In IPC-A-600 it states in section 2.4.2 Dewetting, on page 23, the Acceptable condition for Class 2, 3 is that dewetting is acceptable on conductors and ground or voltage planes. It is ok on 5% or less of each land area for solder connections.
 
Acceptable Class 1,
 
On conductors and ground or voltage planes
On 15% or less of each land area for solder connection.
 
So Class 2, 3 no more dewetting that 5% of areas to be soldered, Class 1 no more than 15% of areas to be soldered.
 
Hope this helps.
 
Leo Lambert
Technical Director
EPTAC Corp
[log in to unmask]
www.eptac.com
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Somtawin Pornpottanamas
Sent: Friday, November 07, 2003 9:09 AM
To: [log in to unmask]
Subject: [TN]

Do anybody know the acceptant criteria  for % dewetting on  solder coating on PCB board?

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