I am still fairly new to PCB design and I am studying for the IPC
design cert. I cam across IPC -2222 9.1.2 Thermal relief in conductor planes
which states the relationship between the hole size, land and web area is
critical. Typically, divided 60% of the minimum land area diameter by the
number of webs desired to obtain the width of each web in accordance with
the following example:
        I understand this with no problem but where does it state the air
gap or expansion size? Is it the same value all the way around the land
area? or does the current control the distance?

Thank you,

Ted Tontis
Engage Networks Inc.
[log in to unmask]
PH 414.273.7600 Ext. 7607    <http://www.engagenet.com>

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