JPH02282703A - Production of color filter - Google Patents

Abstract

PURPOSE:To prevent the generation of recessed parts on an over coat surface which cannot be removed and corrected by a polishing stage and to improve the yield in mass production by forming >=2 layers of the over coat layer while allowing the 1st layer in contact with the colored layer to remain. CONSTITUTION:A thermosetting resin is applied on the surface of the colored layer 102 formed on a glass substrate 101 by a spin coating method and is then baked in an oven. The recessed parts 11 are partially generated on the baked over coat 1 at this time. The over coat 2 is thereafter obtd. in the state of maintaining nearly a uniform film thickness on the over coat 1 near the recessed parts 11 when the over coat 2 is applied on the over coat 1 by the method similar to the method for forming the over coat 1. The structure of the flat surface is obtd. if the surface is polished in this state until about the film thickness slightly below the average film thickness of the over coat 1 is attained. The always high yield is assured in this way regardless of substrate sizes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field J] This invention relates to a method for manufacturing a color filter used in color liquid crystal displays and the like.

[Conventional technology] Conventionally, by filling in the steps of a colored layer formed on a glass substrate,
The technology for manufacturing a color filter with a flat surface is to coat the overcoat material thickly on the surface of the colored layer at once, harden it by heating etc. to form an overcoat layer, and then polish the surface. There is a method of manufacturing a color filter having a flat surface by doing this.

[Problem to be solved by the invention]

However, in order to thickly apply the overcoat material on the colored layer at once, it is necessary to use a relatively high viscosity material, and when such a high viscosity material is applied, air is likely to be drawn in during application. These air bubbles may become trapped in the overcoat layer after application. If the overcoat layer is cured by heating etc. in this state, depressions will be generated on the overcoat surface after curing, as shown in Figure 2(a).
), depending on the depth of the recesses, some may not be removed even by polishing, making it impossible to obtain a color filter with a flat surface (
As shown in FIG. 2(b)), in mass production, there was a problem in that the yield was significantly reduced.

Therefore, in order to solve these conventional problems, the present invention has developed a color filter that can prevent the occurrence of concavities on the overcoat surface that cannot be removed or corrected in the polishing process, and can significantly improve the yield in mass production. The purpose is to provide a manufacturing method for.

[Means for Solving the Problems] In order to solve the above problems, the method for manufacturing a color filter of the present invention includes a step of forming one colored layer on a glass substrate, and a step of forming an overcoat layer on the colored layer. In the method for producing a color filter, forming two or more overcoat layers on the surface of the pre-colored layer, and polishing the upper overcoat layer leaving the first layer in contact with the colored layer. It is characterized in that it is removed by.

[For production]

As described above, by applying the overcoat material twice or more times, even if a deep recess exists in the first layer, the recess can be filled in with the second and subsequent layers. With multiple application steps.

The probability that a recess will occur again at the same location as the first layer is extremely low, so polishing the multiple overcoat layers configured in this way up to the first layer will ensure that the color filter has a flat surface. can be obtained.

[Embodiment 1] An embodiment of the present invention will be described below in detail based on the drawings. FIGS. 1(a) to 1(c) are diagrams showing each step of the manufacturing method of the present invention using cross-sectional views of color filters. After applying a thermosetting resin to the surface of the colored layer 102 formed on the glass substrate lot by a spin code method,
Baking is performed in an oven. At this time, as shown in FIG.
occurs. Thereafter, overcoat 2 is applied on overcoat 1 in the same manner as overcoat 1, to obtain a structure as shown in FIG. 1(b). That is, in the vicinity of the recess 11, the overcoat 2 is obtained with a substantially uniform film thickness maintained on the overcoat 1. On the other hand, recess 1
A new recess 12 may be formed on the overcoat 2 at a location different from the vicinity of the recess 12. By polishing in the state shown in Figure 1(b) until the film thickness is slightly less than the average thickness of overcoat 1, the surface is flat as shown in Figure 1(c). obtain a structure.

The following comparative tests were conducted on the color filters produced by the manufacturing method of the present invention obtained in the above examples and those produced by the conventional manufacturing method (FIG. 2).

Color filters manufactured by the manufacturing method of the present invention (Samples 1 to 4)
) and those made using the conventional manufacturing method (Comparative Examples 1 to 4), 4 each, for a total of 8 pieces.
The number of recesses larger than μm was compared with the number of recesses existing on the surface after polishing. The results are summarized in Table 1. 1st
The average film thickness before and after polishing is also listed in the table. Note that all polishing was performed under the same conditions. Further, the substrate size of the color filter used was 300 mm x 300 mm.

As is clear from Table 1, those of the present invention (Samples 1 to 4)
Because the overcoat is applied twice, the number of surface depressions after coating and firing is approximately twice as large as that of conventional products (Comparative Examples 1 to 4). In comparison, with the conventional method, deep (5um or more) depressions after coating and firing are not removed, whereas with the method of the present invention, the depressions are reliably removed during the polishing process due to the effect of filling in the depressions. It can be seen that it has been removed and a flat surface has been obtained.

Effects of the Invention 1 As explained above, in the color filter manufacturing method of the present invention, by forming multiple layers of overcoat films, the process of forming each layer is Since the recesses that suddenly occur can be compensated for, the recesses can be reliably removed in the subsequent polishing process and a completely flat color filter can be efficiently manufactured. In particular, as the size of the color filter substrate increases, the number of recesses that occur during overcoat application increases, so with conventional manufacturing methods, a decrease in yield in mass production was unavoidable as the substrate size increased, but the present invention This manufacturing method can always ensure a high yield regardless of the substrate size, and has great effects in mass production.

A process diagram of a method for manufacturing a tar.

lot・ 102 ・ l・ 2・ glass substrate colored layer overcoat overcoat recess Surface after polishing (1st layer) (Second layer) Below

Claims (1)

[Claims] A method for producing a color filter comprising the steps of forming a colored layer on a glass substrate, forming a colored layer provided on the glass substrate, and an overcoat layer covering the colored layer, the colored layer Production of a color filter characterized in that two or more overcoat layers are formed on the surface of the color filter, and the upper overcoat layer is removed by polishing, leaving the first layer in contact with the colored layer. Method.