PCB etching? - Page 1
Forum section: electronics / projects

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 10, 2017, 10:19:17 pm
content: Hi,I've been thinking about using PCB etching for my nixie tube clock project. I was first going to use perfboard but I want this project to come out good so I thought I could also learn how to etch PCB's with this project.Now, I don't own a laser printer so I can't print out the design. So I thought I could use a thin sharpie to draw onto the copper clad.As for the etching solution, I don't have a store nearby that sells ferric cloride and on Canadian amazon it seems quite expensive. So I came across this instructable on how to make your own etching solution with 2 ingredients I can get from a hardware store and drug store.http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/Would this be a good idea or should I stick with making it on perfboard?

author: tautech
author_rank: Super Contributor
timestamp: January 10, 2017, 10:36:31 pm
content: Some threads that should make things clearer: (In no order of importance)https://www.eevblog.com/forum/beginners/my-first-try-at-making-a-pcb/https://www.eevblog.com/forum/beginners/pcb-etching-where-do-i-start/https://www.eevblog.com/forum/beginners/smallest-pitch-for-home-made-pcb-that-is-doable-for-experienced-guys/The HCL etchant you propose etches very quickly and initially needs be mixed with great care to detail.Take care with all etchants, HCL more so.

author: george graves
author_rank: Super Contributor
timestamp: January 10, 2017, 10:59:06 pm
content: You could draw it by hand, but you have to get the right marker for it - the sharpies that they sell at the big box stores (or I should say the ones I've tried) don't work very well at all.Also, if you can't get your hands on a laser printer, you can easily find one at at copy shop.Drug store peroxide is usually really weak (3% or so) and will etch well on it's first use, then it kind goes down hill from there. I use stuff from a beauty supply shop (usually called "developer" for hair coloring) and it's more like 30-40%. That will etch so fast you have to watch it for under cutting traces and it's more then a bit exothermic.

author: Benta
author_rank: Super Contributor
timestamp: January 10, 2017, 11:03:06 pm
content: Using a permanent marker to draw track and solder pads directly on the copper of raw PCB material is perfectly feasible. It saves all the film/lighting/development etc. I've done this so many times myself for simple boards with leaded components.There are actually special pens for this available.Concerning etching:I've mostly used ferric chloride in the past, and it works well for etching. For everything else around that, it's a major pain. It's a mess to get rid of, if you spill a drop you'll have a brown stain that will never go away etc. I don't use it anymore, but my workshop, floor, plumbing still show that I didHCl + peroxide + water: I've used that as well a couple of times. Very hard to control, your etch takes less than a minute, so underetching is preprogrammed, and you're working in a cloud of chloride gas (think WW1). Not recommended.The last 20 years or so, I've worked exclusively with Sodium Persulfate, Na2S2O8.It's easy to work with and provides excellent results with very little underetch. It's clean and easy to dispose of. Etching time is around 20 min.Only thing to look out for: the solution must be warm, 50 degrees C is optimal.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 11, 2017, 12:33:01 am
content: With regard to PCB etching... I found another recipe that uses Vinegar, Salt and Hydrogen peroxide.https://www.eham.net/ehamforum/smf/index.php?topic=93977.0But it seems sort of unreal that this would work. Vinegar doesn't seem like a strong enough ingredient to eat away at copper...

author: tautech
author_rank: Super Contributor
timestamp: January 11, 2017, 01:45:10 am
content: It's probably best to start with the "predictable" etchants like Ferric Chloride or Ammonium Persulfate both of which are simple to use and etching is comparatively slow and not so easy to over etch. Both work best as a heated solution.

author: cdev
author_rank: Super Contributor
timestamp: January 11, 2017, 02:52:52 am
content: Its fun making PCBs but for me the biggest driver was basically needing to because I wanted to do some things with VHF and above RF. For a one off design thats 10 MHz or less, I would use perfboard unless you want to do something fun and new. It would probably take around the same amount of time and require the same amount of work.You can use (laser printer/toner transfer with) hydrogen peroxide, vinegar and salt for etching too.. nail polish remover at the end for cleaning off the black gunk. (This process makes it very simple and fast)

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 11, 2017, 03:12:49 am
content: Quote from: cdev on January 11, 2017, 02:52:52 amSo I wouldn't be able to etch the pcb with hydrogen peroxide, vinegar and salt if it was hand drawn?

author: tautech
author_rank: Super Contributor
timestamp: January 11, 2017, 06:29:04 am
content: Quote from: PotatoBox on January 11, 2017, 03:12:49 amOf course you can if you use the right pen, Dalo pens have been around for decades and you should be still able to buy them. Some time back there was discussion on pens for plotters and IIRC a industrial Sharpie was the most suitable for PCB work. Hey there might be mention of it in the reads I linked but if you use the forum search button (not box) you shouldn't have to look too hard to find it.There used to be transfers for masking up PCB tracks, pads and various footprints, IIRC some were available from Letraset but there was another more famous and well known brand that I can't remember the name of which the oldies here would have used.I suggest you etch a small trial first, it can be quite small say matchbox size with some different pens to check which give the least porosity mask.I use the HCL HO3 H2O brew for which in a thread I linked I gave the recipe that worked OK for me.I have a homemade vertical etching tank with a "pinholed" bubbling tube across the bottom supplied from an aquarium bubbler and I suspend a PCB inside some folded plastic mesh, actually a leaf gutter guard product. With the mesh and when using the fast etching HCL brew it's easy to lift the PCB out and back in to check the etching process progress.HCL brew storage is in a KLIP IT 1.4 L steamer as you want a quite tough container that can handle the rigors of reheating were etch brews work best.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 11, 2017, 12:00:11 pm
content: Quote from: tautech on January 11, 2017, 06:29:04 amI came across these pens which seem to be meant for pcb etching.http://m.ebay.ca/itm/2PCS-CCL-Anti-etching-PCB-circuit-board-Ink-Marker-Pen-For-DIY-PCB-/201498235455?nav=SEARCH

author: SingedFingers
author_rank: Frequent Contributor
timestamp: January 11, 2017, 12:46:24 pm
content: I occasionally do a board by hand for a one off, because I hate using the computer as it's the day job. I've done this for 20 years fine without iron on stuff, photoresist or any of that faff. Only when I can be bothered though - most of the time I'll do deadbug.You need:1. Staedtler Lumocolor 318 for etch resist + insulation tape for big fills (ebay)2. Transparency (supermarket food box window plastic is fine).3. PVA glue4. 0.8mm drill bit + drill5. Ferric chloride - I get this off ebay ready diluted to 40%. It's not expensive, it's reliable and lasts a long time. 500ml has done me 20-30 boards. You don't need a lot!6. Tupperware box7. Sink.8. Boiling water.9. Isopropyl alcohol.10. Kitchen paper towel.11. FR4 board. Use SRBP if you really want. It doesn't cut easily though using score and snap. Just shatters!Process:1. Draw it on squared paper first (not to scale) in pencil roughly.2. Draw it on a transparency to scale. Just draw the pads and the traces roughly. I don't buy any specific transparency for this - just an old food container window plastic.3. Stick the transparency to the TOP of the board with PVA glue. I use single sided FR4.4. Drill all the holes through the top with an 0.8mm HSS bit. I use a big old DIY hand drill for this. If you're careful, they last quite a while. Then peel off the PVA and transparency. If you're lucky you might get another board out of it6. Scrub the board with a washing up scouring pad to get any tarnish off the copper side.5. Play join the dots on the bottom with the lumocolor using the transparency as a reference being careful not to touch it anywhere.6. Enlarge the pads with the lumocolor.7. Stick insulation tape over any large fills (helps stopping pitting)8. Throw tupperware box in sink full of boiling hot water so it floats.9. Pour just enough ferric chloride in the box to cover the bottom of the board.10. Place the board in upside down and wiggle it back and forward for about 5-8 minutes by hand then check it.11. Keep checking every 2 minutes after that until all traces are etched.12. Get the board out and wash it under the tap.13. Carefully tip the ferric chloride back into the container. Stick kitchen paper towel in the box to soak up the ferric chloride dregs, then stick that in a ziplock bag and place it in your non recyclable bin and rinse the rest of the box out. If you get a little bit down the sink, run the tap for a while as it will eat your pipes. It's not a big deal - some of the other shit that ends up down there is much worse than a few drops of FeCl14. Use a kitchen paper towel soaked with IPA to rub the board down and remove the tape and etch resist.15. Solder stuff onto itCut board to size first obviously!I've tried sharpies and they never work properly.NOTE: I don't use gloves and poke the board around with a cocktail stick as I don't mind the odd yellow finger but it will stain anything it touches. Wear crappy old clothes and don't do it in a plastic sink. Metal is best. DO WEAR EYE PROTECTION. WASH YOUR HANDS if you get any on them straight away - not because it'll burn your skin as that takes forever but if you rub it in your eyes.Edit: forgot to mention: don't make the tracks too thin or you'll have to jump them. Also make sure the pads aren't too small or they will disappear. This is good enough for anything up to about 50 - 80 pads on a board. It gets tedious after that! If you have a large project, plan on having more than one board - it's easier than making a big one and easier to rework if you screw up.

author: cdev
author_rank: Super Contributor
timestamp: January 11, 2017, 02:22:09 pm
content: The only time I tried using a permanent marker, I thought that I had the wrong kind so didn't try it again.But my experience might have been negative because at that point I don't think I was abrading the copper properly. (In my experience the board has to be thoroughly de-greased and buffed with steel wool before the toner transfer (to make the toner adhere to the copper)Yes, vinegar, peroxide and salt works well. But you should still minimize contact with the solution especially as it absorbs more dissolved copper. You add small amounts of additional salt to re- energize the etching reaction.The biggest advantage is you can buy the etchant easily and disposal is not complicated.I also use nail polish remover at the end to remove a black coating that coats the copper parts of the boards. Once the black stuff is removed the boards look good.Then you just treat them as you would with any other etching method.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: January 11, 2017, 02:30:25 pm
content: Yeah you have to scrub it pretty well. Washing up liquid/detergent can be used to degrease as well.The really annoying thing about doing it with permanent markers is when you wipe them off afterwards with the solvent they always seem to run into the edges of the boards slightly which means you get the odd spotty blue edge.

author: Ian.M
author_rank: Super Contributor
timestamp: January 11, 2017, 02:34:53 pm
content: If the copper surface isn't clean to start with, you've FUBARed it before you even start. One fingerprint in the wrong place is a disaster as it's likely to cause the resist to lift while etching. Wear gloves, and only handle the board by its edges.Seehttp://www.ctgclean.com/tech-blog/it-clean-oil-and-hydrophobic-films-water-break-testfor how to determine if the board is clean enough.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 12, 2017, 10:52:57 pm
content: Will drawing the IC's be a problem? or is all I need is a steady hand?

author: tautech
author_rank: Super Contributor
timestamp: January 12, 2017, 11:28:48 pm
content: Quote from: PotatoBox on January 12, 2017, 10:52:57 pmMaybe.It no doubt can be done with a fine pen and you might even be able to leave holes in the mask BUT for IC's with more than just a few pins getting the spacing right will be problematic.An alternative approach would be just to mask out some "not so fine" tracks without pads or holes and bend the IC leads to suit, ah la SMD style. Dead bug style could be worth considering too.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: January 12, 2017, 11:34:09 pm
content: Drilling the holes first makes ICs easier. If you do it after, unless you have a really nice drill press, you risk buggering up the pads. Use an archimedes drill by hand for accuracy.I've done 6 DIP packages on a hand drawn board.

author: Paul Price
author_rank: Super Contributor
timestamp: January 12, 2017, 11:44:22 pm
content: http://www.diverseelectronics.com/Educational-Products-c1010/PCB-Fabrication-amp-Chemicals-c1096/You can get FeCl3 solution, boards, pens, other etching reagents in powder form, etc here if you are in Canada.$17 CaD for 1 L of FeCl3This source is cheap and handy enough for me when I am in the Great White North.One L is enough to etch a buncha boards.Diverseelectronics.com5400 Thimens Blvd., St-LaurentQuebec, H4R 2K9, CanadaTel.: (514)-388-7308Toll Free: 1 (800) 381-7308

author: Benta
author_rank: Super Contributor
timestamp: January 12, 2017, 11:52:48 pm
content: If laying out ICs directly on a raw PCB, I use the following technique:On a transparent drawing foil with 0.1" grid, mark all holes (ICs and discretes) with a pencil (just a dot is enough).Attach the drawing foil to the PCB (eg, with a couple of superglue dots) so it´s nicely aligned and stretched over the copper side of the substrate.With a sharp, pointed punch, using the foil grid as reference, mark the holes in the copper with a light tap. Remove the foil and clean the copper (fine steel wool etc.)Do your artwork with your pen and etch. The punch marks act as drill guides afterwards.

author: Cupcakus
author_rank: Contributor
timestamp: January 13, 2017, 08:11:15 am
content: With prototype PCBs so cheap and fast from China now I'm not sure why you would want to etch and drill your own boards? Then your project would look super nice, and you will spend much less. Just something else to consider.

author: IonizedGears
author_rank: Regular Contributor
timestamp: January 13, 2017, 09:23:07 am
content: Quote from: Cupcakus on January 13, 2017, 08:11:15 amMinimum orders unless you want your boards to be really expensive. 2-3 week lead time if you want your boards really cheap. Etc.With etching you get results really quick which means faster design cycles. Why wait 3 weeks until you can test the board only to find an issue so you have a ton of unusable boards and then you have to wait another 3 weeks.If you're still designing and you want to test it, etching a board is the best way. If you've finished designing and you want a bunch of boards, getting them made is the best way.

author: Ian.M
author_rank: Super Contributor
timestamp: January 13, 2017, 10:02:22 am
content: A home etched PCB with hand drawn tracks is a serious constraint on your possible layout. Unless you fully pre-drill the board, you cant do double sided because of the alignment issue, (although a ground plane + isolating holes where required with a Veroboard track cutter is possible) and without the use of transfers for the DIL footprint, you cant effectively route tracks between IC pads.As the commercial PCB will require digital artwork with totally different constraints, if you cant do toner transfer or photomasking at home from the same artwork, there is no point in doing a hand drawn home etched prototype except as a proof of concept, and even then its advantage over point to point wiring on a good protoboard is minimal.

author: george graves
author_rank: Super Contributor
timestamp: January 13, 2017, 11:05:37 am
content: Quote from: Cupcakus on January 13, 2017, 08:11:15 amI agree with the cheap part....But "Fast?" 14 days is fast?If your design is simple enough to do one sided, and mostly or totally surface mount, etching becomes a real option. You just have to seal the board when done. Polyurethane works well for that.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: January 13, 2017, 11:18:42 am
content: My boards are 2 hour turnaround. My interest wanes before anything from China will appear.You don't have to seal the board. If you use FR4, tin it (solder powder and a heat gun works) which is the sort of thing Marconi were doing in the early 1980s looking at my 2019A then it'll last fine. A pulse generator my father built in 1972 ish is still fine with bare copper tracks.

author: cdev
author_rank: Super Contributor
timestamp: January 13, 2017, 03:29:29 pm
content: The magic of having an idea and turning it into a PCB in a few hours is addictiveQuote from: Cupcakus onTodayat 03:11:15

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 14, 2017, 01:58:02 am
content: I don't have a drill press but I saw these mini hand drills and the bits are quite small enough for a PCB. Would these be alright?http://www.ebay.ca/itm/Aluminum-Mini-Micro-Hand-Drill-With-Keyless-Chuck-10-Twist-Drills-Rotary-Tools-/182272336416?hash=item2a70472220:g:EQ0AAOSwnbZYEbcU

author: Ian.M
author_rank: Super Contributor
timestamp: January 14, 2017, 05:22:13 am
content: An Archimedes Drill will do for SRBP if you have enough patience, although the smaller bit sizes will break so easily you'll be lucky to get 2 or 3 holes per bit, but FR4 is a lot tougher and will break or blunt the bits faster than you can believe. Best kept for modding existing PCBs. There is *NO* substitute for a low runout precision drill press, preferably with an effective way of quickly clamping the board.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: January 14, 2017, 10:42:35 am
content: I can get about 30 holes with an archimedes drill and some FR4. The biggest problem is the ache you getAnother option I do occasionally is take a bit of FR4 and groove it with a junior hacksaw in a mini mitre block every 0.1" or so in both directions. Works for TH and SMD prototyping quite well. You solder the TH components to the top. Also good for carrier boards when you're doing deadbug design and want to drop an expensive IC in without ruining it:Note: don't bend turned pin socket pins too close to the base or they snap off

author: george graves
author_rank: Super Contributor
timestamp: January 14, 2017, 12:26:54 pm
content: Quote from: Ian.M on January 14, 2017, 05:22:13 amI took a chance on a standard drill press - and have drilled hundreds if not thousands of holes with it.http://www.sears.com/craftsman-8inch-craftsman-drill-press-with-13-pc/p-00947747000P?sid=IDx01192011x000001&gclid=CjwKEAiAtefDBRDTnbDnvM735xISJABlvGOv0KWlYA48FhUhFRfeJ5tnpbx0EfwBLjdEvqA96oSxAxoCDQnw_wcB&gclsrc=aw.dsAlmost no run out, and the speed gets up to 3140 RPM - a little on the slow side, but not bad.The key is the proper drill bits. I get mine from drillbitcity on ebay. They are resharpened, but slightly shorter bits that were uses at real board houses.You actually can made single sided boards at home for cheap(cheaper then china? I think so - I'd have to break it down) - and if they are mostly SMT, then even better. But the moment you have to drill 50 holes in it, it becomes a painful exercise.The down side is that you're exposing yourself to fiberglass dust, and chemicals. So you might want to factor that in.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: January 14, 2017, 04:47:55 pm
content: Fibreglass dust isn't particularly harmful unless you are doing something on an industrial scale. It is 100% expelled from your respiratory tract for example and it's not a carcinogen. The main risk is the abrasive nature so keep it away from your eyes.

author: Ian.M
author_rank: Super Contributor
timestamp: January 14, 2017, 08:41:54 pm
content: Well cured epoxy fibreglass dust is not particularly hazardous, but its quite easy to become sensitised to epoxies if you often use the adhesives and/or laminating resins, and don't scrupulously avoid any skin contact with uncured or partially cured resin and avoid breathing any dust from cutting or abrading recently cured resin. Once sensitised, the reaction can vary from mild skin irritation to severe enough to force a change of career to avoid epoxy use. Also unless the laminate is high temperature cured, or aged for several months, once sensitised, the dust from cured laminate can trigger the reaction. Problems are most common if you work in boatbuilding, but can crop up in other industries.SRBP has its own set of problems - cellulose fibres + Phenol Formaldehyde resin makes fairly nasty dust.Occasional one-off projects are unlikely to trigger any problems unless you have a history of allergies, though safety glasses and a dust mask are well worth wearing. but if you are planning to do a lot of DIY PCB drilling or cutting work you should take the same precautions that you would if using power tools to cut and sand toxic hardwoods.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 14, 2017, 09:03:32 pm
content: I had thought of another idea... how about I print the schematic on my inkjet printer, then go to a Copy and Print store and photo copy it there. They do use toners don't they? So I could use the toner transfer method.

author: tautech
author_rank: Super Contributor
timestamp: January 14, 2017, 09:20:37 pm
content: Quote from: PotatoBox on January 14, 2017, 09:03:32 pmYes you could BUT to have the best chance of success you'd want to use one of the transfer films like PressnPeel that are made for PCB toner transfer. A semi gloss paper works OK too but you'll likely have to soak it off.Every printer produces different results and we've all done some amount of trial and error to find a transfer methodology that produces repeatable results.But sure, give them a try.

author: Ian.M
author_rank: Super Contributor
timestamp: January 14, 2017, 09:49:07 pm
content: They can probably laser print from PDF as well.There's also the photosensitised PCBs (precoated with UV photosensitive etch resist) and transparencies method. Seehttp://www.electricstuff.co.uk/pcbs.htmlRemember the printed side MUST contact the PCB surface to prevent blurring, and you'll need to buy or improvise a UV light box.

author: Cupcakus
author_rank: Contributor
timestamp: January 14, 2017, 11:37:12 pm
content: Quote from: george graves on January 13, 2017, 11:05:37 amI submitted my Gerber files to pcbway last Sunday and the boards arrived on Friday. Granted I live in California so maybe it's a bit faster for me, but 5 business days for 10 prototype boards for $30 shipped is pretty good. I wouldn't vouch for their quality but they're much better than anything I've hand drawn and etched.For comparison I ordered some replacement caps for a PSU from digikey that same Sunday, still waiting for those.I do agree that sometimes you just want to whip up something quick, that's what the big pile of perf board is forBut the OP didn't want something quick, but something that looks good.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 15, 2017, 02:14:18 am
content: I saw this thermal transferable paper on ebay. I guess this will be good enough for toner transfer.http://www.ebay.ca/itm/5-10-50-100Pcs-A4-Heat-Toner-Transfer-Thermal-Paper-For-Iron-PCB-Prototype-Board-/172409974614?var=&hash=item28246f6f56:m:m24MfgnKCS32Dbl9nnSZFZQI've also heard some people use glossy photo paper, but I've also had some people say that they had no luck with it.

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2017, 02:42:26 am
content: Quote from: PotatoBox on January 15, 2017, 02:14:18 amYeah, that one should be OK.I use a laminator to bond the toner, 2 passes.If/when you get a laser printer you can print to plain paper first then stick a cutting of this stuff over the image and print again, then you can stretch out the usage of each sheet of transfer paper.Be wary of the printer scaling and if you're getting somebody else to do it take something along so you can measure and check scaling settings are correct.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 15, 2017, 02:48:01 am
content: Quote from: tautech on January 15, 2017, 02:42:26 amThats why you get them to photo copy it.So that its 1:1.

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2017, 02:56:48 am
content: Quote from: PotatoBox on January 15, 2017, 02:48:01 amForewarned is forearmed.

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2017, 03:08:04 am
content: Quote from: PotatoBox on January 10, 2017, 10:19:17 pmThis is a very bad article about mixing dangerous chemicals so please ignore! Ferric Chloride is actually very environmental friendly because you can use it indefinitely (as in until the end of times). Just add HCl (10% from the grocery store) to regenerate it. Technically you'll be etching with Cupric Chloride but it works just as well. I can highly recommend to get a spray etcher because it will be fast with Ferric/Cupric Chloride. I have used toner transfer method in the past but never went back when I started using the photo transfer method with a UV lighting box. I use thin tracing paper as film and a laser printer to print it. Then again I have not used my etching setup for over a year. It has become very cheap and easy to order professionally made boards so investing in all the equipment and materials isn't worth it nowadays.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 15, 2017, 04:29:53 am
content: what are some good PCB design software? Something that doesn't have a high learning curve?

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2017, 04:41:41 am
content: Quote from: PotatoBox on January 15, 2017, 04:29:53 amFrom EEVblog, Daves Wiki and the forum:http://www.eevblog.com/wiki/index.php?title=PCB_CAD_programshttps://www.eevblog.com/forum/eda/pcbeda-software-list/Pick the flavour you like most.

author: PotatoBox
author_rank: Regular Contributor
timestamp: January 15, 2017, 05:53:26 am
content: Is tin plating necessary?

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2017, 07:26:53 am
content: Quote from: PotatoBox on January 15, 2017, 05:53:26 amNo.Without some protection copper traces will tarnish quite badly over time and if in a corrosive or humid environment can corrode through tracks. It's not common but does happen. There's a few ways to counter this, not all provide protection forever except potting/coating the entire PCB.Simplest to hardest PCB protection steps:Make traces wider and/or use a heavier weight copper PCB.PCB spray on lacquers. (Pre and/or post population.)Tin all traces etc. with solder.Conformal coatings/Potting. (post population)Dry film mask.Tin PCB.There'll be argument over which is best but it's not about that, more what you can easily DIY.I only use a $15 aerosol can of spray on PCB lacquer applied immediately after etching/drilling and clean up and another coat when finished soldering. The stuff I use is easily soldered through and even double coats have no effect on the possibility of rework or repair.

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2017, 03:49:29 pm
content: Quote from: PotatoBox on January 15, 2017, 05:53:26 amNo but you have to apply a protective coating otherwise the traces will erode away quickly. I have been using SK10 from Kontakt Chemie for decades on my self etched boards. It is both a conformal coating and flux.

author: Wimberleytech
author_rank: Super Contributor
timestamp: January 15, 2017, 07:01:29 pm
content: Quote from: tautech on January 15, 2017, 04:41:41 amI use ExpressPCB...it is very simple. I use it in a way not intended however. Here is my short explanation.Lay out the board in ExpressPCBPrint to PDFEdit PDF using Adobe Illustrator. Mirror the image (not always required depending on through hole or surface mount)Also make duplicates on the page while in Illustrator. SavePrint to laser printer on to toner transfer paper, magazine paper, (or your favorite transfer medium).Transfer the image to pcb using iron or laminator (I have done both).Etch with Ferric Chloride (I have also experimented with vinegar and H2O2 but Ferric Chloride is far better). I also heat the etchant on a hot plate.Drill the board (as necessary) with a dremel on my barely adequate dremel drill pressPopulate and testIf I like the result, I will send the layout to ExpressPCB and and use their mini-board service for about 50 bucks (in five days ish).I do lay out the board as double-sided. However, I minimize the back-side traces. For the single-sided board I make, I use jumpers for the back-side traces. Not great, but since this is generally a test for functionality and mechanicals, it is not such a big deal.ExpressPCB software has an easy copper pour which has adjustable parameters. I always use this because it reduces the amount of copper etched and also balances the etching (more or less) throughout the board. I use the same trace width everywhere.I use 30mil fr4 so it goes through the unmodified laminator without a problem.

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2017, 08:06:49 pm
content: For DIY PCB's some hassles can be reduced by using Phenolic or Paxolin PCB's as it's much easier to drill and work with for the hobbyist unlike FR4.It's also known as SRBP. (SYNTHETIC RESIN BONDED PAPER)These guys call it FR-1https://othermachine.co/support/materials/fr-1/Trying a few keywords you'll get all sorts of hits trying to find it and Bakelite (similar substance) finds some more.Can be a bit tricky to find on eBay as it's often referred to as PP blank PCB material.http://www.ebay.com/sch/i.html?_odkw=PP+pcb&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XPP+blank+pcb.TRS0&_nkw=PP+blank+pcb&_sacat=0https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20170115120319&SearchText=bakelite+blank+pcb+boardWhile looking for more definitive info I came across mention that it is referred to as FR-2, FR stands for Flame Resistance.https://en.wikipedia.org/wiki/FR-2

author: Wimberleytech
author_rank: Super Contributor
timestamp: January 15, 2017, 08:31:43 pm
content: Quote from: tautech on January 15, 2017, 08:06:49 pmI bought some CEM-1 and its OK but I made the mistake of buying the 60mil thickness. Works OK if I use an iron instead of the laminator. I am not married to FR-4 but I need a 30mil solution. Will probably use up what I have before worrying about it though...which may take some time...

author: cdev
author_rank: Super Contributor
timestamp: January 21, 2017, 11:19:53 pm
content: Phenolic PCB material is lossy enough to be noticeably inferior to FR4 at higher frequencies.

author: tautech
author_rank: Super Contributor
timestamp: January 21, 2017, 11:32:04 pm
content: Quote from: cdev on January 21, 2017, 11:19:53 pmQuite so and as I see RF is your area of interest FR-4 is probably the best solution for you.Then there's more suitable materials for VHF too but maybe beyond what the hobbyist would need or want.https://www.rogerscorp.com/documents/2272/acm/articles/Selecting-PCB-Materials-for-High-Frequency-Applications.pdf

author: SingedFingers
author_rank: Frequent Contributor
timestamp: January 22, 2017, 09:57:35 am
content: For VHF I'd avoid using a PCB and use it as a ground plane only. Probably not worth a PCB if it's a one shot.

author: james_s
author_rank: Super Contributor
timestamp: January 25, 2017, 06:46:23 am
content: IMHO without a laser printer it's not worth trying to etch at home, it's just way more work than it's worth. I still etch boards myself when I'm in a hurry because I can go from finished CAD design to board ready to assemble in less than an hour but otherwise I just send out for them. From Smart-Prototyping I can get 10 boards for around 20 bucks shipped and that's double sided with plated through holes and silkscreen on both sides.As far as actual etching, I use hydrochloric acid mixed with hydrogen peroxide. It quickly turns into a green solution of (IIRC) cupric chloride which turns brown as it absorbs etched copper. Adding a capful of peroxide turns it light green again and it can be reused. It does require good air bubble agitation though.