What are the requirements for the spacing of printed circuit board wires?
The editor believes that the distance between adjacent wires must meet electrical safety requirements, and in order to facilitate operation and production, the distance should be as wide as possible. The minimum distance must be at least suitable for the withstand voltage. This voltage generally includes working voltage, additional fluctuating voltage, and peak voltage caused by other reasons. If the relevant technical conditions allow a certain degree of metal residues between the wires, the spacing will be reduced. Therefore, designers should take this factor into consideration when considering voltage. When the wiring density is low, the spacing of the signal lines can be increased appropriately, and the signal lines with high and low levels should be as short as possible and increase the spacing.
The minimum width of the conductor of the printed circuit board is mainly determined by the adhesion strength between the conductor and the insulating substrate and the current value flowing through them. When the thickness of the copper foil is 0.05mm and the width is 1-1.5mm. With a current of 2A, the temperature will not be higher than 3 ℃, and the wire width of 1.5mm can meet the requirements. For integrated circuits, especially digital circuits, 0.02-0.3mm wire width is usually selected. Of course, as long as possible, use as wide a line as possible. Especially for power lines and ground lines, the minimum spacing of wires is mainly determined by the insulation resistance and breakdown voltage between the wires in the worst case. For integrated circuits, especially digital circuits, as long as the process permits, the spacing of the wires can be as small as 5-8mm.
But for large currents, if the current load is calculated at 20A/mm2, when the thickness of the copper clad is 0.5MM, (usually so much), the current load of the 1MM (about 40MIL) line width is 1A, so The width of 1-2.54MM (40-100MIL) can meet the general application requirements. The ground wire and power supply on the high-power equipment board can be appropriately increased according to the power level. In the low-power digital circuit, in order to improve Wiring density, the minimum line width is 0.254-1.27MM (10-15MIL) to meet.
There are both high-voltage and low-voltage circuits on the printed circuit board. The components of the high-voltage circuit part and the low-voltage part should be separated from each other. The isolation distance is related to the withstand voltage. Normally, the distance between the board is 20mm at 2000V. , If you want to withstand 3000V withstand voltage test, the distance between high and low voltage lines should be more than 35mm. In many cases, to avoid creepage, it is still on the printed circuit board. Slotted between the high and low pressure on the top. The circuit boards we made also have high and low voltage circuits, and the circuit spacing between the high and low voltages is 10mm.