MEMS chip is cut, the die-mounted station picture is silica gel, the MEMS chip is attached to the silica gel surface, the MEMS chip and the PCB are bonded by the silica gel, and the die-mounted station picture is baked in an oven. In this process, the thickness of silica gel can influence the MEMS chip slope, and is great to the influence of product sensitivity change, and needs the wide and internal width of gluing of control silica gel, and glue is in MEMS chip below after the MEMS chip is pasted, can't monitor, if overflow glue too much flows into the sound hole and can influence the product acoustic performance.

Disclosure of Invention

The invention mainly aims to provide a microphone packaging process and a microphone packaging structure, and aims to provide the microphone packaging process which can conveniently monitor a glue layer and effectively avoid glue overflow, and the microphone packaging process can effectively improve the acoustic performance of the microphone packaging structure.

In order to achieve the above object, the present invention provides a microphone packaging process, which includes:

forming a through hole by punching on the film;

attaching the mounting film to an MEMS chip so that the through hole corresponds to a sound hole of the MEMS chip;

attaching the MEMS chip to a substrate;

attaching an ASIC chip to the substrate;

and arranging the packaging shell on the substrate, and enclosing the packaging shell with the substrate to form a containing cavity, so that the ASIC chip and the MEMS chip are contained in the containing cavity.

In an embodiment, the die attach film includes a dicing film and a glue layer that are stacked, and the step of forming the through hole by forming the hole in the die attach film includes:

and opening holes in the adhesive layer in a cutting or laser mode, so that the through holes are formed in the adhesive layer.

In an embodiment, the attaching the die attach film to the MEMS chip such that the through hole corresponds to a sound hole of the MEMS chip includes:

attaching an MEMS wafer to one side of the adhesive layer, which is opposite to the dicing film, so that the through holes correspond to the sound holes;

and cutting the MEMS wafer and the adhesive layer in a scribing or cutting mode to form the MEMS chip.

In one embodiment, the step of mounting the MEMS chip to a substrate includes:

the MEMS chip is adsorbed by a suction nozzle, so that the adhesive layer is separated from the scribing film;

and attaching one side of the MEMS chip, which is attached with the adhesive layer, to the substrate so as to bond and fix the adhesive layer and the substrate.

In an embodiment, before the step of attaching the side of the MEMS chip to which the adhesive layer is attached to the substrate so that the adhesive layer and the substrate are bonded and fixed, the method further includes:

and placing the substrate on a track of a machine body, and controlling the machine body to heat the track to ensure that the temperature of the track is 80-150 ℃.

In an embodiment, the die attach film further includes a protective film laminated on a side of the adhesive layer opposite to the dicing film, and before the step of attaching the die attach film to the MEMS chip, the die attach film further includes:

and removing the protective film.

In an embodiment, after the step of attaching the ASIC chip to the substrate, the method further includes:

and forming an interconnection path between the ASIC chip and the circuit of the substrate through a wire bonding process.

In an embodiment, before the step of disposing the package housing on the substrate, the method further includes:

and connecting the gold wire with the MEMS chip and the ASIC chip in a bonding mode.

In an embodiment, the step of disposing the package housing on the substrate and enclosing the package housing with the substrate to form a accommodating cavity, so that the ASIC chip and the MEMS chip are accommodated in the accommodating cavity includes:

spot-coating solder paste on copper foil around the substrate;

and sticking the solder paste on the periphery of the packaging shell corresponding to the substrate, and melting the solder paste through reflow soldering to enable the packaging shell to be welded with the substrate.

The invention also provides a microphone packaging structure, which is manufactured by adopting the microphone packaging process.

According to the microphone packaging technology, the chip mounting film is utilized, the through holes are formed in the chip mounting film, and the through holes of the chip mounting film correspond to the sound holes of the MEMS chip, so that the chip mounting film is adhered to the MEMS chip, the chip mounting film is convenient to monitor, the MEMS chip adhered with the chip mounting film is further adhered to the substrate, the baking and curing steps are omitted, the glue overflow phenomenon is effectively avoided, the ASIC chip and the packaging shell are further adhered to the substrate, and the ASIC chip and the MEMS chip are contained in the containing cavity formed by enclosing the packaging shell and the substrate, so that the packaging processing of the microphone packaging structure is completed. The microphone packaging process provided by the invention not only can be used for conveniently monitoring the adhesive layer, but also can be used for effectively avoiding adhesive overflow, and can be used for effectively improving the acoustic performance of the microphone packaging structure.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

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

FIG. 2 is a schematic cross-sectional view of a mounting film according to an embodiment of the present invention;

FIG. 3 is a schematic view showing a structure of a mounting film with a protective film removed according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a glue layer according to an embodiment of the invention;

FIG. 5 is a schematic flow chart of a microphone packaging process according to an embodiment of the invention;

FIG. 6 is a schematic flow chart of a microphone packaging process according to another embodiment of the invention;

FIG. 7 is a flowchart illustrating an embodiment of the step S20 in FIG. 5 and FIG. 6;

FIG. 8 is a schematic diagram of a MEMS chip attached to a mounting film according to an embodiment of the invention;

FIG. 9 is a schematic diagram of a MEMS chip with an adhesive layer according to an embodiment of the invention;

FIG. 10 is a flowchart illustrating an embodiment of step S30 in FIGS. 5 and 6;

fig. 11 is a flowchart of the first embodiment of step S70 in fig. 5 and 6.

Reference numerals illustrate:

the achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

Meanwhile, the meaning of "and/or" and/or "appearing throughout the text is to include three schemes, taking" a and/or B "as an example, including a scheme, or B scheme, or a scheme that a and B satisfy simultaneously.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.

Based on the conception and the problems, the invention provides a microphone packaging process. It is understood that the microphone packaging process is applied to the manufacturing process of the microphone packaging structure 100. As shown in fig. 1, the microphone package structure 100 includes a substrate 1, a package case 2, a MEMS chip 3, and an ASIC chip 4, where the package case 2 is disposed on the substrate 1 and encloses with the substrate 1 to form a receiving cavity 21, and the MEMS chip 3 and the ASIC chip 4 are disposed on the substrate 1 and received in the receiving cavity 21.

Referring to fig. 1, 5 and 6, the present invention provides a microphone packaging process, in this embodiment, a substrate 1, a MEMS chip 3, an ASIC chip 4, a package housing 2 and a die attach film 5 are provided.

Referring to fig. 5, the microphone packaging process includes the following steps:

s10: the dicing film 5 is perforated to form a through hole 521.

In this embodiment, as shown in fig. 2, the dicing film 5 includes a dicing film 51, a glue layer 52, and a protective film 53, and the dicing film 51, the glue layer 52, and the protective film 53 of the dicing film 5 are laminated in this order. It will be appreciated that the dicing film 51 serves to support and attach the glue layer 52 and to protect against curing or damage of the glue layer 52, etc. The protective film 53 serves to protect the adhesive layer 52 and is also conveniently used for removal, thereby facilitating the use of the adhesive layer 52.

It will be appreciated that the dicing film 51 may be a UV film, and the dicing film 51 may be bonded and fixed to the adhesive layer 52 by an adhesive, and the dicing film 51 has a high stretching ability. The protective film 53 is attached to the side of the glue layer 52 facing away from the dicing film 51. The protective film 53 may be selected as a release film. The adhesive layer 52 is a film with double-sided adhesive properties, and is mainly composed of active resin and filler (catalyst, etc.), and active groups are crosslinked when heated, so that the adhesive layer shows adhesive properties, and different requirements can be met by using different types of resin and filler. In the present embodiment, the thickness of the adhesive layer 52 is set according to the specific use environment, and is not limited herein.

In the present embodiment, the through hole 521 is formed in the die pad 5 by forming the hole on the die pad 5, so that the positioning is facilitated by the through hole 521 and the sound hole 31 of the MEMS chip 3 when the die pad 5 is attached to the MEMS chip 3. It will be appreciated that the size, dimension or contour of the through-hole 521 is determined by the design of the sound hole 31 of the MEMS chip 3 when the die-attach film 5 is perforated, and is not limited herein.

In one embodiment, the step S10 includes:

the adhesive layer 52 is perforated by cutting or laser, so that the through holes 521 are formed in the adhesive layer 52.

In this embodiment, as shown in fig. 3, the dicing film 5 includes a dicing film 51 and a glue layer 52 that are stacked, and the glue layer 52 of the dicing film 5 is perforated by cutting or laser drilling, so that the glue layer 52 is formed with a through hole 521. It will be appreciated that the openings of the dicing film 5 are only required to be formed in the adhesive layer 52 of the dicing film 5, that is, the dicing film 51 and the protective film 53 are not provided as openings.

Of course, in other embodiments, for convenience of process implementation, the whole of the die attach film 5 may be perforated, that is, the dicing film 51, the adhesive layer 52 and the protective film 53 of the die attach film 5 may be perforated simultaneously to form the through holes 521, which is not limited herein.

S20: the die attach film 5 is attached to the MEMS chip 3 such that the through hole 521 corresponds to the sound hole 31 of the MEMS chip 3.

In this embodiment, the MEMS chip 3 may convert external physical and chemical signals into electrical signals. MEMS is an abbreviation for Micro-Electro-Mechanical System, chinese name Micro-Electro-mechanical systems. In short, the MEMS chip 3 is an electromechanical system fabricated on a silicon wafer by using semiconductor technology, and then is a micro-nano mechanical system, which can convert external physical and chemical signals into electrical signals. The most commonly used chips are those that perform sensing functions and are somewhat similar to human sensory systems throughout a large information system, e.g., MEMS microphone chips correspond to human ears that can sense sound; the MEMS speaker chip is equivalent to the mouth of a person and can emit sound; the MEMS accelerometer, the gyroscope and the magnetic sensor chip are equivalent to the cerebellum of a person, and can sense the direction and the speed; the MEMS pressure chip is equivalent to human skin and can sense pressure; the MEMS chemical sensor is equivalent to the nasal cavity of a person, and can sense taste and temperature and humidity. The MEMS sensor is formed by packaging one MEMS chip 3 and one application specific integrated circuit chip (ASIC chip) together. That is, the microphone package 100 manufactured by the present process is a MEMS sensor.

It can be appreciated that the perforated mounting film 5 is attached to the MEMS chip 3, so that the through hole 521 of the mounting film 5 is used to align the sound hole 31 of the MEMS chip 3, and the MEMS chip 3 is prevented from being offset.

In order to avoid that the die attach film 5 is attached to the MEMS chip 3, the MEMS chip 3 extrudes and tilts the die attach film 5, in this embodiment, as shown in fig. 4, the adhesive layer 52 of the die attach film 5 includes a first adhesive surface 522, a heat conducting layer 525, a supporting body 523 and a second adhesive surface 524, the heat conducting layer 525 is sandwiched between the first adhesive surface 522 and the second adhesive surface 524, and the supporting body 523 is disposed in the heat conducting layer 525, so that the supporting body 523 can be utilized to effectively prevent the MEMS chip 3 from extruding and tilting the die attach film 5.

In this embodiment, the adhesive layer 52 of the die attach film 5 is prepared by the following steps. A layer of high heat conduction resin liquid is spread on the second adhesive surface 524, a supporting body 523 is spread on the high heat conduction resin liquid, the high heat conduction resin liquid is poured into the layer formed by the supporting body 523 to form a heat conduction layer 525 provided with the supporting body 523, and the first adhesive surface 522 is spread on the surface of the heat conduction layer 525 to obtain the adhesive layer 52.

It can be understood that the supporting body 523 is disposed on the heat conducting layer 525, or the supporting body 523 is added into the high heat conducting resin liquid and mixed uniformly to obtain a mixture; the mixture is uniformly spread on the second adhesive surface 524 and covers the first adhesive surface 522, thus obtaining the adhesive layer 52.

In the present embodiment, the dicing film 5 is obtained by laying the above-mentioned adhesive layer 52 on the dicing film 51 and covering a protective film 53. In use, the protective film 53 is peeled off, and the adhesive layer 52 of the die attach film 5 is attached to the chip, which is not limited herein.

In one embodiment, before step S20, the steps of the microphone packaging process further include:

the protective film 53 is removed.

It will be appreciated that, in order to facilitate the adhesion of the adhesive layer 52 of the die attach film 5 to the MEMS chip 3, the protective film 53 on the die attach film 5 for protecting the adhesive layer 52 needs to be torn off, so that the adhesion of the adhesive layer 52 to the MEMS chip 3 is more firm.

S30: the MEMS chip 3 is mounted on the substrate 1.

In this embodiment, the substrate 1 is provided with a circuit layer, has a copper layer, and has a mounting site for mounting a chip, the mounting site having contacts such as pads for connecting the internal circuits of the substrate 1, and the surface of the substrate 1 is provided with signal contacts for connection with external circuits.

The MEMS chip 3 attached with the adhesive layer 52 of the dicing film 5 is attached to the substrate 1 by a dicing process, so that the MEMS chip 3 is firmly adhered to the substrate 1 by the adhesive layer 52. It can be appreciated that the adhesive layer 52 of the sheet film 5 is attached to the MEMS chip 3, so that the baking and curing step required for bonding by the silicone is effectively avoided, and the silicone is easy to overflow in the curing process, so that the overflow flows into the sound hole 31 of the MEMS chip 3 or the sound hole 11 of the substrate 1, and the acoustic performance of the microphone package structure 100 is affected.

S40: the ASIC chip 4 is mounted on the substrate 1.

In the present embodiment, the ASIC chip 4 may be attached to the substrate 1 through a silicone gel or a die-attach film 5, which is not limited herein. Of course, in other embodiments, the ASIC chip 4 may be mounted on the substrate 1 by Flip chip (Flip chip) technology, where solder balls are deposited on the mounting location of the substrate 1, and then the chip is flipped and heated to combine with the substrate 1 by using the molten solder balls, so as to achieve the purpose of mounting the ASIC chip 4 on the substrate 1. Meanwhile, a gap is formed between the ASIC chip 4 and the substrate 1, and then the gap can be filled with underfill through an underfill process, so that the reinforcement purpose is achieved.

It will be appreciated that the MEMS chip 3 may convert external physical and chemical signals into electrical signals, while the ASIC chip 4 further processes and transmits the electrical signals generated by the MEMS chip 3 to a next stage of circuitry. In this embodiment, by mounting the MEMS chip 3 and the ASIC chip 4 on the substrate 1, the electrical connection between the MEMS chip 3 and the ASIC chip 4 is achieved, and the electrical signal generated by the MEMS chip 3 may be transmitted to the ASIC chip 4 for further processing, and then output to the outside through the ASIC chip 4.

In this embodiment, an adhesive may be coated on the ASIC chip 4, and the ASIC chip 4 is adhered to the substrate 1, so that the ASIC chip 4 and the MEMS chip 3 are disposed at intervals, and the adhesive is baked to cure the adhesive. It can be understood that the adhesive is conductive adhesive, and the ASIC chip 4 is fixed on the substrate 1 by the adhesive, and electrical connection is achieved. And heating and solidifying the viscose to realize the reinforcement effect.

Of course, in order to avoid the influence of the baking and curing of the adhesive of the ASIC chip 4 on the performance of the adhesive layer 52 of the die attach film 5, the step of attaching the ASIC chip 4 to the substrate 1 may be performed first, that is, after the step of attaching the ASIC chip 4 to the substrate 1 is completed, and the step of attaching the MEMS chip 3 to the substrate 1 is not limited herein.

S70: the package case 2 is disposed on the substrate 1, and forms a housing cavity 21 around the substrate 1, so that the ASIC chip 4 and the MEMS chip 3 are housed in the housing cavity 21.

It can be appreciated that, by connecting the package housing 2 with the substrate 1, the purpose of packaging the MEMS chip 3 and the ASIC chip 4 is achieved, and the package housing 2 can play a role of isolation and shielding, so as to prevent the electrical performance from being degraded due to corrosion of the circuit of the microphone package structure 100 by impurities in the air. On the other hand, the microphone package 100 formed after packaging is also more convenient to install and transport.

According to the microphone packaging process, the chip mounting film 5 is utilized, the through holes 521 are formed by punching holes on the chip mounting film 5, and the through holes 521 of the chip mounting film 5 correspond to the sound holes 31 of the MEMS chip 3, so that the chip mounting film 5 is adhered to the MEMS chip 3, the chip mounting film 5 is convenient to monitor, the MEMS chip 3 adhered with the chip mounting film 5 is further adhered to the substrate 1, the baking and curing steps are omitted, the glue overflow phenomenon is effectively avoided, the ASIC chip 4 and the packaging shell 2 are further adhered to the substrate 1, and the ASIC chip 4 and the MEMS chip 3 are accommodated in the accommodating cavity 21 formed by enclosing the packaging shell 2 and the substrate 1, so that the packaging processing of the microphone packaging structure 100 is completed. The microphone packaging process provided by the invention not only can be used for conveniently monitoring the adhesive layer, but also can be used for effectively avoiding adhesive overflow, and can be used for effectively improving the acoustic performance of the microphone packaging structure 100.

Referring to fig. 7, 8 and 9, in an embodiment of the present invention, the step of attaching the die attach film 5 to the MEMS chip 3 so that the through hole 521 corresponds to the sound hole 31 of the MEMS chip 3 includes:

s21: attaching a MEMS wafer to the side of the adhesive layer 52, which is opposite to the dicing film 51, so that the through hole 521 corresponds to the sound hole 31;

s22: the MEMS wafer and the glue layer 52 are diced by dicing or dicing to form the MEMS chip 3.

It can be understood that the dicing film 51 and the adhesive layer 52 of the dicing film 5 are of a whole block structure, and a plurality of through holes 521 are formed in the adhesive layer 52 of the dicing film 5 by cutting or laser drilling. The whole MEMS wafer is attached to the side, opposite to the dicing film 51, of the adhesive layer 52, so that the MEMS wafer and the adhesive layer 52 are firmly bonded, and meanwhile, the plurality of sound holes 31 on the MEMS wafer are respectively arranged in one-to-one correspondence with the plurality of through holes 521.

In this embodiment, for convenience, the whole MEMS wafer is divided into a plurality of MEMS chips 3, and dicing or cutting is performed on the whole MEMS wafer, so that the MEMS wafer and the adhesive layer 52 are cut simultaneously, that is, the dicing film 51 cut from the MEMS wafer to the dicing film 5 faces one side of the adhesive layer 52, that is, the dicing film 51 is not cut, thereby facilitating the separation of the MEMS chips 3 and the corresponding adhesive layers 52 from the dicing film 51.

Referring to fig. 10, in an embodiment of the invention, the step of mounting the MEMS chip 3 on the substrate 1 includes:

s31: the MEMS chip 3 is absorbed by a suction nozzle, so that the adhesive layer 52 is separated from the scribing film 51;

s33: and attaching the side, to which the adhesive layer 52 is attached, of the MEMS chip 3 to the substrate 1 so as to enable the adhesive layer 52 to be adhered and fixed with the substrate 1.

It can be understood that the suction nozzle of the suction device sucks the MEMS chip 3 attached to the adhesive layer 52 of the die attach film 5, and the MEMS chip 3 is a single chip structure after dicing the whole MEMS wafer. In the adsorption process, the suction nozzle can adsorb the MEMS chip 3 to drive the adhesive layer 52 to separate from the dicing film 51, namely, the step of attaching the dicing film 5 to the MEMS chip 3 is completed, so that the through hole 521 corresponds to the sound hole 31 of the MEMS chip 3.

In this embodiment, the suction nozzle of the suction device is further utilized to suck and move the MEMS chip 3 with the adhesive layer 52 to the substrate 1, so that the side of the MEMS chip 3 attached with the adhesive layer 52 is attached to the substrate 1, and the adhesive layer 52 is adhered and fixed to the substrate 1, so that the MEMS chip 3 is firmly attached to the substrate 1.

Referring to fig. 10, in an embodiment of the invention, step S33: before the step of attaching the side to which the adhesive layer 52 is attached to the substrate 1 so that the adhesive layer 52 and the substrate 1 are bonded and fixed, the method further includes:

s32: placing the substrate 1 on a track of a machine body, and controlling the machine body to heat the track to enable the temperature of the track to be 80-150 ℃.

It can be appreciated that by placing the substrate 1 on the track of the machine body, on one hand, the track of the machine body is utilized to provide a supporting foundation for the substrate 1, and the machine body is also convenient to control and heat the track, so that the temperature of the track is 80-150 ℃, and after the adhesive layer 52 contacts with the substrate 1, the adhesive layer 52 can be softened, and the connection firmness of the adhesive layer 52 and the substrate 1 is improved. Alternatively, the temperature of the rail may be selected from 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, etc., without limitation.

Referring to fig. 6, in an embodiment of the invention, step S40: after the step of mounting the ASIC chip 4 on the substrate 1, the step of the microphone packaging process further includes:

the ASIC chip 4 is formed into an interconnection path with the circuitry of the substrate 1 by a wire bonding process.

In this embodiment, a wire bonding process is adopted to connect the ASIC chip 4 with the internal circuit of the substrate 1, so as to form an interconnection path, so that the ASIC chip 4 processes the signal fed back by the MEMS chip 3 and transmits the processed signal to the substrate 1, and thus, the bonding pad on the substrate 1 is used to connect with the external circuit, so as to realize the signal transmission.

In this embodiment, a plurality of connectors are prepared on the substrate 1 at intervals; the ASIC chip 4 is placed on the side of the connection facing away from the substrate 1.

It can be understood that the connecting piece is a tin-lead ball, and the conductive bump on the ASIC chip 4 and the tin-lead ball on the substrate 1 are connected by a certain process, so as to connect the ASIC chip 4 and the substrate 1, and realize the normal output of the performance of the ASIC chip 4. In a typical flip-chip package, the ASIC chip 4 is attached to the substrate 1 by bumps that are 3 to 5 mils (mils) thick, and an underfill may be used to protect the bumps and the connectors.

Referring to fig. 6, in an embodiment of the invention, step S70: before the step of disposing the package housing 2 on the substrate 1, the step of the microphone package process further includes:

gold wires 41 are connected to the MEMS chip 3 and the ASIC chip 4 by bonding.

It will be appreciated that the process of connecting the electrodes on the MEMS chip 3 with the electrodes or pins or pads on the ASIC chip 4 by wires is gold wire bonding 41. In this embodiment, the MEMS chip 3 and/or the ASIC chip 4 are provided with a bonding pad or a bonding pad structure, and the bonding pad or the bonding pad of the MEMS chip 3 is electrically connected with the bonding pad or the bonding pad of the ASIC chip 4 by the gold wire 41 bonding method, so that when the step of bonding the gold wire 41 is performed, no glue overflow exists on the bonding pad in the prior art, and therefore, the electrical performance of the MEMS chip 3 and the ASIC chip 4 after bonding the gold wire 41 can be ensured.

Referring to fig. 11, in an embodiment of the present invention, the step of disposing the package housing 2 on the substrate 1 and enclosing the package housing with the substrate 1 to form a receiving cavity 21, so that the ASIC chip 4 and the MEMS chip 3 are received in the receiving cavity 21 includes:

s71: spot-coating solder paste on the copper foil around the substrate 1;

s72: and sticking the solder paste on the periphery of the packaging shell 2 corresponding to the substrate 1, and melting the solder paste through reflow soldering to enable the packaging shell 2 to be welded with the substrate 1.

Solder paste is a novel welding material. Solder paste is a paste formed by mixing solder powder, soldering flux and other additives. The solder paste has certain viscosity at normal temperature, can be used for initially adhering the electronic components at a set position, and is used for welding the components to be welded with the printed circuit bonding pads together to form permanent connection along with volatilization of the solvent and part of the additives at the welding temperature. In this embodiment, the connection between the package case 2 and the substrate 1 is realized by solder paste.

According to the microphone packaging process, holes are formed in the chip mounting film 5 according to the size and the position of the sound hole 31 of the MEMS chip 3, an MEMS wafer is attached to the chip mounting film 5, the MEMS chip 3 is obtained through cutting, the MEMS chip 3 with the chip mounting film 5 is attached to the PCB substrate 1, the substrate 1 is heated by utilizing the track of the bearing substrate 1, the adhesive layer 52 of the chip mounting film 5 is softened, and therefore the bonding with the substrate 1 is firmer.

It can be understood that the mounting film 5 with the through hole 521 is pre-mounted on the back surface of the MEMS chip 3, so that the through hole 521 is utilized to facilitate alignment with the sound hole 31 of the MEMS chip 3, and simultaneously, the adhesive layer 52 of the mounting film 5 is convenient to monitor; when the MEMS chip 3 with the chip mounting film 5 is combined with the PCB substrate 1, the adhesive layer 52 of the chip mounting film 5 is softened and adhered to the PCB substrate 1 by utilizing the track heating function, so that the connection firmness is improved. The thickness of the upper adhesive layer 52 of the mounting film 5 is a fixed value set during film pasting, and the inclination of the MEMS chip 3 is controlled more accurately after the mounting; the bonding of the MEMS chip 3 and the substrate 1 is realized by using the film 5, the glue range overflowed from the edge of the MEMS chip 3 can be controlled within 50um, the glue width can be controlled, the glue inner width can be controlled, and the acoustic performance of MEMS products can be improved.

As shown in fig. 1, the present invention further provides a microphone packaging structure 100, where the microphone packaging structure 100 is manufactured by using the microphone packaging process described above. The specific structure of the microphone packaging process refers to the foregoing embodiments, and since the microphone packaging structure 100 adopts all the technical solutions of all the foregoing embodiments, at least has all the beneficial effects brought by the technical solutions of the foregoing embodiments, which are not described in detail herein.

As shown in fig. 1, the microphone package structure 100 includes a substrate 1, a package housing 2, an ASIC chip 4, and a MEMS chip 3, where the package housing 2 is disposed on the substrate 1 and encloses with the substrate 1 to form a receiving cavity 1a; the ASIC chip 4 is arranged in the accommodating cavity 1a and is attached to the substrate 1; the MEMS chip 3 is disposed in the accommodating cavity 1a, and is attached to the substrate 1 and spaced from the ASIC chip 4.

As can be appreciated, a filling glue is filled between the ASIC chip 4 and the substrate 1; the MEMS chip 3 and the ASIC chip 4 are connected by two ends of the gold wire 41, respectively, so that the electrical connection between the MEMS chip 3 and the ASIC chip 4 is realized.

The foregoing description is only of the optional embodiments of the present invention, and is not intended to limit the scope of the invention, and all equivalent structural modifications made by the present description and accompanying drawings or direct/indirect application in other related technical fields are included in the scope of the present invention.

Claims

1. A microphone packaging process, the microphone packaging process comprising:

forming a through hole by punching on the film; the die bonding film comprises a die bonding film and a glue layer, wherein the die bonding film and the glue layer are arranged in a stacked mode, the glue layer comprises a first glue surface, a heat conducting layer, a supporting body and a second glue surface, the heat conducting layer is clamped between the first glue surface and the second glue surface, the supporting body is arranged in the heat conducting layer, the die bonding film is provided with holes, and the step of forming through holes comprises the following steps: perforating the adhesive layer by cutting or laser to form the through hole on the adhesive layer;

attaching the MEMS chip to a substrate;

attaching an ASIC chip to the substrate;

2. The microphone packaging process of claim 1, wherein the attaching the die attach film to the MEMS chip such that the through hole corresponds to a sound hole of the MEMS chip comprises:

3. The microphone packaging process of claim 1, wherein the step of mounting the MEMS chip to a substrate comprises:

4. The microphone packaging process of claim 3, wherein before the step of attaching the MEMS chip to the substrate with the adhesive layer to bond the adhesive layer to the substrate, the process further comprises:

5. The microphone packaging process of claim 1, wherein the die attach film further comprises a protective film laminated on a side of the glue layer facing away from the dicing film, and before the step of attaching the die attach film to the MEMS chip, the process further comprises:

and removing the protective film.

6. The microphone packaging process of any one of claims 1 to 5, further comprising, after the step of mounting an ASIC chip to the substrate:

7. The microphone packaging process of any one of claims 1 to 5, further comprising, prior to the step of disposing a package housing on the substrate:

8. The microphone packaging process as claimed in any one of claims 1 to 5, wherein the step of disposing the package case on the substrate and enclosing the substrate to form a receiving cavity, and the step of receiving the ASIC chip and the MEMS chip in the receiving cavity includes:

spot-coating solder paste on copper foil around the substrate;

9. A microphone package structure, wherein the microphone package structure is manufactured by the microphone package process according to any one of claims 1 to 8.