Printed circuit board and power supply equipment

Abstract

The utility model relates to a printed circuit board and a power supply device, the printed circuit board enables current to change directions for multiple times through a first separation strip and a second separation strip, the inductive reactance of the circuit is increased, the increased inductive reactance is equivalent to a common mode inductor, the first separation strip enables a first overcurrent conductor to form an inductor, and the second separation strip enables a second overcurrent conductor to form an inductor. The first separation strip enables the first overcurrent conductor to form one inductor, the second separation strip enables the second overcurrent conductor to form the other inductor, the first overcurrent conductor and the second overcurrent conductor are used as inductors in the EMC filter circuit for eliminating high-frequency noise, the filtering effect can be achieved without additionally arranging the EMC filter circuit, the cost is lower, the PCB layout is simpler, and the EMC performance is improved on the basis of reducing products.

Description

Technical Field

[0001] The utility model relates to the field of EMC filtering, in particular to a printed circuit board and a power supply device. Background Art

[0002] The power circuit in a power supply device steps up or down the voltage of electrical energy to provide a suitable supply voltage for the load. The MOS transistors and diodes in the power circuit can introduce electromagnetic interference (EMI) during operation. To reduce EMI, an EMC filter circuit can be used to eliminate interference signals input from the signal lines and various induced interference. Both the EMC filter circuit and the power circuit can be installed on the printed circuit board of the power supply device.

[0003] However, if an EMC filter circuit is installed on a printed circuit board, the PCB layout will be complicated, the production process will be complicated, and the circuit cost will be high. At the same time, the EMC filter circuit itself will also have filtering errors and losses. Utility Model Content

[0004] The embodiments of the present utility model aim to provide a printed circuit board and a power supply device, which can achieve EMC filtering effects without adding filtering components, reduce costs, and make the PCB layout simpler.

[0005] In order to solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a printed circuit board, comprising: a circuit board body, and a first overcurrent conductor and a second overcurrent conductor disposed on the circuit board body;

[0007] The first end of the first overcurrent conductor is electrically connected to the first output end of the power circuit in the power supply device, and the second end of the first overcurrent conductor is the first differential output end of the printed circuit board;

[0008] The first end of the second overcurrent conductor is electrically connected to the second output end of the power circuit, and the second end of the second overcurrent conductor is the second differential output end of the printed circuit board;

[0009] Among them, a plurality of first separators are provided on the first overcurrent conductor, and the length of each of the first separators is smaller than the width of the first overcurrent conductor; a plurality of second separators are provided on the second overcurrent conductor, and the length of each of the second separators is smaller than the width of the second overcurrent conductor.

[0010] In some embodiments, the first overcurrent conductor and the second overcurrent conductor are both copper foils on the circuit board body.

[0011] In some embodiments, a plurality of the first dividing strips are arranged at intervals; and / or a plurality of the second dividing strips are arranged at intervals.

[0012] In some embodiments, a plurality of the first separation strips are spaced apart along the length direction of the first overcurrent conductor; and / or a plurality of the second separation strips are spaced apart along the length direction of the second overcurrent conductor.

[0013] In some embodiments, if the width of the first overcurrent conductor is b1 and the vertical distance between adjacent first separation strips is a1, then the ratio of b1 to a1 is greater than a first preset threshold; and,

[0014] If the width of the second overcurrent conductor is b2 and the vertical distance between adjacent second separation strips is a2, then the ratio of b2 to a2 is greater than a first preset threshold.

[0015] In some embodiments, if the width of the first separator is c1 and the minimum width of the current-carrying conductor that meets the current carrying requirement is n, then the difference between b1 and c1 is less than n; and

[0016] If the width of the second dividing strip is c2, the difference between b2 and c2 is less than n.

[0017] In some embodiments, the first overcurrent conductor and the second overcurrent conductor are symmetrically arranged.

[0018] In some embodiments, the opening directions of adjacent first dividing strips are opposite to each other, and the opening directions of adjacent second dividing strips are opposite to each other.

[0019] In some embodiments, if the direction in which the first end of the first overcurrent conductor points to the second end of the first overcurrent conductor is a first direction, the first dividing strip is perpendicular to the first direction; and

[0020] If the direction from the first end of the second overcurrent conductor to the second end of the second overcurrent conductor is the second direction, the second dividing strip is perpendicular to the second direction.

[0021] In a second aspect, an embodiment of the present invention provides a power supply device, comprising an external power supply, a power circuit, and a printed circuit board as described above, wherein the external power supply is electrically connected to the input end of the power circuit, and the output end of the power circuit is electrically connected to the first overcurrent conductor and the second overcurrent conductor in the printed circuit board.

[0022] In various embodiments of the present invention, the printed circuit board changes the direction of the current multiple times through the first dividing strip and the second dividing strip, thereby increasing the inductive reactance of the circuit. The increased inductive reactance is equivalent to the common-mode inductance. The first dividing strip forms an inductance with the first overcurrent conductor, and the second dividing strip forms another inductance with the second overcurrent conductor. The first overcurrent conductor and the second overcurrent conductor are used as inductors in the EMC filter circuit for eliminating high-frequency noise. The filtering effect can be achieved without setting up an additional EMC filter circuit, and the cost is lower, the PCB layout is simpler, and the EMC performance is improved on the basis of reducing the product size. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0024] Figure 1 This is a schematic diagram of the structure of a power supply device provided by an embodiment of the present utility model;

[0025] Figure 2 This is a schematic structural diagram of a printed circuit board provided by an embodiment of the present utility model;

[0026] Figure 3 It is a schematic diagram of the length direction of a first overcurrent conductor and the length direction of a second overcurrent conductor provided by an embodiment of the present utility model;

[0027] Figure 4 Schematic diagram of the width of a first overcurrent conductor, the length of a first separator, and the vertical distance between adjacent first separators, as well as a schematic diagram of the width of a second overcurrent conductor, the length of a second separator, and the vertical distance between adjacent second separators, provided in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the EMC test results without using an EMC filter circuit;

[0029] Figure 6 Schematic diagram of the EMC test results of the printed circuit board provided in the embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to 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.

[0031] Please also refer to Figure 1 and Figure 2 , Figure 1 The power supply device is provided by the embodiment of the utility model, Figure 2 The utility model discloses a structure diagram of one kind of printed circuit board, as shown in the figure, Figure 1 The power supply device 100 includes an external power supply 20, a power circuit 10, and a printed circuit board 30. The external power supply 20 is electrically connected to the input end of the power circuit 10. The output end of the power circuit 10 is electrically connected to the load 200 through the printed circuit board 30. The power circuit 10 is used to convert the electrical energy output by the external power supply 20 and supply the converted electrical energy to the load 200.

[0032] If the external power supply 20 provides alternating current electrical energy, the power circuit 10 converts the alternating current electrical energy into direct current electrical energy and boosts or reduces the direct current electrical energy. The boosted or reduced direct current electrical energy is used to supply power to the load 200. If the external power supply 20 provides direct current electrical energy, the power circuit 10 boosts or reduces the direct current electrical energy. The boosted or reduced direct current electrical energy is used to supply power to the load 200.

[0033] In some embodiments, the power supply device 100 further includes a control circuit 40. The control circuit 40 is electrically connected to the power circuit 10. The control circuit 40 controls the working state of the power circuit 10 to realize the corresponding conversion function. For example, the power circuit 10 includes a plurality of MOS tubes and diodes. The control circuit 40 controls the working state of the power circuit 10 by controlling the conduction and cutoff of the MOS tubes to realize rectification, boosting, or reduction.

[0034] The power circuit 10 and the control circuit 40 are arranged on the printed circuit board 30. The input end and the output end are led out on the printed circuit board 30. The input end is electrically connected to the external power supply 20. The output end is electrically connected to the load 200. The input end includes two differential input ends. One is a positive input end connected to the positive pole of the external power supply 20. The other is a negative input end connected to the negative pole of the external power supply 20. The output end includes two differential output ends. One is a positive output end. The other is a negative output end. The positive output end and the negative output end are electrically connected to the two ends of the load 200.

[0035] The MOS tubes and diodes in the power circuit 10 may cause electromagnetic interference (EMI) during operation. In order to reduce EMI, an EMC filter circuit can be used to eliminate the interference signals input on the signal line and various disturbances induced. On the one hand, the EMC filter circuit filters the common-mode electromagnetic interference on the signal line. On the other hand, the EMC filter circuit suppresses the electromagnetic interference emitted by itself to avoid affecting the normal operation of other electronic devices in the same electromagnetic environment.

[0036] The main component of an EMC filter circuit is a common-mode inductor, which consists of two common-mode inductor coils wound on the same iron core with the same number of turns and phase. Therefore, when the normal current in the circuit flows through the common-mode inductor, the normal current generates opposite magnetic fields in the inductor coils wound in the same phase, which cancel each other out. At this time, the normal current is mainly affected by the resistance of the inductor coil (with a small amount of damping caused by leakage inductance). When common-mode current flows through the inductor coil, due to the isotropic nature of the common-mode current, it generates isotropic magnetic fields within the inductor coil, increasing the inductive reactance of the inductor coil, making the inductor coil appear high impedance and producing a strong damping effect, thereby attenuating the common-mode current and achieving the purpose of filtering. When differential-mode current flows through the inductor coil, due to the isotropic nature of the differential-mode current, it generates opposite magnetic fields within the inductor coil, which cancel each other out.

[0037] However, if an EMC filter circuit is provided on the printed circuit board 30 , the layout of the printed circuit board 30 will be tight, the production process will be complicated, and the circuit cost will be high. In addition, the EMC filter circuit itself will also have filtering errors and losses.

[0038] Based on the above reasons, the embodiment of the present invention provides a printed circuit board, specifically, as Figure 2 As shown, the printed circuit board 30 includes a circuit board body 301 and a first overcurrent conductor 302 and a second overcurrent conductor 303 disposed on the circuit board body 301 , wherein the power circuit 10 and the control circuit 40 are both disposed on the circuit board body 301 .

[0039] Furthermore, a first end of the first overcurrent conductor 302 is electrically connected to the first output terminal of the power circuit 10 in the power supply device 100, and a second end of the first overcurrent conductor 302 serves as a first differential output terminal of the printed circuit board 30. A first end of the second overcurrent conductor 303 is electrically connected to the second output terminal of the power circuit 10, and a second end of the second overcurrent conductor 303 serves as a second differential output terminal of the printed circuit board 30. The first differential output terminal and the second differential output terminal are electrically connected to two ends of the load 200, respectively, and serve as current output terminals OUT.

[0040] The first overcurrent conductor 302 is provided with a plurality of first separators, each of which is as long as the width of the first overcurrent conductor 302 . The second overcurrent conductor 303 is provided with a plurality of second separators, each of which is less long than the width of the second overcurrent conductor 303 .

[0041] The current provided by the external power supply 20 flows into the current input terminal IN and is converted into output current through the action of the power circuit 10. The positive current in the output current is output from the first output terminal of the power circuit 10 through the first overcurrent conductor 302 to the first differential output terminal, and the negative current in the output current is output from the second output terminal of the power circuit 10 through the second overcurrent conductor 303 to the second differential output terminal. The current direction is shown by the arrow in the figure.

[0042] If there are no first separator strips and second separator strips, the positive current flows directly to the first differential output terminal, and the negative current flows directly to the second differential output terminal. The first separator strips and the second separator strips cause the current direction to change multiple times, increasing the inductance of the circuit. The increased inductance is equivalent to the common-mode inductance, that is, the first separator strip causes the first overcurrent conductor 302 to form an inductor, and the second separator strip causes the second overcurrent conductor 303 to form another inductor. The first overcurrent conductor 302 and the second overcurrent conductor 303 are used as inductors in the EMC filter circuit to eliminate high-frequency noise. The filtering effect can be achieved without setting up an additional EMC filter circuit, and the cost is lower, the PCB layout is simpler, and the EMC performance is improved on the basis of reducing the product size.

[0043] In some embodiments, the first overcurrent conductor 302 and the second overcurrent conductor 303 are both copper foil on the circuit board body 301. Copper foil is a cathodic electrolytic material, forming a thin, continuous layer of metal foil deposited on the circuit board body 301. As the conductor of the printed circuit board 30, it easily adheres to the insulating layer, accepts the printed protective layer, and forms a circuit pattern after corrosion. In this embodiment, the first overcurrent conductor 302 and the second overcurrent conductor 303 are copper foil forming the circuits on the circuit board body 301. The copper foil forming the circuits is generally copper foil that has been plated with copper to increase the thickness of the base copper.

[0044] In some embodiments, as Figure 3 As shown, multiple first separators are spaced apart, and / or multiple second separators are spaced apart. Specifically, multiple first separators are spaced apart along the length of the first overcurrent conductor 302, and / or multiple second separators are spaced apart along the length of the second overcurrent conductor 303. The length direction A1 of the first overcurrent conductor 302 refers to the direction from the first output terminal of the power circuit 10 to the first differential output terminal. If there are no first separators, it also refers to the overflow direction or current direction of the positive current from the first output terminal of the power circuit 10 to the first differential output terminal. Similarly, the length direction A2 of the second overcurrent conductor 303 refers to the direction from the second output terminal of the power circuit 10 to the second differential output terminal. If there are no second separators, it also refers to the overflow direction or current direction of the negative current from the second output terminal of the power circuit 10 to the second differential output terminal.

[0045] In some embodiments, if the direction from the first end of the first overcurrent conductor 302 to the second end of the first overcurrent conductor 302 is a first direction, the first separator is perpendicular to the first direction, and if the direction from the first end of the second overcurrent conductor 303 to the second end of the second overcurrent conductor 303 is a second direction, the second separator is perpendicular to the second direction. The first direction is the flow direction of positive current, or the length direction of the first overcurrent conductor 302, and the second direction is the flow direction of negative current, or the length direction of the second overcurrent conductor 303.

[0046] In some embodiments, the openings of adjacent first dividing strips are oriented in opposite directions, and the openings of adjacent second dividing strips are oriented in opposite directions. This prevents current from flowing through the openings. Since adjacent dividing strips have opposite openings, the direction of the current changes with each passing separation strip, resulting in a serpentine current flow and increasing inductive reactance.

[0047] In some embodiments, the number of dividers can be as large as possible to allow for multiple changes in current direction, increase inductive reactance, and enhance the overcurrent conductor's effectiveness as an inductor for filtering high-frequency noise. However, the number of dividers cannot be increased indefinitely, as consideration must be given to current sharing and temperature rise in the power circuit. Therefore, the number of dividers can be limited by the width of the overcurrent conductor and the vertical distance between adjacent dividers.

[0048] Specifically, if Figure 4 As shown, if the width of the first overcurrent conductor 302 is b1 and the vertical distance between adjacent first separators is a1, then the ratio of b1 to a1 is greater than the first preset threshold. If the width of the second overcurrent conductor 303 is b2 and the vertical distance between adjacent second separators is a2, then the ratio of b2 to a2 is greater than the first preset threshold.

[0049] The first preset threshold can be set as needed. In this embodiment, the first preset threshold is 3, that is, (b1 / a1)>3, and (b2 / a2)>3.

[0050] In some embodiments, the provision of the separator reduces the area where current flows, affecting the current carrying capacity of the current carrying area. Therefore, the length of the separator needs to meet the current carrying capacity requirements. Figure 4 , if the width of the first separator is c1, and the minimum current conductor width that meets the current carrying requirement is n, then the difference between b1 and c1 is less than n. Similarly, if the width of the second separator is c2, then the difference between b2 and c2 is less than n. That is, (b1-c1) <n,且(b2-c2)<n。

[0051] It should be noted that the widths of the first dividing strips may be the same or different, and the widths of the second dividing strips may be the same or different, and the widths of the first dividing strips and the second dividing strips only need to meet the above conditions.

[0052] In some embodiments, the printed circuit board 30 may be a double-layer board or a multi-layer board, for example, a 2-layer board, a 4-layer board, a 6-layer board, or an 8-layer board, etc. The first overcurrent conductor 302 and the second overcurrent conductor 303 are disposed on the same layer or different layers of the printed circuit board 30 .

[0053] The EMC test was used to test the filtering effect of the embodiment of the utility model. Figure 5 This is a schematic diagram of the EMC test results without using an EMC filter circuit. Figure 6 Schematic diagram of EMC test results of an embodiment of the present utility model. Figure 5 and Figure 6 The horizontal axis is frequency, and the vertical axis is noise signal amplitude. Curve L1 is the peak data curve of the EMC test value, curve L2 is the EMC first peak standard limit curve, and curve L3 is the EMC second peak standard limit curve. The first peak limit minus 6 is the second peak limit. If the peak data exceeds curve L2, it indicates that the EMC exceeds the standard. If the peak data is lower than curve L2 but higher than curve L3, it indicates that the EMC test is qualified but the data is too high. If the peak data is lower than curve L3, it indicates that the EMC filtering effect is good.

[0054] Figure 5 This indicates that the EMC test does not exceed the standard, and the overall test data is below the EMC limit. However, the noise signal amplitude is high, and the noise signal amplitude corresponding to many frequency points exceeds curve L2. Figure 6 The overall EMC test data decreased, and the noise signal amplitudes corresponding to most frequency points did not exceed the curve L3, indicating that the embodiment of the present invention achieved a good EMC filtering effect.

[0055] To summarize, the printed circuit board changes the direction of the current multiple times through the first and second separators, thereby increasing the inductive reactance of the circuit. The increased inductive reactance is equivalent to the common-mode inductance. The first separator forms an inductor with the first overcurrent conductor, and the second separator forms another inductor with the second overcurrent conductor. The first overcurrent conductor and the second overcurrent conductor are used as inductors in an EMC filter circuit for eliminating high-frequency noise. The filtering effect can be achieved without setting up an additional EMC filter circuit, and the cost is lower, the PCB layout is simpler, and the EMC performance is improved while reducing the product size.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of ​​the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of this application.

Claims

1. A printed circuit board, characterized in that: include: A circuit board body and a first overcurrent conductor and a second overcurrent conductor provided on the circuit board body; The first end of the first overcurrent conductor is electrically connected to the first output end of the power circuit in the power supply device, and the second end of the first overcurrent conductor is the first differential output end of the printed circuit board; The first end of the second overcurrent conductor is electrically connected to the second output end of the power circuit, and the second end of the second overcurrent conductor is the second differential output end of the printed circuit board; Among them, a plurality of first separators are provided on the first overcurrent conductor, and the length of each of the first separators is smaller than the width of the first overcurrent conductor; a plurality of second separators are provided on the second overcurrent conductor, and the length of each of the second separators is smaller than the width of the second overcurrent conductor.

2. The printed circuit board according to claim 1, wherein: The first overcurrent conductor and the second overcurrent conductor are both copper foils on the circuit board body.

3. The printed circuit board according to claim 1, wherein: A plurality of the first dividing strips are arranged at intervals; and / or a plurality of the second dividing strips are arranged at intervals.

4. The printed circuit board according to claim 3, wherein: A plurality of the first separation strips are arranged at intervals along the length direction of the first overcurrent conductor; and / or a plurality of the second separation strips are arranged at intervals along the length direction of the second overcurrent conductor.

5. The printed circuit board according to claim 3, wherein: If the width of the first overcurrent conductor is b1 and the vertical distance between adjacent first separation strips is a1, then the ratio of b1 to a1 is greater than a first preset threshold; and, If the width of the second overcurrent conductor is b2 and the vertical distance between adjacent second separation strips is a2, then the ratio of b2 to a2 is greater than a first preset threshold.

6. The printed circuit board according to claim 3, wherein: If the width of the first separator is c1, and the minimum width of the current-carrying conductor that meets the current-carrying requirement is n, then the difference between b1 and c1 is less than n; and, If the width of the second dividing strip is c2, the difference between b2 and c2 is less than n.

7. The printed circuit board according to claim 1, wherein: The first overcurrent conductor and the second overcurrent conductor are symmetrically arranged.

8. The printed circuit board according to claim 1, wherein: The opening directions of adjacent first dividing strips are opposite to each other, and the opening directions of adjacent second dividing strips are opposite to each other.

9. The printed circuit board according to claim 1, wherein: If the direction in which the first end of the first overcurrent conductor points to the second end of the first overcurrent conductor is a first direction, the first dividing strip is perpendicular to the first direction; and If the direction from the first end of the second overcurrent conductor to the second end of the second overcurrent conductor is the second direction, the second dividing strip is perpendicular to the second direction.

10. A power supply device, characterized in that: The device comprises an external power supply, a power circuit, and a printed circuit board according to any one of claims 1 to 9, wherein the external power supply is electrically connected to an input end of the power circuit, and an output end of the power circuit is electrically connected to the first overcurrent conductor and the second overcurrent conductor in the printed circuit board.

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