Membrane microelectromechanical system (mems) waterproof microphone

Abstract

The application discloses a MEMS waterproof microphone, comprising: a substrate comprising a first area provided with a sound hole; a waterproof air-permeable film attached to the first area and covering the sound hole; a metal pad provided with a through hole and stacked above the waterproof air-permeable film; and a MEMS chip stacked above the metal pad; wherein the aperture of the sound hole is larger than the aperture of the through hole. The application uses the metal pad as a transfer intermediate, which can increase the size of the sound hole of the substrate and the air-permeable area of the waterproof air-permeable film without being affected by the size of the chip. The larger sound hole and air-permeable area can reduce the obstruction to the sound signal, provide a higher signal-to-noise ratio, and achieve good waterproof performance, thereby improving the comprehensive performance of the MEMS microphone.

Description

Technical Field

[0001] This application relates to the field of microphone technology, specifically to a MEMS waterproof microphone. Background Technology

[0002] MEMS (Micro-electromechanical Systems) microphones are microphones manufactured based on MEMS technology. Compared with traditional microphones, MEMS microphones can be manufactured using surface mount technology, can withstand high reflow soldering temperatures, are easily integrated with CMOS (Complementary Metal-Oxide-Semiconductor) technology and other audio circuits, and have improved noise cancellation performance and good RF (Radio Frequency) and EMI (Electromagnetic Interference) suppression capabilities. They are currently widely used in smart terminal fields such as voice calls and intelligent voice interaction.

[0003] As the application scenarios for MEMS microphones increase, their waterproof performance is crucial for improving product reliability and expanding application scenarios. Conventional waterproof solutions for MEMS microphones typically involve directly attaching a waterproof membrane to the sound port. However, this approach, limited by the size of the MEMS device, cannot achieve both waterproofing and a high signal-to-noise ratio. Specifically, while waterproof and breathable membranes do provide waterproofing, they also impede sound to some extent, leading to a decrease in product performance. Utility Model Content

[0004] The main technical problem addressed in this application is to provide a MEMS waterproof microphone that achieves waterproofing while maintaining product performance.

[0005] This application provides a MEMS waterproof microphone, comprising:

[0006] The substrate includes a first region, wherein the first region is provided with an acoustic hole;

[0007] A waterproof and breathable membrane is applied to the first area, covering the acoustic pores;

[0008] A metal pad, with through holes, is stacked on top of the waterproof and breathable membrane;

[0009] MEMS chips are stacked on top of the metal pad;

[0010] The diameter of the acoustic hole is larger than the diameter of the through hole.

[0011] In some alternative implementations, the acoustic aperture and the through-hole are coaxial.

[0012] In some alternative embodiments, silicone adhesive is used to bond the substrate and the waterproof and breathable membrane, the waterproof and breathable membrane and the metal pad, and the metal pad and the MEMS chip.

[0013] In some alternative embodiments, the substrate further includes a second region, and the MEMS waterproof microphone further includes an AISC (Application-Specific Integrated Circuit) chip mounted in the second region.

[0014] In some alternative embodiments, epoxy adhesive is used to bond the substrate and the AISC chip.

[0015] In some alternative embodiments, the MEMS waterproof microphone further includes a housing that forms a cavity with the substrate, wherein the waterproof and breathable membrane, the metal pad, the MEMS chip, and the AISC chip are located within the cavity.

[0016] In some alternative embodiments, the substrate and the housing are sealed together using solder paste.

[0017] In some alternative implementations, the housing is a metal housing.

[0018] In some alternative implementations, the MEMS chip and the AISC chip are connected by wire bonding, and the AISC chip and the substrate are connected by wire bonding.

[0019] In some alternative embodiments, the metal pad is a stainless steel pad.

[0020] As described above, this application proposes a MEMS waterproof microphone. From the above technical solutions, it can be seen that the embodiments of this application have the following advantages:

[0021] This application utilizes a metal pad as a relay intermediate, which can increase the size of the substrate's acoustic aperture and the breathable area of ​​the waterproof and breathable membrane without being affected by the chip size. The larger acoustic aperture and the larger breathable area can reduce the obstruction of sound signals and provide a higher signal-to-noise ratio, thereby achieving good waterproof performance while improving the overall performance of the MEMS microphone. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments and the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is an exploded structural diagram of a MEMS waterproof microphone according to an embodiment of this application.

[0024] Reference numerals: 1. Outer shell; 2. MEMS chip; 3. Metal pad; 4. Waterproof and breathable membrane; 5. First region; 6. Second region; 7. Substrate; 8. AISC chip; 9. Acoustic hole; 10. Through hole. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0026] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0027] The following detailed descriptions will be provided through specific embodiments.

[0028] refer to Figure 1 This application provides an embodiment of a MEMS waterproof microphone, comprising:

[0029] The substrate 7 includes a first region 5, and the first region is provided with a sound hole 9;

[0030] A waterproof and breathable membrane 4 is attached to the first area 5, covering the acoustic holes 9;

[0031] Metal pad 3, with through holes 10, is stacked on top of waterproof and breathable membrane 4;

[0032] MEMS chip 2 is stacked on top of metal pad 3;

[0033] Among them, the diameter of the acoustic hole 9 is larger than the diameter of the through hole 10.

[0034] In some alternative embodiments, the sound hole 9 and the through hole 10 are coaxial, and when viewed from above, the projection of the through hole 10 falls entirely within the area of ​​the sound hole 9. This ensures the transmission of sound signals.

[0035] In some alternative embodiments, silicone adhesive is used to bond the substrate 7 to the waterproof and breathable membrane 4, the waterproof and breathable membrane 4 to the metal pad 3, and the metal pad 3 to the MEMS chip 2. Silicone has excellent stress resistance and cushioning properties.

[0036] In some alternative implementations, the substrate 7 also includes a second region 6, and the MEMS waterproof microphone also includes an AISC chip 8 mounted on the second region 6.

[0037] In some alternative implementations, epoxy adhesive is used to bond the substrate 7 and the AISC chip 8. Epoxy adhesive has a cost advantage over silicone adhesive.

[0038] In some alternative embodiments, the MEMS waterproof microphone also includes a housing 1 that forms a cavity with the substrate 7, with a waterproof and breathable membrane 4, a metal pad 3, a MEMS chip 2, and an AISC chip 8 located within the cavity. The housing 1 provides support and protection, preventing external impacts or vibrations from damaging the sensitive components.

[0039] In some alternative implementations, the housing 1 is a metal housing, which can reduce external electromagnetic interference to the microphone.

[0040] In some alternative embodiments, the substrate 7 and the housing 1 are bonded together using solder paste. For example, the bonding of the substrate 7 and the housing 1 can be accomplished by a reflow soldering process.

[0041] In some alternative implementations, the MEMS chip 2 and the AISC chip 8 are connected by wire bonding, and the AISC chip 8 and the substrate 7 are connected by wire bonding. Wire bonding has advantages such as mature manufacturing process and good electrical performance.

[0042] In some alternative implementations, the metal pad 3 can be a stainless steel pad, which can provide better support for the MEMS chip 2.

[0043] As described above, this application discloses a MEMS waterproof microphone, wherein an ASIC chip and a waterproof and breathable membrane are attached to different areas of a substrate, and a metal pad and a MEMS chip are stacked sequentially on top of the waterproof and breathable membrane.

[0044] Traditional MEMS microphones mount the MEMS chip directly onto the substrate or through a waterproof and breathable membrane. Due to the size of the MEMS chip, the aperture of the sound hole on the substrate cannot be made too large. It is necessary to ensure that the MEMS chip completely covers the sound hole to ensure a sealed connection.

[0045] This application utilizes a metal pad as an intermediate relay, which is unaffected by the size of the MEMS chip and allows for an increase in the size of the acoustic aperture on the substrate and the breathable area of ​​the waterproof and breathable membrane. Specifically, the MEMS chip is mounted on the metal pad, which separates the MEMS chip from the substrate. Therefore, the aperture of the acoustic aperture on the substrate is no longer affected by the size of the MEMS chip and can be made larger, while the breathable area of ​​the waterproof and breathable membrane can also be increased. Larger acoustic apertures and a larger breathable area both improve the performance of the MEMS microphone. Thus, the waterproof MEMS microphone of this application can provide a higher signal-to-noise ratio, achieving excellent waterproof performance while improving the overall performance of the MEMS microphone.

[0046] The technical solution of this application has been described in detail above through specific embodiments. In the above embodiments, the descriptions of each embodiment have their own emphasis, and for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0047] It should be understood that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and protection scope of the technical solutions of the embodiments of this application.

Claims

1. A MEMS waterproof microphone, characterized in that, include: The substrate includes a first region, wherein the first region is provided with an acoustic hole; A waterproof and breathable membrane is applied to the first area, covering the acoustic pores; A metal pad, with through holes, is stacked on top of the waterproof and breathable membrane; MEMS chips are stacked on top of the metal pad; The diameter of the acoustic hole is larger than the diameter of the through hole.

2. The MEMS waterproof microphone according to claim 1, characterized in that, The acoustic hole and the through hole are coaxial.

3. The MEMS waterproof microphone according to claim 1, characterized in that, Silicone adhesive is used to bond the substrate to the waterproof and breathable membrane, the waterproof and breathable membrane to the metal pad, and the metal pad to the MEMS chip.

4. The MEMS waterproof microphone according to claim 1, characterized in that, The substrate further includes a second region, and the MEMS waterproof microphone further includes an AISC chip mounted in the second region.

5. The MEMS waterproof microphone according to claim 4, characterized in that, The substrate and the AISC chip are bonded together using epoxy adhesive.

6. The MEMS waterproof microphone according to claim 4, characterized in that, The MEMS waterproof microphone also includes a shell that forms a cavity with the substrate, and the waterproof and breathable membrane, the metal pad, the MEMS chip, and the AISC chip are located inside the cavity.

7. The MEMS waterproof microphone according to claim 6, characterized in that, The substrate and the housing are sealed together using solder paste.

8. The MEMS waterproof microphone according to claim 7, characterized in that, The outer casing is a metal casing.

9. The MEMS waterproof microphone according to claim 4, characterized in that, The MEMS chip and the AISC chip are connected by wire bonding, and the AISC chip and the substrate are connected by wire bonding.

10. The MEMS waterproof microphone according to claim 1, characterized in that, The metal pad is a stainless steel pad.

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