Wire-wound resistor and method of manufacturing the same

Abstract

The application discloses a wire-wound resistor and a preparation method thereof. The wire-wound resistor comprises a solid ceramic rod base body which is sintered by using raw materials with an aluminum oxide content of 80-85% by mass percentage; an alloy resistor wire which is wound on the outer surface of the solid ceramic rod base body along the axial direction of the solid ceramic rod base body, and the first end and the last end of the alloy resistor wire extend to the two ends of the solid ceramic rod base body respectively; two support lead wires which are connected to the two ends of the solid ceramic rod base body at the connecting ends, and the free ends of the two support lead wires extend to the outer side of the solid ceramic rod base body along the radial direction of the solid ceramic rod base body; and the first end and the last end of the alloy resistor wire are electrically connected to the connecting ends of the two support lead wires. The wire-wound resistor can prevent the PCB from being burned, carbonized or deteriorated due to local high temperature, and improve the reliability and service life of the PCB. The wire-wound resistor can improve the heat dissipation efficiency of the solid ceramic rod base body, reduce the working temperature rise of the alloy resistor wire, and ensure the resistance stability and long-term reliability of the wire-wound resistor.

Description

Technical Field

[0001] This invention relates to the field of electronic component technology, and mainly to a wire-wound resistor and its preparation method. Background Technology

[0002] Resistors are among the most frequently used fundamental electronic components in electronic circuits. Their core physical characteristic lies in their ability to convert electrical energy into heat when current flows through them. By selecting appropriate materials and structural designs, this heat can be rapidly dissipated into the surrounding environment, thus meeting the component's rated power requirements. In circuit design, resistors are widely used for voltage division, current limiting, and energy absorption, making them crucial components for ensuring stable circuit operation.

[0003] As electronic devices rapidly evolve towards higher power density and miniaturization, various industries are placing higher demands on the power handling capacity and reliability of resistive components. Wire-wound resistors, with their advantages of large power capacity, strong impact resistance, and wide resistance range, have become the mainstream choice for high-power applications.

[0004] Currently, common high-power wire-wound resistors on the market typically employ the following structure: alloy resistance wire is evenly wound around the outer wall of a hollow ceramic rod to form a resistor body; then a sealing layer is wrapped around the outside of the resistor body to achieve electrical insulation and physical protection; finally, metal leads are led out from both ends of the resistor body for direct soldering onto a PCB board during use.

[0005] While the aforementioned structure boasts mature technology and low cost, it suffers from significant heat dissipation performance bottlenecks in practical applications. The heat generated by the resistance wire must be conducted through the ceramic rod's wall thickness to its inner wall, and then dissipated outwards via natural convection and radiation from the air within the internal cavity. Due to the low thermal conductivity of air and the limited internal space of the hollow ceramic rod, air convection is poor, leading to a substantial accumulation of heat on the inner wall of the ceramic rod, resulting in a pronounced heat buildup effect and inadequate heat dissipation.

[0006] To address the aforementioned issues, existing wire-wound resistors urgently need improvement. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a wire-wound resistor, comprising: Solid ceramic rod substrate (10) is made by sintering raw materials with an aluminum oxide content of 80-85% by mass; Alloy resistance wire (20) is wound around the outer surface of solid ceramic rod base (10) along the axial direction, and the first and last ends of the alloy resistance wire (20) extend to the two ends of solid ceramic rod base (10), respectively. Two support leads (30) are connected to the two ends of the solid ceramic rod base (10) respectively. The free ends of the two support leads (30) extend radially away from the solid ceramic rod base (10) to the outside. The beginning and end of the alloy resistance wire (20) are electrically connected to the connection ends of the two support leads (30) respectively. The free ends of the two bracket leads (30) are used to insert into the corresponding through holes of the PCB board to achieve fixation and electrical connection with the PCB board, and to form a gap of a preset height between the alloy resistance wire (20) and the PCB board.

[0008] Preferably, the bracket lead 30 includes an integrally formed bracket body (33), pins (31) and end caps (32), the pins (31) and end caps (32) are located at opposite ends of the bracket body (33), and the end caps (32) are connected to the end of the solid ceramic rod substrate (10) by interference fit; After the pin (31) is inserted into the corresponding through hole of the PCB board and fixed and electrically connected to the PCB board, a gap of a preset height is formed between the alloy resistance wire (20) and the PCB board.

[0009] Preferably, the preset height is 1mm to 5mm.

[0010] Preferably, the bracket lead wire (30) is made of iron, and its surface is provided with a copper plating layer and a tin plating layer from the inside to the outside.

[0011] Preferably, the alloy resistance wire (20) is a single-wire alloy resistance wire, a double-wire alloy resistance wire, or a triple-wire alloy resistance wire.

[0012] Preferably, the alloy resistance wire (20) is made of nickel and chromium as raw materials; or it is made of nickel, chromium, aluminum and iron as raw materials.

[0013] Preferably, the wire-wound resistor further includes: A non-combustible insulating encapsulation layer covers the connection ends of a solid ceramic rod substrate (10), an alloy resistance wire (20), and a support lead (30), the free ends of which are exposed outside the non-combustible insulating encapsulation layer.

[0014] This invention also provides a method for preparing a wire-wound resistor, comprising the following steps: S10 is a solid ceramic rod matrix prepared by sintering raw materials with an aluminum oxide content of 80-85% by mass. S20, the alloy resistance wire is wound along the axial direction of the solid ceramic rod matrix on the outer surface of the solid ceramic rod matrix, and the first and last ends of the alloy resistance wire are extended to both ends of the solid ceramic rod matrix, respectively. S30, connect the connecting ends of the two bracket leads to the two ends of the solid ceramic rod base respectively, so that the free ends of the two bracket leads extend radially away from the solid ceramic rod base; so that after the free ends of the two bracket leads are inserted into the corresponding through holes of the PCB board during the subsequent assembly of the wire-wound resistor and the PCB board, a gap of a preset height can be formed between the alloy resistance wire and the PCB board. S40, the first and last ends of the alloy resistance wire are welded to the connection ends of the two bracket leads respectively to form an electrical connection; S50 yields the wire-wound resistance.

[0015] Preferably, S30 specifically includes: Two end caps are respectively connected to the two ends of the solid ceramic rod base by interference fit, so that the two pins extend radially away from the solid ceramic rod base; so that after the free ends of the two pins are inserted into the corresponding through holes of the PCB board during the subsequent wire-wound resistor and PCB assembly process, a gap of a preset height can be formed between the alloy resistance wire and the PCB board.

[0016] Preferably, after step S40, the method further includes: S41, a non-combustible insulating coating is used to coat and encapsulate the connection ends of the solid ceramic rod substrate, alloy resistance wire, and support lead. After the coating is cured, a non-combustible insulating encapsulation layer is formed, and the free end of the support lead is exposed outside the non-combustible insulating encapsulation layer.

[0017] Compared with the prior art, the beneficial effects of this application are as follows: The wire-wound resistor provided by this invention has two support leads connected to the two ends of a solid ceramic rod substrate. The free ends of the two support leads extend radially away from the solid ceramic rod substrate (10) to the outside. This allows the wire-wound resistor to be mounted on a PCB board, with a predetermined height gap between the alloy resistance wire wound on the solid ceramic rod substrate and the PCB board. This allows the wire-wound resistor body to be suspended above the PCB board. The heat generated by the wire-wound resistor during operation is dissipated through the air and the support leads, preventing the alloy resistance wire from directly contacting or baking the PCB board at close range. This effectively prevents the PCB board from burning, carbonizing, or deteriorating due to local high temperatures, thus improving the reliability and service life of the PCB board. In addition, the gap area can also be used as a wiring channel or installation space for electronic components, which can improve the space utilization of the PCB board surface and is beneficial for the miniaturization and high-density integration design of the PCB board. Furthermore, the solid ceramic rod matrix of the present invention is sintered from raw materials with an aluminum oxide content of 80-85% by mass. Due to the high thermal conductivity and good heat resistance of aluminum oxide, the high aluminum oxide content of the solid ceramic rod matrix can quickly conduct the heat generated during the operation of the alloy resistance wire to the entire solid ceramic rod matrix, avoiding local heat accumulation. At the same time, the solid structure of the solid ceramic rod matrix has a larger heat capacity and a more complete heat conduction path compared to the hollow structure, which can absorb and store more heat and quickly dissipate it to the surrounding air and support wires through the outer surface and both ends of the solid ceramic rod matrix. The synergistic effect of the two can significantly improve the overall heat dissipation efficiency of the solid ceramic rod matrix, reduce the operating temperature rise of the alloy resistance wire, ensure the resistance stability and long-term reliability of the winding resistor, and extend the service life of the winding resistor. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0020] Figure 1 This is a schematic diagram of the wire-wound resistor of the present invention.

[0021] Figure 2 This is a schematic flowchart of the method for preparing the wire-wound resistor of the present invention.

[0022] Figure 3 This is another schematic diagram of the preparation method of the wire-wound resistor of the present invention. Detailed Implementation

[0023] The following drawings disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0024] It should be noted that all directional indications in the embodiments of the present invention, such as up, down, left, right, front, back, etc., are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indication will also change accordingly.

[0025] Furthermore, in this invention, the use of terms such as "first," "second," etc., is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish items or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0026] See Figure 1 This is a schematic diagram of the wire-wound resistor of the present invention. The wire-wound resistor provided by the present invention includes: a solid ceramic rod substrate 10, which is sintered from raw materials with an aluminum oxide content of 80-85% by mass; an alloy resistance wire 20, which is wound axially around the outer surface of the solid ceramic rod substrate 10, with its first and last ends extending to both ends of the solid ceramic rod substrate 10; two support leads 30, the connecting ends of which are respectively connected to both ends of the solid ceramic rod substrate 10, and the free ends of which extend radially away from the solid ceramic rod substrate 10; the first and last ends of the alloy resistance wire 20 are electrically connected to the connecting ends of the two support leads 30. The free ends of the two bracket leads 30 are used to insert into the corresponding through holes of the PCB board (not shown in the figure) to achieve fixation and electrical connection with the PCB board, and to form a gap of a preset height between the alloy resistance wire 20 and the PCB board.

[0027] In this invention, the alloy resistance wire 20 wound around the solid ceramic rod substrate 10 maintains a preset height gap with the PCB board, allowing the wire-wound resistor body to be suspended above the PCB board. The heat generated by the wire-wound resistor during operation is dissipated through the air and the support leads 30, preventing the alloy resistance wire 20 from directly contacting or baking the PCB board at close range. This effectively prevents the PCB board from burning, carbonizing, or deteriorating due to localized high temperatures, thus improving the reliability and service life of the PCB board. In addition, the gap area can be used as a wiring channel or mounting space for electronic components, improving the space utilization of the PCB board surface and facilitating the miniaturization and high-density integration design of the PCB board.

[0028] In this invention, the solid ceramic rod substrate 10 is sintered from raw materials with an aluminum oxide content of 80-85% by mass. Due to the high thermal conductivity and good heat resistance of aluminum oxide, the high aluminum oxide content of the solid ceramic rod substrate 10 can quickly conduct the heat generated by the alloy resistance wire 20 during operation to the entire interior of the solid ceramic rod substrate 10, preventing localized heat accumulation. Simultaneously, the solid structure of the solid ceramic rod substrate 10, compared to a hollow structure, has a larger heat capacity and a more complete heat conduction path, enabling it to absorb and store more heat. This heat is then quickly dissipated to the surrounding air and the support lead wire 30 through the outer surface and both ends of the solid ceramic rod substrate 10, which has high thermal conductivity. The synergistic effect of these two factors significantly improves the overall heat dissipation efficiency of the solid ceramic rod substrate 10, reduces the operating temperature rise of the alloy resistance wire 20, thereby ensuring the resistance stability and long-term reliability of the wound resistor and extending its service life.

[0029] See Figure 1 The bracket lead 30 includes an integrally formed bracket body 33, pins 31, and end caps 32. Pins 31 and end caps 32 are located at opposite ends of the bracket body 33. The end caps 32 are interference-fitted to the end of the solid ceramic rod substrate 10. After the pins 31 are inserted into corresponding through holes on the PCB board and fixed and electrically connected to the PCB board, a predetermined gap of height is formed between the alloy resistance wire 20 and the PCB board. The end caps 32 and the connection point between the end caps 32 and the bracket body 33 together constitute the connection end of the bracket lead 30. Pins 31 constitute the free end of the bracket lead 30. The predetermined height can be set according to the actual needs of the PCB board, generally ranging from 0.5mm to 5mm. Specifically, it can be set to 0.5mm, 1.5mm, 3mm, 4.5mm, or 5mm.

[0030] Compared to existing separate welding structures, the pins 31, end caps 32, and the support body 33 in this invention adopt an integral molding structure. The pins 31 and end caps 32 are located at opposite ends of the support body 33, eliminating the welding points between the pins 31 and end caps 32. This avoids reliability issues such as solder melting, cold solder joints, and desoldering caused by high current overload or thermal cycling shocks, thus improving the stability of the wire-wound resistor. Since the pins 31, end caps 32, and support body 33 are integrally molded metal substrates, the pins 31 have high mechanical strength and can effectively resist bending stress during installation and vibration stress during operation, reducing the risk of pin breakage or loosening.

[0031] Further, see Figure 1 The free end of the pin 31 is provided with a through hole 311. When the free end of the pin 31 is inserted into the corresponding through hole of the PCB board for soldering, the solder can pass through the through hole 311 and solidify to form a solder rivet structure, which enhances the pull-out resistance and vibration fatigue resistance between the pin 31 and the PCB board and prevents the solder joint from falling off.

[0032] Furthermore, the bracket lead 30 is made of iron, and its surface is successively coated with a copper plating layer (not shown in the figure) and a tin plating layer (not shown in the figure) from the inside out. In this invention, the bracket lead 30 uses iron material as the base material, and the base surface is coated with a copper layer and a tin layer from the inside out. This aims to comprehensively utilize the advantages of each metal material. The iron core can ensure that the bracket lead has sufficient mechanical strength and effectively control manufacturing costs. The middle copper layer is used to improve the conductivity of the bracket lead 30 and provide a good adhesion base for subsequent tin plating. The outer tin layer gives the bracket lead 30 excellent solderability and oxidation and corrosion resistance, thereby achieving the best balance between electrical performance, processing reliability and economy.

[0033] Furthermore, the alloy resistance wire 20 is: a single-wire alloy resistance wire, a double-wire alloy resistance wire, or a triple-wire alloy resistance wire.

[0034] The alloy resistance wire winding method of the wire-wound resistor of this invention can be divided into three types: single-wire, double-wire, and triple-wire winding. Among them, the single-wire alloy resistance wire uses a single alloy resistance wire tightly wound in a single direction, which is the simplest process and has the lowest cost. This structure will produce significant parasitic inductance, and the impedance will increase significantly with increasing frequency. It is mainly used in DC circuits, low-frequency power circuits, or general protection and voltage division applications where there are no strict requirements for inductive effects.

[0035] Dual-wire alloy resistance wire: This type of resistance wire is made by folding an alloy resistance wire in half and winding two parallel strands, with the current in adjacent strands in opposite directions. Based on the principle of electromagnetic cancellation, this method of dual-strand parallel winding can effectively cancel the magnetic field of the coil, achieving low or zero inductance characteristics. This type of dual-strand parallel winding resistor is suitable for high-frequency circuits, audio amplifier circuits, and pulse loads, as well as other applications that are sensitive to inductive reactance and require high-precision purely resistive loads.

[0036] Three-wire alloy resistance wire: This type of resistance wire is made by winding three parallel resistance wires together. It is typically used to form a resistor network with a center tap, or to achieve specific non-standard resistance values ​​through complex series and parallel combinations. It can also further homogenize the distributed parameters to reduce residual inductance. This type of three-wire parallel winding resistor is often used in attenuators, balanced shunts, or high-frequency matching circuits that require a precise center tap.

[0037] In summary, the wire-wound resistor provided by this invention can be wound with single-wire alloy resistance wire, double-wire alloy resistance wire, or triple-wire alloy resistance wire according to the actual application scenario.

[0038] Furthermore, the alloy resistance wire is made from nickel and chromium; or from nickel, chromium, aluminum, and iron.

[0039] When the alloy resistance wire 20 of this invention uses nickel-chromium alloy as raw material, it has high resistivity, good high-temperature strength, and a dense chromium oxide protective film that easily forms on its surface, exhibiting excellent oxidation resistance and thermal stability. Simultaneously, it has good processing and welding performance, and relatively low production costs. When using nickel-chromium-aluminum-iron alloy as raw material, compared to nickel-chromium alloy, its resistivity is further improved, its temperature coefficient of resistance is significantly reduced, its resistance changes very little with temperature, its resistance drift rate is low over long-term use, and its thermoelectric potential to copper is weak, ensuring the stability of circuit signals and measurement accuracy.

[0040] Further, see Figure 1The wire-wound resistor further includes a non-combustible insulating encapsulation layer (not shown in the figure), which covers the connection ends of the solid ceramic rod substrate 10, the alloy resistance wire 20, and the support lead 30, with the free end of the support lead 30 exposed outside the non-combustible insulating encapsulation layer. Specifically, the connection ends of the support lead 30 include end caps 32 and the connection point between the support body 33 and the end caps 32. Due to its non-combustible and insulating properties, the non-combustible insulating encapsulation layer can prevent the spread of flames in the event of overload or abnormal heating of the wire-wound resistor; the alloy resistance wire 20 and the end caps 32 are completely electrically isolated from the external environment, avoiding the risk of short circuits and leakage in the wire-wound resistor and ensuring the safety of its use. In addition, the non-combustible insulating encapsulation layer tightly seals the alloy resistance wire 20 to the surface of the solid ceramic rod substrate 10, forming a stable integrated structure that can resist external vibrations and impacts, preventing the alloy resistance wire 20 from shifting, loosening, or breaking, and ensuring the stability and reliability of the wire-wound resistor. Meanwhile, by partially encapsulating the bracket lead 30, that is, by covering the end cap 32 and the connection between the end cap 32 and the bracket body 33, the pin 31 is exposed, achieving all-round sealing protection for the alloy resistance wire 20 and the end cap 32, preventing moisture, salt spray and corrosive gases from penetrating, and ensuring that the pin 31 has good solderability and conductive contact performance, which facilitates subsequent PCB board soldering and installation, and avoids the non-flammable insulating encapsulation layer from contaminating the solder joints or affecting the electrical connection.

[0041] See Figure 2 , Figure 2 This is a schematic diagram of the process for preparing the wire-wound resistor according to the present invention. The method for preparing the wire-wound resistor provided by the present invention includes the following steps: S10 is a solid ceramic rod matrix prepared by sintering raw materials with an aluminum oxide content of 80-85% by mass.

[0042] Step S10 employs a conventional resistance-core ceramic rod sintering method to prepare a solid ceramic rod matrix. The raw materials used, by mass percentage, contain 80-85% alumina, with the remainder being auxiliary materials. These auxiliary materials include talc powder and conventional sintering aids, performance modifiers, and molding aids. The talc powder is used to improve the mechanical strength and electrical properties of the solid ceramic rod matrix. The specific types and proportions of the sintering aids, performance modifiers, and molding aids can be conventionally selected by those skilled in the art based on the actual sintering process and molding requirements.

[0043] The alloy resistance wire provided by the present invention uses conventional nickel-chromium alloys or nickel-chromium-aluminum-iron alloys as raw materials and is prepared by conventional resistance wire preparation processes. The specific components and contents of the alloy are conventionally set and will not be described in detail here.

[0044] The bracket lead wire provided by this invention uses an iron material as the substrate and is integrally formed into a bracket lead wire blank through machining such as turning or stamping. The blank includes an integrally formed bracket body, pins, and end caps. Subsequently, the iron blank undergoes conventional pre-plating treatment, such as degreasing and pickling activation. Then, a conventional electroplating process is used to sequentially plate a copper layer and a tin layer on the surface of the blank from the inside out, forming a composite plating structure of iron substrate, copper transition layer, and tin outer coating. After cleaning and drying, the bracket lead wire is obtained. The specific operations of the above copper and tin plating, including the composition of the plating solution, current density, temperature, and time, are all conventional technical means in the art. Those skilled in the art can adjust them according to actual needs, and will not be elaborated here.

[0045] S20, the alloy resistance wire is wound along the axial direction of the solid ceramic rod substrate on the outer surface of the solid ceramic rod substrate, and the first and last ends of the alloy resistance wire are extended to both ends of the solid ceramic rod substrate, respectively.

[0046] Step S20 specifically includes: spirally and uniformly winding the alloy resistance wire along the axial direction of the solid ceramic rod substrate onto the outer surface of the solid ceramic rod substrate. During winding, one end of the alloy resistance wire is first fixed to one end of the solid ceramic rod substrate. Then, a predetermined tension is applied, causing the alloy resistance wire to be wound turn by turn along the axial direction of the solid ceramic rod substrate with a constant pitch under tension, until the other end of the solid ceramic rod substrate is reached. During the winding process, the spacing between adjacent turns of the alloy resistance wire is controlled to a set value to ensure that the alloy resistance wire is evenly distributed on the surface of the solid ceramic rod substrate.

[0047] S30, connect the connecting ends of the two bracket leads to the two ends of the solid ceramic rod base respectively, so that the free ends of the two bracket leads extend radially away from the solid ceramic rod base; so that after the free ends of the two bracket leads are inserted into the corresponding through holes of the PCB board during the subsequent winding resistor and PCB assembly process, a gap of a preset height can be formed between the alloy resistance wire and the PCB board.

[0048] Step S30 specifically includes the following processing: Two end caps are respectively connected to both ends of the solid ceramic rod base via an interference fit, so that each of the two leads extends radially away from the solid ceramic rod base. This ensures that after the free ends of the two leads are inserted into the corresponding through holes on the PCB during subsequent wire-wound resistor and PCB assembly, a predetermined gap of height is formed between the alloy resistance wire and the PCB. Specifically, the inner diameter of the end cap is smaller than the outer diameter of the end of the solid ceramic rod base, and the difference between the two constitutes a predetermined interference fit, wherein the predetermined interference fit ranges from 0.02mm to 0.05mm. During assembly, an axial compression embedding method is used, applying a pressing force along the axial direction of the solid ceramic rod base to ensure a tight fit between the inner wall of the end cap and the outer wall of the end of the solid ceramic rod base, thereby achieving interference fit fixation between them. After assembly, the pins on the two end caps are aligned along the circumferential direction of the solid ceramic rod base, and each pin extends radially away from the solid ceramic rod base to ensure that the pins are positioned correctly during subsequent PCB board installation. This also ensures that after the wire-wound resistor is installed on the PCB board, a gap of a preset height is formed between the alloy resistance wire and the PCB board.

[0049] S40, the first and last ends of the alloy resistance wire are welded to the connection ends of the two bracket leads respectively to form an electrical connection.

[0050] S40 specifically includes: connecting two end caps to both ends of the solid ceramic rod base via interference fit; and pulling the beginning and end of the alloy resistance wire along the axial direction of the solid ceramic rod base to the end cap positions at both ends of the solid ceramic rod base, then using spot welding or butt welding to weld and fix the beginning of the alloy resistance wire to the outer wall or end face of the end cap at one end of the solid ceramic rod base, and simultaneously welding and fixing the end of the alloy resistance wire to the outer wall or end face of the end cap at the other end of the solid ceramic rod base, forming a physical locking and electrical connection. Since the end cap, the same-side bracket body, and the pin are integrally formed, after welding, the alloy resistance wire is directly conductive to the pin through the end cap, realizing external electrical connection.

[0051] S50 yields the wire-wound resistance.

[0052] The winding resistor of the present invention is obtained by following the above steps.

[0053] See Figure 3 , Figure 3 This is another schematic flowchart of the method for preparing the wire-wound resistor according to the present invention. The method for preparing the wire-wound resistor provided by the present invention further includes, after step S40: S41, a non-combustible insulating coating is used to coat and encapsulate the connection ends of the solid ceramic rod substrate, alloy resistance wire, and support lead. After the coating is cured, a non-combustible insulating encapsulation layer is formed, and the free end of the support lead is exposed outside the non-combustible insulating encapsulation layer.

[0054] In step S41, a conventional non-combustible insulating coating is used to coat and encapsulate the connection ends of the solid ceramic rod substrate, alloy resistance wire, and support leads through impregnation or spraying. Before coating, conventional masking methods are used to protect the leads. After coating, the coated semi-finished product is placed in an oven for heating and curing. The curing temperature and time are set according to the selected coating type and its conventional process conditions, typically 150℃~200℃ for 30~60 minutes, allowing the coating to cross-link and cure to form a dense non-combustible insulating encapsulation layer. After curing, the masking material on the leads is removed, exposing the leads to the non-combustible insulating encapsulation layer.

[0055] In summary, the wire-wound resistor provided by this invention has two support leads connected to the two ends of a solid ceramic rod substrate, and the free ends of the two support leads extending radially away from the solid ceramic rod substrate. This allows the alloy resistance wire wound around the solid ceramic rod substrate to form a predetermined height gap with the PCB board after the wire-wound resistor is mounted on the PCB board. This allows the wire-wound resistor body to be suspended above the PCB board, and the heat generated by the wire-wound resistor during operation is dissipated through the air and the support leads. This avoids the alloy resistance wire directly contacting or baking the PCB board at close range, effectively preventing the PCB board from burning, carbonizing, or deteriorating due to localized high temperatures, thus improving the reliability and service life of the PCB board. In addition, the gap area can also serve as a wiring channel or mounting space for electronic components, improving the space utilization of the PCB board surface and facilitating the miniaturization and high-density integration design of the PCB board. Furthermore, the solid ceramic rod matrix of the present invention is sintered from raw materials with an aluminum oxide content of 80-85% by mass. Due to the high thermal conductivity and good heat resistance of aluminum oxide, the high aluminum oxide content of the solid ceramic rod matrix can quickly conduct the heat generated during the operation of the alloy resistance wire to the entire solid ceramic rod matrix, avoiding local heat accumulation. At the same time, the solid structure of the solid ceramic rod matrix has a larger heat capacity and a more complete heat conduction path compared to the hollow structure, which can absorb and store more heat. The heat is then quickly dissipated to the surrounding air and support wires through the outer surface and both ends of the solid ceramic rod matrix with high thermal conductivity. The synergistic effect of these two factors can significantly improve the overall heat dissipation efficiency of the solid ceramic rod matrix, reduce the operating temperature rise of the alloy resistance wire, ensure the resistance stability and long-term reliability of the winding resistor, and extend the service life of the winding resistor.

[0056] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A wire-wound resistor, characterized in that, include: Solid ceramic rod substrate (10) is made by sintering raw materials with an aluminum oxide content of 80-85% by mass; Alloy resistance wire (20) is wound around the outer surface of solid ceramic rod base (10) along the axial direction, and the first and last ends of the alloy resistance wire (20) extend to the two ends of solid ceramic rod base (10), respectively. Two support leads (30) are connected to the two ends of the solid ceramic rod base (10) respectively. The free ends of the two support leads (30) extend radially away from the solid ceramic rod base (10) to the outside. The beginning and end of the alloy resistance wire (20) are electrically connected to the connection ends of the two support leads (30) respectively. The free ends of the two bracket leads (30) are used to insert into the corresponding through holes of the PCB board to achieve fixation and electrical connection with the PCB board, and to form a gap of a preset height between the alloy resistance wire (20) and the PCB board.

2. The wire-wound resistor according to claim 1, characterized in that, The bracket lead 30 includes an integrally formed bracket body (33), pins (31) and end caps (32). The pins (31) and end caps (32) are located at opposite ends of the bracket body (33). The end caps (32) are connected to the end of the solid ceramic rod substrate (10) by interference fit. After the pin (31) is inserted into the corresponding through hole of the PCB board and fixed and electrically connected to the PCB board, a gap of a preset height is formed between the alloy resistance wire (20) and the PCB board.

3. The wire-wound resistor according to claim 1 or 2, characterized in that, The preset height is 1mm to 5mm.

4. The wire-wound resistor according to claim 1 or 2, characterized in that, The bracket lead wire (30) is made of iron, and its surface is provided with copper plating and tin plating from the inside to the outside.

5. The wire-wound resistor according to claim 1 or 2, characterized in that, The alloy resistance wire (20) is: a single-wire alloy resistance wire, a double-wire alloy resistance wire, or a triple-wire alloy resistance wire.

6. The wire-wound resistor according to claim 1, characterized in that, The alloy resistance wire (20) is made of nickel and chromium as raw materials; or it is made of nickel, chromium, aluminum and iron as raw materials.

7. The wire-wound resistor according to claim 1 or 2, characterized in that, Also includes: A non-combustible insulating encapsulation layer covers the connection ends of a solid ceramic rod substrate (10), an alloy resistance wire (20), and a support lead (30), the free ends of which are exposed outside the non-combustible insulating encapsulation layer.

8. The method for preparing the wire-wound resistor according to any one of claims 1 to 7, characterized in that, Includes the following steps: S10 is a solid ceramic rod matrix prepared by sintering raw materials with an aluminum oxide content of 80-85% by mass. S20, the alloy resistance wire is wound along the axial direction of the solid ceramic rod matrix on the outer surface of the solid ceramic rod matrix, and the first and last ends of the alloy resistance wire are extended to both ends of the solid ceramic rod matrix, respectively. S30, connect the connecting ends of the two bracket leads to the two ends of the solid ceramic rod base respectively, so that the free ends of the two bracket leads extend radially away from the solid ceramic rod base; so that after the free ends of the two bracket leads are inserted into the corresponding through holes of the PCB board during the subsequent assembly of the wire-wound resistor and the PCB board, a gap of a preset height can be formed between the alloy resistance wire and the PCB board. S40, the first and last ends of the alloy resistance wire are welded to the connection ends of the two bracket leads respectively to form an electrical connection; S50 yields the wire-wound resistance.

9. The method for preparing a wire-wound resistor according to claim 8, characterized in that, S30 specifically includes: Two end caps are respectively connected to the two ends of the solid ceramic rod base by interference fit, so that the two pins extend radially away from the solid ceramic rod base; so that after the free ends of the two pins are inserted into the corresponding through holes of the PCB board during the subsequent wire-wound resistor and PCB assembly process, a gap of a preset height can be formed between the alloy resistance wire and the PCB board.

10. The method for preparing a wire-wound resistor according to claim 8, characterized in that, The process following step S40 also includes: S41, a non-combustible insulating coating is used to coat and encapsulate the connection ends of the solid ceramic rod substrate, alloy resistance wire, and support lead. After the coating is cured, a non-combustible insulating encapsulation layer is formed, and the free end of the support lead is exposed outside the non-combustible insulating encapsulation layer.

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