JPH11256238A - Low thermal expansion alloy for electronic parts excellent in etching property and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a low thermal expansion alloy for electronic parts free from the generation of etching defects such as the unevenness of stripes or the like causing the local deterioration in the visibility of an image and capable of etching with high precision and to provide a method for producing it. SOLUTION: An ingot melted by an ingot making method or a slab melted by a continuous casting method, composed of an Fe-Ni series alloy contg., by weight, 30 to 45% Ni or composed of an Fe-Ni-Co series alloy contg. 20 to 40% Ni and <=7% Co, and in which the total content of Ni+Co is made to 27 to 40% is subjected to blooming or forging in such a manner that, in the case the ratio of the thickness (a) of the equi-axed crystals in the center part obtd. from the cross-section to the total thickness (b) of the slab, i.e., a/b is a/b<0.2, the draft is made to >=40%, in the case of a/b=0.2 to 0.5, the draft is made to >=20%, and in the case of a/b>0.5, the draft is made to >=5% and is thereafter subjected to hot rolling and cold rolling to obtain a low thermal expansion alloy for electronic parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-thermal-expansion alloy used for electronic parts subjected to fine etching such as a shadow mask and a lead frame, and more particularly, to a high-definition shadow mask used for a computer display. The present invention relates to a low thermal expansion alloy excellent in etching properties and a method for producing the same.

[0002]

2. Description of the Related Art Electronic parts such as shadow masks and lead frames are generally used after being subjected to etching.
At this time, there is a demand for a material having a high etching rate and a high etching property which is excellent in the end shape and dimensional accuracy of the hole after etching.

Hereinafter, a shadow mask will be described as an example. Shadow masks are used in television cathode-ray tubes, and are used to provide a specific color tone by precisely irradiating an electron beam emitted from an electron gun to a predetermined position on a phosphor screen supported by a glass body. Has pores. In this case, about 20% of the emitted electron beam passes through the pores and is irradiated on the phosphor, and the remaining 8
Since the crack collides with the shadow mask, the temperature of the shadow mask becomes higher than that of the glass body supporting the phosphor screen. In addition, mild steel sheets such as low-carbon rimmed steel and low-carbon aluminum-killed steel that have been conventionally used as materials for shadow masks have a much larger coefficient of thermal expansion than the glass body that supports the phosphor screen, An electron beam cannot be accurately irradiated to a predetermined position on the phosphor screen due to a positional deviation between them, and the image often becomes unclear.

In order to prevent the image from becoming unclear, attempts have been made to compensate for the above-mentioned misalignment by devising a structure of a support which is a suspension position of the shadow mask, but it is not always sufficient. Absent. Further, in recent years, with the enlargement, higher quality, and higher luminance of television screens, these positional shift problems have become apparent.

[0005] Therefore, as a shadow mask material, Fe-Ni containing 36 wt% Ni, which is a low thermal expansion material, is used.
Use of base alloys is expanding. This alloy has a coefficient of thermal expansion of about 1/10 smaller than that of conventional low carbon steel, and maintains its low expansion property even with electron beam heating on a high-brightness screen. In the shadow mask thus manufactured, color shift due to thermal expansion hardly occurs.

[0006] Fe-Ni alloy thin sheets for shadow masks are usually produced by adjusting an alloy steel ingot by a continuous casting method or an ingot-making method, and then subjecting it to slab rolling, hot rolling, cold rolling and annealing. You. After forming an electron beam passage hole in the alloy thin plate by photo-etching, the shadow mask is manufactured by performing various processes such as annealing, molding, and blackening.

[0007] However, a shadow mask made of a Fe-Ni alloy thin plate has excellent low thermal expansion characteristics, but is poor in etching properties, so that it is difficult to obtain a good hole shape by photoetching. In some cases, poor definition of an image may occur due to poor etching.
Therefore, attempts have been made to improve the etching properties of this Fe—Ni-based alloy thin plate.

For example, in Japanese Patent Publication No. 59-32859, in order to make the hole shape after photoetching uniform over the entire shadow mask, the etching rate is kept constant by preventing the crystal orientation of the etching surface from being irregular. If necessary, the degree of orientation of the {100} crystal plane is improved to 35% or more to achieve improvement.

[0009]

However, in recent years,
With the enlargement of television screens and the expansion of applications to computer displays, the demand for finer images and higher brightness has been further increased, and as a result, holes for passing electron beams have been drilled with higher brightness. Etching has become necessary.

In particular, a high-definition shadow mask used for a computer display mainly has a thickness of 0.1 mm.
5 mm or less material is used, for example, 120 μm in diameter
Are pierced at a pitch of 270 μm, and further fine pitching is being attempted.

[0011] In order to accurately drill such fine holes in the etching surface, the material of the raw material has been improved together with the improvement of the etching technique, but the hole shape caused by the local etching defect still remains. Has occurred, which is one of the causes of the local poor definition of the image.

[0012] This etching defect is observed as fine linear unevenness in the mask portion along the rolling direction of the alloy thin plate, and is called "line unevenness". Most of the stripe unevenness has a width of several tens μm to several mm, and reaches from one side of the mask portion to the opposite side. It has been known that uneven stripes occur due to segregation of Ni or impurities, and several techniques have been proposed for the segregation diffusion treatment by soaking to suppress the uneven stripes.

For example, in Japanese Patent Application Laid-Open No. 2-54744, it is assumed that streak unevenness is caused by segregation of impurity elements such as C, Si, Mn, and Cr, or by a solidified structure at the time of casting. % Of B and heating the slab under specific conditions to prevent segregation, reduce the columnar crystal structure, and suppress streak unevenness. However, in actuality, in a material such as a shadow mask which requires fine etching and low thermal expansion, elements such as C, Si, Mn, and Cr are reduced to 1 wt% in total so as not to deteriorate the characteristics. The amount is reduced as much as possible, and streak unevenness due to such segregation cannot occur, and this technique does not eliminate uneven streak occurring in the Fe-36% Ni alloy thin plate. On the other hand, in the blackening process of the shadow mask, if B exceeds 0.02 wt%, uneven blackening occurs and local color shift occurs.

In Japanese Unexamined Patent Publication No. 60-128253, the cause of the stripe unevenness is the segregation of the Ni component,
By heating the Ni-based alloy steel ingot at a temperature of 850 ° C. to the melting point or less and forging with one or more heats and a cross-sectional reduction rate of 40% or more, to improve Ni segregation,
A method has been proposed in which the shape of the etching hole is improved and uneven stripes are eliminated. However, in a shadow mask for a computer display which needs to form finer etching holes at a high density, the cross-sectional reduction rate is simply reduced by 40%.
% Or more cannot eliminate line unevenness.

In Japanese Patent Publication No. 7-78270, continuous casting slabs having an equiaxed crystal ratio of 30% or less are heated at 1100 ° C. or more for at least one hour, and 950 ° C. if the equiaxed crystal ratio is less than 30%. The above suggests a method of eliminating streak unevenness by heating for one hour or more. However, simply changing the heating conditions according to the magnitude of the equiaxed crystal ratio cannot eliminate streak unevenness in a computer display shadow mask that needs to drill finer etching holes at a high density. is there.

As described above, even if any of the above techniques is used, it is not possible to effectively prevent uneven stripes due to etching, such as occurs in an Fe-36% Ni alloy thin plate. With the progress of etching, etching defects such as uneven stripes tend to increase, and a countermeasure is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an electronic component capable of performing high-precision etching without causing etching defects such as stripe unevenness that causes a local decrease in image sharpness. It is an object of the present invention to provide a low thermal expansion alloy for use and a method for producing the same.

[0018]

Means for Solving the Problems The present inventors have proposed Fe-N
As a result of various studies on the etching properties of the i-type low thermal expansion alloy thin plate, it was found that not only the above-mentioned streak unevenness but also the etching failure was caused not only by the concentration fluctuation amount of Ni microsegregation but also by hot rolling and cold rolling. It was also found that it was influenced by the morphology of the solidified structure inside the steel plate.

That is, when the cross-sectional structure of the solidified steel ingot (ingot casting method) or slab (continuous casting method) is all columnar crystal structure, the ingot or slab has a rolling reduction of 20% and is subjected to slab rolling. The sheet was subjected to soaking at 1250 ° C. for 40 hours, hot rolled, and repeatedly manufactured by repeatedly performing cold rolling and annealing.
When uneven rolling occurs in the etching of a thin plate having a thickness of 75 mm, when the slab is rolled at a reduction rate of 75%, the strip unevenness occurs in the etching of a thin plate manufactured under the same conditions except for the rolling reduction of the slab. Did not occur. Therefore, in the case of the columnar crystal structure, the rate of occurrence of uneven stripes differs even under the same heating conditions depending on the rolling reduction in slab rolling or forging.

On the other hand, when the columnar crystal structure and the equiaxed crystal structure are mixed in the cross-sectional structure of the solidified steel ingot or slab, as the equiaxed crystal ratio increases, the reduction rate of the strip in the bulk rolling or forging increases. The effect on unevenness is small, and the equiaxed crystal ratio is 50
% Or more, it was clear that it was not necessary to apply the reduction by slab rolling.

This is due to the fact that, in the columnar crystal structure, a thin plate-like segregation structure exists as a stack of columnar crystals after hot rolling, cold rolling and annealing. The dendrites of the columnar crystals are Fe-enriched and Ni-enriched between the trees, and the amount of dissolution in the etching is different, so that unevenness occurs at the interface of the pores, and the reflection state of the transmitted light changes. When the rolling reduction of the slab rolling and forging is small, the columnar crystal structure extends obliquely in the sheet thickness direction, and is easily recognized as streak unevenness. When the rolling reduction at the time of bulk rolling and forging is large, the columnar crystal structure becomes parallel and it becomes difficult to recognize streak unevenness.

On the other hand, in the equiaxed crystal structure, even after cold rolling and annealing after hot rolling, since the equiaxed crystal is only extended linearly and not in a plate shape, the rolling reduction is small. In both cases, the solidified structure does not extend obliquely in the plate thickness direction, and the influence of the rolling reduction on the occurrence of uneven stripes is small. That is,
It is necessary to control the rolling reduction of the steel ingot or slab to be used according to the mixed state of the columnar crystal structure and the equiaxed crystal structure as well as the soaking condition.

The present invention has been made based on such findings, and firstly, a steel made of an Fe—Ni-based alloy containing 30 to 45 wt% of Ni and melted by an ingot-making method. The reduction ratio of the slab produced by the ingot or continuous casting method is shown below in correspondence with the ratio a / b of the thickness a of the equiaxed crystal at the center to the total thickness b of the slab obtained from the sectional view thereof. And performing hot rolling and cold rolling after slab rolling or forging in the above-mentioned method, and provides a method for producing a low thermal expansion alloy for electronic parts having excellent etching properties. a / b <0.2 Reduction rate 40% or more a / b = 0.2-0.5 Reduction rate 20% or more a / b> 0.5 Reduction rate 5% or more

Second, Ni: 20 to 40 wt%, Co:
7 wt% or less, and Ni + Co is 27 to 40 w
A steel ingot made of an Fe-Ni-Co-based alloy having a t% and ingot produced by an ingot-making method or a slab produced by a continuous casting method is prepared by adding a thickness of an equiaxed crystal at a central portion obtained from a cross-sectional view thereof. The hot-rolling and cold-rolling are performed at the following reduction ratio corresponding to the ratio a / b to the total thickness b of the slab a, and then hot rolling and cold rolling are performed. An object of the present invention is to provide a method for producing an excellent low thermal expansion alloy for electronic components. a / b <0.2 Reduction rate 40% or more a / b = 0.2-0.5 Reduction rate 20% or more a / b> 0.5 Reduction rate 5% or more

Third, the present invention provides a low-thermal-expansion alloy for electronic parts which is excellent in etching properties and manufactured by the first manufacturing method.

Fourth, the present invention provides a low-thermal-expansion alloy for electronic parts which is excellent in etching properties and manufactured by the second manufacturing method.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, in order to obtain a sufficiently low thermal expansion property so as not to cause a dimensional change or a positional shift that deteriorates the performance of an electronic component, Fe containing 30 to 45 wt% of Ni is used.
-Use a Ni-based alloy. By using such an alloy, the average coefficient of thermal expansion from room temperature to 100 ° C. is 2.0 × 10
Low thermal expansion of ^-6 / ° C or less is realized.

In another embodiment of the present invention, 7w
An Fe-Ni-Co alloy to which t or less Co is added is used. In this case, Ni: 20 to 40 wt%, Co:
7 wt% or less, and Ni + Co is 27 to 40 w
t%. By using an alloy having such a composition, the same low thermal expansion property as that of the above-described Fe—Ni-based alloy can be obtained. If the Co content exceeds 7 wt%, the etching property is remarkably reduced. Therefore, the upper limit of the Co content is set to 7 wt%.

The alloy used in the present invention may be, in addition to the above elements, S as long as the effects of the present invention are not impaired.
i, Mn, B, N, O, etc. may be contained, but Si ≦
0.07wt%, Mn ≦ 0.5wt%, B ≦ 0.02w
It is desirable to limit the range to t%, N ≦ 0.005 wt%, and O ≦ 0.002 wt%.

Of these elements, Si can be used as a deoxidizing element for molten steel. However, if present in excess, it is concentrated in the surface layer of the sheet during the blackening treatment and hinders the formation of a homogeneous black oxide film. It is desirably 0.07 wt% or less. Mn is useful for ensuring good hot workability, but when present excessively, it lowers the etching property, and in the blackening treatment, it concentrates on the surface layer of the plate, hindering the formation of a uniform and black oxide film. Therefore, the content is desirably 0.5 wt% or less. B has the effect of improving hot workability and suppressing scale formation. However, if B is excessively present, it is concentrated on the surface layer of the plate during the blackening treatment and inhibits the formation of a uniform black oxide film. It is desirable to make the following. Since N causes deterioration of press workability and etching property, it is preferable to set N to 0.005 wt% or less. O inhibits the growth of crystal grains during softening annealing before pressing and degrades the press formability. Therefore, the content of O is preferably 0.002 wt% or less.

In order to obtain a low-thermal-expansion alloy sheet having the above-mentioned composition, in the present invention, first, an alloy having the above-mentioned composition is melted in a converter or an electric furnace, and slab (continuous casting) is performed by a continuous casting method or an ingot casting method. Method (in the case of the ingot casting method) or ingot (in the case of the ingot making method). In this case, if the equiaxed crystal ratio represented by a / b in the sectional view shown in FIG. 1 is less than 0.2, the reduction ratio of the slab or the steel ingot is 40% or more, and the equiaxed crystal ratio is 0.2. Bulking or forging is performed so that the rolling reduction is 20% or more at 0.5 to 0.5% and the rolling reduction is 5% or more when the equiaxed crystal ratio is 0.5 or more to a thickness of 120 to 300 mm.

Here, in the continuous casting method, the equiaxed crystal structure is as follows:
Low temperature casting at T = 20 ° C. or less (ΔT: temperature measurement of tandishes-liquidus temperature of Fe—Ni alloy according to the present invention)
And the molten metal is stirred by an electromagnetic stirring device (EMS). Ingot casting is obtained by ultrasonic vibration instead of cold casting and electromagnetic stirring. On the other hand, the columnar structure is △
Obtained by high-temperature casting at T> 20 ° C. In the present invention, since the draft is defined in accordance with the equiaxed crystal ratio, it is not necessary to specify the equiaxed crystal ratio itself. A predetermined equiaxed crystal ratio can be obtained by changing electromagnetic stirring conditions or ultrasonic vibration conditions.

Prior to slab rolling or forging, soaking can be performed from the viewpoint of microsegregation diffusion. The conditions at that time are a heating temperature of 1000 ° C. or more and a holding time of 1 hour or more.

FIG. 2 shows that the etching hole pitch is 300.
For thin plates of μm or less, the equiaxed crystal ratio of the steel ingot smelted by the ingot-making method and the slab smelted by the continuous casting method, and the rolling reduction during slab rolling or forging, of the produced shadow mask It is a figure which shows the influence which has on the presence or absence of the generation | occurrence | production of the stripe unevenness. Details of the manufacturing conditions at this time are shown in Table 2 in Examples described later.

From FIG. 2, it is found that when the equiaxed crystal ratio is less than 0.2, the rolling reduction is in the range of 40% or more, and when the equiaxed crystal ratio is 0.2 to 0.5, the rolling reduction is in the range of 20% or more. In the range where the crystallinity exceeds 0.5, the reduction ratio is in the range of 5% or more, and the plate thickness is 0.09 to
It is clear that this is a region in which stripe unevenness does not occur in a shadow mask etched from a 0.25 mm thin plate.

As described above, in a solidified structure in which columnar crystals having an equiaxed crystal ratio of less than 0.2 are dominant, good results can be obtained when the rolling reduction is 40% or more. This is because, even after the cold rolling, the sheet exists obliquely with respect to the sheet thickness direction and uneven stripes easily occur. On the other hand, when the rolling reduction is 40% or more, the columnar crystals are crushed and such a phenomenon does not occur.

When the equiaxed crystal ratio is 0.2 to 0.5, as shown in FIG. 1, the center of the solidified structure becomes equiaxed and the rolling reduction is 20%.
% Or more gives good results. This is because even if the columnar crystal structure exists obliquely to the sheet thickness direction even after cold rolling, the influence of the columnar crystal is reduced because the equiaxed crystal structure remains in the center of the sheet thickness, and the equiaxed crystal ratio Is less than 0.2, the oblique columnar crystals are less noticeable. However, when the rolling reduction is less than 20%, the inclination angle of the columnar crystal with respect to the plate thickness direction becomes large, and uneven streaks tend to occur. Such a phenomenon does not occur when the rolling reduction is 20% or more.

In a solidified structure in which equiaxed crystals having an equiaxed crystal ratio of 0.5 or more are dominant, the rolling reduction has no effect on the occurrence of streak unevenness. However, when the rolling reduction is less than 5%, the work amount and productivity of the steel ingot and the slab by the oxide scale and the sub-scale increase, and the workability and productivity are deteriorated. Therefore, 5%
Block rolling or forging is performed at the above reduction ratio. This cracks the oxide scale and the subscale and causes them to separate, reducing the amount of care. At a rolling reduction of less than 5%, the grain boundary oxidized portion extends long inside the alloy, and the grain boundary oxidized portion hardly cracks, so that the amount of care increases.

It is not always necessary to specify the upper limit of the rolling reduction for the purpose of the present invention, but about 90% is almost the upper limit due to equipment restrictions.

Thereafter, heat treatment is performed at 1000 ° C. or more for 1 hour or more, and a hot-rolled steel sheet having a thickness of 2 to 4 mm is obtained by hot rolling. About this hot-rolled steel sheet, cold rolling and annealing at 750 ° C. or more are performed once or more, and the thickness is 0.09 to 0.25 m.
m is manufactured. At this time, the cumulative rolling reduction from the steel ingot or slab to the thin plate is 99.9% or more. As a result, the desired low thermal expansion alloy thin plate for electronic components can be obtained.

The present invention is generally applied to an alloy thin plate for an electronic component to be etched. Particularly, the present invention is applied to a shadow mask having a hole pitch of 300 μm or less by etching with high precision and low thermal expansion. It is suitable as a method for producing a material. In the present invention, the shadow mask made of a Fe-Ni-based or Fe-Ni-Co-based alloy thin plate having a low thermal expansion characteristic has a small displacement due to thermal expansion, so that an image of a cathode ray tube using the same is sharper. .

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the alloy thin plate of the present invention is used as a material for a shadow mask will be described below. Table 1 shows the chemical composition of the steel used in this example. Here, four types A to D, which can obtain low thermal expansion characteristics, blackening properties and press moldability required as a material for a shadow mask, were melted.

[0043]

[Table 1]

Some of the ingots and slabs obtained by melting these steels were partially heated at 1100-1300 ° C. for 5-5 hours.
A heat treatment for 0 hour was performed, and then slab rolling or forging was performed. Subsequently, heat treatment is performed at 1000 to 1200 ° C. for 30 minutes to 5 hours, followed by hot rolling to a thickness of 2.0 to
A hot-rolled steel sheet of 4.0 mm was obtained. Cold rolling and 700
Annealing at a temperature of at least ℃ is performed 1 to 4 times to obtain a sheet thickness of 0.09 to
The thin plate No. 1 to 25 were produced. In addition, No. Nos. 1 to 20 are examples of the present invention. 2
1 to 25 are comparative examples.

These Nos. Table 2 shows the soaking conditions and rolling reductions of steel ingots and slabs when 1 to 25 thin plates were manufactured. The presence or absence of poor etching was evaluated for thin plates manufactured using these steel ingots and slabs. Table 2 also shows the results.

[0046]

[Table 2]

The etching performance was evaluated by performing a photoetching hole test using a photomask having an electron beam passing hole diameter of 120 μmφ and a hole pitch of 270 μm. Presence and processing accuracy were determined. The photoetching at this time was performed under the conditions of spraying an aqueous solution of ferric chloride having a solution temperature of 60 ° C. and a concentration of 47 Baume at a spray pressure of 2.0 kgf / cm ² . Whether there is an etching defect
It was determined by visual observation using transmitted light and reflected light using a one-way light source.

As shown in Table 2, No. 1 of the present invention was used.
In Nos. 1 to 20, the maintenance load on the steel ingot or the slab was small, and a low thermal expansion alloy thin plate with minute unevenness in the line was obtained.

On the other hand, in Comparative Example No. 21,
No. In No. 23, the thickness of the grain boundary oxidized portion was large, the slab care load was large, and uneven stripes due to Ni segregation occurred. N
o. 22, no. In No. 24, although the care load was small, uneven stripes occurred due to Ni segregation. No. In No. 25, the stripe unevenness was minute, but the care load of the slab was excessive.

[0050]

As described above, according to the present invention,
A low thermal expansion alloy for electronic components, which uses a Fe-Ni-based alloy or a Fe-Ni-Co-based alloy of a specific composition as a material, reduces the care load of ingots and continuous cast slabs, and hardly causes poor etching, and its production A method is provided. The low thermal expansion alloy for electronic components manufactured by the method of the present invention is particularly suitable as a material for a shadow mask used for a computer display requiring high-precision processing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a solidification structure of an Fe—Ni alloy.

FIG. 2 is a diagram showing the influence of the equiaxed crystal ratio and the rolling reduction on the etching property and the manufacturability.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Awajiya 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) Inventor Masami Komatsu 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (72) Takashi Ariizumi, 1-2-1, Marunouchi, Chiyoda-ku, Tokyo

Claims (4)

[Claims] 1. Fe containing 30 to 45% by weight of Ni.
A slab made of a Ni-based alloy and ingot produced by the ingot casting method or a slab produced by the continuous casting method is subjected to a slab total thickness b having an equiaxed crystal thickness a at a central portion obtained from a sectional view thereof; Low-expansion alloy for electronic parts excellent in etching properties, which is subjected to slab rolling or forging at a reduction ratio as shown below corresponding to the ratio a / b to hot rolling and cold rolling. Manufacturing method. a / b <0.2 Reduction rate 40% or more a / b = 0.2-0.5 Reduction rate 20% or more a / b> 0.5 Reduction rate 5% or more 2. Ni: 20 to 40 wt%, Co: 7 wt%
% Or less, and a slab made of an Fe-Ni-Co-based alloy in which Ni + Co is 27 to 40 wt% and ingot by an ingot method or ingot by a continuous casting method.
After slab-rolling or forging at a reduction ratio as shown below corresponding to the ratio a / b of the thickness a of the equiaxed crystal at the center determined from the cross-sectional view to the total thickness b of the slab, hot rolling and A method for producing a low-thermal-expansion alloy for electronic components having excellent etching properties, characterized by cold rolling. a / b <0.2 Reduction rate 40% or more a / b = 0.2-0.5 Reduction rate 20% or more a / b> 0.5 Reduction rate 5% or more 3. A low-thermal-expansion alloy for electronic parts, which has excellent etching properties and is manufactured by the manufacturing method according to claim 1. 4. A low-thermal-expansion alloy for electronic parts having excellent etching properties, which is manufactured by the manufacturing method according to claim 2.