Timeline for What should I do when clearance boundaries overlap with SMD pins?
Current License: CC BY-SA 4.0
7 events
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| Jun 30 at 4:01 | comment | added | NickRand | Awesome, this is all exactly what I needed to know. Thank you very much for taking the time to answer my questions extensively. You have been a tremendous help and I greatly appreciate it! | |
| Jun 28 at 4:21 | comment | added | Tim Williams | Cheers, that makes more sense. Pours, won't really be much room around these, you'll have to make supply connections (i.e. bypass cap) one side, and inductor the other. Trace or poly doesn't much matter, but you can widen the path as soon as it clears the neighboring pads. And yes the trace width will be "too narrow" for ampacity, but that's fine for short lengths where heat is still spreading out. More copper sticking out the opposite side will just reduce clearance or increase distance to nearby components; keeping the layout compact is priority. | |
| Jun 28 at 2:43 | comment | added | NickRand | I am so sorry, I was looking at incorrect information. I see now that the required minimum web is 0.1mm, not 0.2mm. I will go for a 0.23mm pad width and a soldermask expansion of 0.07mm. Given the distance between pads and two mask expansions, this should leave room (0.13mm) for a soldermask web that exceeds the minimum requirement. Thank you very much. I have one more small question if you do not mind; should I extend the copper pour connected to my pin such that it encompasses the entire pin + a little extra around the pin? Or fit it perfectly according to the dimensions of the pin? | |
| Jun 28 at 1:57 | comment | added | Tim Williams | Are they saying (or are you reading correctly) the distance between (copper) pads, two mask expansion plus one web width? | |
| Jun 28 at 0:59 | vote | accept | NickRand | ||
| Jun 28 at 0:58 | comment | added | NickRand | Thank you very much for your detailed response! Lesson learned about trusting footprints found online. I have decreased the pad width down to 0.23mm for all pads so that the soldermask. According to JLCPCB's capabilities, they state that a minimum gap for Solder Mask between pads is 0.2mm. With a pad width of 0.23mm and a soldermask expansion of 0.07mm, the solder mask web in-between each pad is 0.13mm. Does this render the soldermask expansion useless in this case? Could I decrease the soldermask expansion to meet to 0.2mm minimum? Or is that not possible for proto fabs? | |
| Jun 27 at 5:43 | history | answered | Tim Williams | CC BY-SA 4.0 |