JP2846397B2 - Copper alloy for connectors and terminals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention has excellent workability, and also has high strength and high reliability, such as connectors, terminal materials, spring materials, and lead frame materials. The present invention relates to a copper alloy suitable as a material for electronic and electrical equipment.

[Problems to be solved by conventional technology and invention]

In recent years, the reduction in size and weight of the electronic and electrical industry has promoted the reduction in size and weight of devices used therein, and accordingly, there has been a demand for further reduction in the size, weight and performance of components. In response to this demand, it is desired to reduce the thickness of the structural material constituting the component substrate, the connector, the lead frame material, etc. in order to reduce the size and weight, and accordingly, a material having higher strength is required. Was.

In contrast, precipitation hardening alloys such as "Cu-Be" and "Cu-Ti" and spinodal decomposition alloys such as "Cu-Ni-Sn" have been used, but these alloys are common. However, heat treatment at a high temperature and subsequent aging treatment are indispensable, and this step serves to enhance the properties of the material, but on the other hand, it is a factor of fluctuating the properties, and the control method is not easy, so As a result, the introduction of equipment and an increase in the number of processes have been caused, which has contributed to a rise in prices.

Furthermore, the use environment has become more severe in conjunction with the reduction in size and weight, and there has been a demand for higher reliability.However, among the above alloys, the thermal aging degradation of the adhesion with Sn alloy plating is remarkable. Some things are not usable.
Also, it has been considered that electrical short-circuiting or the like frequently occurs due to the electromigration phenomenon, and the reliability is lost.

[Means for solving the problem]

The present invention solves the difficulty of manufacturability commonly encountered by spinodal decomposition type alloys such as precipitation hardening alloys such as `` Cu-Be '' and `` Cu-Ti '' and `` Cu-Ni-Sn '', Developed a high-performance copper alloy that can be manufactured easily at low cost, has excellent strength, ductility, and workability equal to or better than that, and also has the function of suppressing the deterioration of plating adhesion with time and electromigration. It was done.

That is, one of the alloys of the present invention is Mn 5 to 60 wt%, Al 2 to 20 wt%
And Zn in an amount of 0.2 to 14 wt%, the balance being Cu and unavoidable impurities.

Another one of the alloys of the present invention is Zn 0.3 to 14 wt%, and Mn and Al are (Mn, Al) = (5 wt%, 15 wt%) in the Cu--Mn--Al ternary phase diagram shown in FIG. ), (40wt%, 10wt%),
(5 wt%, 2.5 wt%) (48 wt%, 2.5 wt%), including the amount within the range surrounded by the four points, the balance being Cu and inevitable impurities.

Furthermore, another one of the alloys of the present invention is Zn 0.3 to 14 wt%,
In the Cu-Mn-Al ternary phase diagram shown in FIG. 1, Mn and Al are (Mn, Al) = (5 wt%, 15 wt%), (40 wt%, 10 wt%),
(5 wt%, 2.5 wt%) (48 wt%, 2.5 wt%), including the amount within the range enclosed by the four points, and 0.1 to 3.5 wt% of Co, Ni,
One or more of Si, Sn, Cd, and / or
Or 0.001 to 0.5 wt% of Mg, P, Be, Sb, Cr, As, Zr, B, Y, La
0.001 or more of any one or more of them
It is characterized by containing 7.0 wt%, the balance being Cu and unavoidable impurities.

In addition, the copper alloy according to the present invention can obtain sufficiently satisfactory characteristics without heat treatment such as liquefaction treatment and aging treatment.

(Operation)

The reasons for adding the alloy components constituting the high-strength composite copper alloy of the present invention and the reasons for limiting the composition range will be described below.

First, Mn and Al elements, which are the main components of the present invention, are co-added and contained, so that the structure is mainly composed of β phase (fcc) and α phase (bcc) and other uncertain phases are mixed. State. And, in this structure state, although the reason has not been elucidated yet, it shows extremely excellent workability and at the same time shows high strength, but if it is less than the specified range, its effect is weak and it should be particularly satisfied It is difficult to get strength.
Conversely, if the content exceeds the above range, a γ phase showing difficult processability is generated, and the excellent processability characteristic of the present invention is reduced, so the content range is limited.

Next, regarding the content of Zn, although the exact reason is not known,
Zn acts to suppress the diffusion and concentration of plating elements, Mn, Al, and other sub-components at the plating interface, thereby preventing the formation of a brittle phase at the “plating material-substrate interface”. Furthermore, Zn
The element also has a function of suppressing the diffusion growth (migration phenomenon) of the copper alloy element and the plating element to the outside as an influence of the above effect on the outside. The former effect of suppressing interfacial diffusion is remarkable when the Zn content exceeds 0.3%, and it is sufficient when the Zn content is at most 2%. The effect range for the latter migration phenomenon is gradually seen when the Zn content exceeds 1.0%.
The above content is desirable for improving migration. On the other hand, if the content exceeds 14%, the structure is changed and the hot workability is reduced, so that the content is limited.

Regarding the subcomponent, it is possible to have higher strength without deteriorating the excellent workability characteristic of the present invention, and Co, Sn, Mg, Si, and V are particularly effective. or,
P, Be, Sb, Cr, As, Zr, B, Y, La prevent coarsening of crystal grains due to heat history during hot rolling and annealing, and reduce the surface properties of the bent part required for connector materials. Demonstrate the work of raising. Addition of these sub-components beyond the above-specified ranges, on the other hand, impairs the workability, which is a characteristic of the strength obtained, and significantly lowers the melting and casting properties, resulting in low cost and easy production. It is limited because it will not be possible.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

An alloy having the composition shown in Table 1 was melted, cast into a 30 mm thick ingot, and immediately after hot holding at 850 ° C. for one hour, hot rolling was started from that temperature, and a hot rolled material having a thickness of 10 mm was obtained. Then, the surface was chamfered to produce a plate material having a thickness of 5 mm. Next, this was subjected to cold rolling to a thickness of 1 mm, subjected to sintering at 500 ° C. for 2 hours, and then cold rolled to 20% to obtain a 0.8 mm sheet material.
o.16 was obtained. Then, using this test material,
Each characteristic shown in the table was measured.

About tensile strength and 0.2% proof stress, it performed based on JIS-Z2241.

The hot workability was determined based on the presence or absence of cracks during hot rolling when hot rolling was performed under the hot rolling conditions under which this test material was prepared. (Normally referred to as the edge surface) was evaluated as “△” when it was broken, and “×” when cracked until rolling.

The deterioration with time of heat resistance over time of Sn plating adhesion is achieved by using a material that has been subjected to electric field degreasing and pre-treatment of activation treatment, a 0.1 μm underlying Cu plating, and then a 2.0 μm Sn plating. After 400 hours passed in an atmospheric high-temperature furnace maintained at 180 ° C, a tape peeling test was performed, and “X” indicates that the entire surface was peeled, “Δ” indicates that 10% or more was peeled, and 10% of the peeled portion The samples with less than ○ were indicated by “○”, and those that did not peel at all were indicated by “◎”.

Regarding the migration resistance, as shown in FIG. 2, each test material (2) having the same composition cut into 40 × 20 mm on a filter paper (1) dried after being immersed in a 10 ppm NaCl solution and having a gap of 5 mm was used. At 40 ° C, 98R
After being left in H for 1 hour, DC 100V was applied for 4 hours, the migration length of Cu observed between the gaps was measured, and the average was evaluated. The short-circuited ones are indicated by “x”, those of 3 mm or more are indicated by “△”, those of 3 to 1.5 mm are indicated by “○”, and those of less than 1.5 mm are indicated by “◎”.

Flexibility was determined according to the JIS-Z2248V block method.
The bending angle is 90 degrees, and the ratio between the inner radius of bending and the thickness of the plate is
The state of the outer surface of the bend was observed at 1.0, and the smooth surface was evaluated as “○”, the wrinkle was observed as “△”, and the broken surface was evaluated as “×”.

The conventional “Cu-Be” alloy was No. 17, “Cu-Ni-S
Each property test was performed in the same manner as above, with the “n” type alloy being No. 18, and the results are also shown in Table 1.

As is clear from Table 1, the alloys of the present invention No. 1 to 10
It can be seen that is excellent in hot workability, bendability and migration resistance while having the same strength as that of the conventional materials Nos. 16 to 17. On the other hand, Comparative Alloy No. 11, which has a small amount of Mn and Al and does not contain Zn, has low strength and poor plating adhesion. Comparative alloy with too much Al or Zn
In No. 12 and No. 13, the specimens could not be obtained because the cracks were severe in the hot rolling. Furthermore, comparative alloys No. 14 and No.
15 shows that hot workability and bendability are inferior.

〔The invention's effect〕

As described above, according to the present invention, it is possible to easily and inexpensively and easily manufacture a material having high strength and ductility, and excellent reliability such as excellent bendability, plating property, and migration property. It is most suitable for use in connectors and terminal materials, which are required to be manufactured, and has a remarkable industrial effect.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a main part of a Cu-Mn-Al ternary phase diagram, and FIG. 2 is an explanatory view of an apparatus for measuring migration resistance. 1. Filter paper 2. Test material

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masato Asai 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Yuichi Suzuki 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Inside Electric Industry Co., Ltd. (72) Inventor Mamoru Takeda 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (56) References JP-A-56-47535 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) C22C 9/00-9/10 H01R 9/00-9/28

Claims (3)

(57) [Claims] 1. Mn 5-60 wt%, Al 2-20 wt% and Zn 0.2-14 w
Copper alloy for connectors and terminals, characterized by containing t% and the balance being Cu and unavoidable impurities. 2. The composition according to claim 1, wherein said Zn is 0.3 to 14% by weight and Cu-Mn-A shown in FIG.
l In the ternary phase diagram, Mn and Al are (Mn, Al) = (5 wt%,
(15 wt%), (40 wt%, 10 wt%), (5 wt%, 2.5 wt%) (48
(wt%, 2.5wt%). A copper alloy for connectors and terminals, characterized by the balance of Cu and unavoidable impurities including the amount within the range enclosed by the four points. 3. The composition according to claim 1, wherein said Zn is 0.3 to 14 wt% and said Cu-Mn-A
l In the ternary phase diagram, Mn and Al are (Mn, Al) = (5 wt%,
(15 wt%), (40 wt%, 10 wt%), (5 wt%, 2.5 wt%) (48
wt%, 2.5 wt%), and each one or more of Co, Ni, Si, Sn, Cd of 0.1 to 3.5 wt%, respectively, and / Or 0.001-0.5wt% each
Of at least one of Mg, P, Be, Sb, Cr, As, Zr, B, Y, and La in a total amount of 0.001 to 7.0 wt%, with the balance being Cu and unavoidable impurities Copper alloy for connectors and terminals.