Clearance and Creepage Rules for PCB Assembly

Electrical spacing rules become significant from a product safety perspective when the normal operating voltage is greater than 30VAC or 60VDC. It may come as a surprise that voltages above these levels are considered hazardous  and that these designs are therefore considered high voltage.

Having designed a number of high voltage and mixed technol­ogy boards recently, I have had to research current standards, definitions, and methodologies used to implement high voltage spacing rules in confined spaces. I say spacing rules because, in addi­tion to the normally-supplied “clearance rules,” there is another set of spacing rules that are just as important to follow for high voltage designs—namely, “creepage” rules.

This link clearly explains the difference between both and also discusses few of the common rules for PCB designing.

 

Aniruddh

Ani-Lab