The most popular way to build SILICON CHIP electronic projects is from a kit. However, not every project is available as a kit. While project components are generally readily available from component retailers, the PCB is not.
Only recently has SILICON CHIP started selling PCBs and for the most part, they are mainly for recent projects.
And this doesn’t help the home constructor who wants to design his own PCB.
So what to do?
Here’s a method of producing near-commercial quality PCBs in either single or double-sided format using an image from a laser printer (note – inkjet printers are NOT suitable). The toner from the laser printer is transferred to a blank printed circuit board and used as a resist for standard etchants.
Laser printer toner is mostly plastic particles that when fused makes good etchant resist. There are plenty of articles on the web explaining the theory behind this method and I will not repeat them here.
If you don’t have a laser printer but do have access to a laser photocopier, this can usually be used – laser photocopier toner is not too different to laser printer toner, so as long as you can print out a black inkjet copy AND your laser photocopier can handle film (many can’t!) you may still be in business.
One other point to watch with both printers and copiers is that some do not give a true 1:1 print or copy. Obviously if the print or copy is distorted (in either direction) it may be useless for this process.
You will need the following:
Obviously, you need the PCB artwork. If it’s a SILICON CHIP project, download it from the SILICON CHIP website (www.siliconchip.com.au).
If you are designing your own, you’ll need some CAD software for designing PCBs. This is freely available (eg, Autotrax, KiCAD, Eagle, etc), so with the method I describe below, you can easily make PCBs for your own projects as well as SILICON CHIP projects.
Access to a laser printer with 600 dpi resolution (or a laser photocopier).
Toner transfer film called “Press ‘n’ Peel PCB film”. It’s available from both Altronics (Cat No. H0770) and Jaycar (Cat No. HG9980) as well as other sources. This film has a special coating that allows printing the PCB track pattern onto the film with a laser printer and then transferring it to the copper surface of a blank PCB.
A cheap A4 laminator (the ones that have synthetic rubber rollers, eg, the GBC brand or similar that retails for under $50.00). This provides both the heat and the pressure to transfer the Press ‘n’ Peel film image to the blank PCB.
Incidentally, just last month Aldi stores had an A4 laminator on sale for just $16.99 . . .
Suitable etchant and a suitable disposable plastic container to etch in. Ferric chloride etchant is arguably easier to use as it can work at room temperature (and may produce better results). But it is also much messier; ammonium persulphate is much cleaner but requires heating to be effective.