JPH07109016B2 - Copper alloy for flexible printing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a copper alloy for flexible printing, more specifically, for flexible printing and IC tape carrier having excellent tensile strength and flexibility and good conductivity. It relates to a suitable copper alloy.

[Prior art and its problems]

Flexible printed wiring boards are relatively new components in printed wiring boards, and their major feature is to utilize flexibility. This flexible printed wiring board was originally used as a substitute for a wire or cable that requires flexibility, and is still mainly used as a substitute for electric wires and cables. A flexible printed wiring board uses flexibility and bends or twists to be used as a three-dimensional wiring material in devices such as cameras, calculators and telephones, and because of its excellent flexibility, it can be used in electronic devices such as printer heads. It is also used for wiring to moving parts of equipment.

Furthermore, in the field of integrated circuits, with the recent miniaturization of light, thin, short,
IC packages are also undergoing various changes, but the TAB method (Tape Automated Bo
A material suitable for the packaging of nding) is desired.

Conventionally, tough pitch copper has been mainly used for these applications, but there is a problem that tensile strength and flexibility are insufficient although the conductivity is good at about 100% IACS.

[Problems to be solved by the invention]

As a result of studying the above problems, the present invention has developed a copper alloy for flexible printing, which has substantially the same conductivity as that of tough pitch copper and has significantly higher tensile strength and flexibility than tough pitch copper.

[Means and Actions for Solving Problems]

The present invention includes Cr 0.0001 to 0.5 wt%, Sn 0.0001 to 0.5 wt%, further Zn, Mn, Mg, Fe, Ni, Al, Si, Co, Ca, Ti,
Zr, V, Ag, Cd, Ga, Ge, In, As, Sb, Bi, Be, P,
One or two or more of Y, Nb, B, Te, etc., alone is 0.00
01-0.3wt%, total 0.0001-0.3wt%, total 0.0001-
It is a copper alloy for flexible printing, characterized in that it contains 0.5 wt% and the balance is Cu and unavoidable impurities, and the O ₂ content in the unavoidable impurities is 500 ppm or less and the S content is 10 ppm or less.

That is, the present invention adds a small amount of Cr and Sn to Cu, as a sub-component, Zn, Mn, Mg, Fe, Ni, Al, Si, Co, C
a, Ti, Zr, V, Ag, Cd, Ga, Ge, In, As, Sb, Bi, B
By adding one kind or two kinds or more of e, P, Y, Nb, B, Te, etc., the resistance and flexibility are remarkably improved without significantly lowering the conductivity. In the present invention, the reason why the alloy composition is limited as described above is as follows. Cr is 0.0001 to 0.5 wt% because Cr is a Cr simple substance and is finely intervened in the matrix of the alloy. Is an element that improves
If it is less than 0.5%, the effect is small, and if it exceeds 0.5% by weight, coarse Cr precipitates are likely to be formed, and the above properties are deteriorated. The reason why Sn is 0.0001 to 0.5 wt% is that this element improves the flexibility, but if it is less than 0.0001 wt%, its effect is small, and if it exceeds 0.5 wt%, the conductivity is lowered.

In addition, Zn, Mn, Mg, Fe, Ni, Al, Si, Co as auxiliary components,
Ca, Ti, Zr, V, Ag, Cd, Ga, Ge, In, As, Sb, Bi, B
e, P, Y, Nb, B, Te, etc. not only act as deoxidizing and desulfurizing elements, but also have the effect of further improving tensile strength and flexibility. If the total amount exceeds 0.5 wt%, the conductivity will decrease.

Further, the unavoidable impurities in the present invention refer to impurities contained in ordinary metal or impurities that enter into the manufacturing process, such as As, Sb, Bi, PbS, Fe, O _{2 and the} like. It specifies the amount of O ₂ and S, and O ₂ is 500ppm.
The reason for the above is that if it exceeds this value, a coarse Cr oxide is likely to be formed, the tensile strength and flexibility are lowered, and the adhesion to the resin after the surface roughening treatment is deteriorated. S
The amount is set to 10 ppm or less because if it exceeds this, S is likely to be concentrated in the crystal grain boundaries, impairing the hot rolling property and decreasing the productivity.
In addition, Cr is also likely to form a coarse compound, resulting in poor properties. It should be noted that impurities other than O ₂ and S may be contained in any amount as long as they are usually contained, and those which overlap with the subordinate components of the present invention such as As, Sb, Bi and Fe are contained together in the above composition range. If it does, it will exert the effect as an accessory ingredient.

〔Example〕

 An embodiment of the present invention will be described below.

The alloys of the present invention shown in Table 1 were melt-cast to have a width of 480 mm and a thickness of 1
After obtaining an ingot with a length of 30 mm and a length of 2200 mm, it is hot rolled at a temperature of 850 to 930 ° C to a thickness of 12 mm and immediately cooled to around room temperature with cooling water. Cold rolled to the thickness of 480 ℃ 3 in non-oxidizing atmosphere
It was annealed for a period of time and cold-rolled to a thickness of 0.035 mm to obtain a test material.

As a comparative alloy, tough pitch copper has a width of 480 mm and a thickness of 130 m.
m, length 2200 ingots are hot-rolled at a temperature of 860 ° C, then the upper and lower surfaces are chamfered by 0.5m, cold-rolled to 0.5mm, and annealed at 420 ° C for 3 hours in a non-oxidizing atmosphere, It was cold-rolled to 0.0035 mm to obtain a test material.

Each of the above-mentioned test materials was 500 ° C. for the alloy of the present invention, and 270 for the comparative material.
Annealing was performed at 0 ° C. to obtain an annealed material, and the characteristics such as flexibility, tensile strength, elongation, conductivity, and adhesion were measured. For flexibility, a folding endurance test was carried out according to JIS P8115 using a test material with a width of 15 mm, a load of 500 gf, a radius of curvature r = 0.38 mm, n = 1.
It was set as 0 and the average value was adopted. The tensile strength and the electrical conductivity were obtained by measuring the tensile test and the electrical resistance using a strip sample having a width of 10 mm. Regarding the adhesiveness to the resin, the peel strength was determined after the test material surface was roughened by etching and then adhered to the phenol substrate. The results are shown in Table 2 and Table 2. In addition, Table 2 shows the test pieces taken in the direction parallel to the rolling direction, and Table 2 shows the test pieces taken in the direction perpendicular to the rolling direction.

As is clear from Tables 1 and 2, the alloy No. 1 of the present invention
Compared to the conventional tough pitch copper Nos. 6 and 7, Nos. 5 to 5 have a slightly lower conductivity, but are significantly superior in tensile strength and flexibility, and also have significantly high peel strength, making them suitable for flexible printing. I understand. On the other hand, comparative material N
The characteristics of o.8 are degraded due to the large amount of O ₂ . Although the direction of sampling the sample is slightly lower in the direction perpendicular to the rolling direction than in the parallel direction, the tendency of the above characteristics is exactly the same.

〔effect〕

As described above, according to the present invention, flexibility is required, which is excellent in flexibility, conductivity, tensile strength, adhesion, etc. and is suitable for flexible printing and also as a base material for an IC tape carrier. It is also suitable for rigid printing and is also effective for rigid printing, and exhibits remarkable industrial effects.

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Claims (1)

[Claims] 1. Cr 0.0001 to 0.5 wt%, Sn 0.0001 to 0.5 wt%,
Furthermore, Zn, Mn, Mg, Fe, Ni, Al, Si, Co, Ca, Ti, Zr,
V, Ag, Cd, Ga, Ge, In, As, Sb, Bi, Be, P, Y, N
b, B, Te and the like alone or in combination of two or more 0.0001 ~
Copper alloy for flexible printing characterized by containing 0.3 wt%, 0.0001 to 0.5 wt% in total, the balance consisting of Cu and inevitable impurities, O ₂ content of 500 ppm or less and S content of 10 ppm or less in the unavoidable impurities. .