CN219349968U - Patch transformer - Google Patents

Abstract

The utility model relates to a patch transformer, which is characterized in that: the winding device comprises a drum-shaped core coated with an insulating coating, an electric conductive coil and a magnetic conductive cover plate, wherein the drum-shaped core is provided with a winding post, and a first side leg and a second side leg which are perpendicular to the length direction of the winding post are arranged at two ends of the winding post in the length direction; the magnetic conduction cover plate is parallel to the drum core type winding column and is attached to the top planes of the first side leg and the second side leg; the conductive coil is wound on the drum-shaped core winding column, electrodes are arranged on the bottom planes of the first side leg and the second side leg of the drum-shaped core, and the wire ends of the conductive coil are welded on the electrodes on the bottom planes of the first side leg and the second side leg. Based on the transformer with the structure, the drum-shaped core is covered by insulation, so that the transformer can bear higher withstand voltage; in addition, the joint of the drum-shaped core and the cover plate is free of insulating paint, so that the air gap can be minimized, and the high inductance can be maintained.

Description

Patch transformer

Technical Field

The utility model belongs to the field of transformers, and particularly relates to a surface-mounted patch transformer.

Background

Currently, transformers are applied to switching power supplies and have the functions of voltage transformation, current transformation, impedance transformation, isolation, voltage stabilization, energy storage, energy transmission and the like. As the technology of switching power supplies is continuously developed toward miniaturization, energy saving and high efficiency, transformers used in the switching power supplies are required to have higher efficiency and smaller volume.

The isolation transformers used by the existing micropower isolation power supply modules are mostly magnetic ring transformers in early stages. The magnetic circuit of the magnetic ring transformer is closed, no air gap exists, and the transformer can achieve high inductance; on the other hand, the magnetic ring transformer directly winds the magnetic ring, so that the winding window has high utilization rate. However, when the magnetic ring transformer is used, manual spot welding is required to be performed on the magnetic ring transformer assembled on the power module PCB, so that the efficiency is low and the automation is difficult to realize. With the development of industry, a transformer formed by a special-shaped magnetic core and a matched framework is developed, a coil is wound on the framework, and then the special-shaped magnetic core is sleeved on the framework, and the framework is provided with pins capable of automatically attaching, so that the problem that the annular transformer is difficult to realize automation is solved; however, the skeleton occupies a part of the winding window, so that the transformer manufactured by using the special-shaped magnetic core has a larger size, thereby increasing the occupied area of the system and being unfavorable for the miniaturization design of products.

Disclosure of Invention

In view of the shortcomings of the prior art, the utility model aims to provide a novel patch transformer so as to solve the problems that the assembly of a magnetic ring transformer is difficult to realize automation and the miniaturization of a special-shaped transformer is difficult to realize.

In order to achieve the above purpose, the present utility model adopts the following technical scheme:

a patch transformer comprises a drum-shaped core coated with an insulating coating, an electric coil and a magnetic conduction cover plate, wherein the drum-shaped core is provided with a winding post, and a first side leg and a second side leg which are perpendicular to the length direction of the winding post are arranged at two ends of the length direction of the winding post; the magnetic conduction cover plate is parallel to the drum core type winding column and is attached to the top planes of the first side leg and the second side leg; the conductive coil is wound on the drum-shaped core winding column, electrodes are arranged on the bottom planes of the first side leg and the second side leg of the drum-shaped core, the wire ends of the conductive coil are welded on the electrodes on the bottom planes of the first side leg and the second side leg, the metal electrodes on the side legs of the drum-shaped core are spaced at intervals of more than or equal to 0.4mm, and the spacing between the metal electrodes and the minimum longitudinal vertical distance from the top surface of the side leg to the non-insulating coating area is less than or equal to 2 times.

Preferably, the top planes of the first side leg and the second side leg of the drum-shaped core are magnetic material planes from which the insulating coating is removed.

Preferably, the electrode on the bottom plane of the drum core is provided with at least 4 metal electrodes, the first side leg is provided with at least 2 metal electrodes arranged at intervals, a groove which is concave along the bottom plane of the side leg towards the top surface of the side leg and can cut off creepage breakdown between the two metal electrodes is arranged between the two metal electrodes, the second side leg is provided with at least 2 metal electrodes arranged at intervals, and a groove which is concave along the bottom plane of the side leg towards the top surface of the side leg and can cut off creepage breakdown between the two metal electrodes is arranged between the two metal electrodes.

Preferably, the distance between the grooves arranged on the first side leg is more than or equal to 0.4mm and less than or equal to 2 times of the shortest longitudinal vertical distance from the metal electrode to the non-insulating coating area on the top surface of the side leg, wherein the shortest linear distance between the adjacent 2 metal electrodes along the long side direction of the side leg.

Preferably, the conductive coil includes a primary conductive coil and a secondary conductive coil, where the end of the wire of the primary conductive coil is welded to a metal electrode different from the secondary conductive coil, and when the metal electrode welded by the primary conductive coil and the metal electrode welded by the secondary conductive coil are located on the same side leg, a groove is required to be disposed between the two metal electrodes to isolate creepage breakdown between the two metal electrodes.

Preferably, resin substances for adhesion and fixation are filled between the top planes of the first side leg and the second side leg of the drum-shaped core and the joint surface of the magnetic conduction cover plate.

Preferably, the drum core and the magnetic conductive cover plate are soft magnetic conductive materials containing iron, nickel, cobalt and the like.

Preferably, the conductive coil comprises a primary conductive coil and a secondary conductive coil, the primary conductive coil and the secondary conductive coil are formed by winding thick-film high-voltage-resistant enameled wires, and the withstand voltage between an enameled wire for the primary conductive coil and an enameled wire stranded wire for the secondary conductive coil is greater than or equal to that between two nearest adjacent metal electrodes on any 2 different winding sides.

Preferably, the insulating coating is made of polyimide as a main material, and is added with a mixed paint of inorganic filler, epoxy resin and other materials, and the thickness of the insulating coating is greater than or equal to 60um.

Preferably, the drum core is composed of mainly manganese zinc ferrite.

The utility model has the beneficial effects that: the outer surface of the drum-shaped core is provided with an insulating coating with higher resistivity than the resistivity of the core body, so that the isolation voltage of the isolated patch transformer manufactured by the drum-shaped core can be improved; second, the insulating coating between the drum core and the magnetically permeable cover sheet is removed, so that the air gap between the drum core and the magnetically permeable cover sheet can be minimized, and the transformer can maintain a high inductance.

Drawings

Fig. 1 is a perspective view of a transformer according to embodiment 1 of the present utility model.

Fig. 2 is a side view of the transformer according to embodiment 1 of the present utility model.

Fig. 3 is a perspective view showing a structure of a magnetic core and a winding according to embodiment 1 of the present utility model.

Detailed Description

The utility model and its advantageous effects will be described in further detail below with reference to the detailed description and the accompanying drawings, but the detailed description of the utility model is not limited thereto.

Example 1

Referring to fig. 1, 2 and 3, fig. 1 is a schematic structural diagram of a chip transformer according to the present embodiment, in the present embodiment, there is provided a chip transformer 801, including: the drum core 301, the cover sheet 201, the primary winding 501 and the secondary winding 502 wound on the drum core 301, the insulating wrapping 601 coated on the drum core 301, the electrodes 101, 102, 103 and 104, the electrode 101 and the electrode 104 are positioned on the same side leg 701, and the electrode 102 and the electrode 103 are positioned on the same side leg 702. Fig. 2 is a side view of a patch transformer according to this embodiment, and fig. 3 is a bottom perspective view of the patch transformer according to this embodiment without a cover plate.

Specifically, the bonding surface 401 (shown in fig. 3) of the drum core 301 and the cover sheet 201, in which the drum core is exposed, is removed of the insulating wrap prior to combination with the magnetically permeable cover sheet. The drum-shaped core of the patch transformer has insulating coating and can bear higher withstand voltage; in addition, the joint of the drum-shaped core and the cover plate is free of insulating paint, so that the air gap can be minimized, and the high inductance of the patch transformer can be maintained.

Specifically, the drum core 301 and the magnetic conductive cover piece 201 are common soft magnetic materials containing magnetic conductive substances composed of materials such as iron, nickel, cobalt and the like; such as manganese zinc ferrite, nickel zinc ferrite, etc.

Preferably, in the present embodiment, the cover 201 is not covered with an insulating coating, so that the air gap between the drum core and the cover is minimized after the cover 201 is combined with the drum core combining surface 401, the inductance of the magnetic core can be maintained at a high level, and thus the transformer can obtain a high inductance. The conventional transformer is mainly composed of nickel-zinc ferrite, while the patch transformer described in this embodiment is mainly composed of manganese-zinc ferrite, and the inductance of the transformer is 60uH and the inductance of the patch transformer is 100uH when the number of turns of the conductive winding is 21, so that the transformer described in this embodiment can obtain high inductance. It should be noted that, in this embodiment, the cover sheet 201 is completely free of the insulating coating, which not only minimizes the air gap at the joint surface with the drum core, but also saves energy in the processing procedure of the cover sheet; however, also, the cover sheet may be insulated from the bonding surface with the drum core, if desired.

Specifically, the insulating coating 601 is a mixed coating using polyimide as a main material and added with inorganic filler, epoxy resin and other materials, and in order to meet the requirement of high voltage resistance, the thickness of the insulating coating 601 needs to be greater than 60um.

Further, the primary winding 501 is wound on the winding post of the drum core 301, and the winding is welded on the electrodes 101 and 102 of the drum core; the secondary winding 502 is wound around the drum core 301, and the winding is welded to the electrodes 103 and 104. It is foreseeable that because the primary winding and the secondary winding are welded on the electrode of the drum core 301, the specific resistance of the surface of the drum core bare core is far insufficient for the case of the isolation transformer requiring high withstand voltage because the specific surface resistance of the drum core bare core is very low; therefore, an insulating layer can be formed between the electrode and the drum-shaped core bare core body through the insulating coated magnetic core, so that insulation between the electrode and the drum-shaped core body is realized, and even if the primary side winding and the secondary side winding are welded on the magnetic core at the same time, the insulation short circuit of the primary side winding and the secondary side winding through the magnetic core body can be stopped, and the design requirement of high withstand voltage is met.

Further, as will be understood by those skilled in the art, in the present embodiment, the primary winding is wound on and wound on the electrodes 101 and 102, the secondary winding is wound on and wound on the electrodes 103 and 104, the electrodes 101 and 104 are disposed on the same leg 701, the electrodes 102 and 103 are disposed on the same leg 702, the adjacent 101 and 104, or the distance between the adjacent 102 and 103 is very close, even if the surface of the magnetic core is covered with the insulating coating, and under the high voltage condition of several hundred to several kv, the short distance of the electrodes 101 and 104 may be directly creeped down to cause the withstand voltage failure without passing through the intermediate path of the magnetic core body. Therefore, according to the design of this embodiment, grooves recessed along the bottom plane of the leg toward the top surface of the leg and capable of isolating the creepage breakdown between the two metal electrodes are provided between the primary winding electrode 101 and the adjacent secondary winding electrode 104 of the same leg 701 or between the primary winding electrode 102 and the adjacent secondary winding electrode 103 of the same leg 702, the length a (as shown in fig. 2) of the grooves needs to be at least greater than 0.4mm and is set according to the actual voltage-withstanding requirement, and the distance between the two electrodes formed by the length a of the grooves on the leg is generally greater than or equal to 0.4mm and less than or equal to 2 times the minimum vertical distance from the adjacent 2 metal electrodes to the non-insulating coating area on the top surface of the leg along the length of the leg. The depth c (shown in fig. 2) of the groove is required to be greater than 0.2mm, the width of the groove is equal to the width of the edge leg, the groove is a through groove, and the part between the two electrodes on the edge leg is dug to form a spacing groove between the two electrodes, so that creepage breakdown between the two metal electrodes can be isolated. The length of the groove is at least more than 0.4mm to meet the minimum wall thickness requirement of solid insulation, and the depth of the groove is more than 0.2mm to enable the minimum creepage distance between two adjacent electrodes to be more than 0.4mm; it is contemplated that if the winding up of the primary winding 501 is disposed on leg 701 and the winding up of the secondary winding 502 is disposed on leg 702, the distance between the two legs is already far, in which case no recess may be provided between the adjacent two electrodes 101 and 104 or 102 and 103.

Further, we recognize that the surface of the drum core where the magnetic conductive cover plate is combined is exposed, so that any two electrodes of the four electrodes 101/102/103/104 of the drum core can climb to the exposed plane of the drum core along the surface of the magnetic core, and breakdown voltage is formed by taking the magnetic core as an intermediate; comparing the electrode spacing a between two adjacent different winding sides of the same side leg with the electrode spacing a, firstly defining the vertical distance from any one electrode of the drum-shaped core to the top surface of the drum-shaped core as b, then climbing the two electrodes to the exposed surface of the magnetic core along the b, and setting the total creepage distance as 2b; when 2b is larger than a, the two different winding side electrodes break down along the creepage of a direction, so in the case, the voltage withstand requirement can be met by designing a size of a to meet the voltage withstand requirement and enabling 2b to be larger than a and enabling the voltage withstand of any 2 different winding side adjacent electrodes.

Further, in the high-isolation transformer, the conductive coil of the primary winding and the conductive coil of the secondary winding are formed by winding thick-film high-voltage-resistant enameled wires, the primary winding and the secondary winding are wound on the same winding post, and no extra insulation is added between the two windings, so that the withstand voltage of the enameled wire for the conductive coil of the primary winding 501 and the withstand voltage of the enameled wire stranded wire for the conductive coil of the secondary winding 502 is greater than or equal to the withstand voltage between any 2 adjacent nearest electrodes at different winding sides, and the withstand voltage between the windings meets the design requirement.

The foregoing is merely a preferred embodiment of the present utility model, and it should be noted that the foregoing preferred embodiment should not be considered as limiting the present utility model, and it should be understood by those skilled in the art that several modifications and adaptations may be made thereto without departing from the spirit and scope of the present utility model, and that modifications and adaptations of the chip transformer and micro-power isolation power module structure should and are intended to be covered by the present utility model, and that the scope of the present utility model shall be defined by the claims without further description of the embodiment.

Claims (9)

1. Paster transformer, its characterized in that: the winding device comprises a drum-shaped core coated with an insulating coating, an electric conductive coil and a magnetic conductive cover plate, wherein the drum-shaped core is provided with a winding post, and a first side leg and a second side leg which are perpendicular to the length direction of the winding post are arranged at two ends of the winding post in the length direction; the magnetic conduction cover plate is parallel to the drum core type winding column and is attached to the top planes of the first side leg and the second side leg; the conductive coil is wound on the drum-shaped core winding column, electrodes are arranged on the bottom planes of the first side leg and the second side leg of the drum-shaped core, the wire ends of the conductive coil are welded on the electrodes on the bottom planes of the first side leg and the second side leg, the metal electrodes on the side legs of the drum-shaped core are spaced at intervals of more than or equal to 0.4mm, and the spacing between the metal electrodes and the minimum longitudinal vertical distance from the top surface of the side leg to the non-insulating coating area is less than or equal to 2 times.

2. The patch transformer of claim 1; the drum-shaped core is characterized in that the top planes of the first side leg and the second side leg of the drum-shaped core are magnetic material planes from which the insulating coating is removed.

3. The patch transformer of claim 1; the drum-shaped electrode is characterized in that at least 4 metal electrodes are arranged on the bottom plane of the drum core, at least 2 metal electrodes are arranged on the first side leg at intervals, grooves which are concave along the bottom plane of the side leg towards the top surface of the side leg and can cut off creepage breakdown between the two metal electrodes are arranged between the two metal electrodes, at least 2 metal electrodes are arranged on the second side leg at intervals, and grooves which are concave along the bottom plane of the side leg towards the top surface of the side leg and can cut off creepage breakdown between the two metal electrodes are arranged between the two metal electrodes.

4. The patch transformer of claim 1; the electric conduction coil is characterized by comprising a primary side electric conduction coil and a secondary side electric conduction coil, wherein the end part of a wire of the primary side electric conduction coil is welded on a metal electrode which is different from the secondary side electric conduction coil, and when the metal electrode welded on the primary side electric conduction coil and the metal electrode welded on the secondary side electric conduction coil are positioned on the same side leg, a groove capable of isolating creepage breakdown between the two metal electrodes is arranged between the two metal electrodes.

5. The patch transformer of claim 2; the method is characterized in that: resin substances for adhesion and fixation are filled between the top planes of the first side leg and the second side leg of the drum-shaped core and the joint surface of the magnetic conduction cover plate.

6. The patch transformer of claim 1; the method is characterized in that: the drum-shaped core and the magnetic conduction cover plate are made of magnetic conduction materials containing soft magnetism.

7. The patch transformer of claim 1; the method is characterized in that: the conductive coil comprises a primary side conductive coil and a secondary side conductive coil, the primary side conductive coil and the secondary side conductive coil are formed by winding thick-film high-voltage-resistant enameled wires, and the withstand voltage between an enameled wire for the primary side conductive coil and an enameled wire stranded wire for the secondary side conductive coil is greater than or equal to the withstand voltage between two nearest adjacent metal electrodes on any 2 different winding sides.

8. The patch transformer of claim 1; the method is characterized in that; the thickness of the insulating coating is greater than or equal to 60um.

9. The patch transformer of claim 1; the method is characterized in that; the drum-shaped core is mainly made of manganese-zinc ferrite.

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