Electronics Forum | Wed Apr 13 12:10:47 EDT 2022 | winston_one
Hello! We have a strange effect. Some pads of big trough-hole DDR slot just dessapear. Initialy it was soldered with selective soldering process (leaded, 290 degrees, ImSn finish, very short storage). Then some connectors with poor barrel fill we hav
Electronics Forum | Thu Apr 14 13:49:34 EDT 2022 | winston_one
Thank you for reply, Stephen. No, As I wrote it was leaded process. I heard that it is possible with lead free solder at higher temps an dwell time. At NPL Defect Database I've find this case wich looks exactly the same: http://defectsdatabase.npl.co
Electronics Forum | Fri Sep 14 15:31:02 EDT 2001 | davef
How in earthly heaven would someone else have a report analyzing the defects on your boards? Among the good failure analysis labs that can assess situations like yours are: * Robisan Laboratory 6502 East 21 St Indianapolis, IN 46219 317-353-6249 fax
Electronics Forum | Wed Feb 26 23:59:48 EST 2003 | Mike Konrad
Grant, No-Clean paste + IPA = White Residue! #1: Stop using IPA #2: Switch to either a solvent-based de-fluxing chemical or an aqueous-based de-fluxing chemical. If you are using an ultrasonic cleaner for your boards as stated, do not use sapon
Electronics Forum | Thu Mar 23 10:15:57 EDT 2017 | solderingpro
Rob, That is where Bob works. ------------------------------------------------------- There are many companies that exist offering multiple different products and procedures for cleaning pcb assemblies. I agree, in my practice, most companies str
Electronics Forum | Fri Apr 29 14:16:16 EDT 2011 | ppcbs
Below is the long explanation. This defect is most commonly found with BGA components, but can arrise with all components. I see it happening more now with lead free boards that are being assembled with a no clean flux. Best short term remedy is t
Electronics Forum | Mon Nov 06 21:06:13 EST 2000 | Dave F
Thomas: Wheeee, a 40% failure rate. Now, that make your boss chase you around the room won�t it? As you indicated, x-ray won�t do dip about helping to identifying problems [or ball cracks either]. Consider using an ERSA scope [er whatever they ca
Electronics Forum | Fri Jan 19 17:43:30 EST 2001 | davef
Intermetalic Layer (IL). A compound formed at the interface of two different metals, whose atoms have an extremely high natural attraction for each other, so high, that they do not bond to other elements by any other means. Also, intermetalic compo
Electronics Forum | Wed Feb 02 21:17:55 EST 2000 | Steve Harshbarger
Istvan, The advise from both Roni and Mike sounds right on the money. The problem is most likely that your PCB is not completely dry (the flux has not completely evaporated) in the area where these solder balls occur. You have a number of differen
Electronics Forum | Wed Oct 17 09:38:55 EDT 2001 | fmonette
Dear Daniel, I assume that these components are moisture-sensitive. If they have absorbed too much moisture prior to reflow you might be experiencing popcorning. This typically shows up as a bulge over the surface of the die, in the center of the p
