MEMS chip packaging structure and electronic equipment

Abstract

The utility model discloses an MEMS chip packaging structure and an electronic device, and the MEMS chip packaging structure comprises a substrate which is provided with a first groove and a second groove which are communicated with each other, an MEMS chip with a first cavity, and an ASIC chip with a second cavity. The MEMS chip and the ASIC chip are arranged on the substrate side by side, the side, provided with the first cavity, of the MEMS chip covers the first groove, the first cavity is communicated with the first groove, the side, provided with the second cavity, of the ASIC chip covers the second groove, and the second cavity is communicated with the second groove. The first groove and the second groove which are communicated are formed in the substrate to expand the back cavity of the MEMS, and effective expansion of the back cavity can be achieved under the condition that the size of the packaging structure is not increased. The second cavity arranged in the ASIC chip makes full use of the space in the thickness direction in the same row of space, the space utilization rate is improved, the size of the back cavity is further expanded while the size of the packaging structure is not affected, and the sensitivity of the MEMS chip is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of chip packaging, in particular to a packaging structure of a MEMS chip and an electronic device. Background Art

[0002] With the continuous iteration and advancement of technology, the size of MEMS sensor chips is getting smaller and smaller. The advantage of making chips smaller is that it can reduce production costs.

[0003] However, as chips become smaller, the size of their back cavity also shrinks. On the one hand, when the back cavity size decreases, air flow is restricted and air damping increases. This causes the sensor's vibration to decay faster, making it unable to maintain vibration for long periods of time, thus significantly reducing sensitivity. On the other hand, low-frequency signals typically vibrate more slowly, requiring the sensor to maintain vibration for a longer period of time to capture these signals. However, due to the greater air damping when the back cavity size is small, the sensor element quickly "braks" under the damping effect, making it difficult to keep up with the rhythm of the low-frequency signal. This results in a poor low-frequency response for smaller MEMS chips, making it difficult to accurately detect low-frequency external changes. Utility Model Content

[0004] The embodiments of the present invention provide a MEMS chip packaging structure and an electronic device to improve the working sensitivity and low-frequency response effect of the MEMS chip.

[0005] In order to solve the above technical problems, the embodiments of the present utility model disclose the following technical solutions:

[0006] On the one hand, a MEMS chip packaging structure is provided, comprising:

[0007] A substrate, wherein a first groove and a second groove communicating with each other are formed on one side surface of the substrate;

[0008] A MEMS chip having a first cavity;

[0009] an ASIC chip, wherein the ASIC chip has a second cavity;

[0010] The MEMS chip and the ASIC chip are arranged side by side on a surface of a side of the substrate having a first groove and a second groove, and the MEMS chip and the ASIC chip are electrically connected. The side of the MEMS chip having a first cavity is connected to the substrate and covers the first groove, and the first cavity is connected to the first groove. The side of the ASIC chip having a second cavity is connected to the substrate and covers the second groove, and the second cavity is connected to the second groove.

[0011] In addition to one or more of the features disclosed above, or as an alternative, the present invention further includes a packaging shell, which is connected to a side surface of the substrate and together with the substrate forms a receiving cavity, and the MEMS chip and the ASIC chip are both located in the receiving cavity.

[0012] In addition to or as an alternative to one or more of the features disclosed above, a side wall of the packaging shell facing away from the substrate is provided with a sound hole penetrating through the side wall.

[0013] In addition to one or more of the features disclosed above, or as an alternative, the MEMS chip and the ASIC chip separate the accommodating cavity into a front cavity connected to the outside of the accommodating cavity through a sound hole and a closed back cavity, and the first cavity, the first groove, the second groove and the second cavity together constitute the back cavity.

[0014] In addition to or as an alternative to one or more features disclosed above, on a surface of the substrate perpendicular to the thickness direction, a projection of the acoustic hole and a projection of the MEMS chip do not overlap.

[0015] In addition to or as an alternative to one or more features disclosed above, the first groove and the second groove are spaced apart in the substrate, and a through groove is opened in the substrate, the through groove is located between the first groove and the second groove, and connects the first groove and the second groove.

[0016] In addition to or as an alternative to one or more of the features disclosed above, in the thickness direction of the substrate, a distance X1 from a surface of the ASIC chip facing away from the substrate to a surface of the substrate is less than or equal to a distance X2 from a surface of the MEMS chip facing away from the substrate to the substrate.

[0017] In addition to or as an alternative to one or more features disclosed above, the substrate is a circuit board, the ASIC chip is electrically connected to the circuit in the substrate via gold wires, and the MEMS chip is electrically connected to the circuit of the ASIC chip via gold wires.

[0018] On the other hand, an electronic device is provided, comprising the packaging structure of any MEMS chip disclosed above.

[0019] One of the above technical solutions has the following advantages or beneficial effects: the present application arranges the MEMS chip and the ASIC chip side by side, and arranges a second cavity on the ASIC chip, and connects the second cavity of the ASIC chip with the first cavity of the MEMS chip. With such a design, in actual operation, the first cavity serves as the main body of the back cavity, and the second cavity serves as the expansion cavity of the back cavity. By optimizing the spatial layout of the ASIC chip, the space utilization in the thickness direction is improved, and the effective expansion of the back cavity is achieved without increasing the overall size of the MEMS chip and the packaging structure, and the sensitivity and low-frequency response capability of the MEMS chip are significantly improved. Furthermore, by connecting the first cavity and the second cavity through the first groove and the second groove opened on the substrate, the connection between the first cavity and the second cavity is achieved while keeping the package size unchanged, and the space of the back cavity is further increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0021] Figure 1 It is a structural schematic diagram of a MEMS chip packaging structure provided according to an embodiment of the present application.

[0022] Description of reference numerals:

[0023] 10. Base plate; 11. First groove; 12. Second groove; 13. Through groove;

[0024] 20. MEMS chip; 21. first cavity;

[0025] 30. ASIC chip; 31. Second cavity;

[0026] 40. Packaging shell; 41. Accommodating cavity; 42. Sound hole; 43. Front cavity; 44. Back cavity. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are only for the purpose of explaining the present invention and are not intended to limit the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.

[0029] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections, direct connections, or indirect connections through an intermediate medium; they may refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0030] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0031] The present application embodiment discloses a packaging structure of a MEMS chip, referring to Figure 1, comprising: a substrate 10, a MEMS chip 20, and an ASIC chip 30. A first groove 11 and a second groove 12 are formed on one side of the substrate 10. The MEMS chip 20 has a first cavity 21. The ASIC chip 30 has a second cavity 31. The MEMS chip 20 and the ASIC chip 30 are arranged side by side on the side of the substrate 10 on which the first groove 11 and the second groove 12 are formed, and the MEMS chip 20 and the ASIC chip 30 are electrically connected. The side of the MEMS chip 20 with the first cavity 21 is connected to the substrate 10 and covers the first groove 11, and the first cavity 21 is connected to the first groove 11. The side of the ASIC chip 30 with the second cavity 31 is connected to the substrate 10 and covers the second groove 12, and the second cavity 31 is connected to the second groove 12. For example, the ASIC chip 30 generally includes a stacked functional circuit layer and a substrate layer. The substrate layer mainly provides mechanical support. The second cavity 31 can be formed on the side of the substrate layer of the ASIC chip 30 facing away from the functional circuit layer, and the side of the substrate layer facing away from the functional circuit layer is fixedly connected to the substrate 10.

[0032] In the embodiment disclosed in the present application, the back cavity 44 of the MEMS chip 20 when working is composed of the first groove 11, the second groove 12, the first cavity 21 and the second cavity 31. The first cavity 21 serves as the main body of the back cavity 44, and the first groove 11, the second groove 12 and the second cavity 31 serve as the expansion cavity of the back cavity 44. Compared with the prior art (the prior art usually relies on other auxiliary shell structures provided on the substrate 10 to expand the back cavity 44 of the MEMS chip 20), the present application expands the back cavity 44 of the MEMS by opening a first groove 11 and a second groove 12 connected to each other on the substrate 10. It can achieve effective expansion of the back cavity 44 without increasing the size of the packaging structure. In addition, in the present application, the ASIC chip 30 and the MEMS chip 20 are placed side by side, and the first cavity 21 of the MEMS chip 20 occupies part of the space in the thickness direction of the substrate 10. On this basis, the second cavity 31 provided by the ASIC chip 30 fully utilizes the space in the thickness direction of the same row of space, thereby improving space utilization. While not affecting the size of the packaging structure, the size of the back cavity 44 is further expanded, thereby improving the sensitivity of the MEMS chip 20.

[0033] In some embodiments, both the MEMS chip 20 and the ASIC chip 30 can be bonded to the surface of the substrate 10 by adhesive. The substrate 10 is a circuit board, and the ASIC chip 30 is electrically connected to the circuit within the substrate 10 via gold wires. The MEMS chip 20 is also electrically connected to the circuit of the ASIC chip 30 via gold wires.

[0034] In some embodiments, the packaging structure of the MEMS chip further includes a packaging shell 40, which is connected to a side surface of the substrate 10 and encloses the substrate 10 to form a receiving cavity 41. The MEMS chip 20 and the ASIC chip 30 are both located in the receiving cavity 41. There is a gap between the side wall of the packaging shell 40 facing away from the substrate 10 and the side surface of the MEMS chip 20 facing away from the substrate 10. There is also a gap between the side wall of the packaging shell 40 facing away from the substrate 10 and the side surface of the ASIC chip 30 facing away from the substrate 10. In some embodiments, in the thickness direction of the substrate 10, the distance X1 between the side surface of the ASIC chip 30 facing away from the substrate 10 and the side surface of the substrate 10 having the first groove 11 and the second groove 12 is less than or equal to the distance X2 between the side surface of the MEMS chip 20 facing away from the substrate 10 and the side surface of the substrate 10 having the first groove 11 and the second groove 12. In other words, in the thickness direction of the substrate 10, the space occupied by the ASIC is less than or equal to the space occupied by the MEMS chip 20.

[0035] The MEMS chip 20 and the ASIC chip 30 separate the accommodating cavity 41 into a front cavity 43 and a closed back cavity 44. The side wall of the packaging shell 40 facing away from the substrate 10 is provided with a sound hole 42 that passes through the side wall. The front cavity 43 is connected to the outside of the packaging shell 40 through the sound hole 42. The first cavity 21, the first groove 11, the second groove 12 and the second cavity 31 are connected to each other and together constitute the back cavity 44. In some embodiments, the first groove 11 and the second groove 12 are spaced apart on the surface of the substrate 10, and a through groove 13 is provided inside the partition structure between the first groove 11 and the second groove 12 (that is, the through groove 13 is located between the first groove 11 and the second groove 12). The first groove 11 and the second groove 12 are connected through the through groove 13. At this time, the first cavity 21, the first groove 11, the through groove 13, the second groove 12 and the second cavity 31 together constitute the closed back cavity 44 after the MEMS chip 20 is packaged. It should be noted that this application does not limit the groove depth of the first groove 11 and the second groove 12. Figure 1 The first groove 11 and the second groove 12 are for reference only.

[0036] In some embodiments, in the thickness direction of the substrate 10, the projection of the acoustic hole 42 on the substrate 10 and the projection of the MEMS chip 20 on the substrate 10 do not overlap. Separating the acoustic hole 42 from the MEMS chip 20 prevents the airflow from directly acting on the MEMS chip 20 after entering the front cavity 43 from the acoustic hole 42, thereby reducing the direct impact of the airflow on the diaphragm of the MEMS chip 20. At the same time, the acoustic hole 42 is directly open to the outside, which makes it easy for dust or other particulate matter to be introduced. By making the projections of the acoustic hole 42 and the MEMS chip 20 on the surface of the substrate 10 perpendicular to the thickness direction non-overlap, the direct deposition of contaminants on the surface of the MEMS chip 20 can be reduced, which helps to improve the reliability and long-term performance of the device.

[0037] The present application also discloses an electronic device including any of the above-disclosed MEMS chip packaging structures. For example, the electronic device may be an electronic component such as a microphone, or an electronic product such as a computer or a mobile phone.

[0038] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A packaging structure of a MEMS chip, characterized in that: include: A substrate (10), wherein a first groove (11) and a second groove (12) communicating with each other are formed on one side surface of the substrate (10); A MEMS chip (20), wherein the MEMS chip (20) has a first cavity (21); An ASIC chip (30), wherein the ASIC chip (30) has a second cavity (31); The MEMS chip (20) and the ASIC chip (30) are arranged side by side on a surface of a side of the substrate (10) on which a first groove (11) and a second groove (12) are provided, and the MEMS chip (20) and the ASIC chip (30) are electrically connected. The side of the MEMS chip (20) on which the first cavity (21) is provided is connected to the substrate (10) and covers the first groove (11), and the first cavity (21) is communicated with the first groove (11). The side of the ASIC chip (30) on which the second cavity (31) is provided is connected to the substrate (10) and covers the second groove (12), and the second cavity (31) is communicated with the second groove (12).

2. The MEMS chip packaging structure according to claim 1, characterized in that: The device further comprises a packaging shell (40), the packaging shell (40) being connected to a side surface of the substrate (10) and enclosing together with the substrate (10) to form a receiving cavity (41), wherein the MEMS chip (20) and the ASIC chip (30) are both located in the receiving cavity (41).

3. The packaging structure of the MEMS chip according to claim 2, characterized in that: A sound hole (42) penetrating the side wall of the packaging shell (40) facing away from the substrate (10) is provided.

4. The MEMS chip packaging structure according to claim 3, characterized in that: The MEMS chip (20) and the ASIC chip (30) separate the accommodating cavity (41) into a front cavity (43) communicating with the outside of the accommodating cavity (41) through a sound hole (42) and a closed back cavity (44); the first cavity (21), the first groove (11), the second groove (12), and the second cavity (31) together constitute the back cavity (44).

5. The MEMS chip packaging structure according to claim 4, characterized in that: On a surface of the substrate (10) perpendicular to the thickness direction, a projection of the acoustic hole (42) and a projection of the MEMS chip (20) do not overlap.

6. The MEMS chip packaging structure according to claim 1, wherein: The first groove (11) and the second groove (12) are spaced apart in the base plate (10); a through groove (13) is provided in the base plate (10); the through groove (13) is located between the first groove (11) and the second groove (12), and connects the first groove (11) and the second groove (12).

7. The MEMS chip packaging structure according to claim 1, wherein: In the thickness direction of the substrate (10), a distance X1 from a side surface of the ASIC chip (30) facing away from the substrate (10) to the surface of the substrate (10) is less than or equal to a distance X2 from a side surface of the MEMS chip (20) facing away from the substrate (10) to the substrate (10).

8. The MEMS chip packaging structure according to claim 1, characterized in that: The substrate (10) is a circuit board, the ASIC chip (30) is electrically connected to the circuit in the substrate (10) via a gold wire, and the MEMS chip (20) is electrically connected to the circuit of the ASIC chip (30) via a gold wire.

9. An electronic device, characterized in that: A packaging structure comprising a MEMS chip (20) as claimed in any one of claims 1 to 8.

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