JP2765119B2 - Manufacturing method of color filter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color separation color filter used in a color image sensor capable of reading a color original with high accuracy and ease, and a method of manufacturing the same.

2. Description of the Related Art In recent years, image sensors have become
Along with the development, development is progressing as an image input device for a facsimile, an intelligent copy, a computer, or the like, or as an input unit of various test devices. In particular, there is a great demand for a need for colorization, which has spurred development. In order to color the image sensor, it is necessary to insert a color separation filter in any process in the optical path from the light source to the optical sensor. As a method, there are a light source switching method, b filter switching method, c filter bonding method, d on-chip method, and the like. As shown in FIG. 5, the light source switching method a uses a plurality of light sources (54 to 56) having different spectral characteristics, repeats turning on and off sequentially, and collects light by the light collecting lens 52 by time-sharing. The color light 53
Can be read. In this method, the image sensor 51 may be of a monochrome color type. However, the light source space is large, the optical path is complicated, and the amount of heat generated by the light source is large. As shown in FIG. 6, the filter switching method of b is performed between the white light source 61 and the color original 53 or between the color original 53 and the image sensor 51.
In this method, a plurality of color separation filter plates 62 to 64 having different spectral characteristics are used, and the positions of the filter plates are switched by time division, and one image sensor 51 reads. Even in this method, the image sensor may be a monochrome color image sensor, but requires color filter plates 62 to 65 having uniform spectral characteristics and a mechanism 65 for moving them. FIG. 7C shows a method in which a color separation filter 73 formed on a transparent substrate 72 as shown in FIG. Color original 53 with light from a white light source 61
Information can be read. Further, d is a color separation filter 81 on the image sensor device 71 as shown in FIG.
The light of the white light source 61 is similar to c,
The color original 53 is read after color separation. In c and d, the image sensor device 71 is used for color, but the entire device is reduced in size and becomes a maintenance-free reading device.

On the other hand, as a method of forming a filter, a dyeing method, a printing method, an electrodeposition coating method, an interference film method, and the like have been studied. The contact type image sensor has a resolution of 400 dots / inch (DP
In the case of I), the pitch is 63.5 μm. Therefore, as a contact-type image sensor or a color separation filter for a liquid crystal display or the like having a considerable resolution, a printing method having excellent mass productivity, spectral characteristics, and light resistance has been developed, although the pattern resolution is somewhat difficult. I have.

Problems to be Solved by the Invention In the configuration based on the printing method as described above, the cross section of the color separation filter generally has a shape whose central portion is upwardly convex due to the surface tension of the coloring material and the resin. FIG. 3a shows an example.

On the other hand, as shown in FIG. 2A, if the reflection at the filter interface is ignored between the thickness t of the filter 21 and the spectral transmittance T, T = exp (−α (λ) t) T = I _out / I _in α (λ): There is a relationship of absorption coefficient at wavelength λ. Therefore, the spectral transmittance T is easily affected by the thickness t. FIG. 2b shows an example of such a case where α (λ)
= 0.1,0.15,0.3,0.5,0.75,1,1.25 (μm ^-1 ). The influence of the thickness of the spectral transmittance is large around α (λ) t = 1 in the absolute amount of the change in the transmittance, and becomes larger as α (λ) is larger in the relative amount.

Accordingly, as shown in FIG. 3A, if there is a local variation in the thickness of the color separation filter, it also has an adverse effect on the spectral characteristics. For example, the effect of the color separation filter 31 on the spectral transmittance as shown in FIG.
When viewed as a function of t, the change is as shown in FIG. 3C, and particularly at the place where the transmittance is low, the spectral characteristics vary. Here, in FIG. 3c, as an example, t _○ = 3 μm
However, it is not necessarily limited.

The present invention has been made in view of the above problems, and provides a color filter manufacturing method and a color image sensor that reduce variations in spectral characteristics caused by a cross-sectional shape of a color separation filter formed by a printing method.

Means for Solving the Problems In order to achieve the above object, according to the present invention, after forming a plurality of colored patterns, a concave portion which is a non-pattern portion is filled with a resin mainly composed of the same resin as the colored pattern. This is a manufacturing method comprising a step of forming a colored pattern after printing a resin mainly containing the same resin as the colored pattern in advance at a position to be a non-patterned portion. In addition, a filter formed by the above-described manufacturing method is provided on a chip, and is configured to obtain stable spectral characteristics in a color image sensor.

According to the present invention, in the above-described manufacturing method, in a single pattern, a color filter having a convex structure with a protruding central portion is filled in a non-pattern with a resin mainly composed of the same resin as that of the color filter. The filter has a flattened filter shape due to the surface tension, and can obtain stable spectral characteristics.

Embodiment Hereinafter, a structure method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a method of manufacturing a color filter according to a first embodiment of the present invention.
In FIG. 1, 1 is a substrate, 2 is a first color pattern, 3 is a second color pattern, and 4 is a third color pattern.

Using a printing means such as flat plate offset printing, letterpress offset printing, intaglio offset printing, screen printing, or the like, the first color pattern 2 is formed on the substrate 1 by using an epoxy resin or an acrylic resin mixed with a coloring material, and the film thickness is reduced. 2
It is directly formed uniformly at a thickness of about 5 μm. Next, in the same manner, the second color pattern 3 is formed directly on the substrate 1 in the vicinity of the first color pattern 2.
Further, similarly, a plurality of coloring patterns (for example, 2 to 4
Are formed on the substrate 1. Here, the colored patterns 2 to 4 may be stripe-shaped, mosaic-shaped, or may have other shapes. After forming the colored patterns of all colors, before heating and curing, the pattern 5 is adjacent to the concave portion which is a non-pattern portion by using a resin having the same resin as the colored pattern as a main component by the same method. It is formed so as to be in contact with the edges of the colored patterns 2 to 4. As a result, individual colored patterns are separated individual patterns by the filling resin,
As a result, the structure becomes one structure 6 and the surface shape becomes as shown in FIG. 1e due to the surface tension. If a leveling time is provided during this time, it appears more effectively. Thereafter, the color filter 6 was baked and cured by heating. The filling resin may be formed in advance after forming all the colored patterns, instead of forming it. That is, the substrate 1 is printed using the same printing method.
After the pattern 5 is formed with the receiving resin at the position where the pattern becomes a non-pattern portion, a plurality of colored patterns (2
4) may be formed such that each edge is in contact with the edge of the pattern 5 formed of the filling resin, and after leveling, baking and heat curing to form the color filter 6.

A second embodiment will be described with reference to the drawings. FIG. 4 is a structural sectional view of a color image sensor according to a second embodiment of the present invention. In the figure, 41 is an image sensor chip, 42 is an optical sensor section, 43 is a light receiving section of the optical sensor, and 44 is a separation area for separating adjacent optical sensors.
In the manufacturing method according to the first embodiment, a filter is formed on an image sensor chip in a wafer state. Here, the coloring filters 45 to 47 are formed on the light receiving portion 43 of the optical sensor 42, and the filling resin 48 is formed on the separation region 44. Filling resin 48
In general, black resin is preferably used for the isolation region 44 to shield the outer periphery of the light sensor light receiving portion. However, especially in the case of the contact type, even if the resolution is 400 dots / inch (DPI),
Since the separation region 44 can be formed at a pitch of 63.5 μm, for example,
A relatively large value of about 10 to 20 μm can be obtained. Therefore, when there is no light sensitivity in the separation region 44 or when light shielding by the aluminum wiring is performed, the filling resin 48 is more preferably transparent.
Thereby, in the alignment at the time of forming the filling resin 48,
Further, it is possible to reduce the number of man-hours and increase the yield.

Effect of the Invention As described above, the present invention forms a plurality of colored patterns each having a predetermined spectral characteristic by a printing method by using an epoxy resin or an acrylic resin mixed with a coloring material. Filling the concave portion, which is the non-pattern portion, with a resin mainly composed of the same resin as the colored pattern so as to come into contact with the edge of the adjacent colored pattern, and forming a color separation filter, the surface shape due to surface tension is reduced. By the flattening, it is possible to obtain a color separation filter having stable characteristics in which variations in spectral characteristics due to uneven thickness of the peripheral portion of the coloring filter are reduced.

Further, by forming a color filter on the light receiving portion of the image sensor and printing the separation region with the filling resin, a color image sensor with stable spectral characteristics and high reading quality can be obtained.

[Brief description of the drawings]

1 (a) to 1 (e) are process sectional views showing a method of manufacturing a color separation color filter according to a first embodiment of the present invention, and FIG. 2 (a) shows the dependence of transmittance on filter thickness. 3 (b) is a transmittance characteristic diagram calculated by the model, FIG. 3 (a) is a cross-sectional view of a color filter, and FIG. 3 (b) is a spectrum which depends on thickness non-uniformity of the color filter. Sectional view of a filter model showing characteristics, FIG.
Is a characteristic diagram showing an example of transmittance calculated by the model, FIG. 4 is a sectional view of a color image sensor having a color separation filter according to the second embodiment of the present invention, and FIG. FIG. 6 is a configuration diagram of a sensor unit, FIG. 6 is a configuration diagram of a filter switching type image sensor unit,
FIG. 7 is a configuration diagram of an image sensor unit based on a filter bonding system, and FIG. 8 is a configuration diagram of an image sensor unit based on an on-chip system. 1 ... substrate 2 ... first color pattern 3 ... second color pattern 4 ... third color pattern 5 ... filled resin pattern 6 ... one structure The filter group that became, 41 ... Image sensor chip, 42 ...
... light sensor, 43 ... light receiving part, 44 ... separation area, 45, 46, 47
... coloring pattern, 48 ... filling resin pattern.

Claims (2)

(57) [Claims] A first color pattern having a predetermined spectral characteristic is directly formed on an optically transparent substrate by using an epoxy resin or an acrylic resin mixed with a coloring material; Similarly, a second color pattern is formed close to the first color pattern.
After sequentially forming colored patterns of a plurality of colors in close proximity to each other, in a method of manufacturing a color filter that becomes a colored filter layer by heating and curing, after forming all of the colored patterns, a concave portion that is a non-colored pattern portion before being heated and cured. A method of manufacturing a color filter, characterized in that a portion is filled with a resin mainly composed of the same resin as the colored pattern so as to be connected to an edge of the colored pattern. 2. The method according to claim 1, wherein the substrate is a light receiving portion of the image sensor.