Electronics Forum | Mon Jun 18 13:29:34 EDT 2001 | nifhail
What is the recommanded profile for board which consist of 0402 & 0201 comps. to reduce the effect of tomb-stone. Slow ramp rate ? how slow is considered as slow. Soak time 60 or 120 C,at which end should I stick to? what is the best time before reac
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 | Tue Jan 17 11:52:07 EST 2006 | pms
Got a wierd one here, 0402's tomb-stoning. Scenerio---- Double sided PCB, paste both sides, 0402 on both sides. Reflow bottom side first--- no problems. Reflow topside next----no problems with topside components, BUT, the bottom side that was ref
Electronics Forum | Sun Sep 11 05:48:32 EDT 2005 | Mika
If 0 or 180 degr. make v-shape openings to each other left & riht, if 90 or 270 degr. top/ bottom, on the stencil apertures; well, you understand... We use this and 87 % reduction of stencil apertures for 0603:s and 0402:s. 0.127 mm stencil thicknes
Electronics Forum | Fri Dec 08 16:54:42 EST 2006 | flipit
My experience with SMT LED packages is that certain LED package styles tend to float. This floating is caused because the LED is often only terminated on the bottom side of the LED package. Sometimes the LEDs are terminated like a SMT resistor with
Electronics Forum | Wed Jul 25 11:16:34 EDT 2007 | lloyd
Hi Folks, I hope someone can help me, Is the homeplate stencil design (for reduced solder paste) the same for preventing solder balls as it is for reducing tombstones? i.e. the reduction of solder paste under the component termination. I'm trying to
Electronics Forum | Sun May 02 18:52:36 EDT 1999 | JohnW
| Tombstoning 0805s w/palladium/platinum/silver terminations | | We are experiencing tombstoning problems on 0805 packages that have paladium/platinum/silver terminations. It comes & goes...... | | I�ve checked the reflow profile, and paste deposi
Electronics Forum | Wed Jan 18 10:35:17 EST 2006 | pms
Thanks folks !! I'll experiment with the bottom side heaters. Unfortunatly I don't think our Vitronics-Soltec oven has the option for adjusting the heater fan speeds. And I'll check the conveyor chains. This is our first project using 0402 parts, wh
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 | Tue Sep 08 13:12:05 EDT 2020 | spoiltforchoice
> Tombstone is often caused by an imbalance of > temperature, pad shape or spacing, component > termination, and component positioning. Pate > formulation and reflow atmosphere are other > common causes. Looking at the pads and &
