A method for manufacturing a miniaturized surface mount inductor

Abstract

The present invention relates to the technical field related to the manufacture of surface mount inductors, and specifically to a method for manufacturing a miniaturized surface mount inductor, comprising: placing granulated powder in a mold, or kneading the granulated powder into a magnetic core and placing it therein; using an insertion jig to transport a coil into the mold, with the beginning and end of the coil bent upward and fitted to the inner wall of the mold; placing a magnetic powder block in the mold and covering the coil, and processing it into a molded body by applying pressure or pressurized heating; the beginning and end of the coil leak out on the top surface and / or side surface of the molded body; grinding the top surface or side surface of the molded body according to the purpose, removing the film of the wire at the end of the coil, and connecting it to an external electrode, thereby forming a surface mount inductor. The beginning and end of the coil are directly folded upward under the action of the mold, so that the exposed parts of the beginning and end of the coil can be directly or directly on the top of the molded body after grinding, reducing the folding of the beginning and end of the coil, which is conducive to maximizing the volume of the built-in coil.

Description

Technical Field

[0001] The invention relates to the technical field related to the manufacture of surface mounted inductors, and in particular to a method for manufacturing a miniaturized surface mounted inductor. Background Art

[0002] Inductors can hinder the change of current in a conductor and have the functions of filtering, anti-electromagnetic interference, signal screening, current stabilization, and noise filtering. They are widely used in electronic products. With the miniaturization of electronic products, inductors are increasingly miniaturized. In particular, the market requires power inductors used in power circuits to have low DC resistance and high saturation current. Generally speaking, the larger the volume of the built-in coil, the easier it is to meet the requirements.

[0003] Surface mount inductors formed by granulating materials composed of magnetic materials and resins and having built-in coils are widely used. China's authorized patent CN105895303B discloses an electrode structure and an electronic component using the electrode structure and a manufacturing method thereof. The manufacturing method adopts a T-shaped magnetic core. The surface mount inductor is directly wound on the T-shaped magnetic core, and the end is bent at the bottom of the T-shaped magnetic core for wiring. Then, the wound T-shaped magnetic core is placed in a molding mold, and then granulating materials are added from above, and a molding body is formed by pressure alone or by pressure and heating. The end of the coil is exposed at the bottom of the molding body, and an external electrode is formed here, thereby forming a surface mount inductor.

[0004] The surface mount inductor manufactured by the above manufacturing method needs to be bent at the beginning and end of the coil. Since the inductor increases the volume of the bend, the volume of the built-in coil is reduced and the characteristics are deteriorated. If the wire is thicker, the bending volume is larger, which causes the built-in coil to be smaller, further resulting in deterioration of the characteristics, which is not conducive to the thinness of the inductor. Summary of the invention

[0005] The object of the present invention is to provide a method for manufacturing a miniaturized surface mount inductor to solve the problems mentioned in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: A method for manufacturing a miniaturized surface-mount inductor, comprising the following steps: placing granulated powder in a mold, or kneading the granulated powder into a magnetic core and placing it in; using an insertion jig to transport the coil into the mold, with the beginning and end of the coil bent upward and fitted to the inner wall of the mold; placing a magnetic powder block in the mold and covering the coil, and processing it into a molded body by applying pressure or pressurized heating; the beginning and end of the coil leak out from the top surface and / or side of the molded body.

[0007] Furthermore, the magnetic core comprises a T-shaped magnetic core, and the granulated powder is placed in a mold and pressed into the T-shaped magnetic core through a T-shaped magnetic core forming mold.

[0008] Furthermore, the magnetic core comprises a U-shaped magnetic core, and the granulated powder is placed in a mold and pressed into the U-shaped magnetic core through a U-shaped magnetic core forming mold.

[0009] Furthermore, the magnetic core includes a second I-type magnetic core, and the second I-type magnetic core is pressed and formed by granulated powder.

[0010] Furthermore, the magnetic core is directly placed in the mold after being formed.

[0011] Furthermore, the process of exposing the formed body at the beginning and end of the coil includes: after coating with insulating resin, grinding and removing the resin and wire film at the exposed parts of the beginning and end of the coil, and copper electroplating the ground parts, and then nickel base electroplating on the basis of copper electroplating, and then tin plating to form external electrodes; or grinding the film at the beginning and end of the coil to expose it, and then coating the exposed parts with conductive resin, and then electroplating nickel and tin to form external electrodes.

[0012] Furthermore, the coil is a hollow coil, which is formed by three-dimensional winding using round wire or flat wire.

[0013] Furthermore, the width of the insertion jig is smaller than the width of the mold cavity, and the width of the gap between the two sides of the insertion jig and the inner wall of the mold is larger than the thickness of the wire; an extrusion slope is provided at the upper opening of the mold, and the coil is placed on the insertion jig, and the insertion jig transports the coil from top to bottom to the inside of the mold, and the beginning and end of the coil are first bent upward under the action of the extrusion slope, and then exposed from the gap between the insertion jig and the inner wall of the mold, and as the insertion jig is inserted, the beginning and end of the coil are bent upward and close to the inner wall of the mold.

[0014] Furthermore, when the magnetic powder block is placed on the coil in the mold, the width of the magnetic powder block is smaller than the width between the beginning and end of the coil built into the mold. During molding, the magnetic powder block is deformed under the action of pressure and flows toward the inner wall of the mold to fill and mold. At the same time, the beginning and end of the coil are pressed toward the inner wall of the mold under the action of the flow of the magnetic powder block, and are finally exposed on the surface of the molded body.

[0015] Furthermore, the magnetic powder block includes a first I-type magnetic core or granulated powder.

[0016] Furthermore, a hot pressing head is used to apply pressure to the magnetic powder block.

[0017] Furthermore, when the beginning and the end of the coil need to leak out from the top surface of the formed body, a convex block is formed on the contact surface between the hot pressing head and the magnetic powder block, and the formed body is in a "concave" shape.

[0018] Furthermore, when the beginning and the end of the coil need to leak out from the side of the formed body, the contact surface between the hot pressing head and the magnetic powder block is planar, and the top surface of the formed body is planar.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: the beginning and end of the coil are directly folded upward under the action of the mold, so that the exposed parts of the beginning and end of the coil can be directly or directly on the top of the formed body after grinding, reducing the folding of the beginning and end of the coil, which is conducive to maximizing the volume of the built-in coil, reducing resistance, increasing saturation current, and achieving characteristic optimization; at the same time, the design freedom of the inductor is improved, the material selection that can be used is wider, the design degree of the wire and the coil is greatly improved, and the thicker the wire used, the more obvious the characteristic improvement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a process flow chart of forming a formed body in Example 1 of the method for manufacturing a miniaturized surface mount inductor;

[0021] Figure 2 It is a process flow chart of forming a formed body in Example 2 of the manufacturing method of a miniaturized surface mount inductor;

[0022] Figure 3 It is a process flow chart of forming a formed body in Example 3 of the manufacturing method of a miniaturized surface mount inductor;

[0023] Figure 4 It is a process flow chart of forming a formed body in Example 4 of the manufacturing method of a miniaturized surface mount inductor;

[0024] Figure 5 is a process flow chart of forming a formed body in Embodiment 5 of the method for manufacturing a miniaturized surface mount inductor;

[0025] Figure 6 is a process flow chart of forming a formed body in Example 6 of the method for manufacturing a miniaturized surface mount inductor;

[0026] Figure 7 The process flow of the manufacturing method of the miniaturized surface mount inductor in Embodiments 1-3 in which the beginning and the end of the coil are exposed to the molded body Figure 1 ;

[0027] Figure 8 The process flow of the manufacturing method of the miniaturized surface mount inductor in Embodiments 1-3 in which the beginning and the end of the coil are exposed to the molded body Figure 2 ;

[0028] Fig. 9 A flow chart of changes in the coil in a method for manufacturing a miniaturized surface mount inductor;

[0029] Fig.10The process flow of the method for manufacturing a miniaturized surface mount inductor in Example 4-6 in which the beginning and end of the coil are exposed to the molded body Figure 1 ;

[0030] Fig.11 The process flow of the method for manufacturing a miniaturized surface mount inductor in Example 4-6 in which the beginning and end of the coil are exposed to the molded body Figure 2 .

[0031] In the figure: 1-mold, 101-extrusion ramp, 2-insertion jig, 201-A axis, 202-B axis, 3-granulated powder, 4-coil, 5-first I-type magnetic core, 6-hot pressing head, 601-bump block, 7-T-type magnetic core molding mold, 8-T-type magnetic core, 9-U-type magnetic core, 10-second I-type magnetic core, 11-U-type magnetic core molding mold, 12-insulating resin layer, 13-copper plating layer, 14-nickel / tin plating layer, 15-conductive resin layer. DETAILED DESCRIPTION

[0032] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0033] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0034] In addition, in order to better illustrate the present application, numerous specific details are provided in the specific embodiments below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, and elements well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0035] See also Figure 1-Figure 8 In an embodiment of the present invention, a method for manufacturing a miniaturized surface mount inductor includes the following steps: placing granulated powder 3 in a mold 1, or kneading the granulated powder 3 into a magnetic core and placing it therein; using an insertion jig 2 to transport a coil 4 into the mold 1, and the beginning and end of the coil 4 are bent upward and fit against the inner wall of the mold 1, wherein the coil 4 is a hollow coil formed by three-dimensional winding using round wire or flat wire; placing a magnetic powder block in the mold 1 and covering the coil 4, and processing it into a molded body by applying pressure or pressurizing and heating, wherein the magnetic powder block includes but is not limited to a first I-type magnetic core 5 and granulated powder 3; the beginning and end of the coil 4 leak out from the top surface, the side surface, or both the top surface and the side surface of the molded body.

[0036] Specific:

[0037] Example 1

[0038] Please refer to Figure 1 The magnetic core is a T-shaped magnetic core 8. The granulated powder 3 is placed in the mold 1 and pressed into the T-shaped magnetic core 8 through the T-shaped magnetic core forming mold 7. The coil 4 is mounted on the insertion jig 2. The insertion jig 2 transports the coil 4 to the inside of the mold 1. Since the lateral span of the beginning and end of the coil 4 is larger than the inner space of the mold 1, after the beginning and end of the coil 4 contact the mold 1, the beginning and end of the coil 4 are squeezed and folded upward. After the coil 4 is mounted on the T-shaped magnetic core 8, the insertion jig 2 is removed from the mold 1, and then A magnetic powder block is placed in the mold 1 so that the magnetic powder block is placed on the coil 4. Then, a hot press head 6 is used to apply pressure or pressurize and heat so that the T-shaped magnetic core 8 and the magnetic powder block are wrapped around the outside of the coil 4. Finally, the molded body is cooled to form a molded body. The molded body is taken out. The contact surface between the hot press head 6 and the magnetic powder block is formed with a protruding block 601, so that there are protruding parts at both ends of the top surface of the molded body. The beginning and end of the coil 4 are wrapped around the protruding parts, and the overall front view is "concave"; the process of the beginning and end of the coil 4 being exposed from the molded body includes: please refer to Figure 8 , the molded body is coated with an insulating resin to form an insulating resin layer 12, the resin and wire film at the exposed parts of the beginning and end of the coil 4 are ground and removed, and the ground parts are subjected to copper electroplating to form a copper plating layer 13, and nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form an external electrode; or refer to Figure 7 , the raised part of the molded body is ground and removed, exposing the beginning and end of the coil 4, and then coated with insulating resin to form an insulating resin layer 12, the resin at the exposed part of the beginning and end of the coil 4 is ground and removed, and copper electroplating is performed on the ground part to form a copper plating layer 13, nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor; or refer to Fig.11 The beginning and end of the coil 4 are subjected to film grinding to expose the film, and then a conductive resin is applied to the exposed part to form a conductive resin layer 15 (including but not limited to silver paste), and then nickel and tin electroplating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor.

[0039] Example 2

[0040] Please refer to Figure 2The magnetic core is a U-shaped magnetic core 9. The granulated powder 3 is placed in the mold 1 and pressed into the U-shaped magnetic core 9 through the U-shaped magnetic core forming mold 11. The coil 4 is mounted on the insertion jig 2. The insertion jig 2 transports the coil 4 to the inside of the mold 1. Since the lateral span of the beginning and end of the coil 4 is larger than the inner space of the mold 1, after the beginning and end of the coil 4 contact the mold 1, the beginning and end of the coil 4 are squeezed and folded upward. When the coil 4 is placed in the U-shaped magnetic core 9, the insertion jig 2 is removed from the mold 1, and then A magnetic powder block is placed in the mold 1 so that the magnetic powder block is placed on the coil 4. Then, a hot press head 6 is used to apply pressure or pressurize and heat so that the U-shaped magnetic core 9 and the magnetic powder block are wrapped around the outside of the coil 4. Finally, the molded body is cooled to form a molded body. The molded body is taken out. The contact surface between the hot press head 6 and the magnetic powder block is formed with a protruding block 601, so that there are protruding parts at both ends of the top surface of the molded body. The beginning and end of the coil 4 are wrapped around the protruding parts, and the overall front view is "concave"; the process of the beginning and end of the coil 4 being exposed from the molded body includes: please refer to Figure 8 , the molded body is coated with an insulating resin to form an insulating resin layer 12, the resin and wire film at the exposed parts of the beginning and end of the coil 4 are ground and removed, and the ground parts are subjected to copper electroplating to form a copper plating layer 13, and nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form an external electrode; or refer to Figure 7 , the raised part of the molded body is ground and removed, exposing the beginning and end of the coil 4, and then coated with insulating resin to form an insulating resin layer 12, the resin at the exposed part of the beginning and end of the coil 4 is ground and removed, and copper electroplating is performed on the ground part to form a copper plating layer 13, nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor; or refer to Fig.11 The beginning and end of the coil 4 are subjected to film grinding to expose the film, and then a conductive resin is applied to the exposed part to form a conductive resin layer 15 (including but not limited to silver paste), and then nickel and tin electroplating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor.

[0041] Example 3

[0042] Please refer to Figure 3The magnetic core is a second I-type magnetic core 10, which is formed by pressing the granulated powder 3. The coil 4 is mounted on the insertion jig 2, and the insertion jig 2 transports the coil 4 to the inside of the mold 1. Since the lateral span of the beginning and end of the coil 4 is larger than the inner space of the mold 1, after the beginning and end of the coil 4 contact the mold 1, the beginning and end of the coil 4 are squeezed and folded upward. When the coil 4 is mounted on the second I-type magnetic core 10, the insertion jig 2 is removed from the mold 1 and then placed in the mold 1. The magnetic powder block is placed on the coil 4, and then the hot pressing head 6 is used to apply pressure or pressurize and heat so that the second I-type magnetic core 10 and the magnetic powder block are wrapped around the outside of the coil 4, and finally cooled into a molded body, and the molded body is taken out, and the contact surface between the hot pressing head 6 and the magnetic powder block is formed with a convex block 601, so that there are convex parts at both ends of the top surface of the molded body, and the beginning and end of the coil 4 are wrapped in the convex parts, and the overall front view is "concave"; the process of the beginning and end of the coil 4 exposing the molded body includes: please refer to Figure 8 , the molded body is coated with an insulating resin to form an insulating resin layer 12, the resin and wire film at the exposed parts of the beginning and end of the coil 4 are ground and removed, and the ground parts are subjected to copper electroplating to form a copper plating layer 13, and nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form an external electrode; or refer to Figure 7 , the raised part of the molded body is ground and removed, exposing the beginning and end of the coil 4, and then coated with insulating resin to form an insulating resin layer 12, the resin at the exposed part of the beginning and end of the coil 4 is ground and removed, and copper electroplating is performed on the ground part to form a copper plating layer 13, nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor; or refer to Fig.11 The beginning and end of the coil 4 are subjected to film grinding to expose the film, and then a conductive resin is applied to the exposed part to form a conductive resin layer 15 (including but not limited to silver paste), and then nickel and tin electroplating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor.

[0043] Example 4

[0044] Please refer to Figure 4, the magnetic core is a T-shaped magnetic core 8, the granulated powder 3 is placed in the mold 1, and is pressed into the T-shaped magnetic core 8 through the T-shaped magnetic core forming mold 7, the coil 4 is sleeved on the insertion jig 2, and the insertion jig 2 transports the coil 4 to the inside of the mold 1. Since the lateral span of the beginning and end of the coil 4 is larger than the inner space of the mold 1, after the beginning and end of the coil 4 contact the mold 1, the beginning and end of the coil 4 are squeezed and folded upward. When the coil 4 is sleeved on the T-shaped magnetic core 8, the insertion jig 2 is removed from the mold 1, and then a magnetic powder block is placed in the mold 1, so that the magnetic powder block is placed on the coil 4, and then a hot pressing head 6 is used to apply pressure or pressurize and heat so that the T-shaped magnetic core 8 and the magnetic powder block are wrapped around the outside of the coil 4, and finally cooled into a molded body, and the molded body is taken out, the contact surface between the hot pressing head 6 and the magnetic powder block is flat, the top surface of the molded body is flat, and the beginning and end of the coil 4 are wrapped on both sides of the molded body; the process of the beginning and end of the coil 4 exposing the molded body includes: please refer to Fig.10 , the molded body is coated with an insulating resin to form an insulating resin layer 12, the resin and wire film at the exposed parts of the beginning and end of the coil 4 are ground and removed, and the ground parts are subjected to copper electroplating to form a copper plating layer 13, and nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form an external electrode; or refer to Fig.11 The beginning and end of the coil 4 are subjected to film grinding to expose the film, and then a conductive resin is applied to the exposed part to form a conductive resin layer 15 (including but not limited to silver paste), and then nickel and tin electroplating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor.

[0045] Example 5

[0046] Please refer to Figure 5 , the magnetic core is a U-shaped magnetic core 9, the granulated powder 3 is placed in the mold 1, and is pressed into the U-shaped magnetic core 9 through the U-shaped magnetic core forming mold 11, the coil 4 is mounted on the insertion jig 2, and the insertion jig 2 transports the coil 4 to the inside of the mold 1. Since the lateral span of the beginning and end of the coil 4 is greater than the inner space of the mold 1, after the beginning and end of the coil 4 contact the mold 1, the beginning and end of the coil 4 are squeezed and folded upward. When the coil 4 is placed in the U-shaped magnetic core 9, the insertion jig 2 is moved out of the mold 1, and then a magnetic powder block is placed in the mold 1, so that the magnetic powder block is placed on the coil 4, and then a hot press head 6 is used to apply pressure or pressurize and heat so that the U-shaped magnetic core 9 and the magnetic powder block are wrapped around the outside of the coil 4, and finally cooled into a molded body, and the molded body is taken out, the contact surface between the hot press head 6 and the magnetic powder block is flat, the top surface of the molded body is flat, and the beginning and end of the coil 4 are wrapped on both sides of the molded body; the process of exposing the beginning and end of the coil 4 to the molded body includes: please refer to Fig.10, the molded body is coated with an insulating resin to form an insulating resin layer 12, the resin and wire film at the exposed parts of the beginning and end of the coil 4 are ground and removed, and the ground parts are subjected to copper electroplating to form a copper plating layer 13, and nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form an external electrode; or refer to Fig.11 The beginning and end of the coil 4 are subjected to film grinding to expose the film, and then a conductive resin is applied to the exposed part to form a conductive resin layer 15 (including but not limited to silver paste), and then nickel and tin electroplating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor.

[0047] Example 6

[0048] Please refer to Figure 6 , the magnetic core is a second I-type magnetic core 10, the second I-type magnetic core 10 is pressed and formed by granulating powder 3, the coil 4 is sleeved on the insertion jig 2, and the insertion jig 2 transports the coil 4 to the inside of the mold 1. Since the lateral span of the beginning and end of the coil 4 is greater than the inner space of the mold 1, after the beginning and end of the coil 4 contact the mold 1, the beginning and end of the coil 4 are squeezed and folded upward. When the coil 4 is sleeved on the second I-type magnetic core 10, the insertion jig 2 is moved out of the mold 1, and then a magnetic powder block is placed in the mold 1, so that the magnetic powder block is placed on the coil 4, and then a hot press head 6 is used to apply pressure or pressurize and heat so that the second I-type magnetic core 10 and the magnetic powder block are wrapped around the outside of the coil 4, and finally cooled into a molded body, and the molded body is taken out, the contact surface between the hot press head 6 and the magnetic powder block is flat, the top surface of the molded body is flat, and the beginning and end of the coil 4 are wrapped on both sides of the molded body; the process of the beginning and end of the coil 4 exposing the molded body includes: please refer to Fig.10 , the molded body is coated with an insulating resin to form an insulating resin layer 12, the resin and wire film at the exposed parts of the beginning and end of the coil 4 are ground and removed, and the ground parts are subjected to copper electroplating to form a copper plating layer 13, and nickel base electroplating is performed on the basis of copper electroplating, and then tin plating is performed (forming a nickel / tin plating layer 14) to form an external electrode; or refer to Fig.11 The beginning and end of the coil 4 are subjected to film grinding to expose the film, and then a conductive resin is applied to the exposed part to form a conductive resin layer 15 (including but not limited to silver paste), and then nickel and tin electroplating is performed (forming a nickel / tin plating layer 14) to form external electrodes, thereby forming a complete surface mount inductor.

[0049] The insertion jig 2 described above includes an A-axis 201 and a B-axis 202, wherein the A-axis 201 is sleeved on the outside of the B-axis 202. In the initial state, the B-axis 202 protrudes from the A-axis 201 toward one end of the mold 1, and the coil 4 is sleeved on the B-axis 202. Then the A-axis 201 and the B-axis 202 move toward the mold 1 synchronously. When the B-axis 202 approaches the magnetic core, the B-axis 202 stops moving, and the A-axis 201 continues to move downward to push the coil 4 off the B-axis 202. Then the A-axis 201 and the B-axis 202 are reset to complete the conveying process, wherein the width of the insertion jig 2 is smaller than the width of the mold cavity, and the width of the gap between the two sides of the insertion jig 2 and the inner wall of the mold 1 is greater than the thickness of the wire.

[0050] In summary, the beginning and end of the coil 4 are directly folded upward under the action of the mold 1, so that the exposed parts of the beginning and end of the coil 4 can be directly or directly on the top of the molded body after grinding, reducing the folding of the beginning and end of the coil 4, which is conducive to maximizing the volume of the built-in coil 4 and improving the characteristics. The thicker the wire used, the more obvious the improvement effect of the characteristics.

[0051] The manufacturing method of the miniaturized surface-mount inductor provided by this invention can greatly improve the internal design freedom of the inductor. Taking the 201210 size inductor as an example, the bottom electrode can increase the design effective volume range by 19%, and the side electrode can increase the design effective volume range by 36%. Assuming that all of this volume is used for the coil, the Rdc of the formed bottom electrode can be reduced by 16%, and the Rdc of the formed side electrode can be reduced by 24%; assuming that all of this volume is used for the magnetic body, the cross-sectional area of ​​the magnetic circuit will increase, and the inductance value and saturation current will be improved; assuming that this volume is equally divided for the coil and the magnetic circuit cross-sectional area, the thicker the wire, the better the improvement effect of the characteristics.

[0052] Regarding the side exposure method, since no wall is required when the wire is exposed, the smaller the inductor, the more improvement effect can be achieved.

[0053] Regarding the bottom surface exposure method, since there is no need to directly wind the wire on the core, there is no risk of core damage, and the smaller the inductor, the greater the improvement effect.

[0054] The granulated powder 3 mentioned above is made by mixing magnetic powder and resin, and can be formed by pressurization or heating and pressurization.

[0055] Furthermore, an extrusion slope 101 is provided at the opening of the mold 1, and the coil 4 is placed on the insertion jig 2. The insertion jig 2 conveys the coil 4 from top to bottom to the inside of the mold 1. The beginning and end of the coil 4 are first bent upward under the action of the extrusion slope 101, and then exposed from the gap between the insertion jig 2 and the inner wall of the mold 1. As the insertion jig 2 is inserted, the beginning and end of the coil 4 are bent upward and close to the inner wall of the mold 1. The setting of the extrusion slope 101 can make the curved surfaces of the beginning and end of the coil 4 smooth, thereby preventing the problem of breakage or cracks at the beginning and end of the coil 4.

[0056] Furthermore, when the magnetic powder block is placed on the coil 4 in the mold 1, the width of the magnetic powder block is smaller than the width between the beginning and the end of the coil 4 built into the mold 1. During molding, the magnetic powder block is deformed under the action of pressure and flows toward the inner wall of the mold 1 to fill and mold. At the same time, the beginning and the end of the coil 4 are pressed toward the inner wall of the mold 1 under the action of the flow of the magnetic powder block, and finally exposed on the surface of the molded body.

[0057] It should be added that the top surface of the molded body is the bottom surface of the inductor.

[0058] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0059] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for manufacturing a miniaturized surface mount inductor, characterized in that: The following steps are involved: Granulated powder (3) is placed in a mold (1), or the granulated powder (3) is kneaded into a magnetic core and placed therein; a coil (4) is conveyed into the mold (1) using an insertion jig (2), and the beginning and end of the coil (4) are bent upward and fit against the inner wall of the mold (1); a magnetic powder block is placed in the mold (1) and covers the coil (4), and is processed into a molded body by applying pressure or applying pressure and heating; the beginning and end of the coil (4) leak out from the top surface and / or side surface of the molded body; the width of the insertion jig (2) is smaller than the width of the mold cavity, and both sides of the insertion jig (2) are The width of the gap between the inner wall of the mold (1) and the inner wall of the mold (1) is greater than the thickness of the wire; an extrusion slope (101) is provided at the upper opening of the mold (1); a coil (4) is placed on the insertion jig (2); the insertion jig (2) conveys the coil (4) from top to bottom to the inner side of the mold (1); the beginning and end of the coil (4) are first bent upwards under the action of the extrusion slope (101), and then exposed from the gap between the insertion jig (2) and the inner wall of the mold (1); as the insertion jig (2) is inserted, the beginning and end of the coil (4) are bent upwards and closely adhere to the inner wall of the mold (1).

2. The method for manufacturing a miniaturized surface mount inductor according to claim 1, characterized in that: The magnetic core comprises a T-shaped magnetic core (8), and the granulated powder (3) is placed in a mold (1) and pressed into the T-shaped magnetic core (8) by a T-shaped magnetic core forming mold (7).

3. The method for manufacturing a miniaturized surface mount inductor according to claim 1, characterized in that: The magnetic core comprises a U-shaped magnetic core (9), and the granulated powder (3) is placed in a mold (1) and pressed into the U-shaped magnetic core (9) by a U-shaped magnetic core forming mold (11).

4. The method for manufacturing a miniaturized surface mount inductor according to claim 1, characterized in that: The magnetic core comprises a second I-type magnetic core (10), wherein the second I-type magnetic core (10) is pressed and formed by granulated powder (3).

5. The method for manufacturing a miniaturized surface mount inductor according to claim 1, characterized in that: After being formed, the magnetic core is directly placed in the mold (1).

6. A method for manufacturing a miniaturized surface mount inductor according to any one of claims 1 to 4, characterized in that: The process of exposing the formed body at the beginning and end of the coil (4) comprises: after coating with insulating resin, grinding and removing the resin and wire film at the exposed parts of the beginning and end of the coil (4), and subjecting the ground parts to copper electroplating, and then subjecting the ground parts to nickel base electroplating on the basis of copper electroplating, and then tin plating to form external electrodes; or grinding the film at the beginning and end of the coil (4) to expose it, and then coating the exposed parts with conductive resin, and then subjecting the exposed parts to nickel and tin electroplating to form external electrodes.

7. The method for manufacturing a miniaturized surface mount inductor according to claim 1, characterized in that: The coil (4) is a hollow coil, formed by three-dimensional winding using round wire or flat wire.

8. The method for manufacturing a miniaturized surface mount inductor according to claim 1, characterized in that: When the magnetic powder block is placed on the coil (4) in the mold (1), the width of the magnetic powder block is smaller than the width between the beginning and the end of the coil (4) in the mold (1). During molding, the magnetic powder block is deformed under the action of pressure and flows toward the inner wall of the mold (1) to fill the mold. At the same time, the beginning and the end of the coil (4) are pressed toward the inner wall of the mold (1) under the action of the flow of the magnetic powder block, and finally exposed on the surface of the molded body.

9. The method for manufacturing a miniaturized surface mount inductor according to claim 8, characterized in that: The magnetic powder block comprises a first I-type magnetic core (5) or granulated powder (3).

10. The method for manufacturing a miniaturized surface mount inductor according to claim 9, characterized in that: A hot pressing head (6) is used to apply pressure to the magnetic powder block.

11. The method for manufacturing a miniaturized surface mount inductor according to claim 10, characterized in that: When the beginning and the end of the coil (4) need to leak out from the top surface of the molded body, a protruding block (601) is formed on the contact surface between the hot pressing head (6) and the magnetic powder block, and the molded body is in a "concave" shape.

12. The method for manufacturing a miniaturized surface mount inductor according to claim 10, characterized in that: When the beginning and the end of the coil (4) need to leak out from the side of the molded body, the contact surface between the hot pressing head (6) and the magnetic powder block is flat, and the top surface of the molded body is flat.

Images