Electronics Forum | Fri May 23 16:38:28 EDT 2008 | wayne123
Well if you are getting bridges under, one thing that we used to do was flood the part with flux and then run it back through the reflow. Keep in mind we were not a High reliability manufacturer. This practice didn't hurt OUR boards, and most of the
Electronics Forum | Tue Aug 17 15:58:14 EDT 2010 | rob_thomas
IPC-7711/7721 states under Scope section: "This document does not limit the maximum number of rework, modification or repair actions to a Printed Circuit Assembly". This is from Rev B of this standard. There are many factors that play a role in the d
Electronics Forum | Thu Oct 08 15:15:49 EDT 2015 | huske
BGA's are by far much easier to process correctly and inspect. As for LGA's you'll never get 100% of the materiel out from under it during the cleaning process. The voiding issue is magnified with and LGA, the low standoff is the reason for the v
Electronics Forum | Wed Mar 15 04:36:16 EDT 2017 | Rob
@ Sr.Tech, Any voiding means that the part of the package under the void is not forming a solid thermal interface with the PCB, therefore it's heatsinking capability is reduced. With the drive for smaller packages with higher power handling capabil
Electronics Forum | Wed Mar 15 10:21:08 EDT 2017 | pzappella
Hello Rob, I totally agree with you. Is this a real problem that is being shoved under the rug or just whatever voiding we get from a belt furnace is good enough. I think vacuum reflow can do much better but is a batch approach and not contin
Electronics Forum | Mon Apr 09 13:53:45 EDT 2018 | dleeper
I've never placed one of these before, but it looks like a poorly designed part. It has pads scattered asymmetrically around the body of the part. when it reflows this is going to apply uneven forces to the component, causing it to skew. I guess hav
Electronics Forum | Fri Mar 06 10:32:34 EST 2009 | fountain42
Yes, We've already experienced this same problem. 1) What kind of flux are you using? No Clean? Rosin? OA? 2) If it's OA, What kind of water wash do you do? Do you use DI water? How Hot? Who's machine? What are the pressures? 3) Have you performed a
Electronics Forum | Thu Feb 10 13:54:22 EST 2000 | Kris W
Hi All, We are in the process of converting from RMA solder paste to no-clean process across the shop. This will allow me to carry my semi-aqueous cleaner out of the building and set it ablaze using the terpenes as the fire water. Then I can go ab
Electronics Forum | Mon Dec 17 11:55:08 EST 2007 | chef
I recently had the same problems, solder bridges on every thing I made, different customers boards, etc. I wave with no-clean flux. As I sorted out problems (pin holes, blow holes, splatter, etc.) I found a lot of variable factors. I changed flux,
Electronics Forum | Tue Mar 24 17:14:44 EDT 2009 | bas251
In my experience, before my current employment, I have personally seen damage from the water soluable fluxes left under a BGA. In consideration, I have not seen it from an assembly process where the boards are cleaned thoughly, but I have seen it dur
