Thanks.  I try to use the manufacturers' recommended land patterns
whenever possible, put they do not always supply them.  Specifically,
Motorola and Hitachi don't seem to provide this information.  Since I am
inexperienced at board design, I hate to start from scratch with land
patterns.  What suggestions do you have (or anybody) for creating a land
pattern from the package outlines.

Keith Kraver
GSRA
_______________________________________
University Of Michigan
Advanced Computer Architecture Lab
1301 Beal Ave. EECS
Ann Arbor, MI 48109 

(313) 764-9363 
(313) 763-4617 fax
[log in to unmask]


On Thu, 29 May 1997, JoAnn Amerson wrote:
> 
> We don't use IPC-SM-782 here.  The man who in in charge of the SMT department 
> determines what pad sizes and spacings he needs for the pick and place machine. 
>  I wanted to warn you that the physical dimensions of a TQFP can vary depending 
> on the manufacturer.  We are currently struggling through some land pattern 
> problems with the 44 pin QFP.  We have two different size footprints and have 
> determined that a third may be helpful, if not necessary.  Being the design 
> librarian is not without it's challenges!  :-)
> 
> Good luck in your search for knowledge.
> 
> JoAnn L. Amerson
> Design Librarian
> Red Lion Controls, Inc.
> E-mail: [log in to unmask]
> Voice: (717) 767-6961 ext 6308
> 

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