Ultrasonic transducer, ultrasonic fingerprint sensor and manufacturing method of ultrasonic transducer

A fingerprint sensor and ultrasonic technology, applied in the re-radiation of sound waves, acquisition/organization of fingerprints/palmprints, instruments, etc., can solve the problems of manufacturing difficulties, poor yield, poor parameter consistency, etc., to reduce manufacturing costs and improve finished products. rate, the effect of reducing difficulty

Active Publication Date: 2017-09-26
HANGZHOU SILAN MICROELECTRONICS
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the ultrasonic transducer includes a cavity structure under the piezoelectric stack, which is not only difficult to manufacture, but also causes frequency instability, poor parameter consistency, and poor yield of the ultrasonic fingerprint sensor due to process deviations.

Method used

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  • Ultrasonic transducer, ultrasonic fingerprint sensor and manufacturing method of ultrasonic transducer
  • Ultrasonic transducer, ultrasonic fingerprint sensor and manufacturing method of ultrasonic transducer
  • Ultrasonic transducer, ultrasonic fingerprint sensor and manufacturing method of ultrasonic transducer

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Embodiment Construction

[0069] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. In the various figures, identical elements are indicated with similar reference numerals. For the sake of clarity, various parts in the drawings have not been drawn to scale. Also, some well-known parts may not be shown.

[0070] In the following, many specific details of the present invention are described, such as device structures, materials, dimensions, processing techniques and techniques, for a clearer understanding of the present invention. However, the invention may be practiced without these specific details, as will be understood by those skilled in the art.

[0071] The invention can be embodied in various forms, some examples of which are described below.

[0072] figure 1 A flow chart showing a manufacturing method of an ultrasonic fingerprint sensor according to a first embodiment of the present invention. The method includes forming a stac...

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Abstract

The invention discloses an ultrasonic transducer, an ultrasonic fingerprint sensor and a manufacturing method of the ultrasonic transducer. The method comprises the steps that a CMOS circuit is formed, and the ultrasonic transducer is formed on the CMOS circuit. In the method, the forming process of the ultrasonic transducer comprises the steps that a sacrificial layer is formed; the sacrificial layer is patterned; a mask layer is formed on the sacrificial layer, and the mask layer covers and surrounds the sacrificial layer; an opening for reaching the sacrificial layer is formed on the mask layer; gas phase etching is carried out through the opening, and therefore the sacrificial layer is removed to form a cavity; and a piezoelectric stack is formed on the mask layer. The cavity is formed by patterning the sacrificial layer, accordingly, the manufacturing cost can be reduced, and the performance of the sensor can be improved.

Description

technical field [0001] The present invention relates to a fingerprint sensor, and more particularly, to an ultrasonic transducer, an ultrasonic fingerprint sensor and a manufacturing method thereof. Background technique [0002] Biometric recognition is a technology used to distinguish different biological characteristics, including fingerprints, palm prints, faces, DNA, voice and other recognition technologies. Fingerprints refer to the uneven lines on the skin on the front of the end of a human finger, and the lines are regularly arranged to form different patterns. Fingerprint identification refers to identification by comparing the detailed feature points of different fingerprints. Due to its lifelong invariance, uniqueness and convenience, the application of fingerprint identification is more and more extensive. [0003] In fingerprint recognition, a sensor is used to obtain fingerprint image information. According to different working principles, fingerprint sensors...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B06B1/06G06K9/00
CPCB06B1/064B06B2201/55G06V40/1306G01S15/8925
Inventor 季锋闻永祥刘琛周浩
Owner HANGZHOU SILAN MICROELECTRONICS
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