Method of material processing by laser filamentation

Abstract

A method is provided for the internal processing of a transparent substrate in preparation for a cleaving step. The substrate is irradiated with a focused laser beam that is comprised of pulses having an energy and pulse duration selected to produce a filament within the substrate. The substrate is translated relative to the laser beam to irradiate the substrate and produce an additional filament at one or more additional locations. The resulting filaments form an array defining an internally scribed path for cleaving said substrate. Laser beam parameters may be varied to adjust the filament length and position, and to optionally introduce V-channels or grooves, rendering bevels to the laser-cleaved edges.; Preferably, the laser pulses are delivered in a burst train for lowering the energy threshold for filament formation, increasing the filament length, thermally annealing of the filament modification zone to minimize collateral damage, improving process reproducibility, and increasing the processing speed compared with the use of low repetition rate lasers.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to U.S. Provisional Application No. 61 / 363,568, entitled "Method of Material Processing by Laser Filamentation," filed July 12, 2010, the U.S. The entire content of the provisional application is hereby incorporated by reference, and this application claims the 61st article entitled "Method of Material Processing by Laser Filamentation" filed on August 12, 2010. / 372,967, the entire contents of which are hereby incorporated by reference. technical background [0003] The present disclosure relates to methods of laser processing of materials. More specifically, the present disclosure relates to methods of separating and / or dicing wafers, substrates, and plates. [0004] In current manufacturing processes, the separation, dicing, scoring, dicing, and faceting of wafers or glass sheets are critical process steps that typically rely on diamond cutting, eg at speeds of 30 cm / sec for flat pan...

AI Technical Summary

Problems solved by technology

The process produces poor-quality edges, micro-cracks, wide kerf widths, and large amounts of debris, which are major drawbacks in terms of product life, quality, and reliability, and incur additional cleaning and polishing steps

The cost of deionized water to run a diamond scriber is greater than the cost of purchasing the scriber and this technique is not environmentally friendly as the water is polluted and needs to be purified which also adds to the expense

Through improved technology, the chips on the wafer have become smaller and closer to each other, which limits the diamond scribing

30um is a good scribe width, but 15um is a challenge

While the method potentially offers a fast scribing speed of 300mm / s, there are limited kerf widths, surface damage, rough cut surfaces, and ablation debris due to internally formed voids reaching the surface

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