milling and chemical etching when it comes to physical variations exerted on the object. Whereas mechanical milling and chemical etching exact physical stress on the board, laser etching offers non-contact surface removal, making it a superior option for PCBs where precision and geometric accuracy are at a premium, such as RF and microwave designs. Laser drilling is more precise, has extremely low power consumption compared with other techniques, requires less maintenance, does not use lubricants or drill bits, low rates of wear, does not use abrasive materials, does not ruin the boards, is more eco friendly, and in the most high-powered machines, the drilling is instant, but is expensive. An additional emerging alternative to milling and laser etching is an additive approach based upon printing the conductive trace. Such PCB printers come at a range of price points and with differing features but also offer rapid in-house circuit manufacture, with very little to no waste. An example of such a technology that produces simpler, low layer count PCBs is Voltera. A system at the higher layer-count end of the additive manufacturing approach is Nano Dimension's DragonFly technology which prints complex high layer count circuits as well as electro-mechanical parts. References External links Software review and how-to's on RepRap wiki Printed circuit board manufacturing