Method for material processing by laser filamentation

Abstract

A method for internal processing of a transparent substrate prepared by a cutting step is provided. The substrate is irradiated with a focused laser beam comprising pulses having an energy and pulse duration selected to generate filaments within the substrate. The substrate is translated relative to the focused laser beam to illuminate the substrate and generate additional filaments at one or more additional locations. The filaments produced therein form an arrangement defining an internal scribe path for cutting the substrate. Laser beam parameters can be varied to adjust wire length and position, and optionally introduce V-channels or grooves, to provide bevels to the laser cut edges. Preferably, the laser pulses are delivered in pulse trains to lower the energy threshold for filament formation, increase filament length, thermally anneal filament modified regions to minimize collateral damage, improve process repeatability, and be compatible with the use of low Repetition rate increases processing speed compared to laser.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to U.S. Provisional Application No. 61 / 363,568, filed July 12, 2010, entitled "Method of Material Processing by Laser Filamentation," which is adopted in its entirety by Incorporated herein by reference, and this application claims priority to U.S. Provisional Application No. 61 / 372,967, filed August 12, 2010, entitled "Method of Material Processing by Laser Filamentation," the U.S. The entire content of the provisional application is incorporated herein 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 s...

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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