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| Reply To: | TechNet E-Mail Forum. |
| Date: | Fri, 6 Sep 2002 15:47:15 -0500 |
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I have seen a couple of alternatives: paste, adhesive application (not screened on) and then reflow. Then in the wave process use either a selective solder pallet or wave as is and take the rework for bad layout issues. Or another option is to assemble with paste on the solder side w/o adhesive and use a pin to paste for the through hole parts. Maybe even a solder doughnut with a gel flux for the through hole parts. Also tried once on a really bad design latex masking over all of the sm parts on the solder side. We had to use a lot of mask though so the parts inside the mask wouldn't partially reflow. It was pretty successful. Even programmed up an older adhesive dispenser to dispense the latex mask unto the PCB. Had to go back over some spots 5-6 times to get the right thickness of goo.
Be careful with the high temp paste and the through hole parts thermally.
Have fun
Kat
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<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2715.400" name=GENERATOR></HEAD>
<BODY style="MARGIN-TOP: 2px; FONT: 8pt MS Sans Serif; MARGIN-LEFT: 2px">
<DIV><FONT size=1>I have seen a couple of alternatives: paste, adhesive
application (not screened on) and then reflow. Then in the wave process
use either a selective solder pallet or wave as is and take the rework for bad
layout issues. Or another option is to assemble with paste on the solder
side w/o adhesive and use a pin to paste for the through hole parts. Maybe
even a solder doughnut with a gel flux for the through hole parts. Also
tried once on a really bad design latex masking over all of the sm parts on the
solder side. We had to use a lot of mask though so the parts inside the
mask wouldn't partially reflow. It was pretty successful. Even
programmed up an older adhesive dispenser to dispense the latex mask unto the
PCB. Had to go back over some spots 5-6 times to get the right thickness
of goo. </FONT></DIV>
<DIV><FONT size=1></FONT> </DIV>
<DIV><FONT size=1>Be careful with the high temp paste and the through hole parts
thermally. </FONT></DIV>
<DIV><FONT size=1></FONT> </DIV>
<DIV><FONT size=1>Have fun</FONT></DIV>
<DIV><FONT size=1></FONT> </DIV>
<DIV><FONT size=1>Kat</FONT></DIV></BODY></HTML>
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information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
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