Electronics Forum | Fri Nov 08 17:10:04 EST 2002 | rspoerri
Is that square inscribed or circumscribed with respect to the pad? It sounds like you're saying circumscribed (overprint) given the volume comment. Wanted to confirm though. Kim
Electronics Forum | Thu Dec 19 13:25:19 EST 2002 | russ
We actually look at it like this, The area of a circle that will fit into a square is less. (slight overprint with square aperture with radiused corners) Russ
Electronics Forum | Wed Apr 27 13:50:01 EDT 2005 | russ
You will want the square in this case to be .013" with rounded corners (slight overprint). I do not see why you would need a type 4 paste for this. the aperture as it sits should release well but obviously there is something wrong.
Electronics Forum | Thu Jul 14 16:15:04 EDT 2005 | russ
Can flux really prevent wetting? This seems odd to me. I am actually thinking the opposite of Bman, I am wondering if using a homeplate with an overprint condition might help? Russ
Electronics Forum | Wed Dec 06 06:09:02 EST 2006 | Loco
Would say about the same as above, 8mm according to a cookson presentation we had, of course it would depend a bit on the paste you are using.
Electronics Forum | Mon Dec 11 08:52:11 EST 2006 | beta
Hi, I checked out your component.They are differnet dimensions. You say you are not using the recommended overprint ? if this is the case, I would imagine that is your problem. If you want to contact me off line to discuss further plesae feel free.
Electronics Forum | Thu Sep 13 01:37:15 EDT 2007 | pavel_murtishev
Good morning, Overprint, i.e. make stencil openings for your LED larger. Add printer accuracy to aperture size so that paste would always cover the pad. BR, Pavel
Electronics Forum | Thu Apr 05 07:46:18 EDT 2012 | aj
if you want to get some sort of a joint even to allow AOI to inspect you can overprint on on the outer lead by 3 thou or so. This will give you a joint that can be seen from the side for inspection purposes.
Electronics Forum | Fri Feb 15 12:29:35 EST 2013 | mikesewell
What foil thickness? Type 3 or 4 paste? Have you checked your area ratio(s)? You could overprint or drop your foil thickness by one mil to improve the ratio and paste transfer. As always you can search the fine SMTnet archives for more info.
Electronics Forum | Fri Oct 11 16:25:43 EDT 2013 | scdunlap
Also coplanarity can be poor on these parts so overprinting the paste (beyond the pad perimeter) can increase volume to insure robust solder joint.
