JPS59232607A - Manufacture of metallic plate for shadow mask - Google Patents

Abstract

PURPOSE:To improve the adhesive strength of the photoresist coated surface of a metallic plate to an original plate and to improve copying by finishing a work roll so as to have specific surface roughness and denseness in its surface by liquid honing, in finish rolling a metallic plate for shadow mask. CONSTITUTION:In a finish cold rolling or a temper rolling of a metallic plate for shadow mask, the surface of a work roll is finished by liquid honing so as to have 0.5-4.0mumRa surface roughness and 10-80HRC/2.5mm. denseness in its surface. In this case, the surface of metallic plate is adjusted to 0.2-2.4mumRa surface roughness and 10-80HRC/2.5mm. denseness in its surface. A photoresist is coated on the surface of a metallic plate prepared by said surface conditions, to overlap the metallic plate on a thick plate, and air existing between both plates is perfectly removed by evacuating the gap to bring the plate into tight contact with the original plate. Thus a copying is performed excellently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metal plate for a shadow mask, and more particularly, to a method for manufacturing a metal plate for a high-quality shadow mask that has a relatively rough surface roughness and a high density of roughness. .

Conventionally, metal plates for shadow masks have been produced by first cold rolling a low carbon hot rolled steel strip or a high alloy steel strip such as invar, and then annealing it to remove strain by box annealing (including open coil annealing) or continuous annealing. The main manufacturing process is to perform secondary cold rolling, or further secondary cold rolling, temper rolling, and slitting. Therefore, the surface finish of a metal plate for a shadow mask, which is a product, is prepared through a secondary cold rolling or temper rolling process, which is finish rolling, and the surface condition affects the performance of the color cathode ray tube, which is a final product. More specifically, the surface finish of the work roll used for the finish rolling is itself transferred to the metal plate with considerable fidelity, so the surface finish of the work roll is the most important requirement. .

Next, the production of a shadow mask using a metal plate for shadow masks will be described. Hereinafter, the metal plate for the Nyadu mask may be simply referred to as the material.

FIG. 1 is a diagram showing the manufacturing process of a shadow mask.

In Fig. 1, after pre-processing the material such as degreasing, photoresist is applied to both sides of the material, and then vacuum is applied to make the original plate adhere to the surface of the material. The original pattern is printed onto the material by exposing both sides simultaneously. Then, in a developing step, the non-exposed portions of the photoresist are removed, and in a burning step, the photoresist 2 is hardened with light m ub to form an acid-resistant film. Then, in the etching step, a ferric chloride solution is used to perforate the exposed portion of the material, and the material is sent to a shearing and inspection step.

In this way, a flat mask is completed.

Next, in order to give this flat mask workability, the mask is annealed in a dry or wet atmosphere, then passed through a leveler several times to correct the shape and prevent Luders lines (leveling process), and then press-formed into a spherical shape. Process it into Next, blackening treatment is performed in water vapor and/or gas to prevent rust and scattering of electron beams during the process, and a shadow mask is completed.

Note that the above mask annealing and leveling may not be performed. In this case, in the manufacturing process of the metal plate for the shadow mask, the metal plate is pre-annealed after finishing rolling, and then tempered, rolled or leveled.

The above is a process for manufacturing a shadow mask from a metal plate for a shadow mask.Next, the vacuum exposure process according to the present invention will be explained in more detail.

Figure 2 is Photo-JIS l-2! FIG. 3 is a perspective view showing a state in which the metal sheet work after the cloth is vacuumed and the original plate 3 is brought into close contact with the metal plate. In FIG. 2, a degassing pipe 4 connected to a vacuum pump sucks and exhausts air remaining in the space between the photoresist 2 and the surface of the original 3 in an airtight area.

FIG. 3 shows one side (a cross-section during evacuation showing the state of degassing of the air remaining between the photoresist and the original plate).

In FIG. 3, the photoresist 2 is in close contact with the metal plate 1, but there is a partial space between it and the original plate 3, and internal resist air remains. When this is evacuated in the direction of arrow (■), the remaining air is removed, and the original plate 3 is pressurized in the direction of arrow A by atmospheric pressure, so that it comes into close contact with the photoresist. It is desirable for this phenomenon to occur uniformly over the entire surface, but in reality, it is not possible to uniformly arrange a large number of degassing pipes compared to the area to be degassed (vacuum degassing pipes are ), the deaeration path tends to be blocked and deaeration takes a long time, and complete deaeration is difficult if you try to deaeration in a short period of time. There was an unavoidable tendency for voids (non-adhesive areas) to remain in areas other than the periphery of the area.

In other words, it is extremely difficult to perform sufficient degassing in a short time with a small number of degassing tubes and to create an efficient vacuum with conventional material roughness.

Therefore, the present inventors were faced with the need to manufacture a metal plate for a shadow mask that is dense and has a roughness with a large difference in peak and valley elevation in the microscopic cross section I, and as a result of various tests and research,
The inventors have discovered that the above-mentioned problems can be solved by using a liquid honing roll as a finish rolling work roll, and have arrived at the present invention.

The progress leading to the present invention will be briefly described below.

In other words, conventional finish rolling work rolls for manufacturing metal plates for shadow masks are processed by (1) coarse grindstone polishing or (
2) The surface was finished by shot blasting. However, method (1) is not suitable because the scratch marks of the grindstone tend to be transferred to the metal plate and the hole shape of the shadow mask tends to be irregular after etching. In addition, in method (2), the roll surface roughness cross-sectional shape has waviness (
Microscopically large wave-like heights and protrusions were generated, which tended to have a negative effect on the shadow mask hole shape. In other words, the undulations cause the linear portion of the shadow mask slot hole to become non-linear, and the protrusion causes a missing portion called a crater in the shadow mask slot hole.

Therefore, method (2) was also inappropriate. Therefore, in order to improve method (2), we conducted a test using a roll whose surface after shot blasting was finished with a soft grindstone such as a vinyl grindstone, but although the crater formation of the shadow mask hole disappeared, the effect of waviness was small. It wasn't doubled. The above is the research progress that led to the present invention, and therefore, the adoption of liquid honing coolant was by no means a mere idea.

An object of the present invention is to provide a method for manufacturing a metal plate for a shadow mask that can achieve uniform evacuation in a short time in the shadow mask manufacturing process.

Another object of the present invention is to provide a method for manufacturing a metal plate for a shadow mask that is dense and has a high Ra degree.

Still another object of the present invention is to provide a method for manufacturing a metal plate for a shadow mask, which is a shadow mask material suitable for high-quality color picture tubes and capable of obtaining accurate hole shapes.

The present invention provides a method for manufacturing a metal plate for a shadow mask, which is characterized in that a liquid honing roll is used as a work roll in finish cold rolling or temper rolling.

The present invention will be described in detail below using examples.

Figure 4 is a work roll surface roughness profile (comparative example) measured using a stylus type surface roughness meter using the conventional shot blasting method, and Figure 5 is a work roll surface roughness profile that has been subjected to liquid honing on the same scale. It is a surface roughness profile diagram (Example).

In both cases, the horizontal magnification is 50x, and the vertical magnification is 2.0.
00 times.

Table 1 shows the surface roughness values shown in FIGS. 4 and 5 expressed numerically.

Here, Da is the center line average roughness, and a part of measurement length L is extracted from the roughness curve with the low frequency cutoff in the direction of the center 4J1, and the center line of that part is The direction of magnification is the y-axis, and the roughness curve is expressed as y = f (x) +::7.
- Also, H2O has the number of peaks per unit length (High 5pot
Count), and a certain measurement length L from the cross-sectional curve (in this case, L = 2.5■
And so. ) is extracted and the peaks and valleys are distinguished based on whether they are above the average line.It is expressed as the number of peaks.

Regarding rice grains, in Table 1, Ra is almost the same in both the comparative example and the inventive example, but when compared with H2O, in the example it is about 3 times higher than in the comparative example I, that is, the roughness This shows that the density is extremely high. This fact is also clear by comparing Figures 4 and 5. The shadow mask metal plate to which the roughness of the example of the present invention (FIG. 5) is transferred during finish rolling shows almost the same roughness profile, so an exhaust passage is ensured during evacuation as described above. The original plate adheres to the resist-coated metal plate even if the vacuum is applied for a short time. Therefore, a shadow mask with good hole shape can be obtained in terms of performance.

The reason why the surface roughness of the work roll is set to 0.5 to 40 μm Ra is that if Ra is smaller than 0.5 μm, the exhaust passage will be clogged during vacuuming, so Ra is 4.0 μm.
This is because if it is larger than m, the hole shape of the shadow mask will be warped and become inaccurate.

In addition, the density of the work roll surface roughness is 10 to 80H8C.
/ The reason for setting it to 2.5 is that if I (SC is less than 10), the roughness becomes plain with few irregularities as in the conventional example (see Fig. 4), and the shape of the shadow mask hole becomes poor.
This is because it is difficult to implement industrially anything with H2O exceeding 80 using the current liquid honing technology.

The reason for limiting the surface roughness of the product metal plate is the same as that of the work roll surface roughness. However, due to the transfer rate, only Ra was empirically set to 0.2 to 2.4 μm.

In addition to mild steel, the material of the metal plate is amber, 4296Ni.
-Fe alloy, Covar/L7 (Fe-Ni-Co alloy), permalloy, etc., but it goes without saying that it can also be applied to materials other than these.

By carrying out the present invention as described above, all of the above objects have been achieved and it has become possible to industrially produce high quality shadow masks.

[Brief explanation of the drawing]

Figure 1 is a manufacturing process diagram of the shadow mask, Figure 2 is a perspective view of the vacuuming process, Figure 3 is a sectional view of the vacuuming process, and Figure 4 is a cross-sectional view of the vacuuming process.
5 and 5 are work roll surface roughness profile diagrams of a comparative example and an example of the present invention, respectively. 1...Metal plate, 2...
...Photoresist, 3...Original version
4・・・・・・・・・Deaeration pipe. Patent applicant Toyo Kohan Co., Ltd. Agent Patent attorney Mukai 1) Masa Mistake 1
Figure 2: Manufacturing process of metal plate for Nyadou mask Figure 3

Claims (3)

[Claims] (1) A method for producing a metal plate for a shadow mask, characterized in that a liquid honing roll is used as a work roll in finish cold rolling or temper rolling. (2) Work roll surface roughness is 0.5 to 4.0μ
mRa and roughness density is 10-80 H8C
/2.5 The manufacturing method according to claim 1, which is column 2.5. (3) The surface roughness of the product metal plate is 0.2 to 2.4 μmRa
and the density of roughness is 10 to 80 H8C/2.
5. The manufacturing method according to claims 1 and 2.