Method for manufacturing flexible-substrate-based self-encapsulation passive wireless pressure sensor

Abstract

The invention discloses a method for manufacturing a flexible-substrate-based self-encapsulation passive wireless pressure sensor. The method comprises the following steps of: (10) manufacturing an upper flexible substrate: electroplating an upper metal layer on the lower surface of a flexible substrate, and photoetching the upper metal layer so as to form an upper capacitance pole plate and a planar inductance coil; (20) manufacturing a middle flexible substrate: boring a flexible substrate so as to form cavities and electrical through holes; (30) manufacturing a lower flexible substrate: electroplating a lower metal layer on the upper surface of a flexible substrate, and photoetching the lower metal layer so as to form a lower capacitance pole plate and a lower connecting wire; (40) manufacturing connecting wires: coating the electrical through holes with a conductive adhesive so as to form the connecting wires; and (50) manufacturing the pressure sensor: laminating the upper flexible substrate, the middle flexible substrate and the lower flexible substrate so as to form an oscillation circuit, thereby manufacturing the passive wireless pressure sensor. The method has the advantages that the self alignment of the substrates can be realized, the self encapsulation of the sensor can be realized, the process is simple, and the consistency and reliability are high.

Description

technical field [0001] The invention relates to a method for preparing a pressure sensor, in particular to a method for preparing a self-encapsulated passive wireless pressure sensor based on a flexible substrate. technical background [0002] Pressure sensors are widely used in many occasions. In some special applications, such as: inside the human body, food packaging and other sealed environments, pressure sensors are required to have wireless telemetry capabilities. There are currently two types of wireless telemetry pressure sensors: active telemetry and passive telemetry. Active telemetry means that the sensing system has a power source. This type of telemetry can transmit sensor signals in both directions over long distances, but the system is complex, large in size, and the battery needs to be replaced. Passive telemetry means that there is no power source in the sensing system, and signals are acquired by using inductive coupling or radio frequency (RF) reflection ...

AI Technical Summary

Problems solved by technology

The inductance can be an on-chip inductance integrated with a capacitive sensor, but it is generally difficult to obtain a high quality factor Q for this inductance, thereby limiting the overall characteristics of the device; in addition, an externally wound metal wire inductance coil can also be used. But this will increase the size of the device, and it is difficult to process in batches

In addition, polysilicon is commonly used as a deformable plate at present, and its mechanical properties are not as good as flexible substrates, and the thickness of flexible substrates can be flexibly changed.

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