JP3011853B2 - Substrate cleaning residue inspection method and inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for manufacturing a flat display such as a liquid crystal display device, and a cleaning residue inspection for a substrate for detecting acid or alkali remaining on the substrate after cleaning the substrate constituting the flat display. The present invention relates to a method and an inspection device.

[0002]

2. Description of the Related Art Generally, in a process of manufacturing a flat display such as a liquid crystal display device, a surface inspection of a glass substrate constituting the flat display is performed. For such a surface inspection, for example, a contact angle measurement method, which is a method for inspecting the physical properties of a material surface, an Auger electron spectrometer, or a method utilizing gas chromatography is used. Further, as a method for detecting dirt due to sebum or oil film on a glass substrate, for example, Japanese Patent Application Laid-Open No. H4-2587
As disclosed in Japanese Patent Publication No. 62-62, there is disclosed a method of detecting the above-mentioned dirt by the dew condensation state on a substrate using water vapor and an inert gas.

In the process of manufacturing the flat display, when a transparent electrode is formed on the glass substrate or when a resist film or an alignment film is printed, the substrate is etched with an acid or washed with caustic soda. Is performed. At this time, if the acid or alkali is not completely removed and remains as a residue on the glass substrate, a defect such as a defect of the transparent electrode, printing unevenness, and repelling of printing occurs,
This leads to a lower non-defective rate. When a cyano-based liquid crystal material is used as a liquid crystal material, an amide compound is generated when such an acid or alkali residue reacts with the above-described cyano-based liquid crystal material. This may cause display failure on the display.

However, none of the above-described conventional surface inspection methods can accurately detect an acid or alkali remaining on a glass substrate after cleaning. For example, in the contact angle measurement method, it is possible to detect the presence or absence of a residue on a glass substrate, but it is not possible to specify the components. Auger electron spectrometers are generally large and unsuitable for such inspections.
Since residues other than acid and alkali are also detected at the same time,
It is difficult to distinguish only acids and alkalis from the detected residues.

When gas chromatography is used, it is possible to specify the components of the generated residue, but it is not possible to confirm the state of generation of the residue. Further, the method disclosed in Japanese Patent Application Laid-Open No. 4-258762 is aimed at detecting sebum, oil film and the like as described above, and therefore cannot detect acids and alkalis.

Therefore, it is conceivable to determine the acid or alkali on the glass substrate by dropping a phenolphthalein reagent used for determination of acidity or alkalinity onto the glass substrate.

[0007]

However, the use of a phenolphthalein reagent only detects the presence or absence of an acid or alkali present on the surface of a glass substrate.
It is impossible to estimate the amount of residue on the substrate based on this result. Furthermore, it is difficult to accurately capture even the amidation crystallization phenomenon caused by the reaction between an acid or alkali and a liquid crystal.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to keep a surface state of a glass substrate constituting a flat display constant and to form a transparent electrode, a resist film, an alignment film and the like. In order to stably and uniformly form various layers and prevent display defects of the flat display, the amount of residue on the substrate can be easily measured in the inspection of the cleaning residue on the substrate performed in the manufacturing process of the flat display. It is an object of the present invention to provide a method and an inspection device capable of accurately and accurately detecting.

[0009]

According to a first aspect of the present invention, there is provided a substrate residue inspection method for detecting an acid or alkali remaining on a substrate after cleaning the substrate. Is characterized in that a reagent for crystallizing a compound by reacting with an acid and an alkali is supplied onto the washed substrate, and the state of the crystal deposited on the substrate is evaluated.

A method for inspecting cleaning residues of a substrate according to a second aspect of the present invention is based on the first aspect.
In the cleaning residue inspection method for a substrate described in the above, a cyano-based liquid crystal material containing at least 100 ppm of water is used as the reagent, and after supplying the cyano-based liquid crystal material onto the substrate, the substrate is heated and further cooled. It is characterized in that the state of the crystal of the amide compound precipitated on the substrate due to the reaction of the cyano liquid crystal material with an acid, an alkali or an alkali is evaluated.

According to a third aspect of the present invention, there is provided a substrate cleaning residue inspection apparatus for detecting an acid or alkali remaining on a substrate after cleaning the substrate. The apparatus is characterized in that the apparatus is provided with a reagent supply means for supplying a reagent for crystallizing out a compound by reacting with an acid and an alkali onto the washed substrate.

[0012] In order to solve the above problem, the substrate cleaning residue inspection apparatus according to the invention of claim 4 is based on claim 3.
In the apparatus for inspecting residue of cleaning a substrate described in the above, the heating means for heating the substrate after supplying the reagent and the cooling means for cooling the substrate after heating are provided, and the reagent supplying means has a water content of at least 100 ppm as a reagent. Is characterized by using a cyano-based liquid crystal material containing

[0013]

According to the method of the present invention, when a reagent for reacting with an acid and an alkali to precipitate a compound is supplied onto the substrate, when an acid or an alkali is present on the substrate as a cleaning residue, Since crystals of the generated compound precipitate, the presence or absence and the amount of acid or alkali residues on the substrate can be detected by evaluating the presence and amount of the crystals. Therefore, in a simple way, without the need for large equipment,
More accurate inspection of acid or alkali cleaning residues.

For example, in the manufacturing process of a flat display, when this method is performed to inspect the cleaning residue,
Since a substrate having an acid or an alkali on the surface can be accurately detected, only a substrate having a uniform surface state without such a cleaning residue can be used for manufacturing a flat display. Thereby, it is possible to prevent defects of the transparent electrode caused by the washing residue of the acid or the alkali, the printing unevenness of the resist film, the alignment film, etc., and the repelling of the printing, and stably form the various layers described above. And can be performed uniformly.

Further, when a cyano-based liquid crystal material containing at least 100 ppm of water and supplied on the substrate is used as the reagent as in the method of claim 2, when an acid is present on the substrate, the liquid crystal material contains Included, general formula

[0016]

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The 3PCH shown in the above undergoes a hydrolysis reaction as shown below by heating to produce an amide compound.

[0018]

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When an alkali is present on the substrate, the above-mentioned 3PCH causes a hydrolysis reaction as described below to generate an amide compound.

[0020]

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The amide compound thus produced is dissolved in the liquid crystal, but precipitates as crystals when cooled. These crystals, once deposited, are difficult to dissolve into the liquid crystal at room temperature, so that the acid or alkali, which is a cleaning residue on the substrate surface, can be easily, quickly, and accurately detected depending on the generation state of the crystals of the amide compound. Therefore, in the manufacturing process of a liquid crystal display element or the like, when the cleaning residue is inspected by this method, the presence or absence of the acid or alkali on the substrate and the amount of the residue can be easily and quickly determined.
Not only can it be detected accurately, but also the amidation crystal phenomenon that causes display defects can be easily detected.

Further, according to the constitution of the third aspect, the reagent for crystallizing a compound by reacting with an acid or an alkali is supplied from the reagent supply means onto the substrate, so that the acid on the substrate can be easily removed. Alternatively, the presence or absence of alkali and the amount of residue can be detected. Therefore, it is possible to provide an inexpensive apparatus that can quickly and accurately inspect a cleaning residue on a substrate with a simple configuration. In addition, if inspection of cleaning residues in the manufacturing process of a flat display is performed using such an apparatus, defects and defects can be observed when various layers are formed on a substrate.
It is possible to prevent print unevenness, print repelling, and the like from occurring.

According to the fourth aspect of the present invention, a cyano liquid crystal material containing at least 100 ppm of water is used as a reagent, and the substrate after supplying the cyano liquid crystal material by a reagent supply means is heated. Heating means,
Cooling means for cooling the heated substrate is provided. If an acid or alkali is present on the substrate, when heated by a heating means, the cyano liquid crystal material supplied as a reagent is hydrolyzed to generate an amide compound. When the amide compound is cooled by the cooling means, it precipitates as crystals. Therefore, for example, in a manufacturing process of a liquid crystal display element, if inspection of a cleaning residue using this apparatus is performed, only the presence or absence of an acid or an alkali and the amount of the residue are determined. In addition, it is possible to detect the generation state of the crystal of the amide compound that causes display failure.

[0024]

【Example】

Embodiment 1 FIGS. 1 and 2 show an embodiment of the present invention.
This will be described below.

As shown in FIG. 1, the apparatus for detecting residue of cleaning of a substrate according to the present embodiment has
A liquid crystal dropping device (reagent supply means) 3 for dropping a cyano liquid crystal material 2 containing water of 00 ppm or more, and a glass substrate 1
A heating device 6 for heating the inspection substrate 5 having the elementary glass 4 bonded thereto and a cooling device 7 for cooling the inspection substrate 5 after heating are provided.

In the present embodiment, the nematic-isotropic transition point 90 ° C.
And the general formula

[0027]

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A nematic liquid crystal containing 20% by weight of a cyanophenylcyclohexane-based liquid crystal material represented by the following formula was used. The water content of the liquid crystal material determined by the Karl Fischer method was 200 ppm.

Next, a method for detecting a cleaning residue using the apparatus having the above configuration will be described with reference to FIG. First, as shown in FIG. 2B, the above-mentioned cyano-based liquid crystal material 2 is applied to the glass substrate 1 (see FIG. Is dropped in several places. As shown in FIG. 1C, a glass 4 is bonded to the glass substrate 1, and the cyano liquid crystal material 2 sandwiched between the glass substrate 1 and the glass 4 is spread over the entire surface of the glass substrate 1. Then, an inspection substrate 5 is formed.

The inspection substrate 5 is heated by the above-mentioned heating device 6 at a temperature equal to or higher than the liquid crystal transition point (here, 100 ° C.) for one hour. The heated inspection substrate 5 (see FIG. 4D) is cooled in the cooling device 7 at 0 ° C. for 1 hour, and the cooled inspection substrate 5 (see FIG. 4E). The presence or absence of an acid or alkali is detected depending on whether or not crystals are precipitated.

For example, in a cleaning apparatus that cleans a substrate with 2% caustic soda, a substrate in which alkali remains as a residue is inspected by the above-described method because an output reduction abnormality has occurred in a pure water ultrasonic cleaning tank that performs a cleaning finishing step. Then, the cyano-based liquid crystal material 2 dropped on the glass substrate 1 by the heat treatment
Is hydrolyzed by an alkali to produce an amide compound. The amide compound precipitates as a crystal by the cooling treatment. For example, assuming that alkali is present in a portion surrounded by a circle in FIG. (E), as shown in FIG. Crystal 8 of the amide compound precipitates.

When a cleaning residue is inspected in the same manner as described above using a glass substrate that has been etched with an acid or the like, the portion where the acid remains on the substrate is heated by heating. Since the cyano liquid crystal material 2 is hydrolyzed to form an amide compound, the same crystal precipitation as described above is observed by cooling. The precipitated crystals are hard to dissolve into the liquid crystal at room temperature, so that the precipitated state of the crystals can be clearly observed. Further, when the crystals were examined by gas chromatography, they were confirmed to be amide compounds.

As described above, when an acid or an alkali is present on the glass substrate 1 as a cleaning residue, crystals are deposited by performing the above-described processing.
The presence or absence, the absolute amount, and the like of the above acid or alkali can be easily, quickly, and accurately detected from the crystal deposition state.

As the glass substrate 1 to be inspected, a substrate actually used for manufacturing a flat display may be used, or a dummy substrate which has been subjected to the same processing as a substrate constituting a flat display may be used. You may.

The above-mentioned inspection is performed by using a simple apparatus having a thermostat and a cooling bath which are generally used.
Even when the measurement was performed on a glass substrate sample cut into small pieces of about cm square, the washing residue consisting of acid or alkali could be easily, quickly and accurately detected. As described above, the inspection as described above can be performed even with an apparatus that can be configured at low cost.

When such an inspection is incorporated into, for example, a manufacturing process of a liquid crystal display device, the state of acid or alkali existing as a cleaning residue on a glass substrate used for the liquid crystal display device and the amount of the residue can be detected more accurately. Therefore, it is possible to prevent defects of the transparent electrode which occur in the liquid crystal display element due to these residues, printing unevenness of a resist film, an alignment film and the like, and print repelling. Further, since it is possible to prevent a crystal from being generated due to a chemical reaction between the acid or the alkali and the liquid crystal material, it is possible to avoid a display defect caused by the crystal.

Embodiment 2 Next, another embodiment of the present invention will be described below with reference to FIG.
For the sake of convenience, members having the same functions as those shown in the drawings of the above-described embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

The cleaning residue inspection apparatus according to this embodiment includes an acid,
Alternatively, the cleaning step using an alkali and the inspection step for a cleaning residue can be performed consistently. Therefore, as shown in FIG. 3, the cleaning residue inspection apparatus 10 includes a cleaning unit 11 for cleaning the glass substrate 1 using, for example, 2% caustic soda.
A liquid crystal dropping unit 12, a glass bonding unit 13, a hot plate bath 14, a cool plate bath 15, and a determination unit 16 that automatically counts the amide compounds precipitated as crystals and determines whether or not the test is successful. , In this order. The glass substrate 1 is sequentially conveyed from the cleaning tank 1 side to the determination unit 16 side. Further, the cleaning residue inspection apparatus 10 is provided with a control box 17 for controlling the above-described units and displaying the inspection results by the determination unit 16 and the like.

The liquid crystal dropping section 12 includes a syringe 18 filled with a cyano liquid crystal material of 100 ppm or more, and a dispenser 19 for operating the syringe 18 using N ₂ gas.
And a Z-axis operation rod 20 for vertically moving the syringe 18. The glass attaching section 13
The raw glass 4 bonded to the glass substrate 1 can be held and released, and a Z-axis operation rod 21 for vertically moving the held raw glass 4 is provided.

The hot plate tank 14 is set at 100 ° C., and the cool plate tank 15 is set at 0 ° C.
The determination unit 16 includes a light source 22 having a polarizing plate (not shown),
CCD (Charge Coupled Dev) equipped with a polarizing plate (not shown)
ice) camera 23, an XY table 24 for moving the CCD camera 23 to an inspection point, and a monitor television 25 for displaying an image captured by the CCD camera 23. The determination unit 16 counts the amide compound precipitated as a crystal based on the image captured by the CCD camera 23 and outputs the count value and the inspection result of the pass / fail determination to the control box 17.

The cleaning residue inspection apparatus 10 normally performs a smooth cleaning operation at a production tact as a production line, and controls the control box 17 every designated number of sheets or before starting the line. Switching is performed based on a preset program, and an inspection is performed by executing the above-described processing in each unit.

Next, the cleaning of the glass substrate 1 and the inspection of the cleaning residue performed by the cleaning residue inspection apparatus 10 having the above configuration will be described.

First, the glass substrate 1 is sent to the cleaning section 11, where 2% caustic soda is sprayed on the glass substrate 1. After passing through the cleaning unit 11, the glass substrate 1
It is transported to the liquid crystal dropping unit 12. In the liquid crystal dropping section 12,
When the glass substrate 1 is conveyed, the syringe 18 is lowered to the optimum position by the Z-axis operation rod 20, and the dispenser 19 is further operated. A similar cyano-based liquid crystal material is dropped. Glass substrate 1 after dropping liquid crystal material
Is subsequently conveyed to the glass attaching section 13. In the glass attaching section 13, the Z-axis direction operating rod 21
The elementary glass 4 is placed and adhered on the glass substrate 1, and the above-described cyano-based liquid crystal material is spread over the entire surface of the glass substrate 1, thereby forming the same inspection substrate as in the first embodiment.

Thereafter, the inspection substrate is transferred to a hot plate tank 14 and heated at 100 ° C. for 1 hour. After the heating, the substrate is transferred to a cool plate tank 15 and cooled at 0 ° C. for 1 hour. At a location on the glass substrate 1 where an acid or alkali is present, the cyano-based liquid crystal material dropped on the glass substrate 1 is hydrolyzed with an acid or alkali by heating to generate an amide compound. The amide compound generated on the glass substrate 1 is subsequently precipitated as crystals by performing a cooling process.

The cooled inspection substrate is transported to the determination unit 16 and is photographed by the CCD camera 23 while being irradiated with light by the light source unit 22. Thereby, the crystals precipitated on the glass substrate 1 can be observed, and the number thereof is automatically counted by the determination unit 16.

As described above, in this embodiment, the inspection process of the cleaning residue can be incorporated into a normal production line only by performing a simple modification. In addition, since the judgment of the inspection can be automatically performed, the inspection is further simplified, and the inspection can be performed quickly and accurately. Therefore, by performing such an accurate inspection, for example, in a manufacturing process of a liquid crystal display element, a defect of a transparent electrode, a resist film, an alignment film, or the like due to an acid or an alkali present on a glass substrate is caused. In addition to preventing the occurrence of print unevenness, print repelling, etc., it is also possible to prevent the amidation crystal phenomenon that causes display failure.

In this embodiment, the case where the cleaning process is performed using caustic soda in the cleaning section has been described. However, the cleaning liquid is not limited to the above-mentioned caustic soda. In the case of performing the inspection, it is possible to perform the inspection using an apparatus having a similar configuration.

[0048]

According to the method for inspecting cleaning residues of a substrate according to the first aspect of the present invention, as described above, a reagent for crystallizing a compound by reacting with an acid and an alkali is supplied onto the cleaned substrate, The purpose is to evaluate the state of the crystals deposited on the substrate.

Therefore, the presence or absence and the amount of acid or alkali residues on the substrate can be detected by evaluating the presence and amount of crystals precipitated by supplying the reagent onto the glass substrate. In addition, the present invention has the effect that the acid or alkali cleaning residue can be more accurately inspected by a simple method without requiring a large-sized apparatus.

Further, for example, in the flat display manufacturing process, if the cleaning residue is inspected by this method, it becomes possible to use only a substrate having no cleaning residue and a uniform surface state for flat display manufacturing.
Defects in the transparent electrode caused by washing residues of acid or alkali, and resist unevenness, printing unevenness of the resist film, alignment film, etc. can be prevented, and the formation of the various layers described above can be stably and uniformly performed. It also has the effect of being able to do so.

According to a second aspect of the present invention, there is provided a method for inspecting the cleaning residue of a substrate, wherein a cyano liquid crystal material containing at least 100 ppm of water is used as the reagent, and the cyano liquid crystal material is placed on the substrate. After the substrate is heated, the substrate is heated and further cooled, and the state of the crystal of the amide compound precipitated on the substrate due to the reaction of the acid or alkali with the cyano-based liquid crystal material is evaluated.

Therefore, in addition to the effect according to claim 1,
Not only can the presence or absence of acid or alkali and the amount of residue on the substrate be detected easily, quickly and accurately,
There is an effect that an amidation crystal phenomenon that causes display failure can be easily detected.

Further, according to the third aspect of the present invention, as described above, the reagent for reacting with an acid and an alkali to deposit a compound on a cleaned substrate is provided. This is a configuration including a supply unit.

Therefore, it is possible to provide an inexpensive apparatus capable of quickly and accurately inspecting a cleaning residue on a substrate with a simple configuration, and to inspect the cleaning residue in a flat display manufacturing process using such an apparatus. If you do
When the various layers are formed on the substrate, it is possible to prevent the occurrence of defects, print unevenness, print repelling, and the like.

The substrate cleaning residue inspection apparatus according to the fourth aspect of the present invention includes the heating means for heating the substrate after the supply of the reagent and the cooling means for cooling the heated substrate. In addition, the reagent supply means uses a cyano-based liquid crystal material containing at least 100 ppm of water as a reagent.

Therefore, in addition to the effect according to claim 3,
If an acid or alkali is present on the substrate, the cyano-based liquid crystal material supplied on the substrate generates an amide compound when heated by the heating means, and the amide compound is further cooled by the cooling means. And because it crystallizes,
For example, in the process of manufacturing a liquid crystal display element, inspection of the cleaning residue using this device can detect not only the presence or absence of acid or alkali and the amount of residue, but also the generation state of amide compound crystals that cause display defects. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a substrate cleaning residue inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a state change of a glass substrate to be inspected by the cleaning residue inspection apparatus.

FIG. 3 is a perspective view showing a substrate cleaning residue inspection apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate (substrate) 2 Cyano liquid crystal material (reagent) 3 Liquid crystal dropping device (reagent supply means) 6 Heating device (heating means) 7 Cooling device (cooling means) 8 Crystal 10 Cleaning residue inspection device 12 Liquid crystal dropping portion (reagent) Supply means) 14 Hot plate tank (heating means) 15 Cool plate tank (cooling means)

Claims (4)

(57) [Claims] In a method for inspecting residues of a substrate for washing after detecting the acid or alkali remaining on the substrate after the substrate is washed, a reagent for crystallizing a compound by reacting with an acid and an alkali to form a compound on the substrate after washing is provided. And evaluating the state of crystals precipitated on the substrate. 2. The method according to claim 1, wherein the reagent is at least 100 ppm.
After supplying the cyano-based liquid crystal material onto a substrate, the substrate is heated and further cooled, and the acid or alkali reacts with the cyano-based liquid crystal material. 2. The method according to claim 1, wherein the state of the crystal of the amide compound deposited on the substrate is evaluated. 3. A substrate cleaning residue inspection apparatus for detecting an acid or an alkali remaining on the substrate after the substrate is washed, wherein a reagent for reacting with an acid and an alkali to precipitate a compound to form a crystal is provided on the cleaned substrate. A cleaning residue inspection apparatus for a substrate, comprising: a reagent supply means for supplying a reagent to a substrate. 4. A heating means for heating a substrate after supplying a reagent,
Cooling means for cooling the heated substrate; and the reagent supply means includes at least 100
4. The apparatus according to claim 3, wherein a cyano liquid crystal material containing ppm water is used.