Crawls Backward (When Alarmed)

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Making a PCB for an Effects Pedal, Pt. 2

There are a couple of places on my transfer that, well, didn't transfer.  See the red arrows in the picture.

Fortunately, you can use a marker pen to touch them up.

Now we're ready to etch the copper off the board.

I have a small plastic container I'm going to use as my 'tank' for the etchant.

The etchant is Ferric Chloride.  I understand it stains clothes, skin, etc., so I am wearing gloves while I handle it.

There is just enough etchant in the tank to cover the board.  Crazy picture - my camera focused on the reflection of things in the liquid!  But you get the idea.

I tilted the container every few minutes to agitate the ferric chloride, and using some plastic tweezers, lifted the board to check the progress.  It took about 15 minutes for the copper to dissolve.

An environmental note:  ferric chloride will dissolve copper pipes.  It is hazardous and should not be disposed of by pouring it down a drain.  You have two choices for disposal: take it to a hazmat disposal station (many jurisdictions now have them), or add baking soda to neutralize it.  This will turn it into a solid which can be safely disposed of in the trash (I did the latter).

Here's the board after etching.  Crazy, huh?

Now we use acetone to wipe the resist off the circuit traces.  Do this in a well ventilated area - I did it outside.

Now you can drill the component holes with a small drill.  I used a #50 (I think...) in my Dremel.  Word of warning: these tiny drills bend very easily.  Don't ask how I know this.

And voila!  We now have a finished Crawfish Instruments Red Pepper Fuzz PCB ready to stuff!

It's not perfect, but it came out well I think for a first try - I learned a lot while doing it.  Of course, now I want to do more.  But first I need to build this pedal.

 
 
 
 

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