Weather-resistant PPTC resettable fuse

Abstract

The utility model provides a weather-resistant PPTC resettable fuse. The weather-resistant PPTC resettable fuse comprises a packaging frame body and a chip main body, the packaging frame body is configured into a regular rectangular structure; the chip main body is made of a positive temperature coefficient composite material; the positive temperature coefficient composite material at least comprises polyvinylidene fluoride and conductive particles; the chip main body comprises a first chip layer and a second chip layer; the first chip layer is located on the upper layer and the right side of the first chip layer is hollowed to form a first abdicating area used for avoiding the right electrode. The second chip layer is located on the lower layer and the left side of the second chip layer is hollowed to form a second abdicating area used for avoiding the left electrode. A hollow through space is formed in the middle area of the packaging frame body, and the first chip layer and the second chip layer are adaptively embedded in the through space in a press fit manner; compared with the prior art, a simpler packaging frame body is adopted, production and installation are facilitated, the overall mechanical strength and stability can be effectively improved, and the rectangular packaging frame body is beneficial to ensuring reasonable layout of the PPTC chip and facilitating electrical connection and heat dissipation design.

Description

Technical Field

[0001] The utility model relates to the technical field of fuses, and in particular to a weather-resistant PPTC resettable fuse. Background Art

[0002] A PPTC resettable fuse is a component that automatically disconnects circuit protection devices in an overcurrent condition. Its core material is a positive temperature coefficient (PTC) composite material with a self-resetting function. Its operating principle is based on the material's temperature response. When the current exceeds a safe limit, the PTC material in the PPTC fuse expands due to the current flow, rapidly increasing its resistance and limiting or shutting off the current, thus achieving overcurrent protection. Once the temperature returns to normal, the material's structure recovers, and the circuit is reopened, eliminating the need to replace the fuse.

[0003] As a result, PPTC resettable fuses, with their efficient overcurrent protection, self-reset function, and maintenance-free operation, have become a vital component in the circuit protection field. With technological advancements, PPTC fuses continue to innovate in structural design and material improvements, providing reliable protection for the safe operation of outdoor equipment, industrial control, and consumer electronics.

[0004] Compared to traditional one-time-blow fuses, PPTC resettable fuses can be used multiple times without replacement and have an automatic reset function. However, when used outdoors, the chip of existing PPTC resettable fuses is mostly exposed to the outside, making them easily affected by moisture and sunlight, which can significantly reduce their performance. Utility Model Content

[0005] In view of this, an object of the present invention is to provide a weather-resistant PPTC resettable fuse to solve the above-mentioned problem.

[0006] The utility model adopts the following scheme:

[0007] The present application provides a weather-resistant PPTC resettable fuse, comprising: a packaging frame and a chip body; the packaging frame is configured into a regular rectangular structure; the chip body is composed of a positive temperature coefficient composite material; the positive temperature coefficient composite material contains at least polyvinylidene fluoride and conductive particles distributed therein; the chip body comprises a first chip layer and a second chip layer stacked on each other; the first chip layer is located in the upper layer and is hollowed out on its right side to form a first clearance area for avoiding the right electrode, and the second chip layer is located in the lower layer and is hollowed out on the left side to form a second clearance area for avoiding the left electrode; the packaging frame is constructed with a hollow through space in the middle area, and the first chip layer and the second chip layer are adapted to be buried in the through space in a pressed form.

[0008] As a further improvement, copper is electroplated from top to bottom along the first clearance area of ​​the first chip layer to form a right pad and a right electrode connected thereto onto the second chip layer.

[0009] As a further improvement, a left pad and its conductive left electrode are electroplated on the first chip layer along the opposite side by copper deposition, and are located just above the second clearance area.

[0010] As a further improvement, the wall thicknesses of the four sides of the packaging frame are configured to be equal in width.

[0011] As a further improvement, the side edges of the first chip layer and the second chip layer are completely placed in the packaging frame.

[0012] As a further improvement, the thickness of the packaging frame is equal to the sum of the thicknesses of the two chip layers, and the upper surface of the first chip layer and the lower surface of the second chip layer are respectively flush with the packaging frame.

[0013] As a further improvement, the first making way area and the second making way area are both configured as semicircular arc structures with the same size specifications.

[0014] As a further improvement, each of the clearance areas occupies 1 / 8 to 1 / 6 of the area of ​​the corresponding chip layer.

[0015] By adopting the above technical solution, the utility model can achieve the following technical effects:

[0016] 1. The weather-resistant PPTC resettable fuse of this application adopts a simpler packaging frame setting, which is not only convenient for production and installation, but also effectively increases the overall mechanical strength and stability. The rectangular packaging frame helps to ensure the reasonable layout of the PPTC chip, facilitating electrical connection and heat dissipation design.

[0017] 2. The hollow through-space in the middle area of ​​the package frame provides effective space to accommodate the chip layer and help dissipate heat, and effectively wraps the outer side of the chip to improve the overall weather resistance. The through-space design can also reduce weight and reduce costs, while enhancing the heat dissipation performance of the upper and lower surfaces, ensuring that the chip does not fail due to overheating during overcurrent protection.

[0018] 3. The chip body is composed of two layers of PTC composite materials stacked on each other. The first chip layer is located on the upper layer and the second chip layer is located on the lower layer, forming a superimposed structure, which provides multiple protection functions and significantly improves the overall thermal stability and current control capability.

[0019] 4. The clearance area on the right side of the first chip layer is designed to avoid the installation position of the right electrode. The clearance area on the left side of the second chip layer is designed to avoid the position of the left electrode. The hollowing design avoids interference from the electrodes, ensuring that the current can flow smoothly, while also ensuring the compactness of the structure and effective space utilization.

[0020] 5. Because PPTC chip material heats up rapidly when overcurrent occurs, a two-layer chip structure facilitates rapid heat dissipation. Chip heat can be dissipated through the through-hole and outside the package frame, preventing chip failure due to heat accumulation. The first and second chip layers are pressed and fitted into the through-hole. This structure not only ensures a tight fit between the chips but also enhances the mechanical strength and heat dissipation of the entire fuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a weather-resistant PPTC resettable fuse according to an embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A schematic diagram of the structure of the encapsulation frame in FIG.

[0023] Figure 3 yes Figure 1 A schematic structural diagram of the first chip layer in FIG.

[0024] Figure 4 yes Figure 1 A schematic structural diagram of the second chip layer in FIG.

[0025] Figure 5 This is a cross-sectional view of a weather-resistant PPTC resettable fuse according to an embodiment of the present invention.

[0026] Icons: 1-package frame; 11-through space; 2-chip body; 21-first chip layer; 211-first clearance area; 22-second chip layer; 221-second clearance area. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the utility model for which protection is claimed, but merely represents selected embodiments of the present invention.

[0028] Example

[0029] Combine Figures 1 to 5 This embodiment provides a weather-resistant PPTC resettable fuse, comprising: a package frame 1 and a chip body 2. The package frame 1 is configured in a regular rectangular structure, and the chip body 2 is composed of a positive temperature coefficient composite material. The positive temperature coefficient composite material contains at least polyvinylidene fluoride and conductive particles distributed therein.

[0030] The chip body 2 includes a first chip layer 21 and a second chip layer 22 stacked on top of each other. The first chip layer 21 is located on the upper layer and has its right side hollowed out to form a first clearance area 211 for avoiding the right electrode. The second chip layer 22 is located on the lower layer and has its left side hollowed out to form a second clearance area 221 for avoiding the left electrode. The packaging frame 1 has a hollowed-out through-space 11 in the middle area. The first chip layer 21 and the second chip layer 22 are adapted to be buried in the through-space 11 in a pressed form.

[0031] The weather-resistant PPTC resettable fuse described above is configured using a simpler packaging frame 1, which is not only convenient for production and installation, but also effectively increases the overall mechanical strength and stability. The rectangular packaging frame 1 helps ensure a reasonable layout of the PPTC chip, facilitating electrical connection and heat dissipation design.

[0032] The hollow through space 11 in the middle area of ​​the packaging frame 1 provides an effective space to accommodate the chip layer and help dissipate heat, and effectively wraps the outer side of the chip to improve the overall weather resistance. The design of the through space 11 can also reduce weight and reduce costs, while enhancing the heat dissipation performance of the upper and lower surfaces to ensure that the chip does not fail due to overheating during overcurrent protection.

[0033] The chip body 2 is composed of two layers of PTC composite materials stacked on each other, with the first chip layer 21 located on the upper layer and the second chip layer 22 located on the lower layer, forming a stacked structure, which provides multiple protection functions and significantly improves the overall thermal stability and current control capability.

[0034] The clearance area on the right side of the first chip layer 21 is designed to avoid the installation position of the right electrode. The clearance area on the left side of the second chip layer 22 is designed to avoid the position of the left electrode. The hollow design avoids interference from the electrodes, ensuring that the current can flow smoothly, while also ensuring the compactness of the structure and effective space utilization.

[0035] Because PPTC chip material heats up rapidly when overcurrent occurs, a two-layer chip structure facilitates rapid heat dissipation. Chip heat can be dissipated through through-hole 11 and the exterior of package frame 1, preventing chip failure due to heat accumulation. The first and second chip layers 21, 22 are pressed and fitted within through-hole 11. This structure not only ensures a tight fit between the chips but also enhances the mechanical strength and heat dissipation of the entire fuse.

[0036] Preferably, the material of the packaging frame 1 is a highly weather-resistant polymer or plastic with good UV resistance, moisture resistance, corrosion resistance and impact resistance, so that the PPTC resettable fuse can work stably for a long time outdoors and in harsh environments.

[0037] Furthermore, in order to enhance weather resistance, the packaging frame 1 and the chip surface can be coated with a moisture-proof coating and an anti-ultraviolet coating, which can effectively protect the chip from environmental factors such as moisture, dust, and ultraviolet rays, ensuring its long-term stable performance.

[0038] It should be mentioned that polyvinylidene fluoride (PVDF) is used as the main material of the positive temperature coefficient composite material, and polyvinylidene fluoride (PVDF) has high thermal stability and aging resistance, so that the PPTC fuse can still maintain stable performance in high temperature environments and is suitable for outdoor and high temperature conditions. In addition, the conductive particles include at least carbon black and calcium carbonate. Each conductive particle is configured to be evenly mixed into the polyvinylidene fluoride after being broken up. Carbon black has good conductivity. Using it as the main conductive particle can significantly improve the overall conductivity of the composite material layer, so that the PPTC fuse maintains a low resistance under normal operating current. Calcium carbonate, as a filler, can enhance the thermal stability and aging resistance of the polyvinylidene fluoride matrix. Under high temperature conditions, calcium carbonate can provide stable physical support, prevent the material from performing poorly after multiple expansion and contraction, and extend the service life of the PPTC fuse.

[0039] In this embodiment, a right pad and its associated right electrode (not shown) are plated from top to bottom along the first clearance area 211 of the first chip layer 21 onto the second chip layer 22. Accordingly, a left pad and its associated left electrode (not shown) are plated along the opposite side onto the first chip layer 21, directly above the second clearance area 221. Obviously, the copper plating process and the arrangement of the pads and electrodes are conventional techniques and are not described here in detail.

[0040] like Figure 1 and Figure 2As shown, in this embodiment, the wall thicknesses on all four sides of the packaging frame 1 are constructed to be of equal width. On the one hand, the equal width wall thickness can ensure that the packaging frame 1 evenly distributes stress in all directions, thereby improving the impact resistance and pressure resistance of the structure. Regardless of the direction from which the external pressure comes, the packaging frame 1 can provide consistent protection to avoid damage or failure caused by local wall thickness being too thin or too thick. On the other hand, the equal width wall thickness design helps to dissipate heat evenly. The entire packaging frame 1 can conduct heat at a consistent rate, thereby avoiding problems such as local overheating or uneven temperature, which is crucial for the thermal response and self-recovery performance of the PPTC fuse during overcurrent protection.

[0041] like Figures 3 to 5 As shown, in this embodiment, the side edges of the first chip layer 21 and the second chip layer 22 are completely placed in the packaging frame 1. Specifically, the thickness of the packaging frame 1 is equal to the sum of the thicknesses of the two chip layers, and the upper surface of the first chip layer 21 and the lower surface of the second chip layer 22 are respectively flush with the packaging frame 1. Thus, the thickness of the two chip layers is completely matched with the thickness of the packaging frame 1, making the entire component more compact and avoiding excessive gaps or unnecessary waste of space. Moreover, the upper surface of the first chip layer 21 and the lower surface of the second chip layer 22 are flush with the packaging frame 1, which means that heat can be more evenly conducted from the chip layer to the packaging frame 1, avoiding heat accumulation. In addition, the chip layer is completely placed in the packaging frame 1, and the edges are not exposed, which makes the packaging of the entire component better and prevents the chip from being damaged by external impact, moisture or dust.

[0042] like Figure 3 and Figure 4 As shown, in this embodiment, the first clearance area 211 and the second clearance area 221 are both configured as semicircular arc structures with the same dimensions. By designing the clearance area as a semicircular arc, the electrode position can be more accurately avoided, preventing the electrode from contacting the chip body 2, which does not need to be directly conductive. This ensures stable electrode access while maximizing the area of ​​the chip layer and reducing space waste. The semicircular arc design also helps optimize the current flow path, preventing the smooth flow of current from being affected by improper electrode positioning, thereby improving overcurrent protection performance.

[0043] Preferably, each clearance area occupies 1 / 8 to 1 / 6 of the area of ​​the chip layer to which it belongs. This provides sufficient space to avoid electrodes while ensuring the functionality of the chip layer without wasting too much chip area. A reasonable area ratio maximizes chip performance without unduly affecting the compactness of the structure.

[0044] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention fall within the protection scope of the present invention.

Claims

1. A weather-resistant PPTC resettable fuse, characterized in that: include: The packaging frame is configured into a regular rectangular structure; The chip body is composed of a positive temperature coefficient composite material; the positive temperature coefficient composite material at least contains polyvinylidene fluoride and conductive particles distributed therein; The chip body includes a first chip layer and a second chip layer stacked on each other; the first chip layer is located in the upper layer and is hollowed out on its right side to form a first clearance area for avoiding the right electrode; the second chip layer is located in the lower layer and is hollowed out on its left side to form a second clearance area for avoiding the left electrode; Furthermore, a hollowed-out through space is constructed in the middle region of the packaging frame, and the first chip layer and the second chip layer are adapted to be buried in the through space in a pressed form.

2. The weather-resistant PPTC resettable fuse according to claim 1, characterized in that: From top to bottom, a right pad and a right electrode connected thereto are formed by copper plating corresponding to the first clearance area of ​​the first chip layer onto the second chip layer.

3. The weather-resistant PPTC resettable fuse according to claim 2, characterized in that: A left pad and a left electrode connected thereto are electroplated on the first chip layer along the opposite side by copper deposition, and are located just above the second clearance area.

4. The weather-resistant PPTC resettable fuse according to claim 1, characterized in that: The wall thicknesses of the four sides of the packaging frame are configured to be equal in width.

5. The weather-resistant PPTC resettable fuse according to claim 1, characterized in that: The side edges of the first chip layer and the second chip layer are completely placed in the packaging frame.

6. The weather-resistant PPTC resettable fuse according to claim 5, characterized in that: The thickness of the packaging frame is equal to the sum of the thicknesses of the two chip layers, and the upper surface of the first chip layer and the lower surface of the second chip layer are respectively flush with the packaging frame.

7. The weather-resistant PPTC resettable fuse according to claim 1, characterized in that: The first and second clearance areas are both configured as semicircular arc structures with the same size specifications.

8. The weather-resistant PPTC resettable fuse according to claim 7, characterized in that: Each of the give-away areas occupies 1 / 8 to 1 / 6 of the area of ​​the corresponding chip layer.

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