PDF - Iron it On
Etch your own Circuit Board

This is easier to do than it reads!

Check out this excellent Yahoo Thread on PC Board making.

Here is my experience:    (Read completely before beginning)

Buy the PC Board & Etchant first, if you can't etch a good circuit board you don't need the parts!

The silkscreen of the component graphics "might not" iron onto the Radio Shack board effectively.

* If you can buy a one sided copper epoxy board from another store do it! *

The RS Theremin PDF file will open in Adobe Acrobat looking crude, yet prints a crystal clear image that is reversed for the iron on pattern.

In Adobe un-check the boxes, especially the "Fit to Page" box.

Paper to Use:

Laser Toner type printers are available today for less than a $100, check with Fry's Electronics.

Use a Laser Printer like the HP-4. Print the PDF files onto a blank piece of 70#, 80# or 100# glossy paper like that used in magazines. Gloss computer photo printer paper can work but I prefer the 70#, it is thinner and more transparent after ironing. These HP-4 laser type printers use a big plastic container of black powdered toner.

or 

Others have recommended:

This paper at Staples - HP Soft Gloss Presentation Laser Paper as of 06/28/08   www.staples.com  $14.99 - 200 sheets 

View My Board Photo (before & after)

Start: (Once you have everything ready, ironing, etching and drilling takes about an hour)

If you use the Radio Shack two sided copper board when building the RS Theremin projects, the unused copper side must be completely etched away. (removed)  Cut your raw copper clad circuit board to the proper size. You could leave your board larger if you're unable to cut it.

Clean your raw pc board with something like Windex window cleaner or a light bleach mixture and scrub the copper to remove any oxidation or grease films. Scrub the board vertical and horizonally. The fine scratches give the black toner some to grip.  Do a final cleaning with pure water, then dry without touching the copper surface with your fingers.

Cut apart the top and bottom board PDF images which were printed on the laser printer. Scissor trim each PDF image to have about 1/2" to 1" (1.3 cm) to (2.5 cm) overhang around the raw copper board size.

I like to cut each corner off of the laser printed circuit board image so I can see the toner to match the corner edges of my copper clad circuit board which is cut to the ideal size. You could also mark the the lines at each cut off corner with an ink pen so you can see them with the PDF up side down.

Place your copper clad board on a piece of aluminum foil so you can move it around under the iron PDF printed sheet.

Position the PDF black line pattern against the copper on the raw board, the sheet should lay out flat with about a 1" to 2" overhang. Secure one side with tape so it won't move and you can lift if up.

With aluminum foil under the circuit board you can move the board around to line up under the PDF.

Note: The component silkscreen patterns align on the opposite side of the circuit board after you have etched the excess copper and drilled all your holes!  Thank you Meghan B. for the feedback!

Place a second piece of blank 8.5" x 11" typing paper over the PDF paper and tape down two corners of one side. This keeps the underneath PDF in place while ironing.

Pre-heat your iron on the cotton setting or hotter (no steam, duh). Place the iron on the top blank paper, heat up everything for about 30 seconds. If your iron is too hot the toner/ink between the IC pads could melt together but not likely, to cold and the toner  transfer will not adhere properly. 

The paper must look a bit scorched from this iron pre-heat. It the paper does not scorch then iron is not hot enough and you will not get a good transfer of toner.

With firm rubbing pressure,  iron the pattern onto your copper board using the tip and edges of the iron. Give extra iron edge pressure around the outside edges of the board.

You must use the edge of the iron and the tip for solid contact.

The toner/ink liquidizes onto the copper with solid adhesion if the board is clean!

Let the board cool down naturally, don't shock it in cold water which can make the paper more difficult to remove.

Now soak the board in a bowl of warm water for about 10 minutes or more to saturate the paper. Peel back the excess paper, use gentle rubbing of your finger and your finger nail in between pads. The black toner/ink will stick tight to the properly cleaned copper.

If rubbing the gray paper off and it starts to show the black toner stop rubbing that area.

Use a soft toothbrush to clean the small lettering and tight spots.

In between the eight IC pads use a point if needed to carefully scratch a line so you can visually see raw copper. This way proper etching will occur between the pads.

If you have one weak line or pad the best thing to do is protect the area with a BIC Wite-Out correction pen. As a last resort use a medium tip black ink zippy resist marker. 

Don't proceed with a board that has a defective transfer of the black laser toner!

Small areas like  print lettering should look crisp! 
If the PDF moved while ironing you get a blurred double strike image. Don't use it!

If you are not happy with your results, consider your first try practice and do the above again. I removed the black toner by heating up the board a again  with the iron, using a scrub pad, charcoal lighter or Kerosene and some elbow power. If the board is hot the black toner scrubs off easily.

*******

A light gray coating from the papers gloss glaze is left on top of the black toner. Leaving a little gray glaze is better than rubbing off the black toner transfer. It is this gray gloss glaze that allows the black printer toner to release from the paper fibers when soaked.

In between the IC pads use a needle or sharp point to scratch a line to be certain in between the pads etches  properly.

Now you need a rubber bowl, but only if you are happy with your results so far.

This etched board looks crisp because the gray glaze over the black toner looked crisp!

If you use the Radio Shack two sided copper board make certain the opposite side copper is completely removed. Make certain the bottom of the board has room for the enchant to move freely. If you use a round bowl the sides of the bowl could hold the board away from the bottom. Pour enough Etchant so the board is covered about 1/4" (6mm).

ferric chloride solution Radio Shack # 276-1499

Use a rubber bowl and gently rock it back and forth to manually agitate the solution while the etching occurs. Try and find a bowl with curved sides so it holds the board away from the bottom. This makes it easier to see any areas that are not fully etched. Have the bowl deep enough so rocking does not splash the ferric chloride solution out.

Etching in the ferric chloride solution takes about 30 minutes if warmed to above 75 degrees F, I set my solution in the sun while working. Cover the board about 1/4" (6mm) so you can observe the etching process easily. Carefully watch for the last area of copper as it begins to dissolve away, make certain in between the IC pads are etched properly, then your done.  

Now rinse your board thoroughly under tap water. 

The solution will stain so use caution in how you rinse!

Scrub off the protective black laser toner from the copper traces with a kitchen scrub pad. Use charcoal lighter or kerosene. A hot board and elbow grease is the key.

Drill using the smallest drill bit you can purchase so the part wire leads fit snuggly through the copper pad holes. A drill press and a ¹/₃₂ bit works great for most resistor and DIP holes. A #66 bit is even better.  A slightly larger bit for the output cables and pots is preferred.
.

Dremel Accessories a Lowe's Hardware have a drill combination 5 pack with one 1/32"  bit.

Drill Bit City has mail order #66 drill bits with a fatter shank for holding in the chuck. 5 bits $8.15 usd

Mom & Pop hardware stores usually carry good assortment of small drill bits. Ace Hardware

If needed use a small center punch or nail to dimple the pad if etching did not make a mark. After drilling use a disposable shaving razor to clean the component side of the board of drilling bumps and debris.

After Drilling the holes and shaving, place the pc board a piece of aluminum foil so you can move it around under silkscreen PDF laser toner printout. Observe the drilled holes on the side opposite of the copper traces and pads to get the silkscreen direction correct.

I like to cut each corner off of the printed circuit board image so I can see the toner to match the corner edges of my previously etched circuit board which is cut to the ideal size. You could also mark the the lines at each cut off corner with an ink pen so you can see them with the PDF up side down.

Use the foil under the board to align the board under the silkscreen 

Secure a second sheet of paper over the printed silkscreen to keep it from moving. Now set the iron on the paper on the board for 30 seconds to preheat the board and with pressure iron on the component images. Use the tip and edges of the iron for solid contact. Give extra iron edge pressure around the outside edges of the board.

 After a natural cool down, once again soak the board in hot water.  Soak for over 10 minutes to release the paper. Peel back the excess paper, use gentle rubbing of your finger or a "very soft" toothbrush to gently remove the gray paper glaze that adheres to the top of the black toner on the board. What I have found that works best for removing the gray coating on top of the black toner is Woolite OxyDeep carpet stain remover in a spray jug. 

After rinsing and drying the board thoroughly I spray the black toner silkscreen patterns with a clear lacquer coating to darken the images and protect the toner from scratching off easily.

Special Notes:

After you complete the circuit board etching and silkscreen ironing use baking soda for a final cleaning of the copper foil patterns. This will slow down the oxidation that will occur over time.

* I like to spray the top of the board silkscreen images before mounting the components with a light coating of lacquer spray paint to protect them from scuffing and enhance the contrast.

* When the board assembly is finished it is wise to cover any unused copper pads with a light coating of solder for any future connections. Then spray lacquer paint on the copper foil patterns to prevent the rapid oxidation of the copper that does occur. The pre-soldered pads will allow for new solder connections without paint removal. It is best to mount all the components, solder and spray lacquer paint all on the same day!