Rick,
4 tooling holes is preferred, if a carrier is required for supporting
the board thru your SMT process. This is typically required if the
perimeter is odd shaped or too thin to process without a carrier. 2
holes are stationary. The other 2 are used to provide tension, keeping
the board secure thru the process.

Regards,
Rey 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Smith, Richard
Sent: Friday, February 02, 2007 7:54 AM
To: [log in to unmask]
Subject: [TN] Tooling Hole Quantity

Folks,
 
Can you think of any (legitimate) reasons why more than 3 tooling holes
would be necessary on a PWB? 
 
Thanks Much!
 
Rick
 

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