Passive wireless pressure sensor preparation method based on flexible substrate

Abstract

The invention discloses a passive wireless pressure sensor preparation method based on a flexible substrate. The preparation method comprises the following steps: 10) preparing an upper flexible substrate: electroplating an upper metal layer on the upper surface of the flexible substrate, forming a capacitance upper plate and a planar inductor coil on the upper metal layer in a photoetching mode, and drilling a hole to form an upper through hole, 20) preparing a middle flexible substrate: drilling holes in the flexible substrate to form a hollow cavity and a middle through hole, 30) preparing a lower flexible substrate: electroplating a lower metal layer on the lower surface of the flexible substrate, and drilling a hole to form a lower through hole, 40) manufacturing a capacitor: using a laminating technique to enable the upper flexible substrate, the middle flexible substrate and the lower flexible substrate to be connected fixedly to manufacture the capacitor of a pressure sensor and 50) manufacturing the pressure sensor: electroplating the upper through hole, the middle through hole and the lower through hole to form a guide line to manufacture the passive wireless pressure sensor. The passive wireless pressure sensor preparation method based on the flexible substrate can be used for the mass production of capacitive pressure sensors, and is simple in technology and high in consistency and reliability.

Description

technical field [0001] The invention relates to a method for preparing a pressure sensor, in particular to a method for preparing a 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 modulation. This t...

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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