I always wanted to create my own PCBs for my Arduino projects but most methods were too tedious / expensive / chemical for me. Now I got a laser engraving machine and so I had the idea to create my own PCBs using the laser engraver... ONLY.
Is this possible? Correct me, if I am wrong, but etching is used to remove that part of the copper coating that you do NOT want to use - so wouldn't it be much easier to just use a laser engraver to do so?
I would only require a negative image of the circuit and then the laser could be used to remove all parts outside the circuit itself - no etching needed anymore?
Wouldn't this work? I wonder because I wasn't able to find a single tutorial on this. Even WHEN a laser engraver was used in a tutorial to create a PCB, the creator still used etching.
So what am I missing? Can you create PCBs using a laser engraver ONLY - or do you still need etching? And if so, why?
My guess would be no. Laser etchers work by heating a tiny point on the surface and burning/vaporising it. This works well on materials that are heat insulators like plastic and wood. But copper is a good heat conductor, so it's hard to get a point up to a high temperature because the heat flows quickly away from the point.
If the copper is covered in a resist layer, a laser etcher could burn that away to expose the copper. Then that copper can be chemically etched away.
There are many hits if you google "laser pcb etching".
In principle, of course you can "etch" PCBs with a laser, it's just a question of physics and money. Whether you can use the machine you have is a different question.
The two issues are power and wavelength. Some materials absorb some wavelength better than others. For reflective materials like copper, you might need to coat the copper with a darker layer first. Precision with a laser can be quite fine, but of course if you have fine precision it takes a while to remove large areas. It might be better to adopt the Voroni method used by milling.
Even if you have the ability to etch with a laser, there is more to making PCBs than etching a single side. Drilling holes, through hole plating, solder mask, silk screen.
True laser engraving of copper PCB is obviously technically possible, not sure why people think it can't be done. However, a 30W fiber laser is not cheap, using a typical cheap CO2 or diode laser engraver would be a struggle.
Reflectivity is not an issue. Not sure about heat conductivity.
Not so long ago I visited a company that was laser cutting stainless steel, including pipes of 1-2 mm thickness. I don't know how much power that laser has, other than that it's a lot, and it's a type (wavelength of the light) that's specifically suited for cutting stainless steel.
Most consumer type lasers can engrave materials like aluminium and glass, but not cut it.
CNC milling is indeed a fairly common way of milling one-off PCBs at home. Nonetheless I would prefer to wait a few more days and have it made properly in China.
It's going to depend on the wattage and type of laser you have. Is it a Q switched pump diode, IR, solid state, etc.? Ablating the surface will also require some heavy duty ventilation so keep that in mind as well.
CNC milling is a lot more common and since it is common I assume there is existing software that accepts Gerber files. I haven't researched it, but the cost of a small CNC machine is probably in the same ballpark as a powerful laser engraver.
And with laser, you'd still have to drill the holes and it's not easy to precisely drill small holes.
I've been really happy with Seeed Studio. I can get 10-20 small boards for around $100 USD (including about $30 for DHL shipping from China). Mine were double-sided (but you can order single-sided or multi-layer) with plated-thru holes & vias, silkscreened, and solder-masked.
It does take a couple of weeks, and the two times I've done it, I had errors in my design and had to re-order so the cost & delay was double. I wasn't THAT surprised because I work in electronics (not as a PCB designer) and I've never seen a board come-back perfect the first time. But of course, I THOUGHT design was perfect!!!
Seeed is pretty competitive for bare PCBs ($4.90 for 10x 100mm*100mm boards.)
I would assumes that the $100 number includes assembly, and perhaps even parts and postage.
I should have given that info, I am sorry - it's a 5W diode laser. I'll probably order some copper coated PCB plates and do a test run, just to prove it. Otherwise, a small engraving machine (CNC-like) might the right tool if I don't want to etch
I really want to do this myself - if I should make any mistakes with the layout, the entire batch ordered would be useless and I would have to send in another try, wait a couple of weeks again... it'd be a cool thing to be able to do this all alone whenever I need to.
It turns out that copper is moderately TRANSPARENT to the IR wavelengths used in "consumer" laser engravers (in addition to the heat dissipation issues that have already been mentioned.)
You can engrave circuit boards with a laser, but it takes a special machine (or one stupidly overpowered), and not one of the common engraver/cutters that have appeared in the marketplace in recent years. (and expect sticker-shock.)
Here's one example: LPKF ProtoLaser PCB Structuring| LPKF
I have done it a couple of ways. With the laser engraver I would coat the PCB with black appliance epoxy paint. Then I would laser away all of the the paint over the copper I wanted to be etched.
I would then etch the copper away with a formula of acid and hydrogen peroxide. Then i would have to remove the excess paint with paint thinner. Lastly I put it on the router to drill the holes. After mounting the electronics I would coat it with conformal coating.
There are some serious issues with doing it this way. First messing with the chemicals is hazardous, even with a good exhaust hood. Secondly aligning the pcb for drilling the holes was a challenge. This process produced some really nice boards. I have projects that have been in service for more than 5 years now.
The best way to make your own in my opinion is to just etch it with a good router. A program called copper cam lays it out for you. If you do it right you can make some really nice boards too. Then the only chemical you have to deal with is the conformal coating.
I have gotten lazy though and now I just send them out to a pcb mfg.
I wasn't THAT surprised because I work in electronics (not as a PCB designer) and I've never seen a board come-back perfect the first time. But of course, I THOUGHT design was perfect!!! 