JPS5832446B2 - Manufacturing method of image pickup tube target - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an image pickup tube target for color television, etc., which is most suitable for a small color television camera equipped with a color separation line filter.

In general, a color television image pickup tube equipped with a color-separating striped filter includes a color-separating striped filter interposed between a light-transmitting substrate and a transparent electrode using various methods, and then a photoconductive layer is placed on the transparent electrode. It is constructed by vacuum-sealing a target part with a built-in color separation line filter on which a film is formed and an electron gun part in a tube.

Furthermore, the structure and manufacturing method of the target section with a built-in color separation line filter will be described in detail.

The structure of a conventional target section with a built-in color separation line filter is shown in FIG.

In Figure 1, 11 is a transparent substrate with a linear expansion coefficient of 45.
E-2 glass (manufactured by Ichihara Kogaku Co., Ltd.) with a temperature of X 10-7/°C,
7059 glass (manufactured by Kohang Co., Ltd.) having a linear expansion coefficient of 46 x 10-7/'C is used.

12 is a color separation line filter.

13 is a transparent thin film with a linear expansion coefficient of 5, 5 x 10-7/
℃ quartz glass is mainly used.

If the transparent thin film 13 cracks due to thermal strain, the same type of glass as the transparent substrate 11 is used.

14 is a transparent electrode, and S n 02, In2O3 film, etc. are used.

15 is a photoconductive film, and an Sb2S3 film is used.

Next, a method of manufacturing the above conventional structure will be described.

Figures 2a and 2b show its structure and manufacturing process.

The number of each part of the structure corresponds to the number of each part shown in the first diagram.

First, in the process of forming the color separation line filter in A.
Color separation line filter 1 is fabricated using vapor deposition method and IC technology on 1.
form 2.

Next, in the step of forming a light-transmitting thin film at the mouth, the color-separating striped filter 12 is covered with a light-transmitting thin film 13 by electron beam evaporation, sputtering, or the like.

Next, in the smoothing step (c), the surface irregularities of the light-transmitting thin film 13 are smoothed by a polishing method or the like.

Next, in the second step of forming a transparent electrode, a transparent conductive film 14 such as an S n 02 film or an In2O3 film is formed by a spraying method, a vapor deposition method, a sputtering method, or the like.

Next, in the photoconductive film forming step (e), the photoconductive film 15 of 5b203 is formed by vapor deposition at a substrate temperature of room temperature.

With the structure and manufacturing process described above, a conventional target with a built-in color separation line filter was obtained.

In conventional targets, especially when using a photoconductive film containing (ZnxCdt-xTe)y(In2Te3)x-y, it is essential to heat-treat the photoconductive film at 300 to 700°C in the manufacturing process. Cracks occur in the transparent thin film due to dirt on the filter surface or adsorption of chemicals inside the filter, which in turn affects the photoconductive film, resulting in problems such as deterioration of image quality and increase in dark current. However, a target with a built-in color separation stripe filter could not be obtained.

The present invention provides a manufacturing method that can prevent deterioration of image quality and increase of dark current in an imaging target in which a color separation striped filter, a transparent thin film, and a photoconductive film are formed on a transparent substrate. It is something.

Next, the present invention will be described.

FIG. 3 is a sectional view of a target with a built-in color separation line filter, showing the structure of the present invention.

In the figure, 31 is a transparent substrate with a linear expansion coefficient of 56
10-7/'C~ll0XIO-,/'C.

32 is a color separation line filter.

33 is a transparent thin film with a linear expansion coefficient of 56 X 1 o-y
°C to 110XIO-7°C.

34 is a transparent electrode.

35 is a photoconductive film, for example (Zn Cd, -Te)
, (In2Te3) IXX (0≦X≦1), (0<y≦1).

In the structure shown in FIG. 3, the linear expansion coefficient of both the transparent substrate 31 and the transparent thin film 33 is s 6 X 10-'
/'C to 110 x 10-'//'C is more preferable in terms of image quality and dark current.

FIGS. 4a and 4b show an embodiment of the manufacturing process of the present invention.

The numbers of each part of the structure correspond to the numbers of each part in FIG. 3 showing the structure of the present invention.

In the step of forming the color separation striped filter of (a), the transparent substrate 31
A color separation stripe filter material is deposited on top and the filter 32 is patterned using IC technology.

Next, in the heat treatment process of the mouth, 300°C to 6000G in air or an inert gas containing oxygen, that is, an oxygen atmosphere,
Heat treatment is performed for 30 minutes to iso minutes to clean the surface of the filter 32, which is made of a multilayer film made of inorganic materials, and to remove adsorbed components.

In the next step of forming a transparent thin film, a transparent thin film 33 is formed to a thickness of several microns to 10 microns by sputtering.

Next, in a second smoothing step, the surface irregularities of the light-transmitting thin film 33 are smoothed by a polishing method.

Next, in the step of forming a transparent electrode (e), a transparent electrode 34 made of an S n 02 film is formed by a spraying method.

Next, in the process of forming a photoconductive film, the first layer is a Zn5e film, and the second layer is a (Zn077CdO,3T e )0.95
A photoconductive film 35 made of (I n2 T e3 )0.05 is formed by vapor deposition.

Next, in the heat treatment step (g), heat treatment is performed at 550° C. for several minutes to several tens of minutes in a vacuum.

The image pickup tube target is manufactured as described above.

As can be seen from the comparison between the conventional manufacturing process shown in FIG. 2 and the manufacturing process according to the present invention shown in FIG. Equipped with a heat treatment process.

If this step is not provided, the image quality will be extremely degraded and the dark current will also tend to increase somewhat.

By including such a heat treatment process, image quality,
The improvement in dark current, etc. is thought to be due to the effects of heat treatment of filters made of inorganic materials, such as cleaning the surface and stabilizing the crystallinity of the filter, as described above. Translucent thin film 3 formed on
This seems to be because cracks and the like in No. 3 were reduced, making it possible to form a good light-transmitting thin film and even a good photoconductive film.

Further, due to the presence of oxygen, organic components such as resist used when forming the pattern of the filter 32 can be effectively removed.

Incidentally, the surface unevenness of the light-transmitting thin film 33 needs to be smoothed because of breakage of the transparent electrode 34 and deterioration of the characteristics of the photoconductive film 35.

Normally, the unevenness is around 1 μm and smoothing is performed by a polishing method.

At this time, polishing is generally performed at a low speed, and the polishing time varies greatly depending on the material of the transparent thin film.

For example, quartz glass and sapphire require several hours to smooth.

In contrast, crown glass, flint glass, and even crown and flint glass can be smoothed in several tens of minutes and are extremely easy to manufacture.

As explained above, the present invention involves forming a color separation striped filter made of an inorganic material on a light-transmitting substrate, and then heat-treating the filter in an oxygen atmosphere to form a light-transmitting thin film and a photoconductive film. It can improve image quality and dark current, and greatly contributes to the production of high-quality image pickup tube targets.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional target with a built-in color separation line filter, FIGS. A cross-sectional view of a target with a built-in color separation line filter created by the method of the example, and FIGS. 4a and 4b are a manufacturing process diagram and an explanatory diagram of the same target. 31... Transparent substrate, 32... Color separation striped filter, 33... Transparent thin film, 34...
...Transparent electrode, 35...Photoconductive film.

Claims (1)

[Claims] 1. A step of forming a color-separating striped filter made of an inorganic material on a transparent substrate and then heat-treating it in an oxygen atmosphere, a step of forming a transparent thin film on the substrate and the filter, and a step of forming a transparent thin film on the thin film. 1. A method for manufacturing an image pickup tube target, comprising a step of forming an electrode and a photoconductive film.