Cumulative Design Review

Foxboard bottom PCB

Foxboard bottom PCB

by Henri Kemppainen -
Number of replies: 10

This is the first of three PCBs that I need.

Unfortunately I'm behind on the schedule and don't have the other two ready for review as of yet.  The good news is that the other two are much simpler than the board I just finished.  One will host the key matrix and leds (including necessary components such as diodes, level shifter, some capacitors and resistors), the other is just for mechanical support and has no electrical features.

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In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Henri Kemppainen -
Obligatory KiCad render.

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Attachment foxboard-bottom-kicad3d.png
In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Mark Hughes -
I like the overall design Henri -- very snazzy. Hey -- I'm happy to run additional DFMs for you -- but now that the activity is closed, I don't get updates about new files. So please ping me!. I am curious as to what all the extra mounting holes are there for. Is that part of your enclosure design?

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In reply to Mark Hughes

Re: Foxboard bottom PCB

by Henri Kemppainen -
Ok I just pulled an all nighter to get the rest of the boards done. I also did a little bit of tweaking on the bottom board (around mounting holes & vias mostly). I also fixed a possible short between the fox and the trace beside the ear, noticed by Tony (thanks!).

I don't have any enclosure planned yet. The story of the mounting holes is that I need some way to stack my boards on top of each other, and I didn't have a lot of time to think about how exactly I'm going to mount them or where exactly each hole is going to be. But the switch matrix on the middle PCB is quite dense and can't accommodate large screws.. probably nothing larger than M2.5. So I just wanted a decent number of holes for solid mounting with these tiny screws. And since I didn't know exactly what my middle & top layers were going to look like, I took the approach of going over the board and placing a hole in just about every seemingly viable spot (it's the last thing I did on this PCB). It's easier to live with extra holes than it is to add them later (and if I decide to make an enclosure or need a way to hide unplanned jumper wires, well, here's something). It's also easier to remove them while routing the other boards than it is to reroute stuff to make room for new holes after the fact.. I actually had to (re)move a few holes when doing middle PCB, and I'm glad I didn't need to think of a new location for them them!

I'd like to have those DFMs for these three boards.

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In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Henri Kemppainen -

And here's the top.  (Only two attachments are allowed?)

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In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Mark Hughes -
Yeah -- it's an attempt to limit number of files. I have unlimited storage space -- but a hard limit on the overall number of files I can store.

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In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Mark Hughes -
Hi Henri -- no DFM errors detected in top layer. Also, no PTHs detected -- which is likely intentional in this design.

One potential issue -- by including the word "top" in the gerber filenames, you are potentially confusing the RegEx used to detect layer type. For example, a PTH file in my program incorrectly identified the layer as the top copper. Consider changing to something less common. "Upper", "tp", etc...
The keywords you're trying to avoid are "front", "back", "top", "bottom"

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In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Henri Kemppainen -
FWIW for some reason tracespace shows a couple spots with missing solder mask on the middle board. Weird. I don't see it in gerbview.  I'd like to know if this is something in my files or on their end..

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Attachment tracespace.png
In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Mark Hughes -
Foxboard-middle came up with a few same net space errors -- places where you can modify the copper slightly to remove holes/gaps etc...  
A fab shop may/may not hold your project due to a few of these.  For example, #59 might be a problem. #60 certainly is not.
The silk errors are only errors if they exceed the fab capabilities of the shop you choose.

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In reply to Henri Kemppainen

Re: Foxboard bottom PCB

by Mark Hughes -

All in all Henri, an excellent job!  There is nothing to keep you from ordering your board.  I even took the liberty of panelizing it for you.  Although I'd not use the panel I provided (it's always better to let your fab shop do the panelization), it was a fun exercise.

Just an FYI -- I tried the file on tracespace.io and it's still spinning after five minutes -- might be too much for it.

As for ordering -- you've got 2-layer and 4-layer boards.  4-layer are twice the cost of 2 layer -- so you'll want to group the boards accordingly.  (no need to fabricate a 2 layer design on a 4 layer board).

All in all, a neat design -- I can't wait to see it in physical form.  Do you have a 3D render?

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