Electronics Forum | Mon Sep 24 11:12:56 EDT 2001 | nwyatt
Hi. We are currently using an unconventional method to rework a micro BGA - removing component with hot air, fluxing the area, placing the part with pick and place, then reflowing it in the oven. The reason we are doing it this way and not with a r
Electronics Forum | Mon Oct 06 10:04:29 EDT 2003 | davef
Excess low residue flux is very dangerous to leave on your finished assembly, because it can: * Be corrosive to your solder connections * Promote dendrite growth. To prevent this, follow your supplier's recommendations on: * Applying the proper amou
Electronics Forum | Fri Mar 21 21:13:03 EST 2003 | iman
Russ, u mean excess flux causes "blow hole" defect?
Electronics Forum | Fri Apr 04 14:49:51 EDT 2008 | tombstone
Flux seperation is a common problem observed due to expiration of paste. The symptom is a yellow layer of flux when you open the jar. Excess flux separation will cause priting problems such as smearing and slumping.
Electronics Forum | Tue Jan 16 20:44:07 EST 2007 | davef
Bridging Causes: Insufficient flux, Excessive pre-heat, High conveyor speed, Solder contamination Look here: * http://www.smtnet.com/library/files/upload/Reflow%20Wave%20Poster.pdf * http://smt.pennnet.com/Articles/Article_Display.cfm?Section=Archi
Electronics Forum | Tue Sep 25 09:57:40 EDT 2001 | nwyatt
In regards to your last question, - problem is failures and most think it is due to too much flux - we apply flux with a brush - amount applied depends on the operator applying it - the flux is very thick and will hold the part in place before reflo
Electronics Forum | Sat Mar 25 16:05:13 EST 2006 | loz
Hi, sounds unusual if your profile is accurate that you have so many residues. Had a similar problem before with no clean flux and with various flux manufacturers, and all residues were down to excess flux. This does not help your case though. How a
Electronics Forum | Wed Apr 28 15:08:10 EDT 2004 | russ
This could be a long shot but here goes. I have found that if flux is applied in excess that it will actually "move the solderballs" during reflow. I have actually seen where the balls are completely outside the package and oviously there are short
Electronics Forum | Mon Sep 24 20:38:27 EDT 2001 | davef
Mike's comments are well taken. Your technique works fine with BGA, but uBGA are less forgiving. Again, let's take about: * Specifics of the problem. * Amount and method of applying flux. * What's holding the uBGA in-place before the solder ball an
Electronics Forum | Fri Sep 28 16:51:41 EDT 2001 | pcmarch
I have had success by applying the paste flux with my finger, using a finger cot and spreading it on the PCB. This seems to put it on more consistently than using a brush.
