Electronics Forum | Tue Feb 17 10:55:49 EST 2004 | bobbyv40
Hi Dave, 1. As far as speed of removing componants, we use a board preheater to bring board temp to about 150 C. Then add a flux and then flood all 4 sides of the componant with the low temp solder. Using a suction tool the part comes right off. The
Electronics Forum | Fri Feb 20 08:56:42 EST 2004 | davef
We successfully clean WS flux on 1mm and 1.25mm pitch BGA. For 0.8mm pitch BGA, we use no clean, because we cannot remove the flux residue from under them efficiently. Use ion chromatography testing to be sure it is clean under the BGA. IC is the on
Electronics Forum | Thu Mar 04 22:57:32 EST 2004 | Ken
I have an Aqueous Technologies stencil cleaner and I can see many SAWA advantages over the "larger" machines. 1. Floor space savings 2. Chemical cost (up to 30 dollars a gallon) 3. Hand ultra sonic cleaning could never destroy the webbing and bon
Electronics Forum | Sat Mar 20 08:37:06 EST 2004 | Primus
The BioAct SC-10 wipes work great, but I've noticed some contamination in our solder joints after I began using them on the stencils. After cleaning the paste off the stencil with the wipes, I started spraying the stencil down with isoproponal and bl
Electronics Forum | Mon Mar 08 09:03:17 EST 2004 | russ
Is this problem really related to the size of the BGA OR the size/thickness of the PCB? Would I be correct in assuming that your pre-heater is small in size? Usually a board warps like this when the ramp is to great at the localized area. the imme
Electronics Forum | Thu Mar 18 16:39:14 EST 2004 | Jed Johnson
A few good points have been made here: The profile could be ramping too fast. The profile could be gettting too hot. The profile may need to have more "soak" time before reflow to allow the board temperatue to equalize and the board to "relax" and st
Electronics Forum | Wed Mar 24 10:04:09 EST 2004 | Marc Apell
183C, 60 +- 15 seconds). The quesiton to use a straight ramp or soak profile comes down to the product your are soldering. The key is to get the whole assembly at the same peak temp (minimized delta) and same TAL for effective formation of the so
Electronics Forum | Fri Apr 02 09:50:40 EST 2004 | cedams
Yup. It was definitely checking the fiducials as well as the block skip marks and it used to work pretty well. What it did was started at the center of where the fiducial should be and scanned left. When it found a change in contrast it scanned righ
Electronics Forum | Mon Apr 12 09:39:38 EDT 2004 | cedams
Ken, Thanks for the feedback. Unfortunately (or fortunately) I am in Mexico and we make our own PCBs. That is another conversation entirely and another of my fix-it projects but currently we drill the PCBs and align the artwork to the holes visually
Electronics Forum | Sun Apr 04 08:03:41 EDT 2004 | davef
There certainly is a problem, but it�s unclear from your description whether the source of the problem is: * Design * Soldering * Component quality * A combination Recognizing the SMT connectors see stress that other SMT component do not, you give t
