A highly integrated MEMS sensor package structure and a packaging method thereof

Abstract

The application discloses a highly integrated MEMS sensor packaging structure and a packaging method thereof, and the packaging structure comprises a cavity surrounded by several substrates, several chips and / or electronic components are arranged in the cavity, and a gas hole is arranged on the cavity, and the air pressure inside and outside the cavity is the same. In the application, the packaging structure is obtained by adopting a three-layer substrate pressing process, and flip chip mounting of the FCCSP chip is performed in the packaging structure, so that the functions of the MEMS sensor chip are realized, the FCCSP chip can also be used as a control chip, the area of the packaging structure is effectively reduced, and the cost is reduced; the gas hole on the packaging structure can meet the functional requirements of the MEMS sensor such as acoustics and air pressure, can reduce the collision of the FCCSP chip in reflow soldering, and the air pressure inside and outside the packaging structure is balanced due to the existence of the gas hole, so that the reliability and high heat dissipation requirements are met; the structure of the application is highly integrated and small in size, and provides a new idea for the development of the MEMS sensor.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor packaging technology, specifically relating to a highly integrated MEMS sensor packaging structure and its packaging method. Background Technology

[0002] The government's investment in and support for the core component industry, such as sensors, is becoming increasingly evident. my country has reached a critical juncture in its pursuit of self-sufficiency in core components like chips. MEMS sensors, as a next-generation semiconductor product and a replacement for traditional sensors, will undoubtedly become a fiercely contested industrial high ground among major powers.

[0003] The development of MEMS sensors has been slow due to Moore's Law, and product functions are trending towards high integration and miniaturization. Therefore, they are becoming increasingly reliant on packaging technology. New packaging technologies demand lighter, thinner, smaller, higher-density, higher-speed, and lower-cost designs, evolving from 2D to 3D development. Therefore, this invention proposes a highly integrated MEMS sensor packaging structure and its packaging method. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention aims to provide a highly integrated MEMS sensor packaging structure and packaging method thereof.

[0005] To achieve the above objectives and technical effects, the technical solution adopted by this invention is as follows:

[0006] A highly integrated MEMS sensor packaging structure includes a cavity surrounded by several substrates, in which several chips and / or electronic components are integrated. The types of chips may be the same or different. Several air holes are opened on the cavity, and the air pressure inside and outside the cavity is the same.

[0007] Furthermore, the cavity is formed by a first substrate, a second substrate, and a third substrate, with the first substrate and the third substrate facing each other and connected to each other through the second substrate.

[0008] Furthermore, the cavity is a square structure formed by a first substrate, two second substrates and a third substrate. The second substrates are symmetrically arranged at opposite ends of the first substrate, and the first substrate and the third substrate face to face and have the same length.

[0009] Furthermore, chips are respectively disposed on the first substrate and the third substrate, the first substrate and the chips thereon are interconnected, and a plurality of air holes are formed on the second substrate or the third substrate.

[0010] Furthermore, electronic components, MEMS chips, and ASIC chips are disposed within the cavity and on the first substrate. The MEMS chips and ASIC chips are interconnected with the first substrate. Several FCCSP chips are disposed within the cavity and on the third substrate.

[0011] Furthermore, a MEMS chip and an ASIC chip are respectively glued onto the first substrate.

[0012] Furthermore, the MEMS chip is bonded to the first substrate using low-stress silicone, and the ASIC chip is bonded to the first substrate using insulating adhesive or DAF.

[0013] Furthermore, two FCCSP chips are disposed on the side of the third substrate facing the cavity, and a high-temperature resistant adhesive film is attached to the side of the third substrate facing away from the FCCSP chips. The high-temperature resistant adhesive film is removed before the third substrate is pressed onto the first substrate.

[0014] This invention also discloses a highly integrated MEMS sensor packaging method, comprising the following steps:

[0015] 1) Prepare the first substrate, the second substrate, and the third substrate;

[0016] 2) Attach electronic components to the first substrate and attach the second substrate to its opposite ends respectively. Then attach several chips of the same or different types to the surface of the first substrate. The chips and electronic components on the first substrate are located on the same side of the first substrate. Then wire bonding is performed to make the first substrate interconnected with the chips on it.

[0017] 3) Flip-chip mounting of FCCSP chips is performed on the front side of the third substrate. A high-temperature resistant adhesive film can be applied to the back side of the third substrate, which needs to be removed later, or it can be left unapplied. Then, adhesive is applied to the FCCSP chips to enhance their soldering strength. Next, adhesive or solder paste is applied around the third substrate, while the high-temperature resistant adhesive film on the back side of the third substrate is removed.

[0018] 4) The substrate obtained in step 3) is flipped onto the substrate obtained in step 2) to form a three-layer substrate lamination structure with a cavity. This structure is the required packaging structure and has several air holes.

[0019] 5) Print and cut the product to form individual finished pieces;

[0020] Steps 2 and 3 are not in any particular order.

[0021] Furthermore, in step 2), a MEMS chip and an ASIC chip are mounted on the first substrate, and the MEMS chip and the ASIC chip are interconnected with the first substrate.

[0022] The highly integrated MEMS sensor packaging method of the present invention specifically includes the following steps:

[0023] Step 1: First, prepare the first substrate and make a stencil. Then, print solder paste on the surface of the first substrate using stencil printing.

[0024] Step 2: Prepare the second substrate. First, mount the electronic components on the surface of the first substrate using SMT surface mount technology. Then, use general substrate lamination technology to bond the second substrate to the first substrate through reflow soldering.

[0025] Step 3: Mount the MEMS chip and ASIC chip onto the surface of the first substrate using adhesive. The electronic components, MEMS chip, and ASIC chip are mounted on the same side of the first substrate. Low-stress silicone is preferably used for bonding the MEMS chip, and insulating adhesive or DAF is preferably used for bonding the ASIC chip.

[0026] Step 4: Perform wire bonding to interconnect the MEMS chip and ASIC chip with the first substrate through gold wires;

[0027] Step 5: Prepare the third substrate;

[0028] Step 6: Perform flip-chip mounting of the FCCSP chip on the front side of the third substrate;

[0029] Step 7: Apply underfill adhesive to the FCCSP chip to enhance its soldering strength, ultimately allowing the FCCSP chip to be mounted on the front side of the third substrate using the underfill adhesive;

[0030] Step 8: Apply adhesive or solder paste around the third substrate, and at the same time peel off the high-temperature resistant adhesive film on the back of the third substrate.

[0031] Step 9: The substrate obtained in Step 8 is attached to the substrate obtained in Step 4 using a substrate lamination technique to form a three-layer substrate lamination structure with pores.

[0032] Step 10: Print the lettering and cut the piece to form a single finished product.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1) This invention discloses a highly integrated MEMS sensor packaging structure and packaging method. In this packaging method, a three-layer substrate lamination process is used to obtain a three-layer substrate lamination structure with a cavity. There is no need to set a metal cover or similar structure. The FCCSP chip is flip-chip mounted on the top third substrate. This can realize the function of MEMS sensor chip. At the same time, the FCCSP chip can also be used as a control chip. When the FCCSP chip needs to have high heat dissipation requirements, heat dissipation is carried out through air holes, which can prevent the chip from burning out due to excessive temperature.

[0035] 2) This invention integrates the FCCSP chip inside the packaging structure, effectively reducing the area of ​​the packaging structure and the space occupancy rate, and significantly reducing costs without affecting normal use;

[0036] 3) The vents in the packaging structure of this invention allow sound and gas to enter and exit, which can meet the functional requirements of MEMS sensors such as acoustics and air pressure, and at the same time reduce the impact on the FCCSP chip during reflow soldering, avoiding cracks or breaks. The presence of vents ensures that the air pressure inside and outside the packaging structure is balanced, with no pressure difference, thus meeting reliability requirements. The location of the vents can be selected according to actual needs. In this invention, the vents are preferably located on the second substrate, that is, the sidewall of the packaging structure, with at least two vents. Both the first and third substrates can be used as soldering surfaces when mounting the PCB module at the back end, which is convenient for end customers to choose flexibly. Increasing the number of vents helps to accelerate the gas flow inside and outside the packaging structure, and can also reduce the risk of the substrate bursting during soldering and reflow soldering.

[0037] 4) The packaging structure of this invention is a highly integrated design with a tendency towards miniaturization, providing new ideas for the future development of MEMS sensors. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure in the first step of a highly integrated MEMS sensor packaging method according to the present invention;

[0039] Figure 2 This is a schematic diagram of the structure in the second step of a highly integrated MEMS sensor packaging method according to the present invention;

[0040] Figure 3 This is a schematic diagram of the structure in step 3 of a highly integrated MEMS sensor packaging method according to the present invention;

[0041] Figure 4 This is a schematic diagram of the structure in step 4 of a highly integrated MEMS sensor packaging method according to the present invention;

[0042] Figure 5This is a schematic diagram of the structure in step 5 of a highly integrated MEMS sensor packaging method according to the present invention;

[0043] Figure 6 This is a schematic diagram of the structure in step 6 of a highly integrated MEMS sensor packaging method according to the present invention;

[0044] Figure 7 This is a schematic diagram of the structure in step 7 of a highly integrated MEMS sensor packaging method according to the present invention;

[0045] Figure 8 This is a schematic diagram of the structure in step 8 of a highly integrated MEMS sensor packaging method according to the present invention;

[0046] Figure 9 This is a schematic diagram of the structure in step 9 of a highly integrated MEMS sensor packaging method according to Embodiment 1 of the present invention;

[0047] Figure 10 This is a schematic diagram of the structure in step 9 of a highly integrated MEMS sensor packaging method according to Embodiment 2 of the present invention. Detailed Implementation

[0048] The present invention will now be described in detail so that its advantages and features can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0049] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0050] like Figure 1-10 As shown, a highly integrated MEMS sensor packaging structure includes a cavity surrounded by several substrates. Several chips and / or electronic components 4 are integrated in the cavity. The types of chips can be the same or different. Several air holes 11 are provided on the cavity. By setting the air holes 11, sound, gas, etc. can enter and exit, and the air pressure inside and outside the cavity can be the same without pressure difference. It can also play a role in heat dissipation. The air holes 11 can be set on the top or side wall of the cavity according to actual needs.

[0051] As one embodiment of the present invention, the highly integrated MEMS sensor packaging structure includes a cavity surrounded by a first substrate 1, a second substrate 3 and a third substrate 7. Electronic components 4 and several chips of the same or different types are disposed in the cavity and on the first substrate 1. Preferably, electronic components 4, MEMS chips 5 and ASIC chips 6 are disposed on the first substrate 1. Several FCCSP chips 9 are disposed in the cavity and on the third substrate 7. Several air holes 11 are opened in the cavity. Preferably, several air holes 11 are opened on the second substrate 3 or the third substrate 7 so that the air pressure inside and outside the cavity is the same and there is no pressure difference.

[0052] A highly integrated MEMS sensor packaging method includes the following steps:

[0053] 1) Prepare the first substrate 1, the second substrate 3, and the third substrate 7;

[0054] 2) Electronic components 4 are mounted on the first substrate 1 and second substrates 3 are attached to their opposite ends respectively. Then, several chips of the same or different types are mounted on the surface of the first substrate 1. The chips and electronic components 4 on the first substrate 1 are located on the same side of the first substrate 1. Then, wire bonding is performed to make the first substrate 1 interconnected with the chips on it.

[0055] 3) Flip-chip mounting of FCCSP chip 9 is performed on the front side of the third substrate 7. A high-temperature resistant adhesive film 8 can be applied to the back side of the third substrate 7 according to actual needs, or the high-temperature resistant adhesive film 8 can be omitted. Then, adhesive is applied to FCCSP chip 9 to enhance the soldering strength of FCCSP chip 9. Then adhesive or solder paste is applied around the third substrate 7, and the high-temperature resistant adhesive film 8 on the back side of the third substrate 7 is peeled off.

[0056] 4) The substrate obtained in step 3) is inverted onto the substrate obtained in step 2) to form a three-layer substrate lamination structure with a cavity. This structure is the required encapsulation structure, which has several vents 11, such as... Figure 9 or Figure 10 As shown;

[0057] 5) Print and cut the product to form individual finished pieces;

[0058] Steps 2 and 3 are not in any particular order.

[0059] Example 1

[0060] like Figure 1-9As shown, a highly integrated MEMS sensor packaging structure includes a first substrate 1, two second substrates 3, and a third substrate 7. The first substrate 1, the second substrates 3, and the third substrate 7 form a square cavity. Electronic components 4, MEMS chips 5, and ASIC chips 6 are disposed in the cavity and on the first substrate 1. Several FCCSP chips 9 are disposed in the cavity and on the third substrate 7. An air hole 11 is opened on the third substrate 7 to make the air pressure inside and outside the cavity the same and without pressure difference.

[0061] A highly integrated MEMS sensor packaging method includes the following steps:

[0062] Step 1: As Figure 1 First, prepare the first substrate 1, make a stencil, and print solder paste 2 on the surface of the first substrate 1 by stencil printing.

[0063] Step 2: As Figure 2 Prepare the second substrate 3. First, the electronic components 4 are mounted on the surface of the first substrate 1 by SMT surface mounting. Then, the second substrate 3 is bonded to the first substrate 1 by reflow soldering using general substrate lamination technology.

[0064] Step 3: As Figure 3 The MEMS chip 5 and ASIC chip 6 are mounted on the surface of the first substrate 1 using adhesive. The electronic component 4, MEMS chip 5, and ASIC chip 6 are mounted on the same side of the first substrate 1. The MEMS chip 5 is preferably bonded using low-stress silicone adhesive, and the ASIC chip 6 is preferably bonded using insulating adhesive or DAF.

[0065] Step 4: As Figure 4 Wire bonding is performed so that both MEMS chip 5 and ASIC chip 6 are interconnected with the first substrate 1 via gold wire 1-1;

[0066] Step 5: As Figure 5 Prepare a third substrate 7. The third substrate 7 has an air hole 11 on one side. A high-temperature resistant adhesive film 8 is attached to the back of the third substrate 7. Its function is to allow the third substrate 7 to be vacuum adsorbed on the platform of the equipment.

[0067] Step 6: As Figure 6 FCCSP chip 9 is flip-chip mounted on the front side of the third substrate 7;

[0068] Step 7: As Figure 7 Underfill adhesive is applied to the FCCSP chip 9 to enhance its soldering strength, ultimately allowing the FCCSP chip 9 to be mounted on the front side of the third substrate 7 via the underfill adhesive 10.

[0069] Step 8: As Figure 8Apply adhesive or solder paste around the third substrate 7, and at the same time peel off the high-temperature resistant adhesive film 8 on the back of the third substrate 7.

[0070] Step 9: The substrate obtained in Step 8 is laminated onto the substrate obtained in Step 4 using a substrate lamination technique, forming a three-layer substrate lamination structure, such as... Figure 9 As shown;

[0071] Step 10: Print the lettering and cut the piece to form a single finished product.

[0072] Example 2

[0073] like Figure 1-4 and Figure 10 As shown, a highly integrated MEMS sensor packaging structure includes a first substrate 1, two second substrates 3, and a third substrate 7. The first substrate 1, the second substrates 3, and the third substrate 7 form a square cavity. Electronic components 4, MEMS chips 5, and ASIC chips 6 are disposed in the cavity and on the first substrate 1. Several FCCSP chips 9 are disposed in the cavity and on the third substrate 7. Air holes 11 are symmetrically opened on the two second substrates 3 located on both sides of the first substrate 1, so that the air pressure inside and outside the cavity is the same and there is no pressure difference.

[0074] A highly integrated MEMS sensor packaging method includes the following steps:

[0075] Step 1: As Figure 1 First, prepare the first substrate 1, make a stencil, and print solder paste 2 on the surface of the first substrate 1 by stencil printing.

[0076] Step 2: As Figure 2 Prepare a second substrate 3. Two second substrates 3 are symmetrically provided with air holes 11. First, electronic components 4 are mounted on the surface of the first substrate 1 by SMT surface mounting. Then, the second substrate 3 is bonded to the first substrate 1 by reflow soldering using general substrate lamination technology.

[0077] Step 3: As Figure 3 The MEMS chip 5 and ASIC chip 6 are mounted on the surface of the first substrate 1 using adhesive. The electronic component 4, MEMS chip 5, and ASIC chip 6 are mounted on the same side of the first substrate 1. The MEMS chip 5 is preferably bonded using low-stress silicone adhesive, and the ASIC chip 6 is preferably bonded using insulating adhesive or DAF.

[0078] Step 4: As Figure 4 Wire bonding is performed so that both MEMS chip 5 and ASIC chip 6 are interconnected with the first substrate 1 via gold wire 1-1;

[0079] Step 5: Prepare the third substrate 7. In this embodiment, the back of the third substrate 7 does not need to be covered with a high-temperature resistant adhesive film 8.

[0080] Step 6: Perform flip-chip mounting of FCCSP chip 9 on the front side of the third substrate 7;

[0081] Step 7: Apply underfill adhesive to the FCCSP chip 9 to enhance its soldering strength, ultimately allowing the FCCSP chip 9 to be mounted on the front side of the third substrate 7 via the underfill adhesive 10;

[0082] Step 8: Apply adhesive or solder paste around the perimeter of the third substrate 7;

[0083] Step 9: The substrate obtained in Step 8 is laminated onto the substrate obtained in Step 4 using a substrate lamination technique, forming a three-layer substrate lamination structure, such as... Figure 10 As shown;

[0084] Step 10: Print the lettering and cut the piece to form a single finished product.

[0085] Same as Example 1.

[0086] Any parts or structures not specifically described in this invention can be made using existing technologies or products, and will not be elaborated upon here.

[0087] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A highly integrated MEMS sensor packaging method, characterized by, The highly integrated MEMS sensor packaging structure includes a cavity surrounded by several substrates, in which several chips and / or electronic components are integrated. The types of chips may be the same or different. Several air holes are opened on the cavity, and the air pressure inside and outside the cavity is the same. The cavity is formed by a first substrate, a second substrate, and a third substrate, wherein the first substrate and the third substrate face to face and are connected by the second substrate. The cavity is a square structure formed by a first substrate, two second substrates and a third substrate. The second substrates are symmetrically arranged at opposite ends of the first substrate. The first substrate and the third substrate face to face and have the same length. Chips are respectively disposed on the first substrate and the third substrate, and the first substrate is interconnected with the chips thereon. A plurality of air holes are formed on the second substrate or the third substrate. Electronic components, MEMS chips, and ASIC chips are disposed within the cavity and on the first substrate. The MEMS chips and ASIC chips are interconnected with the first substrate. Several FCCSP chips are disposed within the cavity and on the third substrate. A MEMS chip and an ASIC chip are respectively glued onto the first substrate; The MEMS chip is bonded to the first substrate using low-stress silicone, and the ASIC chip is bonded to the first substrate using insulating adhesive or DAF. Two FCCSP chips are disposed on the side of the third substrate facing the cavity, and a high-temperature resistant adhesive film is attached to the side of the third substrate facing away from the FCCSP chips. The high-temperature resistant adhesive film is removed before the third substrate is pressed onto the first substrate. The packaging method includes the following steps: 1) Prepare the first substrate, the second substrate, and the third substrate; 2) Attach electronic components to the first substrate and attach the second substrate to its opposite ends respectively. Then attach several chips of the same or different types to the surface of the first substrate. The chips and electronic components on the first substrate are located on the same side of the first substrate. Then wire bonding is performed to make the first substrate interconnected with the chips on it. 3) Flip-chip mounting of the FCCSP chip is performed on the front side of the third substrate; then, adhesive is applied to the FCCSP chip to enhance its soldering strength; adhesive or solder paste is then applied around the perimeter of the third substrate. 4) The substrate obtained in step 3) is flipped onto the substrate obtained in step 2) to form a three-layer substrate lamination structure with cavities and pores. 5) Print and cut the product to form individual finished pieces; Steps 2) and 3) are not in any particular order; In step 2), a MEMS chip and an ASIC chip are mounted on the first substrate, and the MEMS chip and the ASIC chip are interconnected with the first substrate.

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