Want to start making my own circuit board where to start

[tautech]

I have never had issues with toner not sticking to the laminate except when I have rushed the job through the laminator and the board remained too cold for the toner to fuse properly.

2 passes through the laminator fixes a poor toner bond. 

[Zero999]

I've used both toner transfer and the photo process and although I may prefer the latter, I wouldn't tell a beginner to not bother with toner transfer or say that the photographic method is the only way to make PCBs.

Why does it have to turn into a flame war about which process is better? This is getting pathetic!

[KL27x]

I wouldn't want to change anyone's mind, for gosh sake. if you like UV, then do it. If you are trying to do toner transfer, at least do it right. I'm the laziness dude I know. If I could do toner transfer without doing a pre-etch, I would. I have tried every shortcut I can. The pre-etch is worth the time, period.

If you could never get toner transfer to work consistently, I know you didn't experiment with pre-etch. You thought you knew better. You rationalized it such that it doesn't matter. So you wouldn't have to do it. Because shiny boards are so much prettier. (And the guy telling you to do the pre-etch is a dick and you want him to be wrong.) But my laminator been doing these gross-looking boards for 8 years and it is not any issue on the roller.

If you find UV is easier faster and more consistent, it is because you failed at toner transfer. You listened to the advice of hacks. You used a clothes iron and crappy free paper because someone else said it worked for them. You skipped step which someone said is not important. You achieved mediocre results once or twice, and then you moved on to UV. You should not give advice to noobs telling them to skip vital steps.

[Buriedcode]

Whilst it seems everythign has been covered, I'll just add my advice to the OP.

Unless you have LOTS of one-off, single sided, simple boards to be made, dont' bother.   Places like PCBway, will do 10 medium sized boards (10x10cm?) for $5-10.  You have to pay about $30 for DHL shipping, plus they will charge you another fee I suspect (at least they did in the UK) for import tax but.... that's delivered in 4 days..  However, you get 10 very nice boards, and if you're clever each one can have multiple designs on it.

I did the toner transfer method for about a decade for hobby stuff (where I only needed one PCB, only a few vias, and needed ti the same day).  You can get really quite impressive results, but it is tedious, somewhat messy, and takes time, even practice.  Frankly, after the first few batches I got very sick of it, the worst being the drilling - broken bits from a shoddy drill press, skewed holes, general unpleasantness.  The *only* advantage I saw was that I could have an idea in the morning, and by late afternoon have a working, populated PCB doing its thing.  Total costs being <£5, but mostly time.  Thinking about it, I still hate it.

It requires quite a lot of 'stuff', not just equipment, but consumables, and the start up costs - if you dont' already own a printer, hobby drill and drill press - can be quite high.  There are many threads on this, and the web is full of advice about it. 

My $0.02 is.. use SMT where-ever possible. Use 1206 or 0805 0-ohm resistors as jumpers, components on the backside, and connectors on the top.  ALL to avoid drilling holes for components/jumpers/vias.

[KL27x]

Thats a good point. On avoiding vias.

I got pretty good at making air wire pads instead of stopping to add resistors to the schematic. Just route an extra length of wire in Eagle,  escape, and do the same on the other side of the obstruction. Then increase the width of the last segment on either side to make pads. The schematic doesnt need to be changed.

But dont buy all SS board. Other side can be used as a powerplane. And if only 1 or 2 traces are needex, u can cut sometimes cut them physically,  instead of lining up the two sides for transfer.

[janoc]

scrubbing the board clean with a scouring pad and then properly degreasing it will do the same job,

No, it doesn't. The scouring/sanding degreases the board. It might add some very little bit of surface texture. I clean/degrease the board, too. This is an unrelated step. (I have used scotchbrite in the past, but steel wool and dish soap is the fastest and easiest to me.)

Scouring does not degrease the board! What it does is that it removes the top oxidized layer and roughens the surface up, so that the toner sticks better. Degreasing is a separate step, I usually swab the board with alcohol, some people use acetone for that.

I'm not talking about the toner just falling off. It will also FATTEN the traces making them 2 or even 3x thicker than the original print. This will cause bridges.

That I have never seen and I have made boards with 0.5mm pin pitch TQFPs like this, which is about the finest that toner transfer is reasonable usable for. That "fattening" sounds more like the toner smearing - either because of too high temperature or some shearing force (e.g. my laminator "pulls" more strongly at the ends of the roller than in the middle due to uneven pressure, so the board could twist if I am not careful).

When I pre etch in my cupric, this does not just put little micro pits/texture on the surface of the board. It leaves a fine, porous, fragile surface. It binds the toner and prevents it from squishing out laterally. It sucks up liquid toner. This fattening/smearing issue is why this guy has spent so much time to fine tune the exact temp in his process. He is striving to get the toner just hot enough to transfer without liquefying. This is a fools errand because gauging the temp is difficult. The exact settings and time will depend on the size and thickness of the board. 

That I agree with - if the toner is liquefying, the temperature is waay too hot. The question is whether to rely on the pre-etching to keep this in check or simply turn the heat down instead. You don't need to be exact to a degree celsius here.

I am using a cheap office laminator (unmodified) for this and never had this issue with Samsung toner (maybe other formulations melt at lower temps). I have to usually pass the board through 10-15 times before it is hot sufficiently that the toner actually sticks to it (it is visible on the paper, I don't have any exact method for this).

I guess this is normal because the cheap laminators are usually running up to 140-150C max, the fusers in printers go up to 200 C. On the other hand, clothes iron turned up to max reaches 240C no problem, so molten toner is a real possibility.

In my process, there is no upper limit. There is no calibration. The sky is the limit. And I can get down to 6/6 when needed. For 8/8 and higher, there is no careful temp or pressure regulation. There are no inspections and redo's. It works. Across the entire board. Every time. And it doesn't work like this without the pre-etch.

Yes, if you are doing 6/6 boards, ok, I will give you that. I haven't tried to go that low, my crappy 600dpi laser is marginal for 8/8 boards already.

For so fine pitch boards I prefer to order them - as you said, your time is more worth it to you than the materials. In  my case the aggravation of having to deal with a 6/6 board without solder mask and made using a marginal process is not worth it to me, especially as the small boards cost like $3-5 from OSHPark for 3 copies, delivered. Just have to wait two weeks for them.

[KL27x]

If you don't use enough heat, the toner falls off. If you use too much heat, the toner will fatten/smear. This means there's a window for success.

If your setup does not allow you to get TOO hot (standard laminator won't even get that hot), then your struggle is in getting the toner to stick. Particularly on large boards. You might be running the board through 5 or 6 times to get it to (hopefully) stick.

I pre-etch. I blast the board with a heat gun while it goes through a laminator. I get the board HOT. I get great transfer accuracy, every time. I'm not shooting for a tight window. I'm just clearing the lower bar by a mile and a half, plus or minus a mile. I don't make a silent prayer and squint my eyes at the moment when the paper comes off. When you are doing the second side, there's too much potential wasted time to bother with maybes.

If you don't have any problem with toner falling off or fattening/bridging, you can do 1000 boards in a row and have zero issues, and you can do 8/8 reliably, then you are set. I wouldn't be close without a pre-etch. But with pre-etch, I can do THAT. Yes.

Scouring does not degrease the board!

Sorry, yeah. I scour with wet stainless steel wool and dishsoap. Then rinse. Board is degreased. And wet. So dunking it in the etch tank and the swishing it in a bucket of water only adds another half a minute. I don't think alcohol will successfully degrease the board unless it is scoured before/during, so I think of it as the same step. Else I'm not even going to scour my boards; just quick and easy wipe with alcohol. I'm pretty sure that doesn't work. There's always little pits and such where a tiny bit of grease will hide. Scouring razes the earth and removes all the hiding places. Nowhere for grease (or toner) to hide. I scour to get the board clean. I pre-etch to add the texture. Oxidization? Who cares? Plastic toner doesn't bond chemically with clean unoxidized copper any better than oxidized copper or copper compounds left by pre-etch. Remove grease, add texture. We agree there. Scouring/sanding the board doesn't hold a candle to the porous surface left by pre-etch. Show me the machining marks in paper which allows the toner to bond to it. There are none. The paper is porous on a very fine level.

the toner smearing - either because of too high temperature

What I'm telling you is you can remove this from your toner-transfer vocabulary. Anyone who sometimes gets fattened traces, just try it. I've already tried everything out there.

[M4trix]

scrubbing the board clean with a scouring pad and then properly degreasing it will do the same job,

No, it doesn't. The scouring/sanding degreases the board. It might add some very little bit of surface texture. I clean/degrease the board, too. This is an unrelated step. (I have used scotchbrite in the past, but steel wool and dish soap is the fastest and easiest to me.)

Scouring does not degrease the board! What it does is that it removes the top oxidized layer and roughens the surface up, so that the toner sticks better. Degreasing is a separate step, I usually swab the board with alcohol, some people use acetone for that.

Well, I'm not sure what kind of greasy and dirty boards you people are using but here I only use something similar to Scotch brite ( not a kitchen sponge ) and a lot of tap water and of course, rubber gloves. I just scrub it thoroughly and do a test with water. If the water film on the PCB surface is unbroken for at least 20-30 seconds then it's good to go. I use dry film photoresist and you guys know how this stuff is notorious when it comes to uncleaned boards. Never had problems.     

[KL27x]

I agree, scouring > alcohol. I don't use alcohol. Scouring is the most important part of removing the grease. You're removing entire surface, all little pits/cracks which have sucked in grease. But why not add a drop of soap, while you're at it? It will prevent any bit of grease from readhering to the fresh surface you are making. Grease from your own fingers, even. (I dont wear gloves at any point, personally. I d9nt need to)

@janoc, I agree. There could be lots of things "wrong" with the way I do toner transfer. From my laminator, my temps, and whatever else. But the fact that the pre-etch allows me to ignore these "mistakes" is pretty strong evidence that IT IS DOING SOMETHING. Something potentially very useful to everyone doing toner transfer. You may have just the right setup to work for you consistently. At least with one size of board. Other people, including the guy who wrote the article for Hackaday, find that they need to calibrate the temp very carefully to get consistent results, because of fattening of the toner traces/pads. They may like to learn what the pre-etch does. Scouring and degreasing the board does not do the same thing. Because you don't run into an issue doesn't mean it doesn't exist. It doesn't mean your method is wrong. It doesn't mean my method is wrong. But you're wrong if you think they do the same thing. The pre-etch GREATLY increases margin for error. If you use regular laminator without additional heat, you barely have enough to make the process work, at all. I wonder if you ever try to make a larger board or with thicker pour if you will have problems.

I haven't tried the Pulsar paper, 12-15 euro before tax for 10 sheets (Farnell or Mouser) is heck expensive for what it is! I am normally using regular paper for non critical things and for very fine stuff I am using self-adhesive vinyl. Stick a piece on a regular paper as a carrier, print on the vinyl and then laminate it on the board. The vinyl will cleanly release the toner once hot and soft. That way you won't get any paper "hairs" and much less pitting and hairline breaks in the traces so common with paper. On the other hand, the vinyl is much more prone to smearing.

@Janoc, BTW, this is so weird to me you use vinyl method for higher accuracy. Is self-sticking vinyl that cheap? Or do you reuse it, over and over? Pulsar doesn't have any of the problems you described. As for smearing with the vinyl, maybe you can increase your accuracy with pre-etching. This also holds the toner better if you are the penny pincher using magazine/photo paper. It will be much harder to accidentally rub the toner away when you're removing the paper fibers from your board with the toothbrush. If vinyl might smear, but it leaves no fibers and releases like magic (or like pulsar?), seems like I would be using IT for the simple, large pitch stuff. Going back to my earlier years, I used to just do 4 of every board to make up for errors. Nowadays, one will do fine.

[M4trix]

I agree, scouring > alcohol. I don't use alcohol. Scouring is the most important part of removing the grease. You're removing entire surface, all little pits/cracks which have sucked in grease. But why not add a drop of soap, while you're at it? It will prevent any bit of grease from readhering to the fresh surface you are making. Grease from your own fingers, even. (I dont wear gloves at any point, personally. I d9nt need to)

I once tried with this Arf scouring cream and it was awful. Instead of washing it leaves a strange greasy film !    So, after some trials and errors, I found that just plain tap water and this 'scotch brite' ( it's more abrasive than scotch brite ) is the best solution. Regarding gloves...if I don't wear them, then my OCD kicks in.   

   

[tggzzz]

When you are doing the second side, there's too much potential wasted time to bother with maybes.

Do both sides simultaneously.

Put a some fiducial 1mm holes on the board near opposite corners. Drill them. Put paper on both sides of the board, lining the fiducial holes up with the pre-drilled holes. Then use whatever technique you prefer to transfer the toner.

[janoc]

Well, I'm not sure what kind of greasy and dirty boards you people are using but here I only use something similar to Scotch brite ( not a kitchen sponge ) and a lot of tap water and of course, rubber gloves. I just scrub it thoroughly and do a test with water. If the water film on the PCB surface is unbroken for at least 20-30 seconds then it's good to go. I use dry film photoresist and you guys know how this stuff is notorious when it comes to uncleaned boards. Never had problems.     

I am only wiping it with alcohol after scouring to remove any accidental fingerprints from my clumsy fingers just before transfering the toner. If you are using gloves/are less clumsy than me, then this may not be really necessary.

[janoc]

I agree, scouring > alcohol. I don't use alcohol. Scouring is the most important part of removing the grease. You're removing entire surface, all little pits/cracks which have sucked in grease. But why not add a drop of soap, while you're at it? It will prevent any bit of grease from readhering to the fresh surface you are making. Grease from your own fingers, even. (I dont wear gloves at any point, personally. I d9nt need to)

As I wrote to someone else already, the alcohol/acetone isn't really absolutely necessary - I am using it only just before transferring the toner to get rid of any potential fingerprints that could have gotten on the surface after the scouring/washing. If you are using gloves or are just careful, there is no need for it. I prefer to do it to be sure, it takes 10 seconds and I am sure the board is good to go.

But you're wrong if you think they do the same thing. The pre-etch GREATLY increases margin for error. If you use regular laminator without additional heat, you barely have enough to make the process work, at all. I wonder if you ever try to make a larger board or with thicker pour if you will have problems.

Well, it does work for a lot of people without pre-etching. All I am saying is that it might not be necessary to do it (saves a messy etching step). If it works for you and improves your yield, more power to you. The pre-etched surface is certainly more "porous" than just scoured one.

Re laminator - I think you are right on that one. I didn't modify mine yet, mostly because of laziness. After a while it gets hot enough to allow the transfer, using normal 1.6mm FR4 (thicker likely won't fit between the rollers anyway), so I didn't bother with hacking it. The multiple passes are mostly required to get the board up to temperature, because only a little heat gets on the board during the 10 seconds or so that it takes for it move through the rollers.

I made boards of up to 100x80mm with it, with fairly large pours and it worked - the largest problem was the pitting and banding in the pour areas from the poor coverage of my laser, not really the laminator once it got hot enough. Where my laminator tends to suck are the edges and corners of the board because it doesn't heat/press uniformly over the entire board. So I either have rotate the board between passes (risking smearing) or design around it, keeping important stuff away from the edges/corners.

I may still try to open it and tweak the thermostat inside, it is the basic bimetal type, so it shouldn't be too hard to get it to a bit higher temperature.

@Janoc, BTW, this is so weird to me you use vinyl method for higher accuracy. Is self-sticking vinyl that cheap? Or do you reuse it, over and over?

The roll of vinyl I am using costs about 15 EUR or so, definitely less that 20 EUR (don't recall exactly, it has been a long time since I have bought it). It is the kind used for decorating, kinda like self-adhesive wallpaper. I am calling it vinyl but maybe it is something else (perhaps some form of PVC?) - it is a smooth, shiny plastic on a paper carrier that you peel off when you want to stick it on something. Mine has a German vendor logo on the back, I think it is from d-c-fix (https://www.d-c-fix.com/). I am using a plain white one for the PCB work, but you could likely use any color/pattern.

I am not reusing it - maybe one could do that, but it is rarely worth the trouble, with it being wet, potentially stretched from the water and lamination, etc. I just cut a piece of it slightly larger than my board, stick it on a regular paper as a carrier (that's where the self-adhesive part comes handy) and print on it.  Then I cut it out and do the transfer. And then I toss it.

The difference vs Pulsar is that I can get this from a self-improvement store around the corner whenever I need it. The Pulsar/toner transfer paper I would have to order by mail, which adds another 10 bucks minimum for shipping - and I get 10 A4 sheets in one pack. The vinyl roll is 5 meters x 50cm or so, for the same price.

Pulsar doesn't have any of the problems you described. As for smearing with the vinyl, maybe you can increase your accuracy with pre-etching. This also holds the toner better if you are the penny pincher using magazine/photo paper. It will be much harder to accidentally rub the toner away when you're removing the paper fibers from your board with the toothbrush. If vinyl might smear, but it leaves no fibers and releases like magic (or like pulsar?), seems like I would be using IT for the simple, large pitch stuff. Going back to my earlier years, I used to just do 4 of every board to make up for errors. Nowadays, one will do fine.

Vinyl is definitely easier to smear because the toner doesn't stick to it so well. It also doesn't like high temperatures - if it gets too soft too fast (before the toner fuses to the board) or, worse, starts melting, you are screwed. It needs to be just soft enough to release the toner.

However, it certainly leaves no fibers (which has been my major peeve with paper - who doesn't love hairline shorts caused by these!). And when it transfers, it transfers super cleanly - there is rarely even a trace of toner left on it, everything is on the board. That may not be as important if you have a good coverage from your laser and higher resolution, but with my crappy 600dpi Samsung I need every grain of toner I can get. Furthermore, you don't need to rub it to dissolve it like the paper - I just get water between the board and the vinyl and carefully peel it off. Much faster and cleaner.

I may try the pre-etching with it next time, though - if it reduces the smearing chances, great.


BTW, there is also this cold transfer method for toner transfer:


I haven't tried this myself, though.

[Beamin]

So this is what I have on hand:
Ink jet printers
Blacklight
decent Laminator machine.(does it het hot enough without modification?)
3% H2O2
33% Conc. HCl (I have a few gallons)

I would need to buy regardless of method:
1oz coper board
Etchant (or could I just use the HCl/H2O2 with any method?)

So if I go UV I can use the black light and tracing paper to print on from the ink jet? The most expensive part seems to invest in a laser printer and I don't have a lot of space. So I would need to buy some type of photo resist? Wouldn't that wet and cause problems with the paper?

If I go tonner transfer I would need magazine or Pulsar paper (I'm guessing you can get that in the US). Then laminate on. Put on HCl, drill and be good to go? That seems really easy. I don't have to do anything super fine and like to work with through hole parts.

As far as software goes are their free programs? I could use MS paint maybe, but I could see how that would become difficult.


The reason why I want to do it at home is because I want to make simple RF circuits that don't work on a bread board and there is ALOT of trial and error and I don't want to wait around for things to come in the mail especially when I might just need to add part or do reorientation. Also I can't see making more then one board since I'm not selling or producing anything. 

[janoc]

Etchant (or could I just use the HCl/H2O2 with any method?)

Forget about that acid/peroxide combo, it is cheap, but the results are fairly terrible and the acid fumes will corrode everything in range. Also you will need a ton of that peroxide - 3% is very weak, that's essentially just water that is diluting the acid. Order some ferric chloride instead.

So if I go UV I can use the black light and tracing paper to print on from the ink jet? The most expensive part seems to invest in a laser printer and I don't have a lot of space. So I would need to buy some type of photo resist? Wouldn't that wet and cause problems with the paper?

You can buy an used office laser printer for less $100, no problem. Most are built like tanks and will last you a long time. If you want to do UV instead, you can use inkjet and either use presensitized boards ($$$) or buy the dry film resist that you laminate on regular copperclad. Don't bother with the resist sprays, those are pretty much useless because unless you have a lot of practice and a dust-free room to spray it and then dry it you won't be able to obtain good results.

The resist doesn't "wet", not sure what do  you mean by that. 

Also don't forget to buy a developer for the UV resist - the type depends on what resist you are using, the presensitized boards typically use a different developer than the dry film resist.

While at it, you may also want to get a drill stand for drilling the boards and some 0.8mm (or whatever is that in imperial sizes) drills - don't cheap out on that, if you try to drill the boards with a Dremel (or the wobbly piece of plastic crap they sell as a drill stand for it), you will quickly hate the job. I have one of the Proxxon Micromot tools and stands, works great.

If I go tonner transfer I would need magazine or Pulsar paper (I'm guessing you can get that in the US). Then laminate on. Put on HCl, drill and be good to go? That seems really easy. I don't have to do anything super fine and like to work with through hole parts.

Toner transfer process is well documented online, you can find a ton of videos showing how to do it.

Just don't use HCl + peroxide, for your own sake. It is a crappy etchant that will give you poor results because of undercutting. Also unless you have a bit of experience with chemistry and handling chemicals, you could seriously hurt yourself or at least make a nasty mess. For example, if you by mistake pour acid in the etching tray first and then add peroxide, you are asking for nasty splashes of concentrated acid in your face (you are wearing safety goggles, right?) due to the violently exothermic reaction the dilution of the acid produces.

Ferric chloride is outright tame compared to that, even though the etching could take you 30 minutes instead of 5 if you don't have a bubbling tank and/or some other more fancy gear.

As far as software goes are their free programs? I could use MS paint maybe, but I could see how that would become difficult.

There is plenty - Kicad is totally free (as in freedom and beer), Eagle has a free as in beer version, there is Diptrace, probably few others. Depends on what you want to do with it, each has its pros and cons. You certainly *could* use MS Paint, but that is some serious masochism.

If you only need a quick and dirty board for a few simple components, drawing the tracks by hand using a permanent market/sharpie works a treat too. Just make sure to use a fresh one, so that there is enough of the paint on the board to act as resist. Then etch/drill as normal.

[tautech]

Have a read of the OT discussion in this thread to see how others etch PCB's:
https://www.eevblog.com/forum/projects/pcb-milling-failure/msg1268256/#msg1268256

And following pages.

[sleemanj]

... snip ...

Tosh.

HCL+H2O2 works fine

It's not some massive dangerous thing, wear gloves and goggles and preferably work outdoors, as you should with Ferric Chloride too.

If you are generating copious fumes or having a reaction more than small bubbles forming at the surface of the copper being etched you are doing it wrong, acid should be dilute to below fuming, add peroxide a tiny amount at a time until the etching is working at a controlled rate

Keep it in a suitable capped bottle, in your garden shed/garage, not in your office

If you spill some, neutralise, dilute, and wipe up, you won't have to deal with ferric chloride stains on everything

A laser printer can be had for a few dollars used, if you spend a hundred dollars on a used laser you are doing it wrong

Dry film developer can be purchased at every supermarket on the planet (sodium carbonate, either straight, or as a constituent of various laundry powders)

[KL27x]

If I go tonner transfer I would need magazine or Pulsar paper (I'm guessing you can get that in the US). Then laminate on. Put on HCl, drill and be good to go? That seems really easy. I don't have to do anything super fine and like to work with through hole parts.

In the US, you can buy Pulsar through Digikey. You can find it just by putting "pulsar paper" in the product search bar.

As far as the laminator goes, possibly yes, possibly no. There's plenty info in the thread and you can believe what you like. You can start a flame war / popularity contest, but ultimately you have to decide for yourself what is good enough vs what could use some improvement.

Etchant has been covered, as well. Tons of people use HCl and peroxide. It is a convenient etchant, especially if you can buy 30% peroxide. Even with 3% peroxide it's easy to make but harder to reuse. Board manufacturers use all kind of etchants other than this, but you're not a board manufacturer.

If you live in Europe you might be able to buy pcb tack pins much cheaper. The ones I have are made by Arrow err, maybe it's Harwin Electrronics, rather. (I threw out the box and am going by memory; yikes!) And apparently they are imported from Europe. Cost me a shiny penny, but you get a lot of them. They look like this:
https://electronics.stackexchange.com/questions/192388/via-connection-pins
If you can handle the min size of via, these are faster to stick and break off than stringing wire through your pcb. You just have to get the drill size right, so they stick and stay in until you solder them. I want to say they need a 64 gauge hole. 

OP: When I started doing this, everything you just said about toner transfer was good enough, at a minimum, to work most of the time. I did large traces with large clearances and I learned to make 4 of any board to make up for defects. I started out with Paint, even. You may find this good enough, at your stage in the game, too. Over the years, you might learn how to do this much better and easier and how to save yourself a lot of time and trouble. Which you will have to do for yourself, since you can't believe what you read, and the internet is actively trying to make you dumber.

[oldway]

I never had success with toner transfer.

To go cheap for the production of UV's, I use a 400W Phillips tanning lamp purchased in a flea market for 5 euros.
Leave a distance of about 50cm between the lamp and the printed circuit board.
Exposure time 2 to 3 minutes.

I install the lamp lying on the floor between 2 chairs, I place a glass plate between the two chairs and the circuit board on the glass.

Put a book on the circuit board to apply pressure.

[Buriedcode]

I think this link should be in every DIY PCB thread:

http://www.electricstuff.co.uk/pcbs.html

Although its old, the information is still relevant for almost every aspect of DIY PCB's.  Not brown-nosing here but mike really knows his stuff, and gives practical advice.

I fell into the trap that so many do, and that's trying to perfect ones technique by buying more equipment, better drill bits, a laminator etc.. it becomes more expensive than getting them professionally made, and you still have restrictions on trace width, hole sizes, no solder mask (dont' bother with DIY solder mask, its a ball-ache).

[KL27x]

Do both sides simultaneously.

Put a some fiducial 1mm holes on the board near opposite corners. Drill them. Put paper on both sides of the board, lining the fiducial holes up with the pre-drilled holes. Then use whatever technique you prefer to transfer the toner.

I have tried it this way, and it didn't stick for me. I tend to drill 2 or 4 holes in the transfer papers to make pinholes, and then transfer 1 side. And then I center punch the board using the holes as the guide, and drill thru with tiny gauge drill bit. So my first side is technically more accurate/precise with no chance of shifting when stuffed thru the laminator and no need of tape. I'm only dealing with that with the other side. With UV it maybe doesn't matter, but another issue is using tape to fix transfer paper can make local areas of failed transfer next to the tape, so to ensure good transfer, you should remove the tape and run it again after it's been stuck.

I concede this is personal preference. But in either case it takes time to do the drilling and lining. And a failure of any kind in the transfer is wasting this time. With pre-etch and what would be considered excessive heat to the un-initiated, success is automatic. You can put more time and effort into lining up the board, because you know it will not be wasted. There's only one outcome.

I do some very thin boards, SS 0.007, which physically curl at a pretty tight radius. It may be of interest to others that if I do not pre-etch the board, "too much" heat is very noticeable. Aside from fattening the traces, the paper will physically separate from the board as it comes out the other side of the laminator, because the toner is liquid and it just "breaks" into two parts. One on the paper and one horrible smear on the pcb.* With the pre-etch, this will not occur even if I heat the board to the point where the FR4 starts to bubble**... i.e., using much more heat that it takes to terribly ruin a non-pre-etched board. The surface of the etched copper sucks up the liquid toner and the traces do not fatten and the paper clings to the curly board for dear life. The effect of pre-etch is night and day, and the resolution is not noticeably degraded even at insane temp. I know I use "too much heat." This is my process.

*I notice the paper side is still fine. It is not fattened or distorted. The unetched copper side is what turns to a mess. If you pre-etch the copper with ferric/cupric, neither side can smear or distort. I don't know what happens with other etchants.

**At this level of overcook, some fattening may be noticeable. But 10/10 all day. If doing 8/8, you will want to take a wee bit more care for accuracy sake (as well as physical damage to the board).

[Beamin]

I work with HCl and H2O all the time I aware of how it ruins all the metal in the room you are using it.

So right now I could etch a board two ways:

Masking tape a board cut out traces with a pin the HCl it.

Take a dark sharpie make traces and HCL it. Then use alcohol to et off the ink since HCL and H2O2 wont hurt it.

Correct?


Whats looking the best right now is buying the film you stick to the board. Putting a thin ink jet printed paper mask over it, Black light for a few minutes, HCl for a few minutes and clean! And I only have to buy one part: the film. Simple!!

[KL27x]

I've done Sharpie, and it barely works, at best. I have tried some highly regarded pens, including Lumicolor and even compared all the different colors. I've tried baking the ink after drawing. On clean and etched copper.

Even the best results I have gotten are not that great. For 1/2 oz board it works pretty well. But 1 oz, the ink can just barely hold on by the time the etch is nearing completion. I gave up even trying to do spot repairs on a bad transfer. Sometimes they work halfway, sometimes they don't do anything. I still have some boards done completely in Sharpie, and it can be made to work, but there's hardly any room for error. (More like you have to live with some error and hope it's good enough.) There are surely better pens out there, but Sharpie, Industrial Sharpie, and Lumicolor aren't that great to me, using ferric/cupric etchant. I'm not positive, but I feel like HCl and peroxide is probably even more challenging with these types of pen resists.

Re UV, don't forget you have to develop the resist after you expose it. This washes away the exposed (or unexposed, depending on type of resist) areas so that the HCl can etch it. Also you have to scrub the copper clad clean and put the film on (with a laminator?).

[Rerouter]

for sharpie, you need to let it dry very well before you try and etch with it, if there is any solvent left, it will float right off the board, and will leave you cursing.

Fine point felt tip pens i have found the best for this stuff, but you really will burn through a pen per board if your doing anything bigger than 5x5cm, as you need the coating to be quite thick.

[janoc]

for sharpie, you need to let it dry very well before you try and etch with it, if there is any solvent left, it will float right off the board, and will leave you cursing.

Fine point felt tip pens i have found the best for this stuff, but you really will burn through a pen per board if your doing anything bigger than 5x5cm, as you need the coating to be quite thick.

Well, as I have said, it is for quick and dirty stuff where accuracy and resolution are not a problem.

I used to make circuit boards using a drafting pen filled with alcohol-soluble paint as well. That works much better than a sharpie or a felt tip pen but it is a bit more messy because of the inevitable paint stains. However, that was last time some 20 years ago when cheap lasers were not available and most diy stuff was through-hole only.