Step 12: Etching Revisited (October 24th edit)

As many people in the comments have noted my boards had pinholes all over them and I was just as unsatisfied with that as anyone. As such I started to do some more research and try to find ways to correct this issue. Among the many suggestions I received I put two at the top of my list for researching. Firstly, I looked into a better etching setup as I've been considering this for some time and this seemed like the right project for the upgrade to a heated, aerated tanks. Secondly, a few people mentioned the ink I am using and that the proper setting temperature may be higher than I am actually achieving with my heat gun. Since those two things seemed easy enough to remedy I focused on them first to try and solve my pinhole problem.

To start I began looking at a few different etching tank designs and thinking about what I wanted out of my design. I came to the conclusion that I wanted something nice, but not overly expensive and building my own setup was the best option. As such I took a plastic cereal container that I found lying around the house and decided to use it as my tank base. This container is nice because it's large enough to fit bigger boards and has a snap on airtight lid, but not too large that it takes a whole gallon of etching solution to fill. From there I visited the local pet shop and purchased an air pump, some plastic tubing, a bubbling rock, and a small aquarium heater. With all the materials together I hot glued the bubbling rock into the bottom of the container and the plastic tubing up the wall of it. Finally I inserted the heater and was ready for the etching solution.

My second improvement was to heat the boards hotter and set the ink better in hopes it would adhere to the boards better. This was an easy fix as I found a coupon for a dual temperature heat gun at Harbor Freight Tools. This heat gun cost me $10 and has two settings of 570 degrees (F) and 1110 degrees (F) or so. This is more than enough heat as through some research I found the ideal heat for setting my ink is around 425 degrees (F). This is also great because at about 425 degrees (F) the copper clad board will start to turn a bit purple due to oxidation and the heat.

With my two problems solved I printed 2 new boards and tried out the new heat gun. This is where I must issue a warning. As much as you may think the higher 1110 degree (F) setting will heat your board faster and set the ink more easily do not try it. If you heat the board too fast it will warp. If you heat it too much, as I did with my first board, the adhesive holding the copper to the board will melt and the copper will bubble up. All that bubble took was a second on 1110 degrees (F) and the copper popped off.

My second board however I was patient with and used the 570 degree (F) setting and slowly heated the entire board until it started to turn purple. I tried to take an image of this for reference, but it's not visible on camera so you just have to keep your eye on your boards as you do this. Once the ink was set at this higher temperature I fill up my etching tank with some Ferric Chloride and let it heat up and bubble for a bit. When the solution was nice and warm I dipped my board into it and checked it every 30 to 40 seconds for progress. After about 3 minutes my board was done etching. (This type of tank and etching method is so much faster than rocking a container around by hand so I'd recommend the upgrade to everyone.)

After my board was complete I rinsed it off and took some pictures for this page. As you can see these two tweaks in my method produced results that are significantly better as this board has crisper traces and none of the pinholes that plagued the first few boards that I etched.
The aluminum angle you're using is 1/4 tall, correct?
I believe it was yes. Although you could use any size that fits your printer model.
one more thing i ve 1 epson c 90 lying around can it be modified as yours?
the mechanism i made was just like baby cradle which moves back n forth so that the echant keeps agitated and the copper contamination wont affect process<br>.
dear pourcim thanks for posting noce n useful instble.all in one i found that its about raising the printer mechanism to accomodate copper clad in place of paper. well done.just one query about the mis pro cart and its chip setting .what exactlt it is? n one suggestion anout itching process which i my self tried during manual pcb making.i used a rectangular container n made it moving with motor n cam mechanism n found the itching was faster than isual without eating the copperclad. <br>however thanx again 8n keep exploring things .all the best!!!!
<p>Stumbling across this instructable has turned on so many lights...I NEVER knew the fine difference between printheads in inkjet printers. I had hoped that the HP PSC 1210v I have laying around could be modified for this, but with a short amount of research I discovered that Canon and HP use Thermal and Epson is the ONLY manufacturer to use Piezo. Happier now that I purchased the Artisan730. I realize this is an old instructable...but WOW. Thanks for sharing!!</p>
<p>Thank you for the instructable. </p><p>How would you print a protective print layer on the PCB after it's been etched?</p><p>i.e what ink would you us? And do you have to design a new PDB layout, with the print layout, and lettering for components, etc?</p>
I haven't worked out a process to print a solder mask yet. I've tried simply printing the MISPRO ink over the board after etching, but it didn't stand up very well. Currently I'm experimenting with some glass paint called Pebeo Vitrea. The paint is heat set and from what I've seen on a few sites can produce a nice mask when applied properly. When I finish the laser cutter I'm building currently I hope to use the laser to cure or remove various type of coatings as an experimental mask.
<p>Sir, may I ask if the Epson C80 family of printers is still available in the market? We are planning to use this idea of yours as our project but we're having a hard time searching for the printer. Is it possible to use other types of inkjet printer? Thanks for the reply.</p>
I actually don't know if the printer is being produced any longer. If you're looking for a different printer the important thing is to get a printer that uses piezo printheads. Epson printers had this on some models last I checked, but I can't tell you exactly which ones do currently.
<p>but where is the point to to waist so much time to convert printer if u can just use photo cooper clad and get pro level pcb's with no hassle... </p>
I don't feel like it was a waste of time for a few reasons. First this project really only took me a few hours over two weekends to get everything complete so probabaly 6 hours total. Second I already had the printer and a lot of the parts on hand so there really wasn't much if any cost. Third I would of had to build or buy an exposure box for the photo method anyway. And finally the process now that it's built is really as simple or perhaps simpler than the photosensitive boards. I don't have to expose or rinse the boards at any point. I just print, drop them in my etching tank and in 5 minutes I have pro level boards too. Everyone has their own preference and this ends up being mine.
<p>A good technique to remove all copper instead of ferric chloride is use 60ml of peroxide and 40ml of sulfuric acid, mix both and put in the plaque and it will be ready in a few minutes.</p>
Wow, I'm amazed that this is possible - never considered this as an option. Does the kind of ink you use matter (other than the fact that yellow works best)? Thanks, Bill <a href="http://www.castleink.com" rel="nofollow">Castle Ink&nbsp;</a>
Quick question, does it have to be yellow? Can I use magenta or some other color?
From what I've seen online in various forums yellow seems to work the best so that's what I went with. I'm sure you can experiment though as I've seem magenta used before as well. Just need to make sure and get a thicker layer of ink on the board.
Would this method/ink work with electrolytic etching using salt water and electricity? Or would this ink not withstand it?
I can't tell you for sure if it would withstand the salt water and electricity. I had some issues with hydrogen peroxide and hydrochloric acid eating right through the ink, but ferric chloride didn't damage it. Those are really the only two etching methods I've tried thus far with the PCBs.
Can anyone tell me what is the minimum possible line thickness can be achieved
This depends on several factors the main three are (once perfect lines are produced) <br>The under-etching of the edges Due to (1)Etch-ant type,(2)time exposed, and the (3) irregularity of the mixes composition, (usually overcome by running through a low volume all plastic water pump ) design circuit to the amount of current the copper has to take,Otherwise eat away to zero.
Currently with the Ethernet Arduino board that I've printed and etched the thinnest trace printed would be about the size of the 74HC08 surface mount chips leads. That is to say that they are approximately .3 to .4 mm wide roughly. I don't have an exact way to measure something this small at the moment, but from the datasheet for the 74HC08 I can estimate them at about that thickness.<br><br>As for the thinnest etched spaces on the board I have a few areas that are even thinner and I would estimate at about .1 to .2 mm wide roughly. I'd venture to say probably more around the .15mm area. <br><br>I know there are a lot of others out there using this setup too and maybe some of them are getting different results, but that's what I can tell you from my experience so far. I'm working on my own board design for another project currently so once I can that board all designed and ready to print I may be able to give you more measurements straight from Eagle.
thank you very much. <br>but have one question,can i use canon printer.
Great write up, well written and covering all the bases. Excellent job. <br> <br> I have been considering a very similar mod, but not had the time to attempt it yet. What I am considering is replacing the print head with a laser diode; which could then expose a presensitized board. This of course would require some new control boards/software - possibly Arduino based, but should be able to generate very high quality boards. First thoughts were of course just cutting the copper with the laser, but my guess on that would be a very powerful laser given the heat transfer properties of copper. Anyone ever tried either; or anyone want to take the idea that does have some time to work on it - feel free!
Hello, <br> <br>i had a question. I am working at a startup and we are making comic publications. We need to print rolls of size 4inch by 150 ft long! and this is on bible (thin paper). The question i had was, we cant afford these fancy large format printers which are able to do this. Neither can we outsource as the cost is too high per unit. We need to print these cheaply and with inexpensive equipment. Any ideas if it is possible to convert a normal printer into something which can print 150 feet long documents. <br> <br>The print quality is only 300 DPI and black and white. <br> <br>Would really appreciate some help.
Wow. I had no idea you could even do this. Does this make the <a href="http://www.dpoe.com/products/image-flex-managed-image-flex-managed-print-service/index.asp" rel="nofollow"> printers multifunctional</a>?
I'm really glad I found this. It's been a while since I've had to worry about this, but my friend has been looking into <a href="http://www.fasttracksignsandprinting.com" rel="nofollow">printing in Edmonton</a> and I think he should try it himself. I think he'll do this, thanks for sharing.
hi really like the idea, but having trouble with the ink, I thought it would be possible to use laser printer instead of ink jet....
I'm not 100% sure how to approach the idea of using a laser printer truthfully. There's a lot to consider that complicates the process. While you may be able to do it I don't think it will prove to be nearly as simple as this modification was. The laser printer has a more complicated system with the fact that it uses toner and then as the name suggests has a laser which melts or sets the toner powder into an actual ink. If you do try to modify a laser printer let me know as I think it would be quite interesting, but I don't know how much help I can give you without directly having access to the printer and seeing the inner workings that need modification.
The laser only writes the image onto the drum. The photo conductive drum is charged with a positive charge. The laser writes onto the drum, where the laser hits, the drum becomes conductive and discharges the positive charge. Positively charged toner particles then stick to the uncharged parts of the drum. The paper is negativley charged and the toner transfers from the drum to the paper. The paper and toner go through heated rollers (like a laminator) and the plastic toner melts and fuses to the paper.<br> <br> Two main problems in conversion are,<br> The paper path is never straight, impossible to make it so without very major modifications.<br> The copper on the PCB will not hold a static charge&nbsp;as it is conductive.<br> <br> Though if anyone does do it I would be very interested in seeing it. :)<br>
I haven't tried it myself, but I have a friend that uses his laser printer to print out the PCB drawing on parchment paper, then transfers it to the board by ironing it on. I've heard of others using regular paper the same way
That's the typical method of making homemade PCBs. My upgrade to this system was to make more intricate and more consistent boards. There are a lot of options out there though if you search Instructables for other methods.
Awesome work. Question- could a laser printer be modified in this same way to directly print toner onto a board?
I would say probably not.<br> <br> The paper path in most laser printers is a sideways U.&nbsp; That means the paper has to bend around the drum and rollers, a normal PCB won't.<br> <br> Even if you could get a laser printer with a straight path the PCB is too thick and you would need to modify the actual drum/toner assembly and the fuser assembly.&nbsp; Not easy at all.<br> <br> Lastly the transfer of toner to paper relies on a static charge given to the paper to attract the toner.&nbsp; I don't think the conductive copper will hold the charge well enough, if at all.
I have been curious about the same thing actually. The short answer is I'm not sure. <br> <br>The longer answer is it would depend on the construction of the printer and how easily you could &quot;lift&quot; it. Factor into that the different printhead system and whatever other mechanisms a laser printer might have and it could complicate the build. I don't really have access to a &quot;junk&quot; laser printer so I haven't been able to test this idea out. I'd need to take it apart and look at the specific printer to decide how to go about modifying it. <br> <br>If you do decide to try it and are successful or find some helpful things out make sure to let me know as I would like to try that in the future.
Well done, very thorough instructable.&nbsp; Especially your experiments and results on etching.<br> <br> I've been converting an Epson T21 but for various reasons haven't finished it yet (over 3 years !)&nbsp;<br> <br> The T21 has the whole printing mechanisim and electronics&nbsp;on a vertical steel plate that is held by 2 screws to the base.&nbsp; I just need spacers under the screws to raise it, no cutting, no brackets.&nbsp; I&nbsp;was lucky&nbsp;on that part.<br> <br> &nbsp;I really should finish it and put up an instructable.
Hi, Did you modify the programming if not then how did you tell the printer to only print with the cartridge you filled with the yellow ink, or did you fill all of them???
You could fill all of the cartridges if you'd like to and then you wouldn't have to worry about what color printed, but I didn't go that far. I only filled the black ink cartridge. <br> <br>I've just been designing things in all black and then printing them using a black and white option in the printer settings and that has been working fine. <br> <br>Additionally the program I use the most with this printer is EAGLE and it has an option on the print screen to only print in black which thus far has worked fine for me.
I just thought somebody has to say this... your a smart person...
Dear Sir,Your video is not available here.
i was recently thinking about hacking a printer like this for a slightly different purpose, and i checked instructables to see if it was already done by someone else, this was the closest. my idea was to mount a lightscribe DVD burner laser on the printer head of a cheapish $50 printer (bought the DVD drive, not the printer yet) and link it up so that as well as depositing ink it could reduce graphite oxide film into graphene, on a glass or, (optimistically)- a cellulose acetate substrate for the purpose of making an active matrix pixel array for creating OLED displays (including the field effect transistors+capacitors for each pixel in the same process, using the semiconducting and conducting properties of the graphite oxide and graphene, respectively), the electroluminescent doped polymers could possibly be dissolved in acetone or perhaps a weaker solvent that wouldnt attack a printer cartridge too much, then printed over the transparent graphene electrodes, one for each subpixel in alternating formation according to the RGB dopants and corresponding subpixel.<br><br>the idea i had was having the printer rollers actually moving the entire printer along rack and pinion type rails on each side of the build surface, and i wasnt sure if the steppers would be powerful enough, got some heartier steppers around though, but different current ratings to most printer steppers so i'd have to make a breakout board to drive them if i had to use them for it. (which would be fairly straight-forward, i got a cnc lathe/mill and a UV LED PCB developing glass table)<br><br>anyway, what my question really is, would you know of how to mess with the printer driver program and/or circuitry to use it as a plotter as well, so it could laser reduce graphene oxide in continuous lines while changing from one axis to another instead of rastering? rastering would be fine for the deposition of the EL polymer but i think the graphene would have a more continuous molecular formation if it was reduced as a continuous trace.<br><br>apologies for lack of caps and the grammar, i are retard.<br><br>i would very much appreciate a reply if you have any information i might find useful to achieve this objective.
Very well done. Something that I might try in the future.<br><br>Is is just me, or does the final etched product seem rough around the edges for the copper pads and traces, doesn't look very clean in the pictures?<br>If this is the case, would a better quality printer be the way to a better etch, or is it simply the &quot;DIY&quot;ness of it all that produces the 'rough' results?
The first boards I did while still testing the printer and trying to iron out the kinks do have rough edges on them yes.<br><br>As I got everything fixed and calibrated right though the boards got better. I have pictures of the better board I made in there a few places, but now that I know exactly how long to preheat the boards for and how to set the ink better and have a better etching tank the boards are coming out smooth.<br><br>I haven't had a chance to post anything new recently because it's been pretty cold outside and I haven't been able to etch boards yet. The new etching tank is nice, but the bubbling ferric chloride isn't something I like to use inside very much. I'm working on designing a few of my own boards currently and when I get a chance to etch them I plan on posting updated photos.
i still don't believe my eyes. this instructables is incredilble. big thanks. will make one because i have the same printer
Is there something about the MIS ink that makes it more suitable for this task than other pigment inks?
Just wanted to post a comment and thank everyone who voted for me and viewed my Instructable. I'm a finalist in the Epilog Challenge and I really appreciate it. Here's hoping I can win and bring you more cool projects with that Zing laser cutter.
Thank you so much. I have been dreaming of something like this for a while but have been to busy (way too lazy) to go through the trial and error myself. I look forward to building one of these soon. You definitely have my vote for most awesome in show!
The build really isn't all that hard once you've got a plan of attack for everything and it's definitely worth the time you put in because my new boards are coming out very nicely now that I have the heating and etching problems sorted out. Hope the build goes well for you and thanks for the vote it's much appreciated.
interesting!!! great work!
Thanks. It was a fun project to work on and the goal of better PCBs made it even more so.
Hi, I'm moderator of Homebrew_PCBs and Inkjet_PCB_Construction on Yahoogroups, which is where a lot of the information on Massmind.com comes from.<br><br>I would suggest that you put MISPRO yellow in all four cartridges. It can be very difficult to get an inkjet printer to print from only one ink shade. More printheads printing may mean more dots filled in, too.<br><br>As for the curing, from all reports the temperature and hold time are very important. Volkan, the gentleman who first discovered this process of printing and heat curing pigmented ink, would heat it to the point where the copper just turns purple and hold it there. Others have experimented and found that holding it at 230C/446F for about 3 minutes does the trick, but that it is a very narrow window of temperature.<br><br>I just ordered a &quot;Mini SMD Preheater&quot; 21-10135 from MCM that is a hot air rework station, set the board on top of it and it heats between 100C and 350C, temperature controlled. My intention is to use it for pigment ink cure and SMD reflow soldering. I got it on sale earlier today for $40. A toaster oven with a better thermostat should work, too.<br><br>To the gentleman asking about using an HP inkjet printer, as you mentioned the MISPRO pigmented inks probably won't work since just about every desktop HP inkjet printer is a bubblejet and uses dye colors. However, there is the hybrid toner method - print using any ink, as long as it doesn't run, and dust laser toner across the ink. The ink stays tacky for quite a long time on a nonporous surface. Then heat until the toner turns shiny.

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Bio: I have a Master's degree in Biomedical Engineering. I'm always looking for new challenges and projects. I'm interested in science, math, art ... More »
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