AVR-Chat

Hi Chuck,
 
Based on Roberts suggestion on vias, if you go for getting a professional
board made up, you can have it soldermasked and avoid the via shorting
issues, but you need to make sure the vias are tented (cover with
soldermask) so need to check how Eagle does this.
 
Professional boards are not that expensive with a number of companies
offering a 1 or 2 off service at a very competitive price. www.ezpcb.com is
one and then there is www.pcb123.com. You can then worry little about doing
through holes and make the via's smaller as you won't have to solder pins in
to join each side. Actually, you would need to make sure there were none
under your AVR if you are going to hand solder as the base of the IC only
has about 0.1mm of clearance with the board surface.
 
Robert has a good point about REV number etc on the PCB. This way you will
know at a glance which version this is, if you happen to make a few modified
versions over time.
 
Dave.
 
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of Robert Adsett
Sent: 08 November 2010 12:14
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] Looking for critique on board layout
 
  
On 11/6/2010 11:54 AM, Chuck Hackett wrote:
> I know this is dangerous, but ... :-)
>
> I'm looking for a critique of the board layout for my first significant
project.
>

A few suggestions

- Use Eagles via restrict layer to keep layers from underneath 
connectors and chips. Especially valuable when hand populating since it 
considerably reduces the chances of a short and since vias are now 
accessible the are available for adding test points or patches. You may 
have to accept some vias in unfortunate places but I'd at least try to 
remove the issue. Auto-routers will relieve you of tedious work but they 
need a lot of guidance to work well.
- Add a silkscreen rectangle (or several) for notes in marker such as 
stuff date, version etc...
- I normally put PCB part number and rev in copper (the stuffed board 
gets a part number and rev written by marker on silkscreen rectangles)

Robert




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