-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
Paul James E.
Sent: Thursday, March 23, 2006 9:30 PM
To: piclist@mit.edu
Subject: Re: [EE]: hand soldering smt's

> More to the point.   You shouldn't hand solder small parts like this.
> The reason being it is difficult to not get them too hot while soldering, 
> and possibly delaminating the layers of caps and/or resistors, or changing
> their value out of their spec.


(Giggle)
Assuming the soldering iron is at the right temperature to begin with...
What do you think we DO with our soldering ovens? Magic?

The entire board of parts gets as hot as necessary to flow the solderpaste.
If the parts can change because of soldering temperatures they will NEVER
work on a surface mount board.  Hand soldered or not.

IM(ns)HO Delamination occurs mostly with mechanical stress.
Sure the heat makes the copper bonding loose, but failures seem to be
related to pushing, pulling components.

Tom
  *
  |  __O    Thomas C. Sefranek  tcs@cmcorp.com
  |_-\<,_   Amateur Radio Operator: WA1RHP
  (*)/ (*)  Bicycle mobile on 145.41MHz PL74.4
 
ARRL Instructor, Technical Specialist, VE Contact.
http://hamradio.cmcorp.com/inventory/Inventory.html
http://www.harvardrepeater.org


-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist