Electronics Forum | Fri Jan 12 16:35:00 EST 2001 | Steve Thomas
I've got a question: Can a joint look good externally, even under 45X magnification, and not be mechanically and/or electrically sound? I thought that if the wetting angles were sufficient, there's no discoloration from extreme thermal distress, or
Electronics Forum | Wed Jul 05 20:54:17 EDT 2000 | Dave F
Hi Patrick: Mike is correct. Taking it a little differently ... The approach you take is dependent on: 1 Type of gold finish 2 Source of the staining. Since you�re talking gold fingers, this is probably hard gold. So, � * If it�s a water or an o
Electronics Forum | Thu Oct 26 08:59:57 EDT 2000 | ptvianc
Performing a wetting balance test would be very difficult. The flux cored wire "configuration" is just not compatible with the methodology of the wetting balance test. If the wetting balance is a must, then you might ask the vendor for the flux for
Electronics Forum | Thu Apr 22 18:07:38 EDT 1999 | Tom B.
| On various PCB's after building processes,such as reflow, flowsolder and wash. The soldermask on the PCB's have become discoloured, like a 'marble' effect all along the solder side of the board, it is lighter in contrast than normal, although when
Electronics Forum | Wed May 20 20:16:29 EDT 1998 | D. Lange
| We notice that DI water seems to tarnish or discolor the metal packaging on crystals and DIN connectors. Our marketing types like the shiney metal surfaces. We don't want to hand solder these parts after washing. | Any suggestions? | Dave F Dave,
Electronics Forum | Thu May 05 12:31:27 EDT 2005 | russ
Not in this case, these BGAs were lead free and the profile used was for a lead part. I guess I will give you the whole story. These boards were sent to us from a customer to have the BGAs replaced for an unknown to us reason. We removed the parts
Electronics Forum | Wed Dec 21 21:24:59 EST 2005 | davef
Primary differences between Matte Tin plating and Bright Tin plating are: * Temperature compatibility ** Matte Tin is compatible with the elevated temperatures of lead-free, reflow processing (250-260C). ** Bright Tin has a tendency to discolor (turn
Electronics Forum | Fri Mar 27 10:04:51 EDT 2009 | ericthered
We have been having problems with proper wetting when running mainly lead free but also leaded solder in our Ersa Hotflow 3. Solder either often looks grainy or doesn't flow over the whole pad. This is generally the case when my profile is 170 firs
Electronics Forum | Thu May 14 22:45:46 EDT 2009 | davef
You're correct. It's a peculiar looking defect. With measling, we expect to see discrete white spots or crosses just below the surface of the base material. We don't see that here. We do see a similar condition at almost every PTH in the picture, a
Electronics Forum | Mon Mar 07 10:59:17 EST 2011 | SheanDalton
RK, what are you trying to remove? What are you trying to remove it from? And, what type of equipment do you have? Generically, I suggest a saponifier, related to other aqueous chemistries, is associated with: -- higher PH -- need for effective che
