Laser cutter for hobbyist/non pro enthusiast, what are range of application(s)

[Sideshow Bob]

Refering to this thread http://www.sonsivri.to/forum/index.php?topic=63428.msg182291;topicseen#msg182291 I got somewhat curious. Laser cutter for the  hobbyist/non pro enthusiast what are the range of applications. I understand of course that the effect of the laser is a quite limiting factor.

[Parmin]

One of application that come to mind for low wattage cutter is to cut vinyl PCB traces mask for etching.

[Sideshow Bob]

One of application that come to mind for low wattage cutter is to cut vinyl PCB traces mask for etching.

Do you mean by that. Using some sort of self adhesive vinyl on a PCB copper clad, and then cout the vinyl. So areas that should be expoced can be peeled away. Even if that may work in theory. I can only see some practical use in very basic PCB projects

[pickit2]

Using vinyl for pcb production is being used now, you cut the vinyl while still on the sheet, then apply to pcb, and remove to expose the area to be etched.

How about coating the pcb with Photo resist and laser print the resist, could be done with a low power laser.

[mars01]

How about coating the pcb with Photo resist and laser print the resist, could be done with a low power laser.

I think I remember someone saying that he is doing just that. It was on the discussion section of http://flatcam.org/discussion.
In the development version of FlatCAM there is a "paint" function that could work. You will need to focus the laser in a very narrow beam (the flatness of the bed will be crucial in order to have fine details as intended) and then paint the traces and polygons. But for that you could use your CNC.

Some people use lasers to cut SMD stencils out of teflon sheets.

[Parmin]

Yes I stuck vinyl to the PCB, cut and remove the parts to be etched.
Works very well with very thin book covering vinyl, or packing tapes.
Thick vinyl does not work well, maybe the adhesive is not suitable.

Tried the paint resist method as well, not doing well due to the lines the laser made when burning off the resist.

Never tried exposing resist with laser, not sure how this will work.
Rather than laser exposing, maybe can use focused UV led to do the exposure.
Again never tried this, maybe someone would do it and give review?

I use transparency plastic sheets for SMD stencil.

[mars01]

Parmin, you are right, I mixed things. I was referring to UV light when I said about focusing the beam and painting the traces and polygons.

How are the stencils cut from transparency plastic sheets? Are they suitable for, let's say, 0603 packages?

[Sideshow Bob]

Rather than laser exposing, maybe can use focused UV led to do the exposure.

That would actually be a photoplotter. Then a laser is used the method is named Laser Direct Imaging (LDI). LDI is used in sometimes in PCB production
http://www.allflexinc.com/blog/laser-direct-imaging-ldi-for-flexible-circuits/

[Parmin]

How are the stencils cut from transparency plastic sheets? Are they suitable for, let's say, 0603 packages?

So far I have only work down to 0805, SOT and TQFP packages.
With 0603 and 0402 components, I purchased the stencil.
I have also tried chemical milling thin metal sheets (stainless) for the stencil, made a mess and now no longer do it.

[CocaCola]

I don't have a laser cutter but I have had many stencils cut for me on laser etchers from other people out of Kapton and they work great down to 0603 and every other package I have used them for as long as the person has a properly focused laser machine...  I can also easily get 100s of screenings out of Kapton stencils if I take my time and care, so they are great for even small production runs, I suspect with care they could probably push the 1000 use mark, although I have only every pushed them to about 250ish as any run larger then that I can usually justify a proper metal one being made...

[bobcat1]

Hi

Any one can recommend a good and lower source for PCB stencils?

All the best

Bobi   

[vern]

depends on the country you live in.
Here in Europe I get my stencils form pcb-pool.com, top quality, quick turnaround and good price.
A stainless steel stencil with about 1000 cutouts and 0.1mm thickness is about 40 - 50 Euros, depending on the overall size.
This is good for 0.5mm BGA and 0402 parts.
Not worth making your own stencils, especially if you have those really small parts.
For bigger parts 0805 / 1mm BGA you could try and use Kapton, but smaller parts are tricky. I also don't know about the thickness of Kapton, to much solder paste produces lots of short circuits without improving the solder joint. I use 0.125mm for larger parts >0805 and 1mm BGA, but if I have a smaller BGA grid or a QFN package with a 0.5mm pitch I use 0.1mm
You don't want to have a short circuit under your BGA.
If you have ICs with leads you can always fix it, but with BGA you need to get it right the first time.

[CocaCola]

I use oshstencils.com for stencils...

If you want generic stencils for this or that component, there are many 'repair stencil' offerings that can be found at some of the big Asian import sites or Ebay...