JPH09259756A - Manufacture of shadow mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a shadow mask by which manufacturing efficiency is improved and configurational failure is not caused. SOLUTION: In a method of manufacturing a shadow mask by forming a large number of through holes in a metallic raw material 1 by using a photoetching method, the through holes are formed, and after a corrosion resistant coating film on a surface of the metallic raw material 1 is separated, an ultrasonic cleaning process in a pure water tank 10 in which an ultrasonic wave device 9 is arranged, a spray cleaning process by pure water after coming out of the pure water tank 10 and an air blow process by compressed air after the spray cleaning, are performed on the metallic raw material 1 to be carried.

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 having a plurality of openings penetrating a metal material by a photoetching method, and particularly to a high-definition shadow having a small opening diameter and a large number of openings. The present invention relates to a mask manufacturing method.

[0002]

2. Description of the Related Art Conventionally, a shadow mask used for a color picture tube or the like has generally been manufactured by a process using a photoetching method. For example, FIG. 3 shows an example of a manufacturing process of a shadow mask using a photo etching method. That is, for example, a low carbon steel plate having a thickness of 0.13 mm is used as a metal material (hereinafter, referred to as a shadow mask material 1), and both surfaces thereof are degreased, surface-treated and washed, and then casein or polyvinyl alcohol and heavy chromium are applied to both surfaces. A water-soluble photosensitive solution composed of ammonium acid or the like is applied and dried to form a photosensitive resin layer.

Then, a small-hole image negative pattern is exposed on one surface of the shadow mask material 1 and a large-hole image negative pattern is exposed on the other surface through an exposure mask having a predetermined pattern. After that, a developing treatment for dissolving the photosensitive resin layer in the unexposed and uncured portion is performed with warm water, and then the remaining photosensitive resin layer is subjected to a hardening treatment and a burning treatment. As shown in FIG. 5, a small-hole side corrosion-resistant coating (hereinafter referred to as resist film 2) in which the shadow mask material 1 is exposed through the opening and a large-hole side resist film 2b are obtained.

Then, etching is performed from both sides of the shadow mask material 1 to form an opening 3 penetrating the shadow mask material 1 as shown in FIG. 3 (b). Then, FIG.
As shown in (c), the resist film 2 is brought into contact with a stripping solution such as an alkaline solution, and after the resist film 2 is stripped, washing and drying are performed. After that, the shadow mask 4 is obtained by cutting unnecessary portions.

As a corrosion resistant coating, there is also a method of forming an etching prevention layer in addition to the resist film 2 and dividing the etching into two steps to form the opening 3 penetrating the shadow mask material 1. For example, after forming the resist film 2 having holes, the first stage etching is performed halfway from both sides of the shadow mask material 1 to form a small hole concave portion on the small hole resist film 2a side and a large hole resist film 2b side. A large hole recess is formed. Then, for example, a photocurable resin is applied and filled in the concave portion on the small hole side by a gravure coating method or the like, and then the resin is irradiated with light to form an etching prevention layer on the small hole resist film 2a side. Then, the second stage etching is performed from the large hole resist film 2b surface side to form the opening 3 penetrating from the large hole side to the small hole.
Then, the resist film and the etching prevention layer are peeled off,
This is to get a shadow mask.

[0006]

However, in the shadow mask obtained by the photoetching method described above,
When the resist film and the etching prevention layer are stripped from the shadow mask material 1, there is a problem that residues of the resist film and the etching prevention layer adhere to the shadow mask material 1 as foreign matter.

Conventionally, the removal of the etching prevention layer and the resist film after etching is performed by the method shown in the example of FIG. First, the shadow mask material 1 is immersed in a film stripping tank 6 having a film stripping solution such as an alkaline solution to perform film stripping treatment of an etching prevention layer and a resist film, and then, for example, a washing chamber 7 having a washing spray nozzle 11 for washing. Wash with water. After that, it is dried in a drying furnace 8 such as an infrared heater. However, a part of the etching prevention layer and the resist film becomes a minute slag and remains attached on the shadow mask material 1 without being stripped, or after the slag is once stripped in the stripping tank, the slag is removed. Redeposit on. Even after washing with water after the stripping process, the spray pressure of water is low, for example, about ² to 10 kg / cm ^2, and foreign matter (hereinafter referred to simply as foreign matter 5) formed by the etching prevention layer adhering to the shadow mask material 1 and the residue of the resist film. Is not completely removed from the shadow mask material 1 and remains attached to the shadow mask 4 as shown in FIG.

The foreign matter 5 which remains attached to the shadow mask material 1 by the peeling process is washed with water and then dried.
The foreign matter 5 sticks firmly to the shadow mask material 1, and the foreign matter 5 once stuck firmly to the shadow mask material 1 cannot be easily removed even by rubbing with a brush or the like.

For this reason, in particular, as shown in FIG. 4, when the portion to which the foreign matter 5 is attached is the opening 3, the following problems and the like occur. That is, it is general to inspect whether or not the opening 3 formed in the shadow mask by etching has a desired shape after the film peeling step. For example, as an inspection method, light irradiation is performed from one surface of the shadow mask, and then the light passing through the opening 3 of the shadow mask is received by an inspection machine provided on the other surface of the shadow mask. A method for determining the quality of the opening shape can be raised. Further, since a large number of openings 3 must be inspected, and manual inspection is time-consuming, mechanical inspection, that is, inspection using an automatic inspection machine is generally performed.

However, even if the opening 3 having a desired shape is formed by etching, if the foreign matter 5 adheres to the opening 3, the foreign matter 5 may be present during the above-described inspection.
The adhered part of the shadow becomes a shadow, and it is determined that the shape is defective. For this reason, even if the desired opening shape, an error that is determined to be a defective shape due to adhesion of foreign matter, that is, a pseudo error, frequently occurs in the inspection by the automatic inspection machine, and the accuracy of the inspection by the automatic inspection machine is lowered. I can say.

For this reason, when a shape defect is detected by the automatic inspection machine, it is manually inspected again by using a magnifying glass such as a microscope whether the detected shape defect is a pseudo error due to adhesion of foreign matter or a true shape defect. Although it had to be done, it took time to re-examine. Further, as a result of the re-inspection, if the defective shape is due to the adhesion of foreign matter, the foreign matter 5 is manually removed by using a brush or the like. However, as described above, the foreign matter is firmly stuck to the shadow mask,
It can be difficult and time consuming to remove. Also, in order to reduce the detection of pseudo errors, if the inspection accuracy of the automatic inspection machine is lowered, a true shape defect will not be detected,
It is also pointed out that a shadow mask having a poorly shaped opening may flow out as a good product as it is.

Further, the shape of the opening 3 formed in the shadow mask is preset so that the color picture tube or the like can exhibit desired performance when the shadow mask is incorporated in the color picture tube or the like. is there. However, if the foreign matter 5 remains attached to the opening 3 of the shadow mask during the film peeling process, the color cathode ray tube or the like may not be able to exhibit the desired performance when the shadow mask is incorporated into the color cathode ray tube or the like. It can be said that there is.

As described above, if foreign matter remains attached to the shadow mask in the film peeling process, it takes time and effort for the inspection, the inspection accuracy is deteriorated, and the quality of the shadow mask is deteriorated. This is a problem in terms of production efficiency and quality of the shadow mask.

The present invention has been made in view of the above circumstances. That is, it is an object of the present invention to provide a method for manufacturing a shadow mask that solves the above-mentioned problems by removing the foreign matter 5 attached to the shadow mask material 1 in the film removing process.

[0015]

In order to achieve the above object in the present invention, first, in Claim 1, a photomasking method is used to form a large number of through holes in a metal material to form a shadow mask. In the method for producing, the through-hole is formed, and after the corrosion-resistant film is peeled off on the surface of the metal material, the metal material to be transported, an ultrasonic cleaning step in a pure water tank provided with an ultrasonic device, After leaving the pure water tank, a spray cleaning step with pure water, and an air blowing step with compressed air after the spray cleaning are carried out.

According to a second aspect of the present invention, in the ultrasonic cleaning step, an ultrasonic reflector is provided on the surface of the metal material opposite to the surface provided with the ultrasonic device so as to face the ultrasonic device. The method of manufacturing a shadow mask according to claim 1 is characterized by the following.
The surface of the ultrasonic reflector facing the metal material is a semi-cylindrical surface or a paraboloid, and the inside of the ultrasonic reflector is
The method of manufacturing a shadow mask according to claim 2, wherein the cavity is a vacuum.

Furthermore, in claim 4, the pure water in the pure water tank is circulated through a foreign matter removing filter, and the shadow mask manufacturing method according to claim 1 or 2, In the fifth aspect, the method of manufacturing a shadow mask according to claim 4, wherein water sucked from the bottom of the pure water tank and overflow water from the pure water tank are circulated.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the long strip shadow mask material 1 supplied from the take-up roll has been conventionally etched up to the shadow mask material according to the steps described in the above (Prior Art). 1 has an opening 3 formed therethrough, and the stripping process of the resist film and the etching prevention layer has been completed in the stripping tank 6 shown in FIG.

First, after the film stripping process is completed, the shadow mask material 1 is conveyed from left to right as shown by the arrow in FIG.
In the washing chamber 7 provided with the spray nozzle 11,
Washing with water is performed at a spray pressure of washing water of, for example, about ² kg / cm ² .

Next, in the method for producing a shadow mask of the present invention, as shown in FIG. 1, the conveyed shadow mask material 1 is passed through a pure water tank 10 provided with an ultrasonic device 9 to be ultrasonically cleaned. Step, after leaving the pure water tank 10, a step of performing spray cleaning with pure water 12, and after the spray cleaning,
And a step of performing air blowing with compressed air.

By performing ultrasonic cleaning at an output of 2000 W and a frequency of 25 KHz in a deionized water tank 10 provided with an ultrasonic device 9, it adheres to the shadow mask material 1 during the film stripping process and is washed with water in the previous stage. The foreign matter 5 such as the residue of the resist film and the etching prevention layer which could not be removed by the cleaning is removed.

Here, even if the foreign matter is removed by ultrasonic cleaning, the foreign matter deposited in the pure water tank 10 is removed before the shadow mask material 1 after ultrasonic cleaning is carried out from the pure water tank 10. It reattaches to the shadow mask material 1. Therefore, in the present invention, the spray nozzle 11 is provided, and the shadow mask material 1 carried out from the pure water tank 10 is
For example, pure water 12 is sprayed at a spray pressure of about 1.5 kg / cm ² to perform spray cleaning. As a result, the foreign matter redeposited on the shadow mask material 1 in the pure water tank 10 is cleaned and removed.

Next, in the present invention, in order to completely remove the foreign matter, air blowing with compressed air is performed on the shadow mask material 1 after spray cleaning. That is, it can be said that, after the spray cleaning, a part of the cleaning water used for the spray cleaning may take in foreign matters and remain on the shadow mask material 1. When the cleaning water remaining on the shadow mask material 1 has taken in foreign matter, the foreign matter adheres to the shadow mask material 1 when the cleaning water evaporates. Therefore, the cleaning water remaining on the shadow mask material 1 is blown away by, for example, an air blow with an injection pressure of about 3.0 kg / cm ² to completely remove the foreign matter.

In the embodiment shown in the drawing, in order to prevent re-adhesion of foreign matter to the shadow mask material 1 through the surface of the transfer roll provided between the spray cleaning and the air blow, the roll is used. A cleaning shower is provided and the surface of the transfer roll is washed with water to remove foreign substances attached to the surface of the transfer roll.

Next, the present invention proposes to efficiently remove foreign matter in the ultrasonic cleaning in the pure water tank 10 described above. That is, as the invention according to claim 2, as shown in FIG.
The ultrasonic device 9 on the side opposite to the surface on which the ultrasonic device 9 is provided.
It is proposed to increase the cleaning efficiency by providing an ultrasonic wave reflector 15 facing the above.

In the deionized water tank 10, the ultrasonic waves applied to the shadow mask material 1 by the ultrasonic device 9 are reflected by the ultrasonic reflector 15 provided on the opposite surface side, and the shadow mask material 1
Is irradiated again. As a result, the shadow mask material 1 is irradiated with ultrasonic waves from both sides, and it is possible to improve the foreign matter removal efficiency.

Incidentally, it is conceivable to provide ultrasonic devices on both sides of the shadow mask material 1 in order to improve the foreign matter removal efficiency. In that case, however, there arises a problem of interference between the irradiated ultrasonic waves, rather the foreign matter removal efficiency is increased. Is likely to result in lowering. Therefore, it can be said that it is desirable to use the above-described ultrasonic reflector 15 to irradiate ultrasonic waves from both sides of the shadow mask material 1.

Next, in order to improve the foreign matter removal efficiency on both surfaces of the shadow mask material 1 described above, it is desirable to improve the reflection efficiency when the ultrasonic wave is reflected by the ultrasonic wave reflector 15. Therefore, as an invention according to claim 3, the surface of the ultrasonic reflector 15 facing the shadow mask material 1 is a semi-cylindrical or parabolic concave surface, and the inside of the ultrasonic reflector 15 is It is proposed that the cavity be a vacuum. If the ultrasonic reflector 15 having such a structure is used, the ultrasonic waves incident on the ultrasonic reflector 15 can be totally reflected, and the concave surface can concentrate the shadow mask material 1 and re-irradiate the ultrasonic wave. Thus, the shadow mask material 1 can be efficiently re-irradiated with ultrasonic waves. Depending on the shape of the ultrasonic reflector 15, if the inside is evacuated, the structural strength of the ultrasonic reflector may be weakened.
In that case, the inside does not necessarily have to be a vacuum,
It may be simply a space filled with air.

The foreign matters removed from the shadow mask material 1 by ultrasonic irradiation are successively accumulated in the pure water tank 10. As the foreign matter concentration in the pure water 12 increases, the foreign matter in the pure water 12 increases. The foreign matter is easily reattached to the shadow mask material 1. Therefore, the present invention proposes to successively remove the foreign matter deposited in the pure water tank 10. That is, as the invention according to claim 4,
It is proposed that the pure water 12 in the pure water tank 10 be circulated through a foreign matter removing filter 13 and reused as shown in FIG. As a result, the foreign matter removal filter 13
The foreign matter deposited therein is removed to prevent the foreign matter from reattaching to the shadow mask material 1. In the example of FIG. 1, the pure water 12 is circulated by providing the circulation pump 14 in front of the foreign matter removal filter 13, and the circulation path of the pure water 12 is shown by a dotted line.

It is preferable to circulate and reuse the pure water 12 as described above from the viewpoints of removing foreign matters in the pure water 12 and saving water resources and preventing pollution. Further, if the filter diameter of the foreign matter removal filter 13 is about 10 μm,
The present inventors have obtained empirically that foreign substances in pure water can be removed to the extent that there is no practical problem.

Further, the present invention proposes a method for efficiently removing foreign matter when circulating the pure water to remove foreign matter. That is, as the invention according to claim 5,
As shown in FIG. 1, it is proposed to circulate the water sucked from the bottom of the pure water tank 10 and the overflow water from the pure water tank 10.

Generally, it can be said that a foreign substance is made of an organic substance or the like, and the specific gravity of the foreign substance is different from that of water. Therefore, when the specific gravity of the foreign matter is larger than that of the water, the foreign matter deposited in the pure water settles to the bottom of the pure water tank 10, and when the specific gravity of the foreign matter is smaller than that of the water, the foreign matter floats on the water surface. That is, it can be said that the water sucked from the bottom of the pure water tank 10 and the overflow water from the pure water tank 10 contain a large amount of foreign matter. Thus, by circulating the water sucked from the bottom of the pure water tank 10 and the overflow water from the pure water tank 10 through the foreign matter removal filter 13, the foreign matter deposited in the pure water 12 can be efficiently removed. Is. By the way, in the embodiment shown in FIG. 1, when water is sucked from the bottom of the pure water tank 10, an inclination is provided at the bottom of the pure water tank 10 so that foreign matters settled at the bottom can be easily sucked.

In the method for producing a shadow mask of the present invention, the shadow mask material 1 from which the foreign substances have been removed in the above-mentioned steps is passed through the drying furnace 8 and then the required steps such as cutting are carried out in the conventional manner to form the shadow mask. I will get it.

The embodiment of the present invention is not limited to the above-mentioned drawings and description, and it goes without saying that various modifications can be made based on the spirit of the present invention. For example, the ultrasonic irradiation conditions, the spray pressure for spray cleaning, the air pressure of the air blow, and the like described above may be set to optimal condition values depending on the manufacturing conditions of the shadow mask.
Furthermore, in the embodiment of FIG. 1, a foreign matter removal filter
The circulating water after removing foreign matter through 13 is used for spray cleaning, but pure water may be separately supplied and used for spray cleaning, and pure water is used to prevent rust of the shadow mask. A rust preventive may be added therein.

[0036]

As described above, in the method for manufacturing a shadow mask according to the present invention, ultrasonic shadow cleaning, spray cleaning using pure water, and air blow are performed to re-create the shadow mask material 1 in the film peeling process. It becomes possible to remove the adhered foreign substances and the foreign substances still attached.
As a result, as described in the above (Problems to be solved by the invention), the present invention is caused by the adhesion of foreign matter, which makes the inspection time-consuming and deteriorates the inspection accuracy, and the quality of the shadow mask. To reduce the manufacturing efficiency and quality of the shadow mask.

[0037]

[Brief description of drawings]

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

FIG. 2 is an explanatory view showing an example of a conventional film peeling process.

3A to 3C are cross-sectional views showing an example of a method of manufacturing a shadow mask in the order of steps.

FIG. 4 is an explanatory diagram showing an example of foreign matter adhesion.

[Explanation of symbols]

 1 Shadow Mask Material 2 Resist Film 3 Opening 4 Shadow Mask 5 Foreign Material 6 Stripping Tank 7 Rinsing Chamber 8 Drying Furnace 9 Ultrasonic Device 10 Pure Water Tank 11 Nozzle 12 Pure Water 13 Filter 14 Pump 15 Ultrasonic Reflector

Claims (5)

[Claims] 1. A method for producing a shadow mask by forming a large number of through holes in a metal material by using a photo-etching method, wherein the through holes are formed and a corrosion resistant film on the surface of the metal material is stripped. After that, the metal material to be conveyed is subjected to an ultrasonic cleaning step in a pure water tank provided with an ultrasonic device, a spray cleaning step with pure water after leaving the pure water tank, and a compressed air after the spray cleaning. A method for manufacturing a shadow mask, which comprises performing an air blowing step. 2. In the ultrasonic cleaning step, an ultrasonic reflector is provided on the surface of the metal material opposite to the surface on which the ultrasonic device is provided so as to face the ultrasonic device. 1. The method for manufacturing the shadow mask according to 1. 3. A surface of the ultrasonic reflector facing the metal material is a semicylindrical or parabolic concave surface, and the inside of the ultrasonic reflector is a vacuum cavity. The method for manufacturing a shadow mask according to claim 2, wherein the shadow mask is manufactured. 4. The pure water in the pure water tank is circulated through a foreign matter removing filter.
A method for manufacturing a shadow mask according to. 5. The method of manufacturing a shadow mask according to claim 4, wherein water sucked from the bottom of the pure water tank and overflow water from the pure water tank are circulated.