A method for manufacturing a center-supported mems chip packaging structure

Abstract

The invention discloses a production method for a centre support type MEMS (Micro Electro Mechanical System). A chip structure is protected through adoption of a method for spraying photoresist. The photoresist at the bottom of a silicon substrate of a chip is patterned, thereby forming an etching mask. Through adoption of an anisotropic etching technology, a center support structure with a relatively large area and a plurality of auxiliary support structures with relatively small areas are etched on the substrate of an MEMS chip. The MEMS chip is fixed in a ceramic tube shell cavity through adhesion or bonding, thereby carrying out metal lead bonding. A ceramic tube shell comprising the MEMS chip is integrally placed into an etching cavity. Etching is carried out through anisotropic etching gas, so the auxiliary support structures are completely etched and removed, and part of the center support structure is reserved and is not etched and removed. The center support structure is processed on the silicon substrate and the MEMS chip is supported in a packaging pipe shell approximate to suspension, so the packaging stress on the MEMS chip is greatly reduced, and the MEMS chip is packaged under low stress. The method has the advantages that a packaging technology is simple, the packaging cost is not increased clearly, and the realization is easy.

Description

technical field [0001] The invention relates to the field of electronics, in particular to a low-stress package of a quasi-suspended MEMS capacitive sensor using a center support. Background technique [0002] MEMS (Micro Electro Mechanical System) capacitive sensors have the advantages of small size, light weight, low power consumption, and low cost, and are widely used. The MEMS capacitive sensor realizes the measurement of the corresponding physical quantity to be measured by measuring the capacitance change formed by the tiny sensitive structure. Usually MEMS sensors need to be packaged in a certain structure to provide the electrical connection, mechanical connection and corresponding chemical environmental protection required by the sensor. [0003] Metal packaging, plastic packaging and ceramic packaging are the three most common packaging forms of MEMS chips. Ceramic packaging is the most widely used because of its good thermal conductivity and air tightness. [0...

AI Technical Summary

Problems solved by technology

[0019] Invention patents "MEMS Inertial Sensor Package Structure with Stress Isolation", "Package Structure That Can Reduce Package Stress", "Chip Attach Stress Isolation", "A Pressure Sensor Based on Silicon-Silicon Bonding Isolated Package Stress", " A Thermal Stress Isolation Structure for MEMS Devices" and "A MEMS Device and Its Manufacturing Method" all add a special isolation structure under the existing MEMS bare chip to reduce the impact of packaging stress on chip deformation. The disadvantage of the method is that an additional structural layer is required, thus increasing the overall thickness of the device

Invention patent "Method for Reducing MEMS Chip Packaging Stress Through Back Patterning" Although the etching process is used to process a special graphic structure on the back of the chip, which reduces the contact area between the chip and the package, there are still many parts on the bottom of the chip The problem of fixed connection with the shell, multi-position fixed connection will still generate thermal stress, resulting in deformation of the chip

Its disadvantage is that the packaging cavity and blocking filler need to be specially customized, which increases the processing complexity and cost

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