JP2010256685A - Exposure method, color filter, and optical alignment layer substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure method which achieves satisfactory alignment even in a terminal part in a moving direction in an exposure area, when forming a color pixel by slit exposure to a pattern of a black matrix. <P>SOLUTION: In an exposure apparatus including a forward imaging camera CM, a lower imaging camera CM-C is provided which images a mark for guide on a substrate 50 to acquire an amount of movement of the substrate, and a mark area 24 for guide is preliminarily provided on the outside of a pixel region on the substrate, and the amount of the movement of the substrate, which is acquired by imaging the mark for guide, and an alignment mark K2 of a photomask are adjusted in a terminal part C of an exposure area with respect to position, thereby a pattern (aperture) of the photomask is aligned to a first pattern to radiate the exposure light. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exposure method for aligning and forming colored pixels with a black matrix pattern formed on a substrate by, for example, slit exposure, and in particular, imaging that images a registration mark and adjusts the position. The present invention relates to an exposure method that does not cause a phenomenon that alignment is not satisfactorily performed at the end portion in the moving direction of an exposure region even when an exposure apparatus provided with a camera is used.

  In a display device such as a liquid crystal display device, it is a useful means to use a color filter for purposes such as color display, reflectance reduction, contrast adjustment, and spectral characteristic control. In many cases, the color filter used in this display device is formed and used as a pixel. As a method for forming a pixel of a color filter used in a display device, a printing method, a photolithography method, and the like can be given as methods that have been practically used.

  FIG. 1 is an enlarged plan view illustrating an example of a pixel of a color filter used in a liquid crystal display device. 2 is a cross-sectional view taken along line XX of the pixel of the color filter shown in FIG. As shown in FIGS. 1 and 2, the color filter used in the liquid crystal display device has a black matrix (21), a colored pixel (22), and a transparent conductive film (23) on a glass substrate (50) sequentially. It is formed.

  As a method of manufacturing the color filter used in the liquid crystal display device, first, a black matrix (21) is formed on a glass substrate (50), and then black on the glass substrate on which the black matrix (21) is formed. A method of forming a colored pixel (22) in alignment with a matrix pattern (opening) and further forming a transparent conductive film (23) is widely used.

  The black matrix (21) has a light-shielding property, determines the position of the colored pixels on the glass substrate at the opening, makes the size uniform, and is not preferable when used in a display device. It has a function of blocking light and making an image of a display device a uniform image with no unevenness and an improved contrast. The black matrix (21) is formed by, for example, providing a black photoresist coating film on a glass substrate (50), and forming the black matrix by exposing and developing the coating film through a photomask. Lithography is used.

The colored pixel (22) has a function of, for example, red, green, and blue color reproduction filters, and pigments and other pigments are dispersed on a glass substrate (50) on which a black matrix is formed. A photolithographic method is employed in which a coating film of a negative type colored photoresist is provided, and colored pixels are formed by exposure and development to the coating film through a photomask.
The transparent conductive film (23) is formed by forming a transparent conductive film on a glass substrate on which colored pixels are formed by sputtering using, for example, ITO (Indium Tin Oxide).

  When a large number of color filters are manufactured, a color filter having a size corresponding to a single liquid crystal display device is often manufactured in a state of being multifaceted on a large glass substrate. For example, a 17-inch diagonal color filter is manufactured by attaching four faces to a large glass substrate of about 650 mm × 850 mm.

The exposure at this time is performed using a photomask in which, for example, a mask pattern for forming a color filter having a diagonal size of 17 inches is provided on a mask substrate having a size approximately equal to the size of the glass substrate. The method is widely adopted. This is a so-called batch exposure method in which the entire four screens of the four-sided mask pattern are collectively performed by one exposure.
In this case, for example, a plurality of color filters of the same type, i.e., the same color filter size and color filter finish size, are used.

  In order to solve the problem of high cost due to the increase in mask size and the problem of bending due to the mask's own weight, the exposure method is uniaxial from the batch exposure method from the fourth generation with a glass substrate size of, for example, about 730 mm × 920 mm. The step exposure method begins to be adopted, and the glass substrate size shifts from the fifth generation of, for example, about 1000 mm × 1200 mm to the XY (biaxial) step exposure method (so-called step-and-repeat method). ing.

FIG. 3 is a plan view for explaining an example of step exposure when a color filter is manufactured by an XY step exposure method.
The example shown in FIG. 3 is an example in which six exposures of the first exposure to the sixth exposure were performed on the large-sized glass substrate (50). Each exposure after the second exposure is performed every five step movements (Py, Px) counted from the first exposure. Reference numerals (1Ex to 6Ex) represent first to sixth exposure regions, respectively.

By shifting to such a step exposure method, an increase in cost due to an increase in mask size is suppressed, and the problem of bending due to its own weight has been solved.
However, as the size of the glass substrate shifts to, for example, the sixth generation of about 1500 mm × 1800 mm or the eighth generation of, for example, about 2100 mm × 2400 mm, the mask size increases. Accompanying, the high cost and the problem of deflection are rekindling.

  Therefore, in order to avoid the high cost of the accompanying photomask when the size of the glass substrate is further increased, the color filter is made by reducing the mask size rather than increasing the mask size. Various exposure methods have been tried to produce the above.

  FIG. 4 is a plan view for explaining an example of slit exposure when a color filter is manufactured by slit exposure. The example shown in FIG. 4 is an example in which two exposures of the first exposure and the second exposure are performed on a large glass substrate (50). 5A and 5B are cross-sectional views taken along line XX in FIG. FIG. 5A shows a state where the first exposure is started, and FIG. 5B shows a state where the first exposure is finished.

  As shown in FIGS. 4 and 5, a photomask (PM2) is arranged above the glass substrate (50) placed on the exposure stage (60). The photomask (PM2) is fixed in the exposure apparatus and does not move in the X, Y, and Z axis directions. The exposure stage (60) below the photomask (PM2) moves at a constant speed in the X-axis direction to the left in the figure with the glass substrate (50) placed thereon. Further, step movement is performed in the Y-axis direction.

In slit exposure, a slit (S) that is short in the length direction (X-axis direction) and long in the width direction (Y-axis direction) is provided in the exposure apparatus, and the slit (S) or the glass substrate is a glass substrate. This is an exposure method in which light through the slit (S) is applied to the coating film (54) on the glass substrate (50) while being moved in the length direction (X-axis direction), and the entire surface of the glass substrate is exposed.
Since the slit exposure at the time of manufacturing the color filter forms a stripe-shaped colored pixel, the slit (S) has a width (Wi) corresponding to the width of the stripe of the colored pixel as an opening (51), and others. This part is a light shielding part (52). The opening (51) is provided on the photomask (PM2) as a mask pattern corresponding to the formation of the colored pixels.

FIG. 6 is an enlarged plan view showing a slit (S) portion in an example of a photomask (PM2) used for slit exposure. This photomask (PM2) is an example corresponding to a negative photoresist.
As shown in FIG. 6, the longitudinal direction (Ls) of the slit (S) is parallel to the Y axis, and a large number of openings (51) are arranged in the longitudinal direction (Ls). The portion other than the opening (51) is a light shielding portion (52). Below the photomask (PM2), the light transmitted through the opening (51) is moved to the glass substrate (50) while moving the exposure stage (60) in the direction indicated by the white thick arrow in FIG. 6 (X-axis direction). The top coating (54) is irradiated continuously. Reference numeral (Pi) represents the pitch of the opening (51), reference numeral (Wi) represents the width of the opening (51), and reference numeral (Li) represents the length of the opening (51).

FIG. 5A shows a state in which the first exposure through the slit of the photomask (PM2) is started on the photoresist coating film (54) applied on the glass substrate (50). . Further, (b) shows a state in which the first exposure is completed. In FIG. 5, the exposure light (E) is continuously passed through the slit of the photomask (PM2) while moving the exposure stage (60) to the left in the figure (X-axis direction) as indicated by the thick white arrow. Then, the first exposure indicated by the oblique lines in FIG. The second exposure is performed after the step movement (Py) shown in FIG. 4 is given to the exposure stage (60).
As described above, the slit exposure is a method that enables exposure of a large area without increasing the mask size, but rather by reducing the mask size and extending in the X-axis direction.

  FIG. 7 is a plan view showing an example of a stripe pattern obtained by development processing after exposure. As shown in FIG. 7, a stripe pattern having a pitch (Pi) and a width (Wi), for example, a striped colored pixel (22) is formed on a glass substrate (50).

FIG. 8 is an explanatory view showing an example of a color filter manufactured by such slit exposure. As shown in FIG. 8, this color filter is in a state in which colored pixels (22R, 22G, 22B) of red, green, and blue are formed on a glass substrate on which a black matrix (21) is formed. .
The colored pixels of each color are continuous stripes without interruption between pixels in the X-axis direction in FIG. Further, in the Y-axis direction, the respective stripe-like colored pixel columns are repeatedly arranged in the order of red, green, and blue. That is, this is an example in which the slit exposure method is suitably applied.

FIG. 9 exemplifies an imposition state when a color filter having a size corresponding to one liquid crystal display device is manufactured in many ways on a large glass substrate by such slit exposure. . In FIG. 9, reference numerals (M1 to M6) denote first to sixth exposure regions in which color filters having a size corresponding to one liquid crystal display device are formed.
Reference numerals (m1 to m6) denote non-exposed areas between the first to sixth exposed areas and outside the exposed areas.

  In FIG. 9, the white arrow indicates the direction (X-axis direction) in which the glass substrate (50) placed on the exposure stage (60) is moved below the photomask. Accordingly, the striped colored pixels (22) shown in FIG. 7 are formed in parallel with the X-axis direction in FIG. A part of the colored pixels (22) formed in the first to sixth exposure regions is represented by a dotted line. Colored pixels (22) are not formed between the exposed areas and in the non-exposed areas (m1 to m6) outside the exposed areas.

At this time, the exposure of the coating film on the glass substrate (50) through the photomask is performed by moving the glass substrate (50) placed on the exposure stage (60) to each exposure region (M1 to M6). ) Are sequentially passed under the photomask, for example, the shutter provided above the photomask is opened and the exposure light from the light source is irradiated.
Further, a method is adopted in which the shutter is closed and the exposure light from the light source is shielded in synchronization with the passage between the exposure areas (m1 to m4) sequentially passing under the photomask.

  Compared with the method of manufacturing by XY step exposure, the method of manufacturing a color filter by slit exposure as described above certainly has a striped pattern formed on the entire surface of a large glass substrate with a small photomask. It is possible to form with multiple faces.

FIG. 10 is an enlarged plan view showing the vicinity of the first exposure region (M1) shown in FIG. 9, but the black matrix (1) of the first exposure region (M1) already formed on the glass substrate (50). 21) When the colored pixel (22) is formed in alignment with the pattern (not shown), the front end (A) and the center (B) of the glass substrate (50) indicated by the white thick arrow are formed. ), The alignment is performed satisfactorily.
However, in FIG. 10, there is a problem that the color pixel (22) is not properly aligned with the pattern of the black matrix (21) at the end portion (C) represented by the oblique line in the moving direction. It has been observed that this phenomenon occurs similarly in other exposure regions other than the first exposure region (M1).

  FIG. 11 is a partial cross-sectional view of an example of an exposure apparatus that employs slit exposure. FIG. 11 is an explanatory diagram of a method for forming the colored pixels (22) by aligning with the pattern of the black matrix (21) formed on the glass substrate (50) using the exposure apparatus shown in this example. FIG. 11 shows a cross section taken along line X2-X2 in the central portion (B) in the moving direction of the glass substrate (50) shown in FIG. 10, and is between FIGS. 5 (a) and 5 (b). This corresponds to the moving state of the glass substrate.

As shown in FIG. 11, in this exposure apparatus, an imaging camera (CM) is provided above the photomask (PM2). The position of the imaging camera (CM) is the direction opposite to the moving direction of the glass substrate (X in FIG. 11) from the optical axis of the exposure light (E) irradiated onto the opening (51) from above the photomask (PM2). It is a position separated by a distance (L ₀ ) in the axial right direction).

  This imaging camera (CM) is formed on the lower glass substrate (50) from above the photomask (PM2) through the imaging opening (53) provided in the photomask (PM2). This is for imaging the black matrix alignment mark (K1) and the pattern of the black matrix (21).

As shown in FIG. 6, the photomask (PM2) has an imaging opening at a position away from the slit (S) provided with its longitudinal direction parallel to the Y-axis by a distance (L ₀ ) in the right direction of the X-axis. A part (53) is provided. The longitudinal direction of the imaging opening (53) is parallel to the Y axis in the same manner as the slit (S).
Similar to the opening (51), the imaging opening (53) is a translucent part where the surface of the photomask substrate is exposed. Exposure light (E) from above the photomask (PM2) irradiates the slit (S), but does not irradiate the imaging aperture (53).
The photomask (PM2) is provided with a photomask alignment mark (K2) for alignment (not shown).

As shown in FIG. 11, a black matrix (21) is already formed on the glass substrate (50) placed on the exposure stage (60), and colored pixels (21) are formed on the black matrix (21). A coating (54) for forming 22) is provided.
The black matrix (21) is provided with a black matrix alignment pattern (opening) and a black matrix alignment mark (K1) for alignment (not shown).

  The pattern of the photomask (PM2) with respect to the pattern of the black matrix (21) when the exposure light (E) is irradiated to the first exposure region (M1) through the opening (51) on the photomask (PM2). For example, when the imaging camera (CM) images the black matrix alignment mark (K1) on the glass substrate (50) moving under the photomask, the black matrix alignment mark is detected. (K1) and the alignment mark (K2) of the photomask are adjusted so that the predetermined positional relationship is set in advance, whereby the pattern of the black matrix (21) and the pattern of the photomask are changed. It is designed to be aligned.

  FIG. 12 shows the movement of the exposure stage (60) in the direction indicated by the thick arrow from the tip (A) to the end (C) in the moving direction of the first exposure region (M1) shown in FIG. It is sectional drawing explaining the state which irradiates continuously the exposure light (E) which permeate | transmitted the opening part (51) of the slit to the coating film (54) on a glass substrate (50).

FIG. 12A is a cross section taken along line X1-X1 in FIG. 10, and shows a state in which the exposure light (E) irradiates the tip (A) of the first exposure region (M1). It is. FIG. 12B is a cross section taken along the line X2-X2, and the state of the central portion (B) of the first exposure region (M1). FIG. 12C is a cross section taken along the line X3-X3. The state of the terminal part (C) of a 1st exposure area | region (M1) is represented.
As shown in FIG. 12 (a), the portion (a) of the tip (A) of the first exposure region (M1) where the irradiation with the exposure light (E) is started is caused by the movement of the exposure stage (60). , Has reached the lower part of the opening (51), and irradiation from the part (a) to the tip (A) is started.

  On the other hand, the imaging camera (CM) has a black matrix alignment mark (K1) (not shown) that passes below the imaging opening (53) before the part (a) reaches below the opening (51). 2), the black matrix alignment mark (K1) is imaged, and the position information of the black matrix alignment mark (K1) is acquired. By adjusting the position of the black matrix alignment mark (K1) and the photomask alignment mark (K2) so as to have a predetermined positional relationship, the black matrix ( The alignment of the photomask pattern with respect to the pattern 21) is performed.

  This alignment is completed before the part (a) where irradiation is started reaches below the opening (51). Accordingly, the photomask for the pattern of the black matrix (21) is shown at the left end portion (A) in FIG. 12 (a) after the portion (a) where the exposure light (E) irradiation is started. Pattern alignment is performed well, and exposure light (E) is irradiated. The black matrix alignment mark (K1) is appropriately provided over the entire first exposure region (M1) from the vicinity of the portion (a) where irradiation is started to the vicinity of the portion where irradiation is ended. It has been.

As shown in FIG. 12B, in the central portion (B) of the first exposure region (M1), the position information of the black matrix alignment mark (K1) acquired by the imaging camera (CM) is used. The alignment of the photomask pattern with respect to the pattern of the black matrix (21) is always satisfactorily performed, and the exposure light (E) is irradiated.

However, as shown in FIG. 12 (c), when reaching the end portion (C) of the first exposure region (M1), the imaging aperture (53) is located after the terminal portion (c) of the end portion (C). The black matrix alignment mark (K1) that passes below is lost, and the photomask pattern is not aligned with the black matrix (21) pattern based on the position information of the black matrix alignment mark (K1). It becomes.
That is, in FIG. 10, the phenomenon that the coloring pixel (22) is not properly aligned with the pattern of the black matrix (21) at the end portion (C) indicated by hatching is the end portion (C). This is because the position information of the black matrix alignment mark (K1) cannot be obtained.

  As a method for eliminating such a state where the alignment is not performed well, the exposure stage (60) on which the glass substrate is mounted is moved regardless of the position information of the alignment mark (K1) of the black matrix. A method of determining the amount of movement per unit time obtained from the speed as a theoretical value, and using this theoretical value, aligning the pattern of the photomask with the pattern of the black matrix (21) in the terminal portion (C). Is mentioned.

  For example, the amount of deviation of the pattern of the photomask with respect to the pattern of the black matrix (21) is measured using a sample prepared in advance, and this measured value is corrected as an offset value. It is possible to obtain an accuracy comparable to the alignment based on the position information of the alignment mark (K1) of the black matrix by a slight distortion of the drive system for moving the exposure stage (60) and a slight shift of the movement amount. Have difficulty.

  Moreover, even if the alignment is performed well by this method, in actual work, since the offset value differs depending on the individual product, a sample is prepared for each product in advance and the amount of deviation is measured. It takes a considerable amount of time for the preparation work, which is not a preferable method.

JP 2008-216593 A JP 2007-121344 A

The present invention has been made in order to solve the above-described problems. For example, exposure is performed when a colored pixel is aligned with a black matrix pattern already formed on a substrate by slit exposure. Even if an exposure apparatus provided with an imaging camera that images the black matrix alignment mark and adjusts the position to align the photomask pattern with the black matrix pattern is used as an apparatus on the substrate. An exposure method that does not cause the phenomenon that the colored pixels are not properly aligned with the black matrix pattern at the end of the exposure area on the substrate in the moving direction of the multi-faceted exposure area. The issue is to provide.
It is another object of the present invention to provide a color filter and a photo-alignment film substrate manufactured using the above exposure method.

In the present invention, when the second pattern is aligned and formed with respect to the first pattern already formed on the substrate by slit exposure,
As an exposure apparatus, an exposure apparatus provided with a front imaging camera for acquiring positional information of the first pattern alignment mark is used, and as a photomask, the first pattern alignment mark on the substrate is imaged by the front imaging camera. Using a photomask provided with a front imaging opening for image capturing, the first pattern alignment mark on the substrate moving below the photomask is imaged with a front imaging camera, and the position of the first pattern The position information of the alignment mark is acquired, and the position information and the alignment mark of the photomask are adjusted to align the position of the photomask pattern (opening) with respect to the first pattern. In the exposure method to be irradiated,
1) The exposure apparatus is provided with a lower imaging camera that images a guide mark on the substrate from below the substrate and obtains a movement amount of the substrate,
2) When forming the second pattern by aligning the first pattern already formed on the substrate, a) providing guide marks outside the pixel region on the substrate in advance,
b) At the end of the exposure area where the first pattern alignment mark cannot be imaged, the amount of movement of the substrate acquired by imaging the guide mark with the lower imaging camera and the alignment mark of the photomask are positioned. By adjusting, the alignment of the photomask pattern (opening) with respect to the first pattern is performed, and exposure light is irradiated.

Further, the present invention is the exposure method according to the above invention. 1) In the exposure apparatus, at least an exposure head composed of at least a light source, a photomask, and a front imaging camera is perpendicular to the moving direction of the exposure stage. A plurality of groups are provided in the direction (Y-axis direction),
2) Outside the pixel region where the guide mark is provided is a peripheral edge portion in the width direction (Y-axis direction) on the substrate.
3) The lower imaging camera is an exposure method characterized in that a plurality of groups are provided below the guide marks on both side portions of the plurality of exposure heads.

  In the exposure method according to the present invention, the exposure is characterized in that the first pattern is a black matrix pattern constituting a color filter, and the second pattern is a colored pixel constituting a color filter. Is the method.

  According to the present invention, in the exposure method according to the above invention, the first pattern is a pixel region on a substrate constituting a liquid crystal display device, and the second pattern is a photo-alignment film region provided in the pixel region, or The exposure method is a divided photo-alignment film region obtained by dividing the photo-alignment film region.

  In addition, the present invention is a color filter manufactured using the exposure method according to claim 3.

  Moreover, the present invention is a photo-alignment film substrate manufactured using the exposure method according to claim 4.

The present invention uses an exposure apparatus provided with a front imaging camera as an exposure apparatus, uses a photomask provided with a front imaging aperture as a photomask, and uses the front imaging camera to obtain position information of the alignment marks of the first pattern. In the exposure method in which the position information and the alignment mark of the photomask are acquired, and the position of the photomask pattern (opening) is aligned with the first pattern, and exposure light is irradiated ,
1) The exposure apparatus is provided with a lower imaging camera. 2) A guide mark is provided in advance outside the pixel area on the substrate, and the guide mark is imaged by the lower imaging camera at the end of the exposure area. Since the movement amount of the substrate acquired in this way and the alignment mark of the photomask are adjusted, the alignment of the photomask pattern (opening) with respect to the first pattern is performed, and the exposure light is irradiated. For example, when forming a black matrix pattern that has already been formed on a substrate by aligning colored pixels by slit exposure, the entire area from the front end to the end of the exposure area that is multifaceted on the glass substrate Thus, an exposure method is achieved in which the colored pixels with respect to the black matrix pattern are well aligned.

  In the present invention, the exposure apparatus is provided with a plurality of exposure heads in a direction perpendicular to the moving direction of the exposure stage. Outside the pixel area where the guide marks are provided, both ends in the width direction on the substrate Since the lower imaging camera is provided at the periphery and below the guide marks on both ends of the exposure head row, the size of the glass substrate is further increased, and the size of the photomask is further reduced. However, it is an exposure method that maintains the accuracy of slit exposure and exposes the entire surface of the glass substrate in a single exposure to produce a color filter at low cost.

In addition, since the present invention is a color filter manufactured by the above exposure method, the color filter in which the color pixels for the black matrix pattern are well aligned over the entire area from the front end to the end of the exposure area It becomes.
Further, since the present invention is a photo-alignment film substrate manufactured by the above exposure method, the alignment of the photo-alignment film region or the divided photo-alignment film region is good over the entire region from the front end to the end of the exposure region. The photo-alignment film substrate formed in step 1 is used.

It is a top view which expands and shows an example of the pixel of the color filter of a liquid crystal display device. It is sectional drawing in the XX line of the pixel of the color filter shown in FIG. It is a top view explaining an example of XY step exposure. It is a top view explaining an example of slit exposure. (A), (b) is sectional drawing in the XX of FIG. It is the top view to which the part of the slit of an example of the photomask for slit exposure was expanded. It is a top view which shows an example of the stripe pattern obtained by the image development process after exposure. It is explanatory drawing which shows an example of the color filter manufactured by slit exposure. This is an example of an imposition state when a color filter having a size corresponding to one liquid crystal display device is produced by applying many colors on a large glass substrate. FIG. 10 is an enlarged plan view showing the vicinity of a first exposure region shown in FIG. 9. It is a fragmentary sectional view of an example of the exposure apparatus which employ | adopted slit exposure. It is sectional drawing explaining the state which moves an exposure stage and irradiates a 1st exposure area | region. It is a fragmentary top view of an example of the exposure apparatus used in this invention. FIG. 14 is a cross-sectional view taken along line X11-X11 in FIG. FIG. 14 is a cross-sectional view taken along line X12-X12 in FIG. The state at the tip will be described. The state in the central part will be described. The state at the end will be described. It is a top view which shows an example of the exposure apparatus used for the invention concerning Claim 2. (A) is sectional drawing which expands and shows the cross section in the X21-X21 line | wire in FIG. (B) is sectional drawing which expands and shows the cross section in a X22-X22 line | wire.

The exposure method according to the present invention will be described in detail below based on the embodiment.
FIG. 13 is a partial plan view of an example of an exposure apparatus used in the present invention. 14 and 15 are sectional views taken along lines X11-X11 (X2-X2) and X12-X12 in FIG. FIG. 13 is a partial plan view showing a corresponding portion in the vicinity of the fourth region (M4) in FIG.

As shown in FIGS. 13 to 15, an example of this exposure apparatus is shown in FIG. 11, the guide mark on the glass substrate is imaged from below the glass substrate on the exposure apparatus showing the partial cross section of the glass substrate, A lower imaging camera (CM-C) that acquires the amount of movement is provided.
This lower imaging camera (CM-C) is located outside the fourth region (M4) at the peripheral edge of the glass substrate (50) placed on the exposure stage (60), that is, the pixel region on the glass substrate. It is provided below the outside (non-exposure area (m6)).

  The optical axis of the exposure light (E) that irradiates the slit (S) on the photomask from above is on a straight line in the Y-axis direction, and in FIG. 13, on the Y11 line orthogonal to the X-axis (X12-X12). is there. The optical axis of the lower imaging camera (CM-C) shown in FIG. 15 facing upward from below the glass substrate (50) is an extension line of exposure light (E) (Y11 line indicated by a dotted line in FIG. 13). And at the intersection of the center line (line X12-X12) of the guide mark area (24). The lower imaging camera (CM-C) captures a guide mark on the glass substrate from below the glass substrate (50), and acquires the movement amount of the glass substrate.

  The guide mark area (24) is provided outside the fourth area (M4) at the peripheral edge of the side edge of the glass substrate (50), that is, outside the pixel area on the glass substrate, in parallel with the X axis (X12-X12). ing. The guide mark area (24) is an area where a guide mark (K3) (not shown) is provided, and the lower imaging camera (CM-C) images the guide mark (K3) in this area. The movement amount of the glass substrate is acquired. In addition, the exposure stage (60) uses a translucent material, for example.

As shown in FIG. 14, in this exposure apparatus, an imaging camera (CM) is provided above the photomask (PM2). The imaging camera (CM) is located at a position (L ₀ ) away from the optical axis of the exposure light (E) in the direction opposite to the movement direction of the glass substrate (50) (rightward in the X axis in FIG. 14). This imaging camera (CM) is a black matrix formed on the lower glass substrate (50) from above the photomask (PM2) through the imaging opening (53) provided in the photomask (PM2). The alignment mark (K1) is imaged, and position information of the black matrix alignment mark (K1) is acquired.

  The pattern of the photomask (PM2) with respect to the pattern of the black matrix (21) when the exposure light (E) is irradiated to the fourth exposure region (M4) through the opening (51) on the photomask (PM2). For example, when the imaging camera (CM) images the black matrix alignment mark (K1) on the glass substrate (50) moving under the photomask, the black matrix alignment mark is detected. (K1) and the alignment mark (K2) of the photomask are adjusted so that the predetermined positional relationship is set in advance, whereby the pattern of the black matrix (21) and the pattern of the photomask are changed. It is designed to be aligned.

  The lower imaging camera (CM-C) captures the guide mark (K3) in the guide mark area (24) on the glass substrate (50) moving upward, and the amount of movement of the glass substrate is determined. When acquired, the movement amount and the alignment mark (K2) of the photomask are adjusted so that the predetermined positional relationship is set in advance, whereby the pattern of the black matrix (21) and the photomask are adjusted. The patterns are aligned. The position information of the black matrix is used in the front end portion (A) to the center portion (B) in the moving direction of the fourth region (M4), and the amount of movement of the glass substrate by the guide mark is used in the end portion (C).

16 to 18, the exposure stage (60) is moved in the direction indicated by the white thick arrow from the tip (A) to the end (C) in the moving direction of the fourth exposure region (M4) shown in FIG. It is sectional drawing explaining the state which irradiates continuously the exposure light (E) which permeate | transmitted the opening part (51) of the slit to the coating film (54) on a glass substrate (50).
FIG. 16 illustrates the state at the tip (A). 13A is a cross section taken along line X1-X1 in FIG. 13, and FIG. 13B is a cross section taken along line X12-X12.

As shown in FIG. 16 (a), the portion (a) of the tip (A) of the fourth exposure region (M4) where the irradiation with the exposure light (E) is started is caused by the movement of the exposure stage (60). , Has reached the lower part of the opening (51), and irradiation from the part (a) to the tip (A) is started.
The imaging camera (CM) captures the black matrix alignment mark (K1) and acquires position information of the black matrix alignment mark (K1). The position information and the alignment mark (K2) of the photomask are adjusted so that the predetermined positional relationship is set in advance, whereby the pattern of the photomask with respect to the pattern of the black matrix (21) is adjusted. Positioning is performed and exposure light (E) is irradiated.

FIG. 17 illustrates the state at the center (B). (A) is the cross section in the X2-X2 line in FIG. 13, (b) is the cross section in the X12-X12 line.
As shown in FIG. 17A, in the central portion (B) of the fourth exposure region (M4), the position information of the black matrix alignment mark (K1) acquired by the imaging camera (CM) is used. The alignment of the photomask pattern with respect to the pattern of the black matrix (21) is always satisfactorily performed, and the exposure light (E) is irradiated.

FIG. 18 illustrates a state at the end portion (C). (A) is a cross section taken along line X3-X3 in FIG. 13, and (b) is a cross section taken along line X12-X12.
As shown in FIG. 18A, when reaching the end portion (C) of the fourth exposure region (M4), the portion after the terminal portion (c) of the end portion (C) is below the imaging opening (53). The black matrix alignment mark (K1) that passes through is eliminated.

  The lower imaging camera (CM-C) below the glass substrate (50) images the guide mark (K3) in the guide mark area (24), and acquires the movement amount of the glass substrate. By adjusting the position of the movement amount and the alignment mark (K2) of the photomask so that a predetermined positional relationship is set in advance, the pattern of the black matrix (21) and the pattern of the photomask are changed. Alignment is performed, and exposure light (E) is irradiated.

  As described above, according to the exposure method of the present invention, the pattern of the black matrix (21) and the pattern of the photomask are aligned at the end of the exposure region on the glass substrate depending on the amount of movement of the glass substrate. As a result, the alignment of the colored pixels with respect to the pattern of the black matrix (21) is good over the entire exposure area.

  FIG. 19 is a plan view showing an example of an exposure apparatus used in the invention according to claim 2. FIG. 19 is a partial plan view showing the upper part of the exposure stage (60) of the exposure apparatus. FIG. 20A is an enlarged sectional view taken along line X21-X21 in FIG. Further, (b) is an enlarged cross-sectional view taken along line X22-X22.

  In the exposure apparatus for performing slit exposure shown in FIG. 4, a glass substrate (50) is obtained by using a photomask (PM2) having a size ((e) × (f)) and performing the first and second exposures twice. To expose the entire surface. The photomask (PM2) used in this exposure apparatus has a size in the X-axis direction of several minutes compared to the size ((g) × (h)) of the photomask (PM) in the XY step exposure method shown in FIG. 1 ((e) << (g), (f) ≈ (h)) is illustrated as being downsized.

  In the example of the exposure apparatus shown in FIG. 19, when the size of the glass substrate (50) is further increased, the accuracy of slit exposure is maintained, the size of the photomask is further reduced, and the exposure can be performed once. It is an example of the exposure apparatus which exposes the whole surface of a glass substrate and manufactures a color filter cheaply.

In FIG. 19, reference numeral (H) represents an exposure head that is integrally formed of a light source, a photomask, and a front imaging camera. The size of a photomask (not shown) mounted on the exposure head is a small photomask that is smaller than the size of the photomask (PM2) shown in FIG. 4, particularly small in the Y-axis direction.
As shown in FIG. 19, a plurality of exposure heads (H) are provided in rows that are spaced in the direction (Y-axis direction) perpendicular to the moving direction of the substrate stage (60). The optical axes of the exposure light (E) from the light source of each exposure head (H) are aligned on a straight line represented by reference numeral (Y13) or (Y12) in FIG. The column composed of a plurality of exposure heads (H) is an example in which two columns are used in view of the size of the exposure head (H).

  FIG. 19B shows an array of exposure head rows. The front exposure head row (HA) provided in the direction opposite to the moving direction of the substrate stage (60) (X-axis right direction in FIG. 19) is composed of odd-numbered exposure heads (H1 to H9). The rear exposure head row (H-B) provided in the moving direction of the substrate stage (60) is composed of even-numbered exposure heads (H2 to H10). The front exposure head row (HA) and the rear exposure head row (H-B) complement each other, aligning the optical axis of the exposure light (E) on a straight line in the Y-axis direction, and an integrated exposure unit It is functioning as.

Guide mark areas in which guide marks (K3) (not shown) are formed are provided in the X-axis direction at two locations on the peripheral edges of both ends of the glass substrate (50) (24R, 24L). . As the lower imaging camera (CM-C), four lower imaging cameras are provided. The lower imaging camera 1 (CM-C1) and the lower imaging camera 3 (CM-C3) each have an extension line (Y12) of the optical axis of the exposure light (E) at both ends of the front exposure head row (HA). ) And the center line of the guide mark area (24R), and the intersection of the optical axis extension line (Y12) and the center line of the guide mark area (24L).

  Further, the lower imaging camera 2 (CM-C2) and the lower imaging camera 4 (CM-C4) are extended lines of the optical axis of the exposure light (E) at both ends of the rear exposure head row (H-B), respectively. They are provided at the intersection of (Y13) and the center line of the guide mark area (24R) and at the intersection of the optical axis extension line (Y13) and the center line of the guide mark area (24L).

  As shown in FIG. 20A, in the exposure area, the position information acquired by each front imaging camera in the front exposure head row (HA) and the alignment mark (K2) of each photomask. However, the position of the photomask pattern is aligned with the pattern of the black matrix (21) by adjusting the position so that the predetermined positional relationship is set in advance, and the exposure light (E) is irradiated.

  Further, the positional information acquired by each front imaging camera in the rear exposure head row (H-B) and the alignment mark (K2) of each photomask are in a predetermined positional relationship set in advance. By adjusting the position, the pattern of the photomask is aligned with the pattern of the black matrix (21), and the exposure light (E) is irradiated.

  As shown in FIG. 20B, outside the exposure area, the lower imaging camera 1 (CM-C1) and the lower imaging camera 3 (CM-C3) are for guiding in the guide mark areas (24R, 24L). The mark (K3) is imaged and the movement amount of the glass substrate is acquired. By adjusting the position of the movement amount and the alignment mark (K2) of each photomask in the front exposure head row (HA) so as to be in a predetermined positional relationship, black The pattern of the matrix (21) and the pattern of the photomask are aligned, and exposure light (E) is irradiated.

  Further, the lower imaging camera 2 (CM-C2) and the lower imaging camera 4 (CM-C4) capture the guide mark (K3) in the guide mark area (24R, 24L) and acquire the movement amount of the glass substrate. To do. By adjusting the position so that this movement amount and the alignment mark (K2) of each photomask in the front exposure head row (H-B) have a predetermined positional relationship set in advance, black is obtained. The pattern of the matrix (21) and the pattern of the photomask are aligned, and exposure light (E) is irradiated.

  As described above, according to the invention according to claim 2, even if the size of the glass substrate is further increased and the size of the photomask is further reduced, the accuracy of slit exposure is maintained and one exposure is performed. Thus, the entire surface of the glass substrate is exposed to provide an exposure method for producing a color filter at a low cost.

  The exposure method according to the present invention includes a plurality of imaging cameras (CM) and a plurality of lower imaging cameras (CM-C) in the moving direction (X-axis direction) of the glass substrate. Based on the acquired position information and movement amount, the alignment of the photomask pattern with respect to the pattern of the black matrix (21) is not limited to the X-axis and Y-axis directions, but the glass substrate has the Z-axis direction as the rotation axis. It is possible to adjust the alignment corresponding to the inclination (θ direction) of the substrate.

On the other hand, in a liquid crystal display device, a contact rubbing method has been widely used so far in order to align liquid crystal molecules in one direction on a substrate surface and develop a pretilt angle. However, as the size of the glass substrate is increased to, for example, the eighth generation of about 2100 × 2400 mm, non-contact liquid crystal alignment is required.
In the conventional photo-alignment method as the non-contact type alignment method, it is necessary to irradiate UV light obliquely with respect to the substrate surface, and, for example, restrictions on the apparatus are large.

  In recent years, a technique has been proposed in which a pretilt angle of liquid crystal is expressed by light irradiation from a direction perpendicular to a glass substrate. For example, it is a technique for expressing linearly polarized light having a periodic intensity distribution by applying slit exposure while moving the glass substrate on the photo-alignment film. The invention according to claim 4 is different for each of the divided photo-alignment film regions (domains) when the pre-tilt angle is expressed in the photo-alignment film region provided in the pixel region on the substrate or the photo-alignment film region is divided. This is suitable as a light irradiation method for developing the pretilt angle.

  As described above, the exposure method according to the present invention will be described using the color filter constituting the liquid crystal display device as an example, and the alignment film on the substrate constituting the liquid crystal display device is exposed to the pixel region corresponding to the pixel. However, the exposure method according to the present invention is not limited to the pattern (pixel) formation of the substrate constituting the liquid crystal display device, and is widely applied when aligning and exposing the pattern by slit exposure. This exposure method can be used.

21 ... Black matrix 22 ... Colored pixel 23 ... Transparent conductive film 24 ... Guide mark area 50 ... Substrate (glass substrate)
51 ... Opening 52 of the slit 52 ... Shading part 53 ... Imaging opening 54 ... Coating film 60 ... Exposure stage CM ... Imaging camera CM-C ... Lower imaging camera E ..Exposure light HA, front exposure head row HB, rear exposure head row Li, opening length Ls, slit longitudinal direction M1-M6, color filter Formed first to sixth exposure areas PM, PM2... Photomask S... Slits m1 to m6 on the photomask.

Claims (6)

When the second pattern is aligned with the first pattern already formed on the substrate by slit exposure,
As an exposure apparatus, an exposure apparatus provided with a front imaging camera for acquiring positional information of the first pattern alignment mark is used, and as a photomask, the first pattern alignment mark on the substrate is imaged by the front imaging camera. Using a photomask provided with a front imaging opening for image capturing, the first pattern alignment mark on the substrate moving below the photomask is imaged with a front imaging camera, and the position of the first pattern The position information of the alignment mark is acquired, and the position information and the alignment mark of the photomask are adjusted to align the position of the photomask pattern (opening) with respect to the first pattern. In the exposure method to be irradiated,
1) The exposure apparatus is provided with a lower imaging camera that images a guide mark on the substrate from below the substrate and obtains a movement amount of the substrate,
2) When forming the second pattern by aligning the first pattern already formed on the substrate, a) providing guide marks outside the pixel region on the substrate in advance,
b) At the end of the exposure area where the first pattern alignment mark cannot be imaged, the amount of movement of the substrate acquired by imaging the guide mark with the lower imaging camera and the alignment mark of the photomask are positioned. An exposure method comprising: aligning a photomask pattern (opening) with respect to the first pattern by adjusting and irradiating exposure light. 1) The exposure apparatus is provided with a plurality of exposure heads that are integrated with at least a light source, a photomask, and a front imaging camera in a direction (Y-axis direction) perpendicular to the moving direction of the exposure stage. And
2) Outside the pixel region where the guide mark is provided is a peripheral edge portion in the width direction (Y-axis direction) on the substrate.
3) The exposure method according to claim 1, wherein the lower imaging camera is provided with a plurality of groups below the guide marks on both side portions of the plurality of exposure heads.   3. The exposure method according to claim 1, wherein the first pattern is a black matrix pattern constituting a color filter, and the second pattern is a colored pixel constituting a color filter.   The first pattern is a pixel region on a substrate constituting a liquid crystal display device, and the second pattern is a photo-alignment film region provided in the pixel region, or a divided photo-alignment film region obtained by dividing the photo-alignment film region The exposure method according to claim 1 or 2, wherein   A color filter manufactured using the exposure method according to claim 3.   A photo-alignment film substrate manufactured using the exposure method according to claim 4.

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