Homebrew PCBs

----- Original Message ----- 
From: "Howard" <hj.payne@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, July 19, 2008 5:29 PM
Subject: [Homebrew_PCBs] Re: PCB Probs


> --- In Homebrew_PCBs@yahoogroups.com, "Leon" <leon355@...> wrote:
>>
>> ----- Original Message ----- 
>> From: "Howard" <hj.payne@...>
>> To: <Homebrew_PCBs@yahoogroups.com>
>> Sent: Saturday, July 19, 2008 4:50 PM
>> Subject: [Homebrew_PCBs] PCB Probs
>>
>>
>> > Hi All
>> >
>> > I have got some fotoboard 2 pcb (Rapid electronics) and a
>> > LV 202E Exposure box, the tubes are about 2" from the glass.
>> >
>> > Anyone know how long to expose this make of board ?
>> > Also i did a board the other day using fotoboard 2 (about 5 mins
> exposure)
>> > and it came out crap, all the edges looked pitted and the tracks
> had what
>> > looked like lines etched in them!!
>> >
>> > I use ohp transparency film (www.5star.co.uk), and it is for inkjet
>> > printers (Epson, Canon)
>> > and my printer is the Epson R300.
>>
>> Try using JetStar film, also available from Rapid.
>>
>> I used to get get good results with Fotoboard 2 and JetStar with an
> Epson
>> printer. I now use JetStar Premium with an HP printer, which works even
>> better.
>>
>> Leon
>>
> Hi
> Thanks for that info Leon.
> is the exposer time ok for Fotoboard 2 (aprox 5 mins)?
> also i think that the developer (costic soda) was abit strong
> it started to work as soon as i placed the board into it !!
> it was done in a mater of seconds hi hi.

You have to experiment to get the correct exposure time, I use 11 mins. Use 
a test strip and move a piece of cardboard across the PCB every minute to 
get the optimum exposure.

I use about 12 g/l of NaOH. It takes about 20 secs but depends on the 
temperature. You might have it too strong.

Look at your transparencies with a lens and make sure that they are opaque. 
That might be the cause of the problem.

Leon