Homebrew PCBs

I have to investigate this more... it looks like a photosensitive
film that "develops" in water, and sticks down without heat.

It is made for sandblast etching/carving. But if the hardened film
stands up in water, perhaps it could be used for acid etching.

http://www.rayzist.com

Steve

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> I have to investigate this more... it looks like a photosensitive
> film that "develops" in water, and sticks down without heat.
> 
> It is made for sandblast etching/carving. But if the hardened film
> stands up in water, perhaps it could be used for acid etching.
> 
> http://www.rayzist.com
 

Well price wise it looks like it runs $5.71/sheet for 25 sheets upto 
$6.90/sheet for 5 sheets.

Did not see anything about how it stands up in water, they use water 
to wash it out after exposure.  Don't know what it does once it has 
dried.

Hello,

I read the how to use it instructions, and there appear to be a 
couple of concerns. 

First, it is not clearly stated but it seems that this is NOT 
a "there" or "not there" film. Rather the film is thick enough to 
resist the blast in the non-image areas, but in the "image"(means 
sandcarved) areas, there is still a thin film which must be abraded 
by the blaster. (I say this because they show no step to remove 
any "backing" film at ant point, and also because they recommend 
using a wire brush for fine detail areas, calling it a "membrane 
popper". My belief is that the membrane they refer to is the thin 
film remaining which holds everything together. Because they are not 
affixing the film to the product until AFTER exposure, developing, 
and washout...

Next, the ultimate removal of the film is by placing in water. And 
that part of the instructions says that all their films are water 
soluble...

Based on this, I don't think it will work well for us, if at all...

Ballendo













  

--- In Homebrew_PCBs@yahoogroups.com, "Ben H. Lanmon" <bhleavi@y...> 
wrote:
>  > I have to investigate this more... it looks like a photosensitive
> > film that "develops" in water, and sticks down without heat.
> > 
> > It is made for sandblast etching/carving. But if the hardened film
> > stands up in water, perhaps it could be used for acid etching.
> > 
> > http://www.rayzist.com
>  
> 
> Well price wise it looks like it runs $5.71/sheet for 25 sheets 
upto 
> $6.90/sheet for 5 sheets.
> 
> Did not see anything about how it stands up in water, they use 
water 
> to wash it out after exposure.  Don't know what it does once it has 
> dried.

Hello ballendo,

  Monday, March 22, 2004, 12:07:34 PM, you wrote:

b> I read the how to use it instructions, and there appear to be a 
b> couple of concerns. 

b> First, it is not clearly stated but it seems that this is NOT 
b> a "there" or "not there" film. Rather the film is thick enough to 
b> resist the blast in the non-image areas, but in the "image"(means 
b> sandcarved) areas, there is still a thin film which must be abraded 
b> by the blaster. 

<snip>

have you any thaughts on using photopolymer films used for silkscreen printing? I will try to obtain some samples and will post the results.

-- 
 Sincerely,
ø¤º°``````````````````````````````````````````````````````°º¤ø
ZAS ElMed                        | mailto:zasto@...
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    elektronike i automatike     | Tel/Fax: (011) 344-0748
                                 | 
 Zoran A. Scepanovic             |     Mob: (063) 609-993
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*********
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[Non-text portions of this message have been removed]

Darn, I missed the part about removal by water.

Thanks,
Steve

--- In Homebrew_PCBs@yahoogroups.com, "ballendo" <ballendo@y...> wrote:

> Hello,
> 
> I read the how to use it instructions, and there appear to be a 
> couple of concerns. 
> 
> First, it is not clearly stated but it seems that this is NOT 
> a "there" or "not there" film. Rather the film is thick enough to 
> resist the blast in the non-image areas, but in the "image"(means 
> sandcarved) areas, there is still a thin film which must be abraded 
> by the blaster. (I say this because they show no step to remove 
> any "backing" film at ant point, and also because they recommend 
> using a wire brush for fine detail areas, calling it a "membrane 
> popper". My belief is that the membrane they refer to is the thin 
> film remaining which holds everything together. Because they are not 
> affixing the film to the product until AFTER exposure, developing, 
> and washout...
> 
> Next, the ultimate removal of the film is by placing in water. And 
> that part of the instructions says that all their films are water 
> soluble...
> 
> Based on this, I don't think it will work well for us, if at all...
> 
> Ballendo

Zoran,

I don't know about screen printing resist. Perhaps others have tried?
(Crazy because not more than 10 feet from where I'm sitting is a 
complete screen printing setup. Not the film, though. We use the 
liquid and a curtain coater.) If I weren't so busy with machines, I 
might be able to answer your question.

But the real reason I'm writing is that it seems to me that the 
resist and etch part of making boards is kinda solved... Through 
holes too. 

It's the soldermask part that IMO needs addressed. Anybody have a 
GOOD DIY technique for soldermask? Can we screen print IT? (What 
material do we use?) By material I mean goop, not cloth.

I did see the testor's paint idea. But as someone else wrote, if you 
can solder "through it", it's not much of a solder mask is it<G> 
Maybe more of a conformal coating... 

Ballendo

P.S. I was really into the idea of inkjet printing resist direct 
until the question about two sided board registration came up, and I 
thought, "So much for that idea." Because I think it is going to be 
much harder than some have written to solve this with the standad 
feed of an inkjet.) I used to work on copiers, and even with the 
better quality of registration rollers and clutches used there; there 
is still a lot more variation than a reasonably "tight" 2-sided board 
would allow.

But it would seem a VERY good idea to try to determine whether the 
alignment needed for 2 sided boards is possible using the BEST case 
scenario first. Using paper and inkjet ink. Because if you can't do 
it with these, why would you expect that after... Changing the paper 
path, adjusting for board thickness, and printing onto metal
(the "slickness" factor), is gonna make it work better! 

It might be possible to do a soldermask that way though.(Since the 
registration needs are only one side at a time, and a bit looser 
overall.) Avecia has the material; it's just a matter of getting it 
in small quantities, and figuring out how to make it work with "SOHO" 
inkjets, as the inkjets it is designed for are the industrial HIGH 
$$$ types... Neither of these will be easy, IME.


--- In Homebrew_PCBs@yahoogroups.com, "Zoran A. Scepanovic" 
<zasto@y...> wrote:
> have you any thoughts on using photopolymer films used for 
silkscreen printing? I will try to obtain some samples and will post 
the results.