At 06:32 AM 7/03/2002 -0000, you wrote:
>--- In Homebrew_PCBs@y..., Adam Seychell <adam_seychell@y...> wrote:
>> I'm afraid it doesn't work like that. Buying a secondhand plating
>machine
>> ain't going to make you PCBs.
>
>I didn't mean second hand. I have been looking at the Prototype
>plating machines. Like QuickPLATE. But they all seem to use the
>process of squeezing conductive ink into the hole manually. The INK
>in itself is expensive.
>
>BTW: In your process the board is completely coated then plated
>correct? So the board must have a thinner layer of copper to work
>with in the first place or the thickness would be uneven correct?
>
>Lates.
>
>--
>John Hallows
>
By starting off with blank copper cladded board you mean ? then yes.
The process is called "pattern plate" which I think is the most common
method of making through hole boards, both double sided and multilayer. The
other widely used method is "panel plate". This requires better setup with
photoresist and it must "tent" the hole walls to stop etchant from removing
copper inside the holes.
The carbon black though hole method is not suitable for making large
surfaces conductive. The holes are of relatively short dimension so the
contacts made to the carbon (i.e. at the hole ends where it meets up with
copper foil) can propagate copper through the hole wall during the first 1
to 2 minutes of the copper electroplating process.
Here is a good link describing the steps on manufacturing a multilayer
board (pattern plating).
http://www.pha.jhu.edu/~akeeney/PWB/some more PCB info can be had at;
http://www.epa.gov/dfe/pubs/pwb/tech_rep/usecluster/pr_toc.htm