JPH03287733A - Copper alloy excellent in migration resistance - Google Patents

Abstract

PURPOSE:To obtain a copper alloy excellent in migration resisiance and furthermore having good electrical conductivity and strength by specifying a compsn. constituted of Ti, Ni and Cu. CONSTITUTION:This copper alloy is a one contg., by weight, 0.1 to 1.0% Ti and 0.3 to 2.5% Ni, furthermore contg., at need, 0.5 to 10% Zn and the balance Cu with inevitable impurities. The alloy is excellent in migration resistance as well as has good electrical conductivity and strength and is suitable for the use to connectors, bus bars or the like. Thus, by using this copper alloy, the miniaturization and high capacitation of electronic and electrical equipment parts can be attained.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a copper alloy with excellent migration resistance suitable for use in electrical and electronic equipment parts such as connectors and busbars for electrical junction boxes of automobiles, etc. It is something.

[Prior Art and its Problems] Conventionally, 7/3 brass, tough pitch copper, and the like have been used for busbars for electrical connection boxes used in automobiles, machine tools, and the like. In addition to these materials, phosphor bronze containing 2 to 8% Sn (hereinafter abbreviated as %) is widely used in connectors for electrical and electronic equipment. Of these, 7/3 brass is widely used as a material for terminals and is a material with stable quality.
Since it contains a large amount of Zn as an alloy component, the conductivity is low. For this reason, as parts such as busbars and connectors become smaller and thinner due to the miniaturization of electrical and electronic equipment in electrical junction boxes, which has been rapidly progressing in recent years, Joule heat generation is too large, making it no longer a suitable material. There is.

On the other hand, tough pinochonous copper has high conductivity, so it is advantageous when it comes to heat generation problems caused by miniaturization of electrical connection boxes and electric/electronic equipment parts, but it tends to cause the migration phenomenon in environments where moisture is present. Furthermore, tough pitch copper has low strength, and its use is also restricted due to the lack of strength of the member when miniaturizing electrical and electronic equipment parts.

Although phosphor bronze has excellent moldability and spring properties, it also has low electrical conductivity and has the problem of generating heat due to Joule heat, and is also poor in migration resistance.

The migration phenomenon is a phenomenon in which a leakage current occurs between a pair of opposing conductors (for example, busbars, etc.) to which an electric field is applied in an environment where moisture is present, resulting in electrolytic corrosion of the conductors. If the leakage current due to this migration phenomenon becomes large, heat generation may cause electrical connection boxes and electrical/electronic equipment parts to become abnormally hot, which may lead to accidents such as fire. Therefore, tough pitch copper and phosphor bronze have good reliability when used in electrical and electronic equipment parts such as semiconductor parts, connectors, switchgear parts, printed wiring boards, and mechanical parts such as bus bars, which are used in environments where moisture may be involved. There was a problem that the amount was low.

In order to address these problems, materials have been developed in recent years, such as copper alloys containing Zn and having migration resistance. (Unexamined Japanese Patent Publication No. 62-116744.62-116745
．． 62-136539.62-146231, 62-
199741.62247141, 62-25013
7 etc.) All of these copper alloys have improved migration resistance compared to conventional copper alloys by adding Zn to Cu. However, this level of improvement cannot sufficiently prevent migration due to deterioration of the environment surrounding electrical junction boxes and electrical and electronic equipment, and further improvements are strongly required.

[Problem to be solved by the invention]

The present invention was made as a result of intensive studies in view of the above points, and its purpose is to provide a copper alloy that has excellent migration resistance and good conductivity.

[Means to solve the problem]

The first aspect of the present invention is that Ti is 0.1% by weight or more and 1% by weight or more.
．． It is a copper alloy with excellent migration resistance characterized by containing 0% by weight or less, NiO, 3% or more and 2.5% by weight or less, and the remainder consisting of Cu and unavoidable impurities.

In addition, the second invention is characterized in that Ti is 0.1% by weight or more and 1.0% by weight or less, Ni is 0.3% by weight or more and 2.5% by weight or less, Zn0.
It is a copper alloy with excellent migration resistance, which is characterized by containing 5% by weight or more and 10% by weight or less, with the remainder consisting of Cu and unavoidable impurities.

[Function] When Ti and Ni are simultaneously added as alloying elements to Cu, migration resistance is improved. This effect is caused by the addition of Zn to Cu.
It becomes even larger than when adding . The reason for limiting the Ti content to 0.1% or more and 1.0% or less is that
Although i improves migration resistance when it coexists with Ni, if it is less than 0.1%, the effect is insufficient, and if it exceeds 1.0%, the effect is saturated. This is because, in particular, melt casting becomes extremely difficult, which increases manufacturing costs. The reason why the Ni content is 0.3% or more and 2.5% or less is that Ni is T.
Although it improves migration resistance in coexistence with i, if it is less than 0.3%, the effect is insufficient, and if it exceeds 2.5%, the effect is saturated, and
This is because the electrical conductivity decreases significantly and heat generation due to Joule heat during use increases.Furthermore, Zn improves migration resistance, but if it is less than 0.5%, Ti
Even if Ni and Ni coexist, the effect of improving migration resistance is insufficient, and if it exceeds 10%, the conductivity decreases greatly and the stress corrosion cracking susceptibility increases, resulting in a decrease in reliability.

Note that Sn, Fe, Cr, Co, Zr, Mg2Mn, Y
,,Ag,Aj! ,Pb, ,P, ,In, Mi7'/
Even if elements such as yumetal are contained in a total amount of 0.5% or less, the migration resistance will not deteriorate, and their addition is permissible.

As mentioned above, the alloy of the present invention has excellent migration resistance as well as good conductivity and strength, so it can be used in electrical and electronic equipment parts such as semiconductor parts, connectors, terminals, switchgear parts, printed wiring boards, and busbars. It has a wide range of uses as a material for various parts such as mechanical parts where migration phenomenon between adjacent conductors and heat generation during energization are a problem.

[Example] Next, one embodiment of the present invention will be described.

A copper alloy having the composition shown in Table 1 was melted and cast, and after hot rolling,
A plate material having a thickness of 0.4 mm (final processing rate of 40%) was manufactured by repeating cold rolling and annealing.

Using this plate material, place it in a resin mold type electrical junction box with dimensions of 15 x 10 x 5 C1, and the circuit length is 1 m and the thickness is 0.
Migration resistance was measured by installing various busbars with a length of 4 m. The test was conducted in an atmosphere of 25° C. and 90% relative humidity, and the leakage current was measured when a total current of 25 A was applied for 100 hours.

The electrical conductivity of these test materials was also measured.

The results are also listed in Table 1.

As is clear from Table 1, the alloys Nα1 to 13 of the present invention
All of them have good migration resistance with a leakage current of 0.3 A or less, and have excellent conductivity, with electrical conductivity of 50% or more.

On the other hand, the comparative alloy k14.15, which has a small amount of Ti and Ni, has a large leakage current and poor migration resistance. In addition, the comparative alloy Nn18, which has a small amount of Zn, has a smaller reduction in leakage current than the alloy of the present invention, which has a large amount of Zn, and has less effect on improving migration resistance when coexisting with Ti and Ni. Comparative example alloy Nα15.1619, which has large amounts of Ti, Ni, and Zn, has good migration resistance but poor electrical conductivity.

(Effects of the Invention) As explained above, the alloy of the present invention has excellent migration resistance and good conductivity, making it possible to miniaturize and improve functionality of electronic and electrical equipment parts, etc. This has a remarkable effect.

Claims (2)

[Claims] (1) Ti0.1% by weight or more and 1.0% by weight or less, Ni0
．． A copper alloy with excellent migration resistance, characterized in that it contains 3% by weight or more and 2.5% by weight or less, with the remainder consisting of Cu and unavoidable impurities. (2) Ti0.1% by weight or more and 1.0% by weight or less, Ni0
．． A copper alloy with excellent migration resistance characterized by containing 3% by weight or more and 2.5% by weight or less of Zn, 0.5% by weight or more and 10% by weight or less of Zn, and the remainder consisting of Cu and unavoidable impurities.