Element arrangement rule
- under normal conditions, all of the components shall be arranged on the same side of the printed circuit, only in the top element is too dense, can be highly limited and small heat devices, such as chip resistor, SMD capacitors, IC paste on the bottom.
- under the premise of ensuring the electrical properties the components should be placed on the grid and parallel or vertical arrangement, in order to tidy and beautiful, generally do not allow elements overlap; elements are arranged to be compact, as far as possible from the input and output elements.
- some components or wires may have higher potential difference, so they should increase their distance so as to avoid unexpected short circuit due to discharge and breakdown.
- the components with high voltage shall be arranged as far as possible when the hand is not touched at the time of debugging.
- the component on the edge of the board has at least 2 plates with a thickness of 6 away from the edge of the plate. The element should be evenly distributed and uniformly distributed throughout the panel surface.
Following the signal to the layout principle
- the position of each functional circuit unit is usually arranged one by one according to the flow of the signal, and the core component of each function circuit is arranged around it.
- the layout of the components should be easy to signal flow, so that the signal to maintain a consistent direction as much as possible . In most cases, the flow of the signal is arranged from left to right or from top to bottom, and the components directly connected to the input and output should be placed close to the input, output connector or connector.
Preventing electromagnetic interference
- the components of the electromagnetic radiation field and the components which are sensitive to electromagnetic induction should increase their distance or be shielded from each other. The orientation of the elements should be crossed with the adjacent printed ones.
- as far as possible to avoid high voltage devices, mixed with each other, strong and weak signals of the device together.
- To produce a magnetic field components, such as transformers, inductors and other speakers, the layout should pay attention to reduce the lines on cutting printed conductors, adjacent element magnetic field direction should be perpendicular to each other, reduce the coupling between each other.
- shielding the interference source, the shield should have good grounding.
- In high frequency operation of the circuit, consider the influence of the distribution parameters between the components.
Suppressing thermal interference
- For heating elements, priority should be given to the position where heat dissipation is provided. If necessary, a radiator or a small fan can be provided separately to reduce the temperature and reduce the influence on the adjacent components.
- Some large power consumption of the integrated block, resistors and other components, to be arranged in a place where easy to heat, and with other components separated by a certain distance.
- Thermal components should be close to the measured components and away from the high temperature area, so as not to be affected by other heat equivalent components, causing malfunction.
- When placing the components on both sides, the bottom layer is generally not placed in the heating element.
Adjustable component layout
For the potentiometer, variable capacitor, adjustable inductor coil or micro switch and other adjustable components of the layout should take into account the structural requirements of the machine, if the machine outside the regulation, its location to And adjust the knob on the chassis panel position to adapt; if the machine is adjusted, it should be placed in the printed circuit board in the adjustment of the place.