Electronics Forum | Sat Jul 26 07:31:14 EDT 2008 | bobwillis
We have created a new online free database on process defects at NPL which you can search. http://defectsdatabase.npl.co.uk There are many reasons for solder balling on wave and reflow and examples are provided. You could always use the database t
Electronics Forum | Wed Nov 20 09:23:53 EST 2019 | alpha1
We had a board we fought with for a while with solder balls. Checked everything, Stencil thickness at .004, reduced apertures, changed paste 3 times, changed profile 3 times. Finally changed board vendors. Went from HASL to Emersion Gold. Problem sol
Electronics Forum | Wed May 09 11:25:29 EDT 2001 | medernach
What type of preheaters do you have on you're wave? I have to agree with Dave. Your leads are not cold, they are hotter than the annular ring on the PCB. This would cause the solder to go to the lead only rather than the component and land pad / a
Electronics Forum | Thu May 17 08:28:14 EDT 2001 | wavemaster
I would have to agree that the leads are probably geting to hot, but there are many factors that could be the root cause. I would suggest doing a experiment with a solder sample and make 2 recipes. One with a relativly cold profile and one with a r
Electronics Forum | Tue Jul 20 02:36:03 EDT 2004 | yukim
Hi, The solder paste is SE5-M951X-9. Comparing with the previous one we used, we are having much more tombstoning problems. The reflow profile is such as: room temp to 140C: 85~95 sec 140 to 170 C: 80 sec 170 to 200 C: 20 ~ 23 sec Above 200 C: 44 ~
Electronics Forum | Fri Nov 15 00:08:01 EST 2019 | ramesh_10377
hi i recommend following actions. 1) check the location where most solder ball is finding 2) verify the printer setting parameter if the problem is still persisting please go below action 1. Stencil thickness should be 4 mil 2. Aperture ope
Electronics Forum | Wed Jul 07 02:20:48 EDT 2004 | Koki
Please let me know exactly the Koki specification that has managed to solve the balling issue and we can look at the level of residue or the cosmetic may be what you wish to improve.
Electronics Forum | Fri Jul 18 16:29:30 EDT 2008 | grics
Thats it. 6 mils works great with a 10% reduction. We had also had some issues with our p&p placing the parts to hard and smashing out paste causing a bead to form in the middle of our 0805 packages.
Electronics Forum | Mon Jul 28 06:13:35 EDT 2008 | cobar
Your problem is being caused by to much paste being printed.Reduce apeture size on stencil. http://www.shanelo.co.za/technical_paper_about_stencil_de.htm or http://www.shanelo.co.za/SMD%20Assist.htm
Electronics Forum | Wed Nov 13 12:06:53 EST 2019 | slthomas
The answer is usually either too much paste or paste being deposited where it doesn't belong. In some instances the two are related. You don't say what kind of parts you're having problems with and that matters too. I agree with the previous poste
