Homebrew PCBs

Well done Rick
Sounds Like your findings with parchment paper was what I was finding with old Fax paper , Did the job but not so reliable.
Dave


________________________________
 From: Rick Sparber <rgsparber@...>
To: Homebrew_PCBs@yahoogroups.com 
Sent: Sunday, 18 August 2013, 22:02
Subject: RE: [Homebrew_PCBs] Re: Easy Fast Laser Print DIY Circuit Boards - Dave's toner-transfer freezing technique
 


  
I thought I had some white powder coat paint but was wrong. I do have some
aluminum "coil" which seems to have been powder coated. One side is tan and
the other white. I laser printed to both the "magic" wax paper from China
and the far more easily found but inferior kitchen parchment paper. The wax
paper worked perfectly every time I have tried it. 

The parchment paper worked about 80% of the time. This means that it is best
to print a few copies of the artwork onto the parchment and then pick the
one that has no defects for transfer to the metal. 

As for resolution, my capital letters are 0.04" tall and my lower case are
0.03" tall. Just as crisp as out of the laser printer. My finest lines are
around 0.001" wide and look faint. The next size up is about 0.005" wide and
are dark.

As I write this email, it is starting to make sense to me why the toner
holds so solidly to the coil. The toner is essentially powder coat plastic.
The coil is coated with the same stuff. So when they are heated and
compressed, the plastic reflows and fuses. 

After the first try I used a 3M pad saturated with dish soap to clean off
the toner. Not so easy to do. After about 2 minutes of hard rubbing, it came
off. The paint on the coil is a lot lighter too. So this supports my theory
that the toner fuses into the powder coat. 

As a further test, I taped the wax paper to just the front end of the metal
sample as I ran it through the laminator. This let me peak under the wax
paper and see how much transferred after each pass. All of it transferred
after the first pass!

Now I'm testing with the parchment paper. As expected, the toner does not
release nearly as well as the wax paper so I went all out: taped the artwork
down in all 4 corners, ran 10 passes, and then 15 minutes in the freezer. At
least this time, the toner transferred from the parchment paper to the coil
perfectly. 

Time to write this up and an article...

Rick


 

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