Decapsulation method for chip laminated plastic capsulated MEMS inertial device

Abstract

The invention discloses a decapsulation method for a chip laminated plastic capsulated MEMS (micro electro mechanical system) inertial device to expose an accelerometer MEMS, a gyroscope MEMS and an ASIC (application specific integrated circuit) chip in the device. The decapsulation method includes: acquiring the preliminary internal structure information of the device, acquiring a cavity position and detailed distribution information of the chip, and according to the detailed distribution information, conducting chemical corrosion treatment and inspection analysis respectively on the laminated structure MEMS inertial device with the ASIC chip located at an upper layer and the accelerometer MEMS and gyroscope MEMS located at a lower layer and the laminated structure MEMS inertial device with the ASIC chip located at the lower layer and the accelerometer MEMS and gyroscope MEMS located at an upper layer. The method provided by the invention can expose the accelerometer MEMS, the gyroscope MEMS, the common ASIC chip and the like respectively, also can ensure an intact structure of the device in a capsulation cavity, and meets the internal visual inspection demands of the chip laminated plastic capsulated MEMS inertial device.

Description

Technical field [0001] The present invention relates to the field of inertial technology, and in particular to a method for unsealing a MEMS inertial device packaged with a chip-on-chip plastic. Background technique [0002] Inertial technology is the core technology of navigation and positioning, guidance control, aiming and image stabilization, and attitude measurement. The technical status of inertial gyroscopes and accelerometers is the basis of inertial technology. Among them, the gyroscope is used to measure the angular velocity of the moving body, and the accelerometer is used to measure the acceleration of the moving body. MEMS (Micro Electro Mechanical System) inertial devices refer to micro-mechanical gyroscopes and micro-accelerometers whose sensitive structures are processed by micro-machining methods. MEMS inertial devices are widely used because of their small size, light weight, low power consumption, mass production, low cost, and strong anti-overload capability....

AI Technical Summary

Problems solved by technology

However, the chemical etching solution cannot corrode silicon, so the capped silicon wafer cannot be directly etched away, and the accelerometer MEMS and gyroscope MEMS in the cavity formed by the capped silicon wafer cannot be exposed, so they cannot be observed and analyzed

For the ASIC chip placed under the capped silicon wafer, after the external plastic packaging material of the MEMS inertial device is removed by the chemical etching method of plastic packaged integrated circuits, what is obtained is the back of the capped silicon wafer, and it cannot be observed. Accelerometer MEMS and gyroscope MEMS in the formed cavity

[0005] In order to solve the problem of complex packaging and difficult unsealing of MEMS inertial devices packaged in chip-on-chip plastic packages, a MEMS inertial device unsealing technology for this type of packaging structure characteristics is needed to make up for the shortcomings of traditional unsealing technology. The internal purpose of this type of packaging device Provide technical support

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