Circuit board, display screen and vehicle-mounted equipment

Abstract

The invention provides a circuit board, a display screen and vehicle-mounted equipment. The circuit board comprises a power supply chip and a filter device, the filter device comprises a first inductor, a first capacitor and a second capacitor; wherein the first inductor, the first capacitor and the second capacitor form a first filtering loop, and the first inductor and the second capacitor form a second filtering loop. The relative positions of the first inductor, the first capacitor, the second capacitor and the power supply chip are configured to enable the current flow direction of the first filtering loop to be the same as the current flow direction of the second filtering loop. The direction of the magnetic field generated by the first filtering loop is the same as that of the magnetic field generated by the second filtering loop, so that the amplitude of the variable magnetic field is reduced, and the anti-interference capability of the vehicle-mounted display screen is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a circuit board, a display screen and a vehicle-mounted device. Background Art

[0002] Electromagnetic compatibility (EMC) refers to the ability of a device or system to operate in accordance with requirements in its electromagnetic environment and not to cause intolerable electromagnetic interference to any device in its environment. Therefore, EMC includes two requirements: on the one hand, it requires that the electromagnetic interference generated by the device to the environment during normal operation should not exceed a certain limit, namely, electromagnetic interference (EMI); on the other hand, it requires that the device has a certain degree of immunity to electromagnetic interference in the environment, namely, electromagnetic sensitivity (EMS).

[0003] In the EMC test of the whole vehicle, most EMC problems are caused by the vehicle display screen, and the wiring layout of the circuit board is an important factor affecting EMC. Therefore, how to reasonably design the wiring layout of the circuit board, effectively improve the EMC problem of the vehicle display screen, and improve the anti-interference ability of the vehicle display screen is a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0004] In order to solve the above problems, the inventors found the causes of the problems through research and development and formed solutions.

[0005] In a first aspect, the present invention provides a circuit board, which includes a power chip and a filter device;

[0006] The filter device comprises a first inductor, a first capacitor and a second capacitor;

[0007] The first inductor, the first capacitor and the second capacitor form a first filter circuit, the first inductor and the second capacitor form a second filter circuit, and the relative positions of the first inductor, the first capacitor, the second capacitor and the power chip are configured so that the current flow direction of the first filter circuit is the same as the current flow direction of the second filter circuit.

[0008] Furthermore, in the above-mentioned circuit board, the first inductor is located in the area where the power chip outputs the gate voltage signal;

[0009] The first capacitor and the second capacitor are both located on a side of the first inductor away from the power chip;

[0010] The first inductor, the first capacitor and the second capacitor are all arranged along the length direction of the circuit board, and the first capacitor and the second capacitor are arranged in sequence along the length direction of the circuit board;

[0011] The first end of the first inductor is connected to the first end of the second capacitor and the first interface of the power chip, and the second end of the first inductor is connected to the second interface of the power chip;

[0012] The first end of the first capacitor is connected to the third interface of the power chip, and the second end of the first capacitor is connected to the second end of the second capacitor;

[0013] Wherein, the third interface, the second interface, and the first interface are arranged in sequence along the length direction of the circuit board.

[0014] Furthermore, in the above-mentioned circuit board,

[0015] The second end of the first capacitor is connected to the second end of the second capacitor through a ground via.

[0016] Furthermore, the circuit board described above further includes a third capacitor and a fourth capacitor located on the same side of the first end of the first inductor, wherein the third capacitor is located between the first inductor and the fourth capacitor;

[0017] At least the fourth capacitor, the first capacitor, and the second capacitor are connected to a common ground.

[0018] Furthermore, the circuit board described above further includes a second inductor, a fifth capacitor and a sixth capacitor located on the same side as the second end of the first inductor;

[0019] The second inductor is located at a side of the first inductor away from the third capacitor;

[0020] The fifth capacitor is located at a side of the second inductor away from the first inductor;

[0021] The sixth capacitor is located on a side of the second inductor and the fifth capacitor away from the power chip.

[0022] Furthermore, in the above-mentioned circuit board, the first inductor is located in the area where the power chip outputs the liquid crystal driving voltage signal, and the power chip and the first inductor are arranged in sequence along the length direction of the circuit board;

[0023] Wherein, the first inductor is arranged along the width direction of the circuit board;

[0024] The first capacitor and the second capacitor are located on the same side of the first inductor and are arranged in sequence along the width direction of the circuit board.

[0025] Furthermore, in the above-mentioned circuit board, the first capacitor is arranged along the length direction of the circuit board, and the second capacitor is arranged along the width direction of the circuit board.

[0026] Furthermore, the circuit board described above further includes a seventh capacitor and an eighth capacitor corresponding to the first capacitor, and a ninth capacitor, a tenth capacitor and an eleventh capacitor corresponding to the second capacitor;

[0027] Wherein, the seventh capacitor and the eighth capacitor are both located on a side of the first capacitor away from the second capacitor, and the seventh capacitor and the eighth capacitor are arranged in sequence along the width direction of the circuit board, or the seventh capacitor and the eighth capacitor are arranged in sequence along the length direction of the circuit board;

[0028] The ninth capacitor is located on a side of the second capacitor away from the first capacitor;

[0029] The tenth capacitor is located on a side of the second capacitor away from the power chip;

[0030] The eleventh capacitor is at least partially located on a side of the ninth capacitor away from the chip body;

[0031] The ninth capacitor, the eleventh capacitor, and the second capacitor are connected to a common ground, and the first inductor, the seventh capacitor, and the eighth capacitor are connected to a common ground.

[0032] In a second aspect, the present invention provides a display screen comprising any one of the circuit boards described above.

[0033] In a third aspect, the present invention provides a vehicle-mounted device, which includes the display screen described above.

[0034] The above one or more technical solutions of the present invention have at least one or more of the following beneficial effects:

[0035] When implementing the technical solution of the present invention, by adjusting the relative positions of the first inductor, the first capacitor, the second capacitor and the power chip, the current flow direction of the first filter circuit formed by the first inductor, the first capacitor and the power chip is the same as the current flow direction of the second filter circuit formed by the first inductor, the second capacitor and the power chip. In this way, the direction of the magnetic field generated by the first filter circuit can be the same as the direction of the magnetic field generated by the second filter circuit, thereby reducing the variable magnetic field amplitude and improving the anti-interference ability of the vehicle display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The disclosure of the present invention will become more easily understood with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In addition, similar numbers in the drawings are used to represent similar components, wherein:

[0037] Figure 1 It is a filter circuit diagram of VGH voltage;

[0038] Figure 2 It is a schematic diagram of the filter circuit of the VGH voltage in the circuit board;

[0039] Figure 3 It is a magnetic field diagram of the circulating circuit in the filter circuit of the VGH voltage;

[0040] Figure 4 is a schematic structural diagram of a circuit board according to an embodiment of the present invention;

[0041] Figure 5 yes Figure 4 A schematic diagram of the magnetic field of the circulating current circuit in the circuit board shown;

[0042] Figure 6 It is a schematic diagram of the filter circuit of the VSN voltage in the circuit board;

[0043] Figure 7 is a schematic structural diagram of another circuit board according to an embodiment of the present invention;

[0044] Figure 8 Is adopted Figure 2 and Figure 6 Schematic diagram of the results of EMC testing of a circuit board;

[0045] Fig. 9 It is a schematic diagram of the result of EMC testing using the circuit board of the present invention. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0047] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, in the present invention, unless otherwise clearly specified and defined, the terms "connected", "connected", and the like should be understood in a broad sense. For example, it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0048] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0049] In the EMC test of the whole vehicle, most EMC problems are caused by the vehicle display screen, and the wiring layout of the circuit board is an important factor affecting EMC. On this basis, a study on the wiring layout of the circuit board found that common EMC problems in the vehicle display screen are mostly related to incorrect filtering circuit processing.

[0050] Specifically, since each filter circuit can be regarded as a loop antenna, it will generate electromagnetic radiation, thus causing EMI problems and interfering with other circuits on the circuit board. The reason for the generation of electromagnetic radiation is that the current generates a magnetic field. The current is changing, so the magnetic field will also change. This can easily cause a large amplitude of the variable magnetic field, thus causing EMC problems.

[0051] Based on the above findings, a study on the circuit board found that in some power filter circuits in the circuit board, the variable magnetic field amplitude is large due to the placement of components. Specifically, Figure 1 It is a VGH voltage filter circuit diagram. Figure 2 This is a schematic diagram of the VGH voltage filter circuit in the circuit board. Figure 3 It is a schematic diagram of the magnetic field of the circulating circuit in the filter circuit of the VGH voltage.

[0052] like Figures 1 to 3As shown, the filter circuit of the VGH voltage usually includes a power chip U, a first inductor L1, a first capacitor C1 and a second capacitor C2. The filter circuit of the VGH voltage forms two filter loops in the circuit board, namely the first filter loop l1 (solid line in the figure) and the second filter loop l2 (dashed line in the figure). According to the mesh current method, the grid current method, etc., it can be known that the current of the first filter loop l1 flows to the second capacitor C2, the first inductor L1, and the first capacitor C1. The current of the second filter loop l2 flows to the second capacitor C2 and the first inductor L1. However, for Figure 2 In terms of the layout of the components, the current directions of the two current loops are as follows: Figure 2 As shown by the arrow in the middle, it can be seen that the current of the first filter loop l1 flows in the counterclockwise direction, and the current of the second filter loop l2 flows in the clockwise direction. The current directions of the two are opposite, so the magnetic fields generated by the two are also opposite, see Figure 3 In the example, the first magnetic field F1 corresponding to the first filter circuit l1 and the second magnetic field F2 corresponding to the second filter circuit l2, the variable magnetic field amplitude caused by the first magnetic field F1 and the second magnetic field F2 is relatively large. Figure 3 Medium variable magnetic field F3.

[0053] It should be noted that in the above embodiment, only the VGH voltage filter circuit causing a large variable magnetic field amplitude is used as an example for explanation. In practical applications, this phenomenon may also exist in some other voltage filter circuits, such as the VSN voltage filter circuit, which will not be explained one by one here.

[0054] Based on the above findings, the present invention arranges the wiring layout of the partial voltage filter circuit so that the magnetic fields generated by the two filter loops in the filter circuit have the same direction. In this way, the variable magnetic field amplitude caused by the two is greatly reduced, thereby effectively improving the EMC problem.

[0055] Specifically, based on Figures 1 to 3 It can be known that the filter circuit of a certain voltage usually includes a power chip U and a filter device. Among them, the filter device includes a first inductor L1, a first capacitor C1 and a second capacitor C2. The first inductor L1, the first capacitor C1 and the second capacitor C2 form a first filter loop l1, and the first inductor L1 and the second capacitor C2 form a second filter loop l2. When the above components are laid out in the PCB, the relative positions between the first inductor L1, the first capacitor C1, the second capacitor C2 and the power chip U can be adjusted so that the current flow direction of the first filter loop l1 is the same as the current flow direction of the second filter loop l2. In this way, the current directions generated by the two filter loops are the same, which can greatly reduce the variable magnetic field amplitude caused by the two, thereby effectively improving the EMC problem.

[0056] The structure of the circuit board is described below with a specific example:

[0057] Figure 4 is a schematic diagram of the structure of a circuit board according to an embodiment of the present invention. Figure 4 As shown, the circuit board Figure 2 The circuit board shown is adjusted based on the circuit board shown, that is, the wiring layout is carried out for the filter circuit of the VGH voltage.

[0058] like Figure 4 As shown, the first inductor L1 can be set in the area where the power chip U outputs the gate voltage signal, that is, the area where the pins related to the output VGH voltage signal are located. Figure 4 In the circuit board, the area can be the area below the power chip U. The first capacitor C1 and the second capacitor C2 are both arranged on the side of the first inductor L1 away from the chip body, that is, the first capacitor C1 and the second capacitor C2 are both located below the first inductor L1. In other words, in the width direction of the circuit board, the power chip U, the first inductor L1, the second capacitor C2 and the first capacitor C1 are arranged in sequence. The width direction of the circuit board can be Figure 4 The y-axis direction is used as the reference for the width of the circuit board in the subsequent descriptions.

[0059] In a specific implementation process, the first inductor L1, the first capacitor C1 and the second capacitor C2 are all arranged along the length direction of the circuit board, and the first capacitor C1 and the second capacitor C2 are arranged in sequence along the length direction of the circuit board. Figure 4 The x-axis direction is perpendicular to the width direction of the circuit board, and the subsequent descriptions regarding the length direction of the circuit board are based on this.

[0060] It should be noted that the arrangement along the length direction of the circuit board described in this embodiment refers to the relative position relationship of the pins of each component, such as the relative position between the first pin of the first inductor L1 and the second pin of the first inductor L1 is arranged along the length of the circuit board. The arrangement in sequence along the length direction of the circuit board described refers to the relative position relationship between different components, such as the first capacitor C1 and the second capacitor C2 are arranged along the first capacitor C1 and the second capacitor C2 respectively.

[0061] In a specific implementation process, in order to make the current flow direction of the first filter loop l1 and the current flow direction of the second filter loop l2 in the filter circuit the same, the power chip U, the first inductor L1, the second capacitor C2 and the first capacitor C1 satisfy the following connection relationship:

[0062] The first end of the first inductor L1 is connected to the first end of the second capacitor C2 and the first interface of the power chip U, and the second end of the first inductor L1 is connected to the second interface of the power chip U; the first end of the first capacitor C1 is connected to the third interface of the power chip U, and the second end of the first capacitor C1 is connected to the second end of the second capacitor C2; wherein the third interface, the second interface, and the first interface are arranged in sequence along the length direction of the circuit board. The second end of the first capacitor C1 is connected to the second end of the second capacitor C2 through a ground via.

[0063] It should be noted that, although the above description only describes the connection between the second end of the first capacitor C1 and the second end of the second capacitor C2 through a ground via, the connection between other interfaces, ports, etc. can also be selected according to actual needs to choose whether to connect through vias, or adopt other feasible connection methods, and this embodiment does not make specific restrictions.

[0064] Based on the above position and connection relationship, the current flow direction of the first filter loop l1 and the current flow direction of the second filter loop l2 can be obtained as follows: Figure 4 As shown by the arrows in the figure, the flow directions of both are clockwise. In this way, the directions of the magnetic fields generated by the two are also the same, and the variable magnetic field amplitude caused by the two magnetic fields will be significantly reduced. For details, see Figure 5 .

[0065] Figure 5 yes Figure 4 The magnetic field diagram of the circulating circuit in the circuit board shown is as follows: Figure 5 As shown, the first magnetic field F1 corresponding to the first filter circuit l1 and the second magnetic field F2 corresponding to the second filter circuit l2 have the same direction, and the variable magnetic field amplitude caused by the two is relative to Figure 3 The amplitude of the variable magnetic field is greatly reduced, such as Figure 5 Medium variable magnetic field F3.

[0066] It should be noted that after the above layout of the components, it has been measured that the area of ​​the two filter loops is relatively Figure 2 The area of ​​the two filter loops is significantly reduced, so the electromagnetic radiation is also reduced accordingly, further reducing the amplitude of the variable magnetic field caused between the two filter loops.

[0067] Continue to see Figure 4 The circuit board also includes a third capacitor C3 and a fourth capacitor C4 located on the same side as the first end of the first inductor L1, and a second inductor L2, a fifth capacitor C5 and a sixth capacitor C6 located on the same side as the second end of the first inductor L1.

[0068] The third capacitor C3 is located between the first inductor L1 and the fourth capacitor C4, and the second inductor L2 is located on the side of the first inductor L1 away from the third capacitor C3; the fifth capacitor C5 is located on the side of the second inductor L2 away from the first inductor L1; the sixth capacitor C6 is located on the side of the second inductor L2 and the fifth capacitor C5 away from the power chip U. Among them, at least the fourth capacitor C4, the first capacitor C1, and the second capacitor C2 are grounded (not shown in the figure). The second interface of the power chip U is also connected to the first pin of the fifth capacitor C5, and the second pin of the fifth capacitor C5 is connected to the first pin of the sixth capacitor C6, that is, the first inductor L1, the second capacitor C2, the fifth capacitor C5, and the sixth capacitor C6 can share a voltage signal line.

[0069] Based on the above settings, the filter circuit and other capacitors and inductors around it can be made denser, more components can share a common ground, and the common ground area and the connection of common voltage signals are increased. This can also improve the EMC problem of the PCB.

[0070] Figure 6 This is a schematic diagram of a filter circuit for the VSN voltage in a circuit board. The positions of the first inductor L1, the first capacitor C1, and the second capacitor C2 in the filter circuit are shown in FIG. Figure 6 Among them, since the output voltage signal is different, the corresponding filter connection method is also different, and the corresponding circuit schematic diagram is not shown here. Although the power chip U, the first capacitor C1, the second capacitor C2, and the first inductor L2 are also used later, they are different from Figure 4 The corresponding components in the filter circuit may not be the same. For the filter circuit, the corresponding first filter loop l1 is formed by the first inductor L1 and the first capacitor C1, and the second filter loop l2 is formed by the first inductor L1 and the second capacitor C2. The current directions of the two filter loops are as follows: Figure 6 As shown by the arrows in the figure, the current of the first filter loop l1 flows in a clockwise direction, and the current of the second filter loop l2 flows in a counterclockwise direction, and the directions of the two are opposite. Therefore, in order to avoid the two filter loops in the VSN voltage filter circuit from affecting the EMC of the circuit board, the present invention provides the following technical solutions:

[0071] Figure 7 is a schematic diagram of the structure of another circuit board according to an embodiment of the present invention. Figure 7 As shown,

[0072] The first inductor L1 is located in the area where the power chip U outputs the liquid crystal driving voltage signal, that is, the area where the pins related to the output VSN voltage signal are located. Figure 4 The middle is the area where the upper right corner of the power chip U is located.

[0073] Continue to see Figure 7 , the power chip U and the first inductor L1 are arranged in sequence along the length direction of the circuit board, and the first inductor L1 is arranged along the width direction of the circuit board, that is, the first pin of the first inductor L1 and the second pin of the first inductor L1 are arranged in the vertical direction. The first capacitor C1 and the second capacitor C2 are located on the same side of the first inductor L1 and are arranged in sequence along the width direction of the circuit board. The first capacitor C1 is arranged along the length direction of the circuit board, and the second capacitor C2 is arranged along the width direction of the circuit board.

[0074] In this way, Figure 6 On the basis of the first inductor L1, the first capacitor C1 and the second capacitor C2 are moved, and in the resulting layout structure, the current direction of the first filter loop L1 and the current direction of the second filter loop L2 in the VSN voltage filter circuit are as follows: Figure 7 As shown by the arrows in the figure, the two flows are in the same direction, and the magnetic fields generated are also the same, which reduces the variable magnetic field amplitude between the two magnetic fields. And according to actual measurements, the areas of the two filter loops are relatively small, which further reduces the electromagnetic radiation and further reduces the variable magnetic field amplitude.

[0075] Continue to see Figure 7 , the circuit board also includes a seventh capacitor C7 and an eighth capacitor C8 corresponding to the first capacitor C1, and a ninth capacitor C9, a tenth capacitor C10 and an eleventh capacitor C11 corresponding to the second capacitor C2;

[0076] Wherein, the seventh capacitor C7 and the eighth capacitor C8 are both located on a side of the first capacitor C1 away from the second capacitor C2, and the seventh capacitor C7 and the eighth capacitor C8 are arranged in sequence along the width direction of the circuit board, or the seventh capacitor C7 and the eighth capacitor C8 are arranged in sequence along the length direction of the circuit board;

[0077] The ninth capacitor C9 is located on a side of the second capacitor C2 away from the first capacitor C1;

[0078] The tenth capacitor C10 is located at a side of the second capacitor C2 away from the power chip U;

[0079] The eleventh capacitor C11 is at least partially located at a side of the ninth capacitor C9 away from the chip body;

[0080] The ninth capacitor C9, the eleventh capacitor C11, and the second capacitor C2 are connected to a common ground, and the first inductor L1, the seventh capacitor C7, and the eighth capacitor C8 are connected to a common ground.

[0081] Based on the above settings, the filter circuit and other capacitors around it can be made denser, more components can share the same ground, and the common ground area is increased. In this way, the EMC problem of the PCB can also be improved.

[0082] Figure 8 Is adopted Figure 2 and Figure 6 Schematic diagram of the results of EMC testing of a circuit board. Fig. 9 Schematic diagram of the result of EMC test using the circuit board of the present invention. Figure 8 and Fig. 9 As shown, Figure 8 The peak values ​​of the EMC test waveforms are mostly above the limit value of the quasi-peak detection QP and the limit value of the average detection AV, which has a great impact on the EMC test. Fig. 9 In the figure, the waveform peaks of the EMC test are less likely to be above the limit value of the quasi-peak detection QP and the limit value of the average detection AV, indicating that the circuit board of the present application effectively improves the EMC problem and enhances the anti-interference ability of the vehicle display.

[0083] Furthermore, the present invention also provides a display screen, which includes the circuit board of the above embodiment.

[0084] Furthermore, the present invention also provides a vehicle-mounted device, which includes the display screen of the above embodiment.

[0085] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A circuit board, characterized in that: Including power chips and filter components; The filter device comprises a first inductor, a first capacitor and a second capacitor; The first inductor, the first capacitor and the second capacitor form a first filter circuit, the first inductor and the second capacitor form a second filter circuit, and the relative positions of the first inductor, the first capacitor, the second capacitor and the power chip are configured so that the current flow direction of the first filter circuit is the same as the current flow direction of the second filter circuit.

2. The circuit board according to claim 1, characterized in that: The first inductor is located in the area where the power chip outputs a gate voltage signal; The first capacitor and the second capacitor are both located on a side of the first inductor away from the power chip; The first inductor, the first capacitor and the second capacitor are all arranged along the length direction of the circuit board, and the first capacitor and the second capacitor are arranged in sequence along the length direction of the circuit board; The first end of the first inductor is connected to the first end of the second capacitor and the first interface of the power chip, and the second end of the first inductor is connected to the second interface of the power chip; The first end of the first capacitor is connected to the third interface of the power chip, and the second end of the first capacitor is connected to the second end of the second capacitor; Wherein, the third interface, the second interface, and the first interface are arranged in sequence along the length direction of the circuit board.

3. The circuit board according to claim 2, characterized in that: The second end of the first capacitor is connected to the second end of the second capacitor through a ground via.

4. The circuit board according to claim 2, characterized in that: Also comprising a third capacitor and a fourth capacitor located on the same side of the first end of the first inductor, wherein the third capacitor is located between the first inductor and the fourth capacitor; At least the fourth capacitor, the first capacitor, and the second capacitor are connected to a common ground.

5. The circuit board according to claim 2, characterized in that: Also included are a second inductor, a fifth capacitor and a sixth capacitor located on the same side as the second end of the first inductor; The second inductor is located at a side of the first inductor away from the third capacitor; The fifth capacitor is located at a side of the second inductor away from the first inductor; The sixth capacitor is located on a side of the second inductor and the fifth capacitor away from the power chip.

6. The circuit board according to claim 1, characterized in that: The first inductor is located in the area where the power chip outputs the liquid crystal driving voltage signal, and the power chip and the first inductor are arranged in sequence along the length direction of the circuit board; Wherein, the first inductor is arranged along the width direction of the circuit board; The first capacitor and the second capacitor are located on the same side of the first inductor and are arranged in sequence along the width direction of the circuit board.

7. The circuit board according to claim 6, characterized in that: The first capacitor is arranged along the length direction of the circuit board, and the second capacitor is arranged along the width direction of the circuit board.

8. The circuit board according to claim 7, characterized in that: Also includes a seventh capacitor and an eighth capacitor corresponding to the first capacitor, and a ninth capacitor, a tenth capacitor and an eleventh capacitor corresponding to the second capacitor; Wherein, the seventh capacitor and the eighth capacitor are both located on a side of the first capacitor away from the second capacitor, and the seventh capacitor and the eighth capacitor are arranged in sequence along the width direction of the circuit board, or the seventh capacitor and the eighth capacitor are arranged in sequence along the length direction of the circuit board; The ninth capacitor is located on a side of the second capacitor away from the first capacitor; The tenth capacitor is located on a side of the second capacitor away from the power chip; The eleventh capacitor is at least partially located on a side of the ninth capacitor away from the chip body; The ninth capacitor, the eleventh capacitor, and the second capacitor are connected to a common ground, and the first inductor, the seventh capacitor, and the eighth capacitor are connected to a common ground.

9. A display screen, characterized in that: A circuit board comprising the circuit board according to any one of claims 1 to 8.

10. A vehicle-mounted device, characterized in that: Includes the display screen as claimed in claim 9.

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