JPH08109442A - Iron-nickel alloy sheet for electronic parts, excellent in etching characteristic - Google Patents

Abstract

PURPOSE: To produce the sheet suitable for shadow mask, lead frame, etc., by specifying, in the region where (100) orientation degree is locally different, the fluctuation index of the orientation degree and the width of the region in the direction perpendicular to a rolling direction, respectively. CONSTITUTION: In this Fe-Ni alloy sheet, in the region where the degree of orientation of (100) with respect to a rolling surface is locally different, the fluctuation index of (100) orientation degree, defined by expression |(100)C-(100)A≫/(100)A ×100%, is <=50% and also the width of the region in the direction perpendicular to rolling direction is >=100μm. In the expression, (100)C means (100) orientation degree with respect to rolling surface, measured by an etch pit method or an ECP method, and also (100)A means (100) orientation degree with respect to rolling surface, measured by an X-ray diffraction method. This alloy sheet has superior etching characteristic and is minimal in the occurrence of striped irregularity causing local deterioration in image visibility after shadow mask etching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Fe-type electronic component such as a shadow mask and a lead frame to be etched.
The present invention relates to a Ni-based alloy thin plate, and particularly to a Fe—Ni-based alloy thin plate suitable as a material for a shadow mask that requires excellent etching properties.

[0002]

2. Description of the Related Art Electronic components such as shadow masks and lead frames are etched during the manufacturing process.
The shadow mask will be described below as an example.

A shadow mask provided in a cathode ray tube of a television or a display device is a fine mask for precisely irradiating a predetermined point on a fluorescent screen with an electron beam emitted from an electron gun to give a specific color tone. It has holes. Conventionally, mild steel sheets such as low carbon rimmed steel and low carbon aluminum killed steel have been used as materials for shadow masks. However, when a cathode ray tube using a shadow mask manufactured from such a material is continuously used, the temperature of the glass body and the shadow mask that support the phosphor screen irradiated with the electron beam gradually increases. In particular, since the electron beam is also applied to the non-opening portion of the shadow mask, the temperature of the shadow mask becomes higher than that of the glass body supporting the fluorescent screen.

Moreover, since the shadow mask has a much larger coefficient of thermal expansion than the glass body that supports the phosphor screen, misalignment occurs between the shadow mask and the electron beam to a predetermined point on the phosphor screen accurately. It becomes impossible to illuminate and the image becomes unclear. In order to prevent the image from becoming unclear, attempts have been made to compensate for mutual misalignment by devising the structure of the support that serves as a suspension system for the shadow mask, but this is not always sufficient.

Therefore, in recent years, it has been proposed to use a thin plate of a low thermal expansion material made of Fe-Ni alloy such as Invar for the shadow mask. The Fe-Ni alloy thin plate for a shadow mask is usually prepared by continuously casting or ingoting an alloy ingot, and then the alloy ingot thus prepared is subjected to slab rolling, hot rolling and cold rolling. It is manufactured by rolling and annealing.

[0006] Usually, the shadow mask alloy thin plate produced as described above is formed with electron beam passage holes by photoetching, and then well-known processes such as annealing, forming and blackening treatment are performed. Then, a shadow mask is manufactured.

A shadow mask made of a Fe-Ni alloy thin plate was supposed to have good results in terms of image sharpness, but this alloy thin plate is inferior in etching property, and a shadow mask is manufactured. Since a good etching hole shape cannot be obtained during photoetching perforation in the process of forming, there is a problem in image sharpness. In particular, weight% (hereinafter, composition%
Represents weight%) and Fe containing 20 to 55% of Ni
-Ni-based alloy thin plate, or an additional component 1 such as Co
The occurrence of this defect is remarkable in the shadow mask made of the Fe-Ni alloy thin plate containing 0% or less.

With respect to the Fe-Ni alloy thin plate for shadow mask, the etching property of the whole thin plate has been improved.

For example, in Japanese Patent Publication No. 59-32859, in order to make the hole shape after photoetching uniform over the entire surface of the shadow mask, the etching rate must be constant over the entire surface of the shadow mask. It is said that {100} is required to be oriented at 35% or more because it is necessary to prevent the crystal orientation of the etched surface from being non-uniform.

Further, in Japanese Patent Laid-Open No. 61-39343, it is said that the non-uniformity of the hole shape after photoetching is caused by the difference in the etching rate depending on the size of the crystal grains of the opening wall. The number of crystal grains on the aperture wall is 50 /
It is said that it is necessary to make the particles finer than mm.

Further, in Japanese Unexamined Patent Publication No. 5-311357, it is effective to make the crystal grains finer and to randomize the crystal plane with respect to the rolling plane, and it is effective to make the etching uniform. It is said that the degree of orientation of 0 or more and {100} with respect to the rolled surface needs to be 35% or less.

[0012]

However, with the recent increase in the size of television screens and the expansion of the use of computers for display devices, the demand for finer image quality is increasing. Correspondingly, the through holes of the electron beam of the shadow mask should be further finely processed at a higher density, for example, the hole diameter pitch should be 30.
Photo-etching processing has become to be performed so as to have a thickness of 0 μm or less. When such a photo-etching process is performed, a local defect in the sharpness of an image, which is not considered in the above-mentioned prior art, has become a problem.

As one of the local poor definition of images,
There is a local defect of the hole shape due to a local defect of photoetching of the shadow mask. When this etching failure part is visually observed from the surface of the shadow mask, there are some that are recognized as fine linear irregularities along the rolling direction of the alloy thin plate for the shadow mask. This etching failure is usually called streak unevenness.

It has been known so far that streak unevenness occurs due to segregation of Ni or segregation of impurities.

For example, Japanese Patent Laid-Open No. 61-223188 discloses that the uneven streaks are caused by the segregation of Ni, and in order to prevent the uneven streaks, the segregation rate of nickel is 10% or less, and the segregation zone of Ni is not. A technique for making the length 300 mm or less is disclosed.

Further, in Japanese Patent Laid-Open No. 2-54744, it is assumed that the streak unevenness is due to the segregation of impurity elements or the difference in the crystal structure of the slab, and 0.001 to 0.03% of B is added together with specific conditions. The slab is heated by the method to improve it.

However, regardless of the presence or absence of segregation of Ni or the segregation of impurity elements, there are cases where a large number of slight streaks are generated after photoetching the shadow mask, but the cause of the streaks has not been clarified yet. Not not.

In view of the above situation, the present invention provides an Fe-Ni alloy thin plate for electronic parts, which is free from uneven streaks that cause local deterioration of the sharpness of the image and has excellent etching properties. The purpose is.

[0019]

The present inventors have found that Fe--N
i-based alloy thin plate, especially Fe containing 20 to 55% Ni
Various studies were carried out on the etching properties of the -Ni-based alloy thin plate and the Fe-Ni-based alloy thin plate containing the additional component of 10% or less. As a result, it has been found that the above-mentioned streak unevenness is closely related to the locally varying state of the degree of orientation of {100} with respect to the rolled surface.

The present invention was made on the basis of the above findings, and the gist of the present invention is as follows.

In the region where the degree of orientation of {100} with respect to the rolled surface of the Fe-Ni alloy thin plate is locally different, the variation index of the degree of orientation of {100} defined by the following equation (2) is 50% or less. In addition, the width of the region in the direction perpendicular to the rolling direction is 100 μm or more, and the Fe—Ni-based alloy thin plate for electronic parts is excellent in etching property.

[0022]

[Equation 2]

Where {100} _C : degree of orientation of {100} with respect to the rolled surface measured by the etch pit method or ECP method {100} _A : degree of orientation of {100} with respect to the rolled surface measured by X-ray diffraction method

[0024]

The present invention will be described below. The streak unevenness will be described with reference to FIGS. 1 and 2. FIG. 1 shows Fe-36.
% Ni alloy thin plate as a material, on the shadow mask after photo-etching (etching condition: solution temperature 60 ° C., spray treatment with ferric chloride aqueous solution of concentration 47 Baume at spray pressure 2.0 kgf / cm ² ). It is a schematic diagram which shows the state of stripe unevenness. In FIG. 1, reference numeral 1 indicates streak unevenness. As shown in the figure, the streak unevenness 1 extends linearly in the rolling direction of the alloy thin plate for shadow mask.

FIG. 2 shows macro etching (etching condition: concentration 10%) of the portion A (streak unevenness and its vicinity) in FIG.
FIG. 3 is an enlarged view showing the distribution of crystal orientation after immersion treatment in a ferric chloride solution for 2 minutes at room temperature). In FIG. 2, reference numeral 2
Indicates a crystal having an orientation of {100}, and reference numeral 3 indicates a crystal having an orientation other than {100}. From FIG. 2, when seen microscopically, the streak unevenness 1 means that there is no unevenness in the {10
It can be seen that the orientation degree of 0} is different. Hereinafter, a region in which the degree of orientation of {100} with respect to the rolled surface is locally different is referred to as a colony. Since the colony extends linearly in the rolling direction of the alloy thin plate for shadow mask, the streak unevenness 1 is recognized linearly.

The colony extending linearly in the rolling direction has a difference in corrosion rate from other areas in a microscopic view, and therefore the surface roughness of the etching hole interface is in other areas. Is slightly different from. As a result, it is considered that the colony and the other regions have different streaks due to the different light reflectivity at the etching hole interface. Further, it is considered that the stripe unevenness is greatly influenced by the fluctuation of the orientation degree of {100} because the etching rate of {100} is particularly large as compared with other crystal orientations.

Regarding the fluctuation of the orientation degree which causes the above-mentioned uneven stripes, the fluctuation in a very narrow region becomes a problem. The degree of orientation in such a narrow region cannot be obtained by a commonly used X-ray diffraction method. It is effective to obtain the degree of orientation in this region by the etch pit method or the ECP method.

The etch pit method utilizes the fact that when a thin plate is corroded with a corrosive liquid, the shape of the corrosion pits that are generated differs depending on the orientation of the crystals oriented on the surface. This is a method of identifying the corresponding crystal orientation from the shape of the corrosion pit formed on the. In the case of using the etch pit method, the Fe-Ni alloy thin plate is not particularly limited, but for example, the alloy thin plate may have a concentration of 5 to 1
Immerse in 0 wt% ferric chloride solution for 2 minutes at room temperature,
After taking out and drying, the degree of orientation of {100} can be determined as the area ratio of the obtained corroded thin plate sample surface by image processing or photography.

In the case of the ECP method, the surface crystal image of the thin plate is observed in advance, and then each of the crystal orientations is specified from the electron channeling pattern (ECR) by a scanning electron microscope (SEM), Based on the results
The degree of orientation can be obtained from the area ratio of {100}. Either method is a powerful method for determining the crystal orientation of a microscopic region or the degree of orientation of a specific crystallographic orientation of a microscopic region. {100} _A is the degree of orientation of {100} in a macroscopic region, which is {10} by X-ray diffraction.
It can be obtained from the relative intensity ratio of the 0} peak.

The method of obtaining the degree of orientation by X-ray diffraction referred to here is a method which is generally used. For example, Rigaku Denki Co., Ltd., "X-ray Diffraction Guide, Revised Fourth Edition" 81-82. The method described on the page.

The degree of orientation of {100} with respect to the rolled surface of the colony obtained by the etch pit method or the ECP method is {1}.
00} _C , {10 with respect to the rolled surface obtained by X-ray diffraction method
When the degree of orientation of 0} is {100} _A and the variation index of the orientation degree of {100} of a colony is expressed by the following equation (3), the variation index and the width of the colony in the direction perpendicular to the rolling are stripes. It was found that there was a good correlation with the occurrence of unevenness, and that the variation index was 50% or less and the stripe unevenness was small when the width of the colony in the direction perpendicular to the rolling direction was 100 μm or more.

[0032]

(Equation 3)

When the variation index of the {100} orientation degree of the colony exceeds 50%, the difference in local variation of the {100} orientation degree becomes large, and the difference between the sparse portion and the other portion is large. The difference in corrosion behavior becomes large and the occurrence of streak unevenness becomes remarkable. Therefore, the variation index of the orientation degree of {100} is 5
It should be 0% or less.

The width of the colony in the direction perpendicular to the rolling direction is 100 μm
When it is less than 1, even if the variation index of the degree of orientation of {100} is 50% or less, the colonies are localized in an extremely small portion in the width direction, and the stripe unevenness becomes conspicuous. Therefore, the width needs to be 100 μm or more.

The Fe-Ni alloy thin plate of the present invention is Fe-
Ni is the basic composition, but in order to obtain low thermal expansion characteristics,
Ni is preferably 20 to 55%, more preferably 32 to 43%.

The Fe-Ni alloy thin plate of the present invention includes one in which Co and / or Cr is added to improve corrosion resistance in order to obtain more excellent low thermal expansion characteristics. Excess C
Since o and Cr deteriorate the low thermal expansion characteristics, their amounts are preferably 7% or less and 3% or less, respectively.

The other components of the present invention are preferably as follows. Mn: This is a preferable element for improving hot workability, but the addition of excess Mn forms a strong oxide film in the manufacturing process of the etching base plate and hinders the etching property during photoetching, so its amount is Is preferably 1.0% or less.

Si, Al: Can be used alone or in combination as deoxidizing elements for molten steel, but excess Si, A
Since 1 deteriorates the blackening processability, it is desirable to set the content to 0.30% or less and 0.05% or less, respectively.

C: The etching rate at the time of photo-etching is lowered and the productivity is hindered, so the amount is 0.05%.
The following is desirable.

N: 0.0 because the press formability is deteriorated.
It is desirable that the content is 04% or less.

O: Since it inhibits the growth of crystal grains during pre-press annealing and deteriorates press formability, it is preferably 0.005% or less.

The Fe-Ni alloy thin plate of the present invention is
Si, Co, Cr, Mn, Ti, Mo, Nb, B, V, if necessary for improving mechanical properties and other purposes.
One or more elements of Be, Al, Ta and W can be added in a range of 10% or less in total. Also in this case, the effect of the present invention is not impaired.

The present invention is intended for all Fe-Ni alloy thin plates for electronic parts to be etched, and is particularly suitable as a material for a shadow mask which requires excellent etching properties.

Since the shadow mask made of a Fe-Ni alloy thin plate having a low thermal expansion characteristic has a small positional deviation due to thermal expansion, the image of the Braun tube using this shadow mask becomes clearer.

Next, a method for manufacturing the Fe-Ni alloy thin plate of the present invention will be described. In the present invention, it is an important requirement to make the existing state of colonies appropriate. Colonies, in the manufacturing process of the alloy thin plate of the present invention, the localized uneven distribution of orientation generated in the process before the hot-rolled material annealing process disappears while being elongated in the rolling direction while changing the shape in the subsequent process. None of them remain, which eventually causes uneven streaks that occur during etching.

In order to reduce the number of colonies, in the method for producing a Fe-Ni alloy thin plate which is commonly used, the slab produced by slab rolling or continuous casting is subjected to uniform heat treatment at a heating temperature of 1200 ° C. or less and 10 It is necessary to perform the heating time of less than or equal to the time. If possible, it is desirable not to perform this homogenizing heat treatment. This is because excessive heat treatment for homogenization leads to yield reduction due to oxidation of the slab surface, generation of defects due to oxidative roughness of the slab surface, and abnormal formation of colonies.

Further, it is necessary to carry out the hot working at a finishing temperature of 800 ° C. or higher and a cumulative rolling reduction of 90% or higher. This is to prevent the re-generation of colonies due to the columnar crystals formed in the stage of solidification by casting of steel.

Further, by annealing the hot-rolled material obtained by the hot working described above, it is possible to make the orientation in the micro region uniform, so that the width of the colony in the direction perpendicular to the rolling direction should be increased. You can In particular, the annealing temperature is 800-9
It is effective to set the temperature in the range of 00 ° C.

The manufacturing method of the Fe-Ni alloy thin plate of the present invention is not limited to the above-mentioned method, and the same effect can be obtained even if other manufacturing methods are satisfied as long as the constitution of the present invention is satisfied. To do.

[0050]

EXAMPLES Table 1 shows the chemical compositions of alloy steels of the present invention and comparative examples.

[0051]

[Table 1]

Fe-N of the invention examples 1 to 5 shown in Table 1
After the ingot of the i-based alloy is melted into a slab by melting in an electric melting furnace, a vacuum degassing furnace, a continuous melting furnace, etc., hot working is performed at a finishing temperature of 800 ° C. or higher and a cumulative reduction ratio of 98 without performing homogenizing heat treatment. % To obtain a hot-rolled sheet having a thickness of 3.0 mm. Further, this hot rolled sheet was annealed at 850 ° C., and then cold rolling and annealing were repeated to obtain a 0.12 mm thin sheet. The thin plate thus prepared was subjected to a photoetching perforation test with a high-definition mask having a pitch of 300 μm and a diameter of 30 μm. Photoetching is performed at a liquid temperature of 60 ° C,
Spray pressure of ferric chloride solution of 47 baume concentration 2.0
It was carried out by spraying with kgf / cm ² .

The evaluation of the etching property was made by visually observing the appearance of the shadow mask after photoetching based on the presence or absence of streak unevenness.

{100} _C was obtained by measuring the orientation degree of {100} of the shadow mask after the etch pit method, that is, after the macro etching. The macro-etching was performed under the condition of immersion treatment in a 10% ferric chloride solution at room temperature for 2 minutes.

Further, {100} _A was obtained from the relative intensity ratio of {100} peaks by the X-ray diffraction method.

The Fe-Ni alloy of Comparative Example 6 shown in Table 1 has a cumulative rolling reduction of 85%, and the Fe-Ni alloy of Comparative Example 7 is annealed by hot rolling. A thin plate having a thickness of 0.12 mm was manufactured under the same manufacturing conditions as those of the above-mentioned examples of the present invention except that the above was not performed. Also in these comparative examples, as in the case of the present invention, the etching property and {100}
Was investigated.

Regarding the examples of the present invention and the comparative examples, {10
Table 2 shows the variation index of the orientation degree of 0} and the occurrence of streak unevenness.

[0058]

[Table 2]

The index of variation of the degree of orientation of colonies exceeds the range of the present invention. No. 6, the width of the colony is out of the range of the present invention. In No. 7, uneven streaks are occurring. On the other hand, streak unevenness does not occur in the example of the present invention.

[0060]

As described above, according to the present invention, the variation index of the orientation degree of the colony of {100} and the width of the colony in the direction perpendicular to the rolling direction are set in a specific range, so that the stripe unevenness is small and the etching property is high. Fe- for excellent electronic parts
A Ni-based alloy thin plate can be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a state of stripe unevenness after etching a shadow mask alloy thin plate.

FIG. 2 is an enlarged view in the vicinity of the stripe unevenness generating portion in FIG. 1, showing a distribution of crystal orientations.

[Explanation of symbols]

 1 streak unevenness 2 crystal with an orientation of {100} 3 crystal with an orientation other than {100}

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Kage 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Hiroshi Wakasa 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Date Main Steel Pipe Co., Ltd.

Claims (1)

[Claims] 1. A variation index of the degree of orientation of {100} defined by the following formula (1) is 50 in a region where the degree of orientation of {100} with respect to a rolled surface of a Fe—Ni alloy thin plate is locally different. %, And the width of the region in the direction perpendicular to the rolling direction is 100 μm or more, the Fe-Ni alloy thin plate for electronic parts having excellent etching properties. [Equation 1] However, {100} _C : degree of orientation of {100} with respect to the rolling surface measured by the etch pit method or ECP method {100} _A : degree of orientation of {100} with respect to the rolling surface measured by X-ray diffraction method