On Thu, 08 Dec 2005 22:03:42 +0100, soffee83 <
soffee83@...> wrote:
> I just looked up my email here. The solid beige stuff I bought is
> supposedly CEM1 @.047. The double-sided I was just trying to print on
> is the FR4 and it's .093 (yikes!). Either one seems rigid enough for
> what I'm doing though and everything will likely be supported on
> standoffs or something, especially stuff with controls.
>
>
> I don't believe either of these has taken toner well, but I can
> probably find a working combo for printing the tops of the flatter
> single-sided etches. I'm looking at a CAT5 tester on that beige stuff
> I built here, which I printed a bunch of junk on and everything stuck
> but one letter. However, that was with Staples paper, so it has that
> nasty gray film on it. I coated it with a spray to darken it some, but
> it's still gray. Wetting that residue makes it a bit better looking,
> but then it dries out. I wonder if there's a paint, etc. that would
> keep it black? Weird thing is, transfers tend to fuse into the PCB
> material unlike the copper, so even the ones that didn't take have a
> leftover ghost if you try to wipe them off.
Ah, glad to hear i'm not seeing ghosts then ;-). It's the same here with
the fused in toner.
About the white residue, i also thought it would go black with laquer, but
the damn thing doesn't want to cooperate. You can get it black by
polishing with abrasive kitchen cleaner or toothpaste and a rag. Nowadays
i use silicone coated paper for legend to avoid the residue.
> Sanding or leveling the top with something seems like it may help. A
> lot of mine has that "cloth" texture which probably doesn't encourage
> a good transfer. I don't know if sanding would just bring up more
> cloth though.
Probably only on sides where no copper was etched away. The copper leaves
about the roughest surface you can possibly get (for good adhesion), and
the toner holds very well if kept oil-free.
The cloth texture doesn't seem to be a problem here, however don't try to
peel boards apart in the middle and transfer on the _really_ cloth
textured surfact then ;-)
> Anyone struggling with it may try a light spray before the toner goes
> on. Krylon "crystal clear" acrylic made a world of difference on
> aluminum with the JetPrint paper. It may even take less heat and
> heating time, as it sort of fuses into and "grabs" the toner.
I haven't tried that. It might just allow me to transfer to the blank side
of FR4, which despite sanding doesn't work great for me.
> To anyone here-
> Other than the obvious strength and copper thickness or quality
> factors, what exactly should be our concerns with the different types
> of PCB substrate? I'm not in danger of excessive heat either, but I
> don't think I would care for any "warping", etc.
Mechanically the full glass materials are much the same strength i think,
the CEM stuff with paper in between a bit less and real FR4 a tiny bit
more stiff than the yellowish stuff. The rest is mostly fire retardancy
and electrical properties that mostly don't matter.
ST