This is my first ever attempt at etching a pcb.  My project is to connect a sparkfun adxl322 +/-2g accelerometer to the Analog inputs on an Xbee pro unit. The circuit is quite simple with a switch, a 3v watch battery, xbee unit and the adxl322.

Although the PCB in the pictures is pretty lame I hope to refine the process to produce better results in the coming days.

I bought a pcb etching kit from Jaycar electronics which seems to me to be pretty decent value.

First of all I designed my circuit with a free(ish) and very easy to use program called Pad2Pad which although is free to download, they do expect that you order your boards from them (very expensive). Their program is good so I wont complain.

Next…

I went down to my local printing place and got my design printed on a sheet of overhead projector transparency.  Although it’s a black image apparently you can get darker toner coverage if you get a colour print rather than a straight up black and white print.

And then…

Clean your blank boards. Make sure you wash and dry all boards then scrub the copper with iron wool and then clean them again.

and then…

I used an iron on the “wool” setting to transfer the toner onto the blank board.  Place the transparency (toner down) onto your black board then place a piece of baking paper on top. Iron the baking paper to transfer the toner. Experiement with times and heat settings to get a good transfer.

then..

Mix the etchant. I used the prescribed etchant to water ratio printed on the sachet but it took ages. You may want to make a little stronger.

Once the extra copper is completely gone from the board carefully take it out of the etching bath with your tweesers and proceed to wash your board. You can safely scrub all the toner from your design.

Again from Jaycar I bought a rotary toolkit and appropriate drill bits (0.8mm and 1.omm)  to drill the holes.

Future..

I’m planning tomorrow to iron on multiple toner transparancies  to get better toner coverage.

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