Inductors with multiple core sections of different materials

Abstract

The present invention provides an inductor, comprising a plurality of magnetic core parts. The plurality of magnetic core parts together constitute a magnetic core of the inductor. The plurality of magnetic core parts may have different structures or may be made of different materials, so that the inductor has an inductance value-current curve that meets the requirements.

Description

Technical Field

[0001] The present invention relates to an electronic component, and more particularly to an inductor. Background Art

[0002] Inductors are widely used in a variety of electronic circuits, such as filter circuits and power conversion circuits. Specifically, in power conversion circuits, single inductors can be used to connect the switch end and the output end of the power conversion circuit, while coupled inductors can be used to couple the outputs of each phase of a multi-phase power conversion circuit. The design of electronic circuits is usually limited by the characteristics of the components available to the designer. For inductors, designers usually make compromise designs based on the characteristics of the selected components according to the component catalog provided by the supplier. These compromise designs may sacrifice some circuit performance.

[0003] Therefore, it is necessary to provide an inductor with excellent performance and adjustable characteristics according to requirements. Summary of the invention

[0004] In view of one or more technical problems in the prior art, an inductor and a manufacturing method thereof are proposed.

[0005] According to an embodiment of the present invention, an inductor is proposed, comprising: a first magnetic core portion, comprising a first magnetic material; a second magnetic core portion, comprising a second magnetic material, wherein the first magnetic core portion and the second magnetic core portion are adjacent to each other and magnetically coupled to each other; a first coil, wherein the first coil is at least partially wound around the first magnetic core portion or the second magnetic core portion; wherein compared with the second magnetic material, the inductance value of the first magnetic material decreases faster when the inductor is saturated, and the first magnetic material has a higher magnetic permeability.

[0006] According to one embodiment of the present invention, an inductor is proposed, comprising: a magnetic core, comprising a first magnetic core part and a second magnetic core part, the first magnetic core part comprising a first magnetic material, and the second magnetic core part comprising a second magnetic material; a first coil, passing through a first channel formed by the first magnetic core part and the second magnetic core part; and a second coil, passing through the second channel formed by the first magnetic core part and the second magnetic core part.

[0007] According to one embodiment of the present invention, an inductor is proposed, comprising: a first magnetic core part, comprising a first magnetic material; a second magnetic core part, comprising a second magnetic material, the second magnetic core part is adjacent to the first magnetic core part and is magnetically coupled to each other; and a first coil, at least partially wound around the first magnetic core part or the second magnetic core part.

[0008] The inductor and the manufacturing method thereof provided by the above aspects of the present invention have excellent performance and can be manufactured according to application requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to better understand the present invention, the present invention will be described in detail according to the following drawings:

[0010] Figure 1 shows a three-dimensional view of an inductor 122A according to an embodiment of the present invention;

[0011] Figure 2 shows a front view of an inductor 122A according to an embodiment of the present invention;

[0012] Figure 3 1 shows a top view of a magnetic core portion 140 - 1 of an inductor 122A according to an embodiment of the present invention;

[0013] Figure 4 1 shows a side view of the inductor 122A viewed from one side of the coil 120 - 2 according to an embodiment of the present invention;

[0014] Figure 5 shows a front view of an inductor 122B according to an embodiment of the present invention;

[0015] Figure 6 shows a three-dimensional view of an inductor 122C according to an embodiment of the present invention;

[0016] Figure 7 shows a three-dimensional view of an inductor 122D according to an embodiment of the present invention;

[0017] Figure 8 shows a three-dimensional view of an inductor 122E according to an embodiment of the present invention;

[0018] Fig. 9 shows a front view of an inductor 122F according to an embodiment of the present invention;

[0019] Fig.10 1 shows a top view of an inductor 122F according to an embodiment of the present invention;

[0020] Fig.11 shows a side view of an inductor 122F according to an embodiment of the present invention;

[0021] Fig.12 shows a three-dimensional view of an inductor 122G according to an embodiment of the present invention;

[0022] Fig.13 shows a three-dimensional view of an inductor 122H according to an embodiment of the present invention;

[0023] Fig.14 A three-dimensional view of an inductor 122J according to an embodiment of the present invention is shown.

[0024] Fig.15A schematic diagram showing the relationship between the inductance value and the current of the inductor 122 (which may be any one of 122A to 122J) according to an embodiment of the present invention;

[0025] Fig.16 A schematic diagram showing the relationship between the inductance value of an inductor including a ferrite core and the current;

[0026] Fig.17 A schematic diagram showing the relationship between the inductance value and the current of an inductor including a single iron powder core;

[0027] Fig.18 A comparison diagram of inductance value-current curves of inductors with different magnetic cores is shown;

[0028] Fig.19 A schematic diagram of a method for manufacturing an inductor 122 according to an embodiment of the present invention is shown;

[0029] Fig. 20 shows an inductance value-current curve 301 of the inductor 122 after various requirements are given;

[0030] Fig.21 A schematic structural diagram of a multi-phase power conversion circuit 100A according to an embodiment of the present invention is shown;

[0031] Fig. 22 FIG. 1 is a schematic diagram showing a circuit structure of a single-phase power conversion circuit 100B according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not have to be used to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, materials or methods are not specifically described.

[0033] Throughout the specification, references to "one embodiment", "an embodiment", "an example" or "an example" mean that a particular feature, structure or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment", "in an embodiment", "an example" or "an example" that appear in various places throughout the specification do not necessarily refer to the same embodiment or example. In addition, particular features, structures or characteristics may be combined in one or more embodiments or examples in any appropriate combination and / or sub-combination. In addition, it should be understood by those of ordinary skill in the art that the drawings provided herein are for illustrative purposes and that the drawings are not necessarily drawn to scale. It should be understood that when an element is said to be "connected to" or "coupled to" another element, it may be directly connected or coupled to another element or there may be an intermediate element. In contrast, when an element is said to be "directly connected to" or "directly coupled to" another element, there is no intermediate element. The same reference numerals indicate the same element. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0034] Figure 1 FIG. 1 shows a three-dimensional view of an inductor 122A according to an embodiment of the present invention. Figure 1 In the embodiment, the inductor 122A includes a coil 120-1, a coil 120-2, and a magnetic core 160. The magnetic core 160 includes two or more magnetic core components. Figure 1 In the inductor 122A shown, the magnetic core 160 includes a first magnetic core portion 140 - 1 and a second magnetic core portion 140 - 2 .

[0035] The inductor 122A may be a coupled inductor or two single inductors integrated in one package. Figure 1 The inductor 122A shown in FIG. 1 has two coils 120-1 and 120-2. Generally, a coupled inductor such as the inductor 122A or two single inductors integrated in one package includes two or more coils. Each coil has a first end and a second end, wherein the first end is coupled to one end of the electronic circuit and the second end is coupled to the other end of the electronic circuit. For example, when the inductor 122A is applied to Fig.21 When the power conversion circuit 100A is shown, Figure 1 The first end of the coil 120-1 (eg Fig.21 , terminal 141) can be coupled to the switch terminal of the power conversion circuit, and the second terminal of the coil 120-1 (such as Fig.21 , terminal 142) can be coupled to the output terminal of the power conversion circuit; the first terminal of the coil 120-2 (such as Fig.21 , terminal 143) can be coupled to the switch terminal of the power conversion circuit, and the second terminal of the coil 120-2 (such as Fig.21, terminal 142) can be coupled to the output terminal of the power conversion circuit.

[0036] like Figure 1 As shown, the magnetic core 160 has two components 140-1 and 140-2. The magnetic cores in the present invention, like the magnetic core 160, include two or more physically separated parts, which are close to each other and magnetically coupled to each other. In some embodiments, the core parts may have metal contact, that is, the surfaces of the core parts may be in direct contact with each other. According to different application requirements, the gaps between the components of the magnetic core may contain paper, gas, magnetic material, non-magnetic material or other media. The core part material may be a ferromagnet (such as iron), a ferromagnetic composite (such as ferrite), an iron powder material (such as carbon-based iron powder) or other magnetic materials. The core parts may be the same material or different materials.

[0037] exist Figure 1 In the embodiment, the core parts 140-1 and 140-2 are placed close to each other to form a channel 201-1 for placing the coil 120-1, and a channel 201-2 for placing the coil 120-2. Each channel provides a passage for the corresponding coil. In the inductor 122A, the core parts 140-1 and 140-2 provide the upper half and the lower half of each channel respectively.

[0038] Figure 2 FIG. 1 shows a front view of an inductor 122A according to an embodiment of the present invention. In the inductor 122A, the magnetic core portion 140-1 has an "E"-shaped structure, and the magnetic core portion 140-2 has a flat plate structure. The magnetic core portion 140-1 with the "E"-shaped structure has two grooves, which, when combined with the magnetic core portion 140-2 with the flat plate structure, form two channels 201-1 and 201-2.

[0039] Figure 3 FIG. 4 shows a top view of an inductor 122A according to an embodiment of the present invention. Figure 3 As shown by the dashed lines in FIG. 1 , the channels 201-1 and 201-2 longitudinally penetrate the magnetic core 160. The dotted lines show the portions of the coils 120-1 and 120-2 located in the channels 201-1 and 201-2, respectively.

[0040] Figure 4 FIG. 1 shows a side view of the inductor 122A viewed from one side of the coil 120 - 2 according to an embodiment of the present invention. Figure 4It can be seen that coil 120-1 (obstructed by coil 120-2 in the figure) and coil 120-2 are hung down at the channel openings on both sides. Coils 120-1 and 120-2 can extend downward to vias, pads or other points on a PCB (Printed Circuit Board, not shown in the figure) or other substrates. It should be understood that coils 120-1 and 120-2 can also extend directly outward, that is, not hanging down, or have other structures.

[0041] In one embodiment, the coils 120-1 and 120-2 are single-turn coils, that is, the coils 120-1 or 120-2 are wound around the magnetic core 160 only once. Generally, the coils can be single-turn or multi-turn, depending on the application requirements. The coils can be wound around any part of the magnetic core. For example, in the inductor 122A, the coils 120-1 and 120-2 can be wound around the magnetic core part 140-1 or the magnetic core part 140-2.

[0042] In inductor 122A, core portion 140-1 is placed adjacent to core portion 140-2 and coupled to each other. For clarity of the diagram, gaps are shown between adjacent core portions of inductor 122A and other inductors in this specification. However, it should be understood that the core portions may also be in direct contact, such as Figure 5 A front view of an inductor 122B according to an embodiment of the present invention is shown. In the inductor 122B, the bottom surface of the core portion 140-1 is in direct contact with the top surface of the core portion 140-2. The other features of the inductor 122B are the same as those of the inductor 122A.

[0043] In the present invention, the magnetic core may have more than two parts. For example, the magnetic core 140-1 may be composed of multiple smaller magnetic core parts. Also, the magnetic core 160 may also have more magnetic core parts, such as Figure 6 shown.

[0044] Figure 6 FIG. 1 shows a three-dimensional view of an inductor 122C according to an embodiment of the present invention. The inductor 122C is a coupled inductor including a coil 120-1, a coil 120-2, and a magnetic core 160 having multiple components. In the inductor 122C, the magnetic core 160 includes a first magnetic core portion 140-1, a second magnetic core portion 140-2, and a third magnetic core portion 140-3. In the inductor 122C, the second magnetic core portion 140-2 has a flat plate structure, while the first magnetic core portion 140-1 and the third magnetic core portion 140-3 each have an "E" shaped structure. Figure 6As shown, the two "E"-shaped core parts are opened to face each other, and the flat-plate core is located between them. The "E"-shaped core part 140-1 has two grooves, and when it is combined with the flat-plate core part 140-2, two channels 201-1 and 201-2 are formed. Similarly, the "E"-shaped core part 140-3 also has two grooves, and when it is combined with the flat-plate core part 140-2, two channels 201-3 and 201-4 are formed on the other side of the flat-plate core part 140-2. Different from the inductor 122A, each coil of the inductor 122C passes through two channels. Specifically, in the inductor 122C, the coil 120-1 passes through the channel 201-1 and the channel 201-2, and the coil 120-2 passes through the channel 201-3 and the channel 201-4.

[0045] The difference between a single inductor and a coupled inductor is that a coupled circuit has two or more coils passing through a magnetic core, while a single inductor has only a single coil passing through a magnetic core. A coupled inductor can be converted into a single inductor by removing one or more coils. For example, Figure 7 The inductor 122D shown has only a single coil 120-1. The single coil 120-1 passes through the channels 201-1 and 201-2. Other than that, the other structures of the inductor 122D are the same as those of the Figure 1 The inductors 122A shown are identical.

[0046] Figure 8 A three-dimensional view of an inductor 122E according to an embodiment of the present invention is shown. The inductor 122E is a single inductor evolved from the coupled inductor 122A. The inductor 122E includes a coil 120-1 and a magnetic core 160 having multiple components. In the inductor 122E, the magnetic core portion 140-1 has a "U"-shaped structure, and the magnetic core portion 140-2 has a flat plate structure. The magnetic core portion 140-1 of the "U"-shaped structure has a single groove, which forms a channel 201-1 when combined with the magnetic core portion 140-2 of the flat plate structure. In addition, the other parts of the inductor 122E are the same as the inductor 122A.

[0047] The inductors 122D, 122E and other single inductors of the present invention can be applied to a variety of electronic circuits. For example, in a single-phase power conversion circuit, the first end of the coil 120-1 (eg Fig. 22 , terminal 141) can be coupled to the switch terminal of the power conversion circuit, and the second terminal (such as Fig. 22 , terminal 142) can be coupled to the output terminal of the power conversion circuit.

[0048] The components of the magnetic core may have a symmetrical structure, an asymmetrical structure, or other structures. For example, the magnetic core parts 140-1 and 140-2 in the inductor 122A have an asymmetrical structure, while Figure 9-11 The core portions 140 - 1 and 140 - 2 of the inductor 122F shown have a symmetrical structure.

[0049] Fig. 9 A front view of an inductor 122F according to an embodiment of the present invention is shown. The inductor 122F is a coupled inductor, including a coil 120-1, a coil 120-2 and a magnetic core 160 having multiple components. In the inductor 122F, the magnetic core 160 includes magnetic core parts 140-1 and 140-2 having symmetrical structures. The magnetic core parts 140-1 and 140-2 both have an "E"-shaped structure and both include two grooves. The magnetic core parts 140-1 and 140-2 are opposite to each other, and each groove of the magnetic core part 140-1 coincides with the corresponding groove of the magnetic core part 140-2, forming channels 201-1 and 201-2, respectively. The coil 120-1 passes through the channel 201-1, and the coil 120-2 passes through the channel 201-2. Except for the difference in the shape of the above-mentioned magnetic core parts, the other structures of the inductor 122F are the same as those of the inductor 122A.

[0050] Fig.10 and Fig.11 The top and side views of the inductor 122F are shown below. In addition to the slightly different structure of the magnetic core, Fig.10 and Fig.11 The displayed shapes are marked with Figure 3 and Figure 4 The same as shown.

[0051] In addition to the above shapes, the magnetic core may also include a rectangular or non-rectangular (eg cylindrical, annular) magnetic core portion, such as Fig.12 shown.

[0052] Fig.12 A three-dimensional view of an inductor 122G according to an embodiment of the present invention is shown. The inductor 122G is a coupled inductor, including a coil 120-1 and a coil 120-2. In the inductor 122G, the magnetic core includes magnetic core parts 140-1, 140-2, 140-3 and 140-4. The magnetic core parts 140-1 and 140-2 are both planar structures, while the magnetic core parts 140-3 and 140-4 are both cylindrical structures. The magnetic core parts 140-3 and 140-4 serve as intermediate connecting columns, and both ends are covered by the magnetic core parts 140-1 and 140-2. In the inductor 122G, the coil 120-1 is wound on the magnetic core part 140-3, and the coil 120-2 is wound on the magnetic core part 140-4. Usually, the coil will be wound around the magnetic core part for one or more turns.

[0053] Fig.12In the inductor 122G shown, each core portion 140-1, 140-2, 140-3 and 140-4 is combined as separate individuals to form a magnetic core. In some embodiments, two or more core portions can be integrally formed. For example, core portions 140-1 and 140-3 can be integrally formed, and similarly, core portions 140-2 and 140-4 can also be integrally formed. Afterwards, the two integrally formed portions can be assembled again to form the magnetic core of the inductor 122G.

[0054] Fig.13 A three-dimensional view of an inductor 122H according to an embodiment of the present invention is shown. The inductor 122H is a single inductor, including a coil 120-1 and a magnetic core. In the inductor 122H, the magnetic core includes magnetic core parts 140-1, 140-2, 140-3, 140-4 and 140-5. The magnetic core parts 140-1, 140-2, 140-4 and 140-5 all have a planar structure, while the magnetic core part 140-3 is a cylindrical structure. The magnetic core part 140-3 serves as a connecting column, and its two ends are covered by the magnetic core parts 140-1 and 140-2 respectively. In the inductor 122H, the coil 120-1 can be wound around the magnetic core part 140-3 with a single turn or multiple turns. The magnetic core parts 140-4 and 140-5 are located between the magnetic core parts 140-1 and 140-2 as side walls to provide structural support. The core parts 140-1, 140-2, 140-4 and 140-5 form a box without a cover at the front and rear, and both ends of the coil 120-1 wound around the core part 140-3 can pass through the front and rear of the box.

[0055] Fig.14 A three-dimensional view of an inductor 122J according to an embodiment of the present invention is shown. The inductor 122J is a coupled inductor, including: a coil 120-1, a coil 120-2 and a magnetic core 160. In the inductor 122J, the magnetic core 160 has a ring structure, including magnetic core parts 140-1 and 140-2. More specifically, the magnetic core parts 140-1 and 140-2 have semi-ring structures respectively, and are combined together to form a magnetic core 160 of a ring structure. In the inductor 122J, the coil 120-1 is wound around the magnetic core part 140-1 for at least one turn, and the coil 120-2 is also wound around the magnetic core part 140-2 for at least one turn. The inductor 122J can be used as a single inductor by removing the coil 120-1 or the coil 120-2.

[0056] When the current flowing through the inductor coil is determined, the inductance value of the inductor is generally determined. In the present invention, it should be understood that the desired inductance value can be obtained by selecting or designing the material and geometric structure (such as shape, size and connection) of the magnetic core. Other parameters of the inductor, such as coil material, coil size, coil winding method and position, etc., can also be selected or designed to meet the requirements for the inductor. By comprehensively considering and selecting different parameters of the inductor, the supplier can provide a variety of inductors to meet different needs.

[0057] Fig.15 FIG. 1 is a schematic diagram showing the relationship between the inductance value and the current of the inductor 122 (which may be any one of 122A to 122J) according to an embodiment of the present invention. Fig.15 In the figure, the ordinate represents the inductance value L (in nanohenry nH), and the abscissa represents the current I (in ampere A). Fig.15 It can be seen from the curve 301 in that for any coil (120-1 or 120-2), when the current value is greater than 1A and less than 60A, the inductance value of the inductor is greater than 40nH, and even after the current value reaches 60A and reaches the current protection limit (i.e., the overcurrent protection threshold), the inductance value of the inductor 122 is greater than 20nH. In other words, the inductor 122 has a relatively wide and stable inductance value range, which can better balance the efficiency and transient response.

[0058] Fig.16 FIG. 1 is a schematic diagram showing the relationship between the inductance value and the current of an inductor including a ferrite core. Fig.16 In FIG. 3 , the ordinate represents the inductance value L (in nanohenry nH), the abscissa represents the current I (in ampere A), the dotted line 302 represents the inductance value-current curve of the inductor including a single ferrite core, and the solid line 303 represents the inductance value-current curve of another inductor including a single ferrite core. Fig.16 It can be seen from the figure that the inductance value of the inductor with a ferrite core tends to drop sharply when it is saturated. Comparing the curves 302 and 303, it can also be seen that when the inductance value of the inductor with a ferrite core is high, its saturation current tends to be small; and when the current value of the inductor with a ferrite core is small, its saturation current is large.

[0059] exist Fig.16In the figure, there are two different inductance curves because the core structures of the two inductors are different and / or the ferrite purity of the cores is different. By selecting different core structures and / or the ferrite (or other material) purity of the cores, people can obtain an inductor whose inductance-current curve meets their needs. In other words, the core can include multiple core parts, and these core parts have different structures and / or different material ratios to obtain an inductor with a desired inductance-current curve. For example, the first core part has the inductance-current characteristic shown in curve 302, and the second core part has the inductance-current characteristic shown in curve 303. The core obtained by combining the first core part and the second core part can make the inductor have a large inductance value when the current is small, so that the inductor has a higher efficiency, and a small inductance value when the current is large, so that the inductor has a better transient response.

[0060] Fig.17 FIG. 1 is a schematic diagram showing the relationship between the inductance value and the current of an inductor including a single iron powder core. Fig.17 In the figure, the ordinate represents the inductance value L (in nanohenry nH), and the abscissa represents the current I (in ampere A). Fig.17 As shown in the curve 304, the inductance value of the inductor with the iron powder core is small, the saturation current is large, and the inductance value does not drop sharply near the saturation current. It can be seen that compared with the inductor of the iron powder core, the inductor of the ferrite core has a steeper inductance value curve when saturated and generally has a higher magnetic permeability.

[0061] In other words, the required inductance value-current curve can be obtained by using different materials for each core part and then combining them. Fig.18 To elaborate.

[0062] Fig.18 Will Fig.15 The curve 301, Fig.16 The curve 302 and Fig.17 The curve 304 of FIG. 1 is put in the same figure for comparison, the ordinate represents the inductance value L (unit: nanohenry nH), and the abscissa represents the current I (unit: ampere A). As mentioned above, the curve 302 is the inductance value-current curve of the inductor with a single ferrite core, and the curve 304 is the inductance value-current curve of the inductor with a single iron powder core. The inductor 122 can achieve the inductance value-current characteristic of the curve 301 by combining the ferrite core and the iron powder core. For example, in Figure 1In the inductor 122A, the core part 140-1 may be an iron powder core, and the core part 140-2 may be a ferrite core. The effect of the combination of the two is shown as the combination curve 302 and the curve 304. The combination of the iron powder core and the ferrite core can make the inductor 122 have a higher inductance value when the current is small (as shown by the curve 302), and also have a relatively high inductance value when the current is large (as shown by the curve 304). The structure of each core part can be designed according to the requirements.

[0063] Fig.19 FIG. 1 is a schematic diagram showing a method flow of manufacturing an inductor 122 according to an embodiment of the present invention. Fig.19 In the manufacturing method, the manufacturing method first defines the application requirements, namely, size limitation (box 401), target efficiency (box 402), target transient response (box 403) and current protection limitation (box 404).

[0064] The size limit refers to the maximum size of the inductor 122 and / or the shape and structure of the magnetic core. The size and structure should be determined by the application requirements, for example, based on the area of ​​the PCB and the distance from surrounding devices.

[0065] The target efficiency refers to the efficiency requirement for the inductor 122. The target efficiency may be an inductance requirement under a certain current condition. For example, the target efficiency may be an inductance value at or below TDC (Thermal Design Current). The target efficiency characterizes the inductance value of the inductor at a low current. The greater the inductance value at a low current, the higher the efficiency of the inductor 122 and its application circuit.

[0066] The target transient response refers to the requirement for the transient response of the inductor 122 and determines the inductance value at medium and high current levels. The smaller the inductance value, the better the transient response of the inductor 122.

[0067] The current protection limit refers to the maximum current value allowed to flow through the inductor and its application circuit (such as a power conversion circuit). The current protection limit determines the minimum inductance value under the maximum current condition. In other words, under the maximum current condition, the inductance must be higher than this minimum inductance value to avoid triggering the overcurrent protection.

[0068] Given the size constraints, target efficiency, target transient response, and current protection constraints, the inductance value-current curve of the inductor 122 (block 405 ) is determined. Fig. 20 An inductance value-current curve 301 that the inductor 122 should achieve after various application requirements are given is shown.

[0069] exist Fig. 20In the figure, the vertical axis represents the inductance value L (in nanohenry nH), and the horizontal axis represents the current I (in ampere A). Fig. 20 For the inductor of the characteristic curve in , the size limit is a rectangular block of 8mm×9mm×3mm, the target efficiency is the inductance value range under TDC (shown in area 351), the target transient response is the inductance value range under medium and high currents (shown in area 352), and the current protection limit is the minimum inductance value under maximum current.

[0070] Continue to explain Fig.19 By determining the target inductance value-current curve of the inductor (block 405), the influence of the combination of various inductor parameters on the inductance value-current curve can be obtained by data analysis, such as manual calculation, calculation by suitable simulation software, or other estimation means. For example, as mentioned above Figure 1 The core part 140-1 of the inductor 122A can be made of iron powder material, and the core part 140-2 can be made of ferrite material. The simulation software can simulate whether the inductance value-current curve meets the expected curve based on the characteristics of the iron powder core and the ferrite core and their shapes and other factors.

[0071] When the parameters of the inductor are adjusted but still cannot satisfy the expected inductance-current curve, the target inductance value can be modified again, that is, returning from block 407 to block 405 .

[0072] If the inductor parameter set that satisfies the expected inductance value-current curve has been determined, then these inductor parameter sets can be used to make inductor samples and test them, that is, block 407 to block 408. When the obtained inductor sample fails to meet the expected inductance value-current curve after actual testing, the inductor parameter set will be re-evaluated, that is, returning from block 409 to block 406. When the obtained inductor can meet the expected inductance value-current curve after testing, the inductor can be mass-produced, that is, block 409 to block 410.

[0073] It should be understood that the inductor 122 can be used in a variety of electronic circuits, such as power conversion circuits, including DC-DC converters, AC-DC converters, inverters, and the like.

[0074] Fig.21 FIG. 1 is a schematic diagram of a multi-phase power conversion circuit 100A according to an embodiment of the present invention. The power conversion circuit 100A receives an input voltage VIN at an input terminal 130 and provides an output voltage VOUT at an output terminal 131. Fig.21In the embodiment of the present invention, the capacitor CIN receives the input voltage VIN, and the output capacitor COUT establishes the output voltage VOUT. The power conversion circuit 100A may include a plurality of power stages 110 (i.e., 110-1, 110-2, etc.), each power stage corresponding to a phase output. For the sake of simplicity, Fig.21 Only two power stages 110 are shown. It should be understood that the multi-phase power conversion circuit 100A may have two or more power stages 110.

[0075] exist Fig.21 In an embodiment, the power stage 110 includes a control circuit 112, which controls the switching of the high-side power tube Q1 and the low-side power tube Q2, and provides a square wave at the switch terminal SW. Q1 and Q2 can be metal oxide semiconductor field effect tubes (MOSFETs), or other similar tubes. The control circuit 112 can control the power tubes Q1 and Q2 by a control method such as pulse modulation. It should be understood that the specific structure of the control circuit 112 will vary with the topology and type of the power conversion circuit 100A.

[0076] exist Fig.21 In the embodiment of FIG. 1 , the inductor 122 is a coupled inductor, coupling the outputs of the two power stages 110 to the output terminal 131. Fig.21 Inductor 122 can be Figure 1 The inductor 122A shown, Figure 5 The inductor 122B shown, Figure 6 The inductor 122C shown, Fig. 9 The inductor shown is 122F, Fig.12 The inductor 122G and Fig.14 Any one of the inductors 122J shown.

[0077] As mentioned above, the inductor 122 includes a magnetic core 160 and a plurality of coils 120 (120-1, 120-2, etc.). Fig.21 In the embodiment of the present invention, the coil 120-1 has a first end 141 coupled to the switch terminal SW of the power stage 110-1, and a second end 142 coupled to the output terminal 131. Similarly, the coil 120-2 has a first end 143 coupled to the switch terminal SW of the power stage 110-2, and a second end 144 coupled to the output terminal 131.

[0078] Fig. 22 FIG. 1 is a schematic diagram of a circuit structure of a single-phase power conversion circuit 100B according to an embodiment of the present invention. The single-phase power conversion circuit 100B is similar to the power conversion circuit 100A, except that the power conversion circuit 100B has only one-phase output. Accordingly, the power conversion circuit 100B includes a single inductor 122 instead of a coupled inductor. Fig. 22 Inductor 122 can be Figure 7The inductor 122D shown, Figure 8 The inductor 122E shown, Fig.13 The inductor 122H shown and the coil 120-1 or 120-2 removed Fig.14 Any one of the inductors 122J shown.

[0079] The present invention provides an inductor including a plurality of magnetic core parts and a method for making the same. Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be implemented in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, and therefore all changes and modifications that fall within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. An inductor, comprising: A first magnetic core portion including a first magnetic material; a second core portion comprising a second magnetic material, wherein the first core portion and the second core portion are adjacent and magnetically coupled to each other; a first coil, the first coil being at least partially wound around the first magnetic core portion or the second magnetic core portion; in Compared with the second magnetic material, the inductance value of the first magnetic material decreases faster when the inductance is saturated, and has a higher magnetic permeability. When the current flowing through the coil is between 1 ampere and 60 amperes, the inductance value is above 40 nanohenries. When the current reaches 60 amperes to the current protection limit, the inductance value is above 20 nanohenries.

2. The inductor of claim 1, wherein the first magnetic material comprises an iron powder material and the second magnetic material comprises a ferrite material. 3 . The inductor of claim 1 , wherein the first core portion and the second core portion have a symmetrical structure.

4. The inductor of claim 1, wherein the first core portion and the second core portion have an asymmetric structure. 5 . The inductor of claim 1 , wherein the first magnetic core portion and the second magnetic core portion together constitute a first channel and a second channel, and the first coil passes through the first channel and the second channel. 6 . The inductor of claim 1 , further comprising a second coil, wherein the second coil is at least partially wound around the first magnetic core portion or the second magnetic core portion. 7 . The inductor of claim 6 , wherein the first magnetic core portion and the second magnetic core portion together constitute a first channel and a second channel, the first coil passes through the first channel, and the second coil passes through the second channel.

8. The inductor as claimed in claim 6, wherein the first magnetic core portion has a first groove and a second groove, the second magnetic core has a flat plate structure, the first coil passes through a first channel formed by the first groove of the first magnetic core portion and the flat plate surface of the second magnetic core, and the second coil passes through a second channel formed by the second groove of the first magnetic core portion and the flat plate surface of the second magnetic core portion.

9. The inductor of claim 6, wherein the first coil and the second coil each pass through the magnetic core only once.

10. An inductor, comprising: A magnetic core, comprising a first magnetic core portion and a second magnetic core portion, wherein the first magnetic core portion comprises a first magnetic material and the second magnetic core portion comprises a second magnetic material; a first coil passing through a first channel formed by the first magnetic core portion and the second magnetic core portion; as well as a second coil passing through a second channel formed by the first magnetic core portion and the second magnetic core portion; in Compared with the second magnetic material, the inductance value of the first magnetic material decreases faster when the inductance is saturated, and has a higher magnetic permeability. When the current flowing through the coil is between 1 ampere and 60 amperes, the inductance value is above 40 nanohenries. When the current reaches 60 amperes to the current protection limit, the inductance value is above 20 nanohenries.

11. The inductor of claim 10, wherein the first magnetic material comprises an iron powder material and the second magnetic material comprises a ferrite material.

12. The inductor according to claim 10, wherein: The first core portion and the second core portion have a symmetrical structure.

13. The inductor according to claim 10, wherein: The first core portion and the second core portion have an asymmetric structure.

14. An inductor, comprising: A first magnetic core portion including a first magnetic material; a second magnetic core portion, comprising a second magnetic material, the second magnetic core portion being adjacent to the first magnetic core portion and magnetically coupled to each other; as well as A first coil, at least partially wound around the first magnetic core portion or the second magnetic core portion; in When the current flowing through the coil is between 1 ampere and 60 amperes, the inductance value is above 40 nanohenries, and when the current reaches 60 amperes to the current protection limit, the inductance value is above 20 nanohenries. 15 . The inductor of claim 14 , wherein compared with the second magnetic material, the inductance value of the first magnetic material decreases faster when the inductor is saturated, and the first magnetic material has a higher magnetic permeability.

16. The inductor of claim 14, wherein the first core portion and the second core portion have an asymmetric structure.

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