Another 1st PCB

[DGTom]

Hi all,
this is my first real attempt at creating a PCB layout in Eagle (free version)
I doubt I will get this made, but, it was an excercise in getting it together. With what I've learnt today I'll expand this into a quad version & price that out.

I'd really like to get a board made for this little sub-cct. as I use it alot with my CMOS prototypes & it gets a little dull cutting the same traces on stripboard over & over.



here is the schem, very standard fare;



It wastes abit of space I think, the power & ground traces are 1.016, should I make them 1.27? I think there is room. Luckily my "default" board size (fits parallel to a single frac space module) seems to fit into the eagle restrictions.

Since I grabbed the above image, I removed one of the vias as a straight trace on the top layer was possible.

Now, to try & fit a quad into the same space!

[Inventor]

Thomas, I think you've done a great job for a first attempt and it's great to see you getting into this aspect of design. Your layout is way too spread out though, as I'm sure you realize, and you would pay much more than necessary for your boards. So I have a few suggestions.

R7 can be moved to the right side of the board. All the parts can be oriented horizontally, or most of them anyway. The thing I like to do is place the parts as best I can then run the autorouter. Then rip up the traces, reposition parts, and reroute. I continue this process until I'm happy with the placement. Then the choice is yours as to whether you want to hand-route or just use the autorouter.

Eagle has a good autorouter. I remember the earlier days of autorouting when all autorouters sucked, and today I'm quite pleased with Eagle's autorouter. You can set the trace size and spacing to your widest desired dimentions, then just let all of the traces be that wide especially on a board this straigtforward.

Good luck and please post your future results!

Les

[DGTom]

Thanks Les
All help at this stage is much appriciated

Wow! Looking at it now, R7 is in an absurb position! All I had to do is bump the connector up & place it, as you say, on the other side of the board & it would make alot more sense! rather than route that signal criss cross from here to timbuktu!!

Here is the first draft of the quad version;



I'm sure tomorrow morn I'll find a bunch of errors, but, its almost midnight here!

There is still some wasted space at the bottom, but, the main thing is these boards hav to be "compatible" with my method of module building;



Which is bulding 'sandwiches' with all the boards parallel to the frount panel

In fact I've just fixed a few little things on the above Quad layout, especially, moving R11 away from the IC & running ground from it straight down.

I'm using the 'free' demo version of eagle for the time being, so, no aurorouter, for now. I figure if I can get a decent utility board going & once I have a taste for it I will upgrade to the full version

[Inventor]

I also use the free demo version of Eagle (on Mac). It has the autorouter included.

Les

[DGTom]

I coulda sworn I'd tried it & got "you can't do that" pop-up, but, I just followed your method, laid out all my parts then ran the autoroute.

Wow, really does help to clear up the jumble. Thanks for your help Les.

I'm trying to arrange all my resistors etc. horizontal, are there any general rules of thumb for how close to put pads etc?

[Inventor]

Yes Thomas, it's usually best to keep everything on a 0.1" grid if possible.

Les