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My latest Eagle PCB.

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Zero999:
I thought I'd do a more complicated PCB.

The schematic is pretty simple, a ring oscillator with the LEDs configured so one illuminates after another but it's a pain to route. To make things more difficult for myself, I did it on a single side and didn't route between the pins on the IC or capacitors; if I were to make this PCB myself, I wouldn't have a solder resist which means there's a high risk of bridging where there are pins soldered close to neighbouring tracks.

I tried using the autorouter but it's rubbish, worse than A!tium's, in the end I did it the hard way. I didn't expect the autorouter to work because it probably wasn't possible given the way I had placed the parts; when I did it myself, I had to rearrange them.

I know it's probably possible to do a better job. I'm not completely satisfied with it and will have another go at it. I think I'll do a rough sketch first, then I'll place and gate swap accordingly.

TheDirty:

--- Quote from: Hero999 on July 12, 2010, 05:33:13 pm ---I wouldn't have a solder resist which means there's a high risk of bridging where there are pins soldered close to neighbouring tracks.

--- End quote ---
Other people have said this too, but I've never found this to be the case.  If you get a bridge, use a bit of solder wick.

Zero999:

--- Quote ---Other people have said this too, but I've never found this to be the case.  If you get a bridge, use a bit of solder wick.
--- End quote ---
It's never happened to me before, but that's because I've never done it on a home made PCB.

Yes, I know it's fairly easy to fix but it's a huge risk, such a fault could damage a component, for example suppose a gate output was shorted to a power rail? The IC will burn out. Fair enough the 74HC04 isn't expensive but it's still a pain to replace.

Maybe I would do it if I had absolutely no choice and if I do it, I'll try to make sure I only do it with pins and tracks that won't physically damage components, if there's a short.

You might think I'm paranoid but I'd rather spend longer routing a board, than wasting time debugging or money on failed components.

shodan:
could you post the project file ?
I'd like to give a shot at optimizing this layout

TheDirty:

--- Quote from: Hero999 on July 12, 2010, 07:48:35 pm ---Yes, I know it's fairly easy to fix but it's a huge risk, such a fault could damage a component, for example suppose a gate output was shorted to a power rail? The IC will burn out. Fair enough the 74HC04 isn't expensive but it's still a pain to replace.
--- End quote ---

Why would you not see this before you put power to the board?  Especially on single sided where you can just hold the board up to the light and see through.

I've done many 0.5mm IC's on home made boards and even 0.4mm and for me it's a non-issue.

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