PCBs take a fairly large initial investment of your time getting up to speed. Once that is done, getting 2 to 4 layer boards done can be done very quickly, affordabley and give a much more polished result.

Just how bad is it? A related question is, what's the "state-of-the-art" technique for prototyping, ie. NOT production, probably never more than 1 or PCBs of the same layout

 

I prefer PCBs - but they are not without their difficulties. One exists in either case - the ability to think in mirror images - so will not be mentioned further. I think the effort of tracing and re-tracing all connections is the same in either case, but PCBs tend to enforce more rigor up front. I like work up front and no headaches later.

I use a drawing program also, and try to get the drawing as perfect as possible before moving forward. I don't want to think (much) while I'm building. My drawing software (Freehand) allows me to use separate layers for the board, the components, the wires, the solder bridges and the labels. That way it's a trivial operation to show just the solder and board layers, and then invert it to show the backside. Tremendous time saver when you're actually hot.

Freehand is not dedicated to circuits however, and can't do auto-routing. That sounds interesting.

 

After that, I use my UV-light box to transfer the design to the PCB.

It sounds like there are a lot of different techniques to transfer the pattern, including directly printing on the board. I'm guessing there are different etching techniques as well.

Can you elaborate a bit on what procedure you use? Links to suppliers would be great.

 

Once a project becomes too much for breadboarding I almost always go straight to PCB. My method is to use layout software, touch it up to my liking in photoshop, and print durabrite pigment ink (epson) DIRECTLY to the pcb using a modified epson inkjet. Then bake the ink (more like thin paint) in a toaster oven. After that straight to etch and drill.

My Epson printer uses DuraBrite inks but I can't print on disks or PCBs. I'd look into another printer if this is the way to go. Where do you get your supplies? Or, is there a write-up somewhere of the process you follow?

Everyone: First, thanks for all the feedback. I think you can see I'm leaning towards learning a PCB method if it doesn't sound too bad compared to my current perfboarding. I understand the general concepts of the overall PCB process but I'm very curious about the tips and techniques that this community has uncovered to simplify things. I don't want to just walk into Radio Shack and ask them to set me up!

 

FYI, solid model of my current PCB attached below.

What software do you use for the model?

Designed with Eagle Pro Schematic/Layout, processed with a user program called Eagle3D to make a script that runs under a program called POV-Ray.

There are many models of components that come pre-made with Eagle3D, but I had to make custom models of many of the components on my board.

This is one of those areas where the "come up to speed" investment of time is substantial, but the results are also substantial.

PCBs take a fairly large initial investment of your time getting up to speed.

Just how bad is it? A related question is, what's the "state-of-the-art" technique for prototyping, ie. NOT production, probably never more than 1 or PCBs of the same layout

Depends on a lot of things... Your personal abilities, the software you choose, whether or not you believe in reading instruction books or not, etc. It also depends on the complexity of your board. It is possible for a new user to have a simple first board ready to send to a fabricator in a couple of hours, maybe less. But this is highly unlikely. You will more likely spend several days getting functional, several more days designing your first schematic, several more days doing a layout, another day figuring out Gerber files, then a few more days getting correct Gerber files, etc. Once all that is done, you will decide that if you knew then, what you know now, you would have done things completely different. Then, if you're like me, you will start all over again and do a much better job in just a couple of days.

After a few of these adventures, you will be able to do a reasonable board in just a fraction of what it would take you to do any of the other prototyping methods. Of course, you still have to wait for the boards to come back from the fabricators, or do a similar learning process for etching boards at home.

And a clue here. Once you know how to do home etching, it is reasonably easy to accomplish. The people who say how easy it is to do it already know how. But let me assure you, you will not start out already knowing how to do it. The learning process is probably going to be painful before you are able to get reasonable boards doing it at home.

 

Once all that is done, you will decide that if you knew then, what you know now, you would have done things completely different. Then, if you're like me, you will start all over again and do a much better job in just a couple of days.

Hmmm..., I'm familiar with that sort of process. Suddenly poking a few wires thru my perfboard doesn't seem so bad after all.

And a clue here. Once you know how to do home etching, it is reasonably easy to accomplish. The people who say how easy it is to do it already know how. But let me assure you, you will not start out already knowing how to do it. The learning process is probably going to be painful before you are able to get reasonable boards doing it at home.

I may have a leg up here, having spent many years doing chem lab research. Still, I'm already having second thoughts about diving in. How much do the fabricators cost? Do you just send them a Gerber file and get back a PCB?

 

And a clue here. Once you know how to do home etching, it is reasonably easy to accomplish. The people who say how easy it is to do it already know how. But let me assure you, you will not start out already knowing how to do it. The learning process is probably going to be painful before you are able to get reasonable boards doing it at home.

True, experience teaches a LOT, especially little things like "Ferric Chloride is worse than blood for stains, and more visible".

When I started with PCBs, it was using the "Rub Off" trace and pad sheets from Radio Shack (Waaay back when they had parts, early 80's-ish). When in college, there still wasn't any software that graphical PSpice/schematic capture, let alone auto-place/auto-route.

Now that schematic capture, auto-place/auto-route are included in some of the basic to mid level schematic capture and simulation packages, the "Hard Part" (routing and placement), is accelerated to "near instant", relatively. It still takes a bit of brain sweat on the part of the user for placement of some parts, but nothing like having to draw each trace at 5x scale for photoreduction.

Overall, having the software verify the schematic to the PCB, compared to "buzzing out" an etched board with a multimeter to make sure it matches the schematic is kind of "magical".

I think it is the last thing, software design of boards that has put them in the "Easy Category". Once 5 or so have been successfully etched for practice, it is a 20 minute process for a completed "Printed Wiring Board".

 

How much do the fabricators cost? Do you just send them a Gerber file and get back a PCB?

Two questions.

1) "How much do the fabricators cost?"

Varies widely. 2-sided, 4-layer, 28-layer? 13 mil traces or 3.5 mil traces? 2 square inch board area, 89 square inch? Do you need 1 or do you need 3 million? Need it this afternoon or can you wait until sometime in the second quarter of next year.

I've seen places where you can get anything you can fit into a certain number of square inches for $49 (that was a while ago, but similar probably still exists). There are places like BatchPCB that are good for small quantity but maybe not so good for quick turn-around. They wait till they have a full panel, print the whole panel, cut up into the tiny individual boards and distribute them to the many participants. Others places require that you use their software, or some other limiting factor. Others here are probably better at those recommendations.

2) Do you just send them a Gerber file and get back a PCB?

You make it sound so simple . Yes, that's all you do! (We'll just ignore for now the steps it took to get to that point. Pssshht... details!)

If you send a proper set of Gerbers, it's almost that easy. They have to meet the design rules of the house you send them to, and some places have some other limitations, but it is possible to e-mail/FTP Gerber files, and get Fed-X boards back almost the next day.

 

True, experience teaches a LOT, especially little things like "Ferric Chloride is worse than blood for stains, and more visible".

At least it also looks bad, unlike the tinning chemical that is clear, feels like soapy water, but is maybe even nastier for you (don't ask me how I k...k..kn...know.)

When I started with PCBs, it was using the "Rub Off" trace and pad sheets from Radio Shack.

I started with the blue and red tape and the black pads from Bishop Graphics along with their hard-cover book for instructions. What a pain, but it was state-of-the-art at the time. The second commercial board I designed (schematic at a drawing table using the green plastic stencils) and laid-out (Red/Blue tape), back about 1978-9, was still in production in 2002 (haven't checked since then). Probably not the record, but it's up there.

 

My Epson printer uses DuraBrite inks but I can't print on disks or PCBs. I'd look into another printer if this is the way to go. Where do you get your supplies? Or, is there a write-up somewhere of the process you follow?

Everyone: First, thanks for all the feedback. I think you can see I'm leaning towards learning a PCB method if it doesn't sound too bad compared to my current perfboarding. I understand the general concepts of the overall PCB process but I'm very curious about the tips and techniques that this community has uncovered to simplify things. I don't want to just walk into Radio Shack and ask them to set me up!

You need to use an Epson for this method to work. Epson Durabrite Ink is pigment based rather than Dye like other printers, basically its like thin paint and once cured its waterproof. Most cheap "compatible" replacement ink carts use dye ink which wont work. The Epson head is part of the printer and it works differently than others like HP's. Some Epson's have CD printing trays, you can do CD sized boards without any real printer mods on these models. The other epson's will need a bit of modding. I currently use a "Workforce30" which cost me about 49.00 dollars. Mine on mounted on a piece of particle board with a cutom feed tray and a few small washers to raise the carriage assembly a little higher. I use clothing store style gift-boxes (3-pack from dollar store) for the "carrier" sheet.
They have a long thread at cnczone.com about this. the earlier posts were mostly about the older C7x-C8x series printers. The newer cheap plastic printers are easier to mod.
I also picked up a used toaster oven at a salvation army thrift store for about 10.00 and built a vertical bubbler etching tank for about 20 bucks including the aquarium air pump. A variable speed dremel tool in a little dremel drill press set me back another 50 something bucks ( I already had a few dremels on hand). I still want to get a heavy duty paper shear, but for now I'm cutting the boards with a cutting wheel in the dremel (my least favorite part of the WHOLE process).

Here are some video's of other guys direct to PCB inkjet resist setups,

http://www.youtube.com/watch?v=FkHpjzOhzxA
http://www.youtube.com/watch?v=rU3hWZSRw04&feature=related
http://www.cnczone.com/forums/attachment.php?attachmentid=31363&d=1171147504

Vertical bubbler etching tanks(mine is similar);
http://www.youtube.com/watch?v=DXjWZ9gJ4XE&feature=related
http://www.youtube.com/watch?v=AjfnrSgUmoU&feature=related


discussion/development thread;
http://www.cnczone.com/forums/gener...0951-hacking_printer_directly_print_pcbs.html
http://techref.massmind.org/techref/pcb/etch/directinkjetresist.htm

If anybody decides to go down this path be aware of a few quirks of the epson print head, and other tips/lessons learned from this process;

1. Dont let it dry out, dont leave the head exposed for long periods. My printer cannot use the original "pump" setup so I made a cap that fits over the print head out of silicone. It has a vacuum hose connected to a syringe that I use to draw out some initial ink after sitting for long periods (almost 1 year this last time)

2. Dont ever use anything with much alcohol in it to clean a dirty epson head. It will dry out the the clog and leave it setup hard as a rock.

3. Apply suction to draw ink from the nozzles, but dont ever try to force feed ink/cleaner from above. The pressure will frequently "delaminate" the peizo elements/passages. I killed two heads this way before I learned(old used ones that may have been salvageable)

4. buy some aftermarket ink carts with the autoreset chips in them. Then buy any magenta/yellow real "epson durabrite" ink carts you can find and transfer the ink into the clear autoreset carts with a needle/syringe. Stock epson carts will waste at least 50% of the ink with false low reporting, cleaning cycles and such.

5. Avoid buying used epsons with clogged/dried up heads. Even if it prints but has some clogged jets you'll waste at least a whole set of ink carts just trying to get all the nozzles cleared while printing test patterns and running clean cycles. A NEW printer only costs a tiny bit more than just a set of ink carts(and it comes with a new set).

6. print in red with 100% magenta/100% yellow. The Cyan dosent resist very well and the black is only mediocre. magenta/yellow combo is best!

7. Preheat board so that droplets stick better and have less tendancy to puddle/run/fisheye. Bake immediatly after printing!

8. Clean boards very well. I use soft blue scotchbrite pad/sponge with lots of comet, rinse in hot water and wipe down with alcohol. Use whatever works best for you, but the board must be very clean.

9. Etchant can be reused quite a few times. I have a container that holds just enough to fill my etchant tank. I recover about 90% of it each time and re-use it untill it starts loosing its potency, but I never dump the used etchant back into my "main fresh" bottle. Also with the vertical tank I can use a good flashlight behind the board and watch the Etching progress through the board itself.

10. If you re-position the board exactly and have a card carrier setup that allows accurate repeatability you can print your solder mask and artwork afterwards (good use for the blue and black). Still pre-heat/bake it.

11. Quick and dirty experimental 2 sided boards can be made by printing 2 single sided boards and gluing them together.

12. When printing rectangular boards print them along the wide side so that they take less time to feed through the printer. The longer you take, the more the board cools from the pre-heat and the higher likelihood of fisheye or puddling.

13. If you had to remove the pump/squeegee assembly (likely) you need to gently wipe the head before printing. Droplets on the surface of the head will deflect the jets and you'll have a blurry print.

14. un-check "bidirectional" printing in the settings. You'll have a different headspace between the print head and board than the original setup. the bidirectional mode adjusts for distance vs. head velocity and you may get a slight offset/misalignment if it prints on the back-stroke too.

15. Dont work over white carpet!

Hope this helps somebody. I spent several months and wasted at last as much money in failed experimentation/mistakes as what my current system costs.

 

It sounds like there are a lot of different techniques to transfer the pattern, including directly printing on the board. I'm guessing there are different etching techniques as well.

Can you elaborate a bit on what procedure you use? Links to suppliers would be great.

I bought some UV-LED on Ebay. Took about 30 day to get them to Norway. In the mean time I designed a timer schematic.

Everything is put inside a retired flatbed scanner...


This is roughly how I do it.

1. Making schematic/board layout in KiCad.
2. Printing on regular paper - twice.
3. Putting the papers on top of each other, on the UV-LED box.
4. Pouring on some vegetable oil. This makes the paper nearly transparent.
5. Placing a transparent plastic sheet over the oil. That will prevent oil to get on the photoresist PCB.
6. Press timer and wait.....
7. Develop in some chemicals that are common in Norway. To open the drain in the sink, if too much hair or shavings block the water to go out....
8. Etch in Natriumsulfat... Na2S2O8

Here are some links to my extremly novice site (It's in Norwegian, but there are some pictures to illustrate).

The flatbed scanner

UV-LED transfer

(I'm posting the two links, to show MR. wayneh how I do stuff, not to promote me/my work or my poorly site. If this is against AAC / Forum rule, I appoligize... and will not do it again!!)

I will look into the direct print method, because this may be more efficient to time. From finnished board design to the drilling process. Besides you don't need the photodeveloper, and the copperplated boards are cheaper than the photoresist. To me it is importnt to keep the costs as low as possible.

 

bouncing an old thread as google turned this up. i'd think perfboard is good for some projects, i've some circuits based off it.
however, these days smd components is extensive and more mcus are no longer shipped for dip connections.
i'd think there may be no choice but to go pcb sooner than later. has anyone successfully used perfboards with smd components?
i think it is an extreme challenge to do that, but of course if it isn't too many components these days there are quite a lot of sop, tsop to 2.54 (1/10") adapters
https://www.ebay.com/sch/i.html?_from=R40&_nkw=sop++adapter&_sacat=0

 

It's all about the time and money baby!
The fastest way to working hardware wins- while minimizing the risks of project deadline failure.

Home-baked PC boards (toner, milling, etc) require design compromises that do not reflect a real professionally made board.
You cannot do vias, and the geometry needs to match the technique- I would not invest time in CAD to design a board that does not directly translate to a normal commercial PCB.

In prototyping, you often have no option but to use the SMD part, many parts are just not available in thru-hole format.
Designing a test PCB, sending it out, then populating it is very slow- a week at best.
If the board doesn't work, you are often totally out of luck, with no choice but to re-spin and wait another week.
Some times you can do micro-surgery and fix mistakes, as long as the traces are accessible and big enough to work with.

I often give my designs to my PCB designer before I am totally done with the design, to get a jump on time.
I build a breadboard, using a combo of every prototyping technique I know, - wire wrap, surf boards, perf board, point-to-point - anything that gets it working- fast.

Once the hardware is validated and working, the schematics are updated and sent back to the designer, who is 80% done with the layout already.

This strategy gives me the most confidence things are going to work- and folds the time-line on itself as much as possible.
The hand-built proto is painful and takes lots of skill, but nothing can stop this phase except for running out of parts.

When the PCB is done, I am 99.9% sure it's going to work- and the total elapsed time can be crunched down to days instead of weeks.

 

For DIY hobby projects it depends on the complexity of the circuit. Been there, done that. Now I usually go PCB since it is not so costly anymore.

For professional work, it's exclusively PCB.

 

Once I got a reliable process, I make a PCB for pretty much everything. Here are the plusses as I see them.

1. It forces me to create a correct schematic that matches the actual circuit. I then have documentation I can trust months or years later.

2. It reduces the errors in the build, usually to zero. Nearly all of my PCBs are correct on the first try.

3. Soldering the board is a snap.

4. If, for any reason, I need another one, It is almost no work and takes me less than an hour, regardless of the complexity.

Minuses:

1. Higher cost (I use presensitized boards)

2. Longer design time, but total time is competitive unless the strip board or perf board build goes without errors, which never happens.

Bob

 

Another minus is that changes to PCB connections (not part values) is more difficult compared to the type of protoboard shown here by me(post #9) and others: https://forum.allaboutcircuits.com/threads/how-to-build-project-with-hookwire.163547/#post-1436806. Note that Eagle and probably any ECAD can be used to reduce board design errors to almost zero with schematic capture.