Hi, I want to start making my own printed circuit boards to build some of the great projects I want from a popular tech magazine. I know it involves photo resist, a scanner, and some kind of transfer sheet, but I really don't know how the procedure works. Any ideas for a beginner to succeed at actually producing a working board? Thanks
Copying an image from a magazine and trying to make a PCB from it is not that easy. Been a long time since I've done that, but its messy, tedious, and prone to errors on your first projects. Anyhow, to partially answer your question, Digikey sells PCB prototyping materials & kits. from MG Chemicals. If you go to their website, they may have a "How-To" article or 2; http://www.mgchemicals.com/
My prefered method is going with www.ExpressPCB.com or http://www.sunstone.com/ Both sites have free PCB software that lets you create a schematic & then rout it out onto a PCB. You then submit your design back to them and they send you PCBs back. I've mainly stuck with the ExpressPCB software & PWBs. I've done many boards thru them and I've no complaints. You will end up with a better final project and can esily modify stuff from the magazines for size & features.
Thanks for the heads-up! I always thought that a photo resist board would be no big problem once I found the technique printed somewhere. I used to do my own film developing back in the day with the chemicals and a black bag in my bathroom sink, and had pretty good results believe it or not, so I figured this couldn't be that much harder. I like your idea about the free software and ordering the boards. It certainly cut down on my learning curve ( Maybe?). Anyway, I'm looking into now. Thanks for passing along the experience lesson as well. I'm sure it was hard won.
Here's one way to do it at home. I'll link the source when it's finished uploading.
In short, the required steps are to print, clean, cut, paste, iron, brush, etch, and clean. But before we get started, make sure to procure the following items: a magazine, advertising brochure, or any other similar glossy paper, a laser printer, a clothing iron, copper clad laminate board, one liter of etching solution (ferric chloride solution), steel wool, acetone, and adhesive tape.
Designing the PCB guarantees ensure
Any PCB design program will suffice, but for those seeking a user-friendly and open-source design program, consider Fritzing. The freeware allows you to design circuits on a virtual breadboard before automatically producing a schematic representation of the whole system and converting it into an actual PCB layout. Components are available in a large crowd-sourced database, so chances are you’ll not run lack anything.
After successfully transferring the design on to a PCB layout, equip your laser printer with either old magazine paper, mail advertising or any paper that is glossy, thin and cheap. You’ll know you’ve selected the correct paper thickness if added water disintegrates it into a pulpy residue.
Now that the paper’s been fed, it’s time to use the laser printer and print the design. I specify laser printer because of its reliance on plastic toner to replicate images rather than ink. Recall that plastic is resistant to the ferric chloride we use for etching; this is why the circuit design is left behind on the board once we’ve etched away the surface copper. It is imperative that the PCB layout is printed as a mirror image of itself or it will appear reversed once transferred to the copper board.
Before transferring the plastic toner onto the copper-clad board, spotlessly clean the copper surface using steel wool to remove any oxide. Now that the surface has been completely smoothened, it’s time to don a pair of latex gloves and clean off finger residue. The goal is to create a completely pristine board to allow perfect bonding with the plastic toner from the magazine paper.
Cut and paste.
When the copper board is ready, it’s time to cut out the design. Leaving an extra margin on one side makes it easier to correctly align the paper later in the process.
Any household iron is suitable for transferring the toner onto the board so long as it’s set to maximum heat in the cotton position with absolutely no steam. Once you’ve set the iron to its respective temperature, prepare the paper and board as the iron is heating up. First, find a level surface to work with. Ironing boards are not suitable for this task because of their soft surface. Whatever surface you decide to use, be it kitchen table or not, place a flat, heat-resistant material underneath the board. Ensure copper surface of the board is facing upward in preparation for contact with the PCB cut out.
Next, place the PCB cut out on top of the copper board with the toner side facing the copper. Once the correct aligned is established, use tape on the lengthier margin to secure the paper in place. Only tape one side of the print out as the paper will subsequently be flipped to allow us to preheat the copper surface for 30 seconds.
Flip the PCB print out back into position the minute the pre-heating is complete. This is a tricky process because the copper’s already been heated, however the careful positioning prior to locking the paper with tape, permits it to fall into place correctly. After setting the paper in place, cover it with a second sheet of blank paper to more evenly distribute heat. Now press down with the iron for eight to ten minutes and evenly distribute heat as best you can. Too short of an exposure will not attach the toner to the copper surface.
Dunk and brush
As soon as the iron is removed, submerge the copper board in room temperature water for about one minute or until the paper becomes transparent. At this point the paper can be gently removed by scrubbing with your fingertips – remember that pulpy paper we talked about? Any stubborn pieces should be carefully brushed off with a toothbrush.
Etch the copper off the board
Etching is how we remove all non-masked copper from the board to give us those beautiful sharp lines. Recall that the toner we just bonded to the board is resistant to Ferric Chloride, so anything not covered with plastic toner will be melted away by the etchant until the underlying plastic is exposed. When a circuit is converted into a PCB print out, the conductive pathway of the circuit is covered in plastic toner; this is why PCB print outs are analogous to photo-negatives of circuit boards.
The most common solution used for etching is Ferric Chloride, although some use Ammonium Persulfate. Ferric Chloride is cheap, reusable, doesn’t necessarily require heating, and is available in either liquid or powder form. The substance can perform adequately at room temperature, although the etching process is expedited when the chemical is exposed to heat and agitation.
Place the Ferric Chloride in an old plastic freezer container and microwave it for 40 seconds until the container is hot enough to be uncomfortable to hold, and then slosh it around to get it nice and angry. Be careful not to overheat the etchant otherwise it will start producing hydrochloric acid fumes. As a safety precaution, use plastic or latex gloves when handling Ferric Chloride; it stains everything it contacts and irritates skin. Use lots of running water if ever disposing FC or it will corrode your drain pipes.
How long do I etch?
Etching takes between ten to fifteen minutes to complete; because the process gradually reduces the amount of copper through corrosion, nothing may appear to happen for the first ten minutes. Once you’ve noticed the first evidence of plastic, begin to periodically stir and check, as there isn’t much copper left. Stop approximately 30 seconds after you see any copper leftover in larger spaces.
The final touch
The final step is to rinse the board in water until all traces of FC are removed and then proceed to remove the toner. This is accomplished with over the counter acetone or nail polish remover applied to a cotton ball and light pressure. The toner will come right off and leave you with a beautiful set of copper tracks that is your circuit path. That’s the advantage of the laser printer and magazine paper combo: It leaves with perfectly accurate tracks
I read your very informative step by step instructions, and it all looked pretty interesting until I got to the part about maybe turning my hobby into a chemistry lesson. I'm a whimp from a long line of successful, intelligent, non comptetive followers who got that way by not taking un-neccessary chances. The possiblility of turning etchant into hydrocloric acid is somewhere I don't want to go.
I can't thank you enough for the VALUABLE information contained in your reply. Information=safety in my world, and you have given me information I will certainly use. Thanks for being thorough.
Check out the Homebrew PCB's group on Yahoo. It contains a lot of info om making your own PCB's.
You know, I've been using Yahoo for 15 years and didn't know about the homebrew page. I need to get out more! Thanks for the headsup. I'll try and get back to you again after I take a look see and check it out
Hello again. I said I would get back with you once I checked out the yahoo homebrew page link you sent
Do you actually use this link on a regular basis?. I spent an hour on it and it was so convoluted, I couldn't make any sense of it. The message replies go everywhere and I can't seem to follow any of the conversations in the order they occur. Any input you can provide to help me understand how this resource works would be helpful.
In the past I've been active in this group. Unfortunately, Yahoo changed the format of the groups and now they're very hard to navigate. A lot of users are not happy about the change. You can search the conversation for keywords. Also, select the "Conversations" and then below that select the "topics". This will at least group the messages into topic headings that you can click on and follow the message thread. Yahoo really screwed up the groups with the "new look".
Thanks for the quick reply. I'm glad I'm not the only one who went to the Yahoo site and found it to be user un-friendly. On a side note, looks like Microsoft has become the same way. Looks like they both need to rethink what is an improvement and what is just getting in the way of simplicity. They need to remember the advice they got on their first important project from their boss's. KISS the project - Keep It Simple Stupid !
So much has been said about this topic and almost everyone makes a big deal about it.
Making PCBs at home is very simple and it is easy and not nearly as much of a mess as it has been made out to be.
I have had this article up for nearly 10 years with hundreds of thousands of hits. It is a comprehensive explanation on how this is done, even in a college dorm room!
Thanks for the link.
I downloaded the article ( 15 pages! Impressive! ) and gave it a quick look thru. Brought me right back to my early photography years mixing chemicals in the bathroom with a little black bag to keep the negatives safe. ( yeh I said negatives, this was pre-digital) Looks promising. I still need time to digest all the info coming in from everyone. Looks like i'll be trying multiple methods until I find one that "clicks" with me.
...lots of good answers here. 'might as well throw in my two cents worth. My prefered method is to order from PCBFabExpress. They are the cheapest I've found. Just send them your gerber files for each layer and drill and tool files. The toner transfer method mentioned above is good too though it's kind of hard to align for double sided boards. There are several things that I've found make this method more likely to produce good results:
-Use Press & Peel Blue (a powder coated tranparency sheet that releases the toner better.)
-Pre-etch the copper rather than using steel wool or scuff pads. (Dip the board in etchant until all the copper has turned from gold to pink then rinse with distilled -or deionized- water. Don't use tap or spring water. Don't touch the copper with your bare fingers.)
-After ironing on the image, throw the board - toner - backing sandwich right into the freezer and leave it alone until cold.
-After peeling off the backing use a sewing pin or needle to clean any powder out from the pad holes before etching.
-I prefer using amonium persulfate as it is -or al least starts out- completely clear and transparent. Ferric chloride is dark brown.
-An aquarium heater, air pump and bubble stones will significantly speed up the etching process but are not necessary.
Best of luck and have fun.
No problem!! My homework on this project has been growing almost exponentially anyway!! I would not have guessed the question would have sparked as much interest as it did, given how easy it is to get it done for you on the internet... and I thought I was the only one left who likes to do things for himself!! Looks like I was very wrong!!... in a good sort of way. I will look over the video links when I get the chance. Thanks for sending them.
WOW! Great Video's! I've always been better at hands on teaching than written instructions, and these video's couldn't make the process simpler to understand. Thanks for the assist. Looks like my credit card is about to heat up .... A LOT! (LOL)
This may also be of use to you (http://www.pcbweb.com/). It's a free browser-based CAD application for designing and manufacturing electronics hardware.
I know this thread is a little old but since this is something I am doing right now I thought I would throw this out there. I have been documenting my efforts at making a pcb. check it out. Hope its helpful.
Photo Resist pens!! I still have one in my tool box. A couple of years ago, I was helping out a piano tuner friend of mine with some pcb repairs on electic pianos and older electronic organs. It saved a lot of older equipment that would have been trash because there were no replacements for the pcb boards available anymore. I could remove the voltage regulator that was fried by a voltage spike, and repair any damged traces with my handy pen and voila!! MUSIC!! OLD DOESN'T MEAN GONE! Just ask anyone with a 69 Chevy Chevelle SS what he thinks if you want proof.
I get my pens from Elecdirect.com. I think Ramsey has some too!!
Thanks for the update on good supplies to keep fresh in my toolbox
Dude!! Where You Been!! This one was awsome. I love the pictures and the step by step. It's like I have someone next to me passing on the knowlege so it won't die. Thank you!! I'm going to be studying this for a bit, then I need to PIC out a project to build ( pun intended) I'll post somthing as soon as I get going. It will probable include ways to NOT do the process as well, since that just seems to happen when I try something new. MY Rules include: If your not making mistakes, you're not trying hard enough!!
I'll keep you informed
yea, the photo-resist pens are current. google "PRINTED CIRCUIT BOARD SUPPLIES" good luck. You have inspired me to work on this in more detail, but it's going to be proprietary.
pcbmaking.com would be the best option for printed circuit board. It designs professional PCB at cheaper price. You can place your order instantly and get free shipping. Its easy way to get your job done! Good luck!
I sort of agree with mattheww - Unless you're in a really, really big hurry, etching your own PCBs is really, really not the best solution. OSHPark.com is my vendor-of-choice. 3 boards in around two weeks at $5/in^2.
I tried to etch my own boards once. The etching wasn't a problem. The thing that completely wilted my salad was drilling all the holes. I was unable to get them lined up well enough for DIP placement - and I had a drill press. You also won't get through-plating, so you'd need to insert and solder jumpers in all your vias. Last, but not least, there won't be a soldermask, so reflow with SMD parts is a non-starter.
How about choking up on the drill bit so it don,t wobble so much? Can you grind the drill but shorter so it don't wobble so much also? I'm working on something proprietary, but it"s going to be a long time!
Some very interesting options on Instructables
Some great options for etchants too.
Most recent I read was parchment paper for the laser toner release, but haven't tried it yet.
Had OK luck with photo paper for thru hole feature board.