Common mode coupling inductor
By assembling the pre-formed magnetic core and conductor coil separately, and combining it with the thermo-press packaging of the lead frame, the problem of poor soldering and missing soldering in common mode inductors is solved, improving the reliability and production efficiency of inductors and meeting the high-performance requirements of modern electronic equipment.
Patent Information
- Application Number
- CN202520080792.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-14
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2035-01-14
AI Technical Summary
Existing common-mode inductors are prone to poor soldering and missing solder joints during assembly, which increases contact resistance, affects reliability and coupling, and is prone to noise in high-frequency and high-current environments, making it difficult to meet the stringent requirements of modern electronic equipment.
The magnetic core and conductor coil are assembled separately and pre-formed, and then thermo-pressed together with a lead frame. The ends of the conductor coil are welded to the lead frame, and the electrode leads are formed by bending the lead frame, thus eliminating the need for paint stripping and electroplating.
It improves the reliability and stability of common-mode coupled inductors, enhances welding strength, increases production efficiency and yield, and meets the high-performance requirements of modern electronic equipment.
Smart Images
Figure CN223757374U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of power magnetic components, especially a kind of power inductive device of hot-pressing integrated, belong to basic electronic component technical field. BACKGROUND
[0002] Inductor is the most common component in electronic equipment, and is also one of the important components of circuit, which is widely used in various finished products, mainly playing the functions of filtering, energy storage, matching, resonance, etc. One of the common mode choke inductors is widely used in various filter circuits. The assembly structure and processing process of the existing common mode inductor reflect obvious defects: the spot welding processing of the coil inside the device is prone to false welding and missed welding, which increases the possibility of contact resistance, not only reduces the reliability of the common mode inductor, but also increases the overall DC resistance of the device and affects the energy efficiency. In addition, the tolerance of product assembly may affect the coupling of common mode inductor, so that the product cannot achieve the preset filtering effect; when the product is connected to a large current and in a high frequency environment, the internal components are prone to shaking, which generates serious noise.
[0003] With the rapid development of electronic industry and its products. Such as various server applications, AI artificial intelligence related equipment, cloud servers, internet gateways and terminal machines, etc. Under the premise of product size reduction, parameter performance requirement and precision improvement, the requirements for power inductors used therein are also increasingly stringent. SUMMARY
[0004] The utility model aims at providing a common mode coupling inductor, which is committed to improving the reliability of inductor, especially the stability of common mode coupling.
[0005] The technical solution for achieving the above-mentioned purpose of the utility model is: a common mode coupling inductor is composed of a plurality of split preformed magnetic core bodies and conductor coils, including a first magnetic core body with a groove, a second magnetic core body in the form of a columnar body, and a third magnetic core body in the form of a sheet. The conductor coil is provided with a hollow spiral winding section, and the winding section is compatible with the groove. The second magnetic core body is inserted into the cavity of the winding section. The third magnetic core body covers the open end of the groove of the first magnetic core body and covers the second magnetic core body and the conductor coil except the end part. The obtained assembly is hot-pressed and packaged into an integrated body in a forming mold. The conductor coil is a double-wire coupled metal coil, and the conductor coil is integrally assembled on the lead frame through the end part.
[0006] Further, the lead frame is a rectangular copper sheet frame, and a plurality of terminal posts are arranged in the copper sheet frame, two of which are arranged in a group and separated from each other, four end portions of the double-wire parallel-wound conductor coil are horizontally, vertically or obliquely bent and welded to one group of the terminal posts, and the terminal posts are separated from the copper sheet frame in the inductor packaging finished product state and are bent to wrap the magnetic core body to form exposed electrode pins.
[0007] Further, the conductor coil is a coupling coil formed by parallel winding of two metal wires covered with an insulation layer, and the shape of the conductor coil includes a laminated winding type based on flat wire metal wires and an inner-outer double-layer wrapping winding type based on round wire metal wires, and the end portion is led out from the same height position of one end of the winding section.
[0008] Further, the first magnetic core body, the second magnetic core body and the third magnetic core body are cold-pressed bodies formed based on a shape customized mold from a ferrous soft magnetic powder material.
[0009] Further, the second magnetic core body and the third magnetic core body are integrally formed into a T-shaped magnetic core body, the winding section of the conductor coil is sleeved on the columnar portion of the T-shaped magnetic core body, the first magnetic core body is reversely connected to the outer portion of the initial combination of the T-shaped magnetic core body and the conductor coil, and the terminal post connected to the conductor coil end portion of the lead frame is clamped to the joint surface by the two magnetic core bodies.
[0010] Further, the surface of the hot-pressing packaged integrated semi-finished product is coated with an insulating paint, and the surface of the terminal post separated from the lead frame is fully exposed.
[0011] Compared with the prior art, the application of the common-mode coupled inductor has the following advantages: the lead frame is introduced in the inductor manufacturing, and the end portion of the conductor coil is welded to the lead frame before product combination and packaging, so that the firmness of the solder joint during the hot-pressing packaging process is protected, and the electrode pins are directly formed by bending the lead frame part, which saves the paint stripping and electroplating links, and is beneficial to improving the production efficiency and the yield of finished products. At the same time, this is also beneficial to improving the operation environment of the circuit and promoting the development of hardware performance in current multiple application scenarios. BRIEF DESCRIPTION OF DRAWINGS
[0012] Figure 1 is a perspective structure schematic diagram of a preferred embodiment finished product of the common-mode coupled inductor of the application.
[0013] Figure 2 is Figure 1 is an exploded structure schematic diagram of the preferred embodiment.
[0014] Figure 3 is Figure 1 is a packaging structure schematic diagram of the semi-finished product of the preferred embodiment.
[0015] Figure 4 is the explosion structure schematic diagram of the common mode coupled inductor preferred embodiment of the utility model.
[0016] Figure 5 is Figure 4 the packaging structure schematic diagram of the semi-finished product of the preferred embodiment shown.
[0017] Figure 6 is the connected structure schematic diagram of the metal coil and the wire frame of the first kind of flat wire double wire common winding in the utility model.
[0018] Figure 7 is the connected structure schematic diagram of the metal coil and the wire frame of the second kind of round wire double wire common winding in the utility model.
[0019] Figure 8 is the connected structure schematic diagram of the metal coil and the wire frame of the third kind of round wire double wire common winding in the utility model.
[0020] Figure 9 is the connected structure schematic diagram of the metal coil and the wire frame of the fourth kind of round wire double wire common winding in the utility model.
[0021] Figure 10 is the connected structure schematic diagram of the metal coil and the wire frame of the fifth kind of round wire double wire common winding in the utility model. Specific implementation
[0022] In order to make the personnel in the technical field better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.
[0023] The utility model designs and proposes a kind of common mode coupled inductor, it is assembled to be formed by several split pre-pressing magnetic core body and conductor coil, and the design appearance of each magnetic core body and the shape size of conductor coil are mutually matched, and its assembly semi-finished product is tightly combined into a whole after heating and pressurizing forming.
[0024] As Figures 1 to 3As shown, the structure schematic diagram of the finished product, explosion and semi-finished product packaging of a preferred embodiment of the common mode coupled inductor of the utility model is shown. As shown, the inductor comprises a one-piece packaged magnetic core body 1, a conductor coil 2 and an electrode pad 3, wherein the conductor coil is packaged in the magnetic core body and connected to the circuit by the electrode pad and controlled to conduct. From the split structure, the above-mentioned magnetic core body mainly comprises a first magnetic core body 11 with a groove, a second magnetic core body 41 in the form of a columnar body and a third magnetic core body 51 in the form of a sheet body. The conductor coil 2 is provided with a hollow spiral winding segment 21, and the winding segment 21 is compatible with the groove. The second magnetic core body 41 penetrates the cavity of the winding segment 21. Here, the outer diameter of the winding segment 21 matches the inner diameter of the groove of the first magnetic core body (the actual size is the span between the inner walls), and the inner diameter of the winding segment matches the outer diameter and shape of the columnar body of the second magnetic core body. Therefore, the winding segment can be reliably attached between the inner wall of the groove and the columnar body, avoiding noise problems caused by excessive gaps. The third magnetic core body 51 covers the open groove of the first magnetic core body and covers the second magnetic core body and the conductor coil except the end part. That is, the third magnetic core body covers the first stage combination body 121 of the first magnetic core body, the second magnetic core body and the non-exposed part of the conductor coil. The assembly obtained after covering is hot-pressed and packaged into one piece in a forming mold.
[0025] In particular, the conductor coil can be selected from gold, silver, copper, nickel, aluminum and other round wires or flat wires coated with an insulating layer, and is formed into a coupling coil by double-strand twisting. The shape of the conductor coil includes a laminated winding type based on flat wire metal wires and an inner and outer double-layer wrapping winding type based on round wire metal wires. The end part is led out from the same height position of one end of the winding segment. Figures 6 to 10 As shown, before actual product assembly, a plurality of conductor coils are integrally assembled on the lead frame through the respective end parts; and after the welding operation is completed and solidified, the conductor coils are separated from the lead frame. The conductor coils used for assembly are integrally connected with flat strip-shaped metal sheets at each end. Of course, in the case that the hot-pressing forming mold has multiple cavities, batch molding can be performed with the lead frame entering the mold. That is, the terminal post in the inductor packaging finished product state is separated from the copper sheet frame, and is bent and wrapped around the magnetic core body to form the exposed electrode pin.
[0026] More specifically, the lead frame is a rectangular copper sheet frame, and the copper sheet frame is provided with a plurality of terminal posts which are opposite to each other in pairs and are separated from each other. From one group of terminal posts, two terminal posts parallel to each other extend from one long side of the copper sheet frame to the other long side. At the same time, two terminal posts parallel to each other also extend from the corresponding position of the other long side to one long side, and the four terminal posts formed do not contact each other. Here, the terminal post serves as an extended conductor connected to the end of the conductor coil and is bent as an electrode pin after product packaging.
[0027] From the basic process of the inductor, when two enameled metal wires are wound together by winding tool, the end of each conductor coil is then bent and spot welded with the terminal post of the pre-made lead frame. When the terminal post is separated from the copper sheet frame by metal stamping process or cutting tool, one end of each conductor coil has four coplanar and outwardly extending metal sheets. The conductor coil is then combined with various pre-formed magnetic core bodies, which are completely enclosed in the magnetic core body except for part of the metal sheet, and then the complete assembly is transferred to a hot press forming mold. The temperature is between 150-200°C and the pressure is between 5-15 tons / cm². The molding time is usually between 60-120 seconds, which can be adjusted according to the actual situation. After the product is demolded, it is baked at a temperature of 100-180°C for a period of time to completely cure and set. Then the surface of the inductor semi-finished product is fully coated with a spray paint to form an insulating paint. It should be noted that during the process of spraying insulating paint, the above-mentioned terminal posts are protected, and after the insulating paint is completely cured, the protective measures on the terminal posts are removed, so that the exposed copper surface is attached to the outer wall of the enameled magnetic core body and is bent towards the same side of the magnetic core body to form the required electrode pin.
[0028] As shown in a preferred embodiment of Figure 4 and Figure 5 , the main difference from the previous preferred embodiment is the pre-set shape of the magnetic core body and the slightly different assembly structure. Specifically, the second magnetic core body and the third magnetic core body are integrally formed into a T-shaped magnetic core body with a base plate 61 and a central vertical column 62. The winding section 21 of the conductor coil is sleeved on the column portion of the T-shaped magnetic core body, and the first magnetic core body 11 is inversely connected to the outer combination of the T-shaped magnetic core body and the conductor coil. The terminal posts connected to the end of the lead frame and the conductor coil are clamped on the joint surface by the two magnetic core bodies. Compared with the previous basic process description, the wrapping of the base plate 61 can be completed by bending the terminal posts first, and then the post-processing such as hot pressing, drying, spraying (electrode protection or paint stripping after drying) can be performed.
[0029] As shown in Figure 6 , the conductor coil is an example of a flat wire metal wire stacked and wound. The two-way extending end is parallel to the terminal post of the lead frame and has a similar width, so spot welding is convenient and more secure. The illustrated embodiment is a matched connection of four conductor coils and one lead frame. The rightmost conductor coil is connected to the upper two terminal posts as a pair of extension conductors A11, A12, and to the lower two terminal posts as another pair of extension conductors B11, B12.
[0030] The conductor coil is wrapped by the inner and outer double layers of round wire-shaped metal wires. The bidirectional extension of the end part is usually a thin and narrow cable, so there is a large possibility of sweat and incomplete welding when the end part is connected with the terminal post, and even the phenomenon of welding separation under slight external force. Therefore, the end part needs to be properly processed to increase the connection range with the terminal post.
[0031] As shown in the embodiment of Figure 7 , the end part is properly bent and extends flatly along the length direction of the terminal post, and the length of the spot welding is increased. The rightmost conductor coil is connected with the upper two terminal posts as a pair of extension conductors A21 and A22, and is connected with the lower two terminal posts as another pair of extension conductors B21 and B22.
[0032] As shown in the embodiment of Figure 8 , the end part is bent and extends flatly along the width direction of the terminal post, and the length of the spot welding is also increased. The rightmost conductor coil is connected with the upper two terminal posts as a pair of extension conductors A31 and A32, and is connected with the lower two terminal posts as another pair of extension conductors B31 and B32.
[0033] As shown in the embodiment of Figure 9 , one part of the end part is properly bent and extends flatly along the length direction of the terminal post, and the other part of the end part is bent and extends flatly along the width direction of the terminal post, and the length of the spot welding is increased in the combined manner. The rightmost conductor coil is connected with the upper two terminal posts as a pair of extension conductors A41 and A42, and is connected with the lower two terminal posts as another pair of extension conductors B41 and B42.
[0034] As shown in the embodiment of Figure 10 , the end part is properly bent and extends at an oblique angle along the length direction of the terminal post, and the length of the spot welding is increased, which is also beneficial to resist stress in various directions. The rightmost conductor coil is connected with the upper two terminal posts as a pair of extension conductors A51 and A52, and is connected with the lower two terminal posts as another pair of extension conductors B51 and B52.
[0035] In the above embodiments, the magnetic core bodies are all assembled parts obtained by using Fe-based soft magnetic powder material and a customized mold. The powder material used can be one or more than two kinds of mixture of Fe-based / FeSi / FeSiCr / FeSiAl / FeNi / amorphous / nanocrystalline, and 1.5% to 4.5% of one of epoxy resin, silicone resin or acrylic resin per unit weight is added, stirred uniformly and then injected into the preform mold set according to the shape of the device. The cold pressing forming process is used, and the optional forming pressure range is 6-10Tons / cm².
[0036] In summary, the detailed embodiment of the common mode coupled inductor of the utility model is described, and the advantages are verified as follows: the lead frame is introduced in the inductor manufacturing, and the end part of the conductor coil is welded with the lead frame before product combination packaging, so that the firm strength of the welding point in the product hot-press packaging process is realized, and the electrode pin is directly formed by bending the lead frame part, the paint stripping and electroplating links are saved, and the production efficiency and the finished product yield are improved.
[0037] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various changes and modifications to the present application. Any modification, equivalent replacement, improvement, etc. within the principles of the present application shall be included in the protection scope of the present application.
Claims
1. A common-mode coupled inductor, comprising a plurality of pre-formed magnetic cores and conductor coils, including a first magnetic core with a groove, a second magnetic core in the shape of a column, and a third magnetic core in the shape of a sheet. The conductor coil has a hollow helical winding segment that is accommodated in the groove. The second magnetic core passes through the cavity of the winding segment. The third magnetic core covers the groove opening of the first magnetic core and covers the second magnetic core and the conductor coil except for the ends. The resulting assembly is heat-pressed and sealed into one piece in a molding die. The inductor is characterized in that: The conductor coil is a coupled metal coil wound with two wires in parallel, and several conductor coils are integrally mounted on the lead frame at their ends.
2. The common-mode coupled inductor according to claim 1, characterized in that: The lead frame is a rectangular copper sheet frame, and there are several terminals arranged in pairs and separated from each other within the copper sheet frame. The four ends of the conductor coil wound with two wires in parallel are bent and soldered to one of the terminals in a horizontal, vertical or oblique angle shape. In the finished state of the inductor package, the terminals are separated from the copper sheet frame and bent to wrap the magnetic core to form exposed electrode leads.
3. The common-mode coupled inductor according to claim 1, characterized in that: The conductor coil is a coupled coil formed by two metal wires wrapped together with an insulating layer, and the shape of the conductor coil includes a layered winding type based on flat wire and a double-layered winding type based on round wire. The end is led out from the same height position at one end of the winding section.
4. The common-mode coupled inductor according to claim 1, characterized in that: The first magnetic core, the second magnetic core, and the third magnetic core are all cold-pressed bodies made of iron-based soft magnetic powder material based on a mold with a customized shape.
5. The common-mode coupled inductor according to claim 1, characterized in that: The second magnetic core and the third magnetic core are integrally formed into a T-shaped magnetic core. The winding section of the conductor coil is sleeved on the cylindrical part of the T-shaped magnetic core. The first magnetic core is invertedly attached to the initial assembly of the T-shaped magnetic core and the conductor coil. The terminal block connecting the lead frame and the end of the conductor coil is clamped between the two magnetic cores at the joint surface.
6. The common-mode coupled inductor according to claim 1, characterized in that: The surface of the semi-finished product, which is heat-pressed and packaged into one piece, is covered with a layer of insulating varnish, and the surface of the terminals separated from the lead frame is fully exposed.