Electronics Forum | Tue Jun 09 17:01:02 EDT 1998 | Earl Moon
1/8" cutters, although they can only be used | with our newer height-controlled machines. | 3. Reduction of operating parameters. Reduced Z-axis plunge rates for the | larger cutter sizes. | 4. Addition of a 1/2 sec. dwell at the plunges. The small
Electronics Forum | Tue Mar 30 22:30:06 EST 2004 | davef
Tony First, drying at 125*C for an hour is not going to do much drying. Heck, those boards are barely warm to the touch. Second, tell us about: * Pitch of your uBGA * Solder paste flux * Cleaning process and agents
Electronics Forum | Tue Dec 08 18:40:04 EST 1998 | Graham Naisbitt
Hi all, Only observation I would make is that it depends upon what you term as clean? Now isn't that an old thorny question. Care to comment? Regards Graham | Hey there Dave! | | We used to use a batch cleaner when we used water-clean paste.
Electronics Forum | Tue Nov 16 14:10:30 EST 1999 | Bill Schreiber
According to a paper by Richard Clouthier, published in 1996, there are two major factors about normal cleaning chemistries that may affect stencil adhesives. 1) Elevated temperature above 110 degrees F. (45 degrees C). Stencil adhesives are heat c
Electronics Forum | Thu Oct 28 11:50:11 EDT 2010 | phase1
We are having a little trouble with what appears to be a crystalization between our fine pitch parts. The problem appears after a a thourough wash of the pcb when dry. It looks like lead wiskers/haze between the joints.We are using water soluable lea
Electronics Forum | Thu Sep 11 23:50:51 EDT 2003 | Dean
Epoxy is hydroscopic. A cavity will form when the cure furnace reaches the boiling point of water. The steam expansion creates the pocket. It can be large enough to be filled with molten solder from the wave machine and cause a hard short under th
Electronics Forum | Fri Oct 12 14:32:52 EDT 2001 | Mike Konrad
Hi, Maybe Yes� Maybe No� Actually, it most likely is acceptable to clean assembled boards in an ultrasonic cleaning system (40 kHz). There are some concerns in some circles about possible damage to wire bonds in components. There have been publi
Electronics Forum | Wed Aug 17 14:18:11 EDT 2005 | ppwlee
Dave, Answers to your questions: * From your pictures, the white residue appears to be only on the solder mask. Is that correct? If not, what is the location [eg, solder, nonsolder/nonmask areas] of the residue that doesn't show well in the pictur
Electronics Forum | Tue Nov 29 12:53:56 EST 2005 | bschreiber
Hello Billy, You are correct when you say that you may want to look at the detergent (chemistry) you're adding to the stencil wash. However, "geared for epoxy removal" depends on how the chemistry is designed to remove the epoxy. If it is a "water
Electronics Forum | Mon May 31 15:09:56 EDT 1999 | JohnW
| | | | | | | | I have always thought it to be a good practice to wash SMA's with water soluble paste (WS609) soon after reflow. Is there a time limit as to how long a board should sit after reflow before washing said board? For instance; processi
