DIY PCB production

[scubadog]

Hello every one.

I have just completed my PCB dcesign for a project i am doing at university.

I wish to produce a pcb at home.

I have built a LED UV exposure box following some of the designs on line.

My question is what next? I plant to make a pcb using the photoresist method but i am confused as to what chemicals to use.

What developer should I USE?

What is your prefered etching solution?
Two appear to be most widley used; either ferric cloride or hydrochloric acid. Does any one have any preferences or tips on wich ones to use?

I have also seen some DIY etching tanks consiting of aquarium bubbler and heatyer in a tall plastic
jug. I have access to all so is it worth while me using this method?

What method do you use?

Any other hints or tips would be appreciated.

 

[Joe G]

have you done a "search" at the top of the main forum page? There has been a whole lot of debates and uses of the types of etching also as to paper to use, printer
toner and such over the last couple of years. Do the search and enjoy the information that has been discussed on this subject. I use the hydrochloric acid and peroxide mix
with a laser printer w/ photo paper. I just use a shaker for the agitation if the board is complicated.

 

[jpanhalt]

I think he is talking about the photoresist method, not the toner transfer method.

I agree that there is so much written on the subject that a few minutes of searching on his part would help him define his questions quite a bit more.

For starters, he needs to define the photoresist he is using. The one I use (Injectorall) is attacked by HCl/peroxide, so I stick to ferric chloride or cupric chloride. All photoresists are made from a substituted organic resin. Toner is a plastic medium. The organic resin is more susceptible to strong oxidizers, such as HCl/peroxide. I suggest ferric chloride for starters. With success, he can try other etchants.

Most important, he needs to calibrate his system. That means taking a piece of photosensitized board and exposing sections with a simple mask, such as "><" , for different periods, then develop and etch it. That will establish his exposure period. There is no other way to accomplish that, that I am aware of.

Finally, as for developer, read the instructions for your photoresist. Some require relative weakly alkaline solutions made from sodium carbonate; others require strongly alkaline solutions containing NaOH or KOH. For mine, I use the alkali metal hydroxide with excellent results.

John