JP2010131520A - Ultrasonic cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic cleaning device with ultrasonic cleaning heads which obtain uniform cleaning performance and which can reduce the amounts of liquids used when a liquid film is formed between a cleaning liquid feed nozzle and a substrate be to cleaned. <P>SOLUTION: The ultrasonic cleaning device 10 cleaning the substrate to be cleaned 30 by irradiating a fed cleaning liquid with ultrasonic waves includes a substrate supporting element 31 supporting the substrate to be cleaned 30 in a vertical posture, and a plurality of ultrasonic cleaning heads 20a, 20b feeding the cleaning liquid. The ultrasonic cleaning heads 20a, 20b are provided with ultrasonic vibration elements 21a, 21b generating the ultrasonic waves, cleaning liquid feed nozzles 22a, 22b. The plural cleaning heads 20a, 20b, are installed along the cleaning direction of the substrate to be cleaned 30 and the center axes of the openings of the respective cleaning feed nozzles 22a, 22b are crossed to each other between the substrates to be cleaned 30 and the ultrasonic cleaning heads 20a, 20b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic cleaning device used for cleaning a glass substrate of a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, etc., and particularly an impact force generated when an ultrasonic wave is irradiated to a cleaning liquid by a vibrator. The present invention relates to an ultrasonic cleaning apparatus that is used for cleaning using a slab.

  In the manufacturing process of a liquid crystal display device, there is a process required to clean the glass substrate with a high degree of cleaning. In such a process, in order to quickly and reliably remove contaminants such as particles adhering to the substrate surface, cleaning with a plurality of high-concentration chemicals and ultrapure water rinse has been repeatedly performed. However, a large amount of chemicals are used, and a large amount of ultrapure water is required to rinse the adhered chemicals after cleaning.

  For this reason, in recent years, in order to reduce the amount of chemicals to be used and the amount of ultrapure water, a cleaning method using ultrasonic waves has begun to be adopted. In this method, ultrasonic waves are used, and the cleaning liquid to which vibration is applied is sprayed onto the substrate, so that the bonding force of the attached fine particles can be reduced, so that the cleaning effect can be improved compared to the case where vibration is not applied. it can. Furthermore, after degassing the gas in the cleaning liquid in advance, the functional gas is dissolved, thereby increasing the reactivity with contaminants attached to the object to be cleaned and improving the cleaning performance.

  FIG. 6 is a diagram schematically showing an example of such a conventional ultrasonic cleaning apparatus 210. As shown in FIG. 6, the conventional ultrasonic cleaning apparatus 210 includes a cleaning liquid supply line 260 for supplying a cleaning liquid onto the substrate, a degassing membrane module 240 for removing dissolved gas contained in the raw cleaning liquid, and a cleaning liquid. And a cleaning solution supply nozzle 220 including an ultrasonic transducer 221 for irradiating the cleaning solution containing gas with ultrasonic waves. The substrate 230 to be cleaned is held horizontally, and the cleaning liquid 224 is supplied from the upper part thereof. The cleaning liquid 224 contains a gas dissolved by a gas dissolving device, and the cleaning liquid is characterized by irradiating ultrasonic waves of 20 kHz or higher. The cleaning solution irradiated with ultrasonic waves generates radicals with high reactivity in the cleaning solution due to the crushing effect of dissolved gas and cavities, and generates such radicals. It reacts quickly with contaminants on the target substrate to decompose and remove the contamination.

  Further, in order to effectively perform such ultrasonic cleaning and reduce the amount of use, the following Patent Document 1 describes the thickness L of the cleaning liquid on the object to be cleaned at the position where the ultrasonic wave is applied. It describes that it is in a predetermined range in relation to the wavelength λ.

Moreover, when it wash | cleans while hold | maintaining a base material horizontally, there existed a fault that the back surface which contact | connects a conveyor cannot be wash | cleaned. Therefore, Patent Document 2 below describes a thin glass substrate manufacturing apparatus including an ultrasonic cleaning element that discharges a cleaning liquid in a state where the thin glass substrate is suspended as a method for effectively cleaning both surfaces.
JP 2001-205205 A Japanese Patent Laid-Open No. 10-286535

  Since the ultrasonic cleaning head used in the cleaning method described in Patent Document 1 is held horizontally and the cleaning liquid is supplied from above, the cleaning can be performed without any problem. However, when the substrate to be cleaned as described in Patent Document 2 is held vertically, the ultrasonic cleaning head is moved in the vertical direction, and cleaning is performed, if the supply amount of the cleaning liquid is insufficient, the ultrasonic cleaning is performed. A liquid film is not formed between the head and the surface to be cleaned, and ultrasonic waves do not propagate. For this reason, since a liquid film is formed from the ultrasonic cleaning head to the surface to be cleaned, it is necessary to secure a flow rate at which the influence of gravity is negligible, and there is a problem that consumption of the cleaning liquid increases.

  The ultrasonic cleaning head is formed by providing a plurality of vibrators in the width direction of the substrate to be cleaned. For this reason, there is a problem in that residual dirt is present in the joint portion between the vibrators because the cleaning power is uneven. Therefore, a plurality of ultrasonic cleaning heads are provided in the moving direction of the substrate to be cleaned and the joints of the vibrators provided in the cleaning liquid supply nozzle are shifted so as not to cause cleaning unevenness. However, when a plurality of ultrasonic cleaning heads are provided, there is a problem that the consumption of the cleaning liquid is further increased in proportion to the number of ultrasonic cleaning heads.

  The present invention has been made in view of such circumstances, and obtains a uniform cleaning performance of the substrate to be cleaned, and the amount of liquid used when forming a liquid film between the cleaning liquid supply nozzle and the substrate to be cleaned. An object of the present invention is to provide an ultrasonic cleaning apparatus including an ultrasonic cleaning head that can be reduced.

  According to a first aspect of the present invention, in order to achieve the object, in the ultrasonic cleaning apparatus for cleaning the substrate to be cleaned by irradiating the supplied cleaning liquid with ultrasonic waves, the substrate to be cleaned is in a vertical posture. And a plurality of ultrasonic cleaning heads for supplying the cleaning liquid, each of the ultrasonic cleaning heads includes an ultrasonic vibrator for generating ultrasonic waves, and a cleaning liquid supply nozzle for ejecting the cleaning liquid. The plurality of ultrasonic cleaning heads are provided along the cleaning direction of the substrate to be cleaned, and the central axis of the opening of each cleaning liquid supply nozzle is between the substrate to be cleaned and the ultrasonic cleaning head. An ultrasonic cleaning apparatus characterized by intersecting at the above is provided.

  According to claim 1, by providing a plurality of ultrasonic cleaning heads along the cleaning direction of the substrate to be cleaned, the central axis of the opening of each cleaning liquid supply nozzle intersects between the substrate to be cleaned and the ultrasonic cleaning head. The cleaning power can be improved, and the amount of liquid for forming the liquid film can be suppressed to the same level as that of a single conventional ultrasonic cleaning head.

  A second aspect of the present invention provides the ultrasonic cleaning head according to the first aspect, wherein each of the ultrasonic cleaning heads includes a plurality of ultrasonic transducers arranged in a width direction of the substrate to be cleaned, and at least two of the ultrasonic cleaning heads The connection portion of the vibrator is provided at a portion different from each other with respect to the cleaning direction.

  According to the second aspect, the connection portions of the plurality of ultrasonic transducers provided in the ultrasonic cleaning head are connected to the connection portions of the plurality of ultrasonic transducers provided in the other ultrasonic cleaning head. In this case, it is possible to suppress uneven cleaning even when the amount of liquid is the same as that of the prior art.

  A third aspect of the present invention is characterized in that, in the first or second aspect, the discharge amount of the upstream ultrasonic cleaning head is smaller than the discharge amount of the downstream ultrasonic cleaning head in the cleaning direction of the cleaning substrate. .

  According to the third aspect, the amount of the cleaning liquid to be used is reduced by making the discharge amount from the upstream ultrasonic cleaning head smaller than the discharge amount of the downstream ultrasonic cleaning head with respect to the cleaning direction. be able to.

  According to the present invention, it is possible to improve the cleaning power, obtain a uniform cleaning ability of the substrate to be cleaned, and reduce the amount of use when forming a liquid film between the cleaning liquid supply nozzle and the substrate to be cleaned. be able to.

  Hereinafter, preferred embodiments of the cleaning apparatus of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram schematically showing the configuration of an ultrasonic cleaning apparatus 10 according to the present invention. FIG. 2 (a) is an enlarged view of ultrasonic cleaning heads 20a and 20b, and FIG. 2 (b) is a side sectional view. It is. In FIGS. 1 and 2, the description will be made in the form including two ultrasonic cleaning heads, but the number of ultrasonic cleaning heads is not limited, and a structure including three or more ultrasonic cleaning heads may be used.

  The ultrasonic cleaning apparatus 10 of the present invention holds the substrate 30 to be cleaned in a vertical state by the substrate holding means 31 and performs cleaning while lowering the ultrasonic cleaning heads 20a and 20b vertically along the substrate 30 to be cleaned. Do. The ultrasonic cleaning apparatus 10 includes a deaeration membrane module 40 and a gas dissolution membrane module 50. For example, ultrapure water is used as the cleaning liquid and is supplied to the ultrasonic cleaning head 20 from a supply source (not shown) through the degassing membrane module 40 and the gas dissolution membrane module 50.

  The substrate holding means 31 has a function of ascending to the lower end portion of the loaded substrate 30 to be carried and holding the substrate 30 to be cleaned. It has a function of fixing the substrate to be cleaned 30 during the cleaning operation at a predetermined position. The portion that receives the lower end can be made of an elastic body having a shape such as a flat surface, a concave surface, and a groove, or a material and shape that does not damage the substrate to be cleaned 30.

  The degassing membrane module 40 degass excess gas dissolved in the cleaning solution, and a functional gas is dissolved in the cleaning solution degassed by the degassing membrane module 40 by the gas dissolving membrane module 50 to perform ultrasonic cleaning. Supply to the head 20. In this way, after degassing excess gas dissolved in the cleaning liquid, supplying functional gas and dissolving it in water can increase the dissolved amount of gas that contributes to cleaning, cleaning effect Can be further improved. In addition, about the gas to dissolve, ozone, oxygen, hydrogen, nitrogen, argon, helium etc. can be used without being specifically limited. After the gas is dissolved, chemicals such as ammonia and sulfuric acid can be added as necessary for the purpose of decontamination and pH adjustment. Moreover, it is good also as a structure which replaces with the structure which dissolves functional gas in the cleaning liquid deaerated in this way, and saturates air with a cleaning liquid.

  FIG. 2 is an enlarged view of the ultrasonic cleaning heads 20a and 20b. The ultrasonic cleaning heads 20a and 20b include an ultrasonic vibrator 21 that generates ultrasonic waves and a cleaning liquid supply nozzle 22 that ejects a cleaning liquid.

  The cleaning liquid 24 ejected from the cleaning liquid supply nozzle 22 is irradiated with ultrasonic waves by the ultrasonic vibrator 21. The irradiated ultrasonic energy propagates through the cleaning liquid supplied from the opening of the cleaning liquid supply nozzle 22 and reaches the substrate 30 to be cleaned.

  In the present invention, a plurality of ultrasonic cleaning heads 20 are provided. The ultrasonic cleaning head 20 is configured so that the central axis of the cleaning liquid supply nozzle of each ultrasonic cleaning head 20 intersects between the substrate to be cleaned 30 and the cleaning liquid supply nozzle. With such a configuration, the cleaning power can be improved, and the amount of cleaning liquid for forming a liquid film between the substrate to be cleaned 30 and the ultrasonic cleaning head is used alone. Compared to the case, the liquid volume can be suppressed to the same level.

  For example, as shown in FIG. 2, an ultrasonic cleaning head 20b is provided separately from the ultrasonic cleaning head 20a, and the cleaning liquid is supplied upward from below. Therefore, even if only the upper ultrasonic cleaning head cannot form a liquid film between the ultrasonic cleaning head 20a and the substrate 30 to be cleaned due to the influence of gravity, the lower ultrasonic cleaning head 20b Therefore, the ultrasonic wave generated by the ultrasonic vibrator 21 can be reliably propagated to the substrate to be cleaned.

  The number of ultrasonic cleaning heads 20 has been described in the configuration having two ultrasonic cleaning heads in FIGS. 1 and 2, but as shown in FIG. 3, the number of ultrasonic cleaning heads may be three, Moreover, you may have more. When three or more ultrasonic cleaning heads 20 are provided, it is preferable that the central axes of the cleaning liquid supply nozzles intersect at one point. By intersecting at one point, the amount of the cleaning liquid for forming the liquid film can be maintained, so that ultrasonic waves can be propagated and the cleaning power can be improved.

  The ultrasonic vibrator 21 provided in the ultrasonic cleaning head 20 is formed by connecting a plurality of ultrasonic vibrators when the substrate to be cleaned 30 is long in the width direction. Therefore, as shown in FIG. 4, the residual dirt 331 remains at the joint portion of the ultrasonic vibrator, and the cleaning power becomes uneven. Therefore, as shown in FIG. 2B, the ultrasonic transducer head 20 is connected to the ultrasonic transducer at a portion different from the ultrasonic transducer connection portions of the other ultrasonic cleaning heads. Generation of unevenness can be suppressed. By adopting such a configuration, it is possible to suppress the occurrence of cleaning unevenness with the same amount of cleaning liquid as in the past.

  Further, the discharge amount of the cleaning liquid is set so that the discharge amount discharged from the upstream ultrasonic cleaning head is smaller than the discharge amount discharged from the downstream ultrasonic cleaning head with respect to the cleaning direction of the substrate 30 to be cleaned. It is preferable. By increasing the discharge amount on the downstream side, the cleaning liquid discharged from the ultrasonic cleaning head on the upstream side can be dispersed, so it is easy to form a liquid film between the substrate to be cleaned and the ultrasonic cleaning head. Since it can be performed, the cleaning power can be improved even if the amount of the cleaning liquid used is the same as the conventional one.

The arrangement of the ultrasonic cleaning head is not particularly limited as long as the central axis of the opening of the cleaning liquid supply nozzle of each ultrasonic cleaning head can intersect between the substrate to be cleaned 30 and the ultrasonic cleaning head 20. Can be arranged. As a preferred arrangement, the total of the discharge port angles θ of the plurality of cleaning liquid supply nozzles 122 is 180 ° or less. FIG. 5 shows an arrangement when three ultrasonic cleaning heads 120 and 130 are provided. As shown in FIG. 5A, the total angle θ ₁ + θ ₂ + θ ₃ of the discharge ports of the ultrasonic cleaning head is made smaller than 180 °, so that the cleaning liquid discharged from the plurality of cleaning liquid supply nozzles 122 can be removed. The propagating ultrasonic energy can reach the substrate without causing interference. As shown in FIG. 5B, when the total angle θ ₁ + θ ₂ + θ ₃ of the outlets of the ultrasonic cleaning head is arranged to exceed 180 °, the cleaning liquids discharged from the opposing cleaning liquid supply nozzles 132a and 132c Therefore, the ultrasonic energy cannot be sufficiently propagated as compared with the arrangement shown in FIG.

  The cleaning solution irradiated with ultrasonic waves generates highly reactive hydrogen radicals (H.), hydroxy radicals (OH.), Etc. in the cleaning solution due to the crushing effect of dissolved gas and cavities, causing contamination on the substrate to be cleaned. It can react quickly with substances and decompose and remove contaminants.

It is the figure which showed typically the structure of the ultrasonic cleaning apparatus of this invention. It is the enlarged view (a) and side sectional view (b) of an ultrasonic cleaning head. It is an enlarged view which shows other embodiment of an ultrasonic cleaning head. It is the enlarged view (a) and side sectional view (b) of the ultrasonic cleaning head used for the conventional ultrasonic cleaning apparatus. It is the figure which showed the preferable arrangement | positioning of an ultrasonic cleaning head. It is the figure which showed typically an example of the conventional ultrasonic cleaning apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Ultrasonic cleaning apparatus 20, 120, 130 ... Ultrasonic cleaning head, 21, 121, 131 ... Ultrasonic vibrator, 22, 122, 132 ... Cleaning liquid supply nozzle, 24 ... Cleaning liquid, 30 ... Substrate to be cleaned, 31 ... Substrate holding means, 40 ... deaeration membrane module, 50 ... gas dissolution membrane module, 60 ... cleaning liquid supply line

Claims (3)

In the ultrasonic cleaning apparatus that cleans the substrate to be cleaned by irradiating the supplied cleaning liquid with ultrasonic waves,
A substrate holding means for holding the substrate to be cleaned in a vertical posture; and a plurality of ultrasonic cleaning heads for supplying the cleaning liquid,
Each of the ultrasonic cleaning heads includes an ultrasonic vibrator that generates ultrasonic waves, and a cleaning liquid supply nozzle that ejects the cleaning liquid,
The plurality of ultrasonic cleaning heads are provided along the cleaning direction of the substrate to be cleaned, and the central axis of the opening of each cleaning liquid supply nozzle intersects between the substrate to be cleaned and the ultrasonic cleaning head. An ultrasonic cleaning apparatus characterized by: Each of the ultrasonic cleaning heads includes a plurality of ultrasonic transducers arranged in the width direction of the substrate to be cleaned.
2. The ultrasonic cleaning apparatus according to claim 1, wherein in at least two of the ultrasonic cleaning heads, the connection portions of the ultrasonic transducers are provided at different portions with respect to the cleaning direction.   The ultrasonic cleaning according to claim 1, wherein a discharge amount of an upstream ultrasonic cleaning head is smaller than a discharge amount of a downstream ultrasonic cleaning head with respect to a cleaning direction of the cleaning substrate. apparatus.

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