Background Art [2] Generally, power input ends of electronic appliances, such as televisions, video recorders, etc. , are mounted with fuse apparatuses which function to electrically disconnect circuits, to protect the circuits from damage and prevent a board from catching fire when an overcurrent occurs due to lighting.

[3] FIG. 1 is a perspective view illustrating a conventional fuse apparatus.

[4] As shown in FIG. 1, the conventional fuse apparatus includes a fuse element 10 having a glass tube 11, a fusing body 12, and caps 13, and fuse holders 20 to fix the fuse element 10 onto a circuit board 30.

[5] At a center in the glass tube 11, the fusing body 12, including a fusing material that is melted and cut off upon flow of an overcurrent, is longitudinally positioned. The caps 13 are mounted to both ends of the glass tube 11 so that the fusing body 12 is connected to external electric circuits and the glass tube 11 is sealed. Both ends of the fusing body 12 are connected to inner surfaces of the caps 13, respectively. As such, lead (Pb) is used to connect the fusing body 12 and the caps 13. Meanwhile, on the circuit board 30, the fuse holders 20 are mounted to fix the fuse element 10. The caps 13 of the fuse element 10 are fitted into the fuse holders 20 and connected thereto.

Thus, when an overcurrent flows in the circuit board 30, the fusing body 12 is fused to interrupt the circuits, thereby protecting electronic parts and total circuits.

[6] However, since the fusing body 12 and the caps 13 are connected together by lead (Pb) having low heat resistance, a bonding force between the fusing body 12 and the caps 13 is low. Accordingly, where an automated system having a solder bath of high temperatures is used, lead is melted and the fusing body 12 may be separated from the caps 13. Further, attributable to the use of lead regarded as an environmentally harmful material, environmental problems occur.

[7] In addition, the glass tube 11 is conventionally made of glass or earthenware, which has relatively higher heat resistance, but is lower in strength, compared to other parts. Hence, the glass tube 11 may be easily broken. Thereby, it is difficult to perform an automated process by use of an automatic inserting unit, and thus a worker should individually fit a plurality of the fuse elements 10 into the fuse holders 20. Therefore, upon manufacturing the electronic appliances, manufacturing costs due to personnel expenses are increased, along with a working period.

[8] Also, since the fuse element per se is not directly inserted into the board, additional fuse holders are required to insert the fuse element into the board. Hence, spaces to mount the fuse holders are additionally needed, and mounting costs increase.

Disclosure of Invention Technical Problem [9] It is an aspect of the present invention to provide a fuse apparatus, characterized by automating a fuse inserting process while number of parts and size of mounting spaces are minimized, by increasing strength of a fuse element and directly inserting the fuse element into a board without a fuse holder.

[10] It is another aspect of the present invention to provide a fuse apparatus, char- acterized in a fuse element is rapidly and accurately fused when an overcurrent occurs, while having fusing characteristics equal to those of conventional fuse elements, thus increasing reliability and protecting other electronic parts and circuits.

[11] It is a further aspect of the present invention to provide a method of manufacturing the fuse apparatus.

Technical Solution [12] The foregoing and other aspects of the present invention are achieved by providing a fuse apparatus, including a support, a fusible element layer formed to surround the support, spiral grooves formed in the fusible element layer so that both ends of a structure having the support and the fusible element layer have a predetermined resistance, caps formed to surround both ends of the fusible element layer so that the fusible element layer is electrically connected to an outside, lead wires attached to outer sides of the caps, an insulating film formed onto a copper layer and the caps to electrically insulate the copper layer and the caps from an outside, and a protective ac- commodating member to prevent arc energy generated upon fusing of a tin layer from externally transferring.

[13] The fuse apparatus is characterized in that the accommodating member is charged with a filler to absorb the arc energy.

[14] The fuse apparatus is characterized in that the filler is selected from the group consisting of magnesium oxide (MgO), zirconia (ZrO), silica, clay, gypsum, calcium carbonate, mica, alumina, sand, gravel, sandstone, limestone, or mixtures thereof.

[15] The fuse apparatus is characterized in that the fusible element layer includes a material having temperature coefficient not less than 2,000 ppm/° C, and specific resistance of 1.6x 10-1. 8 x 10- sa m.

[16] The fuse apparatus is characterized in that the fusible element layer includes a tin material.

[17] The fuse apparatus is characterized by further including a conductive layer having a conductive material between the support and the fusible element layer.

[18] The fuse apparatus is characterized in that the conductive layer includes a nickel- chromium (Ni-Cr) material.

[19] The fuse apparatus is characterized in that the accommodating member is used to accommodate the caps and the fusible element layer so that parts of the lead wires are externally exposed.

[20] The fuse apparatus is characterized in that the accommodating member includes a nylon-based material.

[21] In addition, the above andbr other aspects are achieved by providing a method of manufacturing a fuse apparatus, the method including preparing a support, forming a conductive layer around the support, forming a fusible element layer on the conductive layer, forming caps at both ends of a first structure including the support, the conductive layer and the fusible element layer so that the first structure is electrically connected to an outside to prepare a second structure, forming spiral grooves having a predetermined width in the conductive layer and the fusible element layer so that both ends of the second structure have a predetermined resistance to prepare a third structure, attaching lead wires to both ends of the third structure, and accommodating the fusible element layer into a protective accommodating member so that arc energy generated upon fusing of the fusible element layer is prevented from externally transferring.

[22] The method is characterized in that a filler to prevent the arc energy from externally transferring is charged in the accommodating member, and then an inlet of the accommodating member is sealed.

[23] The method is characterized in that the caps and the fusible element layer are sealed so that the lead wires are externally exposed.

[24] The method is characterized in that the caps and the fusible element layer are ac- commodated into the accommodating member, and then a rating, a qualifying mark, and a trademark of a manufacturer are represented onto an outer side of the ac- commodating member.

[25] The method is characterized in that a width and a cutting number of the spiral grooves are controlled so that the predetermined resistance is in a range of 10-200 m # Advantageous Effects [26] As apparent from the above description, the present invention provides a fuse apparatus and a method of manufacturing the same, having advantages of the automation of a fuse inserting process while number of parts and size of mounting spaces are minimized.

[27] In addition, upon overcurrent applications, a fuse element is rapidly and accurately fused, thereby increasing reliability of products and protecting other electronic parts and circuits.

[28] Further, in the present invention, a novel manufacturing method is proposed, instead of conventional methods, thus achieving high productivity.

[29] Furthermore, in the present invention, non-lead materials are used, whereby envi- ronmental problems do not occur.

Description of Drawings [30] These and other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which: [31] FIG. 1 is a perspective view illustrating a conventional fuse apparatus; and [32] FIGS. 2 to 9 are sectional views illustrating sequential manufacturing operations of a fuse apparatus, according to the present invention.

Best Mode [33] Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[34] FIGS. 2 to 9 are sectional views illustrating sequential manufacturing operations of a fuse apparatus, according to the present invention.

[35] As shown in FIG. 2, a conductive layer 101 including a conductive material is layered on a surface of a rod-shaped support 100. In the present invention, the support 100 includes a nonconductive ceramic material having high purity. As the conductive material, nickel-chromium (Ni-Cr) is used, which is superimposed on the surface of the support 100 by a conventional electroless plating process.

[36] Thereafter, as shown in FIG. 3, a fusible element layer 102 having fusing charac- teristics is layered on a surface of the conductive layer 101. In the present invention, the fusible element layer 102 is formed mainly of tin (Sn). In addition to tin (Sn), any material may be used so long as it has temperature coefficient not less than about 2,000 ppm/°C and low specific resistance ranging from 1.6 # 10-8 to 1.8 # 10-8 # m. The fusible element layer 102 is melted and fused with heat caused by an overcurrent. In such a case, the temperature coefficient acts as the most important parameter determining the fusing characteristics. If the temperature coefficient is high, the resistance of the fusible element layer 102 increases due to heat caused by the overcurrent. Thereby, the fusible element layer 102 is heated up to a melting point by Joule heat, and thus fused. In the present invention, tin (Sn) used as a material of the fusible element layer 102 has high temperature coefficient, low specific resistance, and low melting point. Thus, the fuse apparatus of the present invention is considerably improved in fusing characteristics, compared to conventional fuse apparatuses.

Thereby, a fusing process is rapidly and accurately carried out.

[37] The fusible element layer 102 is deposited on the surface of the conductive layer 101 by an electrolytic plating process. Alternatively, in addition to the electrolytic plating process, the fusible element layer 102 may be directly deposited on the surface of the support 100 by a sputtering process. In cases where the fusible element layer 102 is layered without the use of the electrolytic plating process, the conductive layer 101 may be omitted.

[38] Initial resistance of both ends of a first structure 110 having the conductive layer 101 and the fusible element layer 102, depending on a composition and a thickness of each of the layers, is maintained in a range of 15-30 m sa , according to the present invention.

[39] Then, as shown in FIG. 4, caps 103 are mounted to both ends of the first structure 110, to prepare a second structure 120. Through the caps 103, the fusible element layer 102 is electrically connected to an outside. The resistance of both ends of the second structure 120 is in the range of 8-15 m # [40] As shown in FIG. 5, spiral grooves 104 are longitudinally formed in the two layers 101 and 102, which are the conductive layer and the fusible element layer, re- spectively, to prepare a third structure 130. The third structure 130 has final resistance of 10-200 m n at both ends thereof. The final resistance is determined according to rotation numbers of spiral cutting, as well as the initial resistance of both ends of the second structure 120. Specifically, the final resistance after the spiral cutting depends on a spiral width, a distance between spirals, a cutting depth, and a cutting width. According to the final resistance, characteristics corresponding to a rated current of the fuse apparatus are determined.

[41] Then, as shown in FIG. 6, lead wires 105 are attached to outer sides of both caps 103 of the third structure 130 by a welding process, to prepare a fourth structure 140.

The lead wires 105 are inserted into a circuit board so that the fusible element layer 102 and the caps 103 are electrically connected to the circuit board.

[42] After a fuse element 140 as in FIG. 6 is fabricated according to a series of operations as mentioned above, the fuse element 140 is placed into a protective ac- commodating member 106 to prevent arc energy generated upon fusing of the fusible element layer from externally transferring, as shown in FIG. 7. The accommodating member 106 is made of a material having high heat resistance and strength (e. g. , a nylon-based material). Further, the accommodating member 106 functions to protect and insulate the conductive fusible element layer 102 from an outside. Onto an outer side of the accommodating member 106, a rating, such as 250V and 4A, a qualifying mark, and a trademark of a manufacturer are represented.

[43] As shown in FIG. 8, a filler 107 is charged between the accommodating member 106 and the fuse element 140. The filler 107 acts to absorb the arc energy generated upon fusing of the fusible element layer 102 to prevent the energy from externally transferring, together with the accommodating member 106. The filler 107 includes any material selected from the group consisting of magnesium oxide (MgO), zirconium dioxide (ZrO2; commonly referred to as 'zirconia'), silica, clay, gypsum, calcium carbonate, mica, alumina, sand, gravel, sandstone, limestone, or mixtures thereof. By using the filler 107, high breaking capacity is exhibited as the most important property of the fuse apparatus. In addition, the filler 107 functions to prolong the fusing period. In the present invention, the filler 107 is charged in a 2/3 volume of a chamber of the accommodating member 106 to the extent of completely surrounding the fuse element 140.

[44] Thereafter, as shown in FIG. 9, an inlet of the accommodating member 106 is sealed by use of a sealing material 108 so that the fuse element 140 and the filler 107 are sealed in the accommodating member 106. The sealing material 108 functions to completely seal the fuse element 140 and powdered filler 107 in the accommodating member 106. In the present invention, the sealing material 108 has an epoxy resin, which is advantageous in terms of quick dry and high heat resistance.

[45] After the inlet of the accommodating member 106 is sealed with the sealing material 108, the sealing material 108 is dried. Then, the outer side of the ac- commodating member 106 is subjected to a mar : Ling process to represent a rating and so on of products. Thereby, the sealed structure is used as a fuse apparatus.

[46] In addition, the completed fuse apparatus may be further subjected to taping at regular intervals, as a preparation process to automatically insert the fuse apparatus into a circuit board by use of an automatic inserting unit.