TW202227889A - Light irradiation device and exposure device including the same - Google Patents

Abstract

The invention provides a light irradiation device for an exposure device, which is capable of avoiding deterioration at the accuracy of a photo-alignment processing to a work, where the photo-alignment processing is performed in the case that a light is made to be emitted from the light source, passed through the polarizing element, and obliquely incident on the work. The light irradiation device 10 comprises a light source 12 having a plurality of light irradiation units 14 that emit a light L obliquely incident on the work X, and a polarizing element 20 that receives a light L from the light source 12 and irradiates a transmitted light L on the work X. Further, each of the light irradiation units 14 comprises an LED 16 and a heat sink 18 on which the LED 16 is arranged. In addition, a light reflection prevention treatment is made to surface 19 of heat sink 18 that is directed toward the polarizing element 20, exposed to the light radiated from the other light irradiation unit 14, and reflected on the surface of the polarizing element 20.

Description

Light irradiation device and exposure device provided with the same

The present invention relates to a light irradiation apparatus mainly used for exposure applications in manufacturing liquid crystal panels, and an exposure apparatus provided with the same.

When the liquid crystal is used as a TN-type display panel, the liquid crystal is enclosed between two glass substrates, and it is impossible to operate normally only by applying a voltage to the transparent electrodes formed on the inner surfaces of the glass plates. This is because the liquid crystal molecules are in a scattered state.

In order to make the liquid crystal operate in the normal TN mode, the liquid crystal molecules must be aligned in a certain direction, and the rising direction of the liquid crystal molecules must also be certain. Specifically, the liquid crystal molecules are aligned in a direction inclined by about 3° with respect to the glass substrate, and such an inclination angle is referred to as a pre-tilt angle.

Next, among the pair of glass substrates having a liquid crystal-like alignment property, one of the glass substrates is arranged in the X direction, and the other glass substrate on the opposite side is arranged in the Y direction perpendicular to the X direction. direction. (TN method)

In this way, liquid crystal alignment treatment is required in the manufacture of liquid crystal panels; conventionally, it has been rubbing treatment in which physical rubbing is performed on the surface of the glass substrate (for example, Patent Document 1). Such a rubbing treatment is a treatment method for forming a film that aligns liquid crystal molecules in a certain direction by rubbing the organic polymer film formed on the glass substrate with a long felt cloth in a predetermined direction.

With the popularization of rubbing treatment, the TN method with a fast response speed has become common, so it is possible to mass-produce liquid crystal panels with stable performance at low cost, and furthermore, it can be used as a display monitor for OA equipment such as personal computers or a monitor for game machines. Therefore, the LCD monitor has become a popular trend.

However, in terms of the rubbing method, there is a problem of lack of uniformity and the possibility of electrostatic breakdown of the TFT. Furthermore, there is also a problem of reliability due to the adhesion of powder debris generated during rubbing.

In addition, the pretilt angle that can be achieved by the rubbing method is, as described above, about 3° in the TN method represented by the horizontally aligned liquid crystal mode. Therefore, it is difficult to form a system capable of low-voltage driving and high-speed response. LCD display panel.

In order to deal with the problem of such a rubbing method, an exposure machine capable of performing a photo-alignment process has been proposed. In such an exposure machine, an attempt has been made to use a long arc mercury lamp as a light source. <Prior Art Documents> <Patent Literature>

<Patent Document 1> Japanese Patent Laid-Open No. 2007-17475

<Problems to be solved by the invention>

However, exposure machines using long arc mercury lamps have also been inferred to be problematic. In general, when the exposure material is set to have a photosensitive characteristic that reflects light of a specific wavelength bandwidth, when the spectral characteristics of the light from a mercury lamp are observed, it can be understood that the light is composed of a large number of bright lines of mercury lines. .

Therefore, when a mercury lamp is used as the light source for exposure, since the light of the wavelength deviating from the photosensitive characteristic of the exposure material increases, it is presumed that the exposure material may be overexposed by light of a wavelength other than the photosensitive wavelength bandwidth. Danger.

Of course, it is also possible to cut off light with wavelengths deviating from the photosensitive characteristics (short-wave side and long-wave side) by selecting the wavelength reflective film. However, a narrow-band cut-off filter (frequency-pass filter) is required. Since high precision is required, the cost of the device increases as a result.

Furthermore, the light emitted by the long-arc mercury lamp spreads over a wide range, so it becomes difficult to control the irradiation angle of the light from the important mercury lamp used for the photo-alignment process. (louver), etc. to block the excess light; however, in such a case, there is another problem that the utilization efficiency of the light emitted from the mercury lamp is low.

In addition, there is also a method of irradiating a glass substrate with collimated (parallelized) light obliquely; however, since this method complicates the optical system, it is presumed that the device becomes large and expensive. The problem.

Also, although it may be considered to perform a photo-alignment process in which the light emitted from the light source passing through the polarizing element is incident on the workpiece obliquely, however, in this case, after the light is emitted from the light source, since the polarization of the polarizing element A part of the light reflected from the surface may re-enter the polarizing element at an unintended angle, so that there may be problems such as deterioration of the precision of the photo-alignment process on the workpiece.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a light irradiation device for an exposure device that implements a method by making light emitted from a light source and passing through a polarizing element obliquely incident on a workpiece In the case of the photo-alignment process, it is possible to avoid a matter of deteriorating the accuracy of the photo-alignment process on the workpiece. ＜Means to solve the problem＞

According to an aspect of the present invention, a light irradiation device can be provided, characterized by comprising: a light source having a plurality of light irradiation units for emitting light obliquely incident on the workpiece; and a polarizing element, which receives the light from the light source and irradiates the transmitted light on the workpiece; wherein Each of the above-mentioned light irradiation units respectively has LEDs and a heat sink capable of installing the above-mentioned LEDs; The surface of the heat sink facing the polarizing element and irradiated by the light radiated from another light irradiating unit and reflected on the surface of the polarizing element is subjected to anti-reflection treatment.

Furthermore, according to another aspect of the present invention, there can be provided a light irradiation device characterized by comprising: a light source having a plurality of light irradiation units for emitting light obliquely incident on the workpiece; and a polarizing element, which receives the light from the light source and irradiates the passed light to the workpiece; wherein Each of the above-mentioned light irradiation units respectively has LEDs and a heat sink capable of installing the above-mentioned LEDs; The surface of the heat sink facing the polarizing element and irradiated by the light radiated from the other light irradiating unit and reflected on the surface of the polarizing element is arranged with a light shielding plate, and the surface of which has been subjected to anti-light reflection treatment. .

Furthermore, according to another aspect of the present invention, there can be provided a light irradiation device characterized by comprising: a light source having a plurality of light irradiating units for emitting light obliquely incident on the workpiece; a polarizing element, which receives the light from the light source and irradiates the transmitted light on the workpiece; wherein Each of the above-mentioned light irradiation units respectively has an LED and a heat sink on which the above-mentioned LED can be installed; wherein The angle formed by the surface of the heat sink facing the polarizer and irradiated by the light emitted from the other light irradiation unit and reflected on the surface of the polarizer and the surface of the polarizer is 90°-( α/2) or more. In addition, "α" here refers to the light having the largest angle with the optical axis of the light irradiating unit among the light emitted by the other light irradiating unit, and the light having the largest angle with the surface of the polarizing element. degree of formation.

According to another viewpoint of this invention, the exposure apparatus provided with the above-mentioned light irradiation apparatus can be provided. <The effect of the invention>

According to the light irradiating device of the present invention, since the heat sink constituting each light irradiating unit is irradiated with light emitted by another light irradiating unit and reflected on the surface of the polarizing element, anti-reflection treatment is performed. Therefore, the light emitted from another light irradiating unit and reflected on the surface of the polarizing element is irradiated on the heat sink of the light irradiating unit, and then reflected and re-emitted to the polarizing element, because the light is opposite to the intended Since the polarizing element is incident in the opposite direction of the direction, it is possible to avoid deterioration of the accuracy of the photo-alignment process with respect to the workpiece.

(Configuration of Light Irradiation Device 10 ) Hereinafter, the light irradiation device 10 according to the embodiment to which the present invention is applied will be described. The light irradiation apparatus 10 is mainly used in combination with an exposure apparatus in order to perform exposure when manufacturing a liquid crystal panel. As shown in FIG. 1 , such a light irradiation device 10 is roughly provided with a light source 12 and a polarizing element 20 .

The light source 12 is a member that irradiates the exposure light L toward the exposure surface A on which the workpiece (exposure object) X is placed; in this embodiment, a plurality of light irradiation units 14 are used. These light irradiating units 14 are provided with LEDs 16 for irradiating light, and heat sinks 18 to which the LEDs 16 can be mounted, respectively.

The light source 12 moves in a certain direction along the exposure surface A to irradiate the exposure light L by scanning the workpiece X. Therefore, the light source 12 is approximately aligned in a direction perpendicular to the moving direction of the workpiece X. It is formed by arranging a plurality of light irradiation units 14 in the same manner. Of course, the light irradiation device 10 may be moved relative to the workpiece X to irradiate the exposure light L, or both the workpiece X and the light irradiation device 10 may be moved.

The LEDs 16 constituting the light irradiation units 14 are arranged relative to the workpiece X in such a manner that the optical axes CL of the LEDs 16 have a first angle θ1 with respect to the workpiece X (ie, the incident angle θ1 ). Inclined with respect to the exposure surface A). By using an alignment film made of light with little variation in angle components irradiated from an oblique direction on a liquid crystal panel, a stable pretilt angle and alignment state can be achieved, and a liquid crystal panel of any alignment mode can be realized.

In addition, the LED16 is not limited to a specific item, and COB (Chip-On-Board) or SMD (Surface Mounting Type) can be used; it may also be a so-called gun type item.

The heat sink 18 radiates heat generated from the light-emitting LED 16 , and thus has a role function to prevent the temperature of the LED 16 from becoming too high, and the LED 16 is mounted on the surface of the heat sink 18 .

The size of the heat sink 18 is required to be an item of a size sufficient to radiate the heat from the LEDs 16 . In addition, the heat sink 18 according to the present embodiment is formed in a rectangular cross-section, and for the light emitted toward the polarizer 20 and from another light irradiation unit 14 and reflected on the surface of the polarizer 20 The irradiated side surface 19 is a characteristic point subjected to anti-light reflection treatment. Specific examples of such an anti-reflection treatment include, for example, black plating, black aluminum oxide (Alumite), black coating, and the like.

In addition, the cross-sectional shape of the heat sink 18 is not particularly limited to a rectangular shape, however, regardless of the shape of the cross-sectional shape, it is preferable for the heat sink 18 to emit light from another light irradiation unit 14 The surface irradiated by the light reflected from the surface of the polarizing element 20 is subjected to anti-reflection treatment.

The polarizing element 20 is an element that transmits and polarizes only the light component that vibrates in one direction in the light irradiated from the light source 12; in this embodiment, a wire grid polarizing element is used. A wire grid polarizer is a type of a transparent substrate (glass substrate) formed by forming a wire grid on the surface of one side. In this embodiment, the formation surface 22 of the wire grid may be the surface on the side of the light source 12 in the polarizing element 20 , or may be the surface on the opposite side of the light source 12 . Moreover, it is preferable that the polarizing element 20 is arrange|positioned parallel to the workpiece|work X (exposure surface A).

(Effects of the light irradiation device 10 according to the present embodiment) According to the light irradiation device 10 according to the present embodiment, in the heat sink 18 constituting each light irradiation unit 14, the surface 19 irradiated by the light emitted from the other light irradiation unit 14 and reflected on the surface of the polarizing element 20 is subjected to Anti-reflective treatment.

Thereby, as shown in FIG. 2 , the light emitted from the other light irradiation unit 14 and reflected on the surface of the polarizer 20 is in contact with the heat sink 18 of the light irradiation unit 14, and is further reflected and directed toward the polarized light again. Element 20: With respect to the polarizing element 20, the light is incident from the opposite direction of the intended direction (refer to the arrow of the dotted line), so that it is possible to avoid the deterioration of the accuracy of the photo-alignment process on the workpiece.

(Variation 1) According to the light irradiation device 10 according to the above-described embodiment, in the heat sink 18 constituting each light irradiation unit 14, the surface irradiated with the light emitted from the other light irradiation unit 14 and reflected on the surface of the polarizing element 20 19 is subjected to anti-reflection treatment; however, as shown in FIG. 3 , it can also be changed to: the angle formed between the surface 19 and the surface of the polarizing element 20 where the light reflected from the surface of the polarizing element 20 in the heat sink 18 is irradiated θ2 is set to be greater than or equal to “90°−(α/2)”.

The “α” refers to the angle formed by the light Lmax having the largest angle with the optical axis CL of the light irradiation unit 14 and the surface of the polarizing element 20 among the light emitted from the other light irradiation unit 14 .

Therefore, even in the case where the light emitted from the other light irradiation unit 14 and reflected on the surface of the polarizing element 20 is reflected on the surface (for example, the side surface) 19 of the heat sink 18 , the reflected light will not be directed toward the polarized light The surface of the element 20 is, as in the above-described embodiment, light is incident from the opposite direction to the intended direction with respect to the polarizing element 20, so that the accuracy of the photo-alignment process on the workpiece can be prevented from deteriorating.

Of course, the angle θ2 formed by the surface 19 of the heat sink 18 on which the light reflected from the surface of the polarizing element 20 is irradiated and the surface of the polarizing element 20 may be set as described above, and the light reflected from the surface of the polarizing element 20 may be set as described above. The surface 19 of the irradiated heat sink 18 is subjected to anti-reflection treatment.

(Variation 2) In addition, the second angle θ3 which is half of the light distribution angle of the light L emitted from each light irradiation unit 14 may be set smaller than the above-described first angle θ1.

(Variation 3) Further, according to the light irradiation device 10 according to the above-described embodiment, the heat sink 18 constituting each light irradiation unit 14 is irradiated with light emitted from another light irradiation unit 14 and reflected on the surface of the polarizing element 20 . The surface 19 is subjected to anti-reflection treatment; however, as shown in FIG. 4 , for example, it may be modified to attach a light-shielding plate 30 to the light-irradiated surface 19 .

The surface of the light shielding plate 30 is subjected to anti-reflection treatment (eg, black aluminum oxide treatment) so as to be arranged along the surface 19 of the heat sink 18 formed at a predetermined angle with respect to the polarizer 20 .

In addition, the end of the light shielding plate 30 on the side away from the polarizer 20 is bent so as not to interfere with the heat sink 18 arranged adjacently.

In addition, the surface 19 of the heat sink 18 to which the light shielding plate 30 can be attached may be as shown in the figure, and the angle θ2 formed by the surface 19 and the surface of the polarizer 20 may be set to be equal to or greater than “90°−(α/2)”, It is also possible to form the face 19 at an angle outside that range (eg, as shown in FIG. 1 or the like).

(Variation 4) Moreover, for example, as shown in FIG. 5, the light irradiation apparatus 10 may be covered with the light shielding box 32 so that the light from the LED16 may not leak to the outside. In addition, it is preferable to perform anti-light reflection treatment on the inner surface of the light-shielding box 32 .

It is worth noting that all the viewpoints of the embodiments disclosed this time are examples, and therefore are not intended to be limiting. The scope of the present invention is not as described above, but it is intended that the scope of the present invention includes those shown in the scope of claims, meanings equivalent to the scope of claims, and all modifications within the scope.

10: Light irradiation device 12: Light source 14: Light irradiation unit 16: LED 18: Radiator 19: (of radiator 18) side 20: Polarizing element 22: The formation surface of the wire grid 30: visor 32: shading box X: Workpiece (object to be exposed) A: Exposure surface L: Exposure light CL: (LED16) optical axis θ1: 1st angle θ2: The angle formed between the surface 19 of the heat sink 18 and the surface of the polarizing element 20 irradiated by the light reflected on the surface of the polarizing element 20 θ3: 2nd angle

FIG. 1 is a diagram showing a light irradiation device 10 including a light source 12 composed of a plurality of light irradiation units 14 to which the present invention is applied. FIG. 2 is a diagram for explaining light emitted from another light irradiating unit 14 and reflected on the surface of the polarizing element 20 . FIG. 3 is a diagram showing the light irradiation device 10 according to Modification 1. As shown in FIG. FIG. 4 is a diagram showing a light irradiation device 10 according to Modification 3. As shown in FIG. FIG. 5 is a diagram showing a light irradiation device 10 according to Modification 4. As shown in FIG.

10: Light irradiation device

12: Light source

14: Light irradiation unit

16: LED

18: Radiator

19: (of radiator 18) side

20: Polarizing element

22: The formation surface of the wire grid

X: Workpiece (object to be exposed)

A: Exposure surface

L: Exposure light

CL: (LED16) optical axis

θ 1: 1st angle

Claims (4)

A light irradiation device, characterized in that it has: a light source having a plurality of light irradiation units for emitting light obliquely incident on the workpiece; and a polarizing element, which receives the light from the light source and irradiates the transmitted light on the workpiece; wherein Each of the aforementioned light irradiating units has an LED and a heat sink mounted on the aforementioned LED, respectively; The surface of the heat sink facing the polarizing element and irradiated by light emitted from another light irradiating unit and reflected on the surface of the polarizing element is subjected to anti-reflection treatment. A light irradiation device, characterized in that it has: a light source having a plurality of light irradiation units for emitting light obliquely incident on the workpiece; and a polarizing element, which receives the light from the light source and irradiates the workpiece with the transmitted light; wherein Each of the aforementioned light irradiation units has LEDs and a heat sink mounted on the aforementioned LEDs respectively; A light shielding plate is arranged on the surface of the heat sink facing the polarizing element and irradiated by the light radiated from the other light irradiating unit and reflected on the surface of the polarizing element, and the surface of the light shielding plate is subjected to anti-light reflection. processed. A light irradiation device, characterized in that it has: a light source having a plurality of light irradiation units for emitting light obliquely incident on the workpiece; and a polarizing element, which receives the light from the light source and irradiates the transmitted light on the workpiece; wherein Each of the above-mentioned light irradiation units respectively has an LED and a heat sink mounted on the above-mentioned LED; The angle formed by the surface of the heat sink facing the polarizer and irradiated by the light emitted from the other light irradiation unit and reflected on the surface of the polarizer and the surface of the polarizer is 90°- (α/2) or more; "α" in the formula refers to the light having the largest angle with the optical axis of the light irradiation unit and the angle formed by the surface of the polarizing element among the light emitted from the other light irradiation unit. An exposure apparatus provided with the light irradiation apparatus as described in any one of Claims 1-3.

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