Electronics Forum | Fri Jun 29 23:10:02 EDT 2001 | Danial
Thanx for the reply guys!! The problem happened on only one PBGA, the balls are eutectic and the paste volume height is at 5.96 mil min. The stencil opening has been increased to 30 mil which initially was 20 mil. You guys are right!! One probable
Electronics Forum | Fri Jan 14 16:58:20 EST 2000 | Dave F
Dave: You're probably correct about too much paste, given that your balling is congrigated near the center of the chips. Three things to consider: 1 Lower temperature profile @ front 3 zones 2 I've heard some stencil suppliers can plate addition
Electronics Forum | Fri Jan 14 17:24:08 EST 2000 | John Thorup
Yeah, it would be kind of expensive to replace all of your stencils but it's the only real answer. Be sure that all your new and replacement stencils have a home base or home plate shape for the passives. This reduces the paste volume near the cent
Electronics Forum | Fri Dec 03 18:17:12 EST 1999 | Dave F
Dave: There's lots of stuff on the web describing BGAs. Examples are: http://www.smtnet.com/bookstore/publications/0speckdo1/s1.html http://www.smtnet.com/bookstore/publications/0shutcco1/ch1p2.html http://www.citizen-america.com/OEM/bga/process
Electronics Forum | Wed Nov 10 18:02:54 EST 1999 | John Thorup
Hi Dave Sounds like what we call a "squeeze ball". Usually caused by excess paste squeezed over the mask between the pads of the component when placed. This sometimes escapes the pull of surface tension back to the fillet and escapes to the side, us
Electronics Forum | Sun Sep 05 12:59:48 EDT 1999 | Dean
| Could someone shares their experience on the causes of 'Open' in the BGA after reflow. | | Single sided BGA assy? Or double sided BGA assy (BGA's on both sides)? I have processed double sided (MIrror assy.) bga assemblies and can tell you it is
Electronics Forum | Thu Aug 05 10:55:09 EDT 1999 | Wolfgang Busko
| | | | | | Hello, | If you are using no-clean and they are entrapped in the flux it is also IPC accepted but i havent found a customer yet who agrees with that. Im sure you have checked your profile. I had the same problem with chip components but
Electronics Forum | Mon Jul 12 09:13:08 EDT 1999 | Mark Charlton
I need some advice concerning reflow of a BGA-292. Since I am not ready to change my entire process to no-clean, I decided to place the lone BGA-292 on a proto run using our BGA re-work station. The pcb is a moderately dense, single-sided, 8-layer
Electronics Forum | Fri Apr 09 12:46:10 EDT 1999 | Bob Barr
I have been using an Air-Vac DRS-22 for almost two years with very good results. Once a profile is developed it is very repeatable. The DRS-22 is no longer available, however. It has been replaced by the DRS-24. Unfortunately, the DRS-24 has a lo
Electronics Forum | Thu Feb 25 10:17:44 EST 1999 | Joe Cameron
I second Dave's encouragement to use the archives. It's a wealth of info and the search engine usually get's me what I want the first time. By the way, Richard, are you soldering your thermocouple to a ball on the BGA with hi-temp solder? It'd hel
