Homebrew PCBs

Markus Zingg wrote:

Drill those two holes so
> as you later can insert a shaft? (hope this is the right word for it)
> into them. 

Actually the english word for what you describe is called a dowel.


> 6) put a very thin layer of 2 minute epoxy (devcon or araldit is fine)
> on both sides of the inner layer. Apply it to the INNER layer and do
> it all in one step. The reason to apply it to the inner layer is to
> make sure there is glue in the etched away parts. Then put the stack
> together again using the two center shafts. Put as much pressure on
> the stack from both endes as you can. I use two wooden blocks on both
> endes and built a wooden construction that holds two vises which
> actually press the stack togeter. I used two vises to have more
> pressing area and power. Of course if you have a press available
> that's better. Let it dry for 5 minutes.
> 

I have tried 5 minute epoxy on PCB material and it doesn't bond 
anywhere near as well as professional multilayer panels.

Professionals bond layers with a special purpose partly cured 
epoxy sheet called "prepreg". I think they insert the prepreg 
between layers. Then they press at something like 20kg/cm.sq 
pressure and heat to 175\ufffdC for several hours. The heat completes 
the cure of the prepreg layers and it develops a super strong 
bond.  Here is a data sheet of found on the web of some prepreg;
http://www.rogers-corp.com/mwu/pdf/RO4400dsandfab.pdf


Can you wedge the PCB layers apart by forcing a screwdriver in 
the edge ?

The only other step you are missing from professional multilayer 
process is the "epoxy etch back" or "hole desemaer" where after 
drilling there is epoxy smeared on the innerlayers and can 
interfere with the through hole plating, so they put the board in 
a hot solution of potassium permanginate/NaOH which removes a 
small amount of epoxy. I have no idea if this step is necessary 
for your application.