DIY PCB Etching with Toner Transfer Method
- Export design from EDA software.
- Transfer design onto copper clad using a laminator.
- Etch exposed copper to create circuit.
- Drill holes.
- Double sided boards: repeat transfer and etch for bottom side.
- Trim to final board dimensions.
- Apply soldermask and expose.
- Double sided boards: repeat soldermask for bottom side.
- Tin all exposed copper.
- Minimum trace width: 0.3 mm
- Minimum trace clearance: 0.2 mm
- Minimum pour width: 0.3 mm
- Pour clearance: 0.4 mm
- Thermal spoke width: 0.5 mm
- Thermal clearance: 0.4 mm
- Via hole diameter: 0.4 mm
- Via pad diameter: 1.5 mm
- Minimum soldermask width: ?
- Soldermask clearance: ?
Warm up laminator to 325°F.
- Export design from EDA software as SVG or PDF.
- For top layer: mirrored; small drill marks; include board edge
- For bottom layer: actual size drill marks; include board edge
- Use Inkscape to center it on the page.
- Prepare transfer paper.
- Cut out light-colored magazine paper slightly larger than board size
- Using kapton tape, tape the magazine paper onto regular paper
- Tape the full width of the magazine paper at the top
- Tape a small portion of the width at the bottom
- Print out the design on regular paper to help with alignment
- Wipe magazine paper with alcohol
- Print design on transfer paper.
- Paper type: plain paper
- Quality: 1200 DPI
- Toner safe: off
- Prepare copper clad.
- Scrub copper with Scotch-Brite and dish soap
- Rinse and dry
- Wipe with copper acetone
- Transfer using the laminator.
- Tape transfer paper to copper using kapton tape
- Run through laminator for at least 10 minutes
- Change position every so often to ensure even transfer
- Do not let copper clad cool down after laminating
- Remove transfer paper.
- Soak in hot water until transfer paper is visibly wetted.
- Gently rub off transfer paper
Touch up any issues with a Sharpie or paint pen.
- Mask off any remaining areas on the copper clad.
- Reduce the amount of copper needed to be etched as much as possible
- Use packaging tape or kapton tape
- Iron out any bubbles and make sure tape is adhered around edges and holes
- Make etchant.
- Mix one part vinegar with one part hydrogen peroxide
- Note: hydrogen peroxide must be fresh
- Add salt until solution is saturated
Warm up etchant to at least 100°F.
- Etch copper clad.
- It will take 30 seconds before enough dissolved copper is in the solution to start the fast etch
- When fast etching, the correct solution will bubble continuously, turn a blueish-green, and form orange precipitate on copper
- Every 10 seconds, wipe precipitate off of copper with paint brush or foam brush
- Make sure not to damage toner with brush
- Fiberglass will become exposed as the etch process finishes
- Remove from solution as soon as all areas have completely etched
- With correct solution at a warm temperature, process should take less than 15 minutes total
Rinse board with water to remove any remaining etchant.
- Remove toner mask.
- Wipe board with acetone
- Completely remove all toner so that copper is bright and clean
- Export soldermask from EDA software as SVG or PDF.
- For top layer: do not tent vias
- For bottom layer: mirrored; do not tent vias
- Use Inkscape to create 3 copies with 1/4” margin around each
Print out soldermask on transparency and cut out copies.
Add alcohol to UV paint to thin it.
Clean board with alcohol.
- Add paint in the center of the board.
- Do not spread out paint
- Align all transparency layers and tape to acrylic.
- Tape must be outside the edge of the board
- Toner side of transparency should face up
Clean transparency with alcohol.
- Slowly place acrylic on board.
- Shim bottom acrylic and top acrylic to get correct soldermask thickness
- Add weights to top acrylic
- Soldermask shouldn’t have any bubbles or thick spots
Expose for 20 minutes.
- Carefully remove acrylic and clean pads with alcohol.