A method for consuming leakage inductance of a flat magnetic device and a flat magnetic device

Abstract

The present invention relates to the technical field of planar magnetic devices, and in particular to a method for consuming leakage inductance of a planar magnetic device and a planar magnetic device. The specific method is as follows: any winding layer in the planar magnetic device is selected, a conductive medium layer is arranged in parallel between the winding layer and the previous layer or between the winding layer and the next layer, a through hole and / or a notch through which a magnetic column of a magnetic core of the magnetic device passes is matched on the conductive medium layer, at least one isolation line is arranged in an area between adjacent magnetic columns on the conductive medium layer, and both ends of the isolation line extend to the edges of the through hole or the notch through which the magnetic column passes, the isolation line does not contain a conductive medium, the coverage area of ​​the conductive medium layer is ≥ the coverage area of ​​the magnetic flux generated by all winding layers, the leakage magnetic flux generated by all winding layers will generate an induced current in the conductive medium layer, and based on the setting of the isolation line, no induced current will be generated around the magnetic core magnetic column, so that while the leakage magnetic flux is consumed, no loss of the main magnetic flux is caused.

Description

Technical Field

[0001] The invention relates to the technical field of planar magnetic devices, in particular to a method for consuming leakage inductance of a planar magnetic device and a planar magnetic device. Background Art

[0002] Existing planar magnetic devices, such as planar transformers and planar inductors, are generally constructed using a low-height magnetic core, and the windings are implemented on the metal layer of a single-layer or multi-layer printed circuit board (hereinafter referred to as a PCB board).

[0003] There are two main ways to implement planar transformers:

[0004] A. Figure 1 As shown, the primary winding and the secondary winding of the transformer are implemented on the same metal layer of the same PCB board. In this way, since the primary winding and the secondary winding are implemented on the same metal layer, the number of winding turns is limited by the PCB area.

[0005] B. Figure 2 As shown, the primary winding and the secondary winding of the transformer are implemented on different metal layers of the same PCB board, and the different layers are connected through metal vias. In this implementation, the two windings are on different metal layers, which makes the PCB area less restricted and can achieve a larger number of winding turns.

[0006] C. The primary winding and the secondary winding of the transformer are implemented on metal layers of different PCB boards, and the different PCB boards are connected through conductive connection components, such as metal vias of the PCB board, with a metal column passing through the via, and the via and the metal column are welded together; the two windings of this implementation method are on different PCB boards, so that the area of ​​the PCB board is less restricted, and a larger number of winding turns can be achieved.

[0007] Similarly, there are two specific ways to implement planar inductors:

[0008] A. Figure 3 As shown in the figure, the inductor winding is implemented on the same metal layer of the same PCB, and the number of winding turns is also restricted by the PCB area;

[0009] B. The inductor winding is implemented on different metal layers of the same PCB, and the different layers are connected through metal vias. In this implementation method, the windings are distributed on different layers of the same PCB board, which makes it less restricted by the PCB board area and can achieve a larger number of winding turns;

[0010] C. The windings of the inductor are implemented on metal layers of different PCB boards, and the different PCB boards are connected through conductive connection components, such as metal vias of the PCB board, with a metal column passing through the via, and the via and the metal column are welded together; the windings of this implementation method are distributed on different PCB boards, so that the area of ​​the PCB board is less restricted, and a larger number of winding turns can be achieved.

[0011] However, in the implementation schemes of the above-mentioned planar transformer and planar inductor, no matter the winding is implemented on the same metal layer or on different metal layers, the magnetic core can only cover a part of the PCB trace, resulting in a part of the magnetic flux generated by the winding not passing through the magnetic core, but passing through the space outside the magnetic core. At the same time, a part of the magnetic flux generated by a part of the winding passes through the magnetic core, but not through another part of the winding. For example: Figure 4 As shown in the figure, in the technical solution of using the same metal layer to realize the primary winding and the secondary winding of the flat transformer, the magnetic fluxes Be1, Be2, Be3 and Be4 do not pass through the magnetic core, but through the space outside the magnetic core. Although the magnetic fluxes Be5 and Be6 pass through part of the magnetic core, they do not pass through another part of the winding. In this way, these leakage magnetic fluxes will form a large leakage inductance. When a planar transformer or planar inductor of this structure is used in a switching power supply, the presence of leakage inductance will cause a large voltage oscillation, which will lead to overvoltage loss of the power device. At the same time, since the leakage inductance passes through the open space, it will also cause electromagnetic interference problems. Summary of the invention

[0012] In view of the problems in the prior art, the present invention provides a method for consuming the leakage inductance of a planar magnetic device and a planar magnetic device designed based on the method.

[0013] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0014] A method for consuming leakage inductance of a planar magnetic device, wherein any winding layer in the planar magnetic device is selected, a conductive medium layer is arranged in parallel between the winding layer and the previous layer or between the winding layer and the next layer, a through hole and / or a notch for a magnetic column of a magnetic core of the planar magnetic device to pass through is matched on the conductive medium layer, at least one isolation line is arranged in a region between adjacent magnetic columns on the conductive medium layer, and both ends of the isolation line extend to the edges of the through hole or the notch through which the magnetic column passes, the isolation line does not contain a conductive medium, the coverage area of ​​the conductive medium layer is larger than the coverage area of ​​the magnetic flux generated by all winding layers, the leakage magnetic flux generated by all winding layers generates an induced current in the conductive medium layer, and based on the setting of the isolation line, the conductive medium layer does not generate an induced current around the magnetic core magnetic column, so that while the leakage magnetic flux of the planar magnetic device is consumed, the main magnetic flux is not lost.

[0015] Based on the above method for consuming leakage inductance of a planar magnetic device, a first planar magnetic device is designed, specifically: a planar magnetic device, comprising a matching upper magnetic core and a lower magnetic core, and a PCB board, wherein at least two magnetic pillars are arranged on the upper magnetic core or the lower magnetic core, and the PCB board is arranged between the upper magnetic core and the lower magnetic core and has a multi-layer structure, each layer of the structure is provided with a through hole and / or a gap for the magnetic pillar to pass through, and the multi-layer structure includes at least two metal layers, wherein one metal layer is used as a conductive medium layer, and the remaining metal layers are used as winding layout layers, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the windings on all the winding layout layers, and at least one isolation line is arranged in the area between adjacent magnetic pillars on the conductive medium layer, and the two ends of the isolation line extend to the edges of the through hole or the gap through which the magnetic pillar passes, respectively, and the isolation line does not have a conductive medium.

[0016] Preferably, the planar magnetic device is a planar transformer, and a magnetic column is respectively provided on both sides of a side of the upper magnetic core facing the lower magnetic core, the PCB board includes two metal layers, one metal layer is used as a winding layout layer, and the other metal layer is used as a conductive medium layer, each metal layer is provided with two through holes for the two magnetic columns of the upper magnetic core to pass through, the primary winding and the secondary winding on the winding layout layer are respectively arranged around the two through holes, the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, at least one isolation line is arranged in the area between the two through holes on the conductive medium layer, and the two ends of the isolation line extend to the edges of the two through holes respectively, and there is no conductive medium in the isolation line.

[0017] Preferably, the planar magnetic device is a planar transformer, the upper magnetic core is an E-type magnetic core, the lower magnetic core is an I-type magnetic core, the PCB board includes N metal layers, N is a positive integer and ≥3, any one metal layer is used as a conductive medium layer, and the remaining metal layers are divided into two parts, one part is used as a primary winding layout layer, and the other part is used as a secondary winding layout layer, each metal layer is provided with three through holes matching the three magnetic columns of the E-type magnetic core, the primary winding on the primary winding layout layer and the secondary winding on the secondary winding layout layer are both arranged around the through hole located in the middle, the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, at least one isolation line is arranged in the area between two adjacent through holes on the conductive medium layer, and the two ends of the isolation line extend to the edges of the two through holes respectively, and there is no conductive medium in the isolation line.

[0018] Preferably, the planar magnetic device is a planar inductor, the upper magnetic core is an E-type magnetic core, the lower magnetic core is an I-type magnetic core, the PCB board includes N metal layers, N is a positive integer and ≥2, any one metal layer is used as a conductive medium layer, and the remaining metal layers are used as winding layout layers, each metal layer is provided with three through holes for three magnetic columns of the E-type magnetic core to pass through, the winding on the winding layout layer is arranged around the through hole located in the middle, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the winding, at least one isolation line is arranged in the area between two adjacent through holes on the conductive medium layer, and the two ends of the isolation line extend to the edges of the two through holes respectively, and there is no conductive medium in the isolation line.

[0019] Based on the above method for consuming the leakage inductance of a planar magnetic device, a second planar magnetic device is designed, specifically: a planar magnetic device, comprising a matching upper magnetic core and a lower magnetic core, at least two magnetic pillars are arranged on the upper magnetic core or the lower magnetic core, a multi-layer PCB board is arranged between the upper magnetic core and the lower magnetic core, each layer of the PCB board is provided with a through hole and / or a notch for the magnetic pillars to pass through, a metal layer of at least one layer of the PCB board is used as a winding layout layer, a metal layer of the PCB board adjacent to any layer of the winding layout layer is used as a conductive medium layer, a coverage area of ​​the conductive medium layer is greater than or equal to a coverage area of ​​the magnetic flux generated by the windings on all the winding layout layers, at least one isolation line is arranged in an area between adjacent magnetic pillars on the conductive medium layer, and two ends of the isolation line respectively extend to the edges of the through hole or the notch through which the magnetic pillars pass through, and there is no conductive medium in the isolation line.

[0020] Preferably, the planar magnetic device is a planar transformer, and a magnetic column is respectively provided on both sides of a side of the upper magnetic core facing the lower magnetic core, and two layers of PCB boards are provided between the upper magnetic core and the lower magnetic core, wherein the metal layer of one layer of PCB boards is used as a winding layout layer, and the metal layer of the other layer of PCB boards is used as a conductive medium layer, and each layer of PCB boards is provided with two through holes for the two magnetic columns of the upper magnetic core to pass through, and the primary winding and the secondary winding on the winding layout layer are respectively arranged around the two through holes, and the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, and at least one isolation line is arranged in the area between the two through holes on the conductive medium layer, and the two ends of the isolation line extend to the edges of the two through holes respectively, and there is no conductive medium in the isolation line.

[0021] Preferably, the planar magnetic device is a planar transformer, the upper magnetic core is an E-type upper magnetic core, the lower magnetic core is an I-type magnetic core, N layers of PCB boards are arranged between the upper magnetic core and the lower magnetic core, N is a positive integer and is ≥3, the metal layer of any one layer of PCB boards is used as a conductive medium layer, and the remaining layers of PCB boards are divided into two parts, the metal layer of one part of the PCB boards is used as a primary winding layout layer, and the metal layer of the other part of the PCB boards is used as a secondary winding layout layer, and the two side edges of each layer of PCB boards are respectively provided with The gaps through which the magnetic columns on both sides pass have a through hole in the center for the central magnetic column of the E-type upper magnetic core to pass through, the primary winding on the primary winding layout layer and the secondary winding on the secondary winding layout layer are both arranged around the through hole, the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, at least one isolation line is arranged in the area between each gap and the through hole on the conductive medium layer, and the two ends of the isolation line are respectively connected to the edges of the gap and the through hole, and there is no conductive medium in the isolation line.

[0022] Preferably, the planar magnetic device is a planar inductor, the upper magnetic core is an E-type magnetic core, the lower magnetic core is an I-type magnetic core, N layers of PCB boards are arranged between the upper magnetic core and the lower magnetic core, N is a positive integer and is ≥2, the metal layer of any one layer of PCB boards is used as a conductive medium layer, and the metal layers of the remaining layers of PCB boards are used as winding layout layers, the two side edges of each layer of PCB boards are respectively provided with notches for the two side magnetic columns of the E-type magnetic core to pass through, and the center is provided with a through hole for the central magnetic column of the E-type magnetic core to pass through, the winding on the winding layout layer is arranged around the through hole, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the winding, at least one isolation line is evenly arranged in the area between each notch and the through hole on the conductive medium layer, and the two ends of the isolation line are respectively connected to the edges of the notch and the through hole, and there is no conductive medium in the isolation line.

[0023] It can be seen from the above description that the present invention has the following advantages: the present invention utilizes the PCB board process, and in the structure of the flat magnetic device, adds a conductive medium layer that can cover or even exceed the coverage area of ​​the magnetic flux generated by the entire winding, and at least one isolation line is arranged on the conductive medium layer, and no conductive medium is arranged in the isolation line, so that the leakage magnetic flux of the flat magnetic device will generate an induced current in the conductive medium layer, and the energy carried by the leakage magnetic flux is consumed by the induced current, and due to the existence of the isolation line, the conductive medium layer will not generate an induced current around the magnetic core column, and will not cause the loss of the alternating magnetic flux of the main magnetic circuit, thereby ensuring that while the leakage magnetic flux of the flat magnetic device is consumed, it will not cause the loss of the main magnetic flux. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of an existing flat-plate transformer;

[0025] Figure 2 It is a structural schematic diagram of an existing flat-plate transformer;

[0026] Figure 3 It is a structural schematic diagram of an existing planar inductor;

[0027] Figure 4 It is a schematic diagram of leakage inductance of an existing planar transformer;

[0028] Figure 5 is a schematic diagram of the induced current in the case where there is no isolation line according to the present invention;

[0029] Figure 6 is a schematic diagram of the induced current in the case of an isolated line according to the present invention;

[0030] Figure 7 is a schematic structural diagram of Embodiment 1 of the present invention;

[0031] Figure 8 is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0032] Fig. 9 is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0033] Fig.10 is a schematic diagram of the structure of Embodiment 4 of the present invention;

[0034] Fig.11 is a schematic structural diagram of Embodiment 5 of the present invention;

[0035] Fig.12 is a schematic diagram of the structure of Embodiment 6 of the present invention;

[0036] Fig.13 It is a schematic diagram of an extended structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail with reference to the accompanying drawings, but no limitation is imposed on the claims of the present invention.

[0038] Based on the principle of electromagnetic induction effect, a changing magnetic field will generate a circulating induced current (called eddy current) in a metal conductor that intersects perpendicularly with the direction of the magnetic field. The eddy current will cause the metal conductor to heat up, thereby dissipating the magnetic field energy. Therefore, a method for consuming the leakage inductance of a planar magnetic device is designed, specifically: any winding layer in the planar magnetic device is selected, and a conductive medium layer is arranged in parallel between the winding layer and the previous layer or between the winding layer and the next layer. The conductive medium layer is matched with through holes and / or gaps through which magnetic columns of the magnetic core of the planar magnetic device pass. At least one isolation line is arranged in the area between adjacent magnetic columns on the conductive medium layer, and the two ends of the isolation line extend to the edges of the through holes or gaps through which the magnetic columns pass, respectively. There is no conductive medium in the isolation line, and the coverage area of ​​the conductive medium layer is greater than the coverage area of ​​the magnetic flux generated by all winding layers. The leakage magnetic flux generated by all winding layers generates an induced current in the conductive medium layer, and based on the setting of the isolation line, the conductive medium layer will not generate an induced current around the magnetic core magnetic column, so that while the leakage magnetic flux of the planar magnetic device is consumed, the main magnetic flux will not be lost.

[0039] like Figure 5 As shown in FIG5 , it is a schematic diagram of the induced current on the conductive medium layer when the above method is specifically applied. As can be seen from FIG5 , the leakage magnetic flux of the planar magnetic device will generate an induced current in the conductive medium layer, and the energy carried by the leakage magnetic flux is consumed by the induced current. In addition, due to the existence of the isolation line, the conductive medium layer will not generate an induced current around the magnetic core column, and will not cause the loss of the alternating magnetic flux of the main magnetic circuit, thereby ensuring that the leakage magnetic flux of the planar transformer or planar inductor is consumed without causing the loss of the main magnetic flux.

[0040] like Figure 6 As shown, Figure 5 In the scheme shown, no isolation line is set. Figure 6 It can be seen that the induced current generated by the alternating magnetic flux Bm1, Bm2, and Bm3 of the main magnetic circuit will cause the loss of the main magnetic flux. Compared with the traditional flat magnetic device, although the influence of the leakage magnetic flux is reduced, it will also cause the loss of the main magnetic flux, thus affecting the performance of the flat magnetic device. Figure 5 Compared with the above-mentioned solutions, this solution has obvious defects, which further proves the necessity of setting the isolation line in the method of the present invention.

[0041] Since the existing planar magnetic devices (such as planar transformers and planar inductors) have winding settings that include at least the three situations mentioned in the background technology, multiple situations will occur when the conductive medium layer is set using the above method. Based on the method of consuming the leakage inductance of the planar magnetic device described in the present invention, combined with the existing planar magnetic device winding settings, planar transformers and planar inductors with different structures are designed.

[0042] like Figure 7-Figure 9 The three embodiments shown are the cases where the winding arrangement layer and the conductive medium layer of the planar magnetic device are on different layers of the same PCB board.

[0043] Example 1: Figure 7 As shown, a flat transformer comprises a matching upper magnetic core 1 and a lower magnetic core 2, and a PCB board, wherein a magnetic column 11 is respectively arranged on both sides of a side of the upper magnetic core 1 facing the lower magnetic core 2, the PCB board comprises two metal layers, one metal layer is used as a winding layout layer 5, and the other metal layer is used as a conductive medium layer 4, each metal layer is provided with two through holes 6 for two magnetic columns of the upper magnetic core to pass through, a primary winding 501 and a secondary winding 502 on the winding layout layer 5 are arranged around the two through holes 6 respectively, a coverage area of ​​the conductive medium layer is greater than or equal to the sum of coverage areas of magnetic fluxes generated by the primary winding 501 and the secondary winding 502, at least one isolation line 7 is arranged in the area between the two through holes 6 on the conductive medium layer 4, and two ends of the isolation line 7 extend to the edges of the two through holes 6 respectively, and there is no conductive medium in the isolation line 7.

[0044] In this embodiment, the primary winding and the secondary winding of the planar transformer are arranged on the same metal layer of the same PCB board.

[0045] Example 2: Figure 8 As shown, a flat transformer includes a matching upper magnetic core 1 and a lower magnetic core 2, and a PCB board, wherein the upper magnetic core 1 is an E-type magnetic core, the lower magnetic core 2 is an I-type magnetic core, and the PCB board includes N metal layers, where N is a positive integer and is ≥3, any one metal layer is used as a conductive medium layer 4, and the remaining metal layers are divided into two parts, one part is used as a primary winding layout layer 51, and the other part is used as a secondary winding layout layer 52, and each metal layer is provided with three through holes 6 matching the three magnetic columns of the E-type magnetic core, The primary winding 501 on the primary winding layout layer 51 and the secondary winding 502 on the secondary winding layout layer 52 are both arranged around the through hole 6 located in the middle, and the coverage area of ​​the conductive medium layer 4 is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding 501 and the secondary winding 502. At least one isolation line 7 is arranged in the area between two adjacent through holes 6 on the conductive medium layer 4, and both ends of the isolation line 7 extend to the edges of the two through holes 6 respectively, and there is no conductive medium in the isolation line 7.

[0046] In this embodiment:

[0047] (1) The metal layer as the conductive medium layer is placed between two primary winding layout layers, the primary winding layout layers have N layers in total, and the secondary winding layout layers have M layers in total;

[0048] (2) The primary windings are connected in the following manner: the V12 end of the first layer of primary windings is connected to the V21 end of the second layer of primary windings, the V22 end of the second layer of primary windings is connected to the V31 end of the third layer of primary windings, and so on, until the penultimate layer of primary windings is connected to the last layer of primary windings; the secondary windings are connected in the same manner; Figure 8 In FIG. 1 , V11 to VN2 represent the ends of the primary winding, and U11 to UM2 represent the ends of the secondary winding.

[0049] In practical application of this embodiment: the first metal layer or the last metal layer can also be selected as the conductive medium layer, and the remaining metal layers can be used as the primary winding layout layer and the secondary winding layout layer. The connection method of the windings on different winding layout layers is the same as Figure 8 The scheme shown is similar.

[0050] In this embodiment, the primary winding and secondary winding of the planar transformer are respectively arranged on different metal layers of the same PCB board, and the total number of metal layers occupied by the primary winding and the total number of metal layers occupied by the secondary winding are not limited, and the specific number of layers can be set according to needs.

[0051] Example 3: Fig. 9 As shown, a planar inductor includes a matching upper magnetic core 1 and a lower magnetic core 2, the upper magnetic core 1 is an E-type magnetic core, the lower magnetic core 2 is an I-type magnetic core, a PCB board includes N metal layers, N is a positive integer and is ≥2, any one metal layer is used as a conductive medium layer 4, and the remaining metal layers are used as winding layout layers 5, each metal layer is provided with three through holes 6 for three magnetic columns (including two side magnetic columns 11 and a center magnetic column 12) of the E-type magnetic core to pass through, a winding 503 on the winding layout layer 5 is arranged around a through hole 61 located in the middle, a coverage area of ​​the conductive medium layer is greater than or equal to a coverage area of ​​a magnetic flux generated by the winding 503, at least one isolation line 7 is arranged in the area between two adjacent through holes 6 on the conductive medium layer 4, and two ends of the isolation line 7 extend to the edges of the two through holes 6 respectively, and there is no conductive medium in the isolation line 7.

[0052] In this embodiment:

[0053] (1) A metal layer as a conductive medium layer is placed between two winding arrangement layers, and the winding arrangement layers have a total of N layers;

[0054] (2) The windings are connected in the following manner: the V12 end of the first winding layer is connected to the V21 end of the second winding layer, the V22 end of the second winding layer is connected to the V31 end of the third winding layer, and so on, until the penultimate winding layer is connected to the last winding layer; Fig. 9 In the figure, V11~VN2 represent the ends of the winding.

[0055] In practical application of this embodiment: the first metal layer or the last metal layer can also be selected as the conductive medium layer, and the remaining metal layers can be used as winding layout layers. The connection method of the windings on different winding layout layers is the same as Fig. 9 The scheme shown is similar.

[0056] In this embodiment, when the total number of metal layers is 2, the windings of the planar inductor are arranged on the same metal layer of the same PCB board; when the total number of metal layers is greater than 2, the windings of the planar inductor are arranged on different metal layers of the same PCB board and the total number of metal layers occupied by the windings is not limited, and the specific number of layers can be set according to needs.

[0057] In the above three embodiments, only the magnets, windings and metal layers used as conductive medium layers involved in the PCB board are limited. When actually designing a flat magnetic device, the PCB board not only includes multiple mechanical insulation layers, solder mask layers, silk screen layers and other non-metal layers for other purposes, but may also include other metal layers that are not used for the flat magnetic device.

[0058] Therefore, the above three embodiments can be summarized as: a flat magnetic device, including a matching upper magnetic core and a lower magnetic core, and a PCB board, at least two magnetic columns are arranged on the upper magnetic core or the lower magnetic core, the PCB board is arranged between the upper magnetic core and the lower magnetic core and has a multi-layer structure, each layer of the structure is provided with a through hole and / or a gap for the magnetic column to pass through, and the multi-layer structure includes at least two metal layers, wherein one metal layer is used as a conductive medium layer, and the remaining metal layers are used as winding layout layers, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the windings on all winding layout layers, at least one isolation line is arranged in the area between adjacent magnetic columns on the conductive medium layer, and the two ends of the isolation line extend to the edges of the through hole or the gap through which the magnetic column passes, respectively, and the isolation line does not contain a conductive medium.

[0059] like Figure 10-12 The three embodiments shown are the cases where the winding layout layer and the conductive medium layer of the planar magnetic device are on different PCB boards.

[0060] Example 4: Fig.10As shown, a flat transformer comprises a matching upper magnetic core 1 and a lower magnetic core 2, wherein a magnetic column 11 is respectively arranged on both sides of a side of the upper magnetic core 1 facing the lower magnetic core 2, and two layers of PCB boards 3 are arranged between the upper magnetic core 1 and the lower magnetic core 2, wherein a metal layer of one PCB board is used as a winding layout layer 5, and a metal layer of another PCB board is used as a conductive medium layer 4, and each layer of the PCB board is provided with two through holes 6 for two magnetic columns of the upper magnetic core to pass through, a primary winding 501 and a secondary winding 502 on the winding layout layer 5 are respectively arranged around the two through holes 6, a coverage area of ​​the conductive medium layer 4 is greater than or equal to the sum of coverage areas of magnetic fluxes generated by the primary winding 501 and the secondary winding 502, and at least one isolation line 7 is arranged in the area between the two through holes 6 on the conductive medium layer 4, and two ends of the isolation line 7 extend to the edges of the two through holes 6, respectively, and there is no conductive medium in the isolation line 7.

[0061] In this embodiment, the primary winding and the secondary winding of the planar transformer are arranged on the same PCB board.

[0062] Example 5: Fig.11 As shown, a flat transformer comprises a matching upper magnetic core 1 and a lower magnetic core 2, wherein the upper magnetic core 1 is an E-type upper magnetic core, and the lower magnetic core 2 is an I-type magnetic core. N layers of PCB boards 3 are arranged between the upper magnetic core 1 and the lower magnetic core 2, wherein N is a positive integer and is ≥3, and a metal layer of any one layer of PCB boards is used as a conductive medium layer 4, and the remaining layers of PCB boards are divided into two parts, wherein a metal layer of one part of the PCB boards is used as a primary winding layout layer 51, and a metal layer of another part of the PCB boards is used as a secondary winding layout layer 52, and two side edges of each layer of PCB boards are respectively provided with two side magnetic layers for the E-type upper magnetic core. The center of the notch 8 through which the column passes is provided with a through hole 6 for the central magnetic column of the E-type upper magnetic core to pass through, the primary winding 501 on the primary winding layout layer 51 and the secondary winding 502 on the secondary winding layout layer 52 are both arranged around the through hole 6, the coverage area of ​​the conductive medium layer 4 is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding 501 and the secondary winding 502, at least one isolation line 7 is evenly arranged in the area between each notch 8 and the through hole 6 on the conductive medium layer 4, and the two ends of the isolation line 7 are respectively connected to the edges of the notch and the through hole, and there is no conductive medium in the isolation line 7.

[0063] In this embodiment:

[0064] (1) A PCB board as a conductive medium layer is placed between two primary winding layout layers, wherein the primary winding layout layers have N layers in total and the secondary winding layout layers have M layers in total;

[0065] (2) The primary windings are connected in the following manner: the V12 end of the first layer of primary windings is connected to the V21 end of the second layer of primary windings, the V22 end of the second layer of primary windings is connected to the V31 end of the third layer of primary windings, and so on, until the penultimate layer of primary windings is connected to the last layer of primary windings; the secondary windings are connected in the same manner; Fig.11 In FIG. 1 , V11 to VN2 represent the ends of the primary winding, and U11 to UM2 represent the ends of the secondary winding.

[0066] In practical application of this embodiment: the first layer of PCB board or the last layer of PCB board can also be selected as the conductive medium layer, and the remaining PCB boards can be used as the primary winding layout layer and the secondary winding layout layer. The connection method of the windings on different winding layout layers is the same as Fig.11 The scheme shown is similar.

[0067] In this embodiment, the primary winding and the secondary winding of the planar transformer are respectively arranged on the metal layers of different PCB boards, and the total number of PCB boards occupied by the primary winding and the total number of PCB boards occupied by the secondary winding are not limited, and the specific number can be set according to needs.

[0068] Example 6: Fig.12 As shown, a planar inductor comprises a matching upper magnetic core 1 and a lower magnetic core 2, wherein the upper magnetic core 1 is an E-type magnetic core, and the lower magnetic core 2 is an I-type magnetic core. N layers of PCB boards 3 are arranged between the upper magnetic core 1 and the lower magnetic core 2, wherein N is a positive integer and is ≥2, a metal layer of any one layer of the PCB boards is used as a conductive medium layer 4, and metal layers of the remaining layers of the PCB boards are used as winding layout layers 5, two side edges of each layer of the PCB boards are respectively provided with notches 8 for the two side magnetic columns 11 of the E-type magnetic core to pass through, and a through hole 6 is provided in the center for the central magnetic column 12 of the E-type magnetic core to pass through, a winding 503 on the winding layout layer 5 is arranged around the through hole 6, a coverage area of ​​the conductive medium layer 4 is greater than or equal to a coverage area of ​​a magnetic flux generated by the winding 503, at least one isolation line 7 is evenly arranged in the area between each notch 8 and the through hole 6 on the conductive medium layer, and two ends of the isolation line 7 are respectively connected to the edges of the notch 8 and the through hole 6, and there is no conductive medium in the isolation line 7.

[0069] In this embodiment:

[0070] (1) A PCB board as a conductive medium layer is placed between two winding layout layers, and the winding layout layers have a total of N layers;

[0071] (2) The windings are connected in the following manner: the V12 end of the first winding layer is connected to the V21 end of the second winding layer, the V22 end of the second winding layer is connected to the V31 end of the third winding layer, and so on, until the penultimate winding layer is connected to the last winding layer; Fig.12 In the figure, V11~VN2 represent the ends of the winding.

[0072] In practical application of this embodiment: the first layer of PCB board or the last layer of PCB board can also be selected as the conductive medium layer, and the remaining PCB boards can be used as winding layout layers. The connection method of the windings on different winding layout layers is the same as Fig.12 The scheme shown is similar.

[0073] In this embodiment, when the total number of PCB boards is 2, the windings of the planar inductor are arranged on the same PCB board; when the total number of PCB boards is greater than 2, the windings of the planar inductor are arranged on different PCB boards and the total number of PCB boards occupied by the windings is not limited, and the specific number can be set according to needs.

[0074] In the above three embodiments, each PCB board is used as a conductive medium layer or a winding layout layer alone, and Fig.11 In the structure shown, the primary winding layout layer and the secondary winding layout layer each use their own PCB board. When actually designing a flat magnetic device, each PCB board can not only include multiple mechanical insulation layers, solder mask layers, silk screen layers and other non-metallic layers for other purposes, but also other metal layers that are not used for the flat magnetic device. In addition, in a mechanism with multiple layers of PCB boards, the following extended structures can also be used:

[0075] (1) When there are multiple layers of PCB boards, a portion of the primary winding occupies several separate layers of PCB boards, a portion of the secondary winding also occupies several separate layers of PCB boards, another portion of the primary winding and another portion of the secondary winding are arranged on different metal layers of the same layer of PCB board, and the conductive medium layer occupies one layer of PCB board.

[0076] (2) When there are multiple layers of PCB boards, a portion of the primary winding occupies several separate layers of PCB boards, a portion of the secondary winding also occupies several separate layers of PCB boards, and another portion of the primary winding and another portion of the secondary winding are arranged on different metal layers of the same layer of PCB board, and the conductive medium layer is arranged on a separate metal layer of any layer of PCB board, for example: Fig.13 The structure shown, Fig.13 The one marked with P is the primary winding, and the one marked with S is the secondary winding.

[0077] (3) When there are multiple layers of PCB boards, the PCB boards used as the primary winding and the secondary winding do not necessarily have to be in accordance with Fig.11 The structure shown is arranged sequentially, or the primary winding and the secondary winding can be arranged alternately in an orderly manner, or in other irregular forms.

[0078] Therefore, the above three embodiments can be summarized as: a flat magnetic device, including a matching upper magnetic core and a lower magnetic core, at least two magnetic columns are arranged on the upper magnetic core or the lower magnetic core, a multi-layer PCB board is arranged between the upper magnetic core and the lower magnetic core, each layer of the PCB board is provided with a through hole and / or a notch for the magnetic column to pass through, the metal layer of at least one layer of the PCB board is used as a winding layout layer, the metal layer of the PCB board adjacent to any layer of the winding layout layer is used as a conductive medium layer, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the windings on all the winding layout layers, at least one isolation line is arranged in the area between adjacent magnetic columns on the conductive medium layer, and the two ends of the isolation line extend to the edges of the through hole or the notch through which the magnetic column passes, and there is no conductive medium in the isolation line.

[0079] In summary, the present invention has the following advantages:

[0080] The present invention utilizes PCB board technology to add a conductive medium layer capable of covering or even exceeding the magnetic flux coverage area generated by the entire winding in the structure of a flat magnetic device such as a flat transformer or a flat inductor, and at least one isolation line is provided on the conductive medium layer, and no conductive medium is provided in the isolation line, so that the leakage magnetic flux of the flat transformer or the flat inductor generates an induced current in the conductive medium layer, and the energy carried by the leakage magnetic flux is consumed by the induced current. In addition, due to the existence of the isolation line, the conductive medium layer does not generate an induced current around the magnetic core column, and does not cause the loss of the alternating magnetic flux of the main magnetic circuit, thereby ensuring that while the leakage magnetic flux of the flat transformer or the flat inductor is consumed, the main magnetic flux is not lost.

[0081] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for consuming leakage inductance of a planar magnetic device, characterized in that: Any winding layer in the planar magnetic device is selected, and a conductive medium layer is arranged in parallel between the winding layer and the previous layer or between the winding layer and the next layer. The conductive medium layer is matched with through holes and / or gaps for the magnetic columns of the magnetic core of the planar magnetic device to pass through. At least one isolation line is arranged in the area between adjacent magnetic columns on the conductive medium layer, and the two ends of the isolation line extend to the edges of the through holes or gaps through which the magnetic columns pass through, respectively. There is no conductive medium in the isolation line, and the coverage area of ​​the conductive medium layer is larger than the coverage area of ​​the magnetic flux generated by all winding layers. The leakage magnetic flux generated by all winding layers generates an induced current in the conductive medium layer, and based on the setting of the isolation line, the conductive medium layer will not generate an induced current around the magnetic core column, so that while the leakage magnetic flux of the planar magnetic device is consumed, it will not cause the loss of the main magnetic flux.

2. A planar magnetic device based on the method for consuming leakage inductance of a planar magnetic device according to claim 1, characterized in that: The invention comprises a matching upper magnetic core and a lower magnetic core, and a PCB board, wherein at least two magnetic columns are arranged on the upper magnetic core or the lower magnetic core, and the PCB board is arranged between the upper magnetic core and the lower magnetic core and has a multi-layer structure, each layer of the structure is provided with a through hole and / or a notch for the magnetic column to pass through, and the multi-layer structure comprises at least two metal layers, wherein one metal layer is used as a conductive medium layer, and the other metal layers are used as winding layout layers, and the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the windings on all winding layout layers, and at least one isolation line is arranged in the area between adjacent magnetic columns on the conductive medium layer, and the two ends of the isolation line respectively extend to the edges of the through hole or the notch through which the magnetic column passes, and the isolation line does not have a conductive medium.

3. The flat magnetic device according to claim 2, characterized in that: The flat magnetic device is a flat transformer, wherein a magnetic column is respectively arranged on both sides of a side of the upper magnetic core facing the lower magnetic core, the PCB board comprises two metal layers, one metal layer is used as a winding layout layer, and the other metal layer is used as a conductive medium layer, each metal layer is provided with two through holes for the two magnetic columns of the upper magnetic core to pass through, the primary winding and the secondary winding on the winding layout layer are respectively arranged around the two through holes, the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, at least one isolation line is arranged in the area between the two through holes on the conductive medium layer, and the two ends of the isolation line respectively extend to the edges of the two through holes, and there is no conductive medium in the isolation line.

4. The flat magnetic device according to claim 2, characterized in that: The planar magnetic device is a planar transformer, the upper magnetic core is an E-type magnetic core, the lower magnetic core is an I-type magnetic core, the PCB board includes N metal layers, N is a positive integer and is ≥3, any one metal layer is used as a conductive medium layer, and the remaining metal layers are divided into two parts, one part is used as a primary winding layout layer, and the other part is used as a secondary winding layout layer, each metal layer is provided with three through holes matching the three magnetic columns of the E-type magnetic core, the primary winding on the primary winding layout layer and the secondary winding on the secondary winding layout layer are both arranged around the through hole located in the middle, the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, at least one isolation line is arranged in the area between two adjacent through holes on the conductive medium layer, and the two ends of the isolation line extend to the edges of the two through holes respectively, and there is no conductive medium in the isolation line.

5. The flat magnetic device according to claim 2, characterized in that: The planar magnetic device is a planar inductor, the upper magnetic core is an E-type magnetic core, the lower magnetic core is an I-type magnetic core, the PCB board includes N metal layers, N is a positive integer and is ≥2, any one metal layer is used as a conductive medium layer, and the remaining metal layers are used as winding layout layers, each metal layer is provided with three through holes for three magnetic columns of the E-type magnetic core to pass through, the winding on the winding layout layer is arranged around the through hole located in the middle, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the winding, at least one isolation line is arranged in the area between two adjacent through holes on the conductive medium layer, and the two ends of the isolation line extend to the edges of the two through holes respectively, and there is no conductive medium in the isolation line.

6. A planar magnetic device based on the method for consuming leakage inductance of a planar magnetic device according to claim 1, characterized in that: The invention comprises a matching upper magnetic core and a lower magnetic core, wherein at least two magnetic columns are arranged on the upper magnetic core or the lower magnetic core, a multi-layer PCB board is arranged between the upper magnetic core and the lower magnetic core, each layer of the PCB board is provided with a through hole and / or a notch for the magnetic column to pass through, a metal layer of at least one layer of the PCB board is used as a winding layout layer, a metal layer of the PCB board adjacent to any layer of the winding layout layer is used as a conductive medium layer, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the windings on all the winding layout layers, at least one isolation line is arranged in the area between adjacent magnetic columns on the conductive medium layer, and the two ends of the isolation line respectively extend to the edges of the through hole or the notch through which the magnetic column passes, and the isolation line does not have a conductive medium.

7. The flat magnetic device according to claim 6, characterized in that: The flat magnetic device is a flat transformer, wherein a magnetic column is respectively arranged on both sides of a side of the upper magnetic core facing the lower magnetic core, and two layers of PCB boards are arranged between the upper magnetic core and the lower magnetic core, wherein the metal layer of one layer of PCB boards is used as a winding layout layer, and the metal layer of the other layer of PCB boards is used as a conductive medium layer, and each layer of PCB boards is provided with two through holes for the two magnetic columns of the upper magnetic core to pass through, and the primary winding and the secondary winding on the winding layout layer are respectively arranged around the two through holes, and the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, and at least one isolation line is arranged in the area between the two through holes on the conductive medium layer, and the two ends of the isolation line extend to the edges of the two through holes respectively, and there is no conductive medium in the isolation line.

8. The flat magnetic device according to claim 6, characterized in that: The planar magnetic device is a planar transformer, the upper magnetic core is an E-type upper magnetic core, the lower magnetic core is an I-type magnetic core, N layers of PCB boards are arranged between the upper magnetic core and the lower magnetic core, N is a positive integer and is ≥3, the metal layer of any one layer of PCB boards is used as a conductive medium layer, and the remaining layers of PCB boards are divided into two parts, the metal layer of one part of the PCB boards is used as a primary winding layout layer, and the metal layer of the other part of the PCB boards is used as a secondary winding layout layer, the two side edges of each layer of PCB boards are respectively provided with notches for the two side magnetic columns of the E-type upper magnetic core to pass through, and the center is provided with a through hole for the central magnetic column of the E-type upper magnetic core to pass through, the primary winding on the primary winding layout layer and the secondary winding on the secondary winding layout layer are both arranged around the through hole, the coverage area of ​​the conductive medium layer is greater than or equal to the sum of the coverage areas of the magnetic flux generated by the primary winding and the secondary winding, at least one isolation line is evenly arranged in the area between each notch and the through hole on the conductive medium layer, and the two ends of the isolation line are respectively connected to the edges of the notch and the through hole, and there is no conductive medium in the isolation line.

9. The flat magnetic device according to claim 6, characterized in that: The planar magnetic device is a planar inductor, the upper magnetic core is an E-type magnetic core, the lower magnetic core is an I-type magnetic core, N layers of PCB boards are arranged between the upper magnetic core and the lower magnetic core, N is a positive integer and is ≥2, the metal layer of any one layer of PCB boards is used as a conductive medium layer, and the metal layers of the remaining layers of PCB boards are used as winding layout layers, the two side edges of each layer of PCB boards are respectively provided with notches for the two side magnetic columns of the E-type magnetic core to pass through, and the center is provided with a through hole for the central magnetic column of the E-type magnetic core to pass through, the winding on the winding layout layer is arranged around the through hole, the coverage area of ​​the conductive medium layer is greater than or equal to the coverage area of ​​the magnetic flux generated by the winding, at least one isolation line is evenly arranged in the area between each notch and the through hole on the conductive medium layer, and the two ends of the isolation line are respectively connected to the edges of the notch and the through hole, and there is no conductive medium in the isolation line.

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