Electronics Forum | Tue Jan 04 09:26:22 EST 2011 | scottp
We've been doing this for over 10 years using flux. We print a tacky flux first using an 0.002 or 0.003" thick stencil, then print paste using a thicker stencil with the underside half etched to keep it away from the flux. In our case, we can't jus
Electronics Forum | Thu Apr 10 14:35:18 EDT 2003 | russ
What flux are you using to put them back on? you should be able to adequately clean the site after removal with alcohol or water depending upon the type of flux. "White grungy" usually comes from a liquid flux such as Alpha 857 being squirted on th
Electronics Forum | Fri Mar 26 15:36:50 EDT 2010 | krish_bala
Hello Graham, We are currently using Tacky Gel Flux during our replacement process. We dip the BGA component on the flux prior to placement. Once it is dipped, the alignment and placement is done. As for the profile, I believe I am hitting the corr
Electronics Forum | Thu Jan 19 06:25:42 EST 2006 | bwet
There are several life studies (see for example http://www.solder.net/stencilquik/articles.asp) which point to higher reliability of reworked BGAs using solder paste vs flux. The theory on the mechanisms which allow this to happen are as follows: 1
Electronics Forum | Mon Aug 06 13:17:31 EDT 2012 | leemeyer
Contact Sipad Systems and see if your board is a match for their process. They use a flux that stays tacky for weeks. We have used them in the past for exactly this reason and everything worked out well.
Electronics Forum | Tue Jun 20 10:15:44 EDT 2006 | samir
Again, the verdict is mixed here as well, but from the seminars, white papers, etc. the consensus seems to be that Pb BGA's are not compatible in a Pb-Free RoHS Process...but... Pb-Free SAC BGA's are compatible in a Sn-Pb process as long as your pro
Electronics Forum | Sun Dec 11 22:55:22 EST 2016 | ppcbs
What type of flux is in your solder paste? Active or No-Clean? With lead free solder you really should be using an active flux. The lead free oxidizes during reflow if you are not using a Nitrogen or Vapor Phase reflow. So a more robust and activ
Electronics Forum | Fri May 13 07:28:29 EDT 2005 | Dasume
We've been using 92J now in an automotive environment for 3 years now, one thing that attracted us to it was its ability to take a abuse and a kicking. no matter how your operators mistreat it, it still prints well. you may want to look into 92H, th
Electronics Forum | Wed Jun 15 13:40:49 EDT 2011 | hegemon
I have seen this before with larger PBGA components. When installed using a rework system, I would advise Convective rather thn IR. In my experience having high power (not high temp) convection is the only way to deal with these problematic devices
Electronics Forum | Mon Feb 11 21:57:24 EST 2013 | jeremymek
the reason for not using alcohol in a stencil cleaning fluid is that while alcohol is great for removing liquid fluxes its not good for the solids in the flux it tends to harden them more and make a tacky surface on the stencil. I have seen apertures
