Air-coupled capacitive micromachined ultrasonic transducer, preparation method and use

A capacitive micro-machining, ultrasonic transducer technology, applied in chemical instruments and methods, vacuum evaporation coating, fluid using vibration, etc., can solve the problems of slow detection speed, etc. The effect of deflection control

Active Publication Date: 2021-02-19
TIANJIN UNIV
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] When the air-coupled ultrasonic probe is applied to the non-destructive testing inside the plate, it is generally scanned by the movement of a single probe to detect the entire plate, so the detection speed is relatively slow

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Air-coupled capacitive micromachined ultrasonic transducer, preparation method and use
  • Air-coupled capacitive micromachined ultrasonic transducer, preparation method and use
  • Air-coupled capacitive micromachined ultrasonic transducer, preparation method and use

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] The purpose of the embodiment of the present invention is to provide a capacitive micro-ultrasonic transducer for ultrasonic nondestructive testing applied to air coupling. The transducer is composed of 16 array elements, and each array element is composed of multiple sensitive elements. See figure 2 (A).

[0049] The structure of each sensitive element is composed from top to bottom: upper electrode 3, diaphragm 1, cavity 5, and base 2 (wherein, base 2 is also used as the lower electrode), see figure 2 (B).

[0050] There is a cavity 5 between the diaphragm 1 and the base 2, which constitutes a capacitor, and a DC voltage is pre-loaded between the upper electrode 3 and the lower electrode 2, so that an electrostatic field is formed in the capacitor, and the diaphragm 1 under the action of the electric field force Deformation occurs under the diaphragm, thereby forming a pre-tightening force in the diaphragm 1, and the diaphragm 1 is in a stable equilibrium state.

...

Embodiment 2

[0054] Combine below figure 1 The scheme in Example 1 is further introduced, see the following description for details:

[0055] The overall structure of the embodiment of the present invention consists of two parts, the vibrating membrane 1 and the base 2 . The vibrating membrane 1 is composed of an upper electrode 3 and a thin film 4 .

[0056] In specific implementation, the thin film 4 may be a single crystal silicon thin film. It may also be set according to requirements in practical applications, which is not limited in this embodiment of the present invention.

[0057] Wherein, the material of the upper electrode 3 can be selected from gold, aluminum and the like. In the embodiment of the present invention, a single crystal silicon thin film is used as a component of the vibrating membrane 1 and the ultrasonic receiving sensitive element.

[0058] The base 2 is jointly formed by a cavity 5 and an insulating layer 6 . The material of the insulating layer 6 is silico...

Embodiment 3

[0061] see figure 2 (B), the embodiment of the present invention provides a preparation method of an air-coupled ultrasonic transducer, the preparation method is corresponding to the air-coupled ultrasonic transducer in Examples 1 and 2, and the preparation method includes:

[0062] The SOI wafer bonding technology adopted in the embodiment of the present invention is a bulk silicon process. This technology overcomes the defect of using a sacrificial layer, and processes a larger unit size through deep etching of the silicon base material, and has high processing reliability. The process flow of SOI wafer bonding process is as follows:

[0063] (A) Prepare silicon substrate 2, what silicon substrate 2 adopts is doped low-resistance silicon, thereby can form parallel plate capacitance with top electrode;

[0064] (B) Reactive ion etching (RIE) or wet etching is used to etch a cavity 5 with a target depth at a desired position, and the depth of the cavity 5 is 5 μm;

[0065]...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
Login to view more

Abstract

The invention relates to an air-coupled capacitive micromachining ultrasonic transducer, a preparation method and application. A transducer array comprises 16 array elements; each array element is formed by multiple sensing units; each sensing unit is structurally formed by an upper electrode 1, a vibrating diaphragm 2, a cavity 3 and a base 5 sequentially from top to bottom; and each base is usedas a lower electrode. The working frequency of the designed transducer is 100kHz to 2MHz. The transducer array is manufactured based on an SOI bonding process; each vibrating diaphragm is made of monocrystalline silicon; each upper electrode is gold or aluminum; an insulating layer 4 is silicon dioxide or silicon nitride; and the array elements of the transducer are divided through etching the low-resistance-silicon bases to form grooves, so that the array with the multiple array elements is formed. According to the air-coupled ultrasonic transducer, an ultrasonic wave in a metal plate or a composite plate is excited through an air coupling manner and is used for nondestructively detecting internal defects of the plate. The transducer is matched with a phased array system, and pulse drivesignals of the array elements are delay-controlled, so that the phase-controlled deflection and the focusing of an acoustic beam are adjusted, and the freedom degree of detecting is increased.

Description

technical field [0001] The invention relates to the field of ultrasonic transducers, in particular to an air-coupled capacitive micro-processed ultrasonic transducer, a preparation method and an application. Background technique [0002] In recent years, ultrasonic testing technology has been widely used in the field of non-destructive testing. The relatively mature testing methods mainly use liquid immersion method or contact method using coupling agent to reduce the energy loss of ultrasonic in the air, but this limits its application. Non-contact ultrasonic non-destructive testing technology has the characteristics of non-contact, no need for water immersion or coupling agent, which makes up for this deficiency well, and is suitable for composite material testing, material property evaluation, food industry, etc. field. [0003] The non-contact detection method based on the air-coupled ultrasonic transducer can be used for the detection of metals, polymers or composite m...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): B06B1/06C30B33/00C30B33/02C30B33/08C23C14/16
CPCB06B1/0629C23C14/16C30B33/005C30B33/02C30B33/08
Inventor 张慧李志郑冠儒刘玉振于露
Owner TIANJIN UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap