IPC-2221
is widely accepted throughout the world as a generic PCB design standard. The table below (which is not an official IPC table) is derived from "IPC 2221", Table 6-1, and provides recommended minimum spacing between conductors and component leads as a function of working voltage level and application. Note that IPC table gives the spacings up to 500V and provides formulas for the spacings above 500V. For your convenience, I added calculated spaces for voltages above 500V and added the columns with inches (IPC currently provides all distances only in metric units). For power conversion circuits
IPC-9592 provides the following circuit board spacing requirements:
SPACING (mm) = 0.6 + Vpeak x .005. For products covered by UL safety standards the creepage and clearance requirements of the respective UL/IEC standard shall take precedence over IPC.
Note that all IPC standards are voluntarily rather than mandatory. For more information see the
Guide to PCB Spacing.
This page is for a general reference only and does not constitude a professional or a legal advice. Consult with respective standards for final design decisions.