Planar transformer and power supply equipment

Abstract

The invention relates to the field of planar transformers, in particular to a planar transformer and power supply equipment. The planar transformer comprises a magnetic core module and a winding module, the magnetic core module comprises a first magnetic core and a second magnetic core which are oppositely arranged, the second magnetic core comprises a body part and a magnetic core middle column, the magnetic core middle column is arranged on the face, facing the first magnetic core, of the body part, and the winding module is arranged on the magnetic core middle column in a sleeving mode. The winding module comprises a substrate and a first winding unit, the substrate comprises a first wiring layer, the first wiring layer comprises a first wiring area, the first winding unit comprises at least two first windings arranged in the first wiring area at intervals, and the at least two first windings are connected in parallel. According to the planar transformer, the winding unit with the too wide wire diameter is divided into the at least two windings, and then the at least two windings are connected in parallel, so that the too wide wire diameter of the winding unit can be avoided, the alternating current loss and the eddy current loss of the winding unit can be reduced, the efficiency of the planar transformer can be improved, and the temperature rise of the planar transformer can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of planar transformers, and in particular to a planar transformer and a power supply device. Background Art

[0002] Planar transformers have the characteristics of high efficiency and energy saving, low radiation, low noise, high temperature resistance, moisture retention and moisture resistance. Compared with traditional transformers, planar transformers consume less power and energy, which can not only effectively reduce electricity costs, but also reduce environmental pollution, thereby achieving the purpose of energy saving and environmental protection.

[0003] At present, when planar transformers are used in high-power applications, the wire diameter of single-turn windings is often designed to be relatively wide because the number of turns of the primary winding and some secondary windings is relatively small and the current that needs to flow is large. However, in high-frequency applications, when the wire diameter of the single-turn winding is too wide, there will be serious skin effect and proximity effect, thereby increasing the AC loss of the planar transformer, namely skin loss and proximity loss. The increased AC loss reduces the efficiency of the planar transformer, and the wider the wire diameter of the single-turn winding, the more eddy current loss is usually increased, resulting in excessive temperature rise of the planar transformer, which not only reduces the efficiency of the planar transformer, but also reduces the stability of the planar transformer. Summary of the invention

[0004] An object of the present invention is to provide a planar transformer and a power supply device to solve the technical problem of low efficiency or low stability of traditional planar transformers.

[0005] In a first aspect, an embodiment of the present invention provides a planar transformer, comprising:

[0006] A magnetic core module, comprising a first magnetic core and a second magnetic core arranged opposite to each other, wherein the second magnetic core comprises a body portion and a magnetic core center column, and the magnetic core center column is arranged on a side of the body portion facing the first magnetic core; and

[0007] The winding module is located between the main body and the first magnetic core, and is sleeved on the center column of the magnetic core. The winding module includes a substrate and a first winding unit. The substrate includes a first wiring layer, the first wiring layer includes a first wiring area, and the first winding unit includes at least two first windings arranged at intervals in the first wiring area, and each first winding is connected in parallel.

[0008] In some embodiments, the line widths of at least two of the first windings increase along the width direction of the body portion and in a direction away from the center column of the magnetic core.

[0009] In some embodiments, an air gap is formed between the center column of the magnetic core and the first magnetic core, the first wiring layer is arranged on a side of the substrate close to the air gap, the substrate also includes a second wiring layer, the second wiring layer is arranged on the other side of the substrate away from the air gap, the first wiring layer also includes a second wiring area, the second wiring area is arranged close to the center column of the magnetic core relative to the first wiring area, the second wiring layer includes a third wiring area corresponding to the first wiring area and a fourth wiring area corresponding to the second wiring area, the winding module also includes a second winding unit, a third winding unit and a fourth winding unit, the second winding unit is arranged in the third wiring area, the third winding unit is arranged in the second wiring area, the fourth winding unit is arranged in the fourth wiring area, the first winding unit and the second winding unit are connected in series to form a first secondary winding, and the third winding unit and the fourth winding unit are connected in series to form a second secondary winding.

[0010] In some embodiments, the second winding unit includes at least two second windings arranged at intervals in the third wiring area, at least two second windings are connected in parallel to each other, and each second winding is arranged in a one-to-one correspondence with each first winding along the extension direction of the center column of the magnetic core.

[0011] In some embodiments, the line widths of at least two of the second windings increase along the width direction of the body portion and in a direction away from the center column of the magnetic core.

[0012] In some embodiments, the third winding unit includes at least two third windings arranged at intervals in the second wiring area, and at least two of the third windings are connected in parallel.

[0013] In some embodiments, the fourth winding unit includes at least two fourth windings arranged at intervals in the fourth wiring area, at least two of the fourth windings are connected in parallel with each other, and each of the fourth windings and each of the third windings are arranged one by one correspondingly along the extension direction of the center column of the magnetic core.

[0014] In some embodiments, the line widths of at least two of the fourth windings or at least two of the third windings increase along the width direction of the body portion and away from the center column of the magnetic core.

[0015] In some embodiments, the substrate also includes at least one third wiring layer, the third wiring layer is located between the first wiring layer and the second wiring layer, the winding module also includes at least one fifth winding unit, at least one fifth winding unit is arranged in at least one third wiring layer, each of the fifth winding units includes at least two fifth windings arranged at intervals in the third wiring layer, and at least two of the fifth windings are connected in parallel to each other.

[0016] In some embodiments, the line widths of at least two of the fifth windings increase along the width direction of the body portion and in a direction away from the center column of the magnetic core.

[0017] In a second aspect, an embodiment of the present invention provides a power supply device, comprising the planar transformer as described above.

[0018] Compared with the prior art, the embodiment of the present invention provides a planar transformer and a power supply device. The planar transformer includes a core module and a winding module, the core module includes a first core and a second core that are arranged opposite to each other, the second core includes a body part and a core center column, the core center column is arranged on the side of the body part facing the first core, the winding module is located between the body part and the first core, and is sleeved on the core center column, the winding module includes a substrate and a first winding unit, the substrate includes a first wiring layer, the first wiring layer includes a first wiring area, the first winding unit includes at least two first windings arranged in the first wiring area at intervals, and the at least two first windings are connected in parallel. Therefore, this embodiment divides the winding unit with a too wide wire diameter into a plurality of windings, and then connects at least two windings in parallel, so that the wire diameter of the winding unit can be avoided from being too wide, thereby reducing the influence of the skin effect and the proximity effect, reducing the AC loss of the planar transformer, thereby reducing the efficiency of the planar transformer, and reducing the eddy current loss of the planar transformer, thereby avoiding excessive temperature rise of the planar transformer, and further improving the efficiency of the planar transformer, and improving the stability of the planar transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0020] Figure 1 A schematic diagram of a circuit structure of a power supply device provided by an embodiment of the present invention;

[0021] Figure 2 An exploded diagram of a planar transformer provided by an embodiment of the present invention;

[0022] Figure 3 An exploded diagram of a planar transformer provided by an embodiment of the present invention;

[0023] Figure 4 A schematic structural diagram of a winding module provided by an embodiment of the present invention;

[0024] Figure 5 A schematic structural diagram of a winding module provided by another embodiment of the present invention;

[0025] Figure 6 A schematic diagram of the structure of a winding module provided in the conventional technology;

[0026] Figure 7 A schematic diagram of current density distribution of a winding module provided in conventional technology;

[0027] Figure 8 A schematic diagram of current density distribution of a winding module provided in an embodiment of the present invention;

[0028] Fig. 9 A schematic diagram of an AC resistance simulation of a first winding unit provided in an embodiment of the present invention;

[0029] Fig.10 A schematic diagram of an AC resistance simulation of a second winding unit provided in an embodiment of the present invention;

[0030] Fig.11 A schematic diagram of an AC resistance simulation of a third winding unit provided in an embodiment of the present invention;

[0031] Fig.12 A schematic diagram of an AC resistance simulation of a fourth winding unit provided in an embodiment of the present invention;

[0032] Fig.13 A schematic diagram of an AC resistance simulation of a fifth winding unit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] It should be noted that, if there is no conflict, the various features in the embodiments of the present invention can be combined with each other, all within the scope of protection of the present invention. In addition, although the functional modules are divided in the device schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described can be performed in a different order from the module division in the device or the flow chart. Furthermore, the words "first", "second", "third", etc. used in the present invention do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0035] See also Figure 1An embodiment of the present invention provides a power supply device, the power supply device 1000 includes a DC power supply VDC, a planar transformer 100, a controller 200, a first switch tube Q1, a second switch tube Q2, a resonant inductor Lr, an excitation inductor Lm, a resonant capacitor Cr, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a seventh diode D7, an eighth diode D8, a first output capacitor Co1, a second output capacitor Co2 and a third output capacitor Co3, the planar transformer 100 includes a primary winding 22, a first secondary winding 23, a second secondary winding 24 and a third secondary winding 25, the first secondary winding 23 includes a first winding unit 231 and a second winding unit 232, the second secondary winding 24 includes a third winding unit 241 and a fourth winding unit 242.

[0036] The positive electrode of the DC power supply VDC is electrically connected to the drain of the first switch tube Q1, the source of the first switch tube Q1 is electrically connected to the drain of the second switch tube Q2 and one end of the resonant inductor Lr, the gate of the first switch tube Q1 and the gate of the second switch tube Q2 are electrically connected to the controller 200, the source of the second switch tube Q2 and one end of the resonant capacitor Cr are electrically connected to the negative electrode of the DC power supply VDC, and the other end of the resonant inductor Lr is electrically connected to one end of the excitation inductor Lm and the same end of the primary winding 22, respectively. The other end of the excitation inductor Lm is electrically connected to the opposite end of the primary winding 22 and the other end of the resonant capacitor Cr, the opposite end of the first winding unit 231 is electrically connected to the anode of the first diode D1, the cathode of the first diode D1 is electrically connected to the cathode of the second diode D2, one end of the first output capacitor Co1 and one end of the first load Ro1, the same end of the first winding unit 231 is electrically connected to the opposite end of the second winding unit 232, the other end of the first output capacitor Co1 and the first load R The other end of o1 is electrically connected, the opposite-name end of the third winding unit 241 is electrically connected to the anode of the third diode D3, the cathode of the third diode D3 is electrically connected to the cathode of the fourth diode D4, one end of the second output capacitor Co2 and one end of the second load Ro2, the same-name end of the third winding unit 241 is electrically connected to the opposite-name end of the fourth winding unit 242, the other end of the second output capacitor Co2 and the other end of the second load Ro2, the opposite-name end of the third secondary winding 25 is electrically connected to the anode of the fifth diode D5 and the cathode of the sixth diode D6, the cathode of the fifth diode D5 is electrically connected to the cathode of the seventh diode D7, one end of the third output capacitor Co3 and one end of the third load Ro3, the same-name end of the third secondary winding 25 is electrically connected to the anode of the seventh diode D7 and the cathode of the eighth diode D8, the anode of the sixth diode D6 is electrically connected to the anode of the eighth diode D8, the other end of the third output capacitor Co3 and the other end of the third load Ro3.

[0037] The working principle of the power supply device 1000 is as follows: the controller 200 controls the first switch tube Q1 and the second switch tube Q2 to be turned on alternately, so that the first switch tube Q1 and the second switch tube Q2 convert the voltage of the DC power supply VDC into a high-frequency square wave, and then the high-frequency square wave enters the resonant cavity composed of the resonant inductor Lr, the excitation inductor Lm and the resonant capacitor Cr, and the resonant cavity eliminates the harmonics of the high-frequency square wave and outputs a fundamental frequency sine wave, and the sine wave couples the energy to the first secondary winding 23, the second secondary winding 24 and the third secondary winding 25 through the primary winding np, so that the first secondary winding 23, the second secondary winding 24 and the third secondary winding 25 are connected to the primary winding np. A secondary winding 23, a second secondary winding 24 and a third secondary winding 25 generate alternating current. The first diode D1 and the second diode D2 rectify the alternating current generated by the first secondary winding 23 and output a stable first direct current voltage. The third diode D3 and the fourth diode D4 rectify the alternating current generated by the second secondary winding 24 and output a stable second direct current voltage. The fifth diode D5, the sixth diode D6, the seventh diode D7 and the eighth diode D8 rectify the alternating current generated by the third secondary winding 25 and output a stable third direct current voltage.

[0038] In some embodiments, the first DC voltage is the main output voltage, the second DC voltage is the auxiliary output voltage, and the third DC voltage is the backlight output voltage. It is understandable that, since the main output voltage is generally relatively low, the number of turns of the first secondary winding 23 is relatively small, usually 1 to 3 turns, and since the auxiliary output voltage is also relatively low, the number of turns of the second secondary winding 24 is also relatively small, usually 1 to 2 times the number of turns of the first secondary winding 23, and since the backlight output voltage is generally relatively high, the number of turns of the third secondary winding 25 is relatively large, usually 5 to 20 times the number of turns of the first secondary winding 23.

[0039] Please also read Figure 2 and Figure 3 , an embodiment of the present invention provides a planar transformer, such as Figure 2 or Figure 3 As shown, the planar transformer 100 includes a magnetic core module 10 and a winding module 20 .

[0040] The magnetic core module 10 includes a first magnetic core 11 and a second magnetic core 12 that are arranged opposite to each other, and the first magnetic core 11 covers the second magnetic core 12. The first magnetic core 11 or the second magnetic core 12 is mainly made of a magnetic core material, wherein the magnetic core material may include ferrite, silicon steel sheet, etc., and the type of ferrite may be nickel-zinc ferrite, manganese-zinc oxide, and nickel-zinc oxide. Those skilled in the art may select a suitable magnetic core material according to actual needs.

[0041] The magnetic core shape of the first magnetic core 11 or the second magnetic core 12 can be any shape such as E-type, I-type, etc. Those skilled in the art can select a suitable magnetic core shape according to actual needs.

[0042] The second magnetic core 12 includes a body portion 121, a core center column 122, a first core side column 123 and a second core side column 124. The body portion 121 is in the shape of a straight plate. The core center column 122 protrudes from the middle of a surface 121a of the body portion 121 facing the first magnetic core 11. The core center column 122 and the body portion 121 are integrally formed. The cross-sectional shape of the core center column 122 can be any shape such as a circle or a square. The first core side column 123 protrudes from a first side of the surface 121a, and the second core side column 124 protrudes from a second side of the surface 121a, and the first side is opposite to the second side. In some embodiments, the height of the first magnetic core side column 123 is the same as the height of the second magnetic core side column 124, and is slightly higher than the height of the magnetic core center column 122. When the first magnetic core 11 and the second magnetic core 12 are covered, the first magnetic core side column 123 and the second magnetic core side column 124 are in contact with the first magnetic core 11, and a certain space is left between the magnetic core center column 122 and the first magnetic core 11. Figure 4 The space is the air gap 10a. The role of the air gap 10a is to reduce the magnetic permeability, so that the line characteristics are less dependent on the initial magnetic permeability of the core material. The air gap 10a can also avoid the magnetic saturation phenomenon under large AC signals or DC bias, and better control the inductance.

[0043] The winding module 20 is located between the main body 121 and the first magnetic core 11 . The winding module 20 is provided with a through hole corresponding to the magnetic core center column 122 . The magnetic core center column 122 passes through the through hole. The winding module 20 is sleeved on the magnetic core center column 122 through the through hole.

[0044] Please also read Figure 1 and Figure 4 , Figure 4 To obtain Figure 3 The cross-sectional view of the planar transformer 100 is obtained by longitudinally cutting the planar transformer 100 through the thick dashed line on the right side of the planar transformer 100 as shown in FIG. Figure 1 and Figure 4 As shown, the winding module 20 includes a substrate 21 , a primary winding 22 , a first secondary winding 23 , a second secondary winding 24 and a third secondary winding 25 .

[0045] The substrate 21 is a basic material for laying out the primary winding 22, the first secondary winding 23, the second secondary winding 24 and the third secondary winding 25. Generally, the substrate 21 can be a copper-clad laminate. In the process of manufacturing the winding module 20, the substrate 21 can be selectively processed by opening holes, chemical copper plating, electrolytic copper plating, etching, etc., and then the primary winding 22, the first secondary winding 23, the second secondary winding 24 and the third secondary winding 25 are laid on the substrate 21 to obtain the winding module 20.

[0046] like Figure 4As shown, the substrate 21 includes a first wiring layer 211, a second wiring layer 212, and at least one third wiring layer 213 ( Figure 4 , the number of the third wiring layers 213 is 4), the fourth wiring layer 214 and the fifth wiring layer 215. The first wiring layer 211 is provided on the side of the substrate 21 close to the air gap 10a (it should be noted that the side close to the air gap 10a refers to a certain area or several areas closest to the air gap 10a along the axial direction of the substrate 21), and the second wiring layer 212 is provided on the other side of the substrate 21 away from the air gap 10a (it should be noted that the other side away from the air gap 10a refers to a certain area or several areas away from the air gap 10a relative to the first wiring layer 211 along the axial direction of the substrate 21).

[0047] The first wiring layer 211 includes a first wiring area 2111 and a second wiring area 2112 . The second wiring area 2112 is arranged relative to the first wiring area 2111 and close to the core center column 122 . The first wiring area 2111 is used to lay out the first winding unit 231 , and the second wiring area 2112 is used to lay out the third winding unit 241 .

[0048] The second wiring layer 212 includes a third wiring area 2121 and a fourth wiring area 2122 . The third wiring area 2121 is arranged corresponding to the first wiring area 2111 for arranging the second winding unit 232 . The fourth wiring area 2122 is arranged corresponding to the second wiring area 2112 for arranging the fourth winding unit 242 .

[0049] Since the first wiring layer 211 is closer to the air gap 10a than the second wiring layer 212, this embodiment can balance the influence of the air gap 10a on the first secondary winding 23 and the second secondary winding 24 by arranging a portion of the first secondary winding 23 and a portion of the second secondary winding 24 on the first wiring layer 211, and arranging another portion of the first secondary winding 23 and another portion of the second secondary winding 24 on the second wiring layer 212, thereby improving the performance of the planar transformer 100.

[0050] The first winding unit 231 includes at least two first windings 2311 arranged at intervals in the first wiring area 2111, and at least two first windings 2311 are connected in parallel to each other. Figure 5, the direction indicated by the dotted arrow represents the direction along the width direction of the main body and away from the magnetic core center column 122. The first winding 2311_1, the first winding 2311_2, the first winding 2311_3, the first winding 2311_4 and the first winding 2311_5 are sequentially arranged in the first wiring area 2111 along this direction. The first winding 2311_1 can be connected in parallel with the first winding 2311_2 to obtain a parallel winding, and the parallel winding, the first winding 2311_3, the first winding 2311_4 and the first winding 2311_5 are then connected in series; or the first winding 2311_1 , the first winding 2311_2 and the first winding 2311_3 are connected in parallel to obtain a parallel winding, and then the parallel winding, the first winding 2311_4 and the first winding 2311_5 are connected in series; or the first winding 2311_2 and the first winding 2311_3 are connected in parallel to obtain a parallel winding, and then the first winding 2311_1, the parallel winding, the first winding 2311_4 and the first winding 2311_5 are connected in series; or the first winding 2311_1, the first winding 2311_2, the first winding 2311_3, the first winding 2311_4 and the first winding 2311_5 are connected in parallel. It can be understood that if a winding unit includes only two windings, the two windings are connected in parallel. If a winding unit includes more than two windings, the windings can be connected in parallel, or two or more windings can be connected in parallel. The parallel windings obtained after parallel connection can be connected in series with the remaining windings.

[0051] In some embodiments, the line width of each first winding is within a preset width range.

[0052] In some embodiments, the preset width range is (0.15 mm, 0.55 mm), where mm is millimeter.

[0053] In some embodiments, an isolation region is provided between two adjacent first windings 2311 . The isolation region may be a region that is grooved or filled with insulating material. The form of the isolation region is not limited here, as long as the isolation region can achieve insulation between the two adjacent first windings 2311 .

[0054] See also Figure 6 In the conventional technology, the line width of the first winding unit 231 is relatively large. In the present embodiment, by dividing the first winding unit 231 into at least two first windings 2311, the line width of the first winding unit 231 which originally has a larger line width can be shared, and the current flowing through each first winding 2311 is reduced relative to the current originally flowing through the first winding unit 231.

[0055] The skin effect loss and proximity effect loss of each coil turn are derived based on Maxwell's equations:

[0056]

[0057] Among them, P ac1 is the skin effect loss, ρ is the resistivity of the copper wire, W n is the width of the coil, N n is the number of copper foil turns of the coil, I n is the current flowing through the coil, K s1 is the skin effect coefficient, P ac2 is the skin effect loss, K s2 is the proximity effect coefficient, L n is the distance from the coil to the air gap 10a.

[0058] Skin effect loss refers to the AC loss caused by the skin effect. The skin effect refers to the phenomenon that the current distribution inside the conductor is uneven when there is AC or alternating magnetic field in the conductor. Proximity effect loss refers to the AC loss caused by the proximity effect. The proximity effect refers to the phenomenon that the AC current in the two conductors of a two-wire transmission line approaches the adjacent conductor.

[0059] If the first winding unit 231 with a wire diameter that is too wide is divided into at least two first windings 2311, and the at least two first windings 2311 are connected in parallel, it can be seen from the above formula that for skin effect loss, the smaller the wire width of the coil and the larger the current, the greater the skin effect loss. Although the wire width of each first winding 2311 is reduced relative to the original wire width, the current is also relatively reduced, so the skin effect loss will not increase. As for proximity effect loss, the larger the wire width of the coil and the larger the current, the smaller the proximity effect loss. Therefore, by dividing the first winding unit 231 with a wire diameter that is too wide into at least two first windings 2311, the proximity effect loss can be reduced, thereby reducing the AC loss of the planar transformer 100.

[0060] It is understandable that when the wire diameter of the winding is too wide, if high-frequency current flows through the winding, a serious skin effect will occur. At this time, the high-frequency current will be concentrated in a certain area, causing the current density distribution of the high-frequency current to be uneven. Some parts have a large current density, while others have a small current density. The space in the part with a small current density is wasted. Therefore, by dividing the first winding unit 231 with an excessively wide wire diameter into at least two first windings 2311, the influence of the skin effect can be weakened, making the current density distribution more uniform, thereby reducing the wasted wiring space and further improving the utilization rate of the substrate 21.

[0061] It can also be understood that according to Faraday's law of electromagnetic induction, magnetically induced electricity is proportional to the cross-sectional area of ​​a closed conductor. The larger the cross-sectional area, the greater the eddy current generated. Therefore, by dividing the first winding unit 231 with an excessively wide wire diameter into at least two first windings 2311, the cross-sectional area of ​​the winding of the first winding unit 231 can be reduced, thereby reducing the eddy current and eddy current losses, thereby preventing the planar transformer 100 from overheating due to excessive temperature rise, thereby improving the stability of the device.

[0062] Therefore, this embodiment divides the first winding unit 231 with an excessively wide wire diameter into at least two first windings 2311, and then connects the at least two first windings 2311 in parallel. This can prevent the wire diameter of the first winding unit 231 from being too wide, thereby weakening the influence of the skin effect and the proximity effect, reducing the AC loss of the planar transformer 100, thereby reducing the efficiency of the planar transformer 100, and reducing the eddy current loss of the planar transformer 100, thereby avoiding excessive temperature rise of the planar transformer 100, and further improving the efficiency of the planar transformer 100, as well as improving the stability of the planar transformer 100.

[0063] In some embodiments, Figure 5 As shown, along the width direction of the body portion 121 ( Figure 5 In the dashed line direction shown in the figure, the line width of the first winding 2311 closest to the core center column 122 is smaller than the line width of the first winding 2311 farthest from the core center column 122. Since the first winding 2311_1 is along the width direction of the main body 121 and closest to the core center column 122, and the first winding 2311_5 is along the width direction of the main body 121 and farthest from the core center column 122, the line width of the first winding 2311_1 is smaller than the line width of the first winding 2311_5.

[0064] It can be understood that the first winding 2311 along the width direction of the main body 121 and closest to the core center column 122 is closest to the air gap 10a, and the first winding 2311 along the width direction of the main body 121 and farthest from the core center column 122 is farthest from the air gap 10a. Therefore, by setting the line width of the first winding 2311 along the width direction of the main body 121 and closest to the core center column 122 to be smaller than the line width of the first winding 2311 along the width direction of the main body 121 and farthest from the core center column 122, it is beneficial to reduce the influence of the air gap 10a on each first winding 2311, thereby helping to reduce the AC loss of the first winding unit 231, and further helping to improve the efficiency of the planar transformer 100.

[0065] In some embodiments, the line widths of at least two first windings 2311 increase along the width direction of the body portion 121 and away from the core center column 122, that is, in at least two first windings 2311, the line widths of all first windings 2311 may increase along the width direction of the body portion 121 and away from the core center column 122, or the line widths of some first windings 2311 may increase along the width direction of the body portion 121 and away from the core center column 122. For example, Figure 5 As shown, the line widths of the first winding 2311_1, the first winding 2311_2, the first winding 2311_3, the first winding 2311_4 and the first winding 2311_5 are 0.2mm, 0.25mm, 0.3mm, 0.35mm and 0.4mm respectively, or are 0.2mm, 0.2mm, 0.3mm, 0.4mm and 0.4mm respectively, or are 0.2mm, 0.3mm, 0.3mm, 0.3mm and 0.4mm respectively.

[0066] Therefore, by setting the line width of at least two first windings 2311 to increase along the width direction of the main body 121 and away from the core center column 122, it is beneficial to further weaken the influence of the air gap 10a on each first winding 2311, thereby helping to further reduce the AC loss of the first winding unit 231, and further helping to further improve the efficiency of the planar transformer 100. In addition, this setting method can make the current density distribution flowing through each first winding 2311 more uniform.

[0067] Please also read Figure 7 and Figure 8 , Figure 7 Schematic diagram of current density distribution of planar transformer in traditional technology. Figure 8 A schematic diagram of current density distribution of a planar transformer provided in this embodiment, such as Figure 7 As shown, the current density in some areas of the first winding unit 231 is very small, while the current density in some areas is very large, and the current density distribution is very uneven. In this embodiment, as shown in FIG. Figure 8 As shown, each first winding 2311 does not have both high current density and low current density. Therefore, compared with the traditional technology, the current distribution density of each first winding 2311 is more uniform.

[0068] The second winding unit 232 includes at least two second windings 2321 spaced apart in the third wiring area 2121 . The at least two second windings 2321 are connected in parallel to each other. Please refer to the above embodiment for the manner in which the at least two second windings 2321 are connected in parallel to each other, which will not be described again.

[0069] Therefore, this embodiment divides the second winding unit 232 with an excessively wide wire diameter into at least two second windings 2321, and then connects the at least two second windings 2321 in parallel. This can prevent the wire diameter of the second winding unit 232 from being too wide, thereby reducing the influence of the skin effect and the proximity effect, reducing the AC loss of the planar transformer 100, thereby reducing the efficiency of the planar transformer 100, and reducing the eddy current loss of the planar transformer 100, thereby avoiding excessive temperature rise of the planar transformer 100, and further improving the efficiency of the planar transformer 100, as well as improving the stability of the planar transformer 100.

[0070] Each second winding 2321 is arranged in one-to-one correspondence with each first winding 2311 along the extension direction of the magnetic core center column 122. Figure 5 As shown, in the third wiring area 2121, the second winding 2321_1, the second winding 2321_2, the second winding 2321_3, the second winding 2321_4 and the second winding 2321_5 are arranged in sequence along the direction indicated by the dotted arrow, and the extension direction of the core column 122 is Figure 5 The solid arrow indicates a direction along which the second winding 2321_1 corresponds to the first winding 2311_1, the second winding 2321_2 corresponds to the first winding 2311_2, the second winding 2321_3 corresponds to the first winding 2311_3, the second winding 2321_4 corresponds to the first winding 2311_4, and the second winding 2321_5 corresponds to the first winding 2311_5.

[0071] In some embodiments, the line widths of the corresponding windings are equal. Figure 5 As shown, the line width of the second winding 2321_1 is equal to the line width of the first winding 2311_1, the line width of the second winding 2321_2 is equal to the line width of the first winding 2311_2, the line width of the second winding 2321_3 is equal to the line width of the first winding 2311_3, the line width of the second winding 2321_4 is equal to the line width of the first winding 2311_4, and the line width of the second winding 2321_5 is equal to the line width of the first winding 2311_5.

[0072] In some embodiments, the line width of each second winding 2321 is within a preset width range. The preset width range can refer to the above embodiment and will not be described again here.

[0073] In some embodiments, an isolation zone is provided between two adjacent second windings 2321 . The isolation zone may be a region that is grooved or filled with insulating material. The form of the isolation zone is not limited here, as long as the isolation zone can achieve insulation between the two adjacent second windings 2321 .

[0074] In some embodiments, Figure 5As shown, the line width of the second winding 2321 along the width direction of the body portion 121 and closest to the core center column 122 is smaller than the line width of the second winding 2321 along the width direction of the body portion 121 and farthest from the core center column 122 .

[0075] Therefore, by setting the line width of the second winding 2321 along the width direction of the main body 121 and closest to the core center column 122 to be smaller than the line width of the first winding 2311 along the width direction of the main body 121 and farthest from the core center column 122, it is beneficial to reduce the impact of the air gap 10a on each second winding 2321, thereby helping to reduce the AC loss of the second winding unit 232, and further helping to improve the efficiency of the planar transformer 100.

[0076] In some embodiments, Figure 5 As shown, the line widths of at least two second windings 2321 increase along the width direction of the body portion 121 and away from the magnetic core center column 122. The line width increasing method of at least two second windings 2321 can refer to the above embodiment and will not be repeated here.

[0077] Therefore, by setting the line width of at least two second windings 2321 to increase along the width direction of the main body 121 and away from the core center column 122, it is beneficial to further weaken the influence of the air gap 10a on each second winding 2321, thereby helping to further reduce the AC loss of the second winding unit 232, and further helping to further improve the efficiency of the planar transformer 100. In addition, this setting method can make the current density distribution flowing through each second winding 2321 more uniform.

[0078] like Figure 7 As shown, in the conventional technology, the current density in one part of the second winding unit 232 is very small, while the current density in another part is very large, and the current density distribution is very uneven. In this embodiment, as shown in FIG. Figure 8 As shown, each second winding 2321 does not have both high current density and low current density. Therefore, compared with the traditional technology, the current distribution density of each second winding 2321 is more uniform.

[0079] The third winding unit 241 includes at least two third windings 2411 spaced apart in the second wiring area 2112 . The at least two third windings 2411 are connected in parallel to each other. Please refer to the above embodiment for the manner in which the at least two third windings 2411 are connected in parallel to each other, which will not be described again.

[0080] Therefore, this embodiment divides the third winding unit 241 with an excessively wide wire diameter into at least two third windings 2411, and then connects the at least two third windings 2411 in parallel. This can avoid the wire diameter of the third winding unit 241 being too wide, thereby weakening the influence of the skin effect and the proximity effect, reducing the AC loss of the planar transformer 100, thereby reducing the efficiency of the planar transformer 100, and reducing the eddy current loss of the planar transformer 100, thereby avoiding excessive temperature rise of the planar transformer 100, and further improving the efficiency of the planar transformer 100, and improving the stability of the planar transformer 100.

[0081] In some embodiments, the line width of each third winding is within a preset width range. The preset width range can refer to the above embodiment and will not be described in detail here.

[0082] In some embodiments, an isolation zone is provided between two adjacent third windings 2411 . The isolation zone may be a region that is grooved or filled with insulating material. The form of the isolation zone is not limited here, as long as the isolation zone can achieve insulation between two adjacent third windings 2411 .

[0083] In some embodiments, Figure 5 As shown, the line width of the third winding 2411 along the width direction of the body portion 121 and closest to the core center column 122 is smaller than the line width of the third winding 2411 along the width direction of the body portion 121 and farthest from the core center column 122 .

[0084] Therefore, by setting the line width of the third winding 2411 along the width direction of the main body 121 and closest to the core center column 122 to be smaller than the line width of the third winding 2411 along the width direction of the main body 121 and farthest from the core center column 122, it is beneficial to reduce the impact of the air gap 10a on each third winding 2411, thereby helping to reduce the AC loss of the third winding unit 241, and further helping to improve the efficiency of the planar transformer 100.

[0085] In some embodiments, Figure 5 As shown, the line widths of at least two third windings 2411 increase along the width direction of the body portion 121 and away from the magnetic core center column 122. The line width increasing method of at least two third windings 2411 can refer to the above embodiment and will not be repeated here.

[0086] Therefore, by setting the line width of at least two third windings 2411 to increase along the width direction of the main body 121 and away from the core center column 122, it is beneficial to further weaken the influence of the air gap 10a on each third winding 2411, thereby helping to further reduce the AC loss of the third winding unit 241, and further helping to further improve the efficiency of the planar transformer 100. In addition, this setting method can make the current density distribution flowing through each third winding 2411 more uniform.

[0087] like Figure 7 As shown, in the conventional technology, the current density in one part of the third winding unit 241 is very small, while the current density in another part is very large, and the current density distribution is very uneven. In this embodiment, as shown in FIG. Figure 8 As shown, each third winding 2411 does not have both high current density and low current density. Therefore, compared with the traditional technology, the current distribution density of each third winding 2411 is more uniform.

[0088] The fourth winding unit 242 includes at least two fourth windings 2421 spaced apart in the fourth wiring area 2122 . The at least two fourth windings 2421 are connected in parallel to each other. Please refer to the above embodiment for the manner in which the at least two fourth windings 2421 are connected in parallel to each other, which will not be repeated here.

[0089] Therefore, this embodiment divides the fourth winding unit 242 with an excessively wide wire diameter into at least two fourth windings 2421, and then connects the at least two fourth windings 2421 in parallel. This can avoid the wire diameter of the fourth winding unit 242 being too wide, thereby reducing the influence of the skin effect and the proximity effect, reducing the AC loss of the planar transformer 100, thereby reducing the efficiency of the planar transformer 100, and reducing the eddy current loss of the planar transformer 100, thereby avoiding excessive temperature rise of the planar transformer 100, and further improving the efficiency of the planar transformer 100, as well as improving the stability of the planar transformer 100.

[0090] Each fourth winding 2421 is arranged in one-to-one correspondence with each third winding 2411 along the extension direction of the magnetic core center column 122. Figure 5 As shown, in the second wiring area 2112, the third winding 2411_1, the third winding 2411_2, the third winding 2411_3, the third winding 2411_4 and the second winding 2411_5 are arranged in sequence along the direction indicated by the thin dotted arrow, and in the fourth wiring area 2122, the fourth winding 2421_1, the fourth winding 2411_2, the fourth winding 2411_3, the fourth winding 2411_4 and the fourth winding 2411_5 are arranged in sequence along the direction indicated by the thin dotted arrow. The extension direction of the core column 122 is Figure 5The direction indicated by the thick solid arrow is such that the fourth winding 2421_1 corresponds to the third winding 2411_1 , the fourth winding 2421_2 corresponds to the third winding 2411_2 , and the fourth winding 2421_3 corresponds to the third winding 2411_3 .

[0091] In some embodiments, the line widths of the corresponding windings are equal. Figure 5 As shown, the line width of the fourth winding 2421_1 is equal to the line width of the third winding 2411_1, the line width of the fourth winding 2421_2 is equal to the line width of the third winding 2411_2, and the line width of the fourth winding 2421_3 is equal to the line width of the third winding 2411_3.

[0092] In some embodiments, the line width of each fourth winding is within a preset width range. The preset width range can refer to the above embodiment and will not be described in detail here.

[0093] In some embodiments, an isolation zone is provided between two adjacent fourth windings 2421 . The isolation zone may be a region that is grooved or filled with insulating material. The form of the isolation zone is not limited here, as long as the isolation zone can achieve insulation between two adjacent fourth windings 2421 .

[0094] In some embodiments, Figure 5 As shown, the line width of the fourth winding 2421 along the width direction of the body portion 121 and closest to the core center column 122 is smaller than the line width of the fourth winding 2421 along the width direction of the body portion 121 and farthest from the core center column 122 .

[0095] Therefore, by setting the line width of the fourth winding 2421 along the width direction of the main body 121 and closest to the core center column 122 to be smaller than the line width of the fourth winding 2421 along the width direction of the main body 121 and farthest from the core center column 122, it is beneficial to reduce the impact of the air gap 10a on each fourth winding 2421, thereby helping to reduce the AC loss of the fourth winding unit 242, and further helping to improve the efficiency of the planar transformer 100.

[0096] In some embodiments, Figure 5 As shown, the line widths of at least two fourth windings 2421 increase along the width direction of the body portion 121 and away from the magnetic core center column 122. The line width increasing method of at least two fourth windings 2421 can refer to the above embodiment and will not be repeated here.

[0097] Therefore, by setting the line width of at least two fourth windings 2421 to increase along the width direction of the main body 121 and away from the core center column 122, it is beneficial to further weaken the influence of the air gap 10a on each fourth winding 2421, thereby helping to further reduce the AC loss of the fourth winding unit 242, and further helping to further improve the efficiency of the planar transformer 100. In addition, this setting method can make the current density distribution flowing through each fourth winding 2421 more uniform.

[0098] like Figure 7 As shown, in the conventional technology, the current density in one part of the fourth winding unit 242 is very small, while the current density in another part is very large, and the current density distribution is very uneven. In this embodiment, as shown in FIG. Figure 8 As shown, each fourth winding 2421 does not have both high current density and low current density. Therefore, compared with the traditional technology, the current distribution density of each fourth winding 2421 is more uniform.

[0099] The primary winding 22 includes at least one fifth winding unit 221, which is arranged in at least one third wiring layer 213. Each fifth winding unit 221 includes at least two fifth windings 2211 arranged at intervals in a third wiring layer 213, and at least two fifth windings 2211 are connected in parallel.

[0100] Please refer to the above embodiment for the manner in which at least two fifth windings 2211 are connected in parallel with each other, which will not be described in detail here.

[0101] Therefore, this embodiment divides the fifth winding unit 221 with an excessively wide wire diameter into at least two fifth windings 2211, and then connects the at least two fifth windings 2211 in parallel. In this way, the wire diameter of the fifth winding unit 221 can be avoided from being too wide, thereby weakening the influence of the skin effect and the proximity effect, reducing the AC loss of the planar transformer 100, thereby reducing the efficiency of the planar transformer 100, and reducing the eddy current loss of the planar transformer 100, thereby avoiding excessive temperature rise of the planar transformer 100, and further improving the efficiency of the planar transformer 100, and improving the stability of the planar transformer 100.

[0102] In some embodiments, the line width of each fifth winding 2211 is within a preset width range. The preset width range can refer to the above embodiment and will not be described in detail here.

[0103] In some embodiments, an isolation region is provided between two adjacent fifth windings 2211 . The isolation region may be a region that is grooved or filled with insulating material. The form of the isolation region is not limited here, as long as the isolation region can achieve insulation between two adjacent fifth windings 2211 .

[0104] In some embodiments, Figure 5 As shown, the line width of the fifth winding 2211 along the width direction of the body portion 121 and closest to the core center column 122 is smaller than the line width of the fifth winding 2211 along the width direction of the body portion 121 and farthest from the core center column 122 .

[0105] Therefore, by setting the line width of the fifth winding 2211 along the width direction of the main body 121 and closest to the core center column 122 to be smaller than the line width of the fifth winding 2211 along the width direction of the main body 121 and farthest from the core center column 122, it is beneficial to reduce the impact of the air gap 10a on each fifth winding 2211, thereby helping to reduce the AC loss of the fifth winding unit 221, and further helping to improve the efficiency of the planar transformer 100.

[0106] In some embodiments, Figure 5 As shown, the line widths of at least two fifth windings 2211 increase along the width direction of the body portion 121 and away from the magnetic core center column 122. The line width increasing method of at least two fifth windings 2211 can refer to the above embodiment and will not be repeated here.

[0107] Therefore, by setting the line width of at least two fifth windings 2211 to increase along the width direction of the main body 121 and away from the core center column 122, it is beneficial to further weaken the influence of the air gap 10a on each fifth winding 2211, thereby helping to further reduce the AC loss of the fifth winding unit 221, and further helping to further improve the efficiency of the planar transformer 100. In addition, this setting method can make the current density distribution flowing through each fifth winding 2211 more uniform.

[0108] like Figure 7 As shown, in the conventional technology, the current density in one part of the fifth winding unit 221 is very small, while the current density in another part is very large, and the current density distribution is very uneven. In this embodiment, as shown in FIG. Figure 8 As shown, each fifth winding 2211 does not have both high current density and low current density. Therefore, compared with the traditional technology, the current distribution density of each fifth winding 2211 is more uniform.

[0109] like Figure 4 As shown, the third secondary winding 25 includes a plurality of sixth windings 251 , a plurality of seventh windings 252 and at least one eighth winding 253 .

[0110] A plurality of sixth windings 251 are arranged at intervals on the fourth wiring layer 214 .

[0111] A plurality of seventh windings 252 are arranged at intervals on the fifth wiring layer 215 .

[0112] At least one eighth winding 253 is arranged on the third wiring layer 213 .

[0113] It can be understood that by connecting multiple sixth windings 251 in series, a first series winding can be obtained, by connecting multiple seventh windings 252 in series, a second series winding can be obtained, and by connecting the first series winding, the second series winding and at least one eighth winding 253 in series, a third secondary winding 25 can be obtained.

[0114] The following describes the comparison of AC resistance between this embodiment and the traditional solution in combination with simulation results.

[0115] Fig. 9 A schematic diagram of an AC resistance simulation of a first winding unit provided in an embodiment of the present invention. Fig. 9 As shown, curve 1 is the AC resistance change curve when the first winding unit is not divided in the traditional solution, and curve 2 is the AC resistance change curve of the first winding unit in this embodiment. By comparing curve 1 and curve 2, it can be seen that within the full frequency range, the AC resistance of the first winding unit in this embodiment is significantly smaller than the AC resistance of the first winding unit in the traditional solution by about 10% to 50%.

[0116] Fig.10 FIG. 1 is a schematic diagram of an AC resistance simulation of a second winding unit provided by an embodiment of the present invention. Fig.10 As shown, curve 3 is the AC resistance change curve when the second winding unit is not divided in the traditional solution, and curve 4 is the AC resistance change curve of the second winding unit in this embodiment. By comparing curve 3 and curve 4, it can be seen that within the full frequency range, the AC resistance of the second winding unit in this embodiment is significantly smaller than the AC resistance of the second winding unit in the traditional solution by about 10% to 50%.

[0117] Fig.11 FIG. 1 is a schematic diagram of an AC resistance simulation of a third winding unit provided in an embodiment of the present invention. Fig.11 As shown, curve 5 is the AC resistance change curve when the third winding unit is not divided in the traditional solution, and curve 6 is the AC resistance change curve of the second winding unit in this embodiment. By comparing curve 5 and curve 6, it can be seen that within the full frequency range, the AC resistance of the third winding unit in this embodiment is significantly smaller than the AC resistance of the third winding unit in the traditional solution by about 10% to 50%.

[0118] Fig.12 FIG. 1 is a schematic diagram of an AC resistance simulation of a fourth winding unit provided in an embodiment of the present invention. Fig.12As shown, curve 7 is the AC resistance change curve when the fourth winding unit is not divided in the traditional solution, and curve 8 is the AC resistance change curve of the fourth winding unit in this embodiment. By comparing curve 7 and curve 8, it can be seen that within the full frequency range, the AC resistance of the fourth winding unit in this embodiment is significantly smaller than the AC resistance of the fourth winding unit in the traditional solution by about 10% to 50%.

[0119] Fig.13 FIG. 1 is a schematic diagram of an AC resistance simulation of a fifth winding unit provided in an embodiment of the present invention. Fig.13 As shown, curve 9 is the AC resistance change curve when the fifth winding unit is not divided in the traditional solution, and curve 10 is the AC resistance change curve of the fifth winding unit in this embodiment. By comparing curve 9 and curve 10, it can be seen that when the frequency is between 100kHz and 500kHz, the AC resistance of this embodiment is significantly smaller than that of the traditional solution, and above 500kHz, the AC resistance of this embodiment will be greater than that of the traditional solution. However, for most applications at present, the operating frequency is less than 150KHz, and 90% of the high-frequency losses are less than 500kHz. Therefore, the fifth winding unit of this embodiment also has great advantages.

[0120] Finally, it should be noted that the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of the present invention. The purpose of providing these implementations is to make the understanding of the disclosure of the present invention more thorough and comprehensive. And under the idea of ​​the present invention, the above-mentioned technical features continue to be combined with each other, and there are many other changes in different aspects of the present invention as described above, which are all considered to be within the scope of the present invention. Further, for those of ordinary skill in the art, improvements or changes can be made according to the above description, and all these improvements and changes should belong to the scope of protection of the claims attached to the present invention.

Claims

1. A planar transformer, characterized in that: include: A magnetic core module, comprising a first magnetic core and a second magnetic core arranged opposite to each other, wherein the second magnetic core comprises a body portion and a magnetic core center column, and the magnetic core center column is arranged on a side of the body portion facing the first magnetic core; as well as The winding module is located between the main body and the first magnetic core, and is sleeved on the center column of the magnetic core. The winding module includes a substrate and a first winding unit. The substrate includes a first wiring layer, the first wiring layer includes a first wiring area, and the first winding unit includes at least two first windings arranged at intervals in the first wiring area, and at least two of the first windings are connected in parallel with each other.

2. The planar transformer according to claim 1, characterized in that: The line widths of at least two of the first windings increase along the width direction of the body portion and in a direction away from the center column of the magnetic core.

3. The planar transformer according to claim 1 or 2, characterized in that: An air gap is formed between the center column of the magnetic core and the first magnetic core, the first wiring layer is arranged on a side of the substrate close to the air gap, the substrate also includes a second wiring layer, the second wiring layer is arranged on the other side of the substrate away from the air gap, the first wiring layer also includes a second wiring area, the second wiring area is arranged close to the center column of the magnetic core relative to the first wiring area, the second wiring layer includes a third wiring area corresponding to the first wiring area and a fourth wiring area corresponding to the second wiring area, the winding module also includes a second winding unit, a third winding unit and a fourth winding unit, the second winding unit is arranged in the third wiring area, the third winding unit is arranged in the second wiring area, and the fourth winding unit is arranged in the fourth wiring area, the first winding unit and the second winding unit are connected in series to form a first secondary winding, and the third winding unit and the fourth winding unit are connected in series to form a second secondary winding.

4. The planar transformer according to claim 3, characterized in that: The second winding unit includes at least two second windings arranged at intervals in the third wiring area, at least two second windings are connected in parallel, and each second winding is arranged in a one-to-one correspondence with each first winding along the extension direction of the core center column.

5. The planar transformer according to claim 4, characterized in that: The line widths of at least two of the second windings increase gradually along the width direction of the body portion and in a direction away from the center column of the magnetic core.

6. The planar transformer according to claim 3, characterized in that: The third winding unit includes at least two third windings arranged at intervals in the second wiring area, and at least two of the third windings are connected in parallel.

7. The planar transformer according to claim 6, characterized in that: The fourth winding unit includes at least two fourth windings arranged at intervals in the fourth wiring area, at least two fourth windings are connected in parallel with each other, and each fourth winding is arranged in a one-to-one correspondence with each third winding along the extension direction of the core center column.

8. The planar transformer according to claim 7, characterized in that: The line widths of at least two of the fourth windings or at least two of the third windings increase gradually along the width direction of the body portion and in a direction away from the center column of the magnetic core.

9. The planar transformer according to claim 3, characterized in that: The substrate also includes at least one third wiring layer, which is located between the first wiring layer and the second wiring layer. The winding module also includes at least one fifth winding unit, which is arranged in at least one third wiring layer. Each of the fifth winding units includes at least two fifth windings arranged at intervals in the third wiring layer, and at least two of the fifth windings are connected in parallel with each other.

10. The planar transformer according to claim 9, characterized in that: The line widths of at least two of the fifth windings increase gradually along the width direction of the body portion and in a direction away from the center column of the magnetic core.

11. A power supply device, characterized in that: Comprising the planar transformer according to any one of claims 1 to 10.

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