KR20170026872A - Baking chamber for manufacturing photo-alignment layer - Google Patents

Abstract

Provided is a baking apparatus for manufacturing a photoalignment film, which can improve light leakage failure due to a photodegradable byproduct generated in a manufacturing process of a photoalignment film. The baking apparatus for manufacturing a photoalignment film comprises: a housing having an inner space storing a substrate on which a photoalignment film including a photodegradable byproduct is formed; a door which opens and closes the inner space; and a coating layer consisting of a low heat conductive material having heat conductivity which is lower than conductivity of a glass while covering an opposing area facing the inner space of an inner surface of the door. The door comprises: a first metal plate; an insulation layer which is disposed in a front side of an inner surface of the first metal plate and consists of the low heat conductive material; and a second metal plate disposed in an opposing area of an inner surface of the insulation layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a baking apparatus for manufacturing a photo alignment layer,

The present invention relates to a baking apparatus for manufacturing a photo alignment film.

2. Description of the Related Art [0002] A liquid crystal display device is one of the most widely used flat panel display devices, and includes two display panels having field generating electrodes such as a pixel electrode and a common electrode, and a liquid crystal layer interposed therebetween. The liquid crystal display displays an image by applying a voltage to the electric field generating electrode to generate an electric field in the liquid crystal layer, thereby determining the alignment direction of the liquid crystals in the liquid crystal layer and controlling the polarization of the incident light.

Conventionally, there is a rubbing method in which a polymer film such as polyimide is applied to a substrate such as glass by a conventional method of orienting the liquid crystal, and the surface is rubbed with a fiber such as nylon or polyester in a predetermined direction. However, the rubbing method may cause fine dust or static electricity when the fiber and the polymer film are rubbed, and these may cause serious problems in manufacturing the liquid crystal panel.

Recently, in order to solve the above problem, an optical alignment method for inducing anisotropy (anisotropy) in a polymer film by light irradiation and arranging liquid crystals using the same is being studied.

An object of the present invention is to provide a baking apparatus for manufacturing a photo alignment layer capable of improving defects in light leakage due to photolytic decomposition by-products generated in a process for producing a decomposition type photo alignment layer.

The problems to be solved by the invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned can be clearly understood by those skilled in the art from the following description.

A baking apparatus for manufacturing a photo alignment layer according to an embodiment of the present invention includes a housing having an internal space for accommodating a substrate on which a photo alignment layer containing photodegradation byproducts is accommodated, a door for opening and closing the internal space, And a coating layer made of a low thermal conductive material covering a facing area facing the inner space and having a thermal conductivity equal to or lower than that of the glass, wherein the door is disposed on the front surface of the inner surface of the first metal plate and the inner surface of the first metal plate A heat insulating layer made of the low thermal conductive material and a second metal plate disposed in the facing area of the inner surface of the heat insulating layer. The coating layer covers the entire inner surface of the second metal plate.

In the baking apparatus for manufacturing a photo alignment layer according to an embodiment, the thickness of the heat insulating layer may be thicker than the thickness of the coating layer.

In the baking apparatus for manufacturing a photo alignment layer according to an embodiment, the coating layer may have a higher thermal conductivity than the heat insulating layer.

In a baking apparatus for manufacturing a photo alignment layer according to an embodiment, the coating layer may cover the entire inner surface of the door.

Another embodiment of the present invention is directed to a baking apparatus for manufacturing a photo alignment layer, comprising: a housing having an internal space for accommodating a substrate on which a photo alignment layer containing photodegradation byproducts is placed; a metal plate for opening and closing the internal space; And a coating layer made of a low thermal conductive material having a thermal conductivity lower than the thermal conductivity of the glass.

In a baking apparatus for manufacturing a photo alignment layer according to another embodiment, the coating layer may cover the entire inner surface of the metal plate.

The low thermal conductive material may be a polymer compound having a thermal decomposition temperature of 180 ° C or higher.

The polymer compound may be at least one selected from the group consisting of polyimide, polyamide-imide, polyparaphenylene terephthalamide, polymetaphenylene isophthalamide, polydimethylsiloxane, , And polyetheretherketone. ≪ / RTI >

The baking process temperature of the substrate on which the photo alignment layer containing the photodegradation by-product is formed may be in the range of 180 ° C to 240 ° C.

The baking apparatus for manufacturing a photo alignment layer according to each embodiment may further include a supply pipe connected to the housing and supplying external air to the internal space and a supply pipe connected to the housing and discharging the photodegradation byproduct and the external air from the storage space to the outside And may further include an exhaust pipe.

The details of other embodiments are included in the detailed description and drawings.

The baking apparatus for manufacturing a photo alignment layer according to each embodiment can minimize or prevent the aggregation of photodegradation by-products on the inner surface of the door by reducing the temperature difference between the outer and inner surfaces of the door.

The baking apparatus for manufacturing a photo alignment layer according to each of the embodiments can provide a liquid crystal display device with improved light leakage defects due to photodegradation byproducts generated in the process of manufacturing the decomposition type photo alignment layer.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the specification.

Figs. 1 and 2 are images of defects of light-shielding in a liquid crystal display panel due to photodegradation by-products.
3 is a schematic perspective view of a conventional baking apparatus for manufacturing a photo alignment film.
Fig. 4 is a partial enlarged view of the conventional baking apparatus for producing a photo-alignment film shown in Fig. 3. Fig.
5 is an image of agglomerated photodegradation by-products present in the door of the conventional photo-alignment film-forming baking apparatus of FIG.
6 is a schematic plan view and a cross-sectional view of a door used in a baking apparatus for manufacturing a photo-alignment film according to an embodiment.
7 is a schematic plan view and a cross-sectional view of a door used in a baking apparatus for manufacturing a photo-alignment film according to another embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from the following detailed description of embodiments thereof taken in conjunction with the accompanying drawings.

The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

Like reference numerals refer to like elements throughout the specification.

The dimensions and relative sizes of layers and regions in the figures may be exaggerated for clarity of illustration.

It is to be understood that when an element or layer is referred to as being "on" or " on "of another element or layer, All included.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

In this specification, the inner surface of the object is one surface facing the inner space, and the outer surface of the object is the opposite surface of the one surface. For example, the inner side of the door is a side facing the inner space, and the outer side of the door is the opposite side of the one side that is in contact with the outside atmosphere (about 25 ° C).

In the present specification, the facing area facing the inner space of the inner surface of the object corresponds to the inner space projected on the inner surface of the object. For example, when the inner space is formed as a rectangular parallelepiped, And is a rectangular area on one side of the inner space projected on the inner side.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Generally, the photo alignment method is a method of inducing chemical anisotropy on the surface of the liquid crystal alignment film by irradiating the liquid crystal alignment film with linearly polarized ultraviolet light (LPUV). Photo-isomerization, photodimerization, and photodegradation are known as photo-alignment methods.

The photodegradation method can orient the liquid crystal in a direction perpendicular to the linearly polarized light direction by irradiating linearly polarized ultraviolet rays to a polymer membrane such as polyimide to photolyzate a polymer chain parallel to the linearly polarized light direction.

The decomposition type photo alignment layer is formed by applying a photo-dispersing agent comprising a polyamic acid, which is formed by polymerizing cyclohexane dianhydride (CBDA) and a derivative thereof and a diamine, onto a substrate, Baking the coated substrate to form a polyimide from the polyamic acid, and then irradiating the polyimide with linearly polarized ultraviolet light.

The substrate may be, for example, a thin film transistor array substrate or a color filter substrate, and the cyclobutanediamine hydride may be, for example, cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride cyclobutan-1,2,3,4-tetracarboxylic dianhydride), and the diamine may be, for example, 1,4-benzenediamine.

Wherein the baking is performed by prebaking baking the substrate coated with the photo-dispersing agent within a temperature range of 70 캜 to 80 캜 to remove the solvent contained in the photo- And a main baking step of baking the substrate coated with the photoflavor to form the polyimide from the polyamic acid.

The linearly polarized ultraviolet ray may use an ultraviolet ray having a wavelength range of 240 nm or more to 380 nm or less, and preferably, ultraviolet ray having a wavelength of 254 nm may be used. When the polyimide is irradiated with ultraviolet rays linearly polarized, the polymer chain parallel to the linearly polarized light direction is photo-decomposed to form a photodecomposition by-product.

When the liquid crystal display device is manufactured using the substrate on which the decomposition type photo alignment layer is formed without removing the photodegradation byproducts, the photodegradation byproducts may cause light leakage in the final product. Figures 1 and 2 are images showing the light leakage (L) due to the photodegradation by-products.

In order to remove the photodegradation by-products and increase the orientation of the decomposition type photo alignment layer, the substrate on which the decomposition type photo alignment layer is formed may be baked once again within a temperature range of 180 ° C to 240 ° C. In the present specification, the post baking process is defined as baking the decomposition type photo alignment film once after irradiating linearly polarized ultraviolet rays to the deposition type photo alignment film.

FIG. 3 is a schematic perspective view of a conventional baking apparatus for producing a decomposition type photo alignment layer, and FIG. 4 is a partial enlarged view of the conventional baking apparatus for producing decomposition type photo alignment layers of FIG. The conventional baking apparatus for producing a decomposition type photo alignment layer can be used in the post baking process.

3 and 4, the conventional baking apparatus for manufacturing a decomposition type photo-alignment layer comprises a housing 10 having a plurality of internal spaces 30 for accommodating a substrate on which a photo-alignment layer including photodegradation by-products is deposited, And may include a plurality of doors 20 for opening and closing a plurality of internal spaces 30. The plurality of doors (20) can independently open and close the plurality of inner spaces (30). The plurality of inner spaces 30 may be partitioned into a plurality of shelves constituting the housing 10.

The door 20 includes a first metal plate 21 and a heat insulating layer 22 disposed on the entire inner surface of the first metal plate 21 and made of a first low thermal conductive material having a thermal conductivity equal to or lower than that of glass, And a second metal plate 23 disposed on an inner surface of the inner space 30 facing the inner space 30. The door 20 is connected to the housing 10 by a white paper so as to open and close the internal space 30. The first metal plate 21 and the second metal plate 23 have a higher thermal conductivity than that of glass. The second metal plate 23 may include a plurality of through holes OP and a part of the heat insulating layer 22 may be exposed to the outside through the through holes OP.

Since the post-baking process proceeds within a temperature range of 180 ° C to 240 ° C, the first low thermal conductive material may preferably be a polymer compound having a thermal decomposition temperature of 180 ° C or higher. The polymer compound having a pyrolysis temperature of 180 ° C or higher can be obtained by, for example, polyimide, polyamide-imide, polyparaphenylene terephthalamide, But is not limited to, one of amide (polymetaphenylene isophthalamide), polydimethylsiloxane, and polyetheretherketone.

The first metal plate 21 and the second metal plate 23 may be, for example, stainless steel.

Table 1 summarizes the thermal conductivity of glass at 23 占 폚, the first low thermal conductive material, and stainless steel.

Thermal conductivity (W / mK, 23 ° C) Pyrolysis temperature (℃) Polyimide 0.10 to 0.35 250-320 Polyamide-imide < / RTI > 0.26 to 0.54 200 ~ 260 Polyparaphenylene terephthalamide < RTI ID = 0.0 > 0.04 180 ~ 245 Polymetaphenylene isophthalamide, 0.13 200-300 Polydimethylsiloxane, 0.22 200 ~ 260 Polyetheretherketone (Polyetheretherketone) 0.25 250 Glass 0.8 to 0.93 - Stainless steel 16.3 to 24.0 -

The conventional baking apparatus for manufacturing a decomposition type photo alignment film has a function of controlling the amount of supply of outside air supplied to the supply pipe P1 and the amount of discharge of outside air discharged to the exhaust pipe P2, The dispersions can be removed.

However, since the post-baking process is performed within a temperature range of 180 ° C to 240 ° C, a temperature deviation of 150 ° C or more occurs between the outer side surface and the inner side surface of the door, and the temperature deviation causes the photodegradation by- And is agglomerated on the inner surface of the metal plate 23. Referring to FIG. 4, after the post-baking process is completed, photolytic degradation by-products I are present in the second metal plate 23. 5 is an image of the coagulated photodegradation by-products I present in the second metal plate 23. Fig.

The agglomerated photolysis byproducts (I) may be introduced into the decomposition type photo alignment layer due to an impact upon opening and closing of the door (20). Therefore, in the conventional baking apparatus for manufacturing a decomposition type photo alignment film, even when the supply amount of the external air supplied to the supply pipe P1 and the discharge amount of the external air discharged to the exhaust pipe P2 are optimized, There may be photolysis byproducts (I) agglomerated in the alignment layer.

6 is a schematic plan view and a cross-sectional view of a door 20 used in a baking apparatus for manufacturing a photo-alignment film according to an embodiment.

6, the entire surface of the inner side surface of the second metal plate 23 is covered with the coating layer 24. As shown in Fig. The coating layer 24 may cover the entire surface of the inner surface of the door 20 of the coating layer 24 and the edge of the heat insulating layer 22 disposed on the outer periphery of the second metal plate 23, The coating layer 24 may be in direct contact with a portion of the heat insulating layer 22 exposed through the edges of the heat insulating layer 22 and the through holes OP .

The coating layer 24 is made of a second low thermal conductive material having a thermal conductivity equal to or less than that of glass.

Since the post-baking process proceeds within a temperature range of 180 ° C to 240 ° C, the second low thermal conductive material may preferably be a polymer compound having a thermal decomposition temperature of 180 ° C or higher. The polymer compound having a pyrolysis temperature of 180 ° C or higher can be obtained by, for example, polyimide, polyamide-imide, polyparaphenylene terephthalamide, But is not limited to, one of amide (polymetaphenylene isophthalamide), polydimethylsiloxane, and polyetheretherketone.

The first low thermal conductive material constituting the heat insulating layer 22 and the second low thermal conductive material constituting the coating layer 24 may be the same or different. The first low thermal conductive material constituting the heat insulating layer 22 preferably has thermal conductivity higher than that of the second low thermal conductive material constituting the coating layer 24 because the heat insulating layer 22 insulates the internal space 30 and the outside. Can be low. In other words, the second low thermal conductive material constituting the coating layer 24 may have a higher thermal conductivity than the first low thermal conductive material constituting the heat insulating layer 22.

On the other hand, since the coating layer 24 is lowered to the thermal conductivity level of the glass on the inner surface of the second metal plate 23 to minimize the aggregation of the photodegradation by-products on the inner surface of the second metal plate 23, The coating layer 24 may be formed to a thickness such that the inner surface of the second metal plate 23 is lowered to the thermal conductivity level of the glass. Since the heat insulating layer 22 should insulate the inner space 30 and the outside, the heat insulating layer 22 may be formed to have a relatively thick thickness as compared with the coating layer 24.

7 is a schematic plan view and a cross-sectional view of a door used in a baking apparatus for manufacturing a photo-alignment film according to another embodiment.

The baking apparatus for manufacturing a photo alignment film according to another embodiment differs from the baking apparatus for manufacturing a photo alignment film of FIG. 3 in that the door 20 is composed of only the first metal plate 21.

The door 20 used in the baking apparatus for producing a photo alignment layer according to another embodiment is composed of the first metal plate 21 and the coating layer 24 covering the entire inner surface of the inner surface of the first metal plate 21, And is different from the door 20.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is to be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

10: Housing
20: Door
21: first metal plate, 22: insulating layer
23: second metal plate
30: Internal space
P1: Supply piping P2: Exhaust piping

Claims (14)

A housing having an internal space for accommodating a substrate on which a photo alignment layer containing photodegradation byproducts is deposited;
A heat insulating layer disposed on a front surface of an inner side surface of the first metal plate and made of a low thermal conductive material having a thermal conductivity equal to or lower than that of the glass and a heat insulating layer disposed on an inner surface of the heat insulating layer, A door formed of a second metal plate and opening / closing the inner space; And
A coating layer covering the entire inner surface of the second metal plate, the coating layer being made of the low thermal conductive material;
And a baking apparatus for manufacturing a photo alignment layer. The method according to claim 1,
Wherein the low thermal conductive material is a polymer compound having a thermal decomposition temperature of 180 DEG C or higher. 3. The method of claim 2,
The polymer compound may be at least one selected from the group consisting of polyimide, polyamide-imide, polyparaphenylene terephthalamide, polymetaphenylene isophthalamide, polydimethylsiloxane, , And a polyetheretherketone. The method according to claim 1,
Wherein the thickness of the heat insulating layer is thicker than the thickness of the coating layer. The method according to claim 1,
Wherein the coating layer has a thermal conductivity higher than that of the heat insulating layer. The method according to claim 1,
Wherein the coating layer covers the entire inner surface of the door. The method according to claim 1,
A supply pipe connected to the housing and supplying external air to the internal space; And
An exhaust pipe connected to the housing and discharging the photodegradation byproduct and the outside air from the storage space to the outside;
Wherein the baking apparatus further comprises: The method according to claim 1,
Wherein the baking process temperature of the substrate on which the photo alignment layer containing the photodegradation by-product is formed is in the range of 180 캜 to 240 캜. A housing having an internal space for accommodating a substrate on which a photo alignment layer containing photodegradation byproducts is deposited;
A metal plate for opening and closing the inner space; And
A coating layer of a low thermal conductive material covering an opposite surface of the inner surface of the metal plate facing the inner space and having a thermal conductivity lower than a thermal conductivity of the glass;
And a baking apparatus for manufacturing a photo alignment layer. 10. The method of claim 9,
Wherein the low thermal conductive material is a polymer compound having a thermal decomposition temperature of 180 DEG C or higher. 11. The method of claim 10,
The polymer compound may be at least one selected from the group consisting of polyimide, polyamide-imide, polyparaphenylene terephthalamide, polymetaphenylene isophthalamide, polydimethylsiloxane, , And a polyetheretherketone. 10. The method of claim 9,
Wherein the coating layer covers the entire inner surface of the metal plate. 10. The method of claim 9,
A supply pipe connected to the housing and supplying external air to the internal space; And
An exhaust pipe connected to the housing and discharging the photodegradation byproduct and the outside air from the storage space to the outside;
Wherein the baking apparatus further comprises: 10. The method of claim 9,
Wherein the baking process temperature of the substrate on which the photo alignment layer containing the photodegradation by-product is formed is in the range of 180 캜 to 240 캜.

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