JPH04180532A - Electrically conductive material - Google Patents

Abstract

PURPOSE:To obtain an electrically conductive material having high electrical conductivity and superior migration resistance by specifying the oxygen content of a Cu alloy contg. prescribed amts. of Si, Ni, Fe, etc., and allowing the added elements to exist as solid soln. CONSTITUTION:The oxygen content of an alloy consisting of 0.05-1.0wt.% Si, 0.05-1.0wt.% one or more among Ni, Fe, Co, Cr and Ti and the balance Cu with inevitable impurities is regulated to <=20ppm and the added elements are allowed to exist as solid soln. to obtain the above-mentioned material. About 0.001-5.0wt.%, in total, of one or more among Zn, Sn, Mg, Mn, Al, B, P, As, Sb, Ag, Pb, Be and Zr as secondary components may further be added to the above-mentioned compsn. as required. The grain size of the obtd. material is preferably about <=30mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a current-carrying material for electrical component materials that suppresses migration between lead frames, terminals, connectors, and bus bars (also referred to as bus bars).

[Prior Art] In recent years, electronic and electrical equipment, etc. have become smaller and lighter, and the parts used, such as connectors, have become smaller and the distances between the parts have also tended to become significantly shorter.

Also, circuits are becoming increasingly integrated. In other words, in the past, individual electronic components were connected by lead wires to form a circuit, but as the number of components increases, circuits become more complex, so circuits are becoming smaller by integrating them. There is.

[Problem to be solved by the invention]

In conventional miniaturized and integrated circuits, different circuits or wiring are spaced apart with a slight spacing for miniaturization, but if an electrolyte such as water is present in this spacing, electrochemical reactions occur. A chemical reaction occurs, and copper ions dissolved from the copper alloy that is the material of the current-carrying part on the high potential side precipitate on the low potential side, and when the amount increases further, a short circuit occurs. This phenomenon is called migration, and when such migration occurs, the circuit will no longer function properly. Therefore, in recent years, there has been a strong desire for materials that have high electrical conductivity and do not cause migration.

[Means to solve the problem]

In view of the above problems, the present inventors have conducted research on migration, and have used 810.05 to 1.0 wt% as a conductive material for terminals, connectors, bus bars, etc. connected to the anode side.
The alloy contains one or more of Ni, Fe, Co, Cr, and Ti in a total amount of 0.05 to 1.0 wt%, and the balance is Cu and inevitable impurities, and the oxygen content is 20 ppm.
It is characterized in that the additive element is in a solid solution state.

Or Si0.05~1.0wt% and Ni, Fe, G
Total amount of one or more of o, Cr, 'Ti is 0.0
Contains 5 to 1.0 wt%, and further contains ZnySn as a subcomponent.
', Mg, Mn, A! , B, P, As, Sb-Ag, P
b, Be, Zr in total amount of one or more
The alloy is characterized in that the oxygen content of the alloy is 20 ppm or less, and the additive element is in a solid solution state.

Furthermore, the alloy is characterized in that the crystal grain size is 30 μm or less.

[Detailed description of the invention]

According to the present invention, the amount of each element added to Cu is determined in consideration of the following.

That is, first of all, Si is an element that has the effect of suppressing the migration property of copper and copper alloys by being contained in copper and copper alloys.

Although the mechanism that suppresses the migration phenomenon is not clear, the presence of Si reduces the amount of Cu ions eluted, and
The formation of the compound impedes the conduction of electricity through the deposited Cu particles.

It is presumed that the migration phenomenon between the electrodes is suppressed.

The reason for setting the Si content to 0.05 to 1.0 wt% is that S
If the i content is less than 5wt%, Q, there is no effect of suppressing the migration phenomenon, and if it exceeds 1.0wt%, there is an effect of suppressing the migration phenomenon, but the conductivity decreases and the amount of heat generated when energized increases. This is because the heat dissipation property is also lowered.

The reason why the content of one or more of Ni, Fe, Co, Cr, and Ti is set to 0.05 to 1.0 wt% is that these elements have the effect of suppressing the migration phenomenon and also contribute to improving the strength. However, if it is less than 0.05 wt%, the effect will be low, and if it exceeds 1.0 wt%, the conductivity will decrease significantly.

Furthermore, Zn, Sn, Mgx Mn, A1, B as subcomponents
, P-As, Sb, Ag, Pb, Be, Zr 1
5. O,001wt% or more of the species or two or more species. Owt%
The following additions are to improve strength, but 0
．． There is no effect at less than 0.001 wt%, and 5.0 wt%
This is because the conductivity decreases if the value exceeds .

The reason why Si, Ni, Fe, Co, Cr, and Ti are in a solid solution state is that Ni, Fe, Co, Cr, and Ti tend to form precipitates with Si, but when the precipitates exceed a certain size, they rapidly This is to maintain migration resistance in a solid solution state, since migration tends to occur easily.

What is the reason for setting the oxygen content to 20 ppm or less?

This is because it has been found that if Si is captured as an oxide in the alloy, it does not contribute to improving migration properties. In other words, in alloys with an oxygen content exceeding 20 ppm, Si is likely to be treated as an oxide, and when Si oxide is generated, Si concentration is likely to occur there, resulting in a rapid decrease in migration properties. be.

The reason why the crystal grain size is 30 μm or less is that the crystal grain size is 30 μm or less.
This is because when the grain size exceeds μm, there is a tendency for workability to decrease and migration performance to decrease as well.

〔Example〕

Specific examples of the present invention are shown below.

First, the alloys of the present invention and comparative alloys having the compositions shown in Table 1 were melted and cast in an inert atmosphere, hot rolled after being solidified, and then cold rolled, annealed and pickled repeatedly to maintain a constant temperature of 400 to 900°C. The grain size was adjusted by final annealing for 3 hours, and after pickling, a plate with a thickness of 0.6 wn was obtained which was cold rolled at a workability of 20%.

Then, the surface was polished with 120° emery paper.

These test materials were evaluated for tensile strength, elongation, electrical conductivity, and migration resistance. To test the migration resistance, the test material was cut into pieces of 10+n x 100++o, set in pairs as shown in FIG. 1, and immersed in tap water (300 cc) as shown in FIG. 2.

Next, a DC voltage of 14 V was applied to these two test materials, and the change in current value with respect to elapsed time was measured using a recorder. A typical example of this result is shown in FIG. Also, the current value in each sample material is 1. Table 1 shows the time until OA (arrow in Figure 3).

From Table 1, it can be seen that the present invention alloys Nα1 to 8 in T size also have a conductivity of 34%lAC3 or higher and excellent micration resistance, and are suitable for use in IJ-frames, automobile terminals, connectors, etc.
It can be seen that this alloy is most suitable as a current-carrying material that requires micration resistance such as bus bars.

In addition, the comparison alloy Na 9 had a lower Sl than the invention alloy No.
Comparative alloy Nα10, which has poor migration resistance because of its low Si content, has low conductivity because it has too much Si content. Comparative alloy NQII has a higher oxygen content than inventive alloy Nα3, and therefore has poorer micromagnetic resistance. Comparison base metal Nα12 has poor migration resistance because elements added to the alloy Nα4 of the present invention become precipitates and are not completely dissolved in solid solution. Comparative alloy No. 13 has crystal grains that are too large compared to the present invention alloy Na 5, and therefore has poor migration resistance.

Comparative alloy Nα14 is a type of brass conventionally used in automobile bus bars and the like, and has high migration resistance but low electrical conductivity.

Comparative alloy Nn15 is oxygen-free copper and has high electrical conductivity but low migration resistance.

〔Effect of the invention〕

The current-carrying material of the present invention has high electrical conductivity and is a material with excellent migration resistance.

Margin below

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a sample material for a migration resistance test, FIG. 2 is an explanatory diagram of the test, and FIG. 3 is a graph showing the measurement results.

Claims (3)

[Claims] (1) Si0.05-1.0wt% and Ni, Fe, Co
, Cr, and Ti or more from 0.05 to
1.0 wt% of the alloy, the balance being Cu and unavoidable impurities, the oxygen content of the alloy is 20 ppm, and the additive element is in a solid solution state. (2) Si0.05-1.0wt% and Ni, Fe, Co
, Cr, and Ti or more from 0.05 to
1.0wt% and further subcomponents such as Zn, Sn, Mg,
Mn, Al, B, P, As, Sb, Ag, Pb, Be,
One or more types consisting of Zr in a total amount of 0.001~
5.0 wt%, the balance being Cu and unavoidable impurities, the oxygen content of the alloy is 20 ppm, and the additive element is in a solid solution state. (3) The electrically conductive material according to items (1) or (2), characterized in that the crystal grain size is 30 μm or less.