Best One-Off DIY PCB Creation Technique

Question

I have finally built up a lab to design electronics in. I have quite a few designs I would like to test. I have tried the printer toner/iron technique a few times but have found that I cannot create small pitch sizes as they tear off while removing the printer paper. A few people have mentioned that this is due to using a Samsung laserjet versus a HP.

I am wondering what methods you use to develop PCBs for one-offs in your lab or at home (like me). I am trying to fast track a move to SMT/SMD components and would like some tips from seasoned experts on the best PCB creation methods to test board concepts before sending them off to a PCB MFG. I would like something that balances cost, time, and beauty of the finished product geared towards a hobbyist (at this point) and geared towards SMT/SMD components.

Please include pics/documentation of your preferred method. Thank you in advance for your post.

Answer 1

For one-offs or prototypes I use:

• Press-n-Peel transfer film with a laser printer (the blue one)
• Steel wool and detergent to clean the PCB blank, then a short etch in ammonium persulphate: that gives a very clean surface, important for a good transfer from the film
• A laminator to transfer the pattern to the PCB; I modified the laminator to raise its operating temperature a bit, and the PCB is a bit thick for the laminator but it works
• Ammonium persulphate made with hot water in an ice-cream container, and that sits in a bath of hot water (a larger ice-cream container)

This gives good results down to 10 mil trace widths; could probably go finer but haven't needed to yet.

For double-sided boards I tape the two layers of Press-n-Peel film to two scraps of PCB at the edges so that I can get the two layers well aligned, then put the PCB blank in and feed it through the laminator. Here are some pictures to illustrate:

The bottom (left) and top (right) of a simple double-sided board (the top one is printed out mirrored so they overlay when its turned over). Normally I would print onto the blue Press-n-Peel film, just using paper here for illustration.

With one side taped to the scrap PCB (left side) and the printed sides facing each other, hold them up to the light and align the other one so that all the holes and the board outline line up.

Here they are both stuck to the PCB scrap. You can now put the clean blank PCB between the two (probably best to tape it to both sides to avoid any movement) and run it through the laminator (or iron it) to transfer the toner onto the PCB.

You can tape the two pieces of film or paper together without using the scrap of PCB, but when you put the blank PCB between them you can get some relative movement as they flex around the thick PCB. With the scrap piece the same thickness as the blank PCB they stay in the right place.

A bench drill is good for any drilling. I use drills down to 0.5 mm diameter but with 3 mm shanks so they are easily held in the drill chuck.

For through holes I solder thin copper wire to the pads on either side. The wire comes from a multi-core flexible cable; individual strands are or about 0.2 mm or 8 mil diameter. This takes some time!

And to solder I place solder paste with a fine-tipped syringe, place parts with fine tweezers then reflow in an electric frying pan. A few more pictures:

Syringing solder paste onto SMD pads.

Placing component with tweezers

A finshed board - the PCB was professionally made but I assembled components and soldered as described here. These are 0402-size resistors and capacitors (quite small, amazingly easy to lose), an accelerometer in a QFN-16 package (4x4 mm) and a memory chip in an 8 pin leadless package, similar size to a SOIC-8. (This is part of a small accelerometer data logger, see vastmotion.com.au).

Good luck!

Answer 2

Unless you're on the tiniest of tiny budgets, just have the boards professionally fabbed.

Really, you can get such a good deal on PCBs, with suppliers like:

• 33Each.com — 60 Square inches, double sided, 6/6 spacing. $33 ea, minimum order: 4 (1 if you have a university address)
• GoldPhoenix — Good for bigger runs, cost varies depending on requirements.
• ExpressPCB — 3 boards for $51 total, double sided, no soldermask or silk, rigid size requirement of 3.8 × 2.5
• AP Circuits — No personal experience, see comments below.
• Sunstone Circuits — As cheap as $28 for a prototype. Fast and good quality, I've never had a problem (From Garrett Fogerlie).
• OSH Park — $5 Sq. In double-sided, $10 Sq. In, 4 layer. Boards come with purple(!) soldermask.

On the whole, I've found that (for me, at least), it's just completely not worth it to try and make my own boards, when I can buy a much nicer board or ~$50.

Also, with most professionally fabbed boards, you get all the niceties, like soldermask and silkscreen. Having a soldermask makes soldering small pitch components far easier, and the silk makes populating components much easier, particularly when boards get large.

How much is your time worth to you?

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Edit: Removed BatchPCB from the list since they no longer exist (sold to OSH Park in 2013).

Answer 3

I get excellent results (down to 8/8 mil) using the photo-etch technique. I use a cheap HP 5940 inkjet printer with Mega Electronics JetStar Premium film for the transparencies with pre-coated positive resist boards, exposed in a home-made UV exposure unit. Boards are developed in sodium hydroxide solution and etched in ferric chloride in a small plastic container in an old washing-up bowl with about 1" of very hot water in it. The small container is agitated manually, and etching takes about 5 minutes. I can make a board in about 20 minutes, not including drilling.

Here is one of my boards.

This group is a very good resource for making PCBs at home.

Answer 4

I'm no seasoned expert but... I have learned from them.

I have the second cheapest Samsung mono printer available and I have no problems with fine traces; I doubt it is your printer.

I have had good success with laminators but someone recently told me this could be dangerous on cheaper models with improper shielding (as the board is highly conductive).

I have returned to ironing for double sided boards as it seems to be a tad more accurate. If you're not getting good transfers try using an electric sander with a very high grit rate to get it much cleaner than any abrasive brush can. Then, the most important thing to do when using an iron is to push hard, like really hard and hold it in place for at least 30s at a time. If you have normal glossy paper and can't see the traces, you're probably not ready to soak.

Another thing I have found to help is to have a 2mm or so border around the whole circuit. This then tends to stick first and helps prevent the paper from moving while you are ironing.

Currently my kit features the following items:

• Tile Cutter (for cutting PCB)
• FFP3 Mask (important if you value your lungs)
• Black & Decker Mouse Sander
• Bubble etch tank (not needed I'm just impatient)
• Wickes 5-Speed Bench Pillar Drill

My new camera arrives today and I intend to launch a "website of journey" as I both learn and experiment with electronics. One of the first videos I will put out will be my PCB production process.

Answer 5

I have just finished creating a tutorial on how to build a Bubble Etch Tank (unheated), at home, with minimal cost and effort. Hopefully this will be helpful to someone:

1. What You’ll Need
2. Plumbing the Air System
3. Making Bubbles
4. The PCB Basket

I'd recommend increasing the resolution to 720p but of course, this is optional.

I'll be adding further updates (such as seeing the tank in action) at 13 Volts fairly soon.

Answer 6

I would vote for cheap Chinese off-shore, too. iteadstudio.com can make 10 boards 50x50mm for $10, and 3-day air shipping for the order is < $30. Total turn-around time is a tad over a week. I hear that seeedstudio.com is very similar (and may actually be using the same PCB fab.) You get solder mask, silk screen, vias, plating, the shole shebang. The only draw-back is they can only do 1 oz copper thickness, and they aren't very precise at tiny pitches (8 mil is their minimum.)

For doing my own, I would recommend against the CNC mill route. Yes, it's nice that you can drill the same board you mill, but the milling generates glass dust that's really bad for your lungs, and it easily breaks the tiny bits you need, and the edge finish is kind-of ragged and not trustworthy for small pitches. Instead, I would go with UV-based photosensitive coated boards. Laser print the mask (inverse) on transparencies. Expose on a UV bed (can be built yourself if you really want to.) Develop. Etch.

Then, that CNC mill may still come in handy, for drilling the board :-) You're still not going to get through-hole plating, vias, etc, this way.

Answer 7

Thanks to everyone so far for your answers. I believe I have made a decision concerning future circuit board design. I have been doing some crazy research and ran into a piece of equipment that I believe might be the best route. It is not only eco friendly but useful in many other ways. Props have to go to Brian for triggering the research that led to the epiphany.

Instead a dealing with chemicals which requires disposal, time, and is not ideal since I live in a condo, I have decided to build a CNC Mill. There are numerous tutorials out there and it appears one can be built for ~$500 (or less if salvaged parts are used). Here are a few links I have found so far.

Instructables

Engaget (1of3), (2of3), and (3of3)

The mill would not only serve the purpose of removing the copper but can also be used to build a solder mask. This would enable easier SMD/SMT manufacturing using the skillet reflow method.

I plan on doing further research to see if a 'combo' cnc machine can be put together which also takes advantage of the RepRap 3D plastic printer. Imagine the possibilities of this killer combo. You could fabricate almost anything and it should cost under $1000.

Answer 8

I wasn't getting reliable results ironing on toner transfer. I modded an old waffle iron - named the PCB Press. I like the ability to produce a prototype board at home in under an hour. If I need something of professional quality I send the tested proto out to fab house.

Answer 9

As this was just flagged as a duplicate of a just closed question:

I have just uploaded a 30 page group discussion on the toner transfer method
to this dropbox file <-- FAR superior format compared to copied version below.

Have a read through there and come back and ask relevant questions if it seems to be of use.

I've posted the first 40% or so below to stop this being a link only answer.
For those interested in this method I strongly suggest you access the complete and better formated dropbox document. There is such a vast range of material from many people in this invaluable document that it's very worth looking at.

Edit: Link updated March 2024

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From: V G x.solarwind.x@gmail.com Date: 20 March 2011 10:15 To: PICLIST piclist@mit.edu

Hi, I like the idea of direct to PCB resist printing, but don't really have the time to modify my own printer. Does anyone know of where I can get a pre-modified printer for this purpose?

http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist

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From: V G x.solarwind.x@gmail.com Date: 22 March 2011 06:38 To: PICLIST piclist@mit.edu

Hm. I guess not :(

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From: Michael Watterson mike@radioway.org Date: 22 March 2011 06:58 To: "Microcontroller discussion list - Public." piclist@mit.edu

Photo exposure is better.

Iron off laser toner next best. Discussed previously here

Any other print solution will be poor

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From: V G x.solarwind.x@gmail.com Date: 22 March 2011 08:53 To: "Microcontroller discussion list - Public." piclist@mit.edu

Sorry for not trimming, replying from phone.

You say photo exposure is best. Would you still say it's the best if the method is using positive photo resist spray and developer? Or is it only good when using pre-sensitized boards?

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From: Michael Watterson mike@radioway.org Date: 22 March 2011 09:10 To: "Microcontroller discussion list - Public." piclist@mit.edu

Never used the spray on. I imagine the board needs to be very clean. polished and degreased just prior to spray.

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From: Byron Jeff byronjeff@mail.clayton.edu Date: 22 March 2011 11:32 To: "Microcontroller discussion list - Public." piclist@mit.edu

This is a current topic of interest for me. Basic parameters:

1. Single sided, one off, SMT boards for hobby prototyping. So occasional processing (not too complicated) and ultra quick turnaround (the faster, the better, ideally 1 hour or less) are at a premium.

2. Most likely targets are SOIC, 0805/0603 type parts.

3. KiCAD is the development target (may or may not be relevant)

What is the best method using the following priorities (in order):

1. Speed from printing of design to population ready.

2. Process repeatibility both in terms of producing a correct board with the process and producing repeat boards using the same process. Presume that this is the occasional hobby board, not a production setup.

3. Cost per board.

In short if I could print chips directly onto the PCB, that would be great. Impossible, but great. Right now I'm looking at using a PCB hot plate type setup for soldering. So the faster I can get setup, the faster I can get finished.

I'm planning on testing both the Toner Transfer and the Photo resist with precoated boards. Both seem to be about the same amount of time in terms of speed. Overall the TT method seems to be cheaper as precoated boards seem to run about 3x the cost. So it seems to me that the real question is process repeatability.

Thoughts?

BAJ

Byron A. Jeff Department Chair: IT/CS/CNET College of Information and Mathematical Sciences Clayton State University http://cims.clayton.edu/bjeff

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From: Bob Blick bobblick@ftml.net Date: 22 March 2011 11:43 To: "Microcontroller discussion list - Public." piclist@mit.edu

Hi Byron,

I've tried using an XY pen plotter directly to PC board and never got good enough etch resistance. All over the net there are recommendations for the RED Staedtler Lumocolor pens but even they are not good enough.

I have used spray-on photoresist. It's OK except for the hairs and dust. In other words, not good for fine pitch because you will have bad spots.

Laser toner transfer is sensitive to your ironing pressure and temperature. I always print a border around my artwork to act as a pressure buffer. It seems to even out the pressure near the edges. Fair to good results if you have finesse. Prepare for lots of do-overs and some touchup before and after etch.

Presensitized board works really well. No question, this is the way to go if you want quality. And unlike the other methods it takes very little talent. Your first board will be good and every one to follow.

I tend to do toner transfer because I am drawn to how immediate it seems, and the fact that you don't really need any consumables. But then after I have ironed on and cleaned off the same board three times before I get a transfer good enough to etch, I rethink my choice of technology, wishing I'd used presensitized board instead. And it's not like there are no consumables, I use acetone to clean the board and lacquer thinner to remove the toner.

Note to self: Since I don't make more than a dozen boards a year I should always use the presensitized board.

Cheerful regards,

Bob

-- http://www.fastmail.fm - A no graphics, no pop-ups email service

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From: Byron Jeff byronjeff@mail.clayton.edu Date: 22 March 2011 12:41 To: "Microcontroller discussion list - Public." piclist@mit.edu

Bob,

This analysis was extremely helpful.

I started working my way through the presensitized boards the last time I was on this roller coaster but did not complete the job. Let me run a brief description of what I have read and see if there are any errors in my thinking:

1. Print mirror of circuit onto transparancy sheet at max toner setting.

2. Bind sheet face down (and flat) to presensitized board. Cover with real glass as it is transparent to UV. Do this in a low light environment.

3. Expose assembly to UV light. Sunlight will work but a UV light box is better. Mine is a black light installed in a toolbox. Never got a clear number on exposure time. Seems to be trail and error but consistent once you get it to work.

4. Peel the transparancy and there should be a outline image of the circuit on the board. Run the board through the developer (some say caustic/washing soda is OK, others hate it. Suggestions?) until the exposed parts a removed. Do not do it too long or risk undercutting the solid unexposed resist.

5. Etch the board.

6. Remove the rest of the photoresist. A bit unclear here. Is this a light and develop a second time step? Or a physical process

Should be ready to shake and bake after this.

On this recommendation, I will attempt this method first. There seems to be repeatability issues with the toner transfer method.

Thanks for the input.

BAJ

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From: Oli Glaser oli.glaser@talktalk.net Date: 22 March 2011 12:21 To: "Microcontroller discussion list - Public." piclist@mit.edu

I agree totally - I have used spray on photoresist (messy, difficult to get even and contaminant free) and Toner Transfer (good, but not as accurate/repeatable as photoresist) With hot etching fluid and agitation you will get fast etching times (~5min) and near board house resolution (we get down to around 0.2mm trace width) after a little practice. Worth investing in a UV light box that gives even exposure, and a decent heated etch tank. However you can get good results with a tray in hot water and a source of UV - I used an old sunlamp to start with, worked perfectly.

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From: AK 00@case.edu Date: 22 March 2011 12:21 To: "Microcontroller discussion list - Public." piclist@mit.edu

When using 'scuffed' shipping label backing and a laminating press, I've found toner transfer to be very reliable and precise, even using it for some small BGA work.  Posted more details here a long time ago, if you're interested.  The good thing about using the mailing label backing is that it peels right off, no soaking, scrubbing, or developing needed.  Just my experience.

Andrew

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From: IVP joecolquitt@clear.net.nz Date: 22 March 2011 12:30 To: "Microcontroller discussion list - Public." piclist@mit.edu

I'd agree with that. The human component is the important variable. Repeatability and detail is there for the getting

Take these examples

PIC + quad amp + 0805 R and C. Very small text under the 'JC 3.11' is my note for the board size. It is just about readable (if you know what it's supposed to read. FWIW it says, mirrored, 1.85 x 2.65  4.70 6.74 @ 600 dpi)

http://home.clear.net.nz/pages/joecolquitt/DIP+SMT.jpg

Printout (0.1" pitch pads)

http://home.clear.net.nz/pages/joecolquitt/detail.gif

Result (a little out of focus, better looking in reality)

http://home.clear.net.nz/pages/joecolquitt/detail.jpg

I read one person's account where he uses a hot-plate with a weight to apply a known pressure for a known time. That's something I'd like to investigate. My gauging of iron pressure is fairly good and but I'd rather it be controlled, for a more consistent Toner Squash Factor, which causes holes to shrink and tracks to widen. That said, SOIC 0.05" pitch is quite easily achievable

Joe

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From: Oli Glaser oli.glaser@talktalk.net Date: 22 March 2011 12:43 To: "Microcontroller discussion list - Public." piclist@mit.edu

Tracing paper works just as well (and is cheaper) The UV gets through fine. Varies with power of light (and I think resist type, so try to stick to one) so a bit of trial and error - Good idea to print a small test board, consisting of traces (with corners) from 1mm down to 0.1mm, a few SMD footprints (TQFP, QFN) and some through hole pads with thin annular rings. Expose a few of these, gradually adjusting time and note down what works best. I use Sodium Metasilicate, it is a lot better than Sodium Hydroxide (Caustic Soda) You don't have to get the timing so accurate (i.e if you leave it in a second too long it won't strip the resist off) Either - you can shove it under the light again then rinse in developer (I do this way) Or I think some folk just use an abrasive pad to clean it off, which I do anyway afterwards to clean the copper, then run a bit of isopropyl alcohol over it. You can actually leave it on too I think - IIRC some resists act as a flux, check the info/documentation on whatever board you buy. Never tried it so not sure how it compares. The steps you outlined look about right overall to me - this is a good page on board making I found very helpful to begin with: http://www.electricstuff.co.uk/pcbs.html

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From: Bob Blick bobblick@ftml.net Date: 22 March 2011 12:58 To: "Microcontroller discussion list - Public." piclist@mit.edu

I would verify if the density setting actually does anything. Every printer is different and on mine it was turning off "economy".

Also you can use cheap 20 LB paper in a pinch if you don't have transparencies.

I've been told inkjets work OK too, in high quality mode. I've used glass and plexiglass and not noticed a difference. I thought glass blocked more UV than plastic?

I have had problems peeling it off afterward. The toner sticks a little bit. Sunlight is nice because it is very much like a point source and you can put the printed side out and still get focus. But if you already made a mirror image that won't work because everything is reversed.

Timing sunlight is near impossible. I made a cumulative timer but never got the right sensor/filter combination to match the sensitizer.

With a UV box you must get your transparency touching flat on the board everywhere.

Timing is trial and error, but it is pretty forgiving, 2:1 once you get in the window. When I was teaching we made our own solution with lye. That was before it got recognized as a component to make meth and consequently harder to find. Now I use the recommended developer. I am a big fan of lacquer thinner, it removes almost anything.

Cheerful regards,

Bob

-- http://www.fastmail.fm - mmm... Fastmail...

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From: Bob Blick bobblick@ftml.net Date: 22 March 2011 13:04 To: "Microcontroller discussion list - Public." piclist@mit.edu

Yes, I remember your suggestion about label backing and adopted it, thank you.

All it takes is to ask someone who uses a UPS printer and then you have an unlimited supply of backing paper :)

A laminating press would make a big improvement, I'm sure it would make my boards lots more consistent.

Best regards,

Bob

-- http://www.fastmail.fm - Send your email first class

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From: Sergey Dryga sergey@dryga.us Date: 22 March 2011 17:31 To: piclist@mit.edu

Both glass and some plastics absorb UV, but at the thickness tipically used (~1 mm for glass) the absorbance is not too high.  More important is that the glass is "optical quality", without swirls. I used a fluorescent lamp at 15-20 cm from the board/mask/glass stack.  It was while ago, but IIRC 75W lamp is OK.  Some even reported the use of 100W incandescent lamp.  It might not work with all sensitized boards, I got mine from Jameco, the brand is DATAK I believe. I scrubbed with a scrubber/foam pad sold for kitchen cleaning. As last step, 200-400 grit sandpaper and water rinse.  I used purified water for final rinse since tap water often has too many minerals in it (actually I have never tested if just tap water is OK, seems easier to just rinse in distilled water any way).

Sergey Dryga http://beaglerobotics.com

V G x.solarwind.x@gmail.com 22 March 2011 18:45 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu On Mon, Mar 21, 2011 at 7:21 PM, AK 00@case.edu wrote:

When using 'scuffed' shipping label backing and a laminating press, I've found toner transfer to be very reliable and precise, even using it for some small BGA work.  Posted more details here a long time ago, if you're interested.  The good thing about using the mailing label backing is that it peels right off, no soaking, scrubbing, or developing needed.  Just my experience.

Hi. Where do you get label backing paper?

[Quoted text hidden]

AK 00@case.edu 22 March 2011 18:56 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu On Tue, Mar 22, 2011 at 2:45 AM, V G x.solarwind.x@gmail.com wrote:

On Mon, Mar 21, 2011 at 7:21 PM, AK 00@case.edu wrote:

When using 'scuffed' shipping label backing and a laminating press, I've found toner transfer to be very reliable and precise, even using it for some small BGA work.  Posted more details here a long time ago, if you're interested.  The good thing about using the mailing label backing is that it peels right off, no soaking, scrubbing, or developing needed.  Just my experience.

Hi. Where do you get label backing paper?

Generally free as a result of shipping other items, using this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160516738494 [Quoted text hidden]

V G x.solarwind.x@gmail.com 22 March 2011 19:00 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu On Tue, Mar 22, 2011 at 2:56 AM, AK 00@case.edu wrote:

Generally free as a result of shipping other items, using this:  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160516738494

Thanks! Are the label backings better than photo paper as recommended everywhere? [Quoted text hidden]

AK 00@case.edu 22 March 2011 19:43 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu On Tue, Mar 22, 2011 at 3:00 AM, V G x.solarwind.x@gmail.com wrote:

On Tue, Mar 22, 2011 at 2:56 AM, AK 00@case.edu wrote:

Generally free as a result of shipping other items, using this:  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160516738494

Thanks! Are the label backings better than photo paper as recommended everywhere?

I began with photo paper as described elsewhere.  My experience has been that a properly prepped backing transfers more cleanly and with much more ease than paper.  In fact, some sheets I've used multiple times after the transfer.  It's likely that you'll get finer details with a refined optical masking process as described by others, but you can't beat this toner transfer process for speed, cost, lack of chemicals, and simplicity. [Quoted text hidden]

V G x.solarwind.x@gmail.com 23 March 2011 08:52 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu On Tue, Mar 22, 2011 at 2:56 AM, AK 00@case.edu wrote:

Generally free as a result of shipping other items, using this:  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160516738494

This is cool. I asked the guy for samples. Hopefully they work out. [Quoted text hidden]

Ing. Marcelo Fornaso mfornaso@yahoo.com 23 March 2011 10:20 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu I'm a little afraid of using this sheets on my laser printer because their surface looks like plastic...

Don't you think there is any risk of fusing it into the printer?

Marcelo Fornaso

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From: V G x.solarwind.x@gmail.com To: Microcontroller discussion list - Public. piclist@MIT.EDU Sent: Tue, March 22, 2011 5:52:05 PM Subject: Re: [EE] Direct to PCB printing (Inkjet) [Quoted text hidden]

Robert Rolf Robert.Rolf@ualberta.ca 23 March 2011 10:30 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu There are generally two kinds of 'clear plastic' sheets out there.

The kind used for overhead transparencies, which have an absolutely glossy surface, and which WILL melt and destroy your printer, and those that are made of acetate, and which are a bit smoky and have a very fine texture surface for the toner to grab on to.

If in doubt, put a soldering iron to them. The dangerous plastic will melt nearly instantly, and stink, the 'laser' grade will curl but you'll have to apply a fair bit of heat to melt into them.

If in doubt, don't use them.

R

Ing. Marcelo Fornaso wrote:

I'm a little afraid of using this sheets on my laser printer because their surface looks like plastic...

Don't you think there is any risk of fusing it into the printer?

Marcelo Fornaso

[Quoted text hidden]

Bob Blick bobblick@ftml.net 23 March 2011 10:37 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu

On Tue, 22 Mar 2011 15:20 -0700, "Ing. Marcelo Fornaso" wrote:

I'm a little afraid of using this sheets on my laser printer because their surface looks like plastic...

Don't you think there is any risk of fusing it into the printer?

With label attached it is intended to run through a printer. I haven't ever had a problem.

It is too slippery to hold the toner until you scuff it up a little bit with a tissue or paper towel.

I don't run it full letter size through the printer. I attach a piece larger than the design on to a sheet of normal paper using a label at the top of the backing paper. Center the design on the sheet so the leading edge of the carrier paper has nothing additional on it.

Cheers,

Bob

-- http://www.fastmail.fm - A no graphics, no pop-ups email service

-- [Quoted text hidden]

Ing. Marcelo Fornaso mfornaso@yahoo.com 23 March 2011 12:05 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu Ok. I got the idea and will give it a try.

Thank you

Marcelo Fornaso

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From: Bob Blick bobblick@ftml.net To: Microcontroller discussion list - Public. piclist@mit.edu Sent: Tue, March 22, 2011 7:37:54 PM Subject: Re: [EE] Direct to PCB printing (Inkjet)

[Quoted text hidden]

Vic Fraenckel windswaytoo@gmail.com 23 March 2011 12:59 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu Do any of you following this thread know that there is a Yahoo Group "Homebrew_PCB" that discusses most of the issues that you are discussing here?

Check the group out here:

http://tech.groups.yahoo.com/group/Homebrew_PCBs/

Vic

Victor Fraenckel KC2GUI windswaytoo ATSIGN gmail DOT com [Quoted text hidden]

William "Chops" Westfield westfw@mac.com 23 March 2011 13:39 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu

On Mar 22, 2011, at 3:20 PM, Ing. Marcelo Fornaso wrote:

I'm a little afraid of using this sheets on my laser printer because their surface looks like plastic...

Sheesh.  Find someplace that uses laser-printable label sheets.  Or even buy some.  Use any remaining labels as ... labels or something, leaving you with a backing  sheet suitable for this sort of toner- transfer.  Any laser-printable labels will have a non-melting backing sheet; probably silicone based.

Try the library.  Our middle school library prints bar codes on sheets of labels for their new books.  This usually doesn't fill up a sheet, and the software doesn't support exact placement of the barcodes on partially filled sheets, so the remaining labels get stamped with the school name/etc for tagging magazines and such.  Eventually they're all used up and the backing sheet is thrown away.

Some backing sheets are nicer than others.

I prefer the destructively processed glossy magazine paper route. The reason that the label backing sheet works so well is that toner doesn't stick to it.  Which also can mean that it's subject to flaking off somewhere in the process before it gets to your board...

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Professional PCB fabrication services get cheaper and cheaper, and more and more convenient to amateurs.  Batched hobbyist services (batchPCB, dorkbot) have "solved" the minimum board size problem, so that you're no longer penalized for wanting a very small board. Direct-from-china suppliers (Itead, Seeed) are doing the cheap- prototypes (~$20) with long lead time thing so that you're no longer forced to use a high-priced quick-turn supplier for "prototypes."  The only remaining advantage of home fabrication is that simplicity (single sided, 16mil design rules) will get you faster and cheaper. But it's getting harder and hard to justify.

BillW [Quoted text hidden]

V G x.solarwind.x@gmail.com 23 March 2011 16:45 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu On Tue, Mar 22, 2011 at 9:39 PM, William "Chops" Westfield westfw@mac.comwrote: [Quoted text hidden] $20 with shipping and tax compared to a few dollars and instant turnaround times is not hard to justify. [Quoted text hidden]

William "Chops" Westfield westfw@mac.com 23 March 2011 17:27 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu

On Mar 22, 2011, at 9:45 PM, V G wrote:

$20 with shipping and tax compared to a few dollars and instant turnaround times is not hard to justify.

It depends.  Couple bucks for blank copper clad.  Couple bucks for etchant.  Significant bucks for the high-grade ink cartridge (for direct to PCB printing) (which may or may not dry up between PCBs (I hate inkjets!)) or a couple bucks for special transfer paper or transparency paper.  Couple bucks for drill bits.  Couple bucks for tool to cut the PCB material.  Moderate amount for an inkjet printer to modify, or for a laminator, or for an iron, or for a contact exposure frame.  Couple buck for other chemicals, sandpaper, etc.

I dunno.  I've spent a couple $K for an LPKF (mill) to get that "instant turnaround."  But it's not really that "instant", and I'm increasingly uncertain that it was a worthwhile purchase.

BillW [Quoted text hidden]

V G x.solarwind.x@gmail.com 23 March 2011 20:17 Reply-To: "Microcontroller discussion list - Public." piclist@mit.edu To: "Microcontroller discussion list - Public." piclist@mit.edu On Wed, Mar 23, 2011 at 1:27 AM, William "Chops" Westfield westfw@mac.comwrote:

It depends.  Couple bucks for blank copper clad.

Agreed.

Couple bucks for etchant.

That's a one time thing. A bottle will last a LONG time. If you use the HCL/H2O2 method, you can make it last forever and it's VERY cheap.

Significant bucks for the high-grade ink cartridge (for direct to PCB printing) (which may or may not dry up between PCBs (I hate inkjets!))

Or, just a laser printer (that most people have anyway) on label backing paper that you can get for free.

or a couple bucks for special transfer paper or transparency paper.

It'll last you a lifetime.

Couple bucks for drill bits.

Tungsten carbide bits will last you pretty much forever and they're pretty cheap.

Couple bucks for tool to cut the PCB material.

Again, it'll last you forever.

Moderate amount for an inkjet printer to modify, or for a laminator, or for an iron, or for a contact exposure frame.  Couple buck for other chemicals, sandpaper, etc.

Sandpaper costs pennies, most people already have a laser printer, most people have a clothes iron.

I dunno.  I've spent a couple $K for an LPKF (mill) to get that "instant turnaround."  But it's not really that "instant", and I'm increasingly uncertain that it was a worthwhile purchase.

So what you only really need is the copper board. Everything is already lying around somewhere or will last "forever" or costs pennies. [Quoted text hidden]