Surface mount type non-shielding power inductor and preparation method thereof

Abstract

The invention discloses a patch type non-shielding power inductor and a preparation method thereof, and belongs to the technical field of inductors. A patch type non-shielding power inductor comprises a magnetic core and a coil wound on the outer wall of the magnetic core, and further comprises split type shells arranged at the two ends of the magnetic core. The positioning assembly is arranged on one side of the split type shell, and the positioning assembly is used for positioning the two ends of the coil; the protection assembly is arranged at one end of the coil in a sleeving mode, and the protection assembly is used for preventing the coil from being damaged; the non-shielding inductor is formed, has good welding resistance and heat resistance, is suitable for common welding and reflow soldering, and is low in cost; therefore, the stability of the PIN pin assembly position structure is enhanced, the situation of material cracking is avoided, the positioning block can move in the first end plate, and the installation adaptation range of the PIN pins is widened; and aiming at a small-size inductor, the guide sleeve is arranged for guiding, so that the end part of the coil is convenient to mount and connect.

Description

Technical Field

[0001] The present invention relates to the technical field of inductors, and in particular to a chip-type non-shielded power inductor and a preparation method thereof. Background Art

[0002] Chip power inductors have the characteristics of miniaturization, high quality, high energy storage and low resistance. They are suitable for surface mounting and have excellent end face strength and good solderability. In addition, chip power inductors are resistant to large currents and can be provided with braided packaging for easy automated assembly. Generally speaking, the enameled wire of unshielded inductors is exposed to the outside without magnetic shielding, that is, unshielded inductors are open magnetic circuits. Open magnetic circuits refer to the presence of obvious air gaps in the magnetic circuit. They are usually small in size and easy to stick to the surface, making them suitable for fully automated production.

[0003] When the existing inductor is in use, a PIN pin for plugging is often provided at the bottom. However, the PIN pin assembly position structure of the existing plug-in inductor at the base is weak, and during the assembly process, the material may easily break, causing the product to be scrapped; even if the assembly is successful, it may cause potential hidden dangers to the reliability of the product, which not only increases the trouble during use, but also increases the cost of use.

[0004] Moreover, the coil size of the existing small-sized, high-inductance chip power inductors is very close to the size of the finished inductor, which is prone to problems such as coil exposure and magnetic leakage, posing a hidden danger to the reliability and safety of the subsequent use of the inductor. It also greatly increases the manufacturing difficulty and cost of small-sized inductors. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the PIN pin assembly position structure of the plug-in inductor at the base is weak in the prior art, and during the assembly process, the material is prone to cracking, causing the product to be scrapped; even if the assembly is successful, it will cause potential hidden dangers to the reliability of the product, which not only increases the trouble during use, but also increases the cost of use. A chip-type non-shielded power inductor and a preparation method thereof are proposed.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A chip-type non-shielded power inductor comprises a magnetic core and a coil wound around the outer wall of the magnetic core, and further comprises: a split housing, the split housing being arranged at both ends of the magnetic core; a positioning component, the positioning component being arranged on one side of the split housing and being used to position the two ends of the coil; and a protective component, the protective component being sleeved on one end of the coil and being used to prevent the coil from being damaged.

[0008] Preferably, the split housing includes a first end plate and a second end plate, through grooves are symmetrically provided on both sides of the first end plate and the second end plate, the second end plate is fixedly connected to the top of the magnetic core, the first end plate is detachably connected to the bottom of the magnetic core by screws, and a groove for accommodating a nail nut of the screw is provided in the first end plate.

[0009] In order to better position, connect and match the ceramic piece and the magnetic core, further, the first end plate and the bottom of the magnetic core are provided with a snap-on assembly, the snap-on assembly includes a limiting cap arranged on the surface of the first end plate, and a limiting groove matching the limiting cap is opened at the bottom of the magnetic core.

[0010] Preferably, a heat dissipation groove is provided on the surface of the magnetic core at the winding position of the coil, the heat dissipation groove is arranged in a spiral shape, and the opening position of the heat dissipation groove and the winding position of the coil are arranged alternately.

[0011] Preferably, the positioning assembly comprises a positioning block, the positioning block is slidably connected to the second end plate, plug blocks are symmetrically arranged at the bottom of the positioning block, a sliding groove is provided in the second end plate, and the plug block and the sliding groove are slidably connected.

[0012] In order to make the pins at both ends of the coil located on the same side for easy installation, further, both ends of the coil pass through the positioning block and extend to the outside of the positioning block, and both ends of the coil are connected to PIN pins, and the PIN pins are connected to the bending section of the coil.

[0013] Preferably, the protection component comprises a guide sleeve sleeved on the surface of the coil, a guide wheel is arranged in the guide sleeve, an annular groove matching the coil is opened in the guide wheel, and the coil runs through two sets of guide wheels.

[0014] In order to reduce wear when the coil passes through the guide sleeve, the guide sleeve is further configured as a hollow tube with a mounting slot provided in the hollow tube. A wheel axle passes through and is connected to the guide sleeve, and both ends of the wheel axle are rotatably connected to the mounting slot.

[0015] Preferably, a telescopic assembly for removing the positioning blocks is provided between the two groups of positioning blocks, the telescopic assembly comprising an ear seat, a bidirectional internal threaded sleeve is rotatably connected to the ear seat, and a left-handed threaded rod and a right-handed threaded rod are symmetrically connected to the bidirectional internal threaded sleeve.

[0016] A method for preparing a chip-type non-shielded power inductor comprises the following steps:

[0017] Step 1: preparing a magnetic core: using spherical powder to prepare a magnetic core of a center layer; performing insulation treatment on the spherical powder, mixing the spherical powder after insulation treatment, a binder and a solvent to obtain a first slurry with suitable viscosity, injecting the first slurry into a tape casting machine for tape casting to obtain a magnetic core;

[0018] Step 2: preparing magnetic sheets: using flaky sendust powder to prepare the first end plate and the second end plate of the outer layer, insulating the flaky sendust powder, and mixing the flaky sendust powder after the insulation treatment, a binder and a solvent to obtain a second slurry with suitable viscosity;

[0019] Step 3: injecting the second slurry into a tape casting machine for tape casting, and then performing a hot pressing treatment to obtain a first end plate and a second end plate;

[0020] Step 4: Assemble the chip inductor: Wind the coil around the outside of the magnetic core to form a center layer, and stack magnetic sheets on both sides of the center layer to obtain an inductor structure;

[0021] Step 5: Perform heat pressing and laser cutting on the inductor structure to obtain a chip inductor.

[0022] Compared with the prior art, the present invention provides a chip-type non-shielded power inductor, which has the following beneficial effects:

[0023] 1. The chip-type non-shielded power inductor forms a non-shielded inductor by arranging a split first end plate and a second end plate at both ends of the magnetic core. The non-shielded inductor has good welding resistance and heat resistance, is suitable for ordinary welding and reflow soldering, and has low cost;

[0024] 2. The chip-type non-shielded power inductor has a positioning block arranged in the second end plate, and the coil end is passed through the positioning block and then bent to arrange the pin, thereby enhancing the stability of the PIN pin assembly position structure and preventing material cracking;

[0025] 3. The chip-type non-shielded power inductor is provided with an insert block and a slide groove respectively, so that the positioning block and the second end plate are slidably connected, so that the positioning block and one end of the coil can be moved to any position on the upper surface of the second end plate, thereby improving the applicable range of the chip inductor installation;

[0026] 4. A guide sleeve with a guide wheel is provided on the outer wall of one end of the coil to protect the coil and prevent the coil from being exposed and leaking magnetic flux. In addition, for small-sized inductors, a guide sleeve is provided for guidance to facilitate the installation and connection of the end of the coil.

[0027] The parts not involved in the device are the same as the prior art or can be implemented by using the prior art. The present invention forms a non-shielded inductor with good solder resistance and heat resistance, suitable for ordinary soldering and reflow soldering, and low cost; thereby enhancing the stability of the PIN pin assembly position structure, preventing material cracking, and the positioning block can move within the first end plate, thereby increasing the installation adaptation range of the PIN pin; protecting the coil to prevent the coil from being exposed and leaking magnetic flux, and, for small-sized inductors, a guide sleeve is provided for guidance to facilitate the installation and connection of the end of the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the three-dimensional structure of a chip-type non-shielded power inductor proposed by the present invention;

[0029] Figure 2 A schematic diagram of a partial cross-sectional structure of a chip-type non-shielded power inductor proposed by the present invention;

[0030] Figure 3 A chip-type non-shielded power inductor proposed by the present invention Figure 2 The enlarged structural diagram of part A in the middle;

[0031] Figure 4 A schematic diagram of a side cross-sectional structure of a chip-type non-shielded power inductor proposed by the present invention;

[0032] Figure 5 A schematic cross-sectional structure diagram of a protective component of a SMD non-shielded power inductor proposed by the present invention;

[0033] Figure 6 A schematic diagram of the three-dimensional structure of a magnetic core of a chip-type non-shielded power inductor proposed by the present invention;

[0034] Figure 7 The present invention provides a schematic diagram of the three-dimensional structure of a telescopic component of a surface-mount non-shielded power inductor.

[0035] In the figure: 1. first end plate; 2. second end plate; 3. magnetic core; 4. coil; 5. positioning block; 6. pin; 7. through slot; 8. screw; 9. limiting cap; 10. limiting slot; 11. groove; 12. insert block; 13. slide slot; 14. guide sleeve; 15. mounting notch; 16. guide wheel; 17. axle; 18. heat dissipation slot; 19. ear seat; 20. bidirectional internal threaded sleeve; 21. left-handed threaded rod; 22. right-handed threaded rod. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0037] Embodiment 1:

[0038] Reference Figure 1-Figure 7 A chip-type non-shielded power inductor includes a magnetic core 3 and a coil 4 wound on the outer wall of the magnetic core 3. A heat dissipation groove 18 is provided on the surface of the magnetic core 3 at the winding position of the coil 4. The heat dissipation groove 18 is arranged in a spiral shape, and the opening position of the heat dissipation groove 18 and the winding position of the coil 4 are arranged alternately. It also includes: a split housing, which is arranged at both ends of the magnetic core 3. The split housing includes a first end plate 1 and a second end plate 2, and both sides of the first end plate 1 and the second end plate 2 are symmetrically provided with through grooves 7.

[0039] In this embodiment, a first end plate 1 and a second end plate 2 are respectively provided to be connected to both ends of the magnetic core 3 to form a non-shielded inductor, which has good welding resistance and heat resistance, is suitable for ordinary welding and reflow soldering, and has low cost.

[0040] It should be noted that through slots 7 are symmetrically provided on both sides of the first end plate 1 and the second end plate 2, so that the inductor has good heat dissipation performance.

[0041] The second end plate 2 is fixedly connected to the top of the magnetic core 3 , and the first end plate 1 is detachably connected to the bottom of the magnetic core 3 by means of screws 8 . A groove 11 for accommodating the nail cap of the screw 8 is provided in the first end plate 1 .

[0042] In this embodiment, a detachable screw 8 is provided between the second end plate 2 and the magnetic core 3. In order to prevent the screw 8 from protruding after connection and affecting the installation of the chip inductor, a groove 11 is opened in the first end plate 1 to solve the above problem.

[0043] A clamping assembly is provided at the bottom of the first end plate 1 and the magnetic core 3 . The clamping assembly includes a limiting cap 9 provided on the surface of the first end plate 1 . A limiting groove 10 matching the limiting cap 9 is provided at the bottom of the magnetic core 3 .

[0044] In this embodiment, a limiting cap 9 is provided on the surface of the first end plate 1, and a limiting groove 10 matching the limiting cap 9 is provided at the bottom of the magnetic core 3. When the first end plate 1 and the magnetic core 3 are connected, they can be snap-fitted and fixed, and then fastened by screws 8 to ensure the stability of the detachable connection structure of the first end plate 1 and the magnetic core 3, thereby ensuring the overall structural stability of the chip inductor.

[0045] The positioning component is arranged on one side of the split housing, and the positioning component is used to position the two ends of the coil 4; the positioning component includes a positioning block 5, the positioning block 5 is slidably connected to the second end plate 2, an insert block 12 is symmetrically arranged at the bottom of the positioning block 5, a slide groove 13 is opened in the second end plate 2, and the insert block 12 and the slide groove 13 are slidably connected.

[0046] In this embodiment, a positioning assembly is arranged on the top of the second end plate 2, including a positioning block 5 and a slide groove 13 for limiting the sliding connection of the positioning block 5, and two groups of plug blocks 12 are symmetrically arranged at the bottom of the positioning block 5. The sliding connection structure of the plug blocks 12 and the slide groove 13 can enable the positioning block 5 and one end of the coil 4 to move to any position on the upper surface of the second end plate 2, thereby improving the application range of the chip inductor installation.

[0047] Both ends of the coil 4 pass through the positioning block 5 and extend to the outside of the positioning block 5 , and both ends of the coil 4 are connected to PIN pins 6 , which are connected to the bending section of the coil 4 .

[0048] In this embodiment, after one end of the coil 4 passes through the positioning block 5 and extends to the outside of the positioning block 5, a PIN pin 6 is provided at the bending part to enhance the stability of the assembly position structure of the PIN pin 6, and prevent material cracking. The positioning block 5 can move within the first end plate 1, thereby improving the installation adaptation range of the PIN pin 6.

[0049] The protective component is sleeved on one end of the coil 4 and is used to prevent the coil 4 from being damaged. The protective component includes a guide sleeve 14 sleeved on the surface of the coil 4, a guide wheel 16 is arranged in the guide sleeve 14, and an annular groove matching the coil 4 is opened in the guide wheel 16, and the coil 4 runs through two sets of guide wheels 16.

[0050] Considering that one end of the coil 4 close to the first end plate 1 needs to be bent and then extended to the positioning block 5 on the second end plate 2, the length of one end of the coil 4 exposed to the outside is increased. Therefore, in this embodiment, a guide sleeve 14 with a guide wheel 16 is provided on the outer wall of one end of the coil 4 to protect the coil 4 and prevent the coil 4 from being exposed and leaking magnetic flux. In addition, for small-sized inductors, the guide sleeve 14 is provided for guidance to facilitate the installation and connection of the end of the coil 4.

[0051] The guide sleeve 14 is configured as a hollow tube, a mounting slot 15 is defined in the hollow tube, a wheel axle 17 is connected through the guide sleeve 14 , and both ends of the wheel axle 17 are rotatably connected in the mounting slot 15 .

[0052] In this embodiment, a mounting slot 15 is symmetrically opened in the guide sleeve 14, and a wheel axle 17 rotatably connected to the mounting slot 15 and a guide wheel 16 are rotatably connected, so that when the coil 4 passes through the guide sleeve 14, the wear on the coil 4 can be reduced and the penetration of the coil 4 can be guided. After the installation is completed, this part of the coil 4 is protected.

[0053] A telescopic assembly for removing the positioning blocks 5 is arranged between the two groups of positioning blocks 5. The telescopic assembly includes an ear seat 19, in which a bidirectional internal threaded sleeve 20 is rotatably connected, and in which a left-handed threaded rod 21 and a right-handed threaded rod 22 are symmetrically connected.

[0054] In this embodiment, due to the use environment of the inductor, after a period of use, some dust will accumulate at the sliding connection position between the positioning block 5 and the second end plate 2, which will cause obstruction when cleaning. In order to facilitate the disassembly of the positioning block 5, a telescopic component is provided. When disassembling, the ear seat 19 is inserted and fixed in the second end plate 2, and the bidirectional internal threaded sleeve 20 inside the ear seat 19 is rotated. By utilizing the structural characteristics of left / right rotation in the same direction and reverse lateral movement, the left-handed threaded rod 21 and the right-handed threaded rod 22 are extended to both sides, so that the positioning block 5 can be pushed out of the slide groove 13 for easy disassembly.

[0055] It should be noted that the telescopic assembly is not installed during the operation of the inductor, so the ear seat 19 and the second end plate 2 are configured as a plug-in structure to facilitate the use of the telescopic assembly.

[0056] Embodiment 2:

[0057] Reference Figure 1-Figure 7 , which is basically the same as the first embodiment, on the basis of the first embodiment, a method for preparing a patch type non-shielded power inductor is proposed, comprising the following steps:

[0058] Step 1: Mix the spherical powder after insulation treatment, the binder and the solvent, and use a casting machine to cast the first slurry obtained after the mixture to obtain a magnetic core 3, and process the heat dissipation groove 18 on the surface of the magnetic core 3;

[0059] Step 2: After insulating the flaky sendust powder, a binder and a solvent are added to mix to obtain a second slurry, which is also tape-casted in a tape casting machine, and hot-pressed to obtain a first end plate 1 and a second end plate 2, and a slide groove 13 is processed in the first end plate 1 and the second end plate 2;

[0060] Step 3: After installing pins 6 at both ends of the coil 4, it is wound around the outside of the magnetic core 3 to form an inductor center layer;

[0061] Step 4: stack magnetic sheets on both sides of the center layer to obtain an inductor structure;

[0062] Step 5: Insert both ends of the coil 4 into the positioning block 5 respectively, and slide the positioning block 5 into the slide groove 13. At the same time, set a guide sleeve 14 on the longer end of the coil 4 for protection, and bend the pin 6 to an angle suitable for inductor installation to obtain a chip inductor.

[0063] The present invention also discloses a method for preparing a chip-type non-shielded power inductor, comprising the following steps:

[0064] Step 1: preparing the magnetic core 3: using spherical powder to prepare the magnetic core 3 of the center layer, insulating the spherical powder, mixing the spherical powder after the insulation treatment, a binder and a solvent to obtain a first slurry with a suitable viscosity, injecting the first slurry into a tape casting machine for tape casting, and obtaining the magnetic core 3;

[0065] Step 2: preparing magnetic sheets: using flaky sendust powder to prepare the first end plate 1 and the second end plate 2 of the outer layer, insulating the flaky sendust powder, and mixing the flaky sendust powder after the insulation treatment, a binder and a solvent to obtain a second slurry with suitable viscosity;

[0066] Step 3: injecting the second slurry into a tape casting machine for tape casting, and then performing a hot pressing treatment to obtain a first end plate 1 and a second end plate 2;

[0067] Step 4: Assemble the chip inductor: wind the coil 4 around the outside of the magnetic core 3 to form a central layer, and stack magnetic sheets on both sides of the central layer to obtain an inductor structure;

[0068] Step 5: Perform heat pressing and laser cutting on the inductor structure to obtain a chip inductor.

[0069] It should be noted that the spherical powder includes any one or a combination of at least two of iron silicon, iron silicon aluminum, iron silicon chromium, iron nickel or iron nickel molybdenum;

[0070] The particle size D50 of the spherical powder is preferably 2-30 μm;

[0071] The flaky Sendust powder is a Sendust soft magnetic alloy powder with high magnetic permeability, and the particle size D50 is preferably 50-70 μm.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A chip-type non-shielded power inductor, comprising a magnetic core (3) and a coil (4) wound around the outer wall of the magnetic core (3), characterized in that: Also includes: A split housing, wherein the split housing is arranged at two ends of the magnetic core (3); A positioning component, the positioning component is arranged on one side of the split housing, and the positioning component is used to position the two ends of the coil (4); A protective component is sleeved on one end of the coil (4) and is used to prevent the coil (4) from being damaged.

2. A chip-type non-shielded power inductor according to claim 1, characterized in that: The split housing comprises a first end plate (1) and a second end plate (2), both sides of the first end plate (1) and the second end plate (2) are symmetrically provided with through grooves (7), the second end plate (2) is fixedly connected to the top of the magnetic core (3), the first end plate (1) is detachably connected to the bottom of the magnetic core (3) by means of screws (8), and a groove (11) for accommodating a nail cap of the screw (8) is provided in the first end plate (1).

3. A chip-type non-shielded power inductor according to claim 2, characterized in that: The first end plate (1) and the bottom of the magnetic core (3) are provided with a snap-fit ​​assembly, the snap-fit ​​assembly comprising a limiting cap (9) arranged on the surface of the first end plate (1), and the bottom of the magnetic core (3) is provided with a limiting groove (10) matching the limiting cap (9).

4. A chip-type non-shielded power inductor according to claim 1, characterized in that: A heat dissipation groove (18) is provided on the surface of the magnetic core (3) at the winding position of the coil (4); the heat dissipation groove (18) is arranged in a spiral shape, and the opening position of the heat dissipation groove (18) and the winding position of the coil (4) are arranged in a staggered manner.

5. The chip-type non-shielded power inductor according to claim 1, characterized in that: The positioning assembly comprises a positioning block (5), the positioning block (5) is slidably connected to the second end plate (2), an insert block (12) is symmetrically arranged at the bottom of the positioning block (5), a slide groove (13) is provided in the second end plate (2), and the insert block (12) and the slide groove (13) are slidably connected.

6. A chip-type non-shielded power inductor according to claim 5, characterized in that: Both ends of the coil (4) pass through the positioning block (5) and extend to the outside of the positioning block (5), and both ends of the coil (4) are connected to PIN pins (6), and the PIN pins (6) are connected to the bent section of the coil (4).

7. The chip-type non-shielded power inductor according to claim 1, characterized in that: The protection component comprises a guide sleeve (14) sleeved on the surface of the coil (4), a guide wheel (16) is arranged in the guide sleeve (14), an annular groove matching the coil (4) is opened in the guide wheel (16), and the coil (4) runs through two sets of guide wheels (16).

8. The chip-type non-shielded power inductor according to claim 7, characterized in that: The guide sleeve (14) is configured as a hollow tube, a mounting slot (15) is provided in the hollow tube, a wheel axle (17) is connected through the guide sleeve (14), and both ends of the wheel axle (17) are rotatably connected in the mounting slot (15).

9. The chip-type non-shielded power inductor according to claim 5, characterized in that: A telescopic assembly for removing the positioning blocks (5) is arranged between the two groups of positioning blocks (5), the telescopic assembly comprising an ear seat (19), a bidirectional internal threaded sleeve (20) being rotatably connected inside the ear seat (19), and a left-handed threaded rod (21) and a right-handed threaded rod (22) being symmetrically connected inside the bidirectional internal threaded sleeve (20).

10. A method for preparing a chip-type non-shielded power inductor, applied to a chip-type non-shielded power inductor according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: preparing a magnetic core (3): using spherical powder to prepare a magnetic core (3) of a central layer; subjecting the spherical powder to insulation treatment, mixing the spherical powder after insulation treatment, a binder and a solvent to obtain a first slurry with suitable viscosity, injecting the first slurry into a tape casting machine for tape casting, and obtaining a magnetic core (3); Step 2: preparing magnetic sheets: using flaky sendust powder to prepare a first end plate (1) and a second end plate (2) of an outer layer, insulating the flaky sendust powder, and mixing the flaky sendust powder after the insulation treatment, a binder and a solvent to obtain a second slurry with a suitable viscosity; Step 3: injecting the second slurry into a tape casting machine for tape casting, and then performing a hot pressing treatment to obtain a first end plate (1) and a second end plate (2); Step 4: Assembling the chip inductor: Winding the coil (4) around the outside of the magnetic core (3) to form a central layer, and stacking magnetic sheets on both sides of the central layer to obtain an inductor structure; Step 5: Perform heat pressing and laser cutting on the inductor structure to obtain a chip inductor.

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