Homemade Circuit Board Tips & Tricks

Note: This process will ruin or stain your personal iron, find an old one at a thrift store.

This step can be avoided: I begin the process by turning on a heating pad which is placed under my flat plastic bowl with ferrite chloride solution and my container with the tin plating solution. Home tin plating is good and reduces the effects of the board oxidation over time but only has a shelf life after mixing for about 30 days. Also etching likes a warmer temperature.

Turn on the clothing iron so it is ready when the time comes to use it. 

Most PDF iron on failures occur because the pc board was not properly cleaned or the iron you are using does not get hot enough.  Set your hot iron on a piece of typing paper for 30 seconds. It should be hot enough to slightly scorch the paper or it is not hot enough. My iron is set to cotton fabrics.

Print the PDF of the circuit pattern on light weight high gloss paper. Use a black toner laser printer; I use a HP Laser Jet P1006 I bought from Fry’s for $70 new with the black toner cartridge installed.

The paper used must be high gloss similar to what magazines are printed on. I have heard of some photo papers working but I don't know what they are or if light shines through it.

Cut your single side copper clad board to the proper size. Larger than the image is most important.

The vacuum tube oscillator board has identical images side by side; this saves time. You can cut apart the paper PDF printout and make one board at a time.

Have a roll of paper towels nearby at all times

* Scrub the board copper clad side with a kitchen non-metallic scratch pad in both directions using household “ammonia”. This will remove all oil residues and make the copper surface more aggressive for the toner to adhere.

I take my pre-cut circuit board and hang it 1/2 " off the edge of a Formica table top with a light shinning up from underneath. This allows me to see the PDF outline of the board. Also I like to cut the outlined corners off the graphic to help with visual alignment of the two corners as the light shines underneath.

Have a small piece of masking tape on the back edge of the PDF paper to secure the image in the proper position on the table top and PDF on the board while it is hanging off, single tape the center back edge of the paper to the table.

The Toner is actually very fine black plastic powder.

Take the very hot iron and briefly (5 sec) set it on the PDF paper which is against the copper clad board. This is to slightly glue the image to the board.

After a brief cooling, without disturbing the image contact, carefully lift the tape holding the back of the PDF paper to the table and slide the board back onto the table so you have a solid surface to do the rest of the real pressure and heat ironing.

Place a second piece of regular typing paper over the PDF print out and tape down the back side in two spots. This second paper gives protection from doing damage to the main PDF paper graphic layout.

Now set your iron on top of the new paper, PDF and board for about 20 seconds to heat everything up. If the iron has the proper heat it will slightly scorch the paper.  Now start your heavy pressure ironing. Use the forward edges of the iron especially around the edges of the copper clad board, this is where non stick image failure most likely will occur. There is a chemical reaction that occurs and the toner image will appear through the top paper slightly while ironing.

Once you feel you have adequately transferred the image let it cool down naturally.

I have discovered that using Kaboom with Oxy-clean makes removing the paper effortless and clean after a 30 minute soaking. Any type of cleaner with Oxy-Clean stain remover should work. Slowly peel away the main PDF graphic paper and pray. If all looks good now clean the rest of the paper residue off under warm running water. As your fingers get a little rougher use the tip as a gentle scrubber. Also use a needle to make sure the area between the IC pads is clean.

If the toner applied properly it will stick to the copper surface very tightly. If part of your image lifts away with the paper removal then consider this attempt a learning experience. The easiest method to remove the black toner from the copper is to lay that extra sheet of paper over the board & black toner, then put the iron on it for twenty seconds to heat up the toner. With another scrub pad and charcoal lighter or kerosene, clean the hot board thoroughly and start from the beginning with the ammonia cleaning process. I call this a darn it moment!#$%

If you have good toner transfer then place the board in ferric chloride solution copper side up. The solution should just cover the top of the board. Agitate it back & forth every five minutes and observing the etch as it occurs. This should take 30 minutes to complete. Watch in between the IC pads, you may need to use a needle to scratch in-between and soak the board a little longer to etch it clean.

The Silkscreen lay down is the exact same process as above. I prefer to iron this on after drilling the holes so you can get the accuracy shining a light from underneath the table and align the parts with the drill holes. After you get a good image on the board use clear lacquer spray paint to permanently adhere and protect it.  

Please iron the silkscreen on the board to make assembly simpler than paint by number!

Now is a good time to rescrub the copper and use a Tin Plating mix to reduce the copper corrosion that will occur. Follow the directions of the supplier you use. The solution does have a short shelf life so maybe mix only half of it.