JPS63270437A - Conductor for fuse - Google Patents

Abstract

PURPOSE:To obtain a conductor for a fuse having excellent fusion characteristics and wire drawability by specifying the compsn. consisting of Al, Cu and Pb, Bi, In, Cd, Sb, Sn, etc. CONSTITUTION:The titled conductor contains, by weight, 0.01-2% Al, 0.01-2% Cu and the balance consisting of one or more kinds among Pb, Bi, In, Cd, Sb and Sn and has the excellent fusion characteristics and wire drawability. Among said components of the conductor, Al has no effect of facilitating the production of a connected fine wire outside of said compsn. area. Cu has further less effect of contributing to the improvement of the tensile strength in the case of below the lower limit, and the desired m.p. temp. can not be obtd. in the case of above the upper limit thereof. In the low m.p. metals except for Pb, the contents are preferably regulated as well to the area of about 0.01-50% Bi, about 0.01-30% In, about 0.01-20% Cd, about 0.01-15% Sb and about 0.01-40% Sn so as to obtain the desired m.p. temp. suitably.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a fuse conductor that functions to instantaneously break when an overcurrent exceeding a rated value flows.

[Prior art] As described in the Japan Institute of Metals, edited [Metal Handbook (revised December 20, 1981, 4th edition, p. 1007),
Conventional fuses include PB, Zn or PB-3.
n alloys are commonly used. Fuse conductors made of these metals or alloys are blown by the Joule heat of the overcurrent, opening an electrical circuit. When attempting to accurately determine the fusing current without being affected by the outside temperature, a fuse conductor made of tungsten wire may be used. Additionally, wood metal, which melts at low temperatures, is used for fuses that melt when the heating atmosphere overheats.

[Problems to be Solved by the Invention] However, when the above-mentioned fuse conductor is used to add a fuse function to semiconductor devices or electronic components, it is difficult to draw the fuse conductor to a usable thin or ultra-fine wire. Difficult to process. Therefore, at present, a separate device having a fuse function is incorporated into the circuit of an electronic device incorporating such a device or component. Alternatively, fuse conductors such as those described above have been used in the form of plates or thick wires, and the cross-sectional area has been reduced by partially inserting notches.

However, thin wires or ultra-fine wires made of AH gold alloy CO or Cu alloy are sometimes used as conductors for fuses.
Fuse conductors such as () were difficult to blow due to overcurrent.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a conductor for a fuse that has excellent fusing characteristics and wire drawability.

[Means for solving the problem] The fuse conductor according to the present invention has an AfJ of 0°0.
1 to 2% by weight, Cu@0.01 to 2mff1%, and the balance is Pb5Bl, in, Cd, 3b.

At least one or more metals selected from the group containing Sn.

[Operations and Effects of the Invention] An alloy in which Cu is added to a metal of Pb, Bi, In, Cd, or Sb%Sn (hereinafter referred to as a low melting point metal) has improved tensile strength compared to the low melting point metal itself. The melting points of these alloys are also not very high compared to the low melting point metals themselves. However, when the Cu content increases, the melting point increases, making it unsuitable for use as a fuse conductor. Therefore, it is necessary to suppress the Cu content within a certain range. It is also recognized that these alloys have excellent fusing characteristics. Therefore, it is desired to utilize these characteristics to obtain a thin alloy wire made of a low melting point metal and Cu as a conductor for a fuse. alloy m
One possible method for obtaining the wire is to inject a molten alloy in the form of a trickle and solidify it.

However, according to this method, it was difficult to obtain continuous thin wires, and only thin wires of several tens of meters could be obtained.

Therefore, the present inventor attempted to manufacture a continuous I8 wire by adding various elements and using the above method. As a result, it was found that continuous thin wires can be manufactured by adding ΔKita to an alloy of a low melting point metal and Cu. At this time, it was also found that as the content of AfL increases, it becomes more difficult to manufacture continuous thin wires. Therefore, it is necessary to suppress the Afl content within a certain range.

Further, the obtained thin wire has good wire drawability, and can be roughly processed into an ultra-m wire. Roughly, low melting point metal and C
It does not impair the good fusing properties of the alloy with u.

This invention is based on such knowledge of the inventor of the present application.

Therefore, in the fuse conductor according to the present invention, A'1 is 0.
01-2% by weight, Cu is 0.01-2m! 1%, and the remainder is at least one or more low melting point metals. AQ content between 0.01 and 2% by weight
The reason for this is that if the AQ amount is less than 0.01% by weight, it will not have the effect of facilitating the production of continuous thin wires, whereas if it exceeds 2% by weight, it will actually make it difficult to produce continuous thin wires.

If the Cu content is less than 0.01% by weight, the effect of contributing to improving the tensile strength required as a fuse conductor is small;
If it exceeds 2% by weight, the temperature at which the composition becomes completely liquid will exceed 700° C., exceeding the melting point temperature suitable for a fuse conductor.

In addition, in the composition of the alloy according to the present invention, when one or more than two low melting point metals other than Pb are contained, the content is preferably within the range shown below, and has excellent wire drawability and fusing properties. There is.

Bi: 0.01-50% by weight In: 0.01-30% by weight Cd: 0.01-20% by weight Sb: 0.01-15% by weight Sn: 0.01-40% by weight By varying the content of the low melting point metal within the above range, the melting point temperature of the fuse conductor can be adjusted to suit the application.

As described above, the fuse conductor of the present invention has excellent fusing characteristics and wire drawability.

In addition, since it can be processed into thin or ultra-fine wires, it can be effectively used as a conductor for fuses in fields where a high resistance value of τ is required and the wires also need to be thin or ultra-fine. Particularly, it is effectively used for lifting boards, etc., where it is desired to add a fuse function to the original function of semiconductor devices (IC1 transistors, etc.) and electronic components (capacitors, etc.). At this time, there is no longer a need for a device having a fuse function, which has heretofore been incorporated into the circuit of an electronic device separately from the semiconductor device or electronic components. This leads to a reduction in the number of parts and makes it possible to manufacture highly reliable electronic devices.

[Example 1] A molten alloy having the composition shown in Table 1 is made into a fine stream and is injected into a cooling medium to avoid solidification, thereby reducing the diameter to 200 μm.
An alloy wire of mφ was obtained. Furthermore, these alloy wires are made with a diameter of 1
The wire was drawn to 00 μIφ.

A current was passed through the obtained alloy wire to examine its fusing characteristics. At this time, the fusing characteristics were evaluated based on the time until fusing occurred when a predetermined current of 10Δ or less was passed. Therefore, the shorter the time until fusing, the better the fusing characteristics.

The alloy wires having the compositions of the invention examples N081 to N088 are 0
．． It melted instantly when a predetermined current of 3 to 10 A was applied. For comparison, the fusing characteristics were investigated in the same manner using a diagonal wire of the same diameter as a conventional example.

At this time, the Am wire was fused within 1 second when a predetermined ftf flow of 7 to 10 Δ was flowed. From the above results, it can be seen that the fuse conductor made of the low melting point metal, Al, and CIJ alloy according to the present invention exhibits far superior fusing characteristics.

In addition, as shown in Table 1, Comparative Examples No. 089 to No.

An alloy wire having a composition of No. 13, that is, an alloy wire having a composition in which the content of Ai or Cu exceeds the upper and lower limits according to the examples of the present invention, or an alloy having a composition in which the content of sn exceeds the upper limit of the preferable range. A continuous wire with a diameter of 200 μmφ could not be obtained.

(Margin below) Table 1 (Note) A: A continuous line was obtained.

B: 4q continuous line was not drawn.

C: Only granular particles were obtained.

[Example 2] Pb-AfL-C consisting of the composition of N093 shown in Table 1
(A diameter of 200 μm was obtained using I alloy in the same manner as in Example 1.)
The alloy wire was made into a lφ alloy wire, and further drawn to a diameter of 150 μlφ. The obtained alloy wire was used as a conductor for connecting the input side of a power transistor, and the wires were connected by ultrasonic bonding to fabricate a power transistor as a prototype. When a current 10 times the rated current value was applied to this power transistor, only the input-side connection conductor melted instantly, preventing overcurrent from flowing to the surrounding wiring.

[Example 3] PI)-Au-C having the composition of NO62 shown in Table 1
A diameter of 200 μm was obtained in the same manner as in Example 1 using U gold alloy.
The alloy wire was made into a φ alloy wire, and further drawn to a diameter of 70 μmφ.

Using the obtained alloy wire, we prototyped a capacitor with a built-in fuse function. The characteristics of the conductor for this fuse are that the tensile load is 209, and the electrical resistance is 5On+Ω/1ml.
, fusing current (minimum current required to melt within 1 second)
The above alloy wire having a diameter of 70 μm and having a diameter of 0.25 A was used.

When a voltage five times the rated voltage value was applied to a capacitor with such a built-in fuse conductor, only the fuse conductor broke, and other electrical circuits (including the capacitor) were not damaged.

[Example 4] A molten metal of an alloy having a composition of No. 8 shown in Table 1 was made into a trickle and sprayed onto a rotating roll,
A ribbon with a thickness of 50 to 500 uI11 was obtained by solidification. These ribbons also exhibited excellent fusing characteristics similar to Example 1.

Claims (1)

[Claims] 0.01 to 2% by weight of Al, 0.01 to 2% by weight of Cu, and the balance is at least one or two or more metals selected from the group containing Pb, Bi, In, Cd, Sb, and Sn. A conductor for a fuse.