I’m slowly getting started… I got a UV lamp, etching tank, chemicals and some single sided PCBs to make my first tests.
Now I ran into a problem. My current printer is a Samsung CLP315 color laser printer. It’s OK for most of the things I do usually but it only has a resolution of 600x600dpi.
I printed one of the Eagle demo projects on a transparent foil (Mylar mat, Ref: AR59) and the quality is extremely bad… and that was even after I adapted the configuration for the best possible settings. Now I have to decide if I simply get a new printer or buy one just for printing the transparent sheets for my PCBs. I don’t think I’ll have the need to print directly onto the PCB at this time which seems to only be possible with Inkjets. I’ll also be using the UV lamp so toner transfer methods can be ignored. And finally, I’m not looking for the cheapest solution but rather for best results with low effort.
Sould I get a Laser or Inkjet printer?
And what would be the minimum resolution to go for? I was reading I should get at least 1200x1200dpi. But I found some printers that have 2400x600dpi resolution.
What would be better? 1200x1200dpi or 2400x600dpi?
As always, thanks a lot for helping me out with this. I’ll be posting some pictures with detailed information on my blog once I made the first useable pcb to help others that are also considering doing this. The few test pieces I made so far (using about 1/3rd of the first 10x15cm board) went straight to recycling… :
When I was doing PCBs by chemical etching I just used an inkjet and inkjet transparencies. I’m not sure exactly what type of material you were trying to print to but I suspect it is not a transparency stock made for inkjets. Your printers resolution should be fine.
I now do mechanical etching, that is I mill the PCBs out on my small CNC mill. It is much quicker and easier than etching.
Thanks a lot for your reply. I was using a Laser printer at 600x600 dpi on transparency film where I asked the vendor specifically for Laser compatibility.
One of my friends has an Inkjet printer (cheap one) that can print high resolutions (for photo print) so I’ll get some inkjet transparency and try it on his printer to compare the results. I’ll also try another brand of laser transparency.
[italic]I wouldn’t mind buying a new printer though since the CLP315 doesn’t have network connectivity and all the usual methods (Samba/Cups server, Apple Airport Express, Windows sharing) didn’t give me any satisfactory results. I have a Win7 Ultimate workstation, MacOS MacMini and a Linux Notebook that all like to print. Right now I’m creating PDF’s and print them from my main Win7 station that has the printer directly connected but in a networked environment that’s kinda pathetic.
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I’m curious about your CNC method. How much did you pay for the equipment?
Is it a stock model or did you build it yourself?
I’ll stick with my etching solution for now since I just got it and don’t plan to make more than one or two boards per month, but it may be interesting if I need a higher volume than that.
From what I understood CNC methods also allow you to do finer trances than what etching can deliver… so it might be something I’d be intersted in sooner or later.
I’d still like to know more about the 1200x1200dpi vs 2400x600dpi though so if anyone has any input on that question I’d really appreciate it.
Please explain what came out bad… The transparency or the etch?
In the early days before proper laser transparencies I used architectural drafting film. It prints beautifully on a laser without wrinkling. It is translucent enough to pass the UV and the toner sticks enough to block it without pitting.
If you over expose, the etch will come out bad. Experimentation and eventually a timer is key.
Just on a different track… I have an HD projector with a broken lamp. Would it be possible to replace the lamp with an UV lamp and do direct projection exposure? Just for fun really but I’m curious.
The transparency is the problem. A black area isn’t solid and tracks have holes in them.
It gets better if I put two or three transparency on top of each other or fix them with a black marker. Since I’m planning to get another printer sooner or later anyways I was simply wondering what could give me better results… the 1200x1200 or the 2400x600 dpi resolution. Since laser printers are quite heavy and I don’t have a car I’d rather not have to bring the printer back to the shop if it turns out not to be an improvement.
I’m going to say the problem is with the media (the transparency) and not the printer.
What happens if you print on plain paper, with the printer set to Dark? Does it still have holes? Can you print down to the resolution you want?
If it works on plain paper, all you have to do is to find a suitable transparent paper that your printer likes.
Consider how a laser printer works for a minute… It uses a laser to electrostatically charge areas on the paper. Toner then sticks to these areas and then the fuser melts the toner (which is plastic) in place.
So, if you use a transparency, is it “friendly” to the laser as well as the static charge and very importantly, can it take the heat during the fusing process so the toner sticks to the media? In your case I’m speculating you’re getting holes because one of the two processes are not working right between the printer and the media.
Try the following:
Try both sides of the transparency. Some of them have a “special” side coated to help the toner stick.
Try inkjet transparencies in the laser printer - use the marked side.
Try trace paper (from an art shop). It passes enough UV to work.
Try drafting paper.
I’ll ask my PCB contact that does this for a living what they do. He makes “DIY” PCB’s using a laser printer and the UV method on a large scale.
I have the same problem. If you hold it up to a light then you see that even where it is black it has darker and lighter blotches.
I print the transparency, then if it looks crap then I clean the same transparency with acetone. That removes the toner. Then I try again. After a few tries I get one that is semi decent…
I will NOT try an inkjet transparency in a laser, unless you can afford to scrap the laser printer. Inkjet transparencies are not designed for the temperatures involved in laser printing, and may melt around the fixer roller. They also have a gelatinous coating that absorbs the liquid ink. Don’t know how well that will go in a laser…
Scrap the idea of the inkjet transparency then… I probably just got lucky. :o
I spoke to my supplier and this is what he had to say…
He abandoned the laser transparency method long ago. The quality is just not good enough. What he now do is to make negatives at a print shop using “opague graphic film”. You can’t print this yourself, but if you’re after decent quality and thin traces it is the only way to go. He panelizes a number of orders onto A4 to have it printed.
I think the days of DIY PCB manufacture seem to be over unless you have a CNC router. Clubbing together into larger orders like DorkbotPDX looks like the way to go.
Many people suggest that if you are printing onto transparencies you need to print multiple transparencies and stack them. This means you get a decrease in the effective resolution because you get edge blurs based on how well you line up the stack, but certainly helps with the less-than-ideal coverage.
Personally I have a handful of press-n-peel paper to make DIY PCBs, and printing onto them in a laser printer seems fine (I spend a bit of time making sure the laser is printing OK onto paper forst, make sure the coverage seems ok ). I am yet to actually etch a board I also make sure I use reasonably sized traces and don’t try to go too fine pitch.
I always use only one transparent sheet over the PCB. The first PCB I made I tried with 2 sheets but the alignment was wrong so I end up throwing that PCB.
Once again thanks everyone for your replies. Well I’m not ready to give up yet…
First off I’ll see what our Xerox Laser printers at work will manage, they should have a better quality than mine. I was also considering PnP paper but it’s hard to get in France for some reason.
I guess for very easy stuff I can still use transfer cards (not sure how they are called) or simply draw the cirquit myself. When I go for printer shopping I’ll take some transparancies whith me and simply ask to have some test prints done. That should make it easier to decide on the proper model.
I’m still curious about the CNC solution. How much would I have to pay for good quality entry level equipment?
The best value for the money spent on a small CNC mill would be the Taig 2019: [url]http://www.soigeneris.com/Taig_CNC_Mill_Packages-details.aspx[/url] (my website). There are a ton of cheaper small DIY type router tables but most all of them suffer from poor accuracy and poor spindle motors (Dremel tool). You can build a nice small router table and use something like a Bosch Colt palm router, with precision collets, for a spindle. You have to have the tools and equipment to build the machine though (and a lot of time) before you even get to making PCBs.
I use Eagle to design the PCBs and a free add-on to Eagle called PCB-GCode to generate the GCode. As an alternitive to PCB-GCode CamBam has added support for importing Gerber files in the latest version. I’ve found that CamBam does a much better job with the toolpaths and the boards route faster.
To make it easier for folks to get started making PCBs I put together two bit sets: [url]http://www.soigeneris.com/PCB_Tools-list.aspx[/url] the Starter kit and Prototyping kit. One of the most confusing parts for me when I started routing PCBs was trying to figure out what bits to use so I wanted to make it easier for others.
In short buying a small mill to do PCB etching and the bits will set you back just over $2200 USD but you’ll have a sturdy CNC milling machine that you can do all sorts of things with. The upfront cost is higher than the photo-etch method.
I would say you can get similar trace widths with both methods. If you have good artwork and a good exposure and etching rig you can get good results. Using a CNC you have to have the machine set up properly to get the best results. Commercial CNC routing machines, like LPKF, have sensors and/or mechanical methods of maintaining a constant penetration into the PCB material, which can be somewhat wavy. This lets them get much better results but there are more low-tech alternatives. (I machine a piece of cast acrylic flat on the mill and use it as a base to mount the PCB material to with carpet tape. This works well with a good quality PCB stock.)
That really looks like a nice machine… especially with the starter kit option as it’s always annoying to buy something and then finding out you need that little extra item which is cheaper than the minimum shipping charge… ???
I’ll have to do some saving first though as I don’t have 2.5K (even in $) laying around. I’ll keep you in mind though when considering to go for CNC PCB making. Right now I’m still set on doing the normal etching process…
It seems the transparency I got when buying the whole kit isn’t made specifically for Laser printers which would explain the poor quality. I ordered some high quality laser transparancy sheets and see how they’ll turn out. I’ll also be checking the printers at work tomorrow as I’m working at home today. Plus I have a Darty right next to the office so I can check out their printers during the lunch break.
Once again thanks everyone for your very helpful replies
I made a lot of nice PCBs with the photo etching process, with a few more tries you’ll get the hang of it. the hardest part is drilling through holes by hand!
For the drilling part I got this machine for 50€, but they didn’t have any drill bits smaller than 1mm. I have ordered a set of 10 bits (2 x 0.6/2 x 0.8/2 x 0.9/1 x 1.1/1 x 1.5/1 x 1.7/1 x 2.0 mm). I haven’t tried the machine yet though…
