I used to make rubber stamps years ago using a similar method, printing with a laser printer and exposing a substrate to ultraviolet lights to harden it. I could get very fine lines, having nothing left of that venture, I can't say it was 4 mil or 5, but it was quite fine.
What I used instead of a transparency was vellum paper, translucent instead of transparent. This seemed to help with the light leaks. Not being familiar with using an incandescent light for this type of work, I can only guess that the biggest difference you would experience other than perhaps quality would be length of exposure time.
The main reason for me is the turnround time - I can make a board in about 30 minutes, not including drilling. Low-cost services like ITead Studio (10 small boards for under $10) are very good value, of course, but it takes two weeks for me to get the boards, unless I pay a lot ($30 or so) for express delivery. I can get a board made in 24 hours by a company here in the UK, but it's expensive, and still takes three days to get to me.
Definitely turnaround time. I will side with Leon and say 30 minutes, and that is being quite generous depending on your exposure setup. Now lets take a simple power supply circuit for example, and lets assume it has pcb mounted transformer, a full wave bridge rectifier, a smoothing capacitor, and a couple junction blocks. Now let's also say that it might take 45 minutes to draw a nice board, and once again that is being generous. Now let's add another 15 minutes to solder it all together. Providing you have all the materials, you can have a fully functional power supply in an hour and a half. Plus it gives you the ability to test different circuit scenarios rather quickly, but I guess that is also turnaround time. Attached is a photo of a power supply board that I would like to start making, the transformer is not PCB mounted, but this board could be made very quickly and it is a very nice concept.
@deadwhale
Thanks for your input. I tried vellum for quite some time, but eventually ended up abandoning it's use. I now have a mask made of matted film and it holds the toner quite well, especially with a clear coat on top, and it is also fairly opaque. I have not tested it yet, but I will very shortly.
The LaserJet 6L uses a C3906A toner cartridge and apparently this cartridge also has something to do with Canon printers. Here is a link to a document about cleaning, refilling, and the theory of operation pertaining to the C3906A.
Since I have come to the conclusion that I will never achieve the detail that I desire with a LaserJet 6L printer, I am abandoning the idea of altering it.
I am really not sure what it has to do with Cannon, perhaps they make the laser cartridge and just package it for HP.
A more modern laser may be able to give you better detail?
It probably would, but if I needed multiple traces less then 0.008", I would probably just have a laser photoplotted mask made. For simple circuits and boards, with traces greater 0.006", the LaserJet 6L will work just fine with a special laser film and a clear coat, and will probably work well for most hobbyists. However, there is also problems associated with very small text and laser printed photomasks.
On the other hand, if you want or need very fine detail, laser photoplotting or the digital to film process is definitely the way to go.
As a result of what I have learned this week, if I need very fine detail, I will order a laser photoplotted mask, and in the meantime, I am also going to attempt to build my own small little laser photoplotter for boards 3" X 4" or less.
The guts of HP LaserJet printers have been made by Canon from day one, starting with the Canon CX. The LaserJet 5L and 6L use the Canon AX print engine.
Comments
What I used instead of a transparency was vellum paper, translucent instead of transparent. This seemed to help with the light leaks. Not being familiar with using an incandescent light for this type of work, I can only guess that the biggest difference you would experience other than perhaps quality would be length of exposure time.
Given all of this effort, what is the primary reason for wanting to roll your own boards as opposed to purchasing them?
This isn't just a question for Bruce, it's for Leon and any others that are producing their own boards.
C.W.
Definitely turnaround time. I will side with Leon and say 30 minutes, and that is being quite generous depending on your exposure setup. Now lets take a simple power supply circuit for example, and lets assume it has pcb mounted transformer, a full wave bridge rectifier, a smoothing capacitor, and a couple junction blocks. Now let's also say that it might take 45 minutes to draw a nice board, and once again that is being generous. Now let's add another 15 minutes to solder it all together. Providing you have all the materials, you can have a fully functional power supply in an hour and a half. Plus it gives you the ability to test different circuit scenarios rather quickly, but I guess that is also turnaround time. Attached is a photo of a power supply board that I would like to start making, the transformer is not PCB mounted, but this board could be made very quickly and it is a very nice concept.
@deadwhale
Thanks for your input. I tried vellum for quite some time, but eventually ended up abandoning it's use. I now have a mask made of matted film and it holds the toner quite well, especially with a clear coat on top, and it is also fairly opaque. I have not tested it yet, but I will very shortly.
Bruce
The LaserJet 6L uses a C3906A toner cartridge and apparently this cartridge also has something to do with Canon printers. Here is a link to a document about cleaning, refilling, and the theory of operation pertaining to the C3906A.
http://www.uninetimaging.com/downloads/technical/TecArtWebAdded/Canon_AX_Toner-Summit_Web.pdf
Bruce
Bruce
A more modern laser may be able to give you better detail?
I am really not sure what it has to do with Cannon, perhaps they make the laser cartridge and just package it for HP.
It probably would, but if I needed multiple traces less then 0.008", I would probably just have a laser photoplotted mask made. For simple circuits and boards, with traces greater 0.006", the LaserJet 6L will work just fine with a special laser film and a clear coat, and will probably work well for most hobbyists. However, there is also problems associated with very small text and laser printed photomasks.
On the other hand, if you want or need very fine detail, laser photoplotting or the digital to film process is definitely the way to go.
As a result of what I have learned this week, if I need very fine detail, I will order a laser photoplotted mask, and in the meantime, I am also going to attempt to build my own small little laser photoplotter for boards 3" X 4" or less.
Bruce
-Phil