Wireless charging shield and manufacturing method thereof and wireless charger using the same

Abstract

The present disclosure relates to a wireless charging shield, a manufacturing method of the shield, and a wireless charger using the shield, which can improve the heat dissipation effect of the transmitting coil. The wireless charging shield according to an embodiment of the present disclosure includes: a placement portion, on which the transmitting coil is placed; and a transfer portion, which integrally extends to the lower part of the placement portion to transfer the heat generated in the transmitting coil, wherein a plurality of transmitting coils are placed on the placement portion, and the height of the placement area where each transmitting coil is placed is set to be different from the height of the placement areas adjacent to each other.

Description

Technical Field

[0001] The present disclosure generally relates to a wireless charging shield, a manufacturing method thereof, and a wireless charger using the same. More specifically, the present disclosure relates to a wireless charging shield capable of improving the heat dissipation effect generated in a transmitting coil, a manufacturing method thereof, and a wireless charger using the same. Background Art

[0002] Generally, charging of electrical devices is divided into contact charging method and non-contact charging method.

[0003] The contact charging method is a method of performing charging by bringing the electrodes of the battery connection of the electrical device and the electrodes of the power supply device into direct contact with each other. This contact charging method is generally widely used due to its simple structure. However, there are inconveniences, such as requiring a connection device such as a connector to physically connect the electrodes of the electrical device and the electrodes of the power supply device to each other.

[0004] In order to solve such problems of the contact charging method, a non-contact charging method has been proposed.

[0005] The contactless charging method, i.e., the wireless charging method, is a charging method using electromagnetic induction. According to the contactless charging method, a primary coil (transmitter coil) is installed in a charger and a secondary coil (receiver coil) is installed in an electrical device to be charged, so that the current generated by the magnetic induction method between the primary coil and the secondary coil is converted into energy to charge the battery.

[0006] Figure 1 FIG. 1 is a diagram showing a configuration of a wireless charger to which a general wireless charging method is applied.

[0007] like Figure 1 As shown, the wireless charger 20 applying a general wireless charging method is configured such that the transmitting coil 21 is mounted on one surface of the shielding plate 22 and the heat dissipation plate 23 is in contact with the other surface of the shielding plate 22. A printed circuit board (PCB) 24 for controlling the operation of the transmitting coil 21 is provided, and a housing 25 for packaging and accommodating the transmitting coil 21, the shielding plate 22, the heat dissipation plate 23 and the PCB 24 is provided.

[0008] When the electrical device 10 containing the receiving coil 11 therein is placed on top of the wireless charger 20 , a battery (not shown) of the electrical device 10 is charged by magnetic induction between the transmitting coil 21 of the wireless charger 20 and the receiving coil 11 of the electrical device 10 .

[0009] On the other hand, the shielding plate 22 accommodated in the wireless charger 20 serves to allow electromagnetic waves generated in the transmitting coil 21 to be transmitted to the receiving coil 11 of the electric device 10 while blocking the electromagnetic waves from reaching other components.

[0010] When the electric device 10 is wirelessly charged by the wireless charger 20, a large amount of heat is generated in the transmitting coil 21 and the PCB 24 of the wireless charger 20. The heat generated in the transmitting coil 21 is transferred to the housing 25 through the shielding plate 22 and the heat dissipation plate 23, and the heat generated in the PCB 24 should be transferred to the housing 25 and then dissipated to the outside, but some heat remains inside the housing 25. When some heat remains inside the housing 25, the heat of the wireless charger 20 may be transferred to the electric device 10, and thus there is a problem that the user's discomfort and operation degradation may be caused due to the heating of the electric device 10.

[0011] On the other hand, in recent years, with the commercialization of wireless charging, a high-output wireless charger that can improve wireless charging efficiency is needed. However, when the output of the wireless charger increases, the charging speed also increases, but the heat also increases, so it is necessary to study the effective dissipation of heat generated in the wireless charger. Summary of the invention

[0012] Therefore, in view of the above-mentioned problems arising in the related art, the present disclosure has been made, and an object of the present disclosure is to provide a wireless charging shielding member, a method for manufacturing the shielding member, and a wireless charger using the shielding member by improving a shielding sheet, wherein the shielding member can improve the dissipation effect of heat generated in a transmitting coil, and the shielding sheet blocks the electromagnetic waves generated in the transmitting coil from propagating to other components.

[0013] According to an embodiment of the present disclosure, a wireless charging shield is a shield for shielding electromagnetic waves generated in a transmitting coil of a wireless charger, the shield comprising: a placement portion on which the transmitting coil is placed; and a transfer portion integrally extending to a lower portion of the placement portion to transfer heat generated in the transmitting coil, wherein a plurality of transmitting coils are placed on the placement portion, and a height of a placement area on which each transmitting coil is placed is set to be different from heights of placement areas adjacent to each other.

[0014] The shielding member may be arranged such that a height of a mounting area where a transmitting coil positioned near the center of the mounting portion among the plurality of mounted transmitting coils is positioned is set higher than heights of mounting areas where other transmitting coils are positioned.

[0015] The shield may be arranged such that the mounting portion is formed with a plurality of mounting areas on which the transmitting coil is mounted, and a wall area, the wall area protrudingly extending upward along an edge to surround the plurality of mounting areas.

[0016] The shield may be provided so that the transfer portion is formed with a plurality of air passages formed so that both ends thereof communicate with each other through a side surface of the transfer portion to allow external air to flow.

[0017] The shielding member may be arranged such that a transmitting coil disposed near the center of the mounting portion among the plurality of transmitting coils is disposed at a position higher than other transmitting coils, and a flow rate of an air channel passing through a lower portion of the transmitting coil disposed near the center of the mounting portion among the plurality of air channels is greater than a flow rate of other air channels.

[0018] The shielding member may be disposed such that a transmitting coil disposed near the center of the mounting portion among the plurality of transmitting coils is disposed at a position higher than other transmitting coils, and an air passage passing through a lower portion of the transmitting coil disposed near the center of the mounting portion among the plurality of air passages is communicated with a cavity formed in a lower portion of the transmitting coil.

[0019] The shielding member may be disposed such that a transmitting coil disposed near the center of the mounting portion among the plurality of transmitting coils is disposed at a position higher than the other transmitting coils, and an interval distance of an air channel passing through a lower portion of the transmitting coil disposed near the center of the mounting portion among the plurality of air channels is narrower than an interval distance of the other air channels.

[0020] The shield may be arranged such that a pipe made of a material having a higher thermal conductivity than a material forming the transfer portion is provided on an inner wall of the air passage.

[0021] The shield may be configured such that the seating portion and the transmitting portion are made of a Mn—Zn-based ferrite material or a Ni—Zn-based ferrite material.

[0022] According to an embodiment of the present disclosure, a method for manufacturing a wireless charging shielding component is provided, which is a method for manufacturing a shielding component for shielding electromagnetic waves generated in a transmitting coil of a wireless charger, the method comprising: a shielding sheet preparation step, preparing a shielding sheet made of a material capable of shielding electromagnetic waves; a foamed plastic preparation step, preparing foamed plastic by mixing thermoplastic plastic and a foaming agent; a lamination step, inserting the foamed plastic between shielding sheets to be laminated in a predetermined pattern, and then laminating the shielding sheets; and a heat treatment step, heat treating the laminated shielding sheets to form air channels in a predetermined pattern by foaming the foamed plastic, and then sintering the laminated shielding sheets.

[0023] The method may be configured such that the material capable of shielding electromagnetic waves in the shielding sheet preparation step is a Mn-Zn-based ferrite material or a Ni-Zn-based ferrite material.

[0024] The method may be configured such that the foamed plastic in the foamed plastic preparing step is prepared by hot injection after mixing 5wt% to 70wt% of thermoplastic plastic and 30wt% to 95wt% of foaming agent.

[0025] The method can be configured so that the heat treatment step includes: a first heating process, raising the temperature of the laminated shielding sheet; a foaming process, foaming the foamed plastic by increasing the temperature to form an air channel; a second heating process, raising the temperature of the shielding sheet after the foaming process is completed; and a sintering process, sintering the shielding sheet at a sintering temperature.

[0026] The method may be configured such that the foaming process is performed at a temperature range of 180°C to 230°C and maintained at 230°C for 30 minutes to 2 hours, with the heating rate at the temperature range of 180°C to 230°C being maintained at 1°C / min or less.

[0027] The method may be configured such that the sintering process is performed at a temperature in the range of 1000°C to 1250°C.

[0028] A wireless charger according to an embodiment of the present disclosure includes: a transmitting coil for wireless charging; a shielding member on the upper surface of which the transmitting coil is mounted and blocks electromagnetic waves generated in the transmitting coil from propagating in lateral and downward directions of the transmitting coil; and a heat dissipation plate contacting the lower surface of the shielding member to receive heat generated in the transmitting coil via the shielding member and dissipate the heat to the outside, wherein the shielding member includes: a mounting portion on which the transmitting coil is mounted; and a transfer portion integrally extending to the lower portion of the mounting portion to transfer the heat generated in the transmitting coil, wherein a plurality of transmitting coils are mounted on the mounting portion, and a height of a mounting area on which each transmitting coil is mounted is set to be different from heights of mounting areas adjacent to each other.

[0029] The charger may be configured to further include a housing, in which the transmitting coil, the shielding member, and the heat dissipation plate are accommodated.

[0030] The charger may be configured such that the transmitting portion is formed with a plurality of air channels configured such that both ends thereof communicate with each other through a side surface of the transmitting portion to allow external air to flow.

[0031] The charger may be configured to further include a housing in which the transmitting coil, the shielding member, and the heat dissipation plate are accommodated, wherein the housing is equipped with a fan through which external air is introduced to flow in the air passage.

[0032] According to an embodiment of the present disclosure, an air channel for air flow is formed in the shielding member, which blocks the electromagnetic waves generated in the transmitting coil from propagating to other components, so that the heat generated in the transmitting coil is dissipated through the air flow in the process of being transferred to the heat dissipation plate via the shielding member, thereby improving the heat dissipation effect of the wireless charger.

[0033] By improving the heat dissipation of the wireless charger in this way, the output of the wireless charger can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description in conjunction with the accompanying drawings, in which:

[0035] Figure 1 is a diagram showing a configuration of a wireless charger to which a general wireless charging method is applied;

[0036] Figure 2 is a configuration diagram showing a wireless charger according to an embodiment of the present disclosure;

[0037] Figure 3 is a view showing a shielding member according to an embodiment of the present disclosure;

[0038] Figure 4 is a view showing a shielding member according to another embodiment of the present disclosure;

[0039] Figure 5 is a view showing a modification of a shielding member according to another embodiment of the present disclosure;

[0040] Figure 6 is a view showing another modification of a shielding member in which a heat transfer device according to another embodiment of the present disclosure is inserted into an air passage;

[0041] Figure 7 is a graph showing measurement results of surface temperature of wireless chargers over time according to an embodiment of the present disclosure and a comparative example; and

[0042] Figure 8 is a graph showing measurement results of inductance values ​​and resistance values ​​of transmitting coils according to the embodiment of the present disclosure and a comparative example. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The present disclosure will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the present disclosure are shown. These embodiments are provided so that the present disclosure will be thorough and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. In the accompanying drawings, the same reference numerals represent the same components.

[0044] Figure 2 is a configuration diagram showing a wireless charger according to an embodiment of the present disclosure, Figure 3 2 is a view showing a shield according to an embodiment of the present disclosure.

[0045] As shown in the figure, the wireless charger 1 according to the embodiment of the present disclosure includes: a transmitting coil 100 for wireless charging; a shield 200 on the upper surface of which the transmitting coil 100 is placed and blocks the electromagnetic waves generated in the transmitting coil 100 from propagating in the lateral and downward directions of the transmitting coil 100; and a heat dissipation plate 300 contacting the lower surface of the shield 200 to receive the heat generated in the transmitting coil 100 via the shield 200 and dissipate the heat to the outside. The wireless charger 1 further includes a housing 500 in which the transmitting coil 100, the shield 200, and the heat dissipation plate 300 are accommodated. In this case, various components constituting the wireless charger 1 such as a PCB 400 for controlling the operation of the transmitting coil 100 may be accommodated in the housing 500.

[0046] The transmitting coil 100 is a device that is coupled with a receiving coil provided in an electrical device in a magnetic induction manner, and can be formed by winding a metal wire such as copper. At this time, the winding shape can be various shapes such as circular, elliptical, rectangular, diamond, etc., and the overall size, the number of windings, etc. can be appropriately controlled and set according to the required characteristics. In addition, as Figure 2 and Figure 3 As shown, three transmitting coils 100 may be provided, but the present disclosure is not limited thereto. One or more transmitting coils 100 may be selectively provided.

[0047] The shield 200 is a device for transmitting electromagnetic waves generated in the transmitting coil 100 only to the receiving coil of the electrical device and blocking the electromagnetic waves from reaching other components, and is made of a material capable of blocking electromagnetic waves. The transmitting coil 100 is disposed on one surface, i.e., the upper surface, of the shield 200, and the heat dissipation plate 300 is in contact with the other surface, i.e., the lower surface, of the shield 200. Therefore, the heat generated in the transmitting coil 100 is transferred to the heat dissipation plate 300 via the shield 200. In particular, a plurality of air passages 221 are formed in the shield 200 so that external air flows to dissipate heat. In addition, the shield 200 is configured so that when a plurality of transmitting coils 100 are placed, the placement heights of the transmitting coils 100 adjacent to each other are different.

[0048] The heat dissipation plate 300 is a device that transfers and dissipates the heat generated in the transmitting coil 100 through the shield 200, and is formed of an aluminum (Al) material plate having high thermal conductivity. In this case, the upper surface of the heat dissipation plate 300 is in surface contact with the lower surface of the shield 200, and the contact area is maximized, thereby easily dissipating the heat generated in the transmitting coil 100. However, the material of the heat dissipation plate is not limited to the aluminum (Al) material, and various materials such as polymers, metals, ceramics, etc. that have high thermal conductivity and provide a desired heat dissipation effect may be applied.

[0049] The PCB 400 is a device configured with a circuit for controlling the operation of the transmitting coil 100. The PCB 400 may be accommodated in the wireless charger 1 in various forms and manners, without being limited to any specific form and manner.

[0050] The housing 500 is a device for accommodating components such as the transmitting coil 100, the shield 200, the heat sink 300, and the PCB 400, and can be implemented in various forms and ways without being limited to any specific form and way. However, the housing 500 is further equipped with a fan 510, and the external air is introduced through the fan 510 to flow in the air channel 221. In addition, the housing 500 may have an exhaust port (not shown) for exhausting the air introduced into the housing 500 by the fan 510 to the outside. In this case, the size and shape of the housing 500 and other components are considered and designed so that the air introduced into the housing 500 by the fan 510 flows in the air channel 221 formed in the shield 200. In this embodiment, for the sake of convenience, a closed housing with other components is described as an example. However, when the wireless charger is used as a convenient device in a vehicle, an open housing will be able to be applied.

[0051] An air passage is formed in the shield, and the air passage will be described in more detail as an integral part of the present disclosure.

[0052] The shielding member 200 includes a mounting portion 210 on which the transmitting coil 100 is mounted, and a transfer portion 220 integrally extending to the lower portion of the mounting portion 210 to transfer heat generated in the transmitting coil 100. A plurality of air passages 221a and 221b are formed in the transfer portion 220 so that both ends of the air passages communicate with each other through the side surface of the transfer portion 220 to allow external air to flow. At this time, it is preferred that the mounting portion 210 and the transfer portion 220 are integrally formed using a material having electromagnetic wave shielding performance. For example, the shielding member 200 including the mounting portion 210 and the transfer portion 220 may be manufactured using an alloy powder-based material and a ferrite-based material. For example, Fe, Fe-Si, Fe-Si-Al, Fe-Si-Cr, Fe-Ni, Fe-Ni-Mo, Fe-Ni-Cr, Fe-Ni-Cu, Fe-Co, Fe-Al, Fe-Ni-Si, Fe-Ni-Mn, and Fe-Ni-Al alloy powders may be used as alloy powder-based materials. As the ferrite-based material, Mn-Zn ferrite material, Ni-Zn ferrite material, Ni-Cu-Zn ferrite material and Mg-Cu-Zn ferrite material can be used. However, in consideration of shielding efficiency and heat transfer characteristics, it is preferred to use Mn-Zn ferrite material or Ni-Zn ferrite material.

[0053] The mounting portion 210 is formed with mounting areas 211a, 211b, and 211c on which the transmitting coil 100 is mounted, and a wall area 212 extending protruding upward along an edge to surround the mounting areas 211a, 211b, and 211c.

[0054] At this time, the placement areas 211a, 211b, and 211c may be implemented in various shapes such as a two-dimensional plane or a three-dimensional step shape according to the number of the transmitting coils 100. Figure 3 When three transmitting coils 100 are provided as shown, the seating areas 211 a , 211 b , and 211 c may be formed with steps implemented in a three-dimensional shape.

[0055] Specifically, since the transmitting coil 100 is formed by winding a metal wire such as copper, the transmitting coil 100 is formed in a substantially circular or elliptical shape. Due to such a winding shape of the transmitting coil 100, when the three transmitting coils 100 are arranged on a two-dimensional plane, a region where electromagnetic waves are generated is small between the transmitting coils 100a, 100b, and 100c, and the charging efficiency may be reduced in each region due to the generation of such a region. Therefore, in this embodiment, the edges of the transmitting coils 100a, 100b, and 100c are arranged to overlap with each other, thereby preventing the generation of a region where electromagnetic waves are small. When the edges of the transmitting coils 100a, 100b, and 100c are arranged to overlap with each other, the heights at which the transmitting coils 100a, 100b, and 100c are arranged may be different from each other to prevent contact between the transmitting coils 100a, 100b, and 100c. Of course, when an insulating coating is applied to the coils constituting the transmitting coil, the transmitting coils 100a, 100b, and 100c may be in contact with each other.

[0056] On the other hand, when a plurality of transmitting coils 100 are provided, most of the charging of the electric device is performed in the transmitting coil 100a provided at the center. Therefore, the edges of the transmitting coils 100 are provided to overlap each other, and the transmitting coil 100a provided at the center is provided at a higher height than the other transmitting coils 100b and 100c, thereby improving the charging efficiency by the transmitting coil 100a provided at the center.

[0057] For this purpose, the height of the placement area 211a where the transmitting coil 100a disposed in the center is placed is set to be different from the heights of the adjacent placement areas 211b and 211c. Preferably, the height of the placement area 211a where the transmitting coil 100a disposed in the center is placed is set to be higher than the heights of the adjacent placement areas 211b and 211c. Figure 3As shown, the edge of the transmitting coil 100a seated in the seating area 211a formed in the center and the edges of the other transmitting coils 100b and 100c arranged in the seating areas 211b and 211c formed around it overlap in the up-and-down direction.

[0058] At this time, the height difference between the seating areas 211a, 211b, and 211c is greater than the height of the transmitting coil 100, thereby preventing the transmitting coil 100a from directly contacting the other transmitting coils 100b and 100c disposed therearound.

[0059] For example, a height H2 of the seating area 211 a formed in the center is higher than a height H1 of each of the transmitting coils 100 b and 100 c .

[0060] In addition, a height H4 of the wall area 212 formed along the edge of the mounting portion 210 is set to be equal to or higher than a height H3 of the top of the transmitting coil 100a mounted in the mounting area 211a formed in the center to block the electromagnetic wave generated in the transmitting coil 100 from propagating in the lateral direction.

[0061] On the other hand, when a plurality of transmitting coils 100 are arranged as described above, since most of the charging of the electric device is performed in the transmitting coil 100a arranged in the center, most of the heat is generated in the transmitting coil 100a arranged in the center. In order to effectively dissipate the heat generated in the transmitting coil 100a arranged in the center, it is preferred that a flow rate of an air passage 221a passing through a lower portion of the transmitting coil 100a arranged near the center of the mounting portion 210 among the plurality of air passages 221 is greater than a flow rate of another air passage 221b.

[0062] like Figure 3 As shown, the inner diameter of the air passage 221 a passing through the lower portion of the centrally disposed transmitting coil 100 a may be set to be larger than the inner diameter of the other air passage 221 b .

[0063] On the other hand, the air passage 221 may be variously modified so that the flow rate of the air passage 221a passing through the lower portion of the transmitting coil 100a disposed near the center of the mounting portion 210 is greater than the flow rate of the other air passage 221b.

[0064] Figures 4 to 6 is a view showing a shielding member according to another embodiment of the present disclosure, wherein Figure 4 and Figure 5 A variation of the shield is shown in which the air passage is altered.

[0065] like Figure 4As shown, the transfer portion of the shield 200 according to the first modification is configured such that a cavity 222 is formed at the lower portion of the transmitting coil 100a disposed at the center, and an air passage 221 passing through the lower portion of the corresponding transmitting coil 100a is formed to communicate with the cavity 222. Therefore, when the air introduced through the air passage 221 passes through the cavity 222 formed at the lower portion of the transmitting coil 100a disposed at the center, the contact area between the air and the shield 200 increases, whereby the heat of the shield 200 can be effectively transferred and dissipated.

[0066] At this time, it is preferable that the air passage 221 is arranged side by side along the transmitting coils 100a, 100b, and 100c arranged side by side in order to effectively radiate heat.

[0067] In addition, if Figure 5 As shown, the shield 200 according to the second modification is configured such that the interval distance of an air passage 221 d passing through the center of the seating portion 210 among the plurality of air passages 221 is narrower than the interval distance of another air passage 221 e .

[0068] In order to make the spacing distance of the air passage 221d passing through the lower part of the transmitting coil 100a disposed in the center of the mounting portion 210 narrower than the spacing distance of the other air passages 221e, as shown in FIG. Figure 5 As shown, as the air channel 221 approaches the center, the inner diameter of the air channel 221 may gradually increase, thereby narrowing the distance between the air channels.

[0069] In addition, the inner diameter of each air channel 221 is the same, and as the air channel 221 approaches the center, the interval distance between the air channels 221 becomes narrower, so that the interval distance between the air channels can be narrowed.

[0070] Figure 6 A variation of the shield is shown in which a heat transfer device is inserted in the air channel to improve the heat transfer efficiency in the air channel.

[0071] like Figure 6 As shown, the shield 200 according to the third modification has a duct 223 provided on the inner wall of the air passage 221 formed in the transfer portion 220, the duct being made of a material having a higher thermal conductivity than the material forming the shield 200. For example, the duct can be formed by using a ceramic-based material having excellent thermal conductivity while maintaining its shape during a sintering process described later. At this time, the duct can be inserted into all the air passages or only into the air passage 221a formed near the center.

[0072] A method of manufacturing the shield member having the above-described structure will be described.

[0073] According to an embodiment of the present disclosure, a method for manufacturing a shielding part for shielding electromagnetic waves includes: a shielding sheet preparation step, preparing a shielding sheet made of a material capable of shielding electromagnetic waves; a foamed plastic preparation step, preparing foamed plastic by mixing thermoplastic plastic and a foaming agent; a lamination step, inserting the foamed plastic between shielding sheets to be laminated in a predetermined pattern, and then laminating the shielding sheets; and a heat treatment step, heat treating the laminated shielding sheets to form air channels in a predetermined pattern by foaming the foamed plastic, and then sintering the laminated shielding sheets.

[0074] The shielding sheet preparation step is a step of preparing a shielding sheet constituting a shielding member, wherein the shielding sheet is prepared by mixing powder made of a Mn-Zn-based ferrite material or a Ni-Zn-based ferrite material capable of shielding electromagnetic waves and a binder and molding it into a sheet shape.

[0075] The foamed plastic preparation step is a step of preparing the foamed plastic for forming the air channel, wherein the foamed plastic is prepared by mixing 5wt% to 70wt% of thermoplastic plastic and 30wt% to 95wt% of foaming agent and then hot-injecting the mixture.

[0076] In this case, the thermoplastic plastic can use foamed plastics of various materials such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PU), polystyrene (PS), phenol resin (PF), urea resin (UF), polyimide (PI), etc., and the foaming agent can use azodicarbonamide series chemical foaming agents.

[0077] Typically, the foamed plastic used for this structure has a foaming agent content of about 10wt%. However, the content of the foaming agent in this embodiment is higher than that of the foamed plastic used for this structure, and is therefore limited to a level of 30wt% to 95wt%. This is because the foamed plastic in this embodiment does not require durability, but only needs to maintain the initial shape so that the foamed plastic foams in the subsequent heat treatment step to form air channels. Therefore, it is preferred that the content of the thermoplastic is limited to a minimum amount, such as 5wt% to 70wt%, so that the foamed plastic maintains its initial shape and is burned off by the heat treatment temperature in the heat treatment step.

[0078] The lamination step is a step of laminating the prepared shielding sheet in a desired shape, and the placement portion can be formed in a three-dimensional shape by cutting the shielding sheet into a predetermined shape as described above. In particular, when the shielding sheet is laminated on an area corresponding to the transmission portion of the shielding member, foamed plastic is inserted between the shielding sheets in a predetermined pattern, and then the shielding sheets are laminated.

[0079] In this case, when the foamed plastic is inserted in a predetermined pattern, it is preferable that the predetermined pattern is formed according to the shape of the air passage formed in the shielding member.

[0080] When lamination of the shielding sheet and the foamed plastic is completed, the foamed plastic is foamed by heat treatment, and then the shielding sheet is sintered.

[0081] To this end, the heat treatment steps include: a first heating process to increase the temperature of the laminated shielding sheet; a foaming process to foam the foamed plastic by increasing the temperature to form an air channel; a second heating process to increase the temperature of the shielding sheet after the foaming process is completed; and a sintering process to sinter the shielding sheet at a sintering temperature.

[0082] The first heating process is a process of heating the shielding sheet and the foamed plastic to the foaming temperature of the foamed plastic. At this time, the heating atmosphere is not limited to a specific atmosphere.

[0083] The foaming process is a process of foaming the foamed plastic to form an air passage between the shielding sheets, and is performed at a temperature range of 180° C. to 230° C. In particular, the heating rate at a temperature range of 180° C. to 230° C. is maintained at 1° C. / min or less, so that the foamed plastic is completely foamed (decomposed), the gas generated from the foamed plastic is sufficiently removed, and the ferrite phase of the shielding sheet does not change into another phase at a temperature range of 180° C. to 230° C. Moreover, by maintaining the foaming process at 230° C. for 30 minutes to 2 hours, the foamed plastic is completely foamed (decomposed).

[0084] At a temperature range of about 200°C to 230°C, the foamed plastic foams (decomposes), generating N 2 NH 3 or CO 2 These gases escape through the spaces where the foamed plastic is placed, thus forming air passages.

[0085] The second heating process is a process of heating the laminated shielding sheets with air passages formed between the shielding sheets to the sintering temperature of the shielding sheets. At this time, the temperature is increased according to the heating atmosphere of the commercially produced shielding sheets.

[0086] The sintering process is a process of sintering the shielding sheet to manufacture the shielding member, and is performed at a temperature range of 1000° C. to 1250° C. The sintering atmosphere for heating to the temperature range for performing the sintering process and for maintaining the shielding sheet in the temperature range for performing the sintering process are determined according to the sintering atmosphere of the commercially produced shielding sheet.

[0087] Next, the improvement of the heat dissipation effect of the present disclosure will be described by comparing the embodiments of the present disclosure with the comparative examples.

[0088] According to the heat dissipation experiment, using Comparative Example 1, Comparative Example 2 and the embodiment of the present disclosure, a cellular phone was wirelessly charged at a power of 10 W, and the surface temperature of the wireless charger was measured over time. The results are as follows: Figure 7 shown.

[0089] Comparative Example 1 uses a Figure 1 The wireless charger of the general shield plate shown in the figure, the comparative example 2 uses a fan capable of introducing external air into the wireless charger of the comparative example 1, and the embodiment of the present disclosure uses a wireless charger provided with a shielding member and a fan formed with an air passage according to the present disclosure.

[0090] like Figure 7 As shown, it is confirmed that the surface temperature of the wireless charger in Comparative Example 2 equipped with a fan is 22°C lower than the surface temperature of the wireless charger in Comparative Example 1, and it is confirmed that the surface temperature of the wireless charger in the embodiment of the present disclosure is 4°C or more lower than the surface temperature of the wireless charger in Comparative Example 2.

[0091] In addition, in order to examine the change in electromagnetic characteristics according to the change in the shape of the shielding member, the inductance value and the resistance value of each transmitting coil of the comparative example 1 and the embodiment of the present disclosure were measured, and the results are as follows: Figure 8 In this case, Comparative Example 1 has three transmitting coils arranged on the same plane, while in the embodiment of the present disclosure, the transmitting coil arranged in the center among the three transmitting coils is arranged higher than the other transmitting coils, so that the edges of the transmitting coils are arranged to overlap each other.

[0092] like Figure 8 As shown, it is confirmed that the inductance of the transmitting coil in the embodiment of the present disclosure is improved compared with Comparative Example 1. When the inductance of the transmitting coil is improved, it can be expected that the charging efficiency of the wireless charger is also improved.

[0093] Although the present disclosure has been described with reference to the accompanying drawings and the preferred embodiments described above, the present disclosure is not limited thereto but is limited by the appended claims. Therefore, it will be appreciated by those skilled in the art that various modifications and changes may be made thereto without departing from the ideas of the appended claims.

Claims

1. A wireless charging shielding member, which is a shielding member used to shield electromagnetic waves generated in a transmitting coil of a wireless charger, the shielding member comprising: A placement portion, on which the transmitting coil is placed; as well as a transfer portion integrally extending to the lower portion of the placement portion to transfer heat generated in the transmitting coil, A plurality of the transmitting coils are placed on the placing portion, and the height of a placing area where each transmitting coil is placed is set to be different from the heights of adjacent placing areas, and The transfer portion is formed with a plurality of air passages configured such that both ends thereof communicate with each other through a side surface of the transfer portion to allow external air to flow.

2. The shielding member according to claim 1, wherein: The height of the placement area where the transmitting coil placed near the center of the placement part among the plurality of the placed transmitting coils is placed is set to be higher than the height of the placement areas where the other transmitting coils are placed.

3. The shielding member according to claim 1, wherein: The mounting portion is formed with a plurality of the mounting areas and a wall area, the transmitting coil is mounted on the plurality of the mounting areas, and the wall area protrudes upward and extends along an edge to surround the plurality of the mounting areas.

4. The shielding member according to claim 1, wherein: The transmitting coil disposed near the center of the mounting portion among the plurality of transmitting coils is disposed at a position higher than other transmitting coils, and Among the plurality of air passages, the flow rate of the air passage passing through the lower portion of the transmitting coil placed near the center of the placing portion is greater than the flow rates of the other air passages.

5. The shielding member according to claim 1, wherein: The transmitting coil disposed near the center of the mounting portion among the plurality of transmitting coils is disposed at a position higher than other transmitting coils, and The air passage passing through the lower part of the transmitting coil placed near the center of the placing part among the plurality of air passages is communicated with the cavity provided in the lower part of the transmitting coil.

6. The shielding member according to claim 1, wherein: The transmitting coil disposed near the center of the mounting portion among the plurality of transmitting coils is disposed at a position higher than other transmitting coils, and Among the plurality of air channels, an interval distance of the air channel passing through the lower portion of the transmitting coil disposed near the center of the mounting portion is narrower than an interval distance of the other air channels.

7. The shielding member according to claim 1, wherein: A pipe made of a material having a higher thermal conductivity than a material forming the transfer portion is disposed on an inner wall of the air passage.

8. The shielding member according to claim 1, wherein: The seating portion and the transmission portion are made of a Mn-Zn-based ferrite material or a Ni-Zn-based ferrite material.

9. A method for manufacturing a wireless charging shield according to claim 1, which is a method for manufacturing a shield for shielding electromagnetic waves generated in a transmitting coil of a wireless charger, the method comprising: a shielding sheet preparation step, preparing a shielding sheet made of a material capable of shielding electromagnetic waves; A foamed plastic preparation step, preparing the foamed plastic by mixing a thermoplastic plastic and a foaming agent; a lamination step of inserting the foamed plastic between the shielding sheets to be laminated in a predetermined pattern and then laminating the shielding sheets; as well as A heat treatment step of heat-treating the laminated shielding sheet to form air passages in a predetermined pattern by foaming the foamed plastic, and then sintering the laminated shielding sheet.

10. The method according to claim 9, wherein: The material capable of shielding electromagnetic waves in the shielding sheet preparation step is a Mn-Zn-based ferrite material or a Ni-Zn-based ferrite material.

11. The method according to claim 9, wherein: The foamed plastic in the foamed plastic preparation step is prepared by mixing 5wt% to 70wt% of the thermoplastic plastic and 30wt% to 95wt% of the foaming agent and then performing hot injection.

12. The method according to claim 9, wherein: The heat treatment step comprises: A first heating process, raising the temperature of the laminated shielding sheet; A foaming process, wherein the foamed plastic is foamed by increasing the temperature to form the air channel; a second heating process of increasing the temperature of the shielding sheet after the foaming process is completed; and The sintering process is to sinter the shielding sheet at a sintering temperature.

13. The method according to claim 12, wherein: The foaming process is performed at a temperature range of 180° C. to 230° C. and maintained at 230° C. for 30 minutes to 2 hours, and a heating rate at a temperature range of 180° C. to 230° C. is maintained at 1° C. / min or less.

14. The method according to claim 12, wherein: The sintering process is performed at a temperature ranging from 1000°C to 1250°C.

15. A wireless charger, comprising: Transmitter coil for wireless charging; a shielding member, on the upper surface of which the transmitting coil is placed, and which blocks the electromagnetic waves generated in the transmitting coil from propagating in the lateral and downward directions of the transmitting coil; as well as a heat dissipation plate contacting a lower surface of the shielding member to receive heat generated in the transmitting coil via the shielding member and dissipate the heat to the outside, The shielding member comprises: a placement portion, on which the transmitting coil is placed; and a transfer portion integrally extending to a lower portion of the receiving portion to transfer heat generated in the transmitting coil, A plurality of the transmitting coils are mounted on the mounting portion, and the height of a mounting area where each transmitting coil is mounted is set to be different from the heights of adjacent mounting areas, and The transfer portion is formed with a plurality of air passages configured such that both ends thereof communicate with each other through a side surface of the transfer portion to allow external air to flow.

16. The charger according to claim 15, further comprising: A housing is provided in which the transmitting coil, the shielding member and the heat dissipation plate are accommodated.

17. The charger according to claim 15, further comprising: a housing, wherein the transmitting coil, the shielding member and the heat sink are accommodated in the housing, The housing is equipped with a fan through which external air is introduced to flow in the air passage.

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