Introduction: PCB Etching Using Laser Printer (Toner Transfer Method)
In this Instructables we will be learning how to etch a PCB using Toner Transfer Method. This method is one of the easiest and cheapest method for printing PCB at home for your hobby projects.
I have been using this method for all my projects and this works really fine for me.
It is one of the easiest and reliable method for hobbyists and for DIY.
I have inserted the video of PCB Etching using toner transfer method. Please do check it out.
Update! In this Instructables i will try to give new tips and suggestions which i learn over time and my experiences. I have uploaded some of the PCB images I used for my projects at the end of this page.
Lets Start! Good Luck!
Step 1: MATERIALS REQUIRED
Materials Required for PCB Etching
- Copper Clad Board
- Ferrous chloride ( PCB Etching solution )
- Dry Iron Box
- Permanent Markers
- OHP Sheets Or Photo Paper
- Acetone (Nail Polish Remover)
- Plastic or Glass Container
- Kitchen Scrub
- Drilling Machine
- Hexa Blade
- 0.8mm - 1.0 mm drill bits
- Adhesive Tape
- Nose pliers
Step 2: Preparation of Copper Clad Board
Copper when exposed to air forms a oxidation layer. Start the process by rubbing the clad board using kitchen scrub. You can also use Stainless Steel brush.
Rub the board until the oxidation layer is removed and the board should look very lustrous (shiny).
Caution: Do Not over do this process because this may degrade the quality of PCB by decreasing the strength of copper layer.
It is always better to buy a highest quality Copper Clad Board with maximum Copper thickness.(1.4 mils to 2.8 mils).
Step 3: Printing the Circuit Design on OHP Sheet
Print the circuit design on the Transparent OHP Sheets using LASER JET PRINTER . This process does not work using Ink Jet Printer.
Do not mirror the Circuit Image while taking the printout.
Now paste the printed side of OHP sheet on the copper side of the Board. Secure it using the Adhesive Tape( Gum Tape). Make sure there are no air bubbles or dust while laying down the printed OHP sheet.
To avoid air bubbles place the PCB on the table and carefully paste the OHP sheet from the corner.
You could also use Photo paper or magazine paper to print. It also works almost the same.
Step 4: Toner Transfer to PCB ( Transfer of Design on PCB)
Set the dry iron box to maximum temperature. The prepared PCB is kept on a flat surface and press and hold the iron on PCB for about 20-30 seconds.
Then rub the surface of PCB using the edge of Iron for 1 minute. Apply heat evenly on the Board for uniform transfer of toner ink from OHP sheet to Copper board.
This is the most fun part of the entire process but you have to be very careful. Do not over heat the board for long duration. And also over temperature may lead to improper toner transfer.
After that allow the board to cool down for a while(1 minute) in cold water. Once the board is cooled down, slowly remove the OHP Sheet very carefully. During the Cool-down period gently rub the surface with your fingers.
If there are any lines missing, just mark the line using a Permanent marker. (CD marker RED or green color gave me best results)
If you don't have access to laser printer you can design the whole PCB using permanent marker only by just drawing the required circuit lines in copper board. But it is a tedious task if you want to design complex large boards.
Step 5: Etching Process _The Most Exiting Part ;)
For the etching process follow the following steps carefully_
Safety First- Wear your eye protection, hand gloves and move the whole apparatus to well ventilated area.
Take a plastic or glass container. Add required amount of Ferrous Chloride ( about 2-4 spoons) and dissolve it using 20-30 ml of cold water. U can also use the concentrated ferrous chloride directly on the board.
Now dip the prepared Copper Board in the Solution.
Keep agitating the mixture until the unwanted copper is dissolved into the solution. Do not over do. Make sure the toner mask is unaffected.
After this process the copper protected by toner ink is Undissolved and the rest is dissolved into the solution.
Once its done rinse the PCB in water and dry it. The ink can be removed by using Acetone( Nail Polish Remover) or by using kitchen scrub gently.
This process takes about 5-25 minutes depending on the concentration of solution.
After this the PCB is ready for drilling.
CAUTION: Do Not use Metallic spoons and containers as the ferrous chloride is very corrosive and can dissolve almost all metals. Carry out this process in well ventilated area and do not inhale the fumes.
You can store the solution in air tight spill proof container for further Etching Process.
Step 6: Drilling and Finishing
The toner ink is removed and the board is again rinsed in water.
Then drill the holes where components are to be placed according to required size using power drill or hand held PCB driller of your choice. The standard drill size for low power application is 0.8 mm or 1.00 mm.
Use solder flux while soldering for better performance and to avoid messing of excess solder as we have not applied Solder Mask on our PCB.
The flux increases the affinity of solder towards copper and removes the oxidation layer from copper which helps in better conductivity..
Even though this process looks easy, this process requires close attention and lot of patience until you learn how to carry out the process. It will be definitely useful for your projects if you master it. The PCB boards makes your project look more professional and also improves the performance of your circuit when dealing with High frequency signals. Projects like audio amplifier, DC-DC Converters, Remote control applications,etc requires the use of PCB for optimal performance.
Congratulations!! You have successfully printed a Circuit Board using toner transfer method.
If you come across any doubts please let me know in the comments section. I will try my best to help you out.
Sandesh Hegde ( THE TECHNOCRAT)