Electronics Forum | Wed Oct 06 04:11:35 EDT 2010 | grahamcooper22
I've done minimal research to this point and > understand my issue with solder on the double > sided boards is due to oxidation that occures on > the unpopulated pads when the board makes its > first trip through the reflow oven. > > We did run
Electronics Forum | Thu Oct 07 08:13:52 EDT 2010 | remullis
I just swapped from the HASL to Immersion Silver mainly because the board house we use could not maintain consistency in keeping the pads level. I was constantly battling bumps and bad finishes on the pads. They are able to give me a consistent board
Electronics Forum | Fri Jun 12 21:36:04 EDT 2020 | SMTA-Josh
Has anyone had an issue with changing from a HASL surface finish to a LF HASL finish if it is still being used in a leaded process? Also we are having issues with the planarity on the fiducials with the HASL finish. Are there any suggestions or ch
Electronics Forum | Mon Jun 15 16:51:05 EDT 2020 | emeto
Tin/Lead has 183C melting point and probably around 220 peak temperature at reflow. Tin has 232C melting point. I would assume that based on this information you would understand why intermetallic joint is questionable. Go to any flat finish. HASL wi
Electronics Forum | Tue Mar 15 10:44:42 EST 2005 | jdengler
-If the aperture volume is the same, there will be more solder on the HASL finish joint due to the solder already present on the pad. This difference is not usually enough to cause insufficiant solder volume but will "look different". Sometimes an
Electronics Forum | Sun Jun 14 03:02:14 EDT 2020 | kylehunter
We did a batch of boards with lead free HASL that we thought was leaded. Using standard leaded paste worked, but we did have some wetting issues. The issues were resolved when switching back to leaded HASL. Can't speak to your specific fiducial issu
Electronics Forum | Tue Jun 16 14:35:13 EDT 2020 | dwl
for the fiducials, try a donut shape instead of a disc. The HASL solder seems to settle more evenly on a donut than it does on a dic.
Electronics Forum | Wed Jan 24 11:27:54 EST 2007 | bradlanger
We have been using SN100C lead free hasl for over a year now with good success. It is very solderable and has good shelf life. You do have to make sure the finish gets applied to the correct thickness. If the lead free hasl finish is not applied thic
Electronics Forum | Tue Mar 15 17:58:56 EST 2005 | darby
Mat, Are you sure you should be using SnPb HASL boards if you are doing prep for lead free? If you aren't actually going to comply with RoHS then fire away. Nearly all of our assemblies are now ENIG and as any re-design comes up on a HASL board it is
Electronics Forum | Wed Jul 29 13:44:45 EDT 1998 | David Spilker
We are investigating alternatives to HASL finishes for more dense PWBs. OSP is not a good choice because of low solid flux and possibly long shelf life. Immersion gold is expensive and so far has been more difficult to wave solder. Has anyone had
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