Homebrew PCBs

----- Original Message ----- 
From: "Jim Lewis" <jim.lewis@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, April 04, 2009 12:12 AM
Subject: [Homebrew_PCBs] Jumping chips


>I have a problem with SMT chips jumping off the board during reflow. I 
>preheat for 2.5 minutes 1/4" above the hot plate and then reflow 1.5 
>minutes directly on the hot plate at 375F with a cover. Paste is from 
>Stencils Unlimited. Any solutions?

Your PCBs might have absorbed moisture if they have been left around for 
some time.

Leon