JP5453754B2 - Alignment mark position detection method and color filter forming substrate manufacturing method - Google Patents

Description

The present invention relates to a method out position detection of the alignment mark portion, the method for manufacturing a color filter formation substrate for a display device using the position detecting method of the alignment mark portion, in particular, the color filter formation substrate for a liquid crystal display panel The present invention relates to a manufacturing method.

In recent years, progress toward an information society has been remarkable, and the use of display devices has been diversified, and various display devices have been developed and put into practical use.
In particular, liquid crystal display devices have been widely used in place of CRT (Cathode-Ray Tube, CRT).
In a liquid crystal panel for color display for a liquid crystal display device, a TFT substrate (TFT; Thin Film Transistor) and a color filter forming substrate (also referred to as a counter substrate) are opposed to each other, and the liquid crystal is sealed between the substrates. In addition, a structure in which a deflection plate is arranged outside the TFT substrate and the color filter forming substrate and a backlight part is arranged outside the TFT substrate, and the light from the backlight part is a color layer composed of colored layers of each color. Light that passes through a filter (hereinafter also referred to as CF) is displayed, but light that passes through a color filter formed of a colored layer of each color is on-off controlled for each pixel using a liquid crystal as a switching element.
As a method of controlling the liquid crystal, a method in which the alignment direction of the liquid crystal is rotated in a plane perpendicular to the substrate by a vertical electric field perpendicular to each substrate (also referred to as a vertical electric field method), and a lateral direction parallel to the substrate are used. There is a method of rotating in a plane parallel to the substrate by an electric field (also referred to as a transverse electric field method).
A typical example of the vertical electric field method is a TN method (Twisted Nematic mode), and the horizontal electric field method is known as an IPS (In-Plane Switching) method.
Usually, in the case of the TN system or the like, such an electric field is controlled by a control electrode made of a transparent conductive film (usually ITO film to tin-doped indium oxide) disposed on both substrates. In the case of the IPS method (lateral electric field method), the control electrode of the transparent conductive film (ITO film) disposed on the TFT substrate is used.
Recently, in the vertical electric field method, in order to control the viewing angle well, a liquid crystal alignment function protrusion has been provided on the color filter forming substrate.

Conventionally, as a mask for forming a TFT circuit or a color filter, the entire picture portion is formed by a plurality of graphic patterns made of a light-shielding film that substantially shields exposure light during transfer on one surface of a transparent substrate. Recently, in order to shorten the manufacturing process of a liquid crystal display panel, a light-shielding film that shields exposure light at the time of transfer on one surface of the transparent substrate, and the exposure light are used. A semi-transparent halftone film is patterned and disposed, and a light-shielding region provided with a light-shielding film, a halftone region provided with a halftone film without a light-shielding film, and a light-shielding film And a transparent area in which neither of the halftone films exists, a gradation mask provided (see Japanese Patent Application Laid-Open No. 2007-188069) and a fine slit below the resolution limit are arranged to adjust the exposure amount. Use of the slit mask (see JP 2002-196474) having fine slits has come to be performed.
For example, a columnar spacer (also referred to simply as a column) and a liquid crystal alignment function for controlling the interval for holding the liquid crystal of a liquid crystal panel in a color filter forming substrate for a liquid crystal display device by performing batch exposure using a gradation mask The protrusions can be formed simultaneously with the process of forming a color filter composed of a colored layer. (See JP 2005-84366 A)
In order to fabricate a gradation mask, for example, a dedicated mask blank in which a translucent film and a light shielding film are laminated on a transparent substrate may be used, and mask pattern plate-making may be performed. This is advantageous in that it is not necessary to arrange fine slits unlike a slit mask.
In such a gradation mask, the resist film thickness after development can be controlled in two stages by controlling the amount of transmitted light according to regions having different transmittances.
JP 2007-188069 A JP 2002-196474 A JP 2005-84366 A

As described above, recently, the process of manufacturing a liquid crystal display panel has been shortened, and columnar spacers, or columnar spacers and liquid crystal alignment function protrusions can be formed simultaneously with the process of forming a color filter composed of a colored layer. Has come to be done.
However, usually, the alignment mark is formed by the first colored layer, and the second and subsequent colored layers are formed in accordance with the mark, but the resin for forming the second and subsequent colored layers One colored layer covers the alignment mark made up of the first colored layer, but the alignment mark made up of the first colored layer in this state cannot be recognized by the current proximity exposure machine. .
For example, in a TN type color filter forming substrate composed of colored layers of resin BM to R, G, and B, an ITO film, and columns in order from the transparent substrate side, the columns are formed of R, G, In the case of forming by laminating the colored layers of B, the colored layers of R, G, and B are formed in this order as a first colored layer, a second colored layer, and a third colored layer, respectively. When forming, since the alignment mark is formed by the first colored layer (R colored layer), the alignment portion in the second and subsequent G and B colored layer forming steps and the BM forming step is 2 The resin colored layer 1 for forming the colored layers after the first layer covers the alignment mark made of the R colored layer. In the current proximity exposure machine, the alignment mark made of the R colored layer is used. Cannot be recognized.
For this reason, alignment is performed by forming the second and subsequent colored layers so that the alignment mark formed by the first colored layer is exposed. (See Japanese Patent Application No. 2008-008024)
In addition, alignment was performed by forming a BM film in a state where the ITO film was applied on the first colored layer. (See Japanese Patent Application No. 2008-011848)
At the time of these alignments, for example, the alignment mark portion is illuminated by ring illumination, and the CCD area sensor is used as an image sensor and the image is taken by the imaging means.
Japanese Patent Application No. 2008-008024 However, in the case of such an alignment method, the alignment mark formed by the first colored layer is exposed or the alignment mark formed by the first colored layer is easy to see. This process is necessary and takes time and is a problem in terms of productivity and yield.

As described above, recently, the process of manufacturing a liquid crystal display panel has been shortened, and columnar spacers, or columnar spacers and liquid crystal alignment function protrusions can be formed simultaneously with the process of forming a color filter composed of a colored layer. Has come to be done.
At that time, alignment is performed by forming the second and subsequent colored layers so that the alignment mark formed by the first colored layer is exposed, or ITO is formed on the first colored layer. In the state where the film is applied, the alignment method is performed in which the alignment is performed by forming the BM film. However, the alignment mark formed by the first colored layer is exposed or the first layer is exposed. A process for making the alignment mark formed of the colored layer easy to see is necessary, which is time-consuming and demanded in terms of productivity and yield.
The present invention is corresponding to this, and in the method for producing a color filter forming substrate, a columnar spacer or a columnar spacer and a liquid crystal alignment function protrusion are formed simultaneously with the step of forming a color filter comprising a colored layer. It is formed with the first colored layer without exposing the alignment mark formed with the colored layer of the eye or making the alignment mark formed with the first colored layer easy to see. It is an object of the present invention to provide a method for detecting the position of an alignment mark that can detect the position of an alignment mark.
At the same time, an object of the present invention is to provide a method for producing a color filter forming substrate using such a method for detecting the position of an alignment mark portion.

The alignment mark portion position detection method of the present invention comprises a mark made of a colored layer and one colored resin layer applied so as to cover the mark on one surface of the transparent substrate, A portion including a region raised along the mark is used as an alignment mark portion, the position of the alignment mark portion is detected, and the detected position is set as the position of the mark. A method for detecting the position of the alignment mark portion, wherein the mark is formed together with the first colored layer by using a colored resin layer as a material by a photolithography method using a photosensitive colored resin layer And the colored resin layer covering the entire mark region of the alignment mark portion is formed when a colored layer other than the first colored layer is formed by a photolithography method. As a colored resin layer formed by coating on the entire surface by the imaging device, via a lens system at the area sensor pixel division such as CCD, an image obtained by photographing a region including the alignment mark region, the image processing The position of the alignment mark portion is detected, and the photographing by the imaging device is for photographing the surface of the alignment mark portion by specularly illuminating the region including the alignment mark portion (epi-illumination). And the inner angle of the alignment mark part from the flat surface to the taper part in the cross section of the alignment mark part across the width of the mark made of the colored layer is the inclination of the taper part, and the average inclination of the taper part is θ If you, theta is less than 90 degrees, and, Ru der those wherein the value of tanθ is 0.028 or more.
Note that, here, the average inclination is roughly a rising portion where the bottom surface of the tapered portion (edge portion) 22b has a gentle slope when the surface shape of the cross section of the alignment mark portion is as shown in FIG. The average gradient of the region excluding the part where the gradient near the apex is gentle.

The method for producing a color filter forming substrate according to the present invention has a color filter portion composed of a colored layer of each color and a BM composed of a colored layer on one surface of a transparent substrate, and the column portion is divided into each color filter portion and BM portion. A method for producing a color filter forming substrate, comprising producing a color filter forming substrate for a liquid crystal display panel, which is formed of a colored layer for forming a color filter, and an ITO layer is disposed on the color filter portion of each color. Then, a photosensitive colored resin for forming each colored layer is applied to one surface of the transparent substrate, selectively exposed through a photomask, and developed to form each colored layer in a desired shape. The photolithography process is performed for the number of colored layers to be formed, and each color filter part, black matrix part, and column part are formed. In each photolithography process, the exposure is performed as described above. The other side of the bright substrate is placed on the stage side, and is performed by a proximity exposure method through a photomask. In the photolithographic process performed a plurality of times, the alignment in each of the second and subsequent photolithographic processes is the transparent Using an alignment mark portion provided on the substrate side and an alignment mark portion made of a light shielding layer such as Cr of a photomask for exposure, each alignment mark portion is obtained by an imaging device provided on the light source side of the photomask. The position is detected by image processing from an image obtained by photographing an area including the alignment mark area with a pixel division area sensor such as a CCD through a lens system, and the position is detected. The position is relatively moved between the photomask and the transparent substrate, and is formed by the first photolithography process. A mark consisting of a color layer, covering the mark, and a photosensitive consisting colored resin colored resin layers one layer for forming a colored layer applied at each photolithography process of second and subsequent colored resin layer There a portion including a along raised areas on the mark, the alignment mark portion, the surface of the alignment mark portion, at regular reflection illumination (epi-illumination), is intended for photographing by the image pickup device, and the 1 In the cross section of the alignment mark section that crosses the width of the mark formed of the colored layer formed by the second photolithography process, the inner angle of the alignment mark section from the flat surface to the tapered section is defined as the inclination of the tapered section, and the average inclination of the tapered section is calculated. When θ is set, θ is less than 90 degrees, and the value of tan θ is 0.028 or more .

(Function)
The position detection method of the alignment mark portion of the present invention has such a configuration, and includes a mark made of a colored layer and one colored resin layer applied so as to cover the mark on one surface of the transparent substrate. The alignment mark portion is used, and the mark position of the alignment mark portion can be detected.
Specifically, the imaging device via the lens system at the area sensor pixel division such as CCD, an image obtained by photographing a region including the alignment mark region, by image processing, the position of the alignment mark portion The detection by the imaging device is achieved by photographing the surface of the alignment mark portion by specularly illuminating the region including the alignment mark portion (epi-illumination). ing.
Specifically, in the present invention, if the surface of the alignment mark portion is photographed and its shape can be sufficiently recognized, the center position of the mark made of a colored layer (also simply referred to as the mark position) is the center position of the photographed alignment mark portion. Based on the recognition that it corresponds to the above, it was found that the shape of the alignment mark part can be fully recognized by photographing with regular reflection illumination (epi-illumination).
In particular, in the cross section of the alignment mark portion that crosses the width of the mark made of the colored layer, the inner angle of the alignment mark portion from the flat surface to the tapered portion is the inclination of the tapered portion, and the average inclination of the tapered portion is θ. If you, theta is less than 90 degrees, and by the value of tanθ is 0.028 or more, it may recognize the real for level.
An alignment mark comprising a mark made of a colored layer and one colored resin layer applied so as to cover the mark on one surface of the transparent substrate, and including a region where the colored resin layer swells along the mark. In this case, the shape of the tapered portion is uneven at each location, and depending on the value of the average inclination of the tapered portion, the light illuminated on the uneven portion at the time of shooting is not scattered in a fixed direction. As a result, the amount of light that enters the CCD area sensor via the lens system of the image pickup device increases, and it becomes difficult to distinguish from the top of the alignment mark and the surface of the edge bottom.
In order to fully recognize the tapered portion, when the gradation of luminance captured by the CCD area sensor of the imaging apparatus is set to 256 gradations from 0 to 255, the luminance of the tapered portion that becomes dark when photographing is increased and becomes brighter. Although it is calculated | required in a practical level that the luminance difference with the top part of an alignment mark part or the surface part of the bottom side of a taper part is calculated | required in the practical level, the said θ is less than 90 degree | times and the value of tan (theta) is 0.028 or more. In this case, it means that the luminance difference can be 10 or more.
In particular, in the patterning of the colored layer in the fabrication of the color filter formation substrate, by a position detection method of the alignment mark portion, it is effective.
As a result, the conventional alignment mark formed by the first colored layer can be exposed, or the process for making the alignment mark formed by the first colored layer easy to see can be eliminated. .

In the method for manufacturing a color filter forming substrate of the present invention, the columnar spacers or the columnar spacers and the liquid crystal alignment function protrusions are formed simultaneously with the color filter forming step of the colored layer by adopting such a configuration. The method for producing the color filter forming substrate does not require a step for exposing the alignment mark formed by the first colored layer or for making the alignment mark formed by the first colored layer easy to see. It is possible to provide a method for manufacturing a color filter forming substrate.
In particular, in the pattern exposure process of color filter manufacturing, by applying incident light to the substrate to recognize the colored alignment mark shape under various resist layers, it is possible to form a pattern with colored laminated columns, and the number of TN product manufacturing processes. Reduction has been realized.

As described above, the present invention provides a method for producing a color filter forming substrate in which a columnar spacer or a columnar spacer and a liquid crystal alignment function protrusion are formed simultaneously with a color filter forming step including a colored layer. It is formed with the first colored layer without exposing the alignment mark formed with the first colored layer or making the alignment mark formed with the first colored layer easy to see. It has become possible to provide a method for detecting the position of the alignment mark that can detect the position of the alignment mark.
At the same time, it is possible to provide a method for manufacturing a color filter forming substrate using such a method for detecting the position of the alignment mark.
In particular, the method for producing a color filter forming substrate of the present invention can be applied from the R, G, and B colored layers without providing an extra step for detecting an alignment mark portion when producing a TN type color filter forming substrate product. The columnar spacers or the columnar spacers and the liquid crystal alignment function protrusions can be formed simultaneously with the process of forming the color filter including the colored layer.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic cross-sectional view showing an example of a method for detecting the position of an alignment mark portion according to the present invention, and FIG. 1B is a view of the alignment mark portion as viewed from the A1 direction in FIG. FIG. 1C is a schematic view showing a photographed image of the alignment mark portion, FIG. 1D is a view showing a cross-sectional shape of the surface of the alignment mark portion, and FIG. 2A is an alignment mark of the present invention. FIG. 2B is a diagram showing a schematic configuration of an example of an alignment method using the position detection method of the portion, and FIG. 2B is a diagram in which the alignment mark portion of the processing substrate and the alignment mark of the mask are overlapped in the same coordinate system. 3 is a flowchart of an example of the process of the alignment method shown in FIG. 2A, FIG. 4 is a flowchart of an example of the method of manufacturing the color filter forming substrate of the present invention, and FIG. Method for producing color filter forming substrate shown in 4 FIG. 6 is a cross-sectional view showing an example of a color filter forming substrate manufactured according to the present invention, and FIG. 6 shows an example of a color filter forming substrate manufactured by another example of the method for manufacturing a color filter forming substrate of the present invention. It is sectional drawing.
In FIG. 1C, the top portion 22a of the alignment mark portion and the surface portion 22c of the edge bottom have high luminance and are shown as white portions, and the dark portion 20B is shown as a shaded portion, and the dark portion 20B is shaded. This is shown for convenience.
Moreover, FIG.1 (d) shows the cross section in A2-A3 of FIG.1 (c).
In addition, the imaging apparatus illustrated in FIG. 1A is illustrated in a simplified manner, and the lens system is omitted.
Further, S1 to S10 in FIG. 3 and S20 to S29 in FIG. 4 indicate processing steps.
1 to 6, 10 is a transparent substrate, 10a is a processing substrate (also referred to as a color filter forming substrate), 20 is an alignment mark portion, 20A is a photographed image (of the alignment mark portion), 20B is a dark portion, and 20C is an alignment portion. Mark portion position, 20X is a line in the x direction, 20Y is a line in the y direction, 21 is a mark (of a colored layer), 22 is a colored resin layer (also called a colored layer), 22a is a top portion, 22b is a tapered portion (edge) 22c is a surface portion (also called a surface portion on the bottom side of the tapered portion), 30 is a mask, 31 is an alignment mark, 35 is a mask holding portion, 40 is an imaging device, 41 is a CCD area sensor, 42 is a half mirror, 43 is a light source (for illumination), 44 is a mirror, 50 is a stage, 55 is a substrate holder, 71 is a first colored layer, 72 is a second colored layer, and 73 is a third layer. The colored layer, 74 is an ITO film, 75 is a BM layer (also referred to as a light-shielding colored layer), 75A is a semi-light-shielding colored layer, 76 is a black matrix portion (also simply referred to as a black matrix), and 80 and 80a are columnar spacers. .

First, an example of the alignment mark portion position detection method of the present invention will be described with reference to FIG.
The position detection method of the alignment mark part of this example is a position detection method of the alignment mark part, which is adopted when patterning the colored layer in the production of the color filter forming substrate. On one surface of the transparent substrate 10, R, G, B And a colored resin layer (also referred to as a colored layer) that is applied so as to cover the mark 21 and that has one color of R, G, and B different from the color of the mark portion. Alignment portion for detecting the position of the mark 21 in the alignment mark portion 20 is defined as a portion including the region where the colored resin layer 22 is raised along the mark 21. This is a method of detecting the position of the mark unit 20 .
Then, the position of the alignment mark part is detected by image processing from an image obtained by photographing the area including the alignment mark part 20 by the CCD area sensor 41 through the lens system (not shown) by the imaging device 40. To do.
In particular, in this example, the imaging device 40 is used for imaging a region including the alignment mark part 20 with specular reflection illumination (epi-illumination), whereby the alignment mark part 20 having such a structure can be obtained. The shape of the raised area along the mark 21, particularly the position of the mark 21 in the alignment mark portion 20 can be recognized.

First, as shown in FIG. 1A, the imaging device 40 is set at the position of the alignment mark portion of the processing substrate 10a, and the light source of illumination light is set.
Then, the alignment mark part 20 is image | photographed with the falling illumination of illumination light with an imaging device. As shown in FIG. 1A, the illumination light from the light source is reflected through the half mirror 42 of the imaging device, and falls on the alignment mark unit 20 and is illuminated.
During shooting, the light reflected from the alignment mark 20 by falling illumination passes through the half mirror 42 of the imaging device, and enters the CCD area sensor 41.
Here, the mark 21 has a cross shape, and as shown in FIG. 1A, the alignment mark portion 20 swells in a cross shape along the mark shape and has a top portion 22a and a tapered portion (edge portion) 22b. Therefore, the intensity of the reflected light is large at the top portion 22a, small at the edge, and large at the bottom surface portion 22c of the tapered portion. Thus, the alignment mark is reflected by the reflected light of the fall-illuminated light. As shown in FIG. 1C, in the image obtained by photographing the portion 20 (see FIG. 1B), the top portion 22a and the edge bottom surface portion 22c are bright and the edge portion is dark.
The outer shape of the cross section at A2-A3 in FIG. 1B is as shown in FIG. 1D, but when the average inclination of the edge portion 22b is θ, the value of tan θ is 0.028 or more. Can be recognized well at a practical level.
The average slope is roughly the average slope of the region excluding the rising portion where the slope of the bottom of the edge portion 22b is gentle and the portion where the slope near the vertex is gentle, as shown in FIG. .

After photographing the alignment mark unit 20, the image processing unit processes the image using the image (see FIG. 1C) obtained by photographing the alignment mark unit 20, for example, the center y position of the line 20X in the x direction. Then, the position (x, y) of the alignment mark portion 20 is obtained from the center y position of the y-direction line 20Y and detected as the position of the mark 21.
In this way, the position of the mark 21 of the alignment mark portion 20 is obtained.
As for image processing, for example, image data of a photographic image displayed in gradation (see FIG. 1C) is binarized at a predetermined slice level for each pixel, and a dark tapered portion is black and aligned. After obtaining binary image data in which bright portions such as the top portion 22a of the mark portion 20 and the bottom surface portion 22c of the taper portion are white, the line image in the x direction is further obtained from the obtained binary image data. The center y position and the center position of the y direction line are obtained.
With respect to the photographed image, smoothed image data obtained by performing smoothing processing on the vicinity region of each pixel is obtained, and this image data is binarized at a predetermined slice level for each pixel so that the dark edge portion is black, alignment mark After obtaining binary image data in which bright portions such as the top portion 22a of the portion 20 and the bottom surface portion 22c of the tapered portion are white, the center of the line in the x direction is further obtained from the obtained binary image data. The y position and the center position of the y direction line may be obtained.
Note that the smoothing process here is, for example, a new pixel value for each pixel of the original image (captured image) data, with the center value of the histogram of all the pixels in the vicinity of the pixel as a new pixel value. Image data is obtained and used as smoothed image data.

As the light source 43 for illumination, for example, when the mark is made of a red (R) colored layer and the resin colored layer covering the mark is blue (B), an infrared LED is used.
The imaging device including the CCD area sensor 41 is not particularly limited.

The transparent substrate 10 is preferably a low expansion and good transparency, and although a glass substrate is used here, it is not limited to this.
A plastic substrate or the like is also used.
As the resin colored layer for forming each colored layer of R, G, and B, here, a pigment dispersion type coloring material in which a pigment, a dye or the like is mixed and dispersed in an ultraviolet curable photosensitive resin, respectively. Is used.

Next, an alignment method using the alignment mark position detection method of the present invention will be briefly described with reference to FIGS.
Here, the alignment mark portion position detection method of the present invention described with reference to FIG. 1 has a color filter portion of each color composed of a colored layer of each color and a BM composed of a colored layer on one surface of the transparent substrate, and a column portion. (Also referred to as a spacer) is formed of a colored layer for forming each color filter part and BM part, and an ITO layer is arranged on the color filter part of each color, and a TN system (Twisted Nematic mode) When producing a color filter forming substrate for a liquid crystal display panel, it is applied to alignment in a photolithography process of a colored layer.
The alignment is performed with an apparatus configuration as shown in FIG.
The processing substrate 10a shown in FIG. 2 has alignment mark portions 20 (see FIG. 1) having marks 21 made of a colored layer at two locations on the processing substrate 10a, and two corresponding locations on the mask 30 for exposure. Alignment is performed with the alignment mark 31.
Here, the processing substrate 10a is subjected to proximity exposure whose position is fixed by the mask holding unit 35 while being held by the substrate holding unit 55 fixed on the stage 55 whose position coordinates are managed. The exposure mask 30 and a predetermined gap interval are provided.
Then, each alignment mark portion 20 of the processing substrate 10a is roughly aligned with the corresponding alignment mark 31 of the exposure mask 30 so that the two alignment marks 31 of the exposure mask 30 can be photographed. The imaging device 40 and the light source unit 43 described in FIG. 1 are set in advance. (S1-S2)
Thereafter, each imaging device 40 photographs each alignment mark of the mask 30 at each position, and captures it as a photographed image at the coordinate position (coordinate position for managing the stage). (S3)
On the other hand, at the coordinate position, each imaging device 40 images the alignment mark portion 20 of the processing substrate 10a as described in FIG. 1, and the captured image at the coordinate position (coordinate position for managing the stage). Capture as. (S4)
Here, alignment marks 31 and 21 having shapes as shown in FIG. 2B are used.
Next, the image data Dm1 and Dm2 of each alignment mark 31 of the mask 30 obtained by photographing by the position detection method of the alignment mark part of the present invention described in FIG. 1 and the image of each alignment mark part 20 of the processing substrate 10a. The positions of the alignment marks 31 and the alignment mark portions 20 are detected from the data Da1 and Da2, respectively. (S4 to S5, S7 to S8)
In FIG. 2B, the center position of each mark in the x and y directions is the position.
The positional deviation between the alignment mark 31 and the alignment mark part 20 at each corresponding position is calculated and extracted. (S9)
Next, based on the extracted displacement amount of each position, a stage movement amount that corrects this is calculated, and the stage movement is performed based on the calculated result. (S10)
In this way, alignment between the mask 30 and the processing substrate 10a is performed.

Next, an example of a method for producing a color filter forming substrate that employs an alignment method using the alignment mark portion position detection method of the present invention will be described with reference to FIG.
In this example, a color filter portion of each color composed of a colored layer of each color and a BM composed of a colored layer are provided on one surface of a transparent substrate, and a column portion (also referred to as a spacer) is formed on each color filter portion and BM portion. A color filter forming substrate for producing a color filter forming substrate for a liquid crystal display panel of a TN mode (Twisted Nematic mode), which is formed of a colored layer for forming a color filter and an ITO layer is disposed on a color filter portion of each color The photosensitive coloring resin for forming each colored layer is applied on one surface of the transparent substrate, selectively exposed through a photomask, and developed, whereby each color is formed into a desired shape. The photolithography process for forming the layers is performed by the number of the colored layers to be formed, and each color filter portion, black matrix portion (also referred to as BM portion), column portion (also referred to as spacer). ) It is intended to form.
In this example, in each of the photolithographic steps, the exposure is performed by a proximity exposure method through a photomask with the other surface of the transparent substrate placed on the stage (mounting table) side. The alignment in the second and subsequent photolithographic steps in the process uses the alignment method described with reference to FIG. 2, and includes an alignment mark portion provided on the transparent substrate side, Cr of a photomask for exposure, etc. The alignment mark portion is made of a light-shielding layer, and each alignment mark portion is detected by an image sensor provided on the light source side of the photomask, by a pixel division area sensor such as a CCD via a lens system. From the image of the area including the area, the position is detected by image processing, and the detected position is The photomask and the transparent substrate side are moved relative to each other, and the mark is made of a colored layer formed by the first photolithography process, and the second and subsequent photolithography processes covering the mark. A colored resin layer made of a photosensitive colored resin for forming a colored layer to be applied in is used as the alignment mark portion, and the alignment mark portion is subjected to specular reflection illumination (epi-illumination illumination). Is taken by

The method for manufacturing the color filter forming substrate of this example is performed by, for example, the processing flow shown in FIG.
In brief, first, a red R layer is formed as a first layer on one surface of a transparent substrate by photolithography. (S20-S21)
As the transparent substrate 10, a substrate having low expansion and good transparency is preferable, and although a glass substrate is used here, it is not limited to this.
A plastic substrate or the like is also used.
At this time, a mark (corresponding to 21 in FIG. 1) is formed.
Next, a photosensitive resin colored layer for forming a blue B layer is applied so as to cover the processing substrate including the mark, and after drying, the alignment according to the present invention described based on FIGS. 2 and 3 is performed. Alignment is performed by an alignment method using the mark position detection method, exposure is performed, and development is performed to form a second B layer. (S22)
Next, similarly, a photosensitive resin colored layer for forming a green G layer is applied so as to cover the processing substrate including the mark, and after drying, the book described based on FIGS. 2 and 3 above. Alignment is performed by the alignment method using the position detection method of the alignment mark portion of the invention, exposure is performed, and development is performed to form a third G layer. (S23)
In the R layer forming process (S21), a red colored layer in which a pigment, a dye, or the like is mixed and dispersed in an ultraviolet curable photosensitive resin is applied to one surface of the transparent substrate 10 and formed into a predetermined shape by photolithography. A first colored layer (also referred to as a red colored layer or R layer) is formed in a predetermined region.
Similarly, in the B layer forming process (S22), the first colored layer of the transparent substrate 10 was formed by dispersing a blue colored layer in which a pigment, a dye or the like was mixed and dispersed in an ultraviolet curable photosensitive resin. A second colored layer (also referred to as a blue colored layer or B layer) is formed in a predetermined region by applying to the side surface and forming a predetermined shape by photolithography.
Similarly, in the G layer forming process (S23), a green colored layer obtained by mixing and dispersing a pigment, a dye, or the like in an ultraviolet curable photosensitive resin is used as the first colored layer, two layers of the transparent substrate 10. A third colored layer (also referred to as a green colored layer or G layer) is formed by applying to a surface on which the colored layer of the eye is formed and applying a predetermined shape by a photolithography method.

Next, an ITO film is formed as a single layer film on each colored layer of the processing substrate by sputtering under a predetermined sputtering condition using an ITO sintered body as a target. (S24)
Sputtering for forming an ITO film for a control electrode is generally performed in a film composition (for example, In ₂ O) under an Ar gas atmosphere under a pressure of 1 × 10 ⁻⁵ torr to 1 × 10 ⁻² torr. ₃ , 90 w% + SnO ₂ , 10 w% composition), and an ITO sintered body having a thickness of 8 mm to 15 mm is used as a target material, and the direct current magnetron sputtering method is used.
As the target, a target plate is usually used in which a Cu plate is used as a backing material, indium solder is used as an adhesive layer, and a large number of sintered target materials are joined together.
In the production of a color filter forming substrate in which an ITO film is disposed as a control electrode, the ITO film is formed by sputtering on the colored layer forming the color filter. In view of the property and degassing from the colored layer forming the color filter, it is required to form the film at a low temperature.

Next, similar to the formation of the second and third colored layers, a photosensitive resin colored layer for forming a black BM layer is applied so as to cover the processing substrate including the mark, and after drying, the above-mentioned Alignment, exposure, and development are performed by the alignment method using the alignment mark position detection method of the present invention described with reference to FIGS. 2 and 3 to form a BM layer. (S25)
In this way, a color filter forming substrate (also referred to as a CF substrate) is formed. (S26)

The color filter forming substrate formed in this way has a shape as shown in FIG. 5, for example.
Here, the columnar spacer 80 is formed so that the colored layers of the respective colors are stacked when the colored layers are formed.
The BM layer is the top layer.
In order to form the colored layer of each color by changing the thickness, here, the light-shielding film that shields the exposure light at the time of transfer onto one surface of the transparent substrate and the semi-transmissive to the exposure light are described here. A halftone film having a light-shielding film, a halftone area in which there is no light-shielding film and a halftone film is provided, and a light-shielding film and a halftone film. A gradation mask provided with a transparent region in which none exists is used.

The color filter forming substrate (S26) of this example thus prepared and the TFT substrate (S27) to be bonded to form a liquid crystal panel are prepared in advance.
Then, an ultraviolet curable sealing material is applied to the outer peripheral sealing region of the color filter forming substrate transparent conductive film forming substrate 110 of this example by, for example, a dispenser or printing to obtain a predetermined height. A spacer is formed, and liquid crystal is disposed in the frame-like spacer by a dropping method, and then bonded to the TFT substrate. (S28)
At the time of bonding, the sealing material is cured by irradiating the sealing material in the sealing region with ultraviolet rays from the transparent substrate (corresponding to 10 in FIG. 1) side of the color filter forming substrate.
In this manner, a liquid crystal display panel using the color filter forming substrate of this example is manufactured. (S29)

Note that the method for producing the color filter forming substrate is one example, and the present invention is not limited thereto.
For example, instead of the light shielding by the BM layer shown in FIG. 5, as shown in FIG. 6, the black matrix portion and the column portion are formed by the light shielding by the R, G, B colored layers and the semi-light-shielding (gray) colored layer. You may do it.
The fabrication in this case is basically the same as the fabrication method described with reference to FIG. 3, and the columnar spacer 80a and the black matrix portion 76 are fabricated when each color of R, G, B is formed.
Also in this case, in order to form the colored layers of the respective colors with varying thicknesses, here, the light shielding film that shields the exposure light at the time of transfer onto one surface of the transparent substrate, and the exposure light described above are used. The semi-transparent halftone film is patterned and arranged, and the light-shielding area provided with the light-shielding film, the halftone area provided with the half-tone film without the light-shielding film, the light-shielding film and the half-tone film A gradation mask provided with a transparent region where none of the tone films exists is used.

FIG. 1A is a schematic cross-sectional view showing an example of a method for detecting the position of an alignment mark portion according to the present invention, and FIG. FIG. 1C is a schematic view showing a photographed image of the alignment mark portion, and FIG. 1D is a view showing a cross-sectional shape of the surface of the alignment mark portion. FIG. 2A is a diagram showing a schematic configuration of an example of an alignment method using the position detection method of the alignment mark portion of the present invention, and FIG. Is superimposed in the same coordinate system. It is a flowchart of an example of a process of the alignment method shown to Fig.2 (a). It is a processing flowchart of an example of the manufacturing method of the color filter formation board | substrate of this invention. It is sectional drawing which showed one example of the color filter formation board | substrate produced with the preparation method of the color filter formation board | substrate shown in FIG. It is sectional drawing which showed one example of the color filter formation board | substrate produced by another example of the production method of the color filter formation board | substrate of this invention.

Explanation of symbols

10 Transparent substrate 10a Processing substrate (also called color filter forming substrate)
20 Alignment mark portion 20A Captured image 20B (of alignment mark portion) Dark portion 20C Alignment mark portion position 20X x-direction line 20Y y-direction line 21 (of colored layer) mark 22 colored resin layer (also referred to as colored layer)
22a Top 22b Taper (also called edge)
22c surface portion (also referred to as a bottom surface portion of the tapered portion)
30 Mask 31 Alignment Mark 35 Mask Holding Unit 40 Imaging Device 41 CCD Area Sensor 42 Half Mirror 43 Light Source 44 (for Illumination) Mirror 50 Stage 55 Substrate Holding Unit 71 First Colored Layer 72 Second Colored Layer 73 3 First colored layer 74 ITO film 75 BM layer (also referred to as light-shielding colored layer)
75A Semi-light-shielding colored layer 76 Black matrix portion (also simply referred to as black matrix)
80, 80a Columnar spacer

Claims (2)

A portion having a mark made of a colored layer and one colored resin layer applied so as to cover the mark on one surface of the transparent substrate, and including a region where the colored resin layer swells along the mark is aligned. A method for detecting the position of an alignment mark when patterning a colored layer in the production of a color filter forming substrate, wherein the position of the alignment mark is detected, and the detected position is the position of the mark. The mark is formed together with the first colored layer using the colored resin layer as a raw material by a photolithography method using a photosensitive colored resin layer, and the entire mark area of the alignment mark portion is formed. colored resin layer which covers, at the time of forming by photolithography a colored layer other than the first colored layer, a colored resin layer formed by coating on the entire surface as a material, An image device detects the position of the alignment mark part by image processing from an image obtained by photographing an area including the alignment mark part area with a pixel division area sensor such as a CCD through a lens system. The imaging by the imaging device is to perform specular reflection illumination (epi-illumination) on the area including the alignment mark portion to photograph the surface of the alignment mark portion , and the width of the mark made of the colored layer is increased. In the cross section of the alignment mark section that crosses, when the inner angle of the alignment mark part from the flat surface to the tapered part is the inclination of the tapered part, and the average inclination of the tapered part is θ, θ is less than 90 degrees and tan θ A value of 0.028 or more is a method for detecting the position of the alignment mark portion. On one surface of the transparent substrate, each color filter portion comprising a colored layer of each color, a BM comprising a colored layer, a pillar portion is formed with a colored layer for forming each color filter portion or BM portion, and A method for producing a color filter forming substrate, wherein a color filter forming substrate for a liquid crystal display panel, in which an ITO layer is disposed on the color filter portion of each color, wherein each colored layer is provided on one surface of the transparent substrate. The number of colored layers to be formed by applying a photosensitive colored resin for formation, selectively exposing through a photomask, and developing to form each colored layer in a desired shape The color filter portion, the black matrix portion, and the column portion are formed, and the exposure in each photolithography step is performed with the other side of the transparent substrate placed on the stage side, Alignment in the second and subsequent photolithographic steps in the photolithographic process performed a plurality of times is performed with an alignment mark portion provided on the transparent substrate side and for exposure. An alignment mark portion made of a light shielding layer such as Cr of the photomask of each photomask is used, and each alignment mark portion is divided into pixel division areas such as a CCD via a lens system by an imaging device provided on the light source side of the photomask. The sensor detects the position of the image including the alignment mark area from the image, and the position is moved relative to the photomask and transparent substrate corresponding to the detected position. And a mark made of a colored layer formed by the first photolithography process and covering the mark twice And a subsequent photosensitive consisting colored resin colored resin layers one layer for forming a colored layer applied at each photolithography process, and a portion where colored resin layer comprises along raised areas on the mark, the alignment A mark portion is formed by photographing the surface of the alignment mark portion with specular reflection illumination (epi-illumination) with the imaging device, and comprising a colored layer formed by the first photolithography process. In the cross section of the alignment mark part across the width, when the alignment mark part internal angle from the flat surface to the taper part is the inclination of the taper part, and the average inclination of the taper part is θ, θ is less than 90 degrees, and A method for producing a color filter forming substrate, wherein a value of tan θ is 0.028 or more .

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