Wafer-level capacitive acceleration meter automatic testing system

Abstract

The invention discloses a wafer-level capacitive acceleration meter automatic testing system comprising a microprocessor, a host computer connected with the microprocessor, four capacitive digital converters, a first digital-to-analog converter, a second digital-to-analog converter, a first relay, and a second relay. The microprocessor controls the digital-to-analog converters and the relays, applies DC voltage to the two fixed electrodes of a capacitive acceleration meter at different time in order to generate electrostatic force and simulate external acceleration. The four capacitive digital converters are controlled by the microprocessor and transmit the capacitance values, acquired at different time, of the capacitive acceleration meter to the microprocessor. A capacitance change value is calculated by the microprocessor. The wafer-level capacitive acceleration meter automatic testing system achieves a purpose of testing a parameter and determines the quality of the capacitive acceleration meter.

Description

technical field [0001] The invention relates to the field of microelectronic testing, in particular to a wafer-level capacitive accelerometer automatic testing system. Background technique [0002] As is known, the capacitive accelerometer is a differential capacitance structure, which has a movable plate and a plurality of fixed electrodes inside, the movable plate is connected to the mass block, and a plurality of fixed electrodes are opposite to it, between the movable plate and the fixed electrode A differential capacitance pair is formed between the electrodes. When an external acceleration is applied to the capacitive accelerometer, its internal mass is displaced, which causes the differential capacitance pair inside the accelerometer to change, thereby causing the differential capacitance value of the differential capacitance to change. Utilize this feature, apply mechanical shock or vibration to the finished circuit of the packaged accelerometer, provide an accelerat...

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Problems solved by technology

[0003] However, in the wafer stage of the capacitive accelerometer, because the chip is placed on the probe station and is in a flat state, external acceleration signals such as mechanical shock and vibration cannot be applied to the capacitive accelerometer chip. Therefore, for the capacitive accelerometer at the wafer stage Accelerometer, unable to follow its finished product test method

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