Electronics Forum | Thu Dec 21 13:33:46 EST 2006 | ppcbs
The problem with super glue is that is has a cyanide base that turns into a toxic gas and evaporates when heated. See IPC-7095. Via's should be fully plugged with solder mask at the fab house. If your PCB designers are not up to speed on IPC requi
Electronics Forum | Thu Dec 07 00:55:51 EST 2006 | billylim
As you are aware the common method to rework BGA is : 1. Remove BGA with hot air reflow machine ( SRT as current practice) 2. Clean the BGA pad using solder iron and solder wick. 3. Replace BGA with SRT rework machine. The problem we have with
Electronics Forum | Fri Jun 09 17:34:08 EDT 2000 | Melanie Mulcahy
I need some information regarding the acceptability/unacceptability of using tented vias with LPI soldermask. Long story on all involved, but basically I have a board that I have had manufactured with no problems which has BGA/uBGA parts, tented via
Electronics Forum | Thu Sep 16 18:59:14 EDT 2004 | Carol
Thanks Everyone, the information was very useful. We use 7095 as a bible. A-610 6.5.3 doesn't allow for any solder balls not entrapped/attached etc. so we will look again at plugging/tenting both ends of the via. We ran into the problem of the mask
Electronics Forum | Tue Sep 14 14:52:22 EDT 2004 | Carol
During processing, the solder in the vias reflows and forms solder balls. PCBs have solder in random PBGA vias from the board manufacturer.The manufacturer says this is a result of the HASL process and is unavoidable. We use HASL finish, multilayer,
Electronics Forum | Tue Sep 14 19:47:16 EDT 2004 | davef
use something other than HASL. "The rest of the world seems to be processing with no problems..." [Hello!!! Earth to Carol. This is a test.] Things you are considering could be more trouble than they�re worth. "1) Reduce via hole size" [If you re
Electronics Forum | Thu Dec 07 12:22:50 EST 2006 | jimby
We have our circuit board vendor put a solder mask dot over the vias after HASL process. It's a little more expensive but eliminates the problem that you are talking about.
Electronics Forum | Fri Dec 08 11:57:46 EST 2006 | russ
Good idea Dave F!! never thought of superglue to cap off the via, easier than remasking and curing for sure Russ
Electronics Forum | Thu Dec 21 22:56:30 EST 2006 | davef
Dennis We know that cyanoacrylates are flammable and breathing hazard before curing, but are unaware that the cured adhesive had those properties also. Can you give us documentation of that fact?
Electronics Forum | Thu Dec 07 20:28:07 EST 2006 | davef
When rushing to get a job done, it's easy to accidently remove solder mask from a nearby via when dressing BGA pads after removing the part. Just hit the via with some super glue [then say a small prayer] and push on. As an alternative, look here:
