MEMS chip and sensor module

Abstract

The utility model provides an MEMS chip and a sensor module, the MEMS chip comprises a support base, and a diaphragm and a back polar plate which are arranged on the support base, and the diaphragm and the back polar plate form a capacitor structure; wherein a hydrophobic structure is arranged on one side, far away from the back polar plate, of the vibrating diaphragm; the hydrophobic structure comprises a convex point arranged on the vibrating diaphragm and a hydrophobic layer wrapping the surface of the convex point; and the vibrating diaphragm is used for collecting signals entering the capacitor structure. According to the utility model, the chip has waterproof, dustproof and self-cleaning functions.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, and more specifically, to a MEMS chip and sensor module. Background Technology

[0002] With societal progress and technological advancements, the size of electronic products such as mobile phones, computers, and wearable devices has been continuously decreasing in recent years. People's performance requirements for these portable electronic products are also increasing, which in turn demands that the size, performance, and consistency of the supporting electronic components be continuously reduced. MEMS (Micro-Electro-Mechanical-System) integrated products have begun to be mass-produced and applied to such electronic products. Their package size is smaller than that of traditional electronic devices, making them favored by most manufacturers.

[0003] Currently, to meet the increasingly high performance demands of electronic products, MEMS chips are typically required to be waterproof and dustproof, and possess high performance, lightweight design, and high reliability in harsh environments. However, existing MEMS waterproof and dustproof solutions usually involve attaching a waterproof membrane. This approach is not only highly dependent on fluorinated compounds, which can easily cause environmental pollution, but the waterproof membrane also lacks the ability to prevent foreign objects from entering and to perform self-cleaning, thus failing to meet the high-performance requirements of the products. Utility Model Content

[0004] In view of the above problems, the purpose of this utility model is to provide a MEMS chip and sensor module to solve the waterproof performance problem of existing chips.

[0005] The MEMS chip provided by this utility model includes: a support base and a diaphragm and a back electrode plate disposed on the support base, wherein the diaphragm and the back electrode plate form a capacitor structure; wherein...

[0006] A hydrophobic structure is provided on the side of the diaphragm away from the back electrode plate;

[0007] The hydrophobic structure includes protrusions disposed on the diaphragm and a hydrophobic layer disposed on the surface covering the protrusions;

[0008] The diaphragm is used to collect signals entering the capacitor structure.

[0009] In addition, an optional structural feature is that the protrusions are evenly spaced on the diaphragm;

[0010] The protruding point is a cylindrical or cuboid structure, and the end of the cylindrical or cuboid structure is dome-shaped.

[0011] In addition, an optional structural feature is that the protrusion is an etched part or a deposited part; or,

[0012] The hydrophobic layer is an etched or deposited element disposed on the protrusion.

[0013] In addition, optional structural features include that the height of the protrusions ranges from 50 to 500 nm, and the spacing between the protrusions is less than 1 μm.

[0014] In addition, an optional structural feature is that a ring-shaped textured diaphragm structure is provided on the diaphragm;

[0015] The membrane structure is distributed in a wavy or serrated pattern.

[0016] In addition, an optional structural feature is that the hydrophobic layer is a polytetrafluoroethylene component, a polychlorotrifluoroethylene component, a polyimide component, a polyetheretherketone component, or a SAM film.

[0017] In addition, an optional structural feature is that the surface contact angle of the hydrophobic layer ranges from 100° to 150°.

[0018] In addition, an optional structural feature is that the diaphragm has symmetrically distributed micro-nano air pores.

[0019] The pore size of the micro-nano breathable pores ranges from 0.1 to 50 μm.

[0020] Furthermore, an optional structural feature is that the support base includes a substrate layer and a support layer located on the substrate layer; wherein,

[0021] Both the diaphragm and the back electrode plate are disposed on the support layer;

[0022] The MEMS chip further includes a first pad, a second pad, and a third pad disposed on the support layer; wherein...

[0023] The first pad is connected to the back electrode plate, the second pad is connected to the diaphragm, and the third pad is connected to the substrate layer.

[0024] On the other hand, the present invention also provides a sensor module, including a substrate and a housing forming an encapsulation structure with the substrate; characterized in that the aforementioned MEMS chip is disposed within the encapsulation structure.

[0025] Using the aforementioned MEMS chip and sensor module, a hydrophobic structure is set on one side of the diaphragm of the MEMS chip. The hydrophobic structure adopts a structure that combines a raised point with a hydrophobic layer set on the surface surrounding the raised point. This can increase the roughness of the diaphragm to achieve hydrophobic performance. When the liquid slides on the surface of the hydrophobic structure, it can combine with foreign matter attached to the surface and carry the foreign matter out by means of the surface hydrophobicity, thus achieving the purpose of self-cleaning. Attached Figure Description

[0026] Other objects and results of this invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings, and with a more complete understanding of the invention. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of a MEMS chip according to an embodiment of the present invention;

[0028] Figure 2 for Figure 1 A magnified view of part A in the middle.

[0029] The reference numerals in the figures include: substrate layer 1, support layer 2, second pad 31, first pad 32, third pad 33, back electrode plate 4, diaphragm 5, micro / nano vents 51, textured film structure 6, hydrophobic structure 7, protrusion point 71, and hydrophobic layer 72.

[0030] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0031] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0032] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0033] To describe the MEMS chip of this utility model in detail, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0034] Figure 1 and Figure 2 The schematic structure of the MEMS chip according to the embodiments of the present invention is shown from different angles.

[0035] like Figure 1 and Figure 2 As shown in the figure, the MEMS chip of this utility model embodiment includes a support base and a diaphragm 5 and a back electrode plate 4 disposed on the support base. The diaphragm 5 and the back electrode plate 4 form a capacitor structure. The diaphragm 5 is displaced according to the signal (e.g., vibration signal) entering the capacitor structure, thereby realizing the signal acquisition function. In order to realize the waterproof, dustproof and self-cleaning performance of the MEMS chip, a hydrophobic structure 7 is provided on the side of the diaphragm 5 away from the back electrode plate 4. The hydrophobic structure 7 includes a protrusion 71 disposed on the diaphragm 5 and a hydrophobic layer 72 disposed on the surface of the protrusion 71. The hydrophobic structure 7 can not only realize the waterproof and dustproof function, but also combine the liquid droplets attached to the protrusion 71 with foreign matter on the surface of the diaphragm 5. Then, based on the hydrophobic property, the liquid carries away the foreign matter to achieve the purpose of self-cleaning, thereby reducing product failure caused by foreign matter and improving the resistance of the MEMS chip to foreign matter.

[0036] The raised points 71 provided on the diaphragm 5 are mainly used to improve the surface roughness of the diaphragm 5. They can be evenly distributed on the diaphragm 5. Each raised point 71 is formed into a cylindrical structure or a cuboid structure, etc., and the end of the cylindrical or cuboid structure is dome-shaped to improve the hydrophobic performance. It can be seen that the raised points 71 can also be set as other three-dimensional structures, such as trapezoidal, conical or other irregular structures. Any structure that can increase the surface roughness of the diaphragm 5 through the raised points 71 is acceptable. The structure of the hydrophobic layer 72 corresponds to the raised points 71.

[0037] Specifically, the protruding point 71 can be an etched or deposited part disposed on the diaphragm 5, while the hydrophobic layer 72 can be an etched or deposited part wrapped around the outer surface of the protruding point 71. The hydrophobic layer 72 can be a polytetrafluoroethylene part, a polychlorotrifluoroethylene part, a polyimide part, a polyetheretherketone part, or a SAM (self-assembled monolayer) film. The surface of the hydrophobic layer 72 can form a contact angle in the range of 100° to 150°. After adjusting the material density of the hydrophobic layer 72, the contact angle can reach more than 150°.

[0038] In one specific embodiment of this utility model, the height of the protrusion 71 can be set to 50-500nm, and the spacing between adjacent protrusions 71 can be set to less than 1um. This structure can realize a superhydrophobic surface, further improve the resistance of MEMS chips to foreign objects, and reduce their sensitivity to foreign objects.

[0039] In addition, to combine the waterproof and breathable functions of the diaphragm 5, micro-nano breathable holes 51 can be set on the diaphragm 5. The pore size of the micro-nano breathable holes 51 ranges from 0.1 to 50 μm. The micro-nano breathable holes 51 can be symmetrically or uniformly distributed on the diaphragm 5 to prevent them from affecting the performance of the diaphragm 5 during the breathable process. In addition, the acoustic impedance of the chip can be reduced by increasing the number of openings. The specific pore size or number of micro-nano breathable holes 51 can be flexibly set according to the waterproof rating and performance requirements of the chip.

[0040] To improve the compliance of the diaphragm 5, a ring-shaped textured structure 6 can be provided on the diaphragm 5. The textured structure 6 is a local wavy or sawtooth structure distributed on the diaphragm 5. By setting the textured structure, the vibration amplitude of the diaphragm 5 can be increased and the mechanical sensitivity can be improved. Specifically, the structure and position of the textured structure can be set and adjusted according to the size and sensitivity requirements of the MEMS chip.

[0041] In the MEMS chip of this utility model, the support base further includes a substrate layer 1 and a support layer 2 located on the substrate layer 1; wherein, the diaphragm 5 and the back electrode plate 4 are both disposed in the support layer 2, and the MEMS chip also includes a first pad 32, a second pad 31 and a third pad 33 disposed on the upper surface of the support layer 2; wherein, the first pad 32 is connected to the back electrode plate 4, the second pad 31 is connected to the diaphragm 5, and the third pad 33 is connected to the substrate layer 1; in addition, in order to save the space occupied by the pads on the surface of the support layer 2, the third pad 33 can also be directly integrated into the interior of the substrate layer 1, extending from the lower surface of the substrate layer 1.

[0042] Corresponding to the aforementioned MEMS chip, this utility model also provides a sensor module, including a substrate and a housing forming an encapsulation structure with the substrate, wherein the aforementioned MEMS chip is disposed within the encapsulation structure.

[0043] It should be noted that the embodiments of the above sensor modules can be referred to the description in the MEMS chip embodiments, and will not be repeated here.

[0044] As can be seen from the above embodiments, the MEMS chip and sensor module of this utility model have a hydrophobic structure on one side of the diaphragm of the MEMS chip. The hydrophobic structure adopts a structure that combines the protrusion point with the hydrophobic layer on the surface surrounding the protrusion point. This can reduce the sensor module's dependence on fluorine-containing compounds and reduce the degree of environmental pollution. At the same time, the hydrophobic performance of the diaphragm is increased by the micro-nano-level rough structure. When the liquid slides on the surface of the hydrophobic structure, it can combine with foreign matter attached to the surface and carry away the foreign matter by means of the surface hydrophobicity, thus achieving the purpose of self-cleaning.

[0045] The MEMS chip and sensor module according to the present invention have been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the MEMS chip and sensor module proposed in the present invention without departing from the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A MEMS chip, characterized by, The MEMS chip comprises a support base, a diaphragm and a back plate disposed on the support base, and the diaphragm and the back plate form a capacitor structure; wherein, A hydrophobic structure is disposed on the side of the diaphragm away from the back plate; The hydrophobic structure comprises a protruding point disposed on the diaphragm and a hydrophobic layer disposed on the surface of the protruding point; The diaphragm is used to collect signals entering the capacitor structure.

2. The MEMS chip according to claim 1, wherein, The protruding points are uniformly spaced on the diaphragm; The protruding points are in a cylindrical structure or a cuboid structure, and the end of the cylindrical structure or the cuboid structure is in a spherical top shape.

3. The MEMS chip according to claim 1, wherein, The protruding points are etching parts or deposited parts disposed on the diaphragm; The hydrophobic layer is an etching part or a deposited part disposed on the protruding point.

4. The MEMS chip according to claim 2, wherein, The height of the protruding point ranges from 50 nm to 500 nm; The distance between the protruding points is less than 1 um.

5. The MEMS chip according to claim 1, wherein, A ring-shaped distributed corrugated structure is disposed on the diaphragm; The corrugated structure is in a wavy or zigzag shape.

6. The MEMS chip according to claim 1, wherein, The hydrophobic layer is a polytetrafluoroethylene part, a polytrifluorochloroethylene part, a polyimide part, a polyether ether ketone part or a SAM film.

7. The MEMS chip according to claim 1, wherein, The surface contact angle of the hydrophobic layer ranges from 100° to 150°.

8. The MEMS chip according to claim 1, wherein, Symmetrically distributed micro-nano air holes are disposed on the diaphragm; The pore size of the micro-nano air holes ranges from 0.1 um to 50 um.

9. The MEMS chip of claim 1, wherein, The support base comprises a substrate layer and a support layer disposed on the substrate layer; wherein, The diaphragm and the back plate are both disposed on the support layer; The MEMS chip further comprises a first pad, a second pad and a third pad disposed on the support layer; wherein, The first pad is connected in conduction with the back plate, the second pad is connected in conduction with the diaphragm, and the third pad is connected in conduction with the substrate layer.

10. A sensor module comprising a substrate and a housing forming an encapsulation structure with the substrate; characterized in that, The packaging structure comprises the MEMS chip according to any one of claims 1 to 9.

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