http://www.ecd.com/blog/index.php/2009/03/17/wavy-reflow-profiles/?utm_source=rss&utm_medium=rss&utm_campaign=wavy-reflow-profiles Sat, 05 Nov 2011 07:47:04 +0000 hourly 1 http://wordpress.org/?v=3.2.1 http://www.ecd.com/blog/index.php/2009/03/17/wavy-reflow-profiles/comment-page-1/#comment-14 TylerShay Wed, 06 May 2009 16:31:09 +0000 http://www.ecd.com/blog/?p=112#comment-14 We've been reflow profiling for a lead-free transition and as such we've been putting thermocouples on the undersides of BGAs to make sure they're hitting a high-enough TAL to melt the solder balls. Anyway, I didn't secure one of the thermocouples well enough and it ended up kind of coming loose but not all the way off the BGA, it was kind of hanging on the edge of it, and it caused the graph to get really wavy because sometimes it would collect air temperature and others it would collect BGA temperature. Live and learn I guess. We’ve been reflow profiling for a lead-free transition and as such we’ve been putting thermocouples on the undersides of BGAs to make sure they’re hitting a high-enough TAL to melt the solder balls. Anyway, I didn’t secure one of the thermocouples well enough and it ended up kind of coming loose but not all the way off the BGA, it was kind of hanging on the edge of it, and it caused the graph to get really wavy because sometimes it would collect air temperature and others it would collect BGA temperature. Live and learn I guess.

]]> http://www.ecd.com/blog/index.php/2009/03/17/wavy-reflow-profiles/comment-page-1/#comment-5 Joe Turnbull Fri, 27 Mar 2009 20:23:29 +0000 http://www.ecd.com/blog/?p=112#comment-5 I have found that wavy plots can be caused by excessive ventilation. This will cause the heaters to cycle more frequently. This will show up in your profile. To much air flow cools the oven tunnel, then the heaters respond. This will also decrease the life of your heating elements. Use a anemometer to check velocity. Adjust to oven manufacturer suggestions. I have found that wavy plots can be caused by excessive
ventilation. This will cause the heaters to cycle more frequently. This will show up in your profile. To much air flow cools the oven tunnel, then the heaters respond. This will also decrease the life of your heating elements. Use a anemometer to check velocity. Adjust to oven manufacturer suggestions.

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