Packaging structure for planar transformer

Abstract

The utility model discloses a packaging structure for a planar transformer, which comprises a circuit board assembly, the circuit board assembly comprises at least two layers of circuit boards, the circuit boards are stacked and electrically connected, the circuit board on the top layer of the circuit board assembly is a first circuit board, and the circuit board on the bottom layer of the circuit board assembly is a second circuit board. The outer surface of the first circuit board and the outer surface of the second circuit board are provided with lipid coating layers. The number of the retaining walls is at least one, and the retaining walls are vertically and fixedly installed on the circuit board assembly. Compared with the prior art, by arranging the retaining wall, the along-surface safety isolation distance of the circuit board assembly is increased by 6.5 mm, so that the planar transformer meets the creepage distance requirement, the problem of creepage risks in the past is solved, and the planar transformer has the advantages of being simple and compact in overall structure, small in size, low in cost and resistant to impact.

Description

TECHNICAL FIELD

[0001] The utility model relates to transformer technical field especially relates to a packing structure for planar transformer. BACKGROUND

[0002] The planar transformer is a high-frequency transformer for a disconnecting switch mode power supply operating at high frequency.

[0003] The existing planar transformer usually contains winding turns made of thick copper sheets, in the case of a large-current winding or a winding etched in a spiral form on a PCB, the thick copper sheets are riveted together at the end of the turns and serve as a soldering point. However, in actual applications, the exposed soldering point of the planar transformer has a specified primary or secondary safety distance of greater than 6.5 mm from the magnetic core. The planar transformer is generally directly soldered on a PCB mainboard. At the same time, during the soldering process, the soldering flux penetrates into the interior of the planar transformer, which easily leads to excessive voltage creepage. The exposed soldering point of the planar transformer or the creepage risk between the point adhesive and the magnetic core often exists. SUMMARY

[0004] The technical problem to be solved by the utility model is to provide a packing structure for a planar transformer and a production method of the structure, by changing the structure of the planar transformer, the planar transformer meets the requirement of the creepage distance, and the problem of the previous creepage risk is solved.

[0005] To solve the above technical problem, the utility model discloses a packing structure for a planar transformer, which comprises a circuit board assembly, at least two layers of circuit boards, each layer of circuit boards is stacked and electrically connected, the circuit board at the top of the circuit board assembly is a first circuit board, the circuit board at the bottom of the circuit board assembly is a second circuit board, the outer surface of the first circuit board and the outer surface of the second circuit board are provided with a lipid coating layer, and a retaining wall is vertically fixed and installed on the circuit board assembly.

[0006] The number of the retaining walls is two, the two retaining walls are vertically and fixedly arranged on the top end surface of the first circuit board or the bottom end surface of the second circuit board, or one of the retaining walls is vertically fixed and installed on the top end surface of the first circuit board, and the other retaining wall is vertically fixed and installed on the top end surface of the second circuit board.

[0007] The number of the retaining walls is four, two of the retaining walls are vertically and fixedly arranged on the top end surface of the first circuit board, and the other two retaining walls are vertically and fixedly arranged on the bottom end surface of the second circuit board.

[0008] The retaining wall and the lipid coating layer on the outer surface of the first circuit board are an integral forming structure.

[0009] The retaining wall and the lipid coating layer on the outer surface of the second circuit board are an integral forming structure.

[0010] The retaining wall is in a rectangular shape.

[0011] The retaining wall is in an L shape.

[0012] The retaining wall is provided with a mounting portion and an extension portion perpendicular to the mounting portion, and the mounting portion is arranged in parallel with the first circuit board or the second circuit board.

[0013] The mounting portion is fixed on the circuit board assembly by riveting, bonding or welding.

[0014] Compared with the prior art, the embodiments of the utility model have the following beneficial effects:

[0015] The packaging structure for the planar transformer of the application, compared with the prior art, increases the creepage distance 6.5mm of the circuit board assembly by arranging the retaining wall, so that the planar transformer meets the requirement of the creepage distance, solves the problem of the previous creep risk, and has the characteristics of small volume, low cost and impact resistance. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0017] Figure 1 It is a structural schematic view of the packaging structure for the planar transformer in embodiment 1.

[0018] Figure 2 It is a front view of the packaging structure for the planar transformer in embodiment 1.

[0019] Figure 3 It is a front view of the packaging structure for the planar transformer in embodiment 2. DETAILED DESCRIPTION

[0020] In order to make the person in the art better understand the technical scheme of the utility model, the technical scheme in the embodiments of the utility model will be described clearly and completely in the following with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model.

[0021] The terms "first", "second", and the like in the description and in the claims of the utility model and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, device, product or end including a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units not listed, or optionally also includes other steps or units inherent to these processes, methods, products or ends.

[0022] Reference herein to "embodiment" means that the particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the utility model. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] Embodiment 1

[0024] The utility model discloses a kind of specific implementation of packaging structure for planar transformer, combined Figure 1 And Figure 2 Packaging structure includes circuit board assembly and retaining wall 2. In this embodiment, circuit board assembly includes three circuit boards, and the number of specific circuit board can be two, three, four or multiple, and can be selectively set according to demand.

[0025] In this embodiment, each circuit board is stacked and electrically connected, the circuit board located at the top layer of the circuit board assembly is the first circuit board 11, the circuit board located at the bottom layer of the circuit board assembly is the second circuit board 12, and the outer surface of the first circuit board 11 and the outer edge surface of the second circuit board 12 are both provided with a lipid coating layer. As a preferred scheme, the lipid coating layer can be made of epoxy resin.

[0026] In the embodiment, the number of the retaining walls 2 is four, two of which are vertically and spacedly fixed on the top end surface of the first circuit board 11, and the other two of which are vertically and spacedly fixed on the bottom end surface of the second circuit board 12. In this way, the along-plane distance of the top end surface and the bottom end surface of the planar transformer can be increased to meet the requirement of the creepage distance. In other embodiments, the number of the retaining walls 2 can be selectively set according to actual needs. Specifically, only two retaining walls 2 can be provided, which are spacedly arranged on the top surface of the first circuit board 11, or on the bottom end surface of the second circuit board 12, or arranged one above the other on the first circuit board 11 and the second circuit board 12, which can be arranged on the same side or diagonally. Such a single-side isolation structure has the characteristic of voltage resistance and is suitable for high-low voltage isolation. The safety distance requirement is met and is greater than 6.5 mm, which belongs to an isolated planar transformer. In addition, the number of the retaining walls 2 can also be one, which can be fixed on the top end surface of the first circuit board 11 or the bottom end surface of the second circuit board 12, as long as the along-plane distance of the circuit board assembly can meet the requirement of the safety distance after the retaining wall is added.

[0027] As a preferred solution, the retaining wall 2 is fixed and installed on the first circuit board 11 or the second circuit board 12 by adhesion. Alternatively, the retaining wall 2 is fixed and installed on the circuit board assembly by a lipid adhesive. That is, after the preparation of the circuit board assembly is completed, the retaining wall 2 is vertically placed on the first circuit board 11 or the second circuit board 12, and then a layer of epoxy resin glue is added to the connection between the two, and the retaining wall 2 is fixed and installed on the first circuit board 11 or the second circuit board 12 by the epoxy resin.

[0028] In other embodiments, the retaining wall 2 and the lipid coating layer on the outer surface of the first circuit board 11 are integrally formed. It can be understood that the retaining wall 2 and the lipid coating layer can be integrally formed by cooperating with a mold during the preparation of the lipid coating layer on the outer surface of the first circuit board 11, which can simplify the assembly process of the retaining wall 2 and improve the packaging efficiency and stability. Similarly, the retaining wall 2 and the lipid coating layer on the outer surface of the second circuit board 12 are integrally formed.

[0029] In the embodiment, the retaining wall 2 is in a rectangular shape, which is convenient for the preparation and production of the retaining wall 2.

[0030] Compared with the prior art, the packaging structure of the planar transformer of the embodiment increases the three-dimensional along-plane distance of the circuit board assembly by setting the retaining wall 2, and the safety distance is reduced by at least 2 mm in size to save costs, and the size of the electronic product is smaller, so that the planar transformer meets the requirement of the creepage distance, solves the problem of the risk of creep in the past, and has the characteristics of small volume and impact resistance.

[0031] The utility model discloses a kind of production methods of packaging structure for planar transformer, including the following steps: step a, two circuit boards with pin welding are stacked and placed;Step b, prepare prefabricated mould, and prefabricated mould is equipped with the cavity for preparing lipid coating;Step c, the circuit board after stacking in step a is placed into the prefabricated mould of step b, injects lipid material, and obtains circuit board assembly after cooling forming;Step d, baffle wall is bonded or formed on the circuit board assembly in step c by mould forming.

[0032] As preferred scheme, in step d, baffle wall is bonded on circuit board assembly by lipid adhesive. In other embodiments, in step d, baffle wall can be formed on circuit board assembly by mould forming, by preparing a mould with shaped baffle wall cavity, and forming baffle wall on circuit board assembly using the mould, so that the material of baffle wall can be different from the material of lipid coating of circuit board, to meet various working conditions or requirements.

[0033] The production method of packaging structure for planar transformer of the application has reasonable process design, and can make the prepared planar transformer meet the requirement of creepage distance, has simple overall process, and has certain economic benefits.

[0034] Example 2

[0035] Example 2 is different from example 1 in that baffle wall 2 is provided in L shape. L-shaped baffle wall 2 is provided with mounting portion 21 and extension portion 22 perpendicular to mounting portion 21, and mounting portion 21 is provided parallel to first circuit board 11 or second circuit board 12. This is more convenient for fixing and limiting baffle wall 2 when baffle wall 2 is packaged later. It should be noted that mounting portion 21 can be fixed on circuit board assembly by riveting, bonding or welding.

[0036] Finally, it should be noted that: the utility model embodiment discloses a kind of packaging structure for planar transformer and the production method of the structure disclosed only for the preferred embodiment of the utility model, only for the technical scheme of the utility model for illustration, not for its limitation;Although the utility model is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that;It can still modify the technical scheme recorded in the foregoing embodiments, or make equivalent substitution to part of technical features;And these modifications or substitutions do not make the essence of corresponding technical scheme deviate from the spirit and scope of the utility model embodiments technical scheme.

Claims

1. A packaging structure for a planar transformer, characterized by comprising: a substrate; a magnetic core; a primary winding; a secondary winding; a magnetic layer; and a magnetic layer support member. The application relates to a circuit board assembly. The circuit board assembly comprises at least two layers of circuit boards, each of the circuit board layers is arranged in a stack and electrically connected, a circuit board at a top layer of the circuit board assembly is a first circuit board, a circuit board at a bottom layer of the circuit board assembly is a second circuit board, and the outer surface of the first circuit board and the outer surface of the second circuit board are provided with lipid coating layers. The circuit board assembly is provided with at least one retaining wall which is vertically fixedly installed on the circuit board assembly.

2. The packaging structure for a planar transformer according to claim 1, wherein The number of the retaining walls is two, and the two retaining walls are vertically and spacedly fixed on the top end surface of the first circuit board or the bottom end surface of the second circuit board.

3. The packaging structure for a planar transformer according to claim 1, wherein The number of the retaining walls is four, and two of the retaining walls are vertically and spacedly fixed on the top end surface of the first circuit board, and the other two retaining walls are vertically and spacedly fixed on the bottom end surface of the second circuit board.

4. The packaging structure for a planar transformer according to claim 1, wherein The retaining wall and the lipid coating layer on the outer surface of the first circuit board are formed in an integral structure.

5. The packaging structure for a planar transformer according to claim 1, wherein The retaining wall and the lipid coating layer on the outer surface of the second circuit board are formed in an integral structure.

6. The packaging structure for a planar transformer according to claim 1, wherein The retaining wall is arranged in a rectangular shape.

7. The packaging structure for a planar transformer according to claim 1, wherein The retaining wall is arranged in an L shape.

8. The packaging structure for a planar transformer according to claim 7, wherein The retaining wall is provided with a mounting portion and an extension portion which is perpendicular to the mounting portion, and the mounting portion is arranged in parallel with the first circuit board or the second circuit board.

9. The packaging structure for a planar transformer according to claim 8, wherein The mounting portion is fixed on the circuit board assembly by riveting, bonding or welding.

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