PRINTED CIRCUIT BOARD CLEARANCE



BASED ON IPC-2221


Home Magnetism Energy and Power Power Supply Guide Software
Tutorial PCB design Computer Connectors Engineering Jobs Disclaimer




IPC-2221 is widely accepted throughout the world as a generic PCB design standard. The table below is derived from "IPC 2221", Table 6-1, which provides recommended minimum spacing between conductors and component leads as a function of working voltage level and application. Note that IPC table lists spacing 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 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 then mandatory. For more information see the Guide to PCB Spacing.
This page is for a general reference only. Consult with respective standards for final design decisions.

Bare Board Assembly
Internal layers External conductors, uncoated External conductors, uncoated, >3050 m External conductors coated External conductors with conformal coating External component leads, uncoated Component leads with conformal coating
Vpk, V mm inch mm inch mm inch mm inch mm inch mm inch mm inch
15 0.05 0.002 0.1 0.004 0.1 0.004 0.05 0.002 0.13 0.006 0.13 0.006 0.13 0.006
30 0.05 0.002 0.1 0.004 0.1 0.004 0.05 0.002 0.13 0.006 0.25 0.01 0.13 0.006
50 0.1 0.004 0.6 0.024 0.6 0.024 0.13 0.006 0.13 0.006 0.4 0.016 0.13 0.006
100 0.1 0.004 0.6 0.024 1.5 0.06 0.13 0.006 0.13 0.006 0.5 0.02 0.13 0.006
150 0.2 0.008 0.6 0.024 3.2 0.13 0.4 0.016 0.4 0.016 0.8 0.032 0.4 0.016
170 0.2 0.008 1.25 0.05 3.2 0.13 0.4 0.016 0.4 0.016 0.8 0.032 0.4 0.016
250 0.2 0.008 1.25 0.05 6.4 0.26 0.4 0.016 0.4 0.016 0.8 0.032 0.4 0.016
300 0.2 0.008 1.25 0.05 12.5 0.5 0.4 0.016 0.4 0.016 0.8 0.032 0.8 0.032
500 0.25 0.01 2.5 0.1 12.5 0.5 0.8 0.032 0.8 0.032 1.5 0.06 0.8 0.032
1000 1.5 0.06 5 0.2 25 0.99 2.33 0.092 2.33 0.1 3.03 0.12 2.33 0.092
2000 4 0.158 10 0.4 50 1.97 5.38 0.22 5.38 0.22 6.08 0.24 5.38 0.22
3000 6.5 0.256 15 0.6 75 2.96 8.43 0.34 8.43 0.34 9.13 0.36 8.43 0.34
4000 9 0.355 20 0.79 100 3.94 11.48 0.46 11.48 0.46 12.18 0.48 11.48 0.46
5000 11.5 0.453 25 0.99 125 4.93 14.53 0.58 14.53 0.58 15.23 0.6 14.53 0.58

FIND PCB PRODUCTS AND SERVICES BY SPEC

© 2008 L.Rozenblat