JPH0443980B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a material for fine etching, and more particularly to a material for fine etching such as a high-definition shadow mask. [Conventional technology] Most IC lead frames have a thickness of 0.10 to 0.30 mm.
It is manufactured from a 42% nickel-iron alloy called 42 alloy by press punching or etching. In addition, although aluminum killed steel has traditionally been used for color cathode ray tube shadow masks, amber material (36% nickel-iron alloy), which has a small coefficient of thermal expansion, has also come to be used.
In addition, it can also be used as a material for various electronic components such as display tubes.
Nickel-iron alloys such as 50% nickel-iron alloy and 52% nickel-iron alloy are used. Products manufactured by such etching processes have a wide tolerance for dimensional accuracy, and the straightness and roundness of the shapes created by etching processes are not very strict, and can be adequately handled by conventional technology. It was hot. However, high-pin products with 100 to 160 pins in lead frames,
There have been several technical problems with microfabricated products such as high-definition shadow masks with a pitch of 0.2 to 0.3 mm, as described below. First, when etching fine-pitch lead frames, shadow masks, and other electronic components, the etching time becomes longer, which reduces the adhesion between the photoresist and the material, and the processed parts of the product formed by etching. There was a problem that the straightness and roundness were impaired. Second, there was a problem in that the cross section formed by etching became rough, resulting in a rough shape. For example, in a shadow mask, such arabi subtly affects the unevenness, and the quality of the mask as a whole deteriorates. Third, inclusions of a size that is not a practical problem in lead frames with a small number of pins and consumer-use shadow masks become a problem in lead frames with a large number of pins and high-definition shadow masks, resulting in a reduction in yield in the etching process. It was hot. [Problems to be Solved by the Invention] Therefore, the problem to be solved by the present invention is to provide a material for fine etching that eliminates the above-mentioned conventional drawbacks. [Means for solving the problems] As a result of research to solve the above problems, the present inventor reduced the carbon content in the material to 0.01% or less, and
Cross-sectional cleanliness specified by JIS G 0555
It was discovered that the intended purpose could be achieved by reducing the content to 0.017% or less, and the present invention was completed based on this knowledge. That is, the gist of the present invention is to produce a 42% Ni-Fe alloy or
In a nickel-iron alloy material for etching made of 36% Ni-Fe alloy, the carbon content in the material is 0.01% or less, and the cross-sectional cleanliness specified by JIS G 0555 is 0.017% or less. It is a material for fine etching processing characterized by the following. Here, 42% Ni-Fe alloy and 36% Ni-Fe alloy are, for example, Military Standard (MIL-I-Fe alloy).
23011C (March 29, 1974) “IRON-NICKEL
ALLOYS FOR SEALING TO GLASSES
AND CERAMICS” (Table Class5,
The so-called 42% of public knowledge stipulated in Class 7))
Alloy, 36% alloy, and specifically means a Ni-Fe alloy containing about 42% Ni or about 36% Ni. [Function] Accordingly, in the present invention, by reducing the carbon content to 0.01% or less, the etching rate is increased and the arabic problem is eliminated. The etching rate of nickel-iron alloys varies depending on the nickel content, and tends to be faster as the nickel content decreases, but when the nickel content is 50
As a result of investigating nickel-iron alloys of less than %
A common phenomenon was observed in multiple nickel-iron alloys with different nickel contents: the etching rate is faster when the carbon content is 0.01% or less. Figure 1 shows the variation of etching rate with carbon content determined for a 42% nickel-iron alloy. As is clear from this figure, the carbon content is 0.02
%, the etching rate is 1.25 to 1.30 when the carbon content is 0.01% or less, which is 25% to 30% faster than when the carbon content is 0.02%. FIG. 2 also shows the change in etching rate with carbon content determined for a 36% nickel-iron alloy. Similarly, the carbon content is 0.01 for 36% nickel-iron alloy and 42% nickel-iron alloy.
% or less, the etching speed becomes faster. Further, by reducing the carbon content to 0.01% or less, defects caused by carbide inclusions are substantially eliminated. Table 1 shows the relationship between the defect rate due to carbide inclusions and the carbon content of 0.3 mm pitch high-definition shadow masks.

[Table] As is clear from this table, the carbon content is 0.01%
In the following cases, the defect rate due to carbide inclusions is 0%. Next, in the present invention, by setting the cross-sectional cleanliness specified by JIS G 0555 to 0.017% or less, the material can be cleaned to the extent that the presence of non-metallic inclusions in the material does not substantially impede microfabrication. The number of nonmetallic inclusions therein is reduced. In iron-nickel alloys, the carbon content
If the content is 0.01% or less, non-metallic inclusions in the material will
The main components are oxides of elements such as Al, Si, Mn, and Ca. Among these oxides, those with a size of 10 μm or more pose a problem in microfabrication. Table 2 shows the relationship between the cross-sectional cleanliness of non-metallic inclusions specified in JIS G 0555 and the number of non-metallic inclusions having a size of 10 μm or more (number per 10 mm x 10 mm).

【table】

〔Example〕

Example 1 0.25 on one side of a material made of a nickel-iron alloy with a plate thickness of 0.13 mm, Ni%: 35.7%, C%: 0.004%, and a cross-sectional cleanliness of 0.004% according to JIS G 0555.
A first resist pattern having a large number of large circular dot-shaped openings (diameter 0.150 mm) arranged at a pitch of 0.1 mm is provided, and the other side has a large number of small circular dot-shaped openings (0.090 mm diameter) arranged at a pitch of 0.25 mm. A second resist pattern with a liquid temperature of 60°C was prepared.
Using 46°Be′ FeCl ₃ etchant, spray etching was performed from both sides at a spray pressure of 20 kg/cm ² to form a large number of holes with a diameter of 0.220 mm in the large hole and 0.110 mm in the small hole. I got it. Example 2 Ni% of plate thickness 0.15mm; 41.5%, C%; 0.007%,
A 160-pin lead frame resist pattern is provided on both sides of a material made of nickel-iron alloy with a cross-sectional cleanliness of 0.008% according to JIS G 0555, and the liquid temperature is 70%.
The product was obtained by spray etching from both sides using a 48° Be′ FeCl ₃ etchant at a temperature of 20 Kg/cm ² at a spray pressure of 20 Kg/cm 2 . [Comparative Example] Comparative Example 1 Example 1 for a material made of a nickel-iron alloy with a plate thickness of 0.13 mm, Ni%: 35.5%, C%: 0.022%, and a cross-sectional cleanliness of 0.033% according to JIS G 0555.
After resist plate making in the same manner as above, the liquid temperature was 60℃.
Using 46°Be′ FeCl ₃ corrosive solution, spray etching was performed from both sides at a spray pressure of 20 kg/cm ² to form a large number of holes with a diameter of 0.220 mm in the large hole and a diameter of 0.110 mm in the small hole to obtain the product. Ta. Comparative example 2 Ni% of plate thickness 0.15mm; 41.8%, C%; 0.023%,
Resist plate making was performed in the same manner as in Example 2 on a material made of nickel-iron alloy with a cross-sectional cleanliness of 0.050% according to JIS G 0555, and then
A product was obtained by spray etching from both sides using a 48°Be′ FeCl ₃ etchant at a spray pressure of 20 Kg/cm ² . Table 4 shows the results of Examples 1 and 2 and Comparative Examples 1 and 2.

〔Effect of the invention〕

As detailed above, the material of the present invention allows fine etching to be performed quickly and with high precision.
No arabi was observed, and no etching defects due to non-metallic inclusions were observed, making it possible to produce etched products of good quality.

[Brief explanation of drawings]

Figure 1 is a graph showing the change in etching rate depending on the amount of carbon determined for a 42% Ni-Fe alloy.
FIG. 2 is a graph showing the change in etching rate depending on the amount of carbon determined for a 36% Ni--Fe alloy.

Claims (1)

[Claims] Plate thickness 0.020 to 0.40 manufactured by cold rolling
A nickel-iron alloy material for etching made of 42% Ni-Fe alloy or 36% Ni-Fe alloy of mm, the carbon content of which is 0.01% or less, and specified by JIS G 0555. A material for fine etching processing characterized by a cross-sectional cleanliness of 0.017% or less.