EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: eeguy on May 20, 2020, 09:37:34 pm
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Hi, I recall that many years ago at school I designed a circuit on the computer. Then, printed it out on an OPH sheet. Somehow I put it on a (copper?) board and bathed it in some kind of chemical solutions for about half a day to make a circuit board. So many years have passed. What is the best way to make circuit boards at home these days?
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The best way to make them at home is DON'T. :D
It's far easier to get some free software (aka, KiCad), draw a schematic and lay out the board (pretty much drag-n-drop components and footprints), then spit that out into a file that you upload to a company that will, within a day or two, produce your board(s) for a few $$ and ship them to you within a week or so. Last time I did it I got 10 boards for "free" (paid only $20 for shipping from China to US) and received them a week after I ordered.
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i make my own using the toner transer method,i then etch them in a mix of fuming hydrochloric acid and hydrogen peroxide mix.
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Big clive explains one method
https://www.youtube.com/watch?v=CrdheP3Dwyc (https://www.youtube.com/watch?v=CrdheP3Dwyc)
however as mentioned above,by the time youve bought all the bits its cheaper to get them made in china,only drawback is if you need a board NOW
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i make my own using the toner transer method,i then etch them in a mix of fuming hydrochloric acid and hydrogen peroxide mix.
If you really want to do it yourself, then this is the best way.
Though i recommend using proper pcb toner transfer paper rather than the plain old glossy magazine paper that some guides recommend.
The two types i know about are.
Press-n-peal blue (used it myself with good results)
Toner transfer system by Pulsar.
It can take some practice, don't try to do a 100 pin TQFP on your first attempt. Stick to TH or SOIC stuff and you will be fine.
The key part is the iron on process. A press iron or feeding through a laminator many times is the best open.
A hand iron tends to move things and smudge the image, or not get uniform coverage.
I used a press iron and pressed for 5min then switched it off and left it to cool down before removing.
Set the printer settings to as dense/black as possible. You want maximum toner on the paper.
Also the toner used in some laser printers doesn't work as well as others. YMMV
It's also important to clean your copper PCB first. Get the oxides off.
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The best way to make them at home is DON'T. :D
Seconded.
PCB fab has moved on so much since the days of stick on pads and etch resist pens - as sold by defunked Maplin. Even PCB milling is a bit 'last year'.
By default, fab houses produce double sided boards with solder masks, silk screens, plated holes/vias and cut slots. Basically, all the layers you create in Kicad, etc. They'll even laser a solder paste stencil if you need one.
And (mostly) boards are made to tolerances way beyond the kitchen sink maker. So let the fab keep a stock of drill sizes and deal with those nasty etch chemicals. Just upload your Gerber and drill files, pay and wait about ten days. So much easier.
Check out OSH Park for small sized small scale boards. https://oshpark.com
Other fabs are available.
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OSHpark is expensive, try to get a quotation with jlcpcb. You can get 5 boards (10x10mm) for $2 + Shipping
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OSH Park boards are made in the USA. Which is why they are not as dirt cheap as Chinese fab houses. But for their basic prototype service, global shipping is inclusive. And the quality is spot on.
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Hi, I recall that many years ago at school I designed a circuit on the computer. Then, printed it out on an OPH sheet. Somehow I put it on a (copper?) board and bathed it in some kind of chemical solutions for about half a day to make a circuit board. So many years have passed. What is the best way to make circuit boards at home these days?
Making your own boards is part of the fun with electronics.
Doing traces down to 0.5mm on 1 oz copper clad is easy. 2oz takes more etching time.
Build the circuit and PCB with KiCad or other program.
I make negative of the pattern on acetate with the toner printer . Then use the Negative Photoresists which gives a much finer detail to the PCB art than toner transfer but not as fine as positive photoresist . Flash with UV and develop .Then use the muratic acid / Hydrogen peroxide etching process. Lots of You Tube videos on the process.
I do it this way because it's just to expensive and takes to much time to send out from where I live. I can whip up a PCB quickly and have it soldered or mostly soldered the same day.
Chemicals like Ferric Chloride are to hard for me to acquire so the only thing I need to order is copper clad which I can buy in bulk.
It also gives a personal sense of pride to do my own boards.
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For quick prototypes I use protoboard PCBs and solder the traces with wires. I used to etch my own PCBs when I was teenager, could not afford a drill so "invented" SMD soldering by bending the through hole pins outwards... that was in the 80s. If I need more than 1 board, I just use Kicad and order from JLCPCB... try to order several designs at the same time to save on shipping
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Despite the cheap Chinese made PCBs, I still make my own one offs and initial prototypes, only single sided.
What has been working for me is toner transfer with Press-N-Peel film from Jaycar.
Judging by Youtube demonstrations, incomplete tone adhesion is expected, I rarely have this problem now.
The blank PCB must not be warped and edges smoothed, cut it with a hacksaw rather than hand shears.
I clean the copper with a green scouring pad and test the surface by pre-etching for a few seconds looking for
an even matt appearance, no shinny patches which will later selectively delay the final etching.
I rinse off the PCB with rain water and dry it with hot air.
My printer's toner density improves when I reduce the moisture content of whatever is being printed to, with hot air.
I spend some time making certain that the film is thoroughly ironed to the PCB, all of the film area appears well burnished.
I etch in Cupric chloride.
The earlier pre-etching seems to result in less track fattening and a more even final etch.
I set my particular iron to "cotton", 150°C average.
https://www.thegoodguys.com.au/russell-hobbs-rapid-steam-iron-rhc902 (https://www.thegoodguys.com.au/russell-hobbs-rapid-steam-iron-rhc902)
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I do mine using toner transfer with Press n Peel blue transfer film and etch in HCl + peroxide, it works the best of anything I've tried. I rarely do it anymore since it's SO cheap to have boards professionally made but I still keep the stuff around because sometimes I want to have a board in an hour instead of weeks.
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How I started was with wire wrapping with through hole components stuck in cardboard. Then move onto etching pcb using ferric chloride with mask made of hand drawn oil paint and later on laserjet toner transfer method.on self etched boards, I used SMD first, to avoid drilling, then I started to use dremel. All of the circuits that i've made, after 10 years, still work, though obsolete and replaced with modern stuff (I kept em for sentimental values).
I stopped after I started an accounting job and I use JLC now.
I suggest, you go the the same route
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Producing PCBs at home doesn't make much sense anymore. Expensive tools, more or less nasty chemicals (sometimes hard to get or get rid of), cumbersome vias, no silkscreen, no solder mask, and swearing. When you have all the machinery and just need a simple single-sided PCB then it's a different story. Personally I use the positive photoresist based process:
- laser-print layout on tracing paper
- apply some special spray to get nice solid black areas
- put layout and board coated with positive photoresist into UV exposure box
- developer bath (NaOH) to remove exposed photoresist
- etching tank (Na2S2O8 at 45°C)
- remove remaining photoresist
- drill PCB
- apply soldering lacquer to protect PCB
With that process I'm able to get traces down to 0.2mm reliably (0.15 is doable, 0.1 is the limit for my setup).
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- apply some special spray to get nice solid black areas
I also use tracing paper. What is this special spray?
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Permanent marker works as well, probably not as good as laser printed heat transfer, but it is a cheaper option
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It's SOLVENT 50, meant to remove labels but also works great as a toner enhancement spray while being less expensive.
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If you browse a bit around on intstuctables or youtube you'll find a bunch of different methods. There is no "best" method. It's always a tradoff between equipment, price, materials, accuracy you need, experience etc.
Big Clive's video looked quite good and informative.
Marco Reps has been experimenting with UV film and a UV laser in a CNC/3D printer for directly developing the film .
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i make my own using the toner transer method,i then etch them in a mix of fuming hydrochloric acid and hydrogen peroxide mix.
Wow! What is wrong with ferric chloride ?
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Really large PCBs are still significantly cheaper to DIY than buying in. E.g. a large "motherboard" or similar item is not cheap to have made.
Large areas of solid ground fill is a problem with the laser toner transfer method. If you avoid that, the toner transfer method is pretty quick and works well.
I get the most accurate results by using photo resist film, with high quality artwork inkjet printed on absorbent transparency. This method has no problems with large ground fills...
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Hi, I recall that many years ago at school I designed a circuit on the computer. Then, printed it out on an OPH sheet. Somehow I put it on a (copper?) board and bathed it in some kind of chemical solutions for about half a day to make a circuit board. So many years have passed. What is the best way to make circuit boards at home these days?
If you want to do it for fun, go the toner transfer method.
IF the desire is to build a complex board with multiple layers and odd features go with a service to make the board for you.
If you are doing a lot of experimentation with odd board designs consider a router. routers can be great for higher power electronics where you actually want to leave most of the copper on the board. Or if there are a lot of structural considerations in the board.
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i make my own using the toner transer method,i then etch them in a mix of fuming hydrochloric acid and hydrogen peroxide mix.
Wow! What is wrong with ferric chloride ?
- It stains everything it touches
- It is very toxic to aquatic life so you should never ever pour it down the drain
- It saturates with copper after a while and you need to dispose and buy more (HCL+Peroixde chemistry is weird, it kinda automatically replenishes itself, you almost never have to replace it. Maybe add a little more peroxide now and then)
- It works best when heated. (HCL+peroxide works fine at room temp)
- It can be harder to source/buy than HCL+Peroxide. (HCL you can get at any hardware store for pools and peroxide at any chemist.)
- It's dark so you cant see if your board is done without taking it out. (HCL+peroxide is transparent blue/green)
IMHO, for hobby stuff hydrochloric acid and hydrogen peroxide is just better in every way.
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i once started with i guess the peroxide thing because i cant get the FeCl supply during that time. bought from china in white salty form once or twice. mix with clear water and becomes blue when etching, it is said it produce friendly oxygen (or H2O?) the annoying thing about it is we cant store it any longer than a few weeks and it loses its etching capability even if you put the whole bag in the water. later i got FeCl supply locally and thats what i currently use and store for years now. i bought like 4 bags, now i'm on 2nd bag after the 1st bag saturated with copper after years of usage.
back to diy pcb, i didnt have much luck with toner transfer method mainly due to laser printer problem, cant give me dense black print on large PCB with ground plane everywhere, the laser drum always like to attract fungus in my climate. i had 2nd laser printer bought just to make pcb developed fungus within weeks after purchase, now its an idle weight on my desk to put things on top of it for years now. getting uniform transfer, the right paper and ironing is another issue. so no more toner transfer, i built a resist ink "scratching" machine similar to below video. with it, ground poor is rock solid, and etching success is like 1-5 percent traces short correction repair, and most of the time 100% correct without needing for repair, given etchant in good healhty condition (not near saturation). btw soic and smd packages is my favourite, and failure rate is increased higher using toner transfer with these footprints. ymmv.
https://www.youtube.com/watch?v=sNh0ubRcTYU (https://www.youtube.com/watch?v=sNh0ubRcTYU)
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Hi, I recall that many years ago at school I designed a circuit on the computer. Then, printed it out on an OPH sheet. Somehow I put it on a (copper?) board and bathed it in some kind of chemical solutions for about half a day to make a circuit board. So many years have passed. What is the best way to make circuit boards at home these days?
I rarely do PCBs at home, now, although I do have the equipment. But, the best way is with dry film resist. I built my own laser photoplotter to make the master artwork with greater precision than a laser printer can do. Especially for two-sided boards, this is necessary, as most printers don't register the images precisely, so the two back to back images won't line up well enough. For small boards, though, you can get away with it. Once you have good master artwork, you can then laminate dry film resist to the blank copper board, expose the resisto to the master artwork, develop the resist and etch in your favorite horrible solution. The etchants are pretty nasty stuff, I use Ferric Chloride. Part of the trick is to get the etching to go as fast as possible, to preserve the drawn details and line and pad witdths. I etch for 90 seconds in 45 C FeCl with a spray etcher.
Jon
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Did you know that you can do toner transfer using a laser printer, printing out your design on the cheapest possible paper, (junk mail works best!) then scuff up your PCB with some steel wool to get it abraded pretty well, then use the iron to transfer the toner to the PCB, using a flat piece of wood as your ironing board. and for the etchant- use hydrogen peroxide, vinegar and salt.
It works great, at least for small boards and is fairly fast. if the etching slows down add more salt. You can keep doing this for quite a while. Oh, after you are finished etching there is a black gunk on your boards, which you need to clean off with acetone or nail polish remover, be careful not to get it on any plastics. that will clean the board and it should look good. Make sure to prtect your boards with some kind of coating or they may corrode if its very humid.
So you can etch with household materials, for cleanup I just pour the used etchant in a gallon jar I have and it dries out and now after years of doing this there is just a bunch of greenish dried out powder in the bottle. So I have not needed to dispose of it yet.
Hi, I recall that many years ago at school I designed a circuit on the computer. Then, printed it out on an OPH sheet. Somehow I put it on a (copper?) board and bathed it in some kind of chemical solutions for about half a day to make a circuit board. So many years have passed. What is the best way to make circuit boards at home these days?
I rarely do PCBs at home, now, although I do have the equipment. But, the best way is with dry film resist. I built my own laser photoplotter to make the master artwork with greater precision than a laser printer can do. Especially for two-sided boards, this is necessary, as most printers don't register the images precisely, so the two back to back images won't line up well enough. For small boards, though, you can get away with it. Once you have good master artwork, you can then laminate dry film resist to the blank copper board, expose the resisto to the master artwork, develop the resist and etch in your favorite horrible solution. The etchants are pretty nasty stuff, I use Ferric Chloride. Part of the trick is to get the etching to go as fast as possible, to preserve the drawn details and line and pad witdths. I etch for 90 seconds in 45 C FeCl with a spray etcher.
Jon
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Did you know that you can do toner transfer using a laser printer, printing out your design on the cheapest possible paper, (junk mail works best!) then scuff up your PCB with some steel wool to get it abraded pretty well, then use the iron to transfer the toner to the PCB, using a flat piece of wood as your ironing board. and for the etchant- use hydrogen peroxide, vinegar and salt.
I started out using junkmail paper for toner transfer and it worked ok, but not nearly as well as Press n Peel film. I often found that the ink on the paper would fill in the pores in the toner and result in perfect etches while the un-printed areas would get a texture to them. In many cases images and printing from the paper page would end up etched on the board. The blue film is consistent.
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+1 for using "proper" toner transfer paper - I use the Pulsar toner transfer paper and it is extremely reliable, cheap enough that it isn't a big deal to use.
My printer will accept the "abuse" of taping a small square of transfer paper onto a letter sized sheet of paper, if I am doing a small board. This way, the transfer paper is super economical to use. Basically, I print the small board on a normal sheet of paper first. Then I tape a square of transfer paper over the area where the print is on the paper, using very thin tape. Then I run the page through the printer again, this time it gets printed exactly on the toner transfer paper. Winner, winner, chicken dinner!
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Come to think of it that has happened to me at least twice (where the ink from the junk mail behaved like toner)
.One time I cleaned it up and the other tie (with an antenna) where it just looked like it would be a PITA, I just redit it.
To be honest with you Ive never used any purpose made products intended for PCB toner transfer. I should try that.
Also, Ive never made a board that requires very very thin traces.
Text has turned out okay.
Did you know that you can do toner transfer using a laser printer, printing out your design on the cheapest possible paper, (junk mail works best!) then scuff up your PCB with some steel wool to get it abraded pretty well, then use the iron to transfer the toner to the PCB, using a flat piece of wood as your ironing board. and for the etchant- use hydrogen peroxide, vinegar and salt.
I started out using junkmail paper for toner transfer and it worked ok, but not nearly as well as Press n Peel film. I often found that the ink on the paper would fill in the pores in the toner and result in perfect etches while the un-printed areas would get a texture to them. In many cases images and printing from the paper page would end up etched on the board. The blue film is consistent.
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What is the Pulsar papers shelf life? (although I guess if it is super cheap it really doesn't matter.)
+1 for using "proper" toner transfer paper - I use the Pulsar toner transfer paper and it is extremely reliable, cheap enough that it isn't a big deal to use.
My printer will accept the "abuse" of taping a small square of transfer paper onto a letter sized sheet of paper, if I am doing a small board. This way, the transfer paper is super economical to use. Basically, I print the small board on a normal sheet of paper first. Then I tape a square of transfer paper over the area where the print is on the paper, using very thin tape. Then I run the page through the printer again, this time it gets printed exactly on the toner transfer paper. Winner, winner, chicken dinner!
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What is the Pulsar papers shelf life? (although I guess if it is super cheap it really doesn't matter.)
+1 for using "proper" toner transfer paper - I use the Pulsar toner transfer paper and it is extremely reliable, cheap enough that it isn't a big deal to use.
My printer will accept the "abuse" of taping a small square of transfer paper onto a letter sized sheet of paper, if I am doing a small board. This way, the transfer paper is super economical to use. Basically, I print the small board on a normal sheet of paper first. Then I tape a square of transfer paper over the area where the print is on the paper, using very thin tape. Then I run the page through the printer again, this time it gets printed exactly on the toner transfer paper. Winner, winner, chicken dinner!
I am not aware that it even has a shelf life in practice - as long as it is stored in dry conditions, like any paper, of course. I have about a dozen sheets here that are at least 5 years old, as good as new.
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I was thinking about this clay coated inkjet photography paper I have (which might even work for toner transfer) It lasts a couple of years but not forever.
I am so ridicuously cheap sometimes.
What is the Pulsar papers shelf life? (although I guess if it is super cheap it really doesn't matter.)
+1 for using "proper" toner transfer paper - I use the Pulsar toner transfer paper and it is extremely reliable, cheap enough that it isn't a big deal to use.
My printer will accept the "abuse" of taping a small square of transfer paper onto a letter sized sheet of paper, if I am doing a small board. This way, the transfer paper is super economical to use. Basically, I print the small board on a normal sheet of paper first. Then I tape a square of transfer paper over the area where the print is on the paper, using very thin tape. Then I run the page through the printer again, this time it gets printed exactly on the toner transfer paper. Winner, winner, chicken dinner!
I am not aware that it even has a shelf life in practice - as long as it is stored in dry conditions, like any paper, of course. I have about a dozen sheets here that are at least 5 years old, as good as new.
Thats actually a good example of my cheapness. I very rarely use air conditioning, unless its over 80 or so or really really humid. Things don't get moldy, usually, its not that bad (I do have a dehumidifier in the basement) but certain things dont do so well in high humidity.
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The Press n Peel (or whatever) transfer film looks expensive but in practice a package of it goes a LONG way, I'm only on the second pack I've ever bought and that's only because I helped a friend etch about a dozen boards he needed right away and didn't have time to send out for.
What I do is print out my layout on ordinary printer paper, then I cut out a piece of transfer film just slightly larger than the layout and tape it along the leading edge right over the pattern I just printed. Then I feed it in the manual feed tray and hit print again, printing the same design on the same sheet, this time onto the piece of transfer film. By doing this I can get a dozen or more small boards out of a single sheet of film.
*edit: I just noticed that SilverSolder already said almost exactly the same thing. I've done the tape trick with a bunch of different printers and never had any trouble with it. As with most things though YMMV.
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We are all economical minds here, it seems! :D
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What really works well with toner transfer is the paper backing from adhesive vinyl used for signs . I could get that stuff for free from a local sign maker and cut it into 8 x 11 sheets for the printer.
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I've had reasonable success using the waxy-paper used on rolls of book contact. Cheap and abundant. I just cut it roughly down to size and my printer is fine with it.
People wonder why I buy book contact only to throw all of the useful half out :P
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Oh, after you are finished etching there is a black gunk on your boards, which you need to clean off with acetone or nail polish remover, be careful not to get it on any plastics
I just drill the holes then use scotch brite with soapy water...polishes the copper and chamfers the hole, and sometimes it pushes the copper around the hole into the hole. The end result is nice and clean holes.
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Making your own boards is part of the fun with electronics.
Doing traces down to 0.5mm on 1 oz copper clad is easy. 2oz takes more etching time.
Build the circuit and PCB with KiCad or other program.
I make negative of the pattern on acetate with the toner printer . Then use the Negative Photoresists which gives a much finer detail to the PCB art than toner transfer but not as fine as positive photoresist . Flash with UV and develop .Then use the muratic acid / Hydrogen peroxide etching process. Lots of You Tube videos on the process.
That's 20 thousandths trace width. I do 8/8, 100% success rate over an entire 6x9" board. Toner transfer.
OP, check the manufacturing thread if you want details. I posted about it in a thread over there, earlier.
This method also practically eliminated any pinholes in ground pours and rough traces. Provided you use a proper etchant. That acid peroxide stuff is very fast and convenient, but the etch is very inaccurate. It gets under and lifts resist. And if you ever try sharpie, you can't get that to work well in acid peroxide.
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I did few small double sided boards with 0.5mm TSSOP ICs back in the day when I was trying to see just how good I could get the process. I even developed a way to make decent vias, drill a hole just large enough to fit a thin solid copper wire, flush cut on both sides as close to the board as I could get it and then crimp it with a small C-clamp. That would mushroom out the nub of wire on both sides of the board resulting in a permanent connection then normally I'd add a touch of solder just for good measure.
These days I tend to only etch my own boards when I want a simple one-off for something without waiting, I don't bother to show off anymore. I still use quite a bit of copper clad but these days it's usually for dead bug/Manhattan or whatever construction. It took a long time for me to get past the ugly nature but it has grown on me and the RF performance is very impressive. Circuits I had difficulty with before, things like radio transmitters or high frequency switching regulators, mosfet bridges and SMPS stuff works with ease. It's still ugly, but dang it works well.
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It's not about showing off. 8-10 mil traces are the perfect size for a 0.5mm pitch IC. Fattening traces and then routing those cows means more work, even when it's not about space/size.
8/8 works every bit as well as 20/x, if you follow my process. There's no reason for me to fatten traces other than for current handling. It doesn't improve my yield. Yield is already effectively 100%. I use 8 mil traces because that is easier and less work to layout. And I use 8 mil traces by default for most of my professionally manufactured PCBs. (My main manufacturer charges more for under 7 mils, FWIW; I've never actually tried 7 with toner transfer, but 6 mils is a no-go due to failure in the print, with my printer).
I promise you I know something very useful about toner transfer that most people don't seem to have learned, otherwise they would also do it.
*This becomes more and more important, when you do larger double-sided boards. When part of the process can fail towards the end, you will waste a whole lot of time, a lot more often than you anticipate. It's like a complex part that requires multiple steps in the machining, and there's a tricky one at the end. You will mess some of those up, and it will be not much fun trying and failing, sometimes repeatedly, repeating boring rote things just to get back to that stressful moment of truth, once again.
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Permanent marker works as well, probably not as good as laser printed heat transfer, but it is a cheaper option
Yup...did that when I was a kid (just a couple of years ago...lol)
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I second the toner transfer method.
I use ferric chloride.
Played around with vinegar and hydrogen peroxide, but feric chloride is faster and gives better results.
I only do single sided, and I dont do them often.
It is kinda fun.
My comment to the "dont" crowd: cool it. Let the guy have some fun in his garage.
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IMHO, its just great to be able to go from a design on your screen to a PCB in a short period of time.
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It's not about showing off. 8-10 mil traces are the perfect size for a 0.5mm pitch IC. Fattening traces and then routing those cows means more work, even when it's not about space/size.
8/8 works every bit as well as 20/x, if you follow my process. There's no reason for me to fatten traces other than for current handling. It doesn't improve my yield. Yield is already effectively 100%.( I use 8 mil traces because that is easier and less work to layout. And I use 8 mil traces by default for most of my professionally manufactured PCBs. (My main manufacturer charges more for under 7 mils, FWIW; I've never actually tried 7 with toner transfer, but 6 mils is a no-go due to failure in the print, with my printer).
I promise you I know something very useful about toner transfer that most people don't seem to have learned, otherwise they would also do it.
*This becomes more and more important, when you do larger double-sided boards. When part of the process can fail towards the end, you will waste a whole lot of time, a lot more often than you anticipate. It's like a complex part that requires multiple steps in the machining, and there's a tricky one at the end. You will not mess some of those up, and it will be not much fun trying and failing, sometimes repeatedly, repeating boring rote things just to get back to that stressful moment of truth, once again.
10 mil traces are easy enough, but I found I had to be really careful to get the pads right for the 0.5mm pitch ICs. It's possible that it was mostly a limitation of the printer I had at the time but I found the pads would end up a bit wider than I intended once it was transferred to the board. Now if I need to do an IC with such fine pitch I send out for boards. SOIC is no problem at all though, I can etch those myself easily.
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...I found the pads would end up a bit wider than I intended once it was transferred to the board.
This sounds like the toner-squishing that I was describing in the other thread, in manufacturing section. The transferred art gets enlarged or smeared in a non-controllable/uniform way. This results in a loss of fidelity when you exceed the melting point of the toner. This is why you always aimed for just the right temperature/heat when you did a transfer. Or maybe you didn't, and you just smeared the board and took it at that.
Pre-etching the board removes this adverse consequence. (There is another, which is fuzzy traces; too hot with many papers, and the board turns into a chia pet; the right paper solves this problem). When you pre-etch the board, you need to melt the toner a little more to adhere even just as well as with a freshly cleaned copper board. So the minimum entry fee is a little higher than a clean board. But there is no distortion of the image; there's no upper limit to the temperature or pressure you can use during the transfer. You just have to get it hot enough. The board is the next point of failure, and that's way, way up there, in temperature. And when you completely liquify the toner, it sucks into the surface of the board, completely. It resists the acid, better, without fuzzy edges or pin holes.
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I order from PCBWay for few years but when I made my own pcbs, I didn’t have much success with toner transfer method. The best method for me was using an old Epson inkjet printer, curb side pick really, and inkjet transparent film. I printed both sides, top side mirrored, aligned and taped them, put the photo sensitive board in between them and taped the film to the board. Then I exposed the board with a simple fluorescent light for about 10 min each side, a simple spiral bulb would do it, and developed with 10% NAOH, it is sold as developer in electronic stores. I etched with ferric chloride that I used for many years before disposing off property at a haz mat disposal centre.
The results were always perfect. Cold printing didn’t create any distortion, details were amazing, perfect alignment between top and bottom, perfect fine traces once I perfected the exposure time and distance.
What I hated was that the printer head got clogged and had to be unclogged before every use, up to a point where it couldn’t be unclogged anymore.
I still have the films that I created many years ago, it literally looks like a film and the ink becomes like a gel that comes in contact with the board and doesn’t allow the light to leak underneath. I even made boards with vias under the TQFP.
Edit: Some pictures attached.
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I order from PCBWay for few years but when I made my own pcbs, I didn’t have much success with toner transfer method. The best method for me was using an old Epson inkjet printer, curb side pick really, and inkjet transparent film. I printed both sides, top side mirrored, aligned and taped them, put the photo sensitive board in between them and taped the film to the board. Then I exposed the board with a simple fluorescent light for about 10 min each side, a simple spiral bulb would do it, and developed with 10% NAOH, it is sold as developer in electronic stores. I etched with ferric chloride that I used for many years before disposing off property at a haz mat disposal centre.
The results were always perfect. Cold printing didn’t create any distortion, details were amazing, perfect alignment between top and bottom, perfect fine traces once I perfected the exposure time and distance.
What I hated was that the printer head got clogged and had to be unclogged before every use, up to a point where it couldn’t be unclogged anymore.
I still have the films that I created many years ago, it literally looks like a film and the ink becomes like a gel that comes in contact with the board and doesn’t allow the light to leak underneath. I even made boards with vias under the TQFP.
Edit: Some pictures attached.
+1 for this method, which I have also used successfully. The "secret sauce" is the gel coated transparency sheets that absorbs dye based ink. It doesn't work well with pigment type ink, but is extremely good with dye type ink. With a high resolution inkjet printer, the output is near perfect. However; it is significantly more work than toner transfer (more steps... the copper has to be coated/laminated with photo resist, exposed, and developed) so depending on the precision you actually need, it may make sense to be able to do both methods.
Note that HP printers have the print heads integrated in the ink cartridge, so when you change the cartridge, you get a new print head as well. Over the years, I have learned to love this principle compared to printers that have "permanent" print heads (Epson). There always comes a point where a print head doesn't respond to cleaning any longer, and has to be changed... this is just so much easier when you have the "disposable" print heads, in that you just stop refilling the problem cartridge and use a fresh one instead.
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I order from PCBWay for few years but when I made my own pcbs, I didn’t have much success with toner transfer method. The best method for me was using an old Epson inkjet printer, curb side pick really, and inkjet transparent film. I printed both sides, top side mirrored, aligned and taped them, put the photo sensitive board in between them and taped the film to the board. Then I exposed the board with a simple fluorescent light for about 10 min each side, a simple spiral bulb would do it, and developed with 10% NAOH, it is sold as developer in electronic stores. I etched with ferric chloride that I used for many years before disposing off property at a haz mat disposal centre.
The results were always perfect. Cold printing didn’t create any distortion, details were amazing, perfect alignment between top and bottom, perfect fine traces once I perfected the exposure time and distance.
What I hated was that the printer head got clogged and had to be unclogged before every use, up to a point where it couldn’t be unclogged anymore.
I still have the films that I created many years ago, it literally looks like a film and the ink becomes like a gel that comes in contact with the board and doesn’t allow the light to leak underneath. I even made boards with vias under the TQFP.
Edit: Some pictures attached.
+1 for this method, which I have also used successfully. The "secret sauce" is the gel coated transparency sheets that absorbs dye based ink. It doesn't work well with pigment type ink, but is extremely good with dye type ink. With a high resolution inkjet printer, the output is near perfect. However; it is significantly more work than toner transfer (more steps... the copper has to be coated/laminated with photo resist, exposed, and developed) so depending on the precision you actually need, it may make sense to be able to do both methods.
Note that HP printers have the print heads integrated in the ink cartridge, so when you change the cartridge, you get a new print head as well. Over the years, I have learned to love this principle compared to printers that have "permanent" print heads (Epson). There always comes a point where a print head doesn't respond to cleaning any longer, and has to be changed... this is just so much easier when you have the "disposable" print heads, in that you just stop refilling the problem cartridge and use a fresh one instead.
Miti, youre right, it does look extremely sharp. Better than what Ive been able to get with toner transfer.
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With a high resolution inkjet printer, the output is near perfect. However; it is significantly more work than toner transfer (more steps... the copper has to be coated/laminated with photo resist, exposed, and developed) so depending on the precision you actually need, it may make sense to be able to do both methods.
Yes, it takes more work but:
1. The nearly 100% success rate once you master the light, exposure time, transparents type, distance, etc. makes up for the toner transfer mishaps.
2. I used to buy pre-sensitized boards, I don't laminate.
3. If you do two layers, being transparent, you can align the two films perfectly, you can't do that easily with toner transfer.
4. It's cold printing so there's no distortion. I tried printing on laser transparents, using laser printer, and the misalignment between top and bottom, once the film cooled, was significant. I'm sure that paper suffers some distortion as well.
5. You can reuse them over and over again and the result should be always the same, if you follow the recipe.
Note that HP printers have the print heads integrated in the ink cartridge, so when you change the cartridge, you get a new print head as well. Over the years, I have learned to love this principle compared to printers that have "permanent" print heads (Epson). There always comes a point where a print head doesn't respond to cleaning any longer, and has to be changed... this is just so much easier when you have the "disposable" print heads, in that you just stop refilling the problem cartridge and use a fresh one instead.
I did not have the same success with HP and Canon. Apparently the ink droplets from the Epson head are smaller and better controlled than the HP. Again, this was years ago and I didn't have access to the best printers probably, but this was my experience at the time. Also, I remember that Epson print options gave me better control than HP.
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1. The nearly 100% success rate once you master the light, exposure time, transparents type, distance, etc. makes up for the toner transfer mishaps.
You can master toner transfer to 100% success rate, too. Sounds like a lot fewer things to master, even. What kind of resolution do you get with UV at 100% success rate, out of curiosity? Sure, PCB fabs get down to 3 or 4 mils. I have heard of people getting down to 6, maybe, using UV. And this took some special attention, doubling of transparencies to make up for defects in the print. I assume the PCB fabs have some equipment to make that easier, and probably have to use ammonium based etchant to get that resolution.
3. If you do two layers, being transparent, you can align the two films perfectly, you can't do that easily with toner transfer.
I can see that being easier. You tape the two together and then slide the pcb between, right? Even so, that is not going to be perfect. It will take a little bit of judgment, the thicker the board gets.
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You can master toner transfer to 100% success rate, too.
No doubt about that with one layer but I have some doubts with two layers. I couldn't.
Sounds like a lot fewer things to master, even.
I'm not sure about this one.
What kind of resolution do you get with UV at 100% success rate, out of curiosity? Sure, PCB fabs get down to 3 or 4 mils. I have heard of people getting down to 6, maybe, using UV. And this took some special attention, doubling of transparencies to make up for defects in the print. I assume the PCB fabs have some equipment to make that easier, and probably have to use ammonium based etchant to get that resolution.
See that 18F4550 in the attached picture? The vertical part of letter F is about 5 mil, the horizontal is less. I was looking for my test board that I made to test the limits of this method but I couldn't find it, my best (thinnest) reliable trace was 5 mil, if I remember correctly. However, I avoided traces thinner than 10 mil.
I did not use UV, I used fluorescent but you may be referring to the UV content of the fluorescent.
I can see that being easier. You tape the two together and then slide the pcb between, right? Even so, that is not going to be perfect. It will take a little bit of judgment, the thicker the board gets.
Depends on your definition of perfect. As long as all the pads align "almost perfect" it's good enough to me. The drilling is way more imperfect than the rest of the process. How do you even align the two sides with toner transfer method?
Look, I'm not advertising this method, I'm just describing my experience.
I'm happy I don't have to do it anymore...
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Why you make your boards at 10 if 5 worked? Was 5 more effort or some chance of failure in resist or etch? (I assume the manufacturers charge more for sub 7 or so mil traces for actual reasons.)
The way I line up a double sided board is by drilling two holes in the papers. Transfer one side and drill the pcb through the 2 holes in that paper. Then put the second side on and line up the holes. Stick that side. Then remove both papers and etch. I don't know what kind of accuracy you need, but this isn't hard or iffy to complete. It is just time-consuming. You save a lot of time elsewhere, though.
If this is a DIY board, only, I might enlarge my vias. But if it might go into production, I will just work with 15 mil vias, 8/8 default traces. The drill holes might break the annular ring on one side, but I will get everything working just fine. So I actually make DIY boards almost exactly the same as production boards, no problems (although I may increase the clearance around pads, due to lack of a soldermask layer; and I can't put vias under SMD IC's). Using 8/8 traces is not "showing off." It's the size that is easiest to route for me, and also once you find the smallest size of traces that does not cause additional issues, you are making your board MORE reliable by reducing the area of the board. The larger your boards, all else equal, the more chance of a failure. With the right process (I assure it is easy), 8/8 is just as reliable as 20 mil traces. So this allows more complex and/or larger boards without adding more work, prep, scrubbing, or chance of a failure due to lack of attention over that larger area.
You can have issues with many toner transfer papers due to distortion. There's no one forcing you to use these inferior papers, though. Magazine paper was the worst, I tried. Enough distortion to cause problems on larger boards. But there are other reasons I would not use magazine paper, anyway.
In short: 90% of people who use UV, it's because they learned toner transfer from internet hacks, and they (quite reasonably) gave up before sorting through the different options, from "make a crappy PCB for free with shit that is in your house right now" to actual pro-level toner transfer. For most people, toner transfer is the better way to go so long as you don't try to cheap out. UV might be cheaper to get into, initially, esp if you don't have a suitable laser printer. But toner transfer is easier and faster in the long run, and in that long run, both methods are dirt cheap. The labor is what matters.
If you are the kind of guy that will spend $100 dollars on various mystical photo papers trying to find a lifetime supply of pcb paper for cheap, well then you can waste years learning subpar toner transfer, trying to convince yourself your latest underground bargain score paper, learned from some dude on the internet, will eventually work perfectly with enough practice. I'm guilty. I got through it, though. I also come to believe that most of us don't know what "perfectly" means when we say it. When we sometimes get something that looks very much like pictures what other people get (from 5 feet away), we assume we "got it." Making a PCB is about reproducing fine details reliably. You have to pay attention to details and consistency to know if your way is "the best."
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You can master toner transfer to 100% success rate, too.
No doubt about that with one layer but I have some doubts with two layers. I couldn't.
I found that putting the toner transfer paper on a light table, I could "see enough" to get good alignment. Then I staple or tape the papers together, just like the transparencies.
But I have never been able to get as fine detail with toner transfer as with the inkjet method (and yes, I have seen distortion due to the heat involved in laser printing).
For many projects, though, you don't need max precision and the ease of use of toner transfer makes it a winner.
I'm also leaning towards just getting the boards made nowadays, in all honesty. At the low prices you can get them made for, there is no way it is economical to DIY. So then there is just the "fast turnaround" aspect, and the "fun hobby" aspect left - which are still good enough reasons to have a go!
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deleted for being irrelevant to the thread.