Packaging structure and microphone

Abstract

The invention relates to the technical field of chip packaging, in particular to a packaging structure and a microphone. The packaging structure comprises a shell and a substrate, a packaging cavity is defined by the shell and the substrate, a mounting groove is formed in the side, facing the packaging cavity, of the substrate, a sound hole is formed in the mounting groove, the packaging structure further comprises an MEMS chip and an ASIC chip, at least part of the MEMS chip is arranged in the mounting groove in the height direction of the substrate and communicated with the sound hole, and the ASIC chip is arranged in the mounting groove and communicated with the sound hole. The mounting groove is arranged on one side, facing the packaging cavity, of the substrate and electrically connected with the MEMS chip and the substrate, and the bonding part is arranged between the MEMS chip and the mounting groove and connected with the MEMS chip and the mounting groove. Sunken installation of the MEMS chip is achieved through the installation groove, lamination occupation in the height direction is reduced, the overall packaging height is reduced, the bonding part achieves fixed positioning and sealing through a gap in the groove, the risk that a thick glue layer at the bottom occupies high is reduced, the assembling stability and the sealing reliability are improved, and therefore the structural strength of the substrate is guaranteed after the packaging height is further compressed.

Description

Technical Field

[0001] This invention relates to the field of chip packaging technology, specifically to a packaging structure and a microphone. Background Technology

[0002] As smartphones, smartwatches, true wireless earbuds, and other terminal products become increasingly miniaturized and ultra-thin, miniature microphone modules used to collect voice signals are also required to achieve lower height and higher acoustic performance within limited installation space. Existing products widely use microphones (Micro-Electro-Mechanical Systems Microphone, or MEMS MIC for short), which typically include a MEMS chip (Micro-Electro-Mechanical Systems), an ASIC chip (Application-Specific Integrated Circuit), a substrate carrying the circuitry, and a cover for forming the acoustic cavity.

[0003] In traditional packaging structures, MEMS chips are typically mounted on the surface of a rigid PCB or ceramic substrate using flip-chip or wire bonding. Acoustic holes are pre-drilled on the substrate, or an acoustic channel is formed by the chip and a metal cap. To ensure mechanical fixation and hermetic sealing of the MEMS chip, a common practice is to coat the bottom or periphery of the chip with adhesives, potting compounds, or other adhesives. Simultaneously, a metal cap, a plastic shell, and the substrate are used to create a sealed cavity above the chip. To meet reliability requirements, the bottom adhesive layer needs a certain thickness and coverage area, and the wire bonding structure also needs sufficient height and safety clearance. This results in the MEMS chip, bonding wires, cavity, and cap being stacked sequentially in the height direction, making it difficult to further compress the overall module height. Summary of the Invention

[0004] The objective of this invention is to at least solve the problem of the difficulty in reducing the height of MEMS packaging structures. This objective is achieved through the following technical solution: This invention proposes a packaging structure, comprising: The housing and the substrate together form an encapsulation cavity. A mounting groove is provided on the side of the substrate facing the encapsulation cavity, and an acoustic hole is provided in the mounting groove. The MEMS chip, along the height direction of the substrate, at least a portion of the MEMS chip is placed in the mounting groove and connected to the acoustic hole; An ASIC chip is disposed on the side of the substrate facing the package cavity and is electrically connected to the MEMS chip and the substrate, respectively. The adhesive portion connects the circumferential outer wall of the MEMS chip and the circumferential inner wall of the mounting groove.

[0005] According to the packaging structure of the present invention, the substrate is provided with a mounting groove, and the MEMS chip is at least partially placed in the mounting groove, so that the MEMS chip forms a sunken mounting relationship in the height direction. The packaging cavity does not need to completely cover the entire thickness of the MEMS chip to achieve the purpose of accommodating it, which structurally reduces the stacking occupation in the height direction, thereby helping to reduce the overall height of the MEMS packaging structure. The adhesive part is provided between the MEMS chip and the mounting groove and connects the two respectively, so that the fixing, positioning and sealing functions of the MEMS chip can be realized by the gap structure in the mounting groove. This reduces the height occupation risk caused by the traditional thick adhesive layer at the bottom, and at the same time improves the assembly stability and sealing reliability of the MEMS chip in the mounting groove, thereby ensuring the structural strength of the substrate after further compression of the supporting packaging height.

[0006] In addition, the packaging structure according to the present invention may also have the following additional technical features: In some embodiments of the present invention, the MEMS chip and the ASIC chip are electrically connected via bonding wires.

[0007] In some embodiments of the present invention, the packaging structure further includes a waterproof membrane sandwiched between the MEMS chip and the bottom of the mounting groove, and the MEMS chip is connected to the acoustic hole through the waterproof membrane.

[0008] In some embodiments of the present invention, the ASIC chip is fixedly attached to the substrate.

[0009] In some embodiments of the present invention, the bottom of the mounting groove is provided with a first pad, and the MEMS chip is soldered to the first pad and electrically connected to the substrate.

[0010] In some embodiments of the present invention, the substrate is provided with a second pad, and the ASIC chip is soldered to the second pad and electrically connected to the substrate.

[0011] In some embodiments of the present invention, at least a portion of the ASIC is disposed within the mounting groove along the height direction of the substrate.

[0012] In some embodiments of the present invention, the ASIC chip is encapsulated with a sealant.

[0013] In some embodiments of the present invention, the substrate is a PCB circuit board.

[0014] The present invention also proposes a microphone, including the above-described encapsulation structure. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the packaging structure according to Embodiment 1 of the present invention is shown. Figure 2 A schematic diagram of the packaging structure according to Embodiment 2 of the present invention is shown. Figure 3 A schematic diagram of the packaging structure according to Embodiment 3 of the present invention is shown. Figure 4 A schematic diagram of the packaging structure according to Embodiment 4 of the present invention is shown. Figure 5 A schematic diagram of the packaging structure according to Embodiment 5 of the present invention is shown. Figure 6 A schematic diagram of the packaging structure according to Embodiment Six of the present invention is shown. Figure 7 A schematic diagram of the packaging structure according to Embodiment 7 of the present invention is shown.

[0016] The attached figures are labeled as follows: 10. Housing; 20. Substrate; 201. Mounting groove; 202. Acoustic hole; 30. Adhesive part; 40. MEMS chip; 50. ASIC chip; 51. Undercoat; 60. Bonding wire; 70. Waterproof membrane; 80. First pad. Detailed Implementation

[0017] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0018] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0019] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0020] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations.

[0021] like Figures 1 to 7 As shown, according to an embodiment of the present invention, a packaging structure is proposed, which includes a housing 10 and a substrate 20. The housing 10 and the substrate 20 cooperate to form a packaging cavity. The packaging cavity is used to accommodate and protect the internal functional chip and related structures, thereby forming an integrated device package.

[0022] A mounting groove 201 is formed on the side of the substrate 20 facing the package cavity. The mounting groove 201 is used to form a receiving space for the chip, so as to realize the sinking mounting of the chip in the height direction. An acoustic hole 202 is formed in the mounting groove 201. The acoustic hole 202 penetrates the substrate 20 or communicates with the outside of the substrate 20, so that the package structure can form an acoustic channel. The position of the acoustic hole 202 is set to correspond to the MEMS chip 40 in the mounting groove 201, so that sound waves can enter the corresponding acoustic sensitive area of ​​the MEMS chip 40 through the acoustic hole 202.

[0023] The packaging structure also includes a MEMS chip 40. At least a portion of the MEMS chip 40 is placed within the mounting groove 201 along the height direction of the substrate 20, forming an embedded arrangement of the MEMS chip 40 relative to the side of the substrate 20 facing the packaging cavity, thereby reducing the height occupied by the MEMS chip 40 within the packaging cavity. The MEMS chip 40 is connected to an acoustic aperture 202. Specifically, the acoustic port of the MEMS chip 40 is positioned facing the acoustic aperture 202, allowing external sound waves to enter the acoustic cavity inside the MEMS chip 40 through the acoustic aperture 202 and act on the diaphragm structure of the MEMS chip 40 to achieve the conversion of acoustic signals to electrical signals.

[0024] The packaging structure also includes an ASIC chip 50. The ASIC chip 50 is disposed on the side of the substrate 20 facing the packaging cavity, and is electrically connected to both the MEMS chip 40 and the substrate 20. Through this electrical connection, the electrical signals output by the MEMS chip 40 can be transmitted to the ASIC chip 50, where the ASIC chip 50 performs amplification, filtering, analog-to-digital conversion, and / or interface output processing of the electrical signals, and further connects to external circuits via the substrate 20.

[0025] The packaging structure also includes an adhesive portion 30. The adhesive portion 30 is disposed between the MEMS chip 40 and the mounting groove 201, connecting the MEMS chip 40 and the mounting groove 201 respectively. The adhesive portion 30 fills the gap formed between the outer periphery of the MEMS chip 40 and the sidewall of the mounting groove 201, and connects to the circumferential outer wall of the MEMS chip 40 and the circumferential inner wall of the mounting groove 201, thereby positioning and fixing the MEMS chip 40 within the mounting groove 201. Furthermore, the adhesive portion 30 can also form a continuous sealing structure between the MEMS chip 40 and the mounting groove 201 to reduce gas or liquid exchange between the inside of the packaging cavity and the outside, improving the sealing reliability of the package. In addition, by providing the adhesive portion 30 between the MEMS chip 40 and the mounting groove 201, the adhesive portion 30 not only achieves positioning and fixing of the MEMS chip 40 and gap sealing, but also provides mechanical support and stress dispersion for locally weak areas after the substrate 20 is slotted. Compared to relying solely on the rigidity of the substrate 20 itself for load bearing, the adhesive portion 30 can reduce stress concentration at the edge of the slot, improve the impact resistance and crack resistance of the slotted area, thereby reducing the risk of the substrate 20 being easily damaged due to the slotting and improving the mechanical reliability of the packaging structure.

[0026] Through the above structural design, the MEMS chip 40 can be at least partially embedded in the mounting groove 201, so that the package cavity does not need to reserve a complete stacking space for the overall thickness of the MEMS chip 40 in the height direction, which is beneficial to reducing the overall height of the package structure. At the same time, the adhesive part 30 is disposed between the MEMS chip 40 and the mounting groove 201 and connects the two, so that the MEMS chip 40 can still be reliably fixed and sealed under the sunken mounting condition, thus taking into account both the ultra-thin requirements and the package reliability. The adhesive part 30 can reduce the stress concentration at the edge of the groove, improve the impact resistance and crack resistance of the grooved area, thereby reducing the risk of the substrate 20 being easily damaged due to the groove, and improving the mechanical reliability of the package structure.

[0027] It is understood that the mounting groove 201 includes a groove bottom and circumferential sidewalls surrounding the groove bottom. When the MEMS chip 40 is flipped and installed in the mounting groove 201, the bottom surface of the MEMS chip 40 is positioned opposite the groove bottom, and a gap is formed between the bottom surface of the MEMS chip 40 and the groove bottom. To prevent adhesive material from entering this gap and affecting the acoustic channel or causing inconsistent assembly height, in this embodiment, no adhesive portion 30 is provided in this gap. In this embodiment, the adhesive portion 30 is provided in the circumferential gap formed between the circumferential sidewall of the MEMS chip 40 and the circumferential sidewall of the mounting groove 201. The adhesive portion 30 is bonded to both the circumferential sidewall of the MEMS chip 40 and the circumferential sidewall of the mounting groove 201, thereby achieving radial positioning and fixation of the MEMS chip 40. The adhesive portion 30 can use adhesives with high bonding strength such as silicone or epoxy, and preferably adhesives with thixotropic properties to maintain stable forming during dispensing or coating, reducing the risk of adhesive seeping downwards into the gap.

[0028] Furthermore, the adhesive portion 30 forms a circumferentially continuous sealing interface in the gap between the MEMS chip 40 and the mounting groove 201, thereby blocking the communication between the space on the bottom side of the MEMS chip 40 and the external space of the mounting groove 201, thus achieving sealing and isolation and improving the sealing reliability of the packaging structure. In some embodiments, the adhesive portion 30 is configured as a circumferentially continuous adhesive ring; in other embodiments, the adhesive portion 30 is configured as multiple adhesive segments or dots distributed circumferentially to balance sealing requirements and stress relief requirements.

[0029] Furthermore, both the MEMS chip 40 and the ASIC chip 50 can be fixed to the substrate 20 by adhesive bonding. Specifically, the MEMS chip 40 can be bonded to the corresponding area within the mounting groove 201 using adhesive material, and the ASIC chip 50 can be bonded to the surface of the substrate 20 using adhesive material. This adhesive bonding method allows for reliable chip positioning within a relatively small height space, reducing the risk of chip displacement due to vibration or impact.

[0030] Specifically, the mounting groove 201 includes a groove bottom and circumferential sidewalls surrounding the groove bottom. An acoustic aperture 202 is formed in the groove bottom to create an acoustic channel. When the MEMS chip 40 is mounted in the mounting groove 201, the bottom surface of the MEMS chip 40 abuts against the groove bottom, thus defining the mounting position of the MEMS chip 40 in the height direction of the substrate 20 by the groove bottom, thereby reducing assembly height dispersion. Furthermore, the acoustic ports of the MEMS chip 40 are aligned with the acoustic aperture, allowing external sound waves to enter the MEMS chip through the acoustic aperture.

[0031] To fix the MEMS chip 40, a circumferential gap is formed between the circumferential sidewall of the MEMS chip 40 and the circumferential sidewall of the mounting groove 201, and an adhesive portion 30 is provided within the circumferential gap. The adhesive portion 30 can be formed by dispensing, ring coating, or potting. The adhesive portion 30 is connected to both the circumferential sidewall of the MEMS chip 40 and the circumferential sidewall of the mounting groove 201, thereby achieving radial positioning and fixation of the MEMS chip 40. The adhesive portion 30 is preferably set as a circumferentially continuous adhesive ring to simultaneously provide a sealing function; alternatively, the adhesive portion 30 can be set as multiple adhesive dots / segments distributed circumferentially to accommodate both buffering and stress relief requirements.

[0032] In this embodiment, no adhesive is provided between the bottom surface of the MEMS chip 40 and the bottom of the groove, so that no thick adhesive stack is formed at the bottom of the MEMS chip 40, thereby avoiding the risk of the adhesive occupying height space and the adhesive flowing into the sound hole, and ensuring the positioning stability of the bottom surface of the MEMS chip 40 against the bottom of the groove.

[0033] In some implementations, the MEMS chip 40 and the ASIC chip 50 are electrically connected using bonding wires 60, which can be gold, copper, aluminum, or alloy wires. Specifically, the pads of the MEMS chip 40 and the pads of the ASIC chip 50 are connected by bonding wires 60, thereby forming a signal transmission path. By using bonding wires 60, electrical connection between the MEMS and ASIC can be achieved without changing the wiring layout of the substrate 20; this process is mature and easy to implement.

[0034] Understandably, the encapsulation structure may also include a waterproof membrane 70. The waterproof membrane 70 is sandwiched between the MEMS chip 40 and the bottom of the mounting groove 201, creating an acoustic path covered by the waterproof membrane 70 between the MEMS chip 40 and the acoustic aperture 202. Specifically, after external sound waves enter through the acoustic aperture 202, they first pass through the waterproof membrane 70 and then enter the corresponding acoustic port of the MEMS chip 40. This maintains acoustic connectivity while improving waterproof and dustproof capabilities and reducing the risk of liquids or particles entering the encapsulation cavity through the acoustic aperture 202.

[0035] In some embodiments, a first pad 80 is provided at the bottom of the mounting groove 201, through which the MEMS chip 40 is electrically connected to the substrate 20. Specifically, the first pad 80 is located in the bottom area of ​​the mounting groove 201. The MEMS chip 40 can be mounted using a flip-chip method, so that the pads of the MEMS chip 40 form a soldered connection or a conductive connection with the first pad 80, thereby realizing the electrical connection between the MEMS chip 40 and the substrate 20. This method helps to shorten the electrical connection path and reduce or avoid the occupation of vertical space by wire bonding structures. To balance acoustic channel connectivity and electrical connection reliability, the first pad 80 is arranged around the acoustic aperture 202.

[0036] Specifically, the acoustic aperture 202 is disposed at the bottom of the mounting groove 201 and communicates with the outside of the substrate 20, forming an acoustic inlet area at the bottom of the groove. The first pad 80 is located on the circumferential outer side of the acoustic aperture 202 and is distributed at intervals or continuously along the circumferential direction of the acoustic aperture 202, thereby forming an annular pad area surrounding the acoustic aperture 202. By arranging the first pad 80 around the acoustic aperture 202, the projected area corresponding to the acoustic aperture 202 can form a pad avoidance area, preventing pads, solder, or conductive adhesive from entering the acoustic aperture 202 channel and causing obstruction or contamination, thus improving the unobstructedness and consistency of the acoustic channel.

[0037] In some optional embodiments, the first pad 80 can be segmented along the circumference of the acoustic aperture 202 to form multiple pad segments. These multiple pad segments are arranged at intervals in the circumferential direction to correspond to the power pad, ground pad, and signal pad of the MEMS chip 40, respectively. By arranging the segments around the acoustic aperture 202, a clear electrical connection functional partition can be formed around the acoustic aperture 202. At the same time, a continuous pad-free area or adhesive-limited area is reserved around the acoustic aperture 202 to further reduce the risk of solder diffusion, flux residue, or adhesive material flowing into the acoustic aperture 202, thereby improving packaging consistency and reliability.

[0038] In some embodiments, the thickness of the MEMS chip 40 is defined as t, and the height (i.e., the recess) of the chip placed in the mounting groove 201 along the height direction of the substrate 20 is defined as h. The groove depth of the mounting groove 201 is matched with the recess of the MEMS chip 40, so that the MEMS chip 40 is partially embedded in the height direction. Preferably, the recess h satisfies: 0.30t ≤ h ≤ 0.95t.

[0039] Furthermore, to adapt to different electrical connection methods and take into account height, assembly and reliability, the following preferred range can be adopted: when the MEMS chip 40 and the ASIC chip 50 are electrically connected through the bonding wire 60, it is preferable to have 0.40t≤h≤0.70t, so that the MEMS chip 40 still has a sufficient part exposed above or close to the opening plane of the mounting groove 201, so as to perform bonding of the bonding wire 60 and control the arc height of the bonding wire 60.

[0040] When the MEMS chip 40 is electrically connected to the substrate 20 via the first pad 80 using a flip-chip method, it is preferable that 0.70t≤h≤0.95t, so that the MEMS chip 40 is sunk as low as possible to free up the height space of the package cavity. At the same time, the flip-chip interconnect does not need to reserve space for the arc height of the bonding line 60, which is conducive to further reducing the overall height.

[0041] Furthermore, a second pad (not shown in the attached figure) may be provided on the substrate 20, through which the ASIC chip 50 is electrically connected to the substrate 20. Specifically, the ASIC chip 50 can be surface-mounted onto the second pad or flip-chip connected to the second pad, thereby achieving the electrical connection between the ASIC chip 50 and the substrate 20. By placing the electrical connection of the ASIC chip 50 on the second pad, the connection between the ASIC chip 50 and the substrate 20 can be made reliable and facilitates mass production.

[0042] In some embodiments, the ASIC chip 50 is at least partially disposed within the mounting groove 201 along the height direction of the substrate 20. Specifically, the ASIC chip 50 may share the mounting groove 201 with the MEMS chip 40, or a portion of the ASIC chip 50 may be recessed into the mounting groove 201, thereby further reducing the required clearance height of the package cavity and facilitating the implementation of thinner package structures in height-constrained scenarios. This arrangement also allows for a shorter interconnection distance between the MEMS chip 40 and the ASIC chip 50, which helps reduce parasitic parameters and improve signal transmission stability.

[0043] In this embodiment, the ASIC chip 50 is completely disposed within the mounting groove 201 in the height direction of the substrate 20. Specifically, the ASIC chip 50 is disposed in the bottom area of ​​the mounting groove 201, with the bottom surface of the ASIC chip 50 facing the bottom of the mounting groove 201, and the top surface of the ASIC chip 50 located below or flush with the opening plane of the mounting groove 201, so that the ASIC chip 50 does not protrude above the side of the substrate 20 facing the package cavity. With this arrangement, the ASIC chip 50 no longer forms an additional protrusion in the height direction, and the required clearance height of the package cavity in the height direction is further reduced, which is beneficial for realizing a lower-height package structure.

[0044] In some embodiments, the ASIC chip 50 is encapsulated with a sealant. The sealant covers at least a portion of the outer surface of the ASIC chip 50 and protects the pad connection areas, bonding wire connection areas, or chip edge areas of the ASIC chip 50. By encapsulating the ASIC chip 50 with sealant, the moisture and corrosion resistance of the ASIC chip 50 and its interconnect structure can be improved, and the impact of external shocks or vibrations on the interconnect structure can be reduced, thereby improving the reliability of the package structure.

[0045] In some embodiments, the substrate 20 is a PCB circuit board. The PCB circuit board can be provided with conductive traces, pads, and acoustic holes 202, and facilitates electrical connection with external circuits. Using a PCB circuit board as the substrate 20 is beneficial for mass production and cost reduction, while also facilitating the integrated design of the acoustic holes 202 and the mounting slots 201.

[0046] In some embodiments, the adhesive portion 30 is a rigid adhesive, which is used to form a high-strength adhesive and support structure between the MEMS chip 40 and the mounting groove 201. The rigid adhesive can be epoxy structural adhesive, UV-curable acrylic structural adhesive, or other adhesive materials with high rigidity after curing.

[0047] Specifically, after the MEMS chip 40 is at least partially placed within the mounting groove 201, an annular gap is formed between the outer periphery of the MEMS chip 40 and the sidewall of the mounting groove 201. Rigid adhesive is injected into this annular gap using dispensing, scraping, or potting methods, allowing the adhesive to simultaneously bond and cure with both the sidewall of the MEMS chip 40 and the sidewall of the mounting groove 201, forming a ring structure around the circumference of the MEMS chip 40. After curing, the rigid adhesive forms continuous reinforcing ribs or support rings at the edge of the mounting groove 201, thereby compensating for the localized decrease in rigidity of the substrate 20 caused by the groove, reducing stress concentration in the edge area of ​​the mounting groove 201 during assembly compression, drop impact, or thermal cycling deformation, and reducing the risk of damage or cracking in the grooved area.

[0048] Furthermore, to prevent the adhesive part 30 from entering the acoustic hole 202 and affecting the acoustic channel, a glue-free area can be reserved at the bottom of the mounting groove 201 near the acoustic hole 202, or a glue dam can be formed along the side wall of the mounting groove 201 before applying glue during the glue application process, so that the hard glue is mainly distributed in the gap between the side walls and the edge area of ​​the groove bottom, thereby achieving fixation and sealing while avoiding obstruction of the acoustic hole 202.

[0049] The curing method of rigid adhesive can be heat curing, UV curing or room temperature curing, and the specific method can be selected according to the substrate material, the chip temperature resistance and production line conditions.

[0050] In some embodiments, the adhesive portion 30 is a gel, which is used to form a flexible adhesive and buffer structure between the MEMS chip 40 and the mounting groove 201. The gel can be silicone gel, polyurethane gel, or other gel-type adhesive materials that have a low elastic modulus and are deformable and resilient after curing.

[0051] Specifically, after the MEMS chip 40 is placed in the mounting groove 201, the jelly adhesive is filled into the annular gap between the MEMS chip 40 and the mounting groove 201, so that the jelly adhesive is simultaneously bonded to both the MEMS chip 40 and the mounting groove 201. Compared with rigid adhesives, the jelly adhesive retains a certain degree of flexibility after curing, thus providing buffer support and vibration damping for the MEMS chip 40 when the slotting of the substrate 20 causes a local reduction in rigidity. When the packaging structure is subjected to external impact or thermal expansion and contraction due to temperature changes, the jelly adhesive can absorb some of the stress through its own deformation, reducing the degree to which stress is directly transmitted to the weak areas of the MEMS chip 40 and the substrate 20, thereby improving structural reliability.

[0052] Furthermore, the jelly adhesive can form a continuous adhesive ring for sealing, or an intermittent dispensing structure to accommodate both cushioning and ventilation requirements. To prevent the jelly adhesive from flowing into the acoustic pore 202, a limiting structure (e.g., forming a circumferential adhesive dam) can be set before dispensing, and the dispensing amount and path can be controlled to ensure that the jelly adhesive is mainly distributed in the gap area of ​​the side walls or the edge area of ​​the tank bottom. The jelly adhesive can be cured at room temperature, by heat, or by two-component curing; no specific method is limited.

[0053] In some embodiments, the adhesive portion 30 adopts a composite form of rigid adhesive and jelly adhesive to simultaneously achieve rigidity compensation and damage resistance as well as cushioning, vibration absorption and stress release.

[0054] Specifically, a rigid adhesive can be applied to the outer periphery near the sidewall of the mounting groove 201. After curing, the rigid adhesive forms a ring-shaped reinforcing structure to enhance the load-bearing capacity of the grooved area and improve its impact and crack resistance. A gel-like adhesive can be applied to the inner periphery near the MEMS chip 40 or near the acoustic aperture 202 to absorb thermal stress and external impacts, reducing the risk of stress transmission to the sensitive structures of the MEMS chip 40. This partitioned approach improves the structural strength and overall reliability of the grooved area of ​​the substrate 20 without significantly increasing the package height, and minimizes the risk of adhesive materials entering the acoustic aperture 202 and causing acoustic performance fluctuations.

[0055] In some embodiments, in order to reduce stress concentration in the groove edge area after the substrate 20 is slotted and improve crack resistance, the packaging structure further includes a reinforcing frame. The reinforcing frame is disposed around the groove of the mounting groove 201 and connected to the substrate 20 to form a continuous crack-resistant frame structure in the circumferential direction of the groove.

[0056] In some embodiments, the reinforcing frame is a metal reinforcing ring. The metal reinforcing ring is arranged in a closed loop around the circumference of the mounting groove 201, with its inner edge surrounding the opening boundary of the mounting groove 201 and its outer edge covering the periphery of the groove on the substrate 20. The metal reinforcing ring can be fixed to the substrate 20 by adhesive bonding. Specifically, an adhesive layer is provided on the contact surface between the metal reinforcing ring and the substrate 20 to firmly bond the metal reinforcing ring to the substrate 20. Alternatively, the metal reinforcing ring can be integrally formed with the substrate 20 by hot pressing, embedding, or other methods. To improve the bonding strength, the contact surface of the metal reinforcing ring can be provided with a roughened structure or a micro-textured structure to increase the bonding area and improve the peel resistance.

[0057] By setting a metal reinforcing ring around the slot, when the packaging structure is subjected to drop impact, assembly extrusion or deformation load caused by thermal cycling, the tensile stress generated at the edge of the slot can be shared by the metal reinforcing ring and diffused circumferentially, thereby reducing the local stress peak at the edge of the slot, inhibiting crack initiation or propagation from the edge of the slot, and improving the crack resistance and damage resistance of the slotted area.

[0058] In some embodiments, the reinforcing frame is a high-modulus resin reinforcing ring. The high-modulus resin reinforcing ring can be made of epoxy resin, glass fiber reinforced resin, or other resin materials with a high elastic modulus after curing, forming a closed-loop structure along the periphery of the mounting groove 201. The high-modulus resin reinforcing ring can be integrally formed with the substrate 20 by injection molding, dispensing, or compression molding. For example, after the substrate 20 is grooved, a molding space is reserved around the groove opening, and the resin material is used to form a continuous annular frame around the groove opening, which is then tightly bonded to the substrate 20 after curing.

[0059] Compared to metal reinforcing rings, high-modulus resin reinforcing rings can provide higher rigidity support while also providing a certain degree of buffering performance. This can reduce local stress concentration caused by abrupt interface changes in hard and brittle materials and improve structural stability under assembly impact and vibration conditions.

[0060] In some embodiments, the reinforcing frame adopts an integrated electrical and mechanical structure, specifically, a grounding annular copper foil is provided around the groove opening of the substrate 20, and a via fence is provided circumferentially around the grounding ring. The grounding annular copper foil forms a closed loop arrangement along the periphery of the groove opening of the mounting groove 201 and is electrically connected to the grounding network of the substrate 20. The via fence is spaced apart circumferentially around the grounding ring, and the vias penetrate at least a portion of the layers of the substrate 20 and are electrically connected to the grounding ring, thereby forming a circumferentially continuous metal reinforcing strip and its three-dimensional reinforcement structure around the groove opening.

[0061] By combining the grounding ring copper foil with the via fence, a metal-frame-like reinforcement effect can be formed around the slot, improving the in-plane rigidity and bending resistance of the slot periphery area and reducing deformation and stress concentration at the slot edge after slotting. Simultaneously, this structure can also serve as part of the electromagnetic shielding and grounding loop, reducing the impact of electromagnetic interference from the ASIC chip 50 on the MEMS chip 40 signal and improving the electrical performance stability of the package structure.

[0062] In some embodiments, the reinforcing frame is located outside the adhesive portion 30, allowing the reinforcing frame to preferentially bear the external assembly pressure and forming a synergistic structure with the adhesive portion 30 for peripheral reinforcement and internal buffering. Furthermore, a preset gap can be maintained between the inner edge of the reinforcing frame and the sidewall of the mounting groove 201 to avoid interference between the reinforcing frame and the sinking arrangement of the MEMS chip 40 and the alignment of the acoustic hole 202, while also reserving space for the adhesive portion 30.

[0063] By setting up the aforementioned reinforcing frame or reinforcing ring, the problem of easy damage to the substrate 20 caused by the slot can be directly addressed. Without significantly increasing the package height, the crack resistance, impact resistance, and assembly reliability of the slot area can be improved, thereby improving the overall mechanical reliability and service life of the package structure.

[0064] In some embodiments, both the MEMS chip 40 and the ASIC chip 50 are disposed within the package cavity and located on the same bearing surface, for example, jointly fixed to the upper surface of the substrate 20. In this case, the MEMS chip 40 and the ASIC chip 50 are arranged side by side on the upper surface of the reinforcing member 30, and their projection areas do not overlap, which facilitates device layout within a limited cavity and provides sufficient process space for bonding interconnection.

[0065] In some implementations, the MEMS chip 40 and the ASIC chip 50 are still located on the same carrier surface, but they are staggered relative to the acoustic aperture 202. Specifically, the MEMS chip 40 is positioned directly above or aligned with the acoustic aperture 202 to ensure the connectivity and alignment accuracy of the acoustic channel. The ASIC chip 50 is offset relative to the acoustic aperture 202 to provide space for the routing of the bonding wire 60, the arrangement of the pads, and the avoidance of the via 302, thereby reducing the risk of interconnection interference and improving assembly consistency.

[0066] In some implementations, the MEMS chip 40 and the ASIC chip 50 are arranged adjacently and compactly, with a small spacing between them to shorten the electrical connection path between them. By shortening the length of the bonding wire 60 or reducing the interconnect span, the risk of wire breakage under vibration and shock can be reduced, and the impact of parasitic parameters on signal transmission can be mitigated.

[0067] This invention provides seven specific embodiments, as follows: Specific Implementation Example 1 like Figure 1 As shown, this embodiment provides a packaging structure, including a housing 10 and a substrate 20. The housing 10 and the substrate 20 together form a packaging cavity, and a mounting groove 201 is provided on the side of the substrate 20 facing the packaging cavity, and an acoustic hole 202 is provided in the mounting groove 201.

[0068] In this embodiment, both the MEMS chip 40 and the ASIC chip 50 are disposed within the mounting groove 201. Along the height direction of the substrate 20, the MEMS chip 40 is at least partially placed within the mounting groove 201 and communicates with the acoustic hole 202, while the ASIC chip 50 is completely disposed within the mounting groove 201 in the height direction. Both the MEMS chip 40 and the ASIC chip 50 are glued and fixed to the substrate 20 using an adhesive ASIC chip 50; 51, thereby achieving the positioning and fixation of the chips within the mounting groove 201.

[0069] In this embodiment, the electrical connection between the ASIC chip 50 and the MEMS chip 40 is achieved through a bonding wire 60. Specifically, the ASIC chip 50 is electrically connected to the MEMS chip 40 via one bonding wire 60 to transmit electrical signals from the MEMS chip 40 to the ASIC chip 50 for processing. The ASIC chip 50 is also electrically connected to the substrate 20 via another bonding wire 60, forming an electrical connection between the ASIC chip 50 and the conductive traces on the substrate 20, thereby establishing an electrical connection path between the ASIC chip 50 and external circuits. By recessing both the MEMS chip 40 and the ASIC chip 50 within the mounting groove 201, it is beneficial to further reduce the height requirement of the packaging cavity, shorten the interconnection distance between chips, and reduce the length and arc height requirements of the bonding wire 60, thereby improving the feasibility of ultra-thin packaging. Specific Implementation Example 2 like Figure 2 As shown, this embodiment provides a packaging structure, the overall structure of which is similar to that of specific embodiment one, the difference being the arrangement of the chips.

[0071] In this embodiment, a mounting groove 201 is formed on the side of the substrate 20 facing the packaging cavity, and an acoustic hole 202 is formed within the mounting groove 201. A MEMS chip 40 is disposed within the mounting groove 201, and at least partially within the mounting groove 201 along the height direction of the substrate 20, communicating with the acoustic hole 202. An ASIC chip 50 is disposed on the side of the substrate 20 facing the packaging cavity, but no mounting groove 201 is provided at the corresponding position on the substrate 20; that is, the ASIC chip 50 is disposed in the ungrooved area of ​​the substrate 20.

[0072] In this embodiment, the MEMS chip 40 is bonded and fixed to the substrate 20 area within the mounting groove 201 using an adhesive ASIC chip 50; 51. The ASIC chip 50 is bonded and fixed to the ungrooved area of ​​the substrate 20 using an adhesive ASIC chip 50; 51. The ASIC chip 50 is electrically connected to the MEMS chip 40 via a bonding wire 60 to achieve signal transmission between the MEMS chip 40 and the ASIC chip 50. The ASIC chip 50 is also electrically connected to the substrate 20 via another bonding wire 60, forming an electrical connection path between the ASIC chip 50 and the conductive traces of the substrate 20. By recessing the MEMS chip 40 into the mounting groove 201 and placing the ASIC chip 50 in the ungrooved area, the package height can be reduced while maintaining the local rigidity of the substrate 20, and the impact of large-area grooves on the strength of the substrate 20 can be reduced. Specific Implementation Example 3 like Figure 3 As shown, this embodiment further provides a waterproof membrane 70 based on specific embodiment two to improve the waterproof and dustproof capabilities of the encapsulation structure.

[0074] Specifically, the packaging structure includes a housing 10 and a substrate 20. The housing 10 and the substrate 20 together form a packaging cavity. A mounting groove 201 is formed on the side of the substrate 20 facing the packaging cavity, and an acoustic aperture 202 is formed within the mounting groove 201. A MEMS chip 40 is disposed within the mounting groove 201 and communicates with the acoustic aperture 202. An ASIC chip 50 is disposed on the side of the substrate 20 facing the packaging cavity and located in the ungrooved area. Both the MEMS chip 40 and the ASIC chip 50 are glued and fixed to the substrate 20 using an adhesive adhesive.

[0075] In this embodiment, a waterproof membrane 70 is disposed between the MEMS chip 40 and the bottom of the mounting groove 201. The waterproof membrane 70 covers the acoustic aperture 202 and forms an acoustically transparent and waterproof interface, allowing the MEMS chip 40 to communicate with the acoustic aperture 202 through the waterproof membrane 70. The ASIC chip 50 is electrically connected to the MEMS chip 40 via a bonding wire 60 and to the substrate 20 via another bonding wire 60. By providing the waterproof membrane 70, the risk of liquid or particles entering the packaging cavity through the acoustic aperture 202 can be reduced, and the reliability of the packaging structure in humid environments can be improved. Specific Implementation Example 4 like Figure 4 As shown, this embodiment further provides a waterproof membrane 70 based on the first embodiment to improve the waterproof and dustproof capabilities of the encapsulation structure while maintaining the advantages of the ultra-thin design.

[0077] Specifically, the packaging structure includes a housing 10 and a substrate 20. The housing 10 and the substrate 20 together form a packaging cavity. A mounting groove 201 is formed on the side of the substrate 20 facing the packaging cavity, and an acoustic aperture 202 is formed within the mounting groove 201. Both the MEMS chip 40 and the ASIC chip 50 are disposed within the mounting groove 201. The MEMS chip 40 is at least partially placed within the mounting groove 201 and communicates with the acoustic aperture 202. The ASIC chip 50 is completely disposed within the mounting groove 201 in the height direction. Both the MEMS chip 40 and the ASIC chip 50 are glued and fixed to the substrate 20 using an adhesive ASIC chip 50; 51.

[0078] In this embodiment, a waterproof membrane 70 is sandwiched between the MEMS chip 40 and the bottom of the mounting groove 201. The waterproof membrane 70 covers the acoustic aperture 202, allowing the MEMS chip 40 to communicate with the acoustic aperture 202 through the waterproof membrane 70. The ASIC chip 50 is electrically connected to the MEMS chip 40 via a bonding wire 60 and to the substrate 20 via another bonding wire 60. By sinking both the MEMS chip 40 and the ASIC chip 50 together and placing the waterproof membrane 70 at the acoustic aperture 202, the waterproof and dustproof capabilities can be improved while reducing the package height. Furthermore, since the chip interconnection is completed within the mounting groove 201, it is beneficial to shorten the length of the bonding wire 60 and reduce the arc height requirement of the bonding wire 60, thereby balancing ultra-thinness and reliability requirements. Specific Implementation Example 5 like Figure 5 As shown, this embodiment provides a packaging structure, including a housing 10 and a substrate 20. The housing 10 and the substrate 20 together form a packaging cavity, and a mounting groove 201 is provided on the side of the substrate 20 facing the packaging cavity, and an acoustic hole 202 is provided in the mounting groove 201.

[0080] In this embodiment, only the MEMS chip 40 is disposed within the mounting groove 201. Along the height direction of the substrate 20, the MEMS chip 40 is at least partially placed within the mounting groove 201 and communicates with the acoustic hole 202. The ASIC chip 50 is disposed on the side of the substrate 20 facing the package cavity, and the area of ​​the substrate 20 corresponding to the ASIC chip 50 is not slotted, that is, the ASIC chip 50 is disposed in the unslotted area of ​​the substrate 20.

[0081] In this embodiment, the MEMS chip 40 is electrically connected to the substrate 20 via the first pad 80. Specifically, the bottom of the mounting groove 201 is provided with the first pad 80, and the MEMS chip 40 is disposed in the mounting groove 201 in a flip-chip manner, so that the pad on the side of the MEMS chip 40 facing the substrate 20 forms a solder connection or conductive connection with the first pad 80, thereby realizing the electrical connection between the MEMS chip 40 and the substrate 20.

[0082] In this embodiment, the ASIC chip 50 is electrically connected to the substrate 20 via two bonding wires 60. Specifically, two bonding wire 60 connection paths are formed between the ASIC chip 50 and the substrate 20. One bonding wire 60 is used to electrically connect the ASIC chip 50 to the conductive structure on the substrate 20 to achieve communication with external circuits. The other bonding wire 60 is used to electrically connect the ASIC chip 50 to the MEMS chip 40. One end of the bonding wire 60 is connected to the pad of the ASIC chip 50, and the other end is connected to the pad of the MEMS chip 40 or the pad of the substrate 20 electrically connected to the MEMS chip 40, so as to realize signal transmission between the MEMS chip 40 and the ASIC chip 50. By using flip-chip bonding of the MEMS chip 40 to eliminate or weaken the wire bonding height requirement on the MEMS side, and by placing the ASIC chip 50 in the ungrooved area, the height can be reduced while mitigating the risk of reduced strength of the substrate 20 caused by large-area grooving. Specific Implementation Example Six like Figure 6 As shown, this embodiment provides a packaging structure, the overall structure of which is similar to that of specific embodiment five, except that the arrangement position of the ASIC chip 50 is different.

[0084] In this embodiment, the MEMS chip 40 is disposed within the mounting groove 201 and connected to the acoustic hole 202, and the ASIC chip 50 is also disposed within the mounting groove 201. Along the height direction of the substrate 20, the ASIC chip 50 is at least partially disposed within the mounting groove 201, preferably the ASIC chip 50 is completely disposed within the mounting groove 201 in the height direction, thereby enabling the MEMS chip 40 and the ASIC chip 50 to form a cooperative recessed arrangement, further reducing the height requirement of the packaging cavity.

[0085] In this embodiment, the MEMS chip 40 is electrically connected to the substrate 20 via the first pad 80, and the specific connection method is the same as in specific embodiment five. The ASIC chip 50 is electrically connected to the substrate 20 via two bonding wires 60. One bonding wire 60 is used to realize the electrical connection between the ASIC chip 50 and the conductive traces of the substrate 20, so that the ASIC chip 50 can communicate with external circuits. The other bonding wire 60 is used to realize the electrical connection between the ASIC chip 50 and the MEMS chip 40. One end of the bonding wire 60 is connected to the pad of the ASIC chip 50, and the other end is connected to the pad of the MEMS chip 40 or the pad of the substrate 20 electrically connected to the MEMS chip 40, thereby realizing the transmission of MEMS output signals to the ASIC for processing. Since both the MEMS and ASIC are located in the mounting slot 201, the length of the bonding wire 60 can be shortened and the arc height requirement of the bonding wire 60 can be reduced, which is beneficial to further compress the package height and improve the interconnection reliability. Specific Implementation Example 7 like Figure 7 As shown, this embodiment provides a packaging structure, including a housing 10 and a substrate 20. The housing 10 and the substrate 20 together form a packaging cavity. A mounting groove 201 is formed on the side of the substrate 20 facing the packaging cavity, and an acoustic hole 202 is formed in the mounting groove 201. A MEMS chip 40 is disposed in the mounting groove 201 and communicates with the acoustic hole 202.

[0087] In this embodiment, the MEMS chip 40 is electrically connected to the substrate 20 via a first pad 80. Specifically, the bottom of the mounting groove 201 is provided with a first pad 80, which preferably surrounds the acoustic hole 202. The MEMS chip 40 is flip-chip connected to the first pad 80 to form a soldered or conductive connection, thereby realizing the electrical connection between the MEMS chip 40 and the substrate 20.

[0088] In this embodiment, the ASIC chip 50 is electrically connected to the substrate 20 via a second pad. Specifically, the substrate 20 has a second pad, and the ASIC chip 50 is disposed on the substrate 20 by direct chip mounting and forms an electrical connection with the second pad. In this embodiment, the ASIC chip 50 is disposed on the substrate 20 using a COB (Chip-on-Board) process, specifically, the ASIC chip 50 is directly mounted on the surface of the substrate 20 and connected to the second pad, and the outer periphery of the ASIC chip 50 can be further encapsulated with sealant for protection.

[0089] In this embodiment, the MEMS chip 40 and the ASIC chip 50 are not directly connected by bonding wires 60, but are electrically connected through wires in the internal layer of the substrate 20. Specifically, the internal conductive layer of the substrate 20 is provided with wires for signal transmission. One end of the wire is electrically connected to the first pad 80, and the other end is electrically connected to the second pad, thereby realizing the electrical connection path between the MEMS chip 40 and the ASIC chip 50. By using wires in the internal layer of the substrate 20, the number of bonding wires 60 and their arc height occupation inside the package cavity can be reduced, and the vibration and shock resistance can be improved. At the same time, the combination of MEMS flip-chip bonding and ASIC COB mounting is beneficial to improving electrical connection stability and mass production consistency while maintaining a low profile.

[0090] The present invention also provides a microphone comprising the packaging structure of any of the above embodiments. By employing the above packaging structure, the microphone can reduce its overall height while satisfying acoustic channel connectivity and packaging reliability, and can be configured in a variety of ways, such as waterproofing, dustproofing, or interconnection, as needed, thus making it suitable for terminal devices with high requirements for height and reliability.

[0091] The present invention also provides an electronic device. The electronic device includes a microphone according to any of the above embodiments. The microphone is used to collect external sound signals and output electrical signals or digital audio signals for the electronic device to perform functions such as voice calls, voice wake-up, noise reduction and sound pickup, ambient sound collection, or recording.

[0092] The electronic device can be a mobile phone, tablet computer, laptop computer, smartwatch, smart bracelet, smart earphone, smart speaker, remote conferencing terminal, vehicle terminal, security camera equipment or other terminal devices with sound acquisition function, and there is no specific limitation.

[0093] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A packaging structure, characterized in that, include: The housing and the substrate together form an encapsulation cavity. A mounting groove is provided on the side of the substrate facing the encapsulation cavity, and an acoustic hole is provided in the mounting groove. The MEMS chip, along the height direction of the substrate, at least a portion of the MEMS chip is placed in the mounting groove and connected to the acoustic hole; An ASIC chip is disposed on the side of the substrate facing the package cavity and is electrically connected to the MEMS chip and the substrate, respectively. The adhesive portion connects the circumferential outer wall of the MEMS chip and the circumferential inner wall of the mounting groove.

2. The packaging structure according to claim 1, characterized in that, The MEMS chip and the ASIC chip are electrically connected via bonding wires.

3. The packaging structure according to claim 2, characterized in that, The encapsulation structure also includes a waterproof membrane sandwiched between the MEMS chip and the bottom of the mounting groove, and the MEMS chip is connected to the acoustic hole through the waterproof membrane.

4. The packaging structure according to claim 3, characterized in that, The ASIC chip is fixedly attached to the substrate.

5. The packaging structure according to claim 1, characterized in that, The bottom of the mounting groove is provided with a first pad, and the MEMS chip is soldered to the first pad and electrically connected to the substrate.

6. The packaging structure according to claim 5, characterized in that, The substrate has a second pad, and the ASIC chip is soldered to the second pad and electrically connected to the substrate.

7. The packaging structure according to any one of claims 1 to 6, characterized in that, At least a portion of the ASIC is disposed within the mounting slot along the height direction of the substrate.

8. The packaging structure according to any one of claims 1 to 6, characterized in that, The ASIC chip is encapsulated with sealant.

9. The packaging structure according to any one of claims 1 to 6, characterized in that, The substrate is a PCB circuit board.

10. A microphone, characterized in that, Includes the packaging structure according to any one of claims 1 to 9.

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