Inductor structure and forming method thereof

Abstract

The invention provides an inductor structure which comprises a magnetic core, a first winding unit, a second winding unit and an insulator / insulating composition, the insulator / insulating composition is small in pressed resilience at normal temperature, and the risk that the magnetic core is broken due to resilience of an insulating material during pressing can be effectively reduced; the resistivity of the insulator / insulating composition is greater than or equal to 2Mohm. M; the melting temperature of the insulator is lower than the annealing temperature of the magnetic material. When the insulator is subjected to high-temperature annealing, the insulator is at least partially molten, and the microporous structures among the magnetic core material particles can effectively buffer volume expansion when the insulator is molten, so that the stress generated by the insulator on the magnetic core is extremely low in the sintering process. And the molten insulating material is bonded with the adjacent magnetic core / winding after being cooled and solidified, so that the magnetic core, the winding and the insulating material form a whole, and the body strength of the inductor structure is greatly improved. The use of the insulator / insulation composition can effectively avoid the potential risks of magnetic core cracking and degradation of inductance characteristics and reliability in the pressing, annealing and use processes of the inductor.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage regulating modules, and in particular to the technical field of insulation materials of inductor structures in voltage regulating modules. Background Art

[0002] In recent years, with the advancement of technologies in data centers, artificial intelligence, and supercomputers, more and more powerful ASICs have been deployed, such as CPUs, GPUs, machine learning accelerators, network switches, and servers. These consume large amounts of current, reaching thousands of amperes, and exhibit rapid current fluctuations. Traditionally, voltage regulator modules (VRMs) composed of step-down (Buck) circuits have been used to supply these loads.

[0003] Existing technologies typically use back-coupling inductor technology to address these issues. This technology offers relatively low leakage inductance, resulting in a faster transient response. It also boasts a higher steady-state equivalent inductance, which improves efficiency. This technology can meet both transient performance requirements and efficiency, making it a common technique used in VRMs. The most crucial aspect of this technology is the design and manufacture of the inductor.

[0004] Existing inductors generally include at least one winding, a magnetic core, and insulation. These inductors typically utilize an iron powder core directly pressed onto the winding, creating an integrated inductor. These inductors are widely used due to their simple processing, ease of automation, and ease of mass production. However, the magnetic and electrical properties of iron powder cores are relatively poor. To obtain high-performance magnetic components, magnetic materials such as sendust (FeSiAl), iron-nickel (FeNi), iron-nickel-manganese (FeNiMo), iron-silicon (FeSi), and iron-silicon-chromium (FeSiCr) are required. However, manufacturing magnetic components from these high-performance magnetic materials requires high-temperature annealing / sintering processes, typically above 500 degrees Celsius, with the annealing temperature for sendust cores typically around 700 degrees Celsius. The insulation in the inductor core is prone to expansion or gasification during the annealing process, subjecting the core to stress from the inside out. When subjected to stress, the core is prone to breakage or cracking, causing the inductor to fail or reduce reliability.

[0005] Furthermore, the annealing / sintering process temperature for the magnetic components far exceeds the maximum temperature resistance of typical organic materials. Furthermore, when the core and windings are pressed together, the pressure can reach as high as 10 tons per square centimeter, far exceeding the compressive strength of typical inorganic materials. Summary of the Invention

[0006] The present invention is directed to the inductor structure, reducing the risk of a magnetic core being broken or causing the inductance characteristics to be reduced.

[0007] One aspect of the present invention provides an inductor structure, comprising:

[0008] Magnetic core;

[0009] a first winding unit, wherein the first winding unit is at least partially disposed in the magnetic core;

[0010] a second winding unit, wherein the second winding unit is at least partially disposed in the magnetic core;

[0011] an insulator, the insulator being disposed between the first winding unit and the second winding unit;

[0012] The insulating material is bonded to the adjacent magnetic core or winding unit after annealing, and the resistivity after annealing is greater than or equal to 2 Mohm·m; the melting temperature of the insulating material is lower than the annealing temperature.

[0013] Optionally, the insulator comprises low melting point glass.

[0014] Optionally, the insulation comprises a low-melting glass composition, wherein the low-melting glass composition comprises granular low-melting glass particles and an inorganic binder / organic binder.

[0015] Optionally, the insulating material is an insulating composition, and the insulating composition is an insulating material, an insulating interlayer and an insulating material arranged in sequence; the insulating interlayer is a high-temperature-resistant insulating material, and its temperature resistance is higher than the annealing temperature.

[0016] Optionally, the fiber material is a fiber woven material, which includes warp yarns formed by multiple strands of fibers and weft yarns formed by multiple strands of fibers.

[0017] Optionally, the magnetic core includes a top surface, a bottom surface, a first side surface and a second side surface, and the first side surface and the second side surface are opposite to each other.

[0018] Optionally, an air gap is formed between the first winding unit and the second winding unit, and the insulator is arranged between the first winding unit and the second winding unit, and the insulator is arranged in the air gap to fill the air gap.

[0019] Optionally, the first winding unit includes a first winding, and the second winding unit includes a second winding; the first winding and the second winding both include a first end and a second end, and pins are provided at both ends of the first winding and the second winding.

[0020] Optionally, the first winding unit also includes a first auxiliary winding coupled to the first winding; the second winding unit also includes a second auxiliary winding coupled to the second winding; the first auxiliary winding and the second auxiliary winding both include a first end and a second end, and the first auxiliary winding and the second auxiliary winding are provided with pins at both ends; an insulating material composition is provided between the first winding and the first auxiliary winding, and an insulating material composition is provided between the second winding and the second auxiliary winding.

[0021] Optionally, the insulating composition is an insulating material, an insulating interlayer and an insulating material arranged in sequence; the insulating interlayer is a high-temperature-resistant insulating material, and its temperature resistance is higher than the annealing temperature.

[0022] Optionally, the first winding and the second winding both pass through the first side surface and the second side surface.

[0023] Optionally, the pins at the first ends of the first winding and the second winding extend from the first side surface to the bottom surface; and the pins at the second ends of the first winding and the second winding extend from the second side surface to the bottom surface.

[0024] Optionally, the pin at the first end of the first winding extends from the first side surface to the bottom surface, and the pin at the second end of the first winding extends from the second side surface to the top surface; the pin at the first end of the second winding extends from the first side surface to the top surface, and the pin at the second end of the second winding extends from the second side surface to the bottom surface.

[0025] Optionally, the first winding and the second winding both pass through the first side surface and the second side surface;

[0026] The pins of the first ends of the first winding and the second winding extend from the first side surface to the bottom surface; the pins of the second ends of the first winding and the second winding extend from the second side surface to the bottom surface;

[0027] The first auxiliary winding has the same shape as the first winding, and the second auxiliary winding has the same shape as the second winding.

[0028] Optionally, the first winding and the second winding both pass through the first side surface and the second side surface;

[0029] The pin of the first end of the first winding extends from the first side surface to the bottom surface, and the pin of the second end of the first winding extends from the second side surface to the top surface; the pin of the first end of the second winding extends from the first side surface to the top surface, and the pin of the second end of the second winding extends from the second side surface to the bottom surface;

[0030] The first auxiliary winding and the second auxiliary winding both extend from the first side surface to the second side surface, and the pins at the first ends of the first auxiliary winding and the second auxiliary winding extend from the first side surface to the bottom surface; the pins at the second ends of the first auxiliary winding and the second auxiliary winding extend from the second side surface to the bottom surface.

[0031] Optionally, the first winding and the second winding are both arc-shaped, and the first winding and the second winding are stacked up and down, both ends of the first winding are arranged on the first side, and both ends of the second winding are arranged on the first side.

[0032] Optionally, the insulator is in a ring shape.

[0033] Optionally, one pin of the first winding and one pin of the second winding are short-circuited in parallel.

[0034] Optionally, the first winding and the second winding are both square, and the first winding and the second winding are stacked up and down, both ends of the first winding are arranged on the first side, and both ends of the second winding are arranged on the first side.

[0035] Optionally, the insulating object is in a “∏” shape.

[0036] The present invention further provides a method for forming any of the above-mentioned inductor structures, comprising the steps of:

[0037] S1. Providing a first winding unit, a second winding unit, at least one blank for forming a magnetic core, and insulation;

[0038] S2, pressing a blank, a first winding unit, a second winding unit, an insulator and another blank or magnetic powder material together to form a combination;

[0039] S3, performing high temperature annealing on the assembly;

[0040] S4, impregnating the annealed assembly with an organic material;

[0041] S5, lead out the pins to form an inductor structure.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] The inductor structure provided by the present invention uses an insulating material whose volume remains almost unchanged after annealing, eliminating the risk of high-pressure gas generated by ordinary materials due to thermal expansion or material decomposition or vaporization during the annealing process of the magnetic core, which may cause the magnetic core to break or reduce the inductance characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figures 1a to 1c Schematic diagram of embodiment 1 of the present invention;

[0046] Figure 2a to Figure 2b This is a schematic diagram of the second embodiment of the present invention;

[0047] Figure 3a to Figure 3b This is a schematic diagram of the third embodiment of the present invention;

[0048] Figures 4a to 4b This is a schematic diagram of a fourth embodiment of the present invention;

[0049] Figure 5a to Figure 5b This is a schematic diagram of a fifth embodiment of the present invention;

[0050] Figures 6a to 6b Schematic diagram of embodiment 6 of the present invention;

[0051] Figures 7a and 7b This is a schematic diagram of Embodiment 7 of the present invention;

[0052] Figure 8 This is a schematic diagram of embodiment 8 of the present invention. DETAILED DESCRIPTION

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0054] Example 1

[0055] Figure 1a-Figure 1b It is a schematic diagram of the inductor structure. Figure 1a-1bAs shown, the inductor structure 100 includes a magnetic core 110, a first winding unit, a second winding unit and an insulator 133. The inductor structure 100 or the magnetic core 110 includes a top surface, a bottom surface, a first side surface and a second side surface, and the first side surface and the second side surface are opposite to each other. Optionally, the inductor structure 100 is a rectangular parallelepiped. Of course, optionally, the inductor structure can also be other cubes. In this embodiment, the first winding unit is parallel to the second winding unit; the main body of the first winding unit and the main body of the second winding unit are in the same plane; the first winding unit is the first winding 121, and the second winding unit is the second winding 122. The first winding 121 is at least partially disposed in the magnetic core 110, and the second winding 122 is also at least partially disposed in the magnetic core 110; the first winding includes a first end and a second end, and the second winding includes a first end and a second end, the first winding is provided with a pin 121a at the first end, and the first winding is provided with a pin 121b at the second end, the second winding is provided with a pin 122a at the first end, and the second winding is provided with a pin 122b at the second end.

[0056] The first winding 121 and the second winding 122 both extend through the first and second side surfaces. The pins at the first ends of the first and second windings extend from the first side surface toward the bottom surface, while the pins at the second ends of the first and second windings extend from the second side surface toward the bottom surface. Both the first and second windings are sheet-shaped, with the main bodies of the first and second windings being sheet-shaped and parallel to the bottom surface. The first and second windings are parallel to each other.

[0057] An air gap is formed between the first winding 121 and the second winding 122, and the insulator 133 is disposed in the air gap to fill the air gap. The insulator is bonded to the adjacent magnetic cores or windings 121 and 122 after annealing, and the resistivity after annealing is greater than or equal to 2 Mohm·m. The temperature at which the insulator begins to melt (i.e., the melting temperature) is lower than the annealing temperature. The insulator is made of a material that does not rebound under pressure and has a low thermal expansion coefficient, which is less than 15X10 -6 / degrees Celsius.

[0058] Optionally, the insulator is in the form of a sheet, and further optionally, the insulator is in the form of a rectangular sheet, the sheet being parallel to the bottom surface. The insulator extends from the first side surface to the second side surface, and the insulator 133 is disposed between the main body of the first winding and the main body of the second winding, completely filling the air gap between the first winding and the second winding.

[0059] In one embodiment, the insulator 133 is a fibrous material. At room temperature, the compressive strength of the fibrous material is greater than or equal to 1.5 GPa, and the tensile strength along the fiber extension direction in the plane of the fibrous material is greater than or equal to 20 MPa. More preferably, the insulator 133 is composed solely of fibrous material. Preferably, the fibrous material is a fiber braid comprising a warp yarn formed from multiple strands of fibers and a weft yarn formed from multiple strands of fibers, and the fibrous material is at least one of glass fiber and ceramic fiber. More preferably, the fibrous material is a fiber braid formed from glass fiber. The insulator 133 is a fibrous material having a low thermal expansion coefficient and no rebound under pressure. At room temperature, when the magnetic core, winding, and fibrous material are co-pressed together, the fibrous material possesses a certain physical shape, stability, and strength. At the core annealing temperature, the fibrous material is at least partially molten, and the microporous structure between the core material particles effectively buffers the slight volume expansion of the fibrous material during melting. As a result, the stress exerted by the insulator on the magnetic core during sintering is extremely low. After cooling and solidifying, the molten insulator 133 bonds with the adjacent magnetic core or winding, making the magnetic core, winding and insulator a whole, which greatly improves the body strength of the inductor structure. Moreover, since the tiny gaps between the magnetic core material particles adjacent to the insulator are at least partially filled with the insulating material, the bonding strength is better. In order to increase the adhesion between the insulator 133 and the windings 121 and 122, the surface of the windings 121 and 122 can be pre-treated. For example, when copper is used as the windings 121 and 122, the copper surface can be oxidized. Therefore, the use of the insulator 133 can effectively avoid the potential risk of cracking of the magnetic core and degradation of the inductor characteristics and reliability during the pressing, annealing and use of the inductor. Furthermore, glass fiber produces no additional chemicals after high-temperature annealing and cooling, and its volume remains unchanged or changes only slightly, causing virtually no stress on the core. This eliminates the risk of core breakage or reduced inductance due to high-pressure gas generated by thermal expansion, decomposition, or vaporization of ordinary materials during the core annealing process.

[0060] In a second embodiment, the insulator 133 is low-melting-point glass. The low-melting-point glass block exhibits no rebound under pressure at room temperature, has a low thermal expansion coefficient at high temperatures, and releases no volatilization gas when molten, making it easy to form a bond with the core material after melting. Furthermore, the low-melting-point glass matches the thermal expansion coefficient of the core material, exhibits minimal shrinkage during solidification, and eliminates internal stress in the core, preventing cracking.

[0061] As a third embodiment, the insulator 133 is a low-melting-point glass composition, which includes granular low-melting-point glass particles and an inorganic binder. After the two are mixed in a certain proportion, the insulator 133 of the desired shape is formed by integral pressing; preferably, the inorganic binder and the inorganic binder in the magnetic material of the magnetic core belong to the same material system. The insulator 133 obtained in this way has a certain fluidity between the internal particles. During the inductor press-forming, the fluidity between the particles inside the insulator absorbs a certain pressure, eliminates the stress between the insulator and the magnetic material, and further ensures that when the inductor is formed, the magnetic material will not be subjected to the stress generated by the rebound of the insulator and cause cracks. During annealing and cooling, the low-melting-point glass particles have a small expansion coefficient, and the inorganic binder and the inorganic binder in the magnetic material are of the same material system. Therefore, the material compatibility is good and the magnetic core will not crack.

[0062] As a fourth embodiment, the insulator 133 is another low-melting-point glass composition, comprising granular low-melting-point glass particles and an organic binder. After the two are mixed in a certain proportion, they are pressed together to form the insulator 133 of the desired shape. Preferably, the volume percentage of the organic binder is less than 3%. Preferably, the starting temperature of the organic binder's cracking is lower than the melting temperature of the low-melting-point glass. The insulator obtained in this manner has a certain degree of fluidity between the particles within. During the inductor press molding, the fluidity between the particles within the insulator absorbs a certain amount of pressure, eliminating the stress between the insulating composition and the magnetic material of the magnetic core, and further ensuring that the magnetic material will not be subjected to the stress generated by the rebound of the insulating composition during the inductor molding, causing cracks. During annealing, due to the gaps between the magnetic core powder particles, the small amount of organic binder is fully cracked during the heating stage, and the generated gas is fully released through the gaps between the magnetic core powder particles, so it does not have a serious impact on the magnetic core. When cooled, the low-melting-point glass particles have a small expansion coefficient and good matching with the magnetic core, which can ensure the integrity of the magnetic core.

[0063] As a fifth embodiment, the insulator 133 is a low-melting-point glass press, which is formed by directly pressing granular low-melting-point glass particles into a blank.

[0064] As a sixth embodiment, Figure 1cAs shown, the insulating material 133 described above is replaced with an insulating composition 132 and disposed within the air gap. The insulating composition 132 includes an insulating material 133, an insulating interlayer 139, and an insulating material 133, disposed in sequence. The insulating interlayer 139 is a highly heat-resistant insulating material having a temperature resistance higher than the annealing temperature of the magnetic core. For example, the highly heat-resistant insulating material is at least one of a ceramic sheet and a high-melting-point glass fiber cloth. Optionally, the insulating material 133 in the insulating composition 132 is any of the insulating materials 133 described in Embodiments 1 to 5 above. Preferably, the insulating material 133 in the insulating composition 132 is low-melting-point glass. The insulating interlayer 139 and the insulating material 133 can be directly composited or bonded together using a small amount of inorganic / organic adhesive. Since low-melting-point glass easily forms a bonded structure after melting, it can effectively prevent cracking of the magnetic core and repair minor cracks that may occur in the highly heat-resistant insulating material during the lamination process. Furthermore, the insulating interlayer 139 can serve as a carrier for the insulating material 133, improving processability. For example, a slurry containing an insulator 133 can be provided on the surface of the insulating interlayer 139 (in addition to the insulator 133, it can also contain auxiliary components such as at least one of a solvent, a dispersant, and a binder), and a semi-finished insulating composition 132 is formed through a certain drying, high-temperature debinding and other processes. After drying and high-temperature debinding, high-temperature sintering can be added to make the insulator 133 in a partially sintered or completely sintered state. The degree of sintering may affect the melting temperature of the insulator 133. Therefore, the degree of sintering can be set as needed, but the melting temperature after sintering should be lower than the annealing temperature of the magnetic core. Further optionally, the insulating interlayer 139 is a high thermal conductivity material with a thermal conductivity greater than 10W / mK, which can further improve the heat transfer performance of the inductor.

[0065] It should be noted that one end of the insulator 133 is exposed on the first side surface and / or the second side surface, providing a stress relief opening, which can further reduce the stress level on the magnetic core during the pressing, sintering, and cooling steps of the inductor forming process.

[0066] Example 2

[0067] Figure 2a is a schematic structural diagram of the inductor structure 100 of this embodiment, Figure 2b yes Figure 2a Exploded diagram of . Figure 2a-2bAs shown, this embodiment has the same technical effects as the first embodiment. The difference between this embodiment and the first embodiment lies in the different configurations of the first winding 121 and the second winding 122. In this embodiment, the pin 121a at the first end of the first winding 121 extends from the first side surface to the bottom surface, and the pin 121b at the second end of the first winding extends from the second side surface to the top surface; the pin 122a at the first end of the second winding 122 extends from the first side surface to the top surface, and the pin 122b at the second end of the second winding 122 extends from the second side surface to the bottom surface. The windings of this embodiment expand the application range of coupled inductors.

[0068] Example 3

[0069] Figure 3a is a schematic structural diagram of the inductor structure 100 of this embodiment, Figure 3b yes Figure 3a Exploded diagram of . Figure 3a-3b As shown, this embodiment has the same technical effects as the first embodiment. The difference between this embodiment and the first embodiment is that the first winding unit and the second winding unit are arranged differently from the embodiment. In this embodiment, the first winding unit and the second winding unit are parallel. The first winding unit includes a first winding 121 and a first auxiliary winding 121f coupled to the first winding 121; the second winding unit includes a second winding 122 and a second auxiliary winding 122f coupled to the second winding 122; the first auxiliary winding 121f and the second auxiliary winding 122f each include a first end and a second end, and the first and second auxiliary windings are provided with pins at both ends; an insulating material composition 132 is arranged between the first winding 121 and the first auxiliary winding 121f, and an insulating material composition 132 is arranged between the second winding 122 and the second auxiliary winding 122f. The air gap between the first winding unit and the second winding unit can be filled with an insulating material 133 or an insulating material composition 132. The two auxiliary windings are adjacent to each other, and the two windings are far away from each other, that is, the first auxiliary winding and the second auxiliary winding are arranged adjacent to each other, and the first winding and the second winding are arranged far away from each other.

[0070] The first winding 121 and the second winding 122 both pass through the first side surface and the second side surface; the pins at the first ends of the first winding 121 and the second winding 122 extend from the first side surface to the bottom surface; the pins at the second ends of the first winding 121 and the second winding 122 extend from the second side surface to the bottom surface; the first auxiliary winding 121f has the same shape as the first winding 121, the second auxiliary winding 122f has the same shape as the second winding 122, and the auxiliary winding is arranged in parallel with the winding, and the auxiliary winding is narrower than the width of the winding.

[0071] Example 4

[0072] Figure 4a is a schematic structural diagram of the inductor structure 100 of this embodiment, Figure 4b yes Figure 4a Exploded diagram of . Figure 4a-4b As shown, this embodiment has the same technical effects as the third embodiment. The difference between this embodiment and the third embodiment lies in the different arrangements of the first winding 121 and the second winding 122. In this embodiment, the first winding 121 and the second winding 122 both extend through the first side surface and the second side surface. The pin at the first end of the first winding 121 extends from the first side surface to the bottom surface, and the pin at the second end of the first winding 121 extends from the second side surface to the top surface. The pin at the first end of the second winding 122 extends from the first side surface to the top surface, and the pin at the second end of the second winding 122 extends from the second side surface to the bottom surface.

[0073] Example 5

[0074] Figure 5a is a schematic structural diagram of the inductor structure 100 of this embodiment, Figure 5b yes Figure 5a Exploded diagram of . Figure 5a-5b As shown, this embodiment has the same technical effects as the first embodiment. The difference between this embodiment and the first embodiment lies in the different configurations of the first winding 121 and the second winding 122. In this embodiment, the first winding 121 and the second winding 122 are both arc-shaped and stacked one above the other. That is, the main body of the first winding 121 and the main body of the second winding 122 are not in the same plane. The pins at both ends of the first winding 121 are located on the first side surface, and the pins at both ends of the second winding are located on the first side surface. The insulator 133 is annular and is located between the first winding 121 and the second winding 122 to fill the air gap. It is directly opposite the projections of the main bodies of the first and second windings. The advantage of this configuration is that the overlapping length of the windings is longer, and the coupling coefficient between the two windings is higher. It should be noted that the pins at both ends of the first winding 121 are located on the first side surface, and the pins at both ends of the second winding 122 are located on the second side surface.

[0075] Example 6

[0076] Figure 6a is a schematic structural diagram of the inductor structure 100 of this embodiment, Figure 6b yes Figure 6a Exploded diagram of . Figure 6a-6b As shown, this embodiment has the same technical effects as the fifth embodiment. The difference between this embodiment and the fifth embodiment is that one pin of the first winding 121 is short-circuited in parallel with one pin of the second winding 122. This arrangement has the advantage of lowering the DC impedance of the two windings, which is conducive to improving efficiency.

[0077] Example 7

[0078] Figure 7a is a schematic structural diagram of the inductor structure 100 of this embodiment, Figure 7b yes Figure 7a Exploded diagram of . Figure 7a-7b As shown, this embodiment has the same technical effects as the fifth embodiment. The difference between this embodiment and the fifth embodiment is that the first winding 121 and the second winding 122 are arranged differently. In this embodiment, the first winding 121 and the second winding 122 are both square, and the first winding 121 and the second winding 122 are stacked up and down, that is, the main body of the first winding 121 and the main body of the second winding 122 are not in the same plane; both ends of the first winding 121 are arranged on the first side, and both ends of the second winding 122 are arranged on the first side. The insulator is in the shape of "∏". The insulator 133 is arranged between the first winding 121 and the second winding 122 to fill the air gap, and is directly opposite to the projections of the main body of the first winding and the main body of the second winding. The advantage of this arrangement is that the overlapping length of the windings is longer and the coupling coefficient between the two windings is higher. At the same time, the two windings are square, which makes the winding production simpler, more efficient, and less expensive.

[0079] Example 8

[0080] Figure 8 FIG. 1 is a schematic diagram of a manufacturing method of the inductor structure 100 of this embodiment. Figure 8 As shown, the present invention provides a method for forming an inductor structure, comprising the steps of:

[0081] S1, providing a first winding unit, a second winding unit, at least one blank 111, 112 forming a magnetic core 110, and an insulator 133;

[0082] S2, pressing a blank 112, a first winding unit, a second winding unit, an insulator 133 and another blank 111 or a magnetic powder material together to form a composite body;

[0083] S3, performing high temperature annealing on the assembly;

[0084] S4, impregnating the annealed assembly with an organic material;

[0085] S5. Lead out the pins to form the inductor structure 100.

[0086] In step S1, the first winding unit can be a first winding or a first winding and a first auxiliary winding, and the second winding unit can be a second winding or a second winding and a second auxiliary winding. Insulator 133 can also be insulating composition 132. In this step, the first winding unit, the second winding unit, and insulator 133 are all pre-formed into desired shapes.

[0087] Embodiment 9

[0088] This embodiment differs from the eighth embodiment in that a slurry containing an insulator 133 (in addition to the insulator 133, it may also contain at least one of a solvent, a dispersant, and a binder) can be applied to the blanks 111 and / or 112. This slurry is then dried, subjected to high-temperature binder removal, and further subjected to high-temperature sintering to achieve a partially or fully sintered state of the insulator 133. However, all pretreatment temperatures and the melting temperature of the insulator 133 after sintering should be lower than the core annealing temperature. This further improves production efficiency.

[0089] Example 10

[0090] The difference between this embodiment and the eighth embodiment is that the first winding unit, the second winding unit and the insulator 133 can be pre-assembled (bonded, sintered) into an assembly.

[0091] The methods in the eighth to tenth embodiments can be applied to manufacture any inductor structure in the first to seventh embodiments.

[0092] The terms "equal," "same," or "equal" disclosed in the present invention must take into account the distribution of engineering parameters, with an error distribution within ±30%; the definition of "parallel" between two line segments or two straight lines is that the angle between the two line segments or two straight lines is less than or equal to 45 degrees; the definition of "perpendicular" between two line segments or two straight lines is that the angle between the two line segments or two straight lines is within the range of [60, 120] degrees; the definition of "phase mismatch" also needs to take into account the distribution of engineering parameters, with an error distribution within ±30% of the degree of mismatch. In addition, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising 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 apparatus. Without further constraints, an element defined by the phrase "comprises a..." does not preclude the existence of additional identical elements in the process, method, article or apparatus that includes the element.

[0093] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0094] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An inductor structure, characterized in that: include: Magnetic core; a first winding unit, wherein the first winding unit is at least partially disposed in the magnetic core; a second winding unit, wherein the second winding unit is at least partially disposed in the magnetic core; an insulator, the insulator being disposed between the first winding unit and the second winding unit; The insulating material is bonded to the adjacent magnetic core or winding unit after annealing, and the resistivity after annealing is greater than or equal to 2 Mohm·m; the melting temperature of the insulating material is lower than the annealing temperature.

2. The inductor structure according to claim 1, wherein: The insulator includes low-melting-point glass.

3. The inductor structure according to claim 2, wherein: The insulation includes a low-melting glass composition, and the low-melting glass composition includes granular low-melting glass particles and an inorganic binder / organic binder.

4. The inductor structure according to claim 1, wherein: The insulating material is an insulating composition, and the insulating composition is an insulating material, an insulating interlayer and an insulating material arranged in sequence; the insulating interlayer is a high-temperature-resistant insulating material, and its temperature resistance is higher than the annealing temperature.

5. The inductor structure according to claim 1, wherein: The insulation includes a glass fiber braid including a warp yarn formed from a plurality of strands of fiber and a weft yarn formed from a plurality of strands of fiber.

6. The inductor structure according to claim 1, wherein: The magnetic core includes a top surface, a bottom surface, a first side surface, and a second side surface, wherein the first side surface and the second side surface are opposite to each other.

7. The inductor structure according to claim 6, wherein: An air gap is formed between the first winding unit and the second winding unit, and the insulator is arranged between the first winding unit and the second winding unit, and the insulator is arranged in the air gap to fill the air gap.

8. The inductor structure according to claim 7, wherein: The first winding unit includes a first winding, and the second winding unit includes a second winding; the first winding and the second winding each include a first end and a second end, and pins are provided at both ends of the first winding and the second winding.

9. The inductor structure according to claim 8, wherein: The first winding unit also includes a first auxiliary winding coupled to the first winding; the second winding unit also includes a second auxiliary winding coupled to the second winding; the first auxiliary winding and the second auxiliary winding both include a first end and a second end, and the first auxiliary winding and the second auxiliary winding are provided with pins at both ends; an insulating material composition is provided between the first winding and the first auxiliary winding, and an insulating material composition is provided between the second winding and the second auxiliary winding.

10. The inductor structure according to claim 9, wherein: The insulating composition comprises an insulating material, an insulating interlayer and an insulating material arranged in sequence; the insulating interlayer is a high-temperature-resistant insulating material, and its temperature resistance is higher than the annealing temperature.

11. The inductor structure according to claim 8, wherein: The first winding and the second winding both pass through the first side surface and the second side surface.

12. The inductor structure according to claim 11, wherein: The pins of the first ends of the first winding and the second winding extend from the first side surface to the bottom surface; the pins of the second ends of the first winding and the second winding extend from the second side surface to the bottom surface.

13. The inductor structure according to claim 11, wherein: The pin at the first end of the first winding extends from the first side to the bottom surface, and the pin at the second end of the first winding extends from the second side to the top surface; the pin at the first end of the second winding extends from the first side to the top surface, and the pin at the second end of the second winding extends from the second side to the bottom surface.

14. The inductor structure according to claim 9, wherein: The first winding and the second winding both pass through the first side surface and the second side surface; The pins of the first ends of the first winding and the second winding extend from the first side surface to the bottom surface; the pins of the second ends of the first winding and the second winding extend from the second side surface to the bottom surface; The first auxiliary winding has the same shape as the first winding, and the second auxiliary winding has the same shape as the second winding.

15. The inductor structure according to claim 9, wherein: The first winding and the second winding both pass through the first side surface and the second side surface; The pin of the first end of the first winding extends from the first side surface to the bottom surface, and the pin of the second end of the first winding extends from the second side surface to the top surface; the pin of the first end of the second winding extends from the first side surface to the top surface, and the pin of the second end of the second winding extends from the second side surface to the bottom surface; The first auxiliary winding and the second auxiliary winding both extend from the first side surface to the second side surface, and the pins at the first ends of the first auxiliary winding and the second auxiliary winding extend from the first side surface to the bottom surface; the pins at the second ends of the first auxiliary winding and the second auxiliary winding extend from the second side surface to the bottom surface.

16. The inductor structure according to claim 8, wherein: The first winding and the second winding are both arc-shaped and stacked up and down. Both ends of the first winding are arranged on the first side surface, and both ends of the second winding are arranged on the first side surface.

17. The inductor structure according to claim 16, wherein: The insulating object is in a circular shape.

18. The inductor structure according to claim 16, wherein: One pin of the first winding and one pin of the second winding are short-circuited in parallel.

19. The inductor structure according to claim 8, wherein: The first winding and the second winding are both square and stacked up and down. Both ends of the first winding are arranged on the first side surface, and both ends of the second winding are arranged on the first side surface.

20. The inductor structure according to claim 19, wherein: The insulating object is in a "∏" shape.

21. A method for forming an inductor structure according to any one of claims 1 to 20, characterized in that: Including steps: S1. Providing a first winding unit, a second winding unit, at least one blank for forming a magnetic core, and insulation; S2, pressing a blank, a first winding unit, a second winding unit, an insulator and another blank or magnetic powder material together to form a combination; S3, performing high temperature annealing on the assembly; S4, impregnating the annealed assembly with an organic material; S5, lead out the pins to form an inductor structure.

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