JPS63310929A - Copper alloy for flexible print - Google Patents

Abstract

PURPOSE:To improve the flexibility, tensile strength, adhesion, etc., of the titled copper alloy by regulating the Mg content. CONSTITUTION:The copper alloy for a flexible print consisting of, by weight, 0.0001-0.5% Mg and the balance Cu with inevitable impurities is prepd. One or more kinds of each 0.0001-0.3% and total 0.0001-0.5% elements among Be, Ca, Ti, V, Cr, Mn, Fe, Y, Zr, Nb, Co, Ni, Ag, Zn, Cd, Al, B, Ga, In, Si, Ge, P, As, Sb, Bi, Te, etc., are furthermore added thereto at need. In the above- mentioned inevitable impurities, about <=500ppm O2 content and about <=10ppm S content are preferably regulated. By such constitution, said alloy has excellent flexibility, tensile strength, adhesion, etc., and is therefore suitable for a flexible print, IC tape carrier, etc.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a copper alloy for flexible printing, and more specifically to a copper alloy for flexible printing and [for C-tape carriers, etc.] that has excellent tensile strength, flexibility, and good conductivity. This relates to a copper alloy suitable for.

[Prior art and its problems]

A flexible printed wiring board is a relatively new component of printed wiring boards, and its major feature is that it utilizes flexibility. This flexible printed wiring board was first used as a substitute for electric wires and cables where flexibility was required, and is still mainly used as a substitute for electric wires and cables. Flexible printed wiring boards utilize their flexibility and can be bent or twisted to be used as internal three-dimensional wiring materials for cameras, calculators, telephones, etc., and due to their excellent flexibility, they can be used for printer heads, etc. It is also used for wiring to moving parts of electronic equipment.

Furthermore, in the field of integrated circuits, with the recent trend toward lighter, thinner, and smaller
IC packages are also undergoing various changes, and among them, the TAB method (Tape A) is expected to increase in demand in the future.
There is a need for materials suitable for automated bonding (Automated Bonding) packages.

Conventionally, tough pitch copper has been mainly used for these applications, but although it has good electrical conductivity of about 100% lAC3, it has had the problem of insufficient tensile strength.

[Problem that the invention seeks to solve]

As a result of studies on the above-mentioned problems, the present invention has developed a copper alloy for flexible printing that has approximately the same electrical conductivity as tough pitch copper, and has significantly better tensile strength and flexibility than tough pitch copper.

[Means and effects for solving the problems] The present invention has the following features:
The first invention is a copper alloy for flexible printing consisting of M g O, 0001 to 0.5 wt%, the remainder Cu and inevitable impurities, and M g O, 0001 to 0.5 wt%.
t%, as well as Be, Ca, Ti, V, and Cr.

Mn, Fe, Y, Zr, Nb, Co5Ni, Ag.

Zn, Cd5Af! ,B,Ga,I n,,S i,G
e.

0.0001 to 0.3 wt% of one or more of P, As, Sb, Bi, Te, etc. alone, 0.0 in total
0.001 to 0.5 wt%, the balance being Cu and unavoidable impurities.

That is, in the present invention, a trace amount of Mg is added to Cu to significantly improve tensile strength and flexibility without significantly lowering the electrical conductivity.Also, a trace amount of Mg is added to Cu, and furthermore, a trace amount of Mg is added to Cu, and further, as a subcomponent, Be, Ca, Ti, V, Cr, Mn, F
e, Y, Zr, Nb, Co, Ni, Ag, Zn,, Cd
, Al, B, , Ga.

Its properties are further improved by adding trace amounts of In5SiSGe, P, As, Sb, Bi, Te, etc.

In the present invention, the alloy composition is limited as described above because
The reason for setting Mg to 0.0001 to 0.5 wt% is that Mg is an element that improves flexibility and tensile strength without significantly reducing conductivity, but less than 0.0001 wt% has little effect. , Q, if it exceeds 5 wt%, castability deteriorates and hot workability decreases. Be again
The following subcomponents act as deoxidizing and desulfurizing elements, improving adhesion with resin and heat workability, and further improving tensile strength and flexibility, but if less than 0.0001%. This is because the effect is small, and if the amount exceeds 0.3 wt% alone or 0.5 wt% in total, the conductivity and productivity will decrease.

In addition, the unavoidable impurities in the present invention refer to impurities contained in ordinary metals or impurities that enter during the manufacturing process, such as As, Sb, Bi, Pb, S, Fe, O, etc. Especially o, lt.

The reason why 08 is defined as 500ρρ- or less is that if it exceeds sl, coarse Cr oxides tend to form, lowering tensile strength and flexibility, and the resin after surface roughening treatment. This is because it deteriorates the adhesion of the film. Si
The reason for setting t to ppm is that if it exceeds this value, S tends to concentrate at grain boundaries, impairing hot rolling properties and reducing productivity.
In addition, Cr tends to form coarse compounds (this is because the properties deteriorate.08. Impurities other than P do not cause any problem as long as they are normally suppressed; As, Sb, Bi
, Fe, etc., which overlap with the subcomponents of the present invention, exhibit effects as subcomponents if they are contained together within the above composition range.

〔Example〕

An embodiment of the present invention will be described below.

Example 1 The alloy of the present invention shown in Table 1 was melted and cast to obtain an ingot with a width of 480 mm, a thickness of 130 mm, and a length of 2200 m.
It was hot-rolled at a temperature of 930°C to a thickness of 12°C, immediately cooled to around room temperature with cooling water, and then the top and bottom surfaces were rolled to a thickness of 0.5°C.
5-After surface cutting, the sample was cold rolled to a thickness of 0.5 m, annealed at 480° C. for 3 hours in a non-oxidizing atmosphere, and further cold rolled to a thickness of 0.035 m to obtain a test material.

As a comparative alloy, Tough Pitch copper has a width of 480 m.

An ingot with a thickness of 130+w+ and a length of 2200mm was hot rolled at a temperature of 860°C, and then the top and bottom surfaces were milled by 0.5m to form a 0.
．． 420 mm in a non-oxidizing atmosphere by cold rolling to 5 m.
The sample material was annealed at °C for 3 hours and cold rolled to LOO35.

Table 1 The above test materials were annealed at 500°C for the invention alloy and 270°C for the comparative material, and properties such as flexibility, tensile strength, elongation, electrical conductivity, and adhesion were measured. did. For flexibility, a bending strength test was conducted using the JIS P8115 method using a sample material with a width of 15a* m and a load of 500gf.
The radius of curvature was set to r = 0.38 mm and n = 10, and the average value thereof was adopted. The tensile strength and electrical conductivity were determined by a tensile test and measuring electrical resistance using a rectangular sample with a width of 10 mm. Regarding adhesion to the resin, the surface of the sample material was roughened by etching and then adhered to the phenol base material, and the peel strength was determined. These results are shown in Table 2. In addition, the table also shows specimens taken parallel to the rolling direction and specimens taken perpendicular to the rolling direction.

Table 2 As is clear from Tables 1 and 2, the present invention alloy N[
11-4 has a slightly lower conductivity than 5.6 for conventional tough pitch copper, but it has much better tensile strength and flexibility, and has significantly higher peel strength, making it suitable for flexible printing. I understand that. On the other hand, the comparative material Nα7 has a large amount of Ot, so its characteristics are degraded.

Although the sampling direction of 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.

Example 2 Test materials were prepared using the alloys of the present invention and comparative alloys having the compositions shown in Table 3 in the same manner as in Example 1, and their respective properties were investigated in the same manner as in Example 1. The results are shown in Table 4.

Table 4 As is clear from Tables 3 and 4, the alloy gap 1 of the present invention
-5 has a slightly lower conductivity than the conventional tough pitch copper bars 6 and 7, but it has much better tensile strength and flexibility, and has significantly higher peel strength, making it suitable for flexible printing. I understand. In contrast, the comparative material
Since there are many owl, the characteristics are degraded. Although the sampling direction of 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 explained above, the present invention has excellent flexibility, conductivity, tensile strength, adhesion, etc., and is suitable for flexible printing and as a base material for IC tape carriers. It is suitable for applications such as printing, is also effective for rigid printing, and exhibits remarkable industrial effects.

Claims (3)

[Claims] (1) A copper alloy for flexible printing consisting of 0.0001 to 0.5 wt% Mg, the balance being Cu and unavoidable impurities. (2) Mg0.0001-0.5wt%, further Be,
Ca, Ti, V, Cr, Mn, Fe, Y, Zr, Nb,
Co, Ni, Ag, Zn, Cd, Al, B, Ga, In
, 0.0001 to 0.3 wt% of one or more of Si, Ge, P, As, Sb, Bi, Te, etc.;
A copper alloy for flexible printing containing a total of 0.0001 to 0.5 wt%, with the remainder being Cu and inevitable impurities. (3) The amount of O_2 in the inevitable impurities is 500 ppm or less, S
The copper alloy for flexible printing according to claim 1 or 2, characterized in that the amount is 10 ppm or less.