1. The PCB board can be structurally divided into single-sided, double-sided, and multi-layer boards. A multi-layer board refers to a printed circuit board with more than two layers, composed of connecting wires on multiple layers of insulating substrates and pads for assembling and soldering electronic components. High-speed PCB boards are generally designed as multi-layer boards. Common multi-layer boards typically have 4 or 6 layers, while more complex designs can have dozens of layers.
2. The characteristics of a multi-layer PCB board include additional internal power supply and grounding layers, which are not present in single-sided or double-sided boards. Power and grounding networks are primarily routed on the power supply layer. Multi-layer board wiring primarily utilizes the top and bottom layers, with additional layers used for internal routing. Multilayer PCB boards consist of Signal Layers, Internal Planes, Mechanical Layers, Solder Mask Layers, Silkscreen Layers, and System Layers. Advantages of multi-layer PCBs include high assembly density, compact size, shorter connections between components, faster signal transmission, and effective shielding.
3. The design of a multi-layer PCB board should ensure symmetry with an even number of copper layers to avoid distortion. Wiring should follow circuit functionality, with more wiring on the solder side and less on the component side to facilitate maintenance and troubleshooting. It is important to separate power, ground, and signal layers to minimize interference. Adjacent layers’ traces should ideally be perpendicular or follow oblique lines and curves to reduce interlayer coupling and substrate interference.
4. The shape and size of the printed board should align with the product’s overall structure. From a production standpoint, the design should be as simple as possible, typically a rectangle with a manageable aspect ratio to ease assembly, enhance production efficiency, and lower labor costs. The number of layers should be based on circuit performance requirements, board size, and circuit density. Common multi-layer boards include four-layer and six-layer configurations, with even numbers of copper layers to prevent warping, especially in surface-mount boards.
5. The position and orientation of components should first adhere to circuit principles and accommodate the circuit’s flow. Proper placement affects board performance, particularly in high-frequency analog circuits. Engineers should analyze the circuit design to determine the locations of key components (e.g., large ICs, high-power transistors, signal sources) and arrange other components to minimize interference. Additionally, a well-organized layout avoids aesthetic issues and simplifies assembly and maintenance.
6. Wire layout on multi-layer boards should follow circuit functions, with more wiring on the solder side and less on the component side to aid maintenance. Thin, dense wires and sensitive signal lines should be routed on inner layers. Even distribution of large copper areas on inner and outer layers helps reduce board warpage and ensures uniform electroplating. To prevent damage during machining, maintain a distance greater than 50 mils between conductive patterns and the board edge.
7. Wire direction in multi-layer boards should separate power, ground, and signal layers to reduce interference. Traces on adjacent layers should ideally be perpendicular or follow oblique lines and curves, avoiding parallel lines to minimize interlayer coupling and substrate interference. Keep wires as short as possible, especially for small signal circuits, to reduce resistance and interference.
8. Safety distances should meet electrical safety standards. Generally, the spacing of outer conductors should be no less than 4 mils, and the spacing of inner conductors should also be no less than 4 mils. Maximize spacing wherever possible to improve board yield and minimize the risk of failure.
9. Enhancing the anti-interference capability of a multi-layer PCB involves adding filter capacitors near each IC’s power supply and ground, typically with values of 473 or 104. Shielded wires should be used for sensitive signals, with minimal routing near signal sources. Choosing an appropriate grounding point on the PCB is also crucial for reducing interference.
2. The characteristics of a multi-layer PCB board include additional internal power supply and grounding layers, which are not present in single-sided or double-sided boards. Power and grounding networks are primarily routed on the power supply layer. Multi-layer board wiring primarily utilizes the top and bottom layers, with additional layers used for internal routing. Multilayer PCB boards consist of Signal Layers, Internal Planes, Mechanical Layers, Solder Mask Layers, Silkscreen Layers, and System Layers. Advantages of multi-layer PCBs include high assembly density, compact size, shorter connections between components, faster signal transmission, and effective shielding.
3. The design of a multi-layer PCB board should ensure symmetry with an even number of copper layers to avoid distortion. Wiring should follow circuit functionality, with more wiring on the solder side and less on the component side to facilitate maintenance and troubleshooting. It is important to separate power, ground, and signal layers to minimize interference. Adjacent layers’ traces should ideally be perpendicular or follow oblique lines and curves to reduce interlayer coupling and substrate interference.
4. The shape and size of the printed board should align with the product’s overall structure. From a production standpoint, the design should be as simple as possible, typically a rectangle with a manageable aspect ratio to ease assembly, enhance production efficiency, and lower labor costs. The number of layers should be based on circuit performance requirements, board size, and circuit density. Common multi-layer boards include four-layer and six-layer configurations, with even numbers of copper layers to prevent warping, especially in surface-mount boards.
5. The position and orientation of components should first adhere to circuit principles and accommodate the circuit’s flow. Proper placement affects board performance, particularly in high-frequency analog circuits. Engineers should analyze the circuit design to determine the locations of key components (e.g., large ICs, high-power transistors, signal sources) and arrange other components to minimize interference. Additionally, a well-organized layout avoids aesthetic issues and simplifies assembly and maintenance.
6. Wire layout on multi-layer boards should follow circuit functions, with more wiring on the solder side and less on the component side to aid maintenance. Thin, dense wires and sensitive signal lines should be routed on inner layers. Even distribution of large copper areas on inner and outer layers helps reduce board warpage and ensures uniform electroplating. To prevent damage during machining, maintain a distance greater than 50 mils between conductive patterns and the board edge.
7. Wire direction in multi-layer boards should separate power, ground, and signal layers to reduce interference. Traces on adjacent layers should ideally be perpendicular or follow oblique lines and curves, avoiding parallel lines to minimize interlayer coupling and substrate interference. Keep wires as short as possible, especially for small signal circuits, to reduce resistance and interference.
8. Safety distances should meet electrical safety standards. Generally, the spacing of outer conductors should be no less than 4 mils, and the spacing of inner conductors should also be no less than 4 mils. Maximize spacing wherever possible to improve board yield and minimize the risk of failure.
9. Enhancing the anti-interference capability of a multi-layer PCB involves adding filter capacitors near each IC’s power supply and ground, typically with values of 473 or 104. Shielded wires should be used for sensitive signals, with minimal routing near signal sources. Choosing an appropriate grounding point on the PCB is also crucial for reducing interference.
