Electronics Forum | Wed Sep 01 08:25:31 EDT 2010 | sachu_70
Tombstoning is a result of imbalanced force experiences by the device during reflow due to unequal behavious of the solder paste across all sides of the device. Could be due to many factors a few of this are: (1) Unequal solder mass distribution, (2)
Electronics Forum | Tue Aug 17 13:36:17 EDT 2010 | hegemon
Since you have home plated the apts and done solder reduction, I would take a look at your soldering profile. We have run into this before when running no-clean and found that reducing the initial ramp rate to the flux activation was a help in the
Electronics Forum | Fri Aug 20 09:40:56 EDT 2010 | namruht
kpm, We were afraid of that, so we have tried several variations with paste usage. New paste, transfered paste from another line, and a new tube from another date code. I think the problem is profile, board design or humidity. I just have to starti
Electronics Forum | Sat Aug 21 02:08:00 EDT 2010 | isd_jwendell
I have noticed that the % metal content in the paste can also be directly correlated to solder balls (less metal, more balls). However, I also found differences between pastes from different manufacturers and the number of solder balls (identical boa
Electronics Forum | Wed Sep 01 05:29:40 EDT 2010 | arjan
We baked the parts just before assembly. 2>we baked the parts and store them in 4 days in drycab (60degC, Rh0,5%)and finally assembly 3> we baked the parts and refowed them on a leadfree profile and finally the assembly on the boards. The same we als
Electronics Forum | Thu Sep 02 06:22:34 EDT 2010 | sachu_70
Good. This is the right way to profile. Let me ask you, have you anytime soldered QFN componets on your boards? The concept of LGA soldering is similar to that used for a QFN package. QFN soldering also exhibits void formations, and is an inherent pr
Electronics Forum | Tue Aug 31 11:13:39 EDT 2010 | davef
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Electronics Forum | Tue Sep 14 21:03:42 EDT 2010 | genesan
Hi Sir, The diameter of the aperature is 17mil and thickness 6mil and since we are using Solder Paste Inspection i believe that should have a good paste deposit on this pad.Let say if no good paste it will more create insufficient solder which X-RAY
Electronics Forum | Fri Sep 17 07:33:56 EDT 2010 | scottp
Based on the last few pictures in the report, the root cause is lousy HASL. In fact, you don't have HASL - you've got SnCu intermetallic. Don't mess with your reflow profile, change paste, or monkey with anything else in your process. Have the boar
Electronics Forum | Fri Sep 24 14:15:58 EDT 2010 | emrtech
we have been doing reflow on SLX PCBs and found out that when lidding, the components have been shifting. Has anyone been doing low temp lidding on SLX PCBs using the flowstar 4036 soldering system? If so, what low temp solder was used and profile
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