Polarization-used fixture, piezoelectric layer polarization method and ultrasonic biometric device manufacturing method

Abstract

The invention relates to a polarization-used fixture, a piezoelectric layer polarization method and an ultrasonic biometric device manufacturing method. The polarization-used fixture is used for beingmounted on a to-be-polarized piece, and comprises a conductive tray, a mask and an electrical connection assembly, wherein the conductive tray is used for mounting the to-be-polarized piece and can be connected with a ground wire; the mask can be arranged on the conductive tray in a covering mode and can cover the to-be-polarized piece in the conductive tray to enable the piezoelectric layer to be exposed, the mask can be cooperated with the piezoelectric layer to completely cover a circuit layer, and the mask is made of polyetherimide plastic; the electrical connection assembly is mounted onthe mask and can be electrically connected with the circuit layer and the conductive tray, and when the mask is arranged on the conductive tray in a covering mode, the electrical connection assemblyis located at the side, facing the conductive tray, of the mask. By using the polarization-used fixture, the piezoelectric layer polarization method is simple to operate, and the piezoelectric layer on a thin film transistor can realize effective polarization.

Description

technical field [0001] The invention relates to the technical field of ultrasonic identification, in particular to a jig for polarization, a method for polarizing a piezoelectric layer, and a method for preparing an ultrasonic biometric identification device. Background technique [0002] Ultrasonic fingerprint recognition technology can scan fingerprints through ultrasonic waves. Compared with traditional fingerprint recognition methods, ultrasonic fingerprint recognition can analyze fingerprints more deeply. Even if there is dirt on the surface of the finger, it will not hinder ultrasonic sampling, and can even penetrate The unique 3D features of fingerprints are identified beneath the surface of the skin. Even when there is water or sweat on the hands, it can still be accurately identified. [0003] Usually, in the manufacturing process of ultrasonic fingerprint identification device, it is necessary to polarize the piezoelectric layer to make the electric domains of the...

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Problems solved by technology

[0003] Usually in the manufacturing process of the ultrasonic fingerprint recognition device, it is necessary to polarize the piezoelectric layer to make the electric domains of the piezoelectric layer consistent to obtain the maximum piezoelectric performance, and the usual steps are to first coat the piezoelectric material On the thin film transistor with the circuit layer formed, the piezoelectric layer is then polarized. Due to the existence of an exposed circuit layer (such as an ITO layer) on the thin film transistor, the exposed circuit layer is easily exposed to high voltage. If the piezoelectric layer is broken down, the polarization of the piezoelectric layer is more difficult, and with the current polarization method, if there are defects or breakdown points in the piezoelectric layer, the piezoelectric layer cannot be effectively polarized, thereby affecting the piezoelectric layer. Piezoelectric properties of layers

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