CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § of 119 of U.S. Provisional Application No. 62/856,444 filed June 3, 2019, the content of which is incorporated herein by reference in its entirety.

FIELD

[0002] The present disclosure relates to cutting glass-metal laminates, and in particular to such methods that use a laser.

BACKGROUND

[0003] Glass laminates are multilayer structures that include at least one glass layer. A glass-metal laminate has at least one glass layer and at least one metal layer, and in the examples considered herein have a "top" glass layer and a "bottom" metal layer. Glass laminates have many applications and have proven especially useful as protective covers and frames for electronic products, as well as for wall panels, doors, marker boards, furniture and architectural products.

[0004] Glass laminates are typically formed in large sheets and then cut to size to define the particular glass laminate articles or products for the given application. Different cutting methods include routers, water-streams, diamond blade saws, table saws, and lasers, such as CO2 lasers. These methods involve directly cutting or heating the glass laminate to make the cut and often result in poorly formed edges thereby requiring post processing. In addition, the mechanical approaches result in tool wear.

SUMMARY

[0005] An embodiment of the disclosure is directed to a method of cutting a glass-metal laminated structure (glass-metal laminate) defined by a glass layer attached to a metal layer. The method comprises: a) directing a moving laser beam having a wavelength through the glass layer to the metal layer in a select direction to cause the moving laser beam to be substantially absorbed by and heat the metal layer to form a hot spot in the metal layer, wherein the hot spot forms a metal-layer cut line due to localized melting of the metal layer; b) locally heating the glass layer with heat from the hot spot formed in the metal layer to form in the glass layer a moving heated region having a strong thermal gradient; and c) rapidly cooling the moving heated region to form a glass-layer fracture line that follows the metal-layer cut line, with the glass-layer cut line and metal-layer cut line defining a laminated-structure cut line.

[0006] Another embodiment of the disclosure is directed to a method of cutting a laminated structure defined by a glass layer attached to a metal layer. The method comprises: directing a moving laser beam in a select direction and through the glass layer to the metal layer to form a moving hot spot in the metal layer that travels in the select direction, wherein the glass layer is not substantially heated by the laser beam; selectively heating and melting the metal layer using heat absorbed from the moving hot spot to form in the metal layer a cut that runs in the select direction by locally melting the metal layer; locally heating the glass layer using heat from the moving hot spot to form a moving heated region within the glass layer; and cooling the moving heated region to generate stress in the glass layer sufficient to form in the glass layer a fracture that runs in the select direction and that coincides with the cut in the metal layer.

[0007] Another embodiment of the disclosure is directed to a cut glass-metal laminate product (or article) formed by a process comprising: a) attaching a glass layer to a metal layer to form a glass-metal laminate; b) directing a moving laser beam having a wavelength through the glass layer to the metal layer of the glass-metal laminate in a select direction to cause the moving laser beam to be substantially absorbed by and heat the metal layer to form a hot spot in the metal layer, wherein the hot spot forms a metal-layer cut line due to localized melting of the metal layer; c) locally heating the glass layer with heat from the hot spot formed in the metal layer to form in the glass layer a moving heated region having a strong thermal gradient; and d) rapidly cooling the moving heated region to form a glass- layer fracture line that follows the metal-layer cut line, with the glass-layer cut line and metal-layer cut line defining a laminated-structure cut line.

[0008] Another embodiment of the disclosure is directed to a cut glass-metal laminate product (or article) formed by a process comprising: attaching a glass layer to a metal layer to form a glass-metal laminate; directing a moving laser beam in a select direction and through the glass layer to the metal layer of the glass-metal laminate to form a moving hot spot in the metal layer that travels in the select direction, wherein the glass layer is not substantially heated by the laser beam; selectively heating and melting the metal layer using heat absorbed from the moving hot spot to form in the metal layer a cut that runs in the select direction by locally melting the metal layer; locally heating the glass layer using heat from the moving hot spot to form a moving heated region within the glass layer; and cooling the moving heated region to generate stress in the glass layer sufficient to form in the glass layer a fracture that runs in the select direction and that coincides with the cut in the metal layer.

[0009] In one aspect, a method of cutting a laminated structure defined by a glass layer attached to a metal layer is provided, comprising: a) directing a moving laser beam having a wavelength through the glass layer to the metal layer in a select direction to cause the moving laser beam to be substantially absorbed by and heat the metal layer to form a hot spot in the metal layer, wherein the hot spot forms a metal-layer cut line due to localized melting of the metal layer; b) locally heating the glass layer with heat from the hot spot formed in the metal layer to form in the glass layer a moving heated region having a strong thermal gradient; and c)rapidly cooling the moving heated region to form a glass-layer fracture line that follows the metal-layer cut line, with the glass-layer cut line and metal- layer cut line defining a laminated-structure cut line.

[0010] In one or more embodiments, the laminated-structure cut line separates the laminated structure into two separate pieces.

[0011] In one or more embodiments, each of the two separate pieces has an edge defined by the laminated-structure cut line, wherein each edge has average edge strength of greater than 60 MPa.

[0012] In one or more embodiments, the glass layer is attached to the metal layer by a securing layer, and wherein a portion of the securing layer is ablated by the laser beam.

[0013] In one or more embodiments, the securing layer comprises an optically clear adhesive.

[0014] In one or more embodiments, the wavelength of the laser beam is in the range from 0.8 microns to 1.1 microns. [0015] In one or more embodiments, the laser beam is generated by either a Nd:YAG laser or a diode-based fiber laser.

[0016] In one or more embodiments, the glass layer has a thickness in the range from 0.1 mm to 5 mm.

[0017] In one or more embodiments, the metal layer has a thickness in the range from 0.1 mm to 20 mm.

[0018] In one or more embodiments, the metal layer comprises a metal selected from the group of metals and their alloys comprising: aluminum, cobalt, copper, iron, magnesium, nickel, tin, and a precious metal.

[0019] In one or more embodiments, the heated region defines a heated surface portion of the glass layer, and wherein the act of rapidly cooling the heated region comprises directing a gas stream at the heated surface portion.

[0020] In one or more embodiments, gas from the gas stream flows through the glass-layer fracture line and through the metal-layer cut line and removes melted metal from the locally melted metal layer before it can solidify.

[0021] In one or more embodiments, the gas stream comprises an inert gas.

[0022] In one or more embodiments, the gas stream comprises a reactive gas.

[0023] In one or more embodiments, the gas stream comprises air, nitrogen, or oxygen.

[0024] In one or more embodiments, the glass layer has a first coefficient of thermal expansion (CTE), the metal layer has a second CTE substantially greater that the first CTE to define a CTE difference, and wherein formation of the stress region comprises adding stress the stress region due to the CTE difference.

[0025] In one or more embodiments, the laminate cut line comprises a straight line.

[0026] In one or more embodiments, the laminate cut line comprises a curve.

[0027] In one or more embodiments, the glass layer has an optical transmittance of greater than 80% at the wavelength of the laser beam.

[0028] In one or more embodiments, the glass layer has an optical transmittance of greater than 90% at the wavelength of the laser beam. [0029] In one or more embodiments, the glass layer comprises a strengthened glass.

[0030] In one aspect, a method of cutting a laminated structure defined by a glass layer attached to a metal layer is provided, comprising: directing a moving laser beam in a select direction and through the glass layer to the metal layer to form a moving hot spot in the metal layer that travels in the select direction, wherein the glass layer is not substantially heated by the laser beam; selectively heating and melting the metal layer using heat absorbed from the moving hot spot to form in the metal layer a cut that runs in the select direction by locally melting the metal layer; locally heating the glass layer using heat from the moving hot spot to form a moving heated region within the glass layer; and cooling the moving heated region to generate stress in the glass layer sufficient to form in the glass layer a fracture that runs in the select direction and that coincides with the cut in the metal layer.

[0031] In one or more embodiments, the fracture in the glass layer and the cut in the metal layer define a laminated-structure cut line that separates the laminated structure into two separate pieces.

[0032] In one or more embodiments, each of the two separate pieces has an edge defined by the laminated-structure cut line, wherein each edge has average edge strength of greater than 60 MPa.

[0033] In one or more embodiments, the laminated-structure cut line comprises a straight line.

[0034] In one or more embodiments, the laminated-structure cut line comprises a curve.

[0035] In one or more embodiments, the glass layer is attached to the metal layer by a securing layer, and wherein a portion of the securing layer is ablated by the laser beam.

[0036] In one or more embodiments, the securing layer comprises an optically clear adhesive.

[0037] In one or more embodiments, the laser beam has a wavelength in the range from 0.8 microns to 1.1 microns.

[0038] In one or more embodiments, the laser beam is generated by either a Nd:YAG laser or a diode-based fiber laser. [0039] In one or more embodiments, the glass layer has a thickness in the range from 0.10 mm to 5 mm.

[0040] In one or more embodiments, the metal layer has a thickness in the range from 0.10 mm to 20 mm.

[0041] In one or more embodiments, the metal layer comprises a metal selected from the group of metals and their alloys comprising: aluminum, cobalt, copper, iron, magnesium, nickel, tin, and a precious metal.

[0042] In one or more embodiments, the moving heated region defines a moving heated surface portion of the glass layer, and wherein the act of rapidly cooling the heated region comprises directing a gas stream at the moving heated surface portion.

[0043] In one or more embodiments, a portion of the gas stream flows through the fracture in the glass layer and the cut in the metal layer and removes melted metal from the locally melted metal layer before it can solidify.

[0044] In one or more embodiments, the gas stream comprises at least one of: a reactive gas, an inert gas, nitrogen, oxygen, and air.

[0045] In one or more embodiments, the glass layer has a first coefficient of thermal expansion (CTE), the metal layer has a second CTE substantially greater that the first CTE to define a CTE difference, and wherein formation of the stress region comprises adding stress the stress region due to the CTE difference.

[0046] In one or more embodiments, the glass layer has an optical transmittance of greater than 80% at the wavelength of the laser beam.

[0047] In one or more embodiments, the glass layer has an optical transmittance of greater than 90% at the wavelength of the laser beam.

[0048] In one or more embodiments, the glass layer comprises strengthened glass.

[0049] In one aspect, a cut glass-metal laminate product formed by a process is provided, comprising: a) attaching a glass layer to a metal layer to form a glass-metal laminate; b) directing a moving laser beam having a wavelength through the glass layer to the metal layer of the glass-metal laminate in a select direction to cause the moving laser beam to be substantially absorbed by and heat the metal layer to form a hot spot in the metal layer, wherein the hot spot forms a metal-layer cut line due to localized melting of the metal layer; c) locally heating the glass layer with heat from the hot spot formed in the metal layer to form in the glass layer a moving heated region having a strong thermal gradient; and d) rapidly cooling the moving heated region to form a glass-layer fracture line that follows the metal-layer cut line, with the glass-layer cut line and metal-layer cut line defining a laminated-structure cut line.

[0050] In one or more embodiments, the cut glass-metal laminate product comprises an edge defined by the laminated-structure cut line, wherein the edge has average edge strength of greater than 60 MPa.

[0051] In one aspect, a cut glass-metal laminate product formed by a process is provided, comprising: attaching a glass layer to a metal layer to form a glass-metal laminate; directing a moving laser beam in a select direction and through the glass layer to the metal layer of the glass-metal laminate to form a moving hot spot in the metal layer that travels in the select direction, wherein the glass layer is not substantially heated by the laser beam;

selectively heating and melting the metal layer using heat absorbed from the moving hot spot to form in the metal layer a cut that runs in the select direction by locally melting the metal layer; locally heating the glass layer using heat from the moving hot spot to form a moving heated region within the glass layer; and cooling the moving heated region to generate stress in the glass layer sufficient to form in the glass layer a fracture that runs in the select direction and that coincides with the cut in the metal layer.

[0052] In one or more embodiments, the cut glass-metal laminate product comprises an edge defined by the laminated-structure cut line, wherein the edge has average edge strength of greater than 60 MPa.

[0053] Additional features and advantages are set forth in the Detailed Description that follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the embodiments as described in the written description and claims hereof, as well as the appended drawings. It is to be understood that both the foregoing general description and the following Detailed Description are merely exemplary, and are intended to provide an overview or framework to understand the nature and character of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the Detailed Description explain the principles and operation of the various embodiments. As such, the disclosure will become more fully understood from the following Detailed Description, taken in conjunction with the accompanying Figures, in which:

[0055] FIG. 1A is an elevated view of an example glass-metal laminate structure (glass- metal laminate) formed by a top glass layer attached to a bottom metal layer using a securing layer sandwiched by the two layers, in accordance with one or more embodiments of the present disclosure.

[0056] FIG. IB is a close-up x-y cross-sectional view of a portion of the glass-metal laminate structure of FIG. 1A, in accordance with one or more embodiments of the present disclosure.

[0057] FIG. 2A is a schematic diagram of an example laser cutting system used to carry out the laser-based cutting methods disclosed herein.

[0058] FIG. 2B is an elevated view of an example glass-metal laminate illustrating the path of a laser beam from the laser cutting system of FIG. 2A as it moves relative to the glass- metal laminate structure, and showing transmission of the laser beam through the glass layer and the formation of a moving hot spot at the metal surface (the securing layer is omitted for ease of illustration), in accordance with one or more embodiments of the present disclosure.

[0059] FIG. 2C is a schematic top-down view of the temperature distribution of the hot spot in the metal layer as formed by the laser beam, with the direction of motion of the hot spot shown by the white arrow (AR), in accordance with one or more embodiments of the present disclosure.

[0060] FIGS. 3A through 3F are close-up cross-sectional schematic diagrams similar to FIG. 2A and showing the laser cutting process at different steps of the method, in accordance with one or more embodiments of the present disclosure. [0061] FIG. 4A is an elevated view of the resulting glass-laminate structure and the cut glass-laminate product (or article) cut into two sections using a straight cut, in accordance with one or more embodiments of the present disclosure.

[0062] FIG. 4B is an elevated view of the resulting glass-laminate structure and the cut glass-laminate product (or article) cut into two sections using a curved cut, in accordance with one or more embodiments of the present disclosure.

DETAILED DESCRIPTION

[0063] Reference is now made in detail to various embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same or like reference numbers and symbols are used throughout the drawings to refer to the same or like parts. The drawings are not necessarily to scale, and one skilled in the art will recognize where the drawings have been simplified to illustrate the key aspects of the disclosure.

[0064] The claims as set forth below are incorporated into and constitute part of this Detailed Description.

[0065] Cartesian coordinates are shown in some of the Figures for the sake of reference and are not intended to be limiting as to direction or orientation.

[0066] Relative terms such as "top" and "bottom" and "vertical" and "horizontal" and like terms are used for convenience and ease of discussion and explanation and are not intended to be limiting as to direction or orientation.

[0067] Glass-metal laminate structure

[0068] FIG. 1A is an elevated view of an example glass-metal laminate structure ("glass- metal laminate") 10. FIG. IB is a close-up x-y cross-sectional view of a portion of the glass- metal laminate of FIG. 1A. The glass-metal laminate 10 is formed by a top glass layer 20 attached to a bottom metal layer 30 using a securing layer 40 sandwiched by the glass and metal layers. The glass layer 20 has a body 21 with a thickness TFIG, a top surface 22 and a bottom surface 24. The metal layer 30 has a body 31 with a thickness TFIM, a top surface 32 and a bottom surface 34. The securing layer 40 has a thickness THIS. The glass-metal laminate 10 has an overall thickness THL and in an example is in the form of a substantially planar sheet such as shown in FIG. 1A. The glass layer 20 has a coefficient of thermal expansion CTE-G while the metal layer has a coefficient of thermal expansion CTE-M, wherein CTE-M » CTE-G (e.g., CTE-M is between 2X and 15X that of CTE-G).

[0069] The glass layer 20 can comprise any glass known in the art for use in forming a glass-metal laminate, including strengthened glass. Examples of strengthened glass include thermally strengthened glass (e.g., annealed glass) or chemically strengthened glass (e.g., ion-exchanged glass). Example ranges on the thickness THG of the glass layer 20 include: a) between 0.10 mm and 5 mm; b) between 0.2 and 4 mm; c) between 0.3 and 4 mm; d) between 0.5 mm and 3 mm; e) between 0.7 mm and 3 mm; and f) between 1 mm and 3 mm.

[0070] The metal layer 30 can comprise any metal known in the art for use in forming a glass-metal laminate. Example metals include aluminum, cobalt, copper, nickel, iron, magnesium, tin, precious metals (e.g., gold, silver, platinum, titanium) and various known alloys of these and other metals (e.g., stainless steels, carbon steels, etc.) and the like. Example ranges on the thickness THM of the metal layer 30 include: a) between 0.10 mm and 20 mm; b) between 0.2 mm and 15 mm; c) between 0.3 mm and 10 mm; d) between 0.7 mm and 10 mm; and e) between 1 mm and 10 mm. Example ranges on the overall thickness THL of the glass-metal laminate include: a) between about 0.20 mm and 25 mm; b) between 0.3 mm and 20 mm; c) between 0.7 mm and 15 mm; and d) between 1 mm and 10 mm.

[0071] The securing layer 40 can comprise an adhesive, such as an optically clear adhesive of the type known and used in the art of glass-metal laminates.

[0072] Laser cutting system

[0073] FIG. 2A is a schematic diagram of an example laser cutting system ("system") 100 used to carry out the laser-based cutting methods disclosed herein and described below.

The system 100 includes a system axis AS along which is arranged laser source 110, an optical system 120 and a gas stream system 130. The system axis AS is shown aligned with the y-direction, though in an example it can be at an angle to the y-direction. The gas stream system 130 is pneumatically connected to a gas supply 134 via a gas line 136. The gas supply 134 stores a gas 138. In an example, the gas 138 can comprise air or oxygen or nitrogen or an inert gas. In an example, the gas 138 can comprise or consist of a reactive gas or comprise or consist of a non-reactive gas. The laser source 110 and the optical system 120 constitute a beam delivery system 125. The beam delivery system 125 and the gas stream system 130 can be supported by a first support stage 150A. In an example, the first support stage 150A is movable (e.g., can move in the x, y and z directions), as shown in part by the movement arrow AR.

[0074] The system 100 also includes a second support stage 150B having a top surface 152B that supports the glass-metal laminate 10 so that it resides in the x-z plane. In an example, the second support stage 150B is movable, i.e., can move in the x, y and z directions. In an example, the first and second support stages 150A and 150B each comprises a precision translation stage.

[0075] The system 100 also includes a controller 180 that can be operably connected to one or more of the beam delivery system 125, the gas stream system 130, the gas source 134 and the first and second support stages 150A and 150B. The controller 180 is configured to control the operation of system 100 to carry out the laser cutting methods disclosed herein. In an example, the controller 180 includes instructions (e.g., software) embodied in a non-transient computer-readable medium to carry out the laser cutting methods disclosed herein. In an example, the controller 180 comprises a computer, a micro-controller or like device used in the art to control the operation and movements of laser-based cutting systems.

[0076] In the general operation of system 100, the laser source 110 generates a laser beam 112 of wavelength l along the system axis AS in the - y direction. In an example, the laser beam wavelength l is a near-infrared (NIR) wavelength that is not readily absorbed by the typical glass used as the glass layer 20. Example NIR wavelength ranges include from 0.75 microns to 2 microns or from 0.8 microns and 1.1 microns. Example laser sources 110 that can be used to generate such a laser beam 112 include Nd:YAG lasers and diode-based fiber lasers. In an example, the laser beam 112 comprises a series of light pulses 112P, as shown in the close-up inset II.

[0077] The optical system 120 receives and processes the laser beam 112 (e.g., expands, focuses, filters, etc.) as needed so that the laser beam 112 travels through the glass layer 20 and forms a laser spot 114 of a select size at the top surface 32 of the metal layer 30, as shown in the close-up inset 12. In an example, the laser spot 114 is substantially circular and can have a diameter DS in the range from 0.15 mm to 2.0 mm or from 0.2 mm to 1.5 mm or from 0.5 mm to 1 mm. In an example, the laser spot 114 is formed by the optical system 120 having a focal length in the range from 20 mm to 100 mm or from 30 mm to 80 mm or from 40 mm to 60 mm.

[0078] Meantime, at least one of the first and second support stages 150A and 150B moves in a select direction so that the laser beam 112 also moves, thereby scanning the laser spot 114 over the top surface 32 of the metal layer 30 at a laser spot speed SL in the select direction. Meanwhile, the gas stream system 130 directs a gas stream 132 of gas 138 to the top surface 22 of the glass layer 20 at or closely proximate to the location where the laser beam 112 is incident upon the top surface of the glass layer. In an example, the gas stream system 130 is configured so that the gas stream 132 is substantially annular and surrounds the laser beam 112. In another example, the gas stream closely follows (i.e., resides just behind) the laser beam 112 as it moves relative to the glass-metal laminate 10.

In an example, the laser spot speed SL is in the range from 2 mm/s to 350 mm/s or from 10 mm/s to 200 mm/s or from 50 mm/s to 100 mm/s.

[0079] FIG. 2B is an elevated view of an example of the glass-metal laminate 10 similar to that of FIG. 1A and illustrates an example path of the laser beam 112 as it moves relative to the glass-metal laminate in the x-direction, as illustrated by the movement arrow AR. The securing layer 40 is not shown in FIG. 2B for ease of illustration. The laser beam 112 is shown as being normally incident upon the top surface 22 of the glass layer 20. In practice, the laser beam 112 can have a slight angle relative to normal incidence to avoid back reflection to the laser source 110. A normal or near-normal incident laser beam 112 is generally beneficial to avoid reflection loss.

[0080] In one example, the glass layer 20 has an optical transmission of at least 80% at the laser beam wavelength l while in another example the optical transmission is at least 90% at the laser beam wavelength l. Thus, the laser beam 112 does not substantially heat the glass layer due to absorption of the laser beam by the glass layer 20. This allows substantially all of the energy in the laser beam 112 that enters the body 21 of the glass layer 20 to reach the top surface 32 of the metal layer 30 and form the laser spot 114 thereon (after having locally ablated or vaporized the securing layer 40, as described below).

[0081] The moving laser spot 114 heats the top surface 32 of the metal layer 30 to form a moving hot spot 116. The moving hot spot 116 moves at substantially the same speed SL as the laser spot 114. FIG. 2C is a schematic top-down view of the temperature distribution of the hot spot 116 formed by the laser spot 114, with the direction of motion of the hot spot shown by the movement arrow AR. The hot spot 116 rapidly heats the metal layer 30 due to the high heat conduction of metal, as explained below. The hot spot 116 shown in FIG. 2C includes example temperature contours to illustrate an elongate temperature distribution along the direction of motion due to heat diffusion effects. For an example laser spot size (diameter) DS of 0.025 mm and for a laser spot speed SL of 2.0 meters/minute, the length H L of the hot spot 116 as defined by the 200 °C contour is about 0.15 mm and the width FIW is about 0.05 mm. Note that the example temperature of 1500 °C of the hottest portion the hot spot (i.e., the dark oval in FIG. 2C) exceeds the melting temperature of the given metal layer 30.

[0082] Example operational parameters for system 100, such as the amount of energy per light pulse 112P, frequency of the light pulses, and speed SL of the laser spot 114 are based on the particular materials used to form the glass-metal laminate 10 being cut. In experiments, an example glass-metal laminate 10 was formed using a chemically strengthened glass layer 20 having a thickness THG of 0.25 mm, an aluminum metal layer 30 having a thickness of about 0.5 mm and an optically clear adhesive as the securing layer 40. An Nd:YAG fiber laser source 110 with an operating wavelength l of 1.06 microns, a light- pulse energy of about 2 kilowatts, a light-pulse frequency (repetition rate) of 450 Hz and a laser spot speed SL of 2 meters/min was effectively employed in system 100. The gas stream system 130 utilized air as the gas 138 for the gas stream 132. The air-based gas stream 132 was annular and surrounded the laser beam 112 and was directed to the top surface 22 of the glass layer 20. The annular gas stream 132 was formed using an annular gas nozzle. The edge strength of the resulting cut glass-metal laminate 10P (see FIGS. 4A,

4B, introduced and discussed below) was measured at 71.2 MPa. The laser cutting methods disclosed herein can in example embodiments provide an average edge strength of greater than 60 MPa without additional edge finishing of the resulting cut glass-metal laminate (i.e., cut glass-metal product or article).

[0083] Forming a cut line in the glass-metal laminate

[0084] FIGS. 3A through 3F are close-up y-z cross-sectional schematic diagrams similar to FIG. 2A showing the laser cutting method at different steps using the system 100 of FIG. 2A. In these Figures, the motion of the laser beam 112 is in the +x-direction, which is out of the page. Also in these Figures, the timing of the various events has been adjusted since the actual timing of events occurs very fast, as discussed below.

[0085] With reference to FIG. 3A, the laser beam 112 travels through the glass layer 20 without being substantially absorbed and is incident upon the securing layer 40. The irradiated portion of the securing layer 40 ablates very quickly so that the (moving) laser spot 114 irradiates the top 32 of the metal layer 30 to form the (moving) hot spot 116. Fleat from the moving hot spot 116 locally heats the portion of the body 31 of the metal layer 30 underneath the hot spot 116 to the melting point and starts to form a metal cut line 202 that extends downward toward the bottom surface 34 of the metal layer and eventually reaches the bottom surface.

[0086] Meantime, with reference to FIG. 3B, the heat from the metal layer 30 caused by absorption of the laser beam 112 at the laser spot 114 transfers to the glass layer 20 by heat conduction and forms a localized heated region 21H within the body 21 of the glass layer. The heated region 21H is defined by a strong thermal gradient 210 as illustrated by dashed temperature contour lines CL. The heated region 21H defines a heated surface portion 22H of the top surface 22 of the glass layer 20. In an example, the peak glass temperature within the heated region 21H of the glass layer body 21 approaches the glass softening point but does not reach the glass melting point. FIG. 3B also shows a completed metal cut line 202 through the metal layer 30. Note that the heated surface portion 22H moves along with the moving heated region 21H as the laser beam 112 moves relative the glass-metal laminate 10. Local heating as used in the present application can mean an area less than or equal to 1000 urn.

[0087] FIG. 3C shows the application of the gas stream 132 to the heated surfaced portion 22H of the glass layer 20 associated with the heated region 21H of the glass layer. The gas stream 132 acts to rapidly cool the heated region 21H of the glass layer 20. In FIGS. 3C through 3F, the laser beam 112 is not shown because in the example considered the laser beam has already moved on to irradiate the next portion of the metal layer 30.

[0088] FIG. 3D shows the method at the time where the heated region 21H of the glass layer 20 has been rapidly cooled by the gas stream 132. This rapid cooling generates large amounts of stress S in the glass body 21 and converts the heated region 21H into a stress region 21S. The stress region 21S includes a vertical centerline CS at which forms a fracture line 204, as shown in FIG. 3E. Contributing to the buildup of stress S in the stress region 21S is the differential in the thermal expansion EG of the glass layer 20 versus the thermal expansion EM of the metal layer 20 since the metal layer has a coefficient of thermal expansion CTE-M that is substantially larger than the coefficient of thermal expansion CTE-G of the glass layer, and noting that the two layers remain secured to one another by the remaining portion of the securing layer 40. The fracture line 204 forms rapidly in response to the rapid buildup of stress S in the stress region 21S. The buildup of stress S in the stress region 21S is performed with the intent of exceeding the ability of the glass to handle the amount and speed of the stress formation to force the formation of the fracture line 204.

[0089] FIG. 3F shows how the fracture line 204 defines a gap through which travels a portion of the gas stream 132. This portion of the gas stream 132 serves to carry away from the bottom 34 of the metal layer 30 the melted portion (dross) 33 from the metal layer 30.

In an example, the second support stage 150B can be configured to accommodate the carrying away of the melted portion 33 of the metal layer 30 during laser processing.

[0090] As noted above, the above-described steps of the method occur rapidly, e.g., all within a fraction of a second and in an example, on the order of milliseconds. For a laser spot speed SL of 10 feet/minute (or about 50 mm/s) and a laser spot size DS of 1 mm, the dwell time T _D of the laser spot over a given point on the scanned top surface 32 of the metal layer 30 is T _D = (DS)/(SL) = (1 mm)/(50 mm/s) = 0.02 seconds or 20 milliseconds. The high thermal conductivity of metal results in the metal layer 30 reaching its melting temperature within the dwell time T _D and defining the metal cut line 202. The formation of the heated region 21H in the body 21 of the glass layer 20 by heat conduction from the metal layer 30, followed by the rapid cooling by the gas stream 132 and formation of the stress region 21S in response thereto, occurs by the time the laser spot 114 has just moved away the point on the metal layer 30 being heated. The fracture line 204 forms in the glass layer body 21 essentially immediately (e.g., within microseconds) upon the formation of the stress region 21S. Thus, by the time the laser spot 114 has moved away from the irradiated location by a distance equal to the laser spot diameter DS (which takes another 20 milliseconds), the fracture line 204 has formed. The lengths of the metal cut line 202 and the fracture line 204 grow, closely following on the heels of the moving laser spot 114. FIG. 2B also shows an example of a linear fracture line 204 (the metal cut line 202 is not shown in FIG. 2B).

[0091] After the laser spot 114 moves on, the remaining heated portions of the glass layer 20 and metal layer 30 cool quickly, and any molten metal re-solidifies. In this case, the re solidified edge portion of the metal layer 30 may exert compressive stresses on the corresponding edge portion of the glass layer 20, thereby enhancing the edge strength of the glass layer.

[0092] FIG. 3F shows that the combination of the metal cut line 202 in the metal layer 30 and the fracture line 204 in the glass layer 20 define a laminate cut line 206 that in an example defines first and second separated sections 10A and 10B of the glass-metal laminate 10. The resulting cut glass-metal laminate 10 also constitutes a cut glass-metal laminate product or article 10P.

[0093] FIG. 4A is an elevated view of an example glass-metal laminate 10 wherein the laminate cut line 206 is a straight line. This linear laminate cut line 206 separates the glass- metal laminate into separated first and second sections 10A and 10B having straight cut edges 12A and 12B. FIG. 4B is similar to FIG. 4A and shows an example where the laminate cut line 206 is curved so that the cut edges 12A and 12B of the first and second sections 10A and 10B are also curved. The coordinated operation of system 100 (e.g., by the controller 180) can be used to form a cut line 206 having any reasonable shape, including relatively complex shapes. The use of precision first and second support stages 150A and 150B under the operation of the controller 180 can be used to generate cut lines 208 having a variety of curved or linear (e.g., rectangular zig-zag) shapes to form a variety of cut glass-metal laminate products (articles) 10P. [0094] The systems and methods disclosed herein can provide cutting rates of greater than 5 meters per minute while forming acceptable cut edges 12A and 12B (e.g., with glass edge chip sizes of less than 0.4 mm).

[0095] Cut glass-metal laminate product

[0096] As noted above, embodiments of the disclosure are directed to cut glass-metal laminate products (or articles) 10P (see FIGS. 4A, 4B) formed using the processes (methods) as described herein. A first embodiment of the cut glass-metal laminate product 10P is formed by a process comprising: a) attaching the glass layer 20 to the metal layer 30 to form the glass-metal laminate 10; b) directing the moving laser beam 112 having a wavelength through the glass layer 20 to the metal layer 30 of the glass-metal laminate 10 in a select direction to cause the moving laser beam to be substantially absorbed by and heat the metal layer to form a hot spot 116 in the metal layer, wherein the hot spot forms a metal- layer cut line 202 due to localized melting of the metal layer; c) locally heating the glass layer 20 with heat from the hot spot 116 formed in the metal layer 30 to form in the glass layer a moving heated region 21H having a strong thermal gradient; and d) rapidly cooling the moving heated region 21H to form a glass-layer fracture line 204 that follows the metal- layer cut line 202, with the glass-layer cut line and metal-layer cut line defining a laminated- structure cut line 206.

[0097] A second embodiment of the cut glass-metal laminate product (article) 10P is formed by a process comprising: attaching the glass layer 20 to the metal layer 30 to form the glass-metal laminate 10; directing the moving laser beam 112 in select direction and through the glass layer 20 to the metal layer 30 of the glass-metal laminate to form a moving hot spot 116 in the metal layer that travels in the select direction, wherein the glass layer is not substantially heated by the laser beam; selectively heating and melting the metal layer 30 using heat absorbed from the moving hot spot 116 to form in the metal layer a cut line 202 that runs in the select direction by locally melting the metal layer; locally heating the glass layer 20 using heat from the moving hot spot 116 to form a moving heated region 21H within the glass layer; and cooling the moving heated region 21H (e.g., using the gas stream 132) to generate stress S in the glass layer 20 sufficient to form a fracture 204 in the glass layer 20 that runs in the select direction and that coincides with the cut 202 in the metal layer 30. [0098] In examples, the cut glass-metal laminate product 10P can comprise one or both of the separated sections 10A and 10B, such as shown in FIGS. 4A and 4B.

[0099] It will be apparent to those skilled in the art that various modifications to the preferred embodiments of the disclosure as described herein can be made without departing from the spirit or scope of the disclosure as defined in the appended claims.

Thus, the disclosure covers the modifications and variations provided they come within the scope of the appended claims and the equivalents thereto.