A laser high-precision machining method for sapphire sub-micron cut surface

Abstract

The invention discloses a laser high-precision machining method for submicron-level cut surfaces of sapphire, which uses a picosecond-level pulse-width laser with a wavelength of high transmittance for sapphire to cause ultrafine phase transition points or electronic state removal points from the lower surface of the material, The laser focus is lifted to form a line parallel to the laser incident direction, and the intersection and connection of the laser action line points are arranged according to the cutting path in a chemical corrosion environment. While forming a phase transition area or an electronic state removal area consistent with the cutting path, The separation of sapphire samples along the processing path is obtained by using the catalysis of chemical corrosion by the microthermal effect of picosecond laser irradiation. The invention overcomes the limitation of beam Gaussian focusing mode and realizes high-precision cutting of sapphire with near-zero taper and no heat-affected zone, and can directly realize ultra-fine sapphire or other same material with high surface quality of micron or even submicron level, which is not limited by thickness and path cutting.

Description

technical field [0001] The invention relates to the field of laser non-ablative cutting processing of hard and brittle transparent materials, in particular to a laser high-precision processing method for submicron cut surfaces of sapphire. Background technique [0002] Sapphire is a single crystal of aluminum oxide, and its Mohs hardness is second only to diamond. Because of its special mechanics, heat, electricity, excellent radiation resistance, thermal conductivity and stable chemical properties, it is widely used in defense industry, aerospace cutting-edge technology research and civilian fields. Traditional mechanical processing methods mainly use diamond wire saws for cutting sapphire. The processing speed, processing freedom, processing quality and precision are low. Contact cutting tools such as saw wires have limited life and high loss. In contrast, laser cutting technology has the characteristics of high energy density and non-contact, which can effectively avoid ...

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Problems solved by technology

Germany -Jungemann et al. used the nonlinear effect of tightly focused femtosecond laser to form microchannels on the surface or inside of sapphire, and then formed hollow microstructures by chemical ultrasound (J.Laser MicroNanoengineering,2010,5(2):145-149.) , the depth of laser processing in this method will be limited due to the influence of laser focal depth, and the subsequent sonochemical processing must be performed due to the tight focus of the femtosecond laser

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