Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "wbblair3" <wbblair3@...> wrote:
<...>
> 2. I placed the board in the 390F pre-heated oven and checked it with
> the Raytek MiniTemp to determine when it reached the oven's ambient
> temperature � it took less than two minutes to do so � BTW, to
make it
> easy to pick up, I put the board on a broiling pan so that one side of
> the board stuck out beyond the pan � also, you don't need a Raytek
> MiniTemp to do this right; just put your board in the oven for a few
> minutes to reach the oven's ambient temperature.
<...>
Bill,

thank you for those experiments.

I started yesterday with toner transfer using a hand iron. Pressing
normal or hard, temperature on linnen or even a bit higher, it all had
inconsistent results.

It seemed to me that applying pressure with the tip of the iron made
the toner stick better, but also smeared it out. And since my first
attempt was making a pcb with SMD components the result was not great.
Especially making track go between the pins of a 1206 resistor was a mess.

So I was wondering what the best treatment would be. More heat, lower
pressure? Tried it but the result was uneven.
Then I started looking around and luckily found this forum with your post.

What I did was apply low pressure with the hand-iron a bit below the
linnen temperature for about a minute, just to make the
paper stick. I did not move the iron. Then placed the PBC in the oven
at 200C for a few minutes. Not having a proper laminator I simply
stroke my thumb in the oven glove over the PCB a few times when I took
it out.

The result is the best I have had sofar. And definately a usable PCB.
Now I only need to scout for better paper. I used Lexmark everyday
glossy inkjet, which seems to work, but sticks too much after bathing.
For this tiny PCB not a real problem, but too much work for a bigger
version.

Anyway thanks for your insight in the "citical temperature oven thing".

Joop