Electronics Forum | Thu Oct 14 23:01:48 EDT 1999 | Dennis O'Donnell
With loaded boards, warpage can be removed by placing the assembly in a wave solder conveyor pallet as you would if you were going to wave solder the assembly. Place board and fixture in a Blue M forced air oven at 90 C for 30 minutes. Let cool to r
Electronics Forum | Thu Oct 14 20:42:07 EDT 1999 | Jeff Ferry
Grace, As deifned in IPC 7721 Procedure 3.2 Bow and Twist Repair "Bow and twist after soldering shall not exceed 1.5% for through hole PC boards and .75% for surface mount PC boards. The bow and twist shall not be sufficient to cause difficulties d
Electronics Forum | Thu Jan 21 15:24:18 EST 1999 | Terry Burnette
| I have received prototype PBGA (256 pins) devices from | Motorola (actual part number = KXPC850ZT50). These parts seemed very warped on the edges. When I put the part on a plain surface, it rocks quite a bit when I press lightly on a corner. I h
Electronics Forum | Thu Mar 02 05:30:45 EST 2006 | arnie
we are encountering a problem wherein the ballast transformer we built on the pcb produced a vibration or a humming sound.? what is the possible cause on it. what may the problem on the assembly of transformer.
Electronics Forum | Thu Mar 02 13:31:25 EST 2006 | russ
That was a good reply for someone that has been Dehumanatized! HAHA
Electronics Forum | Thu Mar 02 13:49:43 EST 2006 | Chunks
Dehummmmmmmm - anized!
Electronics Forum | Thu Mar 02 15:32:30 EST 2006 | russ
got it!
Electronics Forum | Thu Mar 02 07:54:07 EST 2006 | davef
Here's some explanations: http://www.psaudio.com/articles/hum.asp http://www.signweb.com/neon/tips/neontip12.html We like the 'don't know the words' one.
Electronics Forum | Thu Mar 02 13:13:14 EST 2006 | Chunks
A ballast is the device needed to energize fluorescent lamps during operation. In all fluorescent lighting systems, the ballast provides the proper voltage to start the lamp and then regulates the electric current flowing through the lamp to stabiliz
Electronics Forum | Fri Jul 30 17:20:09 EDT 2004 | Francois Monette
A couple of other potential issues are moisture/reflow related issues. This can include internal delaminations inside the component, potentially breaking or lifting the wirebonds. It may also induce warpage where the corners of the BGA will curl up.
