Yes to all of these.
     
        Follow the wave profile for all of your chip components. Caps and 
     ferrite beads will limit your wave profile.
     
        Make sure your spray fluxer and/or foam fluxer can flux the pads. I 
     have seen both shadowed by poor design, mechanical problems, or 
     materials.
     
        Check your dwell time in the wave, especially chip wave. Increased 
     contact time helps.
     
        Check your wave geometry. I have had success with adjusting Hollis 
     exit choke bars, Soltec exit weirs, Hollis front choke bars, and 
     Soltec dross screens.
     
        Please note: +- 5 rpm or 20 pounds of solder in the tank make a 
     difference in yield.
     
        SOTS have been a problem, but are no longer at the top of our yield 
     pareto.
     
     Aric Parr   
        [log in to unmask]

______________________________ Reply Separator _________________________________
Subject: (ASSEM) Wave soldering SOT-23
Author:  [log in to unmask] at internet
Date:    12/10/96 2:02 PM


We are having problems wave soldering SOT's located on the bottom 
side of the boards. The SOT's have insufficient or no solder after 
waving. I have several questions reagarding this problem.
1. Is there a recommended wave profile?
2. Is there a recommended pad geometry for SOT's? 
3. Is there a recommened flux?
4. Does anyone have any reports or technical articles on this issue? 
Thank You,
Tom Rapp
QE
[log in to unmask]
205-582-1800 Ext 1240
     
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