CN219066741U

CN219066741U - Surface-mounted fuse

Info

Publication number: CN219066741U
Application number: CN202223565596.9U
Authority: CN
Inventors: 代建国; 杨永林
Original assignee: AEM Components Co Ltd
Current assignee: AEM Components Co Ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2023-05-23
Anticipated expiration: 2032-12-30

Abstract

The utility model discloses a surface-mounted fuse, which comprises an electrode part, a fusing part and supporting parts, wherein the fusing part is respectively connected with the two electrode parts; the fusing part comprises a first fusing part, a second fusing part and a third fusing part which are sequentially connected in series; the cavity formed by the cavity plates is combined to form a cavity, and the fusing part is positioned in the cavity; the base plate comprises an upper base plate and a lower base plate which are respectively overlapped above and below the cavity plate; the terminal electrode is arranged on the substrate and/or the cavity plate and is electrically connected with the melt; the filler is filled in the first cavity and the second cavity; through the setting of supporting part, overcome the fuse-element that thicker copper foil made among the prior art and upper and lower insulating casing are connected not stable enough problem, ensure the leakproofness of fuse.

Description

Surface-mounted fuse

Technical Field

The utility model relates to the field of electric protection elements, in particular to a surface mount fuse with a supporting wall.

Background

Fuses are widely used for overcurrent protection of various electronic components. The metal conductor is used as a melt to be connected in series in the circuit, the temperature of the melt can be raised due to the heat converted by the current when the fuse is electrified, and the heat generated by the current and the heat radiated by the melt, the shell, the surrounding environment, and the like in the manners of radiation, convection, conduction and the like can be gradually balanced when the normal working current or the allowable overload current is loaded; if the heat dissipation speed is not equal to the heating speed, the heat can be gradually accumulated on the melt to raise the temperature of the melt, and once the temperature reaches or exceeds the melting point of the melt material, the melt can be liquefied or vaporized, so that the current is disconnected, and the safety protection effect on the circuit and the human body is achieved.

At present, the surface-mounted fuse with FR4 as a substrate is formed by laminating the substrate and wires in a multilayer laminating mode, and a fusing part formed by printing the FR4 substrate fuse can only meet the breaking requirement of 200A@250VDC and cannot meet the working environment of high current. In order to improve the breaking capacity of the fuse link, thicker copper foil (0.05-0.3 mm) is needed to manufacture melt to improve the cross section area of the fuse link, but in the copper foil melt in the prior art, the distance between electrodes at two sides is too large, so that a glue film between substrates is separated from the substrates at the upper layer and the lower layer, and an electric arc generated at the moment of breaking is sprayed to two sides due to the blocking of filler or the glue film, so that the problem of air leakage is caused.

Disclosure of Invention

In order to overcome the defects in the prior art, the utility model aims to at least provide a novel surface mount fuse.

The utility model provides a surface mount fuse, comprising:

the melt comprises electrode parts, a fusing part and supporting parts, wherein the fusing part is respectively connected with two electrode parts positioned at the left side and the right side of the melt, the two supporting parts are respectively positioned at the front side and the rear side of the fusing part, and each supporting part is only connected with one electrode part and has a gap with the other electrode part; the first fusing part and the second fusing part are used for fusing when in high overload, and the second fusing part is used for fusing when in low overload;

the cavity plate comprises a first cavity plate provided with a first cavity and a second cavity plate provided with a second cavity, the first cavity and the second cavity are surrounded to form a cavity, and the fusing part is positioned in the cavity;

a substrate including an upper substrate and a lower substrate stacked above and below the cavity plate, respectively;

an end electrode disposed on the substrate and/or the cavity plate, the end electrode being electrically connected to the melt;

and the filler is filled in the first cavity and the second cavity.

In some embodiments, at least a portion of the side wall of the support portion constitutes an outer wall of the surface mount fuse.

In some embodiments, the support includes a plurality of protrusions.

In some embodiments, the protrusion faces the fuse portion.

In some embodiments, the plurality of protrusions undulate.

In some embodiments, the width of the gap gradually increases from outside to inside.

In some embodiments, the device further comprises arc-shaped sections arranged at four corners, wherein the arc-shaped sections penetrate from the upper substrate to the lower substrate, and the surfaces of the arc-shaped sections are plated with metal layers.

In some embodiments, the gaps corresponding to the two supporting portions are arranged in a staggered manner.

In some embodiments, the substrate, the first cavity plate, the melt, the second cavity plate and the lower substrate are sequentially distributed from top to bottom, and the adjacent components are fixedly connected together by hot pressing through a pure adhesive film.

In some embodiments, the upper portion of the first cavity plate and the lower portion of the second cavity plate are both filled with a correspondingly positioned film of pure glue.

The utility model has the beneficial effects that:

compared with the prior art, the surface-mounted fuse provided by the utility model overcomes the problem that the melt made of thicker copper foil is not stably connected with the upper and lower insulating shells in the prior art through the arrangement of the supporting part, avoids the problem of air leakage caused by the fact that an arc generated at the moment of breaking is sprayed to two sides due to the blocking of arc extinguishing filler or a pure adhesive film, and ensures the tightness of the fuse.

Drawings

FIG. 1 is a schematic diagram of an explosion structure of a surface mount fuse in the present utility model;

FIG. 2 is a schematic cross-sectional view of a surface mount fuse of the present utility model;

fig. 3 is a schematic perspective view of a surface mount fuse according to the present utility model;

fig. 4 is a schematic view of a longitudinal section of a surface mount fuse in the present utility model;

FIG. 5 is a schematic view of a melt structure of a surface mount fuse of the present utility model;

FIG. 6 is an X-RAY diagram of a surface mount fuse of the present utility model after low current blowing (2 times rated current);

fig. 7 is an X-RAY diagram of the surface mount fuse of the present utility model after high current blowing (10 times rated current).

The utility model will be further described with reference to the drawings and detailed description.

Detailed Description

The utility model will be further understood by the following specific examples of the utility model, which are given by way of illustration and are not intended to be limiting.

As shown in fig. 1-5, the present embodiment provides a surface mount fuse, which includes a melt 300, a cavity plate, a substrate 100, terminal electrodes, and a filler.

The substrates include an upper substrate 100 and a lower substrate 500 stacked above the first cavity plate 200 and below the second cavity plate 400, respectively, and terminal electrodes for electrical connection with an external circuit are disposed on the substrates and/or the cavity plates, the terminal electrodes being electrically connected with the melt; in this embodiment, the terminal electrode includes a surface terminal electrode 110 on the substrate and a side electrode 2510 on the side wall, and the surface terminal electrode 110 is manufactured by a copper-clad circuit board etching method, specifically, a substrate with one side forming the surface terminal electrode 110 is manufactured by removing a part of copper foil of a circuit board with copper foil attached on the surface. The surface mount fuse in this embodiment includes an upper substrate 100, a first cavity plate 200, a melt 300, a second cavity plate 400, and a lower substrate 500 sequentially from top to bottom, and the foregoing adjacent components are hot pressed together by the pure

adhesive films

150, 250, 350, 450.

The cavity plate is a copper-free insulating plate and comprises a first cavity plate 200 provided with a first cavity and a second cavity plate 400 provided with a second cavity, the first cavity and the second cavity are formed by mechanical processing methods such as milling, stamping and the like, the first cavity and the second cavity are surrounded to form a cavity, and a fusing part of the melt is positioned in the cavity.

The filler 800 is filled in the first cavity and the second cavity, and is mainly used for arc extinction. As shown in fig. 2, in the present embodiment, the upper portion of the first cavity plate 200 and the lower portion of the second cavity plate 400 are filled with the

photoresist films

150 and 450 at corresponding positions, so that the packing is tightly filled, and the arc extinguishing function of the packing is not affected. The filler 800 may be made of materials known in the art, and will not be described in detail herein.

As shown in fig. 5, in the surface mount fuse in the present embodiment, the plate-shaped melt 300 includes electrode portions 310, fusing portions (320, 330, 340) and supporting portions 350, the

fusing portions

320, 330, 340 are respectively connected to two electrode portions 310 located on the left and right sides thereof, the two supporting portions 350 are respectively located on the front and rear sides of the

fusing portions

320, 330, 340, each supporting portion 350 is connected to only one electrode portion 310 with a gap 360 between the other electrode portion 310;

the fusing part comprises a first fusing part 320, a second fusing part 330 and a third fusing part 340 which are sequentially connected in series, wherein the first fusing part 320 and the second fusing part 340 are used for fusing when in high overload, and the surface of the second fusing part 330 is tinned and used for fusing when in low overload; the melt 300 is not tin plated except for the second fuse portion 330. Which uses the copper-tin alloy interdiffusion principle so that it can be broken at the tin-plated second fuse portion 330 at a low current (twice rated current) (see fig. 6). At high current, the second fusing part 330 in the middle is heated up due to the tin plating in the middle, and the third fusing part 340 (line width weak point) of the first fusing part 320 is arranged at both sides, so that the fuse is disconnected at the high current and does not extend to the electrode part 330 (as shown in fig. 7), thus the arc can be instantaneously cut off, and the fuse can bear higher current. In this embodiment, the melt plate 300 is formed by forming a line width by image transfer from a copper foil plate, and forming the second fusing part 330 by electroplating a tin layer in the middle by electroplating tin.

As shown in fig. 3, at least part of the side walls of the supporting portion 350 form the outer wall of the surface mount fuse, the supporting portion 350 in this embodiment includes a plurality of protrusions 370, the protrusions 370 may face the fusing portion or may be away from the fusing portion, the protrusions 370 in this embodiment face the fusing portion, and the plurality of protrusions 370 are in a wave shape. In fact, in the present embodiment, the concave recess is formed by cylindrically cutting the supporting portion 350, and thus the protrusion 370 protruding outward is formed. The space formed by the depressions can accommodate more filler 800, improving the arc extinguishing characteristics of the whole surface mount fuse. In addition, the gap 360 between the support portion 350 and the opposite electrode portion 310 has an "eight" shape with an opening diameter that is increased inward, which is more advantageous in that the filler 800 is gathered in the vicinity of the

fusing portions

320, 330, 340. In this embodiment, the gap 360 at the front side and the gap 360 at the rear side are arranged in a staggered manner, so that the overall balance of the whole surface mount fuse is improved.

In addition, as shown in fig. 1-5, the surface mount fuse in the present embodiment further includes arc segments 900 disposed at four corners, the arc segments 900 penetrate from the upper substrate 100 to the lower substrate 500, that is, the arc segments 900 are disposed at corresponding positions of the upper substrate 100, the first cavity plate 200, the melt 300, the second cavity plate 400 and the lower substrate 500 from top to bottom, and a metal layer is plated on the surfaces of the arc segments 900; after electroplating, the electrode is fixedly and electrically connected with the side electrode 2510, the surface end electrode 110 and the electrode part 310 of the melt 300, so that the connection strength of the side electrode 2510 and the fuse is improved, and the stability of electrical connection is remarkably improved.

The foregoing description of the preferred embodiments of the present utility model is not intended to limit the scope of the claims, which follow, as defined in the claims.

Claims

1. A surface mount fuse, comprising:

a substrate including an upper substrate and a lower substrate stacked above and below the cavity plate, respectively; an end electrode disposed on the substrate and/or the cavity plate, the end electrode being electrically connected to the melt;

and the filler is filled in the first cavity and the second cavity.

2. The surface mount fuse of claim 1, wherein at least a portion of the side walls of the support portion constitute an outer wall of the surface mount fuse.

3. The surface mount fuse of claim 1, wherein the support portion comprises a plurality of protrusions.

4. A surface mount fuse as set forth in claim 3 wherein said protrusion is oriented toward said fuse portion.

5. The surface mount fuse of claim 4, wherein the plurality of protrusions undulate.

6. The surface mount fuse of claim 4, wherein the gap has a width that gradually increases from outside to inside.

7. The surface mount fuse of claim 1, further comprising arcuate segments disposed at four corners, the arcuate segments extending from the upper substrate to the lower substrate, the arcuate segments having a surface plated with a metal layer.

8. The surface mount fuse of claim 1, wherein the gaps corresponding to the two support portions are offset.

9. The surface mount fuse of claim 1, wherein the upper substrate, the first cavity plate, the melt, the second cavity plate, and the lower substrate are sequentially distributed from top to bottom, and adjacent components are fixedly connected to each other by hot pressing with a pure adhesive film.

10. The surface mount fuse of claim 9, wherein an upper portion of the first cavity plate and a lower portion of the second cavity plate are both filled with the corresponding locations of the clear adhesive film.