JP3369612B2 - Manufacturing method of aluminum foil for printed coil board - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum foil for a printed coil substrate used for manufacturing a small-sized printed coil for a motor or a printed coil for a sensor. is there. 2. Description of the Related Art Conventionally, motor coils are enameled wires,
A coil wound with formal wire etc. was used, but in recent years, with the miniaturization and thinning of audio equipment and video equipment etc., a printed coil in which a conductive material such as electrolytic copper is provided in a coil pattern on an insulating substrate Is often used.
Such a printed coil is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-91.
As shown in JP-A-590, it is manufactured through the following steps (a) to (d). (A) a step of forming a resist on a portion other than a pattern portion on a substrate using a metal foil such as an aluminum foil as a substrate, and (b) forming a conductor such as copper by electrolytic plating on the pattern portion using the substrate as a cathode. (C) attaching a conductor to an insulating substrate with the metal foil facing upward, and (d) etching and removing the metal foil. Conventionally, when manufacturing such a printed coil, J is used as a metal foil for a printed coil board.
Aluminum having a chemical composition specified by IS H4160 1N30 cold-rolled to a predetermined thickness was used. [0004] However, such a conventional aluminum foil for a printed coil board is formed by subjecting an aluminum ingot to cold rolling to form a predetermined thickness. However, when the ratio of the hydrated oxide film in the oxide film formed on the surface of the aluminum foil in the aluminum foil manufacturing process (hereinafter referred to as the hydration rate in the oxide film) is high, the hydrated oxide film is porous. Because the film itself causes cohesive failure and the adhesion between the resist and the aluminum foil surface in the step (a) is deteriorated,
In the step (b), the conductor formed by electrolytic plating protrudes outside the pattern portion, and is likely to be short-circuited by contact with the next conductor, thereby increasing the wiring density of the conductor. It was difficult. The present invention solves the above-mentioned problems of the conventional aluminum foil for a printed coil board, and reduces the hydration rate of an oxide film formed on the surface of the aluminum foil to reduce the resist and the aluminum foil. The present invention provides an aluminum foil for a printed coil board that has improved the adhesiveness of the conductor, has no risk of short-circuiting of the conductor, and can increase the wiring density of the conductor, and during the cold rolling during the production of the aluminum foil. The conditions of the intermediate annealing and the cold rolling performed in the aluminum foil for the printed coil board are appropriate for the aluminum foil for the printed coil board, and the hydration rate of the oxide film formed on the surface of the aluminum foil for the printed coil board is reduced to thereby reduce the resist and the aluminum. Improves adhesion to foil, eliminates the possibility of short-circuiting of the conductor, and increases the wiring density of the conductor. It is an object to provide a Ntokoiru manufacturing method of an aluminum foil substrate. [0006] The present invention relates to a method of manufacturing an aluminum foil for a printed coil board,
After homogenizing an aluminum ingot with an aluminum purity of 99.0 to 99.9%, perform hot rolling and cold rolling, perform intermediate annealing at a temperature of 200 ° C. or more with an appropriate thickness, and then once A method for producing an aluminum foil for a printed coil board, characterized in that the aluminum foil is rolled to a predetermined thickness by cold rolling with a rolling amount of 0.5 mm or less. According to the present invention, an aluminum ingot having an aluminum purity of 99.0 to 99.9% is subjected to a homogenizing treatment, then subjected to hot rolling and cold rolling, and then to an appropriate thickness of 200 ° C. or more. A method of manufacturing an aluminum foil for a printed coil board, characterized in that intermediate annealing is performed at a temperature, and then rolling is performed to a predetermined thickness by cold rolling with a rolling amount of 0.5 mm or less per time. Since the production of aluminum foil is performed with the rolling amount per cold rolling reduced, the ratio of the hydrated oxide film of the oxide film on the surface of the aluminum foil generated during cold rolling is extremely small. Hydration rate of the film is 3
It is possible to form an aluminum foil for a printed coil substrate while suppressing the content to 0% or less. The above aluminum
The hydration rate of the oxide film on the surface of the aluminum foil is, for example,
The O ₁ s spectrum of the foil surface was measured by
The spectrum is divided into a peak by Al-O and a peak by Al-OH.
O ₁ s peak of Al-OH peak
It is calculated as the area ratio to the area. Figure 1 shows the XPS
An example of the analysis result is shown. That is, in the manufacturing process of the aluminum foil, the oxide film on the surface of the aluminum foil is mainly formed by hot rolling and cold rolling with a large initial cold rolling amount. The oxide film is hydrated rate by processing heat of the material for a large amount of rolling of the cold rolling is generated becomes high coating inventors result of intensive consider, way cold rolling of aluminum plate It is found that the hydration rate can be reduced by the intermediate annealing performed in
The hydration rate of the oxide film can be reduced to 30 ° C. or more by setting the rolling amount per cold rolling to 0.5 mm or less.
% Or less can be formed. Therefore, according to the manufacturing method of the present invention, the hydration ratio of the oxide film on the aluminum foil surface is reduced to 30% or less by performing the conditions of the intermediate annealing and the conditions of the cold rolling in an appropriate combination. An aluminum foil for a printed coil board having excellent adhesion can be formed stably. When the temperature of the intermediate annealing is lower than 200 ° C., the hydration ratio of the oxide film does not drop below 30%.
The temperature is required to be not lower than 00 ° C., but the lower the temperature, the longer the intermediate annealing takes. The thickness of the aluminum plate during the intermediate annealing is not limited.
If the thickness exceeds 5 mm, the hydration rate of the oxide film becomes high. Therefore, it is preferable to perform the intermediate annealing after reducing the thickness to 2 mm or less from the viewpoint of the productivity of the cold rolling after the intermediate annealing. [0012] And it is manufactured by the manufacturing method of the present invention.
Aluminum foil for printed coil boards is made of aluminum
Aluminum purity of 99.0 to 99.9%.
Giant metal compounds with high luminium purity and impurities
It is not generated during electroplating of conductors.
The conductor is now plated evenly, resulting in missing plating
There is no occurrence of defective wiring. In addition, in the surface oxide film of the aluminum foil
Since the proportion of the hydrated oxide film of
The film on the surface of the aluminum foil itself does not cause cohesive failure.
Excellent adhesion between resist and aluminum foil surface
The conductor formed by electrolytic plating after resist formation
The protrusion does not protrude outside the loop portion. [0014] Further, the present invention is manufactured by the manufacturing method of the present invention.
Aluminum foil for printed coil board is aluminum
The percentage of hydrated oxide film in the surface oxide film of the foil is 30% or less
And when the thickness of the oxide film is 60 ° or less,
The oxide film is thin and cohesive failure of the film itself is further prevented
It has excellent adhesion of the resist, the resist is Arumini c
Resist and aluminum without peeling from the foil
Electroplating without gaps between foil
Conductive material is prevented from entering such gaps,
The body is accurately plated on the printed coil pattern
It does not protrude outside the pattern section. The oxide film has a hydrated oxide film ratio of 30.
%, The thickness of the oxide film is as thin as 60 mm or less.
Even if the
Peeled from minium foil and formed by electrolytic plating
Conductor protrudes outside the pattern area and is adjacent to the conductor
Hydrated oxide film
Is set to 30% or less. The thickness of the aluminum foil for a printed coil substrate obtained by the present invention is preferably in the range of 10 to 300 μm, and more preferably in the range of 20 to 200 μm from the viewpoint of handleability and productivity. In other words, with a foil thickness of 10 μm or less, it is difficult to handle because it has no rigidity,
If the thickness is 300 μm or more, it takes a long time to remove the etching when manufacturing the print coil, and the productivity of the print coil is reduced. Embodiment 1 Next, an embodiment of an aluminum foil for a printed coil board according to the present invention will be described. Aluminum having the composition shown in Table 1 (the component other than Fe and Si is aluminum and contains some other unavoidable impurities). Intermediate annealing at 350 ° C. for 10 hours with a thickness of 0.0 mm, and then cold rolling four times (first time from 1.0 mm to 0.6 mm)
mm the second time from 0.6 mm to 0.3 mm and the third time from 0.3 mm to 0.3 mm.
2 mm and the fourth time from 0.2 mm to 0.1 mm) to obtain an aluminum foil having a thickness of 100 μm. This aluminum foil was used as a substrate, and the following steps (A) to (D) were performed.
Printed coils having conductor widths and conductor intervals shown in Nos. To 8 were manufactured. The manufacturing process includes: (A) forming a resist on a portion other than the pattern portion on the substrate; (B) forming a copper conductor by electrolytic plating on the pattern portion using the substrate as a cathode; and (C) forming a conductor on the insulating substrate. (D) Etching and removing the aluminum foil. Comparative Example 1 On the other hand, as Comparative Example 1, aluminum having a composition with a lower aluminum purity than that of Example 1 shown in Tables 9 to 14 (the component other than Fe and Si is aluminum and other unavoidable impurities) The ingot was subjected to cold rolling under the same conditions as in Example 1 to obtain an aluminum foil having a thickness of 100 μm, and the printed coil was subjected to the above steps (A) to (D). Was manufactured. [Table 1] (1) The number of plating omission defects was determined by observing the number of plating omission defects having a diameter of 5 μm or more in three concentric coil conductors by microscopic observation. As is clear from Table 1, Example 1 of the present invention
Printed coils manufactured using the aluminum foils according to Nos. To 8 as substrates had no defective plating of the conductor portion, and could be suitably used as aluminum foil for printed coil substrates. Embodiment 2 As Embodiment 2 of the present invention, 0.5% Fe and S
aluminum containing 0.1% of i (a component other than Fe.Si is aluminum and contains some other unavoidable impurities). The ingot is homogenized, hot-rolled, and cold-rolled. A sheet thickness condition shown in Table 2 with a sheet thickness of 1.0 mm,
Intermediate annealing is performed under intermediate annealing conditions (temperature, time conditions)
Thereafter , an aluminum foil was obtained by performing cold rolling the number of times shown in Table 2 so that the amount of cold rolling per time was 0.5 mm or less. Example 1 was prepared using this aluminum foil as a substrate.
Through the same manufacturing process as, 1-12 to show the conductor width of the table 2, were produced printed coil with conductor spacing. Table 2 shows the results of observing the state of contact between adjacent conductors for the obtained printed coil. In addition, the results of measuring the thickness of the surface oxide film on the aluminum foil and the hydration rate of the oxide film were calculated using XP.
Table 2 shows the results obtained by the S analysis. Comparative Example 2 On the other hand, as Comparative Example 2 , intermediate annealing was performed under the intermediate annealing conditions (temperature and time conditions) shown in Table 3 , and thereafter ,
An aluminum foil was obtained by cold rolling the number of times shown in Table 3 under different intermediate annealing conditions and cold rolling conditions than in Example 2 for the amount of cold rolling per time. Using this aluminum foil as a substrate, printed coils having conductor widths and conductor intervals shown in Tables 13 to 24 in Table 3 were produced through the same production steps as in Example 1. Table 5 shows the results of observing the state of contact between adjacent conductors in the obtained printed coil. Also,
Table 3 shows the results obtained by measuring the thickness of the surface oxide film on the aluminum foil and the results obtained by XPS analysis of the hydration rate of the oxide film. [Table 2] The "number of conductor contact points" in Table 2 was determined by observing the number of adjacent conductors in 10 concentric coil conductors by microscopic observation. [Table 3] The "number of conductor contact points" in Table 3 was counted by observing how many adjacent conductors were present in 10 concentric coil conductors. As is clear from Table 2, Example 2 of the present invention
The printed coil manufactured using the aluminum foil according to the above as a substrate has excellent adhesiveness of the resist, there is no contact between adjacent conductors, and it is also suitable for a case where the wiring density is high as an aluminum foil for a printed coil substrate. It could be used for On the other hand, in Comparative Example 2 in Table 3 , when used as an aluminum foil for a printed coil board due to the relationship between the thickness of the oxide film and the hydration rate, the distance between the adjacent conductor and the aluminum foil was 10%.
Contact was observed at more than three places, and the defect rate was high. As described above, according to the present invention , an aluminum ingot having an aluminum purity of 99.0 to 99.9% is subjected to a homogenizing treatment, then subjected to hot rolling and cold rolling, and then to an appropriate thickness. An aluminum foil for a printed coil substrate characterized by being subjected to intermediate annealing at a temperature of 200 ° C. or more at a sheet thickness, and then rolling to a predetermined sheet thickness by cold rolling with a rolling amount per time of 0.5 mm or less. Since it is a manufacturing method, it can be manufactured by setting the hydration rate of the oxide film on the aluminum foil surface to 30% or less, whereby the printed coil substrate has excellent resist adhesion and does not cause a short circuit of the conductor. For efficient production of aluminum foil for
An aluminum foil for a printed coil having a high-density pattern in which the width and interval of the conductor are reduced can be stably supplied.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 XS for determining hydration rate of oxide film in the present invention
Explanatory drawing explaining P analysis.

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Claims (1)

(57) [Claims] [Claim 1] After homogenizing an aluminum ingot having an aluminum purity of 99.0 to 99.9%, performing hot rolling and cold rolling, and then appropriately adjusting the thickness of the ingot. perform intermediate annealing at 200 ° C. or higher, a manufacturing method of an aluminum foil for printed coil substrate, characterized by rolling to a predetermined thickness rolling amount by the following cold rolling 0.5mm per thereafter once.