Making PCB's with a diodelaser

Wow!
This is absolutely cool!
Can you tell us a little bit about the necessary components for this cutter?
Is this project realizable for a first time builder?

... in short - it's a conventional CNC-mill equipped with a laser-module as tool.

Any CNC-system with XY-positioning can be modified for laser-engraving - did this several times with CNC-mills, but too with XY-plotters or XY-galvos.

If you already have a 3D-printer, this can be as easy, as mounting a common lasermodule on the Z-axis and wiring the driver input to an I/O-pin of the electronics.

The easiest methode would be to use the STEP pin of the extruder, as it's pulsing synchrone to the XY-moving with adjustable setting for 'steps' (or pulses) per Millimeter.

The laser-modules can be found really cheap from china, but the drivers are very different in quality and behaviour, so I'm building my own.

Essential for laser-engraving/cutting is proper shielding - complete housing for the machine and/or laser goggles for the respective wavelength.

But you need a methode vor venting/filtering/exhausting the fumes too, as they are toxic, corrosive and carcinogen!!

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... did some laser-samples with the blue 3.5W-diode for a fair next week - the spot is not so good/symmetrical, as with the 2W-diode, but good enough.

The blue border, red "smt" and white "2016" are cut from adhesive deco-foil, the logo is "only" engraved

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Still looks really good to me.
Just to be curious: Is that done by cutting out one layer of foil and where more than one color is required you place another piece into the cutout?
Or is done with colored ares under the foil?
In any case I would have been a happy customer if I ordered the signs

... yes, every colour is placed and cut separately (blue for complete cutout) or combined (red+white as one cut-job).

I'm doing this type of sign-making or deko-art since 1988 with my first lasercutter-builds on a DIY-XY-plotter and on a CNC-mill

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Well at least now I know where to ask if I have a need to know how to make proper signs

Edited 1 time(s). Last edit at 04/22/2016 06:45AM by Downunder35m.

... here's the toolpath for a "laser-sign" - the post is in German, but the images are self-explaining

[forums.reprap.org]

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... I'm lasercutting some samples for the next exhibition - actually some "seals" made from different materials:







- best to cut is sponge rubber:





... and a video cutting it with a 'pulsed' blue 3W-diode - [vimeo.com]

Edited 1 time(s). Last edit at 07/22/2016 04:22AM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... did some more testing with foam materials and uploaded a video showing laser-engraving and -cutting red PE-foam, normally used for chest/suitcase-insets:

[vimeo.com]


And the result(s):

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... my boss is on an exhibition in Chicago and I made some samples for this ...

First a two-coloured logo sticker - engraved and cleaned the two colours:




- put an adhesive transfer film on the blue part (note the two triangles!):




- aligned the blue part over the grey dots:




- removed the triangles - now ready to transfer:




- uniform machine name:




- another sample from a powder-coated plate:




********************************************************

A video engraving and cutting plywood -- [vimeo.com]

... and the result:



Edited 3 time(s). Last edit at 09/11/2016 02:09PM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote
VDX
... did some laser-samples with the blue 3.5W-diode for a fair next week - the spot is not so good/symmetrical, as with the 2W-diode, but good enough.

The blue border, red "smt" and white "2016" are cut from adhesive deco-foil, the logo is "only" engraved

[attachment 76764 smt2016-gietec.jpg]

what is the material here that you engraved?

... this was common coloured+anodised aluminium, as used by laser-engravers.

The adhesive sheets were standard types, as found in local stores for decoration ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

is it the colour you engraved at there? i tried some metals with my diode laser and it had no effect on them.

... this is common anodized aluminium with different colours "embedded" in the oxide layer - you'll need energy densities of at least 1 Watt on a spot of 0.07mm diameter, or it won't be strong enough to "bleach" or evaporate the colour particles ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Very cool project!!
Which software do you use to draw? And which one to convert the draw into 3D printer compatible format?

... I'm using different CAD/CAM or sketching programs -- depending on needed fonts, 2D/3D possibilities, importing/conversion formats or special modules.

For 2D drawings mostly Corel versions 10 or X6 (v16) - converting from raster to vector is mostly done with Inkscape, Corel or IsyCAM.

Most of the older laser-work was done with Editasc10 with import capabilities for Isel-NCP or HPGL files -- converting from 2D-vector to Isel-NCP with IsyCAM, HPGL is one of the Corel export formats.

Actually I'm switching to a modified Pronterface (internal name "gieCAPS") with import/converter modules for HPGL, Isel-NCP or SVG (and some other, more customer-related vector formats) ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Does somebody know how the quality, reliability and effort of this laser burning method compares to the toner transfer method? Is burning away the paint more reliable than fixating the toner to the copper? Thanks.

but why do you burn the paint?
I think the use of UV/blue laser + photoresist is simplier, isn'it?

... with UV-curing photoresist you'll need photo-film with it's limited shelf lifetime ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote
lukie80
Does somebody know how the quality, reliability and effort of this laser burning method compares to the toner transfer method? Is burning away the paint more reliable than fixating the toner to the copper? Thanks.

... the result/quality depends on the coating material or toner and used lasers and optics.

While with laser toner transfer you can get resolutions around 600 dpi (around 43 microns pixel resolution) a good engraving laser setup can have a spot diameter of 30 microns and the smallest details can be as small as 5 microns (recalced to 850 dpi or 5000 dpi).

Another point is the needed mechanical or chemical stability of the coating - here paints or even more pre-coating with polyimide or plastic will give a much better stability/resistance ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... Christmas is on the way -- this time I'm testing with some laminating or 3D designs.

Here a video of cutting the layers:

[vimeo.com]



... and here the result more in detail:

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... and now a "serious 3D"-snowflake for some relatives in Frankfurt on the Main - the scene shows the bridge "Eiserner Steg"

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote
lukier
[...] The biggest issue I have is with the paint. I've tried a few, from the cheapest black spray paint (1 GBP at one pound store) to high temperature oven & exhaust paint, to line marking paint (fast drying but ugly drying with bubbles etc) to painting a PCB with a wide tip black marker.
Pretty much every time the laser doesn't go all the way through the paint leaving a thin layer that blocks the etchant. [...]

Same problem here. Residual paint which blocks the etchant. Paint solvent is based on hydrocarbons and needs 24 hours for complete drying. I cleaned with water, soap and plastic brush. The etching result is shown in the attached photo. I used 2W power, maybe 100µm spot size, 10mm/s speed and etched 1h with Peroxydisulfate at 45°C and continuous movements.

Next, I'll try water or alcohol based spray paint.

... you need fast drying paints with pretty high loads of pigments, or a wavelength absorbing base without pigments.

Another point is the thickness of the coating - thinner works better.

When testing slow drying paints I've noticed, that the pigments evaporated instantly, but the clear polymer base could "survive" partially -- so changed to fast drying black paint used for RC cars (fuel-resitant), what worked much better ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks for the valuable info. Residual polymer-carrier, ok.

I just ordered some black RC paint... and remembered afterwards that permanent markers were used for masking too. Did you try the Edding Spray?

Quote
lukie80
... Did you try the Edding Spray?

... not yet - but could give it a try

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I'm still having problems finding the right paint. So far I've tried:

Partial ablation: "Toom: Universal spray laqueur"
Very bad ablation: "RC Car Colours: Racing paint for polycabonate body's"
No ablation: "Edding 405 pen"

However, the burned paint can be removed by mechanical means by using an acrylic piece of cloth and a lot of force or by using baking soda as mechanical peeling but this takes a lot of effort. VDX, can you recommend a specific product? I had no success with my RC color brand.

By the way. I'm using a blue laser (455nm), so in contrast to IR the copper absorbs roughly 40% of laser power. So in worst case I lose 40% of the back reflected power, which results in a total power loss of 20% of my 2W. Maybe the paint does not absorb blue light as good as IR?

... I've tested different paints with NIR (975nm) and blue (445nm) diodes - all dense black paints worked -- attached an image of two of my last used paints.

One point - the IR-diode had a spot diameter of around 0.12mm, the blue of maybe 0.05mm, so I'm mostly engraving two parallel lines in 0.06mm distance with the blue diode to get a line wide enough to have a good isolation between the tracks.

Most people using the blue diodes have much bigger spot diameters (too big focussing distaces), so less energy density too -- what can be one of the problems.

I'm removing the residues in the burned tracks with a fine and pretty soft brush (hand- or tooth-brush) and warm soap water without any presure, to avoid damaging the coating ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks a lot for this valuable information! Indeed I reduced the spot size first by using a second lens very close to the PCB because I did not want to change the spot distance adjusted by my first lens (60mm). It helped a lot. I use 4 outlines spaced by 50µm.

After brushing with soap and water I also had to use a cloth soaked with gasoline to remove the burned RC paint. I have to use some pressure but the unburned paint was kept intact and the burned paint is removed nicely. Etching was also successful (Permanganate, 45°C, 20min).

(I still have to figure out the reason for the path errors visible in the picture. Gcode is fine, so it's either the firmware (backlash compensation) or the mechanics.)

Hey @lukie80, keep us posted on your progress. It's looking beautiful. Do you have pictures of your results and printer? Maybe a video?