Integrated corrosion-resistant MEMS pressure sensor and manufacturing method thereof

Abstract

The invention belongs to the technical field of integrated circuit packaging, and particularly relates to an integrated corrosion-resistant MEMS pressure sensor and a manufacturing method thereof. Comprising a PCB substrate, and an MEMS chip and an ASIC chip are mounted on the PCB substrate. The box dam forms double chambers for physical isolation; the box dam is bonded to the top of the PCB substrate through corrosion-resistant glue, the MEMS chip and the ASIC chip are separated through the double cavities, and the cavities where the MEMS chip is mounted are filled with corrosion-resistant protective gel so as to completely cover the MEMS chip; and the metal cover plate is bonded to the top of the box dam through corrosion-resistant glue, and a through hole is formed in one side of the top of the metal cover plate. According to the MEMS pressure sensor, the problem of miniaturization and standardization of the existing MEMS pressure sensor is solved, and the corrosion resistance requirement is met; the manufacturing process is suitable for batch high-precision machining, the product yield is improved, and the product cost is reduced.

Claims

1. An integrated corrosion-resistant MEMS pressure sensor, characterized in that: include: A PCB substrate, on which a MEMS chip and an ASIC chip are mounted and connected via gold wire bonding; The dam is a corrosion-resistant injection-molded part with a spherical shape to form a dual chamber for physical isolation. The dam is bonded to the top of the PCB substrate with corrosion-resistant glue and separates the MEMS chip from the ASIC chip through the dual chambers. The chamber where the MEMS chip is mounted is filled with a corrosion-resistant protective gel to completely cover the MEMS chip. A metal cover plate is bonded to the top of the dam by corrosion-resistant glue, and a through hole is opened on one side of the top of the metal cover plate for allowing the measured pressure of the MEMS chip sensing area to pass through.

2. The integrated corrosion-resistant MEMS pressure sensor according to claim 1, characterized in that: The bottom of the PCB substrate further includes a plurality of arranged solder pads, and the plurality of solder pads form a square dot matrix, a cross dot matrix or a field-shaped dot matrix.

3. The integrated corrosion-resistant MEMS pressure sensor according to claim 1, characterized in that: The pads on the MEMS chip and the ASIC chip are respectively bonded to the pads on the PCB substrate through gold wires. The PCB substrate also includes a gold-plated wiring layer to achieve electrical signal conduction between the chips.

4. The integrated corrosion-resistant MEMS pressure sensor according to claim 1, wherein: It also includes an L-shaped glue overflow groove, which is opened along a path around the four sides of the bottom of the dam.

5. The integrated corrosion-resistant MEMS pressure sensor according to claim 1, wherein: It also includes a reinforcing shoulder, which is integrally formed at the upper end of the cavity where the ASIC chip is located to form an L-shaped dam cavity structure.

6. The integrated corrosion-resistant MEMS pressure sensor according to claim 1, characterized in that: The connecting end surfaces between the dam and the PCB substrate and the metal cover plate further include etched grooves, and the grooves are in a crisscross grid or a U-shaped structure.

7. The integrated corrosion-resistant MEMS pressure sensor according to claim 6, characterized in that: The cross section of the groove is a wedge-shaped groove or an arc-shaped groove structure, and the etching width of the groove is 30 μm to 50 μm, the etching depth is 30 μm to 50 μm, and the etching spacing is 100 μm to 200 μm.

8. The integrated corrosion-resistant MEMS pressure sensor according to claim 1, wherein: The corrosion-resistant glue is a thermosetting glue.

9. A method for manufacturing an integrated corrosion-resistant MEMS pressure sensor, for manufacturing an integrated corrosion-resistant MEMS pressure sensor according to any one of claims 1 to 8, characterized in that: The steps include: Step S1: providing an integrally formed PCB substrate, a metal cover plate, and an integrally formed dam; Step S2: The MEMS chip and the ASIC chip are attached to the PCB substrate using corrosion-resistant glue, and then gold wire bonding is performed to achieve electrical signal conduction; Step S3: After bonding is completed, the integrally formed dam is mounted on the PCB substrate using corrosion-resistant glue. The mounting position is precisely positioned using corresponding positioning holes on the PCB substrate and the dam and matching tooling. Step S4: After the dam is mounted, a metal cover with holes is mounted on top of the dam using corrosion-resistant glue to form a complete product. Step S5: The entire product is precisely cut in the horizontal and vertical directions using a laser or water jet to form independent sensor packaging modules.

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