Electronics Forum | Wed Jun 01 00:25:28 EDT 2011 | alcatel
I have one pcb which has via holes on both solder pads of 0402 chips. Right now im using type 3 solder paste with 45 degree squeegee. and a lot of these chips are tombstoning. Im guessing with larger particle size of solder paste, the solder will
Electronics Forum | Wed Jul 01 04:54:28 EDT 2015 | jvercamm
hi, the last post on pad cratering dates from 2012. We have (likely similar) problems with a RoHS 783 solder ball BGA size 29x29mm^2 (organic package BT), pitch is 1mm and solder ball diam is 0.5mm the field failure is after 12 months, almost exclu
Electronics Forum | Mon Jun 11 14:25:36 EDT 2001 | CPI
I had the very same problem but, did not question my oven as I knew the profile was good and I should have had even heating. So I then looked at pad size and layout. When Layout and size were found to be ok. I attached a prob to each pad and ran a pr
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 Mar 05 11:53:09 EST 2009 | dcell_1t
Hello to all. for certain time, we have been struggling with some issues on a PCB where have tombstoning on 0402 components (due to pad design) and dewetting in qfp256 0.5 mil pitch (discussed on another threads on this forum) component, we have pro
Electronics Forum | Tue Nov 13 20:29:03 EST 2007 | grantp
Hi, What size via's are you guys seeing, as the ones in our products are incredibly tiny, and via's are very small now days. The via's on the boards we have are dramatically smaller than the pad on an 0402. Grant
Electronics Forum | Wed Nov 14 13:05:40 EST 2007 | rgduval
I had one project with micro-vias in 0805 and larger pads, with no issues. But my most recent project had vias that were larger than the 0402 pads that the via was in. To the point that for a number of the lands, there was no visible pads (a couple
Electronics Forum | Thu Nov 15 08:25:08 EST 2007 | rgduval
I do think that the designer goofed, and used too large vias. I believe he only used on size via on the entire board, regardless of whether it was in a pad, or out on the board. I have seen vias in pad work, though. From a manufacturing standpoint
Electronics Forum | Fri Jun 30 10:42:24 EDT 2000 | Chrys Shea
That pad had a 16 mil dia, so I arrived at 20 mil squares by adding 2 mils to each side of the pad. Following that logic, a 12 mil pad would use a 16 mil square. But a 12 mil pad is on a finer pitch that isn't mentioned, so you should definitely
Electronics Forum | Thu Jun 29 09:46:41 EDT 2000 | sree
Hi Jax, The microbga discussed earlier in the forum is mounted on 16 mils pad whereas mine is on 12 mils pad. Can I use the same aperture opening ?Please advise.
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