The high-frequency board wiring guidelines for PCB manufacturing encompass rules for component arrangement, layout principles based on signal direction, strategies to prevent electromagnetic interference, methods for thermal interference suppression, and the placement of adjustable components.
1. **Component Arrangement Rules**
1. Under typical conditions, all components should be placed on the same side of the printed circuit board. Only when the top layer is overly congested may certain low-profile, low-heat-generating components, such as chip resistors, chip capacitors, and ICs, be positioned on the bottom layer.
2. To ensure optimal electrical performance, components should be arranged on a grid in either parallel or perpendicular alignment, maintaining a neat appearance. Generally, overlapping components is discouraged; the layout should be compact, with input and output components positioned as far apart as feasible.
3. Certain components or wires may experience significant potential differences; therefore, it’s essential to increase the distance between them to prevent accidental short circuits caused by discharge or breakdown.
4. High-voltage components should be situated as far away as possible from areas that are easily accessible during debugging.
5. Components placed at the board’s edge should maintain a distance of at least two board thicknesses from the edge.
6. Components must be evenly and densely distributed across the entire surface of the board.
2. **Signal Layout Principles**
1. The locations of each functional circuit unit are typically arranged sequentially based on the signal flow, with the core components of each functional circuit centrally positioned and surrounding components laid out accordingly.
2. The arrangement of components should facilitate signal flow, keeping signals aligned in the same direction as much as possible. Generally, signal flow is oriented from left to right or top to bottom, and components that connect directly to input and output terminals should be placed in close proximity to the respective connectors.
**Three, Prevent Electromagnetic Interference**
1. For components that emit strong radiated electromagnetic fields and those sensitive to electromagnetic induction, increase the distance between them or provide shielding. Additionally, orient the placement of components to cross the adjacent printed wires.
2. Avoid mixing high-voltage and low-voltage devices, as well as interleaving components with strong and weak signals.
3. For components that produce magnetic fields, such as transformers, speakers, and inductors, ensure that printed wires are not excessively cut by magnetic lines of force during layout. The magnetic field directions of neighboring components should be perpendicular to minimize coupling.
4. Shield the source of interference, ensuring that the shielding cover has a solid grounding.
5. For circuits operating at high frequencies, consider the effects of distribution parameters between components.
**Four, Suppress Thermal Interference**
1. Position heating elements in locations that facilitate heat dissipation. If necessary, consider installing a heat sink or small fan to lower the temperature and mitigate effects on adjacent components.
2. Arrange high-power integrated circuits, large or medium power transistors, and resistors in areas where heat can dissipate easily, keeping them separated from other components.
3. Place thermal elements close to the component being tested and away from high-temperature areas to avoid interference from other heat-generating components.
4. When components are mounted on both sides, avoid placing heating elements on the bottom layer.
**Five, Layout of Adjustable Components**
For adjustable components such as potentiometers, variable capacitors, adjustable inductors, or micro switches, consider the overall structural requirements of the device. If adjustments are made externally, ensure that their position aligns with the adjustment knob on the chassis panel. For internal adjustments, place them on the printed circuit board in proximity to where the adjustments are made.
1. **Component Arrangement Rules**
1. Under typical conditions, all components should be placed on the same side of the printed circuit board. Only when the top layer is overly congested may certain low-profile, low-heat-generating components, such as chip resistors, chip capacitors, and ICs, be positioned on the bottom layer.
2. To ensure optimal electrical performance, components should be arranged on a grid in either parallel or perpendicular alignment, maintaining a neat appearance. Generally, overlapping components is discouraged; the layout should be compact, with input and output components positioned as far apart as feasible.
3. Certain components or wires may experience significant potential differences; therefore, it’s essential to increase the distance between them to prevent accidental short circuits caused by discharge or breakdown.
4. High-voltage components should be situated as far away as possible from areas that are easily accessible during debugging.
5. Components placed at the board’s edge should maintain a distance of at least two board thicknesses from the edge.
6. Components must be evenly and densely distributed across the entire surface of the board.
2. **Signal Layout Principles**
1. The locations of each functional circuit unit are typically arranged sequentially based on the signal flow, with the core components of each functional circuit centrally positioned and surrounding components laid out accordingly.
2. The arrangement of components should facilitate signal flow, keeping signals aligned in the same direction as much as possible. Generally, signal flow is oriented from left to right or top to bottom, and components that connect directly to input and output terminals should be placed in close proximity to the respective connectors.
**Three, Prevent Electromagnetic Interference**
1. For components that emit strong radiated electromagnetic fields and those sensitive to electromagnetic induction, increase the distance between them or provide shielding. Additionally, orient the placement of components to cross the adjacent printed wires.
2. Avoid mixing high-voltage and low-voltage devices, as well as interleaving components with strong and weak signals.
3. For components that produce magnetic fields, such as transformers, speakers, and inductors, ensure that printed wires are not excessively cut by magnetic lines of force during layout. The magnetic field directions of neighboring components should be perpendicular to minimize coupling.
4. Shield the source of interference, ensuring that the shielding cover has a solid grounding.
5. For circuits operating at high frequencies, consider the effects of distribution parameters between components.
**Four, Suppress Thermal Interference**
1. Position heating elements in locations that facilitate heat dissipation. If necessary, consider installing a heat sink or small fan to lower the temperature and mitigate effects on adjacent components.
2. Arrange high-power integrated circuits, large or medium power transistors, and resistors in areas where heat can dissipate easily, keeping them separated from other components.
3. Place thermal elements close to the component being tested and away from high-temperature areas to avoid interference from other heat-generating components.
4. When components are mounted on both sides, avoid placing heating elements on the bottom layer.
**Five, Layout of Adjustable Components**
For adjustable components such as potentiometers, variable capacitors, adjustable inductors, or micro switches, consider the overall structural requirements of the device. If adjustments are made externally, ensure that their position aligns with the adjustment knob on the chassis panel. For internal adjustments, place them on the printed circuit board in proximity to where the adjustments are made.
