JP5455674B2 - Materials for electrical and electronic fuses - Google Patents

Description

  The present invention relates to a material constituting an element of a fuse built in an electric / electronic component such as a capacitor. More specifically, the present invention relates to a material having a melting point within a preferable range for fuse applications and having excellent fusing characteristics and workability.

  When an overcurrent flows, a fuse built in an electric / electronic component such as a capacitor is cut off from energization by the element being blown by Joule heat. In consideration of such functions, the material constituting the element is required to have an appropriate range, specifically, a melting point in the range of about 300 to 360 ° C. This is because when the melting point of the element is high, the operating temperature of the fuse also becomes high, but this damages the circuit board on which the electronic component is mounted, so that it cannot be expected to function as the original protective device of the fuse.

  Conventionally, Sn—Pb-based alloys have been widely used as materials for fuses, but in recent years, application of Pb-free materials has been demanded. Application of Sn alloy, Au-3.15 mass% Si alloy, etc. is being studied.

JP 2001-28228 A

  However, the Au-20 mass% Sn alloy has a problem that the melting point is lower than the above range and the workability is poor. The fuse element needs to be processed into a fine size such as a thin wire shape or a thin plate shape, and a material with poor workability is liable to be disconnected or cracked, resulting in a decrease in yield. Particularly, in recent electronic members, there is a strong demand for downsizing, and a fuse mounted to follow this needs to be thinned and thinned. Therefore, a material with good workability is desired.

  Further, the Au-3.15 mass% Si alloy actually has a slightly higher melting point than the above range and slightly exceeds 360 ° C., and cannot be used actively. Furthermore, since this alloy has low electric resistance, there is a tendency for fusing to be delayed when an overcurrent flows, and there is a problem in the function as a fuse.

  As described above, the conventional fuse material does not have such a serious problem that it cannot be used, but improvement is desired in consideration of future needs and the like. Accordingly, the present invention provides a material for a fuse that has improved workability and electrical resistance, is particularly excellent in fusing characteristics, and has a melting point in a suitable range (specifically, around 300 to 360 ° C.). .

  The present inventors have studied to solve the above problems. First, physical properties of an Au alloy based on Au and added with various metals were evaluated, and in a ternary alloy containing Au, Ga and In, workability and electrical resistance were improved as compared with the conventional one. I understood it. And if it is an alloy which has a predetermined composition range among Au-Ga-In alloys, it will discover that it is excellent in a fusing characteristic, and if a composition range is further limited, melting | fusing point will fall, maintaining a favorable fusing characteristic. As a result, the present invention has been conceived.

  That is, the present invention is made of an Au-Ga-In ternary alloy, and the mass concentration of these elements is point A in the ternary phase diagram (Au: 85%, Ga: 14%, In: 1%). , B point (Au: 74%, Ga: 11%, In: 15%), C point (Au: 74%, Ga: 6%, In: 20%), D point (Au: 78%, Ga: 2) %, In: 20%), and a material for a fuse in a polygonal region having apex at point E (Au: 86%, Ga: 2%, In: 12%).

  A ternary phase diagram showing the composition of the material according to the present invention is shown in FIG. The reason why the ternary alloy is applied in the present invention is that workability and electrical resistance are improved as compared to the conventional Au binary alloy by simultaneously adding two elements of Ga and In to Au. . The reason why the addition amount of Ga and In is set within the above range is because the fusing characteristics are improved. As a method for adjusting the melting point, it is conceivable to increase the content of the element added to the alloy, but in that case, the workability may be affected. Ga and In, which are additive elements in the present invention, can control the melting point with a small amount of addition, and ensure workability.

  And a more preferable composition in this invention is a composition of the area | region where Ga is 5-13 mass% and In becomes 5-15 mass% in the said range. Specifically, in the ternary phase diagram of FIG. 1, point A1 (Au: 82%, Ga: 13%, In: 5%), point B1 (Au: 77%, Ga: 8%, In: 15) %), C1 point (Au: 80%, Ga: 5%, In: 15%), D1 point (Au: 85%, Ga: 10%, In: 5%) Composition. This is because with such a composition, the melting point is lowered and the performance as a fuse can be improved.

  In the production of the alloy according to the present invention, there is no particular difficulty, and it can be produced by a melt casting method in the same manner as a normal alloy (Au alloy). Also, with regard to processing into fuses, the material according to the present invention has good workability, and can be processed into an arbitrary size by extrusion processing or wire drawing processing.

  As described above, the material according to the present invention has a melting point in the vicinity of 300 to 360 ° C., and is within an appropriate temperature range as a melting point range for fuse applications. The material according to the present invention has good processability and is suitable for manufacturing a micro fuse. Furthermore, the electrical resistance is reasonably high, and this point is also suitable for fuse applications.

The Au-Ga-In ternary phase diagram which shows the composition of the material which concerns on this invention. The figure which shows the Au-Ga-In alloy composition of embodiment of this invention and a comparative example

  Hereinafter, embodiments of the present invention and comparative examples will be described. In this embodiment, Au—Ga—In alloys with various compositions were manufactured, and the characteristics of each were evaluated and studied. In the production of the sample, each metal weighed so as to have a predetermined composition was melted and cast, and the wire was drawn to obtain a wire having a diameter of 0.1 mm.

  Each sample was evaluated for melting point, electrical resistance (specific resistance), hardness, workability, and fusing characteristics. About workability, the presence or absence of the generation | occurrence | production of the disconnection by a wire drawing process, a crack, and a burr | flash was observed and evaluated with the actual condition microscope (10 times). For the evaluation of the fusing characteristics, the fusing time when a current of 4 A was applied to the sample wire was measured, and those with a fusing time of less than 0.5 seconds were regarded as non-defective products. In addition, about melting | fusing point, it measured by thermal analysis (TG-DTA), and the electrical resistance measured the specific resistance with the milliohm meter. Table 1 shows the above evaluation results.

  As can be seen from Table 1, the material in which the mass concentration of the element of the Au—Ga—In ternary alloy is within a polygonal region having points A to E in the ternary phase diagram shown in FIG. The melting point was in the range of about 300 to 360 ° C., and the workability and fusing characteristics were also good (Examples 1 to 5). In particular, if the mass concentration is in a polygonal region having points A1 to D1 in the ternary phase diagram shown in FIG. 2, not only the workability and fusing characteristics are excellent, but also the melting point is lowered. As a material for the fuse, it becomes a suitable material (Examples 3 and 4). On the other hand, when the mass concentration of the material deviates from the polygonal region having points A to E in the ternary phase diagram shown in FIG.

The present invention relates to a material constituting a fuse element incorporated in an electric / electronic component such as a capacitor. By using the material according to the present invention, a current fuse excellent in fusing characteristics and workability can be provided.

Claims (3)

  It consists of an Au-Ga-In ternary alloy, and the mass concentration of these elements is point A (Au: 85%, Ga: 14%, In: 1%), point B (Au: Au: ternary phase diagram). 74%, Ga: 11%, In: 15%), C point (Au: 74%, Ga: 6%, In: 20%), D point (Au: 78%, Ga: 2%, In: 20%) ), A material for a fuse in a polygonal region having an E point (Au: 86%, Ga: 2%, In: 12%) as a vertex.   The mass concentrations of Au, Ga and In are A1 point (Au: 82%, Ga: 13%, In: 5%) and B1 point (Au: 77%, Ga: 8%, In: in the ternary phase diagram. 15%), C1 point (Au: 80%, Ga: 5%, In: 15%), D1 point (Au: 85%, Ga: 10%, In: 5%) within the polygonal region The material for a fuse according to claim 1.   A current fuse comprising an element made of the fuse material according to claim 1.

Images