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Old 2nd Dec 2019, 5:10 pm   #1
Wendymott
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Default PCB Artwork transfer

Hi Peeps... This may have been posted before somewhere by other members but I hope this is not a repeat.
As some of you know, I am an avid user of pcb boards, rather than "deadbug" or similar, even for prototypes. Normally I use Photo resist copper and my own laser/acetate method.
However I came across this article on Youtube in which I became very interested, as it allows use of non photo resist copper and expensive acetate .
Here is the link ..https://www.youtube.com/watch?v=cVhSCEPINpM. THe basic concept is that you use very cheap chemicals and substrate to transfer Toner onto the copper. This method negates the use of HOT things like irons and Laminators, just using "Nail varnish" remover.. or Acetone. I just wondered if any of the members out there had better success than me/I .
I have tried various Glossy magazine papers, Nail varnish remover and Acetone, all with varying results, but NONE of them successful, not good enough to commit to the etching tank.
The number of variables I have tried, I lost count of.... The copper is super clean, even tried cleaning with IPA, the trouble is.. the author of the film does not state the type of glossy paper used, the method of paper removal; as in.. is it still wet with fluid .
The reason I like this method.. if it works, is that I can make double sided boards reasonably easily, and for "one offs" it would be very useful.
I have tried the Hot Iron method and that was just as bad as this method is
Over to you
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Old 2nd Dec 2019, 5:56 pm   #2
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Default Re: PCB Artwork transfer

Wendy -for one offs something that can be hand applied to the board is easiest ( in my limited experience). On very successful bit of artwork I did a lot of years ago involved a keypad, where I used the artwork ( with carbon paper underneath ) to trace out the keypad. I then got Swimbo to cover the area in a transparent old nail varnish ( seem to remember it was a shade of light green) and I removed the bits I needed to remove. It etchd clean .
At this time, nail pens were coming out. Sadly, Swimbo could not find one. But she tells me that these pens are now back on the market (and cheap). From what I've seen they are slightly smaller than the old permanent markers, so should give finer lines etc, but being either acetone or gel based will certainly be more resistant to Ferric chloride and the dreaded edge creep.
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Old 2nd Dec 2019, 7:00 pm   #3
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Default Re: PCB Artwork transfer

Hello Wendy

Thanks, I have tried this too with "catalogue page" printed matter and acetone, I confirm that it didn't produce a usable result either. I use the laser print/ hot iron/ ferric chloride method and find it reliable.

It would be good to know if anyone has had success and with which specific combination of materials.

Alan
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Old 2nd Dec 2019, 8:50 pm   #4
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Default Re: PCB Artwork transfer

Hi Oldcodger.... I Totally agree for simple circuits, however this is a tad more complificated, as in pad pitch 0.5 mm and it must be right. I was looking for a simple solution that would save me ordering from China...... however it may not be.
Ok Alan.. we shall wait with bated breath...... The nice thing about the Acetone method is that double sided positioning would be more controllable
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Old 2nd Dec 2019, 10:23 pm   #5
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Default Re: PCB Artwork transfer

Wendy- for more complex stuff, David G4EBT has provided more than a few solutions in his posts, using negative resist. I tnd to use various software to move my chosen PCB software to give me a negative image.
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Old 2nd Dec 2019, 10:23 pm   #6
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Default Re: PCB Artwork transfer

I'm a little baffled why many methods of pcb artwork transfer still exist when the iron on film works so well. I can whip up a pcb in less than 40 minutes once I have the artwork drawn, just print it to the film on my small monochrome laser printer, iron on and etch in ferric chloride and drill, bingo its done.

The film is American made comes from NJ, its supplied by Jaycar part HG9980. In fact I just did one last night , photos attached. When there are very large filled in areas, occasionally it needs a touch over with a pen in the odd place, but not very often.

To do the artwork I merely use a vintage drawing program (Microsoft Picture It) and draw it over a scan of a 2.54mm grid of dots and print it out "exact size".

One of the main tricks is to have the blank pcb larger so the iron on artwork is not near the edges, then cut the pcb to its perimeter size after the etch. The other is to attach the film prior to ironing to the pcb with polyamide tape so it cannot move around during ironing.

I just use our clothing iron, dead easy. I thought everyone else was doing it this way now.
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Old 2nd Dec 2019, 11:08 pm   #7
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Default Re: PCB Artwork transfer

......I don't do too many double sided boards but on one occasion I applied the film to one side, then drilled two small registration holes to position the top film as best possible. Also , looking at the Jaycar site now this film isn't what you would call cheap, I bought a lot of it some years ago and have been working my way though it, it must have been around for many years. I have also read that some people have tried to apply it with a laminator machine, but I doubt that would be as good as a clothing iron. Also I have not used it as much for very fine pitch IC's.

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Old 3rd Dec 2019, 2:14 am   #8
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Default Re: PCB Artwork transfer

Also, the you tube video looks interesting, I might give it a go as its cheaper than the iron on film. I did notice though on his example pcb, on the lower part a little toward the left, where there are some parallel tracks, the transferred "ink" had splotched between the tracks. So it might be one of those things it would take a while to get the knack of to avoid that.
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Old 3rd Dec 2019, 12:58 pm   #9
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Default Re: PCB Artwork transfer

Hi Argus. It looked so simple on the video, but on a closer look, he does not do large areas of ground, and as you say close tracks are a problem too.
I think its a "bin it" situation.. it would have been nice to make a couple of extra PIC Controller and DDS boards for "stock"....
I was thinking about the iron technique......... I had tried it previously using a glossy mag paper, and I wondered if the target material needs pre heating, to negate the heat being dissipated too soon..I will give it one last go before I revert to my method I have used for years.
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Old 3rd Dec 2019, 1:21 pm   #10
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Default Re: PCB Artwork transfer

Quote:
Originally Posted by Alan's MagicEye View Post
Hello Wendy

Thanks, I have tried this too with "catalogue page" printed matter and acetone, I confirm that it didn't produce a usable result either. I use the laser print/ hot iron/ ferric chloride method and find it reliable.

It would be good to know if anyone has had success and with which specific combination of materials.

Alan
I forgot to detail the transfer medium in my last post, I use glossy photo paper to carry the toner to the board and iron this on thoroughly for about 3-4 minutes and dissolve the paper off in warm water to reveal the toner mask, I touch in any areas of missing toner with an indelible marker pen. I think this is a fairly standard method so I'm probably not saying anything new here

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Old 3rd Dec 2019, 1:47 pm   #11
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Default Re: PCB Artwork transfer

Quote:
Originally Posted by Oldcodger View Post
Wendy- for more complex stuff, David G4EBT has provided more than a few solutions in his posts, using negative resist. I tnd to use various software to move my chosen PCB software to give me a negative image.
Firstly, the advantage of the beguiling technique which is the subject of this thread is that it removes the need for a UV exposure box, the need for an acetate mask, and for developer. In the video, I would have liked to have seen a close-up image of the tracks to see the quality of the finished product because I can't say that I was impressed with how he rubbed the image onto the laminate. If doing that only moved the artwork just a fraction of a mm it would be enough to create a junk PCB. With any technique, there are several variables which determine failure or success.

For some time now I've used the negative resist UV dry film technique and stick with it as I get consistently good results.

As with positive resist (such as pre-sensitised board or sprayed on positive UV lacquer), this method requires an acetate mask to be used in a UV light box but the mask must be a negative. With negative resist dry film, and clear areas one exposed and developed will remain as the etch resist and any black areas of the mask, which haven't be exposed to UV, will be washed away in the developer. (Soda ash).

At risk of taking this tread off topic, to answer 'Oldcodger's' query about image inversion to create a negative, it takes only a few moments using a program such as 'MS Paint' to invert a positive image. I've taken some screen shots of a solid state LED magic eye PCB project. The shots aren't very clear but the inversion steps are as follows:

1) Open the image in 'Paint'.

2) Click on 'Select' as shown in red square at top of picture, then using the mouse, encompass the image with your cursor by dragging the cursor around the image. (See the dotted line around the image).

3) With the cursor somewhere on the image, right click with the mouse and a drop down menu will open. At the bottom of the menu is an option 'invert colour'. Left click on that, and the image will change from positive to negative, reversing the colours.

Then save the image as 'PCB Negative Mask' or whatever so you keep the original positive image too.

I hope the pictures - poor as they are - show the three simple steps.

The invert facility is useful in many other ways - not just for PCB masks.

For example, I've mentioned elsewhere that it can be used to seemingly print white lettering on a coloured background by first creating the lettering in the desired colour of the background - black, blue, brown, whatever - then inverting the image. Fourth pic below - a Little Maestro back panel with white lettering on a brown background by inverting the image. (Text written in brown on a white background in the upper image, then the colours inverted in the lower one).

If there is to be any more discussion on this, I think it will have to be in another thread so that this 'cold toner transfer' thread can stay on topic.

It will be interesting to see what results are achieved.
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Old 3rd Dec 2019, 3:28 pm   #12
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Default Re: PCB Artwork transfer

Hi David..... No pictures.... but I get what you mean....I will buy some of this film you use and give it a whirl..as you say in the film he is not doing a complex pcb and any movement will incur registration problems.
To date I have used my Acetate and UV light box, and I can still do that....but it was another method and it looked good.... however.. as in most cases... easy is not always best. Thanks for your input though.
Alan..... I was in as Art shop yesterday looking at glossy white, but being "tight" lol, I decided the expense was not worth an untried method... At that stage I was still trying the youtube method.
I get the warm water release method, I had tried that with the youtube method.. disaster....what I spend on this Film that David uses, will offset the other costs of coated pcb material..
Early days...back soon..
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Old 3rd Dec 2019, 6:03 pm   #13
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Default Re: PCB Artwork transfer

Quote:
Originally Posted by Wendymott View Post
Hi David..... No pictures.... but I get what you mean....I will buy some of this film you use and give it a whirl..as you say in the film he is not doing a complex pcb and any movement will incur registration problems.
Don't know what happened to the pictures in my earlier post Wendy!

They were there when I reviewed the post, but have since disappeared so here they are again.

Re toner transfer, forum member Tony, 'Aerodyne' recently posted a thread on his experiences with film he'd discovered and was impressed with:

https://www.vintage-radio.net/forum/...highlight=PCBs

As to the negative dry film technique that I've used for the last two or three years, there are a couple of youtube videos at the links below. The first one shows an experimental layout which includes very thin tracks, very close together to see how they turned out. He deliberately pushed it to the limits, and the results were variable, but perhaps not as bad as might have been imagined.

https://www.youtube.com/watch?v=2hQfGtSFe_0

https://www.youtube.com/watch?annota...&v=cRCFGZxmob0

To source the negative UV photoresist film, search for:

'30cm x 5M Photosensitive Dry Film For PCB Circuit Production Photoresist Sheets'.

That will find it at 6.68 post free for a 5 metre length 30cms wide.

A search for '15cm 2m Photosensitive Dry Film PCB Portable for Circuit Photoresist Sheets' will find a 2 metre length 15cms wide for 1.60 post free.

The last pic is a PCB made by the UV dry film process.

There have been numerous thread on homebrew PCBs so I won't reiterate what's already been said.
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Old 3rd Dec 2019, 6:39 pm   #14
Wendymott
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Default Re: PCB Artwork transfer

Hi David..... Found those snippets.. thanks.... saved them for reference... I have ordered a roll of film..I will give it a whirl..
I just need to get my head around both negative arts and Reverse for top side..

Thanks David.
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Old 4th Dec 2019, 5:21 am   #15
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Default Re: PCB Artwork transfer

Wendy and David,

One problem I had for years on my home grown pcb's , I was never happy with the quality of the holes, that have a whitish look due to the rough fibreglass and often spayed out at the edges lifting up the copper foil on the hole perimeters, exactly like some of the holes on the pcb shown in post #13.

When I have my pcb maker do the pcb, their tools somehow create perfectly smooth edge holes. Or they are plated through. I bought the "hole plating" kit from RS to try, it works by lining the hole with a thin metal sleeve, it is more useful for repairs than making a hobby pcb.

I've tried a number of pcb drill types and drill speeds, in the end though the only practical way I could find at home to make the holes good was a three step pass, typically an initial drill with 0.60mm, then 0.65mm then 0.7mm to get the holes looking clean and no splaying of the pads around the holes edges (photo attached). Of course it takes three times as long to do it ! so probably only a lunatic would bother doing it, but it works.

Hugo.
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Old 4th Dec 2019, 3:39 pm   #16
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Default Re: PCB Artwork transfer

Nice PCB Hugo - class will show!

As to it 'taking three times as long', in terms of the overal time to produce a PCB, that's not too onerous and as hobbyists, we're our own masters working to our own standards and time is not of the essence.

I think commercial boards that aren't plated through holes are drilled with high speed tungsten carbide bits. Though the bits drill nice clean holes with no burrs, they have larger diameter shank (2.5mm?) so won't fit in the chuck of a mini drill, though they will fit in a pillar drill, which I guess many hobbyists will use. I use a 12V mini drill in an accurate stand, with a homebrew speed controller. For drill bits, I use 8mm HSS ones, and 1mm for terminal pins. They blunt very quickly so I discard them after each board and use a new one or they soon start to throw up burrs and may skid. When I've drilled the board, I remove any burrs with 220g wet and dry paper, then I tin the board before populating it.

The attached pic is perhaps a better example.

I don't kid myself that I can come close to the standards of commercially produced PCBs, but that isn't the yardstick I use, which - with all my homebrew efforts - is: 'in terms of my limited abilities, knowledge and resources, how does this stack up among my fellow hobbyists and would I be happy for them to take the lid off and look inside?' I'm OK with that.
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Old 7th Dec 2019, 3:43 pm   #17
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Default Re: PCB Artwork transfer

A bit OT, but...

Quote "...how does this stack up among my fellow hobbyists...".

Extremely well, judging from the Minimod board supplied by you (and working well). Thanks, David.
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Old 7th Dec 2019, 4:31 pm   #18
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Default Re: PCB Artwork transfer

I been using these drills recently - https://www.ebay.co.uk/itm/PCB-Tungs...53.m2749.l2649 - they fit in a Dremmel chuck. I've got very good results. They are different to standard drills, having a complex flute pattern and they seem to "grind" as they drill, they don't snap easily either.

Andy.
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Old 7th Dec 2019, 11:21 pm   #19
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Default Re: PCB Artwork transfer

Proper pcb drill bits are indeed tungsten-carbide and break very easily.

Used at very high rpm (my CNC drill is 25,000rpm) and must be sharp, as soon as they loose their edge, they will start lifting the edge of the pads.

They also have 3.18mm (1/8") shanks.
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Old Yesterday, 12:01 pm   #20
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Default Re: PCB Artwork transfer

Being the "lazy" sort.. I have various drills.. that saves me changing bits..my main drill has a 0.8mm bit and is illuminated... "old eyes" LOL. then a minidrill with a 1mm bit to over drill for vero pins. I buy my 0.8 mm tungsten bits from China, and they seem to last..occasionally I will break one, being.. in attentive..
But I manage.
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