Electronics Forum | Wed Jun 12 08:24:03 EDT 2002 | davef
Tough. 0402 capacitors are more prone to tomb stoning than resistors. Tailor your process to the 0402 and let the other stuff fall where it falls. Search the fine SMTnet archives for discussion on tomb stoning. Consider: * Changing paste. * Apply
Electronics Forum | Mon Dec 20 22:41:42 EST 2010 | grantp
Hi, We had it for a while, but had to take it out and replace it with normal convection. I mean the soldering quality is absolutely amazing, and the joints looked perfect, however it was a horror for tomb-stoning. We tried all types of stencil apert
Electronics Forum | Thu Apr 12 00:43:38 EDT 2001 | zam_bri
Can anybody gimme some input on the problem I faced currently on 0402 Chip Resistor. At pre-reflow the component are placed nicely but at post reflow, we found the Resistor stands sideway ( both termination, the pad and componant are in contact, fun
Electronics Forum | Fri Jul 16 14:36:40 EDT 1999 | ken
Jeff, if you have not already tried this, try a longer, more gradual reflow phase in your profile. This has worked for me to eliminate tombstoning during similar situations where non standard component pads were used. It may provide you a useable a
Electronics Forum | Sun Sep 09 10:53:05 EDT 2001 | bentzen
For reflow soldering, you are correct ! The higher surface tension of the solder paste in nitrogen atmosphere can increase the number of solder bridges if the component or solder paste print is inaccurate. Another defect that might increase is tomb
Electronics Forum | Mon May 05 11:35:00 EDT 2003 | Grant
Hi, This is an interesting point. I use Koki paste from Japan, and it's wonderful, however what properties of solder paste would make it "anti tombstone" paste? How does led free effect tomb-stoning? That would be interesting to know. We might go
Electronics Forum | Fri Dec 03 11:44:52 EST 2004 | vinod
Hi Barb, First of all I think you are looking for AOI system, not AOL. As per my experience AOI checks for present, absence of the component, wrong polarity, wrong component, misaligned component, tomb stone, upside down etc. It also looks for solde
Electronics Forum | Tue Jan 17 16:09:18 EST 2006 | geb
Tombstoning is usually caused by one joint heating to melting point before the other. Is it possible to have a lower temperature for the heat zones on the underside of the panel, so the paste is less likely to reach melting point. Does there appear t
Electronics Forum | Wed Jan 18 09:18:49 EST 2006 | samir
I had the same exact problem recently. I did exactly as the gentlemen said, and reduced the B/S zones 20 or so degrees, AND changed to medium convection. I'd like to point out that the B/S components still go liquidous (such is the Physics of convec
Electronics Forum | Wed Jan 18 09:55:09 EST 2006 | chunks
Samir brings up a good point with convection ovens. The flow rate of the fans can move parts, which can cause tombstoning to very light/small components. Also, check you conveyor and or chain. If it is not running smoothly, even a slight shake o
