Planar Transformer

Abstract

The present invention relates to a planar transformer, characterized in that it comprises: a flat secondary coil element (200); a flat primary first coil element (110) which is in close contact with one outer side surface (240a) of the secondary coil element (200) so that the secondary coil element (200) generates an induced current; and a flat primary second coil element (120) which is in close contact with the other outer side surface (240b) of the secondary coil element (200) so that the secondary coil element (200) generates an induced current. Thus, the planar transformer has the advantages of reducing magnetic field loss and improving primary to secondary efficiency.

Description

Technical Field

[0001] The present invention relates to a transformer, and more particularly to a planar transformer for a charger or an adapter. Background Art

[0002] Generally speaking, a transformer has a primary coil and a secondary coil. The primary coil is used as an input terminal, and the secondary coil is used as an output terminal.

[0003] Among transformers, technology related to small transformers used in mobile phone chargers and the like has been disclosed through the transformer authorized by Patent No. 10-1579427 (announcement date: December 22, 2015).

[0004] The above-mentioned transformer No. 10-1579427 is a transformer primary coil element composed of a so-called "PCB type primary coil element" which is made by patterning a conductive material on an insulating plate.

[0005] The PCB type primary coil element based on the above conventional technology is manufactured by a method of coating an insulating plate with copper foil and forming a coil circuit pattern by etching or the like.

[0006] However, the transformer No. 10-1579427 has a structure in which a primary coil element is inserted between two secondary coil elements, which has problems with magnetic field loss and efficiency from primary to secondary. In addition, the secondary coil element is divided into upper and lower parts, which increases the height of the product [transformer] as a whole.

[0007] Prior art literature

[0008] Patent Literature

[0009] Document 1: Patent Gazette No. 10-1579427 (Announcement date: 2015.12.22)

[0010] Document 2: Patent Publication No. 10-2016-0041837 (Publication Date: April 18, 2016) Summary of the invention

[0011] (Technical issues to be solved)

[0012] The present invention is proposed to solve the problems of the conventional technology. The purpose of the planar transformer of the present invention is to:

[0013] First, the primary coil element is divided into a primary first coil element and a primary second coil element, which are respectively attached to one outer side surface and the other outer side surface of the secondary coil element. Thus, compared with the conventional technology in which one primary coil element is formed between two secondary coil elements, the primary leakage magnetic flux can be reduced, thereby improving the magnetic coupling force between the primary and the secondary, improving the efficiency from the primary to the secondary, and improving the EMI characteristics.

[0014] Secondly, an insulating sheet is inserted closely between the secondary first and second coil elements to achieve insulation while keeping an extremely close distance (almost touching each other). Since the thickness of the secondary coil element becomes extremely thin, the product (transformer) can be made ultra-thin.

[0015] Third, the insulation sheet is used to form an extremely close distance, that is, a spacing, thereby reducing the secondary leakage magnetic flux and improving the secondary EMI characteristics.

[0016] Fourth, when the first secondary coil, the insulating sheet, and the second secondary coil are tightly attached to each other, all of them are embedded to form an insulating portion insulated from the outside, so that the insulating sheet is fixed between the first secondary coil, the insulating sheet, and the second secondary coil, so that the insulating sheet is stably fixed in a normal position without movement or gap of the insulating sheet, and thus there is no need to use another means (component) for preventing movement or gap of the insulating sheet.

[0017] Fifth, insert molding can form the insulating portion and fix the insulating sheet in one process.

[0018] Sixth, during the high temperature injection molding process, the insulating sheet itself is bonded to the insulating portion, making the insulating sheet more fixed, and being able to more reliably prevent gaps or movements of the insulating sheet.

[0019] Seventh, the insulating film forms the insulating sheet, making it easier to achieve ultra-thin products.

[0020] Eighth, the insulating sheet is fixed to the secondary first coil or the secondary second coil by adhesion or adhesion, thereby improving the processability of the product.

[0021] Ninth, the initial positions of the first and second primary coil elements that are in close contact with the secondary coil element can be easily and conveniently determined.

[0022] Tenth, there is no need to use the commonly used four primary connection pins connected to the main PCB of the finished product [such as a charger or adapter] on which the transformer is installed, thereby reducing the number of parts, reducing the number of assembly workers, and saving the production cost of the product.

[0023] Eleventh, by connecting the secondary coil elements in series, the number of coils can be reduced to half of the previous number.

[0024] Twelfth, since the number of coils is reduced by half compared to the past, the current can be increased by increasing the width and cross-sectional area of ​​the coils while keeping the width constant.

[0025] Thirteenth, since the number of coils is reduced by half compared to the past, the height of the transformer product can be reduced, ensuring the separation distance between the charger or adapter casing, improving product heat generation, reducing leakage magnetic flux and improving efficiency.

[0026] Fourteenth, a planar transformer is provided which is suitable for facilitating capacity increase by connecting secondary coil elements in series or in parallel according to the capacity of the transformer.

[0027] (Methods to solve the problem)

[0028] The planar transformer of the present invention for achieving the above-mentioned purpose is characterized in that it includes: a flat secondary coil element; a flat primary first coil element, which is in close contact with one outer side surface of the secondary coil element so that the secondary coil element generates an induced current; and a flat primary second coil element, which is in close contact with the other outer side surface of the secondary coil element so that the secondary coil element generates an induced current.

[0029] (Effects of the Invention)

[0030] The planar transformer of the present invention having the above-described structure has the following effects.

[0031] First, the primary coil element is divided into a primary first coil element and a primary second coil element, and they are respectively attached to one outer side surface and the other outer side surface of the secondary coil element, thereby having the effect of reducing the leakage magnetic flux of the primary compared to the conventional technology that forms one primary coil element between two secondary coil elements. In addition, it has the effect of improving the magnetic coupling force between the primary and the secondary, improving the efficiency from the primary to the secondary, and improving the EMI characteristics.

[0032] Secondly, an insulating sheet is inserted closely between the secondary first and second coil elements to achieve insulation while maintaining an extremely close spacing [very close spacing almost touching], which has the effect of achieving an ultra-thin product (transformer) because the thickness of the secondary coil element becomes extremely thin.

[0033] Thirdly, the insulation by the insulating sheet forms an extremely close distance, that is, a gap (d1), which has the effect of improving the secondary EMI characteristics by reducing the secondary leakage magnetic flux.

[0034] Fourthly, when the first secondary coil, the insulating sheet, and the second secondary coil are tightly attached to each other, all of them are embedded to form an insulating portion insulated from the outside, which has the effect of fixing the insulating sheet between the first secondary coil and the insulating sheet and the second secondary coil. As a result, the insulating sheet is stably fixed in a normal position without movement or gap of the insulating sheet, so that there is no need to use another means (component) for preventing movement or gap of the insulating sheet.

[0035] Fifth, there is an effect that the insulating portion can be formed in one step by insert molding and the insulating sheet can be fixed at the same time.

[0036] Sixth, during the high-temperature injection molding process, the insulating sheet itself is bonded to the insulating portion, which has the effect of further fixing the insulating sheet, and as a result, has the effect of more reliably preventing gaps or movements of the insulating sheet.

[0037] Seventh, the insulating sheet is formed of an insulating film, which has the effect of making it easier to achieve ultra-thin products.

[0038] Eighth, fixing the insulating sheet to the secondary first coil or the secondary second coil by adhesive force or adhesion force has the effect of improving product workability.

[0039] Ninth, there is an effect that the initial positions of the first and second primary coil elements that are in close contact with the secondary coil element can be easily and conveniently determined.

[0040] Tenth, there is no need to use the commonly used four primary connection pins connected to the main PCB of the finished product [such as a charger or adapter] on which the transformer is installed, thereby having the effect of reducing the number of parts, reducing the number of assembly workers, and saving the production cost of the product.

[0041] Eleventhly, by connecting the secondary coil elements in series, the number of coils can be reduced to half compared to conventional ones.

[0042] Twelfth, since the number of coils is reduced by half compared to the past, when the width is fixed, the width and cross-sectional area of ​​the coil are increased to increase the current.

[0043] Thirteenth, since the number of coils is reduced by half compared to the past, the height of the transformer product can be reduced, ensuring the distance between it and the outer casing of the charger or adapter, which has the effect of improving product heat generation, reducing leakage magnetic flux and improving efficiency.

[0044] Fourteenth, it has the effect of facilitating capacity increase by connecting secondary coil elements in series or in parallel according to the capacity of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1is a plan view of a planar transformer according to an embodiment of the present invention.

[0046] Figure 2 yes Figure 1 AA line section view.

[0047] Figure 3 yes Figure 1 BB line cross-sectional view.

[0048] Figure 4 yes Figure 1 Rear view of .

[0049] Figure 5 yes Figure 1 Front perspective view of .

[0050] Figure 6 1 is an exploded perspective view of a planar transformer according to an embodiment of the present invention, viewed from the back side of a secondary coil element 200 and a primary coil element 100 .

[0051] Figure 7 FIG. 1 is an exploded perspective view of a secondary coil element 200 and a primary coil element 100 in a planar transformer according to an embodiment of the present invention, as viewed from the front.

[0052] Figure 8 FIG. 1 is an exploded perspective view of a secondary coil element 200 in a planar transformer according to an embodiment of the present invention.

[0053] Fig. 9 1 is a plan view of a secondary coil component 200 according to an embodiment in which a secondary first coil 210 and a secondary second coil 220 are connected in series via a series connection portion C1 and are unfolded before being bent into a U shape.

[0054] Fig.10 FIG. 1 is a plan view of a modified embodiment of the secondary coil element 200 in the planar transformer according to the embodiment of the present invention.

[0055] Fig.11 yes Fig.10 The main parts of the floor plan are broken down into Fig.11 (a) is a plan view of the secondary first coil 210 and the secondary second coil 220 connected in series through the series connection portion C1 in an unfolded state, Fig.11 (b) is a plan view of the adapter coil 215.

[0056] Fig.12 yes Fig.10 FIG. 2 is a side view of a secondary coil component 200 according to a modified example.

[0057] Fig.13 yes Fig.10FIG. 2 is a back view of a secondary coil component 200 according to a modified example.

[0058] Description of Reference Numerals

[0059] 100: Primary coil element Sa: Separated space

[0060] 110: primary first coil element 110c: first central hole of the primary first coil element

[0061] 111: primary first coil portion 112: primary first terminal portion

[0062] 113: Primary first terminal

[0063] 120: primary second coil element 120c: second center hole of the primary second coil element

[0064] 121: primary second coil portion 122: primary second terminal portion

[0065] 123: Primary second terminal

[0066] 200: Secondary coil element

[0067] 210: Secondary first coil 210a: First center through hole

[0068] 211: first coil pattern portion 212: secondary first terminal

[0069] 215: adapter coil 215a': third center through hole

[0070] 215a: third coil pattern portion 215b, 215c: third terminal

[0071] 220: Secondary second coil 220a: Second central through hole

[0072] 221: Second coil pattern portion 222: Secondary second terminal

[0073] C1, C2: Series connection

[0074] 230: Insulation sheet 230a: Sheet through hole

[0075] 230-1: Insulation sheet

[0076] 240: Insulation

[0077] 240a: one outer side surface 240b: the other outer side surface

[0078] 240c: Center hole

[0079] 241: first placement protrusion 242: second placement protrusion

[0080] P2: Secondary connection pin DETAILED DESCRIPTION

[0081] Preferred embodiments of the planar transformer of the present invention will be described in detail below with reference to the accompanying drawings.

[0082] The planar transformer of the present invention is a transformer mounted on the main PCB board 10 of the charger or adapter and used for the charger or adapter.

[0083] The planar transformer of one embodiment of the present invention is characterized in that it includes: a flat secondary coil element 200; a flat primary first coil element 110, which is in close contact with an outer side surface 240a of the secondary coil element 200, so that the secondary coil element 200 generates an induced current; and a flat primary second coil element 120, which is in close contact with the other outer side surface 240b of the secondary coil element 200, so that the secondary coil element 200 generates an induced current.

[0084] As described above, the primary coil element 100 is composed of the primary first coil element 110 and the primary second coil element 120, which are respectively attached to one outer side surface 240a and the other outer side surface 240b of the secondary coil element 200. Compared with the conventional technology, i.e., the technology of forming a primary coil element between two secondary coil elements, the primary leakage flux can be reduced, and as a result, the magnetic coupling force between the primary and the secondary is increased, the efficiency from the primary to the secondary is improved, and the EMI characteristics are improved.

[0085] The secondary coil element 200 includes a first secondary coil 210 , a second secondary coil 220 , an insulating sheet 230 and an insulating portion 240 .

[0086] The secondary first coil 210 includes: a first coil pattern portion 211, at least one turn of a flat conductor pattern [in the form of a metal wire or a metal sheet] {the accompanying drawings show 1 turn [1 turn] and 2 turns [2 turns] as examples} formed in a ring or spiral shape, thereby forming a first center through hole 210a in the middle; a secondary first terminal 212 formed at the terminal end of the first coil pattern portion 211.

[0087] The secondary second coil 220 includes: a second coil pattern portion 221, corresponding to the first center through hole 210a, with a second center through hole 220a formed in the middle, corresponding to the first coil pattern portion 211, forming at least one turn of a flat conductor pattern [in the form of a metal wire or a metal sheet] {the accompanying drawings show 1 turn [1 turn] and 2 turns [2 turns] as examples} in a ring or spiral shape; a secondary second terminal 222, formed at the terminal of the second coil pattern portion 221.

[0088] The insulating sheet 230 is closely inserted between the first coil pattern portion 211 and the second coil pattern portion 221 to insulate the first coil pattern portion 211 from the second coil pattern portion 221 .

[0089] When the secondary first coil 210, the insulating sheet 230 and the secondary second coil 220 are tightly attached in sequence, the insulating portion 240 forms a center hole 240c in the middle and is connected to the first center through hole 210a and the second center through hole 220a. The first and second coil pattern portions 211, 221 and the insulating sheet 230 except the secondary first terminal 212 and the secondary second terminal 222 are embedded, and the insulating sheet 230 is tightly fixed between the first and second coil pattern portions 211, 221. The insulating sheet 230 is made of synthetic resin.

[0090] Furthermore, the secondary coil element 200 forms a distance ( d1 ) equal to the thickness ( d1 ) of the insulating sheet 230 between the secondary first coil 210 and the secondary second coil 220 through the insulating portion 240 .

[0091] As a result, the insulation sheet 230 is used to insulate the secondary coil element 200 to form an extremely close spacing (d1), so the thickness (T1) of the secondary coil element 200 becomes very thin, which has the advantage of being able to achieve an ultra-thin product (transformer). This ultra-thin transformer can be said to be a very important effect because the miniaturization trend of chargers and adapters is leading the commodity, which is directly related to the main factor of product sales.

[0092] Furthermore, from the perspective of the circuit, when the insulation is performed by the insulating sheet 230 to form an extremely close distance (d1), there is an advantage that the secondary leakage magnetic flux can be reduced and the secondary EMI characteristics can be improved.

[0093] Moreover, when the secondary first coil 210, the insulating sheet 230 and the secondary second coil 220 are tightly attached to each other in sequence, and an insulating portion 240 embedded therein is formed, the insulating sheet 230 is fastened between the secondary first coil 210, the insulating sheet 230 and the secondary second coil 220, and can be fixed in a normal position without any movement or gap of the insulating sheet 230, thereby eliminating the need for additional means (components) for preventing movement or gap of the insulating sheet.

[0094] Moreover, the insulating sheet 230 corresponds to the first and second center through holes 210a and 220a, and the sheet through hole 230a is formed in the center. The insulating sheet 230 is simultaneously attached to the inner surface of the first coil pattern portion 211 and the inner surface of the second coil pattern portion 221, so that the first coil pattern portion 211 and the second coil pattern portion 221 are insulated.

[0095] According to a planar transformer of one embodiment of the present invention, when the insulating sheet 230 is tightly attached to the secondary first and second coils 210 and 220 and the secondary first and second coils 210 and 220 are inserted into a cavity (not shown in the drawings) of an injection mold (not shown in the drawings), a molding synthetic resin is injected to form an insulating portion 240 that embeds the first and second coil pattern portions 211 and 221 and the insulating sheet 230 while fixing the insulating sheet 230 between the first and second coil pattern portions 211 and 221.

[0096] This has the advantage that the insulating portion can be formed in one insert molding process and the insulating sheet 230 can be fixed. Such an insulating portion 240 is called a molded insulating portion.

[0097] Furthermore, the insulating sheet 230 is integrally bonded to the insulating portion 240. Therefore, during the high temperature injection molding process, the insulating sheet 230 is bonded to the insulating portion 240, and the fixing of the insulating sheet 230 becomes more reliable, thereby having the advantage of being able to reliably prevent gaps or movements of the insulating sheet 230.

[0098] Furthermore, the insulating sheet 230 is formed of an insulating film. If such an insulating film is used, there is an advantage that the thickness (d1) of the insulating film is very thin, and thus the secondary coil element 200 can be easily made ultra-thin.

[0099] Furthermore, preferably, the insulating sheet 230 is a heat-resistant insulating film. During injection molding, the temperature of the mold is approximately 300-350°C. The heat-resistant insulating film has a melting point of 300°C and can withstand temperatures above 300°C.

[0100] Generally, the thickness of the insulating film is 0.1 mm, so the thickness (T1) of the secondary coil element 200 closely inserted into the insulating sheet 230 can be made ultra-thin.

[0101] Furthermore, the insulating sheet 230 is preferably an adhesive insulating film or an adhesive insulating film. Accordingly, the insulating sheet 230 can be fixed to the secondary first coil or the secondary second coil 220 by adhesive force or adhesive force, which has the effect of improving the processability of the product.

[0102] According to an embodiment, the insulating sheet 230 is formed of a thin film synthetic resin sheet formed by film injection molding.

[0103] The planar transformer of an embodiment of the present invention further includes: a first placement protrusion 241, which protrudes outward from an outer side surface 240a of the insulating portion 240 in order to maintain a normal position by fixing one side of the primary first coil element 110 in close contact with an outer side surface 240a of the insulating portion 240.

[0104] Furthermore, it is preferred that the second placement protrusion 242 is formed to protrude outward from the other outer side surface 240b of the insulating portion 240 in order to maintain a normal position by positioning one side of the primary second coil element 120 in close contact with the other outer side surface 240b of the insulating portion 240. This has the advantage of being able to position the primary first and second coil elements 110 and 120 in close contact with the secondary coil element 200.

[0105] like Figures 1 to 10 As shown, the secondary first coil 210 and the secondary second coil 220 are patterned in one circle. Preferably, the secondary first coil 210 and the secondary second coil 220 are in the shape of thin plates. Thus, there are advantages of good heat generation and improved current characteristics.

[0106] like Figures 11 to 13 As exemplarily shown, the secondary first coil 210 and the secondary second coil 220 are patterned with two or more turns.

[0107] The insulating sheet 230 is formed to correspond to the first and second coil pattern portions 211 and 221. That is, when the first and second coil pattern portions 211 and 221 are two turns, the insulating sheet 230 is also formed to correspond to the two turns.

[0108] In addition, whether the first and second coil pattern portions 211 and 221 are set to have one turn or two or more turns depends on the design specifications of the transformer output, and in either case, it belongs to the technical scope of the present invention.

[0109] Preferably, the secondary first coil 210 and the secondary second coil 220 are connected in series.

[0110] like Figures 1 to 9 As shown, preferably, the secondary first terminal 212 is formed at one end of the first coil pattern portion 211, and the secondary second terminal 222 is formed at one end of the second coil pattern portion 221. The planar transformer of one embodiment of the present invention further includes a series connection portion C1 extending from the other end of the first coil pattern portion 211 to form an integral body, and extending from the other end of the second coil pattern portion 221 to form an integral body, connecting the secondary first coil 210 and the secondary second coil 220 in series, and in order to make the insulating sheet 230 close to the first coil pattern portion 211 and the second coil pattern portion 221, the series connection portion C1 is formed in a U-shaped bend.

[0111] Fig. 9 The first and second secondary coils 210 and 220 are shown in a sheet-like state before being bent into a U shape. Fig. 9The secondary first and second coils 210 and 220 unfolded in a sheet shape are formed into the secondary first and second coils 210 and 220 bent in a relatively U-shape through the U-shaped bending series connection portion C1.

[0112] The following is based on Figures 10 to 13 A modified embodiment of the secondary coil element 200 in the planar transformer according to an embodiment of the present invention will be described.

[0113] based on Figures 10 to 13 The secondary coil element 200 of the modified embodiment is characterized in that Figures 1 to 9 The secondary first coil 210 and the secondary second coil 220 shown are basic secondary coil elements. Similar to the secondary first coil 210 and the secondary second coil 220, the coil composed of a coil pattern portion and a terminal is connected in series or in parallel through an adapter coil 215 to form more than one layer, and an adapter insulating sheet 230-1 is added therebetween.

[0114] That is, the secondary coil element 200 is characterized in that it also includes: at least one adapter insulating sheet 230-1, which is closely attached to at least one of the outer side surfaces of the secondary first coil 210 or the outer side surfaces of the secondary second coil 220; at least one adapter coil 215, which is closely attached to the outside of the adapter insulating sheet 230-1 and is connected in series or in parallel to at least one of the secondary first coil 210 or the secondary second coil 220.

[0115] Moreover, the adapter coil 215 is composed of a third coil pattern portion 215a in which a flat conductor pattern is formed in a ring shape or a spiral shape and a third center through hole 215a' is formed in the middle, and secondary third terminals 215b, 215c are formed at the ends of the third coil pattern portion 215a, and one of the secondary third terminals 215b, 215c is connected to at least one of the secondary first coil 210 or the secondary second coil 220.

[0116] Figures 10 to 13 Taking the adapter insulating sheet 230-1 and the adapter coil 215 as one as an example, this is only for the sake of ease of understanding and explanation. According to the power of the transformer and in accordance with the circuit design specifications, more than two layers of secondary coil elements can be formed. The use of more than two adapter insulating sheets 230-1 and adapter coils 215 also falls within the technical scope of the present invention.

[0117] Figures 10 to 13 A case where the adapter coil 215 is connected to the secondary first coil 210 is shown.

[0118] Fig.13The series connection part C2 shown is a necessary component for connecting the secondary first coil 210 and the adapter coil 215 in series. For example, the secondary first terminal 212 of the secondary first coil 210 and one terminal 215c of the adapter coil 215 are respectively connected, wherein the other terminal 215b of the adapter coil 215 is connected to the secondary connecting pin P2 and connected to the main PCB board 10.

[0119] The secondary first coil 210 and the secondary second coil 220 are connected in series in terms of circuit. In this case, one end and the other end of the secondary first and second coil pattern portions are connected to the secondary connection pin P2.

[0120] Next, the primary coil element 100 will be described.

[0121] The primary first and second coil elements 110 and 120 , regardless of their shapes or names, include all coils that have electromagnetic interactions with the secondary second coil 220 and the secondary first coil 210 , respectively.

[0122] Therefore, a specific example is given to illustrate.

[0123] As shown in the figure, the primary first coil element 110 and the primary second coil element 120 are characterized in that they are composed of a PCB type coil element [multilayer printed circuit board (MLB: multilayer printed circuit board)] formed by stacking multiple insulating plates (not shown in the figure) and forming a conductor pattern of metal material in a spiral shape on the insulating plates.

[0124] Since the PCB type coil element (multilayer printed circuit board) is a well-known component disclosed before the application of the present invention, the detailed description thereof is omitted.

[0125] The primary first coil element 110 formed by the PCB type coil element includes: a primary first coil portion 111, forming a first center hole 110c; a primary first terminal portion 112, protruding outward from one side of the primary first coil portion 111 [preferably, toward the main PCB direction] to form a plurality of primary first terminals 113.

[0126] The primary second coil element 120 formed by the PCB type coil element includes: a primary second coil portion 121, forming a second center hole 120c; a primary second terminal portion 122, protruding outward from one side of the primary second coil portion 121 [preferably, toward the main PCB direction] to form a plurality of primary second terminals 123.

[0127] The primary first coil element 110 and the primary second coil element 120 constituted by the PCB type coil element are characterized in that they are vertically mounted to the main PCB board so that the primary first terminal portion 112 and the primary second terminal portion 122 respectively contact the main PCB board 10, and multiple primary first terminals 113 and primary second terminals 123 are connected to the conductive pattern 11 of the main PCB board 10.

[0128] In order to respectively connect the primary first terminal 113 and the primary second terminal 123 to the conductive pattern 11 of the main PCB board 10 , solder ( w1 ) may be used.

[0129] Accordingly, there is no need to connect to the four primary connection pins usually required for the main PCB board 10 on which the primary first coil element 110, the primary second coil element 120, and the finished product of the transformer [such as a charger or an adapter] are mounted, thereby having the advantages of being able to reduce the number of components, reduce the number of assembly workers, and save the production cost of the product.

[0130] Preferably, if Figure 2 As shown, a spacing space portion Sa not occupied by the secondary coil element 200 is formed between the two primary first coil elements 110 and the primary second coil element 120, the primary first coil element 110 and the primary second coil element 120 formed by the PCB type coil element respectively partially penetrate the main PCB board 10 and are vertically installed, the conductive pattern 11 is formed under the main PCB board 10, and the primary first terminal portion 112 and the primary second terminal portion 122 are connected to the conductive pattern 11 formed under the main PCB board 10.

[0131] Furthermore, there are secondary connection pins P2 connected to the secondary first terminal 212 and the secondary second terminal 222 respectively and connected to the main PCB board 10 of the finished product (such as a charger or an adapter) on which the transformer is mounted.

[0132] In addition, in a planar transformer of another embodiment of the present invention, the primary first coil element 110 and the primary second coil element 120 are composed of a winding type coil element (not shown in the drawings) with a hollow center (not shown in the drawings) and insulating coated conductive wires in contact with each other and wound in a flat plate shape. This case also falls within the technical scope of the present invention.

[0133] The preferred embodiments of the present invention are described above. It is self-evident to those skilled in the art that the present invention may have other specific implementation forms in addition to the above embodiments without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the above embodiments are not restrictive but exemplary.

[0134] Compared with the above-mentioned specific embodiments, the scope of the present invention is presented by the claims described below, and all changes or deformation forms derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

Claims

1. A planar transformer, characterized in that: include: A secondary coil element (200) in the form of a plate; A flat-plate-shaped primary first coil element (110) is closely attached to an outer side surface (240a) of the secondary coil element (200), so that the secondary coil element (200) generates an induced current; The flat-plate-shaped primary second coil element (120) is closely attached to the other outer side surface (240b) of the secondary coil element (200), so that the secondary coil element (200) generates an induced current. The secondary coil element (200) comprises: The secondary first coil (210) is composed of a first coil pattern portion (211) in which a flat conductor pattern is formed in a ring or spiral shape and a first central through hole (210a) is formed in the middle, and a secondary first terminal (212) formed at the terminal of the first coil pattern portion (211); The secondary second coil (220) is composed of a second coil pattern portion (221) having a second central through hole (220a) formed in the middle corresponding to the first central through hole (210a) and a flat conductor pattern formed in a ring or spiral shape, and a secondary second terminal (222) formed at the terminal of the second coil pattern portion (221); An insulating sheet (230) is inserted between the first coil pattern portion (211) and the second coil pattern portion (221) to insulate the first coil pattern portion (211) from the second coil pattern portion (221); The insulating part (240) is made of synthetic resin. When the secondary first coil (210), the insulating sheet (230) and the secondary second coil (220) are tightly attached to each other, the central hole (240c) in the middle is connected to the first central through hole (210a) and the second central through hole (220a). The first and second coil pattern parts (211, 221) and the insulating sheet (230) are embedded therein, and the insulating sheet (230) is tightly fixed between the first and second coil pattern parts (211, 221). The insulating portion (240) is used to form a spacing (d1) between the secondary first coil (210) and the secondary second coil (220) that is equal to the thickness (d1) of the insulating sheet (230). The planar transformer further comprises: a first placement protrusion (241) formed protruding outward from one outer side surface (240a) of the insulating portion (240) in order to maintain a normal position by fixing one side of the primary first coil element (110) in close contact with one outer side surface (240a) of the insulating portion (240); and a second placement protrusion (242) formed protruding outward from another outer side surface (240b) of the insulating portion (240) in order to maintain a normal position by fixing one side of the primary second coil element (120) in close contact with another outer side surface (240b) of the insulating portion (240). Accordingly, the planar transformer has the advantage of being able to fix the positions of the primary first coil element (110) and the primary second coil element (120) in close contact with the secondary coil element (200). The primary first coil element (110) and the primary second coil element (120) are formed by a plurality of insulating plates stacked together and a PCB type coil element having a conductor pattern of a metal material formed in a spiral shape on the insulating plates. The primary first coil element (110) formed by the PCB type coil element comprises: A primary first coil portion (111) forming a first central hole (110c); A primary first terminal portion (112) is formed to protrude outward from one side of the primary first coil portion (111) to form a plurality of primary first terminals (113). The primary second coil element (120) formed by the PCB type coil element comprises: A primary second coil portion (121) forming a second center hole (120c); A primary second terminal portion (122) is formed to protrude outward from one side of the primary second coil portion (121) to form a plurality of primary second terminals (123). The primary first coil element (110) and the primary second coil element (120) formed by the PCB type coil element are vertically mounted on the main PCB board so that the primary first terminal portion (112) and the primary second terminal portion (122) respectively contact the main PCB board (10), and a plurality of primary first terminals (113) and primary second terminals (123) are connected to the conductive pattern (11) of the main PCB board (10). A spacing space (Sa) not occupied by the secondary coil element (200) is formed between the two primary first coil elements (110) and the primary second coil elements (120); the primary first coil elements (110) and the primary second coil elements (120) formed by the PCB type coil elements respectively partially penetrate the main PCB board (10) and are vertically installed; the conductive pattern (11) is formed under the main PCB board (10); and the primary first terminal portion (112) and the primary second terminal portion (122) are connected to the conductive pattern (11) formed under the main PCB board (10).

2. The planar transformer according to claim 1, characterized in that: The insulating sheet (230) corresponds to the first and second central through holes (210a, 220a), and a sheet through hole (230a) is formed in the center. The insulating sheet (230) is closely attached to the inner surface of the first coil pattern portion (211) and the inner surface of the second coil pattern portion (221) at the same time, and insulates the first coil pattern portion (211) from the second coil pattern portion (221).

3. The planar transformer according to claim 1, characterized in that: When the secondary first coil (210) and the secondary second coil (220) which are in close contact with the insulating sheet (230) are inserted into the cavity of the injection mold, a molding synthetic resin is injected to form the insulating portion (240) which is embedded with the first and second coil pattern portions (211, 221) and the insulating sheet (230) and is fixed by making the insulating sheet (230) in close contact with the first and second coil pattern portions (211, 221).

4. The planar transformer according to claim 1, characterized in that: The secondary first coil (210) and the secondary second coil (220) are in the shape of thin plates.

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