JP3006855U - Burst prevention structure for chip type fuse - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a chip type fuse capable of preventing a wire fuse from bursting or cracking due to fusing energy and preventing secondary damage to other parts such as a circuit. A wire fuse 2 is connected to a take-out lead 1, and the entire surface of the wire fuse 2 is coated with a bursting prevention coating resin 5 and further sealed with a packaging resin 4. When the wire fuse 2 generates heat and melts, the burst-prevention coating resin 5 vaporizes in parallel with this, and energy that causes the bursting of the exterior resin 4 is generated. This fusing energy is the burst-prevention coating resin. Since it is released to the outside through the exposed portion 6 communicating with the surface of the exterior resin 4 in 5, the occurrence of rupture and cracking is prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rupture prevention structure for a chip-type fuse, and more specifically, in a chip-type fuse that blows to protect a circuit when an overcurrent occurs, prevents rupture and cracking due to a momentarily increasing fusing energy. This is related to the fuse structure.

[0002]

[Prior art]

 As with other electronic components and boards, small fuses are required, but there is a tendency for fuses that can be mounted on boards to be made into chips. For this reason, even if the resin exterior is used, a structure with high-performance fusing characteristics and rupture prevention is required. Therefore, conventionally, as shown in FIG. 5, as a structure of this kind, as shown in FIG. 5, a wire fuse 2 is connected to a lead-out lead 1 and is coated with a coating resin 3 and is further sealed with a packaging resin 4. It is known that the coating resin 3 inside prevents rupture and cracking.

[0003]

[Problems to be solved by the device]

 By the way, in the conventional chip-type fuse shown in FIG. 5, the coating resin 3 inside absorbs the fusing energy when the line fuse 2 is melted. Is unable to absorb the fusing energy that increases rapidly inside, and as shown in FIG. 6, the applied resin 3 and the exterior resin 4 crack, causing rupture, which adversely affects other parts. There was a problem such as a secondary obstacle that caused

The present invention has been made in view of the above-mentioned problems of the conventional technology. Its purpose is to prevent rupture and cracking due to fusing energy and to prevent secondary damage to other parts such as circuits. It is to provide a chip-type fuse capable of preventing the above-mentioned problem.

[0005]

[Means for solving problems]

 To this end, the present invention is a chip-type fuse including a wire fuse, an exterior resin, and a take-out lead, in which the wire fuse is coated with a burst-prevention coating resin and leads to the exterior surface of the burst-prevention coating resin. The feature is that the fusing energy of the wire fuse due to overcurrent is released from the exposed part to the outside to prevent rupture and cracking.

[0006]

【Example】

 An embodiment will be described with reference to the drawings together with the operation thereof. FIG. 1 is a cross-sectional view showing an example of the present invention. As shown in the figure, a wire fuse 2 is connected to a lead-out lead 1 by welding or the like, and the entire surface of the wire fuse 2 is coated for bursting prevention. It is coated with resin 5 and is further sealed with exterior resin 4.

In the present embodiment, when the line fuse 2 generates heat due to overcurrent and melts, the burst preventing coating resin 5 in contact with the line fuse 2 is vaporized in parallel with this, and the exterior resin 4 is removed. The energy that causes the explosion is generated. However, as shown in FIG. 2, this fusing energy is released to the outside through the exposed portion 6 of the burst-prevention coating resin 5 that communicates with the surface of the exterior resin 4 to prevent the occurrence of bursting and cracking. It By the way, according to the present invention, 20% rupture of the conventional product shown in FIG. 5 was 0% at the fusing current of 3 times the rated current.

In another example of the present invention shown in FIGS. 3 and 4, the exposed portion 6 of the coating resin 5 for bursting prevention is taken out to the outer surface of the lead 1 and melted by the exposed portion 6. Energy is released to the outside to prevent rupture and cracking. According to this embodiment, the fusing operation of the wire fuse 2 can be visually confirmed from the outside.

[0009]

[Effect of device]

 According to the present invention, however, the fusing energy at the time of fusing the wire fuse is released to the outside from the exposed portion 6 communicating with the exterior surface of the fuse through the coating resin 5 for rupture prevention, so that the rupture or cracking of the chip fuse is caused. This prevents secondary damage to other parts such as circuits.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of the present invention.

FIG. 2 is a cross-sectional view showing a blown state of a line fuse in the present example.

FIG. 3 is a sectional view showing another example of the present invention.

FIG. 4 is a cross-sectional view showing a blown state of a line fuse in this another example.

FIG. 5 is a cross-sectional view showing a conventional example.

FIG. 6 is a cross-sectional view showing a blown state of a line fuse in a conventional example.

[Explanation of symbols]

 1 Extraction lead 2 Wire fuse 4 Exterior resin 5 Burst prevention coating resin 6 Burst prevention coating resin exposed part

Claims (1)

[Scope of utility model registration request] 1. A chip-type fuse including a wire fuse, an exterior resin, and a take-out lead, wherein the wire fuse is coated with a burst-prevention coating resin and is exposed to an overcurrent from an exposed portion of the burst-prevention coating resin leading to the exterior surface. A rupture prevention structure for a chip-type fuse, characterized in that the fusing energy of the wire fuse is released to the outside to prevent rupture, cracking and the like.