JP2529255B2 - Fuse conductor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuse conductor that functions so as to be instantly disconnected when an overcurrent exceeding a rating flows.

[Prior Art] As described in "Handbook of Metals (Dec. 20, 1982, revised fourth edition p.1007)" edited by The Japan Institute of Metals, conventional fuses are Pb, Zn or Pb-Sn alloys. Is usually used. The fuse conductor made of these metals or alloys is blown by the Joule heat of the overcurrent to open the electric circuit. In order to precisely determine the fusing current without being affected by the outside air temperature, a fuse conductor made of a tungsten wire may be used. Further, wood metal that melts at a constant temperature is used for a fuse of a type that is blown by overheating of a heating atmosphere.

[Problems to be Solved by the Invention] However, as described above, when the fuse conductor is used to add a fuse function to a semiconductor device or an electronic component, it is possible to draw a fine wire or an extra fine wire to a usable degree. It is difficult to process. Therefore, at present, another device having a fuse function is incorporated in a circuit of an electronic device incorporating these devices and parts. Alternatively, the above-described fuse conductor is used in the form of a plate or a thick wire, and the cross-sectional area thereof is reduced by partially forming notches.

A fine wire or an ultrafine wire made of Al, Al alloy, Cu, or Cu alloy may be used as a fuse conductor, but such a fuse conductor is difficult to melt due to an overcurrent.

Therefore, an object of the present invention is to provide a fuse conductor having excellent fusing characteristics and wire drawing.

[Means for Solving the Problems] In the fuse conductor according to the present invention, one of Au and Ag contains 0.01 to 60% by weight, and the balance thereof is P.
The metal is at least one metal or two or more metals selected from the group including b, Bi, In, Cd, Sb, and Sn.

[Advantageous Effects of the Invention] An alloy obtained by adding Au or Ag to a metal of Pb, Bi, In, Cd, Sb, and Sn (hereinafter referred to as a low melting point metal) has a tensile strength higher than that of the low melting point metal itself. improves. The melting points of these alloys are not so high as compared with the low melting point metal itself. However, when the content of Au or Ag increases, the melting point increases and it becomes unsuitable as a fuse conductor. Therefore, it is necessary to keep the content of Au or Ag within a certain range. It is also recognized that these alloys have excellent fusing characteristics. Therefore, by utilizing these characteristics, low melting point metal and Au or Ag
It is desirable to obtain an alloy fine wire composed of and as a conductor for a fuse.

Therefore, the fuse conductor according to the present invention contains 0.01 to 60% by weight of Au or Ag, and the balance is at least one or two or more low melting point metals. If the content of Au or Ag is less than 0.01% by weight, the effect of improving the tensile strength required as a fuse conductor is small,
If it exceeds 5% by weight, the temperature at which the composition is completely in a liquid phase exceeds 700 ° C, which exceeds the melting point temperature suitable for a fuse conductor.

Further, in the composition of the alloy according to the present invention, when one or more low melting point metals other than Pd are contained, the content within the range shown below is preferable, and the wire drawability and the fusing property are excellent.

Bi: 0.01 to 50% by weight In: 0.01 to 30% by weight Cd: 0.01 to 20% by weight Sb: 0.01 to 15% by weight Sn: 0.01 to 40% by weight Further, the content of these low melting point metals is within the above range. It is possible to adjust the melting point temperature as a fuse conductor according to the application by changing the melting point temperature.

As described above, the fuse conductor of the present invention has excellent fusing characteristics and wire drawing workability. Further, since it can be processed into a fine wire or an ultrafine wire, it can be effectively used in a field in which a high resistance value is required as a fuse conductor and a fine wire or an ultrafine wire is required. In particular, it is effectively used when it is desired to add a fuse function to a function originally possessed by a semiconductor device (IC, transistor, etc.) and an electronic part (capacitor, etc.). At this time, a device having a fuse function, which has been incorporated in a circuit of an electronic device separately from a semiconductor device or an electronic part, is not required. Therefore, the number of parts can be reduced, and highly reliable electronic equipment can be manufactured.

[Example 1] An alloy or a metal simple substance having the composition shown in Table 1 was cast by a melt casting method into a mold having a diameter of 20 mmφ. Casting and wire drawing were carried out using the obtained billet to prepare alloy wires or simple metal wires having various wire diameters as shown in Table 1.

An electric current was applied to the obtained alloy wire or metal single wire to examine the fusing characteristics. At this time, the fusing characteristics were evaluated by the time until the fusing when a predetermined current of 10 A or less was applied. Therefore, the shorter the time until melting is, the better the melting characteristics.

The alloy wire consisting of the composition of the present invention No. 1 to No. 8 has 0.3 to 10 A.
It melted instantly when a predetermined current was applied. For comparison, as a conventional example, an Al wire having the same diameter was used to similarly investigate the fusing characteristics. At this time, the Al wire was blown out within 1 second when a predetermined current of 7 to 10 A was applied. From the above results,
It can be seen that the fuse conductor made of the alloy of the low melting point metal and Au according to the present invention exhibits far superior fusing characteristics.

Further, as shown in Table 1, alloy wires or metal single wires having compositions of Comparative Examples No. 9 to No. 12, that is, alloy wires having a composition in which the content of Au exceeds the upper and lower limit values according to the present invention,
Alternatively, a metal single wire or an alloy wire having a composition in which the content of Sn exceeds the upper limit of the preferable range has a diameter of 200 μm.
It was not possible to obtain a continuous wire of φ, or even if a continuous wire could be obtained, it took several seconds for fusing.

[Example 2] Alloy wires or metal single wires having various wire diameters were obtained in the same manner as in Example 1 using the alloys or metal single wires having the compositions shown in Table 2. Then, the fusing characteristics of the obtained alloy wire or single metal wire were examined by the same evaluation method as in Example 1.

Inventive example No. 13 ~ No. 20 alloy wire consisting of composition is 0.3 ~ 1
When a predetermined current of up to 0A was passed, the material melted instantaneously. For comparison, as a conventional example, an Al wire having the same diameter was used to similarly investigate the fusing characteristics. At this time, the Al wire was fused within 1 second when a predetermined current of 7 to 10 A was applied. From the above results, it is understood that the fuse conductor made of the alloy of the low melting point metal and Ag according to the present invention exhibits far superior fusing characteristics.

Further, as shown in Table 2, alloy wires or metal single wires having the compositions of Comparative Examples No. 21 to No. 24, that is, alloy wires having a composition in which the content of Ag exceeds the upper and lower limit values according to the present invention example. , Or a metal single wire, or an alloy wire having a composition in which the content of Sn exceeds the upper limit of the preferable range, a diameter of 200
A continuous line of μmφ could not be obtained, or even if a continuous line could be obtained, it took several seconds for melting.

[Example 3] A Pb-Au alloy having the composition of No. 3 shown in Table 1 was used to draw wires to a diameter of 150 µm in the same manner as in Example 1.
Using the obtained alloy wire as a conductor for connecting the input side of the power transistor, it was connected by ultrasonic bonding to fabricate a power transistor. When a current 10 times the rated current value was applied to this power transistor, only the input side connection conductor melted instantaneously, preventing an overcurrent from flowing in the surrounding wiring.

[Example 4] A Pb-Ag alloy having a composition of No. 14 shown in Table 2 was used to draw a wire having a diameter of 150 µm in the same manner as in Example 1. When the obtained alloy wire was used for a power transistor in the same manner as in Example 3 and a current of 10 times the rated current value was applied,
It was prevented that only the input side connection conductor melted instantaneously and overcurrent flowed to the surrounding wiring.

[Example 5] A Pb-Au alloy having the composition of No. 2 shown in Table 1 was used to draw a wire having a diameter of 70 µm in the same manner as in Example 1. A capacitor with a built-in fuse function was prototyped using the obtained alloy. At this time, as the characteristics of the fuse conductor,
Tensile load is 20g, electric resistance is 50mΩ / mm, fusing current (1
The above-mentioned alloy wire having a diameter of 70 μm and having a minimum current required for fusing within seconds of 0.25 A was used.

When a voltage 5 times the rated voltage value was applied to a capacitor containing such a fuse conductor, only the fuse conductor was broken, and other electric circuits (including the capacitor) were not damaged.

[Example 6] A Pb-Ag alloy having a composition of No. 15 shown in Table 2 was used to draw a wire having a diameter of 70 µm in the same manner as in Example 1.
A capacitor with a built-in fuse function was prototyped using the obtained alloy wire. At this time, as characteristics of the fuse conductor, the above-mentioned alloy wire having a diameter of 70 μm and a tensile load of 17 g, an electric resistance value of 50 mΩ / mm, and a fusing current (minimum current required for fusing within 1 second) is 0.25 A. Using.

When a voltage 5 times the rated voltage value was applied to a capacitor containing such a fuse conductor, only the fuse conductor was broken, and other electric circuits (including the capacitor) were not damaged.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C22C 28/00 C22C 28/00 B H01B 1/02 H01B 1/02 Z H01H 85/06 7346-5G H01H 85/06

Claims (1)

(57) [Claims] 1. One of Au and Ag is 0.01 to
A conductor for a fuse, which comprises 60% by weight and the balance thereof is at least one metal or two or more metals selected from the group containing Pb, Bi, In, Cd, Sb and Sn.