Electronics Forum | Tue Feb 22 14:20:55 EST 2000 | Sal
Please let me rephrase the question. Running passive side first and curing the adhesive using a reflow profile derived for 63/37 solder paste. After curing the board is flipped around, pasted and reflowed. My concern is when curing the adhesive usin
Electronics Forum | Tue Jan 16 13:47:24 EST 2001 | cebukid
10% on various BGA packages. I checked the profile and we are getting "ideal" reflow conditions (~ 60 sec. T.A.L.). Ramp rates, temperature deltas before spike zone, and cooling rates are ideal too. I don't believe it's a profile, print, or paste
Electronics Forum | Mon Jul 16 15:49:33 EDT 2001 | Steve
The solder balls you are talking about are caused by too much paste. Reduce the size of the stencil aperatures. Concerning removing the solder balls, the first thing you need to ask yourself is, do I need to remove them. IPC-610, 12.4.10 states, "Ac
Electronics Forum | Sat May 29 16:04:49 EDT 1999 | M Cox
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; processing a double-sided
Electronics Forum | Wed Oct 03 17:06:43 EDT 2001 | davef
Yes, moisture entrapment causes solder shorts 80% of the time. Cracks occur bottom side of the BGA. Use an acoustic microscope to find the cracks. So, what makes you think your BGA are blowing-off steam? I posted a vid on SMTnet that showed the b
Electronics Forum | Wed Oct 02 12:06:59 EDT 2002 | dragonslayr
Scott - all sounds good. My primary concern is the residual flux left behind under the BGA. Will moisture entrapment become a concern over time? I believe that may be dependent on the flux formulation. I know that some no clean fluxes actually become
Electronics Forum | Thu Dec 05 11:36:30 EST 2002 | William Guatemala
Have you check the flux gravity lately? If not, Check the flux gravity every 6 hours to make sure proper parameters are meet. Here is a list of things that may cause your solder ball problems; Excecive heat, defective fixtures, preheating temperature
Electronics Forum | Mon Dec 09 20:50:08 EST 2002 | MA/NY DDave
Hi I kind of agree without any reliability studies. Where are the Ionics coming from? After Soldering depending on chemistry I think we agree? Yet these are bare boards after many processes and even testing that should scrub out or off the Ionics.
Electronics Forum | Tue Apr 13 10:30:52 EDT 2004 | Ken
Threre has been speculation as to voiding as a function of solder paste liquiduous vs. ball liquiduous. Gas entrapment is thought to result if one melts before the other (I forget which order). Two profiles may yield different results as determined
Electronics Forum | Fri Aug 04 06:27:15 EDT 2006 | CL
Good Morning Everyone, We have started limited production runs of RoHS assemblies. Most of them are prototypes for our customers that are converting to Lead Free. We have seen on several assemblies, solder beads under the chip components that are en
