JP2743668B2 - Method for producing rolled copper alloy foil for film carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rolled copper alloy foil for a film carrier, and more particularly to a method for producing a rolled copper alloy foil for a film carrier which can improve the strength without lowering the conductivity.

[0002]

2. Description of the Related Art Conventionally, oxygen-free copper (OFC) and tough pitch copper (TPC) have been used as rolled foils for film carriers from the viewpoint of high conductivity.

[0003] The thickness of the rolled foil 35μm is the mainstream, as its tensile strength is about 38~43kgf / mm ^2. However, in the future, with fine patterning,
Further, there is a demand for a high-strength rolled foil because of a tendency to be thinner.

[0004]

However, according to the conventional rolled foil for a film carrier, since high conductivity is emphasized, it is impossible to impart strength higher than the current level. For this reason, the pattern is easily deformed at the time of production and mounting of the film carrier, and the pattern may be deformed by external force or the like even after mounting, resulting in low reliability. In order to increase the strength, a method of adding an alloy element to pure copper is generally used. However, if an attempt is made to increase the strength only by adding an alloy element, an addition amount of about 1% or more is necessary. The addition of the amount of not only impairs the conductivity required for the copper alloy for a film carrier, but also increases the cost.

Accordingly, an object of the present invention is to provide a method for manufacturing a rolled copper alloy foil for a film carrier, which can improve the strength while maintaining the conductivity required for the copper alloy for a film carrier and can reduce the cost. To provide.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a copper alloy having an oxygen content of 10 ppm or less in order to improve the strength while maintaining the conductivity required for a film carrier copper alloy. Then, a copper alloy containing at least one or more of Sn, Zr, and Ag in a total amount of 0.01 to 0.5% by weight is cast to a predetermined thickness by hot rolling. Repeated annealing, 90% workability
An object of the present invention is to provide a method for producing a rolled copper alloy foil for a film carrier, which is formed into a sheet thickness of 35 μm or less by the final cold rolling described above.

[0007] If the strain relief annealing is performed at a temperature lower than the softening temperature of the copper alloy after the final cold rolling, the elongation of the rolled foil can be improved.

When the total amount of Sn, Zr, and Ag is 0.01 to
The reason for setting the content to 0.5% by weight is that if the content is 0.01% by weight or less, no improvement in strength can be expected, and if the content is 0.5% by weight or more, the conductivity is significantly reduced as compared with a pure copper rolled foil. is there. The reason why the working ratio of the final cold rolling is set to 90% or more is that the strength rapidly increases at a working ratio of 90% or more.

Hereinafter, a method for producing a rolled copper alloy foil for a film carrier of the present invention will be described in detail.

[0010]

Example 1 0.02 oxygen-free copper having an oxygen concentration of 5 ppm
% Of Zr is cast, and this is rolled to a thickness of 10 mm by hot rolling, and then cold rolling and intermediate annealing are repeated. The final cold working with a working ratio of 93% is performed to add a thickness of 25 μm. Rolled copper alloy foil for film carrier.

This copper alloy rolled foil has a tensile strength of 52 kgf /
It has characteristics such as mm ² , elongation 1.2%, and conductivity 98% IACS, and has high strength while having conductivity almost equivalent to that of pure copper foil.

[0012]

Example 2 0.05% oxygen-free copper having an oxygen concentration of 5 ppm
% Of Zr and 0.08% of Ag were cast and rolled in the same manner as in Example 1 to obtain a 18 μm-thick rolled copper alloy foil for a film carrier, followed by strain relief annealing.

This copper alloy rolled foil has a tensile strength of 54 kgf /
It has characteristics such as mm ² , elongation of 4.2%, and conductivity of 94% IACS. Like Example 1, strength can be improved without lowering conductivity, and strain relief annealing is performed. Thereby, the elongation can be greatly improved.

[0014]

[Comparative example] 0.12% for oxygen-free copper with an oxygen concentration of 5 ppm
Ingot with added Sn and oxygen concentration 5pp
An ingot obtained by adding 0.7% of Sn to m-oxygen-free copper was rolled in the same manner as in Example 1 to obtain a rolled copper alloy foil for a film carrier having a thickness of 25 μm.

The tensile strength of these copper alloy rolled foil, the former is 52kgf / mm ^2, the latter is 62kgf / mm ^2, The electric conductivity of the former is 92% IACS, the latter 64
% IACS. As can be seen, when the addition amount is 0.5% or more, the strength is improved, but the conductivity is greatly reduced. Further, the elongation could be improved from 1.0% to 3.4% by subjecting the rolled copper alloy foil containing 0.12% of Sn to annealing at 250 ° C. × 30 minutes.

As can be seen from the above description, Sn, Zr,
The reason why the amount of Ag added is 0.01 to 0.5% by weight is as follows.
If it is less than 0.01%, improvement in strength cannot be expected, and
If the content is 0.5% or more, the conductivity is significantly reduced.
Further, by performing the final cold working with a working ratio of 90% or more, the strength sharply increases.

[0017]

As described above, according to the method for producing a rolled copper alloy foil for a film carrier of the present invention, at least one of Sn, Zr, and Ag is added to copper having an oxygen content of 10 ppm or less, and a total of 0 or less. After a copper alloy containing 0.11 to 0.5% by weight was cast and hot-rolled to a predetermined thickness, cold rolling and intermediate annealing were repeated to obtain a workability of 90%.
Since the thickness is reduced to 35 μm or less by the final cold rolling, the strength can be improved while maintaining the conductivity required for the film carrier. Therefore, high rigidity can be maintained even when the tape carrier is made thinner in accordance with the fi-patterning, deformation of the leads during or after mounting can be prevented, and reliability can be improved.

Continuation of the front page (56) References JP-A-62-289303 (JP, A) JP-A-63-215306 (JP, A) JP-A-4-228553 (JP, A) JP 4-6443 (JP) , B2) JP-B-57-35267 (JP, B2) JP-B 62-42222 (JP, B2)

Claims (2)

(57) [Claims] 1. The method according to claim 1, wherein copper having an oxygen content of 10 ppm or less is
At least one kind of n, Zr, and Ag is used in a total of 0.0
A copper alloy containing 1 to 0.5% by weight is cast, and after hot rolling to a predetermined thickness, cold rolling and intermediate annealing are repeated, and final cold rolling at a working ratio of 90% or more is performed. A method for producing a rolled copper alloy foil for a film carrier, comprising forming the plate to a thickness of 35 μm or less. 2. A method for producing a rolled copper alloy foil for a film carrier, further comprising performing a strain relief annealing at a temperature equal to or lower than a softening temperature of the copper alloy after the final cold rolling.