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/