JPH08298069A - Manufacture of shadow mask - Google Patents

Abstract

PURPOSE: To provide a highly fine shadow mask with small opening diameter and a large number of openings by forming an etching preventing layer after controlling the surface temperature of a metal material at a desired temperature. CONSTITUTION: A shadow mask material 1 of a belt-shaped long thin plate made of invar or the like is continuously carried, the arrangement of recesses having different sizes is formed on both surfaces in first etching, photo-curing type resin 7 which is an ultraviolet-ray curing type is applied to the surface on small hole side with a resin coating roll 12, then the shadow mask material 1 is carried to second etching. A heating means 16 having a sheet heating element 16 comprising a ceramic heater emitting infrared rays for example is arranged in the position facing the surface where the photo-curing type resin 7 is coated of the shadow mask material 1, in front of the resin coating roll 12, and uniformly heats the surface where the photo-curing resin 7 is coated. A laser type surface thermometer 17 is arranged soon before the resin coating roll 12, and temperature of the surface where the photo-curing type resin 7 is coated is controlled so as to become 35-37 deg.C with a temperature control means 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a shadow mask by a photoetching method, and more particularly to a method for producing a high-definition shadow mask having a small diameter of apertures and a large number of apertures.

[0002]

2. Description of the Related Art Conventionally, a shadow mask used for a color picture tube or the like is manufactured by a process as shown in FIG. That is, metal material (hereinafter referred to as shadow mask material 1)
Long strip metal plate supplied from the winding roll as
For example, using a low-carbon steel plate with a plate thickness of 0.13 mm, degreasing, surface conditioning, and cleaning treatment on both sides, then apply a water-soluble photosensitive solution consisting of casein or polyvinyl alcohol and ammonium dichromate on both sides and dry it. The resist film 2 is formed. Next, one surface of the shadow mask material 1 is exposed with a negative pattern of a small hole image and the other surface is exposed with a negative pattern of a large hole image. After that, by performing a developing treatment with hot water to dissolve the unexposed and uncured photoresist film, as shown in FIG. 3A, a shadow mask having a small hole resist film 2a and a large hole resist film 2b on the front and back sides is formed. Material 1 is obtained.

After that, the resist film 2 is subjected to a film hardening process and a burning process, and the first stage etching is performed from both front and back surfaces, followed by washing with water and drying. The etching solution used is a Baume concentration of 35 to 50 of ferric chloride,
Spray etching with a spray pressure of 1.5 to 3.5 kg / cm ² is generally used. In this first etching step,
As shown in FIG. 3B, it is important to stop the etching progress in the middle. Further, in this first etching step, there is also a method in which a protective film is attached to the surface of the shadow mask material 1 having the large hole resist film 2b and the shadow mask material 1 is etched halfway only from the small hole side.

Next, as shown in FIG. 3 (c), a resin for etching prevention layer (hereinafter referred to as a resin) is applied to the shadow mask material 1 and the small hole side concave portion 3a formed by the preceding etching is formed. An etching prevention layer 4 that completely fills up is formed. The etching prevention layer 4 may be formed on the small hole side or the large hole side, but in most cases, the etching prevention layer 4 is formed on the small hole side. Subsequently, as shown in FIG. 3D, a second etching step of etching the shadow mask material 1 only from the large hole side is performed to form an opening 5 penetrating from the large hole side to the small hole. Finally, the etching prevention layer 4
Then, the resist film 2 is peeled off, washed with water and dried, and then, as shown in FIG.
The flat type shadow mask 6 shown in FIG.

It can be said that in the conventional method using this etching prevention layer, the side etching phenomenon, which cannot be avoided by the photo etching method, is suppressed on the small hole side. That is, the etching prevention layer 4 is formed in the concave portion on the small hole side.
And the small holes are not side-etched in the second etching step, so that the accurate small hole pattern in the first etching step can be maintained. Therefore, for example, it is possible to open a hole having a hole diameter smaller than the thickness of the material metal plate.

As a means for applying the etching preventive layer 4 to the small hole side, a resin applying cylinder roll (hereinafter referred to as a resin applying roll), which is represented by, for example, a roll coating method or a gravure coating method, is used. This is one means. That is, as shown in the example of FIG. 2, the shadow mask material 1 having the small-hole resist film 2a and the large-hole resist film 2b on the front and back sides is the first etching chamber 8
It is first etched in the inside, then washed in the washing chamber 9 with water, and then in the drying unit 10, for example, the heater 11
And dried by heating. Next, the resin application roll 12 having the resin 7 on its surface is brought into contact with the surface of the shadow mask material 1 on which the etching prevention layer is to be formed, for example, the small-hole resist film 2a side, and the resin 7 is applied and filled in the shadow mask material 1. It is a thing. In the example of FIG. 2, the shadow mask material 1 is conveyed from left to right with the small hole resist film 2a side facing down, and the rotation direction of the resin coating roll 12 is opposite to the traveling direction of the shadow mask material 1. I am going to turn around.

At this time, it is general to use an ultraviolet curable resin or a heat curable resin as the resin 7. That is, the shadow mask material 1 coated with the resin 7 is heated and irradiated with ultraviolet rays.
Alternatively, the resin is cured by simply heating it,
Finally, the etching prevention layer 4 is formed.

As described above, the role of the etching prevention layer 4 is to prevent the etching solution from coming into contact with the recess filled with the etching prevention layer in the second etching step. Therefore, it can be said that it is important that the formed etching prevention layer does not contain bubbles.

That is, as shown in FIG. 4A, when there are bubbles 13 in the etching prevention layer 4 filling the small hole concave portion 3a, the opening 5 penetrating from the large hole side to the small hole is formed in the second etching. At the time of formation, the etching liquid may flow into the bubbles 13 and cause unnecessary etching on the shadow mask material 1 as shown in FIG. 4 (b), resulting in enlargement of the shape of the openings. This is a cause of defective hole shape such as not forming a predetermined circle.

Conventionally, the shadow mask material 1 has a long strip shape and is transported on a transport roller 14 as shown in the example of FIG. For this reason, the drying unit 10
Even if the shadow mask material 1 is heated and dried inside,
It is sequentially cooled during transportation depending on the ambient temperature. Therefore, the temperature of the shadow mask material 1 at the time of applying the resin 7 is about room temperature, for example, about 23 ° C., which is low, and it has been estimated that this may cause bubbles to be generated in the etching prevention layer 4.

Generally, a resin has a property that the viscosity decreases when the temperature is high and the viscosity increases when the temperature is low. Therefore, when the temperature of the shadow mask material 1 is low during the application of the resin 7, it can be said that the temperature of the resin 7 applied on the shadow mask material 1 decreases and the viscosity increases. When the resin 7 entraps air during the application of the resin 7 and bubbles 13 are generated in the recess 3, the bubbles 13 escape from the resin 7 if the temperature of the resin 7 is in an appropriate range, that is, if the viscosity is appropriate. There are many. However, when the temperature of the shadow mask material 1 is lower than the appropriate temperature range and the viscosity of the resin 7 is high, it can be said that the bubbles 13 generated in the recess 3 are less likely to escape than the resin 7.

In addition, the resin may be insufficiently dried after washing with water after the first etching, or the surrounding water vapor may adhere when the shadow mask material 1 is cooled during transportation. It was estimated that even if the surface of the shadow mask material 1 had moisture during the application of No. 7, it might cause bubbles in the etching prevention layer 4.

As described above, the resin 7 is heated at the time of curing. However, when the surface of the shadow mask material 1 has moisture, that is, water, the water trapped in the resin 7 is vaporized and evaporated by heating, As a result, bubbles 13 are generated in the etching prevention layer 4.

As described above, in the conventional method for producing a shadow mask, the temperature of the shadow mask material 1 at the time of applying the resin 7 is low, or the surface of the shadow mask material 1 has moisture, so that the etching prevention layer is formed. There was a problem that air bubbles were generated in the sample No. 4 and the resulting shadow mask had open holes with poor shape.

[0015]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention has been accomplished in the shadow mask manufacturing method by devising a method for forming an etching prevention layer that does not generate bubbles. Therefore, an object of the present invention is to provide a method for manufacturing a shadow mask in which the resulting shadow mask does not have openings with defective shapes.

[0016]

That is, according to the present invention, at least one surface of a plate-shaped metal material having a resist film on which both surfaces are partially exposed according to a predetermined pattern is etched. , A first etching step of forming a concave portion on at least this one surface of the metal exposed portion, followed by washing with water and drying, and applying a resin to one surface having the concave portion formed in the first etching step. Forming an etching prevention layer by filling and hardening resin inside the lever recess and etching the surface opposite to the surface on which the etching prevention layer is provided, and forming from this opposite surface to the one surface In the method for producing a shadow mask, which comprises at least a second etching step of forming a concave hole communicating with the formed concave portion and a film peeling step of removing the etching prevention layer and the resist film. The means for heating the metal material being conveyed between the first etching step and the etching prevention layer forming step, and the temperature of the metal material surface when applying the resin to the metal material heated by the heating means. By providing a means for measuring and a means for controlling the heating temperature of the metal material by the heating means on the basis of the measurement result obtained by the temperature measuring means, a metal material having a desired surface temperature can be obtained. By providing a method for manufacturing a shadow mask, which is characterized by performing an etching prevention layer forming step,
This is a solution to the above problem.

A description will be given below with reference to FIG. 1 showing an essential part of an example of a method for producing a shadow mask according to the present invention.
In FIG. 1, the shadow mask material 1 is a long metal plate supplied from a take-up roll, and the first etching, washing with water, and drying steps are performed according to the steps described in the above (Prior Art). It is assumed that recesses are formed on both sides as shown in FIG. 3 (b). Then, for example, an ultraviolet curable photocurable resin 7 is applied to the shadow mask material 1 by using, for example, a gravure coating method on the small hole side of the shadow mask material 1, that is, the surface side of the small hole resist film 2a. is there. In this example, the resin coating roll 12 having the resin 7 on the roll surface is used, and the resin is coated with the lower surface of the shadow mask material 1 facing the small hole resist film 2a.

Here, as described in the section ((Prior Art)), the inventors of the present invention cause the bubbles in the etching-preventing layer during the formation of the etching-preventing layer, which is a cause of the shadow mask material being conveyed. It is proposed that the shadow mask material 1 being heated is heated, paying attention to the point that 1 is cooled by the surrounding atmosphere.

That is, in the method for manufacturing a shadow mask of the present invention, the first etching step is completed and the resin 7
The heating means 15 heats the shadow mask material 1 before being coated by the heating means 15 as shown in FIG. Here, the heating means 15
As a result, the shadow mask material 1 is heated, but when the temperature of the shadow mask material 1 varies at this time, the applied resin 7 has a difference in viscosity due to the temperature difference. As a result, the film thickness of the applied resin 7 varies depending on the site. In order to prevent this, the present inventors propose to use the surface heating element 16 as shown in FIG. 1 as a means for uniformly heating the surface of the shadow mask material 1. By placing the heat generating surface of the surface heating element 16 so as to face the surface of the shadow mask material 1 to be conveyed and set parallel to the surface of the shadow mask material 1, the surface of the shadow mask material 1 facing the surface heating element 16 is It is heated uniformly.

Generally, the temperature of the resin 7 applied to the shadow mask material 1 is, for example, about 30 to 45 ° C. However, if the temperature of the shadow mask material 1 heated by the above means becomes higher than an appropriate value, there is a problem that the etching resistance of the formed etching prevention layer 4 deteriorates. That is, as described above, the viscosity of the resin tends to decrease when the temperature is high. For this reason, when the temperature of the shadow mask material 1 is too high, the viscosity of the applied resin 7 decreases and the resin 7 has fluidity, so that the applied resin 7 cannot maintain the thickness at the time of application, and thus the etching prevention layer 4 is not formed. The film thickness is reduced and the etching resistance is reduced. For this reason, it can be said that, during the second etching, the etching liquid penetrates the etching prevention layer 4 and comes into contact with the shadow mask material 1 to perform unnecessary etching.

In order to prevent this, the following method is proposed. That is, as shown in FIG. 1, a temperature measuring means 17 is provided in front of the resin coating roll 12 to measure the surface temperature of the heated shadow mask material 1 during resin coating. Then, the surface temperature value of the shadow mask material 1 obtained by the temperature measuring means 17 is sent to the temperature controlling means 18, for example, a computer. The temperature control means 18 compares the obtained surface temperature value of the shadow mask material 1 with a preset proper temperature value that the shadow mask material 1 should have when applying the resin. Then, based on the temperature comparison, the temperature control means 18 adjusts the temperature of the heating means 15. That is, the heated shadow mask material 1
If the surface temperature of the shadow mask material 1 is too high, the heating temperature of the shadow mask material 1 by the heating means is lowered.
The control is to raise the heating temperature by the heating means.
As a result, the shadow mask material 1 is coated with the resin 7 at a desired surface temperature.

The surface temperature control of the shadow mask material 1 according to the present invention is intended to make the surface temperature of the shadow mask material 1 a desired surface temperature when the resin 7 is applied. It can be said that it is desirable to control the temperature on the side of the surface on which the etching prevention layer is coated. Therefore, as shown in FIG. 1, it can be said that the heating by the heating means is preferably performed from the etching prevention layer forming surface side, and it is also desirable to perform the heating on the etching prevention layer forming surface side in temperature measurement.

Next, when the temperature measuring means 17 comes into contact with the shadow mask material 1 during the temperature measurement, the shadow mask material 1
May be scratched. Therefore, the present inventors propose, as the temperature measuring means 17, a means such as a thermography or laser type surface thermometer capable of measuring the surface temperature of the measured object without contacting the measured object.
In the example of FIG. 1, a laser-type surface thermometer is used as the temperature measuring means 17, and the surface of the shadow mask material 1 is irradiated with laser light from the laser-type surface thermometer, and the reflected light is received. The surface temperature of the mask material 1 is measured.

Next, the shadow mask material 1 coated with the resin 7 by the resin coating roll 12 is subjected to a conventional manufacturing method, that is, the resin 7 is cured to form the etching prevention layer 4, and then the second layer is formed. Etching and film removal are performed to obtain the flat shadow mask 6 shown in FIG.

The method for manufacturing a shadow mask according to the present invention is not limited to the form shown in FIG. For example, in FIG. 1, the resin is applied with the lower surface of the shadow mask material 1 on the side of the small hole resist film 2a, but the resin is applied with the upper surface of the shadow mask material 1 on the side of the small hole resist film 2a. However, in this case, it can be said that it is desirable to provide the heating means 15 and the temperature measuring means 17 on the upper surface of the shadow mask material 1. Further, although the temperature measuring means 17 is provided at one place, the temperature measuring means 17 is provided in order to improve the measurement accuracy.
It can be said that it may be provided at a plurality of locations. The point is that the heating means, the temperature measuring means, and the temperature control means are provided, and the surface of the shadow mask material 1 after the first etching on which the etching prevention layer is formed is set to a desired surface temperature, and then the resin is applied. It can be said that if it is.

[0026]

In the method for producing a shadow mask according to the present invention, the surface temperature of the shadow mask material is measured after heating the shadow mask material being conveyed after the first etching step by the heating means and before applying the resin. There is. Next, the temperature control means controls the heating temperature of the shadow mask material 1 by the heating means after comparing the measurement result with an appropriate temperature that the shadow mask material 1 should have when applying the resin.
As a result, the shadow mask material 1 is coated with the resin at a desired surface temperature.

[0027]

EXAMPLES Examples of the present invention will be described below. <Example> As the shadow mask material 1, a long-expansion metal plate supplied from a winding roll and having a low expansion coefficient of 0.13 mm was used. Then, the steps up to the first etching step were performed in accordance with the steps described in the above-mentioned (Prior Art) to obtain the shadow mask material 1 having the recesses 3 on the front and back sides, as shown in FIG.

Then, as shown in FIG. 1, a small hole resist film is formed.
The UV-curable resin 7 was applied to the surface of the small hole side of the shadow mask material 1 conveyed with the 2a side as the lower surface, using a resin application roll 12 having a diameter of 30 mm to a film thickness of 30 μm. At this time, according to the present invention, a surface heating element having a plate-shaped ceramic heater as a heating element is provided on the small hole surface side of the shadow mask material 1 to be conveyed.
16 was provided as the heating means 15 in parallel to the surface of the shadow mask material 1. The distance between the heating surface and one surface of the shadow mask material was 30 mm.

Next, as shown in FIG. 1, the surface temperature of the shadow mask material 1 heated by the surface heating element 16 is a laser type surface thermometer (Keyence Co., Ltd.) provided in front of the resin coating roll 12. It was measured by irradiating the surface of the shadow mask material 1 with laser light using a model name "IT2-60" manufactured by the company), and the measured temperature value was sent to the temperature control means 18.

Next, in the case of the resin 7 used in this example,
Since 35 to 37 ° C. is desired as an appropriate temperature that the shadow mask material 1 should have when applying the resin, the temperature control means 18 determines the heating temperature of the surface heating element 16 to the shadow mask material 1 based on the measurement temperature result. Adjustment control was performed. This allows
The ambient temperature around the conveyed shadow mask material 1 is 23.
Although it was ℃, the shadow mask material 1 is a resin coating roll.
The surface temperature on contact with 12 was kept in the range of 35-37 ° C.

Next, the ultraviolet curable resin 7 applied by the resin applying roll 12 is irradiated with ultraviolet rays at the same time as being heated so that the resin is photocured to form the etching preventive layer 4 shown in FIG. 3C. . Next, according to the steps described in the above-mentioned section (prior art), second flat etching, stripping, etc. were performed to obtain the flat shadow mask 6.

Next, in the shadow masks obtained in the above-mentioned embodiments, as described in the above-mentioned (prior art), the hole shape caused by the low surface temperature of the shadow mask material 1 at the time of resin application. The defect was examined, but no defective pore shape was observed.

[0033]

In the method for producing a shadow mask according to the present invention, the surface temperature of the shadow mask material is measured after the shadow mask material being conveyed after the first etching step is heated by the heating means and before the resin is applied. are doing. Next, the temperature control means controls the heating temperature of the shadow mask material 1 by the heating means after comparing the measurement result with the proper temperature that the shadow mask material 1 should have when applying the resin. The shadow mask material 1 is coated with resin at a desired surface temperature.

Thus, in the shadow mask manufacturing method of the present invention, the problem that has occurred in the conventional shadow mask manufacturing method, that is, since the temperature of the shadow mask material at the time of resin application is low, the viscosity of the resin increases, and etching prevention is performed. It is possible to prevent the problem that air bubbles are generated in the layer and a defective pore shape is generated during etching.

Further, conventionally, the surface of the shadow mask material is moist due to insufficient drying in the first etching step or adhesion of water due to cooling during transportation of the shadow mask material, which causes bubbles in the etching prevention layer. However, there is a problem that a defective hole shape occurs during etching. However, in the method for manufacturing a shadow mask of the present invention, since the shadow mask material is heated, moisture on the surface of the shadow mask material is removed by evaporation, and it is possible to prevent the generation of bubbles in the etching prevention layer, which results in the formation of defective pores. It can be said that the present invention is practically excellent in obtaining a high-quality, high-definition shadow mask, such as being able to obtain a good quality shadow mask.

[0036]

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of an embodiment of a method for manufacturing a shadow mask according to the present invention.

FIG. 2 is an explanatory view showing a main part of an example of a conventional shadow mask manufacturing method.

3A to 3E are explanatory views showing an example of a method of manufacturing a shadow mask in the order of steps.

4A to 4B are explanatory views showing an example of an etching hole shape defect due to bubbles generated in a concave portion in the order of steps.

[Explanation of symbols]

 1 Shadow Mask Material 2 Resist Film 3 Recess 4 Etching Prevention Layer 5 Opening Hole 6 Shadow Mask 7 Resin 8 Etching Chamber 9 Water Washing Chamber 10 Drying Unit 11 Heater 12 Resin Coating Roll 13 Bubbles 14 Conveying Roller 15 Heating Means 16 Surface Heating Element 17 Temperature measuring means 18 Temperature control means

Claims (4)

[Claims] 1. At least one surface of a plate-shaped metal material having a resist film on both surfaces of which a metal film is partially exposed according to a predetermined pattern is etched to expose at least one metal surface. After forming a concave portion in the concave portion, a first etching step of washing with water and drying, and a resin is applied to one surface having the concave portion formed in the first etching step, the resin is filled in the concave portion and cured. And a step of forming an etching prevention layer, and etching the surface opposite to the surface on which the etching prevention layer is provided to form a concave hole leading from this opposite surface to the concave portion formed on the one surface. In a method for producing a shadow mask, which comprises at least a second etching step and a film removing step for removing the etching prevention layer and the resist film, the first etching step and the etching step Means for heating the metal material being conveyed between the anti-corrosion layer forming step, means for measuring the temperature of the metal material surface when the resin is applied to the metal material heated by the heating means, and the temperature measurement By providing a means for controlling the heating temperature of the metal material by the heating means based on the measurement result obtained by the means, the etching prevention layer forming step is performed on the metal material having a desired surface temperature. A method for manufacturing a shadow mask, comprising: 2. The method for manufacturing a shadow mask according to claim 1, wherein a surface heating element having a heating surface parallel to the surface of the metal material being conveyed is used as the heating means. 3. The method for producing a shadow mask according to claim 1, wherein heating by the heating means is performed from the etching prevention layer forming surface side and temperature measurement is performed on the etching prevention layer forming surface side. 4. The method for producing a shadow mask according to claim 1, wherein the temperature measuring means is a non-contact type with a metal material using a thermographic or laser type surface thermometer.