Electronics Forum | Fri Feb 29 08:12:56 EST 2008 | davef
Solder paste suppliers often make recommendations on solder paste handling after removing it from the container [eg, jar, cartridge, etc]. For instance, Multicore Solder Paste Handling Guidelines, September 2004 says: As a general rule, paste that h
Electronics Forum | Thu Nov 11 11:11:18 EST 2004 | clampron
D.B., You are justified in your concern over the last requirement. I have been imposed by a customer with the same hand solder/rework requirements. It seems the biggest concern is thermally shocking ceramic chips. You are much less likely to do this
Electronics Forum | Tue May 02 15:09:40 EDT 2006 | PWH
Just a few problems you might have to deal with: 1) Your bare boards must be clean and kept clean though-out the process. You could notice handling contamination that might otherwise have been removed in your wash. 2) You will see solder balls a
Electronics Forum | Thu Oct 25 13:35:47 EDT 2012 | davef
Here's a paper that may help http://www.ipcoutlook.org/pdf/assembly_challenges_bottom_terminated_ipc.pdf Temperature Impact * Profile didn’t have a significant impact on voiding. * Voids slightly increased with higher temperature. Reflow Atmosp
Electronics Forum | Tue Mar 03 09:29:48 EST 2015 | rgduval
A couple of things that have helped me with solder ball issues at wave in the past: 1. Flux. Insure good flux coverage on the bottom of the board. 2. Preheat. Insure that the board is sufficiently preheated for the wave operation. Since you're
Electronics Forum | Sun Apr 03 10:07:40 EDT 2005 | davef
In 2001, IVF evaluated the reliability of IBM CBGA and CCGA, i.e. packages with "hard" balls and columns, in space applications for the European Space Agency. One clear result was that amount of solder paste printed on the solder lands is very critic
Electronics Forum | Thu Jan 05 15:09:37 EST 2006 | grantp
Hi, What studies? Can you post a link? I am not sure what the difference is between a ceramic BGA that the high temp solder ball is not expected to collapse, and a lead free solder ball that's run through a lead process and also does not collapse b
Electronics Forum | Thu Feb 24 11:05:53 EST 2000 | Russ
I usuallly like to have the pad size the same size as the ball up to +2mil, the pcb solder mask opening to be +4 mil from the pad size (I have found this to aid in Xray inspection for opens since you can see the little tail of the solder wicking up t
Electronics Forum | Mon Jan 22 11:35:16 EST 2001 | kirks
Hey Mike, what do you recommend for PCB cleaning if there was a mis-print during the screen printing process. Currently we are hand cleaning them with a SMT solution but are having problems with solder balls in the via's and joints. What cleaning mat
Electronics Forum | Thu May 17 08:28:14 EDT 2001 | wavemaster
I would have to agree that the leads are probably geting to hot, but there are many factors that could be the root cause. I would suggest doing a experiment with a solder sample and make 2 recipes. One with a relativly cold profile and one with a r
