JPS61183427A - High strength copper alloy - Google Patents

Abstract

PURPOSE:To obtain a high strength copper alloy excelling in overall characteristics such as heat resistance, electric conductivity, thermal conductiv ity, solderability, plating suitability, strength, spring characteristic, repeated bendability, and the like, by adding specific amounts of Fe, Ti, Sn and Mg to Cu. CONSTITUTION:The Cu alloy in which, by weight, 0.1-1.0% Fe, 0.05-0.5% Ti, and 0.5-2% Sn are incorporated to Cu or further 0.005-0.2% Mg is added and the weight ratio of Fe to Ti is 1.4-2.8 is manufactured. By performing conventional hot rolling and successive shower water cooling, cold working, and annealing, obviating the necessity of solution heat treatment and water quenching, the high strength copper alloy having overall characteristics suitable as lead material for semiconductor use and material for connector, switch, and the like can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized by heat resistance, electrical and thermal conductivity, soldering properties,
This invention relates to a copper alloy that requires comprehensive properties such as plating properties, mechanical strength, spring properties, bendability, etc., and is suitable for electric parts such as cord materials for shore conductors and connectors and switches.

[Prior art]

In general, 42 alloy (Fs-42% N1 alloy), which has high strength and high heat resistance, is used as the lead material for conductors because it has good sealing properties with the ceramic motherboard.
has been used. However, the use of copper alloys is rapidly increasing due to the spread of resin/base cages and progress in cost reduction.
Mainly CDA I 94 alloy and thin bronze are used. On the other hand, due to the recent progress in high integration of ICs, highly conductive materials are desired, and the progress in miniaturization and thinning of walls to improve packaging density has led to improvements in strength and repeated bending characteristics. is desired.

On the other hand, ODA 194 alloy, thin bronze, etc. have been used as copper alloys for electrical parts such as connectors and switches, but in order to reduce costs by making parts smaller and thinner, higher strength and conductivity are needed. It is desired to have comprehensive properties such as , spring properties, etc.

However, although CDAl94 alloy has good conductivity and strength, its spring properties and heat resistance are somewhat low, and thin-raised copper has excellent strength, spring properties, and bending properties, but has low heat resistance and conductivity. There are advantages and disadvantages.

In general, the following properties are required of copper alloys as electric components such as conductor lead materials and connectors become smaller and thinner.

(1) Excellent thermal and electrical conductivity (approximately evaluated by thermal conductivity and electrical conductivity); (2) High strength that does not cause screws or bends when thinned. (3) Must be able to withstand high temperature heating during bonding and not easily soften; (4) Must be able to withstand repeated bending as a lead material; (5) Must have good soldering properties.

Among these characteristics, metals such as fi, p'e and Ti, Fe and Si, or F's and Ni are disclosed in Japanese Patent Publication No. 34-1253 as meeting the requirements for strength and electrical conductivity. Strongly conductive copper alloys manufactured using the precipitation of intermediate compounds are known. Here Cu
-Fe-Ti ternary alloy requires solution treatment at 1000° C. and water quenching treatment in order to obtain its excellent strength and conductivity, and requires complicated operations.

[Problem that the invention seeks to solve]

The purpose of the present invention is to eliminate the need for solution treatment and water quenching at 1000°C, and to perform ordinary hot rolling, subsequent shower water cooling, cold working, and aging precipitation treatment (annealing). To provide a copper alloy suitable for lead materials for conductors, electrical parts, etc., which has greatly improved strength while suppressing a decrease in conductivity as much as possible, and has improved spring characteristics, 〈reverse bending characteristics, and heat resistance. It is in.

[Means for solving problems]

According to the invention, Fe 0.1 to I To, Ti 0.
05-0.5%, Sn 0.1-2% and the balance essentially 1 ccu, the weight ratio of Fe and Ti is 1.4-2.
．． 8 is provided.

Further, according to the present invention, F・0.1 to 1 inch, Ti 0.05 to
0.5%, an over 0.5% up to 2%, Mg
0. O05~0.2chi and the rest are essentially Cu#
), a copper alloy having a weight ratio of F'@ and Ti of 1.4 to 2.8 is provided.

Next, the reason for adding the alloy components and the reason for limiting the range of the components will be explained. Fe and Ti have a synergistic effect to improve the properties (strength, conductivity) that are the object of the present invention.

This is because Fe and Ti form a compound called Fe 2 Ti, which is finely precipitated in the matrix by heat treatment.

The excellent properties of the alloy of the present invention are basically obtained by the precipitation of a compound of Fe and Ti, so the ratio of Fe to TiO should be set at an appropriate ratio (F), F@/'ri (weight ratio) 1
．． 4 to 2.8, more preferably 1.7 to 2.4. Regarding this weight ratio, the present inventors conducted research on the Cu-Fe-Ti ternary system, and the results shown in Figure 1 are representative of r.
We have obtained knowledge regarding the relationship between e/Ti and the electrical conductivity and strength after aging precipitation treatment. When FeZTi is less than 1.4, the amount of excess Ti dissolved in the matrix increases and the conductivity decreases significantly.When it exceeds 9.2.8, the amount of excess Fe dissolved in the matrix increases and the conductivity decreases. Although the tensile strength also decreases, the decrease in tensile strength becomes particularly large.

Below T10.05To, re o, t*, Fe
The effect of improving strength and softening resistance due to 2Tl precipitates is small, and even if more than 0.5% Ti and 1% Fe are added, the improvement in properties is almost saturated.

Sn forms a solid solution in the Cu-it's-Ti alloy, and through solid solution hardening, it improves the strength of the Cu-Fe-Ti alloy, as well as improves its bendability, heat resistance, and spring characteristics. be. Here, the amount of Sn added is 0.5-
If the thickness is less than 2 inches, the effect of improving bending properties and heat resistance strength will be small, while if it exceeds 2 inches, the conductivity will decrease significantly.

Like Sn, Mg is dissolved in the Cu-Fe-T1 alloy,
Improves strength, heat resistance, and splash characteristics. If the Mg content is less than o, oos*, these effects will be small, and if it is added in an amount exceeding 0.2%, the strength will be saturated and the conductivity will decrease significantly.

Next, examples of the present invention will be described.

Example: Making electrical steel into aluminum using a high-frequency melting furnace?
Inside, the surface of the hot water was coated with charcoal powder, and electrolytic iron, sponge Ti, Sn base metal, Cu-50% Mg master alloy, etc. were added and cast into a mold with an inner diameter of 150Jllφ, and the dimensions were 150mmφX1X10OX. 'The billet was melted. The compositions of these alloys and comparative alloys are shown in Table 1.

This billet was heated to 950℃ and hot extruded to υ8
．． An extruded line of 5 amφ was made. Further, this wire was drawn to a diameter of 0.9 mm without intermediate annealing. The cold working at this time was good with no line breaks on the way.

The wire with a diameter of 0.9 mm was annealed at 500° C. for 3 hours (aging precipitation treatment), and the tensile strength, elongation, and electrical conductivity before and after the annealing were investigated. The results are also shown in Table 1.

In addition, a 90° bending test was conducted on the annealed material. For this bending test, the above line was held vertically in a holder, a 1 kg weight was hung on the lower end of the line, and the holder was held at a 90° angle.
After bending it several times, return it to its original position and count this as one time.

The folding direction is only one direction. This operation was repeated and the number of times it took to break was measured. The results are also shown in Table 1.

In order to compare the performance of the alloy of the present invention, commercially available CDA I 94 alloy and thin bronze were used with a thickness of 0.25 m.

The tempered (H: hard) plate is also processed material (as H material)
The characteristics of the and annealed materials (annealed at 500° C. for 3 hours) were measured, and the results are shown in Table 1. However, a reverse bending test was not performed.

Furthermore, the present invention alloy (Al~5) and the comparative alloy (A6~9)
The samples were annealed at each temperature for 1 hour, and the temperature at which the tensile strength becomes the sum of the initial tensile strength and the tensile strength after complete softening (beef softening temperature) was investigated. This hand softening temperature is also shown in Table 1.

This chemical softening temperature is an index of heat resistance.

Next, the effects of the present invention will be explained with reference to Table 1.

(1) Strength properties 2 Processed materials and annealed materials (aging precipitation treated materials) of the present invention alloys (A 1 to 5) are comparative alloy A8 (CD
The strength is significantly higher than that of the processed material of A194 alloy), and the strength is significantly higher than that of the processed material of comparative alloy flat 9 (thin bronze).
, Ti, and Sn are in low concentrations. With the exception of &1 and 2, they are the same or significantly higher.

Next, when comparing the properties of Cu-Fe-Ti alloys, T
Since various characteristic values vary depending on the amount of i, the same amount of T
It is necessary to compare alloys containing i. Alloys A 3 and 4 of the present invention contain the same amount of Ti, but
When comparing A6 which does not contain Sn and Mg, Sn
, The improvement in properties of the flat sheets 3 and 4 containing Mg is remarkable. In addition, comparative metal-containing A7 has an Fe/Ti ratio of 5.3 and a Fe/Ti ratio (1.4 to 2.8) defined in the present invention.
The strength of the annealed material is significantly reduced due to the unevenness.

(2) Heat resistance 2 The softening temperature of the alloy of the present invention is 550°C or higher, whereas the softening temperature of comparative alloys Nos. 8 and 9 is much lower, at 480°C and 380°C, respectively. Also, Cu −
Comparative alloys A6 and 7 based on Fe--Ti have a remarkable decrease in strength during annealing, and their rod softening temperatures are 5201: and 480°C, respectively.

(3) Thermoelectric conductivity: Since the alloy of the present invention utilizes the precipitation of Fe and T1, the electrical conductivity is significantly improved by annealing, but the electrical conductivity decreases as the amount of Sn added increases. However, the present invention alloy M 5 containing 1.54% Sn exceeds the comparative alloy M 9 (thin bronze) and exhibits good electrical conductivity. Ti 0.15 and 0.14 respectively
The annealed materials of alloys &1 and 2 of the present invention containing 0.21% and 0.22% Sn, respectively, are comparative alloy A8 (CDA19
It has properties equivalent to or better than processed materials of 4 alloys).

(4) Repeated bendability 2 The number of repeated bends of the alloy of the present invention is improved by 1 to 4 times compared to 6.7 times of a comparative alloy that does not contain Sn.

Regarding the soldering properties of the alloys of the present invention (Al~7), the alloys of the present invention were immersed in a solder bath (5n60-Pb40) at 230° C. for 5 seconds and the state of solder adhesion was observed, and no problems were found. We also performed Ag plating on the same sample, but there were no problems at all.

As described above, the alloy of the present invention has improved high strength, heat resistance, and bendability, as well as good electrical conductivity.
Since soldering has no problems with soldering, it can be widely used for lead materials for conductors and electrical parts such as connectors and switches, and it greatly contributes to higher performance, smaller size, and thinner parts.

[Brief explanation of the drawing]

The attached drawing shows the F6/Cu-Fe-Ti ternary alloy.
It is a graph showing the relationship between the 'ri weight ratio and the electrical conductivity and strength after aging precipitation treatment. Mortar/T; (Kou 1ru)

Claims (2)

[Claims] (1) Fe0.1-1% (by weight, the same applies hereinafter), Ti0.05-0.5%, Sn over 0.5% up to 2%, and the balance essentially consisting of Cu, the weight ratio of Fe and Ti. A copper alloy characterized in that the is from 1.4 to 2.8. (2) Fe0.1~1% Ti0.05~0.5% Sn More than 0.5% up to 2% Mg0.005~0.2% and the balance essentially consisting of Cu, weight ratio of Fe and Ti A copper alloy characterized in that the is from 1.4 to 2.8.