JP3604830B2 - Large format thin glass substrate heat treatment equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a single-wafer glass substrate heat treatment apparatus capable of uniformly heating the surface temperature of a glass substrate having various films and structures through various processes. Specifically, a substance applied to a color filter manufacturing line and used to infiltrate a dye into the surface of a glass substrate of a color filter as a substrate to be heat-treated is uniformly applied at a high temperature for a certain period of time (on the surface of the glass substrate). The present invention relates to a single-wafer glass substrate heat treatment apparatus for performing heat treatment to a temperature distribution of a certain value or less.
[0002]
[Prior art]
In the conventional method of heat-treating a glass substrate, the entire surface of the glass substrate is brought into contact with the hot plate surface in order to heat the surface of the glass substrate uniformly at high speed.
Also, when a glass substrate at room temperature is placed on a hot plate at a high temperature, the temperature gradient in the thickness direction of the glass substrate is large, so that the glass substrate warps downward and the temperature distribution is prevented from increasing on the surface of the glass substrate. Several hot plates from room temperature to high temperature, gradually increase the set temperature for each hot plate, reduce the temperature gradient in the thickness direction of the glass substrate, eliminate warpage, The temperature distribution on the surface is kept small.
[0003]
Also, as a method of reducing the temperature gradient between the front and back of the glass substrate to prevent the glass substrate from warping and increasing the temperature distribution on the surface of the glass substrate, the glass substrate is heated only from below. Instead, there is a device provided with a heater for heating (such as an infrared heater) so that heating can be performed from above.
In order to prevent warpage, a hole for suction was formed in the entire hot plate to suck the glass substrate.
[0004]
[Problems to be solved by the invention]
Because the entire surface of the glass substrate was in contact with the hot plate surface, the substance that needs to be heat-treated in the coating process, which is performed before the heat treatment process of the glass substrate, is not only the coated surface (surface) of the glass substrate, However, there are cases where the edge of the glass substrate and the contact surface (back surface) between the hot plate and the hot plate have been wrapped around. A substance requiring heat treatment adheres, and as the number of sheets increases, the substance is laminated, and as a result, the outer peripheral portion of the glass substrate gradually floats on the surface of the hot plate.
[0005]
Then, due to the floating, a part that is in contact with a part that is not in contact is generated, a temperature distribution on the surface of the glass substrate is increased, and a substance requiring heat treatment cannot be uniformly heat-treated. Maintenance was required to prevent the problem.
In order to prevent the glass substrate from warping when the glass substrate is placed on the hot plate, it was necessary to prepare several hot plates and gradually raise the temperature. However, the size increases, the cost increases, and it takes time to raise the temperature to the target temperature.
[0006]
Further, in the case where the heater is provided on both the upper and lower sides, the size of the apparatus is increased by the amount of the upper heater, and the cost is increased. Since the upper heater heats the glass substrate with radiation, it takes much longer than heating from the lower heater, and the set temperature must be set much higher than the target heating temperature of the surface of the glass substrate. It is difficult to set the temperature based on the distance between the heater and the upper heater.
[0007]
If the hot plate is provided with suction holes on the entire surface to prevent warpage, the heating holes are not heated, so the temperature distribution is likely to occur, and the material requiring heat treatment may have uneven heating. May remain, and the whole may not be uniform.
[0008]
[Means for Solving the Problems]
According to the present invention, the surface temperature distribution of a glass substrate on which a substance requiring heat treatment is applied is accurately and uniformly heated, and there is no need for maintenance. In order to reduce costs, a glass substrate on which a substance requiring heat treatment is applied on one side, and the glass substrate is placed and the surface of the glass substrate is uniformly heated to a high temperature. In a hot plate device having a spacer for providing a gap, when a glass substrate is placed on a hot plate with the coated surface facing upward, the gap between the hot plate surface and the surface opposite to the coated surface of the glass substrate is glass. The surface of the hot plate has a shape that is constant over the entire area of the substrate, and the spacer has a slightly convex peripheral portion than the hot plate. A suction hole for sucking the substrate is provided at the center, and the surface of the hot plate is dug down by the amount that the glass substrate bends downwardly convex when the glass substrate is placed on the spacer on the hot plate. It is like that.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Adopted in a color filter production line as a glass substrate to be heat-treated implementing the present invention, a substance applied to the surface of the glass substrate of the color filter as a glass substrate to be heat-treated, a receiving layer for penetrating the dye for a certain time, A single-wafer glass substrate heat treatment apparatus for performing heat treatment uniformly at a high temperature (a temperature distribution on a glass substrate surface is equal to or less than a certain value) will be described below.
[0010]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples based on the drawings, but the present invention is not limited thereto.
[0011]
FIG. 1 shows a single plate type glass substrate heat treatment apparatus in which only a hot plate portion is extracted. The hot plate is made of aluminum. Aluminum is used because the thermal conductivity is high and the temperature distribution on the hot plate surface can be small.
A plurality of cartridge heaters are inserted into the hot plate. A plurality of cartridge heaters are disposed in the vicinity of both end surfaces in the longitudinal direction, and are divided into two or more groups.
[0012]
Each cartridge heater group has a paired temperature sensor that measures the temperature of the portion of the hot plate heated by the cartridge heater group and is used as the current temperature by feedback control.
Then, the temperature of the portion heated by the cartridge heater group is controlled based on the difference between the current temperature and the target temperature.
[0013]
In this way, by controlling each of the cartridge heater groups independently to the target temperature, the hot plate surface temperature distribution can be set to the target temperature ± 0.5 ° C. (at a steady state).
[0014]
The vertical and horizontal dimensions of the hot plate are each several tens mm larger than the size of the glass substrate to be heat-treated. The hot plate is heat-treated at a high temperature in a material stage before being manufactured and processed. This is because the hot plate itself does not deform when the hot plate is heated. A plurality of spacers are provided on the surface of the hot plate for providing a gap between the glass substrate and the surface of the hot plate.
[0015]
As shown in FIG. 6, the spacer, which is called a receiving layer, which is a substance that needs to be subjected to heat treatment and is applied to the coating surface of the glass substrate, is used in the coating process. This is to prevent adhesion to the surface of the hot plate when it reaches the back surface of the side.
[0016]
If the spacer is not provided, the receiving layer attached to the hot plate surface gradually accumulates.Accordingly, when the glass substrate is placed, the outer peripheral portion of the glass substrate moves with respect to the hot plate surface. As a result, the receiving layer on the surface of the glass substrate cannot be heat-treated uniformly over the entire surface. That is, when the dye is permeated into the receiving layer, the color filter product becomes uneven and defective.
[0017]
FIG. 2 shows the shape of the spacer. The spacer has a cylindrical shape projecting 0.1 mm from the surface of the hot plate. However, the shape is not limited to a columnar shape, and may be any shape as long as the glass substrate can be made higher than the surface of the hot plate at a certain height. At the center of the spacer, a suction hole for sucking the glass substrate is formed. In this embodiment, it is a round hole having a diameter of 2 mm. Each of the plurality of spacers on the hot plate surface is provided with this suction hole.
[0018]
A mechanism capable of adsorbing the glass substrate when the glass substrate is placed thereon, such as a vacuum or a vacuum pump, is connected to the tip of the suction holes.
The purpose of sucking the glass substrate by the suction hole is to place a glass substrate that is not heated to the same temperature as the hot plate on a hot plate as shown in FIG. However, since it takes time for the heat to be transmitted to the opposite surface of the glass substrate, there is a large temperature difference between the front and back of the glass substrate, which causes the glass substrate to move relative to the hot plate at the outer peripheral portion. This is to prevent the shape from rising.
[0019]
Immediately after placing the glass, the glass substrate remains flat, but warps after a few seconds.
In this warped state, the temperature distribution on the surface of the glass substrate is large, and the receiving layer applied on the surface cannot be uniformly heat-treated. As a result, unevenness occurs as a color filter product, resulting in a defect.
[0020]
The projecting amount of the spacer is set to 0.1 mm because the receiving layer turned on the back side of the glass substrate does not adhere to the hot plate, and the temperature of the glass substrate needs to be raised as soon as possible. Because I want to.
[0021]
FIG. 3 shows the positions and arrangements of the hot plate, the glass substrate, and the spacer. When the glass substrate is placed on the hot plate, the position of the spacer protruding from the hot plate surface is arranged so as to be located in the non-effective area of the glass substrate.
[0022]
The non-effective area is an area other than a part where a dye is permeated and becomes a color filter product. The purpose of arranging the spacer in the non-effective area is that the heat transfer condition of the receiving layer changes because the heat transfer is different between the part in contact with the spacer and the part not in contact with the spacer. This is to prevent the product from becoming uneven and becoming defective.
[0023]
To this end, the color filter product is disposed at the outer peripheral portion of the glass substrate and at the center of the cross in the portion where the dye does not penetrate. In the present embodiment, four color filters are taken. However, it goes without saying that a spacer can be provided in a portion where the dye does not penetrate even if six or eight color filters are taken.
[0024]
8 and 9 show the arrangement of the spacers and the state of the temperature of the glass substrate surface at that time.
FIG. 8 shows a case where only both ends in the short direction of the glass substrate are sucked. As shown in the figure, when the surface temperature of the glass substrate was measured along AA 'on the diagonal line, the result that the surface temperature was increased toward A' at the center was obtained.
In this case, it is impossible to heat the receiving layer uniformly. This means that the amount of floating on the hot plate surface in the central portion of the glass substrate is smaller than that of the portion adsorbed by the spacer due to the deflection of the glass substrate by its own weight.
[0025]
Therefore, as shown in FIG. 9, the distance between the spacers supporting the glass substrate is shorter than that in the case of FIG. Thus, the deflection of the glass substrate under its own weight is reduced. Then, the gap between the glass substrate and the hot plate surface can be made more uniform as compared with the case of FIG. 8, the temperature distribution on the glass substrate surface becomes more uniform, and the receiving layer is located within the effective area. Heat treatment is performed under the same conditions, and when the dye is permeated, there is no unevenness in the permeation, and a good color filter can be obtained.
[0026]
FIG. 5 shows a procedure for processing a glass substrate for producing a color filter. A black matrix is attached to a glass substrate.
A receiving layer for penetrating the dye is uniformly applied on the entire surface of the glass substrate. Exposure is performed so as to cure the black matrix portion of the receiving layer in order to separate the portion where the three color dyes penetrate and the portion where the three color dyes do not penetrate (the black matrix portion) in the effective area.
[0027]
The heat treatment promotes the effect of the exposure, and makes the portions where the dye penetrates and the portions where the dye does not penetrate clear.
If this process is not performed uniformly, a color filter product will be uneven, or different colors adjacent to each other will be mixed, resulting in a defect.
Thereafter, dyes of three colors are permeated into the receiving layer, and the dyes are dried to complete a series of processing procedures for the glass substrate.
[0028]
FIG. 4 shows the relationship between the effective area on the glass substrate, the portion where the dye penetrates, and the like.
[0029]
(A) shows four effective areas on the glass substrate. Each of the effective areas becomes a product of a color filter. Since the four effective areas are uniformly heated, no adsorbing spacers are arranged and only the non-effective areas which do not directly become color filter products (dye does not penetrate) are arranged. .
[0030]
(B) is an enlarged view of a part of the effective area 3 of (a). Adjacent colors are separated by the black matrix. R _{1 to} R ₃ mean that a red dye is permeated, G _{1 to} G ₃ permeate a green dye, and B _{1 to} B ₃ mean that a blue dye is permeated.
If the heat treatment is not performed uniformly and as intended, the dyes will not penetrate into the squares (the area surrounded by the black matrix) where each of the colors must penetrate, and the dye will not be able to penetrate to the edges. When a layer is used as a color filter product, it remains as a white portion and becomes defective.
[0031]
(C), as can be seen from the cross-sectional view taken along the line BB 'in (b), since the dye-penetrating receptor layer is applied across the black matrix, the heat treatment should be uniform and proper. If this is done, the dye will be properly stopped at the permeation boundary line and will not mix with the adjacent color, but if the gap between the glass substrate and the hot plate surface becomes large, it will be given to the receiving layer. The amount of heat to be supplied is small, and the permeation boundary line is not clear, resulting in color mixing, resulting in poor color filter products.
[0032]
As shown in FIG. 10, a suction spacer is provided on a hot plate at a position where the glass substrate is sucked in the vicinity of the outer periphery and at the center cross as shown in the figure.
Then, when the glass substrate is placed on the spacer, the glass substrate bends under its own weight so that the gap between the back surface of the glass substrate and the surface of the hot plate becomes uniform (parallel) over the entire area of the size of the glass substrate. First, a depression is formed on the hot plate side in advance.
[0033]
For example, in the case of a 360 mm × 465 mm glass substrate, a glass substrate having a thickness of 0.7 mm is used at a maximum of 80 μm, and a glass substrate having a thickness of 1.1 mm is used at a maximum of 32 μm. Is depressed at a certain curvature near the outer periphery and at the center of the cross. By doing so, the distance between the back surface of the glass and the surface of the hot plate becomes constant, and when the glass substrate is heated, the entire surface of the glass substrate is uniformly heated with higher precision than when the hot plate is flat. .
FIG. 11 is a sectional view taken along the line AA ′ of FIG.
[0034]
【The invention's effect】
As described above, according to the present invention, the surface of a glass substrate can be uniformly heated with high precision. In addition, by integrating, the glass substrate can be heated in a state of being floated with respect to the hot plate surface, and by suction, the warpage due to the temperature difference in the thickness direction can be corrected, and the temperature distribution on the glass substrate surface is suppressed. And the glass substrate surface can be uniformly heated with high precision.
[0035]
Further, the heat treatment apparatus of the present invention is indispensable for permeating the dye into the receiving layer to form a color filter. The heat treatment apparatus of the present invention is indispensable for manufacturing a color filter incorporating the structure of the hot plate.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an outline of a glass substrate and a hot plate of a single-wafer glass substrate heat treatment apparatus.
FIG. 2 is a schematic view showing the shape of a spacer.
FIG. 3 is a schematic plan view showing positions and arrangement relationships of a glass substrate, a hot plate, and a spacer.
FIG. 4 is a schematic diagram showing a relationship between an effective area on a glass substrate and a portion where a dye penetrates.
FIG. 5 is a block flow chart showing a processing procedure of a glass substrate for manufacturing a color filter.
FIG. 6 is a schematic cross-sectional view showing a relationship between a receiving layer, a spacer, and a hot plate on a glass substrate.
FIG. 7 is a schematic sectional view showing a state of warpage of the glass substrate on the hot plate.
FIG. 8 is a schematic diagram showing a correlation between the arrangement of spacers and the corresponding temperature of the glass substrate surface.
FIG. 9 is a schematic diagram showing a correlation between the arrangement of spacers and the corresponding temperature of the glass substrate surface.
FIG. 10 is a schematic perspective view showing a glass substrate and a hot plate.
FIG. 11 is a schematic cross-sectional view showing a state of warpage of a glass substrate on a hot plate.
[Explanation of symbols]
R ₁ , R ₂ , R ₃ Red dye part G ₁ , G ₂ , G ₃ Green dye part B ₁ , B ₂ , B ₃ Blue dye part

Claims (1)

A glass substrate having a heat treatment is to be heat-treated material required on the surface, heating pressure to said surface by placing the glass substrate, a hot plate type glass substrate having a spacer for providing a gap between the glass substrate and the hot plate In the heat treatment equipment,
A suction hole provided on the spacer, for suctioning a back surface of the glass substrate,
A depression provided on the surface of the hot plate, in order to prevent the distance from the hot plate from becoming uneven due to the deflection caused by the weight of the glass substrate,
A glass substrate heat treatment apparatus comprising a hot plate surface shape such that a gap between the hot plate surface and the back surface of the glass substrate is constant over the entire size of the glass substrate.

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