Heremetically sealed glass packages and method of preparing same

Abstract

Disclosed herein are embodiments of a hermetically sealed device. The device includes a first glass substrate with first and second major surfaces and a first minor surface extending around a first periphery of the first glass substrate and connecting the first and second major surfaces. The device further includes a second glass substrate with third and fourth major surfaces and a second minor surface extending around a second periphery of the second glass substrate and connecting the third and fourth major surfaces. A functional layer is disposed between the the first glass substrate and the second glass substrate. A sealing element is fused to the first and second minor surfaces, which seals the functional layer between the first glass substrate and the second glass substrate.

Description

HEREMETICALLY SEALED GLASS PACKAGES AND METHOD OF PREPARING SAMECross-reference to Related Applications

[0001] This application claims the benefit of priority of U.S. Provisional Application Serial No. 63 / 603,711, filed on November 29, 2023, the content of which is relied upon and incorporated herein by reference in its entirety.BACKGROUND

[0002] The disclosure relates to a heremetically sealed glass package and more particularly to a stack of glass substrates and functional layer sealed with a sealing element.

[0003] Heremetically sealed glass and metal foil packages are used in a variety of electronics and other devices requiring a heremtic environment for sustained operation. Such devices include televisions, sensors, optical devices, organic light emitting diode (OLED) displays, 3D inkjet printers, solid-state lighting sources, batteries, and photo-voltaic structures. A functional layer is disposed between two glass substrates and heremetically sealed with a metal foil. In existing packages, the metal foil extends over the surfaces of the glass substrates, blocking portions of the surfaces from usability.SUMMARY

[0004] According to a first aspect, embodiments of the present disclosure relate to a device. The device comprises a first glass substrate comprising a first major surface, a second major surface opposite to the first major surface, and a first minor surface extending around a first periphery of the first glass substrate and connecting the first major surface to the second major surface. The device further comprises a second glass substrate comprising a third major surface, a fourth major surface opposite to the third major surface, and a second minor surface extending around a second periphery of the second glass substrate and connecting the third major surface to the fourth major surface. A functional layer is disposed between the second major surface of the first glass substrate and the third major surface of the second glass substrate. A sealing element is fused to the first minor surface of the first glass substrate and to the second minor surface of the second glass substrate. The sealing element hermetically seals the functional layer between the first glass substrate and the second glass substrate.

[0005] According to a second aspect, embodiments of the present disclosure relate to a method. In the method, a first glass substrate, a functional layer, and a second glass substrate are arranged in a stack such that the functional layer is disposed between the first glass substrateand the second glass substrate. A sealing element is laser- welded to a first peripheral edge of the first glass substrate and to a second peripheral edge of the second glass substrate so that the functional layer is hermetically sealed between the first glass substrate and the second glass substrate. The first glass substrate comprises a first major surface substantially perpendicular to the first peripheral edge and the second glass substrate comprises second major surface substantially perpendicular to the second peripheral edge. The sealing element does not cover the first major surface or the second major surface. Thus, preferably the sealing element does not cover any part of the first major surface or the second major surface, that is, the first major surface and the second major surface are free of the sealing element.

[0006] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0007] 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 understanding the nature and character of the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] 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 description serve to explain principles and operation of the various embodiments. In the drawings:

[0009] FIG. 1 depicts a heremetically sealed device, according to one or more exemplary embodiments;

[0010] FIG. 2 depicts a sealing element being laser welded to a first glass substrate of the hermetically sealed device, according to one or more exemplary embodiments;

[0011] FIG. 3 depicts a sealing element being laser welded to a second glass substrate through a first glass substrate and a functional layer of the hermetically sealed device, according to one or more exemplary embodiments;

[0012] FIG. 4 depicts a laser setup for laser welding the sealing element to a glass substrate of the hermetically sealed device, according to one or more exemplary embodiments;

[0013] FIGS. 5A-5C depict minor surfaces of glass substrates having optically flat regions and rough regions, according to one or more exemplary embodiments;

[0014] FIG. 6 is a flow diagram of a method for laser cutting a glass substrate from a glass sheet to form an optically flat region, according to one or more exemplary embodiments;

[0015] FIG. 7 depicts a sealing element disposed around a hermetically sealed device with a gap between opposite ends of the sealing element, according to one or more exemplary embodiments;

[0016] FIGS. 8A and 8B depict two types of patches configured to seal a gap between ends of the sealing element, according to one or more exemplary embodiments;

[0017] FIG. 9 depicts ends of the sealing element fused together, according to one or more exemplary embodiments;

[0018] FIG. 10 depicts a sealing element with tabs provided on ends of the sealing element configured to allow for the ends of the sealing element to be pulled into abutment for welding, according to one or more embodiments;

[0019] FIG. 11 depicts a sealing element with pulling elements attached thereto configured to facilitate pulling of ends of the sealing element into abutment and a block on which to position the hermetically sealed device to facilitate laser welding of the ends, according to one or more embodiments;

[0020] FIGS. 12A and 12B depict a continuous and seamless sealing element in a contracted state around the device and an expanded state to allow for positioning of the sealing element around the device, according to one or more exemplary embodiments;

[0021] FIG. 13 depicts an arbor configured to facilitate elastic expanding of the sealing element for positioning around the glass substrates of the hermetically sealed device, according to one or more embodiments;

[0022] FIG. 14 depicts a method of laser welding a continuous strip of sealing element to glass substrates of a hermetically sealed device, according to one or more embodiments; and

[0023] FIG. 15 depicts an overlap region of ends of the sealing element sealed with epoxy, according to one or more exemplary embodiments.DETAILED DESCRIPTION

[0024] Reference will now be made in detail to various embodiments of a heremetically sealed device having a functional layer disposed between two glass substrates, examples of which are illustrated in the accompanying drawings. The device includes a sealing element laser-welded to peripheral edges of the glass substrates to hermetically seal the functional layer between the glass substrates. In contrast to certain existing heremetically sealed packages, the sealingelement does not cover upper or lower surfaces of the glass substrates and is only bonded to the peripheral edges, thus, preferably the sealing element does not cover any part of the first major surface or the second major surface, that is, the first major surface and the second major surface are free of the sealing element, thereby maximizing the aperture of the device. These and other aspects and advantages of the disclosed hermetically sealed device will be described more fully below. The embodiments discussed herein are presented by way of illustration and not limitation.

[0025] FIG. 1 depicts an embodiment of a hermetically sealed device 100. The device includes a first glass substrate 102, a second glass substrate 104, a functional layer 106 disposed between the first glass substrate 102 and the second glass substrate 104, and a sealing element 108 that hermetically seals the functional layer 106 between the first glass substrate 102 and the second glass substrate 104. As used herein, “hermetically bonded” or “hermetically sealed” refers to a package that includes a hermetic seal in accordance with MIL-STD-750E, Test Method 1071.9.

[0026] The first glass substrate 102 comprises a first major surface 110 and a second major surface 112. The second major surface 112 is opposite to the first major surface 110. A first minor surface 114 extends around a first periphery of the first glass substrate 102 and connects the first major surface 110 to the second major surface 112. In this way, the first minor surface 114 defines a first peripheral edge of the first glass substrate 102.

[0027] The second glass substrate 104 comprises a third major surface 116 and a fourth major surface 118. The fourth major surface 118 is opposite to the third major surface 116. A second minor surface 120 extends around a second periphery of the second glass substrate 104 and connects the third major surface 116 to the fourth major surface 118. In this way, the second minor surface 120 defines a second peripheral edge of the second glass substrate 104.

[0028] The functional layer 106 is disposed between the second major surface 112 of the first glass substrate 102 and the third major surface 116 of the second glass substrate 104. In one or more embodiments, the functional layer 106 may be, for example, a display module, a dielectric material, a nano-imprint lithography grating pattern, an electrochromic module, or a gas, among other possibilities. For example, the functional layer 106 may be a display module, such as an organic light emitting diode (OLED) display or a liquid crystal display (LCD), for an electronic display, such as a television, phone, or other display device. In another example, the functional layer 106 may be a nano-imprint lithography grating pattern configured to direct and project light for an augmented reality device. In still another example, the functional layer 106 may be an electrochromic module configured to transmit, block, or alter light as it passesthrough the device 100 in response to an electrical signal, such as a privacy screen (e.g., window or door). In yet another embodiment, the functional layer 106 may be a gas, such as argon gas, to provide insulation between the glass substrates 102, 104, such as for insulated window or architectural glazing applications. These examples are merely illustrative, and other types of functional layers 106 that may benefit from or require heremetic sealing can also be used.

[0029] The sealing element 108 is disposed around the peripheral edges of the first glass substrate 102 and the second glass substrate 104. The sealing element 108 is fused, in particular through laser welding, to the first minor surface 114 of the first glass substrate 102 and to the second minor surface 120 of the second glass substrate 104. Advantageously, according to embodiments of the present disclosure, the sealing element 108 does not cover the first major surface 110 of the first glass substrate 102 or the fourth major surface 118 of the second glass substrate 104, thus, preferably the sealing element does not cover any part of the first major surface or the second major surface, that is, the first major surface and the second major surface are free ofthe sealing element, permitting the widest possible aperture forthe device 100. That is, the entire first major surface 110 of the first glass substrate 102 and the fourth major surface 118 of the second glass substrate 104 are available to transmit light as they are devoid of the sealing element which would otherwise block the available aperture. In contrast, certain existing heremtically sealed devices include sealing elements that are joined to the first major surface and to the second major surface of the glass substrates, covering millimeters of the glass substrates and decreasing the available aperture.

[0030] In one or more embodiments, the sealing element 108 is a metal foil or a flexible glass strip. In one or more embodiments in which the sealing element 108 is a metal foil, the metal foil is formed from a metal having a melting temperature less than the melting temperature of the glass. In one or more embodiments, the metal foil is comprised of aluminum, copper, nickel, zinc, silver, or alloys thereof, or stainless steel. In one or more embodiments, the metal foil has a thickness in a range from 5 pm to 200 pm, in particular in a range from 10 pm to 50 pm. With respect to the sealing element 108 in the form of a glass strip, the glass strip can be made thin enough so as to be flexible and bend around the first glass 102 substrate and the second glass substrate 104.

[0031] In one or more embodiments, the sealing element 108 is fused to the glass substrates 102, 104 through laser welding techniques. In one or more embodiments, the laser is pulsed in nanosecond durations, such as pulse durations in a range from 1 nanosecond to 100 nanoseconds. In one or more embodiments, the laser has a wavelength of 355 nm, 532 nm, or1064 nm. In one or more embodiments, the energy of each pulse is in a range of 5 microjoules to 50 microjoules. In one or more embodiments, the laser pulses overlap 50% to 99%, in particular 80% to 95%. In one or more embodiments, the laser has a spot size in a range from 2 pm to 15 pm, in particular 3 pm to 10 pm.

[0032] In one or more embodiments as shown in FIG. 2, laser-welding the sealing element 108 to the first glass substrate 102 involves directing a laser beam 120 through the first major surface 110 of the first glass substrate 102 at a first angle 0i relative to the first minor surface 114. In one or more embodiments, the first angle 0i is less than 90°, in particular in a range of 20° to 60°, and most particularly at an angle of about 30°. If the angle is too close to normal (i.e., 0° relative to the first minor surface 114), it is difficult to form a focal spot on the sealing element 108 sufficient to form a laser weld 122. If the angle is too high (approaching 90° relative to the first minor surface 114), much of the light is reflected from the first major surface 110 of the first glass substrate 102.

[0033] In one or more embodiments, the laser beam 120 is directed through the fourth major surface 118 of the second glass substrate 104 at a second angle 02 relative to the second minor surface 120. In such embodiments, the second angle 02 may be the same as the first angle 0i. That is, the device 100 is repositioned relative to the laser beam 120 such that the laser beam 120 is incident on the fourth major surface 118. For example, the laser beam 120 may remain stationary, and the device 100 is flipped over to expose the fourth major surface 118 to the laser beam 120. Alternatively, the device 100 remains stationary, and the laser beam 120 may be moved to the other side of the device 100 such that the laser beam 120 is incident on the fourth major surface 118.

[0034] In one or more alternative embodiments, as shown in FIG. 3, the laser beam 120 is directed onto the first major surface 110 at a second angle 02 such that the laser beam 120 passes through the first glass substrate 102 and through the functional layer 106 into the second glass substrate 104. The second angle 02 is selected such that the laser beam 120 is incident on second minor surface 120 of the second glass substrate 104 so as to weld the sealing element 108 to the second minor surface 120.

[0035] Because the laser beam 120 is directed through the glass substrates 102, 104 at an angle, aberration of the beam 120 may prevent a beam of a certain power from creating the laser weld 122 or require significant additional power to create the laser weld 122. In one or more embodiments as shown in FIG. 4, to provide the appropriate focal spot size and angle to create the laser weld 122 in an economical process, the laser beam 120 is directed through an plano- convexlens 124 and a cylindrical lens 126 prior to being directed through the first major surface110 of the first glass substrate 102 or through the fourth major surface 118 as the case may be. In one or more embodiments, the plano-convex lens 124 has a focusing length of 100 mm, and in one or more embodiments, the cylindrical lens 126 has a focusing length of 1000 mm. In one or more embodiments, the plano-convex lens 124 has a curvature of 51.544 mm, and in one or more embodiments, the cylindrical lens 126 has a curvature of 519.473 mm. In one or more embodiments, a spacing between the plano-convex lens 124 and the cylindrical lens 126 is 42.336 mm, and in one or more embodiments, the distance between the cylindrical lens 126 and the first major surface 110 (or fourth major surface 118) is 34.379 mm. Additional disclosure regarding the lens and laser configurations for laser welding can be found in U.S. Provisional Application No. 63 / 523,196 (“Laser Bonding of Glass to Materials,” filed on June 26, 2023), which is incorporated herein in its entirety by reference thereto.

[0036] To facilitate laser welding, the minor surfaces 114, 120 may be prepared in such as way as to facilitate hermetic sealing with the sealing element 108. In particular, in one or more embodiments as shown in FIGS. 5A-5C, the first minor surface 114 and the second minor surface 120 are laser cut such that the first minor surface 114 and the second minor surface 120 comprise respective optically flat regions 128 and respective rough regions 130. The sealing element 108 is fused to the first minor surface 114 and the second minor surface 120 in the respective optically flat regions 128.

[0037] In one or more embodiments, the optically flat regions 130 can be prepared according to the disclosure of U.S. Patent No. 11,054,574 (“Methods of singulating optical waveguide sheets to form optical waveguide substrates,” filed on May 16, 2019, and issued on July 6, 2021). As generally disclosed therein, the optically flat regions 130 are formed by a method 200 as shown in the flow diagram of FIG. 6. In a first step 201 of the method 200, a glass sheet is irradiated with a focused laser beam at discrete locations along a first irradiation path to form spaced apart first modified regions that define at least one first modified section within the thickness of the glass sheet and extending across the thickness of the glass sheet. The spaced apart first modified regions also define at least one first unmodified section extending across the thickness of the glass sheet. In a second step 202, the glass sheet is separated along the first irradiation path to create the first glass substrate 102 comprising the first minor surface 114. Along the first minor surface 114, the at least one first modified section comprises a first surface roughness, and the at least one first unmodified section comprises a second surface roughness. The first surface roughness is greater than the second surface roughness. Thus, the modified section defines the rough regions 130 shown in FIGS. 5A-5C, and the unmodified sections define the optically flat regions 128. In a third step 203 of the method 200, the secondglass substrate 104 is cut from the same glass sheet or from another glass sheet in the same manner as the first glass substrate 102.

[0038] In order to provide an adhequate hermetic seal around the functional layer 106, the sealing element 108 needs to provide hermetic sealing around the entire periphery, or substantially the entire periphery if provided with additional sealing material, of the first glass substrate 102 and the second glass substrate 104. In order to provide such sealing, the following discussion relates to ways to laser weld the sealing element 108 to the glass substrates 102, 104 and terminate those welds in a hermetic manner. In certain embodiments, as shown in FIG. 7, the sealing element 108 comprises a first end 132 and a second end 134, and the sealing element 108 extends around the first periphery of the first glass substrate 102 and around the second periphery of the second glass substrate 104 from the first end 132 to the second end 134. The second end 134 terminates proximal to the first end 132. In one or more embodiments, a gap 136 may exist between the first end 132 and the second end 134. In one or more embodiments, the gap 136 may be in a range from 0 pm to 150 pm. This gap 136 must be sealed to ensure complete hermetic sealing of the functional layer 106.

[0039] Thus, in one or more embodiments as shown in FIG. 8A, the sealing element 108 further comprises a patch 138 covering the first end 132 and the second end 134. In one or more embodiments, as shown in FIG. 8A, the patch 138 comprises epoxy 140. Advantage souly, using the sealing element 108 with only a patch of epoxy 140 limits the amount of epoxy used to hermetically seal the functional layer 106. In contrast to the metal foil or glass strip of the sealing element 108, epoxy has a higher leak rate, and therefore, it is desirable to limit its use in the sealing element 108. Here, because the epoxy 140 only provides a small patch over the gap 136 between the ends 132, 134 of the sealing element 108, the sealing element 108 still provides robust hermetic sealing of the functional layer 106.

[0040] In one or more other embodiments, as shown in FIG. 8B, the patch 138 comprises a foil 142 wrapped around the first end 132 and the second end 134. In one or more embodiments, the foil 142 is laser welded to the strip of the sealing element 108 and / or to the minor surfaces 114, 120 of the glass substrates 102, 104.

[0041] In one or more embodiments, as shown in FIG. 9, the sealing element 108 extends around the first periphery of the first glass substrate 102 and around the second periphery of the second glass substrate 104 from the first end 132 to the second end 134 such that the second end 134 abuts the first end 132. In one or more such embodiments, the first end 132 is fused to the second end 134 with a laser weld 144.

[0042] In order to abut the second end 134 to the first end 132 while maintaining a tight engagement with the minor surfaces 114, 120 to provide the hermetic seal, the sealing element 108 needs to be tensioned during laser welding to fuse the first end 134 to the second end 132. FIGS. 10 and 11 provide examples of features that can be used to abut the first end 132 and the second end 134 while maintaining tight engagement of the sealing element 108 with the minor surfaces.

[0043] In FIG. 10, the first end 132 includes at least one first tab 146 that can be pulled in a first direction 148, and the second end 134 includes at least one second tab 150 that can be pulled in a second direction 152. The tabs 146, 150 allow for the ends 132, 134 to be pulled tangentially to the periphery of the glass substrates 102, 104. In this way, the sealing element 108 remains in tight engagement with the minor surfaces 114, 120 while abutting the first end 132 with the second end 134. A laser can then weld the first end 132 to the second end 134, forming a weld seam 144 at the abutment. After the ends 132, 134 are joined, the tabs 146, 150 can be trimmed, such as by scoring, grinding, or laser ablating.

[0044] In FIG. 11, the first end 132 and the second end 134 are abutted by pulling on pulling elements attached to the sealing element 108. In particular, a first pulling element 154 is attached to the sealing element 108 at a first location 156 between the first end 132 and the second end 134 in which the first location 156 is closer to the first end 132 than to the second end 134. A second pulling element 158 is attached to the sealing element 108 at a second location 160 between the first end 132 and the second end 134 in which the second location 160 is located closer to the second end 134 than to the first end 132. The stack of the glass substrates 102, 104 with functional layer 106 disposed therebetween and with the sealing element 108 positioned therearound is positioned on a block 162. The block 162 includes a seat 164 having a shape complementary to the peripheral shape of the device 100. The device 100 is seated on the block such that the first minor surface 114 and the second minor surface 120 of the glass substrates 102, 104 are facing the seat 164 of the block 162. Further, the first end 132 and the second end 134 are disposed between glass substrates 102, 104 and the block 162. After the device 100 is positioned on the block 162, the pulling elements 154, 158 are pulled to bring the first end 132 and the second end 134 into abutment. After the ends 132, 134 are abutted, a laser beam is directed through the block 162 to weld the first end 132 to the second end 134. To direct the laser beam through the block 162, the block 162 may include an aperture at the location where the first end 132 and the second end 134 abut, or the block 162 may be sufficiently transparent to the laser beam to allow the beam to travel through the block 162 with sufficient focus to allow for welding of the first end 132 to the second end 134.

[0045] In one or more embodiments, the pulling elements 154, 158 are spot welded to the sealing element 108. In order to remove the pulling elements 154, 158 after the first end 132 is joined to the second end 134, the pulling elements 154, 158 can be cut, polished, ground, or otherwise mechanically removed from the sealling element 108. In one or more other embodiments, the pulling elements 154, 158 can be joined to the sealing element 108 using a perforated seam. Such a perforated seam would allow for the pulling elements 154, 158 to be pulled in a way the tensions the sealing element 108 around the glass substrates 102, 104, but when pulled in the opposite direction after joining the first end 132 and the second end 134, the pulling elements 154, 158 would split and tear away from the sealing element 108.

[0046] In one or more embodiments, such as shown in FIGS. 12A and 12B, the sealing element 108 is continuous and seamless around the first glass substrate 102 and the second glass substrate 104. In one ormore such embodiments, the sealing element 108 defines aring having a perimeter that is substantially the same as the perimeter of the device 100. In one or more such embodiments, the sealing element 108 is expanded (as shown in FIG. 12B) to fit around the device 100 and contracted (as shown in FIG. 12A) to bring the sealing element 108 into tight engagement with the minor surfaces 114, 120.

[0047] In one or more embodiments, the sealing element 108 is expanded and contracted thermally. In particular, the sealing element 108 may be expanded by heating the sealing element 108 an amount sufficient to cause thermal expansion of the sealing element 108. Thereafter, the sealing element 108 can be cooled to cause the sealing element 108 to contract around the glass substrates 102, 104. The amount of heating necessary to allow the sealing element 108 to expand to fit around the glass substrates 102, 104 can be calculated according to methods known in the art based on the coefficient of thermal expansion of the material and the perimeter length of the sealing element 108.

[0048] In one ormore other embodiments, the sealing element 108 is expanded and contracted elastically around the glass substrates 102, 104. The elastic expandability of the sealing element can be determined from the modulus of elasticity and yield strength of the material from which the sealing element 108 is made. In one or more such embodiments, the sealing element 108 is configured such that the sealing element 108 can be elastically deformed to fit around the glass substrates 102, 104 without exceeding about 75% of the yield strength of the material of the sealing element 108. In one or more such embodiments, fitting the sealing element 108 around the glass substrates 102, 104 is facilitated with the use of an arbor 166 as shown in FIG. 13. As can be seen the arbor 166 includes a first end 168 and a second end 170. The second end 170 is positioned at least partially around the glass substrates 102, 104, and thesealing element 108 is positioned over the first end 168. Between the first end 168 and the second end 170 is a tapered surface 172 that gradually increases in diameter. In this way, the sealing element 108 can be moved from the first end 168 to the second end 170 with the arbor 166 expanding the perimeter of the sealing element 108 to fit around the glass substrates 102, 104. When the sealing element 108 reaches the second end 170, the arbor 166 is removed from around the glass substrates 102, 104, allowing the sealing element 108 to elastically contract around the glass substrates 102, 104.

[0049] In still another embodiment, a continuous strip of sealing element 108 is welded to the minor surfaces 114, 120 of the glass substrates 102, 104 as shown in FIG. 14. As can be seen in FIG. 14, the continuous strip of sealing element 108 can be paid off from a spool 174 of sealing element 108. As the sealing element 108 is unwound from the spool 174, the sealing element 108 can be kept in tension to provide a tight engagement of the sealing element 108 with the minor surfaces 114, 120 of the glass substrates 102, 104. While the sealing element 108 is being unwound or otherwise paid out, a laser beam 120 welds the sealing element 108 to the glass substrate 102, 104. Once the sealing element 108 has been welded around the entire perimeter of the glass substrates 102, 104, the continuous strip of sealing element 108 may be cut, leaving a second end 134 as shown in FIG. 15. As can be seen there, the second end 134 may overlap with the first end 132, leaving a small leak path 176 adjacent to the overlap. As shown in FIG. 15, this leak path 176 can be sealed with an epoxy 140 to complete the heremetic seal.

[0050] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that any particular order be inferred. In addition, as used herein, the article “a” is intended to include one or more than one component or element, and is not intended to be construed as meaning only one.

[0051] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the disclosed embodiments. Since modifications, combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the embodiments may occur to persons skilled in the art, the disclosed embodiments should be construed to include everything within the scope of the appended claims and their equivalents.

Claims

What is claimed is:1 . A device, comprising: a first glass substrate comprising a first major surface, a second major surface opposite to the first major surface, and a first minor surface extending around a first periphery of the first glass substrate and connecting the first major surface to the second major surface; a second glass substrate comprising a third major surface, a fourth major surface opposite to the third major surface, and a second minor surface extending around a second periphery of the second glass substrate and connecting the third major surface to the fourth major surface; a functional layer disposed between the second major surface of the first glass substrate and the third major surface of the second glass substrate; and a sealing element fused to the first minor surface of the first glass substrate and to the second minor surface of the second glass substrate; wherein the sealing element hermetically seals the functional layer between the first glass substrate and the second glass substrate.

2. The device of claim 1, wherein the sealing element is present neither on the first major surface of the first glass substrate nor on the fourth major surface of the second glass substrate.

3. The device of claim 1 or claim 2, wherein the sealing element comprises a metal foil.

4. The device of claim 1 or claim 2, wherein the sealing element comprises a glass strip.

5. The device of any one of claims 1-4, wherein the first minor surface and the second minor surface are laser cut such that the first minor surface and the second minor surface comprise respective optically flat regions and respective rough regions and wherein the sealing element is fused to the first minor surface and the second minor surface in the respective optically flat regions.

6. The device of any one of claims 1-5, wherein the sealing element comprises a first end and a second end, wherein the sealing element extends around the first periphery of the first glass substrate and around the second periphery of the second glass substrate from the first end to the second end, wherein the second end is proximal to the first end, and wherein sealing element further comprises a patch covering the first end and the second end.

7. The device of claim 6, wherein the patch comprises epoxy.

8. The device of claim 6, wherein the patch comprises a foil wrapped around the first end and the second end.

9. The device of any one of claims 1-5, wherein the sealing element comprises a first end and a second end, wherein the sealing element extends around the first periphery of the first glass substrate and around the second periphery of the second glass substrate from the first end to the second end, wherein the second end abuts the first end, and wherein the first end is fused to the second end.

10. The device of any one of claims 1-5, wherein the sealing element is continuous and seamless around the first glass substrate and the second glass substrate.

11. The device of any one of claims 1-10, wherein the functional layer comprises a display module.

12. The device of any one of claims 1-10, wherein the functional layer comprises a nanoimprint lithography grating pattern.

13. The device of any one of claims 1-10, wherein the functional layer comprises an electrochromic material.

14. The device of any one of claims 1-10, wherein the functional layer comprises a gas or a dielectric material.

15. A method, comprising: arranging a first glass substrate, a functional layer, and a second glass substrate in a stack such that the functional layer is disposed between the first glass substrate and the second glass substrate; laser-welding a sealing element to a first peripheral edge of the first glass substrate and to a second peripheral edge of the second glass substrate so that the functional layer is hermetically sealed between the first glass substrate and the second glass substrate; wherein the first glass substrate comprises a first major surface substantially perpendicular to the first peripheral edge and the second glass substrate comprises second major surface substantially perpendicular to the second peripheral edge; and wherein the sealing element is present neither on the first major surface nor on the second major surface.

16. The method of claim 15, wherein, prior to arranging, the method further comprises: irradiating a glass sheet with a focused laser beam at discrete locations along a first irradiation path to form spaced apart first modified regions that define at least one first modified section extending across a thickness of the glass sheet and that define at least one first unmodified section extending across the thickness of the glass sheet; separating the glass sheet along the first irradiation path to create the first glass substrate comprising the first peripheral edge; wherein, along the first peripheral edge, the at least one first modified section comprises a first surface roughness and the at least one first unmodified section comprises a second surface roughness, the first surface roughness being greater than the second surface roughness; andwherein, during the laser-welding, the sealing element is welded to the at least one first unmodified section.

17. The method of claim 16, wherein, prior to arranging, the method further comprises: irradiating the glass sheet or a second glass sheet with the focused laser beam at discrete locations along a second irradiation path to form spaced apart second modified regions that define at least one second modified section extending across the thickness of the glass sheet or a thickness of the second glass sheet and that define at least one second unmodified section extending across the thickness of the glass sheet or the thickness of the second glass sheet; separating the glass sheet or the second glass sheet along the second irradiation path to create the second glass substrate comprising the second peripheral edge; wherein, along the second peripheral edge, the at least one second modified section comprises the first surface roughness and the at least one second unmodified section comprises the second surface roughness; and wherein, during the laser-welding, the sealing element is welded to the at least one second unmodified section.

18. The method of any one of claims 15-17, wherein the laser-welding further comprises: directing a laser beam through the first major surface of the first glass substrate at a first angle relative to the first peripheral edge, the first angle being less than 90°.

19. The method of claim 18, wherein the laser- welding further comprises: directing the laser beam through the second major surface of the second glass substrate at a second angle relative to the second peripheral edge, the second angle being less than 90°.

20. The method of claim 18, wherein the laser-welding further comprises:directing the laser beam through the first major surface of the first glass substrate and through the functional layer at a second angle relative to the second peripheral edge, the second angle being less than 90°.

21. The method of any one of claims 18-20, wherein the laser beam is directed through a plano-convex lens and a cylindrical lens prior to being directed through the first major surface or the second major surface.

22. The method of any one of claims 15-21, wherein the sealing element comprises a first end and a second end and wherein the method further comprises: laser-welding the sealing element from the first end to the second end; and covering a gap between the first end and the second end with a patch to hermetically seal the functional layer between the first glass substrate and the second glass substrate at the gap-23. The method of claim 22, wherein covering with the patch comprises applying an epoxy over the first end and the second end.

24. The method of claim 22, wherein covering with the patch comprises wrapping a foil around the first end and the second end.

25. The method of any one of claims 15-21, wherein the sealing element comprises a first end and a second end and wherein the method further comprises: pulling the first end and the second end together; and laser-welding the first end to the second end.

26. The method of claim 25, wherein the pulling the first end and the second end together further comprises: pulling at least one first tab extending from the first end in a first direction;pulling at least one second tab extending from the second end in a second direction opposite to the first direction; laser-welding the first end to the second end; and removing the at least one first tab and the at least one second tab during or after laserwelding.

27. The method of claim 25, wherein the pulling the first end and the second end together further comprises: attaching a first pulling element to the sealing element at a first location between the first end and the second end and a second pulling element to the sealing element at a second location between the first end and the second end, the first pulling element being closer to the first end than the second end and the second pulling element being closer to the second end than the first end; positioning the stack on a block such that the first peripheral edge and the second peripheral edge are facing the block and such that the first end and the second end of the sealing element are disposed between the stack and the block; pulling on the first pulling element and the second pulling element to bring the first end and the second end together; and directing a laser through the block to laser-weld the first end to the second end.

28. The method of any one of claims 15-21, wherein the sealing element is continuous and seamless and wherein, prior to laser-welding, the method further comprises expanding the sealing element to insert the stack inside the sealing element and contracting the sealing element so that the sealing element is in contact with the first peripheral edge and the second peripheral edge.

29. The method of claim 28, wherein the expanding further comprises heating the sealing element to cause thermal expansion of the sealing element and contracting comprises cooling the sealing element to cause thermal contraction of the sealing element.

30. The method of claim 28, wherein the expanding comprises elastically stretching the sealing element around the stack and contracting comprises relaxing the sealing element.

31. The method of claim 30, wherein the elastically stretching comprises pulling the sealing element over a tapered surface of an arbor and relaxing the sealing element comprises removing the arbor from around the stack.

32. The method of any one of claims 15-21, wherein, during laser-welding, the method further comprises: unspooling the sealing element around the stack; and directing at least one laser beam onto the sealing element to weld the sealing element to the first peripheral edge and to the second peripheral through the sealing element.

33. The method of claim 32, wherein the sealing element is unspooled around the stack starting at a first end of the sealing element, wherein the sealing element is unspooled until the sealing element overlaps with the first end, and wherein the method further comprises: laser-welding the sealing element to the sealing element where the sealing element overlaps with the first end; and applying epoxy where the sealing element overlaps with the first end.

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