Electronics Forum | Mon Feb 02 11:51:23 EST 2004 | prs
Hello, I'm working with Nelco 4000-13 material .031 thk and am experiencing some warping. the board is roughly 1" by 3" and the warping is in the long dimension. The grain on the panel is also in the long dimension. Any pointers or advice on contr
Electronics Forum | Mon Feb 02 16:42:03 EST 2004 | davef
Bow & twist for bare boards and panels: IPC-A-610 1.5% for PTH only and 0.75% for SMT. So, what are you doing to these poor boards to make them warp?
Electronics Forum | Fri Sep 03 14:20:38 EDT 1999 | David
| Could someone shares their experience on the causes of 'Open' in the BGA after reflow. | | You must have been in the same meeting I was in earlier today. We are currently having some opens on BGAs. The problem joints are all on the perimeter of
Electronics Forum | Mon Mar 16 09:07:14 EST 1998 | Justin Medernach
| We have just go another batch of PCB's from our loaders, and some of the boards are severely warped. | The boards are PCI cards and one of the boards is 9mm out at one end. The PCB is 210mm long and 4 layers. | I am wondering if anyone knows what
Electronics Forum | Mon Jan 08 18:58:27 EST 2007 | Mike F
Normally someone would have replied to tell you to do a search of the archives. I've read at least 4 or 5 different threads dealing with baking out PWB's, but none were for this special material. First, have you contacted the manufacturer of the PW
Electronics Forum | Mon Mar 08 19:52:54 EST 2004 | Ken
I have processed the following materials in lead free processes: CEM FR1 FR4-120 FR4-140 FR4-170 Each material has different responses to thermal stresses. Issues to consider are: Panel size, smt only, wave only, double sided smt...and smt / wave
Electronics Forum | Mon Jan 24 22:28:57 EST 2005 | davef
In addition to the potential problems you mentioned, add: * Barrel cracking of PTH and via. * Lifted pads. * Warped boards. And the reason you're not using a solder fountain to to solder this connector is? Or use an old trick we've done here on SMT
Electronics Forum | Thu Sep 02 16:06:33 EDT 1999 | Earl Moon
| Has anyone done or seen any studies done documenting what may be the affect of hardware such as screws in the parimeter vicinity of BGAs on a circuit board? | | What I'm really after is anything describing how close a screw/washer/nut combination
Electronics Forum | Thu Sep 02 16:37:23 EDT 1999 | R Scheller
| | Has anyone done or seen any studies done documenting what may be the affect of hardware such as screws in the parimeter vicinity of BGAs on a circuit board? | | | | What I'm really after is anything describing how close a screw/washer/nut combin
Electronics Forum | Thu Jul 29 11:14:46 EDT 1999 | Justin Medernach
| I'm working on a prototype board that requires a 600 pin BGA. This is a metal top BGA being placed on a 11" x 17" PCB about .62" thick. | | The part is 1.77" square with a 50 mil pitch and 30 mil bump diameter. The bumps are located on the
