Tim:
		It is part of the Bow and Twist IPC-TM-650 2.4.22 PCB
test method 7-11d.  Think of a bow that is place with its curvature
towards a table. Measure the height of the curvature and divide it by
its length then multiply it by 100. it will give you the percentage of
bow. That test was part of the J-Std-001B.
	Regards,
	Ramon
 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Tim Mack
Sent: Wednesday, May 23, 2007 3:18 PM
To: [log in to unmask]
Subject: [TN] PCB Flatness

Does anybody know how "flatness" is measured as it relates to circuit
board fabrication? I was told that the boards I am ordering would have a
flatness of less than 0.5%.  0.5% of what? Any help would be
appreciated.

 

Thanks, 

 

North Dakota State University

Center for Nanoscale Science and Engineering 

Tim Mack

www.ndsu.nodak.edu/cnse

Research Engineer

 

 


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