JPH02111834A - High conductive copper alloy for wiring of electrical and electronic parts having excellent migration resistance - Google Patents

Abstract

PURPOSE:To obtain the title Cu alloy by adding and incorporating specific amt. of Mg or furthermore Zn into Cu. CONSTITUTION:To Cu, by weight, 0.2 to 1.5% Mg is added and incorporated, or, in addition to the above Mg, 0.5 to 2.0% Zn is furthermore added and incorporated. The Cu alloy for wiring having excellent migration resistance as the material for wiring of electrical and electronic parts and furthermore having excellent electric conductivity can be obtd.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a highly conductive electric wire with excellent migration resistance.
Regarding copper alloys for electronic component wiring, more specifically, they are used for electrical and electronic component wiring such as semiconductor components (e.g. lead frames), mechanical components (e.g. switch parts, busbars, terminals, connectors, etc.), printed wiring, electrodes, etc. This invention relates to a highly conductive copper alloy with excellent migration properties.

[Conventional technology] (Background technology) In recent years, electrical and electronic components installed in home appliances such as coolers, TVs, and VTRs, industrial electronic equipment, and automobiles have rapidly become smaller and more densely packaged. is made of. Due to the miniaturization and high-density mounting of electrical and electronic components mentioned above, the layout for putting them into practical use! 3 (that is, conductors such as conductive wires that connect electrical and electronic components to each other to form a circuit) are also being influenced by this trend, and are becoming more densely packed or multilayered by shortening the distance between wires.

Furthermore, attempts have been made to improve the current capacity flowing through the wiring in order to respond to the miniaturization of the wiring itself.

(Prior art) By the way, the conventional material for electrical/electronic component wiring is Cu.
, Cu-P or Cu-Zn are used.

However, when attempting to increase the density and multilayer the wiring using Cu or Cu-P, electrochemical migration of the metal occurs and the insulation between the wiring deteriorates. Found out. As a result, it becomes difficult to increase the density and multilayer wiring, which in turn makes it difficult to miniaturize and high-density packaging electrical and electronic components.

The above migration is the following phenomenon.

In other words, when dust that causes dew condensation or moisture adsorption adheres between wires, the metal atoms that make up the wires are ionized by the electric field, and these ionized metal atoms are deposited in the shadows by Coulomb force. Similar to plating (electrodeposition), these deposits grow in the form of trees and branches from the cathode and reach the exposed side, causing a short circuit between wires. This is often accompanied by oxides in the metal crystal and on the surface depending on the environment such as dryness and dew condensation, and the material that makes up the wiring is an insulating material such as plastic, glass, and ceramic that insulates the wiring. They run on the surface in an extremely thin film, and often form multiple strands at the tip. Furthermore, this migration occurs when the applied voltage is from several volts to several tens of volts and the current is from several amperes to several tens of amperes. It has been discovered that copper and copper alloys may also be affected by the development of high-density packaging and multilayer technology.

In addition, mechanical strength is required for switches (for example, microswitches) to withstand frequent opening and closing, but it has been difficult to meet this requirement when Cu-P is used.

On the other hand, brass has excellent migration resistance, but
It has low conductivity and cannot respond to the above-mentioned improvement in current capacity of electrical/electronic component wiring.

[Problems to be Solved by the Present Invention] The present invention has been made in view of the various problems in the conventional art as explained above. Due to the increasing density of printed wiring, electrodes, and other electrical/electronic component wiring, and high-density mounting, the distance between paper materials and T
The distance between the L poles is, for example, 2.54 mm to 0.635 to 1.
27 mm, or even if there is dew condensation, the conductivity is at least 55% I AC5 to suppress the growth of deposits, cause migration, and further improve the current capacity. The object of the present invention is to provide a highly conductive copper alloy for electrical/electronic component wiring, which has improved mechanical properties and heat resistance than pure copper, and has excellent migration resistance.

[Means for Solving the Problems] The present invention provides a highly conductive electrical device with excellent migration resistance, which contains Mg: 0.2 to 1.5%, and the remainder is substantially Cu.・The first gist exists in copper alloys for electronic component wiring, and Mg: 0.2 to 1.5%, Z
n: 0. 5-2. The second feature lies in a highly conductive copper alloy for electrical/electronic component wiring which has excellent migration resistance and is characterized by containing 0% Cu and the remainder substantially consisting of Cu.

[Function] The densification of highly conductive electric/electronic component wiring with excellent migration resistance according to the present invention will be described in detail below.

First, the components and component ratios of the highly conductive copper alloy for electrical/electronic component wiring having excellent migration resistance according to the present invention will be explained.

Mg prevents the migration of Cu when water infiltrates or condensation occurs between the wiring of electric/electronic components to which voltage is applied, and 4? "j" is an essential element for suppressing current; if it is less than 0.2%, the same suppressing effect as brass cannot be obtained, and if it is contained in more than 1.5%, it may inhibit the migration of Cu. Although it has the effect of suppressing Mg formation and suppressing leakage current, the amount of Mg oxide increases rapidly, which deteriorates the fluidity of the molten metal and reduces the agglomeration properties.The conductivity also decreases. Content is 0.2-1.5%
shall be.

Zn further improves conductivity by being co-added with Mg. If it is less than 0.5%, even if it is co-added with Mg, Cu
The effect of suppressing migration formation is small, at 2.0%.
If it exceeds 100%, migration resistance improves, but further improvement in conductivity cannot be expected. Therefore, the Zn content is set to 05 to 2.0%.

Note that B, Ai, Si, Ti, Cr, and Mn.

Ni, Co, Zr, Ag, In and sb are one or two types.
Even if it is appropriately contained in a range that satisfies the conductivity of 55% IAC3 in more than 100%, the migration resistance of the present invention will not be lost.

[Example] Examples of the highly conductive copper alloy for electrical/electronic component wiring having excellent migration resistance according to the present invention will be described.

A copper alloy having the composition shown in Table 1 was melted in the air in a small electric furnace under charcoal coating, and a thickness of 50 mm, a width of 80 mm, and a length of 1 mm was obtained.
An 80 mm ingot was melted.

The front and back sides of the above ingot were milled by 2mm each, and No.1
Brass No. 4 was hot-rolled at 740° C., and the other brasses were hot-rolled at 820° C. to form a plate material with a thickness of 15 mm. After removing the oxidized scale on the surface of the hot-rolled material with 20vol 1% sulfuric acid water, it was cold-rolled at 500℃ for 2 hours except for brass.
, Brass is annealed at 430℃ x 2hr, thickness 0.32mm
It was adjusted to be a board material.

(Migration resistance) A test piece with a thickness of 0.32 mm, a width of 3.0 mm, and a length of 80 mm was taken from the above plate material. These test pieces were made into a set of two, and as shown in Figure 1 (a) and (b), a 1 mm thick A
A BS resin plate (insulator) 2 is interposed between the two test pieces 1.1, and both ends of the test piece 1.1 are held between top and bottom by holding plates 33, and the holding plates 3.3 are insulated on the surface. Set the two test pieces 1 by pressing them with the plastic clip 4.
．． A dry/wet cycle test of [(immersion in tap water for 5 minutes)-(drying for 10 minutes)] was performed for 50 cycles while applying a direct current of 14 V for 1 hour. Note that the immersion in tap water was performed so that the upper surface (indicated by a) of the upper test piece was immersed.

Maximum Kn during that time? ``The L current value was measured with a high-sensitivity recorder.

Note that the smaller the maximum leakage current, the better the migration resistance.

(Mechanical strength) Tensile strength and elongation were measured using a JIS No. 13 B test piece with the longitudinal direction of the test piece parallel to the rolling direction.

(current capacity) Current capacity was evaluated by measuring conductivity.

The conductivity was measured based on JISHO505.

The results shown in Table 2 were obtained from the above experiment.

As is clear from Table 2, the invention alloy Nos. 1 to 11
has a maximum leakage current of 0.4 compared to comparative alloy No. 12.
It can be seen that it is as small as ~0.6A, comparable to No. 14 brass, and has excellent migration resistance.

Furthermore, the electrical conductivity of the alloy of the present invention is more than twice that of brass (No. 114), indicating that it is excellent in this respect as well.

In this test, the applied voltage during the leakage current test was set to 1 for automobiles.
Although 4V is used, copper alloys are generally used in 24V or 100V AC circuits, which are more susceptible to electrical discharge, so it goes without saying that the present invention can also be applied to consumer and industrial applications. stomach.

Furthermore, the alloy of the present invention exhibits much higher tensile strength than the Cu-P alloy (No. 15), indicating that it can be suitably used for wiring that requires strength.

[Effects of the Invention] As explained above, the copper alloy for electrical/electronic component wiring according to the present invention suppresses the migration phenomenon of Cu, thereby eliminating the problem of short circuits even when the distance between the wires is reduced. Furthermore, since a material with a large a-layer is obtained, heat generation, burnout, etc. due to increased current capacity are reduced.

Table 1

[Brief explanation of the drawing]

FIG. 1 is a plan view and a side view showing an experimental method for evaluating migration resistance. 1... Test piece, 2... ABS resin plate, 3... Holding plate, 4... Clip, 5... Electric wire, 6 Battley Table 2

Claims (2)

[Claims] (1) Highly conductive electric wire with excellent migration resistance, containing Mg: 0.2 to 1.5% (weight %, hereinafter the same), with the remainder consisting essentially of Cu. Copper alloy for electronic component wiring. (2) Mg: 0.2-1.5%, Zn: 0.5-2.0
%, and the remainder substantially consists of Cu.