Homebrew PCBs

On Fri, 23 Dec 2005 15:47:42 +0100, adicont2 <adicont2@...> wrote:

> Yes if we solve the pump corosion problem.

A diaphragm pump can be used and doesn't corrode. I'm not sure which,  
either shurflow or flojet was recommended, look in the archives. But they  
are not cheap. (They are usually used for water supply in camping vans and  
stuff).


> "I'm not gonna try that any time soon, since my setup is just too
>
> simple  and too well working to change.
>
>
> Tell me Stefan, you use a homemade tube or a comercialy one like those
>
> make it for aquariums, or a long stone?

I use a aquarium flexible hose. It is made of some foamy material and has  
two rows of very small punctures.
The homemade tube didn't work well (streaks).

>
>
> "duh if a stone is too uneven sitting there then move it"
>
>
> Is perfect true. Moving the bubbler or the board orizontaly is much
>
> better. But this don't solve the problem of differences between top
>
> and bottom of the board.


I don't think this problem can be solved entirely in a vertical immersion  
etcher, well, maybe with the brushes....
Even rotating it will not entirely solve it since the middle is always in  
the middle. (It is kind of the microwave i have here that has a "cold  
spot" exactly in the center. A bloody rotating plate is no help whatsoever  
if there's a cold spot in the center!)

Even with spray etchers this is an issue, a industrial conveyor sprayer  
will show different speeds between the leading edge and the rest of the  
board, because a puddle builds up. On top side that is.



ST