Electromagnetic compatibility structure of DC / DC power supply module

Abstract

The utility model belongs to the technical field of power electronics, and particularly relates to an electromagnetic compatibility structure of a DC / DC power supply module. Comprising an FR-4 printed board, a shielding shell, an external interface module and a power supply module, the power supply module is welded on the FR-4 printed board, the external interface module is arranged in the FR-4 printed board, the external interface module comprises an input end interface and an output end interface, the shielding shell is arranged outside the power supply module, and the DC / DC power supply module is sealed by the shielding shell.

Description

Technical Field

[0001] The utility model belongs to the technical field of power electronics, and in particular relates to an electromagnetic compatibility structure of a DC / DC power supply module. Background Art

[0002] With the rapid development of industry, a large number of electrical equipment have replaced the original mechanical equipment and are used in various fields of electronic power. For some equipment with a relatively small space, the electrical space in the equipment is limited, the design of components, cables and other parts is relatively concentrated, and the electromagnetic spectrum generated covers a wide range. The equipment is very susceptible to interference under normal working conditions; electromagnetic compatibility performance has a direct impact on the performance of electronic power equipment.

[0003] The demand for electromagnetic compatibility is constantly being raised, and the design requirements for electromagnetic compatibility signal shielding in electronic power equipment are also increasing. For DC / DC power modules that are very likely to generate electromagnetic interference signals, the more traditional method is to shield the DC / DC power module, external interface module and FR-4 printed circuit board with a larger power shielding cabin. Although this method can play a positive role in electromagnetic shielding, the size and weight of the power shielding cabin are relatively large.

[0004] Due to the complexity of some application environments, such as aviation and aerospace electronic equipment, these application scenarios have high requirements for electromagnetic compatibility. The electromagnetic compatibility shielding strategy for DC / DC power modules in existing technologies is generally to set the DC / DC power module together with modules such as FR-4 printed circuit boards inside the shielding cabin. This solution has major defects, in that the shielding shell is large in size, the weight is difficult to control, and the cost investment is not advantageous. It has limited application in electronic equipment with small space and equipment with high weight requirements, and it is even difficult to fully achieve the electromagnetic compatibility shielding effect, and cannot meet the high standards and high requirements for electromagnetic compatibility in specific occasions. Utility Model Content

[0005] Purpose of the utility model: to provide an electromagnetic compatibility structure of a DC / DC power supply module, which can effectively reduce the volume and weight of the electromagnetic compatibility shielding shell while ensuring the electromagnetic compatibility performance.

[0006] Technical solution:

[0007] A DC / DC power module electromagnetic compatibility structure includes: an FR-4 printed board, a shielding shell, an external interface module and a power module, wherein the power module is welded on the FR-4 printed board, the external interface module is arranged in the FR-4 printed board, the external interface module includes an input end interface and an output end interface, and a shielding shell is arranged outside the power module, and the shielding shell seals the DC / DC power module.

[0008] Furthermore, the shielding shell and the FR-4 printed circuit board are fixed by mounting screws.

[0009] Furthermore, the external interface module is located outside the shielding space between the shielding shell and the FR-4 printed circuit board.

[0010] Furthermore, the input end of the external interface module is grounded and filtered through the first capacitor C1, the inductor L1 and the second capacitor C2; the output end filters out common mode interference through the fifth capacitor, and the power supply output end is grounded and filtered through the sixth capacitor and the seventh capacitor.

[0011] Furthermore, the power module is fastened to the printed circuit board by direct plug welding.

[0012] Furthermore, a window is opened at the contact position between the FR-4 printed circuit board and the shielding shell, and copper is clad at the position corresponding to the window.

[0013] Beneficial effects:

[0014] The electromagnetic compatibility strategy based on partial shielding of the DC / DC power module disclosed by the utility model includes an external interface module and a power module; the strategy also includes a shielding shell and a FR-4 printed board, the shielding shell and the FR-4 printed board are fastened by screws, and are tightly connected to form a closed cabin, and the power module is placed in the closed cabin to shield the main electromagnetic interference components. Through the electromagnetic compatibility strategy of partial shielding, combined with the external interface circuit, a smaller shielding shell is used to shield the electromagnetic interference caused by the DC / DC power module to the maximum extent. The electromagnetic compatibility strategy can greatly reduce the volume and weight of the shielding cabin of the power supply component. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the electromagnetic compatibility structure of the DC / DC power supply module of the utility model;

[0016] In the figure: 1-shielding shell, 2-FR-4 printed circuit board, 3-mounting screws, 4-power module.

[0017] Figure 2 This is a schematic diagram of the external interface module. DETAILED DESCRIPTION

[0018] In order to overcome the defects of the prior art, an electromagnetic compatibility strategy of local shielding of the DC / DC power supply module is adopted, and the DC / DC power supply module is electromagnetically shielded by using a local shielding shell 1 and an external interface module, mainly enclosing the DC / DC power supply module with greater interference, and effectively reducing the volume and weight of the electromagnetic compatibility shielding shell 1 while ensuring the electromagnetic compatibility performance.

[0019] like Figure 1-2The utility model provides an electromagnetic compatibility structure of a DC / DC power supply module, including: an external interface circuit module, a power supply module 4; the electromagnetic compatibility strategy also includes a shielding shell 1 and a FR-4 printed board 2, the shielding shell 1 is installed on the FR-4 printed board 2 to form a closed shielding shell 1 of the power supply module 4, and the electromagnetic interference is filtered out in combination with the external interface circuit module to realize a new electromagnetic shielding strategy.

[0020] The external interface circuit module is placed on the FR-4 printed circuit board 2 and is located close to the electromagnetic shielding shell 1 .

[0021] The external interface circuit is divided into two interfaces, an input end and an output end. The input end includes a differential mode capacitor and an LC filter circuit, and the output end includes a common mode capacitor and a differential mode capacitor, which effectively filters out signal interference.

[0022] The shielding shell 1 includes a shielding shell and mounting screws 3 , and the shielding shell is equipped with six mounting screws 3 .

[0023] The DC / DC power module 4 is soldered on the FR-4 printed circuit board 2 by direct insertion, and a printed circuit board window opening and copper cladding design is added around the power module 4.

[0024] The shielding shell 1 and the FR-4 printed circuit board 2 can be fastened together by six mounting screws 3 , and the metal shielding shell 1 and the copper-clad window of the FR-4 printed circuit board 2 are tightly connected to form a closed shielding space.

[0025] The DC / DC power supply module 4 is placed in a closed space between the shielding shell 1 and the FR-4 printed circuit board 2 and is tightly connected by mounting screws 3 .

[0026] The external interface module is placed outside the shielding space of the shielding shell 1 and the FR-4 printed circuit board 2, and provides signal input and output filter circuits.

[0027] The external interface module performs filtering processing at the power input and output ends through differential mode capacitors, common mode capacitors and LC filtering circuits.

[0028] The input end of the external interface module includes a first capacitor C1, a second capacitor C2, a first inductor L1, and an eighth capacitor C8; wherein the first capacitor C1 and the second capacitor C2 serve as differential mode capacitors and common mode capacitors for filtering out differential mode interference and common mode interference at the input end, and the first inductor L1 and the eighth capacitor C8 constitute an LC filter circuit for filtering out high-frequency signal interference.

[0029] The output end of the external interface module includes a fifth capacitor C5, a sixth capacitor C6, and a seventh capacitor C7, which form differential mode capacitors and common mode capacitors at the output end to filter out differential mode signal interference and common mode signal interference.

[0030] The present invention is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0031] Embodiment 1

[0032] like Figure 1 As shown, the embodiment of the utility model discloses an electromagnetic compatibility strategy based on partial shielding of a DC / DC power module, and the strategy includes an external interface module, a power module 4, a shielding shell 1, and a FR-4 printed circuit board 2. In this embodiment, the shielding shell 1 includes a shielding shell and mounting screws 3, and the power module 4 includes a DC / DC power module, wherein the DC / DC power module can produce strong electromagnetic radiation, which is easy to interfere with other components or modules.

[0033] In the local shielding strategy, the shielding shell 1 is fastened to the FR-4 printed circuit board 2 by six mounting screws 3 to form a closed cabin, and the power module 4 is placed in the closed cabin.

[0034] Specifically, in this embodiment, an external interface module, a shielding shell 1 and a FR-4 printed circuit board 2 are provided in the local shielding electromagnetic compatibility strategy. The external interface module is provided at the periphery of the shielding shell 1, and electromagnetic interference can be further filtered out through the external interface module.

[0035] Since the electromagnetic waves generated by the DC / DC power module are relatively strong, a fastenable shielding shell is provided on the FR-4 printed circuit board 2. The shielding shell 1 and the FR-4 printed circuit board 2 form a small enclosed conductive space to shield the electromagnetic interference generated by the power module 4, thereby further improving the electromagnetic compatibility performance.

[0036] In order to enable the shielding shell 1 to be fastened to the FR-4 printed board 2, an opening design is made on the FR-4 printed board 2, six M3 mounting holes are reserved, and the shielding shell 1 is fastened to the printed board by installing screws 3; the power module 4 is fastened to the printed board by direct plug welding; in order to enable the shielding shell 1 and the FR-4 printed board 2 to form a small closed conductive space, the contact position of the FR-4 printed board 2 and the shielding shell 1 is opened with a window and copper-clad; the welding position of the DC / DC power module is placed in the closed conductive space formed by the shielding shell 1 and the FR-4 printed board 2 to form an effective electromagnetic shielding space, thereby ensuring the electromagnetic shielding performance.

[0037] The connection line between the external interface module and the DC / DC power module is routed through the PCB layout, effectively avoiding the main circuits and sensitive components, so that the electromagnetic waves generated by the DC / DC power module cannot be transmitted to the outside through the wiring, and the electromagnetic waves from the outside cannot be transmitted to the power module 4. In this example, the routing position avoids devices with strong electromagnetic waves, and the line layout is regular and rational, which can effectively prevent the occurrence of electromagnetic effects.

[0038] The external interface module is divided into a power input terminal and a power output terminal. The power input terminal filters out the differential mode signal interference brought by the two-stage input through the first capacitor C1. The second capacitor C2 is added between the input ground and the chassis ground to eliminate the common mode interference through the added second capacitor C2. The first inductor L1 and the eighth capacitor C8 are added to the power input terminal to form an LC filtering circuit. The relatively high-frequency interference signals in the line will be filtered out, thereby reducing electromagnetic interference.

[0039] A fifth capacitor C5 is added between the positive pole of the power output terminal of the external interface module and the ground, mainly to filter out differential mode signals; a sixth capacitor C6 is connected between the output positive terminal and the chassis ground, and a seventh capacitor C7 is connected between the output ground and the chassis to filter out common mode interference at the output terminal.

[0040] The electromagnetic compatibility strategy based on partial shielding of DC / DC power modules has clear functional division and high recognition, while helping to save costs.

[0041] The electromagnetic compatibility strategy based on local shielding of DC / DC power supply modules disclosed by the utility model has clear ideas and methods. The shielding cabin uses aluminum alloy and other materials. The division of each module part is completed in the principle design stage, the position of the holes that need to be fastened is designed, the copper covering position and signal routing are clarified, so as to form a closed conductive space and improve the electromagnetic compatibility and anti-interference ability.

[0042] A rounded corner is set at the installation corner of the shielding shell 1 to improve the safety design. The size of the shielding shell 1 is close to the size of the power module to ensure the weight. At the same time, the shielding shell 1 is close to the power module, which is beneficial to the heat dissipation of the power module.

[0043] It can be seen from the above embodiments that the electromagnetic compatibility strategy based on local shielding of the DC / DC power supply module disclosed by the utility model partially shields the DC / DC power supply module with higher electromagnetic waves by utilizing local shielding to shield the electromagnetic interference generated by the power supply module 4 to the maximum extent. At the same time, the wiring between the DC / DC power supply module and the external interface is regular to prevent electromagnetic leakage and improve the electromagnetic compatibility capability. This strategy takes into account the advantages of weight, volume and cost of the shielding cabin, has high application value, and provides methods and measures for the electromagnetic compatibility of electronic power equipment with small space and weight restrictions.

[0044] The strategy described in the present invention is not limited to the embodiments shown in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical strategy of the present invention, which also fall within the scope of technical innovation of the present invention.

Claims

1. A DC / DC power module electromagnetic compatibility structure, characterized in that: include: FR-4 printed circuit board, shielding shell, external interface module and power module, wherein the power module is welded on the FR-4 printed circuit board, the external interface module is arranged in the FR-4 printed circuit board, the external interface module includes an input end interface and an output end interface, a shielding shell is arranged outside the power module, and the shielding shell seals the DC / DC power module.

2. The electromagnetic compatibility structure of the DC / DC power supply module according to claim 1, characterized in that: The shielding shell and the FR-4 printed circuit board are fixed by mounting screws.

3. The electromagnetic compatibility structure of the DC / DC power supply module according to claim 1, characterized in that: The external interface module is located outside the shielding space of the shielding shell and the FR-4 printed circuit board.

4. The electromagnetic compatibility structure of the DC / DC power supply module according to claim 1, characterized in that: The input end of the external interface module is grounded and filtered through the first capacitor C1, the inductor L1 and the second capacitor C2; the output end filters out common mode interference through the fifth capacitor, and the power supply output end is grounded and filtered through the sixth capacitor and the seventh capacitor.

5. The electromagnetic compatibility structure of the DC / DC power supply module according to claim 1, characterized in that: The power module is fastened to the printed circuit board by direct plug welding.

6. The electromagnetic compatibility structure of the DC / DC power supply module according to claim 1, characterized in that: A window is opened at the contact position between the FR-4 printed circuit board and the shielding shell, and copper is clad at the corresponding position of the window.

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