Active trigger structure, fuse and preparation process of fuse

Abstract

The invention discloses an active trigger structure, a fuse and a preparation process of the fuse, and the fuse with the active trigger structure comprises a ceramic tube; the two groups of end caps are fixed at the two ends of the ceramic tube through an airtight packaging process; the at least two groups of gradient composite melts are arranged at intervals and are suspended in the ceramic tube in parallel; the arc extinguishing medium coats all the gradient composite melts and fills the internal gaps of the ceramic tube; the active trigger module comprises an embedded sensor embedded in the gradient composite melt, a breaking actuator arranged on the inner side of the end cap and an external control unit, and the control unit receives signals of the embedded sensor and controls the breaking actuator to break a circuit. According to the invention, the gradient composite melt is compounded with the recyclable breaking arc extinguishing medium, so that the compatibility of surge resistance and high breaking is realized, and reliable protection is provided for a high-voltage and high-energy scene.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuse manufacturing, in particular to an active triggering structure, a fuse and a fuse manufacturing process. BACKGROUND

[0002] With the rapid development of new energy vehicle 800V high voltage platform, smart grid and high-power industrial equipment, the circuit protection system is facing unprecedented severe challenges. The traditional fuse has a difficult contradiction between surge resistance, high breaking performance and cycle life, which has become a technical bottleneck restricting the development of high reliability power system: (1) Incompatibility between surge resistance and high breaking: Material limitations: single melting material such as pure silver, tin alloy cannot meet the requirements of high I 2 t value and fast breaking at the same time. For example, slow breaking type, such as Littelfuse 217 series, increases the heat capacity of the melting body to improve the surge resistance I 2 t=35A 2 s, but the breaking capacity is only 35kA, which cannot meet the 100kA breaking requirement of 1500V photovoltaic system; and fast melting type, such as Vishay MOL-100, breaking response <1ms, but the surge resistance is weak, and the misoperation rate is >25% when the motor starts.

[0003] Structural defects: although the double-layer melting body scheme of patent CN113035816A partially alleviates the contradiction, it does not solve the problems of material gradient design and precise control of weak area, resulting in insufficient breaking consistency, and the actual dispersion is ±15%.

[0004] (2) Reliability crisis of single use of arc extinguishing medium: Physical adsorption limitations: traditional media such as quartz sand rely on physical adsorption of arc energy, and form permanent carbonized channels after breaking, which reduces the dielectric strength and the failure rate of secondary breaking is >30%.

[0005] Economic loss: in nuclear power / military scenarios, the single maintenance cost is more than $100,000, and in extreme working conditions such as electromagnetic gun 300kA pulse, the medium carbonization rate is 100%.

[0006] (3) Response delay of passive melting: Traditional fuses rely on thermal accumulation effect, and the response time is >2ms, such as Schurter SF-20E. When the short-circuit current of new energy vehicle 800V battery pack reaches 20kA / ms, the risk of IGBT module explosion increases, and the damage rate of semiconductor devices increases by 40%.

[0007] (4) Precision bottleneck of manufacturing process: The existing melt stacking process, such as Eaton Bussmann HV series, needs to manually assemble multiple layers of melt, resulting in a weak area positioning deviation of > ± 200 μm, a design requirement of ± 20 μm, and a fuse point dispersion; and an arc extinguishing medium filling cavity rate of > 15%, which causes local arc breakdown.

[0008] In view of this, the present application proposes an innovative scheme of fusing gradient material design, self-healing arc extinguishing and intelligent triggering mechanism, realizes the compatibility of surge resistance and high breaking, improves the cycle life and system safety, and provides reliable protection for high-voltage and high-energy scenes. SUMMARY

[0009] To solve the above technical problems, the present application provides an active triggering structure, a fuse and a preparation process of the fuse. The embedded sensor is specifically a fiber Bragg grating etched on the side surface of the eutectic weak area layer of the gradient composite melt, which monitors strain and temperature in real time. The breaking actuator is specifically an explosive bolt arranged on the inner side of the end cap. The control unit determines that the melt is about to be fused when the fiber Bragg grating light deviation is greater than the threshold value, and triggers the breaking actuator to forcibly break the circuit.

[0010] A fuse with an active triggering structure includes: A ceramic tube; Two groups of end caps are fixed on both ends of the ceramic tube by airtight packaging process; At least two groups of gradient composite melts are arranged in parallel and suspended inside the ceramic tube; The arc extinguishing medium is filled in the whole ceramic tube and covers all the gradient composite melts and fills the gap inside the ceramic tube; The active triggering module includes an embedded sensor embedded in the gradient composite melt, a breaking actuator arranged on the inner side of the end cap, and an external control unit, which triggers the breaking actuator to break the circuit in response to the signal of the embedded sensor.

[0011] Further, in the technical scheme of the present application, the gradient composite melt is a five-layer heterogeneous structure, which includes, from the vertical fuse shaft, an electrode layer, a buffer layer, a eutectic weak area layer, a copper framework layer and a platinum-iridium alloy protective layer; a laser etching V-shaped microcrack is pre-set in the middle of the upper end surface of the eutectic weak area layer, and the width of the microcrack is 3-7 μm.

[0012] Further, in the technical scheme of the present application, the preparation steps of the gradient composite melt include: ① In a high vacuum environment, an electrode layer to a copper framework layer is sputtered and deposited on a substrate in sequence; ②Using femtosecond laser to etch micro-cracks at the predetermined position of the eutectic weak zone layer; forming a porous structure by heat treatment of the copper skeleton layer (44); ③Electroplating a platinum-iridium alloy protective layer on the surface of the copper skeleton layer; ④Peeling off the complete five-layer film from the substrate and cutting it into a preset shape by precise laser cutting.

[0013] Further, in the technical scheme of the present application, the eutectic weak zone layer material is a bismuth-tin-indium alloy, and the weight percentage of bismuth, tin and indium is 50-52:28-32:18-20, and the melting point is ≤138℃.

[0014] Further, in the technical scheme of the present application, the arc extinguishing medium comprises the following components: Hydrophobically modified silica aerogel matrix; Self-repairing microcapsules dispersed in the matrix, the wall material is polyurea formaldehyde, and the core material contains dicyclopentadiene and Grubbs catalyst; Boron nitride nanosheets and graphene nanosheets are uniformly dispersed to form a three-dimensional heat-conducting / arc-extinguishing network.

[0015] Further, in the technical scheme of the present application, the hydrophobically modified silica aerogel matrix accounts for 60%-75%, the self-repairing microcapsules account for 15%-25%, the boron nitride nanosheets account for 5%-15%, and the graphene nanosheets account for 5%-10% by weight percentage.

[0016] Further, in the technical scheme of the present application, the inner wall of the ceramic tube is etched with a micro-pyramid array, the pyramid aspect ratio is 1:2 to 1:4, and the depth is 10-30 μm.

[0017] A preparation process of a fuse, comprising the following steps: ①Melt fixation: fixing the pre-made gradient composite melt to the lower end cap through a dissolvable tool; ②Sleeve filling: sleeving into a ceramic tube and filling the arc extinguishing medium powder to completely cover the gradient composite melt by vibration; ③Removing tool: making the gradient composite melt suspended by dissolving or disassembling the tool; ④Cold isostatic pressing: compacting the arc extinguishing medium under a hydrostatic pressure of 200-300 MPa; ⑤End cap packaging: airtight packaging of the upper end cap and the ceramic tube by parallel gap brazing.

[0018] Further, in the technical scheme of the present application, the vibration filling in step ② has a frequency of 50-200 Hz and an amplitude of 0.1-0.5 mm; and the cold isostatic pressing holding time in step ④ is 5-10 minutes.

[0019] Further, in the technical scheme of the present application, the parallel gap brazing of step ⑤ uses gold-tin eutectic preform, the brazing temperature is 280-300 DEG C, the pressure is 20-30 MPa, and the power-on time is 100-500 ms.

[0020] Effective gain: In the technical scheme of the present application, the contradiction between the melting precision and the surge resistance is solved by the gradient melt, the Ag-Cu alloy buffer layer has high specific heat capacity to absorb surge heat energy, and the copper skeleton layer with a porosity of 40% provides mechanical damping, prolongs the surge resistance time, and greatly improves the surge resistance of the gradient composite melt.

[0021] At the same time, the micro-pyramid array prolongs the arc path to 300%, the graphene nanosheet forms a three-dimensional conductive network, accelerates the arc energy dissipation, and improves the breaking capacity of the gradient composite melt; Finally, the self-repairing microcapsule breaks to release DCPD, which is in-situ polymerized under the action of Grubbs catalyst to fill the pits, the boron nitride nanosheet repairs the heat conduction network, and the three-dimensional arc-extinguishing medium realizes self-repairing and full-energy management, which can be recycled for breaking multiple times, greatly prolonging the service life.

[0022] Other features and advantages of the present application will be described in the following description. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 It is a schematic diagram of the fuse structure of the present application; Figure 2 It is a schematic diagram of the fuse preparation process of the present application; Figure 1 A enlarged structure schematic diagram; Figure 3 It is a schematic diagram of the fuse preparation process of the present application; Figure 1 B enlarged structure schematic diagram; Figure 4 It is a schematic diagram of the fuse preparation process of the present application.

[0025] Among them, 1 is a fuse, 2 is an end cap, 3 is a ceramic tube, 4 is a gradient composite melt, 41 is an electrode layer, 42 is a buffer layer, 43 is a eutectic weak area layer, 44 is a copper skeleton layer, 45 is a platinum-iridium alloy protective layer, 5 is an arc-extinguishing medium, 6 is a breaking executor, and 7 is an embedded sensor. DETAILED DESCRIPTION

[0026] In order to make the objects, characteristics and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings of the embodiments of the present application. Obviously, the following described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] In one aspect of the present application, an insurance fuse 1 is provided, comprising: a ceramic tube 3; two groups of end caps 2 fixed to both ends of the ceramic tube 3 by airtight packaging process; at least two groups of gradient composite melts 4 arranged at intervals and suspended in parallel inside the ceramic tube 3; an overall filled arc extinguishing medium 5 covering all the gradient composite melts 4 and filling the internal gap of the ceramic tube 3; an active triggering module, including an embedded sensor 7 embedded in the gradient composite melt 4, a breaking actuator 6 arranged inside the end cap 2, and an external control unit, which triggers the breaking actuator 6 to break the circuit in response to the signal of the embedded sensor 7.

[0028] Please refer to Figure 3 The gradient composite melt 4 is a five-layer heterogeneous structure, which includes, in sequence along the vertical axis of the insurance fuse 1: an electrode layer 41, a buffer layer 42, a eutectic weak zone layer 43, a copper framework layer 44, and a platinum-iridium alloy protective layer 45; the upper end face of the eutectic weak zone layer 43 is pre-set with laser etching V-shaped micro-cracks with a width of 3-7 μm.

[0029] Specifically, the electrode layer 41 is a silver-graphene 90%-10% composite layer with a thickness of 20 μm, which realizes rapid heat dissipation due to the high conductivity and heat conduction of silver-graphene; the buffer layer 42 is a silver-copper alloy layer with a thickness of 30 μm, which has surge resistance and buffering; the eutectic weak zone layer 43 is made of bismuth-tin-indium alloy, and the weight percentage of bismuth, tin and indium is 50-52:28-32:18-20, the melting point is ≤138℃, and the thickness is 10 μm, which is used for low-temperature fuse triggering; the copper framework layer 44 is a porous copper framework with a porosity of 40% and a thickness of 50 μm, which is used for mechanical support and stress release; and the platinum-iridium alloy protective layer 45 is a platinum-iridium alloy electroplating layer with a thickness of 5 μm, which has arc ablation resistance and radiation aging resistance.

[0030] In the present embodiment, the preparation steps of the gradient composite melt 4 include: ①In a high vacuum environment, the electrode layer 41 to the copper framework layer 44 are sputtered and deposited on the substrate in turn. By precisely controlling the target material and process parameters, the composition and microstructure of each layer are realized, and the femtosecond laser is used to etch microcracks at the predetermined position of the eutectic weak area layer 43 to form precise weak areas; and the copper framework layer 44 with voids is formed by heat treatment at 400°C for 1h in Ar gas; Specifically, the sputtering process parameters of each layer of the electrode layer 41 to the copper framework layer 44 are as follows: ②Electroplating platinum-iridium alloy protective layer 45 on the surface of the copper framework layer 44: The electroplating solution formula is: platinum sulfamate Pt(NH2SO3)4: 10 g / L; iridium chloride H2IrCl6: 0.6 g / L; sulfamic acid NH2SO3H: 100 g / L, as complexing agent and buffer.

[0031] The solution pH value is 1.5-2.0, the temperature is 65±2°C, the current density is 0.5 A / dm 2 , and the electroplating time is 50 min.

[0032] Among them, low current density and warming help to improve the density of the plated layer, avoid the generation of voids, and improve the arc ablation resistance of the material.

[0033] ③The complete five-layer film is peeled off from the substrate and cut into a predetermined shape by precise laser cutting.

[0034] It can be understood that the gradient composite melt 4 has an increasing melt resistance from the electrode layer 41 to the platinum-iridium alloy protective layer 45, realizing the optimization of current distribution; the preset microcracks in the eutectic weak area layer 43 guide the fuse position; the multi-layer melt is adopted, and the current path is: end cap 2→electrode layer 41→buffer layer 42→eutectic weak area layer 43→copper framework layer 44→platinum-iridium alloy protective layer 45→another end cap 2, the total length is significantly improved compared with single layer, and the material's tolerance time under 10 times surge current condition is prolonged.

[0035] It should be noted that the gradient composite melt 4 is provided in 2-5 groups.

[0036] In this embodiment, the arc extinguishing medium 5 comprises the following components: Hydrophobically modified silica aerogel matrix; Self-repairing microcapsules dispersed in the matrix, the wall material is polyurea formaldehyde, and the core material contains dicyclopentadiene DCPD and Grubbs catalyst; Boron nitride nanosheets and graphene nanosheets are uniformly dispersed to form a three-dimensional heat-conducting / arc-extinguishing network.

[0037] Specifically, the hydrophobic modified silica aerogel matrix accounts for 60% to 75% by weight, the self-repairing microcapsule accounts for 15% to 25% by weight, the boron nitride nanosheet accounts for 5% to 15% by weight, and the graphene nanosheet accounts for 5% to 10% by weight.

[0038] In this embodiment, the preparation process of the arc extinguishing medium includes: Pre-dispersion: the boron nitride nanosheet BNNS and the graphene nanosheet GNPS are respectively placed in a solvent and ultrasonically dispersed to obtain a stable suspension.

[0039] Mixing: the hydrophobic modified silica aerogel powder is mixed with the two suspensions, and a high-speed shearing emulsifier is used to ensure that the nanomaterials are uniformly attached to the aerogel skeleton.

[0040] Drying: low-temperature drying is performed in a vacuum oven to completely remove the solvent.

[0041] Blending: the dried composite powder and the self-repairing microcapsule are uniformly mixed in a V-type mixer at a low speed to avoid damage to the microcapsule caused by high-speed stirring.

[0042] Screening: the composite arc extinguishing medium powder is screened through a 200-mesh screen to obtain a final usable composite arc extinguishing medium powder with good fluidity.

[0043] Further, the hydrophobic modified silica aerogel matrix is selected from Zhejiang Nano Technology, model NAG-SH-75, contact angle 158±3°; The self-repairing microcapsule is selected from Covestro, model MC-SH-05, wall thickness 200±50 nm, particle size 15-45 μm, DCPD encapsulation rate ≥85%, catalyst loading 5-8 wt%, and the catalyst is Grubbs Catalyst 2nd Generation produced by Merck. After the microcapsule is broken, the catalyst catalyzes the DCPD polymerization reaction to fill the arc erosion pit; The boron nitride nanosheet is selected from Hefei Micro-Nano New Material, model WN-BN50, thermal conductivity: 200 W / m·K, which greatly improves the thermal conductivity uniformity and avoids thermal runaway. The graphene nanosheet is selected from the Sixth Element, model SE1232, electrical conductivity: 3500 S / m, which accelerates the absorption of arc energy.

[0044] In this embodiment, the inner wall of the ceramic tube 3 is etched with a micro-pyramid array, the pyramid aspect ratio is 1:2 to 1:4, the depth is 10-30 μm, and the pyramid inclined angle is 26.5-45°.

[0045] Pyramid array forms jagged crack propagation path by femtosecond laser etching in the inner wall of the ceramic tube 3, the 10-30 μm deep groove forces the crack to repeatedly turn at an angle of 45±5°, and prolongs the actual fracture path; at the same time, the pyramid slope angle of 26.5-45° constitutes a spiral groove, and the electric arc is driven along the groove under the magnetic field, which increases the contact area with the arc extinguishing medium, realizes the arc guiding and energy dissipation; the micro-pyramid array increases the effective heat dissipation area, and cooperates with the boron nitride nanosheet BNNS to form a three-dimensional heat conduction network; the array structure provides mechanical embedding anchor points, and the arc extinguishing medium is embedded into the micropore under the cold isostatic pressure of 200-300 MPa, so that the interface bonding strength is enhanced.

[0046] Another aspect of the present application provides a preparation process of a fuse, comprising the following steps: ①Melt fixation: the pre-prepared gradient composite melt 4 is fixed in the lower end cap 2 by a soluble tooling; Specifically, a precise, soluble or detachable temporary tooling such as PVA plastic material is used, which has at least two sets of precise clamping grooves, and the pre-prepared gradient composite melt 4 is suspended in parallel and equidistantly in the center of the ceramic tube 3. Then the tooling with the fixed gradient composite melt 4 is combined with the lower end cap 2.

[0047] ②Sleeve filling: the ceramic tube 3 is sleeved, and the arc extinguishing medium powder is vibrated to completely cover the gradient composite melt 4; Specifically, the ceramic tube 3 is sleeved outside the entire assembly, and the prepared arc extinguishing medium 5 is loaded into a precise quantitative filling device. Under the condition of 50-200 Hz and amplitude of 0.1-0.5 mm, the powder is slowly filled into the gap between the ceramic tube 3 and the gradient composite melt 4 from above by continuous micro-vibration, and after filling to completely fill, the port is scraped flat. The vibration helps the powder to flow freely, and ensures that the filling is dense, without bridging or voids.

[0048] ③Remove tooling: melt or detach the tooling to make the gradient composite melt 4 suspended; Specifically, the internal temporary fixing tooling is removed carefully by heating and melting or precise mechanical disassembly, and the upper end cap is covered to complete the preliminary assembly. At this time, the three melts are suspended and fixed in the center of the tube by the surrounding compacted powder.

[0049] ④Cold isostatic pressing: compact the medium arc extinguishing medium 5 under the static water pressure of 200-300 MPa; Specifically, the assembled assembly is placed in the flexible mold of the cold isostatic pressing machine, and the static water pressure of 200-300 MPa is applied, and the pressure is maintained for 5-10 minutes. This process makes the loose powder be completely compacted into a solid, and is tightly combined with the melt and the inner wall of the ceramic tube to form a whole.

[0050] ⑤End cap packaging: the upper end cap 2 is airtightly packaged with the ceramic tube 3 by parallel gap brazing.

[0051] Specifically, the final packaging is carried out by parallel gap brazing, the assembly is placed on a welding table, and electrodes are used to press the end cap and the ceramic tube respectively. A large instantaneous current is passed to heat the Au-Sn eutectic preform to above the eutectic point of the preform, i.e. 280-300 DEG C, under a pressure of 20-30 MPa, and the current is passed for 100-500 ms to melt the preform. Under the pressure, the molten solder wets the end face of the ceramic tube and the inner wall of the end cap, and a firm and airtight metallurgical bond is formed after cooling.

[0052] The application also provides an active triggering structure, please refer to Figures 1 to 3 , comprising: An embedded sensor 7, specifically a fiber grating, is located on the side of the eutectic weak zone layer 43 to monitor the strain and temperature of the eutectic weak zone layer 43 in real time. A breaking actuator 6 is arranged on the inner side of the end cap 2, specifically an explosive bolt. A control unit determines that the eutectic weak zone layer 43 is about to be fused when the angle deviation of the fiber grating light is greater than a threshold value, and triggers the breaking actuator 6 to forcibly break the circuit within 0.5 ms.

[0053] In this embodiment, the grating direction is perpendicular to the current direction. The grating is specifically a Bragg grating, the grating length is 5.0±0.1 mm, and the grating period is 530±1 nm.

[0054] Further, the grating is set on the side of the eutectic weak zone layer 43 by means of femtosecond laser oblique projection etching, which is used for detecting the deformation of the eutectic weak zone layer 43. The specific parameters are as follows: laser energy 0.48-0.52 mJ, oblique angle 74.8°-75.2°, helium cooling flow rate 8-12 L / min, and HF etching temperature 24.9-25.1 DEG C.

[0055] It should be noted that the fiber grating is arranged on the side wall region corresponding to the V-shaped micro-crack position to improve the monitoring accuracy and response rate.

[0056] It can be understood that the eutectic weak zone layer 43 is deformed by thermal expansion, the micro-crack of the eutectic weak zone layer 43 expands, the grating period increases due to the tension of the optical fiber, the light diffraction angle deviates, the melt generates heat, the temperature of the optical fiber rises, the refractive index increases, and the light diffraction angle deviates. When the deviation reaches the threshold value, the control unit triggers the breaking actuator 6 to forcibly break the circuit, which can break the circuit before the heat of the gradient composite melt 4 accumulates to completely fuse, thereby reducing the breaking response time.

[0057] In order to further understand the present application, a fuse with an active triggering structure provided by the present application is described below in conjunction with examples, and the protection scope of the present application is not limited by the following examples.

[0058] Experimental Example 1 Gradient composite melt preparation: ①In a high vacuum environment, a thickness of 20 μm electrode layer was sputtered and deposited on a substrate in sequence, a composite target: Ag 90 at% and C 10 at% was used, a sputtering power DC: 2.0 KW, and a deposition time 2000 s; A thickness of 30 μm silver-copper alloy layer was sputtered and deposited, an alloy target: Ag 85 Cu 15 was used, a sputtering power DC: 1.5 KW, and a deposition time 3750 s; A thickness of 10 μm eutectic weak zone layer was sputtered and deposited, an alloy target Bi 52 Sn 28 In 20 was used, a sputtering power DC: 0.8 KW, a deposition time 2000 s, a laser etching of 5 μm micro-cracks was performed, and a Bragg grating was set on the side of the eutectic weak zone layer through a femtosecond laser oblique projection etching, wherein a laser energy was 0.48 mJ, an oblique angle was 74.8°, a helium cooling flow rate was 8 L / min, and a HF etching temperature was 24.9℃; A thickness of 50 μm copper skeleton layer was sputtered and deposited, a high-purity Cu target was used, a sputtering power DC: 2.0 KW, a deposition time 5000 s, and then Ar gas, 400℃, was used for processing 1 h, and a porosity was 40%; ②A thickness of 5 μm platinum-iridium alloy protective layer was electroplated on the surface of the copper skeleton layer, a solution pH value was 1.5-2.0, a temperature was 65±2℃, a current density was 0.5 A / dm 2 , and an electroplating time was 50 min; ③The complete five-layer film was peeled off from the substrate, and was precisely laser cut into a preset shape.

[0059] Experimental Example 2 Gradient composite melt preparation: ①In a high vacuum environment, a thickness of 20 μm electrode layer was sputtered and deposited on a substrate in sequence, a composite target: Ag 90 at% and C 10 at% was used, a sputtering power DC: 2.0 KW, and a deposition time 2000 s; A thickness of 30 μm silver-copper alloy layer was sputtered and deposited, an alloy target: Ag 85 Cu 15 was used, a sputtering power DC: 1.5 KW, and a deposition time 3750 s; A thickness of 10 μm eutectic weak zone layer was sputtered and deposited, an alloy target Bi 50 Sn 30 In 20, sputtering power DC: 0.8 KW, deposition time 2100 s, laser etching 5 μm microcracks; and by femtosecond laser oblique projection etching, wherein the laser energy is 0.52 mJ, the oblique angle is 75.2°, the helium cooling flow rate is 12 L / min, and the HF etching temperature is 25.1℃ to set a Bragg grating on the side of the eutectic weak layer; A copper skeleton layer with a thickness of 50 μm is prepared by using a high-purity Cu target, a sputtering power DC: 2.0 KW, a deposition time of 5000 s, and then Ar gas, 400℃, processing for 1 h, and a porosity of 40%. ②A platinum-iridium alloy protective layer with a thickness of 5 μm is electroplated on the surface of the copper skeleton layer, the solution pH value is 1.5-2.0, the temperature is 65±2℃, the current density is 0.5 A / dm 2 , and the electroplating time is 50 min. ③The complete five-layer film is peeled off from the substrate and cut into a preset shape by precise laser cutting.

[0060] Experimental Example 3 Arc extinguishing medium preparation: Pre-dispersion: 5% boron nitride nanosheets BNNS and 5% graphene nanosheets GNP are respectively placed in acetone solvent, the solid-liquid ratio is 1:10, and ultrasonic dispersion is performed to obtain a stable suspension; Mixing: 70% hydrophobic modified silica aerogel powder is fully mixed with the above two suspensions, and a high-speed shearing emulsifier is used to ensure that the nanomaterials are uniformly attached to the aerogel skeleton; Drying: The solvent is completely removed by drying at 0.1 Pa and 5℃ in a vacuum oven; Blending: The dried composite powder is uniformly mixed with 20% self-repairing microcapsules in a V-type mixer at low speed; Screening: The arc extinguishing medium powder is obtained by passing through a 200-mesh screen.

[0061] Experimental Example 4 Arc extinguishing medium preparation: Pre-dispersion: 15% boron nitride nanosheets BNNS and 10% graphene nanosheets GNP are respectively placed in acetone solvent, the solid-liquid ratio is 1:10, and ultrasonic dispersion is performed to obtain a stable suspension; Mixing: 60% hydrophobic modified silica aerogel powder is fully mixed with the above two suspensions, and a high-speed shearing emulsifier is used to ensure that the nanomaterials are uniformly attached to the aerogel skeleton; Drying: The solvent is completely removed by drying at 0.1 Pa and 5℃ in a vacuum oven; Blending: The dried composite powder is uniformly mixed with 15% self-repairing microcapsules in a V-type mixer at low speed; Sifting: through 200 mesh sieve, get arc-extinguishing medium powder.

[0062] Example 1 Preparation of fuse: ① Three groups of experimental example 1 pre-made gradient composite melt were fixed on the lower end cap by PVA plastic temporary tooling, ensuring that they were parallel and equidistantly suspended in the center of the ceramic tube. The tooling with fixed gradient composite melt was combined with the lower end cap, and then the ceramic tube was outside the entire assembly.

[0063] ② Sleeve filling: the ceramic tube was sleeved, the arc-extinguishing medium prepared in experimental example 3 was loaded into the precise quantitative filling equipment, under the condition of continuous micro-vibration, the frequency was 100 Hz, the amplitude was 0.1 mm, the powder was slowly filled into the gap between the ceramic tube and the gradient composite melt from the top, and after filling completely, the port was scraped flat.

[0064] ③ The gradient composite melt was suspended by precise mechanical disassembly tooling; ④ The assembled assembly was placed in the flexible mold of the cold isostatic press, and a hydrostatic pressure of 200-300 MPa was applied, and the pressure was maintained for 5-10 minutes.

[0065] ⑤ Parallel gap brazing was used for final packaging, the assembly was placed on the welding table, and the electrode was pressed against the end cap and the ceramic tube respectively. A large instantaneous current was passed, the gold-tin eutectic pre-made sheet of the brazing layer was heated to above its eutectic point, 280℃, the pressure was 20 MPa, and the power-on time was 100-500 ms.

[0066] Example 2 Preparation of fuse: ① Three groups of experimental example 2 pre-made gradient composite melt were fixed on the lower end cap by PVA plastic temporary tooling, ensuring that they were parallel and equidistantly suspended in the center of the ceramic tube. The tooling with fixed gradient composite melt was combined with the lower end cap, and then the ceramic tube was outside the entire assembly.

[0067] ② Sleeve filling: the ceramic tube was sleeved, the arc-extinguishing medium prepared in experimental example 4 was loaded into the precise quantitative filling equipment, under the condition of continuous micro-vibration, the frequency was 100 Hz, the amplitude was 0.1 mm, the powder was slowly filled into the gap between the ceramic tube and the gradient composite melt from the top, and after filling completely, the port was scraped flat.

[0068] ③ The gradient composite melt was suspended by precise mechanical disassembly tooling; ④ The assembled assembly was placed in the flexible mold of the cold isostatic press, and a hydrostatic pressure of 200 MPa was applied, and the pressure was maintained for 8 minutes.

[0069]

[0070] Example 3 Preparation of fuse:

[0071]

[0072]

[0073]

[0074] Example 4 Preparation of fuse:

[0075]

[0076] ​​​​​​​​​​

[0077] V. Final encapsulation by parallel gap brazing. The assembly is placed on the brazing table and electrodes are pressed against the end caps and the ceramic tube. A high instantaneous current is applied to heat the Au-Sn eutectic preform above the eutectic point to 280°C, with a pressure of 20 MPa and an electrical current time of 200 ms.

[0078] Comparative Example 1 The alumina sleeve fuse is commercially available from Littelfuse, model LV Spd series.

[0079] Comparative Example 2 I. The three sets of experimental example 2 preform gradient composite melts are fixed in parallel and equidistantly suspended in the center of the ceramic tube by a PVA plastic temporary tool. The tool with the gradient composite melt is combined with the lower end cap, and then the ceramic tube is placed outside the entire assembly; II. Sleeve filling: the ceramic tube is sleeved, the arc extinguishing sand is loaded into a precise quantitative filling device, under the condition of continuous slight vibration, the frequency is 100 Hz, and the amplitude is 0.1 mm, the powder is slowly filled into the gap between the ceramic tube and the gradient composite melt from the top, and after filling completely, the port is scraped flat; The arc extinguishing sand is selected from Sibelco, model QF50; III. The gradient composite melt is suspended by precise mechanical disassembly of the tool; IV. The assembled assembly is placed in a flexible mold of a cold isostatic pressing machine, and a hydrostatic pressure of 200 MPa is applied, and the pressure is maintained for 8 minutes; V. Final encapsulation by parallel gap brazing. The assembly is placed on the brazing table and electrodes are pressed against the end caps and the ceramic tube. A high instantaneous current is applied to heat the Au-Sn eutectic preform above the eutectic point to 280°C, with a pressure of 20 MPa and an electrical current time of 200 ms.

[0080] Comparative Example 3 I. The three sets of ordinary melt are fixed in parallel and equidistantly suspended in the center of the ceramic tube by a PVA plastic temporary tool. The tool with the gradient composite melt is combined with the lower end cap, and then the ceramic tube is placed outside the entire assembly; The ordinary melt is selected from Vishay, model MOL-100; II. Sleeve filling: the ceramic tube is sleeved, the arc extinguishing medium prepared in experimental example 3 is loaded into a precise quantitative filling device, under the condition of continuous slight vibration, the frequency is 100 Hz, and the amplitude is 0.1 mm, the powder is slowly filled into the gap between the ceramic tube and the gradient composite melt from the top, and after filling completely, the port is scraped flat; III. The gradient composite melt is suspended by precise mechanical disassembly of the tool; (4) Put the assembled assembly into the flexible mold of the cold isostatic pressing machine, apply a hydrostatic pressure of 200 MPa, and keep the pressure for 8 minutes; (5) Perform final packaging by parallel gap brazing, place the assembly on the welding table, and press the end cap and the ceramic tube by electrodes respectively. Heat the Au-Sn eutectic preform to above the eutectic point of the Au-Sn eutectic preform by a large instantaneous current, the pressure is 20 MPa, and the power-on time is 200 ms.

[0081] Test Example: The breaking capacity of the fuses prepared in Examples 1-4 and the fuses of Comparative Examples 1-3 is tested according to the test standard IEC 60269-1, and the test results are recorded in Table 1.

[0082] The surge resistance of the fuses prepared in Examples 1-4 and the fuses of Comparative Examples 1-3 is tested according to the test standard UL 248-12, and the test results are recorded in Table 1.

[0083] The breaking response time of the fuses prepared in Examples 1-4 and the fuses of Comparative Examples 1-3 is tested by a high-speed camera, and the test results are recorded in Table 1.

[0084] The service life of the fuses prepared in Examples 1-4 and the fuses of Comparative Examples 1-3 is tested according to the test standard EIA-364-1000 times, and the test results are recorded in Table 1.

[0085] Table 1 Performance test statistics table of examples and comparative examples In summary: the present application provides an active triggering structure, which monitors the strain of the eutectic weak zone layer 43 in real time through the embedded sensor 7, i.e. the fiber Bragg grating, predicts the triggering of the breaking actuator 6 before melting, actively breaks before the gradient composite melt heat accumulates to the limit value, and prevents explosion and combustion; The surge resistance is improved by the five-layer gradient composite melt, the Ag-Cu alloy buffer layer efficiently absorbs surge heat energy due to its high specific heat capacity, and the porous copper skeleton layer with a porosity of 40% significantly prolongs the energy release time through a unique mechanical damping effect. The synergistic effect of the two greatly improves the surge resistance time to nearly 2 ms@10In, as shown in Table 1 Example 1 data, and the surge resistance is more than 4 times that of the traditional melt, as shown in Table 1 Comparative Example 1. In terms of breaking capacity, the micro-pyramid array structure physically extends the arc path by 300%, forcing the arc to fully stretch. At the same time, the graphene nanosheet forms a three-dimensional conductive network in the arc extinguishing medium, which improves the arc energy dissipation efficiency by 230%. As shown in Table 1, the design breaks through the breaking capacity of 100 kA, as shown in Table 1 Example 1, which is 102 kA, fully meeting the extreme breaking demand of 1500V photovoltaic system; Finally, the three-dimensional self-repairing arc-extinguishing mechanism. When the arc is generated, the self-repairing microcapsule rapidly ruptures to release the DCPD monomer, which is in-situ polymerized under the action of Grubbs catalyst to precisely fill the arc crater. At the same time, the boron nitride nanosheet timely repairs the heat conduction network damaged by high temperature to restore the dielectric strength of the medium. This mechanism supports the fuse to realize more than 5 times of repeated breaking under the premise of maintaining the breaking capacity of 102 kA, as shown in Table 1, Example 1, the service life is 5-8 times of that of the conventional fuse, as shown in Table 1, Comparative Example 2.

[0086] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A fuse (1). Characterized by, include: Ceramic tube (3); Two sets of end caps (2) are fixedly installed at both ends of the ceramic tube (3) by an airtight sealing process; At least two sets of gradient composite melts (4), and several sets of the gradient composite melts (4) are suspended parallel to each other inside the ceramic tube (3); The arc-extinguishing medium (5) covers all the gradient composite melt (4) and fills the internal voids of the ceramic tube (3); Actively triggered structure; The gradient composite melt (4) is a five-layer heterogeneous structure, which includes, in sequence along the direction perpendicular to the fuse (1): an electrode layer (41), a buffer layer (42), a eutectic weak region layer (43), a copper skeleton layer (44), and a platinum-iridium alloy protective layer (45); a laser-etched V-shaped microcrack is preset in the middle of the upper end face of the eutectic weak region layer (43), and the width of the microcrack is 3-7μm.

2. The fuse according to claim 1, characterized in that, The eutectic weak region layer (43) is made of bismuth-tin-indium alloy, and the weight percentage of bismuth, tin and indium is 50-52:28-32:18-20. The melting point of the eutectic weak region layer (43) is ≤138℃.

3. The fuse according to claim 2, characterized in that, The preparation steps of the gradient composite melt (4) include: ① Under a high vacuum environment, an electrode layer (41), a buffer layer (42), a eutectic weak region layer (43), and a copper skeleton layer (44) are sequentially sputtered and deposited on the substrate. ② Use a femtosecond laser to etch microcracks at predetermined positions in the eutectic weak region layer (43); and use heat treatment to make the copper skeleton layer (44) have a porous structure; ③ Electroplating a platinum-iridium alloy protective layer (45) onto the surface of the copper skeleton layer (44); ④ Peel the complete five-layer film from the substrate and cut it into a preset shape using a precision laser.

4. The fuse according to claim 1, characterized in that, The arc-quenching medium (5) comprises the following components: Hydrophobically modified silica aerogel matrix; Self-healing microcapsules, with polyurea formaldehyde as the wall material and dicyclopentadiene and Grubbs catalyst as the core material; Boron nitride nanosheets and graphene nanosheets are uniformly dispersed to form a three-dimensional thermally conductive / arc-quenching network.

5. The fuse according to claim 4, characterized in that, By weight percentage: hydrophobic modified silica aerogel matrix accounts for 60%–75%, self-healing microcapsules account for 15%–25%, boron nitride nanosheets account for 5%–15%, and graphene nanosheets account for 5%–10%.

6. The fuse according to claim 1, characterized in that, The inner wall of the ceramic tube (3) is etched with a micro pyramid array, the pyramid having a depth-to-width ratio of 1:2-4, a depth of 10-30μm, and an inclination angle of 26.5-45°.

7. A manufacturing process for a fuse as described in any one of claims 1-6, characterized in that, Includes the following steps: ①Melt fixing: The prefabricated gradient composite melt (4) is fixed to the lower cap (2) by a fusible tooling interval; ② Sleeve filling: Insert ceramic tube (3), and vibrate to fill arc extinguishing medium powder until the gradient composite melt (4) is completely covered; ③Remove tooling: Melt or disassemble the tooling to obtain the workpiece; ④ Cold isostatic pressing: Place the workpiece from step ③ under a hydrostatic pressure of 200-300MPa for 5-10 minutes; ⑤ End cap sealing: The upper end cap (2) and the ceramic tube (3) are hermetically sealed by parallel gap brazing.

8. The manufacturing process of the fuse according to claim 7, characterized in that, The vibration filling frequency in step ② is 50-200Hz, and the amplitude is 0.1-0.5mm.

9. The manufacturing process of the fuse according to claim 7, characterized in that, The parallel gap brazing in step ⑤ uses a gold-tin eutectic preform, with a brazing temperature of 280-300℃, a pressure of 20-30MPa, and an energizing time of 100-500ms.

10. An active triggering structure applied to any one of the fuses described in claims 1-6, characterized in that, include: Embedded sensors (7), including fiber optic gratings, are used to monitor the strain and temperature of the eutectic weak region layer (43) in real time; Specifically, the grating is a Bragg grating with a length of 5.0±0.1 mm and a period of 530±1 nm. The disconnecting actuator (6) is located inside the end cap (2) to control the disconnection of the circuit; An external control unit is used to receive signals from the embedded sensor (7) and send instructions to the disconnect actuator (6) to force disconnect the circuit.

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