Making PCB at Home (3)

The Etching

Now for the messy bit, etching the PCB to remove the unwanted Copper. Please read the warning at the top of the page as it is important to take appropriate precautions before handling the etch chemicals. I recommend you do this outside or in a shed and you must ware glasses and gloves. Keeping the etch chemicals warm (45deg C) is essential as it reduces the etch time from over an hour to about 15mins.

1. Dilute the concentrated Ferric Chloride fluid with water (1:1) and pour into the one letre glass jar and screw the top on

3. Place a sheet of news paper on a flat surface and put the trays on this

2. Fill the kettle with water and boil

3. Heat the Ferric Chloride jar in a bucket of hot water. Caution don't spill any drops and keep away from food

1. Pour 1cm of boiling water into the bottom tray then place the other tray on top
2. Put the PCB copper side up on the top tray and pour all the Ferric Chloride on top
3. Gently rock the top tray to keep the etch fluid moving avoiding spillage
4. After about 15mins all of the unwanted Copper should have disappeared
5. Remove the board and drop it into a bucket of cold water to clean off

Usefull tip: For small boards just drill a 1mm hole in the corner of the board and tie 2ft of strong cotton to this. Now put the board straight into the Ferric Chloride jar with the end of the cotton outside and put the top on the jar. Keep the jar hot by heating in a tray of boiling water and gently rock to keep the etch fluid moving. Every 5mins use the cotton to lift the board out and check progress. This method is much less messy as the Ferric Chloride is always left in the glass jar.