Printed circuit board, vehicle lamp control module and vehicle lamp system

Abstract

The utility model provides a printed circuit board, a vehicle lamp control module and a vehicle lamp system, and belongs to the technical field of vehicle lamp control. The printed circuit board comprises a top layer, a first ground plane, a first wiring layer, a second wiring layer, a second ground plane and a bottom layer. Wherein the first ground plane is arranged between the top layer and the first wiring layer, the second ground plane is arranged between the bottom layer and the second wiring layer, and the first wiring layer is arranged on the side, opposite to the bottom layer, of the second wiring layer; a power line is arranged on the first wiring layer, and a signal line is arranged on the second wiring layer; the first ground plane and the second ground plane are grounded, the first ground plane is used for isolating interference of the top layer on the first wiring layer, and the second ground plane is used for isolating interference of the bottom layer on the second wiring layer. The electromagnetic compatibility of the vehicle lamp control module can be improved, and then the performance stability of the vehicle lamp system is improved.

Description

Technical Field

[0001] This application relates to the technical field of vehicle lamp control. Specifically, it relates to a printed circuit board, a vehicle lamp control module, and a vehicle lamp system. Background Technique

[0002] During the driving process of a vehicle, vehicle lamps not only have the function of illumination but also have the functions of signal interaction and signal indication. Vehicle lamps play a crucial role in the safe driving of vehicles. The printed circuit board (PCB board for short) of the vehicle lamp control module can connect the various electronic components in the vehicle lamp system through the printed circuits on the PCB board, and perform signal transmission and circuit conduction. The PCB board of the vehicle lamp control module, as a key electronic connection device in the vehicle lamp system, the layout design quality of the PCB board will seriously affect the stability and service life of the vehicle lamp. Among them, the layout of the various electronic components on the PCB board of the vehicle lamp control module, the selection of the levels of the various electronic components, the relative positions of the various levels, and the segmentation and distribution positions of the ground plane will all have a great impact on the wiring of the PCB board, signal quality, processing of the interface circuit, and electromagnetic compatibility, and thus directly affect the electromagnetic compatibility of the vehicle lamp system. Therefore, there is an urgent need for a standard layout design of the PCB board of the vehicle lamp control module to improve the electromagnetic compatibility of the vehicle lamp system.

[0003] In the related art, the PCB board of the vehicle lamp control module mainly consists of four levels, namely: the top layer, the bottom layer, a ground plane, and a wiring layer. Among them, power lines and signal lines are both deployed on the top layer and the bottom layer, the power lines and signal lines are both deployed on the wiring layer, the ground plane is deployed between the top layer and the wiring layer, and the wiring layer is deployed between the bottom layer and the ground plane.

[0004] However, when designing the PCB board of the vehicle lamp control module based on the related art, there are problems such as mutual interference between various signals in the vehicle lamp system and easy failure of electromagnetic compatibility. Summary of the Invention

[0005] The purpose of this application is to provide a printed circuit board, a vehicle lamp control module, and a vehicle lamp system, which can achieve the effect of improving the electromagnetic compatibility of the vehicle lamp control module and further improving the performance stability of the vehicle lamp system.

[0006] The embodiments of this application are implemented as follows:

[0007] In the first aspect of the embodiments of this application, a printed circuit board applied to a vehicle lamp control module is provided. The printed circuit board includes: a top layer, a first ground plane, a first wiring layer, a second wiring layer, a second ground plane, and a bottom layer;

[0008] The first ground plane is disposed between the top layer and the first wiring layer, the second ground plane is disposed between the bottom layer and the second wiring layer, and the first wiring layer is disposed on the side of the second wiring layer facing away from the bottom layer;

[0009] Power lines are disposed on the first wiring layer, and signal lines are disposed on the second wiring layer;

[0010] Both the first ground plane and the second ground plane are grounded. The first ground plane is used to isolate the interference of the top layer to the first wiring layer, and the second ground plane is used to isolate the interference of the bottom layer to the second wiring layer.

[0011] As a possible implementation manner, the above printed circuit board further includes: a plurality of electronic components;

[0012] Each electronic component is disposed on the top layer.

[0013] As a possible implementation manner, the plurality of electronic components include: a freewheeling diode, a driving chip, and an inductor;

[0014] The inductor is disposed in the first area of the top layer, the freewheeling diode is disposed in the second area of the top layer, the driving chip is disposed in the third area of the top layer, and the second area is located between the first area and the third area.

[0015] As a possible implementation manner, power lines and signal lines are disposed on the top layer.

[0016] As a possible implementation manner, power lines and signal lines are disposed on the bottom layer.

[0017] As a possible implementation manner, the above printed circuit board further includes: a plurality of through-holes of the first type;

[0018] Each through-hole of the first type respectively connects the top layer and the bottom layer.

[0019] As a possible implementation manner, the above printed circuit board further includes: at least one through-hole of the second type;

[0020] Each through-hole of the second type respectively connects the first wiring layer, the second wiring layer, and the second ground plane.

[0021] As a possible implementation manner, the above printed circuit board further includes: at least one through-hole of the third type;

[0022] Each through-hole of the third type respectively connects the top layer, the first ground plane, the first wiring layer, and the second wiring layer.

[0023] In the second aspect of the embodiments of the present application, a headlight control module is provided. The headlight control module includes the printed circuit board described in the first aspect above.

[0024] In the third aspect of the embodiments of the present application, a vehicle lamp system is provided, and the vehicle lamp system includes the vehicle lamp control module described in the second aspect above.

[0025] The beneficial effects of the embodiments of the present application include:

[0026] A printed circuit board applied to a vehicle lamp control module provided by the embodiments of the present application is composed of six layers, namely a top layer, a first ground plane, a first wiring layer, a second wiring layer, a second ground plane, and a bottom layer. The first ground plane is disposed between the top layer and the first wiring layer, and the second ground plane is disposed between the bottom layer and the second wiring layer. Both the first ground plane and the second ground plane are used to connect the grounding ports of external devices. The first ground plane and the second ground plane form a large ground plane loop in the printed circuit board, which can effectively absorb clutter signals, thereby reducing electromagnetic radiation. Only power lines are disposed on the first wiring layer, and only signal lines are disposed on the second wiring layer. The layered arrangement of power lines and signal lines can effectively reduce the electromagnetic interference of power lines on signal lines and the crosstalk between signal lines. In addition, the electronic components of the printed circuit board are evenly disposed above the top layer, which can effectively reduce the via impedance of signal transmission between electronic components and reduce the loop area of current. In this way, the electromagnetic compatibility of the vehicle lamp control module can be improved, and further the performance stability of the vehicle lamp system can be improved. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a schematic structural diagram of an existing printed circuit board applied to a vehicle lamp control module;

[0029] Figure 2 It is a schematic structural diagram of a printed circuit board applied to a vehicle lamp control module provided by the embodiments of the present application;

[0030] Figure 3 It is a schematic structural diagram of the wiring layer of an existing printed circuit board;

[0031] Figure 4 It is a schematic structural diagram of the first wiring layer of a printed circuit board provided by the embodiments of the present application;

[0032] Figure 5 It is a schematic structural diagram of the second wiring layer of a printed circuit board provided by the embodiments of the present application;

[0033] Figure 6 It is a schematic diagram of the distribution of electronic components on the top layer of an existing printed circuit board;

[0034] Figure 7 It is a schematic diagram of the distribution of electronic components on the bottom layer of an existing printed circuit board;

[0035] Figure 8 It is a schematic diagram of the distribution of electronic components of a printed circuit board provided by an embodiment of the present application;

[0036] Figure 9 It is a schematic diagram of the structure of a vehicle lamp control module provided by an embodiment of the present application;

[0037] Figure 10 It is a schematic diagram of the structure of a vehicle lamp system provided by an embodiment of the present application.

[0038] Reference numerals in the drawings: 10: Printed circuit board; 101: Top layer; 1011: First area; 011: Inductor; 1012: Second area; 012: Freewheeling diode; 1013: Third area; 013: Driver chip; 102: First ground plane; 103: First wiring layer; 104: Second wiring layer; 105: Second ground plane; 106: Bottom layer; 107: First type of via hole; 108: Second type of via hole; 109: Third type of via hole; 20: Vehicle lamp control module; 30: Vehicle lamp system. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0041] It should be noted that: Similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0042] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0043] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0044] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0045] Currently, the printed circuit board used in the headlight control module consists of four layers: a top layer, a ground plane, a wiring layer, and a bottom layer. Among them, the ground plane is disposed between the top layer and the wiring layer. Power lines and signal lines are respectively disposed on the top layer and the bottom layer, and power lines and signal lines are also disposed on the wiring layer. The wiring layer is disposed between the ground plane and the bottom layer. However, this solution has the problem that the clutter signals of the printed circuit board cannot be perfectly shielded, and the distance between the signal lines and the power lines is too close, resulting in crosstalk between high and low level signals and large and small current signals, which causes the electromagnetic compatibility test of the headlight control module to fail.

[0046] To this end, the embodiment of the present application provides a printed circuit board applied to a headlight control module, and the printed circuit board is composed of six layers: a top layer, a first ground plane, a first wiring layer, a second wiring layer, a second ground plane, and a bottom layer. Among them, the first ground plane is arranged between the top layer and the first wiring layer, the second ground plane is arranged between the second wiring layer and the bottom layer, and the newly added second ground plane can further absorb the clutter signal in the headlight control module, and the first wiring layer is arranged on the side of the second wiring layer facing away from the bottom layer. Specifically, the lower surface of the first wiring layer can be bonded to the upper surface of the second wiring layer. The first wiring layer is only arranged with power lines, and the second wiring layer is only arranged with signal lines, which can effectively reduce the crosstalk between high and low levels and large and small signals. In addition, the electronic components of the printed circuit board are all arranged on the top layer, which can effectively reduce the perforation impedance of signal transmission between electronic components and reduce the loop area of ​​current. In this way, the electromagnetic compatibility of the headlight control module can be improved, thereby improving the performance stability of the headlight system.

[0047] The printed circuit board applied to the vehicle light control module, the vehicle light control module and the vehicle light system provided in the embodiments of the present application are explained in detail below in conjunction with the accompanying drawings.

[0048] It is worth noting that the printed circuit board (PCB) will be referred to as the PCB board hereinafter, and this application will not go into details.

[0049] Figure 1 is a schematic diagram of the structure of a printed circuit board used in an existing vehicle light control module, see Figure 1 The printed circuit board used in the existing headlight control module is composed of four layers, namely, the top layer L1, the ground plane L2, the wiring layer L3 and the bottom layer L4. Among them, except for the ground plane L2, wiring is carried out on the top layer L1, the wiring layer L3 and the bottom layer L4. The top layer L1 and the bottom layer L4 are provided with power lines and signal lines. The wiring layer L3 is provided with both power lines and signal lines. The ground layer L2 is used as the reference plane of the PCB board and is connected to the ground terminal of the device. The clutter signal of the PCB board cannot be completely absorbed by the ground layer L2 alone.

[0050] Optionally, the power lines and signal lines are distributed on the same wiring layer. It is inevitable that the power lines and signal lines are staggered. Multiple electronic components are arranged on the PCB board. The staggered distribution of the power lines and signal lines will cut off the key routing between some electronic components, so that the signal transmission of each electronic component needs to be routed through perforations, thereby reducing the real-time and stability of the signal transmission and increasing the loop impedance of the signal transmission.

[0051] As can be seen from the data in Table 1 and Table 2 below, a ground plane L2 cannot completely absorb the clutter signals of the PCB board, and the impact on the electromagnetic compatibility of the products applied to the PCB board caused by evenly distributing the power line and the signal line on a single wiring layer. Among them, Table 1 is the parameter information table of the PCB board applied in the existing headlight control module. According to Table 1, the specific stack structure of the PCB board currently applied in the headlight control module can be understood, and the production parameter information of each layer can be determined; Table 2 is the summary table of the electromagnetic compatibility test failure results of the existing headlight control module. According to Table 2, the impact of signal interference on the electromagnetic compatibility test of the products applying the existing PCB board can be understood.

[0052] Table 1 Parameter Information Table of the PCB Board Applied in the Existing Headlight Control Module

[0053] Layer Material Thickness (mm) Character White Ink 0.01 Solder Mask Matt Black Ink 0.01 Electroplated Copper Foil Cu 0.018 L1 Cu 0.018 PP 0.199 L2 Cu 0.035 Core 1.03 L3 Cu 0.035 PP 0.195 L4 Cu 0.018 Electroplated Copper Foil Cu 0.018 Solder Mask Matt Black Ink 0.01 Character White Ink 0.01

[0054] Table 2 Summary Table of the Electromagnetic Compatibility Test Failure Results of the Existing Headlight Control Module

[0055]

[0056]

[0057] Specifically, referring to Table 3, the specific meanings of the above-mentioned Mode 1, Mode 2, Mode 3, Mode 4, Mode 5, Mode 6, and Mode 7 can be determined. The specific meanings of each mode are as follows:

[0058] Table 3 Summary Table of the Operating Modes of the Existing Headlight Control Module

[0059]

[0060] It should be noted that the Electro-Static Discharge (ESD) experiment.

[0061] Figure 2 is a schematic structural diagram of a printed circuit board applied to a headlight control module provided by the present application. Refer to Figure 2 , the printed circuit board 10 applied to the headlight control module provided by the embodiment of the present application is composed of a top layer 101, a first ground plane 102, a first wiring layer 103, a second wiring layer 104, a second ground plane 105, and a bottom layer 106. Among them, the first ground plane 102 and the second ground plane 105 serve as reference planes. Both the first ground plane 102 and the second ground plane 105 are connected to the grounding end of the external device. The first ground plane 102 and the second ground plane 105 form a huge conductive area, which can effectively shield the circuit signals in the PCB board 10 to reduce the electromagnetic radiation in the PCB board 10 and improve the anti-interference ability of the circuits in the PCB board.

[0062] It should be noted that Figure 2 In the figure, the top layer 101 is represented by the symbol L1, the first ground plane 102 is represented by the symbol L2, the first wiring layer 103 is represented by the symbol L3, the second wiring layer 104 is represented by the symbol L4, the second ground plane 105 is represented by the symbol L5, and the bottom layer 106 is represented by the symbol L6. Among them, L1, L2, L3, L4, L5, and L6 have no special meaning and are only used to distinguish the respective layers of the PCB board 10 provided in the embodiments of the present application.

[0063] Optionally, the upper surface of the top layer 101 of the PCB board 10 is the front side of the entire PCB board 10, the lower surface of the bottom layer 106 of the PCB board 10 is the reverse side or the back side of the entire PCB board 10. There are wirings on the top layer 101, the first wiring layer 103, the second wiring layer 104, and the bottom layer 106 of the PCB board 10. Both the first ground plane 102 and the second ground plane 105 serve as the zero-voltage reference planes of the PCB board 10.

[0064] The first ground plane 102 is disposed between the top layer 101 and the first wiring layer 103, the second ground plane 105 is disposed between the bottom layer 106 and the second wiring layer 104, and the first wiring layer 103 is disposed on the side of the second wiring layer 104 facing away from the bottom layer 106.

[0065] Optionally, the order of the layers of the PCB board 10 from the front side to the back side is the top layer 101, the first ground plane 102, the first wiring layer 103, the second wiring layer 104, the second ground plane 105, and the bottom layer 106 in sequence. Among them, the upper surface of the top layer 101 is the front side of the PCB board 10. The lower surface of the top layer 101 and the upper surface of the first ground plane 102 are adhered together via a board material or an adhesive. The lower surface of the first ground plane 102 and the upper surface of the first wiring layer 103 are adhered together via a board material or an adhesive. The lower surface of the first wiring layer 103 and the upper surface of the second wiring layer 104 are adhered together via a board material or an adhesive. The lower surface of the second wiring layer 104 and the upper surface of the second ground plane 105 are adhered together via a board material or an adhesive. The lower surface of the second ground plane 105 and the upper surface of the bottom layer 106 are adhered together via a board material or an adhesive. The lower surface of the bottom layer 106 is the back side of the PCB board 10.

[0066] Optionally, the first ground plane 102 and the second ground plane 105 can provide a low-impedance path for the PCB board 10, can effectively reduce the impedance of the return paths of the power lines and signal lines in the PCB board 10, reduce the areas of the digital signal loops and circuit loops, can ensure that the current in the PCB board 10 quickly and effectively returns to the ground terminal, reduce the resistance, and improve the stability and noise tolerance of the PCB board 10.

[0067] Optionally, the first ground plane 102 and the second ground plane 105 can reduce the ground loop length of each electronic component in the PCB board 10, reduce the resistance and inductance of the ground loop, and thereby increase the operating frequency and speed of the circuit in the PCB board 10; the first ground plane 102 and the second ground plane 105 are disposed inside the PCB board 10, which can help dissipate the heat generated during the operation of the circuit in the PCB board 10, improve the thermal management ability of the PCB board 10, and ensure the stability and reliability of the operation of the circuit in the PCB board 10.

[0068] It should be noted that the bonding relationship between the layers of the PCB board 10 only indicates that two layers are bonded together in the physical structure, and it does not mean that the two bonded layers are electrically conductive to each other. The conduction relationship between the layers on the PCB board 10 is realized by vias.

[0069] Power lines are disposed on the first wiring layer 103, and signal lines are disposed on the second wiring layer 104.

[0070] Optionally, the first wiring layer 103 and the second wiring layer 104 separate the power lines and signal lines of the PCB board. Only power lines are disposed on the first wiring layer 103, that is, the traces of each electronic component on the PCB board 10 are disposed on the first wiring layer 103, and the first wiring layer 103 serves as the trace layer of the PCB board 10; only signal lines are disposed on the second wiring layer 104, and the second wiring layer 104 serves as the signal layer of the PCB board 10; the first wiring layer 103 and the second wiring layer 104 isolate the trace layer and the signal layer of the PCB board 10.

[0071] Optionally, by separately wiring the signal layer and the trace layer of the PCB board 10 on different levels, the interference of the power lines on the signal lines can be reduced, and thereby the stability and reliability of the signal transmission of the PCB board 10 can be improved; the signal lines are separately disposed on the second wiring layer 104, and the layout distance between the signal lines can be appropriately widened, thereby reducing the mutual interference between the signal lines, and the signal lines and the power lines are disposed on different levels, which can also reduce the electromagnetic coupling between the power lines and the signal lines.

[0072] Optionally, the first wiring layer 103 and the second wiring layer 104 separate the power lines and signal lines of the PCB board 10, which can further reduce the influence of the power lines on the signal lines when transmitting electrical signals, and can improve the noise immunity of the PCB board 10.

[0073] Optionally, the power lines are used to realize the electrical signal transmission between the electronic components on the PCB board 10, such as current signals; the signal lines are used to realize the analog signal transmission between the electronic components on the PCB board 10, such as control signals, etc., and the present application does not make specific limitations thereon.

[0074] Both the first ground plane 102 and the second ground plane 105 are grounded. The first ground plane 102 is used to isolate the interference of the top layer 101 to the first wiring layer 103, and the second ground plane 105 is used to isolate the interference of the bottom layer 106 to the second wiring layer 104.

[0075] Optionally, both the first ground plane 102 and the second ground plane 105 are connected to the ground terminal of the headlight control module applying the PCB board 10, which can enable the current in the PCB board 10 to flow quickly to the ground terminal and ensure the performance stability of the headlight control module.

[0076] Optionally, the first ground plane 102 is arranged between the top layer 101 and the wiring layer. The first ground plane 102 can effectively isolate the mutual interference between large current and small current signals, and the first ground plane 102 can also absorb the clutter signals in the PCB board 10; the second ground plane 105 is arranged between the bottom layer 106 and the signal layer. The second ground plane 105 can effectively isolate the mutual interference between large and small signals, high and low signals, and the second ground plane 105 can also absorb the clutter signals in the PCB board 10.

[0077] From the data in Table 4 and Table 5 below, it can be seen that adding the second ground plane L5 to absorb the clutter signals of the PCB board 10 and adding a wiring layer to separately deploy the signal lines and power lines in the PCB board 10 have beneficial effects on the electromagnetic compatibility of the products applied to the PCB board. Among them, Table 4 is the parameter information table of the PCB board with a six-layer stack structure. According to Table 4, the specific stack structure of the PCB board provided in this application applied to the headlight control module can be understood, and the production parameter information of each layer can be determined; Table 5 is the summary table of the successful results of the electromagnetic compatibility experiment of the improved headlight control module. According to Table 5, the influence of signal interference on the electromagnetic compatibility test of the products applying the existing PCB board can be understood.

[0078] Table 4 Parameter Information Table of the PCB Board with a Six-Layer Stack Structure

[0079] Layer Material Thickness (mm) Character White Ink 0.01 Solder Mask Matt Black Ink 0.01 Electroplated Copper Foil Cu 0.018 L1 Cu 0.018 PP 0.199 L2 Cu 0.035 Core 1.03 L3 Cu 0.035 PP 0.195 L4 Cu 0.018 Core 0.36 L5 Cu 0.035 PP 0.12 L6 Cu 0.018 Electroplated Copper Foil Cu 0.018 Solder Mask Matt Black Ink 0.01 Character White Ink 0.01

[0080] It should be noted that thin insulating material (Prepre, abbreviated as PP); Core is the core board, which is the basic material for making the PCB board 10 and has a fixed rigid structure. PP belongs to a kind of material in the PCB board 10. The PP material is a semi-solid material. PP can be curled, while Core cannot be curled. PP is similar to an adhesive and an insulator. PP is not conductive, while both sides of Core have copper layers, and Core serves as the conductive medium of the PCB board 10.

[0081] Specifically, referring to Table 4, it can be seen that the top layer L1 and the first ground plane L2 are bonded via PP material, the first ground plane L2 and the first wiring layer L3 are connected via Core, the first wiring layer L3 and the second wiring layer L4 are bonded via PP material, the second wiring layer L4 and the second ground plane L5 are connected via Core, and the second ground plane L5 and the bottom layer L6 are bonded via PP material.

[0082] Table 5 Summary of successful results of electromagnetic compatibility test of improved rear light control module

[0083]

[0084]

[0085]

[0086] In the embodiment of the present application, the printed circuit board used for the headlight control module is composed of six layers, namely, the top layer, the first ground plane, the first wiring layer, the second wiring layer, the second ground plane and the bottom layer. The first ground plane is arranged between the top layer and the first wiring layer, and the second ground plane is arranged between the bottom layer and the second wiring layer. Both the first ground plane and the second ground plane are used to connect the ground port of the external device. The first ground plane and the second ground plane form a larger ground plane loop in the printed circuit board, which can effectively absorb clutter signals and thus reduce electromagnetic radiation. Only power lines are arranged on the first wiring layer, and only signal lines are arranged on the second wiring layer. The layered arrangement of power lines and signal lines can effectively reduce the electromagnetic interference of power lines to signal lines and the crosstalk between signal lines. In addition, the electronic components of the printed circuit board are arranged on the top layer, which can effectively reduce the perforation impedance of signal transmission between electronic components and reduce the loop area of ​​current. In this way, the electromagnetic compatibility of the headlight control module can be improved, thereby improving the performance stability of the headlight system.

[0087] Figure 3 FIG. 1 is a schematic diagram of the structure of a wiring layer of an existing printed circuit board. Figure 3 The wiring layer of the existing PCB board has both signal lines and power lines. Since there are many electronic components on the PCB board and the PCB board has a complex structure, laying the signal lines and power lines on the same board layer will cause the signal lines and power lines to be staggered, resulting in the division of key lines between some electronic components. The key lines between electronic components need to be completed through through-hole detours. At the same time, the power lines and signal lines are laid on the same board layer, and the spacing between the power lines and the signal lines is small, which is very easy to produce electromagnetic coupling. The spacing between the signal lines is also small, which will cause crosstalk between the signal lines.

[0088] Figure 4The structural schematic diagram of the first wiring layer of a printed circuit board provided by this application is shown in Figure 4 On the first wiring layer 103 of the printed circuit board 10 provided by the embodiment of this application, only power lines are arranged, which can effectively reduce the electromagnetic coupling between the power lines and signal lines in the PCB board 10.

[0089] Figure 5 The structural schematic diagram of the second wiring layer of a printed circuit board provided by this application is shown in Figure 5 On the second wiring layer 104 of the printed circuit board 10 provided by the embodiment of this application, only signal lines are arranged, which can effectively reduce the signal crosstalk between the signal lines in the PCB board 10.

[0090] Figure 6 The distribution schematic diagram of the electronic components on the top layer of an existing printed circuit board is Figure 7 The distribution schematic diagram of the electronic components on the bottom layer of an existing printed circuit board is shown in Figure 6 and Figure 7 On the top layer of the existing printed circuit board, there are inductors and driver chips arranged. On the bottom layer of the existing printed circuit board, there is a freewheeling diode arranged. The signal interaction between the freewheeling diode and the inductor and driver chip needs to be realized through the vias on the PCB board 10.

[0091] Optionally, on the existing PCB board 10, the driver chip and the freewheeling diode on the drive circuit are not on the same surface of the PCB board 10. When the input power supply supplies power to the driver chip through the switch tube and the inductor when the switch tube is turned on, the freewheeling diode charges the inductor at the same time; among them, the inductor is equivalent to a constant current source and plays the role of energy transfer in the drive circuit; the capacitor is equivalent to a constant voltage source and plays the role of filtering in the drive circuit. When the switch tube is turned off, the energy stored in the inductor needs to form a current loop through the freewheeling diode, and continue to supply power to the driver chip through this current loop, so as to ensure that the driver chip can obtain continuous current.

[0092] As an optional implementation manner, the PCB board 10 further includes a plurality of electronic components, and the electronic components are used to indicate the electronic devices arranged on the PCB board 10. The PCB board 10 realizes specific functions based on the electronic components arranged thereon. Among them, each electronic component is uniformly arranged on the top layer 101, that is, each electronic component on the PCB board 10 provided by this application is uniformly arranged on the front surface of the PCB board, and the signal interaction between the electronic devices does not need to be transmitted through vias, which can effectively reduce the loop impedance of the circuit and reduce the loop area of the current.

[0093] It should be noted that the freewheeling diode, as an important part of the driving circuit of the PCB board 10, is a key electronic component for the rapid change of voltage and current in the driving circuit, and needs to follow the principles of placing electronic components close, on the same plane, with short and thick wiring, and using fewer vias.

[0094] Figure 8 This is a schematic diagram of the distribution of electronic components on a printed circuit board provided by this application. Refer to Figure 8 The electronic components on the printed circuit board 10 provided in the embodiments of this application are respectively: a freewheeling diode 012, a driving chip 013, and an inductor 011.

[0095] It should be noted that the embodiments of this application state that multiple electronic components are deployed on the PCB board 10, and the multiple electronic components include a freewheeling diode 012, a driving chip 013, and an inductor 011, but it does not represent that only these three electronic components are arranged on the PCB board 10 provided in the embodiments of this application, and this application does not make specific limitations on this.

[0096] The inductor 011 is arranged in the first area 1011 of the top layer 101, the freewheeling diode 012 is arranged in the second area 1012 of the top layer 101, and the driving chip 013 is arranged in the third area 1013 of the top layer 101. The second area 1012 is located between the first area 1011 and the third area 1013.

[0097] Optionally, the first area 1011, the second area 1012, and the third area 1013 are only used to represent the layout positions of the electronic components on the front side of the PCB board 10, and there is no distinction in importance among the first area 1011, the second area 1012, and the third area 1013.

[0098] Optionally, the first area 1011 is used to represent the distribution position of the inductor 011 on the upper surface of the top layer 101 of the PCB board 10, the second area 1012 is used to represent the distribution position of the freewheeling diode 012 on the upper surface of the top layer 101 of the PCB board 10, and the third area 1013 is used to represent the distribution position of the driving chip 013 on the upper surface of the top layer 101 of the PCB board 10.

[0099] Optionally, the second area 1012 is located between the first area 1011 and the third area 1013, that is, the freewheeling diode 012 is arranged between the inductor 011 and the driving chip 013. When the freewheeling diode 012 transmits current to the inductor 011 and to the driving chip 013, it does not need to be transmitted through vias, but is directly transmitted through the power line on the top layer, and the power lines between the freewheeling diode 012 and the inductor 011 and the driving chip 013 can be thickened, so as to further reduce the impedance.

[0100] As an alternative embodiment, power lines and signal lines are respectively arranged on the top layer 101 and the bottom layer 106 of the PCB board 10 provided in the embodiments of the present application, and low-power electrical signals and analog signals with relatively low frequencies can be transmitted through the top layer 101 and the bottom layer 106.

[0101] Optionally, the power lines and signal lines arranged on the top layer 101 and the bottom layer 106 are relatively short and thick. After the electronic components on the PCB board 10 are reasonably arranged, the more important, key, and core traces between the electronic components are arranged on the top layer 101 and the bottom layer 106. It is necessary to ensure that the line widths and line spacings of the signal lines and power lines arranged on the top layer 101 and the bottom layer 106 are the optimal results, thereby improving the overall performance of the PCB board 10.

[0102] Optionally, the power line traces arranged on the top layer 101 and the bottom layer 106 must be short and thick, and are often routed in the form of copper pouring; the signal line traces arranged on the top layer 101 and the bottom layer 106 must have the shortest distance, and the situation where the signal line trace passes through irrelevant electronic components or other signal line traces and power line traces should also be avoided.

[0103] Optionally, the signal line traces arranged on the top layer 101 and the bottom layer 106 are short and thick, which can reduce the signal attenuation of the PCB board 10, reduce electromagnetic interference, and improve the signal transmission speed. Among them, the shorter signal line can reduce the attenuation of the signal during transmission and maintain the integrity and clarity of the key signal transmission of the PCB board 10; the shorter signal line trace can reduce the radiation interference between signal lines, thereby reducing the signal interference of the signal line to other signal lines or electronic components; in the high-speed signal transmission circuit between electronic components on the PCB board 10, the shorter signal line can effectively reduce the signal transmission time and improve the performance of the PCB board as a whole.

[0104] Optionally, the power line traces arranged on the top layer 101 and the bottom layer 106 are short and thick, which can reduce the power loss of the PCB board 10, reduce the thermal effect, and suppress electromagnetic radiation. Among them, the shorter power line trace can reduce the loss of current transmission between electronic components on the PCB board 10, thereby improving the power transmission efficiency of the PCB board 10; the shorter power line trace can reduce the heat generated by current transmission on the PCB board 10, reduce the temperature of the PCB board 10, and improve the stability and reliability of the PCB board 10; the shorter power line trace can reduce the electromagnetic radiation generated by current mutation on the PCB board 10 and reduce the interference and damage of the PCB board 10 to the surrounding environment.

[0105] It should be noted that the short power line routing refers to the power line routing distance being limited within 8 millimeters, and the signal line routing refers to the signal line routing distance being limited within 8 millimeters; the thickness of the copper in the PCB board 10 is 35 microns. In this application, the line width of the signal line routing and the power line routing in the boost circuit needs to be greater than or equal to 6 millimeters, the line width of the signal line routing and the power line routing in the buck circuit needs to be greater than or equal to 3 millimeters, and the line width of the signal line routing and the power line routing in other high-side circuits or low-side circuits needs to be greater than or equal to 3 millimeters.

[0106] Optionally, the important power lines are used to indicate the power lines with a very fast current change rate (high dI / dt) and the power lines with a very fast voltage change rate (high dV / dt) on the PCB board 10, where I represents current, V represents voltage, t represents time, and d represents integration; the key signal lines are used to indicate the drive signal lines and feedback signal lines between the various electronic components on the PCB board 10.

[0107] Optionally, the reasonable layout principle of the electronic components on the PCB board 10 is as follows: The electronic components with different functions on different modules are layout in different regions, and the electronic components with the same function are concentrated together, so as to facilitate the unified management and maintenance of the electronic components with the same function, and the unnecessary routing length between the electronic components can be reduced; the power lines are layout at the edge or a specific area of the PCB board 10, which can effectively reduce the interference to other signal lines and electronic components. At the same time, it is also necessary to avoid the parallel routing of the power lines and the signal lines, which can effectively reduce the electromagnetic coupling effect between the signal lines and the power lines.

[0108] As an optional implementation manner, refer to Figure 2 , the printed circuit board 10 provided by this application further includes: a plurality of first type through holes 107, at least one second type through hole 108, and at least one third type through hole 109.

[0109] Optionally, each type of through hole is only used to connect the various board layers of the PCB board 10. Among them, the first type through hole 107 is used to connect all the board layers in the PCB board 10, that is, the first type through hole 107 connects the top layer 101, the first ground plane 102, the first wiring layer 103, the second wiring layer 104, the second ground plane 105, and the bottom layer 106 of the PCB board 10; the second type through hole 108 is only used to connect the first wiring layer 103, the second wiring layer 104, and the second ground plane 105; the third type through hole 109 is only used to connect the top layer 101, the first ground plane 102, the first wiring layer 103, and the second wiring layer 104.

[0110] Each of the first type through holes 107 connects the top layer 101 and the bottom layer 106 respectively.

[0111] Each second - type through - hole 108 is respectively connected to the first wiring layer 103, the second wiring layer 104, and the second ground plane 105.

[0112] Each third - type through - hole 109 is respectively connected to the top layer 101, the first ground plane 102, the first wiring layer 103, and the second wiring layer 104.

[0113] Figure 9 This is a schematic structural diagram of a vehicle - lamp control module provided by the present application. Refer to Figure 9 In the vehicle - lamp control module 20 provided by an embodiment of the present application, the above - mentioned PCB board 10 is included. The specific structure and function of the PCB board 10 are the same as those of the above - mentioned solution, and the present application will not elaborate on this.

[0114] Figure 10 This is a schematic structural diagram of a vehicle - lamp system provided by the present application. Refer to Figure 10 In the vehicle - lamp system 30 provided by an embodiment of the present application, there is arranged Figure 9 the vehicle - lamp control module 20 shown as above.

[0115] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all of them should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0116] The above - mentioned are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A printed circuit board applied to a headlight control module, characterized in that, Comprising: a top layer, a first ground plane, a first wiring layer, a second wiring layer, a second ground plane, and a bottom layer; the first ground plane is disposed between the top layer and the first wiring layer, the second ground plane is disposed between the bottom layer and the second wiring layer, and the first wiring layer is disposed on a side of the second wiring layer facing away from the bottom layer; power lines are disposed on the first wiring layer, and signal lines are disposed on the second wiring layer; both the first ground plane and the second ground plane are grounded. The first ground plane is used to isolate interference from the top layer to the first wiring layer, and the second ground plane is used to isolate interference from the bottom layer to the second wiring layer.

2. The printed circuit board according to claim 1, characterized in that The printed circuit board further comprises: a plurality of electronic components; each electronic component is disposed on the top layer.

3. The printed circuit board according to claim 2, wherein, The plurality of electronic components includes: a freewheeling diode, a driving chip, and an inductor; the inductor is disposed in a first area of the top layer, the freewheeling diode is disposed in a second area of the top layer, the driving chip is disposed in a third area of the top layer, and the second area is located between the first area and the third area.

4. The printed circuit board according to claim 1, wherein Power lines and signal lines are disposed on the top layer.

5. The printed circuit board according to claim 1, wherein Power lines and signal lines are disposed on the bottom layer.

6. The printed circuit board according to claim 1, characterized in that, The printed circuit board further comprises: a plurality of first-type vias; each first-type via respectively connects the top layer and the bottom layer.

7. The printed circuit board according to claim 1, wherein The printed circuit board further comprises: at least one second-type via; each of the second-type vias respectively connects the first wiring layer, the second wiring layer, and the second ground plane.

8. The printed circuit board according to claim 1, wherein The printed circuit board further comprises: at least one third-type via; each of the third-type vias respectively connects the top layer, the first ground plane, the first wiring layer, and the second wiring layer.

9. A vehicle lamp control module, characterized in that, The headlight control module includes the printed circuit board according to any one of claims 1-8.

10. A vehicle lamp system, characterized in that, The headlight system includes the headlight control module according to claim 9.

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