CN117524809B

CN117524809B - High-reliability surface-mounted fuse and manufacturing process thereof

Info

Publication number: CN117524809B
Application number: CN202311650590.8A
Authority: CN
Inventors: 李俊
Original assignee: Shanghai Songshan Electronics Co ltd
Current assignee: Shanghai Songshan Electronics Co ltd
Priority date: 2023-12-04
Filing date: 2023-12-04
Publication date: 2024-09-06
Anticipated expiration: 2043-12-04
Also published as: CN117524809A

Abstract

The application provides a high-reliability surface-mounted fuse which comprises a fusing layer, an upper cavity and a lower cavity, wherein the upper cavity and the lower cavity are used for clamping the fusing layer; the upper cavity and the lower cavity are opposite to the connecting part for clamping the fusion layer, and the two ends of the upper cavity only cover the connecting part of the fusion layer; the whole end surfaces of the upper cavity and the lower cavity and the exposed surface of the connecting part are covered and provided with conductive layers. The connection stability between the conductive layer and the fusing layer is improved, the stripping condition is not easy to occur under the conditions of high temperature, great temperature change, vibration and the like, and the connection stability is high; meanwhile, the rated current of the fusing layer can be increased by increasing the contact area, and higher conduction stability and fusing reliability can be kept in use scenes such as high current.

Description

High-reliability surface-mounted fuse and manufacturing process thereof

Technical Field

The application relates to the technical field of railway track detection, in particular to a high-reliability surface-mounted fuse.

Background

Along with the promotion of the development of science and technology and the consciousness of environmental protection, the electric products tend to be large, particularly the rapid development of electric automobiles, the reliability requirements of the electric products are further improved, and particularly for fuses, the electric products are required to be smaller in size, stronger in performance and higher in reliability; the higher the reliability is guaranteed by the traditional design, the more the protection is needed, the volume of the traditional ceramic patch fuse cannot be guaranteed, the traditional ceramic patch fuse is provided with a ceramic tube, a fuse wire is penetrated in the middle of the traditional ceramic patch fuse, two ends of the traditional ceramic patch fuse are sleeved with end caps, the connection between the end caps and the internal fuse wire is the easiest to cause problems, and the traditional ceramic patch fuse is generally improved by adopting double end caps, but the reliability of the traditional ceramic patch fuse is completely insufficient for high-current and micro-current products. The concrete explanation is as follows:

for high-current products, the fuse is connected by soldering tin, the fuse heats too much under low overload, and the melting point of the tin is too low, so that the problem that the end cap is dropped when the tin melts is easily caused. For low-current products, the fuse wire is too thin, the soldering fuse wire is easy to generate cold joint, and meanwhile, the fuse wire can be broken under vibration and cold and hot impact.

The miniature super surface mount fuse comprises a melt, at least two cavity plates, at least two base plates, end electrodes, filling materials, wherein the base plates are respectively overlapped above and below the cavity plates, the end electrodes are electrically connected with the end electrodes and the melt, the end electrodes are arranged on the base plates and/or the cavity plates, and the filling materials are filled in the cavities, the filling materials are powder with different sizes, and the low overload fusion points and the high breaking fusion points are positioned at corresponding positions of the cavities; the invention also provides a manufacturing method of the surface-mounted fuse; the miniature super surface-mounted fuse can simultaneously protect civil consumer electronic circuits under various overload conditions, and can not generate hidden dangers such as smoke, cracking or explosion of the shell.

However, in the above technical scheme, the connection reliability between the melt and the terminal electrode is poor, the internal fuse and the external electrode are conducted through the coating on the side wall, and the coating and the melt are further aggravated in the peeling condition of the coating and the melt due to the fact that the expansion coefficients of the substrate and the coating are different, and the fuse is required to be installed in a reflow soldering mode when being installed, so that the fuse is in a high-temperature environment (up to 260 ℃), the coating and the melt are easy to peel off at the moment, and the conditions of vibration, bending and the like are also encountered after the fuse is installed.

Secondly, the scheme adopts the mode of gluing to combine a plurality of structural layers, and it adopts the structure of upper and lower symmetry, glues at the chamber edge, then hot pressing is with two rubber coating faces, compresses tightly, and the glue film then can extrude in the cavity, and the glue film is organic matter (such as epoxy glue, acrylic acid glue etc.), and it can be extruded near the fuse even on the fuse, and its production high temperature can decompose the glue film when fuse overload fuses, carbonizes, and so voltage is higher like this, then can strike the arc, leads to the risk such as product burst or burning. Therefore, only when designing, the cavity is enlarged, the thickness of the cavity wall is reduced, but the thinner the cavity wall is, the strength of the fuse is insufficient, and the breaking capacity of the fuse is difficult to further improve. For example, as a thicker fuse product, the thickness of the adhesive layer needs to be increased, but the thickness of the adhesive layer increases, and the adhesive extruded into the cavity also increases, so that under the condition of a certain size of the fuse, the diameter of the fuse adopted is limited.

Further, the method comprises the following steps. The melt is directly attached to the copper-clad plate, so that potential safety hazards exist: the melt is fused to generate high temperature, even if a layer of tin is plated on copper, the lowest temperature of the melt reaches over 231 ℃, and the thickness of the tin is not too high, otherwise, the pulse resistance is affected, so that the actual temperature can reach about 300 ℃; the copper-clad plate is made of organic materials, and a layer of copper foil is pressed on the copper-clad plate, so that the organic materials can be carbonized and even burnt in the environment of 300 ℃, and particularly under the condition of higher voltage, arc starting, serious explosion or combustion and other dangerous conditions can occur. The above is only an environment in which the fuse is actually installed at normal temperature, and the internal temperature thereof is generally higher than normal temperature. For example, automobile engine bins, motor interiors, charger interiors, etc. (since power conversion rates in power supplies cannot reach 100%, most of its idle work is exclusively heat generation, resulting in higher temperatures in the above-mentioned environments).

Finally, the specifications of the above scheme are limited, a higher specification cannot be achieved, the inside of the scheme is connected with the plating layer by adopting one side at the top end, the sectional area of the scheme is too small, and the scheme cannot be used for long-time high-current products, such as products with rated current of 60A, which need to be kept at the current of 60A for more than 4hr, so that the small sectional area is difficult to meet. Further, under the influence of expansion with heat and contraction with cold, the reliability is poorer.

Disclosure of Invention

The application aims to solve the problem of poor reliability of a surface mounted fuse in a small size in the prior art. Therefore, the application provides the surface mount fuse with high reliability, the contact area between the fusion layer and the conductive layer in the surface mount fuse is increased, the connection stability between the conductive layer and the fusion layer is increased, the stripping condition is not easy to occur under the conditions of high temperature, great temperature change, vibration and the like, and the connection stability is higher; meanwhile, the rated current of the fusing layer can be increased by increasing the contact area, and higher conduction stability and fusing reliability can be kept in use scenes such as high current.

The embodiment of the application provides a high-reliability surface-mounted fuse, which comprises a fusion layer, an upper cavity and a lower cavity, wherein the upper cavity and the lower cavity are used for clamping the fusion layer;

the fusing layer comprises a fusing part and connecting parts connected to two ends of the fusing part;

The upper cavity and the lower cavity relatively clamp the connecting part of the fusing layer, and two ends of the upper cavity only cover part of the connecting part of the fusing layer;

The whole end faces of the upper cavity and the lower cavity and the exposed surface of the connecting part are covered and provided with conductive layers.

By adopting the technical scheme, the two ends of the upper cavity only cover part of the connecting part of the fusion layer, so that the end face of the connecting part and at least part of the upper surface are exposed simultaneously, and can be covered by the conductive layer, the contact surface between the conductive layer and the connecting part of the fusion layer is greatly increased, and the connection stability and the practical reliability between the conductive layer and the fusion layer are greatly improved.

In some embodiments, the upper cavity and the lower cavity are disposed corresponding to the fused portion of the fused layer to form a cavity, and a filler is disposed within the cavity.

In some embodiments, the filler is provided as a composite filler, including quartz sand, and,

At least one of mirabilite (sodium sulfate decahydrate), alum (aluminum potassium sulfate dodecahydrate), gypsum, lime, melamine, magnesium hydroxide, aluminum hydroxide and ammonium salt.

By adopting the technical scheme, the upper cavity and the lower cavity are not easy to carbonize at high temperature due to the high temperature generated after the fusing part is fused, so that the safety and the practical reliability of the surface mount fuse after fusing are improved.

In some embodiments, the filler is provided in an amount of not less than 20% of at least one of mirabilite (sodium sulfate decahydrate), alum (potassium aluminum sulfate dodecahydrate), gypsum, lime, melamine, magnesium hydroxide, aluminum hydroxide, and ammonium salt in the composite filler.

In some embodiments, the upper cavity is formed by gluing a first substrate and a second substrate, and the lower cavity is formed by gluing a third substrate and a fourth substrate;

the upper cavity, the fusion layer and the lower cavity are connected in a gluing mode.

By adopting the technical scheme, the surface-mounted fuse can be conveniently processed in a layered gluing mode, the processing process flow can be simplified, and the production cost is reduced.

In some embodiments, the fuse portion is provided in a wire or sheet shape.

The embodiment of the application also provides a manufacturing process of the high-reliability surface-mounted fuse, which comprises the following steps:

S1, processing a first substrate, a second substrate, a fusion layer, a third substrate and a fourth substrate;

S2, carrying out twice hot pressing and fixing connection on the first substrate, the second substrate, the fusion layer, the third substrate and the fourth substrate through an adhesive layer to form a first precast slab;

s3, processing a through hole on the prefabricated plate, and electroplating a conductive layer to form a second prefabricated plate;

s4, cutting and grading the second prefabricated plate to obtain a plurality of surface-mounted fuses.

By adopting the technical scheme, the first substrate, the second substrate, the fusion layer, the third substrate and the fourth substrate are fixedly connected through the adhesive layer by two times of hot pressing, so that the adhesive can be controlled to flow into the cavity at a lower temperature, at a lower pressure or in a shorter time during the first hot pressing, and meanwhile, a few products which flow into the cavity due to abnormality can be detected, and the quality reliability of the final product is ensured; in the second hot pressing, the glue is solidified, so that the fluidity is not high, the higher temperature and the higher pressure can be adopted, the lamination and heat curing stability can be ensured for a longer time, and the connection stability and reliability of the final product are ensured.

In some embodiments, step S1 comprises:

processing a first substrate, processing a plurality of parallel long strip holes extending along a first direction on the first substrate, and etching metal electrodes on two sides of the long strip holes;

Processing a second substrate, processing a plurality of cavities arranged along the first direction on the second substrate, and processing first through holes on two sides of each second cavity along a second direction, wherein the first through holes correspond to the strip holes of the first substrate, and the first direction is perpendicular to the second direction;

machining a fusing layer, namely machining fusing parts corresponding to the cavities of the second substrate one by one on the metal sheet;

Processing a third substrate, and processing a plurality of cavities corresponding to the cavities of the second substrate one by one on the third substrate;

and processing a fourth substrate, and etching a metal electrode corresponding to the first substrate on the fourth substrate.

In some embodiments, step S2 comprises:

s21, fixedly connecting the first substrate, the second substrate, the fusion layer and the third substrate through glue layer hot pressing;

S22, covering the fourth substrate on the third substrate through an adhesive layer, and performing second hot pressing on the first substrate, the second substrate, the fusion layer, the third substrate and the fourth substrate to obtain the first prefabricated plate.

In some embodiments, step S21 further comprises: and filling materials in the cavities of the second substrate and the cavities of the third substrate before the first substrate, the second substrate, the fusion layer and the third substrate are fixed by hot pressing.

By adopting the mode of secondary lamination, compared with the primary lamination, the situation of glue overflow can be obviously improved, thereby further improving the specification of the fusion layer and improving the competitiveness of the product.

In some embodiments, the temperature, pressure, or time of the first heat press is less than the temperature, pressure, or time of the second heat press.

By adopting the technical scheme, the fusing layer is required to be glued between the second substrate and the third substrate during the first hot pressing, so that the overflow of glue into the cavities of the second substrate and the third substrate is avoided, and the overflow of glue into the cavities is reduced by adopting lower temperature, lower pressure or shorter time; in the second hot pressing, only the fourth substrate is required to be hot pressed onto the third substrate, so that a higher temperature, a higher pressure, or a longer time can be used to ensure the stability and reliability of the press-fit heat curing.

In some embodiments, step S3 comprises:

s31, processing through holes communicated with the first substrate on the third substrate, the fourth substrate, the fusing layer and the second substrate;

the via holes are positioned between two adjacent metal electrodes of the fourth substrate, and the via holes and the first via holes on the second substrate are staggered;

S32, electroplating the conductive layer between two adjacent metal electrodes of the first substrate and between two adjacent metal electrodes of the fourth substrate to form a second prefabricated plate.

Additional features and corresponding advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is an end face perspective view of a surface mount fuse according to an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a surface mount fuse of an embodiment per se;

FIG. 3 is a graph showing the effect of the surface mount fuse according to the embodiment of the present application after fusing with the surface mount fuse according to the prior art;

FIG. 4 is a schematic cross-sectional view of a surface mount fuse blowing portion configured as a fuse in accordance with another embodiment of the present application;

FIG. 5 is a schematic view of a surface mount fuse with a fuse portion as a fuse after electroplating according to another embodiment of the present application;

FIG. 6 is a flowchart of a manufacturing process of a surface mount fuse according to an embodiment of the present application;

Fig. 7 is a schematic structural diagram of a first substrate of a manufacturing process of a surface mount fuse according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a second substrate of a manufacturing process of a surface mount fuse according to an embodiment of the present application;

Fig. 9 is a schematic structural diagram of a fusing layer of a manufacturing process of a surface mount fuse according to an embodiment of the present application;

fig. 10 is a schematic structural view of a third substrate of a manufacturing process of a surface mount fuse according to an embodiment of the present application;

Fig. 11 is a schematic structural view of a fourth substrate of a manufacturing process of a surface mount fuse according to an embodiment of the present application;

fig. 12 is a partially enlarged schematic view of a division mode of a manufacturing process of a surface mount fuse according to an embodiment of the present application;

FIG. 13 is a state diagram after the gumming solidification of the prefabricated panel produced by one-time hot press molding;

fig. 14 is a state diagram of a second preformed sheet of a surface mount fuse manufacturing process according to an embodiment of the present application after curing the glue.

Reference numerals illustrate:

1. An upper cavity;

11. A first substrate; 111. a slit hole; 112. a metal electrode;

12. A second substrate; 121. a cavity; 122. a first through hole;

2. A lower cavity;

21. A third substrate;

22. A fourth substrate; 221. metal electrode

3. A fusion layer; 31. a fusing part; 32. a connection part;

4. And a conductive layer.

Detailed Description

Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present specification, by describing the embodiments of the present invention with specific examples. While the description of the invention will be described in connection with the preferred embodiments, it is not intended to limit the inventive features to the implementation. Rather, the purpose of the invention described in connection with the embodiments is to cover other alternatives or modifications, which may be extended by the claims based on the invention. The following description contains many specific details for the purpose of providing a thorough understanding of the present invention. The invention may be practiced without these specific details. Furthermore, some specific details are omitted from the description in order to avoid obscuring the invention. It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.

It should be noted that in this specification, like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may include one or more of the feature, either explicitly or implicitly. In the description of the application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Referring to fig. 1 to 5, fig. 1 is a schematic diagram illustrating an end-face perspective view of a surface mount fuse according to an embodiment of the present application, fig. 2 is a schematic diagram illustrating a cross-section of the surface mount fuse according to an embodiment of the present application, fig. 3 is a comparison diagram illustrating an effect of the surface mount fuse according to an embodiment of the present application after being blown with a surface mount fuse according to the prior art, fig. 4 is a schematic diagram illustrating a cross-section of a surface mount fuse blowing portion according to another embodiment of the present application after being provided with a fuse, and fig. 5 is a schematic diagram illustrating a structure of the surface mount fuse blowing portion according to another embodiment of the present application after being electroplated.

As shown in fig. 1 and 2, the embodiment of the application provides a high-reliability surface mount fuse, which comprises a fusing layer 3, and an upper cavity 1 and a lower cavity 2 for clamping the fusing layer 3;

the fusing layer 3 includes a fusing part 31 and connection parts 32 connected to both ends of the fusing part 31;

the upper cavity 1 and the lower cavity 2 relatively clamp the connecting part 32 of the fusion layer 3, and two ends of the upper cavity 1 only cover the connecting part 32 of part of the fusion layer 3;

the entire end surfaces of the upper and lower cavities 1 and 2, and the exposed surfaces of the connection portions 32 are covered with the conductive layer 4.

By adopting the technical scheme, the two ends of the upper cavity 1 only cover the connecting part 32 of the partial fusing layer 3, so that the end face and at least part of the upper surface of the connecting part 32 are exposed simultaneously, and can be covered by the conductive layer 4, so that the contact surface between the conductive layer 4 and the connecting part 32 of the fusing layer 3 is greatly increased, and the connection stability and the practical reliability between the conductive layer 4 and the fusing layer 3 are greatly improved.

In one embodiment, the upper cavity 1 and the lower cavity 2 are disposed corresponding to the fusing part 31 of the fusing layer 3 to form a cavity 121, and a filler (not shown) is disposed in the cavity 121. The filler absorbs electric arcs, splashed sparks, and the like generated when the fusing part 31 fuses, thereby ensuring the safety when the surface mount fuse fuses.

In one embodiment, the filler is provided as a composite filler, including quartz sand, and,

By adopting the technical scheme, the high temperature generated after the fusing part 31 is fused is unlikely to cause carbonization of the upper cavity 1 and the lower cavity 2 at high temperature, so that the safety and the practical reliability of the surface mount fuse after fusing are improved.

In the prior art, the filler only adopts quartz sand filler and is applied to inorganic shells such as ceramics, glass tubes and the like; however, quartz sand has higher thermal conductivity, and when the upper cavity 1 and the lower cavity 2 are arranged by adopting organic materials, the high temperature generated when the fusing part 31 fuses is easily conducted to the upper cavity 1 and the lower cavity 2, so that carbonization and other conditions occur in the upper cavity 1 and the lower cavity 2, and the use safety of the surface mount fuse is affected.

As shown in fig. 3, the left side in fig. 3 is a surface mount fuse using only quartz sand filler, and when the fuse is fused, the surface of the shell is obviously carbonized. The right side in fig. 3 is a surface-mounted fuse filled with the above composite filler (including quartz sand and mirabilite), and when the fuse is fused, the upper cavity 1 and the lower cavity 2 hardly generate carbonization phenomenon.

In other alternative embodiments, the upper cavity 1 and the lower cavity 2 may not be provided with filler corresponding to the cavity 121 of the fusing part 31 of the fusing layer 3.

In one embodiment, the upper cavity 1 and the lower cavity 2 are made of organic materials, which is favorable for miniaturization of the surface mount fuse, and meanwhile, the toughness of the surface mount fuse is increased, cracking of the surface mount fuse under the conditions of vibration, bending and the like can be avoided, and the reliability of the surface mount fuse is improved.

In one embodiment, the filler is provided in an amount of not less than 20% of at least one of mirabilite (sodium sulfate decahydrate), alum (aluminum potassium sulfate dodecahydrate), gypsum, lime, melamine, magnesium hydroxide, aluminum hydroxide, and ammonium salt in the composite filler. Wherein, mirabilite (sodium sulfate decahydrate), alum (aluminum potassium sulfate dodecahydrate), gypsum and lime are substances such as water absorption, carbon dioxide and the like, thereby reducing the conduction of temperature; and melamine, magnesium hydroxide, aluminum hydroxide, ammonium salts and other substances can decompose and absorb a large amount of heat at high temperature, so that the temperature of the shell is reduced, and the reliability of the fuse is improved.

In one embodiment, the upper cavity 1 is formed by gluing the first substrate 11 and the second substrate 12, and the lower cavity 2 is formed by gluing the third substrate 21 and the fourth substrate 22;

The upper cavity 1, the fusing layer 3 and the lower cavity 2 are connected in a gluing way. The method can facilitate the processing of the surface-mounted fuse by adopting a layered gluing mode, simplify the processing process flow and reduce the production cost.

In one embodiment, the fusing part 31 is provided in a wire shape or a sheet shape.

As shown in fig. 4 and 5, in one embodiment, the fusing part 31 may be a wire wound around a wire harness fuse as a fuse, and after electroplating, the fusing part 31 may be capable of more stably combining the upper cavity 1 and the lower cavity 2, so that stability and reliability of connection are improved when the fuse is used as the fusing part 31, and stability and reliability of the surface mount fuse in use are ensured.

Referring to fig. 6 to 14, fig. 6 is a flowchart illustrating a process for manufacturing a surface mount fuse according to an embodiment of the present application, and fig. 7 to 11 are schematic structural diagrams of a first substrate 11, a second substrate 12, a fusing layer 3, a third substrate 21 and a fourth substrate 22 of the process for manufacturing a surface mount fuse according to an embodiment of the present application; fig. 12 is an enlarged partial schematic view of a division mode of a manufacturing process of a surface mount fuse according to an embodiment of the present application. Fig. 13 is a state diagram after the glue flow of the prefabricated panel manufactured by one-time hot press molding is cured, and fig. 14 is a state diagram after the glue flow of the second prefabricated panel of the manufacturing process of the surface mount fuse according to the embodiment of the application is cured.

As shown in fig. 6 to 12, the embodiment of the present application further provides a manufacturing process of a surface mount fuse with high reliability, including:

s1, processing a first substrate 11, a second substrate 12, a fusing layer 3, a third substrate 21 and a fourth substrate 22;

S2, carrying out twice hot pressing and fixing connection on the first substrate 11, the second substrate 12, the fusing layer 3, the third substrate 21 and the fourth substrate 22 through glue layers to form a first prefabricated plate;

s3, processing a through hole on the prefabricated plate, and electroplating a conductive layer 4 to form a second prefabricated plate;

S4, cutting and grading the second prefabricated plate to obtain a plurality of surface-mounted fuses. As shown in fig. 9, the second prefabricated panel was classified according to a dotted line frame in the drawing to produce a plurality of surface mount fuses.

The first substrate 11, the second substrate 12, the fusing layer 3, the third substrate 21 and the fourth substrate 22 are fixedly connected through glue layers through twice hot pressing, so that the lower temperature, the lower pressure or the shorter time can be adopted in the first hot pressing, the glue is controlled to flow into the cavity, and meanwhile, a few products flowing into the cavity due to abnormality can be detected, and the quality reliability of the final products is ensured; in the second hot pressing, the glue is solidified, so that the fluidity is not high, the higher temperature and the higher pressure can be adopted, the lamination and heat curing stability can be ensured for a longer time, and the connection stability and reliability of the final product are ensured.

As shown in fig. 13 and 14, the glue overflow state of the glue is serious and the quality is difficult to control relative to the prefabricated plate formed by one-time hot pressing; the second prefabricated plate obtained by the manufacturing process in the embodiment of the application has little glue overflow.

In one embodiment, step S1 includes:

processing the first substrate 11, processing a plurality of parallel elongated holes 111 extending in the first direction on the first substrate 11, and etching metal electrodes 112 on both sides of the elongated holes 111;

processing the second substrate 12, processing a plurality of cavities 121 arranged along a first direction on the second substrate 12, and processing first through holes 122 on two sides of each second cavity 121 along a second direction, wherein the first through holes 122 correspond to the long holes 111 of the first substrate 11, and the first direction is perpendicular to the second direction;

Machining the fusing layer 3, and machining fusing parts 31 corresponding to the cavities 121 of the second substrate 12 one by one on the metal sheet;

processing a third substrate 21, and processing a plurality of cavities 121 corresponding to the plurality of cavities 121 of the second substrate 12 one by one on the third substrate 21;

the fourth substrate 22 is processed, and the metal electrode 221 corresponding to the first substrate 11 is etched on the fourth substrate 22.

In one embodiment, step S2 includes:

s21, fixedly connecting the first substrate 11, the second substrate 12, the fusing layer 3 and the third substrate 21 through glue layer hot pressing;

S22, covering the fourth substrate 22 on the third substrate 21 through an adhesive layer, and performing second hot pressing on the first substrate 11, the second substrate 12, the fusing layer 3, the third substrate 21 and the fourth substrate 22 to obtain the first prefabricated plate.

In one embodiment, step S21 further includes: before the first substrate 11, the second substrate 12, the fuse layer 3, and the third substrate 21 are thermally pressed and fixed, the plurality of cavities 121 of the second substrate 12 and the plurality of cavities 121 of the third substrate 21 are filled.

By adopting the mode of secondary lamination, compared with the primary lamination, the situation of glue overflow can be obviously improved, thereby further improving the specification of the fusion layer 3 and improving the competitiveness of the product.

In one embodiment, the temperature, pressure, or time of the first hot press is less than the temperature, pressure, or time of the second hot press.

With the above technical solution, during the first hot pressing, the fusing layer 3 needs to be glued between the second substrate 12 and the third substrate 21, so, in order to avoid the glue from overflowing into the cavities 121 of the second substrate 12 and the third substrate 21, the glue overflowing into the cavities 121 is reduced with a lower temperature, a lower pressure, or a shorter time; at the time of the second heat pressing, only the fourth substrate 22 needs to be heat pressed onto the third substrate 21, and therefore, a higher temperature, a higher pressure, or a longer time may be employed to secure stability and reliability of the press-fit heat curing.

In one example, the secondary thermal compression may include the following processes:

Coating gumming on one side of the first substrate 11 away from the electrode, and attaching the gumming on the second substrate 12; then, filling is performed in the porous cavities 121 of the second substrate 12, and the fusing layer 3 and the third substrate 21 are sequentially attached to the second substrate 12 by the adhesive flow so that the second substrate 12 and the third substrate 21 sandwich the fusing layer 3 and fill in the cavities 121 of the third substrate 21; then, the first substrate 11, the second substrate 12, the fusing layer 3 and the third substrate 21 are thermally pressed at a lower temperature, pressure and time to complete the pre-press and to allow the fluidized bed to be primarily cured. On the one hand, the pressure and time of the thermal compression are less, so that the risk of glue flowing into the cavity 121 can be reduced; on the other hand, the filler can also act as a barrier to the glue and avoid overflowing into the cavity 121.

In other alternative embodiments, the cavities 121 of the second substrate 12 and the third substrate 21 may not be filled with a filler.

In one embodiment, step S3 includes:

S31, processing via holes communicated with the first substrate 11 on the third substrate 21, the fourth substrate 22, the fusing layer 3 and the second substrate 12;

The via holes are located between two adjacent metal electrodes 221 of the fourth substrate 22, and the via holes are staggered with the first via holes 122 on the second substrate 12; at this time, after the second prefabricated panel is cut and classified, one end of each fuse includes two quarter of the through holes and one half of the first through holes 122.

And the plated conductive layer 4 can achieve covering and electrical connection with part of the upper surface and end face of the connection portion 32 of the fuse layer 3.

S32, electroplating the conductive layer 4 between two adjacent metal electrodes 112 of the first substrate 11 and between two adjacent metal electrodes 221 of the fourth substrate 22 to form a second preformed plate.

In one embodiment, the conductive layer 4 may be formed by tin metal plating.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A manufacturing process of a high-reliability surface mount fuse is characterized by comprising the following steps:

s1, processing a first substrate, a second substrate, a fusion layer, a third substrate and a fourth substrate, wherein the method specifically comprises the following steps: processing a first substrate, processing a plurality of parallel long strip holes extending along a first direction on the first substrate, and etching metal electrodes on two sides of the long strip holes;

Processing a second substrate, processing a plurality of cavities arranged along a second direction on the second substrate, and processing first through holes on two sides of the cavities along the second direction, wherein the first through holes correspond to the strip holes of the first substrate, and the first direction is perpendicular to the second direction;

processing a fourth substrate, and etching a metal electrode corresponding to the first substrate on the fourth substrate;

S2, hot-press forming a first prefabricated plate, and carrying out hot-press fixing connection on the first substrate, the second substrate, the fusion layer, the third substrate and the fourth substrate for two times through an adhesive layer to form the first prefabricated plate;

S3, hot-press forming a second prefabricated plate, processing a through hole on the prefabricated plate, electroplating a conductive layer to form the second prefabricated plate, wherein the method specifically comprises the following steps of: s31, processing through holes communicated with the first substrate on the third substrate, the fourth substrate, the fusing layer and the second substrate;

S32, electroplating the conductive layer between two adjacent metal electrodes of the first substrate and between two adjacent metal electrodes of the fourth substrate to form a second prefabricated plate;

2. The manufacturing process according to claim 1, wherein step S2 comprises:

3. The manufacturing process according to claim 2, wherein step S21 further comprises: and filling materials in the cavities of the second substrate and the cavities of the third substrate before the first substrate, the second substrate, the fusion layer and the third substrate are fixed by hot pressing.

4. A high reliability surface mount fuse manufactured by the manufacturing process of any one of claims 1 to 3, comprising a fuse layer, and an upper cavity and a lower cavity sandwiching the fuse layer;

5. The high-reliability surface mount fuse according to claim 4, wherein the upper cavity and the lower cavity are provided to form a cavity corresponding to the fusing part of the fusing layer, and a filler is provided in the cavity.

6. The high reliability surface mount fuse of claim 5 wherein said filler is a composite filler comprising quartz sand and,

At least one of Natrii sulfas (sodium sulfate decahydrate), alumen (aluminum potassium sulfate dodecahydrate), gypsum Fibrosum, lime, melamine, magnesium hydroxide, aluminum hydroxide, and ammonium salt.

7. The high-reliability surface mount fuse according to claim 4, wherein the upper cavity is formed by bonding a first substrate and a second substrate, and the lower cavity is formed by bonding a third substrate and a fourth substrate;

8. The high-reliability surface mount fuse according to claim 4, wherein the fusing part is provided in a wire shape or a sheet shape.