Homebrew PCBs

Hi guys,
   Just a quick note -- it appears the developing chemistry in the Seno 
SN110 roll-on developer is too weak to successfully develop Fotoboard2 
(which is currently sold by Rapid as their "RVFM Photo-Etch PCB"). I've 
just wasted two Eurocard blanks trying to figure out what was going on, 
only to find that the boards developed FAR quicker in a higher-strength 
metasilicate developer.

   Whatever the developer in the SN110 roll-on is, it isn't 
metasilicate. It does work fine on the CIF photo boards (e.g. Farnell 
P/N 126-7748; in fact, it's a really fast-working developer on those). I 
haven't tried it on the Farnell-sourced boards I have (P/N 320-4959) 
though I suspect the results will be similar. From what I can gather, 
these are the MicroTrak boards that Mega sell -- light blue lightproof 
sticker with a white paper label on top of that which covers almost the 
whole 160x100 board. Country of origin is Germany, recommended developer 
is CPD5 (320-4996).

   Also, the Farnell metasilicate developer (320-4996, made by Mega and 
sold by them as CPD5) is FAR too strong at 1:1 strength for these 
boards. The bottle says 1ltr developer to 4ltr water (1+4 mix, or 1/5th 
dev to 4/5ths water). Mixing at this ratio caused the "stringy peeling" 
effect noted in the Rapid datasheet; it seems half or a quarter of this 
concentration may be more appropriate.

   Three and a half hours wasted...

   Does anyone know of any other "incompatibilities" like this?

-- 
Phil.
ygroups@...
http://www.philpem.me.uk/

On 16/03/2010 19:03, Philip Pemberton wrote:
> Hi guys,
>     Just a quick note -- it appears the developing chemistry in the Seno
> SN110 roll-on developer is too weak to successfully develop Fotoboard2
> (which is currently sold by Rapid as their "RVFM Photo-Etch PCB"). I've
> just wasted two Eurocard blanks trying to figure out what was going on,
> only to find that the boards developed FAR quicker in a higher-strength
> metasilicate developer.
>
>     Whatever the developer in the SN110 roll-on is, it isn't
> metasilicate. It does work fine on the CIF photo boards (e.g. Farnell
> P/N 126-7748; in fact, it's a really fast-working developer on those). I
> haven't tried it on the Farnell-sourced boards I have (P/N 320-4959)
> though I suspect the results will be similar. From what I can gather,
> these are the MicroTrak boards that Mega sell -- light blue lightproof
> sticker with a white paper label on top of that which covers almost the
> whole 160x100 board. Country of origin is Germany, recommended developer
> is CPD5 (320-4996).
>
>     Also, the Farnell metasilicate developer (320-4996, made by Mega and
> sold by them as CPD5) is FAR too strong at 1:1 strength for these
> boards. The bottle says 1ltr developer to 4ltr water (1+4 mix, or 1/5th
> dev to 4/5ths water). Mixing at this ratio caused the "stringy peeling"
> effect noted in the Rapid datasheet; it seems half or a quarter of this
> concentration may be more appropriate.
>
>     Three and a half hours wasted...
>
>     Does anyone know of any other "incompatibilities" like this?
>

I use sodium hydroxide solution to develop Fotoboard 2 (12 gm/litre).

Leon
-- 
Leon Heller
G1HSM

Leon Heller wrote:
> I use sodium hydroxide solution to develop Fotoboard 2 (12 gm/litre).

Just tried the CPD5 at half-strength. Works like a charm!
Takes about two minutes to develop if it's mixed with cold tap water, 
but at least that's better than it taking ten seconds and stripping the 
resist before you can rinse off the developer.

It seems the main problem is that my laser printer isn't producing a 
dark enough black on the LaserStar film. Instead, the toner is patching 
and spotting, which is producing matching dots and marks on the board 
(even when it's underexposed by a few stops). Naturally the printer 
doesn't offer any adjustments for toner density, or an option to turn 
the halftoning off... (bloody Kyocera and their completely undocumented 
point-and-drool printer driver). Much as I hate to admit it, I'm 
actually starting to miss my clunky, noisy, unreliable Panasonic B&W 
laser... it had a density setting that went from "almost no toner at 
all" to "dump almost the entire cartridge on the page."

Back to the Canon inkjet and JetStar Premium film, I reckon. Looks like 
I've got an iron-clad reason to give She Who Must Be Obeyed next time 
I'm told to get rid of it :)


Anyone want a couple of packs of LaserStar film? I've got two packs of 
ten A4 sheets sealed new, plus one with about half a dozen A4 sheets 
left... The sealed packs are both from Rapid; the opened one came from 
Farnell.

Cheers,
-- 
Phil.
ygroups@...
http://www.philpem.me.uk/

anyone have tips to have repeatable image registration on the page? i 
want to print an image and then reprint the same page for denser 
image as another image is printed right over the previous image. 
sometimes works and sometimes it is off 1/16" or more. any mods to 
the feed/paper tray? are some printers better at this than others? 
which brand/model would do this best? thanks. William

--- In Homebrew_PCBs@yahoogroups.com, William <walford@...> wrote:
>
> anyone have tips to have repeatable image registration on the page? i 
> want to print an image and then reprint the same page for denser 
> image as another image is printed right over the previous image. 
> sometimes works and sometimes it is off 1/16" or more. any mods to 
> the feed/paper tray? are some printers better at this than others? 
> which brand/model would do this best? thanks. William
>


I've never used a printer that had good enough registration to do this, they just aren't designed for it, even off by a thou will be visible.

What sort of image are you printing? A good printer should be able to do it in a single pass.

At 07:49 PM 3/16/2010, you wrote:


>What sort of image are you printing? A good printer should be able 
>to do it in a single pass.

i guess this is a little off-topic, but might be useful for those 
printing a positive on film for photo resist PC boards. i do some 
glass carving which uses photosensitive masks. kinda like screen 
printing. when the pos image is exposed to the mask, the image must 
be very dense and some carvers report sending their image back 
through the printer repeatedly to achieve this. i've never been able 
to do with any repeatability and wondered if others have 
tweaked/hacked the feed pathway someway to achieve it.


William Alford

GI Motility Medical Research Page
http://alford.grimtrojan.com/ 

[Non-text portions of this message have been removed]

On 16/03/2010 22:33, William wrote:
> anyone have tips to have repeatable image registration on the page? i
> want to print an image and then reprint the same page for denser
> image as another image is printed right over the previous image.
> sometimes works and sometimes it is off 1/16" or more. any mods to
> the feed/paper tray? are some printers better at this than others?
> which brand/model would do this best? thanks. William

Why do you need to print the image several times? I get adequate density 
printing once with the HP Deskjet printer I use.

Leon
-- 
Leon Heller
G1HSM

> 
> Why do you need to print the image several times? I get adequate density 
> printing once with the HP Deskjet printer I use.
> 
> Leon
> -- 
> Leon Heller
> G1HSM
>


It's not the case with all printers, as with any of this hacking stuff, sometimes you get lucky and find a combination of equipment and materials that works great, other times not so much. Certainly easier to find a printer with adequate density than to try and get spot on registration like that though.