Inductor, method of manufacturing an inductor, and power supply circuit comprising an inductor

Abstract

The application discloses an inductor, which comprises a packaging shell, an input pole, an output pole and a metal shielding layer. The inductor is characterized in that the inductor is internally packaged with an inductive component; the input pole is exposed on the surface of the packaging shell and used for receiving an alternating voltage; the output pole is exposed on the surface of the packaging shell and used for outputting a direct current voltage; the metal shielding layer is asymmetrically covered on the surface of the packaging shell and electrically connected with the output pole; and the metal shielding layer still keeps the input pole and the output pole electrically isolated. The application further provides an inductor manufacturing method and a power supply circuit comprising the inductor, solves the problems of small electromagnetic shielding range, poor effect and unstable inductor potential in the prior art, and realizes better electromagnetic shielding effect and stable inductor potential.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor, and particularly relates to an inductor, a manufacturing method of the inductor and a power supply circuit comprising the inductor. BACKGROUND

[0002] An inductor is one of the commonly used components in a power supply circuit. The inductor is a component capable of converting electrical energy into magnetic energy and storing the magnetic energy. In a circuit with 220V alternating current as a power source, some circuits sensitive to electromagnetic interference need to be connected with an inductor at both ends of the power supply input to filter, so as to improve the problems of EMI and ripple noise. However, as a power device, the inductor generates a magnetic field during operation, which is easy to radiate to the outside, thereby affecting the normal operation of other circuits and components. Therefore, it is necessary to magnetically shield the inductor.

[0003] The existing inductor on the market usually winds one or more layers of copper foil on both sides of the inductor, and fixes the copper foil by means of soldering, so as to realize magnetic electromagnetic shielding.

[0004] The inventor found at least the following defects in the implementation of the present application: Since the copper foil only covers the two symmetrical ends and does not cover other positions, the shielding range is small and the shielding effect is poor. Due to the small coverage range, the inductor has a large external magnetic field radiation, which causes radiation problems to the external environment. SUMMARY

[0005] Therefore, the purpose of the present application is to provide an inductor, a manufacturing method of the inductor and a power supply circuit comprising the inductor, which solves the problems of small electromagnetic shielding range, poor effect and unstable potential of the inductor in the prior art, and realizes a good electromagnetic shielding effect, so that the inductor can maintain a stable potential.

[0006] The present application provides an inductor, comprising: a packaging shell, an inductor component is packaged in the inside of the packaging shell; an input pole, exposed on the surface of the packaging shell, used for receiving an alternating voltage; an output pole, exposed on the surface of the packaging shell and electrically isolating the input pole and the output pole, used for outputting a direct current voltage; a metal shielding layer, asymmetrically covering the surface of the packaging shell, the metal shielding layer is in electrical contact with the output pole, and the metal shielding layer still maintains electrical isolation between the input pole and the output pole.

[0007] Further, the metal shielding layer covers at least one surface of the packaging shell.

[0008] Further, the input pole is exposed on the bottom surface of the package shell, and the output pole is exposed on the bottom surface of the package shell together with the input pole, and the metal shielding layer at least covers part or all of the top surface of the package shell relative to the bottom surface.

[0009] Further, the package shell is a flat cuboid, and the areas of the bottom surface and the top surface are larger than those of other surfaces of the flat cuboid.

[0010] Further, the metal shielding layer extends from the top surface of the flat cuboid along the side surface close to the output pole to the bottom surface until contacting the output pole.

[0011] Further, the covered area of the metal shielding layer includes the top surface of the flat cuboid, part of the bottom surface where the output pole is located, and one side surface adjacent to the output pole but not contacting the output pole, and the three areas are integrated.

[0012] Further, the metal shielding layer extends from the top surface of the flat cuboid along multiple side surfaces to the bottom surface, avoids the input pole, and contacts the output pole.

[0013] Further, the covered area of the metal shielding layer includes the top surface of the flat cuboid, part of the bottom surface where the output pole is located, one side surface adjacent to the output pole but not contacting the output pole, and all or part of two side surfaces contacting the output pole, wherein the metal shielding layer covering the two side surfaces contacting the output pole avoids the input pole, so that the output pole and the input pole are electrically isolated.

[0014] For the purpose of the present application, the present application further provides a manufacturing method of an inductor, comprising the following steps:

[0015] An inductor is packaged to form a package shell, and an input pole and an output pole are exposed on the bottom surface of the package shell;

[0016] A metal layer is electroplated on the package shell;

[0017] The electroplated metal layer is subjected to patterning treatment to form a metal shielding layer;

[0018] The patterning treatment makes the metal shielding layer asymmetrically cover the surface of the package shell, the metal shielding layer at least wraps the top surface of the package shell relative to the bottom surface, and the metal shielding layer still makes the input pole and the output pole electrically isolated.

[0019] Further, the metal shielding layer is in electrical contact with the output pole, so that the potential of the metal shielding layer is the same as that of the output pole.

[0020] For the purpose of the present application, the present application also proposes a power supply circuit, comprising: a power circuit for providing an alternating voltage; the inductor as above, the input terminal of the inductor receiving the alternating voltage output by the power circuit; and the circuit forming the power circuit and the inductor loop.

[0021] Compared with the prior art, the present application has the following advantages: by arranging the metal shielding layer on the packaging shell, the shielding area of the inductor can be significantly increased, so that the inductor has better electromagnetic shielding effect, not only can prevent external electromagnetic field interference, but also can maximize the reduction of electromagnetic field interference of the inductor to the outside while keeping the stable potential of the inductor, and the inductor of the present application has simple and reliable manufacturing process. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitation on the present application. In the drawings:

[0023] Figure 1 is a schematic diagram of the power supply circuit of the present application;

[0024] Figure 2 is a schematic diagram of the inductor;

[0025] Figure 3 is a schematic diagram of a metal shielding layer and a packaging shell;

[0026] Figure 4 is a flow chart of the manufacturing method of the inductor. DETAILED DESCRIPTION

[0027] The embodiments of the present application provide an inductor, a manufacturing method of the inductor and a power supply circuit containing the inductor, solve the problems of small electromagnetic shielding range, poor effect and unstable potential of the inductor in the prior art, and achieve better electromagnetic shielding effect and stable potential of the inductor.

[0028] The technical solutions in the embodiments of the present application are to solve the problems in the prior art, and the general idea is as follows:

[0029] The metal shielding layer 125 is arranged on the surface of the packaging shell 121, so that at least part of the input pole 122 and the output pole 123 in the inductor 12 are covered by the metal shielding layer 125, while the input pole 122 and the output pole 123 still maintain electrical isolation, that is, the current received by the input pole 122 will not directly conduct to the output pole 123. In addition, the packaging material between the input pole 122 and the output pole 123 is also provided with an area covered by the metal shielding layer 125, and the device (such as a magnetic core) arranged between the input pole 122 and the output pole 123 can also be wrapped by the metal shielding layer 125, so as to prevent other elements in the circuit power supply from interfering with the magnetic core, so that the inductor 12 can maintain a stable potential.

[0030] The application will be described in detail below with reference to the specific embodiments shown in the drawings, but these embodiments do not limit the application, and the changes made by those skilled in the art in structure, method, or function based on these embodiments are also included in the protection scope of the application.

[0031] As shown in Figure 1 , the application provides a power supply circuit 100, which includes a power circuit 11, an inductor 12, and a circuit for connecting the power circuit 11 and the inductor 12. The circuit can also include capacitors and other components, wherein the power circuit 11 is used to provide an alternating voltage, and the inductor 12 and the capacitor receive the alternating voltage and convert it into a direct current voltage output to the subsequent circuit.

[0032] As shown in Figure 2 , the inductor 12 includes a packaging shell 121, an input pole 122, an output pole 123, and a metal shielding layer 125. The inductor component 124 is packaged in the inside of the packaging shell 121, the input pole 122 is exposed on the surface of the packaging shell 121, and the input pole 122 is used to receive the alternating voltage output from the power circuit 11. The output pole 123 is used to output a direct current voltage, and the output pole 123 is exposed on the surface of the packaging shell 121 and is electrically isolated from the input pole 122 and the output pole 123 by the packaging shell 121. The metal shielding layer 125 is asymmetrically covered on the surface of the packaging shell 121, the metal shielding layer 125 is in electrical contact with the output pole 123, and the metal shielding layer 125 still maintains electrical isolation between the input pole 122 and the output pole 123. The arrangement of the metal shielding layer 125 makes the inductor 12 have good electromagnetic shielding effect, and can reduce the volume of the inductor 12, which is beneficial to the miniaturization of the inductor 12 and can reduce the difficulty of arranging the inductor 12 in the circuit.

[0033] It should be noted that if the area covered by the metal shielding layer 125 is too large, the input pole 122 and the output pole 123 can conduct current through the metal shielding layer 125, so that there is no electrical isolation between the input pole 122 and the output pole 123. In this case, the inductor 12 is very easy to be short-circuited, and even the inductor 12 is at risk of being broken down by current. To prevent the inductor 12 from being short-circuited by the metal shielding layer 125, the metal shielding layer 125 keeps electrical isolation between the input pole 122 and the output pole 123, that is, the metal shielding layer 125 covering the input pole 122 and the metal shielding layer 125 covering the output pole 123 need to keep a certain distance, which makes the input pole 122 and the output pole 123 can keep electrical isolation, so that the inductor 12 can keep normal.

[0034] As an implementation manner, the input pole is exposed on one side of the packaging shell, the output pole is exposed on another side of the packaging shell opposite to the input pole, and the metal shielding layer covers at least two bottom surfaces of the packaging shell adjacent to the side where the output pole is located. In this implementation manner, the metal shielding layer covers the side where the output pole is located and the bottom surface adjacent to the side where the output pole is located, and can be electrically connected with the output pole. This arrangement is conducive to expanding the coverage area of the metal shielding layer 125, so that the metal shielding layer 125 can have a better electric field shielding effect.

[0035] As an implementation manner, the metal shielding layer 125 covers at least one surface of the packaging shell 121. This arrangement makes the metal shielding layer 125 at least isolate the external electric field from radiating to the inductor 12 or isolate the internal electric field of the inductor 12 from radiating to the outside. It can be understood that this arrangement is conducive to expanding the coverage area of the metal shielding layer 125, so that the metal shielding layer 125 can have a better electric field shielding effect. In this implementation manner, the input pole 122 is exposed on the bottom surface of the packaging shell 121, the output pole 123 is exposed on the bottom surface of the packaging shell 121 together with the input pole 122, and the metal shielding layer 125 covers at least part or all of the top surface of the packaging shell 121 opposite to the bottom surface.

[0036] As an implementation, the package shell 121 is a flat cuboid, which can be made of magnetic material or other materials, and is not limited in the embodiment. The flat cuboid is arranged on the input pole 122, the inductor element 124 and the output pole 123. The input pole 122 is arranged on one side of the package shell 121, the output pole 123 is arranged on the side of the package shell 121 away from the input pole 122, and the inductor element 124 is arranged between the input pole 122 and the output pole 123. The bottom surface of the package shell 121 and the top surface opposite to the bottom surface are larger than the area of the other side surfaces of the flat cuboid. As an implementation, the metal shielding layer 125 is wrapped on the top surface of the flat cuboid, and the metal shielding layer 125 extends from the top surface to the bottom surface along the side close to the output pole 123 until it contacts the output pole 123 exposed on the bottom surface, so that the potential of the metal shielding layer 125 is the same as that of the output pole 123. The metal shielding layer 125 extends from the top surface to the side adjacent to the output pole 123 but not in contact with the output pole 123. In this way, the coverage area of the metal shielding layer 125 includes the top surface of the flat cuboid, part of the bottom surface of the area where the output pole 123 is located, and one side adjacent to the output pole 123 but not in contact with the output pole 123. The three areas are connected as a whole, so that the metal shielding layer 125 can expand the coverage area as much as possible, so that the inductor 12 can have better electric field shielding and reduce the radiation of the inductor 12 to the external environment. Generally, the copper foil used in the prior art is mostly covered on the side close to the input pole 122 and the side close to the output pole 123, and the inductor element 124 between the input pole 122 and the output pole 123 is not provided with shielding protection, so that the magnetic force from the outside of the inductor 12 easily affects the inductor element 124, so that the inductor element 124 generates a near-field electric field, thereby changing the potential difference inside the inductor 12 and causing the imbalance of the electron transfer in the inductor 12. The metal shielding layer 125 in the application has a wide coverage area on the surface of the package shell 121, and can isolate the external electric field and prevent the near-field electric field generated inside the inductor 12 from radiating outward. In the application, the alternating voltage received by the input pole 122 is output by the output pole 123 through the inductor element 124, at this time, the voltage output by the output pole 123 is a direct-current stable voltage, that is, there is no induced electromotive force generated at the output pole 123. The metal shielding layer 125 close to the output pole 123 is in contact with the output pole 123 exposed on the bottom surface of the package shell 121, so that the potential of the metal shielding layer 125 is the same as that of the output pole 123. Since the input pole 122 receives the alternating voltage from the power circuit 11, an alternating electric field is generated on the inductor 12, which is shielded by the stable potential or zero potential.The metal shielding layer 125 is electrically connected to the output pole 123, so that the metal shielding layer 125 has a relatively stable electric potential, and at this time, the metal shielding layer 125 can shield the outward radiation of the alternating electric field, thereby suppressing the energy of the alternating electric field and greatly reducing the influence of the inductor 12 on the external environment.

[0037] As shown in Figure 3 As another implementation manner, the metal shielding layer 125 extends from the top surface of the flat cuboid to the bottom surface along multiple side surfaces of the flat cuboid, and on the side close to the input pole 122, the metal shielding layer 125 is arranged away from the input pole 122, and on the side close to the output pole 123, the metal shielding layer 125 is in contact with the output pole 123, so that the electric potential of the metal shielding layer 125 is consistent with that of the output pole 123. In this way, the coverage area of the metal shielding layer 125 includes the top surface of the flat cuboid, part of the bottom surface of the area where the output pole 123 is located, one side surface adjacent to the output pole 123 but not in contact with the output pole 123, and all or part of the two side surfaces in contact with the output pole 123, wherein the metal shielding layer 125 covering the two side surfaces in contact with the output pole 123 maintains a certain interval from the input pole 122, so that the output pole 123 and the input pole 122 are electrically isolated. When the inductor 12 is working, the current input from the input pole 122 passes through the inductive element 124, and the inductive element 124 generates a changing magnetic field. When the magnetic field moves to the top surface of the flat cuboid, the magnetic field intersects with the metal shielding layer 125 to generate eddy current, which can offset the change of the magnetic field. Since the top surface of the flat cuboid is covered with the metal shielding layer 125, the top surface of the flat cuboid can offset most of the magnetic field generated by the inductive element 124, greatly reducing the magnetic field emitted by the inductive element 124 to the outside, and further reducing the magnetic field interference of the inductor 12 itself to the outside.

[0038] The input pole 122 is arranged on the bottom surface of the flat cuboid, and the input pole 122 is at least partially exposed on the bottom surface of the flat cuboid, and the input pole 122 is located on one side of the inductive element 124. The input pole 122 is made of conductive material, and as an implementation manner, the input pole 122 can be a copper foil pin made of copper foil, which can be plug-in welded on the flat cuboid or surface-mounted on the flat cuboid, and the specific implementation is not limited in the embodiment.

[0039] The output pole 123 is also arranged on the bottom surface of the flat cuboid, and the output pole 123 is at least partially exposed on the bottom surface of the flat cuboid, and the output pole 123 is located on the side of the inductive element 124 away from the input pole 122. The output pole 123 is made of conductive material, and as an implementation manner, the input pole 122 can be a copper foil pin made of copper foil, which can be plug-in welded on the flat cuboid or surface-mounted on the flat cuboid, and the specific implementation is not limited in the embodiment.

[0040] The inductor 12 element is located between the input pole 122 and the output pole 123, one end of the inductor 12 element is connected with the input pole 122, and the other end of the inductor 12 element is connected with the output pole 123.

[0041] As shown in the figure, the application also provides a manufacturing method of the above inductor 12, and the specific steps are as follows: Figure 4

[0042] An inductor element 124 is encapsulated to form an encapsulation shell 121, and the input pole 122 and the output pole 123 are exposed on the bottom surface of the encapsulation shell 121;

[0043] A metal layer is electroplated on the encapsulation shell 121;

[0044] The electroplated metal layer is subjected to a patterning process to form a metal shielding layer 125;

[0045] The patterning process makes the metal shielding layer 125 asymmetrically cover the surface of the encapsulation shell 121, the metal shielding layer 125 at least wraps the top surface of the encapsulation shell 121 relative to the bottom surface, and the metal shielding layer 125 still makes the input pole 122 and the output pole 123 maintain electrical isolation.

[0046] The metal shielding layer 125 is in electrical contact with the output pole 123, so that the potential of the metal shielding layer 125 is the same as that of the output pole 123. The metal shielding layer 125 can be a mesh structure or other pattern structure.

[0047] The inductor 12 provided by the application is manufactured by the above method. The manufacturing method adopts an electroplating method to deposit a metal layer on the surface of the encapsulation shell 121, and then uses a patterning process to make the metal layer form a metal shielding layer 125 wrapped on the top surface of the encapsulation shell 121, so as to expand the coverage area of the metal shielding layer 125 as much as possible, and the input pole 122 and the output pole 123 can maintain electrical isolation. The traditional method mainly uses manual operation to wind copper foil, which has low production efficiency and is not conducive to production automation. Compared with the prior art, the manufacturing method provided by the application can improve the production efficiency, the inductor 12 manufactured by the method can have good anti-interference ability, the shielding effect of the inductor 12 is maximized, the inductor 12 can maintain a stable potential, and the risk of open circuit or short circuit of the inductor 12 is reduced.

[0048] ​In the claims, the word "comprising" does not exclude other elements or steps; the word "a" or "an" does not exclude a plurality. In the claims, the use of the ordinal number "first", "second", "third", etc. does not imply an order of priority, sequence or chronology with respect to the actions of the claim elements but is used for the purpose of distinguishing between different claim elements. The use of the term "means" in a claim does not imply that the claim element is a means-plus-function claim element. The use of the term "or" in a claim does not exclude that "and" is intended. Any reference signs in the claims should not be construed as limiting the scope of the claims. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It is noted that the claims can be drafted to exclude any features or steps indicated in the above description or in the following claims. The word "comprise", "comprising", "comprises" or "comprised of" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It is noted that the claims can be drafted to exclude any features or steps indicated in the above description or in the following claims. The word "comprise", "comprising", "comprises" or "comprised of" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It is noted that the claims can be drafted to exclude any features or steps indicated in the above description or in the following claims. The word "comprise", "comprising", "comprises" or "comprised of" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It is noted that the claims can be drafted to exclude any features or steps indicated in the above description or in the following claims.

[0049] While the preferred embodiments of the application have been disclosed in connection with example implementations, those skilled in the art will further appreciate that various adaptations and modifications of the preferred embodiments can be practiced within the scope of the application. Accordingly, although specific embodiments have been illustrated and described herein, it is the intent that the application be practiced not only as described, but in any manner that is dictated by the spirit and scope of the claims.

Claims

1. An inductor characterized by, The application relates to an inductor, comprising: a package shell, in which an inductive component is encapsulated; an input terminal exposed on the surface of the package shell, used for receiving an alternating voltage; an output terminal exposed on the surface of the package shell and electrically isolated from the input terminal and the output terminal by the package shell, used for outputting a direct current voltage; a metal shielding layer asymmetrically covering the surface of the package shell, the metal shielding layer being electrically connected with the output terminal, so that the potential of the metal shielding layer is the same as that of the output terminal, and the metal shielding layer still keeps the input terminal and the output terminal electrically isolated; wherein the alternating voltage received by the input terminal is outputted by the output terminal after passing through the inductive component, and the alternating electric field generated by the alternating voltage is shielded by the stable potential or zero potential.

2. The inductor of claim 1, wherein: The input terminal is exposed on one side of the package shell, the output terminal is exposed on the other side of the package shell opposite to the input terminal, and the metal shielding layer covers at least two bottom surfaces adjacent to the side where the output terminal is located.

3. The inductor of claim 1, wherein: The input terminal is exposed on the bottom surface of the package shell, and the output terminal is exposed on the bottom surface of the package shell together with the input terminal, and the metal shielding layer covers at least the top surface of the package shell opposite to the bottom surface or the whole top surface.

4. The inductor of claim 3, wherein: The package shell is a flat cuboid, and the area of the bottom surface and the top surface is larger than that of the other sides of the cuboid.

5. The inductor of claim 4, wherein: The metal shielding layer extends from the top surface of the flat cuboid to the bottom surface along the side close to the output terminal until contacting the output terminal.

6. The inductor of claim 5, wherein: The covering area of the metal shielding layer includes the top surface of the flat cuboid, the partial bottom surface of the area where the output terminal is located, and the side adjacent to the output terminal but not contacting the output terminal, and the three areas are integrated.

7. The inductor of claim 4, wherein: The metal shielding layer extends from the top surface of the flat cuboid to the bottom surface along multiple sides and avoids the input terminal and contacts the output terminal.

8. The inductor of claim 7, wherein: The covering area of the metal shielding layer includes the top surface of the flat cuboid, the partial bottom surface of the area where the output terminal is located, the side adjacent to the output terminal but not contacting the output terminal, and the whole or part of the two sides contacting the output terminal, wherein the metal shielding layer covering the two sides contacting the output terminal avoids the input terminal, so that the output terminal and the input terminal are kept electrically isolated.

9. A manufacturing method of the inductor according to any one of claims 1-8, comprising: encapsulating an inductive component to form a package shell, and exposing an input terminal and an output terminal on the bottom surface of the package shell, wherein the input terminal can receive an alternating voltage; electroplating a metal layer on the package shell; performing pattern processing on the electroplated metal layer to form a metal shielding layer, and the potential of the metal shielding layer is the same as that of the output terminal. wherein the patterning process causes the metal shield layer to asymmetrically cover the surface of the package housing, the metal shield layer at least wrapping around a top surface of the package housing opposite the bottom surface, and the metal shield layer still causes the input and output poles to remain electrically isolated, the alternating voltage being able to output a direct current stable voltage by the output pole after passing through the inductive component, and the alternating electric field generated by the alternating voltage being shielded by the stable potential or zero potential.

10. The method of claim 9, wherein: The metal shield layer is in electrical contact with the output pole, so that the potential of the metal shield layer is the same as that of the output pole.

11. A power supply circuit, characterized by comprising: The power circuit is configured to provide an alternating voltage. The inductor of any one of claims 1-8, wherein the input pole of the inductor receives the alternating voltage output by the power circuit; and the circuit comprises the power circuit and the inductor circuit. ​

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