Methods and apparatuses for laser processing materials

#The present specification relates generally to the manufacture of materials and, more specifically, to laser processing of materials.

#In recent years, customer demand to reduce the size, weight, and material cost of devices has led to considerable technological growth in flat panel displays for touch screens, tablets, smartphones, and TVs. Industrial lasers are becoming important tools for applications requiring high precision cutting of these materials. However, laser processing can be difficult because the high intensity laser may damage the components utilized in laser processing of the materials.

#Accordingly, a need exists for alternative methods and apparatuses for laser processing materials.

#FIG. 1 schematically depicts a cross-sectional diagram of a multilayered stack undergoing laser processing, according to one or more embodiments shown and described herein.

#Reference will now be made in detail to embodiments of apparatuses and methods for laser processing materials, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. One embodiment of a multilayered stack for laser processing is schematically depicted in FIG. 1. Generally, the laser processing may perforate a material that is transparent to the laser, sometimes referred to herein as the “transparent material,” and the perforation may cause or contribute to cutting the transparent material at the perforation. The multilayered stack generally includes a transparent material which can be perforated or otherwise mechanically deformed by a laser beam incident on the top surface of the transparent material. The transparent material is positioned on a carrier, where at least a portion of the carrier is non- transparent to the laser beam. The carrier generally includes a support base and a laser disruption element positioned between the support base and the transparent material. The support base supports the transparent material and may be utilized to transport the transparent material to be laser processed. In one embodiment, the support base material may be non-transparent to the laser beam and may be damaged if contacted by a portion of a laser beam having an intensity great enough to damage the carrier, such as a focused area of a laser beam. However, the laser disruption element positioned between the transparent material and the support base may disrupt and diffuse a laser beam exiting the transparent material before it can contact the support base, such that upon optical disruption of the laser beam by the laser disruption element, the laser beam does not have sufficient intensity below the laser disruption element to damage the support base. As such, the laser disruption element may act as a shield to protect the support base from damage associated with contact with a portion of a laser beam with sufficient intensity to damage the support base. Various embodiments of methods and apparatuses for use in laser processing transparent materials will be described herein with specific references to the appended claims.

#Referring to FIG. 1, a multilayer stack 100 is schematically depicted. Generally, the multilayer stack 100 comprises a transparent material 160 and a carrier 110 which comprises a laser disruption element 140 and a support base 120. In embodiments described herein, the transparent material 160 is positioned on top of the laser disruption element 140, which is positioned on top of the support base 120. As used herein, reference to a position above or on top of another position assumes that the top or uppermost position is the surface of the multilayer stack 100 upon which the laser beam 180 is first incident. For example, in FIG. 1, the surface of the transparent material 160 that is closest to the source laser 188 is the top surface 162 and placement of the laser disruption element 140 below the transparent material 160 means that the laser beam 180 traverses the transparent material 160 before interacting with the laser disruption element 140. As shown in FIG. 1, the source laser 188 in transmitted through an optical element 184 which forms a focused area of the laser beam 180, such as a focal line 182, which is incident upon the transparent material 160.

#The transparent material 160 may be laser processed with a laser beam 180 which may alone, or with other manufacturing steps, be utilized to cut the transparent material 160. As used herein, laser processing refers to cutting, perforating, ablating, or otherwise altering the mechanical integrity of a material with a laser beam 180. Generally, the laser beam 180 must have a certain intensity at a particular area of the transparent material 160 to alter the mechanical integrity of the transparent material 160. As such, a defocused or disrupted laser beam may not have sufficient intensity to mechanically affect a material at a selected area while a focused laser beam may have sufficient intensity to cut, perforate, or ablate an area of a laser processed material. However, a focused area of a laser beam, such as a laser beam with a focused focal line 182, may have sufficient intensity to perforate the transparent material 160 as well as to damage a support base 120 directly contacted by the focal line 182. A focal line 182 of a laser beam 180 may be produced by an optical assembly 184 which can optically alter the path of a source laser 188. Also, as used herein, in the context of laser beams, “intensity” may be referred to as “energy density” and the two terms are interchangeable. The laser beam 180 has a wavelength, and as used herein, a material that is “transparent” is substantially transparent to electromagnetic radiation of the wavelength of the laser such that the absorption by the transparent material 160 is less than about 10%, less than about 5%, or even less than about 1% per mm of material depth at the wavelength of the laser. “Electromagnetic radiation” may be referred to herein as “light” and the two te1ms are interchangeable and may correspond with electromagnetic radiation both inside and outside of the visible spectrum.