Electronics Forum | Wed May 10 08:41:19 EDT 2006 | russ
Yes, we added some soak, we also use a 5 zone oven. We utilize a .020" x .020" pad with center to center at .042". We only get tombstones on misplacement or bad paste release now. Registration of component is key with pbfree, the parts just don't s
Electronics Forum | Mon Feb 18 03:40:04 EST 2008 | akareti
Hi everybody, I found a defect varistor 0603 Tombstone and poor welting when we use component that terminal is Silver palladium (Ag/ Pd) with Leaded solder paste (63/37). Then we change alternative component that terminal is Ni/ Sn the result not fou
Electronics Forum | Thu Nov 02 17:15:34 EST 2000 | Erdem Bilaloglu
We are using semi-circular land pattern and 0.004" smaller appertures on screen. With stable rising slope (max:2.6degC/sec)we have not experienced any tombstonning so far.
Electronics Forum | Wed May 31 13:14:42 EDT 2000 | Dason C
I learn from Senju Metal, they have a formula with certain percent of Ag and Cu can elimate the tombstone. The hint is the eutectic only one reflow and the new material have two reflow. Please let me know your result. Rgds. Dason
Electronics Forum | Wed Apr 12 09:20:57 EDT 2000 | C.Long
anyone any ideas how to minimise my DPM as regards tombstoning..i have checked oven profile..appeture size on my stencils..placement machine etc and still problems.???????????
Electronics Forum | Wed Apr 12 13:25:51 EDT 2000 | Billy G
Chris, is right! Pad geometry is one of the biggest factors of tomb-stoning. Check Pad size against parts size.
Electronics Forum | Wed Apr 19 08:45:33 EDT 2000 | Mark
THE PROBLEM IS DEFINETLY CAUSED BY INCORRECT PAD DESIGN. A FRIEND DID A INVESTIGATION ON TOMBSTONING AND HAS THE CORRECT SIZES.HE CAN BE E-MAILLED AT NMANSON@AFTE.COOKSON .COM OR TEL. 0094 1355 276 500
Electronics Forum | Fri Apr 21 14:31:20 EDT 2000 | JACOB LACOURSE
I FOUND THAT ONE OF THE MANY REASONS FOR TOMBSTONING COMPONENTS IS MOISTURE IN SOLDER PASTE. ONE WAY TO CONFIRM THIS IS TO CHECK FOR EXCESIVE SOLDER BALLS AROUND THE PART IF THEY ARE PRESENT THEN YOU MAY HAVE A HUMIDITY PROBLEM. GOOD LUCK!!! JAKE
Electronics Forum | Mon Jan 17 04:25:50 EST 2000 | Wolfgang Busko
PC: I guess you talk about something called tombstoning. About causes and adequate countermeasures you will find enough material when you browse the archive with this search item. Try also "tombstone". Good luck Wolfgang
