TWI856721B - Magnetic Component Shielding Methods - Google Patents

Abstract

A magnetic element shielding method includes shielding a plurality of pins of a magnetic element; spraying a conductive paint layer on the surface of the magnetic element; and removing the shielding of each pin. The present invention uses a simple spraying method to make the shielding of the outer side of the magnetic element, so that the conductive paint layer covering the entire magnetic element is used as a shield. Compared with the known shielding method, it is easier to make and is less likely to leave gaps that may leak magnetic fields. The present invention also provides a magnetic element structure with shielding.

Description

Magnetic component shielding method

The present invention relates to a method for manufacturing a shield for a magnetic component, in particular, a method for manufacturing a shield for a magnetic component by spraying conductive paint to manufacture an external shield.

In the era of advanced technology, various electronic devices are pursuing miniaturization and extreme circuit board power density. The spacing of electronic components on circuit boards is constantly shrinking. Many components are activated by the principle of magnetic fields, such as inductors, transformers and other magnetic components. Such magnetic components will release magnetic fields to the surrounding components (that is, electromagnetic interference). When they are close to each other, they will affect the working status of other components. In applications that require high stability (such as automotive electronics), the impact of electromagnetic interference must be paid great attention.

Therefore, a shielded inductor has emerged. For example, Taiwan's patent announcement number TWI734771 discloses a shielding method in which a shell is added to the outside of the inductor body. However, due to the material properties of the die-cast inductor itself, the external dimensions after die-casting are prone to some tolerances. At this time, if it is combined with the pre-made shell, it is easy to have gaps and cannot be tightly fitted; and if too much pressure is applied to the shell to clamp the inductor body during the combination, it may also damage the inductor body; the shell is also difficult to process into a complex shape that can completely cover the inductor body. Usually, as shown in the representative figure of the above-mentioned known patent (Figure 4), there will be gaps in the corners to facilitate bending processing. Therefore, there is room for further improvement in the tightness and coverage between the shield and the inductor body.

In view of this, the inventor of the present invention has devoted himself to research and design, hoping to provide a magnetic element shielding method and a magnetic element with shielding that can completely shield the magnetic element and is easy to process, which is the motivation for the invention.

The main purpose of the present invention is to provide a magnetic element shielding method and a magnetic element with shielding, and to use a method of spraying conductive paint to make the shielding so that the magnetic element can be completely shielded and covered.

The magnetic element shielding method of the present invention includes shielding a plurality of pins of a magnetic element; spraying a conductive paint layer on the surface of the magnetic element; and removing the shielding of each pin. In this way, the shielding is completed. The conductive paint can be a metal conductive paint, such as a conductive paint containing silver particles, copper particles, or silver-plated copper particles.

The conductive paint layer sprayed on the outside of the magnetic component can form a complete and seamless shield, minimizing the possibility of magnetic field leakage; and the shielding effect can be increased by increasing the thickness of the conductive paint layer to meet the needs of various occasions.

If the surface of the magnetic component is not suitable for direct contact with the conductive paint layer, after masking the pins of the magnetic component, you can spray an insulating coating on the surface of the magnetic component, and then spray the conductive paint layer. If the surface of the magnetic component has a grounding terminal, the grounding terminal needs to be masked when spraying the insulating coating, and the shielding of the grounding terminal is removed after the insulating coating is completed.

Since the shield must be grounded, if there is no grounding terminal on the surface of the magnetic component, at least one grounding plate can be set on the surface of the magnetic component before spraying the conductive paint layer. In this way, after spraying the conductive paint layer, the conductive paint layer will naturally be electrically connected to the grounding plate, and the conductive paint layer can be grounded. Since the conductive paint layer can completely cover the magnetic component, the grounding plate can be set on the surface closest to the grounding point, and the grounding plate does not need to extend from the top all the way down like the shield in the known technology. If you want to set up the insulating coating and the grounding plate at the same time, you can apply the insulating coating first and then set the grounding plate, because the grounding plate does not need to be conductive to the body. Alternatively, a grounding plate may be provided first, and then the insulating coating may be provided after the grounding plate is shielded, and the shielding of the grounding plate may be removed after the insulating coating is provided. Alternatively, before a protective paint layer is sprayed on the surface of the conductive paint layer, the conductive paint layer may be shielded at at least one predetermined position, and after the protective paint layer is sprayed on the surface of the conductive paint layer, the shielding of the conductive paint layer may be removed, and then at least one grounding electrode may be produced by electroplating on the conductive paint layer.

To prevent oxidation of the conductive paint layer, a protective paint layer can be sprayed on the surface of the conductive paint layer after spraying the conductive paint layer. If necessary, the grounding plate or the original grounding terminal of the magnetic component can be shielded when spraying the protective paint layer to prevent the protective paint layer from covering the grounding plate or the original grounding terminal of the magnetic component.

The shielded magnetic element of the present invention comprises: a magnetic element, which comprises a body and a plurality of pins; and a conductive paint layer, which is arranged on the surface of the magnetic element, and the conductive paint layer and each pin are in an insulated state.

In one embodiment, an insulating coating layer is further provided between the main body and the conductive paint layer.

In one embodiment, at least one grounding plate is further provided on the main body, and the grounding plate is electrically connected to the conductive paint layer.

In one embodiment, there is further a protective paint layer outside the conductive paint layer.

In one embodiment, the protective paint layer has an opening at at least one predetermined position, and the conductive paint layer has at least one grounding electrode at a position corresponding to the opening.

In order to further understand the features, characteristics and technical contents of the present invention, please refer to the following detailed description of the present invention.

Please refer to the first to fourth figures, which disclose the examples of the implementation of the present invention. The above figures illustrate an implementation (I) of a magnetic element shielding method of the present invention, which includes shielding a plurality of pins 11 of a magnetic element 1 (S1); spraying an insulating coating 2 (S1A) on the surface of the magnetic element 1; providing at least one grounding plate 12 (S1B) on the surface of the magnetic element 1; spraying a conductive paint layer 3 (S2) on the surface of the magnetic element 1; spraying a protective paint layer 4 (S2A) on the surface of the conductive paint layer 3; and removing the shielding of each pin 11 (S3). The magnetic element 1 in this implementation (I) is a molded inductor, and the magnetic element 1 can also be a magnetic element 1 such as a transformer that emits a magnetic field to the outside.

In the present embodiment (I), the conductive paint layer 3 is a metal conductive paint, for example, a conductive paint layer 3 containing silver particles, copper particles or silver-plated copper particles. In the past, the conductive paint layer 3 was often applied to the inner surface of the plastic shell as a shield, but the present invention directly applies the conductive paint layer 3 to the outer surface of the magnetic element 1 as a shield.

The embodiment (I) of the shielded magnetic element of the present invention comprises: a magnetic element 1, which comprises a body 13 and a plurality of pins 11; and a conductive paint layer 3, which is disposed on the surface of the magnetic element 1, and the conductive paint layer 3 and each pin 11 are insulated. As can be seen in the second figure, because each pin 11 is shielded when the conductive paint layer 3 is sprayed, each pin 11 does not contact the conductive paint layer 3, so the conductive paint layer 3 and each pin 11 are insulated. This embodiment (I) further has an insulating coating layer 2 between the main body 13 and the conductive paint layer 3; this embodiment (I) further has at least one grounding plate 12 (two grounding plates 12 in the figure) on the main body 13, and the grounding plate 12 is electrically connected to the conductive paint layer 3; this embodiment (I) further has a protective paint layer 4 on the outer side of the conductive paint layer 3.

The conductive paint layer 3 sprayed on the outer side of the magnetic element 1 can form a complete and seamless shield on the outer surface of the body 13. Unlike the known shielding shell that easily leaves gaps (such as corners) during processing, the body 13 in this embodiment (I) is a rectangular parallelepiped, and the six sides of the body 13 can be sprayed with the conductive paint layer 3 to minimize the possibility of magnetic field leakage. In addition, the spraying method can easily correspond to the various complex and undulating outer surfaces of the magnetic element 1. If a machined shell is used to correspond to the complex undulations, the processing cost will increase significantly. The present invention can increase the shielding effect by increasing the thickness of the conductive paint layer 3 to meet the needs of various different occasions. When the machined shell is thickened, it will be difficult to bend.

In the embodiment (1) of the magnetic element shielding method of the present invention, in order to correspond to the body 13 of the magnetic element 1 which is not suitable for direct contact with the conductive conductive paint layer 3, after shielding the plurality of pins 11 of the magnetic element 1 (S1), an insulating coating 2 (S1A) is sprayed on the surface of the magnetic element 1. If the surface of the magnetic element 1 has a grounding terminal (not shown), the grounding terminal (not shown) needs to be shielded when the insulating coating 2 is sprayed, and the shielding of the grounding terminal (not shown) is removed after the insulating coating is completed.

Since the shield must be grounded, in order to correspond to the magnetic element 1 without a grounding terminal (not shown) on the surface, in this embodiment (I), before spraying a conductive paint layer 3 (S2) on the surface of the magnetic element 1, at least one grounding plate 12 (S1B) is provided on the surface of the magnetic element 1. In this way, after the conductive paint layer 3 is sprayed, the conductive paint layer 3 is naturally electrically connected to the grounding plate 12, and the conductive paint layer 3 can be grounded. Since the conductive paint layer 3 can completely cover the body 13 of the magnetic element 1, the grounding plate 12 can be provided on the surface closest to the grounding point (the side or bottom surface in this embodiment (I)), and the grounding plate 12 does not need to extend all the way down from the top surface like the shield in the known technology. In the present embodiment (I), the insulating coating 2 and the grounding sheet 12 are provided at the same time. The insulating coating 2 can be applied first and then the grounding sheet 12 is provided, because the grounding sheet 12 does not need to be electrically conductive with the body 13. Alternatively, the grounding sheet 12 can be provided first, and then the insulating coating 2 is shielded and then the insulating coating 2 is provided, and then the shielding of the grounding sheet 12 is removed after the insulating coating 2 is provided.

In this embodiment (I), in order to prevent oxidation of the conductive paint layer 3, after spraying a conductive paint layer 3 (S2) on the surface of the magnetic element 1, a protective paint layer 4 (S2A) is sprayed on the surface of the conductive paint layer 3. If necessary, when spraying the protective paint layer 4, the grounding plate 12 or the original grounding terminal of the magnetic element 1 (not shown) can be shielded to prevent the protective paint layer 4 from covering the grounding plate 12 or the original grounding terminal of the magnetic element 1 (not shown).

As can be seen in FIG. 5 , an embodiment (II) of a magnetic element shielding method of the present invention includes shielding a plurality of pins 11 of a magnetic element 1 (S1); spraying an insulating coating layer 2 on the surface of the magnetic element 1 (S1A); spraying a conductive paint layer 3 on the surface of the magnetic element 1 (S2); shielding the conductive paint layer 3 at at least one predetermined position (S2B); spraying a protective paint layer 4 on the surface of the conductive paint layer 3 (S2A); removing the shielding of the conductive paint layer 3 (S2C); electroplating at least one grounding electrode 31 on the conductive paint layer 3 (S2D); and removing the shielding of each pin 11 (S3).

In the second embodiment, the grounding plate 12 is not installed, but the predetermined position is masked after the conductive paint layer 3 is sprayed. In the second embodiment, the bottom surface of the body 13 is not provided with the opposite sides of the pin part 11. After the electrically insulating protective paint layer 4 is sprayed, the masking of the conductive paint layer 3 is removed to perform electroplating to produce the grounding electrode 31. The user can select different production processes. The masking of each pin part 11 is removed after the grounding electrode 31 is completed, so that each pin part 11 will not be affected during the electroplating process.

In FIG. 6 and FIG. 7, the embodiment (II) of the shielded magnetic element of the present invention includes: a magnetic element 1, which includes a body 13 and a plurality of pins 11; and a conductive paint layer 3, which is arranged on the surface of the magnetic element 1, and the conductive paint layer 3 and each pin 11 are insulated. In the embodiment (II), an insulating coating layer 2 is provided between the main body 13 and the conductive paint layer 3; in the embodiment (II), a protective paint layer 4 is provided on the outer side of the conductive paint layer 3, the protective paint layer 4 has an opening at at least one predetermined position, and the conductive paint layer 3 is provided with at least one grounding electrode 31 at the position corresponding to the opening. The protective paint layer 4 of the embodiment (II) has openings on both opposite sides, and the conductive paint layer 3 is provided with a grounding electrode 31 at the position corresponding to the opening by electroplating.

However, the above is only a preferred embodiment of the present invention and should not be used to limit the scope of the present invention. Any changes and modifications that are obviously possible for people skilled in the art should be considered as not deviating from the essential content of the present invention.

1: Magnetic element 11: Pin 12: Grounding plate 13: Body 2: Insulation coating 3: Conductive paint layer 31: Grounding electrode 4: Protective paint layer S1~S3: Steps S1A: Steps S1B: Steps S2A: Steps

The first figure is a flow chart of the embodiment (I) of the magnetic element shielding method of the present invention. The second figure is a three-dimensional diagram of the embodiment (I) of the present invention with a shielded magnetic element. The third figure is a longitudinal cross-sectional diagram (I) of the embodiment (I) of the present invention with a shielded magnetic element. The fourth figure is a longitudinal cross-sectional diagram (II) of the embodiment (I) of the present invention with a shielded magnetic element. The fifth figure is a flow chart of the embodiment (II) of the magnetic element shielding method of the present invention. The sixth figure is a three-dimensional diagram of the embodiment (II) of the present invention with a shielded magnetic element. The seventh figure is a longitudinal cross-sectional diagram of the embodiment (II) of the present invention with a shielded magnetic element.

without

S1~S3: Steps

S1A: Steps

S1B: Steps

S2A: Steps

Claims (5)

A magnetic component shielding method includes: shielding a plurality of pins of a magnetic component; spraying a conductive paint layer on the surface of the magnetic component; and removing the shielding of each pin. In the magnetic element shielding method described in claim 1, after shielding the pin portion of the magnetic element, an insulating coating is sprayed on the surface of the magnetic element. In the magnetic element shielding method described in claim 1, at least one grounding plate is provided on the surface of the magnetic element before spraying the conductive paint layer. In the magnetic component shielding method described in claim 1, after spraying the conductive paint layer, a protective paint layer is sprayed on the surface of the conductive paint layer. As described in claim 4, the magnetic element shielding method includes masking the conductive paint layer at at least one predetermined position before spraying a protective paint layer on the surface of the conductive paint layer, removing the masking of the conductive paint layer after spraying a protective paint layer on the surface of the conductive paint layer, and then electroplating at least one grounding electrode on the conductive paint layer.

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