Was curious if there is any reason I can’t run a trace across a line of SMD pads on a part. See attached picture for an example. The parts are SOIC packages.
If they are on a different layer it’s OK.
In this case, it looks like you do want to tie all those pins together. It should be OK if your board has a solder mask (otherwise it will be hard to solder). I would probably move that trace to just outside of the pads and connect the pads to the trace with some thin traces (this isn’t a hi current path) to improve solderability. Either that or use a pour with thermal pads.
If, as Leon implies, the trace shouldn’t be connecting the pins, it would have to be on a different layer.
/mike
The pads of the SOIC part and the trace are on the same layer. It’s a quad transistor with dual collectors. All the collectors are on the same side of the chip and I want them all connected to VDD. I was thinking I could save a little board space by having the trace run directly across the pads like that (there are 7 total transistor chips on the board).
I’ll probably just take your advice, n1ist, and move the traces below the pins. Not worth the risk of waiting a month for batchpcb and have them show up with a problem.
Nothing wrong with that at all, if you have a soldermask it won’t make a difference either way, if not then it might just be a bit messy (ie solder will flow along the trace and stay between the pins) but it’ll still work fine. Might be hard if you ever want to desolder it though (if there’s no soldermask).
You’d need a bit more heat to solder this though (not much though) as the thicker trace to the other pads will absorb more heat.
In the end its entirely up to you… (by now you’ve probably already gone the other way anyway and ordered your boards :P)