A chip-type wire-wound common-mode inductor

Abstract

The present invention discloses a chip-type winding common-mode inductor, which relates to the technical field of inductors, and includes a magnetic core, a base, a winding, and a solder block. The surface of the solder block is provided with a threading hole, and the solder block is provided with a solder cavity; a deformation element is provided on the solder block, and the deformation element is bent and deformed at high temperature, thereby generating a bending force on one end of the winding that passes through the solder cavity. In the present invention, the assembly of the winding and the solder block is simplified. When the solder block is soldered to the solder pad of an external circuit board, after the molten solder is solidified, the connection area between the molten solder and the solder block is increased, thereby improving the connection reliability between the solder block and the solder pad. In addition, the temperature of the molten solder is relatively high, so that the deformation element is bent and deformed at high temperature, so that the bent and deformed part of the deformation element squeezes the end of the winding, so that the end of the winding is bent. In this way, after the solder is solidified, the end of the winding can be connected to the solder block through the molten solder, and the tensile strength of the winding can be increased, so that the winding is not easy to fall off from the solder block.

Description

Technical Field

[0001] The invention relates to the technical field of inductors, and in particular to a chip-type winding common-mode inductor. Background Art

[0002] A common-mode inductor is a passive electronic component used to suppress common-mode interference. The coil on the inductor is wound on a magnetic core. The main function of a common-mode inductor is to suppress common-mode signals in a circuit while allowing differential-mode signals (i.e., the signals of the two coils are opposite) to pass through.

[0003] For example, a chip-type winding common-mode inductor disclosed in Chinese patent publication number CN217507041U has a structure including a base, a first support block, a winding group, a magnetic connection, a terminal joint, a second support block, an anti-impact protector, and a mounting groove. The mounting groove of the utility model is provided with an anti-impact protector used in combination, and the heat dissipation layer is integrally formed by a groove on the surface of the support frame, which has ventilation performance. A sealing layer and a resistance member whose positions remain unchanged are provided on the support frame. A triangularly supported structure is formed by a combination of side support plates and vertical support plates. The three points are vertically erected and arranged on the bottom wall of the winding group. A support plate is provided at the midpoint structure, which forms a T-shaped structure with the side support plates and the vertical support plates. The structure has stable supporting performance, reduces the installation gap, and increases the compressive performance of the accessories, effectively avoids breaking the accessories due to excessive impact, and has good supporting and protective performance.

[0004] The surface of the existing chip-type wound common-mode inductor is welded with a welding end (or welding block), and the end of the winding is welded to the welding end by soldering. When the inductor is assembled on the circuit board by a placement machine, the solder paste or solder is first heated on the welding pad of the circuit board, and then the welding end of the inductor is placed against the welding pad, and a small pressure is applied to the inductor, so that the welding pad is welded to the welding end of the inductor through the solder paste and solder. However, due to the high temperature of the solder paste or solder during welding, the solder between the welding end of the inductor and the end of the winding may be heated and melted, causing the winding to separate from the welding end, and then causing the winding to fall off. In addition, the contact area between the welding end and the solder paste or solder on the welding pad is small, resulting in a low degree of reliability in the connection between the welding end of the inductor and the welding pad of the circuit board. In the subsequent circuit board cleaning process, the welding end of the inductor may be separated from the welding pad of the circuit board under the action of large stress, so it is necessary to improve the existing chip-type wound common-mode inductor. Summary of the invention

[0005] The object of the present invention is to provide a chip-type wire-wound common-mode inductor to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A chip-type winding common-mode inductor, comprising:

[0008] A magnetic core and a base fixed to two ends of the magnetic core, wherein a winding is wound around the magnetic core;

[0009] A welding block fixedly connected to the surface of the base, wherein the surface of the welding block is provided with a threading hole for the winding end to pass freely, and a solder cavity is provided on a side of the welding block away from the base;

[0010] A deformation element is arranged on the solder block, and the deformation element generates bending deformation under high temperature, thereby generating a bending force on one end of the winding passing through the solder cavity.

[0011] Through the above technical scheme, the winding is passed through the welding block, replacing the method of welding the winding end to the welding block in the prior art, thereby simplifying the assembly of the winding and the welding block. When the welding block is welded to the welding pad of the external circuit board, as the welding block approaches the welding pad, the molten solder on the welding pad enters the solder cavity of the welding block. In this way, after the molten solder solidifies, the connection area between the molten solder and the welding block is increased, thereby improving the connection reliability between the welding block and the welding pad. In addition, the temperature of the molten solder is relatively high, so that the deformation element is bent and deformed at high temperature, so that the bent and deformed part of the deformation element squeezes the end of the winding, so that the end of the winding is bent. In this way, after the molten solder solidifies, the end of the winding can be connected to the welding block through the molten solder, and the tensile strength of the winding can be increased, so that the winding is not easy to fall off from the welding block.

[0012] Furthermore, a side of the base away from the welding block is detachably connected with an anti-impact plate.

[0013] Through the above technical solution, since the magnetic core and the bottom surface of the base are suspended, the impact resistance of the magnetic core is low. Therefore, by setting the impact-resistant plate, when the base is subjected to impact force, the impact force can be dispersed to the impact-resistant plate, thereby reducing the impact on the magnetic core.

[0014] Furthermore, the welding block is located in the center of the surface of the base.

[0015] Through the above technical solution, the base is not prone to tilt after being welded on the pad.

[0016] Furthermore, the deformation element is a memory metal sheet, which includes a first sheet body embedded in the welding block and a second sheet body extending from the end of the first sheet body to the inner side of the solder cavity, and the surface of the welding block is provided with an installation groove for interference fit installation of the first sheet body.

[0017] Through the above technical solution, when the solder block comes into contact with the molten solder on the solder pad, it is affected by the high temperature of the molten solder, and the second sheet is bent and deformed under the high temperature, so that the second sheet bends toward the end of the winding, and then the second sheet squeezes the end of the winding, making the end of the winding bent.

[0018] Furthermore, the second sheet body is in a state of extending obliquely toward the winding end at room temperature.

[0019] Through the above technical solution, the distance between the second sheet and the winding end is relatively close, so that when the second sheet contacts the molten solder, it can bend and deform in time and bend the winding end.

[0020] Furthermore, an exhaust structure is provided in the solder cavity.

[0021] Through the above technical solution, when the solder enters the solder cavity of the solder block, the air in the solder cavity can be discharged by the exhaust structure, so that the solder can enter the solder cavity more smoothly.

[0022] Furthermore, the exhaust structure includes an entry hole opened on the inner wall of the solder cavity, the entry hole is in the form of a blind hole and the hole mouth is connected to the solder cavity, a solder flow hole that passes through the entry hole and the threading hole is opened in the solder block, the hole diameter of the threading hole is larger than the wire diameter of the winding, so that there is a gap between the inner wall of the threading hole and the outer wall of the winding, and the gap is connected to the solder flow hole.

[0023] Through the above technical scheme, when the molten solder enters the solder cavity, the air in the solder cavity can be discharged from the entry hole, the solder flow hole and the gap, so that the molten solder can smoothly enter the solder cavity, and at the same time, part of the molten solder enters the solder flow hole from the entry hole, so that the molten solder can come into contact with the part of the winding located in the solder block, and the molten solder in the solder flow hole is welded to the surface of the winding. After the molten solder solidifies, the part of the winding that passes through the threading hole is also welded to the solder block, thereby improving the tensile strength of the winding.

[0024] Furthermore, the entry hole is arranged between the deformation element and the threading hole.

[0025] Through the above technical solution, when the second sheet is bent and deformed, part of the solder in the solder cavity can be squeezed to the entry hole, so that the solder can enter the solder flow hole and contact the winding surface.

[0026] Furthermore, reinforcement parts are slidably provided on both sides of the base, and two adjacent reinforcement parts are respectively located on both sides of the welding block, and a suction sleeve is fixedly connected to one end of the welding block facing the inner side of the base, and the solder cavity is connected with the middle hole of the suction sleeve, and a suction part is slidably inserted in the suction sleeve, and a floating part is fixedly connected between the reinforcement part and the suction part, and an accommodation cavity is opened on the outer wall of the base for the floating part to pass freely along the sliding direction of the reinforcement part on the base.

[0027] Through the above technical solution, when performing patch installation, the reinforcement part contacts the circuit board before the solder block. As the solder block contacts the circuit board, the solder block moves relative to the reinforcement part, so that the suction part slides in the middle hole of the suction sleeve, and the air in the solder cavity is discharged into the suction sleeve, so that the molten solder on the circuit board pad can smoothly enter the solder cavity, and at the same time avoids the phenomenon that the air in the solder cavity cannot be discharged after the solder flow holes and gaps are filled with solder. In addition, when the suction part slides in the suction sleeve, it will generate suction force on the solder, so that the molten solder enters the solder cavity in time before solidification.

[0028] Furthermore, an elastic member is provided in the placement cavity, and the elastic member exerts a pre-pressure on the floating portion in a direction toward the welding block, so that the surface of the reinforcement portion protrudes to the surface of the welding block.

[0029] Through the above technical solution, the elastic member generates elastic pre-pressure on the floating part, so that during the patch process, the reinforcement part can contact the circuit board before the soldering block.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. In the present invention, the winding is passed through the soldering block, replacing the method of welding the winding end on the soldering block in the prior art, thereby simplifying the assembly of the winding and the soldering block. When the soldering block is soldered to the soldering pad of the external circuit board, as the soldering block approaches the soldering pad, the molten solder on the soldering pad enters the solder cavity of the soldering block, so that after the molten solder solidifies, the connection area between the solder and the soldering block is increased, thereby improving the connection reliability between the soldering block and the soldering pad. In addition, the molten solder has a high temperature, so that the deformable element is bent and deformed at high temperature, so that the bent and deformed part of the deformable element squeezes the end of the winding, so that the end of the winding is bent. In this way, after the molten solder solidifies, the end of the winding can be connected to the soldering block through the molten solder, and the tensile strength of the winding can be increased, so that the winding is not easy to fall off from the soldering block;

[0032] 2. In the present invention, when the molten solder enters the solder cavity, the air in the solder cavity can be discharged through the inlet hole, the solder flow hole and the gap, so that the molten solder can smoothly enter the solder cavity. At the same time, part of the molten solder enters the solder flow hole through the inlet hole, so that the molten solder can contact the part of the winding located in the solder block, and the molten solder in the solder flow hole is welded to the surface of the winding. After the molten solder is solidified, the part of the winding that passes through the threading hole is also welded to the solder block, so that the tensile resistance of the winding is improved;

[0033] 3. In the present invention, when performing patch installation, the reinforcement part contacts the circuit board before the solder block. As the solder block contacts the circuit board, the solder block moves relative to the reinforcement part, so that the suction part slides in the middle hole of the suction sleeve, and the air in the solder cavity is discharged into the suction sleeve, so that the molten solder on the circuit board pad can smoothly enter the solder cavity, and at the same time avoids the phenomenon that the air in the solder cavity cannot be discharged after the solder flow holes and gaps are filled with molten solder. In addition, when the suction part slides in the suction sleeve, it will generate suction force on the molten solder, so that the molten solder can enter the solder cavity in time before solidification. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the overall structure of a chip-type winding common-mode inductor in the present invention;

[0035] Figure 2 for Figure 1 Schematic diagram of the positional relationship after the middle part of the structure is cut open;

[0036] Figure 3 for Figure 2 A magnified schematic diagram of the local structure at point A;

[0037] Figure 4 for Figure 1 Schematic diagram of the positional relationship of the first perspective;

[0038] Figure 5 for Figure 1 Schematic diagram of the explosion decomposition of the structure;

[0039] Figure 6 for Figure 1 Schematic diagram of the positional relationship of the second perspective;

[0040] Figure 7 for Figure 6 An enlarged schematic diagram of the local structure at point B.

[0041] In the figure, the description of each figure mark is as follows: 1. solder cavity; 2. mounting groove; 3. magnetic core; 4. winding; 5. reinforcement part; 6. second sheet; 7. welding block; 8. floating part; 9. elastic member; 10. base; 11. impact-resistant plate; 12. placement cavity; 13. suction part; 14. first sheet; 15. suction sleeve; 16. mounting hole; 17. entry hole; 18. solder flow hole. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1 - Figure 7 The present invention provides a technical solution: a chip-type winding common-mode inductor, comprising a magnetic core 3, two ends of the magnetic core 3 in the length direction are respectively fixedly connected with a base 10, the side projection area of ​​the base 10 is larger than the side projection area of ​​the magnetic core 3, and the magnetic core 3 is located in the side projection area of ​​the base 10, so that the magnetic core 3 is suspended on the bottom surface of the base 10, and the two downward sides of the two bases 10 are commonly connected with an anti-impact plate 11 by screws, and the anti-impact plate 11 can be made of resin material, the outer side of the magnetic core 3 is wound with a winding 4, and the copper cores at both ends of the winding 4 are exposed, and the top surfaces of the two bases 10 are respectively fixedly connected with a welding block 7, and the upper side (or the far side) of the welding block 7 A concave solder cavity 1 is provided on the side of the solder block 7 facing the magnetic core 3, and a threading hole is provided on the side of the solder block 7 facing the magnetic core 3. The diameter of the threading hole is slightly larger than the wire diameter of the copper core of the winding 4, so that the copper core of the winding 4 can freely pass through the threading hole and into the solder cavity 1. In addition, the cross-sectional area of ​​the solder cavity 1 is at least two-thirds of the cross-sectional area of ​​the solder block 7. In addition, the solder block 7 is arranged in the middle of the top surface of the base 10 to ensure that the base 10 and the magnetic core 3 will not be skewed during the soldering process of the solder block 7 being mounted on the circuit board, and also to ensure that the solder block 7 can accurately correspond to the pad position on the circuit board when the solder block 7 is mounted by the placement machine;

[0044] A mounting groove 2 in the form of a through hole is provided on the surface of the solder block 7, the mounting groove 2 is communicated with the solder cavity 1, and a first sheet 14 is installed in the mounting groove 2 with an interference fit, and a second sheet 6 is fixedly connected to the first sheet 14 in an integral manner at one end corresponding to the solder cavity 1, and the first sheet 14 and the second sheet 6 together constitute a memory metal sheet, and the memory metal sheet can be set as a shape memory alloy sheet made of nickel-titanium alloy. At room temperature, the second sheet 6 is inclined downward and extends relative to the first sheet 14, so that the second sheet 6 is close to the end of the winding 4 that penetrates into the solder cavity 1. When subjected to high temperature (usually the welding temperature is greater than 100°C), the second sheet 6 will bend and deform, so that the second sheet 6 bends toward the end of the winding 4, and the first sheet 14 cannot be deformed because it is engaged in the mounting groove 2;

[0045] An inlet hole 17 in the form of a blind hole is provided on an inner side wall of the solder cavity 1 facing the magnetic core 3. The orifice of the inlet hole 17 is communicated with the solder cavity 1. A solder flow hole 18 that is connected with the inlet hole 17 and the threading hole is provided in the solder block 7. The diameter of the threading hole is larger than the wire diameter of the winding 4, so that a gap is provided between the inner wall of the threading hole and the outer wall of the winding 4. The gap is communicated with the solder flow hole 18. Through the setting of the gap, the air in the solder cavity 1 can be discharged through the inlet hole 17, the solder flow hole 18 and the gap. Furthermore, the inlet hole 17 is provided between the first sheet 14 and the threading hole, and the solder is melted. When the molten solder enters the solder cavity 1, the air in the solder cavity 1 can be discharged through the inlet hole 17, the solder flow hole 18 and the gap, so that the molten solder can smoothly enter the solder cavity 1. At the same time, part of the molten solder enters the solder flow hole 18 through the inlet hole 17, so that the molten solder can contact the part of the winding 4 located in the solder block 7, and the molten solder in the solder flow hole 18 is welded to the surface of the winding 4. After the molten solder is solidified, the part of the winding 4 that penetrates the threading hole is also welded to the solder block 7, so that the tensile resistance of the winding 4 is improved;

[0046] A reinforcement part 5 is slidably penetrated on both sides of the base 10, and two adjacent reinforcement parts 5 are respectively located on both sides of the solder block 7. A suction sleeve 15 is fixedly connected to one end of the solder block 7 facing the inner side of the base 10. In addition, a mounting hole 16 for the suction sleeve 15 to pass freely is opened on the inner wall of the base 10. The solder cavity 1 is connected to the middle hole of the suction sleeve 15. The suction part 13 is slidably inserted in the suction sleeve 15. The end of the reinforcement part 5 penetrating into the base 10 is commonly fixedly connected to the floating part 8. The lower end of the suction part 13 is fixedly connected to On the surface of the floating part 8, the outer wall of the base 10 is provided with an accommodation cavity 12 for the floating part 8 to freely pass through along the sliding direction of the reinforcement part 5 on the base 10. An elastic member 9 is provided in the accommodation cavity 12. The elastic member 9 has a pre-pressure on the floating part 8 in the direction of the welding block 7, so that the surface of the reinforcement part 5 protrudes to the surface of the welding block 7. In this embodiment, the elastic member 9 can be set to a light-loaded spring. The elastic supporting force of the light-loaded spring on the floating part 8 is much smaller than the bonding force between the welding block 7 and the solder after solidification.

[0047] Working principle of the present invention:

[0048] When the chip mounter is performing chip mounting, the solder is first heated on the solder pad of the external circuit board to make the solder molten, and then the chip mounter clamps and drives the base 10 to move in the direction of the molten solder, and the reinforcement part 5 contacts the circuit board before the solder block 7, so that the reinforcement part 5 and the solder block 7 are in a relative motion state, and then the suction part 13 moves in the middle hole of the suction sleeve 15 in the direction away from the circuit board, and then the air in the solder cavity 1 enters the suction sleeve 15, thereby producing a suction effect on the molten solder on the circuit board (the molten solder has a certain height relative to the surface of the circuit board, so that when the reinforcement part 5 contacts the circuit board, the mouth of the solder cavity 1 on the solder block 7 just enters or has entered the mouth of the solder cavity 1), so that part of the molten solder can enter the solder cavity 1, and as the solder block 7 continues to move toward the circuit board, part of the molten solder in the solder cavity 1 will enter the solder flow hole 18 through the entry hole 17;

[0049] At the same time, under the influence of the high temperature of the molten solder, the second sheet 6 is bent and deformed, so that the second sheet 6 generates a bending force on the end of the winding 4, thereby making the end of the winding 4 inserted into the solder cavity 1 bent, and the molten solder in the solder cavity 1 and the end of the winding 4 simultaneously produce a welding effect, so that the winding 4 and the solder block 7 are welded together. In addition, a small amount of molten solder enters the threading hole through the entry hole 17 and the solder flow hole 18, and produces a welding effect on the outer wall of the winding 4, thereby improving the tensile resistance of the winding 4. After the molten solder cools and solidifies, the solder block 7 is welded to the circuit board, and the winding 4 is also welded to the solder block 7, thereby completing the patch installation of the inductor and the circuit board.

[0050] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A chip-type wound common-mode inductor, characterized in that: include: A magnetic core (3) and a base (10) fixedly connected to two ends of the magnetic core (3), wherein a winding (4) is wound around the magnetic core (3); A solder block (7) fixedly connected to the surface of the base (10), the surface of the solder block (7) being provided with a threading hole for the end of the winding (4) to pass freely, and a solder cavity (1) being provided on a side of the solder block (7) away from the base (10); A deformation element provided on the solder block (7), wherein the deformation element generates bending deformation at high temperature, thereby generating a bending force on one end of the winding (4) passing through the solder cavity (1); The deformable element is a memory metal sheet, the memory metal sheet comprising a first sheet (14) embedded in the solder block (7) and a second sheet (6) extending from the end of the first sheet (14) to the inside of the solder cavity (1), and a mounting groove (2) for interference fit mounting of the first sheet (14) is provided on the surface of the solder block (7); An exhaust structure is provided in the solder cavity (1); The exhaust structure comprises an inlet hole (17) formed on the inner wall of the solder cavity (1), the inlet hole (17) being in the form of a blind hole and the opening of which is in communication with the solder cavity (1), a solder flow hole (18) penetrating the inlet hole (17) and the threading hole being formed in the solder block (7), the hole diameter of the threading hole being larger than the wire diameter of the winding (4), so that a gap is formed between the inner wall of the threading hole and the outer wall of the winding (4), and the gap is in communication with the solder flow hole (18); A reinforcement part (5) is slidably provided on both sides of the base (10), and two adjacent reinforcement parts (5) are respectively located on both sides of the welding block (7); a suction sleeve (15) is fixedly connected to one end of the welding block (7) facing the inner side of the base (10); the solder cavity (1) is connected to the central hole of the suction sleeve (15); a suction part (13) is slidably inserted in the suction sleeve (15); a floating part (8) is fixedly connected between the reinforcement part (5) and the suction part (13); and an accommodation cavity (12) is provided on the outer wall of the base (10) for the floating part (8) to freely pass through along the sliding direction of the reinforcement part (5) on the base (10); An elastic member (9) is arranged in the placement cavity (12), and the elastic member (9) exerts a pre-pressure on the floating portion (8) in the direction of the welding block (7), so that the surface of the reinforcement portion (5) protrudes to the surface of the welding block (7).

2. A chip-type wire-wound common-mode inductor according to claim 1, characterized in that: A side of the base (10) away from the welding block (7) is detachably connected to an anti-impact plate (11).

3. The chip-wound common-mode inductor according to claim 1, characterized in that: The welding block (7) is located in the center of the surface of the base (10).

4. The chip-type wire-wound common-mode inductor according to claim 1, characterized in that: The second sheet (6) is in a state of extending obliquely toward the end of the winding (4) at room temperature.

5. The chip-type wire-wound common-mode inductor according to claim 1, characterized in that: The entry hole (17) is arranged between the deformation element and the threading hole.

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