Jong,

    The amount of time the PCB will see 20-30 amps plays a role in copper
used
and trace size.  If the board will see this current all of the time, FR4
will
probally not handle it.  We are currntly running a 25 amp power board using
2oz. copper on outer layers that is plated up to 3oz. and then tin-lead
reflowed.
The trace size is a minimum of .325". This PCB only switches 25 amps on for
about
10 seconds at a time.  Check out www.ultracad.com for a trace width
calculator
based on IPC-D-275 charts and also an article Mr. Brooks wrote on "melting
traces".
Best of luck!

-----Original Message-----
From: jong s kadesch [mailto:[log in to unmask]]
Sent: Thursday, February 17, 2000 11:34 AM
To: [log in to unmask]
Subject: [TN] copper weight


Hi Technetters,

What is the max. copper weight I can get on the outer layers of the board
with the current of 20 to 30A?  I'm fairly new to with high current board.
Thanks in advance.

Jong Kadesch

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