Electronics Forum | Tue Jun 07 19:04:07 EDT 2022 | proceng1
IF the two are identical, swap the suspected bad one (#2) position 1, and see if the fuse blows before connecting the second one. Basically the same test process you describe, but swap the units first. See if the problem follows the card, or stays
Electronics Forum | Mon Apr 07 04:33:43 EDT 2003 | Neil
Iman, How long after washing the boards do you process them? Are there any vias or Micro vias on any of the pads you see the blow holes on? A possible cause of a blow hole in a solder fillet or PCB is the escaping of Moisture under extreme temps. Th
Electronics Forum | Thu Apr 07 09:04:19 EDT 2011 | mosborne1
First of all you need a new board house. You should quote us http://www.americancircuits.com. This really looks like a poor drilling operation with the blow holes. Blow holes are usually caused by two main problems. Improper drilling and/or moisture.
Electronics Forum | Thu Jun 28 09:57:50 EDT 2012 | mosborne1
blow holes and via holes are almost always caused by moisture and in PTH they could be moisture and improper drilled holes. If you are seeing solder balls next to the parts than I would say you have a reflow profile problem. Are you using any kind of
Electronics Forum | Fri Sep 17 03:13:00 EDT 2010 | grahamcooper22
In HASL pcb coating you need to fully coat the pads with solder and then blow off any excess solder to leave a nice coating on each pad. Generally pcb manufacturers try to give you a flat pcb pad to make your solder paste printing more consistent. To
Electronics Forum | Wed Mar 21 16:32:03 EST 2001 | mparker
The root cause is dependant on the type of solder "splash", ball, whatever, that you are seeing post reflow. If it is smears, then cleaning the stencil underside is probably the answer. Are you using automatic wipers? How many print cycles between w
Electronics Forum | Fri Nov 19 14:40:48 EST 2004 | glaucon
The R.H of 28-30% is too low! (What about ESD issues?). Have them check to see if the printer/print area has a "breeze blowing" accross it, they can disconnect fans inside if needed to limit airflow from drying the paste out.
Electronics Forum | Mon Feb 21 03:56:34 EST 2005 | abhirami
Agree with Davef. Smaller the chip, more the static charge. I used to see this even with normal chips. Get an ionizer blow. It should solve your problem. May be switch to antistatic tape if affordable.Regards. GV
Electronics Forum | Fri Sep 22 04:43:18 EDT 2006 | greg york
Interesting you should ask this what problems are you seeing. Non wetting and blow holes and shallow fillets at all??? Cheers Greg
Electronics Forum | Fri Sep 17 03:03:29 EDT 2010 | grahamcooper22
Hi Gani, looking at the HASL icture and the poor wetting of the solder over the pads I would imagine that the HASL coating is very thin on the pads and in actual fact isn't 'solder' but is tin /copper intemetallic and this has poor solderability. It
