JPH1128432A - Ultrasonic cleaning machine - Google Patents

Abstract

(57) Abstract: An ultrasonic cleaning machine comprising at least an ultrasonic oscillator, an ultrasonic vibrator, and an ultrasonic focusing horn filled with a cleaning liquid, has an oscillation frequency of 500 kHz or more, An ultrasonic cleaner comprising two transducers, wherein two transducers are arranged so as to be focused at a slit-shaped exit portion of an ultrasonic focusing horn. In ultrasonic cleaning of precision electronic parts, fine particles of about 10 to 0.1 micron are efficiently removed to improve product yield. The present invention has developed an ultrasonic cleaner suitable for fine particle cleaning using an ultrasonic oscillator having an oscillation frequency of 500 kHz or more, and a cleaning apparatus using the cleaner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic cleaning method and an ultrasonic cleaning machine, and more particularly to cleaning of electronic components, particularly substrates such as magnetic disks, semiconductor wafers, and liquid crystals.

[0002]

2. Description of the Related Art In conventional ultrasonic cleaning described in, for example, JP-A-1-105376 and JP-A-1-303724, particularly in ultrasonic cleaning in a high-frequency region, the conversion efficiency of input power-ultrasonic output (intensity) is low. However, since the ultrasonic output (strength) at the point of use was low, the cleaning effect of the high-frequency ultrasonic cleaning could not be sufficiently brought out, and cleaning defects such as residual fine particles occurred.

[0003]

In electronic parts typified by magnetic disks, semiconductor wafers, liquid crystals, etc., the particle size that greatly affects the product yield and must be controlled is about 10 to 0.1 microns. . An object of the present invention is to efficiently remove these fine particles that could not be removed by the conventional technique, and to reduce poor cleaning due to residual fine particles.

[0004]

In the high-frequency ultrasonic cleaning, the oscillation frequency is set to 500 kHz or more and the ultrasonic output (ultrasonic intensity) is improved in order to efficiently remove fine particles of several microns to submicron. The task was achieved by devising the configuration and structure of an ultrasonic cleaning machine that makes it possible.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram of an ultrasonic cleaner according to an embodiment of the present invention. The ultrasonic washer comprises an ultrasonic oscillator 1, an ultrasonic oscillator case 2 containing two ultrasonic oscillators, and an ultrasonic focusing horn 4 having a slit-shaped outlet portion 3. The ultrasonic oscillator 1 and the ultrasonic oscillator case 2 are connected by a cable 5. The inside of the ultrasonic focusing horn 4 is filled with the same cleaning liquid 7 b as the cleaning liquid 7 a that is filled in the water tank 6. When an ultrasonic wave having a frequency of 500 kHz or more is oscillated, the high-frequency ultrasonic wave propagates through the cleaning liquid 7b in the ultrasonic focusing horn 4 to clean the object 8 to be cleaned.

Embodiment 2 FIG. 2 is a side sectional view of an ultrasonic oscillator case according to one embodiment of the present invention. The inside of the ultrasonic oscillator case 2 shown in FIG.
Each ultrasonic oscillator 9 is in focus,
That is, the slit-shaped outlet portion 3 was arranged so as to be located on an extension line of the bisector perpendicular to the surface of the vibrator. With this arrangement, it was confirmed that the ultrasonic output (strength) was improved by 200% or more than when the ultrasonic oscillators 9 were arranged in a line on the same plane.

(Embodiment 3) FIG. 3 shows a comparison between efficiency and efficiency of ultrasonic output by increasing the number of ultrasonic oscillators. As the number of sheets increases, the improvement in ultrasonic output (intensity) reaches a plateau, and the efficiency decreases. Further, under the condition that the efficiency is lowered, the input current to the ultrasonic vibrator 9 increases, and in some cases, the ultrasonic vibrator 9 is damaged by overload.
On the other hand, by arranging two ultrasonic vibrators 9 and focusing on the slit-shaped exit portion 3, an increase in the input current to the ultrasonic vibrator 9 is reduced, and the ultrasonic vibrator is damaged. It became possible to prevent. Although the number of the ultrasonic oscillators 1 is not particularly defined in all the embodiments, one ultrasonic oscillator 9 is driven by one oscillator. Two ultrasonic oscillators are driven by different ultrasonic oscillators. , Any of these methods may be used.

(Embodiment 4) FIG. 4 is a side sectional view of an ultrasonic cleaner according to an embodiment of the present invention. A in the left part of FIG.
The enlarged view seen from the direction is within the circle in FIG. The dimension B indicates the long side of the slit, and the dimension C indicates the short side of the slit. FIG. 5 shows the results of an investigation on the relationship between the distance (C dimension) of the short side of the slit and the ultrasonic output (intensity). As shown in the graph, when the short side of the slit is less than 2 mm, the ultrasonic output (intensity) emitted from the slit-shaped outlet portion 3 is drastically reduced. Therefore, the short side of the slit is set to 2 mm or more.

(Embodiment 5) FIG. 6 is a side sectional view of an ultrasonic cleaner according to an embodiment of the present invention. The distance from the ultrasonic vibrator 9 to the slit-shaped outlet portion 3 is D, and the angle formed by the slit-shaped outlet portion 3 of the ultrasonic focusing horn 4 is E. At an oscillation frequency of 500 kHz to 1.5 MHz, the influence of the D dimension on the ultrasonic output (strength) was investigated. FIG. 7 shows the results of an investigation on the relationship between the D dimension and the ultrasonic output (intensity). As a result of the investigation, it was possible to obtain a high and stable ultrasonic output by setting the D dimension to 80 to 220 mm. FIG. 8 shows the results of an investigation on the relationship between the angle E formed at the slit-shaped exit portion of the ultrasonic focusing horn and the ultrasonic output (intensity). When the angle E formed by the slit-shaped exit portion 3 of the ultrasonic focusing horn 4 exceeds 35 °, the ultrasonic output (intensity) decreases,
The input current to the ultrasonic oscillator 9 increases, and the ultrasonic oscillator 9
Could be damaged. However, by setting the angle E formed by the slit-shaped exit portion 3 of the ultrasonic focusing horn 4 to 35 ° or less, it is possible to prevent the input current to the ultrasonic vibrator 9 from increasing and to prevent the ultrasonic vibrator 9 from being damaged. It becomes possible.

(Embodiment 6) FIG. 9 is a configuration diagram of an ultrasonic cleaner according to an embodiment of the present invention. This is an example of use in which an ultrasonic cleaning machine including an ultrasonic oscillator 1, an ultrasonic transducer case 2, and a cleaning liquid supply pipe 10 for supplying a cleaning liquid into an ultrasonic focusing horn 4 is installed in a water tank 6. In this embodiment, a water flow from the cleaning liquid supply pipe 10 is added to a straight flow generated by high-frequency ultrasonic waves. As a result, an effect of removing fine particles and foreign matter detached from the object to be cleaned 8 is imparted, so that re-adhesion is further prevented and cleaning performance is improved.

(Embodiment 7) In the embodiment of FIG. 9, the cleaning liquid supply pipe 10 is disposed above the ultrasonic focusing horn 4 to supply the cleaning liquid from above. As shown in the configuration diagram of the ultrasonic cleaner, the cleaning liquid supply pipe 10 may be disposed below the ultrasonic focusing horn 4 and the cleaning liquid may be supplied from below.

(Embodiment 8) FIG. 11 is a block diagram of an ultrasonic cleaner according to an embodiment of the present invention. An ultrasonic oscillator 1, an ultrasonic oscillator case 2, an ultrasonic focusing horn 4, and a cleaning liquid supply pipe 10 for supplying a cleaning liquid into the ultrasonic focusing horn. This embodiment is a case where the functional unit of the ultrasonic cleaner is taken out of the water tank. Cleaning liquid supply pipe 10
The cleaning liquid is supplied to the cleaning liquid, and the ultrasonic wave is transmitted to the ultrasonic shower 12 of the cleaning liquid discharged from the slit-shaped outlet portion 3, thereby enabling the cleaning of the object 8 to be cleaned. It is possible to reduce the re-contamination by the removed fine particles as compared with the configuration of FIG. Of course, it is possible to arrange the cleaning liquid supply pipe 10 below the ultrasonic focusing horn 4 and supply the cleaning liquid from below.

Embodiment 9 FIG. 12 is a side sectional view of an ultrasonic cleaner according to an embodiment of the present invention. In the present embodiment, with respect to the direction of the cleaning liquid supply pipe 10 connected to the ultrasonic focusing horn 4, the cleaning liquid supply pipe 10 is arranged so that the water flow 11 of the cleaning liquid flows along the surface of the ultrasonic oscillator 9 when the cleaning liquid is supplied. It was done. When the ultrasonic cleaner of the present invention is oscillated for a long time, a large amount of air bubbles due to deaeration adhere concentrically from the center of the ultrasonic oscillator 9 depending on the type of the cleaning liquid, and the ultrasonic output (strength) decreases. There is a phenomenon that the performance of removing fine particles is significantly reduced due to the cause.
In the embodiment shown in FIG. 12, it is possible to prevent air bubbles from adhering to the surface of the ultrasonic oscillator 9 and to prevent a phenomenon in which the performance of removing fine particles is significantly reduced.

(Embodiment 10) FIG. 13 is a configuration diagram of an ultrasonic cleaning apparatus according to an embodiment of the present invention. Two sets of ultrasonic cleaners were installed facing each other, and the plate-like object 8 was passed between the ultrasonic showers 12 so that both surfaces of the object 8 could be cleaned at the same time. This has made it possible to improve the cleaning throughput. Further, by holding the object to be cleaned 8 between two sets of ultrasonic cleaners and rotating the object to be cleaned 8 in the same plane as the plate surface, more efficient cleaning becomes possible.

(Embodiment 11) FIG. 14 shows the relationship between the ultrasonic output (strength) and the cleaning effect in an ultrasonic cleaner according to an embodiment of the present invention. As shown in this example, the cleaning performance in the ultrasonic cleaning depends on the ultrasonic output (intensity). In the present invention, since the ultrasonic output (strength) can be increased, it is possible to clean fine particles which could not be removed conventionally, and the cleaning performance of the ultrasonic cleaning machine can be greatly improved.

[0017]

By using the washing machine or the washing apparatus of the present invention, the surface of a substrate of an electronic component such as a magnetic disk, a semiconductor wafer, and a liquid crystal can be highly purified. As a result, product yield and reliability can be greatly improved. Further, as an indirect effect, the spread of high-frequency ultrasonic cleaning to the electronic component industry can be promoted.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ultrasonic cleaning machine according to an embodiment of the present invention.

FIG. 2 is a side sectional view of an ultrasonic oscillator case according to one embodiment of the present invention.

FIG. 3 shows a comparison of efficiency and efficiency of ultrasonic output by increasing the number of ultrasonic oscillators.

FIG. 4 is a side sectional view of an ultrasonic cleaner according to one embodiment of the present invention.

FIG. 5 shows a relationship between a distance (C dimension) of a short side of a slit and an ultrasonic output (intensity).

FIG. 6 is a side sectional view of an ultrasonic cleaner according to an embodiment of the present invention.

FIG. 7 is an examination result of a relationship between a D dimension and an ultrasonic output (strength).

FIG. 8 is a result of studying a relationship between an angle E formed at a slit-shaped exit portion of an ultrasonic focusing horn and an ultrasonic output (strength).

FIG. 9 is a configuration diagram of an ultrasonic cleaning machine according to one embodiment of the present invention.

FIG. 10 is a configuration diagram of an ultrasonic cleaner according to an embodiment of the present invention.

FIG. 11 is a configuration diagram of an ultrasonic cleaner according to an embodiment of the present invention.

FIG. 12 is a side sectional view of an ultrasonic cleaner according to an embodiment of the present invention.

FIG. 13 is a configuration diagram of an ultrasonic cleaning machine according to an embodiment of the present invention.

FIG. 14 shows the relationship between the US output (strength) and the cleaning effect in the ultrasonic cleaner of the present invention.

[Explanation of symbols]

1. Ultrasonic oscillator, 2. Ultrasonic oscillator case, 3.
Slit-shaped outlet, 4 ... Ultrasonic focusing horn, 5 ... Cable, 6 ... Water tank, 7a ... Washing liquid (in the water tank), 7b ... Washing liquid (in the ultrasonic focusing horn), 8 ... Washed object, 9 ... Ultrasonic oscillation Numeral 10: Cleaning liquid supply pipe, 10a: Cleaning liquid supply direction, 11: Water flow of cleaning liquid, 12: Ultrasonic shower.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahiro Watanabe 2880 Kozu, Odawara-shi, Kanagawa Storage Systems Division, Hitachi, Ltd.

Claims (9)

[Claims] 1. An ultrasonic cleaning machine comprising at least an ultrasonic oscillator, an ultrasonic vibrator and an ultrasonic focusing horn filled with a cleaning liquid, having an oscillation frequency of 500 kHz or more and two ultrasonic vibrators. Wherein the two vibrators are arranged so as to be focused at the slit-shaped exit portion of the ultrasonic focusing horn. 2. The ultrasonic cleaner according to claim 1, wherein the slit-side exit portion of the ultrasonic focusing horn has a dimension on the short side of the slit of 2 mm or more. 3. An ultrasonic cleaning apparatus according to claim 1, wherein the oscillation frequency is 500 kHz to 1.5 MHz, and the focusing distance (focal length) of the ultrasonic focusing horn is 80 to 200 mm. Machine. 4. The ultrasonic cleaner according to claim 1, wherein a tip angle of a slit-shaped outlet of the ultrasonic focusing horn is 35 ° or less. 5. A cleaning machine according to claim 1, wherein a pipe for constantly supplying a cleaning liquid to the ultrasonic focusing horn is connected,
An ultrasonic cleaner characterized by applying ultrasonic waves to a flow of a cleaning liquid discharged from an outlet of an ultrasonic focusing horn. 6. The cleaning machine according to claim 5, wherein the direction of the pipe connected to the ultrasonic focusing horn is directed toward the surface of the ultrasonic vibrator, and the surface of the ultrasonic vibrator is cleaned with the supplied cleaning liquid. Ultrasonic cleaning machine characterized by its positional relationship. 7. The cleaning machine according to claim 1, wherein the ultrasonic focusing horns of the two sets of cleaning machines are installed at opposite positions, and the plate-shaped objects to be cleaned are ultrasonically controlled by the two sets of cleaning machines. A cleaning apparatus characterized in that both sides of the object to be cleaned can be simultaneously cleaned by passing between the focusing horns. 8. A cleaning apparatus according to claim 7, wherein the object to be cleaned is a magnetic disk substrate, a semiconductor wafer or a liquid crystal substrate. 9. A magnetic disk, semiconductor, or liquid crystal product manufactured by using the ultrasonic cleaner according to claim 1 or the cleaning apparatus according to claim 7.