Monday, March 1, 2010

Laserjet Toner PCB Etch Resist methods...

Ok, this is going to be a short post, only because so much is already googleable about the laser toner etch resist method... This post assumes you already know the basic procedure, ie:

* laser-print the mirror image of your circuit
* laminate or iron the toner onto the PCB
* soak the paper off the PCB, leaving the toner
* etch

Things that WORK WELL (and make this a useable process) for me:

1) Using the BACK SIDE of "HP Everyday Photo Paper" works great. The gloss of the front side is too sticky. The back side is "chalky" enough that the toner will release within minutes of soaking in water.

2) I got lucky and found a "heated roller" laminator at Goodwill of all places. It is the GBC Creative Laminator. I had to hack it a bit, adding a higher-temp fuse, and insulating the temperature-sensor a bit, so I could get a higher temperature. This is DANGEROUS. Hack at your own risk. In any case, the rollers now get up over 300 degrees F, which is perfect.

3) Having a color laser printer, I found that using full-color works much better than black-only. Also, I go into printer settings and manually crank up the density for each of the CMY and K colors all the way.

4) Lightly rough up the copper with 600 grit sandpaper before laminating. Clean with rubbing alcohol.

5) Two passes in the laminator seems to work well. Less, and it's doesn't want to fully adhere to the copper, more, and you risk smearing the toner.

At some point in time, I'll post a full procedure with pics and all. I just wanted to get some of my tips & tricks out there ASAP.

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