JP4715337B2 - Manufacturing method of color filter - Google Patents

Description

  The present invention relates to a color filter of a display device, and more particularly to a color filter provided with a plurality of color filter pieces of a plurality of types having different thickness patterns for each type.

For example, FIG. 3 is a plan view schematically showing an example of a color filter used in a liquid crystal display device. 4 is a cross-sectional view of the color filter shown in FIG. 3 taken along line XX ′.
As shown in FIG. 3 and FIG. 4, the color filter used in the liquid crystal display device is a glass substrate (50) in which a pattern such as a black matrix (51) and a colored pixel (52) is sequentially formed. is there.
3 and 4 schematically show a color filter, and 12 colored pixels (52) are shown. In an actual color filter, for example, several hundreds of pixels are displayed on a 17-inch diagonal screen. A large number of colored pixels of about μm are arranged.

The black matrix (51) is a matrix having light shielding properties, and the colored pixels (52) have, for example, red, green, and blue filter functions.
The black matrix determines the position of the colored pixels of the color filter, makes the size uniform, and shields unwanted light when used in a display device, making the image of the display device uniform and uniform. In addition, it has a function of making an image with improved contrast.

This black matrix (51) is an example in which a resin is used as a black matrix material on a glass substrate (50).
The black matrix (51) pattern is formed on the glass substrate (50) by, for example, a photolithography method using a negative black photoresist for forming a black matrix, and is formed using a resin. This black matrix is referred to as a resin black matrix (51).

  Further, the pattern of the colored pixels (52) is a photo using a negative colored photoresist in which a pigment such as a pigment is dispersed on the glass substrate (50) on which the resin black matrix (51) is formed. It is formed as a colored pixel by a lithography method, that is, by exposure through a photomask to a coating film of a colored photoresist, and development processing. Red, green, and blue colored pixels are sequentially formed.

When a large number of color filters are manufactured, a color filter of a size corresponding to a single liquid crystal display device (hereinafter referred to as a color filter piece) 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.
In this exposure, for example, a photomask in which a mask pattern for forming a color filter piece having a diagonal size of 17 inches is provided on a mask substrate having a size substantially the same as the size of a glass substrate is used. The exposure 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 color filter piece of the same type, that is, a film thickness of a colored pixel that is a pattern, a finished size (size of a color filter piece), or the like, that is, the same type is applied. And in the manufacture, it considers in each process and manufactures so that the variation between surfaces may not occur.

  On the other hand, an exposure method called a step-and-repeat exposure method forms, for example, a 17-inch diagonal color filter piece on a mask substrate that is approximately the same size as a 17-inch diagonal color filter piece. This is a method of using a photomask with one mask pattern for performing the exposure, for example, performing exposure four times, which is the number of multiple faces, on a large glass substrate of about 650 mm × 850 mm. Therefore, the step-and-repeat exposure method requires a corresponding time in the exposure process.

  That is, a manufacturing method by this collective exposure method in which a large-size glass substrate is exposed once using a photomask with a multifaceted mask pattern, and then collectively developed is a photolithographic method. Therefore, it can be said that the production method for producing a color filter is an excellent production method capable of producing a large amount of color filters at low cost.

  On the other hand, in the above step-and-repeat exposure method, although an appropriate time is required for the exposure process, a plurality of different types of color filter pieces are attached to a large glass substrate, for example, the thickness of the colored pixels is different. When two types of 17-inch diagonal color filter pieces are to be manufactured on a large glass substrate, the photomask becomes the second type of photomask during the multiple exposures. By replacing, it can be manufactured relatively easily.

However, in the batch exposure method, even when trying to manufacture a plurality of different types of color filter pieces on the large glass substrate, the specifications of each type, for example, the brightness and saturation of the color filter are defined. When the color pixels to be colored have different film thicknesses, it is extremely difficult to manufacture a large size glass substrate by attaching a plurality of different types of color filter pieces.
JP 2001-235616 A

The present invention has been made to solve the above-described problem. For example, one color filter piece of a plurality of varieties having different film thicknesses of patterns constituting the color filter piece, such as the thickness of a colored pixel. It is an object of the present invention to provide an inexpensive color filter formed by attaching to a large glass substrate.
It is another object of the present invention to provide a method for manufacturing the color filter.

In this way, for example, when a large-sized glass substrate is subjected to multiple facets of a color filter piece of a certain size and a margin portion is generated, the different color filter pieces of different sizes are attached to the margin portion. Thus, it is possible to manufacture the color filter at low cost by effectively using the blank portion.
Alternatively, for example, by attaching a plurality of different types of color filter pieces to a large size glass substrate, delivery of the same size color filter pieces of a plurality of different types is started simultaneously within a short period of time. It becomes possible.

The present invention provides a color filter in which a plurality of color filter pieces of a size corresponding to a single display device are provided on a substrate, the color filter pieces having a plurality of patterns having different film thicknesses for each product type. A color filter piece of a variety, and the pattern constituting the color filter piece is a photomask provided with a plurality of mask patterns for forming the pattern as a photomask. A photomask having a halftone portion having a density for forming a film thickness of each type of pattern is used as a mask pattern on a photomask corresponding to a color filter piece of a type other than a high type, and one through the photomask. A color filter formed by multiple exposure and development processes.

The present invention relates to a negative photoresist provided on a substrate through a photomask provided with a plurality of mask patterns for forming a pattern constituting a color filter piece having a size corresponding to a single display device. A color in which a plurality of color filter pieces are provided on the substrate by performing a single exposure on the coating film and a developing process to sequentially form each pattern constituting the color filter piece on the substrate. In the color filter manufacturing method for manufacturing a filter, when the color filter piece provided on the substrate is composed of a plurality of types of color filter pieces, and the film thickness of the pattern to be formed differs for each type, the photo filter As a mask, on the mask pattern on the photomask corresponding to the color filter piece of the type other than the type with the highest film thickness, A method of manufacturing a color filter, which comprises using a photomask having a halftone portion of the concentration to form a film thickness of the pattern varieties.

  In the color filter manufacturing method according to the present invention, the halftone portion may be a metal oxide film or a chromium film, or a line and space pattern or checkered pattern having a pitch less than the resolution of a system for forming a pattern. A color filter manufacturing method characterized by being a pattern.

The present invention relates to a negative photoresist provided on a substrate through a photomask provided with a plurality of mask patterns for forming a pattern constituting a color filter piece having a size corresponding to a single display device. A color in which a plurality of color filter pieces are provided on the substrate by performing a single exposure on the coating film and a developing process to sequentially form each pattern constituting the color filter piece on the substrate. In the color filter manufacturing method for manufacturing a filter, when the color filter piece provided on the substrate is composed of a plurality of types of color filter pieces, and the film thickness of the pattern to be formed differs for each type, the photo filter As a mask, on the mask pattern on the photomask corresponding to the color filter piece of the type other than the type with the highest film thickness, Since the method of manufacturing a color filter using a photomask having a halftone portion having a density for forming a film thickness of a variety of patterns, the color filter pieces of a plurality of kinds having different film thicknesses of patterns constituting the color filter pieces Can be manufactured at a low cost by attaching a color filter to a large glass substrate.

Embodiments of the present invention are described in detail below.
FIG. 1 is a plan view showing an example of a color filter according to the present invention. As shown in FIG. 1, the color filter (10) shown in this example has three first color filter pieces (CF · P-1) of a size corresponding to one display device on a glass substrate. The second color filter piece (CF · P-2) having a size corresponding to one other display device having a different size is a color filter provided with a plurality of two types of color filter pieces of six types. .

  The thickness of the pattern constituting the first color filter piece (CF · P-1), for example, the thickness of the red colored pixel and the red color constituting the second color filter piece (CF · P-2) The thickness of the colored pixel is a different thickness. The pattern constituting these color filter pieces (CF · P-1, CF · P-2) is substantially the same as the above glass substrate provided with 3 and 6 mask patterns for forming each pattern. It is formed by a single exposure, that is, a so-called batch exposure method through a photomask of the same size, and subsequent development processing.

  The color filter (10) shown in FIG. 1 is a case where the margin portion becomes large when only the first color filter piece (CF · P-1) is applied to the glass substrate. In order to utilize, the size is smaller than the first color filter piece (CF · P-1), and the pattern film thickness is thinner than the pattern thickness of the first color filter piece (CF · P-1). This is an example in which the second color filter piece (CF · P-2) is attached to the first color filter piece (CF · P-1).

FIG. 2 is an explanatory view schematically showing an example of a color filter manufacturing method according to the present invention. FIG. 2A shows, for example, a negative photoresist coating (2) for forming red colored pixels on a glass substrate (1). This shows a state in which irradiation light (7) is given through a photomask (PM).
FIG. 2 is an explanatory view corresponding to a cross section taken along line AA of FIG.

  The photomask (PM) in the present invention is of a type comprising a two-layer metal thin film (5) in which a chromium oxide interference film is formed on the surface of a chromium film on a glass substrate (4). For example, a first mask pattern (MP-1) for forming red colored pixels of the first color filter piece (CF · P-1) on the metal thin film and a second color filter piece (CF · P). -2), for example, a second mask pattern (MP-2) for forming red colored pixels is provided. The density of the light shielding part and the transmittance of the transmission part of the first mask pattern (MP-1) are the same as those of the second mask pattern (MP-2).

  A halftone portion (6) is provided on the second mask pattern (MP-2). As described above, the film thickness of the red color pixel of the second color filter piece (CF · P-2) is, for example, the red color of the first color filter piece (CF · P-1). Since it is thinner than the color pixel, the second mask pattern (MP-2) composed of the same light-shielding part and transmission part as the first mask pattern (MP-1) is thin, for example, a red color pixel The halftone part (6) is provided on the mask pattern on the photomask corresponding to the second color filter piece (CF · P-2), that is, the second mask pattern (MP-2). It was.

The uniform irradiation light (7) from behind the photomask (PM) is attenuated by the halftone part (6) in the second mask pattern (MP-2). Therefore, as shown in FIG. 2B, the film thickness of, for example, the red colored pixel (3-2) of the second color filter piece (CF · P-2) obtained after the development processing is first. The film thickness is smaller than the thickness of the red colored pixel (3-1) of the color filter piece (CF · P-1).

  The density of the halftone portion (6) provided on the second mask pattern (MP-2) is formed on the glass substrate when uniform irradiation light (L) is applied from behind the photomask (PM). The first color filter piece (CF · P-1) has, for example, a red color pixel (3-1) having a normal film thickness, and a second color filter piece (CF · P-). For example, the film thickness of the red colored pixel (3-2) of 2) is set to be a desired thin film thickness.

As the half-tone portion (6), there is a thin film that attenuates ultraviolet rays, for example, a half-tone portion made of a metal oxide film such as ITO, or a half-tone portion obtained by photo-etching a chromium film formed when manufacturing a photomask. It is done.
However, when the number of color filter pieces to be attached on the glass substrate is 3 or more, halftone portions (6) having a plurality of different densities are provided. Therefore, as the halftone portion (6), a pattern is used. A line and space pattern or a checkered pattern having a pitch less than the resolution of the system to be formed is preferable.
This line-and-space pattern or checkered pattern has a pitch equal to or lower than the resolution of the system and has a density corresponding to the film thickness of each product type.

  FIG. 7A is an enlarged plan view showing an example of a line and space pattern. FIG. 7B is a cross-sectional view taken along line X-X ′ in FIG. As shown in FIGS. 7A and 7B, the line-and-space pattern includes a line (L) that blocks light and a space (S) that transmits light. The line and space pattern in the present invention is less than the resolution of the system of the photolithography method used.

The photolithographic system refers to, for example, the entire process of forming a colored pixel, such as an optical system, a photomask, a colored photoresist, and a development process, and the resolution of the resulting colored pixel pattern is the resolution of this system. It depends on.
That is, by making the line and space pattern below the resolution of the system of the photolithography method, the line and space pattern of the halftone portion (6) on the photomask is not made to function as a pattern for forming a line and space image. It functions as a half-tone with a uniform optical density.

FIG. 5 is a plan view showing another example of the color filter according to the present invention. As shown in FIG. 5, this color filter (20) is a color filter piece (CF · P-11) having a chromaticity for a personal computer among color filters used in a liquid crystal display device on a glass substrate. , One color filter piece (CF · P-12) having the same chromaticity for TV and one color filter piece (CF · P-) having the same chromaticity for monitor This is an example in which one of 13) is attached.
By manufacturing these three types of color filter pieces with different color pixel film thicknesses, the delivery of the three types of color filter pieces with different chromaticities will be started simultaneously within a short period of time. It becomes possible.

In the above description, the color pixel is taken as an example of the pattern constituting the color filter piece. However, the color filter manufacturing method according to the present invention can be applied to other patterns constituting the color filter piece. it can.
For example, in a conventional liquid crystal display device, transparent spherical particles (beads) of glass or synthetic resin called spacers are dispersed to form a gap between substrates. Since these spacers are transparent particles, if a spacer is included with the liquid crystal in the pixel, light will leak through the spacer during black display, and the substrate in which the liquid crystal material is enclosed Due to the presence of the spacers between them, the alignment of the liquid crystal molecules in the vicinity of the spacers is disturbed, and light leakage occurs at this part, and the contrast is lowered and the display quality is adversely affected.

As a technique for solving such a problem, a method of forming a photo spacer (protrusion) having a spacer function at a position of a black matrix between pixels by using a photoresist and photolithography is developed and put into practical use. .
FIG. 6 is a partial cross-sectional view of such a color filter for a liquid crystal display device. As shown in FIG. 6, in the color filter (30) for the liquid crystal display device, a black matrix (41), a colored pixel (42), and a transparent conductive film (43) are sequentially formed on a glass substrate (40). A photospacer (44) as a protrusion having a spacer function is formed on the transparent conductive film (43) above the black matrix (41). In the liquid crystal display device using such a color filter for a liquid crystal display device (30), the photo spacer (44) is formed at a position avoiding the inside of the pixel, and thus the contrast is improved.

  Even in such a color filter provided with a photospacer (44), by applying the method for producing a color filter according to the present invention, a color filter piece having a plurality of photospacers having different heights is attached. It can be easily manufactured. Similarly, for example, instead of rubbing treatment, the present invention can be applied to the formation of alignment control protrusions for controlling the alignment of liquid crystal molecules by providing protrusions, or to the formation of the resin black matrix.

It is a top view which shows an example of the color filter by this invention. (A), (b) is explanatory drawing which shows typically an example of the color filter manufacturing method by this invention. It is the top view which showed typically an example of the color filter used for a liquid crystal display device. It is sectional drawing in the X-X 'line | wire of the color filter shown in FIG. It is the top view which showed the other example of the color filter by this invention. It is a fragmentary sectional view of the color filter which has a photo spacer. (A) is a top view which expands and shows the part of an example of a line and space pattern. (B) is sectional drawing in the X-X 'line | wire in (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 4 ... Glass substrate 2 ... Negative photoresist coating 3-1 ... Red colored pixel of the first color filter piece 3-2 ... Red of the second color filter piece Colored pixel 5 ... Metal thin film 6 ... Halftone part 7 ... Irradiation light 10, 20, 30 ... Color filter 40, 50 ... Glass substrate 41, 51 ... Black matrix 42, 52 ... Colored pixel 43 ... Transparent conductive film 44 ... Photo spacer CF / P-1 ... First color filter / piece CF / P-2 ... Second color filter / piece CF / P -11 ... Color filter piece CF / P-12 with chromaticity for personal computer ... Color filter piece CF / P-13 with chromaticity for TV ... with chromaticity for monitor Color filter piece ... line to shield the light MP-1 ... first mask pattern MP-2 ... second mask pattern PM ... photomask S ... space which transmits light

Claims (2)

  To a negative photoresist coating film provided on a substrate through a photomask provided with a plurality of mask patterns for forming a pattern constituting a color filter piece of a size corresponding to one display device Each exposure and development process is performed to sequentially form each pattern constituting a color filter piece on the substrate, and a color filter having a plurality of color filter pieces provided on the substrate is manufactured. In the color filter manufacturing method, the color filter piece provided on the substrate is composed of a plurality of types of color filter pieces, and when the film thickness of the pattern to be configured differs for each type, the photomask The mask pattern on the photomask corresponding to the color filter piece of the product other than the product with the highest film thickness is displayed on the mask pattern Method of manufacturing a color filter, which comprises using a photomask having a halftone portion of the concentration to form a thickness of over emissions. The halftone portion, the metal oxide film or a chromium film or pattern according to claim 1, characterized in that it is a line-and-space pattern or a checkered pattern with a pitch less than the resolution of the system to form a color filter Production method.

Images