Planar transformer

Abstract

The planar transformer comprises an iron core, a plurality of layers of PCBs arranged in a laminated mode and a winding, the iron core is fixed to the PCBs to form a closed magnetic circuit, the winding is composed of thin copper layers, insulating layers are arranged among the thin copper layers, the sectional areas of wires of the thin copper layers are equal, and the insulating layers are arranged between the thin copper layers. The winding is provided with a secondary winding and a primary winding, and the secondary winding and the primary winding are alternately stacked on the multi-layer PCB. The transformer has the advantages that the structure is simple, the size is small, space can be saved, the transformer is suitable for occasions with limited space, the winding can be tightly fixed to the iron core, the distance between the winding and the iron core is shortened, therefore, the magnetic flux density is increased, the magnetic density of the transformer is improved, and the transformer further has the advantages of being high in efficiency, low in leakage inductance, low in EMI radiation and high in insulativity.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to the improvement of planar transformers. Background Art

[0002] With the rapid development of electronic technology, electronic equipment is becoming increasingly miniaturized and lightweight, and the requirements for the volume and performance of internal components are becoming more and more stringent. Due to its three-dimensional structure, traditional transformers have many limitations in space utilization and heat dissipation, and it is difficult to meet the needs of modern electronic equipment. As a new type of transformer, planar transformers have gradually attracted widespread attention due to their unique structural advantages. However, the existing planar transformers still have large winding losses, low magnetic permeability of the core, and unsatisfactory heat dissipation in terms of winding design, core structure, and heat dissipation performance, which affects the overall performance and reliability of the transformer. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a planar transformer having the advantages of simple structure, small size, space saving, and being suitable for occasions with limited space. It also solves the problem that traditional transformers have many limitations in space utilization and heat dissipation due to their three-dimensional structure and are difficult to meet the needs of modern electronic equipment.

[0004] In order to achieve the above advantages of simple structure, small size, space saving and suitability for occasions with limited space, the specific technical solution adopted by the present invention is as follows: it includes an iron core, a multi-layer PCB circuit board and a winding arranged in a stacked manner, the iron core is fixed on the PCB circuit board to form a closed magnetic circuit, the winding is composed of a thin copper layer, an insulating layer is arranged between the thin copper layers in an array, the conductor cross-sectional area of ​​the thin copper layer is equal, the winding is provided with a secondary winding and a primary winding, and the secondary winding and the primary winding are alternately stacked on the multi-layer PCB circuit board.

[0005] Furthermore, the secondary winding is provided with a pad S, a pad F, a via A, a via B, a via C and a via D, the pad S and the pad F are connected to the circuit node or the component pin, and the secondary winding is provided with multiple groups, the secondary winding is a primary winding, and the number of turns is 4 turns, which are the first secondary winding layer, the second secondary winding layer, the third secondary winding layer and the fourth secondary winding layer, respectively, the first secondary winding layer and the second secondary winding layer are connected through the via A, the second secondary winding layer and the third secondary winding layer and the fourth secondary winding layer are connected through the via B, and the third secondary winding layer and the fourth secondary winding layer are connected through the via C and the via D.

[0006] Furthermore, the first secondary winding layer, the second secondary winding layer, the third secondary winding layer and the fourth secondary winding layer are each provided with two layers, and the copper thickness is 7 oz.

[0007] The primary winding is provided with a pad SS, a via X, a via Y, a via U, a via V and a via Z. The primary winding is a secondary winding and has 6 turns, which are the first secondary winding layer, the second secondary winding layer, the third secondary winding layer, the fourth secondary winding layer, the fifth secondary winding layer and the sixth secondary winding layer, respectively. The first secondary winding layer and the second secondary winding layer are connected through the via U, the first secondary winding layer and the second secondary winding layer and the third secondary winding layer are connected through the via V, the third secondary winding layer and the fourth secondary winding layer are connected through the via X, the fourth secondary winding layer and the fifth secondary winding layer are connected through the via Y, and the fifth secondary winding layer and the sixth secondary winding layer are connected through the via Z.

[0008] Furthermore, the first secondary winding layer, the second secondary winding layer, the third secondary winding layer, the fourth secondary winding layer, the fifth secondary winding layer and the sixth secondary winding layer are each provided with two layers, and the copper thickness is 4 oz.

[0009] Furthermore, the transformer is also provided with a shell, and the shell is a magnetic core shielding shell.

[0010] Compared with the prior art, the present invention provides a planar transformer having the following beneficial effects: It has a simple structure and small size, which can save space and is suitable for occasions with limited space. The winding can be tightly fixed on the core, and the distance between the winding and the core is shortened, thereby increasing the magnetic flux density and improving the transformer's magnetic density. It also has the advantages of high efficiency, low leakage inductance, low EMI radiation and high insulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is one of the structural schematic diagrams of the interior of the present invention; Figure 3 This is the second schematic diagram of the structure inside the present invention; Figure 4 It is a schematic diagram of the structure of the present invention; Figure 5 It is a structural schematic diagram of the present invention.

[0013] In the figure: iron core 1, PCB circuit board 2, winding 3, secondary winding 31, primary winding 32, first secondary winding layer 311, second secondary winding layer 312, third secondary winding layer 313, fourth secondary winding layer 314, first secondary winding layer 321, second secondary winding layer 322, third secondary winding layer 323, fourth secondary winding layer 334, fifth secondary winding layer 335, sixth secondary winding layer 336. DETAILED DESCRIPTION

[0014] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0015] According to an embodiment of the present invention, a planar transformer is provided.

[0016] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1-5 As shown, a planar transformer according to an embodiment of the present invention comprises an iron core 1, a multi-layer PCB circuit board 2 arranged in a stacked manner, and a winding 3. The iron core 1 is fixed on the PCB circuit board 2 to form a closed magnetic circuit. The winding 3 is composed of a thin copper layer. An insulating layer is arranged between the thin copper layers of each array. The cross-sectional area of ​​the wires of the thin copper layer is equal to ensure uniform current distribution and reduce the AC resistance loss of the winding. An insulating layer is arranged between the thin copper layers of each array. The insulating layer adopts a high-performance insulating material, such as a polyimide film, etc., which has good insulation strength and high temperature resistance to ensure electrical isolation and safety between the windings of each layer. The winding 3 is provided with a secondary winding 31 and a primary winding 32. The secondary winding 31 and the primary winding 32 are alternately stacked on the multi-layer PCB circuit board 2. The PCB circuit board 2 adopts a substrate with high heat resistance and high insulation performance. The number of layers of the PCB circuit board 2 is determined according to the number of layers of the winding and the electrical performance requirements. The layers are tightly combined through a high-precision pressing process to ensure good electrical connection and mechanical strength.

[0017] In one embodiment, the core 1 is made of a new type of high magnetic permeability, low loss ferrite material or amorphous alloy material. The material has a high initial magnetic permeability and saturation magnetic flux density, which can effectively reduce the core loss and improve the energy conversion efficiency of the transformer. The core is flat in shape to better adapt to the structure of the planar transformer, and fits tightly with the multi-layer PCB circuit board 2 to form a closed magnetic circuit, ensuring efficient transmission and concentration of the magnetic field.

[0018] In one embodiment, the secondary winding 31 is provided with a pad S, a pad F, a via A, a via B, a via C and a via D, the pad S and the pad F are connected to the circuit node or the component pin, the secondary winding 31 is provided with multiple groups, the secondary winding 31 is a primary winding, and the number of turns is 4 turns, which are the first secondary winding layer 311, the second secondary winding layer 312, the third secondary winding layer 313 and the fourth secondary winding layer 314, the first secondary winding layer 311 and the second secondary winding layer 312 are connected through the via A, the second secondary winding layer 312 and the third secondary winding layer 313 and the fourth secondary winding layer 314 are connected through the via B, and the third secondary winding layer 313 and the fourth secondary winding layer 314 are connected through the via C and the via D.

[0019] In one embodiment, the first secondary winding layer 311 , the second secondary winding layer 312 , the third secondary winding layer 313 , and the fourth secondary winding layer 314 are each provided with two layers, and the copper thickness is 7 oz.

[0020] In one embodiment, the primary winding 32 is provided with a pad SS, a via X, a via Y, a via U, a via V and a via Z. The primary winding 32 is a secondary winding, and the number of turns is 6 turns, which are the first secondary winding layer 321, the second secondary winding layer 322, the third secondary winding layer 323, the fourth secondary winding layer 334, the fifth secondary winding layer 335 and the sixth secondary winding layer 336, the first secondary winding layer 321 The first secondary winding layer 321 is connected to the second secondary winding layer 322 and the third secondary winding layer 323 through the via V, the third secondary winding layer 323 and the fourth secondary winding layer 334 are connected through the via X, the fourth secondary winding layer 334 and the fifth secondary winding layer 335 are connected through the via Y, and the fifth secondary winding layer 335 and the sixth secondary winding layer 336 are connected through the via Z.

[0021] In one embodiment, the first secondary winding layer 321 , the second secondary winding layer 322 , the third secondary winding layer 323 , the fourth secondary winding layer 334 , the fifth secondary winding layer 335 and the sixth secondary winding layer 336 are each provided with two layers, and the copper thickness is 4 oz.

[0022] In one embodiment, the transformer is further provided with a shell 5, which is a magnetic core shielding shell, and its main function is to shield the magnetic field generated by the iron core, reduce electromagnetic interference to the outside world, and protect the internal winding 3 and the iron core 1 components.

[0023] Working principle: First, connect the primary winding 32 of the transformer to the external power supply through pads SS and the like, and connect the secondary winding 31 to the load circuit through pads S and F. Ensure that the connection is firm and there is no cold solder joint, short circuit, etc. After the power is turned on, the transformer starts to work, and the current in the primary winding 32 generates a changing magnetic field in the iron core 1, which induces an electromotive force in the secondary winding 31, thereby realizing the transmission of energy from the primary to the secondary and voltage conversion.

[0024] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A planar transformer, characterized in that: It comprises an iron core (1), a stacked PCB circuit board (2) and a winding (3); the iron core (1) is fixed on the PCB circuit board (2) to form a closed magnetic circuit; the winding (3) is composed of thin copper layers; an insulating layer is provided between the thin copper layers in an array; the conductor cross-sectional areas of the thin copper layers are equal; the winding (3) is provided with a secondary winding (31) and a primary winding (32); the secondary winding (31) and the primary winding (32) are alternately stacked on the multi-layer PCB circuit board (2).

2. A planar transformer according to claim 1, characterized in that: The secondary winding (31) is provided with a pad S, a pad F, a via A, a via B, a via C and a via D. The pad S and the pad F are connected to a circuit node or a component pin. The secondary winding (31) is provided with multiple groups. The secondary winding (31) is a primary winding with (4) turns, which are sequentially a first secondary winding layer (311), a second secondary winding layer (312), a third secondary winding layer (313) and a fourth secondary winding layer (314). The first secondary winding layer (311) and the second secondary winding layer (312) are connected through the via A. The second secondary winding layer (312) and the third secondary winding layer (313) and the fourth secondary winding layer (314) are connected through the via B. The third secondary winding layer (313) and the fourth secondary winding layer (314) are connected through the via C and the via D.

3. A planar transformer according to claim 2, characterized in that: The first secondary winding layer (311), the second secondary winding layer (312), the third secondary winding layer (313) and the fourth secondary winding layer (314) are all provided with two layers, and the copper thickness is 7 oz.

4. A planar transformer according to claim 1, characterized in that: The primary winding (32) is provided with a pad SS, a via X, a via Y, a via U, a via V and a via Z. The primary winding (32) is a secondary winding, and the number of turns is (6), which is sequentially a first secondary winding layer (321), a second secondary winding layer (322), a third secondary winding layer (323), a fourth secondary winding layer (334), a fifth secondary winding layer (335) and a sixth secondary winding layer (336). The first secondary winding layer (321) and the second secondary winding layer (322) are connected to each other. The first secondary winding layer (322) is connected through a via U, the first secondary winding layer (321) is connected to the second secondary winding layer (322) and the third secondary winding layer (323) through a via V, the third secondary winding layer (323) is connected to the fourth secondary winding layer (334) through a via X, the fourth secondary winding layer (334) is connected to the fifth secondary winding layer (335) through a via Y, and the fifth secondary winding layer (335) is connected to the sixth secondary winding layer (336) through a via Z.

5. A planar transformer according to claim 4, characterized in that: The first secondary winding layer (321), the second secondary winding layer (322), the third secondary winding layer (323), the fourth secondary winding layer (334), the fifth secondary winding layer (335) and the sixth secondary winding layer (336) are all provided with two layers, and the copper thickness is 4oz.

6. A planar transformer according to claim 1, characterized in that: The transformer is also provided with a shell (5), and the shell (5) is a magnetic core shielding shell.

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