JP7088461B1 - Ultrasonic cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic cleaning device capable of evenly supplying a cleaning liquid to an ultrasonic element. SOLUTION: An ultrasonic cleaning device D has a conical nozzle 1 having an injection port 11 formed at the top, a housing 2 in which the nozzle 1 is installed, and a housing 2 facing the injection port 11 of the nozzle 1. A disk-shaped ultrasonic element 3 to be installed and a supply path 4 formed in the housing 2 for supplying a cleaning liquid to the ultrasonic element 3, and a donut-shaped supply formed around the ultrasonic element. A supply path 4 having a path 42 and a connecting path 41 connected to the upstream side of the donut-shaped supply path 42 is provided. [Selection diagram] Fig. 1

Description

The present invention relates to an ultrasonic cleaning device that cleans an object to be cleaned (work) using a cleaning liquid in which ultrasonic waves are propagated.

Conventionally, a cleaning device for cleaning an object to be cleaned (work) such as a semiconductor wafer has been known. As such a cleaning device, a method is known in which an operator operates a pistol-shaped cleaning gun to clean an object to be cleaned.

For example, Patent Document 1 includes a main body portion, a water reservoir portion, a piezoelectric diaphragm, a water channel, and a valve, and propagates ultrasonic vibration to washing water and propagates ultrasonic vibration from an injection port. A cleaning gun that injects cleaning water to clean an object to be cleaned is disclosed.

Japanese Unexamined Patent Publication No. 2020-20223

However, in the conventional cleaning device including the cleaning gun of Patent Document 1, when water is supplied to the piezoelectric diaphragm, the water channel is connected as it is, so that the bubbles generated at the initial stage of starting cannot be efficiently expelled. .. Therefore, the air bubbles are unevenly distributed on the piezoelectric diaphragm, the temperature of the piezoelectric diaphragm rises, and there is a risk that the capacity of the piezoelectric diaphragm itself is lowered or damaged.

Therefore, an object of the present invention is to provide an ultrasonic cleaning device capable of evenly supplying a cleaning liquid to an ultrasonic element.

In order to achieve the above object, the ultrasonic cleaning device of the present invention has a conical nozzle having an injection port formed at the top, a housing in which a nozzle is installed, and the ultrasonic cleaning device facing the injection port of the nozzle. A disk-shaped ultrasonic element installed in a housing and a supply path formed in the housing for supplying a cleaning liquid to the ultrasonic element, which is a donut shape formed around the ultrasonic element. It has a supply path and a connecting path connected to the upstream side of the donut-shaped supply path.

As described above, the ultrasonic cleaning device of the present invention has a conical nozzle having an injection port formed at the top, a housing in which the nozzle is installed, and a disk installed in the housing facing the injection port of the nozzle. A supply path for supplying the cleaning liquid to the ultrasonic element and the housing, which are formed around the ultrasonic element and are upstream of the donut-shaped supply path and the donut-shaped supply path. It has a connecting path leading to the side. With such a configuration, the cleaning liquid can be evenly supplied to the ultrasonic element through the donut-shaped supply path to expel bubbles, so that the temperature rise of the ultrasonic element can be suppressed and the ultrasonic wave propagation efficiency is good. It becomes an ultrasonic cleaning device.

It is sectional drawing explaining the whole structure of an ultrasonic cleaning apparatus. It is an exploded perspective view which disassembled an ultrasonic cleaning apparatus into parts. It is sectional drawing explaining the characteristic part of the ultrasonic cleaning apparatus. It is explanatory drawing explaining the operation of the ultrasonic cleaning apparatus. It is explanatory drawing which took out and explained the flow of the cleaning liquid. It is an ultrasonic part image of Example 2. (A) is ultrasonic wave application ON, and (b) is ultrasonic wave application OFF.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following examples, the case where the ultrasonic cleaning device D of the present invention is applied to the cleaning of the object to be cleaned (work) including the semiconductor wafer will be described, but the present invention is not limited thereto. For example, by applying it to a coolant used for cooling and reducing friction of a cutter and a work of a machine tool including an NC milling machine and a machining center, it contributes to smoothing of the work cutting surface and can also be applied to cleaning.

(Constitution)
First, the configuration of the ultrasonic cleaning device D of the embodiment will be described with reference to FIGS. 1 to 3. The ultrasonic cleaning device D includes a conical nozzle 1 having an injection port 11 formed at the top, a housing 2 in which the nozzle 1 is installed, and a circle installed in the housing 2 facing the injection port 11 of the nozzle 1. A plate-shaped ultrasonic element 3 and a donut-shaped supply path 42 formed in the housing 2 for supplying a cleaning liquid to the ultrasonic element 3 and formed around the ultrasonic element 3. , A supply path 4 having a connection path 41 connected to the upstream side of the donut-shaped supply path 42. As the cleaning liquid, water, machine oil, or the like can be used.

Then, as shown in FIG. 1, the ultrasonic cleaning device D includes a power cable 70 connected to the ultrasonic element 3 and a liquid supply adapter (lock line) 80 connected to the connection path 41 of the supply path 4. , Is connected from the outside. That is, electricity is supplied to the ultrasonic element 3 through the power cable 70. Further, the cleaning liquid is supplied to the supply path 4 through the liquid supply adapter 80. Although not shown, a pump, a valve, and the like are arranged on the upstream side of the liquid supply adapter 80. In addition, the ultrasonic cleaning device D of the present embodiment is held by a holding arm (preferably a robot arm) (not shown), and can be freely oriented in three dimensions (XYZ directions). ..

As shown in FIGS. 1 and 2, the nozzle 1 has a conical shape as a whole, and the injection port 11 is opened at the tip (top). On the inner surface of the nozzle 1, the cleaning liquid whose vibration is propagated by the ultrasonic element 3 described later is ejected from below in the drawing, and while converging toward the tip portion, the speed is also increased and the nozzle 1 is linear. Is sprayed on. Therefore, as shown in FIG. 3, the apex angle θa of the conical nozzle 1 is set to 45 degrees or less in order to prevent reflected waves, but more specifically, it is set to 30 degrees or less in order to stabilize the output. It is preferable to have.
θa <30 (degrees)

As shown in FIGS. 1 and 2, the housing 2 is composed of an upper housing 21, a middle housing 22, and a lower housing 23, and is fastened and fixed by four fixing screws 61, ... There is. Further, the nozzle 1 is fitted between the upper housing 21 and the middle housing 22 with a packing 51 interposed therebetween. Further, the upper housing 21 and the middle housing 22 are provided with cleaning liquid supply paths 4 (41, 42) as described later.

An ultrasonic element 3 (and a power cable 70 integrated with the packing 52 and 53) is installed between the middle housing 22 and the lower housing 23 with the packings 52 and 53 interposed therebetween. That is, the ultrasonic element 3 is attached to the packings 52 and 53 in a posture facing the nozzle 1 (that is, a state in which the axis of the nozzle 1 and the normal direction of the ultrasonic element 3 coincide with each other and the center also coincides). It is sandwiched and held.

The ultrasonic element 3 is a disk-shaped (disc-shaped) piezoelectric element (piezo element), and has a structure in which a piezoelectric body is sandwiched between electrodes. When a voltage is applied from the high frequency power source, the ultrasonic element 3 vibrates due to the piezoelectric effect. Since the ultrasonic element 3 is in contact with the cleaning liquid supplied from the surrounding donut-shaped supply passage 42, the vibration is propagated to the cleaning liquid and discharged (injected) from the injection port 11 at the tip of the nozzle 1. It will be.

The supply path 4 is formed in the housing 2 and is a supply path 4 for supplying the cleaning liquid to the ultrasonic element 3. The supply path 4 has a donut-shaped supply path 42 formed around the ultrasonic element and a connecting path 41 connected to the upstream side of the donut-shaped supply path 42. Of these, the donut-shaped supply path 42 has a shape that surrounds the periphery of the disk-shaped ultrasonic element 3, so that the cleaning liquid is evenly supplied to the ultrasonic element 3 from the periphery.

At this time, the angle θb for supplying the cleaning liquid from the donut-shaped supply path 42 to the ultrasonic element 3 is, as shown in FIG. 3, the surface of the ultrasonic element 3 in order to prevent bubbles from partially accumulating. It is preferably 80 degrees or more with respect to.
θb> 80 (degrees)

Furthermore, since the cross-sectional area of the flow path is also narrowed stepwise as described later, the cleaning liquid is ejected toward the ultrasonic element 3 with a predetermined force.

Further, in order to discharge air bubbles as soon as possible in the initial stage of operation, the inflow cross-sectional area of the donut-shaped supply path 42 is set to 80% or less of the cross-sectional area of the connecting path 41, and the cross-sectional area of the injection port 11 is set to be 80% or less. It is preferably 80% or less of the inflow cross-sectional area of the donut-shaped supply path 42. This is expressed by a mathematical formula as follows.
a × a × π × 80% ＞ bφ × π × bH × 80% ＞ c × c × π
put it here,
a: Radius bφ of the connecting path 41: Diameter of the vibrating part of the ultrasonic element 3 bH: Inflow height of the donut-shaped supply path into the ultrasonic element 3 c: Radius of the injection port

Then, in the donut-shaped supply path 42 of this embodiment, a baffle plate 43 is installed near a position connected to the connection path 41. That is, at a position connecting the connecting path 41 and the donut-shaped supply path 42, a baffle plate 43 is installed upright in front of the connecting path 41 at a position blocking the flow so as to be orthogonal to the direction of the connecting path 41. The baffle plate 43 is, for example, a quadrangle, but may have any shape.

(Action)
Next, the operation of the ultrasonic cleaning device D will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, the cleaning liquid is pressure-fed and flows into the ultrasonic cleaning device D through the liquid supply adapter 80, is supplied to the ultrasonic element 3 through the supply path 4 inside the housing 2, and is external to the outside through the nozzle 1. Is released to. On the other hand, since a high frequency voltage is applied to the ultrasonic element 3 through the power cable 70, the ultrasonic element 3 vibrates at a predetermined frequency.

Specifically, as shown in FIG. 5, the cleaning liquid flowing into the donut-shaped supply path 42 through the connecting path 41 is blocked by the baffle plate 43 and is evenly distributed to the surroundings. ing. Then, the cleaning liquid is evenly sprayed from the periphery toward the center diagonally downward (in the figure) at a predetermined angle from the donut-shaped supply path 42 toward the ultrasonic element 3.

Then, the vibration is propagated from the ultrasonic element 3 to the cleaning liquid. In particular, in the initial stage of operation, the air (air bubbles) remaining in the space is pushed out by the cleaning liquid evenly supplied from the surroundings through the donut-shaped supply path 42. After that, the cleaning liquid is linearly ejected to the outside through the injection port 11 provided at the top while contacting the inner surface of the nozzle 1. Therefore, the object to be cleaned (work) can be cleaned by the cleaning liquid to which the vibration is propagated.

(effect)
Next, the effects of the ultrasonic cleaning device D will be listed and described.

(1) As described above, the ultrasonic cleaning device D faces the conical nozzle 1 having the injection port 11 formed at the top, the housing 2 in which the nozzle 1 is installed, and the injection port 11 of the nozzle 1. A disk-shaped ultrasonic element 3 installed in the housing 2 and a supply path 4 formed in the housing 2 for supplying the cleaning liquid to the ultrasonic element 3 and formed around the ultrasonic element. It is provided with a supply path 4 having a donut-shaped supply path 42 and a connecting path 41 connected to the upstream side of the donut-shaped supply path 42. With such a configuration, the cleaning liquid can be evenly supplied to the ultrasonic element 3 through the donut-shaped supply path 42 to expel air bubbles, so that the temperature rise of the ultrasonic element 3 can be suppressed and the ultrasonic wave can be obtained. This is an ultrasonic cleaning device D with good propagation efficiency.

That is, the ultrasonic element 3 cannot be used when the temperature reaches 60 degrees or higher. Therefore, it is necessary to operate so as not to leave air bubbles, especially at the initial stage of operation. Therefore, if a donut-shaped supply path 42 is formed around the ultrasonic element 3 and the cleaning liquid is supplied from all directions, the bubbles can be expelled without being biased.

(2) Further, it is preferable that the apex angle θa of the conical nozzle 1 is 30 degrees or less. With such a configuration, it is possible to stabilize the output while preventing the reflected wave from the inner surface of the nozzle 1.

(3) Further, it is preferable that the angle θb for supplying the cleaning liquid from the donut-shaped supply path 42 to the ultrasonic element 3 is 80 degrees or more with respect to the surface of the ultrasonic element 3. With this configuration, it is possible to prevent air bubbles from partially accumulating by ejecting the cleaning liquid toward the surface of the ultrasonic element 3.

(4) Further, the inflow cross-sectional area of the donut-shaped supply path 42 is 80% or less of the cross-sectional area of the connecting path 41, and the cross-sectional area of the injection port 11 is 80 of the inflow cross-sectional area of the donut-shaped supply path 42. % Or less is preferable. With this configuration, air bubbles can be discharged as soon as possible in the initial stage of operation.

(5) Further, in the donut-shaped supply path 42, it is preferable that the baffle plate 43 is installed in the vicinity of the position connected to the connecting path 41. If the baffle plate 43 is installed in this way, the cleaning liquid can be evenly distributed over the entire circumference from the connecting path 41 to the donut-shaped supply path 42.

(About the experiment)
Next, an experiment on "differences in the cutting surface due to application of ultrasonic waves to the cutting coolant" will be described.

(theme)
Application to NC milling cutter with ultrasonic head capable of omnidirectional injection

(Overview)
We created an ultrasonic nozzle developed for experiments that can set the up, down, left, right, and omnidirectional injection directions, and applied ultrasonic waves to the cutting coolant of NC milling cutters using this to measure the surface roughness of the cutting surface. ..

(Purpose)
When cutting with a runt to which ultrasonic waves are applied has an advantage in the roughness of the cutting surface compared to the one using a coolant to which ultrasonic waves are not applied, it is not limited to NC milling cutters, but can be applied to lathes, etc. in the entire cutting process. It is possible to improve the accuracy of.

(Experimental conditions)
Cutting material ・ ・ ・ A5052
Cutting blade ・ ・ ・ φ10mm flat end mill (carbide)
NC control: Spindle speed S4500 F1000 Depth 0.1mm
Coolant ・ ・ ・ Chartona S3 M 68 (mineral oil)
Ultrasonic frequency ・ ・ ・ 1.6MHz 15W (developed omnidirectional nozzle set)
Inspection equipment ・ ・ ・ KEYENCE WI-5000 White Interference 3D Displacement Meter

(Experimental result)
6 (a) and 6 (b) show experimental body images. As a measuring method, ultrasonic waves were turned on and off, and three points were measured at a pitch of 1 mm in the cutting direction at the center position. FIG. 6A is a measurement site image (ultrasonic wave application ON), and FIG. 6B is a measurement site image (ultrasonic wave application OFF).

(Discussion)
When the ultrasonic cleaning device D (ultrasonic head) is applied as a coolant for machine tools (including, for example, NC milling machines and machining centers), it is considered that the superiority of ultrasonic application is seen as a whole.

Thus, in this embodiment,
A conical nozzle with an injection port on the top,
The housing in which the nozzle is installed and
A disk-shaped ultrasonic element installed in the housing facing the injection port of the nozzle,
A supply path formed in the housing for supplying coolant to the ultrasonic element, which is connected to a donut-shaped supply path formed around the ultrasonic element and an upstream side of the donut-shaped supply path. With a connecting path, with a supply path,
Equipped with ultrasonic coolant supply device,
According to the report, the effect of improving the machining accuracy by the machine tool was confirmed.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes to the extent that the gist of the present invention is not deviated are made in the present invention. included.

For example, although not described in detail in the examples, in the initial stage of operation of the ultrasonic cleaning device D, a preparatory step of expelling air bubbles by a cleaning liquid is provided, and a high frequency voltage is applied to the ultrasonic element 3 after a predetermined time has elapsed. It is preferable to do so. By doing so, it is possible to prevent bubbles from remaining on the surface of the ultrasonic element 3 and raising the temperature. That is, the cleaning liquid also has a function as a coolant (coolant) of the ultrasonic element 3.

D Ultrasonic cleaning device 1 Nozzle 11 Injection port 2 Housing 21 Upper housing 22 Middle housing 23 Lower housing 3 Ultrasonic element 4 Supply path 41 Connection path 42 Donut-shaped supply path 51 to 53 Packing 61 Fixing screw 70 Power cable 80 Liquid supply adapter

Claims (5)

A conical nozzle with an injection port on the top,
The housing in which the nozzle is installed and
A disk-shaped ultrasonic element installed in the housing facing the injection port of the nozzle,
A supply path formed in the housing for supplying the cleaning liquid to the ultrasonic element, which is connected to the donut-shaped supply path formed around the ultrasonic element and the upstream side of the donut-shaped supply path. With a connecting path, with a supply path,
Equipped with an ultrasonic cleaning device. The ultrasonic cleaning device according to claim 1, wherein the apex angle of the conical nozzle is 30 degrees or less. The ultrasonic cleaning according to claim 1 or 2, wherein the angle at which the cleaning liquid is supplied from the donut-shaped supply path to the ultrasonic element is 80 degrees or more with respect to the surface of the ultrasonic element. Device. The inflow cross-section of the donut-shaped supply path is 80% or less of the cross-sectional area of the connecting path, and the cross-sectional area of the injection port is 80% or less of the inflow cross-section of the donut-shaped supply path. , The ultrasonic cleaning apparatus according to any one of claims 1 to 3. The ultrasonic cleaning device according to any one of claims 1 to 4, wherein a baffle plate is installed in the vicinity of a position connected to the connection path in the donut-shaped supply path.

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