JPH07252602A - Iron-nickel alloy sheet for shadow mask and its production - Google Patents

Abstract

PURPOSE:To produce an alloy sheet for shadow mask, excellent in adhesion of resist, seizure resistance, thermal strain characteristic, etc., in a manufacturing process of a shadow mask and improved in manufacturing yield. CONSTITUTION:This alloy sheet is an Fe-Ni alloy sheet of <=0.30mm sheet thickness, having a composition containing, by weight, 30-52% Ni, <=0.02% C, <=0.30% Si, <=0.02% Al, and <=0.02% O. Further, in a state of etching material, this alloy sheet has (38 to 52)kgf/mm<2> proof stress, (18 to 48)kgf/mm<2> elastic limit strength, 0.70-2.5mum average surface roughness, and 0.30-2.0 index of deviation from a roughness curve in a height direction. By this method, in a manufacturing process of a shadow mask, the occurrence, e.g. of inferior pit shape at etching, seizure defect at mask annealing, and inferior attachment at cathode ray tube sealing can be prevented, and manufacturing yield can be remarkably improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Fe-Ni alloy thin plate for a shadow mask used in a color cathode ray tube, etc.
The present invention relates to a Fe—Ni alloy thin plate for a shadow mask, which is excellent in seizure resistance and thermal strain characteristics, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Low carbon steel is generally used as a material for color cathode ray tube shadow masks. A color cathode ray tube has a fluorescent plate that emits the three primary colors of red, green and blue applied to the face plate (panel) of the glass bulb that forms the vacuum tube, and the neck part on the opposite side is for stimulating the fluorescent film to emit light. It is equipped with an electron gun that emits an electron beam. The shadow mask is provided between the fluorescent screen and the electron gun in a position close to the fluorescent screen, and three electron beams corresponding to the three primary colors emitted from the electron gun are passed through holes called slots to correspond to each other. It has the function of color selection such that it is applied only to the fluorescent screen. Therefore, it is necessary that the positional relationship between the slots on the shadow mask and the phosphors be accurately matched. However, when the color cathode ray tube is continuously used, about 8 of the electron beam energy is used.
Since 0% is consumed as heat energy on the shadow mask, the temperature of the shadow mask locally rises to about 90 ° C. and thermal expansion makes it impossible to match the electron beam with the phosphor, resulting in an unclear image. Therefore, the structure of the color cathode ray tube has been devised to compensate for the thermal expansion of the shadow mask, but this is not sufficient.

Therefore, as a material for a shadow mask, the coefficient of thermal expansion is extremely smaller than that of low carbon steel.
A low thermal expansion Fe—Ni alloy thin plate containing 52% has been used. However, in the manufacturing process of the shadow mask, such an Fe-Ni alloy thin plate has a problem that the etching piercing property is significantly inferior to the conventional low carbon steel, and the hole shape unevenness due to the resist peeling frequently occurs. Further, there is a decrease in yield due to thermal strain that occurs when the cathode ray tube is sealed, and in a remarkable case, material lot-out / return may occur. Therefore, a Fe-Ni alloy thin plate for a shadow mask used in a color cathode ray tube,
In particular, there is a strong demand for a Fe—Ni alloy thin plate for a shadow mask, which is excellent in resist adhesion, seizure resistance, thermal strain characteristics, etc. in the shadow mask manufacturing process and has a good manufacturing yield, and a method for manufacturing the same.

As a material for a low thermal expansion type shadow mask, for example, a shadow excellent in etching perforation by controlling carbides, sulfides and oxides by limiting the components such as C, S and O of Fe-Ni alloy. The mask material is disclosed in Japanese Patent Laid-Open No. 61-113746. According to this, defects such as etching perforation unevenness due to inclusions can be prevented, but it is not sufficient to prevent defective hole shape due to causes other than inclusions. Furthermore, resist adhesion, seizure resistance, and thermal strain Not considered for characteristics.
Further, as a method for producing a material for a low thermal expansion type shadow mask, for example, a method in which etching roughness is improved by controlling surface roughness, crystal grain size and texture is disclosed in Japanese Patent Laid-Open No.
It is disclosed in JP-A-2-243782. According to this, although the etching perforation rate is improved and the resist adhesion failure and the perforation defect due to the coarse grain structure are improved, it is not sufficient for the improvement of the seizure resistance and the thermal strain property.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a Fe-Ni alloy thin plate for a shadow mask which is excellent in resist adhesion, seizure resistance, thermal strain characteristics, etc. in a shadow mask manufacturing process and has a good manufacturing yield. It is intended to provide a manufacturing method thereof.

[0006]

In order to achieve the above-mentioned object, according to the present invention, as a result of various studies of components, materials and manufacturing processes, trace components are limited, and strength and surface finish of thin plate are properly combined. Further, it was achieved by limiting the sheet thickness before the final annealing, the annealing conditions and the temper rolling conditions. The gist of the present invention is as follows. (1) Ni: 30 to 52% by weight%, C: ≤ 0.02
%, Si: ≦ 0.30%, Al ≦ 0.02%, O: ≦
Fe-N containing 0.02% and having a plate thickness of 0.30 mm or less
It is a thin sheet of i-alloy and has a proof stress σ in the state of etching material.
_0.2 is 38 to 52 kgf / mm ² and the elastic limit strength σ _E is 1
A 8~48kgf / mm ^2, the height direction of the deviation index 0.70~2.5μm and the roughness curve average roughness Ra of the surface is 0.30 to 2.0 in Rsk. (2) Ni: 30 to 52% by weight%, C: ≤ 0.02
%, Si: ≦ 0.30%, Al ≦ 0.02%, O: ≦
An Fe-Ni alloy strip containing 0.02% was cold-rolled to a thickness of 0.30 mm or less, followed by N ₂ of 5-9.
Annealing is performed in a non-oxidizing or reducing atmosphere containing 0 vol.% While maintaining a furnace tension of 0.07 to 3.0 kgf / mm ² and holding at a heating temperature of 700 to 900 ° C. for 1 to 100 seconds. And surface roughness Ra is 1.0 to 3.5
Temper rolling with an elongation of 2 to 10% is performed using a work roll having a μm and an Rsk of −0.50 to −4.0.

[0007]

The reason for limiting the present invention will be described in detail below. First, if the Ni content is less than 30%, the coefficient of thermal expansion becomes extremely high, and the sharpness of the color CRT deteriorates. Even if the content exceeds 52%, the coefficient of thermal expansion becomes high. Therefore, the Ni component range is set to 30 to 52%.
A desirable range is 34 to 38%. When the content of C exceeds 0.02%, iron carbide is remarkably generated, which impairs the etching piercing property and causes piercing defects. Therefore, the C component range is set to 0.02% or less. A desirable range is 0.01% or less (not including 0%). Si
When the content of Si exceeds 0.30%, the formation of SiO ₂ is remarkable, and due to the high ductility due to the hot rolling and the subsequent cold rolling, it remains in a straight chain form, and streaky unevenness of perforation during etching. Cause of. Therefore, the Si component range is set to 0.
It was set to 30% or less. A desirable range is 0.10% or less (not including 0%). Al is effective as a deoxidizing agent, but if its content exceeds 0.02%, the formation of Al ₂ O ₃ is remarkable, and this is cut due to low ductility due to hot rolling and subsequent cold rolling processing. Then, they remain in a linear form and cause streaky unevenness of perforation during etching. Therefore, the Al component range is set to 0.02% or less. The preferred range is 0.
It is 001-0.01%. O has a content of 0.02
If it exceeds 0.1%, oxide-based inclusions are remarkably generated, which impairs the etching perforation property and causes perforation defects and perforation unevenness. Therefore, the O component range is set to 0.02% or less. A desirable range is 0.01% or less (not including 0%).

[0008] The inventors of the present invention, the shadow mask manufacturing process
Resist adhesion, seizure resistance and thermal strain characteristics
Fe for shadow masks, which has excellent manufacturing yield
In order to obtain a Ni alloy thin plate, the plate thickness is 0.30 to 0.
01mm and the proof stress σ in the state of etching material_0.2Is 3
8 to 52 kgf / mm²And the strength of the elastic limit σ_EIs 18 to 48
kgf / mm²And the average surface roughness Ra is 0.70 to
2.5 μm and the deviation index in the height direction of the roughness curve is Rsk
Found that 0.30 to 2.0 is effective
did. Fe-36% Ni alloy thin with 0.20mm thickness
Proof strength σ in the state of etching material using a plate_0.2And bullets
Strength of sex limit σ_ESteps in the shadow mask manufacturing process
Figure 1 shows the results of an investigation of the effect on retention. here,
Proof strength σ_0.2Uses JIS No. 13 B test to JIS Z
It measured based on 2201. Elastic limit strength σ_EIs JI
For moment type tests specified in SH 3130
The spring limit value that was measured more was adopted. Shadow mask
The yield loss in the manufacturing process of
Percentage of the number of dropped sheets divided by the total number after etching processing
It was evaluated by. As can be seen from Fig. 1, etching material
Strength σ under_0.2Is 38 kgf / mm²Less than a line
High yield loss due to hip breakage during striping
I understand. Also, σ_0.2Is 52 kgf / mm²Is exceeded,
On the contrary, since the strength becomes too large, when transferring between lines
Handling defects occur frequently and yield loss increases. Furthermore, etching
Elastic limit strength σ in the material state_EIs 18 kgf / mm²Less than
Then, the shadow mask after etching-pressing is
Due to the large amount of thermal strain when sealing to the round tube
In addition, it is not possible to perform accurate setting with the cathode ray tube and
Therefore, the yield loss is high. σ_EIs 48 kgf / mm²
If it exceeds the limit, the handling flaw will be
It occurs frequently and yield loss becomes high. Therefore, the shadow mask
In order to reduce the yield loss in the manufacturing process to 4% or less,
Proof strength σ in the state of the ching material_0.2Range of 38-52kg
f / mm²And the strength of the elastic limit σ_ERange of 18-48kgf
/ Mm ²And Where, due to physical constraints, σ_EIs σ_0.2
Does not exceed_E/ Σ_{0. 2}Is 1 or less.

Fe-36% Ni having a plate thickness of 0.20 mm
Using an alloy thin plate, the influence of the average roughness Ra of the surface in the state of the etching material and the deviation index (skewness) Rsk in the height direction of the roughness curve on the yield loss in the shadow mask manufacturing process was investigated. The results are shown in Figure 2. Here, the average roughness Ra was measured based on JIS B 0601. The deviation index Rsk in the height direction of the roughness curve is calculated from the following equation when the roughness curve is represented by y = y (x), the average height is represented by y, and the root mean square height is represented by Rq.

[0010]

[Equation 1]

As is apparent from FIG. 2, when the average roughness Ra of the surface in the state of the etching material is less than 0.70 μm, the adhesive force of the resist film is weak and the shape of the holes becomes uneven during the etching in the subsequent process. It can be seen that the residue is high. On the other hand, when Ra exceeds 2.5 μm, the adhesive force of the resist film becomes too large, so that it takes a long time to peel off the resist film and the productivity decreases. Further, if the surface skewness Rsk in the state of the etching material is less than 0.30, seizure occurs between the shadow masks stacked during the softening annealing before press working, resulting in a high yield loss. When Rsk exceeds 2.0, it takes time to vacuum the resist for improving the adhesiveness of the resist after coating the resist, and the productivity is lowered. Therefore, in order to reduce the yield loss in the shadow mask manufacturing process to 3% or less, the range of the average roughness Ra of the surface of the etching material is set to 0.7.
Bias index Rs of 0 to 2.5 μm and height direction of roughness curve
The range of k was 0.30 to 2.0.

The present inventors have found that in a shadow mask manufacturing process, Fe for a shadow mask is excellent in resist adhesion, seizure resistance, thermal strain characteristics, etc. and has a good manufacturing yield.
As a manufacturing method for obtaining a Ni alloy thin plate, a plate thickness of 0.30 mm or less is obtained by cold rolling once or twice or more, followed by non-oxidation containing N _{2 in an} amount of 5 to 90 vol.% Or more. 0.07-3.0kgf in reducing atmosphere
/ Mm ² in the furnace tension imparted by while heating temperature (700 to 90
After annealing at (0 ° C.) × holding time (1 to 100 sec), the surface roughness Ra is 1.0 to 3.5 μm and Rsk is −0.
Using a work roll of 50 to -4.0, the elongation is 2
It was found that a temper rolling of 10% is performed. Using a Fe-36% Ni alloy strip having a plate thickness of 0.20 mm,
In the annealing atmosphere with N ₂ of 25 vol.% And H ₂ of 75 vol.%, Elastic limit strength σ due to furnace tension and annealing temperature
Figure 3 shows the results of an investigation of the effect on _E / yield strength σ _0.2 .
In Fig. 3, σ _E / σ _0.2 improves as the in-furnace tension is applied, but the in-reactor tension reaches its maximum in the range of about 0.5 to 1.0 kgf / mm ² , and decreases with further in-reactor tension. I understand that This tendency is more remarkable as the annealing temperature is lower. The present inventors have found that the tension in the furnace during annealing before temper rolling can control the elastic limit strength σ _E. Therefore, since the sigma _0.2 can be controlled by the growth rate in that temper rolling later, sigma _0.2 in the state of the etching material 38-5
For 2 kgf / mm ² Katsu sigma _E is 18~48kgf / mm ^2, it is necessary to the sigma _E / sigma _0.2 to 0.35 or more. As is clear from FIG. 3, σ _E / σ _0.2 is 0.35
Because of the above, the range of tension in the furnace is 0.07 to 3.0
It is kgf / mm ² . Desirable range is 0.12-2.5
It is kgf / mm ² .

Although the detailed reason why the strength σ _{E of the} elastic limit can be controlled by the tension in the furnace is unknown, it is presumed that the nitriding of the surface during annealing changes the motion state of dislocations near the elastic limit. Therefore, the sheet thickness in the final annealing is 0.
If it exceeds 30 mm, nitriding to the surface does not proceed sufficiently, and it becomes difficult to control σ _E by the tension in the furnace. Therefore, the thickness range is set to 0.30 mm. The desirable range is preferably 0.
It is 25 mm or less. If the N ₂ concentration in the atmosphere in the final annealing is less than 5 vol.%, Nitriding to the surface will not proceed sufficiently and it will be difficult to control σ _E by the tension in the furnace. 90 vol.
%, Selective oxidation to the grain boundaries peculiar to the Fe—Ni alloy occurs and the surface properties deteriorate, so the surface after etching becomes poor. Therefore, the range of N ₂ concentration in the atmosphere is set to 5
It was set to 90 vol.%. Desirable range is 20-50 vol.%
Is. When the annealing temperature in the final annealing is less than 700 ° C., recrystallization does not proceed sufficiently and the expanded grains during rolling remain in the central portion of the plate thickness, resulting in poor hole shape during etching. Further, when the temperature exceeds 900 ° C., the recrystallized grains grow remarkably and coarsely, resulting in poor pore shape during etching. Therefore, the range of the annealing temperature is set to 700 to 900 ° C. When the annealing time in the final annealing is less than 1 second, the temperature distribution in the width direction of the strip is not uniform and the progress of recrystallization is non-uniform in the width direction, resulting in uneven hole shape during etching. Further, even if it exceeds 100 seconds, the effect on the progress to recrystallization is saturated, so that the productivity is lowered and the manufacturing cost is further increased. Therefore, the annealing time range is 1 to 100 se.
c A desirable range is 10 to 60 seconds.

Fe-36% Ni having a plate thickness of 0.20 mm
Using alloy strip, yield strength σ _0.2 due to elongation of temper rolling
The results of investigating the effect on the transfer rate are shown in FIGS. Here, the transfer rate indicates the degree to which the surface roughness of the temper rolling roll is transferred to the surface of the strip plate, and the average roughness of the plate surface after temper rolling is divided by the average roughness of the roll surface. Evaluation was made in percentage. As is clear from FIG. 4A, the proof stress σ _{0.2 in} the state of the etching material is 38 to 52.
In order to achieve kgf / mm ² , the range of elongation in temper rolling is 2 to 10%. Further, in order to set the surface roughness Ra of the etching material to 0.70 to 2.5 μm in Ra and 0.30 to 2.0 in Rsk, the transfer rate needs to be 20% or more. In FIG. 4 (b), the elongation rate is 2 when the annealing temperature is 700 ° C. because the transfer rate is 20% or more.
% Or more, and the elongation rate exceeds 10%, the transfer rate is 70%.
It turns out that the effect is saturated. Therefore, the range of elongation in temper rolling is set to 2 to 10%. On the surface of the temper rolling roll, if the average roughness Ra is less than 1.0 μm and the skewness Rsk is less than −0.50, dullness required as the surface of the shadow mask material cannot be sufficiently processed on the roll surface. Further, when the average roughness Ra exceeds 3.5 μm and the skewness Rsk exceeds −4.0, it takes a very long time for the dulling process, and therefore it is necessary to prepare a large number of spare rolls, which increases the cost. Connected to. Therefore, the surface of the temper rolling roll is in the range of Ra from 10 to 3.
It was set to -0.50 to -4.0 in the range of 5 μm and Rsk. The desirable range is Ra of 1.0 to 3.5 μm and R
Sk is -0.60 to -2.6.

[0015]

EXAMPLES Tables 1 and 2 show examples of the present invention, comparative examples and conventional examples. The target material was an Fe-36% Ni alloy, and a material having a finished plate thickness of 0.20 mm was used. Table 1 and Table 2
Shows the characteristics of the composition, the number of cold rolling and the plate thickness, the final annealing condition, the temper rolling condition and the state of the etching material.
Further, it also shows the overall yield loss against the occurrence of defects in the shadow mask manufacturing process, that is, the etching process, the softening annealing process, the pressing process and the cathode ray tube sealing process. Compared with the comparative example and the conventional example, the inventive example has better etching piercing property in the shadow mask manufacturing process and improves resist adhesion, seizure resistance, and thermal strain characteristics, and therefore has poor hole shape during etching. It can be seen that the yield loss due to the seizure failure during mask annealing and the installation failure during cathode ray tube sealing is significantly reduced.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

As is apparent from the above, when the Fe-Ni alloy thin plate manufactured by the method of the present invention is used, the etching piercing property is good and the resist adhesion, the seizure resistance and the thermal strain are good in the manufacturing process of the shadow mask. Since the characteristics are improved, a defective hole shape at the time of etching, a defective sticking at the time of mask annealing, a defective mounting at the time of sealing a cathode ray tube, etc. are prevented, and the manufacturing yield is greatly improved.

[Brief description of drawings]

FIG. 1 Fe-36% Ni with a finished thickness of 0.20 mm
Proof stress σ in the state of etching material using thin alloy plate
FIG. 8 is a diagram showing the results of an investigation of the effect of yield strength _{0.2 in the} shadow mask manufacturing process due to the strength σ _{E at the} elastic limit.

FIG. 2 Fe-36% Ni with a finished thickness of 0.20 mm
Using an alloy thin plate, the influence of the average roughness Ra of the surface in the state of the etching material and the deviation index (skewness) Rsk in the height direction of the roughness curve on the yield loss in the shadow mask manufacturing process was investigated. It is a figure which shows a result.

FIG. 3 Fe-36% Ni with a finished plate thickness of 0.20 mm
Using an alloy strip, N ₂ is 25 vol.% And H ₂ is 75 vol.
FIG. 5 is a diagram showing the results of an examination of the influence of the tensile strength in the furnace and the annealing temperature on the strength σ _E / proof stress σ _0.2 of the elastic limit in an annealing atmosphere of%.

FIG. 4 Fe-36% Ni with a finished plate thickness of 0.20 mm
Using alloy strip, yield strength σ _0.2 due to elongation of temper rolling
It is a figure which shows the result of having investigated the influence on transfer rate of FIG. 4 (a) and dull roll FIG. 4 (b).

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // C23F 1/00 C 8417-4K

Claims (2)

[Claims] 1. Ni: 30 to 52% by weight%, C: ≦
0.02%, Si: ≤ 0.30%, Al ≤ 0.02%,
O: F containing ≦ 0.02% and having a plate thickness of 0.30 mm or less
An e-Ni alloy thin plate having a proof stress σ _0.2 of 38 to 52 kgf / mm ² and an elastic limit strength σ _{E in} the state of an etching material.
Is 18 to 48 kgf / mm ² and the average surface roughness is Ra
Is 0.70 to 2.5 μm and the deviation index in the height direction of the roughness curve is Rsk is 0.30 to 2.0. 2. Ni: 30 to 52% by weight%, C: ≦
0.02%, Si: ≤ 0.30%, Al ≤ 0.02%,
O: Fe-Ni alloy strip containing ≤ 0.02% is cold-rolled to a thickness of 0.30 mm or less, followed by non-oxidizing or reducing atmosphere containing 5-90 vol.% N ₂ . At a heating temperature of 700 to 900 ° C. for 1 to 100 seconds while applying a furnace tension of 0.07 to 3.0 kgf / mm ² and subsequently, the surface roughness Ra is 1.0 to 1.0
A Fe-Ni alloy thin plate for a shadow mask, characterized by performing temper rolling having an elongation of 2 to 10% by using a work roll having 3.5 μm and Rsk of −0.50 to −4.0. Production method.