Homebrew PCBs

On Thu, 06 Jan 2005 13:42:01 -0000, Vasile Surducan <vasile@...-cj.ro>  
wrote:

>
>  Now, be honest, how many boards produced in the indicated manner
> looks EXACTLY the same? How many problems do you have when are
> mounting SMD devices on those boards? Show me please a picture with
> your highest desity PCB board, homebrewed.
> best regards,
> Vasile


The question is not if they look the same, but could they look the same.
If top quality is your goal you must optimize your process for it, i  
didn't, i wanted a cheap and fast process with OK quality.

Also, maximum component density is not something i optimize for, there are  
practical reasons to have lower component density than possible with the  
process.

I don't have a digital camera but i can show you the layout of a board i  
made.
<http://trethan.at.tf/pub/esr.gif>
it is about the highest component density i'm willing to use.
You see it has DIL ICs, but this is because i had them in stock and  
actually the component density is higher if you use a single sided board.  
(because the DILs are at the "unused" side).
I'm sorry i can't provide a scan of the finished board but it is mounted  
inside a meter and i'm not willing to take it out (it is glued in).

For my first board using compoent legend on copper artwork sucessfully  
look at
<http://trethan.at.tf/pub/comp_bot.jpg>.


Ha, found a scan of the ESR meter board you saw the layout above:
<http://trethan.at.tf/esr_bot.jpg>
You see, the legend went wrong, it was the first try, look at the URL  
above to see how it should be done.
The fault with the legend was apparently why i scanned it.

If you look at the top <http://trethan.at.tf/esr_top.jpg> you will see a  
certain offset in the component legend, another flaw i worked out already.  
You need to mess up a few beers before they are good.

A board i sell:
<http://trethan.at.tf/pub/milliohm/top.jpg>
<http://trethan.at.tf/pub/milliohm/bot.jpg>
<http://trethan.at.tf/pub/milliohm/external.gif>

You see, not top quality, why? It was requested not to use SMD and to make  
it big enough for novices to solder.
The customers wanted a cheap PCB they can easily assemble.

I am very limited with what i can do because i use a ancient LJ IIID  
(300dpi). this makes use of fine pitch SMD very hard, but i'm working on  
getting a new printer.

Homebrew beer. As good as you want it.

ST