US-12616991-B2 - Ultrasonic atomization apparatus

Abstract

In an ultrasonic atomization apparatus being the present invention, a source solution is accommodated in a separator cup being a part of a container. A constituent material of the separator cup is PTFE being one of fluorocarbon resins, whose entire thickness is uniformly 0.5 mm. Therefore, the separator cup satisfies a thin film condition that “the thickness of a bottom surface BP 1 is 0.5 mm or less”.

Inventors

• Hiroyuki Orita
• Takahiro Hiramatsu

Assignees

• TOSHIBA MITSUBISHI-ELECTRIC INDUSTRIAL SYSTEMS CORPORATION

Dates

Publication Date

20260505

Application Date

20200117

Claims (5)

1. 1 . An ultrasonic atomization apparatus comprising: a container including a separator cup configured to accommodate a source solution at a lower part; an internal hollow structure body including a hollow inside being provided above said separator cup in said container; a water tank configured to accommodate an ultrasonic wave conveyance medium inside, said water tank and said separator cup being positioned so that a bottom surface of said separator cup is immersed in said ultrasonic wave conveyance medium; and a plurality of ultrasonic vibrators provided in a bottom surface of said water tank, wherein said separator cup uses fluorocarbon resin as a constituent material, said separator cup is integrally formed by a cylindrical side surface and a bottom surface without a joint member, said bottom surface of said separator cup is inclined from a bottom end of said cylindrical side surface toward a center of said bottom surface of said separator cup, and is formed into a spherical surface shape having a predetermined curvature, said bottom surface of said separator cup includes a plurality of thin film regions corresponding to said plurality of ultrasonic vibrators, and each of said plurality of thin film regions includes an ultrasonic wave transmission region allowing transmission of ultrasonic waves applied from a corresponding ultrasonic vibrator out of said plurality of ultrasonic vibrators, in said bottom surface of said separator cup, said plurality of thin film regions satisfy a first thin film condition, and other region except for said plurality of thin film regions does not satisfy said first thin film condition, in said bottom surface of said separator cup, each of said plurality of thin film regions has a recess at a contact side contacting said source solution and does not have a recess at a contact side contacting said ultrasonic wave conveyance medium, said first thin film condition is that said thickness of said plurality of thin film regions in said bottom surface is 0.5 mm or less, entire thickness of said separator cup including the cylindrical side surface and the bottom surface other than said plurality of thin film regions is uniform and satisfying a second thin film condition, and said second thin film condition is that the entire thickness of said separator cup other than said plurality of thin film regions is larger than 0.5 mm.
2. 2 . The ultrasonic atomization apparatus according to claim 1 , wherein said water tank and said separator cup being positioned so that at least a part of said cylindrical side surface of said separator cup is immersed in said ultrasonic wave conveyance medium in said water tank from horizontal direction.
3. 3 . The ultrasonic atomization apparatus according to claim 1 , wherein said container includes an upper cup having a cylindrical shape, said upper cup and said separator cup are coupled by a connector along circumference of said cylindrical side surface of said separator cup.
4. 4 . The ultrasonic atomization apparatus according to claim 3 , wherein a liquid level of the source solution is positioned lower than a position at which said connector is disposed in lateral view.
5. 5 . The ultrasonic atomization apparatus according to claim 1 , wherein said first thin film condition includes a limited thin film condition that said thickness of said plurality of thin film regions in said bottom surface is 0.3 mm or less.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application is based on PCT filing PCT/JP2020/001494, filed Jan. 17, 2020, the entire contents of which are incorporated herein by reference. This application is related to U.S. patent application Ser. No. 17/429,647, entitled ULTRASONIC ATOMIZATION APPARATUS, filed on the same day as this application and is hereby incorporated by reference. TECHNICAL FIELD The present invention relates to an ultrasonic atomization apparatus that atomizes a source solution into fine mist by using an ultrasonic vibrator and transfers the mist to the outside. BACKGROUND ART In a field of manufacturing electronic devices, an ultrasonic atomization apparatus is used in some cases. In the field of the electronic device manufacturing, the ultrasonic atomization apparatus atomizes a solution by using ultrasonic waves that are oscillated from an ultrasonic vibrator, and sends out the atomized solution to the outside by using transfer gas. When the source solution mist transferred to the outside is sprayed onto a substrate, a thin film for the electronic device is formed on the substrate. Various solvents are used for the source solution used in the film formation, and in order to prevent erosion of the ultrasonic vibrator, a double chamber method, in which the source solution and the ultrasonic vibrator do not come into contact with each other, is used. In the double chamber method, in order to separate the ultrasonic vibrator and the source solution, a separator cup for accommodating the source solution is used separately for a water tank provided with the ultrasonic vibrator in its bottom surface. The separator cup is required to allow transmission of ultrasonic waves, and a material that easily transmits ultrasonic waves, such as polyethylene and polypropylene (PP), is used as its constituent material. Further, polyethylene and polypropylene have properties of being easily subjected to formation as well. One example of the ultrasonic atomization apparatus employing the double chamber method described above is an atomization apparatus disclosed in Patent Document 1. PRIOR ART DOCUMENTS Patent Documents Patent Document 1: WO 2015/019468 SUMMARY Problem to be Solved by the Invention In general, toluene, ether, and the like, which are solvents high in solubility, are used as a solvent of the source solution. This is because toluene and ether have properties of high resin solubility. However, when toluene and ether are used as a solvent of the source solution in a conventional ultrasonic atomization apparatus, the high resin solubility of the solvent may cause a leakage of the source solution due to swelling and deformation of the separator cup using polyethylene or polypropylene as its constituent material, or opening of a hole in the separator cup. This results in deterioration of accommodation stability of the source solution in the conventional ultrasonic atomization apparatus, which poses a problem that the source solution mist of an appropriate atomization amount cannot be generated. The present invention has an object to provide an ultrasonic atomization apparatus that solves the problem as described above, that is excellent in tolerance to a source solution, and that can generate a source solution mist of an appropriate atomization amount. Means to Solve the Problem An ultrasonic atomization apparatus according to the present invention includes: a container including a separator cup configured to accommodate a source solution at a lower part; an internal hollow structure body including a hollow inside being provided above the separator cup in the container; a water tank configured to accommodate an ultrasonic wave conveyance medium inside, the water tank and the separator cup being positioned so that a bottom surface of the separator cup is immersed in the ultrasonic wave conveyance medium; and at least one ultrasonic vibrator provided in a bottom surface of the water tank. The separator cup uses fluorocarbon resin as a constituent material, whose entire thickness is uniform and satisfying a thin film condition. The thin film condition is that “the entire thickness is 0.5 mm or less”. Effects of the Invention The constituent material of the bottom surface of the separator cup in the ultrasonic atomization apparatus being the invention of the present application according to claim 1 is fluorocarbon resin. The fluorocarbon resin has properties of having relatively high tolerance to various solvents. Thus, the separator cup of the ultrasonic atomization apparatus can exert relatively high tolerance to the source solution. In addition, through satisfaction of the thin film condition that “the entire thickness is 0.5 mm or less”, the separator cup being the invention of the present application according to claim 1 enhances transmissiveness of ultrasonic waves in the bottom surface, and can thus generate a source solution mist with an appropriate atomization amount. As a result, th