Dr. John patten, a professor of manufacturing engineering at the University of West Michigan in the United States, developed a micro laser assisted machining technology called μ Lam, which combines laser with diamond tools to heat, soften and cut silicon semiconductor and ceramic materials.

 

"These materials are usually very brittle, and they tend to break easily if you try to deform them or process them," says John patten. By softening these materials, we can increase their flexibility and make them easier to process. "

 

An infrared fiber laser (wavelength range 1000-1500nm) is integrated into the μ - Lam processing device. The laser beam irradiates the workpiece through a single point diamond tool with high optical definition, and heats the workpiece material to above 600 ℃. The diamond cutter with a tip radius of 5 μ m-5mm is connected to the laser mounted in a tungsten or cemented carbide shell by epoxy resin bonding (suitable for milliwatt laser power processing) or welding / brazing (suitable for 1 watt or higher laser power processing).

 

Other engineers have tried to process brittle materials (such as ceramics) in different ways. One method is to heat the workpiece in the furnace, and then process it; the other is to use laser heating and diamond cutting tools respectively. The method invented by patten integrates laser and diamond tools, so it has obvious advantages. He explained, "it's easier because the laser is aligned with the tool itself, and the part heated by the laser is just at the cutting edge of the tool, so the best machining effect can be obtained. In addition, the workpiece material will not be over heated. "

 

Patten said that μ - Lam processing technology can also reduce processing time and cost, and obtain very smooth optical surface. "If an optical element (such as a mirror) is to be manufactured by conventional processing method, it usually needs to start from the casting workpiece blank, and then carry out a series of processing steps: rough grinding, fine grinding, grinding, to finally form. Instead of a series of working procedures, our machining method uses a single point diamond tool to cut on CNC machine tools, and can also obtain excellent surface roughness (ra1-10nm). "

 

Patten is working with a Japanese company to commercialize the μ - Lam system. He expects that the invention will find application in a number of industries, including automobile, aviation, medical equipment, semiconductor and optical industries. "Our initial goal is to target the optical and semiconductor industries, but now it seems that most of its applications will probably be in high-energy, high-temperature microelectronic devices," he said. In the semiconductor industry, silicon is the carrier of chips and integrated circuits. Under high temperature working conditions, people will use silicon carbide. So now, almost all of our energy is focused on the processing of silicon carbide. "