-----Original Message-----
From: jdhar@ENGMAIL=2EUWATERLOO=2ECA [mailto:jdhar@ENGMAIL=2EUWATERLOO=2ECA]
Sent: Tuesday, April 01, 2003 11:58 PM
To: PICLIST@MITVMA=2EMIT=2EEDU
Subject: Re: [EE]: Etchant tank


>>> Would an inkjet printer work? Or are there any methods to produce a positive
>>> film with an inkjet?
>>> Time is not really an issue, these would all be one off's so it's ok=2E If I
>>> wanted to go with a 'standard' lamp, what kind of lamp is that exactLY?
>>> Halogen? Just a regular Incandescent light bulb? And how much are UV lamps
>>> typically?


I get consistent good results from a HP895Cxi, printing Eagle layouts to inkjet t=
ransparencies=2E
Smallest reliable track width/track spacing is about 12 mils=2E
I print two copies of the layout and tape them together=2E I'm not really sure if=
 this is needed, but it gives me some extra scratch protection and UV block=2E

I use an old Philips half-body sunbed (or whatever it's called in english) for th=
e exposure=2E

Board face up, double transparencies, sheet of glass for good contact=2E About 15=
 cm board to tubes - any closer gives uneven exposure=2E
Exposure time differs with make of presensitized board, but is in the 2,5 to 3 mi=
nute range=2E
Then a quick dip in developer, I'd say 10 - 20 s=2E
I've had an etching tank made from 5 mm glass, holds just over 2 l=2E Normal fish=
 tank heater (100 W, thermostat slightly remodeled), air pump and 'bubble block'=20=
(whitch dissolves over time but are=20=
cheap)=2E
Etchant is natriumperoxidsulfat in swedish=2E
Etching takes 10 - 15 minutes depending of state of etchant=2E
I cut boards to size with a guilliotine type paper cutter=2E

This setup gives crisp looking boards in reasonable time=2E

Get a more powerful heater if you can find/fit it, as warmup time is long with my=
 setup=2E


Anyways, thats just how I do it=2E

Best of luck!

/Hugo

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