Electronics Forum | Thu Nov 08 13:12:02 EST 2007 | russ
Annular rings are too big, it is acceptable to have shorts on the common conductors. I would be willing to say the "other" supplier may have modified the artwork as well. Good fluxing, preheat and proper immersion depth are key to eliminating short
Electronics Forum | Wed Oct 21 08:06:06 EDT 2009 | scottp
I agree with Dave. If the device has a lot of power we'll put thermal vias between the solder deposits with annular rings of soldermask to keep solder out of the holes. We've never had to mess with placement pressure. We've been using QFNs for yea
Electronics Forum | Tue Jun 05 02:22:07 EDT 2012 | vileo72
Dear Dave/pr/Reese, Thank you so much for the information and this will certainly help me to align on the query .Would like to know further :During Flying probe testing the vias are also observed that they have pin mark on the annular ring due to the
Electronics Forum | Wed Feb 17 13:02:03 EST 2016 | comatose
The layer count itself isn't going to be what drives yields. What is the trace/space? How much annular ring for vias did you give them to play with? Class 2 or class 3? What's the worst hole aspect ratio? Controlled impedance? The closer you run to y
Electronics Forum | Thu Dec 05 02:15:12 EST 2019 | sssamw
IPC 2221B mentions a minimum clearance of 0.5 mm between adjacent holes. A drill-to-drill spacing of 20 mils is a standard value in manufacturer design rules. For small annular rings and pad-to-pad clearance, the minimum via distance is often defin
Electronics Forum | Mon Jun 29 16:03:24 EDT 2020 | spoiltforchoice
I certainly can on the Paraquda and I suspect the basic algorithms are the same. Slimmer annular rings such as you might get on a plated via hole don't always image quite as well but if for some reason it doesn't pick it up you should be able to inte
Electronics Forum | Fri Aug 03 12:24:14 EDT 2001 | hinerman
I can only describe how the Grid Lok handles component variability. The compliant caps have an annular ring that is very soft and can mold to different shapes. If a component shows up where there was no component before, the outside of the cap bend
Electronics Forum | Mon Dec 13 00:48:33 EST 1999 | armin
Hi All I have a 0.7 mm diameter hole for vias, what�s the minimum annular ring for this hole diameter? What�s the term unsupported and supported holes refer to in IPC-2221 9.1.2 Annular Ring Requirements? I have a proto-type PCB (designed by our R&
Electronics Forum | Tue Dec 17 17:47:49 EST 2002 | Tim Marc
Dave, I�m talking about the 75% vertical fill of solder IPC 6.3 criteria (B), and 6.3.1 Fig 6-5. I also referred to the annular ring of the Plated-Through-Hole, being coated with solder mask. Semantics, yes I did refer to the Plated-Through-Hole (Sup
Electronics Forum | Thu Feb 13 07:13:39 EST 2003 | davef
Tell us more about the location of the bridging [ie, front-to-back, back-to-back, front-to-front, etc]. Thoughts are: * Your annular ring around the hole seems large. You have 0.007", consider 0.003" to be the minimum. Your board fabricator can gi
