Micro inertia sensor and its mfg. method

Abstract

The present invention will provide a micro-inertial sensor characterized by the following content, which includes: a lower glass substrate; a lower silicon substrate on the lower glass substrate for detecting the first edge and the first fixed point and side motion detection structures Layer; including the first edge portion corresponding to the above-mentioned lower silicon layer, the first fixed point and the second edge portion of the side motion detection structure, the second fixed point bonded by the through-hole with the built-in metal line, and the above-mentioned side motion The upper silicon layer including the second detection electrode used to detect the capacitance in the vertical direction between the detection structures; the eutectic bonding layer between the above-mentioned upper silicon layer and the lower silicon layer; located on the upper part of the above-mentioned upper silicon layer, and An upper glass substrate having through-holes provided with metal wiring. In addition, the present invention provides a micro inertial sensor manufacturing method, and the purpose of the present invention is to realize the miniaturization of the product and the simplification of the process.

Description

technical field [0001] The present invention relates to a micro inertial sensor and a manufacturing method thereof. Micro inertial sensors such as a micro gyroscope include an element wafer for a lower structure, a cover wafer for an upper structure, and bonding and wiring structures between them. An object of the present invention is to provide a microsensor with a new structure that is smaller than the conventional structure and can detect vertical motion. Background technique [0002] Generally, when manufacturing microsensors such as microgyroscopes in the past, a method of anodically bonding silicon microstructures provided on silicon or glass wafers to glass wafers to realize wafer-level packaging is used. [0003] However, if this method is used, warpage will be caused at the time of bonding due to the difference in thermal expansion coefficient between the above-mentioned silicon layers. In addition, when the above-mentioned anodic bonding is performed, an outgassin...

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Problems solved by technology

[0017] In order to remove such external fixing points, it has been tried to provide holes in the above-mentioned lid wafer to form electrodes, but at this time, in order to prevent the influence caused by undercut, it is necessary to provide deep through holes to the maximum. If so, then There will be a risk of contact with the wiring passing between the above insulating layers

In this way, it is impossible to open holes at the required positions, which brings certain difficulties to the miniaturization design

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