Chip-type small fuse

Abstract

The utility model provides a chip-type small fuse, which comprises a flat fusible wire, first metal foils which are symmetrically distributed are inserted into the outer sides of the two sides of the fusible wire, and a high-thermal-conductivity substrate is sleeved on the outer sides of the first metal foils. According to the chip-type small fuse, the fusible wire is adopted, so that a circuit can be fused in time when the current is overloaded, the chip-type small fuse has the characteristic of quick response, the current can be cut off in a short time, the safety problems of circuit overheating, equipment damage and the like are effectively prevented, the safety and the stability of the circuit are improved, and the service life of the chip-type small fuse is prolonged. The metal foil is used for bearing current and is not easy to decompose and relatively stable in performance in a high-temperature environment, so that the chip-type small fuse can adapt to different working environments and load conditions, a flexible solution is provided for various circuit protection scenes, the overall reliability of equipment can be greatly improved, the failure rate of the equipment can be reduced, and the service life of the chip-type small fuse is prolonged. And the service life of equipment is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of fuses, and specifically discloses a small-sized sheet-type fuse. Background Art

[0002] Chip-type miniature fuses are components used for circuit protection, with advantages such as small size, compact structure, and high reliability. In traditional chip-type miniature fuses, PTC (Positive Temperature Coefficient) materials are usually used as the main resistance materials. PTC materials have a positive temperature coefficient, that is, when the temperature rises, the resistance value will increase accordingly, thereby limiting the current and achieving the purpose of overcurrent protection. However, traditional chip-type miniature fuses have some problems in some cases.

[0003] First, when traditional chip-type small fuses are performing overcurrent protection, the response speed is slow due to the large heat capacity of the PTC material, and they cannot quickly respond to the instantaneous large current in the circuit, which may damage the circuit or even cause a safety accident. Secondly, when traditional chip-type small fuses are operating in a high-temperature environment, the resistance value of the PTC material will increase sharply with the increase in temperature, which may cause the voltage in the circuit to be too high, thereby causing damage to other components in the circuit. In addition, traditional chip-type small fuses usually use metal oxides as the main component of the PTC material. Metal oxides are easily decomposed in a high-temperature environment, resulting in a decrease in the performance of the PTC material, thereby affecting the service life and reliability of the fuse. Utility Model Content

[0004] In view of the above-mentioned defects or shortcomings in the prior art, the present application aims to provide a sheet-type small fuse, comprising a flat fusible link, wherein first metal foils symmetrically distributed are inserted on the outer sides of both sides of the fusible link, a high thermal conductivity substrate is mounted on the outer side of the first metal foil, a retaining wall is arranged on the top of the high thermal conductivity substrate, second metal foils inserted on the inner side of the first metal foil are clamped on the outer sides of both sides of the high thermal conductivity substrate, an encapsulation layer is arranged on the inner side of the retaining wall, and an insulating layer covering the outer side of the first metal foil is arranged between the encapsulation layer and the high thermal conductivity substrate.

[0005] Preferably, a positioning column is provided on the inner side of the high thermal conductivity substrate.

[0006] Preferably, a first insert with rounded corners is provided on one side of the second metal foil.

[0007] Preferably, a second plug having rounded corners on one side is provided on both sides of the fusible link.

[0008] Preferably, the first metal foil comprises a support plate which is sleeved on the inner side of the high thermal conductivity substrate and movably connected to the outer side of the positioning column, one side of the support plate is provided with an upper spring plate located above the first plug-in plate, and the other side of the support plate is provided with a lower spring plate located below the second plug-in plate, and side spring plates are provided on both sides of the upper spring plate and the lower spring plate. Beneficial Effects

[0009] 1. The chip-type small fuse adopts a fusible element to enable the circuit to be blown in time when the overload current occurs, so that the chip-type small fuse has the characteristics of fast response, can cut off the current in a short time, effectively prevent safety problems such as circuit overheating and equipment damage, and improve the safety and stability of the circuit.

[0010] 2. The chip-type small fuse uses metal foil to carry current. It is not easy to decompose in a high temperature environment and has relatively stable performance. As a result, the chip-type small fuse can adapt to different working environments and load conditions, providing flexible solutions for various circuit protection scenarios, and can greatly improve the overall reliability of the equipment, reduce the equipment failure rate, and increase the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0012] Figure 1 It is a partial cross-sectional view of the structure of the utility model;

[0013] Figure 2 It is an exploded schematic diagram of the structure of the utility model;

[0014] Figure 3 It is a schematic diagram of the structure of the utility model;

[0015] Figure 4 It is a partial schematic diagram of the structure of the utility model;

[0016] Figure 5 It is a schematic diagram of the fusible link of the utility model;

[0017] Figure 6 It is a schematic diagram of the first metal foil of the utility model.

[0018] In the figure: 1, fusible link; 2, first metal foil; 21, supporting sheet; 22, upper spring sheet; 22, lower spring sheet; 24, side spring sheet; 3, high thermal conductivity substrate; 4, retaining wall; 5, second metal foil; 6, encapsulation layer; 7, positioning column; 8, first plug sheet; 9, second plug sheet. DETAILED DESCRIPTION

[0019] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings.

[0020] The accompanying drawings in the embodiments of the present invention: different types of section lines in the drawings are not marked according to national standards, nor do they impose any requirements on the materials of the components. Instead, they are used to distinguish the cross-sectional views of the components in the drawings.

[0021] See also Figure 1-6 A sheet-type small fuse comprises a flat fusible link 1. By setting the fusible link 1 to be flat, the contact area between the fusible link 1 and the first metal foil 2 can be increased, and the conductive connection performance is relatively stable. The outer sides of both sides of the fusible link 1 are plugged with symmetrically distributed first metal foils 2, and the outer sides of the first metal foil 2 are sleeved with a high thermal conductivity substrate 3. A retaining wall 4 is arranged on the top of the high thermal conductivity substrate 3. The outer sides of both sides of the high thermal conductivity substrate 3 are clamped with second metal foils 5 plugged into the inner side of the first metal foil 2. An encapsulation layer 6 is arranged on the inner side of the retaining wall 4. The retaining wall 4 is used to facilitate the packaging of an insulating layer and the encapsulation layer 6 on the outer side of the first metal foil 2. An insulating layer covering the outer side of the first metal foil 2 is arranged between the encapsulation layer 6 and the high thermal conductivity substrate 3. The insulating layer can protect the first metal foil 2 and the first plug 8 located on the inner side of the high thermal conductivity substrate 3.

[0022] The inner side of the high thermal conductivity substrate 3 is provided with positioning posts 7 , and the supporting sheet 21 can be positioned by the positioning posts 7 , so as to facilitate the first metal foil 2 to be mounted on the inner side of the high thermal conductivity substrate 3 .

[0023] Among them, a first plug-in piece 8 with chamfered corners is provided on one side of the second metal foil 5. After the fusible wire 1 and the first metal foil 2 are installed on the inner side of the high thermal conductivity substrate 3 by using the first plug-in piece 8, the second metal foil 5 can be directly installed on the outer side of the high thermal conductivity substrate 3 by plugging. The two do not affect each other, which is convenient for processing and manufacturing the sheet-type small fuse. The rounded corners can guide the first plug-in piece 8 so that the first plug-in piece 8 can be plugged in between the support sheet 21 and the upper spring sheet 22.

[0024] Among them, a second plug-in piece 9 with a rounded corner on one side is provided on both sides of the fusible link 1. The second plug-in piece 9 can increase the contact area between the support piece 21 and the lower spring piece 23, and at the same time, the fusible link 1 can be installed in a plug-in manner. The rounded corner can guide the second plug-in piece 9 to facilitate the plug-in of the second plug-in piece 9 between the support piece 21 and the lower spring piece 23.

[0025] Among them, the first metal foil 2 includes a support sheet 21 which is sleeved on the inner side of the high thermal conductivity substrate 3 and movably sleeved on the outer side of the positioning column 7. An upper spring sheet 22 located above the first plug-in sheet 8 is provided on one side of the support sheet 21, and a lower spring sheet 23 located below the second plug-in sheet 9 is provided on the other side of the support sheet 21. Side spring sheets 24 are provided on both sides of the upper spring sheet 22 and the lower spring sheet 23. The side spring sheets 24 can be used to limit the position of the fuse 1 and the second metal foil 5, so that the fuse 1 and the second metal foil 5 are not easily offset when they are plugged in and installed.

[0026] Among them, the design steps of the chip type small fuse are as follows:

[0027] S1. Material selection: The main materials of the sheet-type miniature fuse include metal foil (the first metal foil 2 and the second metal foil 5) and the fusible wire 1. The metal foil is used to carry current, and the fusible wire is used to cut off the current when overcurrent occurs. In order to improve the performance and stability of the fuse, it is necessary to select a metal material with a suitable melting point as shown in Table 1;

[0028] Table 1: Comparison of metal wire material properties

[0029]

[0030] S2. Structural design: The structural design of the chip-type small fuse needs to consider factors such as the shape and size of the screen-printed lines, the thickness and flatness of the coating, and the uniformity of the sputtered layer. These factors will affect the performance indicators of the fuse, such as the response speed, resistance value, and current resistance;

[0031] S3. Preparation process: The preparation process of chip-type miniature fuses includes multiple steps such as screen printing, coating, sputtering, etc. The level of its preparation process directly affects the performance and stability of the fuse;

[0032] S4. Testing and evaluation: After preparation, the chip-type miniature fuse needs to undergo a series of performance tests and evaluations to ensure that it meets the design requirements and relevant standards. The test contents include current withstand capability, high temperature resistance, response time, etc.

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A sheet-type miniature fuse, comprising a flat fusible link (1), characterized in that: The outer sides of both sides of the fusible link (1) are plugged with first metal foils (2) which are symmetrically distributed; the outer sides of the first metal foils (2) are sleeved with a high thermal conductivity substrate (3); a retaining wall (4) is arranged on the top of the high thermal conductivity substrate (3); the outer sides of both sides of the high thermal conductivity substrate (3) are clamped with second metal foils (5) plugged into the inner sides of the first metal foils (2); an encapsulation layer (6) is arranged on the inner sides of the retaining walls (4); and an insulating layer covering the outer sides of the first metal foils (2) is arranged between the encapsulation layer (6) and the high thermal conductivity substrate (3).

2. A chip-type miniature fuse according to claim 1, characterized in that: A positioning column (7) is provided on the inner side of the high thermal conductivity substrate (3).

3. A chip-type miniature fuse according to claim 1, characterized in that: A first insert sheet (8) with rounded corners is provided on one side of the second metal foil (5).

4. A chip-type miniature fuse according to claim 1, characterized in that: Second inserts (9) with rounded corners on one side are provided on both sides of the fusible link (1).

5. A chip-type miniature fuse according to claim 1, characterized in that: The first metal foil (2) comprises a support sheet (21) which is sleeved on the inner side of the high thermal conductivity substrate (3) and sleeved on the outer side of the positioning column (7); an upper spring sheet (22) located above the first plug sheet (8) is provided on one side of the support sheet (21); and a lower spring sheet (23) located below the second plug sheet (9) is provided on the other side of the support sheet (21); and side spring sheets (24) are provided on both sides of the upper spring sheet (22) and the lower spring sheet (23).

Images