Film vibration device and fabrication method thereof, and cleaning device including the same

Patent metadata

Field	Value
Publication number	US-11969771-B2
Application number	US-202318359139-A
Country	US
Kind code	B2
Filing date	Jul 26, 2023
Priority date	Jul 27, 2022
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

A method of fabricating a film vibration device, including: photoetching a surface of a silicon wafer to form a circular-hole array; etching an aluminum layer on the silicon wafer; etching the silicon wafer to form a through-hole array to obtain a porous silicon wafer; attaching a polyethylene terephthalate (PET) sheet to a side of the porous silicon wafer; ablating the PET sheet to obtain a porous PET film; attaching a polyvinylidene fluoride (PVDF) film to a lower side of the porous silicon wafer; performing vacuumization above the porous silicon wafer, while heating the PVDF film below the porous silicon wafer to create dome micro-structures on the PVDF film; and laminating the porous PET film on each of two sides of the PVDF film to obtain the film vibration device. This application also provides a cleaning device having the film vibration device.

First claim

What is claimed is:

1. A method of fabricating a film vibration device, comprising:
(S 1 ) forming a circular-hole array on a surface of a silicon wafer by photoetching;
(S 2 ) etching an aluminum layer on the silicon wafer;
(S 3 ) etching the silicon wafer to form a through-hole array, so as to obtain a porous silicon wafer;
(S 4 ) attaching a polyethylene terephthalate (PET) sheet to a side of the porous silicon wafer; and subjecting the PET sheet to breakdown with the porous silicon wafer as a mask to obtain a porous PET film;
(S 5 ) attaching a polyvinylidene fluoride (PVDF) film to a lower side of the porous silicon wafer; performing vacuumization above the porous silicon wafer, and simultaneously heating the PVDF film below the porous silicon wafer such that a plurality of dome micro-structures are formed on the PVDF film; and
(S 6 ) laminating the porous PET film on each of two sides of the PVDF film having the plurality of dome micro-structures to obtain the film vibration device;
wherein in step (S 5 ), the heating is performed through three annealing-cooling operations, each comprising:
heating a bottom of the PVDF film at 75-85° C. for 4-6 min; and cooling the PVDF film to room temperature while keeping vacuum above the PVDF film.

2. The method of claim 1 , wherein step (S 1 ) comprises:
(S 1 - 1 ) depositing an aluminum film on the silicon wafer to form the aluminum layer on the surface of the silicon wafer;
(S 1 - 2 ) applying a photoresist to a top of the aluminum film followed by soft baking to form a photoresist layer on the surface of the aluminum layer; and
(S 1 - 3 ) subjecting the photoresist layer to patterning through photoetching followed by exposure and development with a developer.

3. The method of claim 1 , wherein step (S 2 ) comprises:
(S 2 - 1 ) drying the silicon wafer after photoetched; and
(S 2 - 2 ) immersing the silicon wafer in an aluminum etchant to etch an exposed part of the aluminum layer.

4. The method of claim 1 , wherein step (S 3 ) comprises:
(S 3 - 1 ) etching the silicon wafer through a plasma reaction;
(S 3 - 2 ) removing a photoresist layer; and
(S 3 - 3 ) etching a remaining part of the aluminum layer with an aluminum etchant to obtain the porous silicon wafer.

5. The method of claim 1 , wherein step (S 4 ) comprises:
(S 4 - 1 ) attaching the PET sheet to the side of the porous silicon wafer, wherein the PET sheet has a thickness of 45-55 μm; and
(S 4 - 2 ) ablating the PET sheet by a laser grating with the porous silicon wafer as the mask; and separating an ablated PET sheet from the porous silicon wafer to obtain the porous PET film.

6. The method of claim 1 , wherein a thickness of the PVDF film is 8-12 μm.

7. The method of claim 1 , wherein each of two sides of the PVDF film is coated with a silver electrode layer having a thickness of 60-80 nm.

8. A film vibration device prepared by the method of claim 1 , comprising:
a first porous PET film;
a second porous PET film; and
a PVDF film;
wherein the PVDF film is sandwiched between the first porous PET film and the second porous PET film; the first porous PET film and the second porous PET film have the same structure; the first porous PET film is arranged above the PVDF film; and the second porous PET film is arranged below the PVDF film; and
the PVDF film is provided with a plurality of dome micro-structures adapted to a through-hole array of the first porous PET film; the plurality of dome microstructures are embedded in the through-hole array of the first porous PET film; and two sides of the PVDF film are each coated with a silver electrode layer.

9. A cleaning device, comprising:
a container;
a control panel; and
the film vibration device of claim 8 ;
wherein the film vibration device is arranged on a bottom of the container, and is electrically connected with the control panel.

Assignees

• Univ Guangdong Technology

Inventors

• Chen Yun
• Li Biao
• Song Aoke
• Dong Shankun
• Lai Shengbao
• Hou Maoxiang
• Chen Xin

Classifications

• B08B7/028 Primary

  Using ultrasounds · CPC title

• B06B1/0688

  with foil-type piezoelectric elements, e.g. PVDF · CPC title

• B06B2201/56

  Foil type, e.g. PVDF · CPC title

• B06B2201/71

  Cleaning in a tank · CPC title

• G03F7/405

  Treatment with inorganic or organometallic reagents after imagewise removal · CPC title