KR20230051026A - Method of manufaturing wireless charging module coated with magnetic material on the coil surface - Google Patents

Abstract

The present invention relates to a method for manufacturing a coil module that wirelessly receives or transmits power or signals by using an electromagnetic field, the method comprising the steps of: preparing a substrate; forming a coil on the substrate; and forming a magnetic unit that covers at least a portion of the coil by directly coming in contact with the surface of the coil and acts as an electro-magnetic booster that improves the strength of an electromagnetic field generated on the surface of the coil. The magnetic unit is formed by at least one of electroless plating, electrolytic plating, deposition, coating, and printing methods.

Description

Method of manufacturing a wireless charging coil module with magnetic components coated on the coil surface {METHOD OF MANUFATURING WIRELESS CHARGING MODULE COATED WITH MAGNETIC MATERIAL ON THE COIL SURFACE}

The present invention relates to a method of manufacturing a coil module in which a magnetic component is coated on a surface of a coil.

In the present invention, a wireless power transfer (WPT) function, a near field communication (NFC) function, a magnetic secure transmission (MST) function, and the like are recently employed in mobile portable devices. Wireless charging (WPT), near field communication (NFC), and electronic payment (MST) technologies differ in operating frequency, data transmission rate, and amount of power transmitted.

In the case of such a wireless power transmission device, various types of coils are used, and WPT, NFC, and MST technologies are implemented using magnetic and electric fields formed by the coils.

Recently, as the demand for miniaturization and multifunctionalization of electronic devices increases, the need for thinning of wireless charging modules or magnetic sheets included in them is increasing, and at the same time, demand for coil modules with good heat dissipation performance in addition to high-efficiency signal transmission and power transmission is increasing. are doing

An object of the present invention is to provide a method for manufacturing a wireless charging coil module having good heat dissipation effect and high efficiency wireless charging efficiency when transmitting and receiving wireless power for a long time, low power and medium/high power.

The present invention relates to a method for manufacturing a coil module that wirelessly receives or transmits power or a signal using an electromagnetic field, comprising the steps of preparing a substrate; forming a coil on the substrate; and forming a magnetic part that directly contacts the surface of the coil to cover at least a portion of the coil and acts as an electro-magnetic booster to improve the strength of an electromagnetic field generated on the surface of the coil, The magnetic part isolates power between the coils rotating in one direction to reduce a separation effect between a skin effect and a proximity effect of an eddy current generated in the coil. do.

In one embodiment of the present invention, the forming of the magnetic portion may be performed by including at least one of electroless plating, electrolytic plating, deposition, coating, and printing.

In one embodiment of the present invention, when the magnetic part is formed by using at least one of the electroless plating, the deposition, the coating, and the printing method, before forming the magnetic part, a region in which the magnetic part is to be formed is selected. A masking step of covering the excluded coil region may be preceded.

In one embodiment of the present invention, when the magnetic part is formed by using the electrolytic plating method, a current may be applied only to a region where the magnetic part is to be formed.

In one embodiment of the present invention, the step of polishing and removing the magnetic portion formed on the upper surface of the coil may be further included.

In one embodiment of the present invention, the forming of the coil and the forming of the magnetic part may be performed in a single process.

In one embodiment of the present invention, the coil and the magnetic part form a conductive film on the substrate, form a photoresist film on the conductive film, expose and develop the photoresist film to form a photoresist film pattern, and form the photoresist film pattern. It can be manufactured by forming a coil by etching the conductive film using as a mask. Here, the coil and the magnetic part may be manufactured by further including forming a magnetic part on the substrate and lifting off the photoresist film pattern and the magnetic part on the photoresist film pattern.

In one embodiment of the present invention, the photoresist layer may be provided as a dry film type photoresist.

In one embodiment of the present invention, manufacturing the coil module may further include removing the substrate from the coil and the magnetic part and transferring the coil and the magnetic part to a separate substrate. .

In one embodiment of the present invention, at least one step of forming the coil and forming the magnetic part is roll-to-roll and/or panel-to-panel can be performed with

In one embodiment of the present invention, the coil may be provided as a wire having a circular cross section perpendicular to the longitudinal direction.

In one embodiment of the present invention, the magnetic part may cover at least a part of an upper surface and a side surface of the coil.

In one embodiment of the present invention, the magnetic portion provided between the coils adjacent to each other may have a spaced portion between the coils adjacent to each other.

In one embodiment of the present invention, the cross section perpendicular to the longitudinal direction of the coil is a circular wire shape, and the magnetic part may cover the entire outer circumferential surface of the coil.

In one embodiment of the present invention, a cross section perpendicular to the longitudinal direction of the coil may be a quadrangle.

In one embodiment of the present invention, in the coils arranged in the first direction, the magnetic parts may be provided alternately.

In one embodiment of the present invention, the magnetic part is at least one of a metal sintered body, a nanocrystal, amorphous, metallic or ferrite sintered body, a ferrite composite, a Sendust sintered body, and a Sendust composite. can include

In one embodiment of the present invention, the magnetic part Fe, Ni, Co, Mn, Al, Zn, Cu, Ba, Ti, Sn, Sr, P, B, N, C, W, Cr, Bi, Li, It may consist of a combination of two or three or more elements selected from the group consisting of Y and Cd.

In one embodiment of the present invention, the magnetic part may include Fe, Ni, Mn, and C.

In one embodiment of the present invention, the magnetic part may further include Si and B as impurities.

In one embodiment of the present invention, the substrate may be provided as a rigid printed circuit board, a flexible printed circuit board, or a rolled copper printed circuit board.

In one embodiment of the present invention, the coil is provided as a winding wire, and the coil may include at least one of a copper coil, a multi-wire copper coil, a multilayer ceramic capacitor coil, a low-temperature co-fired ceramic coil, and a ceramic winding coil.

According to an embodiment of the present invention, the present invention provides a method for manufacturing a coil module having good heat dissipation effect and high efficiency wireless charging efficiency when transmitting and receiving wireless power for a long time and with low power and medium/high power.

1 is a schematic external perspective view of a wireless charging system according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically illustrating an exploded main internal configuration of FIG. 1 .
3 is a plan view illustrating a coil module according to an embodiment of the present invention.
4 is a plan view illustrating a coil module according to an embodiment of the present invention.
5 illustrates that two coil parts are provided in a coil module according to an embodiment of the present invention.
6 illustrates the shape of a coil according to an embodiment of the present invention.
FIG. 7 is a cross-sectional view taken along the line A-A' of FIG. 3 .
8A to 8E, and FIGS. 9A and 9B are cross-sectional views illustrating the shape of a first spiral coil according to example embodiments.
10A and 10B are cross-sectional views schematically illustrating a manufacturing method according to an embodiment of the present invention.
11A to 11D show various shapes that can be manufactured when a magnetic part is formed using plating.
12A to 12D are cross-sectional views schematically illustrating steps of forming a coil unit using a photoresist film.
13A and 13B are cross-sectional views schematically illustrating some of the steps of forming a coil unit using a photosensitive film.
14 is a cross-sectional view schematically illustrating a method of forming a coil unit using transfer.
15A and 15B conceptually disclose a process performed in a roll-to-roll method or a panel-to-panel method, respectively.

Although the following terms are believed to be well understood by those skilled in the art, the following definitions are provided to facilitate explanation of the presently disclosed subject matter.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the presently disclosed subject matter belongs. Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the presently disclosed subject matter, representative methods, devices, and materials are now described.

The present invention relates to a method for manufacturing a coil module including an antenna or coil used to transmit or receive power or signals using an electromagnetic field, and in particular, a coil module in which a magnetic part is directly coated on a surface of a coil to minimize the proximity effect. It relates to a manufacturing method. The coil is used as an antenna and may also be referred to as an antenna, but in this specification, all are referred to as coils for convenience of description.

In one embodiment of the present invention, the coil module may be used in a wireless charging device, but is not limited thereto and may be used in various signal transmission/reception. Hereinafter, for convenience of description, the coil module will be mainly described as being used in a wireless charging device, but is not limited thereto, and its use may be variously changed within the limits of the concept of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic external perspective view of a wireless charging system according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view schematically showing the disassembled main internal components of FIG. 1 .

Referring to FIGS. 1 and 2 , the wireless charging system may include a wireless power transmitter 20 and a wireless power receiver 10 . The wireless power receiver 10 may be included in various electronic devices 30 such as mobile phones, laptops, and tablet PCs.

The wireless power receiver 10 may include a battery 13 and a receiver coil module 11 for charging the battery 13 by supplying power to the battery 13 .

The battery 13 may be a nickel metal hydride battery or a lithium ion battery capable of charging and discharging, but is not particularly limited thereto. In addition, the battery 13 may be configured separately from the wireless power receiver 10 and implemented in a form that can be attached to or detached from the wireless power receiver 10, or the battery 13 and the wireless power receiver 10 may be It may also be implemented as an integrally configured unit.

The wireless power transmitter 20 is for charging the battery 13 of the wireless power receiver 10 and may include a device substrate and a transmitter coil module 21 therein. The transmitter coil module 21 may be provided on a device substrate.

The wireless power transmitter 20 may convert AC power supplied from the outside into DC power, convert the DC power back into an AC voltage of a specific frequency, and provide the converted AC voltage to the wireless power transmitter 10 . When the AC voltage is applied to the transmitter coil module 21 in the wireless power transmitter 20, the magnetic field of the transmitter coil module 21 is changed. When the magnetic field formed by the transmitter coil module 21 changes, the magnetic field in the receiver coil module 11 of the wireless power receiver 10 also changes, and the voltage changes according to the change in the magnetic field in the receiver coil module 11. When applied, the battery 13 is charged.

The transmitter coil module 21 and the receiver coil module 11 may be coupled electromagnetically. The transmitter coil module 21 and the receiver coil module 11 may each include a coil formed by winding a metal wire such as copper on a plane. In this case, the winding shape of the coil may be circular, elliptical, rectangular, or rhombic, and the overall size or number of windings may be appropriately controlled and set according to required characteristics.

A magnetic sheet may be additionally disposed between the receiver coil module 11 and the battery 13 and/or between the transmitter coil module 21 and the device substrate. It is positioned between them to focus the magnetic flux so that it can be efficiently received at the receiver coil module 11 side. In addition, the magnetic sheet serves to block at least a portion of the magnetic flux from reaching the battery 13 .

In one embodiment of the present invention, in addition to the wireless charging device, the coil may also be used for magnetic secure transmission (MST), near field communication (NFC), and the like. This will be described later.

Hereinafter, when there is no need to specifically distinguish, both the transmitter coil module 21 and the receiver coil module 11 will be referred to as coil modules, and in the following embodiments, the receiver coil module will be described as an example.

3 illustrates a coil module according to an embodiment of the present invention.

Referring to FIG. 3 , an electronic device (eg, a wireless charging device) includes a coil module that wirelessly receives or transmits power or a signal using an electromagnetic field, and the coil module includes a substrate 101 and the substrate 101 ) and a coil unit 110 provided on at least one surface of the.

The substrate 101 has a flat plate shape (or sheet shape) and is disposed on one side of the coil unit 110 . The coil unit 110 may be provided directly on one surface of the substrate 101 or on one surface of the substrate 101 with another component such as an adhesive interposed therebetween. Hereinafter, the coil unit 110 provided on one side of the substrate 101 will be described as an example, but the relationship between the coil unit 110 and the substrate 101 is not limited thereto, and the coil unit 110 is the substrate ( 101) may be provided on both sides.

The substrate 101 is provided with a material having heat resistance and pressure resistance. The substrate 101 may be provided as a magnetic material. That is, the substrate 101 may be provided in the form of a magnetic sheet. The magnetic sheet is provided to efficiently form a magnetic path of the magnetic field generated by the coil 111 . To this end, the magnetic sheet may also be formed of a material in which a magnetic path can be easily formed. The magnetic sheet may be formed of a ferrite sheet. However, the magnetic sheet is not limited to the ferrite sheet as having magnetism, and may be at least one of a ferrite sheet, a soft magnetic metal sheet, and a hybrid type sheet in which metal and ferrite are applied in combination. In addition, it may be a thin sheet manufactured by slicing a metal thin film and dispersing and compressing it in an insulating resin. Various ferrite material compositions may be used, for example, Fe, Fe-Si, Fe-Al-Si, Fe-Ni, Fe-Co, etc. may be used, and various materials other than ferrite may be used as long as they are magnetic materials. can

The substrate 101 may be made of other insulating materials. For example, the substrate 101 may be made of a polymer material such as epoxy resin. However, the material of the substrate 101 is not limited thereto, and the printed circuit board 101 (printed circuit board, PCB), ceramic substrate 101, pre-molded substrate 101, or DBC It may be a direct bonded copper substrate 101 or an insulated metal substrate 101 (IMS). However, the material of the substrate 101 is not limited thereto, and various insulating materials may be used. When the substrate 101 is made of a material other than a magnetic material, a separate magnetic material sheet may be additionally provided between the substrate 101 and the battery. In this case, the additional magnetic material sheet is used to efficiently form a magnetic path and at the same time block the magnetic path toward the battery.

According to this embodiment, the substrate 101 may be provided as rigid, but is not limited thereto, and may be provided as ductility, that is, flexibility. Such a rigid or flexible board may be provided in various forms, such as a rigid printed circuit board, a flexible printed circuit board, or a rolled copper board that may be used as a lead frame.

The coil unit 110 may be provided in the form of a wire on at least one surface of the substrate 101 . That is, the coil unit 110 may be provided on at least one surface of the substrate 101 on a plane formed by one surface of the substrate 101 and may include a spiral coil 110c provided in a spiral shape.

The spiral coil 110c may include a coil 111 made of a conductor, for example, metal, and a magnetic part 113 covering at least a portion of the coil 111 . The coil part 110 may also include first and second drawing parts 117a and 117b provided at both ends of the coil 111 and extending outwardly of the spiral coil 110c, the first and second It may include first and second terminal parts 115a and 115b provided at ends of the lead parts 117a and 117b to be connected to other components (eg, circuit parts). In the present embodiment, the first and second terminal portions 115a and 115b are illustrated as being provided within the rectangular substrate 101, but are not limited thereto, and are formed to extend for electrical connection to the outside and form one side of the substrate 101. can protrude from The first and second terminal units 115a and 115b may include a plurality of connection terminals.

In this embodiment, the coil 111 may be formed of a circular, elliptical, or polygonal planar coil wound in a clockwise or counterclockwise direction. The shape of the coil 111 is not limited to the drawing, and may be formed in the form of a winding wire. It may be formed as a single wire coil, a Litz wire formed with multiple strands, or a polyurethane enameled wire (UEW) coil. In one embodiment of the present invention, the material of the coil is also not limited, and may be made of a material including copper or ceramic. Types of such coils include the aforementioned Litz wire or UEW wire as copper coils, and multilayer ceramic capacitor coils (MLCC) and low-temperature co-fired ceramic coils (LTCC) as materials for winding coils containing ceramics.

In this embodiment, the coil 111 may be arranged in a spiral shape starting from the central portion of the substrate 101 . At this time, according to the embodiment, the rotation direction of the coil 111 may be provided so as to spirally rotate from the inside to the outside. The coil 111 is shown in a circular spiral shape in the drawings, but is not limited thereto, and is formed in a spiral shape and can be applied to any shape capable of generating resonance by rotating in the same current direction.

The above-described coil 111 can function as a coil 111 for WPT when power transmission is required, and can function as a coil 111 for MST when magnetic information needs to be transmitted wirelessly. It may also be provided as a coil 111 for NFC. In this embodiment, the case where the coil 111 performs multi-function has been described as an example, but is not limited thereto, and the coil 111 may be formed of a WPT coil 111 performing a power transmission function.

The coil 111 may be provided only on the front surface of the substrate 101, or may be provided on both the front and rear surfaces. When coils 111 are provided on both the front and rear surfaces, the two coils 111 may be electrically separated from each other, or may be electrically connected by at least partly connected via vias or the like. In other words, when the coils 111 are formed on both sides of the substrate 101, both ends of each coil 111 are electrically connected to form a parallel circuit as a whole, or one central end is connected to form a series circuit. can form To this end, conductive vias (not shown) may be formed inside the coils 111 to electrically connect the coils 111 to each other.

Here, at least one of the first and second lead-out portions 117a and 117b is disposed with an intersecting wire and a separate insulator interposed therebetween to prevent a short circuit with the intersecting wire, or provided on the other side through a via. It may also be configured to be connected through wiring.

The above-described structure of the coil module has been described as an example, and in one embodiment of the present invention, the connection relationship or the number or arrangement of coils 111 may be modified in various forms.

4 is a plan view illustrating a coil module according to an embodiment of the present invention.

Referring to FIG. 4 , in the coil module according to an exemplary embodiment of the present invention, lead parts and terminal parts connected to both ends of the coil unit 110 may be separately manufactured and connected. That is, the coil 111, the first and second lead-out portions 117a and 117b connected to both ends of the coil 111, and the first and second terminal portions 115a and 115b are spiral coils on the substrate 101. It is not disposed on the substrate 101 as in (110c), but may be made of a bridge BR, which is a separate component from the substrate 101, and attached to the substrate 101. Here, first and second pad parts (not shown) are provided at both ends of the coil 111 . The bridge BR includes first and second bridge pads 119a and 119b corresponding to first and second pad parts at both ends of the coil 111, and the first and second bridge pads 119a and 119b. and first and second terminal portions 115a and 115b connected to the first and second lead-out portions 117a and 117b, respectively. The first and second bridge pads 119a and 119b, the first and second lead-out portions 117a and 117b, and the first and second terminal portions 115a and 115b may be formed on the bridge substrate 101. And the bridge substrate 101 may be a rigid or flexible substrate 101.

The first and second bridge pads 119a and 119b are connected to the first and second pad parts of the coil 111 with a conductor. For example, the first and second bridge pads 119a and 119b and the first and second pad portions of the coil 111 may be connected by soldering using heat, ultrasonic waves, laser, etc., but are not limited thereto, and anisotropic It can be bonded in various ways, such as using a conductive film.

Here, the configuration of the bridge BR is shown as an example for electrically connecting both ends of each coil 111 to another configuration, but is not limited thereto, and can be modified in various forms.

5 illustrates that two coil parts are provided in a coil module according to an embodiment of the present invention.

In the present embodiments, in order to distinguish different coil units from each other, the coil unit described in the above-described embodiment is described as the first coil unit 110, and the added coil unit is described as the second coil unit 120, For convenience of description, the description will focus on differences from the above-described embodiment.

In one embodiment of the present invention, the coil module is provided on at least one surface of the substrate 101, the first coil unit 110 having a spiral shape and provided on at least one surface of the substrate, the first coil unit 110 It may include a second coil unit 120 disposed outside.

The first coil part 110 includes a first spiral coil 110c, first and second lead-out parts 117a and 117b connected to the first spiral coil 110c, and first and second terminal parts 115a, 115b), and the second coil unit 120 includes a second spiral coil 120c, and first and second lead-out units 127a and 127b connected to the second spiral coil 120c, respectively, and the first and second spiral coils 120c. It includes second terminal parts 115a and 115b.

Subsequently, the second spiral coil 120c is provided on at least one surface of the substrate 101, and is disposed outside the first spiral coil 110c to surround the first spiral coil 110c as a whole. In the present embodiment, the second spiral coil 120c is illustrated as having a separate lead-out portion and a terminal portion, but is not limited thereto, and one end of the second spiral coil 120c is connected to the first coil and the other end is a terminal portion. may be connected to

The second spiral coil 120c is generally disposed outside the first spiral coil 110c, but is not limited thereto, and at least a portion may be provided in a form crossing the first spiral coil 110c.

In one embodiment of the present invention, the second spiral coil 120c can function as a coil for MST when magnetic information must be transmitted wirelessly, and can also be used as a coil for NFC for short-range wireless communication.

In one embodiment of the present invention, when the frequency band of the second spiral coil 120c is provided higher than that of the first spiral coil 110c, the conductive pattern has a finer line width than that of the first spiral coil 110c. may be formed, and the wiring interval may be formed narrower than that of the first spiral coil 110c.

In one embodiment of the present invention, the coil module may be provided in various shapes.

FIG. 6 shows the shape of a coil according to an embodiment of the present invention, and unlike FIG. 5, the first spiral coil 110c and the second spiral coil 120c have different shapes in a spiral arrangement on a plane. started that.

Referring to FIG. 6 , when viewed from a plane, the first spiral coil 110c has a helical structure but has a square shape, and the second spiral coil 120c has a circular shape as a spiral structure outside the first spiral coil 110c. have The embodiment of FIG. 5 described above is different from the present embodiment in that the first spiral coil 110c has a circular shape and the second spiral coil 120c has a square shape. As such, the first spiral coil 110c and the second spiral coil 120c may have different shapes, and even shapes not shown here may be variously modified without departing from the concept of the present invention.

5 and 6, the first spiral coil 110c and the second spiral coil 120c may be independently used as one of a WPT coil, an NFC coil, and an MST coil. This combination of the first spiral coil 110c and the second spiral coil 120c is, for example, a coil for WPT and a coil for NFC, or a coil for MST and a coil for WPT, or a coil for MST and a coil for NFC, respectively. It can be used as a coil or the like. However, the use of the coil is not limited thereto, and may be used for other purposes, as well as undisclosed coils may be further added.

According to an embodiment of the present invention, in the above-described various coil modules, the coil unit includes a magnetic unit that acts as an electromagnetic booster that enhances the strength of an electromagnetic field generated on the surface of the coil. A detailed description of this is as follows.

FIG. 7 is a cross-sectional view taken along the line A-A' of FIG. 3 and showing the shape of a coil part.

3 and 7 , the coil module includes a substrate 101 and a coil unit 110 provided on at least one surface of the substrate 101, and the substrate 101 and the coil unit 110 An insulating part 103 may be provided between them.

The insulating part 103 is provided in the form of a film or film between the substrate 101 and the coil part 110, and the insulating part 103 is a material capable of insulating between the substrate 101 and the coil part 110. It is not limited to ramen, and may be made of various materials. For example, the insulating unit 103 may be formed of an organic insulating film, an inorganic insulating film, or an insulating film made of an organic-inorganic ionic thermoelectric composite.

The magnetic part 113 may directly contact the coil 111 but may cover at least a portion of an exposed surface of the coil 111 . The magnetic part 113 may be formed on the surface of the coil 111 through a process such as plating, deposition, or coating.

The magnetic part 113 is provided to increase wireless charging efficiency in the transmission and reception coils 111 of the wireless charger and to lower the heating temperature in the charger. For this, the magnetic part 113 needs to directly contact the coil 111, and at least a part of the magnetic part 113 directly contacts the coil 111. If another configuration is interposed between the magnetic part 113 and the coil 111, the effect of the magnetic material and the heat dissipation effect described below may be reduced.

The magnetic material has high magnetic permeability, and as the magnetic material is provided on the coil 111, it serves to strongly boost the strength of an electromagnetic field generated on the surface of the coil 111. do. This phenomenon appears to be due to the addition of a high magnetic component on the coil 111, which improves the magnetic permeability and reduces the investment loss and improves the bandwidth of the frequency used for wireless charging, which increases the efficiency of wireless charging. In addition, it is determined that the surface density of the electromagnetic field generated from the wireless charging coil 111 will be more concentrated on the surface of the metal coil 111.

The magnetic part 113 may be made of a magnetic material. For example, the magnetic material constituting the magnetic part 113 includes a metal sintered body, nanocrystal, amorphous, metallic or ferrite sintered body, ferrite composite, sendust sintered body, and sendust composite. etc. Such a magnetic body material is not particularly limited.

In one embodiment of the present invention, the magnetic part 113 is Fe, Ni, Co, Mn, Al, Zn, Cu, Ba, Ti, Sn, Sr, P, B, N, C, W, Cr, It may be made of an alloy magnetic body or a ferrite magnetic body made of a combination of two or three or more elements selected from the group consisting of Bi, Li, Y, Cd, and the like. In the magnetic part 113, the magnetic permeability of a magnetic material manufactured through a process of heat-treating or mixing the materials may be controlled. In particular, through a process of heat-treating or mixing materials including Fe, Ni, Mn, Si, B, and C, the magnetic permeability (Ur) of the product may be changed. In one embodiment of the present invention, the magnetic part 113 may include, in particular, Ni and Fe as main components, and the magnetic permeability (Ur) and magnetic flux density (Bs) may be controlled by adjusting the content of Fe. In addition, the magnetic part can control the coercive force by adjusting the content of Ni and Fe as a soft magnetic material. In one embodiment of the present invention, Si and/or B may be added as impurities in addition to the material of the magnetic part 113 .

Permeability and investment loss of the wireless transmission/reception device may vary depending on the thickness of the magnetic portion 113, and the thickness of the magnetic portion 113 may be about 0.01 um to about 80 um in one embodiment, and in another embodiment may be from about 0.1 um to about 40 um, and may be from about 1 to about 5 um in another embodiment. In the present embodiment, when the magnetic portion 113 is formed to be excessively thick on the upper surface 111x of the coil 111, the strength of the magnetic field in the upper direction may be lowered, and in this case, there may be a problem in signal transmission or power transmission. . Accordingly, the thickness of the upper surface 111x of the coil 111 may have the above-mentioned value. However, even in this case, this value may be changed according to the state or structure of the coil 111 and other factors. In this embodiment, the magnetic permeability of the magnetic part 113 may be about 50 u' to about 3000 u' in one embodiment, and about 100 u' to about 2000 u' in another embodiment.

The coil 111 may be provided in various shapes when viewed in cross section. In one embodiment of the present invention, the coil 111 may be provided in a circular shape or a polygonal shape contacting the substrate 101 or the insulating portion 103 on the substrate 101 . For example, the coil 111 may have a quadrangular cross section (rectangular shape or trapezoidal shape, etc.). However, the shape of the coil 111 is not limited thereto.

In one embodiment of the present invention, the magnetic part 113 may cover at least a part of the upper surface 111x, the side surface 111y, and the lower surface of the coil 111, for example, the coil 111 ) Covers both the upper surface 111x and the side surface 111y, covers at least one of the upper surface 111x and the side surface 111y, or, if necessary, covers only at least a portion of the upper surface 111x and the side surface 111y. may cover. In addition, the lower surface of the coil 111 can also be covered as needed.

In this embodiment, the magnetic part 113 may cover both the top surface 111x and the side surface 111y of the coil 111 . Here, a spaced portion S may be provided between the coils 111 covered by the magnetic portion 113 and the coils 111 . In this case, an insulating material may be provided in the spaced portion to sufficiently insulate the two adjacent spiral coils 110c from each other. The insulating material may be provided to prevent a short circuit between two magnetic parts 113 adjacent to each other. For example, air may be provided to the spaced portion.

In one embodiment of the present invention, other additional insulation parts other than air may be provided in the spaced part.

For convenience, when the insulating part 103 between the coil 111 and the substrate 101 is referred to as a first insulating part 103 and the insulating part provided on the spiral coil 110c is referred to as a second insulating part, the The first and second insulating parts may be made of various insulating materials, for example, polymer resin. The second insulating part may be provided between adjacent spiral coils 110c and on an upper portion of the spiral coils 110c to cover each of the spiral coils 110c. Materials constituting the first and second insulating parts are not limited thereto, and may be the same as or different from each other.

According to one embodiment of the present invention, the coil module according to one embodiment of the present invention is divided into a plurality of coils 111, the surface is divided into a plurality of pieces, and provided in the form of a wire covered with a magnetic material on the surface, so that the skin The skin effect is maximized. In addition, the proximity effect of interconnections adjacent to each other is reduced through the plurality of separated structures. That is, the magnetic part reduces the skin effect and proximity effect of the eddy current generated in the coil, which uses a magnetic material between coils rotating in one direction. This is done in a way to isolate the power. When the skin effect is increased and the separation effect is reduced in this way, the eddy current effect is minimized, thereby increasing wireless charging efficiency and reducing heat generation.

Through this, the coil module according to an embodiment of the present invention may have a good heat dissipation effect and high efficiency wireless charging efficiency when transmitting and receiving low power and medium/high power wireless power for a long time.

In other words, when the coil module according to an embodiment of the present invention having the above structure is used as a wireless charging transmission/reception coil, a magnetic material having high permeability is added to the surface of the wireless charging transmission/reception coil to provide an electromagnetic field (Electro-magnetic field). ) plays a role in strongly promoting (Booster) strength. Due to the addition of the high magnetic component in the wireless charger, the magnetic permeability is improved, the investment loss is reduced, and the wireless charging use frequency bandwidth is improved, and as a result, the wireless charging efficiency is increased. Here, the surface density of the electromagnetic field (Electro-magnetic-Field) generated from the wireless charging transceiver coil is more concentrated on the coil surface.

In the case of the existing invention, a magnetic sheet is provided under the coil 111 and has a structure in which a heat dissipating sheet such as graphite is laminated as a material for heat dissipation separately from the magnetic sheet. In this laminated structure, the magnetic sheet serves as a gate through which the electromagnetic field emitted from the metal coil 111 passes through the magnetic layer, which activates the horizontal electromagnetic field. play a role However, in the case of the present invention, by covering the coil 111 with the magnetic component as well as the horizontal electromagnetic field (Electro-Magnetic Field) due to the magnetic material in the central portion, the covered magnetic field forms the electromagnetic field (Electro-Magnetic Field) formed by the coil 111. Field) operates as an electromagnetic booster.

In one embodiment of the present invention, the shape of the first spiral coil 110c of the coil unit 110, in particular, the shape of the coil 111 and the magnetic body may be changed in various forms.

8A to 8E, and FIGS. 9A and 9B are cross-sectional views illustrating the shape of the first spiral coil 110c according to example embodiments.

8A to 8E, the magnetic part 113 is provided only on the upper surface 111x of the coil 111 as shown in FIG. 8A, or the coil 111 as shown in FIGS. 8B and 8C. It may be provided only on the side surface 111y of or provided on the side surface 111y and the lower surface of the coil 111 as shown in FIG. 8D. Here, FIGS. 8B and 8C show that a magnetic material is provided between two coils 111 adjacent to each other, with and without a spacer for separating the magnetic material.

In addition, as shown in FIG. 8E , it may be provided only on the top surface 111x and side surface 111y of some coils 111 and may not be provided on the other coils 111 . When the magnetic part 113 is provided in only some of the coils 111 , the coils 111 provided with the magnetic part 113 and the coils 111 not provided may be alternately disposed.

In addition, as shown in FIGS. 9A and 9B, the coil 111 may have a circular cross section, that is, a wire shape, and even when the coil 111 has a circular cross section, the magnetic part 113 may cover the outer surface of the coil 111. Alternatively, the magnetic part 113 may be provided to some coils 111 but not provided to others. Also, the coil 111 and the magnetic part 113 may be surrounded by a second insulating part without a first insulating part or a substrate.

In this way, when the magnetic part 113 is provided on the coil 111, the coil 111 and/or the magnetic part 113 may be regularly or irregularly provided, and the adjacent coils 111 and/or Distances between the magnetic parts 113 may be equal to or different from each other. The magnetic part 113 and the coil 111 can be arranged in various forms, such as the thickness of the coil 111, the arrangement interval of the coil 111, the arrangement form of the coil 111, and the size of the magnetic part 113. It can be deformed into various forms according to the material and magnetic permeability according to the material of the magnetic part 113 .

The coil module according to one embodiment of the present invention described above can be manufactured by various methods. Hereinafter, a method of manufacturing the coil module will be described as an example, and various methods of manufacturing the coil module to be described later may be variously combined or modified without departing from the concept of the present invention.

10A and 10B are cross-sectional views schematically illustrating a manufacturing method according to an embodiment of the present invention.

10A and 10B , the coil module according to an embodiment of the present invention prepares a substrate 101, forms a coil 111 on the substrate 101, and forms a coil 111 on the coil 111. It can be manufactured by forming the magnetic part 113 . The magnetic part 113 is made to directly contact the coil 111 and cover at least a portion of the coil 111 .

The substrate 101 is provided in a plate shape so that the coil unit 110c can be provided on at least one surface. The substrate 101 may be made of a magnetic material having insulating properties.

An insulating portion 103 may be additionally provided on the substrate 101 . In one embodiment of the present invention, after the step of preparing the substrate 101, the step of forming the insulating portion 103 on the substrate 101 may be added. In the following embodiment, the provision of the insulating portion 103 on the substrate 101 will be described as an example, and the provision of only the substrate 101 without indicating the insulating portion 103 will be described as necessary. Even when only the substrate 101 is provided, the insulating portion 103 may be provided on the upper surface of the substrate 101 . The insulating portion 103 may be formed on the substrate 101 in various ways, such as deposition, coating, laminating, and printing, depending on the material.

The coil part 110c is formed on the substrate 101 . As shown in FIG. 10A, the coil part 110c includes the steps of forming the coil 111 on the substrate 101 and, as shown in FIG. 10B, covering at least a portion of the coil 111. Forming the magnetic part 113 is included.

In the step of forming the coil part 110c, the coil 111 may be formed first and then the magnetic part 113 may be formed.

The coil 111 may be made of various conductive materials, in particular, may be made of a metal material, but is not limited thereto.

In order to form the coil 111 on the substrate 101, various methods such as a plating method, a deposition method, a coating method, and a printing method may be used. In the case of using a plating method, the coil 111 may be formed using an electrolytic plating method or an electroless plating method. In the case of using the deposition method, the coil 111 may be formed by depositing a metal film on the entire surface of the substrate 101 and then performing patterning.

The magnetic part 113 directly contacts the coil 111 and is formed to cover at least a portion of the coil 111 . To this end, a magnetic portion 113 is formed on the substrate 101 on which the coil 111 is formed, and the magnetic portion 113 is formed on the entire surface using a deposition method or the like, and then etched to have a specific shape. Patterning may be performed, or the magnetic part 113 may be directly formed into a specific shape without forming the entire surface. In the former case, the coil 111 may be manufactured by using a photoresist film to expose and develop, pattern the photoresist film, and then etch the metal film using the patterned photoresist film as a mask. In the latter case, the coil 111 may be manufactured by performing a region-selective measure, such as masking an area other than the region to be formed or applying current only to the region to be formed. For masking, a polymer resin such as PET, PI, PSA, or the like may be used.

In addition to measures such as etching, measures such as controlling the existence or thickness of the magnetic portion 113 on the upper surface using CMP (Chemical-mechanical polishing) are possible. For example, the magnetic part 113 formed on the upper surface of the coil 111 is removed by polishing to expose the upper surface 111x of the coil 111, or the magnetic part 113 provided on the upper surface of the coil part 110c thickness can be reduced.

For example, when the magnetic part 113 is formed by including the electroless plating, the deposition, and the coating method, before forming the magnetic part 113, a region in which the magnetic part 113 is to be formed is selected. A masking step of covering the area of the coil 111 excluded may be preceded. Also, for example, when the magnetic part 113 is formed by using the electroplating method, current may be applied only to a region where the magnetic part 113 is to be formed.

When the magnetic part 113 is patterned after plating or deposition, it is possible to selectively form the magnetic part 113 in various positions including the upper surface, side surface, or lower surface of the coil 111 .

11A to 11D show various shapes that can be manufactured when the magnetic part 113 is formed using plating.

Referring to FIG. 11A , the magnetic part 113 may be formed to cover both the top surface 111x and the side surface 111y of the coil 111 .

Referring to FIG. 11B , the magnetic part 113 is not formed on the upper surface 111x of the coil 111, but may be formed on the side surface 111y.

Referring to FIG. 11C , the magnetic part 113 may be formed on the upper surface 111x of the coil 111, but may not be formed on the side surface 111y.

Referring to FIG. 11D , the magnetic part 113 may cover both the upper surface 111x and the side surface 111y of the coil 111, but may also cover the lower surface. In the case of this coil 111, after manufacturing the coil 111 in which the magnetic part 113 is formed on the upper surface 111x and the side surface 111y, it is transferred to another substrate 101 to expose the lower surface, and then to the exposed lower surface. It can be manufactured by forming the magnetic part 113 or the like. A method of forming the coil unit 110c using transfer will be described later.

Here, although the wire-shaped coil 111 having a circular cross section is not shown, the magnetic part 113 may be formed on the surface of the wire-shaped coil 111 by directly immersing the wire in a plating solution. In the case of the wire-shaped coil 111, it is not easy to form the magnetic part 113 only on a part of the surface along the circumference, but after arranging the wire on the substrate 101 as necessary, the square-shaped coil 111 The magnetic part 113 may be formed in the same way as the method of forming the magnetic part 113 .

According to one embodiment of the present invention, a photoresist film may be used in the process of patterning after deposition.

12A to 12D are cross-sectional views schematically illustrating steps of forming a coil unit using a photoresist film.

12A to 12D, first, a conductive film ML is formed on a substrate 101, a photoresist film PS is formed on the conductive film ML, and then the photoresist film PS is exposed and The photoresist film pattern PSP is formed by development, the conductive film ML is etched using the photoresist film pattern PSP as a mask to form the coil 111, the photoresist film pattern PSP is removed, and then the photoresist film The coil part 110c may be manufactured by forming the magnetic part 113 on the coil 111 from which the pattern PSP is removed.

As disclosed in FIG. 12A, in this embodiment, the photoresist film PS may be formed on the substrate 101 on which a metal film is formed through coating or the like, but it is manufactured in the form of a photoresist film and formed on the substrate 101. may be laminated

The photosensitive film selectively reacts to specific light (eg, UV), and may be, for example, a dry film including a dry film-type photoresist. The photosensitive film is a film including a photosensitive material layer and may be laminated on a metal layer. Hereinafter, a photosensitive film used as a photosensitive film will be described using the same reference numerals as an example.

Thereafter, the photosensitive film PS may be exposed and developed using a mask (not shown). The mask may be a slit mask or a diffraction mask, and may include a first area that blocks all irradiated light and a second area that transmits all irradiated light.

After exposure, the photosensitive film on the substrate 101 is divided into a first area PSa and a second area PSb according to whether or not there is a photoreaction. After developing the exposed photosensitive film PS, a photosensitive film pattern PSP is formed in an area where all light is blocked, and the photosensitive film is completely removed in an area where all light is transmitted, thereby forming the metal layer 120. surface is exposed. However, in one embodiment of the present invention, a positive type photoresist is used to remove the photoresist from the exposed portion as described above, but it is not limited thereto, and in another embodiment of the present invention, the photoresist from the unexposed portion is removed. It is also possible to use a negative type photoresist film.

After the above process, as shown in FIG. 12B , the metal layer 120 may be etched and patterned using an etchant using the photosensitive film pattern PSP as a mask to form the coil 111 .

A magnetic part 113 may be formed on the formed coil 111 as shown in FIG. 12D. The magnetic part 113 may be formed on the surface of the coil 111 through a process such as plating, deposition, or coating.

In one embodiment of the present invention, when forming the coil unit 110c using the photosensitive film PS, it is possible to form the coil 111 and the magnetic unit 113 in a single process. For example, the metal layer ML may be etched using the photosensitive film pattern PSP, and then the magnetic portion 113 may be formed without removing the photosensitive film pattern PSP. 13A and 13B are cross-sectional views schematically illustrating some of the steps of forming the coil unit 110c using a photosensitive film.

Referring to FIGS. 13A and 13B , a photosensitive film PS is provided on the metal layer ML, the photosensitive film PS layer is exposed and developed (see FIG. 12A ), and then the photosensitive film pattern PSP is used as a mask. After the coil 111 is formed by patterning the metal film (see FIG. 12B), as shown in FIG. 13A, the upper surface of the substrate 101 on which the photosensitive film pattern PSP is formed may be plated. At this time, it may be plated so that both metals adjacent to each other are filled, or a separation space between the two metals is spaced apart from each other. In the drawings, for convenience of description, it is shown that the space between the two metals is completely filled with the magnetic part 113 .

Then, as shown in FIG. 13B , the photosensitive film pattern PSP and the magnetic part 113 on the photosensitive film pattern PSP may be lifted off. By removing only the photosensitive film pattern PSP and the magnetic portion 113 on the photosensitive film pattern PSP, only the coil 111 and the magnetic portion 113 between the coil 111 and the coil 111 remain, and the final An ideal coil unit 110c is formed. Here, a spaced portion may be provided between adjacent coils 111 during plating, or a spaced portion may be provided by an additional patterning process after removing the photosensitive film pattern and the magnetic portion 113 on the photosensitive film pattern.

According to an embodiment of the present invention, the coil part 110c may be directly formed on the substrate 101, but after forming the coil part 110c on a separate auxiliary substrate 101, the substrate 101 is formed. It can also be formed by way of transcription

14 is a cross-sectional view schematically illustrating a method of forming the coil unit 110c using transfer.

Referring to FIG. 14 , a coil 111 and a magnetic part 113 may be formed on a separate temporary substrate 101D. The coil 111 and the magnetic part 113 may be manufactured on the temporary substrate 101D through processes such as plating, deposition, coating, and printing.

The temporary substrate 101D may be removed from the coil unit 110c, thereby preparing the coil unit 110c in which the magnetic unit 113 is formed. The coil part 110c may be used alone, but may be transferred onto the substrate 101 according to an embodiment of the present invention. At this time, an insulating part 103 may be provided on the substrate 101 . An adhesive may be provided on the coil part 110c and the insulating part 103 as needed during transfer. Here, when the coil part 110c manufactured on the temporary substrate 101D is inverted and provided on the substrate 101, the upper surface of the coil part 110c may be exposed to the outside, and if necessary, the upper surface A magnetic part 113 may be additionally formed.

As described above, in the coil module according to an embodiment of the present invention, the coil unit can be manufactured in various ways, and these various methods can be combined with each other within the limit not departing from the concept of the invention.

In one embodiment of the present invention, in the method for manufacturing the coil module described above, at least some steps may be performed in a roll-to-roll or panel-to-panel manner. there is. In particular, at least one of the forming of the coil and the forming of the magnetic part may be performed in a roll-to-roll or panel-to-panel manner. In addition, when manufacturing the coil module, roll-to-roll and panel-to-panel methods may be combined with each other.

15A and 15B conceptually illustrate performing a process in a roll-to-roll or panel-to-panel manner, respectively.

Referring first to FIG. 15A , in one embodiment of the present invention, when manufacturing a coil module, the substrate 101 may be provided as a roll wound in one direction, and a predetermined process may be performed by sequentially unfolding the wound roll. . After the predetermined process is finished, the treated substrate 101 may be wound into a roll again. In addition, the finally processed roll may be cut and/or cut in units of coil modules.

In this drawing, for convenience of description, first, a first roll R1 on which the substrate 101 is wound is provided, and a first step PR1 of forming a coil 111 by sequentially unrolling the first roll R1 is performed. After performing the step of winding with the second roll R2, and performing the twelfth step PR2 of forming the magnetic part 113 by unrolling the second roll R2 again, the step of winding with the third roll R3. has been shown. Here, each of the first to third rolls R3 and the first step PR1 and the twelfth step PR2 are shown as examples to describe the roll-to-roll process, and the first step PR1 and the twelfth step In addition to (PR2), an additional step may be performed, and the substrate 101 may be wound or unwound between the first roll (R1) to the third roll (R3), and also, if any one roll is omitted and the roll is unwound A predetermined step may be performed in the state.

This roll-to-roll method can also be applied to a wire having a circular cross section of the coil 111 . In particular, in the case of wire, it is easier to proceed with the process in the form of winding.

Referring to FIG. 15B, the substrate 101 is provided in the form of a flat panel rather than in the form of a roll, and the first step (PR1) of forming the coil 111 is performed, and then the twelfth step of forming the magnetic part 113 ( PR2) may be performed. Here, the panels may be provided in various sizes and may be simultaneously manufactured in a plurality of coil modules, and the finally processed roll may be cut and/or cut in units of coil modules.

In one embodiment of the present invention, the coil module may be modified in various forms such as its connection relationship or the number or arrangement of coils 111, and such a coil module may be manufactured using the above-described method.

The coil module manufactured by the above-described method may be used in an electronic device thereafter. For example, after manufacturing a coil module, an electronic device may be manufactured by providing a battery on one side of the coil module and providing a magnetic sheet between the coil module and the battery.

As described above, according to an embodiment of the present invention, magnetic parts of various shapes can be easily formed on the coil. Accordingly, manufacturing of the coil module is facilitated. In addition, the coil module manufactured in this way has the effect of improving signal transmission, increasing wireless charging efficiency, and reducing the heating temperature in the coil module.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art or those having ordinary knowledge in the art do not deviate from the spirit and technical scope of the present invention described in the claims to be described later. It will be understood that the present invention can be variously modified and changed within the scope not specified.

Therefore, the technical scope of the present invention is not limited to the contents described in the detailed description of the specification, but should be defined by the claims.

10 Wireless power receiver 11 Receiver coil module
13 battery 20 wireless power transmitter 21 transmitter coil module 101 substrate
103 first insulator 105 second insulator
110 first coil unit 110c first spiral coil
111 Coil 111x Top
111y side 113 magnetic part
115a first terminal part 115b second terminal part
117a first drawing part 117b second drawing part
119a first pad part 119b second pad part
BR Bridge 120 Second Coil Unit
120c Second spiral coil 125a First terminal part
125b second terminal part 127a first lead-out part
127b second drawing part

Claims (24)

A method of manufacturing a coil module that wirelessly receives or transmits power or signals using an electromagnetic field,
Preparing a substrate;
forming a coil on the substrate; and
Forming a magnetic part that directly contacts the surface of the coil to cover at least a portion of the coil and acts as an electromagnetic booster to improve the strength of an electromagnetic field generated on the surface of the coil,
The magnetic part isolates power between the coils rotating in one direction to reduce a separation effect between a skin effect and a proximity effect of an eddy current generated in the coil. Coil module manufacturing method. According to claim 1,
The method of claim 1 , wherein the forming of the magnetic part includes at least one of electroless plating, electrolytic plating, deposition, coating, and printing. According to claim 2,
When the magnetic part is formed by using at least one of the electroless plating, the deposition, the coating, and the printing method, a masking step of covering the coil region except for the region where the magnetic part is to be formed is performed before forming the magnetic part. The preceding coil module manufacturing method. According to claim 3,
When the magnetic part is formed by using the electroplating method, a coil module manufacturing method comprising applying a current only to a region where the magnetic part is to be formed. According to claim 2,
The method of manufacturing the coil module further comprising removing the magnetic part formed on the upper surface of the coil by polishing. According to claim 1,
The method of manufacturing a coil module in which the forming of the coil and the forming of the magnetic part are performed in a single process. According to claim 6,
In the step of forming the coil and the magnetic part,
forming a conductive film on the substrate;
forming a photoresist film on the conductive film;
forming a photoresist pattern by exposing and developing the photoresist film; and
and forming a coil by etching the conductive layer using the photoresist layer pattern as a mask. According to claim 7,
forming a magnetic part on the substrate; and
The method of manufacturing a coil module further comprising lifting off the photoresist film pattern and a magnetic part on the photoresist film pattern. According to claim 7,
The method of manufacturing a coil module wherein the photoresist is provided as a dry film-type photoresist. According to claim 1,
removing the substrate from the coil and the magnetic part; and
The coil module manufacturing method further comprising transferring the coil and the magnetic part on a separate substrate. The method of claim 1 , wherein at least one of the forming of the coil and the forming of the magnetic part is performed in a roll-to-roll manner. 11 . The method of claim 1 , wherein at least one of the forming of the coil and the forming of the magnetic part is performed in a panel-to-panel fashion. According to claim 1,
The coil module manufacturing method wherein the coil is provided as a wire having a circular cross section perpendicular to the longitudinal direction. According to claim 1,
The coil module manufacturing method of claim 1 , wherein the magnetic part covers at least a portion of an upper surface and a side surface of the coil. According to claim 1,
The magnetic part provided between the coils adjacent to each other has a spaced portion between the coils adjacent to each other. According to claim 1,
A cross section perpendicular to the longitudinal direction of the coil is a circular wire shape, and the magnetic part covers the entire outer circumferential surface of the coil. According to claim 1,
The coil module manufacturing method of claim 1 , wherein a cross section perpendicular to the longitudinal direction of the coil is a rectangle. According to claim 1,
In the coils arranged in the first direction, the magnetic parts are alternately provided. According to claim 1,
The magnetic part includes at least one of a metal sintered body, a nanocrystal, an amorphous, metallic or ferrite sintered body, a ferrite composite, a Sendust sintered body, and a Sendust composite. Manufacturing method. According to claim 19,
The magnetic part is selected from the group consisting of Fe, Ni, Co, Mn, Al, Zn, Cu, Ba, Ti, Sn, Sr, P, B, N, C, W, Cr, Bi, Li, Y, and Cd. A method for manufacturing a coil module made of a combination of two or three or more elements. According to claim 20,
The coil module manufacturing method of claim 1, wherein the magnetic part includes Fe, Ni, Mn, and C. According to claim 21,
The coil module manufacturing method of claim 1 , wherein the magnetic part further includes Si and B as impurities. According to claim 1,
The substrate is provided as a rigid printed circuit board, a flexible printed circuit board, or a rolled copper printed circuit board. According to claim 3,
The coil is provided as a winding, and the coil includes at least one of a copper coil, a multi-wire copper coil, a multilayer ceramic condenser coil, a low-temperature co-fired ceramic coil, and a ceramic winding coil.

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