Electronics Forum | Tue Apr 24 02:56:12 EDT 2007 | chrispy1963
If the PCB you are using is a HASL pad finish and is a leaded assembly, we use homeplate pads with a 5 mil stencil. If the circuit has Enig finish and is PB-Free then we use 1:1 apertures with a 5 mil stencil Either method should provide no solde
Electronics Forum | Wed Feb 05 21:24:35 EST 2003 | davef
Stephen's correct. Radiased outer corners on 0402 pads really do seem to improve things. We aim to try "squared-up semicircles".
Electronics Forum | Tue Feb 04 09:03:45 EST 2003 | Russ Roberts
Greetings, I am pretty new to SMT production, and have learned much from this forum. I am getting ready to build a CCA with many 0402 parts that are really close together. I consider these fine pitch. The board also has two QFPS, so my stencil design
Electronics Forum | Mon Apr 16 09:58:55 EDT 2007 | davef
"Although some lead-free pastes performed adequately and newer pastes work better than earlier formulations, this detailed experiment confirmed that tin/lead solder pastes wet back to PCB pads better than lead-free solder pastes. Therefore, a more ac
Electronics Forum | Tue Feb 04 22:28:16 EST 2003 | davef
You could reduce the paste by about 70%. Solder balling and tombstoning will be the issues to fight. The drivers to these don't change with the component size. Use the fine SMTnet Archives for background. Aperture Size and Thickness of Solder Pas
Electronics Forum | Fri May 06 06:51:55 EDT 2016 | abhilash4788
Hi All, One of my customer has provided a pcb design having common pad for 0402 and 1206 package(i.e 3 pads in the gerber, pad1,pad2 belongs to 1206 package and pad2,pad3 belongs to 0402 package) Will this create any solderability issue. Is anyone e
Electronics Forum | Fri Jan 14 11:16:45 EST 2005 | Dan Gosselin
I have heard of people using a round pad or Home plate design to decrease the incidence of tombstoning on 0402's Anyone have any practical experience on this or is everyone just using the IPC 782 recommended land pattern (28mil x 33mil rectangle pad
Electronics Forum | Mon Jan 17 17:56:14 EST 2005 | russ
Haven't noticed any major difference between C's and R's. Our biggest problem is feeders that will advance to the same location and leave the part in the pocket. We see "billboarding" on R's when the feeder isn't working right. If you have a good
Electronics Forum | Fri May 06 08:47:05 EDT 2016 | davef
You're correct. This design will have a record amount of 0402 rework for tombstoning and misalignments. Suggest that the pads on each end of all components be the same size in order to balance wetting forces during reflow.
Electronics Forum | Mon May 09 09:23:45 EDT 2016 | markhoch
I agree with the previous two replies. This is a perfect design....if you're trying to create a graveyard full of tombstones.
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