Novel electrostatic discharge power inductor

Abstract

The utility model belongs to the technical field of inductors, and particularly relates to a novel electrostatic discharge power inductor which comprises a magnetic core, a winding and a bleeder resistor, the magnetic core is a cylindrical magnetic core and facilitates winding processing of equipment, the winding comprises a densely-wound coil and a sparsely-wound coil, the densely-wound coil and the sparsely-wound coil are of an integrated structure, and the bleeder resistor is arranged between the densely-wound coil and the sparsely-wound coil. The close winding and sparse winding combined mode is used for improving turn-to-turn capacitance and optimizing loss, the winding is further connected with two bleeder resistors, in order to absorb turn-to-turn high-frequency signals, the magnetic core is of a sectional structure, and a high-temperature-resistant insulating sheet is arranged between every two sections and used for reducing eddy-current loss. According to the inductor, eddy current loss is reduced through the segmented magnetic cores and the high-temperature-resistant insulating sheets, turn-to-turn capacitance and high-frequency loss are optimized in combination with the densely-wound and sparsely-wound coils, high-frequency signals are absorbed with the help of the bleeder resistor, and the inductor has the advantages of being high in efficiency, low in loss, high in stability and easy to machine.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of inductance, and specifically relates to a novel electrostatic discharge power inductance. BACKGROUND

[0002] In electronic equipment circuit design, electrostatic discharge (ESD) protection is a key technology link to ensure system reliability. As a core component in the ESD protection circuit, the performance of the power inductance directly affects the absorption, discharge and circuit stability of electrostatic energy. Traditional power inductance usually adopts a ferrite core and a multi-layer winding structure, and the main function is concentrated in high-frequency filtering and energy storage, but when dealing with ESD events of transient large current, its inherent design defects gradually appear.

[0003] The structural design of the traditional power inductance lacks a targeted discharge path. Since the electrostatic current directional discharge channel is not integrated, when the ESD pulse invades, the electric charge is easy to accumulate inside the inductance and difficult to release quickly through a low-impedance path. Such charge accumulation not only causes local electric field distortion, leading to a decrease in the insulation performance of the device, but also may cause secondary discharge risk, seriously weakening the response efficiency of the protection circuit. The physical properties of the traditional magnetic core material cause significant eddy current loss problems. Under the action of high-frequency alternating magnetic field, a closed eddy current loop is formed inside the conventional magnetic core such as ferrite, especially under the excitation of the steep rising edge (typically up to several kV / μs) of the ESD pulse, the eddy current loss grows exponentially. Such loss not only reduces the energy conversion efficiency of the inductor, but also causes local temperature rise of the magnetic core, which will accelerate the aging of the material and even cause thermal failure in the long run. The hysteresis loop characteristics of the traditional design exacerbate the magnetic loss problem. Under repetitive ESD impact, the magnetic domain reversal hysteresis effect of the magnetic core material causes the continuous accumulation of hysteresis loss. This not only reduces the overall energy efficiency of the system, but also forces designers to use larger magnetic cores to disperse heat, which contradicts the trend of miniaturization of electronic equipment.

[0004] The saturation current threshold of the traditional power inductance is difficult to meet the ESD protection requirements. When the transient discharge current exceeds the saturation critical point of the magnetic core, the inductance value will drop by more than 90%, causing the filter function to fail. At this time, the high-energy pulse that has not been attenuated will directly impact the subsequent circuit, causing damage to sensitive components. The existing solution usually increases the cross-sectional area of the magnetic core to increase the saturation current, but this will significantly increase the size and cost of the device, and cannot fundamentally improve the problem of uneven magnetic flux density distribution.

[0005] Therefore, it has become a key technical direction to develop a new type of power inductance with directional discharge channel, low eddy current loss characteristics and high saturation current capacity to improve the ESD protection efficiency. SUMMARY

[0006] Based on this, the scheme provides a new type of electrostatic discharge power inductance, which is combined with high-temperature-resistant insulation sheet by segmented magnetic core, and is combined with dense winding and sparse winding coil assisted by discharge resistance to absorb high-frequency signals, and has high performance, low loss, high stability and is easy to process.

[0007] The technical scheme for solving the above technical problems is as follows:

[0008] A new type of electrostatic discharge power inductance, comprising: a magnetic core, a winding and a discharge resistance, the magnetic core is a columnar magnetic core, which is convenient for equipment winding processing, the winding comprises a dense winding coil and a sparse winding coil, which is used for improving inter-turn capacitance and optimizing loss, and the winding is further connected with a discharge resistance for absorbing high-frequency signals between turns.

[0009] Optionally, in an embodiment of the utility model, the magnetic core adopts segmented structure, and high-temperature-resistant insulation sheet is arranged between every two magnetic cores, which is used for reducing eddy current loss, magnetic loss and increasing saturation current.

[0010] Optionally, in an embodiment of the utility model, the magnetic core is a cylindrical structure.

[0011] Optionally, in an embodiment of the utility model, the outer part of the magnetic core is further provided with a heat shrinkable sleeve.

[0012] Optionally, in an embodiment of the utility model, the discharge resistance comprises a first discharge resistance and a second discharge resistance, the first discharge resistance is connected in parallel in the middle section of the winding, and the second discharge resistance is connected at both ends of the winding rear section and the pin of the rear section, and the connection of the discharge resistance and the winding is connected through soldering.

[0013] Optionally, in an embodiment of the utility model, the winding is made of enameled wire.

[0014] Optionally, in an embodiment of the utility model, the dense winding coil and the sparse winding coil are a coherent integrated coil.

[0015] The utility model discloses the beneficial effect is:

[0016] The utility model provides a new type of electrostatic discharge power inductance adopts segmented cylindrical magnetic core, and the equipment is convenient for winding processing, and high-temperature-resistant insulation sheet is arranged between every two magnetic cores, can play the role of reducing eddy current loss, magnetic loss and increasing saturation current, and the winding is arranged on the magnetic core, and the winding comprises integrated dense winding coil and sparse winding coil, adopts the coil that combines dense winding and sparse winding, optimizes inter-turn capacitance and high-frequency loss, and the discharge resistance is further connected in parallel on the winding and absorbs high-frequency signals, and has high performance, low loss, high stability and easy processing characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows, and other related drawings can also be obtained by those of ordinary skill in the art without any creative effort on the basis of these drawings.

[0018] Fig. 1 A novel electrostatic discharge power inductance front structure schematic diagram of the embodiment 1 of the present application;

[0019] Fig. 2 A magnetic core section schematic diagram of the embodiment 1 of the present application;

[0020] The drawings are as follows: magnetic core 1, first magnetic core 101, second magnetic core 102, third magnetic core 103, high-temperature-resistant insulating sheet 104, heat-shrinkable sleeve 105, winding 2, sparse winding coil 201, dense winding coil 202, pin 203, first discharge resistor 301, second discharge resistor 302. DETAILED DESCRIPTION

[0021] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The technical solutions of the present application will be further described below in combination with the drawings of the embodiments of the present application, and the present application is not limited to the following specific embodiments.

[0022] The same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components. In the description of the present application, if the orientations or position relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom" and the like are based on the orientations or position relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, the terms describing the position relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present patent, and for those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0023] Embodiment 1

[0024] Since the existing electrostatic discharge power inductance has many defects in performance, a novel electrostatic discharge power inductance is designed, and the specific scheme is as follows:

[0025] As shown in Figs. 1-2 A novel electrostatic discharge power inductance, comprising: a magnetic core 1, a winding 2 and a discharge resistor, the magnetic core 1 is a columnar magnetic core 1, which is convenient for equipment winding processing, the winding 2 comprises a dense winding coil 202 and a sparse winding coil 201, which is used to improve the turn-to-turn capacitance and optimize the loss, and the winding 2 is also connected with a discharge resistor, which is used to absorb the high-frequency signal between turns.

[0026] Specifically, the magnetic core 1 is a cylindrical structure, which is more convenient for winding processing of the winding 2 on the magnetic core 1 by automatic equipment.

[0027] In the embodiment, the densely wound coil 202 and the sparsely wound coil 201 are a continuous integrated coil, and the winding 2 as a whole is a 15-turn coil, wherein turns 1-10 are the sparsely wound coil 201, and turns 11-15 are the densely wound coil 202, and the winding 2 is wound by enameled wire.

[0028] The magnetic core 1 adopts a segmented structure, and a high-temperature-resistant insulating sheet 104 is arranged between every two magnetic cores 1, for reducing eddy current loss, magnetic loss, and increasing saturation current. In the embodiment, the high-temperature-resistant insulating sheet 104 has a size of 0.8 mm and is made of polyimide film. In the embodiment, the magnetic core 1 is divided into three magnetic cores 1, the outer part of the first two magnetic cores is wound with the sparsely wound coil 201, and the outer part of the last magnetic core is wound with the densely wound coil 202. The first magnetic core 101, the second magnetic core 102, and the third magnetic core 103 are sequentially arranged from the sparsely wound coil 201 to the densely wound coil 202. The cross-sectional size of the first magnetic core 101 is slightly smaller than that of the second magnetic core 102 and the third magnetic core 103. By adjusting the size of the first magnetic core 101, the target inductance can be accurately matched without changing the overall structure. The second magnetic core 102 and the third magnetic core 103 can be reused in the existing design, simplifying the production process. Only the first magnetic core 101 needs to be adjusted, reducing the cost.

[0029] The outer part of the magnetic core 1 is further sleeved with a heat-shrinkable sleeve 105. In the embodiment, the heat-shrinkable sleeve 105 is a Teflon sleeve. The heat-shrinkable sleeve 105 provides mechanical protection and heat conduction. The low dielectric loss characteristic of the heat-shrinkable sleeve 105 can reduce the dielectric loss at high frequency, and the heat dissipation can be enhanced by forced convection or thermal conductive glue filling.

[0030] The bleeder resistor includes a first bleeder resistor 301 and a second bleeder resistor 302. The first bleeder resistor 301 is a first bleeder path, and the second bleeder resistor 302 is a second bleeder path. The first bleeder resistor 301 is connected in parallel at the middle section of the winding 2, and the two ends of the second bleeder resistor 302 are connected to the rear section of the winding 2 and the pin 203 of the rear section, respectively. The bleeder resistor is connected to the winding 2 by soldering. Specifically, the two ends of the first bleeder resistor 301 are connected to the 6th turn and the 11th turn, respectively, and the two ends of the second bleeder resistor 302 are connected to the 11th turn and the pin 203 of the densely wound coil 202, respectively.

[0031] The inductor design is mainly aimed at high-frequency application scenarios, such as electrostatic discharge protection, switching power supply filtering, etc.

[0032] The electrostatic discharge power inductor in this design employs a three-section magnetic core 1 and a high-temperature resistant insulating sheet 104. By physically dividing the magnetic circuit path, it significantly reduces eddy current losses caused by alternating magnetic fields under high-frequency operating conditions. The dielectric constant and thickness of the insulating sheet directly affect the interlayer capacitance; therefore, a low dielectric constant material must be selected to minimize additional capacitance and reduce eddy current losses.

[0033] Technical principle:

[0034] The segmented structure can disperse the magnetic flux density distribution and avoid local magnetic saturation. The first magnetic core 101 has a smaller cross-section and can bear a higher magnetic flux density, so it needs to be made of a material with high saturation magnetic induction intensity, such as iron-silicon-aluminum powder core 1. The second and third magnetic cores 103 can use conventional ferrite materials to reduce costs and improve saturation current.

[0035] By adjusting the cross-sectional area and effective magnetic circuit length of the first magnetic core 1, the inductance value can be finely adjusted while maintaining the overall volume.

[0036] The first bleeder resistor 301 is connected in parallel to the middle section of winding 2 to form a low-frequency energy bleeder path, mainly absorbing transient energy in the mid-frequency band. The second bleeder resistor 302 covers the high-frequency band and reduces lead inductance by shortening the bleeder path length, thereby improving the response speed to ESD pulses.

[0037] Example 2

[0038] In this embodiment, the structural design of the power inductor is basically the same as that in Embodiment 1. The difference is that the first discharge path is replaced by a bidirectional TVS diode connected in parallel with a 10Ω non-inductive thick-film resistor in series between turns 6-11; the second discharge path is replaced by an RC network consisting of a varistor and a 100pF ceramic capacitor connected in parallel with pin 203 at turn 11. Under normal conditions, the TVS / varistor is in a high-resistance state, and the static power consumption is close to zero; when ESD > 24V, the TVS avalanche conduction is triggered, dissipating energy through an extremely fast response speed, and the RC network absorbs residual high-frequency oscillations.

[0039] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A novel electrostatic discharge power inductor characterized by, The utility model relates to a magnetic core, winding and leakage resistance, the magnetic core is columnar magnetic core, facilitates the equipment winding processing, the winding includes dense winding coil and sparse winding coil, is used for promoting interturn capacitance and optimizing loss, the winding still is connected with leakage resistance, is used for absorbing the high frequency signal of interturn. The magnetic core adopts segmented structure, and high-temperature-resistant insulating sheets are arranged between every two segments of the magnetic core to reduce eddy current loss, magnetic loss and increase saturation current.

2. A novel electrostatic discharge power inductor as defined in claim 1, wherein: The magnetic core is in a cylindrical structure.

3. A novel electrostatic discharge power inductor as defined in claim 1, wherein: The magnetic core is further sleeved with a heat-shrinkable sleeve.

4. A novel electrostatic discharge power inductor as defined in claim 1, wherein: The leakage resistance includes a first leakage resistance and a second leakage resistance, the first leakage resistance is connected in parallel at the middle segment of the winding, the second leakage resistance has two ends connected to the rear segment of the winding and the pin of the rear segment respectively, and the connection of the leakage resistance and the winding is connected through soldering.

5. A novel electrostatic discharge power inductor as defined in claim 1, wherein: The winding is made of enameled wire.

6. A novel electrostatic discharge power inductor as defined in claim 1, wherein: The dense winding coil and the sparse winding coil are a coherent integrated coil.

7. A novel electrostatic discharge power inductor as defined in claim 1, wherein: ​

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