JP4066673B2 - Substrate cleaning apparatus and cleaning method using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cleaning apparatus and a cleaning method related to the entire electronics field for cleaning a flat substrate, in particular, a flat substrate receiving cleaning step and a colored pattern substrate intermediate cleaning step in color filter production.
[0002]
[Prior art]
A color filter used in a liquid crystal display or the like is an optical element having a fine red, green, blue pattern or the like. And the manufacture consists of processes, such as apply | coating a photosensitive resist to transparent substrates, such as glass, exposure, and image development, The same process is repeated about each color. The cleaning process is the most numerous process in color filter manufacturing, starting with acceptance cleaning when bringing the substrate into the clean room, from cleaning before application of each color of resist, and cleaning from polishing after coloring pattern to final cleaning. is there. Hereinafter, conventional techniques and problems will be described from the viewpoint of the color filter cleaning process.
[0003]
The purpose of the cleaning process is mainly to remove adhering dust (hereinafter referred to as particles). There are various types of cleaning units, such as UV irradiation, brush cleaning using detergent, ultrasonic cleaning at low frequency, ultrasonic cleaning at high frequency, and two-fluid cleaning that simultaneously jets gas and liquid at high pressure. In addition, a high-pressure shower with pure water can be used. In the color filter cleaning process, these cleaning units are combined to constitute an apparatus with a process design most suitable for each cleaning process.
[0004]
Usually, oils and fats are deposited on the surface of a glass substrate with a standing time including in a clean room. Therefore, when left for a long time, the surface becomes very hydrophobic. The above-mentioned ultraviolet irradiation is generally used as a typical dry surface modification means for removing the oils and fats on the surface to make them hydrophilic and enhancing the effect of wet cleaning.
[0005]
Ultrasonic cleaning is a very common cleaning method, and low frequency cleaning using about 40 kHz and high frequency cleaning using about 1 MHz are mainly used.
[0006]
The background of the increase in the size of the cleaning apparatus year by year is due to the increase in the size of the substrate to be cleaned and the increase in the substrate transfer speed associated with the tact-up. In order to maintain the same cleaning ability at a high transport speed, the number of cleaning units has increased, and as a result, there are major problems such as an increase in equipment size and a large amount of utility usage.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a space-saving, low-cost cleaning device and a cleaning process by adding hydrogen water supply means to a cleaning device having a simple configuration including an ultraviolet irradiation device and an ultrasonic irradiation device. To do.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 is at least an ultraviolet irradiation unit for decomposing an organic compound of fats and oils adhering to the substrate, an ultrasonic cleaning unit for cleaning particles, a drying unit for drying the substrate after cleaning, A substrate cleaning apparatus comprising a transport means for transporting a substrate, comprising hydrogen water supply means for supplying hydrogen water to the ultrasonic cleaning unit, wherein the ultrasonic cleaning unit is composed of two or more machines, At least one machine has an ultrasonic wave transmitting element on the back side of the substrate so as to clean the back side of the substrate, and in the hydrogen water supply means supplied to the ultrasonic cleaning machine having the ultrasonic wave transmitting element on the back side of the substrate, The substrate cleaning apparatus is characterized in that hydrogen water used for cleaning one of the surfaces is provided with a reuse means for cleaning the other surface of the substrate .
The front side must be cleaned with care, but if the back side is not cleaned, dust will be brought into the post-process and will adhere to the front side and cause damage, so the back side must also be cleaned. There is.
The hydrogen water used for cleaning the back side can be the hydrogen water used and recovered in the front side cleaning, and the amount of waste water is reduced by reusing.
[0009]
According to a second aspect of the present invention, in the method for cleaning a substrate,
(1) The organic compound of fats and oils adhering on a board | substrate is decomposed | disassembled with an ultraviolet irradiation unit.
(2) After that, the substrate is transported to an ultrasonic cleaning machine having an ultrasonic transmission element on the back side of the substrate, and ultrasonic waves are applied to the back side of the substrate while supplying the recovered hydrogen water used for surface cleaning. Wash.
(3) After that, the substrate is transported to an ultrasonic cleaning machine having an ultrasonic transmitting element on the substrate surface side, and the particles adhering to the surface side of the substrate are cleaned by irradiating ultrasonic waves while supplying hydrogen water. Wash.
The hydrogen water used for cleaning the front surface is collected in a recovery tank and reused for back surface cleaning in the step (2) to prevent mixed liquid with new liquid .
(4) Thereafter, the substrate is transported to the drying unit and dried. The substrate cleaning method is characterized by passing through at least the above steps.
[0010]
[0011]
[0012]
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Cleaning by irradiating hydrogen water with ultrasonic waves is very effective for particle removal. An object of the present invention is to provide an effect of performing single wafer cleaning with a low flow rate of hydrogen water usage by combining ultraviolet irradiation and hydrogen water cleaning and further reusing hydrogen water. .
[0014]
When employing an application of hydrogen water for washing, a small amount of chemical solution is often added to adjust the pH. The present invention is characterized in that no chemical solution is added and wet cleaning is performed only with neutral hydrogen water.
[0015]
Hereinafter, an example of a substrate cleaning apparatus and a substrate cleaning method of the present invention will be described with reference to the drawings.
[0016]
As shown in FIG. 1, the present invention includes an ultraviolet irradiation unit (1), ultrasonic cleaning units (2) and (3), and a drying air knife (4).
The ultrasonic cleaning unit includes a back side ultrasonic cleaning unit (2) for cleaning the back side of the substrate and two front side ultrasonic cleaning units (3) for cleaning the front side of the substrate.
[0017]
Although the kind of ultraviolet lamp used for the ultraviolet irradiation unit (1) is not particularly limited, it is desirable to have a wavelength region that acts on both oxygen gas and ozone gas to generate active oxygen.
[0018]
As shown in FIG. 1, the back ultrasonic cleaning unit (2) has an ultrasonic oscillation element in the lower block, and the front ultrasonic cleaning unit (3) has an ultrasonic oscillation element in the upper block. The ultrasonic cleaning unit is composed of a total of three machines, one of which is for back surface cleaning and the other two are for surface cleaning. FIG. 1 shows one example, and the number of ultrasonic cleaning units is appropriately increased as necessary according to the cleaning request.
[0019]
Hydrogen water is supplied to the two front-side ultrasonic cleaning units on the downstream side. The supplied hydrogen water is collected together with particles by the hydrogen water new liquid collecting pump (6) and stored in the hydrogen water primary water storage tank (5). Similarly, the hydrogen water leaked without being collected is drained by gravity to the hydrogen water primary water storage tank (5).
[0020]
It is desirable that the hydrogen water to be supplied has a concentration of 1.0 mg / l or more. The supply flow rate has an adjustable mechanism, and the flow rate is changed depending on the size of the substrate to be cleaned. The maximum concentration dissolved in water is about 1.7 mg / l at 1 atmosphere.
[0021]
The hydrogen water accumulated in the hydrogen water primary storage tank (5) is fed by the reused hydrogen water feed pump (7), and further passes through the filter (8) to the back ultrasonic cleaning unit (2) again. Supplied. The supply flow rate also has an adjustable mechanism. The pore size of the filter is not particularly limited, but is preferably 1 μm or less.
[0022]
The hydrogen water re-supplied to the back ultrasonic cleaning unit (2) is recovered together with particles by the reuse hydrogen water recovery pump (9) in the same manner as the front ultrasonic cleaning unit (3), and is drained. Hydrogen water leaked without being collected is also drained by the gravity drain.
[0023]
The tank to which the back ultrasonic cleaning unit (2) and the front ultrasonic cleaning unit (3) are attached must be completely separated. This is to prevent the mixed liquid because the front side ultrasonic cleaning unit (3) uses a new hydrogen water solution and the back side ultrasonic cleaning unit (2) uses a hydrogen water regenerating solution.
[0024]
The ultraviolet irradiation unit (1) is a dry process, and the back ultrasonic cleaning unit (2) is a wet process. Therefore, the flow of liquid into the tank of the ultraviolet irradiation unit (1) must be avoided. In addition to the function of collecting particles, the reuse hydrogen water recovery pump (9) also has a role to prevent liquid from flowing upstream. Therefore, it is necessary to perform sufficient adjustment so that no liquid flows in, and the recovery hole of the ultrasonic cleaning unit (2) should be a boundary line between dry and wet.
[0025]
In the present invention, no unit such as a brush or a high-pressure shower that interferes with the conveyance of the substrate is employed. In other words, this is fundamentally different from a conventional cleaning process in which particles are removed by applying a physical force to the substrate surface. Therefore, the conventionally required presser roller system for transporting the substrate between the upper and lower sides and the transport guide for preventing the meandering of the substrate become unnecessary.
Some lift and meandering of the substrate may occur in the air knife portion, but these can be sufficiently avoided by adjusting the air flow rate and pressure, and the air blowing angle to the substrate.
[0026]
For the conveyance in the substrate cleaning apparatus, for example, conveyance shafts arranged at regular intervals in a direction orthogonal to the substrate conveyance direction are used. By providing the ultrasonic cleaning unit between the shafts, particles on both surfaces of the substrate can be washed away.
[0027]
The light irradiation intensity of the ultraviolet irradiation unit (1) is also increasing year by year, which makes it possible to reduce the space occupied by the ultraviolet irradiation device. In order to realize the apparatus downsizing described in the present invention more remarkably, it is desirable to adopt an ultraviolet irradiation apparatus with high strength and a small number of lamps.
[0028]
The present invention provides a cleaning method sufficient for substrate cleaning, and the detailed configuration and size of the cleaning apparatus are not particularly limited. However, the installation interval of each unit can be arbitrarily designed and more agglomerated. It is desirable to develop the device in a state of being integrated. Since the size of the substrate in the transport direction is not affected, it is not a problem to perform all cleaning steps on one substrate at the same time.
[0029]
【The invention's effect】
According to the substrate cleaning apparatus and the cleaning method according to the present invention, the apparatus size can be significantly reduced as compared with the prior art in order to adopt a simple configuration including only ultraviolet irradiation, ultrasonic cleaning with hydrogen water, and an air knife. It becomes possible. Further, by adopting the reuse of hydrogen water in the method for supplying hydrogen water, the utility to be used can be minimized.
[0030]
Moreover, since no detergent is used, a rinsing step for washing away the detergent is not necessary. Since hydrogen water can be treated as general waste water, it is not necessary to install special waste water treatment equipment.
[0031]
Further, when the cleaning process according to the present invention is applied to the apparatus, a press roller and a meandering prevention guide are not required, and the transport system has a very simple configuration, so that maintenance can be improved.
[Brief description of the drawings]
FIG. 1 illustrates a substrate cleaning apparatus of the present invention,
(A) is a schematic side view of the apparatus, and (b) is a top view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ultraviolet irradiation unit 2 ... Back surface ultrasonic cleaning unit 3 ... Front surface ultrasonic cleaning unit 4 ... Drying air knife 5 ... Hydrogen water primary water storage tank 6 ... Hydrogen water new liquid collection pump 7 ... Reuse hydrogen water feeding liquid Pump 8 ... Reuse hydrogen water supply filter 9 ... Reuse hydrogen water recovery pump 10 ... Substrate to be cleaned

Claims (2)

Consists of at least an ultraviolet irradiation unit for decomposing organic compounds of fats and oils adhering to the substrate, an ultrasonic cleaning unit for cleaning particles, a drying unit for drying the substrate after cleaning, and a transport means for transporting the substrate In the substrate cleaning apparatus that has been
Comprising hydrogen water supply means for supplying hydrogen water to the ultrasonic cleaning unit;
The ultrasonic cleaning unit is composed of two or more machines, at least one machine has an ultrasonic transmission element on the back side of the substrate so as to clean the back side of the substrate,
In the hydrogen water supply means supplied to the ultrasonic cleaning machine having the ultrasonic transmitting element on the back side of the substrate, the hydrogen water used for cleaning one side of the substrate is reused for cleaning the other side of the substrate. A substrate cleaning apparatus, characterized by comprising: In a method for cleaning a substrate,
(1) The organic compound of fats and oils adhering on a board | substrate is decomposed | disassembled with an ultraviolet irradiation unit.
(2) After that, the substrate is transported to an ultrasonic cleaning machine having an ultrasonic transmission element on the back side of the substrate, and ultrasonic waves are applied to the back side of the substrate while supplying the recovered hydrogen water used for surface cleaning. Wash.
(3) After that, the substrate is transported to an ultrasonic cleaning machine having an ultrasonic transmitting element on the substrate surface side, and the particles adhering to the surface side of the substrate are cleaned by irradiating ultrasonic waves while supplying hydrogen water. Wash.
The hydrogen water used for cleaning the front surface is collected in a recovery tank and reused for back surface cleaning in the step (2) to prevent mixed liquid with new liquid .
(4) Thereafter, the substrate is transported to the drying unit and dried.
A substrate cleaning method comprising at least the above steps.

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