What are the PCB creepage and clearance standards?
Clearance – Clearance is the shortest distance in the air between two conductors. You can think of this as the line of sight distance between two mountain tops. Creepage – Creepage is the shortest distance to another conductor along the surface of the insulating material of your PCB.
What is the creepage and clearance distance?
Clearance is the shortest distance in air between two conductive parts. Creepage distance means the shortest distance along the surface of a solid insulating material between two conductive parts.
What is the 3W rule?
3W rule means the distance measured between two trace center lines are at least 3 times the trace width. 3W rule can reduce cross talk flux by about 70%.
What is creepage distance in electrical?
Creepage distance – shortest separation along the surface of an insulating material between two conducting parts.
How does creepage differ from clearance spacing?
The parameters for pad-to-pad, pad-to-trace, trace-to-trace spacing—basically any spacing rule that is applied between conductive elements over an insulating surface—is creepage, not clearance. Spacing between conductive elements through air is clearance.
Can creepage be less than clearance?
Creepage is the shortest distance along the surface of a solid insulating material between two conductive parts. A creepage distance can’t be less than the clearance distance; in other words, the shortest creepage distance will be equal to the clearance distance.
What is the difference between creepage and clearance on a PCB?
Creepage is the shortest distance between conductor traces on a PCB along the surface of the insulation material while clearance is defined as the minimum distance through the air (line of sight) between two conductor traces. Clearance and creepage distances between two PCB conductors.
Where is the creepage on a circuit board?
Creepage is shown in red and is drawn along the surface of the board. Creepage and clearance distances in a circuit board. The diagram above suggests that the creepage distance is always larger than the clearance distance, but this is not always the case.
What to do if your PCB lacks creepage?
In other cases, where creepage is violated while clearance is satisfied, one option is to place a notch that passes through the entire circuit board between components. A knowledgeable CM will be able to recommend the best design changes for your board during a DFM check. Several important standards define clearance and creepage distances in a PCB.
When to use line spacing for creepage and clearance?
The PCB line spacing for creepage and clearance becomes an important factor from a product safety viewpoint when the standard operating voltage is above 30VAC or 60VDC. Voltages above these levels are considered hazardous, and that is why these designs are regarded as high voltage.