Hi,
is it safe to have tracks between the smd package pads ? or resistors pads ?
I use the autorouting jar from https://layouteditor.com/
It’s ok if you make sure there are soldermask dams between the pads
Check your boardhouses’ requirements for minimum dam width. If your dams are smaller than that, there will be no dams, inferring the risk of solder bridges.
JLCPCB specifies 8 mil between pad edges.
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hmm so guess I have to make a custom Attiny package or tell the autorouter to avoid passing between it’s “legs”
I have no idea how to do that
The distance here is 0.675mm. JLCPCB requires 0.2mm. Where is the problem?
As straubm mention, because the copper of the pads is exposed (there is no solder mask on top of them) there should be solder mask in between to avoid solder bridges between exposed copper, in your case the track passing in between will be covered by the solder mask, there is no risk of having a solder bridge between it and the exposed pads.
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There are some components which require (or heavily recommend) not routing under them, for example some coils, and of course any antenna areas etc. See the datasheet: if there’s no recommendation, I would consider it safe to route under it. It’s quite common strategy for efficient routing. Sometimes people even add 0 Ohm resistors to jump over tracks.
FYI… Geeking, more than anything the post reminded me…
My HomeMade Optical Comparator:
A few years ago I was debugging a PCB problem that required using Microscope to reveal Short Circuit. I discovered a Fragment (microscope photo). That led to the next-step of making a HomeMade Optical Comparator, as follows:
For Magnification and Dimensional Inspection, I used a Printer’s Loupe with Gratings and 3D-Printed a Housing to hold a $10 webcam.
(I accidentally broke the webcam so, just ordered a new one (photo)).
With the Loupe placed into housing and adjusted, you can see very good resolution and fairly accurate dimension inspection, verified with micrometer and caliper…
Burr between two Pads
Metal String Under PCB Coating
Opt Comparator without Camera
Printers Loupe Gratings
In Use
Housing designed to use this/similar Camera
You are lucky it’s outside/under and visible.
Once I had a case where there was a conducting connection INSIDE a two layer FR2 pcb.
Every single component was removed one by one to find that bugger.
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