Homebrew PCBs

A kind of intro. So far this has been an interesting group. I made my 
first PCB about 1971 while in college. We created handmade reverse 
negatives, put photo resist on the boards, developed the image and 
finally etched it (read time consuming).

Today I use pre-applied photo resist boards print to a transparency 
and finish off much as I always did. The only difference is I now use 
a trace outline method of etching as much as possible to eliminate 
having to get rid of all that copper. It's easy to eat up a small 
trace while trying to clear large areas evenly. So I don't.

Huge boards are a little "out there" for a guy with my budget.

Here would be my Uber ideal  method. Print to a sheet. Apply with 
heat which fixes the image and conditions only those areas to etch. 
Etch the board. Use a similar process to create an overlay (for both 
sides) complete with labeling (inkjet) applied with heat. Wipe with a 
solution to remove all undesired applicate, wash with water. Solder 
on components. Simplify is my credo. 

Having got into this business a little after tubes had retired, I've 
seen great changes. SMT is a wonderful thing if the scale is not to 
fine (for us enthusiast). I love not having to drill holes and 
troubleshoot through board discontinuities, etc. 

I still haven't found or used any cheap (read free) software that 
aides me with accurate layouts yet. It needs to compute circuit 
analysis to be a screen to board situation. I'm also just getting 
into MCU's but the software is a bit daunting for a noob. I really do 
love technology.

On Thu, 16 Oct 2008 21:52:01 -0000, you wrote:

>A kind of intro. So far this has been an interesting group. I made my 
>first PCB about 1971 while in college. We created handmade reverse 
>negatives, put photo resist on the boards, developed the image and 
>finally etched it (read time consuming).

Did that myself a long while ago.  Remember it well, Kodak KPR, and I
also remember using an 8x10 view camera to backlight the artwork to
make negatives.
>
>Today I use pre-applied photo resist boards print to a transparency 
>and finish off much as I always did. The only difference is I now use 
>a trace outline method of etching as much as possible to eliminate 
>having to get rid of all that copper. It's easy to eat up a small 
>trace while trying to clear large areas evenly. So I don't.
>

Done the photo etch boards, single sided with a transparency.  Turned
out to be rather expensive for my tastes.  Too many compromises trying
to get two 4x3 boards onto a 6x8 sheet.

>Huge boards are a little "out there" for a guy with my budget.
>
>Here would be my Uber ideal  method. Print to a sheet. Apply with 
>heat which fixes the image and conditions only those areas to etch. 
>Etch the board. Use a similar process to create an overlay (for both 
>sides) complete with labeling (inkjet) applied with heat. Wipe with a 
>solution to remove all undesired applicate, wash with water. Solder 
>on components. Simplify is my credo. 

Well:

1) print to paper, run through laminator, dissolve off paper.  Etch
one side of double sided board.  Drill locating holes.  Run board
through laminator with other side sheet lined up.  Protect already
etched side and etch remaining side.

Same thing with silk screen layer (if needed), no etching required.

Toner transfer can work for you.
>
>Having got into this business a little after tubes had retired, I've 
>seen great changes. SMT is a wonderful thing if the scale is not to 
>fine (for us enthusiast). I love not having to drill holes and 
>troubleshoot through board discontinuities, etc. 

1206 is as fine as I want to go.


>
>I still haven't found or used any cheap (read free) software that 
>aides me with accurate layouts yet. It needs to compute circuit 
>analysis to be a screen to board situation. I'm also just getting 
>into MCU's but the software is a bit daunting for a noob. I really do 
>love technology.

Circuit analysis can be had, but there are limited tools available for
it.  You may need to create a separate schematic and simulate it.

For the rest, I do use Eagle 5.20, which works well enough for me. The
interface is not exactly windows standard, and there are people who
will curse it, and people who will praise it.

Microprocessors, well, consider the total cost of the debugging tools,
the software and the support packages.

I use AVR Mega processors, an AVR dragon (50 USD), my laptop, the free
AVR studio (assembly, C support, programming and debugging) WINAVR C
(also free).

Microprocessors are relatively easy hardware wise, they're generally
just black boxes.  Programming can be learned easily enough depending
on your experience.

Harvey

>

. 
> 
> I still haven't found or used any cheap (read free) software that 
> aides me with accurate layouts yet. It needs to compute circuit 
> analysis to be a screen to board situation. I'm also just getting 
> into MCU's but the software is a bit daunting for a noob. I really 
do 
> love technology.
>

Try KiCAD for schematic and layout. It's very intuitive for Win32 and 
Linux users.

http://kicad.sourceforge.net