A MEMS device

Abstract

The present invention discloses a MEMS device, including a substrate, a MEMS chip layer and a mesh membrane, wherein the substrate has a first surface and a second surface, and a first through hole is formed on the substrate; the MEMS chip layer is arranged on one side of the second surface of the substrate; the mesh membrane is arranged on one side of the first surface of the substrate, and a sound-transmitting area is formed on the mesh membrane at a position corresponding to the first through hole, and mesh holes are distributed on the sound-transmitting area. The substrate of the MEMS device of the present invention not only completes the traditional structure packaging and signal transmission, but also plays a good supporting role for the mesh membrane, and simplifies the assembly process of the MEMS device and reduces the manufacturing cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of acoustic-electric conversion, and in particular, the present invention relates to a MEMS device. Background Art

[0002] With the rapid development of electroacoustic technology, various electroacoustic products emerge in an endless stream. Microphone, as a transducer that converts sound into electrical signals, is one of the most important devices in electroacoustic products. Nowadays, microphones have been widely used in many different types of electronic products such as mobile phones, tablets, laptops, VR devices, AR devices, smart watches, and smart wearables. In recent years, for microphone packaging structures, the design of their structures has become the focus and hotspot of research for technicians in this field.

[0003] The existing microphone packaging structure is usually composed of a housing with a housing cavity, in which components such as chip components (for example, MEMS chips and ASIC chips) are fixed; and a sound pickup hole is also provided on the housing. However, it is found in long-term applications that dust, impurities and other particles and foreign objects are easily introduced into the microphone's housing cavity through the sound pickup hole, and these particles and foreign objects will cause certain damage to components such as chip components in the housing cavity, which will eventually affect the acoustic performance and service life of the microphone.

[0004] In response to the above-mentioned problems, the currently adopted solution is usually to set a corresponding isolation component on the sound pickup hole of the microphone packaging structure to block the entry of external particles, foreign objects, etc. The existing isolation component includes a support portion and an isolation mesh. When using the isolation component, the isolation component is installed on the sound pickup hole. However, due to the differences in thickness, size and material properties of the support portion and the isolation mesh, the existing isolation component is prone to cause different degrees of expansion and deformation of the various components in the isolation component after heating, which is prone to stress concentration and deformation damage, affecting the sound quality of the microphone. How to integrate the support portion and the microphone component well to solve the stress concentration will be a key problem that needs to be solved urgently in the field of microphones. Summary of the invention

[0005] An object of the present invention is to provide a MEMS device.

[0006] According to a first aspect of the present invention, there is provided a MEMS device, comprising:

[0007] A substrate, the substrate having a first surface and a second surface, and a first through hole is formed on the substrate;

[0008] A MEMS chip layer, wherein the MEMS chip layer is disposed on one side of the second surface of the substrate, and the MEMS chip layer covers the first through hole;

[0009] A grid membrane is arranged on one side of the first surface of the substrate, the grid membrane forms a sound-transmitting area at a position corresponding to the first through hole, mesh holes are distributed on the sound-transmitting area, and the sound-transmitting area is configured to allow sound to pass through so as to be transmitted to the MEMS chip layer.

[0010] Optionally, the material of the grid membrane is metallic glass.

[0011] Optionally, an insulating layer is disposed on the second surface of the substrate, the MEMS chip layer is disposed on a side of the insulating layer away from the second surface, a second through hole is formed on the insulating layer, and the second through hole is connected to the first through hole.

[0012] Optionally, the sound-transmitting area is rectangular in shape, and a radial end surface of the first through hole is rectangular in shape.

[0013] Optionally, corners of the sound-transmitting area are chamfered.

[0014] Optionally, the mesh is a rectangular hole, and the angle between the edge of the mesh and the edge of the sound-transmitting area is not 0°.

[0015] Optionally, the mesh holes are arc-shaped holes.

[0016] Optionally, the mesh has a shape aspect ratio greater than 2.

[0017] Optionally, the substrate is made of silicon-based material, the first through hole is configured to be formed by an anisotropic etching process, and the sound-transmitting area allows the corrosive agent to pass through.

[0018] Optionally, the grid film is configured to be formed on the substrate by a sputtering or vapor deposition process;

[0019] The sound-transmitting area is configured to form the mesh through a patterned etching process.

[0020] A technical effect of the present invention is:

[0021] The present invention discloses a MEMS device, including a substrate, a MEMS chip layer and a mesh membrane, wherein the substrate has a first surface and a second surface, and a first through hole is formed on the substrate; the MEMS chip layer is arranged on one side of the second surface of the substrate; the mesh membrane is arranged on one side of the first surface of the substrate, and a sound-transmitting area is formed on the mesh membrane at a position corresponding to the first through hole, and mesh holes are distributed on the sound-transmitting area. The substrate of the present invention plays a good supporting role for the mesh membrane.

[0022] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0024] Figure 1 It is a structural schematic diagram of a MEMS device of the present invention;

[0025] Figure 2 This is a schematic structural diagram of a sound-transmitting area of ​​a MEMS device of the present invention;

[0026] Figure 3 A schematic diagram of the structure of another sound-transmitting area of ​​the MEMS device of the present invention;

[0027] Figure 4 This is a schematic structural diagram of another sound-transmitting area of ​​the MEMS device of the present invention;

[0028] Figure 5 This is a schematic structural diagram of another sound-transmitting area of ​​the MEMS device of the present invention.

[0029] Among them: 1-substrate; 101-first surface; 102-second surface; 2-first through hole; 3-MEMS chip layer; 4-grid membrane; 5-sound-transmitting area; 6-insulating layer; 7-second through hole. DETAILED DESCRIPTION

[0030] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0031] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0032] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0033] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0034] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] See also Figure 1 The present invention discloses a MEMS device, comprising:

[0036] A substrate 1, a MEMS chip layer 3 and a grid membrane 4, wherein the substrate 1 has a first surface 101 and a second surface 102, and a first through hole 2 is formed on the substrate 1; the MEMS chip layer 3 is arranged on one side of the second surface 102 of the substrate 1, and the MEMS chip layer 3 covers the first through hole 2; the grid membrane 4 is arranged on one side of the first surface 101 of the substrate 1, and a sound-transmitting area 5 is formed on the grid membrane 4 at a position corresponding to the first through hole 2, and mesh holes are distributed on the sound-transmitting area 5, and the sound-transmitting area 5 is configured to allow sound to pass through so as to be transmitted to the MEMS chip layer 3.

[0037] The grid membrane 4 is disposed on one side of the substrate 1 , and the sound-transmitting area 5 of the grid membrane 4 is configured to allow sound to pass through while preventing external dust and impurities from entering the MEMS device, thereby ensuring the normal operation of the MEMS chip layer 3 .

[0038] Traditional dustproof structures similar to the mesh membrane 4 generally require a carrier to support the mesh membrane, and the mesh membrane is connected to the MEMS device through the carrier. The problem with this is that, on the one hand, the setting of the carrier increases the assembly complexity and manufacturing cost of the MEMS device. More importantly, due to the difference in thickness and material properties, the mechanical properties of the carrier and the MEMS device will be quite different. In this way, during the thermal expansion process, the carrier and the MEMS device will deform to varying degrees, generating very high stress. If these stresses continue to be transmitted to the mesh membrane, since the mesh membrane itself is provided with a large number of through holes, the structural strength of the mesh membrane is low, and large deformation and stress can easily lead to wrinkles or even damage to the mesh membrane. In the present invention, the substrate 1 of the MEMS device also plays the role of a carrier, which can not only provide a good support for the mesh membrane 4, but also simplify the assembly process of the MEMS device and reduce the manufacturing cost.

[0039] Optionally, the material of the mesh film 4 is metallic glass. Metallic glass not only has ultra-high strength similar to that of metal, but also has good ductility, is easy to shape, and can quickly rebound to its original shape after deformation. In this way, when the mesh film 4 is combined with the substrate 1, it can not only maintain high strength and deformation ability, but also can be firmly combined with the substrate 1, thereby improving the structural stability of the MEMS device.

[0040] Alternatively, see Figure 1 An insulating layer 6 is arranged on the second surface 102 of the substrate 1, and the MEMS chip layer 3 is arranged on the side of the insulating layer 6 away from the second surface 102. A through second through hole 7 is opened on the insulating layer 6, and the second through hole 7 is connected to the first through hole 2. The material of the insulating layer 6 is one of plastic and rubber.

[0041] In the MEMS device, the MEMS chip layer 3, as the main component for receiving sound signals, needs to maintain high sensitivity and stability, and then transmits the output signal of the MEMS chip layer 3 to the ASIC chip through the gold wire, and the ASIC chip transmits the signal of the MEMS chip layer 3 to the substrate 1 after processing, and then outputs it to the outside. Therefore, in order to ensure the relative independence of the operation of the MEMS chip layer 3 and the substrate 1, the present invention provides an insulating layer 6 between the substrate 1 and the MEMS chip layer 3.

[0042] The material of the insulating layer 6 is one of plastic and rubber. The plastic can be one or more combinations of PP material, PVC material, PET material, PS material, ABS resin, PC material and PA material. Plastic has the characteristics of light weight, chemical stability, good insulation, good impact resistance, etc., and has good transparency and wear resistance, good formability and colorability, and low processing cost; the rubber can be one or more combinations of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene-propylene rubber, fluororubber, polyurethane rubber, acrylic rubber and chloroether rubber. Rubber has good wear resistance, high elasticity, tear strength and elongation. Therefore, plastic or rubber can not only play a good insulating role for the substrate 1 and the MEMS chip layer 3, but also has very low cost and good forming characteristics.

[0043] Alternatively, see Figure 2 and Figure 3 The sound-transmitting area 5 is in a rectangular shape, and the radial end surface of the first through hole 2 is in a rectangular shape as well as the sound-transmitting area 5 .

[0044] Setting the sound-transmitting area 5 into a rectangular shape facilitates the positioning of the sound-transmitting area 5 and can improve the molding efficiency of the sound-transmitting area 5. More importantly, the mesh membrane 4 is generally made of crystal material, so setting the sound-transmitting area 5 into a rectangular shape can facilitate crystal molding on the one hand, and on the other hand, the rectangular side of the sound-transmitting area 5 can be consistent with the crystal plane and crystal orientation of its crystal, so that a crystal sound-transmitting area 5 with more stable performance can be obtained, which is convenient for the sound-transmitting area 5 to play a good dust-proof effect while passing sound.

[0045] Alternatively, see Figure 4 and Figure 5 The corners of the sound-transmitting area 5 are chamfered.

[0046] In a specific embodiment, Figure 4 In the embodiment, the edges of the sound-transmitting area 5 perpendicular to its plane are arranged to have an arc-shaped chamfer. Since the dense area of ​​the grid membrane 4 has a higher strength, and the sound-transmitting area 5 in the middle of the grid membrane 4 is provided with mesh holes, this will inevitably lead to a lower strength of the sound-transmitting area 5. A larger stress will inevitably be generated between the dense area of ​​the grid membrane 4 and the sound-transmitting area 5. Arranging the edges of the sound-transmitting area 5 perpendicular to its plane to have an arc-shaped chamfer can well disperse the stress and avoid stress concentration on the edges of the sound-transmitting area 5 perpendicular to its plane, thereby improving the protection performance and service life of the grid membrane 4.

[0047] In another specific embodiment, Figure 5 In the embodiment, one side of the plane of the sound-permeable area 5 is set as a surface with a certain slope on the periphery, and the periphery is inclined toward the center. Since the dense area of ​​the mesh membrane 4 has a higher strength, and the sound-permeable area 5 in the middle of the mesh membrane 4 is provided with mesh holes, this will inevitably lead to a decrease in the strength of the sound-permeable area 5, and a large stress will inevitably be generated between the dense area of ​​the mesh membrane 4 and the sound-permeable area 5. By setting one side of the plane of the sound-permeable area 5 as a surface with a certain slope on the periphery, it can be ensured that the connection between the sound-permeable area 5 and the dense area of ​​the mesh membrane 4 is from thick to thin, so that the thick area can bear a larger stress, and the thin area in the center of the sound-permeable area 5 can only bear a smaller stress, which also improves the protection performance and service life of the mesh membrane 4.

[0048] Alternatively, see Figure 2 The mesh is a rectangular hole, and the angle between the edge of the mesh and the edge of the sound-transmitting area 5 is not 0°.

[0049] Traditional mesh holes are generally set as circular holes, but in order to balance the size, number and spacing of the holes, the arrangement of the circular holes will inevitably lead to a low opening rate. However, the mesh holes are set as rectangular holes, and multiple rectangular holes can be arranged side by side, which greatly improves the mesh opening rate of the sound-transmitting area 5.

[0050] Specifically, the sound-transmitting zone 5 is generally made of crystal material with 100 crystal planes and 110 crystal planes. Therefore, by setting the edge of the mesh of the sound-transmitting zone 5 to an angle other than 0° with the edge of the sound-transmitting zone 5, the correlation between the rectangular hole and the 100 crystal plane of the crystal can be improved. Preferably, the opening direction of the rectangular hole is consistent with the 100 crystal plane of the crystal, so that a crystal sound-transmitting zone 5 with more stable performance can be obtained, which facilitates the sound-transmitting zone 5 to play a good dust-proof effect while passing sound.

[0051] Alternatively, see Figure 3 , the mesh is an arc-shaped hole. Similarly, the mesh is set to be an arc-shaped hole, and a plurality of arc-shaped holes can be arranged side by side, which greatly improves the mesh opening rate of the sound-transmitting area 5.

[0052] Optionally, the mesh shape aspect ratio is greater than 2. The mesh shape aspect ratio directly affects the mesh opening rate of the sound-transmitting area 5, and the larger the aspect ratio, the larger the mesh opening rate of the sound-transmitting area 5, so setting the mesh shape aspect ratio to be greater than 2 can significantly increase the mesh opening rate of the sound-transmitting area 5.

[0053] Optionally, the substrate 1 is made of silicon-based material, the first through hole 2 is configured to be formed by an anisotropic etching process, and the sound-transmitting area 5 allows the corrosive agent to penetrate.

[0054] Silicon-based materials have the characteristics of high temperature resistance, radiation resistance, and high electron transfer rate, and can obtain multifunctional substrates with high processing speed and high integration. The atomic density of each crystal direction of silicon-based materials is different, and anisotropic etching can be well completed, that is, the etching rate of the crystal direction with large atomic density is small, while the etching rate of the crystal direction with small atomic density is large, so that a silicon-based material substrate with stable structure and performance can be obtained1.

[0055] Optionally, the mesh membrane 4 is configured to be formed on the substrate 1 by a sputtering or vapor deposition process; and the sound-transmitting area 5 is configured to form the mesh by a patterned etching process.

[0056] Specifically, the molding process of the MEMS device may be:

[0057] A substrate 1 having a first through hole 2 is formed by anisotropic etching;

[0058] Compounding one side of the insulating layer 6 having the second through hole 7 onto the second surface 102 of the substrate 1;

[0059] Connect the MEMS chip layer 3 on the other side of the insulating layer 6;

[0060] forming a complete grid film 4 on the first surface 101 of the substrate 1 by sputtering;

[0061] A mask is provided on a side of the grid film 4 away from the substrate 1, and a mesh pattern is provided at a position of the mask corresponding to the sound-transmitting area 5;

[0062] The sound-transmitting area 5 having mesh holes is formed on the grid film 4 by patterned etching.

[0063] The molding process combines the material and the molding process well, and forms the MEMS device with a stable structure while simplifying the process flow.

[0064] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A MEMS device, characterized in that: include: A substrate, the substrate having a first surface and a second surface, and a first through hole is formed on the substrate; A MEMS chip layer, wherein the MEMS chip layer is disposed on one side of the second surface of the substrate, and the MEMS chip layer covers the first through hole; A mesh membrane, the mesh membrane is arranged on one side of the first surface of the substrate, the mesh membrane is formed with a sound-transmitting area at a position corresponding to the first through hole, mesh holes are distributed on the sound-transmitting area, and the sound-transmitting area is configured to allow sound to pass through so as to be transmitted to the MEMS chip layer; The sound-transmitting area is rectangular in shape, the radial end surface of the first through hole is rectangular in shape, and the material of the grid membrane is a crystalline material; The mesh holes are rectangular holes, and the opening direction of the rectangular holes is consistent with the crystal plane of the crystal.

2. The MEMS device according to claim 1, characterized in that: The material of the grid film is metallic glass.

3. The MEMS device according to claim 1, characterized in that: An insulating layer is disposed on the second surface of the substrate, the MEMS chip layer is disposed on a side of the insulating layer away from the second surface, a second through hole is formed on the insulating layer, and the second through hole is connected to the first through hole.

4. The MEMS device according to claim 1, characterized in that: The corners of the sound-transmitting area are chamfered.

5. The MEMS device according to claim 1, characterized in that: The angle between the edge of the mesh and the edge of the sound-transmitting area is not 0°.

6. The MEMS device according to claim 1, characterized in that: The mesh has a shape aspect ratio greater than 2.

7. The MEMS device according to any one of claims 1 to 6, characterized in that: The material of the substrate is a silicon-based material, the first through hole is configured to be formed by an anisotropic etching process, and the sound-transmitting area is used for the etching agent to pass through.

8. The MEMS device according to any one of claims 1 to 6, characterized in that: The grid film is configured to be formed on the substrate by a sputtering or vapor deposition process; The sound-transmitting area is configured to form the mesh through a patterned etching process.

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