Hi Dee,
Thermal relief is not specified within IPC documents, because the need for them is an "It depends."
As you note, the type of soldering process(es) used as has an impact, whether you solder SnPb or SAC makes a difference, whether you have BGAs or not, the thickness of the innerlayers, the drilled hole diameter—how would you specify all of this?

Werner


 


 

-----Original Message-----
From: Dee Stover <[log in to unmask]>
To: [log in to unmask]
Sent: Mon, 6 Apr 2009 2:58 pm
Subject: [TN] when do vias require a thermal relief









Where in IPC does it specify when a via connected to a plane must 
have thermal relief as opposed to direct connect? 
 

I would think it would have more to do with the assembly process than 
the fabrication process.  For instance - wave, dip or drag soldering. 
 

You input is appreciated. 
 

Thanks, 
 

:-) Dee Stover  [log in to unmask]    x8489 

Tech Associate II 

National Optical Astronomy Observatories 

www.noao.edu  

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