MEMS package structure and electronic device

Abstract

The application provides a MEMS packaging structure and an electronic device. The MEMS packaging structure comprises a MEMS chip, a substrate provided with an acoustic hole penetrating through the substrate, the MEMS chip is arranged on the substrate, and the MEMS chip is arranged opposite to the acoustic hole, and an isolation component is arranged between the MEMS chip and the substrate, and the orthographic projection of the isolation component towards the substrate is larger than the orthographic projection of the MEMS chip towards the substrate. The application can improve the stability and reliability of the performance of the MEMS packaging structure.

Description

Technical Field

[0001] This application relates to the field of MEMS packaging technology, and more specifically, to a MEMS packaging structure and electronic device. Background Technology

[0002] In existing technologies, the diaphragms of MEMS (Micro-Electro-Mechanical Systems) chips are thin-film structures with initial processing tensile stress. Consequently, due to their thin-film characteristics, they are highly sensitive to external forces, making their performance susceptible to failure caused by external displacement loads, such as after the entire device is soldered or after the MEMS package structure is subjected to high-temperature impact. Furthermore, because the diaphragm's geometry is at the nanometer or micrometer scale, its stiffness is low, and because the material is typically brittle, it is easily broken when subjected to impact energy such as high-speed vibration or airflow, for example, when the MEMS package structure is dropped or directly blown by a hair dryer. Therefore, based on these issues, MEMS package structures generally suffer from poor stability and reliability.

[0003] Therefore, a new technical solution is needed to solve the above-mentioned technical problems. Utility Model Content

[0004] One objective of this application is to provide a new technical solution for MEMS packaging structure and electronic devices.

[0005] According to a first aspect of this application, a MEMS packaging structure is provided, wherein the MEMS packaging structure includes: MEMS chips; A substrate having an acoustic aperture extending through it; a MEMS chip disposed on the substrate, with the MEMS chip positioned opposite to the acoustic aperture; An isolation component is disposed between the MEMS chip and the substrate, and the orthographic projection of the isolation component toward the substrate is greater than the orthographic projection of the MEMS chip toward the substrate.

[0006] Optionally, the isolation component includes an isolation layer and a flexible adhesive layer, wherein the isolation layer is connected to the MEMS chip and the flexible adhesive layer is connected to the substrate; Wherein, at least a portion of the isolation layer is disposed over the acoustic hole, and the isolation layer includes a connecting hole that communicates with the acoustic hole.

[0007] Optionally, the material of the insulating layer includes at least one selected from polyimide, stainless steel, aluminum alloy, and copper; The material of the soft adhesive layer is silicone.

[0008] Optionally, the thickness of the isolation layer is less than 50 μm; The thickness of the soft adhesive layer is 30~50μm.

[0009] Optionally, the soft adhesive layer includes silicone and a silica filler filling the silicone, wherein the thickness of the silica filler is 25~35μm.

[0010] Optionally, the Young's modulus of the silicone is 0.5~1.5 MPa.

[0011] Optionally, it also includes an ASIC chip disposed on the substrate; A rigid adhesive layer is provided between the ASIC chip and the isolation component; or, a rigid adhesive layer is provided between the ASIC chip and the substrate.

[0012] Optionally, it also includes an adhesive layer disposed between the MEMS chip and the isolation component.

[0013] Optionally, the rotation angle of the MEMS chip on the substrate ranges from 0° to 50°.

[0014] According to a second aspect of this application, an electronic device is provided, comprising a MEMS packaging structure as described in any of the first aspects.

[0015] The MEMS packaging structure in this application, by setting an isolation component between the MEMS chip and the substrate, and setting the orthogonal projection of the isolation component onto the substrate to be greater than the orthogonal projection of the MEMS chip onto the substrate, enables the isolation component to absorb external displacement loads and impact energy, thereby effectively improving the stability and reliability of the MEMS packaging structure performance.

[0016] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments of this application with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0018] Figure 1 This is a schematic diagram of the MEMS packaging structure in the first embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the MEMS packaging structure in the second embodiment of this application.

[0020] Figure 3This is a schematic diagram of the MEMS packaging structure in the third embodiment of this application.

[0021] Explanation of reference numerals in the attached figures: 1. MEMS chips; 2. Substrate; 201. Sound hole; 3. Isolation component; 301. Isolation layer; 3011. Connecting hole; 302. Soft adhesive layer; 4. ASIC chip; 5. Adhesive layer; 6. Outer shell; 7. Receiving cavity. Detailed Implementation

[0022] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0023] The embodiments of this application will now be described in detail, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0025] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "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 based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not 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 application.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0028] According to one embodiment of this application, a MEMS packaging structure is provided, see [link to embodiment]. Figures 1 to 3 The MEMS packaging structure includes a MEMS chip 1, a substrate 2, and an isolation component 3. The substrate 2 is provided with an acoustic hole 201 that passes through the substrate 2. The MEMS chip 1 is disposed on the substrate 2 and is disposed opposite to the acoustic hole 201. The isolation component 3 is disposed between the MEMS chip 1 and the substrate 2, and the orthographic projection of the isolation component 3 onto the substrate 2 is greater than the orthographic projection of the MEMS chip 1 onto the substrate 2.

[0029] Specifically, the MEMS packaging structure in this embodiment includes a housing 6 and a substrate 2. The housing 6 is a shell with an opening, and the substrate 2 is a plate-like structure that can close the opening of the housing 6. The housing 6 can be integrally formed with the substrate 2 by means of welding, bonding, screwing, or riveting, so as to form a receiving cavity 7 between the housing 6 and the substrate 2. Electronic components such as a MEMS chip 1, an ASIC (Application Specific Integrated Circuit) chip, an integrated circuit, a connector, and a processor can be fixedly disposed in the receiving cavity 7. Multiple electronic components are interconnected to form the circuit of the MEMS packaging structure.

[0030] The substrate 2 serves to support electronic components such as the MEMS chip 1, ASIC chip 4, integrated circuits, connectors, and processor, thereby improving the overall stability and reliability of the MEMS packaging structure. The substrate 2 can be a PCB (Printed Circuit Board) to ensure good electrical connectivity of the MEMS packaging structure. An acoustic aperture 201 is provided on the substrate 2, allowing the receiving cavity 7 to communicate with the outside environment. The MEMS chip 1 is disposed on the substrate 2, and is positioned opposite the acoustic aperture 201, so that external airflow can drive the diaphragm of the MEMS chip 1 on the substrate 2 to vibrate and generate a capacitance signal.

[0031] The MEMS packaging structure also includes an isolation component 3, which is disposed between the MEMS chip 1 and the substrate 2, and the orthogonal projection of the isolation component 3 onto the substrate 2 is greater than the orthogonal projection of the MEMS chip 1 onto the substrate 2.

[0032] Therefore, this embodiment provides the MEMS chip 1 with an elastic energy-absorbing space and energy-insulating effect through a large-area isolation component 3. On the one hand, the isolation component 3 can perfectly absorb the displacement load generated after the entire assembly is soldered or the displacement load generated by the high-temperature impact on the MEMS packaging structure, thus isolating the displacement load from the MEMS chip 1 and preventing the displacement load from being transmitted to the MEMS chip 1 and causing the diaphragm of the MEMS chip 1 to fail. On the other hand, the isolation component 3 can also perfectly absorb the mechanical vibration generated when the MEMS packaging structure is dropped or the airflow impact generated when it is directly blown by a hair dryer, preventing the mechanical vibration and airflow impact from directly acting on the diaphragm of the MEMS chip 1 and causing the diaphragm to break. Thus, by setting the isolation component 3, this embodiment not only effectively ensures the stability of the MEMS packaging structure performance, but also greatly improves the reliability of the MEMS packaging structure under extreme working conditions.

[0033] In one embodiment, the isolation component 3 includes an isolation layer 301 and a soft adhesive layer 302. The isolation layer 301 is connected to the MEMS chip 1, and the soft adhesive layer 302 is connected to the substrate 2. At least a portion of the isolation layer 301 covers the acoustic hole 201, and the isolation layer 301 includes a connecting hole 3011, which communicates with the acoustic hole 201.

[0034] Specifically, such as Figures 1 to 3 As shown, the isolation layer 301 in this embodiment is a thin-layer structure. The orthographic projection of the thin-layer isolation layer 301 onto the substrate 2 is greater than the orthographic projection of the MEMS chip 1 onto the substrate 2. This allows the isolation layer 301 to transform the traditional direct bonding method between the MEMS chip 1 and the substrate 2 into a thin-layer isolation design. Thus, the isolation layer 301, through its isolation design, isolates and absorbs dangerous driving energy such as external displacement loads, mechanical vibrations, or airflow impacts, effectively protecting the diaphragm of the MEMS chip 1.

[0035] Among them, such as Figures 1 to 3 As shown, at least part of the isolation layer 301 is covered on the acoustic hole 201 so that the airflow impact generated when the MEMS packaging structure is directly blown by a hair dryer can be effectively absorbed by the isolation layer 301, so as to prevent the airflow impact from directly acting on the diaphragm of the MEMS chip 1 and causing the diaphragm to break.

[0036] The isolation layer 301 includes a connecting hole 3011, which is connected to the acoustic hole 201, so that external airflow can pass through the acoustic hole 201 and the connecting hole 3011 in sequence to drive the diaphragm of the MEMS chip 1 to vibrate and form a capacitance signal.

[0037] In addition, the soft adhesive layer 302 in this embodiment can be a fully covered soft adhesive, that is, the orthogonal projection of the soft adhesive layer 302 toward the substrate 2 is greater than the orthogonal projection of the MEMS chip 1 toward the substrate 2, so that the isolation component 3 as a whole has a certain height, thereby improving the energy absorption and unloading capacity of the isolation layer 301.

[0038] Of course, in other embodiments, when the MEMS packaging structure itself has a sufficiently large size, the soft adhesive layer 302 can also be disposed only on the periphery of the isolation layer 301, that is, the orthogonal projection of the soft adhesive layer 302 toward the substrate 2 is smaller than the orthogonal projection of the MEMS chip 1 toward the substrate 2, so that the soft adhesive layer 302 is disposed on the edge of the isolation layer 301 near the outer shell 6, and the isolation layer 301 forms a suspended thin layer structure. At this time, due to the characteristics of the thin layer structure itself, the manufacturing cost of the MEMS packaging structure is effectively reduced while ensuring the stability and reliability of the MEMS packaging structure performance.

[0039] In one embodiment, the material of the insulating layer 301 includes at least one of polyimide, stainless steel, aluminum alloy and copper; the material of the soft adhesive layer 302 is silicone.

[0040] Specifically, since polyimide has a high Tg (Glass Transition Temperature), it can ensure the stability of the material at high temperatures during reflow and improve the production quality of the isolation layer 301. Therefore, this embodiment of the application selects polyimide as the material of the isolation layer 301 to effectively improve the stability and reliability of the MEMS packaging structure performance.

[0041] Of course, in other embodiments, the material of the isolation layer 301 can also be at least one of stainless steel, aluminum alloy and copper, as long as it can provide the MEMS chip 1 with an elastic energy absorption space and energy isolation effect. Those skilled in the art can choose according to actual needs, and this application does not make specific restrictions here.

[0042] In addition, since silicone has good stress resistance and cushioning effect, this embodiment of the application further improves the energy absorption and unloading capacity of the isolation layer 301 by selecting silicone as the material of the soft adhesive layer 302.

[0043] Of course, in other embodiments, the material of the soft adhesive layer 302 can also be any one of UV adhesive, polyurethane adhesive or acrylic adhesive. Those skilled in the art can choose according to actual needs, and this application does not make specific restrictions here.

[0044] In one embodiment, the thickness of the isolation layer 301 is less than 50 μm; the thickness of the soft adhesive layer 302 is 30~50 μm.

[0045] Specifically, the thickness of the isolation layer 301 in this embodiment is preferably less than 50 μm, so as to avoid the excessively thick isolation layer 301 from occupying the rear cavity space of the MEMS packaging structure and thus weakening the performance of the MEMS packaging structure. Furthermore, since the isolation layer 301 is a thin layer structure, the thinner isolation layer 301 can also make the overall isolation effect of the isolation component 3 better.

[0046] Furthermore, the thickness of the soft adhesive layer 302 in this embodiment is preferably 30~50μm to further isolate the stress level change of the MEMS chip 1 caused by the deformation of the substrate 2 due to the welding of the whole machine, to ensure the stability of the performance of the MEMS chip 1 itself, and to avoid the performance reduction of the MEMS packaging structure caused by the MEMS chip 1 in the whole machine application of the MEMS packaging structure.

[0047] In one embodiment, the soft adhesive layer 302 includes silicone and a silica filler filling the silicone, wherein the thickness of the silica filler is 25~35μm.

[0048] Specifically, in this embodiment of the application, by setting the soft adhesive layer 302 to include silicone and a silica layer filler filling the silicone, not only does the originally soft silicone become harder, but it also ensures that the silicone still has high elasticity, thereby further improving the energy absorption and unloading capacity of the isolation layer 301.

[0049] In addition, to ensure that the silicone still has high elasticity, the thickness of the silica layer filler is preferably 25~35μm.

[0050] When the thickness of the soft adhesive layer 302 is 40μm, by setting the thickness of the internally filled silica layer to 30μm, not only can the energy absorption and unloading capacity of the isolation layer 301 be effectively improved, but the overall stability of the soft adhesive layer 302 can also be guaranteed.

[0051] In one embodiment, the Young's modulus of the silicone is 0.5~1.5 MPa.

[0052] Specifically, in this embodiment of the application, by setting the Young's modulus of the silicone to 0.5~1.5MPa, the stress level change of the MEMS chip 1 caused by the deformation of the substrate 2 due to the welding of the whole machine is further isolated, thus ensuring the stability of the performance of the MEMS chip 1 itself.

[0053] In one embodiment, the MEMS packaging structure further includes an ASIC chip 4 disposed on the substrate 2; wherein a rigid adhesive layer is disposed between the ASIC chip 4 and the isolation component 3; or, a rigid adhesive layer is disposed between the ASIC chip 4 and the substrate 2.

[0054] Specifically, in this embodiment, the ASIC chip 4 can be directly disposed on the substrate 2. For example, the ASIC chip 4 can be connected to the isolation component 3 through a rigid adhesive layer, or the ASIC chip 4 can also be connected to the substrate 2 through a rigid adhesive layer. This allows the MEMS packaging structure to utilize the substrate 2 to arrange and support the ASIC chip 4, and facilitates wire bonding of the ASIC chip 4, resulting in higher assembly efficiency. The ASIC chip 4 can be electrically connected to the MEMS chip 1 to receive and process the capacitance signal generated by the vibration of the diaphragm of the MEMS chip 1.

[0055] Of course, in other embodiments, the ASIC chip 4 can also be fixed on the substrate 2 by means of solder connection and gold-tin solder pad connection. Those skilled in the art can choose according to actual needs, and this application does not make specific restrictions here.

[0056] In addition, the material of the rigid adhesive layer can be any one of high-filler epoxy insulating adhesive, conductive silver paste or thermosetting resin adhesive. Those skilled in the art can choose according to actual needs, and this application does not impose specific restrictions here.

[0057] In one embodiment, the MEMS packaging structure further includes an adhesive layer 5, which is disposed between the MEMS chip 1 and the isolation component 3.

[0058] Specifically, this application implements a method to connect the MEMS chip 1 and the isolation component 3 through an adhesive layer 5, which further improves the stability and reliability of the MEMS chip 1.

[0059] The adhesive layer 5 can be made of any one of silicone, UV adhesive, polyurethane adhesive or acrylic adhesive. Those skilled in the art can choose according to actual needs, and this application does not impose specific restrictions.

[0060] In one embodiment, the rotation angle of the MEMS chip 1 on the substrate 2 ranges from 0° to 50°.

[0061] Specifically, the assembly method of the MEMS chip 1 on the substrate 2 in the embodiments of this application can be, in addition to being as follows: Figure 1 and Figure 2 In addition to the normal placement shown, it can also be placed as follows: Figure 3 The biased placement shown means that the MEMS chip 1 can be rotated at a certain angle before being placed on the substrate 2, thereby enabling the MEMS chip 1 to have greater bending stiffness.

[0062] When the packaging space of the MEMS packaging structure is small, the rotation angle of the MEMS chip 1 on the substrate 2 is preferably 15°; when the packaging space of the MEMS packaging structure is large, the rotation angle of the MEMS chip 1 on the substrate 2 is preferably 45°.

[0063] According to another embodiment of this application, an electronic device is provided, the electronic device including the MEMS packaging structure described in this application.

[0064] Specifically, the electronic device described in this application embodiment can be any one of mobile phones, tablet computers, personal digital assistants, televisions, smart wearable products, virtual reality terminal devices, augmented reality terminal devices, rechargeable small household appliances (such as soy milk makers and robot vacuum cleaners), drones, radar, aerospace equipment, and vehicle-mounted equipment.

[0065] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0066] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A MEMS packaging structure, characterized in that, include: MEMS chip (1); A substrate (2) is provided with an acoustic hole (201) passing through the substrate (2); a MEMS chip (1) is disposed on the substrate (2), and the MEMS chip (1) is disposed opposite to the acoustic hole (201); An isolation component (3) is disposed between the MEMS chip (1) and the substrate (2), and the orthographic projection of the isolation component (3) onto the substrate (2) is greater than the orthographic projection of the MEMS chip (1) onto the substrate (2).

2. The MEMS packaging structure according to claim 1, characterized in that, The isolation component (3) includes an isolation layer (301) and a soft adhesive layer (302). The isolation layer (301) is connected to the MEMS chip (1), and the soft adhesive layer (302) is connected to the substrate (2). At least a portion of the isolation layer (301) is disposed over the acoustic hole (201), and the isolation layer (301) includes a connecting hole (3011) that communicates with the acoustic hole (201).

3. The MEMS packaging structure according to claim 2, characterized in that, The material of the isolation layer (301) includes at least one of polyimide, stainless steel, aluminum alloy and copper; The material of the soft adhesive layer (302) is silicone.

4. The MEMS packaging structure according to claim 2, characterized in that, The thickness of the isolation layer (301) is less than 50 μm; The thickness of the soft adhesive layer (302) is 30~50μm.

5. The MEMS packaging structure according to claim 2, characterized in that, The soft adhesive layer (302) includes silicone and a silica filler filling the silicone, wherein the thickness of the silica filler is 25~35μm.

6. The MEMS packaging structure according to claim 5, characterized in that, The Young's modulus of the silicone is 0.5~1.5 MPa.

7. The MEMS packaging structure according to claim 2, characterized in that, It also includes an ASIC chip (4), which is disposed on the substrate (2). A hard adhesive layer is provided between the ASIC chip (4) and the isolation component (3); or, a hard adhesive layer is provided between the ASIC chip (4) and the substrate (2).

8. The MEMS packaging structure according to claim 1, characterized in that, It also includes an adhesive layer (5) disposed between the MEMS chip (1) and the isolation component (3).

9. The MEMS packaging structure according to claim 1, characterized in that, The rotation angle of the MEMS chip (1) on the substrate (2) ranges from 0° to 50°.

10. An electronic device, characterized in that, Includes the MEMS packaging structure as described in any one of claims 1-9.

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