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 | Fri Jun 17 10:06:13 EDT 2005 | Doug
We have had some experience with the immersion tin. The appearance can be "bright" or "dull". Don't discount the fact that it is "bright" doesn't necessarily make it HASL. Furthermore, I personally have never heard of a board manufacturer "stripping
Electronics Forum | Fri Dec 13 09:06:30 EST 2002 | russ
One thing I have found when using square or diamond etc... Fiducials is, if it is a HASL finish board, the finish may be thick and the fid camera will see them having rounded edges different sizes etc.. and will cause quality failures. Russ (My sp
Electronics Forum | Mon Feb 21 18:13:23 EST 2005 | gpaelmo
As davef states above, you would like to have flat surfaces below 25 mil. We are a contract manufacturer also and we've done thousands of 15 mil QFP's with HASL finish with no problems. Your success will depend on quality of PCB supplier providing th
Electronics Forum | Thu Dec 16 11:54:45 EST 1999 | Mike Naddra
At reflow an inert atmosphere is used to mitigate the occurance of oxidation, to me the decision weather to move from an inert atmosphere is based on several things ; PCB surface finish - are you using a HASL finish, OSP or another surface finish and
Electronics Forum | Wed Aug 19 18:18:02 EDT 2009 | smt_guy
Thanks Sir Dave. Yeah my apologies. To clarify, we built the product PCB whcih has a Lead-Free HASL Finish using a Sn63/Pb37 Solder paste. My major concern regarding reliability is that my profile whish is between 215'C-225'C was insufficient to ref
Electronics Forum | Mon Sep 09 08:21:37 EDT 2002 | mk
What kind of changes could be expected by changing from a HASL finish to gold? We have a board the had been being coated with HASL but was changed to gold to make priting easier. Now, even though the soldering looks fine, we are getting fallouts at G
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 | 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 | Mon Jun 25 16:16:01 EDT 2012 | rway
I have some suggestions. We have been fighting bad fids for years. Some things we have tried that have helped is: 1) Look at your relief area around your fid. Does it butt up against the solder mask. We allow 20 mil around the fid as a relief ar
.gif)
.png)
