Smallest pitch for home made PCB that is doable for experienced guys. - Page 1
Forum section: electronics / beginners

author: Rick Law
author_rank: Super Contributor
timestamp: May 04, 2015, 04:42:22 am
content: As someone with limited experience, I have been kicking around the idea of trying out etching my own PCB just for the fun of it.I am wondering for home-made PCBs, with laser printed (HP5P) thermo-transfer, what would be the precision limit one can expect from aexperiencedperson.I want to set a goal that while I may not be able to do immediately, but is doable as I improve. Printer will be a laserjet 5P (not buying a new printer just for doing PCB's).I want to (eventually) do a PCB for which amount other things will have an ADS1115 (instead of using the Adafruit breakout). It is a0.5mm pitchVSSOP chip. I wonder if that is even achievable (given home-made limitations) even for experienced guys - each solder pad is merely 0.3mm wide.If that is too ambitious, what pitch do you thing an experience guy should be able to do with home made PCB?Thanks for your input,Rick

author: lapm
author_rank: Frequent Contributor
timestamp: May 04, 2015, 04:58:14 am
content: With good equipment its doable.. And with good equipment i mean stereo microscope/mantis, proper tip/hotair soldering, patience...

author: redshift
author_rank: Contributor
timestamp: May 04, 2015, 05:21:28 am
content: The smallest pin-pitch I've bothered to etch is 0.025" (~0.65mm).My method: I transfer toner using a laser printer, glossy paper, and a hot clothing iron. Then use ferric chloride to etch away the copper. Lastly, acetone to clean off the toner.I don't have a hot-air station or a microscope. Just my hakko fx-888 and a magnifying glass to look at things afterward. So I'm willing to bet 0.5mm is possible(especially if you have these things).Another suggestion: If you don't think you can reliably make a footprint with small trace widths, you can always solder your VSSOP to a breakout board and then solderthatinto your pcb.

author: Cloud
author_rank: Regular Contributor
timestamp: May 04, 2015, 05:21:35 am
content: For very thin lines and pads its better if you use PCB with photo sensitive coating and foil.

author: Rick Law
author_rank: Super Contributor
timestamp: May 04, 2015, 06:27:39 am
content: Quote from: lapm on May 04, 2015, 04:58:14 amSince you talked about proper tip/hotair, I take it you mean the soldering phase of the project.I am confident with the soldering part. I blew out the ADS1115 by over-volt and I had to replace it on the Adafruit breakout. I have merely a 4x loupe and no hotair station. That ADS1115 replacement job was successful the first try but it did required a great deal of patience. Difficult for sure, but I know I can do it.It was the difficult with soldering that ADS1115 replacement that leads me to think: I can't "magic marker" fix the thermo transfer, there is no chance I can draw anything 0.3mm width. So fix up any imperfection in the thermo transer on the copper plate will be darn near impossible and I would be relying on pretty much a perfect transfer... Which is why I wonder if it is a realistic "home project" to make PCB for something like that.Thanks for the input!Quote from: evb149 on May 04, 2015, 05:20:15 amThanks, evb149. Lots of info for me to digest. I know 100% success rate is unreasonable. My bar is: more good ones than bad ones.I have to digest the details of your post. It is too interesting to merely gloss over reading it just once.Thanks.Quote from: redshift on May 04, 2015, 05:21:28 amThat is encouraging that .65 pitch is possible. How long did it take you to get that far?Or may be a better question is, how many PCB have you made before you get to the point that you try and then succeed in making .65 pitch? By success, I suppose I mean better than 50/50 chance of having a useful board coming out at the end.I will forgo breakout board. I want to get the sense of accomplishment of "doing it myself". Using the breakout board defeats that.I only have a 4x loupe for magnification (and my reading glasses) and no hot air station either.I think if I can do .65mm, I can be happy. I don't have a .65mm pitch project in mind yet however.ThanksQuote from: Cloud on May 04, 2015, 05:21:35 amInteresting. I had thought toner transfer is the better method. I think I used photo method before.Over 20 years ago when I last was interested in doing EE, I etched my first PCB taking the layout from a magazine. I only recalled it worked but I have no recollection how I etched that. (Funny how the brain works. I recall the drive to Radio Shack to get the stuff, and the tray I used to etch, but I actually do not recall how I did the etching and not even remember what circuit it was! But I can picture that white tray in my mind just now, and picture my squarting down at the store inspecting the bare copper side of the PCB to select the one to purchase at the store... Strange)I have to keep that in mind. May be if I do decide to give etching a go, I have to research present day photo sensitive PCB etching.Thanks

author: Dago
author_rank: Frequent Contributor
timestamp: May 04, 2015, 07:01:47 am
content: Why do you want to make your own PCBs? Practically nobody makes their own PCBs anymore because you can get professionally made 2-layer PCBs (10 pieces, 50x50mm) for 9,99$ from China. 4-layer boards are like 25$.Photosensitive board is definitely the better method. You can easily make boards for 0.5mm pitch. It is pretty useless though because there is no good method for making vias, other than making "huge" holes and soldering pieces of wires there. I never got the toner transfer thing to work well or reliably.

author: lapm
author_rank: Frequent Contributor
timestamp: May 04, 2015, 07:09:09 am
content: Becouse there are times you dont want to wait couple weeks to get prototype going. Its art form thats is fading how ever...

author: tautech
author_rank: Super Contributor
timestamp: May 04, 2015, 07:40:40 am
content: 15 mil tracks and 10 mil clearances is as fine as I'm happy to go for reliable results.Do give it go, for us that mucked with Dalo pens years ago, CAD and TT is very rewarding.Plenty of threads if you hunt for them, a recent one:https://www.eevblog.com/forum/projects/pcb-at-home-guide/

author: tggzzz
author_rank: Super Contributor
timestamp: May 04, 2015, 08:30:30 am
content: You should carefully distinguish between designing and manufacturing the PCB and assembling the components on the PCB.Manufacturing the PCB at home is, of course, possible. The major limitation in my limited experience is the quality of the etch resist - imperfect resists means the tracks will be pitted. Using the laser toner on grotty paper method, it is just about possible to get a single track between the pins of a 0.1" pitch through-hole IC. I will continue to use toner transfer if I need a medium complexity board fast; if I need a tiny board I will use a dremel/cnc, and for most boards I will wait 10 days for a 10 cheap boards from China (and visually inspect them carefully!)Assembling the components onto a PCB is much easier; SMD 0.5mm/0603 is easy with cheap equipment, as I have described here:https://entertaininghacks.wordpress.com/tag/smd/(note the split into designing, manufacturing, assembling and reference material)

author: tautech
author_rank: Super Contributor
timestamp: May 04, 2015, 08:55:05 am
content: Quote from: tggzzz on May 04, 2015, 08:30:30 amWhat, haven't you heard of modding pads for better clearances or to open other routing posibilities?

author: tggzzz
author_rank: Super Contributor
timestamp: May 04, 2015, 08:57:45 am
content: Quote from: tautech on May 04, 2015, 08:55:05 amOf course! It is more a comment on my ok-but-not-wonderful etch resist.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 04, 2015, 09:03:56 am
content: The limiting factor is often via size and lack of plating rather than line width - you can't go too small with vias as it's hard to get good alignment, and laser printers can have small dimensional errors.

author: ion
author_rank: Regular Contributor
timestamp: May 04, 2015, 09:59:40 am
content: I've not had much luck with thin traces using toner transfer so I've been meaning to move to photo sensitive boards.So far I have only done a couple of exposure tests, but looking at the board right now the lines only start breaking up below 0.4mm.There's also a QFP-32 footprint on the test board and >75% of the 0.2mm wide pads came out fine. I suspect tweaking the exposure time would fix that.

author: Psi
author_rank: Super Contributor
timestamp: May 04, 2015, 11:00:12 am
content: I've done 0.5mm TQFP with press-n-peel blue toner transfer. It was pushing things about as far as you'd want to go.I had to tin the small pcb tracks with solder to bridge some tiny scratches.If you attempt it i'd advise you to make the tracks wider than the gaps because they will side etch. The smaller the track is the worse this gets. For example, a 0.2mm track will end up more like 0.1mm after etch.So, if you want 0.2mm track and 0.2mm gap, make it 0.3mm track and 0.1mm gap

author: redshift
author_rank: Contributor
timestamp: May 04, 2015, 05:43:32 pm
content: Quote from: Rick Law on May 04, 2015, 06:27:39 amI probably had less than 50% success when I tried this. I remember wasting at least a few pcb's but I don't etch boards very often...

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 04, 2015, 05:51:46 pm
content: Quote from: Rick Law on May 04, 2015, 04:42:22 amEven with my horrible setup and the worst process control imaginable i etched a 0.3mm pitch board just recently on a 4 year old photo PCB that was never properly stored.0.3mm should be no problem at all if you have a decent printer.Your printer and paper is the most important piece.I use normal copy paper, no fancy stuff, brush the oposite side of the paper with acetone to set the toner a bit after printing.With decent paper and a good printer 0.3mm is absolutely no problem at all.Edit:Do not bother with toner transfer, that technique is inferior and only for people who are afraid of harmless chemicals(Harmless as long as you wear eye protection)

author: tggzzz
author_rank: Super Contributor
timestamp: May 04, 2015, 06:07:09 pm
content: Quote from: PeterFW on May 04, 2015, 05:51:46 pmInteresting.How does acetone improve the end result? Are there any other tips/techniques associated with that?By "copy paper", do you mean filled, unfilled, inkjet, laser printer paper, etc?QuoteWhat chemicals do you use?

author: fubar.gr
author_rank: Unknown
timestamp: May 04, 2015, 06:47:54 pm
content: I've done 0.65" pitch using the toner transfer method with amazing results.The problem with this method is that you need to find the "magic" combination of printer model, printer settings, toner type and paper.If something of the above is changed, the final result might suffer significantly.

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 04, 2015, 09:22:19 pm
content: Quote from: tggzzz on May 04, 2015, 06:07:09 pmIt does not have to be acetone, you can use a number of solvents.The best i came across is d-limonene (orange terpene, if that is the correct english translation), often sold as label remover.The acetone will increase the opacity of the toner so the layout will have a higher contrast. In turn this gives you a wider exposure time sweet spot.The fuser in the printer will not bake the toner properly, the acetone dissolves the toner slightly and when it evaporates toner settles more dense.I use a brush from the back side because otherwise i will smear the toner because the acetone will dissolve every aerosol pump i haveIf you get the label remover you can just lightly spray it from the top side.Edit:Here is a comparison picture on transparent film, but it has the same effect on laser printer paper.http://www.pixelklecks.de/pictures/solvent50.jpgTransparency film may be allergic to acetone, in that case you have to use d-limonene.QuoteNormal laser printer paper, the cheapest you can get, because the high end may have UV blocking stuff in it and is thicker.But it helps if it is smooth paper but it does not have to be.The draw back is that the exposure time is very, very long.With proper transparent film the exposure time can be 30 senconds, with laser printer paper its about 10 to 20 minutes.If you can, you should use the transparent film but im to cheap for that...QuoteJust NaOH (sodium hydroxide) to develop and Na2S2O8 (sodium persulfate) to etch, both are rather harmless unless you drink it but the same can be said about every cleaning agent in your house.The NaOH is caustic so eye protection is a must, if you get that in your eye, thats bad news.The sodium persulfate needs to be warmed to 40° to etch properly but in turn it is translucent and you can observe the etching process.You can etch with ferric oxide but that is a brown goop, i do not like brown goop.I would prefer another method of etching but that one can only be done outdoors or in a fume hood. Too much trouble...Greetings,Peter

author: Rick Law
author_rank: Super Contributor
timestamp: May 05, 2015, 02:45:28 am
content: Quote from: Psi on May 04, 2015, 11:00:12 amPsi, that is impressive! Beautiful PCB you've made. Fair to say, that is the kind of DYI board that I am hoping I can do some day.I have to rethink what I should do for "before some day". This discussion alerted me I am overlooking something.The boards I have in mind will be mix of thought hole and SMD. The idea of drilling dozens of precision holes could be very difficult with just a drimmel.I had in my mind imagine my DYI board like the production boards I've worked on - in fact, the finished DYI board would not be like that!- I come to rely on the solder mask when soldering the SMDs; it gives me some confidence on my ability easy to reduce or to remove solder bridges. Not having soldered SMD on home made boards, I am not sure exactly what the bare-copper impact would be on my ability to solder them nicely.- Often, I have tiny flicks of solder on the board that I later remove with my sharp tip needle. Without the solder mask, these tiny flicks would be sticking where they fall.- I have in mind I can do two sided, worst cast is doing to boards and glue them together on the non-copper side. How about vias. How about alignment. The idea of just gluing the non-copper side is not as simple as I pictured in my mind.Another thing for sure is that my DYI board will look nothing like say the Adafruit breakout or other production-boards I repaired. So techniques I have practiced on those production boards may no work well on a DYI board, and the end product may not look so good.So, my ideas of how to do it was way too simplistic to begin with. The knowledge you folks brought to the table is waking me up a bit.I just saw the expected road block (small pitch) and lost sight of the other difficulties.Still I am itching to try. I have to think it some more. I now know for sure the ADS1115-using project should wait - it is not a case of print/toner-transfer/etch/solder and done. I had hope toner-transfer would be easy. From what I learned here just now: It still may be easy but would be more limiting and likely not for VSSOP until I get very very good with etching it and drilling it and...With the project that needs ADS1115 put aside, now I've to first find myself a project that uses larger than .65 pitch for the first go. I also need to do more learning before I hit this. So, for now it is on hold - till I found something else interesting that is > .65 pitch.Thanks guys, for the very educational responses you have given me. Thanks again!Rick

author: tautech
author_rank: Super Contributor
timestamp: May 05, 2015, 07:59:08 am
content: I've never tried a double sided board.Just the odd wire link were a trace would be.It's a great challenge IMO to route a SS PCB, I'll spend considerable timeuntill routing options are exhausted, some overcome with TH components to provide routing pathways. Don't be too precious and do mix SMD and TH to make a PCB "work".A good SS PCB is the holy grail, shown mine to a Dr of EE and have been highly commended.From there the etching is easy by comparison, only the TT artwork reproduction is the tricky bit.No room for error, if it doesn't look perfect, scrub it off the PCB and try again.Your 5MP shoud be OK, I used a 6MP (600 dpi) untill I wasn't happy with the "blackness" of polygon pours.Some porosity on pours can be tolerated, but for traces 15 mil or less NO.Finding the "right" combination of printer, paper and transfer method is critical to good results.I thought I "had" it untill I changed to my OKI 1200 dpi printer and had to rework my methods again.Home laminator for TT, in the card carrier, 2 passes.I did use persulphate but changed to HCl and peroxide for re-useability and lesser cost.Now I can etch cold and always in a home made air bubble etching bath.Aquarium air pump pushing into a needle perforated tube horizontal in the bottom of the bath.PCB suspended in "gutter guard" plastic mesh for easy removal and checking of progress.Recent PCB with a new etch batch was 2 minutes flat, 1 oz copper SS.Again artwork reproduction is the key.

author: Psi
author_rank: Super Contributor
timestamp: May 05, 2015, 08:19:47 am
content: You're far better off learning how to use a PCB CAD package and paying the $10 to get the PCBs made from Elecrow or similar company.You're also right about home made multilayer pcbs being hard to align and then drill out. It really is quite annoying and time consuming.When it cost like the same as a few coffee's to get PCBs made you really have to ask yourself, "do i really need to make these myself"

author: tggzzz
author_rank: Super Contributor
timestamp: May 05, 2015, 09:06:52 am
content: Quote from: Psi on May 05, 2015, 08:19:47 amA double-sided laser toner board is relatively easy to align. Put ~four fiducial "standard" size holes in easily recognisable places. Use sticky tape to hold one side's paper in position, and drill through those fiducial holes. Then position the other side's paper over those holes, tape, and put through a laminator or iron in the normal way.Without trying hard, I achieved positioning accuracy of <1mm across a 75mm board - i.e. the holes were within the pad on both sides of the board, albeit not centred.

author: redshift
author_rank: Contributor
timestamp: May 05, 2015, 02:33:22 pm
content: You said you're concerned about turn-around time. So I thought of another method you may be interested in.PCB Plotters/Routers are a quick and cheap way to make pcbs. They use a subtractive process where a moving drill cuts around both sides of the traces into the substrate. Having traces widths of even 0.01" are very possible. Double-sided boards are ok too they just take a bit of aligning. You still don't end up with solder-mask or plated vias, but you don't get those with etching either.These machines are expensive(for individuals), but perhaps if you live near a university or hackerspace they might let you use one.

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 05, 2015, 06:00:26 pm
content: You can etch double sidet in one go, just buy photo board with copper on both sides.About the soldering... the lack of soldermask is no problem.Soldering SMD components is as easy as on normal boards, even a bit better because too much solder will just flow away instead of piling up on the pad.Here is a crappy picture of the first board i ever made years ago and my first attempt at smd soldering, but this one is not etched at home because it is double sidet and i gave up after a few triesBut as you have pointed out, you should think about why you want to etch your own board.I only work with SMD parts and only do single sidet boards.No drilling, no alignment issues and no jumper wire mess.Most times you can get away with single sidet boards when you make it big enough, if you use 1206 passives you can easily get a wire between the pads but i dont do that anny more.There are maybe a few jumper wires from time to time but thats it, just a couple of mounting or connector holes to drill.You can make "semi double sidet" boards, you route just one side and use the other one as one big ground/power plane.Every via gets a little hole drilled, wire and soldered on both sides.Of course you need a FR4 board with copper on both sides.And i only make those boards because it is faster, way faster, i dont like soldering on proto board with smd parts, it is just a mess.I only make small boards to test out parts or circuits.That way when i order a proper board i have nerly all the problems solved allready.

author: con-f-use
author_rank: Unknown
timestamp: May 05, 2015, 09:11:42 pm
content: Smallest component I've ever had on a home-made PCB:NOA1212(CUDFN6). Success rate was 6 out of 7 though I thing on failed because I burned the IC not because the traces were bad.My process is optimized for speed and also uses Blue Press'n'Peel toner transfer sheets. It is doable but not for a noob and not with the cheapest materials.

author: kingofkya
author_rank: Regular Contributor
timestamp: May 05, 2015, 09:34:03 pm
content: Check out this channel he was doing some interesting tests with home etch stuff.

author: Rick Law
author_rank: Super Contributor
timestamp: May 05, 2015, 10:37:14 pm
content: Quote from: PeterFW on May 05, 2015, 06:00:26 pmNow that is one good looking board. I am impressed!I have to rework my approach in my mind. I think I will try some, but I gotta figure out what I am trying to accomplish beside "yeah, I made that".

author: jeff.remus
author_rank: Contributor
timestamp: May 06, 2015, 12:17:13 pm
content: Soldering surface mount is far easier than leaded parts. Use swipe solder techniques learn from OEM videos only. Hot air is for removing components with exception to BGA and don't forget to get a copy of IPC-7711/21 and don't let amateur teach you bad habits

author: nukie
author_rank: Frequent Contributor
timestamp: May 07, 2015, 02:49:00 am
content: I used toner transfer mostly but often limited by pitting of large area and I got sick of patching these area with permanent marker. There is a limit to toner transfer method for fine pitch traces. Then one day I found a cheap new Lexmark printer suitable for mod and I moved on to Direct Laser Printing. Thanks to Mark on instructables. super fine pitch no problem. DLP isn't as simple, you need acetone to 'bake' the toner on to the copper.Etching speed is very important. I tried many methods. Slow speed will result in under etching which you don't want. I use Hydrochloric and Hydrogen peroxide. It would eat the copper in around 5 seconds. The fastest possible method will result closest to the printout. That's my experience.When I prototype I use only SMD, waiting for my board to arrive from a fab takes too long. With DLP it's just at max 30 minutes for a board.

author: Psi
author_rank: Super Contributor
timestamp: May 07, 2015, 03:03:34 am
content: Quote from: nukie link=topic=47277.msg668123#msg66812330 min plus hours of drilling holes and joining vias

author: Rick Law
author_rank: Super Contributor
timestamp: May 07, 2015, 05:18:36 am
content: Quote from: Psi on May 07, 2015, 03:03:34 amI think my inexperience is allowing me to vastly under estimate the complexity of this tasks the first time around.I think I may try this first: make a few SMD to through hole adapter/breakout. Like a sot-223, so-8, something like those. An adapter will have short and simple traces with nothing much to debug (or to check) - just the pads to holes to mount it as through hole. That will give me more ideas on how to proceed with the (slightly) more complex - bonus is the end product is actually something useful.For the more complex boards, I would likely use those proto-board maker.Any suggestion for good freeware software to do the layout for those proto-board?WinXP preferred.Ahem, for me, a relative newbie, complex means > 20 components.ThanksRick

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2015, 05:43:20 am
content: Quote from: Rick Law on May 07, 2015, 05:18:36 amNot at all. I wouldn't at all call myself "experienced". Just done enough to get mostly reliable results.The smallest, finest I've done is SOT-23/6 and got a 15 mil trace to each center pin from underneath the package. SOIC is relatively straight forward, even 3 or 4 traces to pins from underneath.Never done 0603, had no need to, 0805 good enough for my needs.Most of my methodology has been gained from the many sites on the net on the subjects of etching and toner transfer. Study up and mod the processes to suit the gear you have.Starting again I'd go for Autotrax (DEX) @ US$39 to EEVblog members.Good on you for persisting, you have to give a go to find out.

author: tggzzz
author_rank: Super Contributor
timestamp: May 07, 2015, 07:57:20 am
content: Quote from: nukie on May 07, 2015, 02:49:00 amHow do you do that? I use acetone to remove etch resists?QuoteWhat concentrations? It is relatively easy to get hold of strong HCl, but concentrated H2O2 is difficult to obtain.

author: tggzzz
author_rank: Super Contributor
timestamp: May 07, 2015, 08:00:21 am
content: Quote from: Rick Law on May 07, 2015, 05:18:36 amI use DesignSparkPCB and other tools for the reasons outlined here:https://entertaininghacks.wordpress.com/2015/03/25/designing-pcbs-with-surface-mount-components/It is a Windows tool, but I manage to run it under Wine

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2015, 08:12:00 am
content: Quote from: tggzzz on May 07, 2015, 07:57:20 amMy 2 main PCB etching reference documents from the net, sorry link lost and forgive me for not crediting the author.Etching has a few of my notes on last page.

author: tec5c
author_rank: Frequent Contributor
timestamp: May 07, 2015, 08:24:19 am
content: This guy has a few videos where he etches a board with 0.5mm pitch. His end result is one of the best I've seen for a home made board.

author: BradC
author_rank: Super Contributor
timestamp: May 07, 2015, 11:35:06 am
content: Quote from: Psi on May 07, 2015, 03:03:34 amActually, with a Proxxon TBM-220 I've never spent more than 30 mins drilling holes, and stitching vias is now about a 10 minute process.I use .2mm wire and .35mm holes for the vias and just stitch them together like sewing (ie, in one length, up - down - up - down) then just solder them both sides and cut the wires with an X-acto knife. Makes tiny, thin vias that comfortably sit under SMD chips.I don't doubt I'd be _loads_ better off getting boards made externally, but I can have a prototype up and running in hours if I need something in a hurry.I'll admit, before the Proxxon and the via techniques it took a _lot_ longer, but once I figured it all out it's a breeze. I tried .2mm holes with the Proxxon, but I just kept snapping bits.I just do toner transfer with a modified $20 laminator and Pulsar-Pro paper. I aim for a minimum of 8/8 mil and typically do 10/10, but I can comfortably get to 6/6 if I need to go between pins on an SOIC.Practice makes perfect, and homebrew makes versatile and quick.

author: Rick Law
author_rank: Super Contributor
timestamp: May 07, 2015, 05:43:31 pm
content: To all of you folks replied:You guys are great! I have learned a lot and have pointers to resources that will permit me to learn even more!I sincerely appreciate your input!With much thanksRick

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2015, 08:17:13 pm
content: Quote from: BradC on May 07, 2015, 11:35:06 amThat's impressive.Printer?@ RickDrilling can be a challenge, much less so with SMD.For the few I do I've only needed HSS bits .6, .8, 1.0 mm and a Dremel in a Dremel press.Quite slow speed, first or second step on.Centering can be a problem, HSS bits will wander but set hole size for ALL holes in the artwork package to 0.5 mm (20 mil) and this helps keep the drill in the center of the pad.Even mounting holes, place a pad, set hole size @ 0.5 mm and pad size small enough to be completely removed by the drill.BTW for a start I'd recommend you use PP PCB, much cheaper and easier to work woth than FR4.http://www.ebay.com/itm/4pc-PP-Blank-PCB-board-100x200mm-t-1-6mm-1-oz-1-side-RoHS-NAN-YA-Taiwan-or-Equal-/130860759993?pt=LH_DefaultDomain_0&hash=item1e77e8bbb9

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 07, 2015, 09:07:57 pm
content: Quote from: tautech on May 07, 2015, 08:17:13 pmUsually you go for the highest RPM possible, why on such a low setting?I only drilled very, very few holes with HSS i use carbide bits at 30K RPM, but even with HSS the best resulsts are achived with the speed cranked up to elven.If you use eagle you can run the "drill-aid.ulp", this fills very via and pad and leaves a small drill guide hole.I set it at 0.3mm, this way the drill will not wander off and i can use big pads.

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2015, 09:28:18 pm
content: Quote from: PeterFW on May 07, 2015, 09:07:57 pmNo, usually you go for high RPM.I've done a fair bit of engineering in my time and experience has taught me to feel for the correct speed for the material drilled and the drill used.The very small HSS bits are much longer than Tungsten and DO oscillate at high speed. This affects accuracy.Most of the hobbyist PCB's I make are with PP (Paper Phenolic) that is MUCH softer and kinder on drills. I've probably done 1000 holes with 1x 0.6 mm HSS drill for a fraction of the cost of a carbide drill.I do concede quality of your drill press will have a influence on the speed you can run drills at.

author: BradC
author_rank: Super Contributor
timestamp: May 08, 2015, 12:24:07 am
content: Quote from: tautech on May 07, 2015, 08:17:13 pmHP2200, but with original toner. I keep a genuine HP toner cartridge in a bag to use when I do toner transfer, then I just swap the $30 refill back in. The toner absolutely makes a difference.

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 08, 2015, 12:42:44 am
content: Quote from: tautech on May 07, 2015, 09:28:18 pmAh... yes. That makes sense.I only got a 1/4 collet so HSS drills only go into the cordless drill when something goes wrongQuoteWell... i get those carbide bits for about <4 Euros, a decent HSS drill is not that far off that price point.But yes, unless you have a stable drill press those .6mm carbide bits will not have a long life, HSS is much more forgiving.I settled for FR4 since i allready had a small semi-stable mill that can be locked and has a return spring for drill operations.I hate FR2/Phenolic/Paper boards, i hate them with a passion

author: nukie
author_rank: Frequent Contributor
timestamp: May 25, 2015, 10:23:16 am
content: To bake toner powder onto PCB, use a glass container with some standoff. The PCB should float on top of Acetone with the container covered. Let the Acetone vapor do its work.I use 40vol hydrogen peroxide for hair bleaching. The additives isn't a problem its only slightly foamy results.Drilling isn't a problem I use thin PCB under 0.8mm. I usually do single sided and mostly SMD so sometimes I don't even need to drill. Due to space constraints I use 0402 regularly. My prototype boards are mostly 3 inch diameter and under.Quote from: tggzzz on May 07, 2015, 07:57:20 am