I was looking for more info on the type of boards I use today, hoping to find out which wavelengths of UV it was sensitive to, though it sounds as if you have that covered.
Found nothing about uv, but I did notice that the shelf life of this particular board was given as "at least a year", so limited enough for small volume users. Presumably storage in a cool dry place is best.
The inconsistency you describe in your results makes me think you're right about the board being suspect. And I'm relieved to hear you're going for the tracing paper.
Found nothing about uv, but I did notice that the shelf life of this particular board was given as "at least a year", so limited enough for small volume users. Presumably storage in a cool dry place is best.
The inconsistency you describe in your results makes me think you're right about the board being suspect. And I'm relieved to hear you're going for the tracing paper.
Tracing paper... paper or polyester drafting film????
Laserstar feels very much like the polyester drafting film or paper we used in the 70s and 80s..... anyway - if you use it , make sure you print the image reversed, so that you end up with the toner side towards the PCB resist.
This gives you much better control over the trace edges.
It may very well be that you have some bad boards..... I have experienced problems with old resist.... it somewhat looses someof its sensistivity, and also don't dissolve well in teh developer. I have sometimes used cotton pads and lightly wipe the board while still in the developer, to release the sticky resist residues. Not good - but it works....
As for the light sources, the resist has its ma sensistivity in the range 3600-4000 nm, defined as "near UV". If my memory hasn't failed me completely, I think the tubes we use at work are designated TLA-15....
Laserstar feels very much like the polyester drafting film or paper we used in the 70s and 80s..... anyway - if you use it , make sure you print the image reversed, so that you end up with the toner side towards the PCB resist.
This gives you much better control over the trace edges.
It may very well be that you have some bad boards..... I have experienced problems with old resist.... it somewhat looses someof its sensistivity, and also don't dissolve well in teh developer. I have sometimes used cotton pads and lightly wipe the board while still in the developer, to release the sticky resist residues. Not good - but it works....
As for the light sources, the resist has its ma sensistivity in the range 3600-4000 nm, defined as "near UV". If my memory hasn't failed me completely, I think the tubes we use at work are designated TLA-15....
Don't be too put off by your tribulations with this stuff Billy.
I discovered on receipt of the 200 uv leds I was using to build an exposure unit that the 20 degree figure quoted for 'viewing angle' was using a different definition of viewing angle to the one I'd presumed it would.
So in order to get even board exposure, I ended up making a jig and filing flat the led ends, then repolishing them. Which took a little while.
I discovered on receipt of the 200 uv leds I was using to build an exposure unit that the 20 degree figure quoted for 'viewing angle' was using a different definition of viewing angle to the one I'd presumed it would.
So in order to get even board exposure, I ended up making a jig and filing flat the led ends, then repolishing them. Which took a little while.
Just a note NaOH used to be sold almost everywhere in the U.S. as it is used in evrything from painting to soap making. These days it is off the consumer market. Not because it is hazardous, but that it can be used to make illegal drugs. So it is a bit harder to find!
Ferric Chloride is the more common etchant here.
Ferric Chloride is the more common etchant here.
Hmm. Would you think me a typically cynical Brit if I wondered aloud whether:
a) A drugs lab chemist might just possibly be able to manufacture their own NaOH out of salt and electricity (watch out for the hydrogen and chlorine kids!).
b) It suits certain business interests to sell new-improved-advertised-on-tv Supa-Dray-No, the product you can trust.
Yes? Thought so.....
I go with FeCl3 for etching too. H2O2 & HCl? Do me a favour. Anyway, blokes buying H2O2 here get specially rendered ....unless they run a hairdressing salon of course.
@Billy
I work as a copier engineer, not sure if this will help at all, but here goes....
If using a colour laser printer the best way to print a thicker layer is by using 4 colour black. This lays C M Y K on top if each other giving a thicker layer of toner and a deep rich black. The same may be done with inkjets.
You could also increase the print density to the darkest if not already tried, And switch off eco mode or similar which reduces toner use.
If i remember correctly 4 colour black can normally be configured in the print driver.
I work as a copier engineer, not sure if this will help at all, but here goes....
If using a colour laser printer the best way to print a thicker layer is by using 4 colour black. This lays C M Y K on top if each other giving a thicker layer of toner and a deep rich black. The same may be done with inkjets.
You could also increase the print density to the darkest if not already tried, And switch off eco mode or similar which reduces toner use.
If i remember correctly 4 colour black can normally be configured in the print driver.
Hi all
Full of excelent ideas.
I mean polyester draft paper from Farnell, is what I use til now. I will try paper tracing papr, much cheaper.
If you can't find NaOH maybe you could try and replace it by KOH (potassium hydroxid) which shoud work as well. Easy to find in those websites who sell goods for making soap, they call it 'lye'.
I'll also improve insoltion with that nice black driver setting on my printer.
All this should indeed help.
Thanks to the community !
Full of excelent ideas.
I mean polyester draft paper from Farnell, is what I use til now. I will try paper tracing papr, much cheaper.
If you can't find NaOH maybe you could try and replace it by KOH (potassium hydroxid) which shoud work as well. Easy to find in those websites who sell goods for making soap, they call it 'lye'.
I'll also improve insoltion with that nice black driver setting on my printer.
All this should indeed help.
Thanks to the community !
Actually it is even easier to make than that. All you do is take the ashes from a wood burning fireplace and dissolve them in water. Filter the water to get the crud out and let it dry. What is left is lye good enough to make soap. (Yes that is how it was done. The fat for the soap was from whatever you shot for food.)
Apparently you mix lye with Sudafed and make low grade methamphetamines.
Here is a site with directions for the really stupid. However Red Devil Lye is no longer sold. http://mirror.bagelwood.com/textfiles/uploads/metanf.txt
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