Electronics Forum | Wed Dec 27 21:12:30 EST 2000 | Dave F
From a process perspective, I don�t know if you should be concerned ... You've told us nothing about your process. THE BOOK JEDEC MO-51 allows 6 thou warp in smaller [1mm pitch] BGA and 8 thou in larger [ 1.27mm and 1.5mm pitch] BGA. The increase
Electronics Forum | Fri Feb 27 10:12:36 EST 2004 | stefwitt
The front plate of the S15 head gives you access to the signal amplifier boards. You'll find 4 potentiometers adjusting the voltage and the symmetry of track A and B. A digital scope turned to X+Y provides an image of a circle, which is been adjusted
Electronics Forum | Wed Jul 06 20:33:39 EDT 2005 | davef
Pat In response to your questions: Q1. How did you measure the area reduction (loss of weight or reduction of diameter/thickness)? A1. We measured the starting and ending diameter. Then calculated the area [assuming symmetry]. Q2. How did you tak
Electronics Forum | Thu Feb 13 03:30:28 EST 2020 | tamasmagyar
Hi Nizar, Pick and Place nozzle, pick-up speed, component symmetry if it has to be rotated while picked up are just some things I would look at. See also if the trays you pick connectors up from, are programmed correctly to the machine. You can al
Electronics Forum | Mon Mar 12 10:13:43 EST 2001 | CAL
At APEX I was able to witness the BEAM WORKS Selective Laser Soldering machine operate.Truly impressive. When they told me they could solder a BGA component, I old them they were HIGH as a kite. The board they demonstrated had 4 BGA's on it. When the
Electronics Forum | Tue May 22 17:21:43 EDT 2001 | davef
BGA require placement accuracy of only 0.3mm (�12 thou), compared with a required placement accuracy of 0.08mm (�3 thou) for fine pitch devices. Even with this level of misalignment, plastic BGA self-center / self-correct during reflow due to symmetr
Electronics Forum | Tue Apr 29 07:38:42 EDT 2008 | davef
Warpage typically (not always) kinda, sorta points to a fabrication bake induced issue that is the racking technique & may be relieved by "flat baking" under weight. Your baking at 125* won't do dip. You need to get the laminate temperature above it'
Electronics Forum | Mon Jul 16 21:39:40 EDT 2001 | davef
The method you suggest is about the only way to �clean-up� this terrible situation. Realistically, this is a "memory" type condition induced by design, build symmetry, "cross ply construction", excessive cool down rates during lamination or reflow a
Electronics Forum | Tue Feb 26 10:55:58 EST 2002 | davef
This could be an electroless nickel / immersion gold specification. While the symmetry of the numbers is pleasing to the eye, but as Joyce Marchand says, "It doesn't blow-up my skirts." Problems with your specification are: * Lower end of the gold
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