Inductor manufacturing process

Abstract

The invention provides an inductor manufacturing process, which comprises the following steps of: winding a wire rod into a coil on a winding mold, and respectively bending two ends of the wire rod to form pins for external connection; assembling the coil and the magnetic core so that the coil is wound on at least part of the magnetic core; the assembled coil and magnetic core are placed in a first mold, first injection molding is conducted on the coil and magnetic core through an injection molding material, the coil and magnetic core are connected into a whole, and a middle mold part is obtained; the ceramic cooling fin and the middle module are placed in a second mold, and the inner side surface of the ceramic cooling fin is attached to the peripheral face of the coil; and carrying out secondary injection molding on the ceramic cooling fins and the middle module through an injection molding material, and wrapping the ceramic cooling fins and the middle module into a whole through an injection molding layer formed by injection molding to obtain the integrated inductor with the outer side surfaces of the ceramic cooling fins and the pins exposed out of the injection molding layer. The inductor manufacturing process is used for solving the technical problems that an existing inductor is insufficient in heat dissipation performance and low in production rate.

Description

Technical Field

[0001] The present invention relates to the field of inductors, and in particular to a manufacturing process of an inductor. Background Art

[0002] At present, new energy vehicles and hybrid vehicles characterized by automobile electrification are gradually replacing traditional fuel vehicles and becoming one of the important means for countries to cope with the greenhouse effect of climate. The core of automobile electrification is to achieve efficient electromechanical coupling of driving through power battery energy storage and motor drive, so as to achieve the purpose of saving fuel or completely eliminating the use of fuel. In the operation mechanism of automobile electrification, the significant feature of battery charging and battery energy discharge driving motor is the high-power voltage conversion of high-voltage electric energy. The high-power inductor component in the conversion circuit has become one of its indispensable and important core components.

[0003] At present, high-power inductors for automobiles are usually potted with thermally conductive silicone, which fixes the inductor coil and the magnetic core and can conduct the heat generated by the inductor coil and the magnetic core. However, the manufacturing process of potted inductors is relatively complicated and the inductor molding efficiency is low. In order to improve the molding efficiency, injection molding is also used to manufacture inductors, but there is a technical problem that it cannot take into account the heat dissipation performance and product volume. Summary of the invention

[0004] The main technical problem solved by the present invention is to improve the current technical problem of low inductor forming efficiency and failure to balance heat dissipation performance and product volume.

[0005] The solution to achieve the technical purpose of the present invention is a process for manufacturing an inductor, comprising the following steps:

[0006] The wire is wound into a coil on a winding die, and both ends of the wire are bent to form pins for external connection;

[0007] Assembling the coil and the magnetic core so that the coil is wound on at least a portion of the magnetic core; placing the assembled coil and the magnetic core into a first mold, performing a first injection molding on the coil and the magnetic core with an injection molding material, connecting the coil and the magnetic core as a whole, and obtaining an intermediate mold;

[0008] The ceramic heat sink and the intermediate module are placed in a second mold, and the inner surface of the ceramic heat sink is attached to the outer peripheral surface of the coil; the ceramic heat sink and the intermediate module are subjected to a second injection molding process using an injection molding material, and the ceramic heat sink and the intermediate module are wrapped together by an injection molding layer, thereby obtaining an integrated inductor in which the outer surface of the ceramic heat sink and the pins are exposed in the injection molding layer.

[0009] In an optional embodiment, the coil has four sides, two opposite sides are first sides, and the other two opposite sides are second sides;

[0010] Winding the wire into a coil specifically includes: winding the wire on a winding die with a rectangular cross section to obtain a coil having two directly opposite first side surfaces and two directly opposite second side surfaces, and making the area of ​​the first side surface of the coil larger than the area of ​​the second side surface;

[0011] The inner surface of the ceramic heat sink is attached to the outer peripheral surface of the coil, specifically: the inner surface of the ceramic heat sink is opposite to and directly in contact with the first side surface of the coil.

[0012] In an optional embodiment, the wire is wound into a coil, which specifically also includes: winding the wire on a winding mold with a rectangular cross-section to obtain a coil having two opposing first side surfaces and two opposing second side surfaces, and making the ratio between the area of ​​the first side surface of the coil and the area of ​​the second side surface not less than 2.

[0013] In an optional embodiment, the inductor manufacturing process also includes: matching the size of the ceramic heat sink, the size of the coil, and the size of the magnetic core so that the overall size of the obtained inductor satisfies: on the cross-section of the inductor perpendicular to the winding axis of the coil, the size of the inductor corresponding to the first side is L, and the size of the inductor corresponding to the second side is H, and L:H≥3:1.

[0014] In an optional embodiment, the ceramic heat sink and the intermediate module are subjected to a second injection molding process using an injection molding material, which specifically includes: matching the structure of the second mold with the process parameters of the second injection molding process so that the outer surface of the ceramic heat sink of the obtained integrated inductor is flush with the outer surface of the insulating layer where it is located.

[0015] In an optional embodiment, the magnetic core includes a center column magnetic core and two yoke magnetic cores; the inductor manufacturing process specifically includes:

[0016] Along the axial direction of the middle column magnetic core, the coil is sheathed outside the middle column magnetic core;

[0017] Placing the assembled coil and magnetic core into a first mold, specifically comprising: placing the assembled coil and middle column magnetic core into the first mold, performing a first injection molding on the coil and the middle column magnetic core with an injection molding material, connecting the coil and the middle column magnetic core into one, and obtaining an intermediate module;

[0018] The yoke core, ceramic heat sink and intermediate module are placed in a second mold so that the two yoke cores are relatively placed at the two axial ends of the middle column core and are connected to the middle column core. The mold is closed so that the inner surface of the ceramic heat sink is in direct contact with the outer peripheral surface of the coil, and the ceramic heat sink, yoke core and intermediate module are injection molded for a second time using the injection molding material.

[0019] In an optional embodiment, the magnetic core also includes two bypass magnetic cores; placing the ceramic heat sink and the intermediate module in the second mold, specifically also including: placing two yoke magnetic cores at both ends of the intermediate module along the axial direction of the middle column magnetic core and connecting them to both ends of the middle column magnetic core, and then placing the two bypass magnetic cores opposite to each other on both sides of the intermediate module so that the yoke magnetic core and the bypass magnetic core are connected end to end; the ceramic heat sink is fitted to the side of the coil exposed between the two bypass magnetic cores.

[0020] In an optional embodiment, the two ends of the wire are bent to form pins for external connection, which specifically includes: winding the coil on a winding mold, winding the wire with a set number of turns along the axial direction of the winding mold to form the main body of the coil;

[0021] The two ends of the wire are bent along the pin bending path of the winding mold respectively; the first end of the wire is bent toward the axial direction of the winding mold to form a first pin; the second end of the wire is first bent away from the first pin by a predetermined distance, and then bent three times to form a U-shaped portion for placing two yoke cores and one of the bypass cores, and finally bent once toward the axial direction of the winding mold to form a second pin, so that the first pin and the second pin are located at the same end of the coil and both extend along the winding axis of the coil.

[0022] In an optional embodiment, the number of the ceramic heat sinks is two, and the two ceramic heat sinks are arranged opposite to each other;

[0023] Placing the ceramic heat sink and the middle module in the second mold specifically includes fixing a ceramic heat sink through the upper mold and the lower mold of the second mold respectively, placing the middle module in one of the upper mold and the lower mold and fixing it, and closing the upper mold and the lower mold so that the two ceramic heat sinks are arranged opposite to each other and respectively contact the two opposite sides of the coil.

[0024] In an optional embodiment, the ceramic heat sink and the middle module are subjected to a second injection molding using an injection molding material, specifically including adding a PPS material and subjecting the ceramic heat sink and the middle module to a second injection molding using the PPS material.

[0025] According to the inductor manufacturing process of the above-mentioned embodiment, a two-time injection molding process is adopted. The secondary injection molding connects and fixes the ceramic heat sink and the intermediate module into one molding solution, which can reduce the difficulty of production, improve production efficiency, and effectively take into account the flatness of the product's appearance. Compared with the inductor of the related art, the main difference is that the present invention directly uses the ceramic heat sink as a part of the inductor. The thermal conductivity of the ceramic heat sink is much greater than the thermal conductivity of common soft thermal pads such as silicone thermal pads. Therefore, thanks to the excellent properties of the ceramic heat sink in all aspects, it can also take into account the overall volume control of the product and the improvement of the product's heat dissipation performance. It is different from the inductor in which part of the coil is directly exposed in the related art in both composition and structure, and no additional thermal pad is required during application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the process flow of the inductor manufacturing process disclosed in the present invention.

[0027] Figure 2 A schematic diagram of the overall structure of an inductor provided in some embodiments of the present invention.

[0028] Figure 3 for Figure 2 Exploded diagram of the inductor in FIG.

[0029] Figure 4 for Figure 3 Another perspective diagram of .

[0030] Figure 5 for Figure 2 Front view of the inductor.

[0031] Figure 6 for Figure 5 AA schematic diagram.

[0032] Figure 7 for Figure 5 BB schematic diagram.

[0033] Figure 8 for Figure 2 Schematic diagram of the structure of the coil in the inductor.

[0034] Fig. 9 for Figure 2 Schematic diagram of the structure of the intermediate module in the inductor.

[0035] Fig.10 for Figure 2 Schematic diagram of the intermediate module, yoke core, bypass core and ceramic heat sink in the inductor.

[0036] Figure markings: 1000-inductor; 100-inductor assembly; 110-core; 111-middle column core; 112-sub-core; 113-yoke core; 114-bypass core; 115-avoidance portion; 120-coil; 121-first side; 122-second side; 123-pin; 1231-first pin; 1232-second pin; 124-main body; 125-U-shaped portion; 200-injection molding layer; 300-ceramic heat sink; 400-intermediate module. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0038] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0039] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0040] The present invention discloses an inductor manufacturing process, which is used to improve the current technical problems of insufficient heat dissipation performance and low production rate of the inductor 1000. Figure 1 , the manufacturing process of the inductor 1000 includes the following steps:

[0041] The injection molding layer 200 is wrapped as a whole, and the wire is wound into a coil 120 on a winding mold, and both ends of the wire are bent to form pins 123 for external connection. The pins 123 serve as a structure for electrically connecting the coil 120 of the inductor 1000 to the outside.

[0042] The coil 120 and the magnetic core 110 are assembled so that the coil 120 is wound on at least part of the magnetic core 110 to form an inductor assembly 100 that can generate an inductance effect. The assembled coil 120 and the magnetic core 110 are placed in a first mold, and the coil 120 and the magnetic core 110 are first injection molded by the injection molding material, and the coil 120 and the magnetic core 110 are connected as a whole to obtain an intermediate mold 400. By forming the coil 120 on the winding mold, the size of the hollow cavity of the coil 120 can be slightly larger than the size of the part of the magnetic core 110 on which the coil 120 is sleeved on the basis of ensuring that the overall shape of the coil 120 is regular, so that a certain gap is provided between the inner surface of the coil 120 and the outer surface of the corresponding part of the magnetic core 110. The injection molding material can enter the matching gap between the inner surface of the coil 120 and the magnetic core 110, so as to stably connect and fix the coil 120 and the magnetic core 110. At the same time, if the first mold for injection molding has a high flatness, the first mold and the first injection molding process can be used to shape the outer surface of the coil 120, so that the outer surface of the coil 120 in the obtained intermediate module 400 also has a high flatness.

[0043] The ceramic heat sink 300 and the intermediate module 400 are placed in the second mold, and the inner surface of the ceramic heat sink 300 is attached to the outer peripheral surface of the coil 120. The ceramic heat sink 300 and the intermediate module 400 are subjected to a second injection molding process using an injection molding material, and the ceramic heat sink 300 and the intermediate module 400 are wrapped as a whole by the injection molding layer 200, thereby obtaining an integrated inductor 1000 in which the outer surface of the ceramic heat sink 300 and the pins 123 are exposed in the injection molding layer 200.

[0044] In the above-mentioned preparation step of the second injection molding and the step of the second injection molding, on the one hand, since the second mold used for the second injection molding has a high flatness, the appearance consistency of the product can be effectively guaranteed by setting the process parameters of the second mold and the second injection molding. The ceramic heat sink 300 and the intermediate module 400 are both placed in the second mold, and the injection molding material can be filled between the ceramic heat sink 300 and the intermediate module 400. Finally, the various parts of the inductor 1000 are connected and fixed by the injection molding layer 200, which can effectively improve the stability of the product, reduce the difficulty of production, and improve the production efficiency of the product.

[0045] On the other hand, the ceramic heat sink 300 is a hard component with a certain compressive resistance. After the mold is closed and during the injection molding process, the ceramic heat sink 300 and the coil 120 are closely attached to each other, which increases the contact area between the ceramic heat sink 300 and the surface of the coil 120 and ensures the tightness of the contact. The ceramic heat sink 300 and the coil 120 are in more uniform contact at all locations. The heat at the coil 120 can be directly transferred to the ceramic heat sink 300 and then transferred to the outside by the ceramic heat sink 300. Since the ceramic heat sink 300 has a high thermal conductivity and good insulation properties and air tightness, the inductor 1000 is connected to the outside through the exposed ceramic heat sink 300 for heat exchange. The ceramic heat sink 300 can directly exchange heat with the air, or can be in contact with an external heat exchange device to achieve heat exchange, or can even be directly in contact with metal to dissipate heat. Under the action of the insulating layer and the ceramic heat sink 300, the ceramic heat sink 300 meets the electrical safety requirements when connected to the outside.

[0046] In addition, the presence of the ceramic heat sink 300 can greatly improve the heat dissipation performance of the inductor 1000. On the basis of the greatly improved heat dissipation performance of the inductor 1000, a coil 120 with a smaller wire diameter can be selected. At the same time, since the outer surface of the coil 120 has a high flatness in the process of obtaining the intermediate module 400 through injection molding of the first mold, and the second mold and the ceramic heat sink 300 themselves have a high flatness, the outer surface of the coil 120, the second mold and the ceramic heat sink 300 all have good flatness, so it can be ensured that the ceramic heat sink 300 will not be damaged and cracked due to stress concentration during the second injection molding process, and a thinner ceramic heat sink 300 can be selected to be molded on the inductor 1000. The thinner ceramic heat sink 300 is sufficient to meet the requirements of electrical isolation. At the same time, the heat transfer depth of the coil 120-ceramic heat sink 300-exterior can be shortened, which is conducive to the ceramic heat sink 300 to exchange heat with the outside more quickly. A thinner ceramic heat sink 300 in combination with a coil 120 with a smaller wire diameter can significantly reduce the volume of the inductor 1000, thereby effectively reducing the overall volume of the inductor 1000 while improving the heat dissipation performance, thus achieving a good balance between heat dissipation performance and product volume.

[0047] In summary, according to the manufacturing process of the inductor 1000 of the present invention, compared with the solution of fixing the ceramic heat sink 300 by other means, such as pasting, bolting, etc., the manufacturing process of the inductor 1000 of the present invention adopts a two-shot molding process. The molding solution of connecting and fixing the ceramic heat sink 300 and the intermediate module 400 as one body by the secondary injection molding can reduce the production difficulty, improve the production efficiency, and effectively take into account the flatness of the product's external surface. Compared with the inductor 1000 of the related art, the main difference is that the present invention directly uses the ceramic heat sink 300 as a part of the inductor 1000. The thermal conductivity of the ceramic heat sink 300 is much greater than the thermal conductivity of common soft thermal pads such as silicone thermal pads. Therefore, thanks to the excellent characteristics of the ceramic heat sink 300 in all aspects, it can also take into account the overall volume control of the product and the improvement of the heat dissipation performance of the product. It is different from the inductor 1000 in which part of the coil 120 is directly exposed in the related art in terms of composition and structure, and no additional thermal pad is required when it is used.

[0048] It should be noted that, in the inductor 1000 produced by the above-mentioned manufacturing process of the inductor 1000 , the ceramic heat sink 300 serves as the main heat dissipation component, and the exposed structure of the injection molding layer 200 can also play a role in assisting heat dissipation.

[0049] The wire diameter mentioned above refers to the cross-sectional area of ​​the wire. As is common knowledge in the art, the larger the wire diameter of the coil 120, the lower the heat generated. Conversely, the smaller the wire diameter of the coil 120, the higher the heat generated. Therefore, the inductor 1000 in the related art does not have good heat dissipation performance, and it is difficult to reduce the volume of the coil 120. The inductor 1000 produced by the present invention can select a wire with a smaller wire diameter to prepare the coil 120.

[0050] In some embodiments, the thickness of the ceramic heat sink 300 can be configured to be 0.2 mm to 0.5 mm. Since the ceramic heat sink 300 has good insulation properties and excellent air tightness, a thinner ceramic heat sink 300 can also ensure that the electrical isolation requirements are met. Therefore, by controlling the thickness of the ceramic heat sink 300 to be between 0.2 mm and 0.5 mm, the size of the inductor 1000 in the direction of the thickness of the ceramic heat sink 300 can be further controlled on the basis of ensuring the performance of the inductor 1000, which is beneficial to reducing the overall volume of the inductor 1000.

[0051] In some embodiments, please refer to Figure 2-Figure 10The coil 120 has four sides, two opposite sides are first sides 121, and the other two opposite sides are second sides 122. In the manufacturing process of the inductor 1000, the wire is wound into the coil 120, specifically including: winding the wire on a winding die with a rectangular cross section to obtain a coil 120 having two opposite first sides 121 and two opposite second sides 122, and making the area of ​​the first side 121 of the coil 120 larger than the area of ​​the second side 122. The inner surface of the ceramic heat sink 300 is attached to the outer peripheral surface of the coil 120, specifically: the inner surface of the ceramic heat sink 300 is opposite to and directly in contact with the first side 121 of the coil 120. In other words, in the cross section perpendicular to the winding axis of the coil 120, the closed figure enclosed by the outer surface of the coil 120 is roughly rectangular, rather than the common square, and the ceramic heat sink 300 is arranged on the outer side of the large surface of the coil 120, i.e., the first side surface 121, and the ceramic heat sink 300 is tightly fitted to the first side surface 121.

[0052] When designing the inductor 1000, the prior art usually chooses to make the cross-sectional shape of the coil 120 as close to a square as possible, taking into account the inductance performance of the inductor 1000. However, the applicant has found that the use of a coil 120 with a relatively large length-to-thickness ratio in the cross-sectional shape does not have a significant impact on the overall performance, and by reasonably arranging the coil 120 and the ceramic heat sink 300, the heat transfer area between the coil 120 and the ceramic heat sink 300 can be effectively increased, and the heat transfer depth can be shortened, which is beneficial to the overall heat dissipation. At the same time, the improvement of the heat dissipation performance is also beneficial to the reduction of the overall volume of the inductor 1000. By reasonably reducing the wire diameter of the coil 120, the thickness dimension of the inductor 1000 and / or the corresponding winding axial dimension of the coil 120 can be effectively reduced, and finally the volume of the inductor 1000 can be reduced or even significantly reduced. The thickness dimension of the inductor 1000 is the dimension of the inductor 1000 corresponding to the thickness direction of the ceramic heat sink 300.

[0053] In some embodiments, the wire is wound into the coil 120, specifically including: winding the wire on a winding die with a rectangular cross section to obtain a coil 120 having two opposite first side surfaces 121 and two opposite second side surfaces 122, and making the ratio between the area of ​​the first side surface 121 of the coil 120 and the area of ​​the second side surface 122 not less than 2. The size of the cross section of the winding die can be configured according to requirements, as long as the area ratio of the first side surface 121 to the second side surface 122 is finally satisfied to be not less than 2. By making the ratio between the area of ​​the first side surface 121 of the coil 120 and the area of ​​the second side surface 122 not less than 2, the heat dissipation area of ​​the coil 120, the contact area between the coil 120 and the ceramic heat sink 300, and the depth of the heat transfer path are greatly increased, and the auxiliary heat dissipation of the ceramic heat sink 300 can greatly improve the heat dissipation performance of the inductor 1000.

[0054] In some coils 120 with rounded corners at four corners, the cross-sectional areas at the corners can be respectively included in the first side surface 121 and the second side surface 122 for calculation, so that the ratio of the area of ​​the first side surface 121 to the area of ​​the second side surface 122 satisfies not less than 2. The length dimension a corresponding to the first side surface 121 of the coil 120 and the length dimension b corresponding to the second side surface 122 of the coil 120 can also be used as a measurement standard, that is, the coil 120 can be directly made to meet: the ratio of the length dimension a corresponding to the first side surface 121 of the coil 120 to the length dimension b corresponding to the second side surface 122 of the coil 120 is not less than 2.

[0055] In some embodiments, the manufacturing process of the inductor 1000 further includes: matching the size of the ceramic heat sink 300, the size of the coil 120, and the size of the magnetic core 110, so that the overall size of the obtained inductor 1000 satisfies: on the cross section of the inductor 1000 perpendicular to the winding axis of the coil 120, the size of the inductor 1000 corresponding to the first side 121 is L, and the size of the inductor 1000 corresponding to the second side 122 is H, L:H≥3:1. By increasing the length-to-thickness ratio of the entire product, and the length-to-thickness ratio of the product is not less than 3, the heat transfer depth of the coil 120 can be further shortened. In addition, if the size L of the injection layer 200 formed by the second injection molding is large, it is beneficial to increase the size and heat dissipation area of ​​the ceramic heat sink 300, and then it is beneficial to further increase the heat dissipation area between the ceramic heat sink 300 and the coil 120.

[0056] In some embodiments, the ceramic heat sink 300 and the intermediate mold 400 are subjected to a second injection molding by using an injection molding material, and specifically, the second injection molding process parameters are matched to make the outer surface of the ceramic heat sink 300 of the obtained integrated inductor 1000 flush with the outer surface of the insulating layer. By making the ceramic heat sink 300 not protrude from the side of the injection molding layer 200, the size of the inductor 1000 in the thickness direction corresponding to the ceramic heat sink 300 can be controlled and the length of the heat transfer path can be effectively shortened, so as to take into account both the heat dissipation performance and the volume control of the inductor 1000. In addition, since the outer surface of the ceramic heat sink 300 is flush with the outer surface of the side surface of the injection-molded layer 200, the side surface of the ceramic heat sink 300 of the inductor 1000 is a plane. Then, when in use, the ceramic heat sink 300 and the side surface of the injection-molded layer 200 can be contacted and connected with the external structure at the same time, and the ceramic heat sink 300 and the injection-molded layer 200 can realize contact heat exchange with the external structure at the same time, which can increase the overall heat exchange area between the inductor 1000 and the external structure.

[0057] In some embodiments, the coil 120 has rounded corners at all four corners, the inner surface of the ceramic heat sink 300 is attached to the surface of the coil 120, and a corner gap space is formed between the corner of the coil 120 and the ceramic heat sink 300, and the outer surface of the ceramic heat sink 300 is more protruding than the coil 120 and the magnetic core 110 as a whole, so that the injection molding material flows into the corner gap space, and the ceramic heat sink 300 and the coil 120 are connected. The outer surface of the ceramic heat sink 300 can be flush with the outer surface of the injection molding layer 200 through parameter setting, and then the outer surface of the ceramic heat sink 300 is exposed to the injection molding layer 200 to increase the heat dissipation area of ​​the ceramic heat sink 300.

[0058] In some embodiments, please refer to Figure 2-Figure 3 , the inductor 1000 can be configured such that the area of ​​the ceramic heat sink 300 exposed on the injection molding layer 200 is S1, and the area of ​​the side of the injection molding layer 200 where the ceramic heat sink 300 is located is S2, satisfying S1:S2≥30%, so as to further improve the overall heat dissipation performance of the inductor 1000. For example, the percentage of S1:S2 can be 30%, 35%, 38%, 40%, 45% or 50%, etc.

[0059] The above-mentioned “coil 120 is wound around the magnetic core 110 ” means that, in some embodiments, the magnetic core 110 may have multiple parts, and the coil 120 may be wound around only part of the magnetic core 110 . In other embodiments, the magnetic core 110 may be a complete structure, and the coil 120 may be directly wound around the outside of the magnetic core 110 .

[0060] In some embodiments, please refer to Figure 3-Figure 7 The magnetic core 110 includes a center column magnetic core 111 and two yoke magnetic cores 113; the manufacturing process of the inductor 1000 specifically includes:

[0061] The coil 120 is mounted outside the middle column magnetic core 111 along the axial direction of the middle column magnetic core 111; the assembled coil 120 and the middle column magnetic core 111 are placed in a first mold, and the coil 120 and the middle column magnetic core 111 are firstly injected with an injection molding material to connect the coil 120 and the middle column magnetic core 111 as a whole, thereby obtaining an intermediate module 400;

[0062] The yoke core 113, the ceramic heat sink 300 and the intermediate module 400 are placed in the second mold, so that the two yoke cores 113 are relatively placed at the two ends of the axial direction of the middle column core 111 and are connected to the middle column core 111. The mold is closed so that the inner surface of the ceramic heat sink 300 is in direct contact with the outer peripheral surface of the coil 120, and the ceramic heat sink 300, the yoke core 113 and the intermediate module 400 are injected for the second time through the injection molding material. The two yoke cores 113 are connected through the middle column core 111, and the two yoke cores 113 form a protective structure around the middle column core 111 and the coil 120. While improving the inductance performance, the two yoke cores 113 can also assist the intermediate module 400 in positioning in the second mold, and can also improve the rigidity and compressive resistance of the inductor assembly 100 to a certain extent. The injection molding layer 200 formed by the second injection molding covers the intermediate module 400, the ceramic heat sink 300 and the two yoke cores 113.

[0063] In some embodiments, please refer to Figure 7 The middle column magnetic core 111 may include at least two sub-magnetic cores 112, which are arranged in sequence along the winding axis, and each sub-magnetic core 112 is wound with a wire of the coil 120 to improve the inductance effect of the middle column magnetic core 111. For example, in some embodiments, the number of the sub-magnetic cores 112 may be three.

[0064] In some embodiments, please refer to Figure 3 , Figure 4 , Figure 6 and Fig.10 , the magnetic core 110 also includes two bypass magnetic cores 114; the ceramic heat sink 300 and the middle module 400 are placed in the second mold, specifically including: placing two yoke magnetic cores 113 at both ends of the middle module 400 along the axial direction of the middle column magnetic core 111 and connecting them with the two ends of the middle column magnetic core 111, and then placing two bypass magnetic cores 114 on both sides of the middle module 400 opposite to each other, so that the yoke magnetic core 113 and the bypass magnetic core 114 are connected end to end; the ceramic heat sink 300 is fitted with the side of the coil 120 exposed between the two bypass magnetic cores 114. On the one hand, it is convenient to assemble the yoke magnetic core 113, the bypass magnetic core 114 and the middle module 400. On the other hand, the magnetic core 110 includes multiple independent parts, and the yoke magnetic core 113 and the bypass magnetic core 114 are both flat, without inflection points and corner structures, which further simplifies the structure and is conducive to further improving the inductance performance of the inductor component 100. The two yoke cores 113 and the two bypass cores 114 are connected to each other, and the two yoke cores 113 and the two bypass cores 114 together form a rectangular protection frame, which further improves the inductance performance, rigidity and pressure resistance.

[0065] In some embodiments, the two pins 123 can be located on any side of the injection layer 200, that is, in different embodiments, the two pins 123 can be located on the same side of the injection layer 200, or on different sides of the injection layer 200. In order to control the total volume of the coil 120 and the magnetic core 110, an escape portion 115 for the wire to pass through is correspondingly provided on two of the two yoke magnetic cores 113 and the two bypass magnetic cores 114.

[0066] In some embodiments, please refer to Figure 3 and Figure 4 , the two yoke cores 113 are both provided with an avoidance portion 115 , and the two pins 123 are located on the same side of the injection molding layer 200 . In the manufacturing process of the inductor 1000, the two ends of the wire are bent to form pins 123 for external connection, which specifically includes: winding the coil 120 on a winding mold, and winding the wire for a set number of turns along the axial direction of the winding mold to form the main body 124 of the coil 120; bending the two ends of the wire along the bending path of the pin 123 of the winding mold; the first end of the wire is bent toward the axial direction of the winding mold to form a first pin 1231; the second end of the wire is first bent away from the first pin 1231 by a predetermined distance, and then bent three times to form a U-shaped portion 125 for placing two yoke cores 113 and one of the bypass cores 114, and finally bent once toward the axial direction of the winding mold to form a second pin 1232, so that the first pin 1231 and the second pin 1232 are located at the same end of the coil 120 and both extend along the winding axis of the coil 120. On the one hand, the second end of the wire is bent multiple times and extended around the yoke core 113 and the bypass core 1141, which effectively controls the overall volume of the inductor assembly 100, and the yoke core 113 and the bypass core 114 can also provide rigid support for the wire. On the other hand, the first pin 1231 and the second pin 1232 are arranged on the same side of the injection molding layer 200, and the first pin 1231 and the second pin 1232 extend in the same direction, which facilitates the external electrical connection of the inductor 1000.

[0067] In some embodiments, the ceramic heat sink 300 can be attached to the outer circumference of the coil 120 before the second mold is closed. In other embodiments, the ceramic heat sink 300 can be attached to the outer circumference of the coil 120 after the second mold is closed. Adaptive adjustments can be made according to actual needs and circumstances.

[0068] The above-mentioned inductor 1000 may include two or more ceramic heat sinks 300. In some embodiments, if there is a higher requirement for the heat dissipation performance of the inductor 1000, more than two ceramic heat sinks 300 may be provided. The heat dissipation rate may be further improved by using more than two ceramic heat sinks 300 on different sides. That is, the number of ceramic heat sinks 300 may be adaptively adjusted according to actual needs.

[0069] In some embodiments, please refer to Figure 3 , Figure 4 and Fig.10 , the number of the ceramic heat sinks 300 is two, and the two ceramic heat sinks 300 are arranged opposite to each other. The manufacturing process of the inductor 1000 of the present invention places the ceramic heat sink 300 and the intermediate module 400 in the second mold, specifically including: fixing a ceramic heat sink 300 through the upper mold and the lower mold of the second mold respectively, placing the intermediate module 400 in one of the upper mold and the lower mold and fixing it, and closing the upper mold and the lower mold so that the two ceramic heat sinks 300 are arranged opposite to each other and contact the two opposite side surfaces of the coil 120 respectively, so that the two ceramic heat sinks 300 can be pre-positioned in the upper mold and the lower mold respectively, so as to ensure the flatness of the final outer surface of the product.

[0070] The present invention does not limit the selection of injection materials and molding preparation schemes for the first injection molding and the second injection molding. It can be any material feasible in the prior art, such as PPS, PA, PET, etc., which will not be described in detail here. Please refer to the relevant technology for details.

[0071] In some embodiments, the ceramic heat sink 300 and the middle module 400 are subjected to a second injection molding using an injection molding material, specifically including adding a PPS material and subjecting the ceramic heat sink 300 and the middle module 400 to a second injection molding using the PPS material.

[0072] In order to meet the ultra-wide temperature range, severe mechanical vibration and shock, high-voltage insulation, high-power heat dissipation and other use conditions and requirements of the vehicle, the vehicle-mounted high-power inductor is often made of engineering plastics such as PPS with good heat resistance, insulation, good thermal conductivity, resistance to high and low temperature thermal shock, oil resistance, and extremely high mechanical strength for one-piece molding and injection molding, which can greatly improve the energy storage density of high-power inductor components. It is understandable that PPS can also be selected as the injection material for the first injection molding.

[0073] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A process for manufacturing an inductor, characterized in that: The following steps are involved: The wire is wound into a coil on a winding die, and both ends of the wire are bent to form pins for external connection; Assembling the coil and the magnetic core so that the coil is wound on at least a portion of the magnetic core; placing the assembled coil and the magnetic core into a first mold, performing a first injection molding on the coil and the magnetic core with an injection molding material, connecting the coil and the magnetic core as a whole, and obtaining an intermediate mold; The ceramic heat sink and the intermediate module are placed in a second mold, and the inner surface of the ceramic heat sink is attached to the outer peripheral surface of the coil; the ceramic heat sink and the intermediate module are subjected to a second injection molding process using an injection molding material, and the ceramic heat sink and the intermediate module are wrapped together by an injection molding layer, thereby obtaining an integrated inductor in which the outer surface of the ceramic heat sink and the pins are exposed in the injection molding layer.

2. The inductor manufacturing process according to claim 1, characterized in that: The coil has four sides, two opposite sides are first sides, and the other two opposite sides are second sides; The step of winding the wire into a coil specifically comprises: winding the wire on a winding die having a rectangular cross section to obtain a coil having two directly opposite first side surfaces and two directly opposite second side surfaces, and making the area of ​​the first side surface of the coil larger than the area of ​​the second side surface; The inner surface of the ceramic heat sink is attached to the outer peripheral surface of the coil, specifically: the inner surface of the ceramic heat sink is opposite to and directly in contact with the first side surface of the coil.

3. The inductor manufacturing process according to claim 2, characterized in that: The method of winding the wire into a coil specifically includes: winding the wire on a winding mold with a rectangular cross-section to obtain a coil having two opposing first side surfaces and two opposing second side surfaces, and making the ratio between the area of ​​the first side surface of the coil and the area of ​​the second side surface not less than 2.

4. The inductor manufacturing process according to claim 2, characterized in that: The inductor manufacturing process also includes: matching the size of the ceramic heat sink, the size of the coil and the size of the magnetic core so that the overall size of the obtained inductor satisfies: on the cross section of the inductor perpendicular to the winding axis of the coil, the size of the inductor corresponding to the first side is L, the size of the inductor corresponding to the second side is H, and L:H≥3:

1.

5. The inductor manufacturing process according to claim 1, characterized in that: The second injection molding of the ceramic heat sink and the intermediate module using the injection molding material specifically includes: matching the structure of the second mold with the process parameters of the second injection molding so that the outer surface of the ceramic heat sink of the obtained integrated inductor is flush with the outer surface of the insulating layer where it is located.

6. The inductor manufacturing process according to claim 1, characterized in that: The magnetic core includes a center column magnetic core and two yoke magnetic cores; the inductor manufacturing process specifically includes: Along the axial direction of the middle column magnetic core, the coil is sheathed outside the middle column magnetic core; Placing the assembled coil and magnetic core into the first mold specifically includes: placing the assembled coil and the middle column magnetic core into the first mold, performing a first injection molding on the coil and the middle column magnetic core with an injection molding material, connecting the coil and the middle column magnetic core into one, and obtaining an intermediate module; The yoke core, the ceramic heat sink and the intermediate module are placed in a second mold, so that the two yoke cores are relatively placed at the two axial ends of the middle column core and are connected to the middle column core. The mold is closed so that the inner surface of the ceramic heat sink is in direct contact with the outer peripheral surface of the coil, and the ceramic heat sink, the yoke core and the intermediate module are injection molded for a second time using the injection molding material.

7. The inductor manufacturing process according to claim 6, characterized in that: The magnetic core also includes two bypass magnetic cores; placing the ceramic heat sink and the intermediate module in the second mold, specifically also includes: placing two yoke magnetic cores at the two ends of the intermediate module along the axial direction of the middle column magnetic core and connecting them to the two ends of the middle column magnetic core, and then placing the two bypass magnetic cores opposite to each other on both sides of the intermediate module so that the yoke magnetic core and the bypass magnetic core are connected end to end; the ceramic heat sink is fitted to the side of the coil exposed between the two bypass magnetic cores.

8. The inductor manufacturing process according to claim 7, characterized in that: The two ends of the wire are bent to form pins for external connection, which specifically includes: winding the coil on a winding mold, winding the wire with a set number of turns along the axial direction of the winding mold to form the main body of the coil; The two ends of the wire are bent along the pin bending path of the winding mold respectively; the first end of the wire is bent toward the axial direction of the winding mold to form a first pin; the second end of the wire is first bent away from the first pin by a predetermined distance, and then bent three times to form a U-shaped portion for placing two yoke cores and one of the bypass cores, and finally bent once toward the axial direction of the winding mold to form a second pin, so that the first pin and the second pin are located at the same end of the coil and both extend along the winding axis of the coil.

9. The inductor manufacturing process according to claim 1, characterized in that: The number of the ceramic heat sinks is two, and the ceramic heat sinks are arranged opposite to each other; Placing the ceramic heat sink and the middle module in the second mold specifically includes fixing a ceramic heat sink through the upper mold and the lower mold of the second mold respectively, placing the middle module in one of the upper mold and the lower mold and fixing it, and closing the upper mold and the lower mold so that the two ceramic heat sinks are arranged opposite to each other and respectively contact the two opposite sides of the coil.

10. The inductor manufacturing process according to claim 1, characterized in that: The second injection molding of the ceramic heat sink and the intermediate module using the injection molding material specifically includes adding PPS material and performing the second injection molding of the ceramic heat sink and the intermediate module using the PPS material.

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