Making Circuit Boards with a Low Wattage Laser Cutter

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By Michael Colombo
Posted 2013/01/25 @ 12:00 pm
Category Electronics

The prevailing wisdom states that one can’t cut metal with low-powered hobbyist laser cutters. Rich Olson of Nothing Labs has owned his Full Spectrum 40W laser cutter for 1.5 years and has been trying to buck that trend ever since.

Through a contact at Seattle’s Metrix Create Space, he caught wind that it was possible to do so through .001″ mild steel. After some practicing to get the process perfected, Rich has been successfully churning out circuit boards (LCCBs instead of PCBs?) that are not only functional, but are also appealing to the eye when mounted on a clear acrylic substrate.

Since steel is not as good a conductor as copper, your mileage may vary when it comes to certain circuits. Even so, if it works for the board you’ve designed, it’s a whole lot faster than acid etching them yourself.

In the Maker Shed

9 Responses to Making Circuit Boards with a Low Wattage Laser Cutter

Joel on January 25th, 2013 at 12:56 pm said:

I’m not familiar with laser etching, but is there something fundamental here why you can’t cut through 1mil copper instead?

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- trkemp on January 25th, 2013 at 1:47 pm said:
  
  In his blog he says that the copper reflects the IR laser too much and that copper is also too thermally conductive to work.
  
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Ross Hershberger on January 26th, 2013 at 3:57 am said:

This is correct. I work on industrial YB-YAG IR lasers from about 1KW to 8KW (around 1nm wavelength). CO2 lasers (10nm) actually use copper mirrors because it’s almost perfectly reflective at that wavelength. Copper is a bear to work with photons. Steel cuts and welds very well with light. The electrical resistance of steel for wide traces over circuit board distances should be minimal. And steel is ductile and rugged, opening up the possibility of 3D circuits made from bent laser cut steel ‘traces’.

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Geotek on January 26th, 2013 at 5:10 am said:

Stainless steel solders very well. But you need to use a HCl/HF based flux. If you clean it well after soldering it should not be too bad of a corrosion risk. Mild steel can be easily copper plated using an electroless process. Dip the well cleaded steel in a solution of CuS03. A few drops of H2S04 helps keep the Ph low and hilps with the plating. You can follow that with an electroless tin plate for a real nice look.

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Joel on January 26th, 2013 at 6:57 am said:

Informative comments, everybody. I read through his blog comments and someone there also mentioned an electroplating process would be possible. Over there he also mentions that his traces are a minimum of around 1/16″ which makes it too large for many SMD components. Is that also a practical limitation of these lasers or is this something that is limited by something else and continually coming down? I’m wondering what is the potential that one day I could print a SMD-compatible board, electroplate it with copper, and , high-quality DIY circuit board printing?

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- Joel on January 26th, 2013 at 6:58 am said:
  
  Sorry that was supposed to say “*bingo*, high-quality DIY circuit board” but it didn’t like the brackets I put around the word
  
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amsh on January 30th, 2013 at 7:51 am said:

is this also possible with all types of laser like ruby, helium-neon or semiconductor?

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Leif on January 31st, 2013 at 10:09 am said:

What is the result of the copper being too reflective? What I’m wondering is, does this reflect enough that the reflected beam can damage things? Or does it just mean that not enough energy is absorbed to get a cut?

The reason I ask is I am wondering what would happen if one spray painted a regular blank PCB and then used the laser to etch off the spray paint. Would that work? I assume the reflectivity of the copper wouldn’t come into play until after the paint is already removed from the spot so it wouldn’t prevent the laser from etching the paint. But would it be dangerous? Would the reflected beam cause damage?

Once the paint has been etched, the remaining paint could act as etch-resist in a regular acid bath.

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Circuit board depaneling on April 16th, 2013 at 11:56 pm said:

Nowadays this technology is taking good position in market to make PCBs.

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