On Thursday 22 May 2003 12:07, Stefan Trethan scribbled:
> i think all processes are capable of providing nearly the same results if
> used properly. the one thing is the resist, it must be suited for the
> etchant.
I use the positive photo-resist boards from MG.
> the second, underetching under the resist, can be prevented if the process
> is used the right way. i think if all is right (aeriation if needed,
> stirring, heating) and all is set up to result in a even etch over the
> whole board there is nearly no under-etching.
Doing all that -- agitation and heating.
> i think the most of the listed processes are also used in professional
> setups(some more often, some less).
> therefore they all should be suitable to provide perfect results.
>
> i think for setting up a etch it is important to consider the following:
> availability of the chemicals.
Yep -- I found Ammonium Persulphate at Fry's, which is why I thought I'd try
it, instead of FeCl, which I was getting from RadioShack.
> disposal regulations / possibilities.
Still need to investigate this for Ammonium Persulphate.
> required speed.
It's been taking me 10-15 mins or so for FeCl. Whereas a few minutes would be
really nice, I'm willing to compromise here.
> available room.
Bathroom. In a apartment for now, so no garage. I can do this out on the
patio, but I avoid anything outdoors since I've had bugs get in it before.
> time you want to invest, money you want to invest.
Time I can get. Money, as little as possible :-)
> very important: number of pcbs per time unit you want.
I make one PCB every week (on average). I'm in no rush.
> ability to build etching compartments (more complicated with
> spraying/aeration)
I'm in the middle of doing this now -- re-building my etching "system". I'm
using tall, slimmish plastic containers. They have covers, so I intend to
leave the solutions in the containers for the next time. Once I have it
setup, I'll write it up.
> you can use methods which need virtually no preparation/maintainance but
> also need more time/money when actually making a pcb. but in methods like
> cucl you have to prepare the etch quite a time before and also you need
> time for regeneration etc.
>
>
> if you really want to make pcbs in your garage you have to read
> descriptions for all methods. you have to look at your stores what you can
> get easily. only then you can decide. you will soon find arguments against
> the one or other method.
Yep, which is why I'm on this list. :-)
>
>
> regards
> st
Thanks,
-Neil.