A high-temperature-resistant surge protector and a preparation method thereof

Abstract

The application discloses a high-temperature-resistant surge protector and a preparation method thereof. The application is characterized in that a heat-conducting glue is filled in a filling cavity formed between a pressure-sensitive resistor and a shell, so that the pressure-sensitive resistor can quickly dissipate heat to the surrounding in each surge protection module in the surge protector, the heat dissipation effect is improved, the thermal breakdown time of the pressure-sensitive resistor is effectively prolonged, and the thermal runaway phenomenon of the surge protection module is avoided. Meanwhile, the instantaneous heat generated by the pressure-sensitive resistor is promptly and evenly released to the surrounding, so that the tripping point is not out of control due to the instantaneous heat generated on the pressure-sensitive resistor, and the effectiveness and safety of the surge protector are improved. In addition, the heat-conducting glue is constructed by spherical alumina, spherical zinc oxide and hexagonal boron nitride to form a dense and continuous heat-conducting structure, so that the overall heat-conducting performance is significantly improved. Meanwhile, a flame retardant is added to the heat-conducting glue to endow the heat-conducting glue with excellent flame-retardant protection capability, so that the use risk brought by high-temperature working conditions is effectively resisted, and the safety of the surge protector is further ensured.

Description

Technical Field

[0001] This invention relates to the field of surge protector technology, and in particular to a high-temperature resistant surge protector and its preparation method. Background Technology

[0002] Surge protectors are critical protective devices in fields such as power, communications, and photovoltaics. They can stably discharge lightning / operating overvoltage energy under high temperatures and transient surges, block surge impacts, and ensure equipment safety. As the core component of surge protectors, varistors rely on nonlinear volt-ampere characteristics to quickly conduct and clamp voltage and discharge energy. However, their heat resistance depends not only on their own performance but also on the assembly structure.

[0003] Currently, the assembly method of existing surge protectors typically involves placing the varistor directly into the mounting cavity within the housing, secured only by the leads at both ends of the varistor or a small amount of adhesive. This results in a gap between the varistor and the inner wall of the mounting cavity, failing to form an effective sealing and thermal management structure. Due to the extremely low thermal conductivity of air, the instantaneous and continuous heat generated when the varistor withstands high current surges or experiences a degraded chemical frequency fault cannot be dissipated in time, instead forming severe localized heat accumulation inside the resistor. This heat retention not only accelerates the thermal breakdown process of the resistor, but more critically, under lightning strike conditions, the accumulated instantaneous heat can easily combine with the ambient temperature, causing the tripping mechanism to malfunction; and under short-circuit fault conditions, the lag in heat transfer leads to delayed tripping action, failing to disconnect the circuit before a fire occurs.

[0004] In view of this, it is necessary to provide a high-temperature surge protector that can operate stably under high-temperature conditions and its preparation method. Summary of the Invention

[0005] Based on the high performance requirements of surge protectors in the prior art, this invention provides a high-temperature resistant surge protector and its preparation method.

[0006] A high-temperature surge protector includes a base and a plurality of surge protection modules inserted into the base. The base has a plurality of insertion holes corresponding to the surge protection modules. Each surge protection module includes a housing, inside which is a mounting base and a varistor. A first electrode connector and a second electrode connector are respectively mounted on the left and right sides of the mounting base. The varistor has a first electrode plate and a second electrode plate. The first electrode connector includes a first pin mounted on the right side of the mounting base and a thermal release component located on the front side of the mounting base. Both ends of the thermal release component are welded to the first pin and the first electrode plate respectively using a low-melting-point alloy. One end of the second electrode connector is connected to the second electrode plate. The first and second pins extend out of the housing and are correspondingly inserted into the insertion hole. The varistor is mounted on the rear side of the mounting base, and a potting cavity is formed between the varistor and the housing. The potting cavity is filled with a thermally conductive adhesive. Each component of the thermally conductive adhesive, calculated by weight, includes the following: 53-70 parts epoxy resin, 100-130 parts spherical alumina, 12-18 parts spherical zinc oxide, 8-15 parts hexagonal boron nitride, 25-35 parts flame retardant, 1.2-2.0 parts silane coupling agent, 30-40 parts curing agent, 0.3-0.8 parts defoamer, 5-9 parts diluent, and 2.5-3.5 parts thixotropic agent.

[0007] Preferably, the housing includes a main body with an opening at the bottom, and the bottom of the mounting base is provided with a sealing plate. The sealing plate is provided with a pair of through slots for the first pin and the second pin to pass through. The mounting base is inserted into the main body through the opening, so that the sealing plate is installed on the opening.

[0008] Preferably, the mounting base has a mounting groove on its left side that communicates with the second electrode connector; the mounting base has mounting holes that extend through both sides, the first electrode plate passes through the mounting holes and is welded to the thermal release component; the second electrode plate passes through the mounting groove and is welded to one end of the second electrode connector.

[0009] Preferably, the base is provided with microswitches corresponding to the surge protection modules; the bottom of the mounting base is provided with an opening; a fixing plate is provided on the right side of the mounting base, and a rotating shaft is also provided on the front side of the mounting base, with a rotating component rotatably connected to the rotating shaft; a contact rod corresponding to the opening is provided at the bottom of the rotating component; a spring is connected to one end of the rotating component away from the rotating shaft, the other end of the spring is connected to the fixing plate, and the rotating component abuts against the thermal release component; when the surge protection module is inserted into the base, the contact rod passes through the microswitches; when the thermal release component is desoldered, the spring pulls the rotating component to continue rotating around the rotating shaft in the direction close to the thermal release component and drives the contact rod to disengage from the microswitches.

[0010] Preferably, the epoxy resin comprises 35-45 parts of bisphenol F type epoxy resin and 18-25 parts of o-cresol formaldehyde epoxy resin.

[0011] Preferably, the spherical alumina comprises spherical alumina I and spherical alumina II in a mass ratio of 1.5:1, and the particle size of spherical alumina I is smaller than that of spherical alumina II.

[0012] Preferably, the flame retardant comprises 15-20 parts of aluminum hypophosphite and 10-15 parts of melamine cyanurate.

[0013] Preferably, the thermally conductive adhesive further comprises: 0.5-2 parts of accelerator; the curing agent is an acid anhydride curing agent.

[0014] Preferably, the thixotropic agent is fumed silica.

[0015] A method for manufacturing a high-temperature surge protector, used to manufacture a high-temperature surge protector as described above; characterized in that it comprises: Step S1: Dust removal, oil removal and drying treatment of the interior of the main body and the mounting base, and opening an injection hole and an exhaust port at the preset position of the main body; Step S2: Install the varistor, the first electrode connector, and the second electrode connector in the corresponding positions on the mounting base, and use a low melting point alloy to weld the thermal release component to the first pin and the first electrode sheet. Then weld the second electrode connector to the second electrode sheet to obtain the inner core assembly. Step S3: Install the inner core assembly into the main body and fix the sealing plate of the mounting base on the opening of the main body, so that a potting cavity is formed between the varistor and the main body to obtain the surge protection assembly; wherein, the vent is located at the top of the potting cavity and the glue injection hole is located on the bottom side of the potting cavity. Step S4: Fix the surge protection component on a platform so that the vent is above the injection hole. Then inject the thermally conductive adhesive from the injection hole at a constant speed until the thermally conductive adhesive overflows from the vent. Then gently vibrate the surge protection component to remove bubbles, and then seal the injection hole and the vent. Step S5: Place the surge protection module after the glue is applied in step S4 into a constant temperature chamber for curing. After curing and cooling, trim and remove excess glue from the surface to obtain the surge protection module. Step S6: Insert several of the surge protection modules into the corresponding sockets of the base through the first and second pins in sequence to obtain the high-temperature surge protector.

[0016] The beneficial effects of this invention are as follows: This invention provides a high-temperature surge protector by encapsulating thermally conductive adhesive in the potting cavity formed between the varistor and the housing. This allows the varistor in each surge protection module to quickly dissipate heat to the surroundings, improving heat dissipation and effectively extending the thermal breakdown time of the varistor, thus preventing thermal runaway of the surge protection module. At the same time, the instantaneous heat generated by the varistor is released evenly and promptly to the surroundings, preventing the tripping point from going out of control due to the instantaneous heat generated on the varistor, thereby improving the effectiveness and safety of the surge protector.

[0017] In addition, by precisely compounding epoxy resin, spherical alumina, spherical zinc oxide, hexagonal boron nitride, flame retardant, silane coupling agent, curing agent, defoamer, diluent, and thixotropic agent in specific weight proportions, a dense and continuous multidimensional thermal conductivity pathway is constructed within the prepared thermally conductive adhesive, significantly improving the overall thermal conductivity of the adhesive layer. Simultaneously, the addition of flame retardant endows the thermally conductive adhesive with excellent flame-retardant and fire-resistant properties, eliminating the problems of combustion and carbonization failure of the thermally conductive adhesive layer under high-temperature conditions; effectively resisting the usage risks brought about by high-temperature conditions, and further ensuring the safety of surge protector use.

[0018] In addition, the present invention also provides a method for manufacturing a surge protector. By filling the potting cavity of each surge protection module with thermally conductive adhesive, an efficient heat conduction path is constructed, which can quickly dissipate the heat generated by the varistor during operation, effectively reduce the junction temperature of the core component, and thus significantly improve the stability and service life of the surge protector in high-temperature environments. Attached Figure Description

[0019] Figure 1 A three-dimensional structural diagram of a high-temperature surge protector provided by the present invention; Figure 2 A three-dimensional structural diagram of the surge protection module provided by the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the surge protection module provided by the present invention; Figure 4 This is a schematic diagram of the internal structure of the surge protection module provided by the present invention; Figure 5 A schematic diagram of the separate structure of the surge protection module provided by the present invention; Figure 6 A schematic diagram of the first electrode connector structure provided by the present invention; Figure 7 This is a schematic diagram of the structure of the second electrode connector provided by the present invention; Figure 8 This is a schematic diagram of the preparation method of a high-temperature surge protector provided by the present invention. Attached Figure Labels

[0020] 1. Base; 11. Socket; 12. Microswitch; 2. Surge protection module; 21. Housing; 211. Main body; 22. Mounting base; 221. Mounting groove; 222. Mounting hole; 223. Opening; 224. Fixing plate; 225. Rotating shaft; 226. Rotating component; 227. Abutment rod; 228. Spring; 229. Sealing plate; 230. Through groove; 23. Varistor; 231. First electrode plate; 232. Second electrode plate; 24. First electrode connector; 241. First pin; 242. Thermal release component; 25. Second electrode connector; 251. Second pin; 3. Encapsulation cavity; 4. Thermally conductive adhesive. Detailed Implementation

[0021] To provide a more detailed description of the present invention, the following description is provided in conjunction with the accompanying drawings. It should be noted that the embodiments described below are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Example 1

[0022] Combination Figure 1 As shown, a high-temperature surge protector includes a base 1 and several surge protection modules 2 inserted into the base. In this embodiment, there are four surge protection modules 2.

[0023] Specifically, refer to Figures 2 to 7 As shown, the base 1 is provided with a plurality of plug holes 11 corresponding to the surge protection module 2; the surge protection module 2 includes a housing 21, and the housing 21 is provided with a mounting base 22 and a varistor 23; the mounting base 22 is provided with a first electrode connector 24 and a second electrode connector 25 on its left and right sides respectively.

[0024] The varistor 23 is provided with a first electrode plate 231 and a second electrode plate 232; the first electrode connector 24 includes a first pin 241 installed on the right side of the mounting base 22 and a thermal release member 242 located on the front side of the mounting base 22; both ends of the thermal release member 242 are welded to the first pin 241 and the first electrode plate 231 respectively by low melting point alloy; one end of the second electrode connector 25 is welded to the second electrode plate 232, and the other end is provided with a second pin 251; the first pin 241 and the second pin 251 both extend out of the housing 21 and are correspondingly inserted into the insertion hole 11.

[0025] When the line experiences abnormal overvoltage or continuous high current surge, the varistor 23 will generate a large amount of heat. The low-melting-point alloy will melt rapidly under heat, causing the connection between the thermal trip unit 72 and the first pin 241 and the first electrode plate 232 to be quickly disconnected. This will instantly cut off the fault circuit and terminate the abnormal power supply state in a timely manner, effectively avoiding safety accidents such as equipment damage, line short circuits and fires caused by the overheating failure of the varistor 23, thereby improving the reliability and safety of the surge protector.

[0026] The varistor 23 is mounted on the rear side of the mounting base 22, and a potting cavity 3 is formed between the varistor 23 and the housing 21; a thermally conductive adhesive 4 is potted in the potting cavity 3.

[0027] By potting thermally conductive adhesive 4 into the potting cavity formed between the varistor 23 and the housing 213, the varistor 23 in each surge protection module 2 of the surge protector can quickly dissipate heat to the surroundings, improving the heat dissipation effect and thus effectively extending the thermal breakdown time of the varistor 23, avoiding thermal runaway of the surge protection module. At the same time, the instantaneous heat generated by the varistor 23 is released to the surroundings in a timely and even manner, so that the tripping point does not go out of control due to the instantaneous heat generated on the varistor 23, improving the effectiveness and safety of the surge protector.

[0028] The thermally conductive adhesive 4 comprises the following components by weight: 53-70 parts epoxy resin, 100-130 parts spherical alumina, 12-18 parts spherical zinc oxide, 8-15 parts hexagonal boron nitride, 25-35 parts flame retardant, 1.2-2.0 parts silane coupling agent, 30-40 parts curing agent, 0.3-0.8 parts defoamer, 5-9 parts diluent, and 2.5-3.5 parts thixotropic agent. In this embodiment, the thixotropic agent is fumed silica.

[0029] Spherical alumina possesses excellent thermal conductivity, serving as a core filler to construct a stable main heat transfer framework within the colloid, ensuring the rapid dissipation of high heat flux generated during surge protection operation. Spherical zinc oxide fills the microscopic gaps in this main heat transfer framework, repairing heat transfer interruptions while also providing excellent insulation, moisture resistance, and aging resistance, further solidifying the stability of the heat dissipation path. Hexagonal boron nitride utilizes its unique lamellar structure to connect discrete particles, laterally linking lateral heat transfer pathways. This not only effectively improves the heat uniformity within the colloid surface and prevents the accumulation of local hot spots but also significantly enhances the overall thermal shock resistance and high-temperature resistance of the material.

[0030] Therefore, by using spherical alumina to construct a three-dimensional thermally conductive backbone framework, spherical zinc oxide to fill gaps and complete the heat transfer path, and hexagonal boron nitride to laterally bridge and connect network nodes, the three inorganic thermally conductive fillers interweave to form a dense three-dimensional thermally conductive network. This comprehensively reduces internal heat transfer obstacles and significantly improves overall heat dissipation efficiency. Simultaneously, it synergistically enhances the structural strength, insulation protection, and thermal shock resistance of the thermally conductive adhesive 4, making it suitable for the complex operating conditions of surge protectors involving high-frequency heating and instantaneous high-current surges. Furthermore, flame retardants are added to the thermally conductive adhesive 4, giving it excellent flame-retardant protection capabilities, effectively mitigating the risks associated with high-temperature operating conditions and further ensuring the safety of surge protector use.

[0031] In this embodiment, the epoxy resin comprises 35-45 parts of bisphenol F epoxy resin and 18-25 parts of o-cresol epoxy resin. Bisphenol F epoxy resin has excellent flexibility and strong adhesion, allowing the thermally conductive adhesive 23 to adhere tightly to the inner surface of the housing 21 and the outer surface of the varistor 23, and to buffer stress deformation caused by current surges. o-cresol epoxy resin has high heat resistance and high crosslinking density, exhibiting excellent high-temperature aging resistance and electrical insulation properties. The combination of these two epoxy resins forms a structurally stable adhesive carrier that uniformly supports various thermally conductive and flame-retardant fillers, while also resisting alternating high and low temperature changes under operating conditions, maintaining the overall structural integrity and electrical safety of the potting compound for a long time, and ensuring the overall mechanical and insulating properties of the adhesive substrate.

[0032] Preferably, the spherical alumina comprises spherical alumina I and spherical alumina II in a mass ratio of 1.5:1, and the particle size of spherical alumina I is smaller than that of spherical alumina II. By using spherical alumina with different particle sizes for synergistic filling, the small-diameter powder fills the gaps between the large-diameter particles, thereby effectively increasing the packing density of the filler, which helps to improve the thermal conductivity and heat transfer efficiency of the colloidal material and reduce internal pore defects.

[0033] Preferably, the flame retardant comprises 15-20 parts of aluminum hypophosphite and 10-15 parts of melamine cyanurate. Aluminum hypophosphite, as a phosphorus-based flame retardant, promotes dehydration and charring of the matrix in the condensed phase, forming a dense, heat-insulating char layer; melamine cyanurate dilutes the concentration of combustible smoke and oxygen in the gas phase and absorbs a large amount of heat. Through the synergistic effect of the two flame-retardant components, the fire resistance and flame retardancy rating of the thermally conductive adhesive 4 can be significantly improved, mitigating the risk of high-temperature ignition, thus enabling the surge protection module 2 to possess excellent flame-retardant performance.

[0034] Preferably, the thermally conductive adhesive further comprises: 0.5-2 parts of accelerator; the curing agent is an anhydride-based curing agent. The accelerator can effectively regulate the curing reaction rate between the anhydride-based curing agent and the epoxy resin, shorten the curing cycle, and ensure sufficient and uniform cross-linking reaction, avoiding incomplete local curing.

[0035] Preferably, the thermally conductive adhesive comprises, by weight percentage, 40 parts of bisphenol F epoxy resin, 22 parts of o-cresol epoxy resin, 115 parts of spherical alumina, 15 parts of spherical zinc oxide, 12 parts of hexagonal boron nitride, 30 parts of flame retardant, 1.6 parts of silane coupling agent, 35 parts of acid anhydride curing agent, 0.5 parts of defoamer, 7 parts of diluent, and 3 parts of fumed silica.

[0036] To clearly verify the role and value of each key raw material in the thermally conductive adhesive formulation of this invention, samples were prepared using the optimal proportion of the components. A total of 5 sets of thermally conductive adhesive components with the above-mentioned preferred mass percentages were prepared. The first sample was used as a test example, and the "spherical alumina", "spherical zinc oxide", "hexagonal boron nitride", and "spherical alumina, spherical zinc oxide and hexagonal boron nitride" in the second to fifth samples were replaced with an equal amount of epoxy resin. The second to seventh samples were designated as control groups 1, 2, 3, 4 and 5, respectively. After the thermally conductive adhesive was made from the raw materials with these percentages, it was potted and placed in a surge protection module 2 of the same specification. The various properties of the thermally conductive adhesive 4 were then tested using conventional techniques. For example, the thermal conductivity was tested using a tester based on the stable heat flow method, and the volume resistivity was tested using the high-resistivity electrode method to measure the volume resistance of the adhesive insulation, and then the resistivity value was calculated. The flame retardancy rating was determined according to the UL94 vertical burning test standard. The sample was held vertically and the flame retardancy rating was determined by standard flame burning. Long-term heat resistance stability was demonstrated by aging the thermally conductive adhesive 4 in a 120℃ constant temperature chamber for 500 hours, observing cracking, discoloration, deformation, and aging failure. The density of the adhesive was determined using microscopic cross-sectional observation and the water absorption rate method, statistically analyzing the proportion of internal pores to assess density.

[0037] The performance comparison of thermally conductive adhesive 4 prepared with that of Test Example 1 is shown in the table below:

[0038] As shown in the table above, adding one or more of spherical alumina, spherical zinc oxide, and hexagonal boron nitride to thermal conductive adhesive 4 significantly improves its heat dissipation capacity and long-term heat resistance stability compared to thermal conductive adhesive without these inorganic fillers. Furthermore, using a synergistic combination of these three types of inorganic fillers, compared to using a single filler, also significantly improves thermal conductivity and long-term heat resistance stability.

[0039] Meanwhile, compared to thermally conductive adhesives without these inorganic fillers, inorganic fillers such as spherical alumina, spherical zinc oxide, and hexagonal boron nitride can effectively improve the high insulation properties of thermally conductive adhesive 4, and can also play an auxiliary flame-retardant role, improving the fire protection capability of thermally conductive adhesive 4.

[0040] In addition, the three types of thermally conductive fillers work together to optimize the internal structure of the thermally conductive adhesive 4, reduce pore defects, improve heat aging resistance and overall density, and thus help ensure the long-term operational reliability of the surge protector.

[0041] Preferably, in conjunction with the reference Figure 1 , Figure 4 As shown, the mounting base 22 has a mounting groove 221 on its left side that communicates with the second electrode connector 25; the mounting base 22 has mounting holes 222 that pass through both sides, the first electrode piece 231 passes through the mounting holes 222 and is welded to the thermal release member 242; the second electrode piece 232 passes through the mounting groove 221 and is welded to one end of the second electrode connector 25, thereby achieving a fixed connection between the first electrode piece 231, the second electrode piece 232 and the mounting base 22.

[0042] The base 1 is provided with a micro switch 12 corresponding to the surge protection module 2; the base 1 is provided with a remote signaling mechanism; the bottom of the mounting base 22 is provided with an opening 223; the right side of the mounting base 22 is provided with a fixing plate 224; the front side of the mounting base 22 is also provided with a rotating shaft 225, and a rotating component 226 is rotatably connected to the rotating shaft 225; the bottom of the rotating component 226 is provided with an abutment rod 227 corresponding to the opening 223; a spring 228 is connected to one end of the rotating component 226 away from the rotating shaft 225, the other end of the spring 228 is connected to the fixing plate 224, and the rotating component 226 abuts against the thermal release component 242. At this time, the spring 228 is in a stretched state.

[0043] When the surge protection module 2 is plugged into the base 1, the abutment rod 227 triggers the micro switch 12 on the base 1 through the opening 223; when the thermal release component 242 is desoldered, the rotating component 226 loses its abutment, the spring 228 retracts, and then drives the rotating component 226 to continue rotating around the axis in the direction close to the thermal release component 242 and drives the abutment rod 227 to disengage from the micro switch 12.

[0044] When the surge protector malfunctions or is overloaded, the rotation of the rotating part 226 releases the pressure on the micro switch 12, thereby issuing a warning to prompt the user to replace the damaged surge protector module in time.

[0045] The remote signaling mechanism enables the surge protector to monitor the contact status between the contact rod and the micro switch in real time. When the contact rod triggers the micro switch 12, the remote signaling mechanism sends a first status signal, indicating that the surge protection module is in normal working condition. When the contact rod 227 disengages from the micro switch 12, the remote signaling mechanism sends a second status signal, indicating a possible fault or abnormal situation. This enhances the surge protector's status monitoring capability, allowing users to remotely or centrally monitor the surge protector's operating status, thus improving the system's reliability and safety.

[0046] Preferably, refer to Figure 5 As shown, the housing 21 includes a main body 211 with an opening at the bottom, and the mounting base 22 has a sealing plate 229 at the bottom. The sealing plate 221 has a pair of through slots 230 for the first pin 241 and the second pin 251 to pass through. The opening 223 is located on the sealing plate 229. The mounting base 22 is inserted into the main body 211 through the opening, so that the sealing plate 229 is installed on the opening. Example 2

[0047] refer to Figure 8 As shown, the present invention also provides a method for preparing a high-temperature surge protector, which is used to prepare a high-temperature surge protector as described above, comprising: Step S1: Dust removal, oil removal, and drying treatment are performed on the interior of the main body 211 and the mounting base 22. An injection hole and an exhaust port are opened at a preset position on the main body. Cleaning the main body 211 helps to improve the adhesion between the thermally conductive adhesive and the main body 211.

[0048] Step S2: Install the varistor 23, the first electrode connector 24, and the second electrode connector 25 on the mounting base 22 at the corresponding positions, and use a low melting point alloy to weld the thermal release component 242 to the first pin 241 and the first electrode sheet 231. Then weld the second electrode connector 25 to the second electrode sheet 232 to obtain the inner core assembly. Step S3: Insert the inner core assembly into the main body 211, and fix the sealing plate of the mounting base 22 to the opening of the main body 211, so that a potting cavity 3 is formed between the varistor 23 and the main body 211, thereby obtaining the surge protection assembly; wherein, the vent is located at the top of the potting cavity 3, and the glue injection hole is located on the bottom side of the potting cavity 3.

[0049] The bottom-filling method, with the filling hole at the bottom and the vent at the top, and by utilizing gravity and overflow principles, ensures that the air in the potting cavity is completely expelled, avoiding partial discharge or uneven heat dissipation caused by residual air bubbles, and ensuring the fullness and consistency of the potting.

[0050] Step S4: Fix the surge protection component on a platform so that the vent is above the injection hole. Then inject the thermally conductive adhesive 4 into the injection hole at a constant speed until the thermally conductive adhesive 4 overflows from the vent. Then gently vibrate the surge protection component to remove bubbles, and then seal the injection hole and the vent. Step S5: Place the surge protection module after the glue is applied in step S4 into a constant temperature chamber for curing. After curing and cooling, trim and remove excess glue from the surface to obtain surge protection module 2. Step S6: Insert several of the surge protection modules 2 into the corresponding plug holes of the base 1 through the first plug 241 and the second plug 251 in sequence to obtain the high temperature surge protector.

[0051] By filling the potting cavity 3 of each surge protection module 2 with thermally conductive adhesive, an efficient heat conduction path is constructed, which can quickly dissipate the heat generated by the varistor 23 during operation, effectively reducing the junction temperature of the core component, and thus significantly improving the stability and service life of the high-temperature surge protector in high-temperature environments.

[0052] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention and do not limit the invention to the specific implementations described. Obviously, other modifications and variations can be made based on the content of this specification. The embodiments selected and specifically described in this specification are intended to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. They are not intended to limit the invention, and any simple modifications to the invention fall within the scope of protection of this invention.

Claims

1. A high-temperature surge protector, comprising a base and a plurality of surge protection modules inserted into the base, characterized in that, The base is provided with several plug-in holes corresponding to the surge protection module; The surge protection module includes a housing, inside which a mounting base and a varistor are provided; a first electrode connector and a second electrode connector are respectively provided on the left and right sides of the mounting base. The varistor is provided with a first electrode plate and a second electrode plate; the first electrode connector includes a first pin mounted on the right side of the mounting base and a thermal release component located on the front side of the mounting base; both ends of the thermal release component are welded to the first pin and the first electrode plate respectively by a low melting point alloy; one end of the second electrode connector is welded to the second electrode plate, and the other end is provided with a second pin; both the first pin and the second pin extend out of the housing and are correspondingly inserted into the insertion hole; The varistor is mounted on the rear side of the mounting base, and a potting cavity is formed between the varistor and the housing; the potting cavity is filled with a thermally conductive adhesive, and each component of the thermally conductive adhesive, calculated by weight, specifically includes the following: The composition includes 53-70 parts epoxy resin, 100-130 parts spherical alumina, 12-18 parts spherical zinc oxide, 8-15 parts hexagonal boron nitride, 25-35 parts flame retardant, 1.2-2.0 parts silane coupling agent, 30-40 parts curing agent, 0.3-0.8 parts defoamer, 5-9 parts diluent, and 2.5-3.5 parts thixotropic agent.

2. The high-temperature surge protector according to claim 1, characterized in that, The housing includes a main body with an opening at the bottom, and a sealing plate is provided at the bottom of the mounting base. The sealing plate has a pair of through slots for the first pin and the second pin to pass through. The mounting base is inserted into the main body through the opening, so that the sealing plate is installed on the opening.

3. A high-temperature surge protector according to claim 1, characterized in that, The mounting base has a mounting groove on its left side that communicates with the second electrode connector; the mounting base has mounting holes that extend through both sides, the first electrode plate passes through the mounting holes and is welded to the thermal release component; the second electrode plate passes through the mounting groove and is welded to one end of the second electrode connector.

4. A high-temperature surge protector according to claim 1, characterized in that, The base is equipped with microswitches corresponding to the surge protection modules; the bottom of the mounting base has an opening; the right side of the mounting base has a fixing plate, and the front side of the mounting base also has a rotating shaft with a rotating component rotatably connected to it; the bottom of the rotating component has an abutment rod corresponding to the opening; a spring is connected to one end of the rotating component away from the rotating shaft, the other end of the spring is connected to the fixing plate, and the rotating component abuts against the thermal release component; When the surge protection module is plugged into the base, the abutment rod passes through the micro switch; when the thermal release component is desoldered, the spring pulls the rotating component to continue rotating around the axis in the direction close to the thermal release component and drives the abutment rod to disengage from the micro switch.

5. A high-temperature surge protector according to claim 1, characterized in that, The epoxy resin comprises 35-45 parts of bisphenol F type epoxy resin and 18-25 parts of o-cresol formaldehyde epoxy resin.

6. A high-temperature surge protector according to claim 1, characterized in that, The spherical alumina comprises spherical alumina I and spherical alumina II in a mass ratio of 1.5:1, and the particle size of spherical alumina I is smaller than that of spherical alumina II.

7. A high-temperature surge protector according to claim 1, characterized in that, The flame retardant comprises 15-20 parts of aluminum hypophosphite and 10-15 parts of melamine cyanurate.

8. A high-temperature surge protector according to claim 1, characterized in that, The thermally conductive adhesive also includes: 0.5-2 parts of accelerator; the curing agent is an acid anhydride curing agent.

9. A high-temperature surge protector according to claim 1, characterized in that, The thixotropic agent is fumed silica.

10. A method for preparing a high-temperature surge protector, used to prepare a high-temperature surge protector as described in claim 2; characterized in that, include: Step S1: Dust removal, oil removal and drying treatment of the interior of the main body and the mounting base, and opening an injection hole and an exhaust port at the preset position of the main body; Step S2: Install the varistor, the first electrode connector, and the second electrode connector in the corresponding positions on the mounting base, and use a low melting point alloy to weld the thermal release component to the first pin and the first electrode sheet. Then weld the second electrode connector to the second electrode sheet to obtain the inner core assembly. Step S3: Install the inner core assembly into the main body and fix the sealing plate of the mounting base on the opening of the main body, so that a potting cavity is formed between the varistor and the main body to obtain the surge protection assembly; wherein, the vent is located at the top of the potting cavity and the glue injection hole is located on the bottom side of the potting cavity. Step S4: Fix the surge protection component on a platform so that the vent is above the injection hole. Then inject the thermally conductive adhesive from the injection hole at a constant speed until the thermally conductive adhesive overflows from the vent. Then gently vibrate the surge protection component to remove bubbles, and then seal the injection hole and the vent. Step S5: Place the surge protection module after the glue is applied in step S4 into a constant temperature chamber for curing. After curing and cooling, trim and remove excess glue from the surface to obtain the surge protection module. Step S6: Insert several of the surge protection modules into the corresponding sockets of the base through the first and second pins in sequence to obtain the high-temperature surge protector.

Images