Electronics Forum | Tue Aug 22 14:52:55 EDT 2000 | John Thorup
Jax - absolutely right - the archives are a valuable tool and deserve to be used more than they seem to be. Caumel - Are your blobs on the solder side or the component side? Are your vias tented on the component side? What size are your vias? Is th
Electronics Forum | Thu Aug 10 13:30:54 EDT 2000 | Bob Willis
Solder skips on SOT23 parts is the most common issue when soldering surface mount designs. The two most common causes are the wave height too low or there is too much gassing of the flux as it contacts and seperates the wave. Stck some parts on your
Electronics Forum | Thu Jul 20 10:03:30 EDT 2000 | Bob Willis
All the points raised so far are correct. Only use QFPs if rearly pushed as the yield on your process will suffer. I have wave soldered parts down to 0.020" in nitrogen with OK results but the pads and drainage pads need to be worked on. Another r
Electronics Forum | Thu Jul 20 14:44:26 EDT 2000 | Bob Willis
If you are getting skips on these parts the most common reason for skips is gassing and wave too low. I would agree that wave soldering these parts is not ideal. If the shorts are always in the same location on one or two pins a glue dot done during
Electronics Forum | Mon Dec 13 18:17:44 EST 1999 | Calvin Wong
We have this solder ball & beads around chip components since day one of manufacturing using non-clean process. We managed to eliminate the solder beads around ceramic type chip componenets when we have a slow ramp up of pre heat at solder reflow. Ho
Electronics Forum | Tue Jun 04 16:12:41 EDT 2002 | Bob
The original profile had a higher ramp rate, and the apertures were 100%. The ramp rate is now much gentler and the addition of a small soak area around 160 � 170 degrees should burn off any excess flux. Appertures are now smaller and we get no leac
Electronics Forum | Thu Mar 16 15:03:35 EST 2006 | slthomas
The right way is to know what velocity numbers would net you the required flow for your oven and then measure with a manometer. The required velocity is primarily a function of pipe diameter (and blower rpms) but length and how bendy it is contribute
Electronics Forum | Fri Feb 08 06:26:03 EST 2008 | jdumont
Hey that was me way back! Anyways, use Dow 3140 (self leveling) or Dow 3145 (peanut butter consistency) and call it a day. No out gassing/acidic properties. 3140 also contains a UV tracer for black light inspection. Any tall caps should be epoxied if
Electronics Forum | Mon Aug 18 17:15:15 EDT 2008 | jlawson
This can be seen on leaded soldering also as well as LF (worse with LF). To reduce this you can look at your stencil and profile. Printing a cross-hatch deposit can reduce the voiding as it allow gasses to release when in reflow - thats the theory
Electronics Forum | Tue Oct 27 16:22:00 EDT 2009 | davef
It's not the first thing we think of in looking at your picture. First off, the lack of copper in the region of the red oval makes us think of a plating defect. We don't expect that moisture out-gassing through the barrel wall to show-up on opposite
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