MINIATURE SUPER SURFACE MOUNT FUSE AND MANUFACTURING METHOD THEREOF

Abstract

The present disclosure discloses a miniature super surface mount fuse, comprising: a fuse element provided with a low overload fusing point and at least two high breaking capacity fusing points connected in series with the low overload fusing point and respectively arranged on two sides of the low overload fusing point, at least two cavity plates provided with cavities, the low overload fusing point and the high breaking capacity fusing points being located at corresponding positions of the cavities; the present disclosure further provides a manufacturing method for a surface mount fuse; the miniature super surface mount fuse of the present disclosure can provide the protection for the civil consumer electronic circuit under various overload conditions without the occurrence of safety hazards such as smoking or cracking of the housing or explosion.

Claims

1. A miniature super surface mount fuse, wherein, comprising: a fuse element, the fuse element comprising at least one low overload fusing point for fusing at low overload and high breaking capacity fusing points for fusing at high overload, the high breaking capacity fusing points at least comprising a first fusing point and a second fusing point, the first fusing point, the low overload fusing point and the second fusing point being connected in series, one end of the low overload fusing point being connected with the first fusing point, and the other end of the low overload fusing point being connected with the second fusing point; cavity plates, the cavity plates comprising 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 being closed up to form a cavity body, the low overload fusing point and the high breaking capacity fusing points being positioned within the cavity body; substrates, the substrates comprising an upper substrate stacked above the cavity plates and a lower substrate stacked below the cavity plates; a terminal electrode, the terminal electrode being provided on the substrates and/or on the cavity plates, and being electrically connected to the fuse element; a filler, the filler being filled in the first cavity and the second cavity, and the filler comprising a powder having unequal particle sizes; the powder comprising but not limited to, one or more selected from the group consisting of metal oxides, ceramic, glass and metal hydroxides.

2. The miniature super surface mount fuse according to claim 1, wherein, the fuse element is made of a high-melting-point conductive metal material, a surface of the low overload fusing point is coated by a low-melting-point metal layer.

3. (canceled)

4. The miniature super surface mount fuse according to claim 1, wherein, the fuse element further comprises connecting portions for connecting the low overload fusing point and the high breaking capacity fusing points, and cross sectional areas of the high breaking capacity fusing points are less than cross sectional areas of the connecting portions.

5. The miniature super surface mount fuse according to claim 4, wherein, two ends of the fuse element in a length direction thereof are respectively provided with a first end portion and a second end portion, and a distance from the first fusing point to the first end portion is one-fifth to one-third of a distance between the first end portion and the second end portion.

6. The miniature super surface mount fuse according to claim 5, wherein, a distance from the second fusing point to the second end portion is one-fifth to one-third of a distance between the first end portion and the second end portion.

7. The miniature super surface mount fuse according to claim 1, wherein, the surface mount fuse further comprises a fuse element plate, the fuse element plate is positioned between the first cavity plate and the second cavity plate, and faces of the fuse element plate facing the first cavity and the second cavity are respectively attached with the fuse element.

8. The miniature super surface mount fuse according to claim 1, wherein, a surface of the fuse element is coated by an arc extinguishing material.

9. The miniature super surface mount fuse according to claim 1, wherein, the filler has a particle size between 80 and 500 mesh.

10. The miniature super surface mount fuse according to claim 9, wherein, the filler having a particle size of 120-200 mesh is 30%-80% in all of the filler by volume.

11. The miniature super surface mount fuse according to claim 1, wherein, the upper substrate, the first cavity plate, the fuse element, the second cavity plate and the lower substrate are pressed successively by an adhesive material from top to bottom, and the adhesive material forms a plurality of adhesive layers, wherein, between the upper substrate, the first cavity plate, the fuse element, the second cavity plate and the lower substrate are respectively positioned an upper adhesive layer, a middle-upper adhesive layer, a middle-lower adhesive layer and a lower adhesive layer, and an upper portion of the first cavity is filled with the upper adhesive layer.

12. The miniature super surface mount fuse according to claim 11, wherein, a lower portion of the second cavity is filled with the lower adhesive layer.

13. The miniature super surface mount fuse according to claim 11, wherein, the middle-upper adhesive layer is hollowed out or filled with the adhesive material at a corresponding position of the cavity body.

14. The miniature super surface mount fuse according to claim 11, wherein, the middle-lower adhesive layer is hollowed out or filled with the adhesive material at a corresponding position of the cavity body.

15. A manufacturing method of a miniature super surface mount fuse, wherein, the method comprises steps of: coating a fuse element of metal material onto an insulating plate to form a fuse element plate, forming at least two narrowed regions on the fuse element as high breaking capacity fusing points, and coating a low-melting-point metal layer at a position near the middle of the fuse element to form a low overload fusing point; disposing terminal electrodes on insulating plates to form substrates comprising an upper substrate and a lower substrate; opening cavities on insulating plates to form a first cavity plate having a first cavity and a second cavity plate having a second cavity; pre-adhering the first cavity plate, the fuse element plate and the second cavity plate successively via a pure adhesive film, the high breaking capacity fusing points and the low overload fusing point positioned within a cavity body formed by the first cavity and the second cavity; filling the first cavity with a filler, and pre-adhering the upper substrate and the first cavity plate utilizing a pure adhesive film; filling the second cavity with a filler, and pre-adhering the lower substrate and the second cavity plate utilizing a pure adhesive film, to produce a pre-finished product; pressing the pre-finished product; opening an elongated slot on the substrate corresponding to the position of the terminal electrode, extending the elongated slot at least to the lower substrate, electroplating an inner wall of the elongated slot with a conductive layer, and cutting the substrate to produce one miniature super surface mount fuses.

16-17. (canceled)

18. The manufacturing method of a miniature super surface mount fuse according to claim 15, wherein, the high breaking capacity fusing point is formed by pattern transfer.

19. (canceled)

20. The manufacturing method of a miniature super surface mount fuse according to claim 15, wherein, the substrate is made by etching a copper-clad circuit board to remove copper foil.

21. The manufacturing method of a miniature super surface mount fuse according to claim 15, wherein, the cavity body is made by milling or stamping, and the like.

22. The manufacturing method of a miniature super surface mount fuse according to claim 15, wherein, the filler comprises a powder having unequal particle sizes.

23. The manufacturing method of a miniature super surface mount fuse according to claim 15, wherein, the pre-finished product is pressed in a hot press.

24. The manufacturing method of a miniature super surface mount fuse according to claim 15, wherein, the fuse element is made from a conductive metal sheet by etching, milling, stamping, and the like.

25-26. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] FIG. 1 is a schematic solid diagram of a miniature super surface mount fuse of Embodiment 1 of the present disclosure;

[0047] FIG. 2 is an exploded view of the layers of the miniature super surface mount fuse of Embodiment 1 of the present disclosure;

[0048] FIG. 3 is a top view of the fuse element plate of the miniature super surface mount fuse of Embodiment 1 of the present disclosure;

[0049] FIG. 4 is a schematic diagram of the longitudinal section structure of the miniature super surface mount fuse of Embodiment 1 of the present disclosure;

[0050] FIG. 5 is an X-RAY diagram of the miniature super surface mount fuse of Embodiment 1 of the present disclosure after suffering low overload conditions (two times of rated current);

[0051] FIG. 6 is an X-RAY diagram of the miniature super surface mount fuse of Embodiment 1 of the present disclosure after suffering high overload conditions (300 VAC/300 A);

[0052] FIG. 7 is a schematic flow chart of a manufacturing method of the miniature super surface mount fuse of the present disclosure;

[0053] FIG. 8 is a schematic diagram of cutting the miniature super surface mount fuse of the present disclosure;

[0054] FIG. 9 is an exploded view of the layers of the miniature super surface mount fuse of Embodiment 2 of the present disclosure;

[0055] FIG. 10 is a schematic structure diagram of the fuse element of the miniature super surface mount fuse of Embodiment 3 of the present disclosure;

[0056] in the drawings: 2500miniature super surface mount fuse; 100upper substrate; 150upper adhesive layer; 200first cavity plate; 250middle-upper adhesive layer; 300fuse element plate; 320first fusing point; 340second fusing point; 330low overload fusing point; 310fuse element end portion; 350middle-lower adhesive layer; 400second cavity plate; 450lower adhesive layer; 500lower substrate; 800filler; 110terminal electrode; 2510side terminal electrode.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0057] The present disclosure can be further clearly understood by the following specific embodiments of the present disclosure, but they are not intended to limit the present disclosure.

Embodiment 1

[0058] As shown in FIGS. 1-4, Embodiment 1 of the present disclosure provides a miniature super surface mount fuse comprising an upper substrate 100, a first cavity plate 200, a fuse element plate 300 made from a PCB board bonded with fuse elements on an upper surface and a lower surface thereof, a second cavity plate 400 and a lower substrate plate 500 pressed successively by a pure adhesive film from top to bottom, and the pure adhesive film comprises an upper adhesive layer 150, a middle-upper adhesive layer 250, a middle-lower adhesive layer 350 and a lower adhesive layer 450.

[0059] The fuse element comprises at least one low overload fusing point 330 for fusing at low overload and high breaking capacity fusing points for fusing at high overload, the high breaking capacity fusing points comprise at least a first fusing point 320 and a second fusing point 340, the first fusing point 320, the low overload fusing point 330 and the second fusing point 340 are connected in series, an end of the low overload fusing point 330 is connected with the first fusing point 320, the other end of the low overload fusing point 330 is connected with the second fusing point 340, and the first fusing point 320 and the second fusing point 340 are respectively connected with the fuse element end portions 310 on both sides. The fuse element end portions 310 comprise a first end portion and a second end portion respectively provided along a length direction of the fuse element, a distance from the first fusing point 320 to the first end portion is one-fifth to one-third of a distance between the two fuse element end portions 310, and a distance from the second fusing point 340 to the second end portion is one-fifth to one-third of a distance between the two fuse element end portions.

[0060] The first cavity plate 200 provided with a first cavity and the second cavity plate 400 provided with a second cavity form the cavity plates of the present disclosure, the first cavity and the second cavity are closed up to form a cavity body, the fuse element plate 300 is positioned within the cavity body, and the low overload fusing point 300, the first fusing point 320 and the second fusing point 340 are all positioned within the cavity body. The first cavity and the second cavity are filled with a filler 800, and the filler 800 comprises a powder of different particle sizes, and the powder has a particle size between 80 and 500 mesh, wherein the powder having a particle size of 120-200 mesh is 30%-80% in all of the powder by volume. The powder comprises, but not limited to, quartz sand, silicon oxide powder, alumina powder, and the like.

[0061] An upper surface of the upper substrate 100 and a lower surface of the lower substrate 500 are provided with terminal electrodes 110 for realizing the electric connection between the surface mount fuse of the present disclosure and a circuit, the electric connection between the terminal electrodes 110 and the fuse element is realized by the fuse element end portions 310 and a side terminal electrode 2510 at a side of the surface mount fuse.

[0062] The fuse element is made of copper foil, the surface of the low overload fusing point 330 is coated by a tin metal layer, and the fuse element further comprises connecting portions for connecting the low overload fusing point 330 and the high breaking capacity fusing points, and cross sectional areas of the high breaking capacity fusing points are less than cross sectional areas of the connecting portions. The surface of the fuse element is coated by an arc extinguishing material.

[0063] The adhesive material forms a plurality of adhesive layers, wherein, between the upper substrate 100, the first cavity plate 200, the fuse element, the second cavity plate 400 and the lower substrate 500 are respectively positioned an upper adhesive layer 150, a middle-upper adhesive layer 250, a middle-lower adhesive layer 350 and a lower adhesive layer 450, and an upper portion of the first cavity and a lower portion of the second cavity are respectively filled with the upper adhesive layer 150 and the lower adhesive layer 450, to press the filler 800 filled in the first cavity and the second cavity tightly.

[0064] The middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 is hollowed out at a corresponding position of the cavity body, and at this time, the fuse element is in direct contact with the filler. The pure adhesive film on the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 is thinner and has worse fluidity than the pure adhesive film on the upper adhesive layer 150 and the lower adhesive layer 450, and mainly functions as an adhesive.

[0065] As shown in FIG. 5, after the surface mount fuse of the present disclosure fuses under a low overload condition (two times of the rated current), only the low overload fusing point 330 fuses, and other portions of the fuse element remain intact. Due to the copper-tin alloy diffusion principle, the low overload fusing point 330 has a lower melting point than other portions of the fuse element, such that it can be broken at the low overload fusing point 330 at low currents.

[0066] As shown in FIG. 6, after the surface mount fuse of the present disclosure fuses under a high overload condition (300 VAC/300 A), only the low overload fusing point 330 remains intact, and other portions of the fuse element made from high-melting-point metals have fused. At high current, due to the tin plated middle section, the hot melt value of the middle section is increased, and meanwhile, the high-breaking melting points 320/340 (line width weak points) are provided on both sides, which highlights the hot melt value of the tin plated middle section, therefore, it will be broken at both ends at high current, and the tin plated middle section will remain, as a result, the arc can be instantly cut off, and so that the fuse can withstand higher current.

[0067] As shown in FIGS. 7-8, the manufacturing method of the surface mount fuse of the present disclosure comprises the following steps:

[0068] S1) manufacturing a fuse element: combining a fuse element of copper or copper alloy material with a PCB board by thin film technique to form a multilayer two-dimensional planar fuse elements in parallel plate 300, forming at least two narrowed regions on the fuse element as the high breaking capacity fusing points 320/340 by means of pattern transfer, and electroplating a tin layer in the middle of the fuse element to form the low overload fusing point 330;

[0069] S2) manufacturing a substrate: etching a copper-clad circuit board to remove copper foil to form the substrate comprising the upper substrate 100 and the lower substrate 500, and providing terminal electrodes on the substrate;

[0070] S3) manufacturing cavity plates: coating a pure adhesive film on the insulating plate, penetrating through the insulating plate and a cavity of the pure adhesive film by milling or stamping and the like, forming a first cavity plate 200 having a first cavity and a middle-upper adhesive layer 250 as well as a second cavity plate 400 having a second cavity and a middle-lower adhesive layer 350, and hollowing out the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 at corresponding positions of the first cavity and the second cavity;

[0071] S4) adhering the cavity plates and the fuse element: pre-adhering the first cavity plate 200, the fuse element plate 300 and the second cavity plate 400 successively via the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350, disposing the high breaking capacity fusing points 320/340 and the low overload fusing point 330 within a cavity body formed by the first cavity and the second cavity;

[0072] S5) filling the first cavity plate: filling the first cavity with a filler 800, the filler comprises a powder having unequal particle sizes, and pre-adhering the upper substrate and the first cavity plate utilizing the pure adhesive film;

[0073] S6) filling the second cavity plate: filling the second cavity with a filler 800, the filler comprises a powder having unequal particle sizes, and pre-adhering the lower substrate and the second cavity plate utilizing the pure adhesive film, to produce a pre-finished product; S7) hot pressing: adding a steel plate to each of the upper and lower sides of the pre-finished product, and pressing the pre-finished product in a hot press;

[0074] S8) electroplating and cutting: milling an elongated slot on the substrate, extending the elongated slot at least to the lower substrate, electroplating an inner wall of the elongated slot with a copper layer to form the side terminal electrode 2510, and cutting the substrate to produce single miniature super surface mount fuses 2500.

Embodiment 2

[0075] Embodiment 2 of the present disclosure provides a miniature super surface mount fuse comprising an upper substrate 100, a first cavity plate 200, a fuse element plate 300 made from a PCB board bonded with fuse elements on an upper surface and a lower surface thereof, a second cavity plate 400 and a lower substrate plate 500 pressed successively by a pure adhesive film from top to bottom, and the pure adhesive film comprises an upper adhesive layer 150, a middle-upper adhesive layer 250, a middle-lower adhesive layer 350 and a lower adhesive layer 450.

[0076] The fuse element comprises at least one low overload fusing point 330 for fusing at low overload and a high breaking capacity fusing point for fusing at high overload, the high breaking capacity fusing point comprises at least a first fusing point 320 and a second fusing point 340, the first fusing point 320, the low overload fusing point 330 and the second fusing point 340 are connected in series, an end of the low overload fusing point 330 is connected with the first fusing point 320, the other end of the low overload fusing point 330 is connected with the second fusing point 340, and the first fusing point 320 and the second fusing point 340 are respectively connected with the fuse element end portions 310 on both sides. The fuse element end portions 310 comprise a first end portion and a second end portion respectively provided along a length direction of the fuse element, a distance from the first fusing point 320 to the first end portion is one-fifth to one-third of a distance between the two fuse element end portions 310, and a distance from the second fusing point 340 to the second end portion is one-fifth to one-third of a distance between the two fuse element end portions.

[0077] The first cavity plate 200 provided with a first cavity and the second cavity plate 400 provided with a second cavity form the cavity plates of the present disclosure, the first cavity and the second cavity are closed up to form a cavity body, the fuse element plate 300 is positioned within the cavity body, and the low overload fusing point 300, the first fusing point 320 and the second fusing point 340 are all positioned within the cavity body. The first cavity and the second cavity are filled with a filler 800, and the filler 800 comprises a powder of different particle sizes, and the filler has a particle size between 80 and 500 mesh, wherein the powder having a particle size of 120-200 mesh is 30%-80% in all of the powder by volume. The powder comprises, but not limited to, quartz sand, silicon oxide powder, alumina powder, and the like.

[0078] An upper surface of the upper substrate 100 and a lower surface of the lower substrate 500 are provided with terminal electrodes 110 for realizing the electric connection between the surface mount fuse of the present disclosure and a circuit, the electric connection between the terminal electrodes 110 and the fuse element is realized by the fuse element end portions 310 and a side terminal electrode 2510 at a side of the surface mount fuse.

[0079] The fuse element is made of copper foil, the surface of the low overload fusing point 330 is coated by a tin metal layer, and the fuse element further comprises connecting portions for connecting the low overload fusing point 330 and the high breaking capacity fusing points, and cross sectional areas of the high breaking capacity fusing points are less than cross sectional areas of the connecting portions. The surface of the fuse element is coated by an arc extinguishing material.

[0080] The adhesive material forms a plurality of adhesive layers, wherein, between the upper substrate 100, the first cavity plate 200, the fuse element, the second cavity plate 400 and the lower substrate 500 are respectively positioned an upper adhesive layer 150, a middle-upper adhesive layer 250, a middle-lower adhesive layer 350 and a lower adhesive layer 450, and an upper portion of the first cavity and a lower portion of the second cavity are respectively filled with the upper adhesive layer 150 and the lower adhesive layer 450, to press the filler 800 filled in the first cavity and the second cavity tightly.

[0081] As shown in FIG. 9, the present embodiment differs from Embodiment 1 by that: the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 is filled with the pure adhesive film at a corresponding position of the cavity body. The pure adhesive film on the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 is thinner and has worse fluidity than the pure adhesive film on the upper adhesive layer 150 and the lower adhesive layer 450, and mainly functions as an adhesive.

[0082] As shown in FIGS. 7-8, the manufacturing method of the miniature super surface mount fuse of the present disclosure comprises the following steps:

[0083] S1) manufacturing a fuse element: combining a fuse element of copper or copper alloy material with a PCB board by thin film technique to form a multilayer two-dimensional planar parallel fuse element plate 300, forming at least two narrowed regions on the fuse element as the high breaking capacity fusing points 320/340 by means of pattern transfer, and electroplating a tin layer in the middle of the fuse element to form the low overload fusing point 330; S2) manufacturing a substrate: etching a copper-clad circuit board to remove copper foil to form the substrate comprising the upper substrate 100 and the lower substrate 500, and providing the terminal electrode on the substrate;

[0084] S3) manufacturing cavity plates: opening cavities on the insulating plate by milling, stamping, and the like, to form a first cavity plate 200 having a first cavity and a second cavity plate 400 having a second cavity;

[0085] S4) adhering the cavity plates and the fuse element: pre-adhering the first cavity plate 200, the fuse element plate 300 and the second cavity plate 400 successively via the pure adhesive film, disposing the high breaking capacity fusing points 320/340 and the low overload fusing point 330 within a cavity body formed by the first cavity and the second cavity;

[0086] S5) filling the first cavity plate: filling the first cavity with a filler 800, the filler comprises a powder having unequal particle sizes, and pre-adhering the upper substrate and the first cavity plate utilizing the pure adhesive film;

[0087] S6) filling the second cavity plate: filling the second cavity with a filler 800, the filler comprises a powder having unequal particle sizes, and pre-adhering the lower substrate and the second cavity plate utilizing the pure adhesive film, to produce a pre-finished product;

[0088] S7) hot pressing: adding a steel plate to each of the upper and lower sides of the pre-finished product, and pressing the pre-finished product in a hot press;

[0089] S8) electroplating and cutting: milling an elongated slot on the substrate, extending the elongated slot at least to the lower substrate, electroplating an inner wall of the elongated slot with a copper layer to form the side terminal electrode 2510, and cutting the substrate to produce single miniature super surface mount fuses 2500.

Embodiment 3

[0090] Another embodiment of the present disclosure provides a miniature super surface mount fuse comprising an upper substrate 100, a first cavity plate 200, a fuse element, a second cavity plate 400 and a lower substrate plate 500 pressed successively by a pure adhesive film from top to bottom, and the pure adhesive film comprises an upper adhesive layer 150, a middle-upper adhesive layer 250, a middle-lower adhesive layer 350 and a lower adhesive layer 450. The fuse element comprises at least one low overload fusing point 330 for fusing at low overload and a high breaking capacity fusing point for fusing at high overload, the high breaking capacity fusing point comprises at least a first fusing point 320 and a second fusing point 340, the first fusing point 320, the low overload fusing point 330 and the second fusing point 340 are connected in series, an end of the low overload fusing point 330 is connected with the first fusing point 320, the other end of the low overload fusing point 330 is connected with the second fusing point 340, and the first fusing point 320 and the second fusing point 340 are respectively connected with the fuse element end portions 310 on both sides. The fuse element end portions 310 comprise a first end portion and a second end portion respectively provided along a length direction of the fuse element, a distance from the first fusing point 320 to the first end portion is one-fifth to one-third of a distance between the two fuse element end portions 310, and a distance from the second fusing point 340 to the second end portion is one-fifth to one-third of a distance between the two fuse element end portions.

[0091] The first cavity plate 200 provided with a first cavity and the second cavity plate 400 provided with a second cavity form the cavity plates of the present disclosure, the first cavity and the second cavity are closed up to form a cavity body, the fuse element plate 300 is positioned within the cavity body, and the low overload fusing point 300, the first fusing point 320 and the second fusing point 340 are all positioned within the cavity body. The first cavity and the second cavity are filled with a filler 800, and the filler 800 comprises a powder of different particle sizes, and the filler has a particle size between 80 and 500 mesh, wherein the powder having a particle size of 120-200 mesh is 30%-80% in all of the powder by volume. The filler comprises, but not limited to, quartz sand, silicon oxide powder, alumina powder, and the like.

[0092] An upper surface of the upper substrate 100 and a lower surface of the lower substrate 500 are provided with terminal electrodes 110 for realizing the electric connection between the surface mount fuse of the present disclosure and a circuit, the electric connection between the terminal electrodes 110 and the fuse element is realized by the fuse element end portions 310 and a side terminal electrode 2510 at a side of the surface mount fuse.

[0093] The adhesive material forms a plurality of adhesive layers, wherein, between the upper substrate 100, the first cavity plate 200, the fuse element, the second cavity plate 400 and the lower substrate 500 are respectively positioned an upper adhesive layer 150, a middle-upper adhesive layer 250, a middle-lower adhesive layer 350 and a lower adhesive layer 450, and an upper portion of the first cavity and a lower portion of the second cavity are respectively filled with the upper adhesive layer 150 and the lower adhesive layer 450, to press the filler 800 filled in the first cavity and the second cavity tightly.

[0094] The middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 is hollowed out at a corresponding position of the cavity body, and at this time, the fuse element is in direct contact with the filler. The pure adhesive film on the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 is thinner and has worse fluidity than the pure adhesive film on the upper adhesive layer 150 and the lower adhesive layer 450, and mainly functions as an adhesive.

[0095] As shown in FIG. 10, unlike Embodiment 1, the fuse element in the present embodiment is formed from a metal sheet by mechanical processing such as etching, milling, and stamping. The fuse element can flexibly set its own properties such as the shape, thickness and material according to requirements, and the present disclosure will not provide the embodiment thereof. The fuse element further comprises connecting portions for connecting the low overload fusing point 330 and the high breaking capacity fusing points, and cross sectional areas of the high breaking capacity fusing points are less than cross sectional areas of the connecting portions.

[0096] As shown in FIGS. 7-8, the manufacturing method of the miniature super surface mount fuse of the present disclosure comprises the following steps:

[0097] S1) manufacturing a fuse element: forming the fuse element from a metal sheet by mechanical processing such as etching, milling, and stamping, forming at least two narrowed regions on the fuse element as the high breaking capacity fusing points 320/340, and electroplating a tin layer in the middle of the fuse element to form the low overload fusing point 330;

[0098] S2) manufacturing a substrate: etching a copper-clad circuit board to remove copper foil to form the substrate comprising the upper substrate 100 and the lower substrate 500, and providing the terminal electrode 110 on the substrate;

[0099] S3) manufacturing cavity plates: coating a pure adhesive film on the insulating plate, penetrating through the insulating plate and a cavity of the pure adhesive film by milling or stamping and the like, forming a first cavity plate 200 having a first cavity and a middle-upper adhesive layer 250 as well as a second cavity plate 400 having a second cavity and a middle-lower adhesive layer 350, and hollowing out the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350 at corresponding positions of the first cavity and the second cavity;

[0100] S4) adhering the cavity plates and the fuse element: pre-adhering the first cavity plate 200, the fuse element and the second cavity plate 400 successively via the middle-upper adhesive layer 250 and the middle-lower adhesive layer 350, disposing the high breaking capacity fusing points 320/340 and the low overload fusing point 330 within a cavity body formed by the first cavity and the second cavity;

[0101] S5) filling the first cavity plate: filling the first cavity with a filler 800, the filler comprises a powder having unequal particle sizes, and pre-adhering the upper substrate 100 and the first cavity plate 200 utilizing the pure adhesive film;

[0102] S6) filling the second cavity plate: filling the second cavity with a filler 800, the filler comprises a powder having unequal particle sizes, and pre-adhering the lower substrate 500 and the second cavity plate 400 utilizing the pure adhesive film, to produce a pre-finished product;

[0103] S7) hot pressing: adding a steel plate to each of the upper and lower sides of the pre-finished product, and pressing the pre-finished product in a hot press;

[0104] S8) electroplating and cutting: milling an elongated slot on the substrate, extending the elongated slot at least to the lower substrate 500, electroplating an inner wall of the elongated slot with a copper layer to form the side terminal electrode 2510, and cutting the substrate to produce single miniature super surface mount fuses 2500.

[0105] Compared with the prior art, the super fuse provided by the present disclosure which can satisfy the protection for circuits against various kinds of overload conditions, and achieves the control of sectionally fusing the fuse element under various kinds of overload conditions, and meanwhile, the filler having different particle sizes is filled in the cavities, so that the pore size between the particles of the filler is suitable and uniform, and the arc generated during the breaking can be instantaneously extinguished, and the thermal shock or radiation of the arc is avoided to cause smoke, cracking or carbonization of the fuse housing.

[0106] The above is only the preferred embodiments of the present disclosure, and the scope of right of the present disclosure is not limited thereto, and the equivalent variations made by the scope of the present disclosure remain within the scope of the present disclosure.