Chip package structure and electronic device

Abstract

The application relates to a chip packaging structure and electronic equipment, wherein the chip packaging structure comprises a substrate, a first recess is formed in one side surface of the substrate; a MEMS chip comprises a substrate and a diaphragm, the diaphragm is fixed to one side surface of the substrate, a back cavity is formed in the side of the substrate away from the diaphragm, and the diaphragm covers the first recess on the side away from the substrate; a shell is connected with the substrate and surrounds the MEMS chip; and waterproof glue is filled in the back cavity through a first through hole and covers the surface of the diaphragm exposed in the back cavity. In the application, the front and back surfaces of the diaphragm are in an effective sealing state, the invasion of moisture, oil gas and other pollutants is blocked, and the reliability and long-term stability of the chip packaging in a high-humidity or harsh environment are remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of chip packaging, and more particularly to a chip packaging structure and electronic device. Background Technology

[0002] In the field of microelectromechanical systems (MEMS), packaging technology is crucial for ensuring chip performance and reliability. To prevent moisture intrusion, MEMS sensor chips are typically encapsulated by coating their surfaces with resin. This encapsulation method effectively prevents direct contact between moisture and the chip surface, ensuring normal operation under basic working conditions. However, these resin coatings typically do not provide complete waterproof protection, especially in high humidity or extreme environments, where sensors may still be affected by moisture intrusion, impacting their accuracy and reliability. Utility Model Content

[0003] This application provides a chip packaging structure and an electronic device, aiming to improve the waterproof performance of the chip packaging structure to enhance its accuracy and reliability.

[0004] To achieve the above objectives, according to a first aspect of this application, a chip packaging structure is provided, comprising: a substrate having a first groove formed on one side surface; A MEMS chip includes a substrate and a diaphragm. The diaphragm is fixed to one side surface of the substrate. A back cavity is formed on the side of the substrate away from the diaphragm. The side of the diaphragm away from the substrate covers the first groove. The housing is connected to the side surface of the substrate where the first groove is formed, surrounds the MEMS chip, and the housing has a first through hole that communicates with the back cavity; Waterproof adhesive is filled into the back cavity through the first through hole and covers the surface of the diaphragm exposed in the back cavity.

[0005] Optionally, it also includes a sealing ring located in the first groove, one end of which is connected to the bottom of the first groove, and the other end of which is connected to the side of the diaphragm away from the substrate.

[0006] Optionally, the housing is a molded housing, which covers one side surface of the substrate where the first groove is formed and encloses the outer periphery of the MEMS chip, with the back cavity of the MEMS chip exposed at the first through hole.

[0007] Optionally, it also includes: An ASIC chip is located on the side surface of the substrate where the first groove is formed, and the molded housing encloses the ASIC chip. Optionally, the housing and the substrate together form a receiving cavity, the first through hole is connected to the receiving cavity, the MEMS chip is located in the receiving cavity, and the waterproof adhesive seals the first through hole.

[0008] Optionally, it further includes: an ASIC chip located on the side surface of the substrate where the first groove is formed, and located within the accommodating cavity.

[0009] Optionally, a bonding pad is provided between the MEMS chip and the substrate, the MEMS chip is electrically connected to the substrate through the bonding pad, the ASIC chip is electrically connected to the substrate through a lead, and the MEMS chip is electrically connected to the ASIC chip through the substrate.

[0010] Optionally, a second through hole is provided on the side of the substrate away from the housing, and the second through hole is connected to the first groove; The waterproof adhesive is also filled into the first groove through the second through hole and covers the surface of the diaphragm exposed in the first groove.

[0011] Optionally, the waterproof adhesive is an elastic material. According to a second aspect of this application, an electronic device is provided, comprising a chip packaging structure as described in any of the above disclosures.

[0012] In the chip packaging structure of this application embodiment, the side of the MEMS chip's diaphragm facing away from the substrate is covered by a first groove, forming a closed structure with the first groove in this area. This design not only provides sufficient deformation space for the diaphragm, allowing it to undergo minor deformations according to changes in the external environment, but also effectively seals the chip's diaphragm, preventing external contaminants or moisture from negatively impacting the MEMS chip. Furthermore, the side of the MEMS chip's diaphragm facing away from the substrate is exposed in the back cavity. In this application embodiment, the back cavity of the MEMS chip is filled with waterproof adhesive, effectively sealing and protecting the back cavity and the surface of the diaphragm exposed in the back cavity. This prevents the intrusion of moisture, oil, and other external contaminants, improving the reliability and long-term stability of the chip's packaging structure in high humidity or harsh environments.

[0013] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0015] Figure 1 This is a schematic diagram of a chip packaging structure disclosed in an embodiment of this application; Figure 2 This is a schematic diagram of another chip packaging structure disclosed in the embodiments of this application; Figure 3 This is a schematic diagram of another chip packaging structure disclosed in an embodiment of this application.

[0016] Figure 4 This is a schematic diagram of another chip packaging structure disclosed in the embodiments of this application.

[0017] Figure 5 This is a schematic diagram of another chip packaging structure disclosed in the embodiments of this application.

[0018] Explanation of reference numerals in the attached figures: 1. Substrate; 11. First groove; 12. Second through hole; 2. MEMS chip; 21. Substrate; 211. Back cavity; 22. Diaphragm; 3. Shell; 31. First through hole; 4. Waterproof adhesive; 5. Sealing ring; 6. ASIC chip; 7. Receptacle cavity; 8. Solder pads; 9. Lead wire. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0020] As described in the background section, in the field of microelectromechanical systems (MEMS), packaging technology is crucial for ensuring chip performance and reliability. To prevent moisture intrusion, MEMS sensor chips are typically encapsulated by coating the surface with resin. This encapsulation method effectively prevents direct contact between moisture and the chip surface, ensuring normal operation under basic working conditions. However, such resin coatings typically do not provide complete waterproof protection, especially in high humidity or extreme environments, where sensors may still be affected by moisture intrusion, impacting their accuracy and reliability.

[0021] Therefore, in order to improve the waterproof performance of the chip packaging structure and thus enhance its accuracy and reliability, this application discloses a chip packaging structure.

[0022] Reference Figure 1 The packaging structure disclosed in Embodiment 1 of this application includes: a substrate 1, a MEMS chip 2, a housing 3, and a waterproof adhesive 4. A first groove 11 is formed on one side surface of the substrate 1. The MEMS chip 2 includes a substrate 21 and a diaphragm 22. The diaphragm 22 is fixed to one side surface of the substrate 21. A back cavity 211 is formed on the side of the substrate 21 opposite to the diaphragm 22, and the side of the diaphragm 22 opposite to the substrate 21 covers the first groove 11. The housing 3 is connected to the side surface of the substrate 1 with the first groove 11 and surrounds the MEMS chip 2. A first through-hole 31 is formed on the housing 3, and the first through-hole 31 communicates with the back cavity 211. The waterproof adhesive 4 fills the back cavity 211 through the first through-hole 31 and covers the surface of the diaphragm 22 exposed in the back cavity 211.

[0023] Specifically, in Embodiment 1, the housing 3 is fixedly connected to the substrate 1 by welding or bonding, and together with the substrate 1, they enclose a receiving cavity 7. The first through hole 31 is connected to the receiving cavity 7, the MEMS chip 2 is located inside the receiving cavity 7, and the waterproof adhesive 4 seals the first through hole 31.

[0024] In Embodiment 1 of this application, the side of the diaphragm 22 of the MEMS chip 2 facing away from the substrate 21 is covered by a first groove 11, forming a closed structure with the first groove 11 in this area. This design not only provides sufficient deformation space for the diaphragm 22, allowing it to undergo minor deformations according to changes in the external environment, but also prevents external contaminants or moisture from negatively impacting the MEMS chip 2. Furthermore, the MEMS chip 2 is disposed in the accommodating cavity 7. In Embodiment 1 of this application, the back cavity 211 of the MEMS chip 2 is filled with waterproof adhesive 4, while simultaneously sealing the first through-hole 31. This design not only effectively seals and protects the back cavity 211 of the MEMS chip 2 and the surface of the diaphragm 22 exposed within the back cavity 211, preventing the intrusion of moisture, oil, and other external contaminants, but also seals the accommodating cavity 7, placing the MEMS chip 2 in a sealed space, further improving the reliability and long-term stability of the chip's packaging structure in high humidity or harsh environments.

[0025] In some embodiments, the packaging structure of the MEMS chip further includes a sealing ring 5. The sealing ring 5 is located in the first groove 11, with one end connected to the bottom of the first groove 11 and the other end connected to the side of the diaphragm 22 opposite to the substrate 21.

[0026] Specifically, the outer peripheral wall of the sealing ring 5 is fitted with the inner sidewall of the first groove 11, and its two ends are respectively connected to the bottom of the first groove 11 and the side of the diaphragm 22 away from the substrate 21. With this design, the diaphragm 22, the sealing ring 5 and the first groove 11 together form a sealed space. This sealed space effectively isolates the diaphragm 22 of the MEMS chip 2 from the external environment, further improving the reliability and long-term stability of the chip's packaging structure in high humidity or harsh environments.

[0027] In some embodiments, the end of the sealing ring 5 facing away from the first groove 11 protrudes from the surface of the substrate 1, so that a gap is formed between the side of the diaphragm 22 facing away from the substrate 21 and the substrate 1, so as to effectively prevent moisture, oil or other contaminants from entering the first groove 11 from the gap between the MEMS chip 2 and the substrate 1 and depositing on the diaphragm 22 of the MEMS chip 2.

[0028] In some embodiments, the sealing ring 5 is made of silicone pad or fluororubber.

[0029] In some embodiments, the MEMS chip packaging structure further includes an ASIC chip 6. The ASIC chip 6 is located on the side surface of the substrate 1 where the first groove 11 is formed, and is situated within the accommodating cavity 7, and is electrically connected to the MEMS chip 2. Specifically, the ASIC chip 6 can be fixed to the substrate 1 using an adhesive material, such as silver paste or epoxy resin, and is electrically connected to the substrate 1 via gold wires. To further improve the waterproof performance of the chip packaging structure, a waterproof adhesive 4 can also be used to encapsulate the ASIC chip 6 and the gold wires.

[0030] It should be noted that, in this embodiment, the substrate 1 can be a PCB circuit board, and both the ASIC chip 6 and the MEMS chip 2 are electrically connected to the substrate 1. Specifically, the ASIC chip 6 is electrically connected to the substrate 1 via leads 9, and the MEMS chip 2 is electrically connected to the substrate 1 via pads 8. The ASIC chip 6 and the MEMS chip 2 are electrically connected through interlayer circuitry in the substrate 1. This configuration shortens the signal transmission distance between the MEMS chip 2 and the ASIC chip 6, effectively reducing signal loss and power consumption.

[0031] In some embodiments, the waterproof adhesive 4 is an elastic material; specifically, it can be silicone or fluoropolymer. The elasticity of the waterproof adhesive 4 ensures that, after sealing the back cavity 211, it does not adversely affect the free vibration of the diaphragm 22. Due to the elasticity of the waterproof adhesive 4, it can adapt to the minute deformations or vibrations that occur in the diaphragm 22 during operation without hindering the diaphragm 22 from responding normally to changes in external pressure. This ensures the high accuracy and sensitivity of the sensor.

[0032] Reference Figure 2 , Figure 2 This is the second embodiment disclosed in this application. Embodiment two protects a chip packaging structure. Unlike embodiment one, a second through hole 12 is provided on the side of the substrate 1 away from the housing 3. The second through hole 12 is connected to the first groove 11. In this embodiment, waterproof adhesive 4 is filled into the first groove 11 through the second through hole 12 and covers the surface of the diaphragm 22 exposed in the first groove 11.

[0033] In this embodiment, the waterproof adhesive 4 not only fills the back cavity 211 and the first through hole 31, but also fills the first groove 11 through the second through hole 12, covering the surface of the diaphragm 22 exposed in the first groove 11. Both sides of the diaphragm 22 are covered with the elastic waterproof adhesive 4, whether from the housing 3 side or the substrate 1 side, greatly enhancing the waterproof, dustproof, and corrosion-resistant protection capabilities of the diaphragm 22.

[0034] In practical applications, the accommodating cavity 7 inside the housing 3 is connected to the system under test through the first through hole 31 and bears the pressure to be measured; the first groove 11 is connected to the outside or a preset reference channel (which can be designed as atmospheric pressure or other reference pressure source) through the second through hole 12; the diaphragm 22 forms a pressure chamber under test and a reference pressure chamber on both sides of the substrate 1 in the thickness direction, and the two act on the two sides of the diaphragm 22 to generate differential pressure, which constitutes a differential pressure sensing unit, improving the accuracy, stability and environmental adaptability of the sensor.

[0035] Reference Figure 3 , Figure 3This is the third embodiment disclosed in this application. The third embodiment protects a chip packaging structure. Unlike the first embodiment, the housing 3 is a molded housing. The housing 3 covers one side surface of the substrate 1 where the first groove 11 is opened and covers the outer periphery of the MEMS chip 2. The back cavity 211 of the MEMS chip 2 is exposed at the first through hole 31.

[0036] Specifically, in Embodiment 3, the housing 3 is not connected to the substrate 1 by adhesive or welding, but rather plastic material is molded onto the outer periphery of the substrate 1 and the MEMS chip 2 to form an integrated molded housing.

[0037] Furthermore, the first through hole 31 on the housing 3 can be formed by pre-installing a metal mandrel with a diameter, position, and shape matching the first through hole 31 inside the cavity of the injection mold. During injection molding, molten plastic flows into the cavity under high temperature and pressure, and the plastic solidifies around the mandrel. After the mold is opened, the molded part is removed, and the mandrel is removed from the housing 3, thus forming the first through hole 31 on the housing 3.

[0038] In Embodiment 3, the ASIC chip 6 is located on the side surface of the substrate 1 where the first groove 11 is formed, and is electrically connected to the MEMS chip 2. A molded housing encloses the ASIC chip 6. Specifically, a pad 8 is provided between the MEMS chip 2 and the substrate 1. The MEMS chip 2 is electrically connected to the substrate 1 through the pad 8, and the ASIC chip 6 is electrically connected to the substrate 1 through a lead 9. The MEMS chip 2 is electrically connected to the ASIC chip 6 through the substrate 1. Through the above-mentioned electrical connection method, the signal transmission path between the MEMS chip 2 and the ASIC chip 6 is significantly shortened, which can effectively reduce parasitic parameters and transmission losses during signal transmission, reduce signal delay, and reduce overall power consumption, thereby improving signal integrity and the electrical performance stability of the device.

[0039] In other embodiments, reference is made to Figure 4 Similar to Embodiment 3, the housing 3 is a molded housing, covering the side surface of the substrate 1 where the first groove 11 is formed and enclosing the outer periphery of the MEMS chip 2. Waterproof adhesive 4 is applied to both the diaphragm 22 and the back cavity 211 of the MEMS chip 2. Unlike Embodiment 3, the substrate 21 of the MEMS chip 2 is fixedly connected to the substrate 1, the back cavity 211 faces the substrate 1, and the diaphragm 22 faces the first through-hole 31. The MEMS chip 2 is directly electrically connected to the ASIC chip 6 via leads 9. It should be noted that... Figure 4 In one specific embodiment shown, a second through hole 12 is provided on the substrate 1, and the back cavity 211 is connected to the second through hole 12. In some other embodiments, the second through hole 12 is not provided on the substrate 1, and the back cavity 211 is in an absolute pressure environment.

[0040] Reference Figure 5 , Figure 5 This is the fourth embodiment disclosed in this application. The fourth embodiment protects a chip packaging structure. Unlike the third embodiment, the substrate 1 has a second through hole 12 on the side away from the housing 3. The second through hole 12 is connected to the first groove 11. The waterproof adhesive 4 is also filled into the first groove 11 through the second through hole 12 and covers the surface of the diaphragm 22 exposed in the first groove 11.

[0041] In this embodiment, the waterproof adhesive 4 not only fills the back cavity 211, but also fills the first groove 11 through the second through hole 12, covering the exposed area of ​​the diaphragm 22 facing away from the substrate 21 in the first groove 11. Whether from the housing 3 side or the substrate 1 side, both sides of the diaphragm 22 are covered with the elastic waterproof adhesive 4, greatly enhancing the waterproof, dustproof, and corrosion-resistant protection capabilities of the diaphragm 22.

[0042] In practical applications, the diaphragm 22 is located on the side facing away from the substrate 1, with the first through hole 31 connected to the system under test and bearing the pressure to be measured. The diaphragm 22 is located on the side facing the substrate 1, with the first groove 11 and the second through hole 12 connected to the outside world or a preset reference channel (which can be designed as atmospheric pressure or other reference pressure sources). The diaphragm 22 forms a pressure chamber to be measured and a reference pressure chamber on both sides of the substrate 1 in the thickness direction. The two chambers act on the two sides of the diaphragm 22 to generate a differential pressure, which constitutes a differential pressure sensing unit, improving the accuracy, stability and environmental adaptability of the sensor.

[0043] This application also discloses an electronic device, which includes a package structure of a chip comprising any one of the above-mentioned components.

[0044] It should be noted that in the accompanying drawings of this application, arrows are used to indicate virtual structures (such as back cavity 211, first through hole 31, etc.), and solid dots are used to represent physical structures (such as substrate 1, MEMS chip 2, etc.).

[0045] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0046] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0047] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0048] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A chip packaging structure, characterized in that, include: The substrate (1) has a first groove (11) formed on one side surface; MEMS chip (2) includes a substrate (21) and a diaphragm (22). The diaphragm (22) is fixed to one side surface of the substrate (21). A back cavity (211) is formed on the side of the substrate (21) away from the diaphragm (22). The side of the diaphragm (22) away from the substrate (21) covers the first groove (11). The housing (3) is connected to the side surface of the substrate (1) where the first groove (11) is provided, surrounds the MEMS chip (2), and the housing (3) is provided with a first through hole (31), which is connected to the back cavity (211); Waterproof adhesive (4) is filled into the back cavity (211) through the first through hole (31) and covers the surface of the diaphragm (22) exposed in the back cavity (211).

2. The chip packaging structure according to claim 1, characterized in that, It also includes a sealing ring (5), which is located in the first groove (11), with one end connected to the bottom of the first groove (11) and the other end connected to the side of the diaphragm (22) away from the substrate (21).

3. The chip packaging structure according to claim 1, characterized in that, The housing (3) is a molded housing. The housing (3) covers one side surface of the substrate (1) where the first groove (11) is provided and covers the outer periphery of the MEMS chip (2). The back cavity (211) of the MEMS chip (2) is exposed at the first through hole (31).

4. The chip packaging structure according to claim 3, characterized in that, Also includes: An ASIC chip (6) is located on one side surface of the substrate (1) where the first groove (11) is formed, and the molded housing encloses the ASIC chip (6).

5. The chip packaging structure according to claim 1, characterized in that, The housing (3) and the substrate (1) together form a cavity (7), the first through hole (31) is connected to the cavity (7), the MEMS chip (2) is located in the cavity (7), and the waterproof adhesive (4) seals the first through hole (31).

6. The chip packaging structure according to claim 5, characterized in that, Also includes: An ASIC chip (6) is located on one side surface of the substrate (1) where the first groove (11) is formed, and is located in the accommodating cavity (7).

7. The chip packaging structure according to claim 4 or 6, characterized in that, A pad (8) is provided between the MEMS chip (2) and the substrate (1). The MEMS chip (2) is electrically connected to the substrate (1) through the pad (8). The ASIC chip (6) is electrically connected to the substrate (1) through the lead (9). The MEMS chip (2) is electrically connected to the ASIC chip (6) through the substrate (1).

8. The chip packaging structure according to claim 1, characterized in that, The substrate (1) has a second through hole (12) on the side away from the housing (3), and the second through hole (12) is connected to the first groove (11); The waterproof adhesive (4) is also filled into the first groove (11) through the second through hole (12) and covers the surface of the diaphragm (22) exposed in the first groove (11).

9. The chip packaging structure according to any one of claims 1 to 6, characterized in that, The waterproof adhesive (4) is made of an elastic material.

10. An electronic device, characterized in that, The packaging structure includes the chip as described in any one of claims 1 to 9.

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