Inductor and preparation method thereof

Abstract

The embodiment of the invention provides an inductor and a preparation method thereof, and the inductor comprises a magnetic core which comprises a body, a first end and a second end, the first end and the second end are respectively located at the two ends of the body along a first direction, and the first end and the second end protrude in a second direction relative to the body; an insulating layer covering the magnetic core; one end of the coil is arranged on the side, away from the body, of the first end, the middle of the coil is wound around the body, and the other end of the coil is arranged on the side, away from the body, of the second end; and the shielding layer completely covers the body, and the shielding layer partially covers the coil, so that the parts, which are positioned at the first end and the second end and are far away from the body, of the coil are exposed, and an extraction electrode is formed. According to the inductor and the preparation method thereof provided by the embodiment of the invention, due to the arrangement of the insulating layer, in the forming process of the inductor, no large pressure and friction exist between the coil and the magnetic core, no welding point exists on the extraction electrode, and hidden dangers of short circuit and open circuit are effectively avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of inductors, and in particular, relates to an inductor and a method for preparing the same. Background Art

[0002] Power inductors are mainly used in switching power supply modules that power chips, and they play a role in stabilizing the power level. The circuit requires the inductor to be able to withstand large operating currents, withstand high temperatures, have low power consumption (reduce heat generation), and improve shielding capabilities to reduce interference with external circuits. The same is true for the improvement and development of inductors. For example, in terms of magnetic core materials, from ferrite to metal powder core materials with higher saturation magnetization and higher Curie temperature, from bare coils to integrated coils and magnetic powder. Integrated molded inductors have the advantages of high saturation current and good shielding performance.

[0003] The current mainstream integrated inductor is to mix atomized alloy powder, carbonyl iron powder, or amorphous powder with thermosetting or thermoplastic epoxy resin, stir and knead them evenly, then granulate and press them into shape, bake and solidify the block as magnetic material, and use round copper wire or flat copper wire as electrode. However, in the current inductor preparation process, the friction between the powder and the coil will damage the insulation layer, and there is a risk of short circuit and open circuit. Summary of the invention

[0004] In view of this, the embodiments of the present application provide an inductor and a method for preparing the same, so as to solve the technical problem in the existing inductor preparation process that the friction between the powder and the coil may damage the insulation layer and cause the risk of short circuit and open circuit.

[0005] In a first aspect, an embodiment of the present application provides an inductor, including:

[0006] A magnetic core, comprising a body, a first end and a second end, wherein the first end and the second end are respectively located at two ends of the body along a first direction, and the first end and the second end protrude relative to the body in a second direction;

[0007] an insulating layer, covering the magnetic core;

[0008] a coil, one end of which is disposed on a side of the first end away from the body, a middle portion of the coil being wound around the body, and the other end of the coil being disposed on a side of the second end away from the body; and

[0009] The shielding layer completely covers the body, and the shielding layer partially covers the coil, so that the parts of the coil located at the first end and the second end away from the body leak out and form lead-out electrodes.

[0010] In some embodiments, the insulating layer completely covers the body, the first terminal and the second terminal, and the thickness of the insulating layer is greater than or equal to 5 microns.

[0011] In some embodiments, the thickness of the shielding layer is greater than or equal to 50 microns.

[0012] In some embodiments, a protective layer is further provided between the shielding layer and the insulating layer, and the protective layer completely covers the body and partially covers the coil, so that the lead-out electrode is exposed.

[0013] In some embodiments, the protective layer has a thickness of 20 μm to 60 μm.

[0014] In some embodiments, the protection layer and the insulation layer include any one of ceramic material, epoxy resin, polyurethane, and silicone resin.

[0015] In some embodiments, the length of the magnetic core is a, the height is b, the height of the first end and the second end is e, and the length of the first end and the second end is f;

[0016] Among them, e=(0.1~0.3)×b; f=(0.2~0.25)×a.

[0017] In a second aspect, an embodiment of the present application provides a method for preparing an inductor, which is used to prepare the inductor described in the first aspect, and the preparation method comprises the following steps:

[0018] preparing the magnetic core;

[0019] forming the insulating layer on the surface of the magnetic core;

[0020] One end of the coil is disposed on a side of the first end away from the body, the middle of the coil is disposed around the body, and the other end of the coil is located on a side of the second end away from the body;

[0021] The shielding layer is formed on the coil and the insulating layer, and the coil located at the first end and the second end away from the body is leaked relative to the shielding layer to form the lead-out electrode.

[0022] In some embodiments, before forming the shielding layer on the coil and the insulating layer, the step further includes:

[0023] The protection layer is formed on the coil and the insulating layer, and the protection layer partially covers the coil, so that the lead-out electrode is exposed to the outside of the protection layer.

[0024] In some embodiments, one end of the coil is disposed on a side of the first end away from the body, the middle of the coil is disposed around the body, and the other end of the coil is located on a side of the second end away from the body, comprising:

[0025] The silver electrode is printed on the surface of the magnetic core by using a 3D printing process to form the coil and the lead-out electrode.

[0026] In some embodiments, the shielding layer is formed on the coil and the insulating layer, and the coil located at the first end and the second end away from the body is leaked relative to the shielding layer to form the lead-out electrode, including:

[0027] Providing magnetic powder and organic silicon resin for mixing and stirring to prepare casting slurry;

[0028] Passing the coil-wound magnetic core through the casting slurry waterfall multiple times to form the shielding layer;

[0029] The shielding layer located at the first end and the second end on the side away from the body is peeled off to expose a portion of the coil to form the lead-out electrode.

[0030] In some embodiments, the preparation material of the magnetic core includes at least one of reduced iron powder, amorphous powder, carbonyl iron powder, iron silicon chromium powder, and iron silicon chromium alloy powder.

[0031] In some embodiments, the magnetic core is prepared by a sintering process.

[0032] The inductor and its preparation method provided by the embodiment of the present application, through the setting of the insulating layer, there is no great pressure and friction between the coil and the magnetic core. In the inductor structure design and molding process of the embodiment of the present application, there is no welding point in the lead-out electrode, which effectively avoids the hidden dangers of short circuit and open circuit. Specifically, the presence of the insulating layer can increase the insulation between the magnetic core and the coil, and prevent short circuit caused by reasons such as excessive voltage or excessive environmental humidity. When the alternating current passes through the inductor coil, eddy currents will be generated inside the magnetic core. These eddy currents will cause energy loss, and the insulating layer can effectively divide the magnetic core, reduce the eddy current path, and thus reduce the eddy current loss. The insulating layer can protect the magnetic core from physical damage to a certain extent, especially from shocks and vibrations that may be encountered during the assembly process or during the use of the product. The insulating layer can also help the magnetic core better resist the influence of temperature changes and keep its performance stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 is a schematic diagram of the structure of an inductor provided in an embodiment of the present application;

[0035] Figure 2 yes Figure 1 Side view of

[0036] Figure 3 yes Figure 2 Schematic diagram of the cross section in the AA direction;

[0037] Figure 4 This is a schematic diagram of a partial structure of an inductor provided in an embodiment of the present application. Figure 1 ;

[0038] Figure 5 This is a schematic diagram of a partial structure of an inductor provided in an embodiment of the present application. Figure 2 ;

[0039] Figure 6 Schematic diagram 1 of the structure of the magnetic core in the inductor provided in an embodiment of the present application;

[0040] Figure 7 This is a second structural diagram of a magnetic core in an inductor provided in an embodiment of the present application;

[0041] Figure 8 This is a third structural diagram of the magnetic core in the inductor provided in an embodiment of the present application.

[0042] Among them, the figure numbers are:

[0043] 10. magnetic core; 11. body; 12. first terminal; 13. second terminal; 100. insulating layer; 101. protective layer;

[0044] 20. coil; 200. lead-out electrode;

[0045] 30. Shielding layer. DETAILED DESCRIPTION

[0046] In the following description, specific details such as specific system structures, technologies, etc. are proposed for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the embodiments of the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from hindering the description of the embodiments of the present application.

[0047] It should also be understood that the term “and / or” used in the description of the embodiments of the present application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0048] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0049] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0050] In addition, in the description of the embodiments of the present application and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0051] References to "some embodiments" or "some embodiments" etc. described in the specification of the embodiments of the present application mean that one or more embodiments of the embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Thus, the statements "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in the different parts of this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. "Multiple" refers to two or more.

[0052] The mainstream one-piece molded inductor currently adopts the method of mixing atomized alloy powder, carbonyl iron powder, or amorphous powder with thermosetting or thermoplastic epoxy resin, stirring and kneading them evenly, then granulating and pressing them into shape, and the block material after baking and curing is used as the magnetic material, and round copper wire or flat copper wire is used as the electrode. There are usually the following designs: the first one uses round copper wire to wind the coil and weld it on the lead-out frame, then places the empty coil in the mold cavity, pours in the granulated magnetic powder to press it into shape, bends the lead-out end, and then bakes and cures; the second one presses the magnetic powder into a T-shaped center column with a base, then puts the wound flat copper coil into the bent lead-out end, then places the assembled T-shaped center column of the coil into the mold, pours in the granulated magnetic powder for the second pressing and forming, and then bakes and cures; the third one presses the magnetic powder into two small squares, then clamps a flat copper wire with two small squares, presses it again, bends the lead-out end, and then sintered under the protection of a reducing atmosphere.

[0053] The disadvantages of the above designs are: the first one is that due to the existence of the coil, the molding pressure in the center area of ​​the coil wrap is lower than the surrounding area, resulting in the inability to be dense, so the actual magnetic permeability of the material is not high, and the solder joints are under high pressure and there is a risk of short circuit, and the friction between the powder and the coil will damage the insulation layer and there is a risk of short circuit; the second one has a complicated process and a longer production process, the secondary molding efficiency is very low, and the contact area between the powder and the coil is larger, and the probability of the insulation layer being damaged and the risk of short circuit is greater; the magnets of the first two technologies are bonded with epoxy resin, which is prone to aging and decomposition at high temperatures and is difficult to withstand high temperatures for a long time; the third one, because it is currently difficult to solve the insulation problem of copper wire under high sintering temperatures, only a single-layer electrode through-core structure can be used, which limits the development of high inductance models and the miniaturization of inductors. At the same time, when the magnetic powder and copper electrodes are co-fired, there is also a risk of short circuit between the electrode and the magnetic powder.

[0054] In summary, current inductors and their manufacturing processes generally have friction between electrodes and magnetic core powder, resulting in short circuits or potential short circuit risks.

[0055] Based on this, the first aspect of the embodiment of the present application provides an inductor, such as Figures 1 to 6 As shown, it includes a magnetic core 10, an insulating layer 100, a coil 20 and a shielding layer 30;

[0056] The magnetic core 10 includes a body 11, a first end 12 and a second end 13, wherein the first end 12 and the second end 13 are respectively located at two ends of the body 11 along a first direction, and the first end 12 and the second end 13 protrude relative to the body 11 in a second direction;

[0057] The insulating layer 100 covers the magnetic core 10;

[0058] One end of the coil 20 is disposed on a side of the first end 12 away from the body 11, the middle of the coil 20 is wound around the body 11, and the other end of the coil 20 is disposed on a side of the second end 13 away from the body 11;

[0059] The shielding layer 30 completely covers the body 11 , and partially covers the coil 20 , so that the portion of the coil 20 at the first end 12 and the second end 13 away from the body 11 is exposed to form an extraction electrode 200 .

[0060] In the inductor provided in the embodiment of the present application, the presence of the insulating layer 100 can increase the insulation between the magnetic core 10 and the coil 20, and prevent short circuits caused by reasons such as excessive voltage or excessive ambient humidity. When alternating current passes through the inductor coil 20, eddy currents are generated inside the magnetic core 10. These eddy currents will cause energy loss, and the insulating layer 100 can effectively divide the magnetic core 10, reduce the eddy current path, and thus reduce eddy current losses; the insulating layer 100 can protect the magnetic core 10 from physical damage to a certain extent, especially from shocks and vibrations that may be encountered during the assembly process or during product use; the insulating layer 100 can also help the magnetic core 10 better resist the influence of temperature changes and maintain its stable performance.

[0061] It should be noted that if Figure 3 , Figure 6 as well as Figure 7 As shown, the first direction mentioned above is the X direction in the figure, that is, the length direction of the inductor (magnetic core 10), the second direction is the Z direction in the figure, that is, the height direction of the inductor (magnetic core 10), and the width direction of the inductor (magnetic core 10) is the Y direction in the figure. The above is only for the convenience of explaining and understanding the technical solution of the present application, and should not be understood as limiting the scope of protection of the embodiments of the present application.

[0062] In application, the magnetic core 10 is one of the most important parts of the inductor. It is mainly used to enhance the magnetic field generated by the coil 20 and increase the inductance. The material and shape of the magnetic core 10 have a direct impact on the inductance value. The magnetic core 10 is composed of a body 11, a first terminal 12 and a second terminal 13. Such a design can optimize the magnetic field distribution, reduce magnetic leakage, and help improve the mechanical stability of the inductor. The insulating layer 100 covers the magnetic core 10, and its main function is to prevent a short circuit between the coil 20 and the magnetic core 10 to ensure the safe operation of the circuit. In addition, the insulating layer 100 can also play a certain role in moisture and corrosion protection, protecting the internal structure from environmental influences. The coil 20 is a key component for generating an electromagnetic field in the inductor. The magnetic field is generated by the flow of current in the coil 20, thereby realizing the conversion of electrical energy to magnetic energy. Parameters such as the number of turns and diameter of the coil 20 directly affect the inductance value of the inductor. The two ends of the coil 20 are respectively arranged on the side of the first terminal 12 and the second terminal 13 of the magnetic core 10 away from the body 11. Such a design is conducive to improving the working efficiency and performance of the inductor. The main function of the shielding layer 30 is to reduce the impact of external electromagnetic interference on the inductor, and also to prevent the magnetic field generated by the inductor itself from interfering with other electronic components. The design of the shielding layer 30 partially covering the coil 20 can effectively reduce electromagnetic radiation while maintaining the performance of the inductor. The lead-out electrode 200 is a contact point led out from the coil 20 for connecting to an external circuit. The lead-out electrode 200 design of the present application (i.e., the coil 20 is located at the first terminal 12 and the second terminal 13 and is partially leaked away from the body 11) is not only convenient for connection with other circuit elements, but also helps to reduce signal loss during the connection process, thereby improving the reliability and efficiency of the entire circuit.

[0063] In some embodiments, the insulating layer 100 completely covers the body 11, the first terminal 12 and the second terminal 13, and the thickness of the insulating layer 100 is greater than or equal to 5 microns. In this way, the insulation performance can be effectively improved. Increasing the thickness of the insulating layer 100 can significantly improve the insulation performance of the inductor and prevent accidental short circuits between the coil 20 and the magnetic core 10 or other components, which is particularly important for high voltage applications. The insulating layer 100 of more than 5 microns can provide a sufficient insulation barrier to ensure that the inductor can operate safely and reliably under various working conditions. The thicker insulating layer 100 can better resist the influence of humidity, dust and other environmental factors and extend the service life of the inductor. In some harsh working environments, such as high temperature, high humidity or corrosive gas, the thick insulating layer 100 can provide additional protection to ensure the long-term stability of the inductor. The insulating layer 100 can not only serve as a means of electrical isolation, but also enhance the overall mechanical strength of the magnetic core 10. In particular, when the insulating layer 100 evenly and fully covers the entire magnetic core 10, it can effectively reduce damage caused by vibration or impact and improve the durability of the inductor.

[0064] In some embodiments, the thickness of the shielding layer 30 is greater than or equal to 50 microns. Such a setting can enhance the electromagnetic shielding effect. A thickness of more than 50 microns can provide a stronger electromagnetic shielding effect, ensuring that the inductor can still maintain stable performance in high-frequency and high-power applications. The increase in thickness can effectively reduce the penetration of electromagnetic waves and improve the shielding effectiveness, especially in the high-frequency band, which is particularly important. The thicker shielding layer 30 can enhance the overall mechanical strength of the inductor, making it more rugged and durable. This is very important during transportation, installation and use, and can reduce damage caused by physical shock or vibration. The increase in mechanical strength also helps to protect the internal coil 20 and magnetic core 10, extending the service life of the inductor.

[0065] In some embodiments, Figure 3 As shown, a protective layer 101 is further provided between the shielding layer 30 and the insulating layer 100, and the protective layer 101 completely covers the body 11 and partially covers the coil 20, so that the lead electrode 200 is exposed. The protective layer 101 completely covers the body 11 of the magnetic core 10 and partially covers the coil 20, which can provide additional mechanical protection to prevent external physical damage. In particular, during transportation, installation and use, the protective layer 101 can reduce damage caused by impact, scratches, etc., and improve the durability and life of the inductor. The protective layer 101 can further enhance the moisture-proof, dust-proof and corrosion-proof properties of the inductor. In a humid, dusty or corrosive gas environment, the protective layer 101 can effectively block these harmful factors and ensure that the internal structure of the inductor is not damaged. The protective layer 101 can provide an additional insulating barrier between the insulating layer 100 and the shielding layer 30, further improving the electrical insulation performance of the inductor. This helps to prevent breakdown under high voltage and improve the reliability of the inductor in high voltage and high frequency applications. The protective layer 101 can play a certain role in heat insulation, helping to evenly distribute the heat generated inside and reduce local overheating. This helps to improve the thermal stability of the inductor and extend its service life. The protective layer 101 partially covers the coil 20, exposing the lead-out electrode 200, which can ensure reliable connection between the lead-out electrode 200 and the external circuit. The exposed lead-out electrode 200 can be easily welded or plugged in, ensuring good electrical contact of the inductor in the circuit.

[0066] In some embodiments, the thickness of the protective layer 101 is 20 μm to 60 μm. In some specific embodiments, the thickness of the protective layer 101 can be any value within the range of 20 μm to 60 μm, such as 20 μm, 22 μm, 24 μm, 25 μm, 26 μm, 30 μm, 35 μm, 40 μm, 42 μm, 45 μm, 46 μm, 48 μm, 50 μm, 52 μm, 55 μm, 58 μm, 60 μm, etc. Such a setting can effectively enhance the mechanical protection of the inductor as well as the moisture-proof, dust-proof and corrosion-proof properties.

[0067] In some embodiments, the protective layer 101 and the insulating layer 100 include any one of a ceramic material, an epoxy resin, a polyurethane, and a silicone resin. In some embodiments, the ceramic material includes silicon dioxide. Ceramic materials have very high dielectric constants and insulation resistances, and can provide excellent electrical insulation properties. Ceramic materials can remain stable at high temperatures and are suitable for high power and high temperature environments. Epoxy resins have good electrical insulation properties and are suitable for use as insulating layers 100 and protective layers 101. Epoxy resins can adhere well to various substrates to ensure the uniformity and integrity of the coating. Polyurethanes have high elasticity and flexibility and can withstand large deformations without breaking. Polyurethanes have good electrical insulation properties and are suitable for use as insulating layers 100 and protective layers 101. Silicone resins can remain stable at high temperatures and are suitable for use in high power and high temperature environments. Silicone resins have excellent electrical insulation properties and are suitable for use as insulating layers 100 and protective layers 101.

[0068] In some embodiments, Figure 7 and Figure 8 As shown, the length of the magnetic core 10 is a, the height is b, the height of the first end 12 and the second end 13 is e, and the length of the first end 12 and the second end 13 is f;

[0069] Among them, e = (0.1 ~ 0.3) × b; f = (0.2 ~ 0.25) × a.

[0070] In this way, e occupies 10-30% of the length of b, ensuring that there is a gap between the electrode in the middle of the bottom and the bottom surface and will not directly contact the circuit board. f is 20-25% of the length of a to ensure the proportion of the end area size, which is conducive to the fixation of the inductor. The appropriate height can optimize the distribution of the magnetic field around the magnetic core 10, reduce magnetic leakage, and improve the magnetic coupling efficiency. Higher ends can provide better mechanical support to prevent the magnetic core 10 from being displaced or deformed during use. The height of the end determines the position of the lead-out electrode 200, which helps to ensure the reliable connection and electrical performance of the lead-out electrode 200.

[0071] In application, by adjusting the ratio of e and f, the distribution of the magnetic field around the magnetic core 10 can be optimized, magnetic leakage can be reduced, and the magnetic coupling efficiency can be improved. This is very important for increasing the inductance value of the inductor and reducing losses. Higher terminals and longer terminals can provide better mechanical support, prevent the magnetic core 10 from being displaced or deformed during use, and improve the durability and reliability of the inductor. The height e of the terminal determines the position of the lead-out electrode 200, which helps to ensure the reliable connection and electrical performance of the lead-out electrode 200. Appropriate terminal height can facilitate welding or plugging, reducing the risk of poor contact or short circuit. The length f of the terminal affects the layout and winding method of the coil 20, which helps to improve the uniformity and consistency of the coil 20. This can reduce the parasitic capacitance and inductance between the coils 20 and improve the high-frequency performance of the inductor.

[0072] In some applications that require miniaturization, a smaller ratio (such as e = 0.1 × b, f = 0.2 × a) can be selected to reduce the total volume of the inductor. In applications that require high performance and high reliability, a larger ratio (such as e = 0.3 × b, f = 0.25 × a) can be selected to optimize magnetic field distribution and mechanical stability.

[0073] In the application, Figure 7 and Figure 8 Where c is the thickness of the magnetic core 10 , and d is the distance between the first end 12 and the second end 13 .

[0074] The embodiment of the present application further provides a method for preparing an inductor, which is used to prepare the inductor described in the first aspect, and the preparation method comprises the following steps:

[0075] S10, preparing a magnetic core;

[0076] S20, forming an insulating layer on the surface of the magnetic core;

[0077] S30, placing one end of the coil on a side of the first end away from the body, placing the middle of the coil around the body, and placing the other end of the coil on a side of the second end away from the body;

[0078] S40, forming a shielding layer on the coil and the insulating layer, and making the coil located at the first end and the second end away from the body leak out relative to the shielding layer to form a lead-out electrode.

[0079] According to the method for preparing the inductor provided in the embodiment of the present application, during the molding process of the inductor, there is no great pressure and friction between the lead-out electrode and the powder of the magnetic core, and there is no welding point on the lead-out electrode, thereby avoiding the hidden dangers of short circuit and open circuit; the magnetic core wrapped by the coil is a sintered magnetic core, which has a higher magnetic permeability than the bonded magnet and can withstand high temperature for a long time, and the shielding layer adopts silicone resin which is more resistant to high temperature than epoxy resin; the coil adopts a multi-turn design, which can cover a wide range of inductance, and the process is easy to automate.

[0080] In step S10, the magnetic core is prepared by a sintering process. Specifically, the reduced iron powder or atomized alloy powder or carbonyl iron powder or amorphous powder is pressed into a desired shape, and then sintered in a reducing atmosphere to obtain a magnetic core. Figure 6 The core shown. The core wrapped around the coil is a sintered core, which has a higher magnetic permeability than bonded magnets and can also withstand high temperatures for a long time.

[0081] In step S20, an insulating layer is formed on the surface of the magnetic core. Specifically, it includes using silicone resin to repeatedly roll-spray and dry on the surface of the magnetic core to form a nano-silicon dioxide coating of a certain thickness (more than 5μm). An insulating layer is formed on the surface of the magnetic core to prevent a short circuit between the coil and the magnetic core and ensure the safe operation of the circuit. The insulating layer can provide effective electrical isolation, prevent short circuits, and ensure the safety and reliability of the inductor in high voltage and high frequency applications. The insulating layer can prevent the intrusion of moisture, dust and corrosive gases, and improve the environmental adaptability and service life of the inductor. The insulating layer can enhance the overall mechanical strength of the magnetic core and improve the durability of the inductor.

[0082] In step S30, one end of the coil is arranged on a side of the first terminal away from the body, the middle part of the coil is arranged around the body, and the other end of the coil is located on a side of the second terminal away from the body. The coil is wound in a specific manner to ensure that the layout and connection of the coil are correct. The correct coil layout can optimize the inductance value and improve the electrical performance of the inductor. Uniform coil winding can reduce the parasitic capacitance and inductance between the coils and improve the high-frequency performance of the inductor. The two ends of the coil are respectively arranged on the side of the first terminal and the second terminal away from the body to ensure that the position of the lead-out electrode is accurate, facilitate subsequent welding or plugging, and reduce the risk of poor contact.

[0083] In some embodiments, one end of the coil is disposed on a side of the first end away from the body, the middle of the coil is disposed around the body, and the other end of the coil is disposed on a side of the second end away from the body, comprising:

[0084] The 3D printing process is used to print silver electrodes on the surface of the magnetic core to form coils and lead electrodes.

[0085] In the application, the 3D printing process is used to print the surface of the sintered core as shown in Figure 4 and Figure 5 The structure in the circuit is printed out, and silver electrodes are formed into lead electrodes and coils. In this way, the coil layout can optimize the inductance value and improve the electrical performance of the inductor. Uniform coil winding can reduce the parasitic capacitance and inductance between coils and improve the high-frequency performance of the inductor. The two ends of the coil are respectively arranged on the side of the first end and the second end away from the body to ensure the accurate position of the lead electrode, facilitate subsequent welding or plugging, and reduce the risk of poor contact.

[0086] In step S40, a shielding layer is formed on the coil and the insulating layer, and the coil located at the first end and the second end away from the body is leaked relative to the shielding layer to form a lead-out electrode. In this way, a shielding layer is formed to reduce external electromagnetic interference while ensuring reliable connection of the lead-out electrode. Enhanced electromagnetic shielding effect: The shielding layer can effectively reduce the impact of external electromagnetic interference on the inductor, while preventing the magnetic field generated by the inductor itself from interfering with other electronic components, thereby improving the electromagnetic compatibility (EMC) of the inductor. The shielding layer can further enhance the overall mechanical strength of the inductor, and improve its durability and reliability. The shielding layer can play a certain role in heat insulation, help evenly distribute the heat generated inside, reduce local overheating, and improve the thermal stability of the inductor. The shielding layer partially covers the coil, exposing the lead-out electrode, ensuring reliable connection between the lead-out electrode and the external circuit, and reducing the risk of poor contact or short circuit.

[0087] In some embodiments, before step S40 and after step S30, a protective layer is formed on the coil and the insulating layer, and the protective layer partially covers the coil, so that the lead-out electrode is exposed relative to the protective layer, thereby further strengthening the protection of the magnetic core and the coil, improving the mechanical properties, improving the anti-corrosion performance, etc.

[0088] In application, S40 specifically includes:

[0089] S41, providing magnetic powder and organic silicon resin, mixing and stirring to prepare casting slurry;

[0090] S42, passing the coil-wound magnetic core through a tape casting slurry waterfall for multiple times to form a shielding layer;

[0091] S43, peeling off the shielding layer located on the side of the first end and the second end away from the body to expose part of the coil, thereby forming a lead-out electrode.

[0092] In step S41, the magnetic powder includes at least one of reduced iron powder, amorphous powder, carbonyl iron powder, iron silicon chromium powder, and iron silicon chromium alloy powder. Reduced iron powder has a high saturation magnetic induction intensity and is suitable for occasions requiring high magnetic flux density. Reduced iron powder has good magnetic conductivity and can effectively improve the magnetic permeability of the magnetic core. Compared with other magnetic powders, reduced iron powder has a lower cost and is suitable for large-scale production. Amorphous powder has a very high initial magnetic permeability and is suitable for occasions requiring high magnetic permeability. Amorphous powder has low magnetic loss at high frequencies and is suitable for high-frequency applications. The magnetic properties of amorphous powder remain stable over a wide temperature range. Carbonyl iron powder has high purity, few impurities, and excellent magnetic properties. Carbonyl iron powder has fine particles and can be made into dense magnetic cores to improve magnetic permeability. Carbonyl iron powder is easy to shape and is suitable for complex magnetic core structures. Iron silicon chromium powder has a high saturation magnetic induction intensity and is suitable for occasions requiring high magnetic flux density. The magnetic properties of iron silicon chromium powder remain stable over a wide temperature range. Iron silicon chromium powder has low magnetic loss at high frequencies and is suitable for high-frequency applications. Iron-silicon-chromium alloy powder has a high initial magnetic permeability and is suitable for applications that require high magnetic permeability. The magnetic properties of iron-silicon-chromium alloy powder remain stable over a wide temperature range. Iron-silicon-chromium alloy powder has low magnetic loss at high frequencies and is suitable for high-frequency applications.

[0093] In step S42, the lead electrode of the inductor is placed and fixed on the base with the lead electrode facing downward, and the base is driven by the guide rail to repeatedly pass through the cast slurry waterfall and then dried. In step S43, the inductor is turned over and the silicone film on the lead end surface is peeled off using a laser peeling machine to expose the silver electrode (i.e., the lead electrode).

[0094] In the application, a layer of nickel is plated on the surface of the silver electrode by electroplating, and then a layer of tin is plated on it to form a lead electrode. In this way, the performance and reliability of the inductor can be significantly improved.

[0095] Example

[0096] Example 1

[0097] The present invention provides an inductor and a method for manufacturing the same, wherein the method for manufacturing the inductor comprises the following steps:

[0098] S10, preparing a magnetic core;

[0099] Specifically, the process includes: adding 2.0% polyethylene glycol by weight to the reduced iron powder whose surface is coated with silicon dioxide, pressing the reduced iron powder under a pressure of 2000 MPa, and then sintering the reduced iron powder under nitrogen protection. The sintering temperature curve is from room temperature for 3 hours to 900°C and then naturally cooling down for 1-2 hours. The length ratio of a:b:c is 14:10:7.

[0100] S20, forming an insulating layer on the surface of the magnetic core;

[0101] Specifically, it includes: using silicone resin to repeatedly roll spray and dry on the surface of the magnetic core to form a nano silicon dioxide coating (i.e., an insulating layer) of a certain thickness on the surface;

[0102] S30, placing one end of the coil on a side of the first end away from the body, placing the middle of the coil around the body, and placing the other end of the coil on a side of the second end away from the body;

[0103] Specifically include: using 3D printing technology to form a sintered magnetic core surface as shown in Figure 5 or Figure 6 The silver electrode is printed in the shape shown, and then repeatedly rolled and sprayed on the surface of the magnetic core to form a nano-silicon dioxide coating (i.e., a protective layer) of a certain thickness on the surface;

[0104] S40, forming a shielding layer on the coil and the insulating layer, and making the coil located at the first end and the second end away from the body leak out relative to the shielding layer to form a lead-out electrode.

[0105] Specifically include:

[0106] S41, using a manganese-zinc ferrite core with a magnetic permeability of 2500, crushing it into powder using a Raymond mill by dry grinding process, screening D50 = 6μm, mixing and stirring with 20% silicone resin by weight of the powder to prepare a casting slurry, filtering through a 500-mesh sieve to remove coarse particles for standby use;

[0107] S42, placing the lead electrode of the inductor downward on the base and fixing it, and driving the base through the casting slurry waterfall repeatedly under the guidance of the guide rail, and then drying it;

[0108] S43. Turn the inductor over, and use a laser stripping machine to peel off the silicone resin film on the surface of the lead end to expose the silver electrode; use an electroplating method to plate a layer of nickel on the surface of the silver electrode, and then plate a layer of tin to form a lead electrode.

[0109] Finally, a low-cost inductor with reduced iron powder ferrite shielding was obtained.

[0110] Example 2

[0111] The present invention provides an inductor and a method for manufacturing the same, wherein the method for manufacturing the inductor comprises the following steps:

[0112] S10, preparing a magnetic core;

[0113] Specifically, the method comprises: mixing amorphous powder with a surface coating of silica having a D50 of 10 to 13 μm, carbonyl iron powder with a D50 of 7 to 9 μm, and carbonyl iron powder with a D50 of 2 to 4 μm in a ratio of 2:4:4, adding polyethylene glycol in an amount of 2.0% by weight of the total powder, pressing and molding at a pressure of 600 to 900 MPa, and then sintering in a nitrogen-protected reducing atmosphere, wherein the sintering temperature curve is from room temperature for 3 hours to 900°C and then naturally cooled down for 2 hours, wherein the length ratio of a:b:c is 14:10:7.

[0114] S20, forming an insulating layer on the surface of the magnetic core;

[0115] Specifically, it includes: using silicone resin to repeatedly roll spray and dry on the surface of the magnetic core to form a nano silicon dioxide coating (i.e., an insulating layer) of a certain thickness on the surface;

[0116] S30, placing one end of the coil on a side of the first end away from the body, placing the middle of the coil around the body, and placing the other end of the coil on a side of the second end away from the body;

[0117] Specifically include: using 3D printing technology to form a sintered magnetic core surface as shown in Figure 5 or Figure 6 The silver electrode is printed in the shape shown, and then repeatedly rolled and sprayed on the surface of the magnetic core to form a nano-silicon dioxide coating (i.e., a protective layer) of a certain thickness on the surface;

[0118] S40, forming a shielding layer on the coil and the insulating layer, and making the coil located at the first end and the second end away from the body leak out relative to the shielding layer to form a lead-out electrode.

[0119] Specifically include:

[0120] S41, mixing iron-silicon-chromium powder with a D50 of 4-6 μm and 20% of the powder mass of silicone resin to prepare a casting slurry, filtering through a 500-mesh sieve to remove coarse particles for later use;

[0121] S42, placing the lead electrode of the inductor downward on the base and fixing it, and driving the base through the casting slurry waterfall repeatedly under the guidance of the guide rail, and then drying it;

[0122] S43. Turn the inductor over, and use a laser stripping machine to peel off the silicone resin film on the surface of the lead end to expose the silver electrode; use an electroplating method to plate a layer of nickel on the surface of the silver electrode, and then plate a layer of tin to form a lead electrode.

[0123] Finally, a highly saturated inductor is obtained.

[0124] Example 3

[0125] The present invention provides an inductor and a method for manufacturing the same, wherein the method for manufacturing the inductor comprises the following steps:

[0126] S10, preparing a magnetic core;

[0127] Specifically, the method comprises: mixing amorphous powder with a surface coating of silicon dioxide and having a D50 of 7 to 10 μm and iron-silicon-chromium powder with a D50 of 2 to 4 μm in a ratio of 5:5, adding polyethylene glycol at a total powder weight of 2.0%, pressing and molding at a pressure of 900 MPa, and then sintering in a nitrogen-protected reducing atmosphere, wherein the sintering temperature curve is from room temperature for 3 hours to 900°C and then naturally cooled for 2 hours, wherein the length ratio of a:b:c is 14:10:7.

[0128] S20, forming an insulating layer on the surface of the magnetic core;

[0129] Specifically, it includes: using silicone resin to repeatedly roll spray and dry on the surface of the magnetic core to form a nano silicon dioxide coating (i.e., an insulating layer) of a certain thickness on the surface;

[0130] S30, placing one end of the coil on a side of the first end away from the body, placing the middle of the coil around the body, and placing the other end of the coil on a side of the second end away from the body;

[0131] Specifically include: using 3D printing technology to form a sintered magnetic core surface as shown in Figure 5 or Figure 6 The silver electrode is printed in the shape shown, and then repeatedly rolled and sprayed on the surface of the magnetic core to form a nano-silicon dioxide coating (i.e., a protective layer) of a certain thickness on the surface;

[0132] S40, forming a shielding layer on the coil and the insulating layer, and making the coil located at the first end and the second end away from the body leak out relative to the shielding layer to form a lead-out electrode.

[0133] Specifically include:

[0134] S41, mixing iron-silicon-chromium powder with a D50 of 4-6 μm and 20% of the powder mass of silicone resin to prepare a casting slurry, filtering through a 500-mesh sieve to remove coarse particles for later use;

[0135] S42, placing the lead electrode of the inductor downward on the base and fixing it, and driving the base through the casting slurry waterfall repeatedly under the guidance of the guide rail, and then drying it;

[0136] S43. Turn the inductor over, and use a laser stripping machine to peel off the silicone resin film on the surface of the lead end to expose the silver electrode; use an electroplating method to plate a layer of nickel on the surface of the silver electrode, and then plate a layer of tin to form a lead electrode.

[0137] Finally, a low power consumption inductor is obtained.

[0138] Example 4

[0139] The present invention provides an inductor and a method for manufacturing the same, wherein the method for manufacturing the inductor comprises the following steps:

[0140] S10, preparing a magnetic core;

[0141] Specifically, the method comprises: mixing D50=20-26μm iron-silicon-chromium alloy powder whose surface is coated with silicon dioxide, D50=7-9μm carbonyl iron powder, and D50=2-4μm carbonyl iron powder in a ratio of 4:4:2, adding 2.0% polyethylene glycol of the total powder mass, pressing and molding at a pressure of 600-900MPa, and then sintering in a nitrogen-protected reducing atmosphere, wherein the sintering temperature curve is from room temperature for 3 hours to 900°C and then naturally cooling down for 3 hours, wherein the length ratio of a:b:c is 14:10:7.

[0142] S20, forming an insulating layer on the surface of the magnetic core;

[0143] Specifically, it includes: using silicone resin to repeatedly roll spray and dry on the surface of the magnetic core to form a nano silicon dioxide coating (i.e., an insulating layer) of a certain thickness on the surface;

[0144] S30, placing one end of the coil on a side of the first end away from the body, placing the middle of the coil around the body, and placing the other end of the coil on a side of the second end away from the body;

[0145] Specifically include: using 3D printing technology to form a sintered magnetic core surface as shown in Figure 5 or Figure 6 The silver electrode is printed in the shape shown, and then repeatedly rolled and sprayed on the surface of the magnetic core to form a nano-silicon dioxide coating (i.e., a protective layer) of a certain thickness on the surface;

[0146] S40, forming a shielding layer on the coil and the insulating layer, and making the coil located at the first end and the second end away from the body leak out relative to the shielding layer to form a lead-out electrode.

[0147] Specifically include:

[0148] S41, mixing and stirring the flaky sendust powder with D50=15-20 μm and 20% silicone resin by weight of the powder to prepare a casting slurry, filtering through a 500-mesh sieve to remove coarse particles for later use;

[0149] S42, placing the lead electrode of the inductor downward on the base and fixing it, and driving the base through the casting slurry waterfall repeatedly under the guidance of the guide rail, and then drying it;

[0150] S43. Turn the inductor over, and use a laser stripping machine to peel off the silicone resin film on the surface of the lead end to expose the silver electrode; use an electroplating method to plate a layer of nickel on the surface of the silver electrode, and then plate a layer of tin to form a lead electrode.

[0151] Finally, a high-inductance inductor is obtained.

[0152] Example 5

[0153] The present invention provides an inductor and a method for manufacturing the same, wherein the method for manufacturing the inductor comprises the following steps:

[0154] S10, preparing a magnetic core;

[0155] Specifically, the method comprises: mixing D50=20-26μm iron-silicon-chromium alloy powder whose surface is treated with silicon dioxide coating, D50=7-9μm carbonyl iron powder, and D50=2-4μm carbonyl iron powder in a ratio of 4:4:2, adding 2.0% polyethylene glycol of the total powder mass, pressing and molding under a pressure of 900MPa, and then sintering in a nitrogen-protected reducing atmosphere, wherein the sintering temperature curve is from room temperature for 3 hours to 900°C and then naturally cooling down for 2 hours, wherein the length ratio of a:b:c is 7:2:7.

[0156] S20, forming an insulating layer on the surface of the magnetic core;

[0157] Specifically, it includes: using silicone resin to repeatedly roll spray and dry on the surface of the magnetic core to form a nano silicon dioxide coating (i.e., an insulating layer) of a certain thickness on the surface;

[0158] S30, placing one end of the coil on a side of the first end away from the body, placing the middle of the coil around the body, and placing the other end of the coil on a side of the second end away from the body;

[0159] Specifically include: using 3D printing technology to form a sintered magnetic core surface as shown in Figure 5 or Figure 6 The silver electrode is printed in the shape shown, and then repeatedly rolled and sprayed on the surface of the magnetic core to form a nano-silicon dioxide coating (i.e., a protective layer) of a certain thickness on the surface;

[0160] S40, forming a shielding layer on the coil and the insulating layer, and making the coil located at the first end and the second end away from the body leak out relative to the shielding layer to form a lead-out electrode.

[0161] Specifically include:

[0162] S41, mixing and stirring the flaky sendust powder with D50=15-20 μm and 20% silicone resin by weight of the powder to prepare a casting slurry, filtering through a 500-mesh sieve to remove coarse particles for later use;

[0163] S42, placing the lead electrode of the inductor downward on the base and fixing it, and driving the base through the casting slurry waterfall repeatedly under the guidance of the guide rail, and then drying it;

[0164] S43. Turn the inductor over, and use a laser stripping machine to peel off the silicone resin film on the surface of the lead end to expose the silver electrode; use an electroplating method to plate a layer of nickel on the surface of the silver electrode, and then plate a layer of tin to form a lead electrode.

[0165] Finally, a thin inductor is obtained.

[0166] Performance Comparison

[0167] The flat wire integrated inductor and copper-iron co-fired inductor on the market are compared with the inductor provided in the embodiment of the present application. The specific parameters are shown in the following table:

[0168]

[0169] As shown in the table above, the inductor provided by the embodiment of the present application has a much larger range of inductance than the inductance range of the flat wire one-piece molded inductor and the copper-iron co-fired inductor on the market, and the short-circuit rate is zero. After 12 hours at 180°C and 20A current, a large amount of black oil stains appeared around the flat wire one-piece molded inductor, and the strength decreased, while the inductor provided by the embodiment of the present application did not change, which reflects the inductor and its preparation method provided by the embodiment of the present application. During the forming process of the inductor, there is no great pressure and friction between the coil and the lead-out electrode and the magnetic core, and there is no welding point on the lead-out electrode, which avoids the hidden dangers of short circuit and open circuit; the magnetic core wrapped by the coil is a sintered magnetic core, which has a higher magnetic permeability than the bonded magnet, and can also withstand high temperature for a long time. The shielding layer uses silicone resin, which is more resistant to high temperature than epoxy resin; the coil adopts a multi-turn design, which can cover a wide range of inductance.

[0170] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0171] The above-described embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application are described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the embodiments of the present application, and should all be included in the protection scope of the embodiments of the present application.

Claims

1. An inductor, characterized in that: include: A magnetic core, comprising a body, a first end and a second end, wherein the first end and the second end are respectively located at two ends of the body along a first direction, and the first end and the second end protrude relative to the body in a second direction; an insulating layer, covering the magnetic core; a coil, one end of which is disposed on a side of the first end away from the body, a middle portion of the coil being wound around the body, and the other end of the coil being disposed on a side of the second end away from the body; and The shielding layer completely covers the body, and the shielding layer partially covers the coil, so that the parts of the coil located at the first end and the second end away from the body leak out and form lead-out electrodes.

2. The inductor according to claim 1, characterized in that The insulating layer completely covers the body, the first terminal and the second terminal, and the thickness of the insulating layer is greater than or equal to 5 microns; And / or, the thickness of the shielding layer is greater than or equal to 50 microns.

3. The inductor according to claim 1, characterized in that A protective layer is further provided between the shielding layer and the insulating layer. The protective layer completely covers the body and partially covers the coil, so that the lead-out electrode is exposed.

4. The inductor according to claim 3, characterized in that The thickness of the protective layer is 20 μm to 60 μm; And / or, the protective layer and the insulating layer include any one of ceramic material, epoxy resin, polyurethane, and silicone resin.

5. The inductor according to claim 1, wherein: The length of the magnetic core is a, the height is b, the height of the first end and the second end is e, and the length of the first end and the second end is f; Among them, e=(0.1~0.3)×b; f=(0.2~0.25)×a.

6. A method for preparing an inductor, characterized in that: Used to prepare the inductor according to any one of claims 1 to 5, the preparation method comprises the following steps: preparing the magnetic core; forming the insulating layer on the surface of the magnetic core; One end of the coil is disposed on a side of the first end away from the body, the middle of the coil is disposed around the body, and the other end of the coil is located on a side of the second end away from the body; The shielding layer is formed on the coil and the insulating layer, and the coil located at the first end and the second end away from the body is leaked relative to the shielding layer to form the lead-out electrode.

7. The preparation method according to claim 6, characterized in that: Before forming the shielding layer on the coil and the insulating layer, the method further includes: The protection layer is formed on the coil and the insulating layer, and the protection layer partially covers the coil, so that the lead-out electrode is exposed to the outside of the protection layer.

8. The preparation method according to claim 6, characterized in that: The method of arranging one end of the coil on a side of the first end away from the body, arranging the middle of the coil around the body, and arranging the other end of the coil on a side of the second end away from the body comprises: The silver electrode is printed on the surface of the magnetic core by using a 3D printing process to form the coil and the lead-out electrode.

9. The preparation method according to claim 6, characterized in that: The shielding layer is formed on the coil and the insulating layer, and the coil located at the first end and the second end away from the body is leaked relative to the shielding layer to form the lead-out electrode, including: Providing magnetic powder and organic silicon resin for mixing and stirring to prepare casting slurry; Passing the coil-wound magnetic core through the casting slurry waterfall multiple times to form the shielding layer; The shielding layer located at the first end and the second end on the side away from the body is peeled off to expose a portion of the coil to form the lead-out electrode.

10. The preparation method according to any one of claims 6 to 9, characterized in that: The preparation material of the magnetic core includes at least one of reduced iron powder, amorphous powder, carbonyl iron powder, iron silicon chromium powder, and iron silicon chromium alloy powder; And / or, the magnetic core is prepared by a sintering process.

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