In very dense applications such as 1.27mm pitch BLM connectors (shown in the figure below, grid size 5mil), it would be very helpful if I can individually set inner pads' sizes to allow easier routing. Eagle currently has "restring" setting in DRC which can be of help, but the setting is global which would effect all my internal pads.
Thanks!
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Solved by jorge_garcia2. Go to Solution.
Hi,
Greatly appreciate posting your comment on the forum, your participation is very helpful. Please remember that Restring compares the value defined in the library and the value calculated by restring, whatever value is greater wins. If you are certain you wish to have full control of your pad diameter, then set the DRC/Restring values to have really small results. For example, lower the default Restring 25% to 5% instead, set the Min values to 0. Setting values this low should then force EAGLE to use the values set in the library.
This was established this way to avoid ever having drill sizes be larger than the pad diameter.
I hope this helps.
Best Regards,
Edwin
Hi Edwin,
Thanks for your reply! Your help is greatly appreciated.
Sorry if I did not get your idea correctly. My understanding is, since we only have access to the "overall" size of a pad using the combination of its "drill size" and "diameter", I can either:
1. make one single pad very thin from top to bottom, by setting its diameter close to its drill size. But in that case the pad would be almost impossible to solder, plus my PCB fab house might have some problem manufacturing it
2. using the method you proposed, which I guess would reduce the width of all pad on inner layers. Again, that's because we cannot directly set a pad's size on inner layers, which is globally defined in DRC rules. That means I can either make one pad very thin on all layers, or make all pads thin in inner layers...
Please correct me if I did not understand the topic correctly.
Again, thanks for your time.
Best,
Chad
Hello Chad,
Thank you for participating. You are correct, at this point in time there is no explicit way to define the diameter on the inner layers however the restring option does offer an implicit way to do this.
What you would do is set the inner restring values to produce small annular rings on the inner layers that way any copper planes you have on the inner layers don't get broken up as much by the vias that go through it.
The inner restring settings are global to all pads, vias, and micro vias as you are aware. When looking at the board you are always looking from the top via so the larger surface diameters on your vias will eclipse the inner diameters. With that said there are ways to observe the difference so that you can get what you want. See this blog post here about how Restring works.
Please accept as solution if my post fully resolves or you issue, or reply with additional details if the problem persists.
Let me know if there's anything else I can do for you.
Best Regards,
Hi Jorge,
Thanks for your reply.
I've checked the post before. It was very close to what I needed. If there's no better solution as you suggested, I guess that would be the way to go for now.
Also, are figure 2 and 3 in that post swapped?
Best,
Chad
Hi Chad -
Moving forward, explicit pad stacks are on the roadmap (including also complex pad geometries). I can't be specific as to when they'll be rolled out (though we need them for multiple reasons, including improving import from other file formats); however we've got them on the list of things to do! Just wanted to add my two-cents and make sure you knew this is something we're looking to improve!
Best regards,
Matt.
Autodesk