WO2021108079A1

WO2021108079A1 - Fabricating laminate glass with blind vias

Info

Publication number: WO2021108079A1
Application number: PCT/US2020/058459
Authority: WO
Inventors: Jin Su Kim; Daniel Wayne Levesque Jr.; Aize LI; Heather Nicole VANSELOUS
Original assignee: Corning Incorporated
Priority date: 2019-11-27
Filing date: 2020-11-02
Publication date: 2021-06-03

Abstract

Methods for fabricating laminate glass articles with blind vias in the form of through holes etched in one or more glass layers of the laminate glass articles. The methods may include forming a modified track or a pilot hole in a laminate glass. The laminate glass article includes a first glass layer formed of a first glass composition and a second glass layer and/or a third glass layer formed of a composition that is different from the first glass composition. After forming a modified track or pilot hole, the laminate glass may be exposed to etching conditions that etch a through hole in at least one of the second glass layer and / or third glass layer at the location of the modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the modified track or pilot hole.

Description

FABRICATING LAMINATE GLASS WITH BLIND VIAS

BACKGROUND

[0001] This application claims the benefit of priority to U.S. Provisional Application

Serial No. 62/941,385 filed on November 27, 2019, the content of which is relied upon and incorporated herein by reference in its entirety.

Field

[0002] The present disclosure relates to laminate glasses including blind vias and methods of fabricating through vias using laminate glasses. In particular, the present disclosure relates to method of forming through vias using laminate glasses having glass layers with etch rates configured to form blind vias during an etching process.

Background

[0003] Glass and glass ceramic substrates with vias are desirable for many applications, including three-dimensional (3D) interposers used as an electrical interface, RF filters, and RF switches. The current substrates of choice include polymer or silicon. Polymer interposers suffer from poor dimensional stability while silicon wafers are expensive and suffer from high dielectric loss due to semiconducting properties. There is a trend, therefore, toward use of glass as a superior substrate material due to its low dielectric constant, thermal stability, and low cost. For example, 3D glass interposers with through glass via (TGV) interconnects that connect a logic device on one side and a memory on the other side are useful in high bandwidth devices.

[0004] Currently, there are a number of challenges in metallizing TGV s. In particular, copper breakout during thermal cycling after metallization is problematic. Conformal filling of TGVs can be accomplished, but these features are not hermetic, which may be necessary for downstream processing steps such as thin- film-transistor (TFT) placement. TGVs may alternatively be fully filled, which must then be followed by polishing steps to remove any overburden.

[0005] Accordingly, a continued need exists for new fabrication techniques for creating glass articles with vias for various applications. BRIEF SUMMARY [0006] The present disclosure is directed to methods for creating blind vias with controlled depths, diameters, and/or morphologies, laminate glasses having blind vias formed using the methods described herein, and glass layers with through vias made using the laminate glasses having the blind vias. A combination of laser modification and an etching process may be used to create blind vias in a laminate glass article. The laser may create an electromagnetically modified region extending fully or partially through a plurality of glass layers of a glass laminate. After formation of the electromagnetically modified region, the glass laminate may be etched with an etching solution to preferentially etch the electromagnetically modified region until the etching solution reaches an interface between one glass layer (e.g., a clad layer) and another glass layer (e.g., a core layer) of the glass laminate. At this interface, the etch rate of the etching solution is significantly slowed due to a change in the glass composition of the layers. In other words, the interface acts as an etching barrier. When the etch rate of one glass layer is significantly slower than the other glass layer, further etching may serve to widen the effective diameter of a blind via in the other glass layer, rather than increasing a depth of the via. [0007] By utilizing glass laminates and method disclosed herein, the depth of a blind via may be strictly controlled by the thickness of a glass layer (e.g., a clad layer). Additionally, the diameter of a blind via is controllably and reliably determined by etching time once the blind via reaches its desired depth at an interface between two glass layers. Laminate glasses with blind vias and glass layers with through vias as disclosed herein can be utilized in various electronic applications, including SIW (system-integrated waveguide) antenna, high- density interposer, and microelectronics packaging applications. [0008] A first aspect (1) of the present application is directed to a method including forming a modified track or a pilot hole in a laminate glass with a laser, the laminate glass including a first glass layer and a second glass layer disposed over the first glass layer, where the modified track or the pilot hole extends through the second glass layer and into a portion of the first glass layer, the first glass layer is formed of a first glass composition, the second glass layer is formed of a second glass composition different from the first glass composition; and after forming the modified track or the pilot hole, exposing the laminate glass to etching conditions that etch the first glass composition at a first etch rate and etch the second glass composition at a second etch rate, where the second etch rate is three times or more higher than the first etch rate, and the etching conditions etch a through hole in the second glass layer at a location of the modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the modified track or pilot hole. [0009] In a second aspect (2), the method according to the first aspect (1) is provided, and further includes removing the first glass layer after forming the etched through hole in the second glass layer. [0010] In a third aspect (3), the method according to the first aspect (1) or the second aspect (2) is provided, and the second glass layer is disposed on the first glass layer. [0011] In a fourth aspect (4), the method according to any of aspects (1) – (3) is provided, and the second glass layer is disposed on the first glass layer. [0012] In a fifth aspect (5), the method according to any of aspects (1) – (3) is provided, and the second etch rate is ten times or more higher than the first etch rate. [0013] In a sixth aspect (6), the method according to any of aspects (1) – (5) is provided, and the laminate glass is a fusion-drawn laminate. [0014] In a seventh aspect (7), the method according to any of aspects (1) – (6) is provided, and the etching conditions include an etching solution including hydrofluoric acid. [0015] In an eighth aspect (8), the method according to any of aspects (1) – (7) is provided, and further includes plating the laminate glass with a metallic material after etching the through hole in the second glass layer. [0016] In a ninth aspect (9), the method according to the eighth aspect (8) is provided, and the plating includes plating a sidewall of the through hole with the metallic material. [0017] In a tenth aspect (10), the method according to the eighth aspect (8) or the ninth aspect (9) is provided, and the plating fills the through hole with the metallic material. [0018] In an eleventh aspect (11), the method according to any of aspects (8) – (10) is provided, and the plating the laminate glass is an electroplating process. [0019] In a twelfth aspect (12), the method according to any of aspects (8) – (11) is provided, and the metallic material is copper. [0020] In a thirteenth aspect (13), the method according to any of aspects (8) – (12) is provided, and further includes removing the first glass layer after plating the laminate glass with the metallic material. [0021] In a fourteenth aspect (14), the method according to any of aspects (1) – (13) is provided, and the laminate glass includes a third glass layer, the second glass layer is disposed over a first surface of the first glass layer, and the third glass layer is disposed over a second surface of the first glass layer opposite the first surface. [0022] In a fifteenth aspect (15), the method according to the fourteenth aspect (14) is provided, and the second glass layer is disposed on the first surface of the first glass layer and the third glass layer is disposed on the second surface of the first glass layer. [0023] In a sixteenth aspect (16), the method according to the fourteenth aspect (14) or the fifteenth aspect (15) is provided, and further includes removing the first glass layer and the third glass layer after forming the etched through hole in the second glass layer. [0024] In a seventeenth aspect (17), the method according to any of aspects (14) – (16) is provided, and further includes forming another modified track or pilot hole in the laminate glass with the laser, where the another modified track or pilot hole extends through the third glass layer and into a portion of the first glass layer. [0025] In an eighteenth aspect (18), the method according to the seventeenth aspect (17) is provided, and the third glass layer is formed of a third glass composition different from the first glass composition, the etching conditions etch the third glass composition at a third etch rate that is three times or more higher than the first etch rate, and the etching conditions etch a through hole in the third glass layer at a location of the another modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the another modified track or pilot hole [0026] In a nineteenth aspect (19), the method according to any of aspects (14) – (16) is provided, and the modified track or pilot hole extends through the second glass layer, the first glass layer, and the third glass layer of the laminate glass. [0027] In a twentieth aspect (20), the method according to the nineteenth aspect (19) is provided, and the etching conditions etch the through hole in the second glass layer and another through hole in the third glass layer at the location of the modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the modified track or pilot hole. [0028] A twenty-first aspect (21) of the present application is directed to a method including forming a modified track or a pilot hole in a laminate glass with a laser, where the laminate glass includes a first glass layer formed of a first glass composition, a second glass layer disposed over a first surface of the first glass layer and formed of a second glass composition different from the first glass composition, and a third glass layer disposed over a second surface of the first glass layer opposite the first surface and formed of a third glass composition different from the first glass composition, and where the modified track or the pilot hole extends through the second glass layer and into a portion of the first glass layer; and after forming the modified track or the pilot hole, exposing the laminate glass to etching conditions that etch a through hole in the second glass layer at a location of the modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the modified track or pilot hole. [0029] In a twenty-second aspect (22), the method according to the twenty-first aspect (21) is provided, and the etching conditions are configured to etch the second glass layer at a second etch rate, the etching conditions are configured to etch the first glass layer at a first etch rate, and the second etch rate is three times or more higher than the first etch rate. [0030] In a twenty-third aspect (23), the method according to the twenty-first aspect (21) or the twenty-second aspect (22) is provided, and further includes plating the laminate glass with a metallic material to at least partially fill the through hole with the metallic material. [0031] In a twenty-fourth aspect (24), the method according to any of aspects (21) – (23) is provided, and further includes removing the first glass layer and the third glass layer after forming the etched through hole in the second glass layer. [0032] A twenty-fifth aspect (25) of the present application is directed to a laminate glass article, including a first glass layer formed of a first glass composition; a second glass layer disposed over a first surface of the first glass layer and formed of a second glass composition, the second glass composition being different from the first glass composition; an etched through hole in the second glass layer; and an electromagnetically modified region located on the first surface of the first glass layer exposed to the etched through hole in the second glass layer. [0033] In a twenty-sixth aspect (26), the laminate glass article according to the twenty- fifth aspect (25) is provided, and the electromagnetically modified region includes a modified track or a pilot hole. [0034] In a twenty-seventh aspect (27), the laminate glass article according to the twenty- fifth aspect (25) or the twenty-sixth aspect (26) is provided, and further includes a metal plating disposed in the etched through hole of the second glass layer. [0035] In a twenty-eighth aspect (28), the laminate glass article according to any of aspects (25) – (27) is provided, and the second glass layer is disposed on the first glass layer. [0036] In a twenty-ninth aspect (29), the laminate glass article according to any of aspects (25) – (28) is provided, and the first glass composition has a first etch rate in an etching solution including hydrofluoric acid, the second glass composition has a second etch rate in the etching solution including hydrofluoric acid, and the second etch rate is three times or more higher than the first etch rate. [0037] In a thirtieth aspect (30), the laminate glass article according to any of aspects (25) – (29) is provided, and further includes a third glass layer disposed over a second surface of the first glass layer opposite the first surface. [0038] In a thirty-first aspect (31), the laminate glass article according to the thirtieth aspect (30) is provided, and the second glass layer is disposed on the first surface of the first glass layer and the third glass layer is disposed on the second surface of the first glass layer opposite the first surface. BRIEF DESCRIPTION OF THE DRAWINGS [0039] The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of the present disclosure. Together with the description, the figures further serve to explain the principles of and to enable a person skilled in the relevant art(s) to make and use the disclosed embodiments. These figures are intended to be illustrative, not limiting. Although the disclosure is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the disclosure to these particular embodiments. In the drawings, like reference numbers indicate identical or functionally similar elements. [0040] FIG.1A shows a cross-section of a two-layer laminate glass according to some embodiments. FIG.1B shows a cross-section of a three-layer laminate glass according to some embodiments. [0041] FIGS. 2A–2C illustrate a method for forming blind vias in a laminate glass according to some embodiments. [0042] FIG.3A illustrates a plated laminate glass according to some embodiments. FIG. 3B illustrates a glass layer including plated through vias according to some embodiments. [0043] FIG.4 shows a cross-section of a laminate glass according to some embodiments. [0044] FIGS. 5A–5C illustrate a method for forming blind vias in a laminate glass according to some embodiments. [0045] FIG.6 shows a cross-section of a plated laminate glass article according to some embodiments. [0046] FIGS. 7A–7C show various glass laminate samples with blind vias according to some embodiments. [0047] FIG.8 shows a laminate fusion-draw apparatus according to some embodiments. [0048] FIG.9A schematically depicts the formation of a contour of defects in a transparent workpiece according to some embodiments. [0049] FIG.9B schematically depicts an example pulsed laser beam focal line during processing of a transparent workpiece according to some embodiments. [0050] FIG.10 schematically depicts an optical assembly for pulsed laser processing according to some embodiments. DETAILED DESCRIPTION [0051] The following examples are illustrative, but not limiting, of the present disclosure. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the field, and which would be apparent to those skilled in the art, are within the spirit and scope of the disclosure. [0052] Traditional processes for formation of through and /or blind vias include the use of a single-layer glass substrate. Vias can be formed in the single-layer glass substrate using a combination of laser modification and wet chemical etching. Chemical etching, a diffusion limited process, preferentially etches along either a laser-induced modified track through the glass substrate or a laser ablated pilot hole (for example, about a 10 µm diameter pilot hole) to form the via. To generate a blind via at a certain depth in the single-layer glass substrate, the chemical etching must be stopped at a precise time. Localized process variations that can affect the etch rate, such as temperature and etching chemistry, produce variability in blind via dimensional consistency (e.g., depth consistency) for a single substrate and / or across a batch of substrates. Further, the blind via shapes created by these traditional processes are largely controlled by the composition of the single-layer glass substrate. [0053] The present application discloses methods for creating blind vias in glass with controlled and consistent dimensions (e.g., depth) and morphologies using laminate glass. The laminate glass includes one or more layers having a relatively high etch rate (sometimes referred to herein as a “clad layer”) and another layer having a relatively low etch rate (sometimes referred to herein as a “core layer”). In some embodiments, clad layers with a relatively high etch rate may be disposed over opposing sides of a core layer with a relatively low etch rate. Regions of the laminate are electromagnetically modified, using for example laser energy, to form modified tracks or pilot holes extending through all or a portion of the thickness of the glass laminate. The electromagnetically modified regions may each extend through a clad layer and into at least a portion of a core layer. In some embodiments, through-thickness regions of the glass laminate are electromagnetically modified, using for example laser energy, to form modified tracks or pilot holes extending through the thickness of the laminate. [0054] After formation of the electromagnetically modified regions, the glass laminate is chemically etched to formed vias in the clad layer(s) at the location of the electromagnetically modified regions. During etching, the interface(s) between the clad layer(s) and the core layer act as an etching barrier to precisely control the blind via depth. By utilizing a clad / core interface as an etching barrier, blind via formation processes disclosed herein have less sensitivity to local etching process variations than traditional blind via formation techniques. [0055] Using formation techniques disclosed herein, laminate glass articles with dimensionally controlled and / or consistent blind vias can be produced. Laminate glass articles disclosed herein have clad and core layers with compositions tailored to facilitate fast etching of one or more clad layers, such as clad layers on opposing sides of a slower etching core layer. By tailoring the compositions of the clad and core layers, blind vias having a desired geometry, e.g. cylinder or pyramid, on one or both sides of the glass can be precisely and reproducibly formed. Blind via depth is controlled by, and can be consistently equivalent to, the thickness of the clad layer in which a blind via is formed. Further, various blind via effective diameters and morphologies can be created by controlling the interaction between laser conditions and etch conditions. Since the depth dimension of blind vias is self-limited by the interface(s) between the clad layer(s) and the core layer, the tuning of laser conditions and etch conditions can be focused on tailoring the diameter and / or morphology of blind vias formed in a laminate glass. [0056] Advantages of the blind via formation processes disclosed herein compared to traditional blind via formation techniques include the following. (1) Blind via morphology (e.g. cylinder vs. pyramid) can be highly controlled due to the self-limiting nature of the etching processes. (2) The processes facilitate the ability to create desired via shapes by modifying laser conditions. In some cases, these desired via shapes may be more compatible with metallization processes. (3) Uniformity in terms of via depth and shape can be improved. (4) The process sensitivity to etch time and etch chemistry is less significant. (5) The processes enable easier manufacturing through consistent etching depth. (6) The processes can create wider processing windows to improve manufacturing yields. [0057] After formation of blind vias in a glass layer of a laminate glass, other layers of the laminate glass can be removed to form a glass layer with through vias. In some embodiments, removal of the other layers may be achieved using an etching process that selectively etches away the layers of the laminate not including the blind vias. In some embodiments, removal of the other layers may alternatively or additionally include a mechanical polishing or grinding process. In some embodiments, removal of the other layers may be performed after plating the blind vias formed in the laminate glass. [0058] Additionally, blind vias disclosed herein can be advantageous over through vias for the following reasons. (1) Blind vias generally have better mechanical strength, which can improve overall manufacturing yields. Relatedly, articles with blind vias generally have higher mechanical strength than articles with through vias, which can also improve manufacturing yields. (2) Blind vias facilitate the ability to relax hermetic requirements when placing electronics, for example thin-film-transistors, if polishing to form through vias is performed after metallization and placing of the electronics. Since the laminate glass would retain its hermetic characteristics, the hermetic requirement can be relaxed. (3) Blind vias can be metallized faster due to the closed nature of the vias. The speed of metallization can also be faster if the blind via depth is shallower than a through via. (4) Blind vias enable different metallization techniques than those used for through-glass vias, which may be better suited for particular applications. (5) Blind vias can be conformally filled, which can result in less polishing needed to remove any overburden. [0059] For purposes of the present application, blind vias may be vias that have an effective diameter less than or equal to the thickness of a laminate glass in which they are formed. For example, both a via with a 40 µm (micron) and a 400 µm diameter in 0.4 mm (millimeter) glass laminate would be considered a blind via. Blind vias formed in a layer of a laminate glass are also referred to herein as “through holes,” meaning that they extend through the entire thickness of a glass layer. [0060] In some embodiments, electromagnetically modified regions in a laminate glass may be formed using a quasi-non-diffracting Bessel or Gauss-Bessel laser beam. The wavelength of the laser energy may be 532 nm (nanometers). This technique uses a focal line to create an electromagnetically modified region, and the electromagnetically modified region may extend through the entire thickness of the glass laminate. The electromagnetically modified regions created by this technique can have an effective diameter of a few microns and can be termed “modified tracks.” In some embodiments, lower power Nano perforations may be utilized to ensure that the modified track / etchant doesn’t extend past a desired distance into a core layer. As used herein, the term “quasi-non-diffracting beam” is used to describe a laser beam having low beam divergence as mathematically described below. In particular, the laser beam used to form defects in the embodiments described herein. The laser beam has an intensity distribution I(X,Y,Z), where Z is the beam propagation direction of the laser beam, and X and Y are directions orthogonal to the beam propagation direction, as depicted in the figures. The X-direction and Y-direction may also be referred to as cross- sectional directions and the X-Y plane may be referred to as a cross-sectional plane. The coordinates and directions X, Y, and Z are also referred to herein as x, y, and z; respectively. The intensity distribution of the laser beam in a cross-sectional plane may be referred to as a cross-sectional intensity distribution. [0061] The quasi-non-diffracting laser beam may be formed by impinging a diffracting laser beam (such as a Gaussian beam) into, onto, and/or thorough a phase-altering optical element, such as an adaptive phase-altering optical element (e.g., a spatial light modulator, an adaptive phase plate, a deformable mirror, or the like), a static phase-altering optical element (e.g., a static phase plate, an aspheric optical element, such as an axicon, or the like), to modify the phase of the beam, to reduce beam divergence, and to increase Rayleigh range, as mathematically defined below. Example quasi-non-diffracting beams include Gauss-Bessel beams, Airy beams, Weber beams, and Bessel beams. [0062] Referring to FIGS.9A and 9B and 10, the pulsed laser beam 912 used to form the defects has an intensity distribution I(X,Y,Z), where Z is the beam propagation direction of the pulsed laser beam 912, and X and Y are directions orthogonal to the direction of propagation, as depicted in the figures. The X-direction and Y-direction may also be referred to as cross-sectional directions and the X-Y plane may be referred to as a cross-sectional plane. The intensity distribution of the pulsed laser beam 912 in a cross-sectional plane may be referred to as a cross-sectional intensity distribution. [0063] The pulsed laser beam 912 at the beam spot 914 or other cross sections may comprise a quasi-non-diffracting beam, for example, a beam having low beam divergence as mathematically defined below, by propagating the pulsed laser beam 912 (e.g., outputting the pulsed laser beam 912, such as a Gaussian beam, using a beam source 910) through an aspheric optical element 920, as described in more detail below with respect to the optical assembly 900 depicted in FIG.10. Beam divergence refers to the rate of enlargement of the beam cross section in the direction of beam propagation (i.e., the Z direction). As used herein, the phrase “beam cross section” refers to the cross section of the pulsed laser beam 912 along a plane perpendicular to the beam propagation direction of the pulsed laser beam 912, for example, along the X-Y plane. One example beam cross section discussed herein is the beam spot 914 of the pulsed laser beam 912 projected onto the transparent workpiece 960. Transparent workpiece 960 may be any of the laminate glasses described herein. [0064] The length of the laser beam focal line produced from a quasi-non-diffracting beam is determined by the Rayleigh range of the quasi-non-diffracting beam. Particularly, the quasi-non-diffracting beam defines a laser beam focal line 913 having a first end point and a second end point each defined by locations where the quasi-non-diffracting beam has propagated a distance from the beam waist equal to a Rayleigh range of the quasi-non- diffracting beam. The length of the laser beam focal corresponds to twice the Rayleigh range of the quasi-non-diffracting beam. A detailed description of the formation of quasi-non- diffracting beams and determining their length, including a generalization of the description of such beams to asymmetric (such as non-axisymmetric) beam cross sectional profiles, is provided in U.S. Provisional Application Serial No.62/402,337 and Dutch Patent Application No. 2017998, which are incorporated by reference in their entireties. [0065] The Rayleigh range corresponds to the distance (relative to the position of the beam waist as defined in Section 3.12 of ISO 11146-1:2005(E)) over which the variance of the laser beam doubles (relative to the variance at the position of the beam waist) and is a measure of the divergence of the cross sectional area of the laser beam. The Rayleigh range can also be observed as the distance along the beam axis at which the peak optical intensity observed in a cross sectional profile of the beam decays to one half of its value observed in a cross sectional profile of the beam at the beam waist location (location of maximum intensity). Laser beams with large Rayleigh ranges have low divergence and expand more slowly with distance in the beam propagation direction than laser beams with small Rayleigh ranges. [0066] Beam cross section is characterized by shape and dimensions. The dimensions of the beam cross section are characterized by a spot size of the beam. For a Gaussian beam, spot size is frequently defined as the radial extent at which the intensity of the beam decreases to 1/e² of its maximum value. The maximum intensity of a Gaussian beam occurs at the center (^ = 0 and ^ = 0 (Cartesian) or ^ = 0 (cylindrical)) of the intensity distribution and radial extent used to determine spot size is measured relative to the center. [0067] Beams with Gaussian intensity profiles may be less preferred for laser processing to form defects because, when focused to small enough spot sizes (such as spot sizes in the range of microns, such as about 1-5 µm or about 1-10 µm) to enable available laser pulse energies to modify materials such as glass, they are highly diffracting and diverge significantly over short propagation distances (low Rayleigh range). To achieve low divergence (high Rayleigh range), it is desirable to control or optimize the intensity distribution of the pulsed laser beam to reduce diffraction. Pulsed laser beams may be non- diffracting or weakly diffracting. Weakly diffracting laser beams include quasi-non- diffracting laser beams. Representative weakly diffracting laser beams include Bessel beams, Gauss-Bessel beams, Airy beams, Weber beams, and Mathieu beams. [0068] Non-diffracting or quasi-non-diffracting beams generally have complicated intensity profiles, such as those that decrease non-monotonically vs. radius. By analogy to a Gaussian beam, an effective spot size ^_^,^^^ can be defined for any beam, even non- axisymmetric beams, as the shortest radial distance, in any direction, from the radial position of the maximum intensity (r = 0) at which the intensity decreases to 1/e² of the maximum intensity. Further, for axisymmetric beams ^_^,^^^ is the radial distance from the radial position of the maximum intensity (r = 0) at which the intensity decreases to 1/e² of the maximum intensity. A criterion for Rayleigh range ZR based on the effective spot size ^_^,^^^ for axisymmetric beams can be specified as non-diffracting or quasi-non-diffracting beams for forming modified regions in Equation (1), below:

where ^_^ is a dimensionless divergence factor having a value of at least 10, at least 50, at least 100, at least 250, at least 500, at least 1000, in the range from 10 to 2000, in the range from 50 to 1500, in the range from 100 to 1000. For a non-diffracting or quasi-non- diffracting beam the distance (Rayleigh range), ^_ோ in Equation (1), over which the effective spot size doubles, is ^_^ times the distance expected if a typical Gaussian beam profile were used. The dimensionless divergence factor ^_^ provides a criterion for determining whether or not a laser beam is quasi-non-diffracting. As used herein, the pulsed laser beam 912 is considered quasi-non-diffracting if the characteristics of the laser beam satisfy Equation (1) with a value of ^_^ ³ 10. As the value of ^_^ increases, the pulsed laser beam 912 approaches a more nearly perfectly non-diffracting state. [0069] Additional information about Rayleigh range, beam divergence, intensity distribution, axisymmetric and non-axisymmetric beams, and spot size as used herein can also be found in the international standards ISO 11146-1:2005(E) entitled “Lasers and laser- related equipment—Test methods for laser beam widths, divergence angles and beam propagation ratios—Part 1: Stigmatic and simple astigmatic beams”, ISO 11146-2:2005(E) entitled “Lasers and laser-related equipment—Test methods for laser beam widths, divergence angles and beam propagation ratios—Part 2: General astigmatic beams”, and ISO 11146-3:2004(E) entitled “Lasers and laser-related equipment—Test methods for laser beam widths, divergence angles and beam propagation ratios—Part 3: Intrinsic and geometrical laser beam classification, propagation and details of test methods”, the disclosures of which are incorporated herein by reference in their entirety. [0070] Referring now to FIGS 9A and 9B, a transparent workpiece 960 is schematically depicted undergoing laser processing according to the methods described herein. In particular, FIGS.9A and 9B schematically depict directing a pulsed laser beam 912 that is output by a pulsed beam source 910, such as a Gaussian pulsed beam source, and oriented along a beam pathway 911 into the transparent workpiece 960 to form a defect 972. In particular, the pulsed laser beam 912 propagates along the beam pathway 911 and is oriented such that the pulsed laser beam 912 may be focused into a pulsed laser beam focal line 913 within the transparent workpiece 960, for example, using an aspheric optical element 920 and one or more lenses (FIG.10). The pulsed laser beam focal line 913 generates an induced absorption within the transparent workpiece 960 to produce the defect 972 within the transparent workpiece 960. Furthermore, a contour of defects 972 may be formed by translating at least one of the pulsed laser beam 912 and the transparent workpiece 960 relative to one another such that the pulsed laser beam 912 translates relative to the transparent workpiece 960 in a translation direction 901. [0071] As also shown in FIG.9A, the pulsed laser beam 912 forms a beam spot 914 projected onto a first surface 962 of the transparent workpiece 960, which further comprises a second surface 964, opposite the first surface 962, and an edge surface 966 extending between the first surface 962 and the second surface 964. While the pulsed laser beam 912 is depicted initially irradiating the transparent workpiece 960 at the first surface 962 in FIG.9A (such that the first surface 962 comprises an impingement surface), it should be understood that in other embodiments, the pulsed laser beam 912 may instead initially irradiate the transparent workpiece 960 at the second surface 964. [0072] In some embodiments, the pulsed laser beam 912 may be focused into the pulsed laser beam focal line 913 using a lens 932. While a single lens 932 is depicted in FIG.9A and 9C, some embodiments may include a lens assembly 930 including a first lens 931 and a second lens 932, and repetitions thereof (FIG.10) to focus the pulsed laser beam 912 into the pulsed laser beam focal line 913. Other standard optical elements (e.g. prisms, beam splitters etc.) may also be included in lens assembly 930. As depicted in FIG.9A, the pulsed laser beam 912 may comprise an annular shape when impinging the lens 932. While the lens 932 is depicted focusing the pulsed laser beam 912 into the pulsed laser beam focal line 913 in FIG.9A, other embodiments may use the aspheric optical element 920 (FIG. 10), which modifies the pulsed laser beam 912 such that the pulsed laser beam 912 has a quasi-non- diffracting character downstream the aspheric optical element 920, to also focus the pulsed laser beam 912 into the pulsed laser beam focal line 913. In other words, in some embodiments, the lens 932 may be the final focusing element and in other embodiments, the aspheric optical element 920 may be the final focusing element. The pulsed laser beam focal line 913 may have a length in a range of from about 0.1 mm to about 100 mm or in a range of from about 0.1 mm to about 10 mm. Various embodiments may be configured to have a pulsed laser beam focal line 913 with a length l of about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.7 mm, about 1 mm, about 2 mm, about 3 mm, about 4 mm, or about 5 mm e.g., from about 0.5 mm to about 5 mm. [0073] Referring now to FIG. 10, an optical assembly 900 for producing a pulsed laser beam 912 that is quasi-non-diffracting and forms the pulsed laser beam focal line 913 at the transparent workpiece 960 using the aspheric optical element 920 (e.g., an axicon 922) is schematically depicted. The optical assembly 900 includes a pulsed beam source 910 that outputs the pulsed laser beam 912, and the lens assembly 930 comprising the first lens 931 and the second lens 932. The transparent workpiece 960 may be positioned such that the pulsed laser beam 912 output by the pulsed beam source 910 irradiates the transparent workpiece 960, for example, after traversing the aspheric optical element 920 and thereafter, both the first lens 931 and the second lens 932. [0074] The aspheric optical element 920 is positioned within the beam pathway 911 between the pulsed beam source 910 and the transparent workpiece 960. In operation, propagating the pulsed laser beam 912, e.g., an incoming Gaussian beam, through the aspheric optical element 920 may alter, for example, phase alter, the pulsed laser beam 912 such that the portion of the pulsed laser beam 912 propagating beyond the aspheric optical element 920 is quasi-non-diffracting, as described above. The aspheric optical element 920 may comprise any optical element comprising an aspherical shape. In some embodiments, the aspheric optical element 920 may comprise a conical wavefront producing optical element, such as an axicon lens, for example, a negative refractive axicon lens (e.g., negative axicon), a positive refractive axicon lens, a reflective axicon lens, a diffractive axicon lens, a phase axicon, or the like. [0075] While the optical assembly 900 is primarily described as altering the pulsed laser beam 912 into a quasi-non-diffracting beam using the aspheric optical element 920, it should be understood that a quasi-non-diffracting beam also be formed by other phase-altering optical elements, such as a spatial light modulator, an adaptive phase plate, a static phase plate, a deformable mirror, diffractive optical grating, or the like. Each of these phase- altering optical elements, including the aspheric optical element 920, modify the phase of the pulsed laser beam 912, to reduce beam divergence, increase Rayleigh range, and form a quasi-non-diffracting beam as mathematically defined above. [0076] In some embodiments, when the aspheric optical element 920 comprises an axicon 922 (as depicted in FIG. 10), the axicon 922 may have a laser output surface 926 (e.g., conical surface) having an angle of about 1.2°, the angle measured relative to the laser input surface 924 (e.g., flat surface) upon which the pulsed laser beam 912 enters the axicon 922. The angle may be from 0.5° to 5°, such as from 1° to 1.5°, or from 0.5° to 20°, for example, 0.5°, 1°, 1.5°, 2°, 2.5°, 5°, 7.5°, 10°, 15°, or any range having any two of these values as endpoints, or any open-ended range having any of these values as a lower bound. Further, the laser output surface 926 terminates at a conical tip. Moreover, the aspheric optical element 920 includes a centerline axis 925 extending from the laser input surface 924 to the laser output surface 926 and terminating at the conical tip. In operation, the aspheric optical element 920 phase alters the incoming pulsed laser beam 912 to shape the incoming pulsed laser beam 912 (e.g., an incoming Gaussian beam) into a quasi-non-diffracting beam, which, in turn, is directed through the first lens 931 and the second lens 932. [0077] Referring still to FIG.10, the lens assembly 930 comprises two sets of lenses, each set comprising the first lens 931 positioned upstream the second lens 932. The first lens 931 may collimate the pulsed laser beam 912 within a collimation space 934 between the first lens 931 and the second lens 932 and the second lens 932 may focus the pulsed laser beam 912. Further, the most downstream positioned second lens 932 of the lens assembly 930 may focus the pulsed laser beam 912 into the transparent workpiece 960, which may be positioned at the imaging plane 904 of this second lens 932. In some embodiments, the first lens 931 and the second lens 932 each comprise plano-convex lenses. When the first lens 931 and the second lens 932 each comprise plano-convex lenses, the curvature of the first lens 931 and the second lens 932 may each be oriented toward the collimation space 934. In other embodiments, the first lens 931 may comprise other collimating lenses and the second lens 932 may comprise a meniscus lens, an asphere, or another higher-order corrected focusing lens. In operation, the lens assembly 930 may control the position of the pulsed laser beam focal line 913 along the beam pathway 911. Further, the lens assembly 930 may comprise an 8F lens assembly, a 4F lens assembly comprising a single set of first and second lenses 931, 932, or any other known or yet to be developed lens assembly 930 for focusing the pulsed laser beam 912 into the pulsed laser beam focal line 913. Moreover, it should be understood that some embodiments may not include the lens assembly 930 and instead, the aspheric optical element 920 may focus the pulsed laser beam 912 into the pulsed laser beam focal line 913. [0078] Referring again to FIGS.9A-10, the pulsed beam source 910 is configured to output pulsed laser beam 912. In operation, the defects 972 of the contour 970 are produced by interaction of the transparent workpiece 960 with the pulsed laser beam 912 output by the pulsed beam source 910. In operation, the pulsed laser beam 912 output by the pulsed beam source 910 may create multi-photon absorption (MPA) in the transparent workpiece 960. MPA is the simultaneous absorption of two or more photons of identical or different frequencies that excites a molecule from one state (usually the ground state) to a higher energy electronic state (i.e., ionization). The energy difference between the involved lower and upper states of the molecule is equal to the sum of the energies of the involved photons. MPA, also called induced absorption, can be a second-order or third-order process (or higher order), for example, that is several orders of magnitude weaker than linear absorption. It differs from linear absorption in that the strength of second-order induced absorption may be proportional to the square of the light intensity, for example, and thus it is a nonlinear optical process. [0079] In some embodiments, the pulsed beam source 910 may output a pulsed laser beam 912 comprising a wavelength of, for example, 1064 nm, 1030 nm, 532 nm, 530 nm, 355 nm, 343 nm, or 266 nm, or 215 nm. Further, the pulsed laser beam 912 used to form defects 972 in the transparent workpiece 960 may be well suited for materials that are transparent to the selected pulsed laser wavelength. Suitable laser wavelengths for forming defects 972 are wavelengths at which the combined losses of linear absorption and scattering by the transparent workpiece 960 are sufficiently low. In embodiments, the combined losses due to linear absorption and scattering by the transparent workpiece 960 at the wavelength are less than 20%/mm, or less than 15%/mm, or less than 10%/mm, or less than 5%/mm, or less than 1%/mm, such as 0.5%/mm to 20%/mm, 1%/mm to 10%/mm, or 1%/mm to 5%/mm, for example, 1%/mm, 2.5%/mm, 5%/mm, 10%/mm, 15%/mm, or any range having any two of these values as endpoints, or any open-ended range having any of these values as a lower bound. As used herein, the dimension “/mm” means per millimeter of distance within the transparent workpiece 960 in the beam propagation direction of the pulsed laser beam 912 (i.e., the Z direction). Representative wavelengths for many glass workpieces include fundamental and harmonic wavelengths of Nd³⁺ (e.g. Nd³⁺:YAG or Nd³⁺:YVO₄ having fundamental wavelength near 1064 nm and higher order harmonic wavelengths near 532 nm, 355 nm, and 266 nm). Other wavelengths in the ultraviolet, visible, and infrared portions of the spectrum that satisfy the combined linear absorption and scattering loss requirement for a given substrate material can also be used. [0080] Referring still to FIGS.9A-10, in operation, the contour 970 may be formed by irradiating a contour line 965 with the pulsed laser beam 912 and translating at least one of the pulsed laser beam 912 and the transparent workpiece 960 relative to each other along the contour line 965 in the translation direction 901 to form the defects 972 of the contour 970. While the contour 970 depicted in FIG.9A is linear, it should be understood that the contour 970 may be non-linear, for example, curved. Further, in some embodiments, the contour 970 may be a closed contour, such as a circle, rectangles, ellipses, squares, hexagons, ovals, regular geometric shapes, irregular shapes, polygonal shapes, arbitrary shapes, and the like. [0081] Directing or localizing the pulsed laser beam 912 into the transparent workpiece 960 generates an induced absorption (e.g., MPA) within the transparent workpiece 960 and deposits enough energy to break chemical bonds in the transparent workpiece 960 at spaced locations along the contour line 965 to form the defects 972. According to one or more embodiments, the pulsed laser beam 912 may be translated across the transparent workpiece 960 by motion of the transparent workpiece 960 (e.g., motion of a translation stage 990 coupled to the transparent workpiece 960), motion of the pulsed laser beam 912 (e.g., motion of the pulsed laser beam focal line 913), or motion of both the transparent workpiece 960 and the pulsed laser beam focal line 913. By translating at least one of the pulsed laser beam focal line 913 relative to the transparent workpiece 960, the plurality of defects 972 may be formed in the transparent workpiece 960. [0082] As used herein, a “defect” refers to a region of a transparent workpiece that has been modified by a laser beam. Defects include regions of a transparent workpiece having a modified refractive index relative to surrounding unmodified regions of the transparent workpiece. Common defects include structurally modified regions such as void spaces, cracks, scratches, flaws, pilot holes, perforations, densifications, or other deformities in the transparent workpiece produced by a pulsed laser beam focal line. Defects may also be referred to, in various embodiments herein, as defect lines or modified tracks. A defect or modified track is formed through interaction of a pulsed laser beam focal line with the transparent workpiece. As described more fully below, the pulsed laser beam focal line is produced by a pulsed laser. A defect at a particular location along the contour line is formed from a pulsed laser beam focal line produced by a single laser pulse at the particular location, a pulse burst of sub-pulses at the particular location, or multiple laser pulses at the particular location. Relative motion of the laser beam and transparent workpiece along the contour line results in multiple defects that form a contour. [0083] In some embodiments, the electromagnetically modified regions in a laminate glass may be formed using a Gaussian beam, i.e. a focal spot, to percussively ablate a hole through the laminate glass. This technique creates pilot through-holes in the laminate glass. These pilot through holes may have an effective diameter of approximately 10 microns. The depth of these pilot holes is controlled by the energy per pulse and number of pulses incident on the laminate glass. In some embodiments, pilot holes may be through holes extending through the entire thickness of the glass laminate. In some embodiments, pilot holes may be holes extending only through the thickness of a clad layer. [0084] As used herein, the term “glass laminate structure,” “glass laminate,” or “laminate glass” refers to a glass substrate that has multiple distinct layers bonded together. In some embodiments, glass layers of a glass laminate may be fused together, for example by a fusion-draw process. Two layers “fused” together means that the layers are joined together via chemical bonds between elements of the respective layers. Two layers “fused” together are in directed contact with each other, with no intervening layer disposed between them. During a fusion draw process, for example, molten clad glasses overflow on top of a molten core glass. As the glasses are being cooled, the core and clad glasses fuse together. [0085] As used herein, the term “directly adjacent” means that two layers / surfaces are in direct contact with each other. No intervening materials (e.g., adhesives) or layers are located between two layers / surfaces described as “directly adjacent” to each other. [0086] As used herein, the term “etching conditions” or “etch conditions” means the process parameters for an etching step including at least: the etching temperature, the type of etchant(s), the concentration of the etchant(s) in an etching solution, the etching time, and, if used, any mechanical agitation, such as ultrasonic energy agitation. [0087] Unless specified otherwise, the term “etch rate” means the total thickness loss per unit time of a glass composition determined by measuring the thickness loss of a surface of a glass sample composed of that composition relative to the original thickness of the sample after the surface is contacted by an etching solution for a particular set of etching conditions. It is important to note that this rate encompasses the activity on both surfaces and, in the event of masking, a single sided etch rate (half of the expressed etch rates in Table 1) would be most appropriate. An “etch rate” is expressed in terms of an amount of thickness loss per unit time for a sample exposed to the etching conditions. [0088] The “etch rate” of a particular glass composition is measured using a glass sample having only that glass composition (not a laminate) formed with a process as close as possible to that used to form the laminate (e.g., where the laminate is formed by fusion draw, so is the glass sample used to measure etch rate). Similarly, the glass sample should be subject to the same post-formation processing such as heat treatment, cleaning and polishing, etc. as the corresponding layer in the laminate structure. For purposes of testing an etch rate, test glass coupons for a glass composition having a 50 mm width and a 50 mm length can be used. [0089] As used herein, the term “effective diameter” is utilized to describe the size of through holes or blind vias, but this term should not be interpreted as requiring a through hole or via to have a circular diameter or shape. Instead, through holes or vias may have non- circular shapes, and in such embodiments the term “effective diameter” is intended to refer to the maximum cross-sectional dimension of the shape. For example, the “effective diameter” of a through hole or via having a square cross-sectional shape would be the diagonal dimension across the square. For a through hole or via having an effective diameter that varies along the depth of the through hole or via (e.g., a pyramid shape), the effective diameter is the largest effective diameter. [0090] As used herein, the term “etched through hole” or “etched via” means a through hole or via formed using an etching step. A glass surface that has been etched has distinctive structural characteristics, and one of skill in the art can tell from inspecting a glass surface whether that surface has been etched. Etching often changes the surface roughness of the glass. So, if one knows the source of the glass and the roughness of that source, a measurement of surface roughness can be used to determine whether the glass has been etched. In addition, etching generally results in differential removal of different materials in the glass. This differential removal can be detected by techniques such as electron probe microanalysis (EPMA). [0091] As used herein, the term “glass” is meant to include any material made at least partially of glass, including glass and glass-ceramics. “Glass-ceramics” include materials produced through controlled crystallization of glass. In some embodiments, glass-ceramics have about 30% to about 90% crystallinity. Non-limiting examples of glass ceramic systems that may be used include Li₂O × Al₂O₃ × nSiO₂ (i.e. LAS system), MgO × Al₂O₃ × nSiO₂ (i.e. MAS system), and ZnO × Al₂O₃ × nSiO₂ (i.e. ZAS system). [0092] For glass compositions described herein as components of glass structures, the concentration of constituent components (e.g., SiO2, Al2O3, Na2O and the like) of the glass compositions are given in mole percent (mol%) on an oxide basis, unless otherwise specified. Glass compositions disclosed herein have a liquidus viscosity that renders them suitable for use in a fusion-draw process and, in particular, for use as a glass cladding composition or a glass core composition in a fusion laminate process. As used herein, unless noted otherwise, the terms “glass” and “glass composition” encompass both glass materials and glass-ceramic materials, as both classes of materials are commonly understood. Likewise, the term “glass structure” should be understood to encompass structures containing glasses, glass ceramics, or both. [0093] As used herein, the term “CTE” refers to the coefficient of thermal expansion of the glass composition averaged over a temperature range from 20 °C to 300 °C. Unless specified otherwise, a coefficient of thermal expansion for a layer is expressed in terms of ppm (10^-6)/K and is determined using a push-rod dilatometer in accordance with ASTM E228-11. [0094] As used herein, “disposed on” means that a first layer and/or component is in direct contact with a second layer and/or component. A first layer and/or component “disposed on” a second layer and/or component may be deposited, formed, placed, or otherwise applied directly onto the second layer and/or component. In other words, if a first layer and/or component is disposed on a second layer and/or component, there are no layers disposed between the first layer and/or component and the second layer and/or component. If a first layer and/or component is described as “disposed over” a second layer and/or component, other layers may or may not be present between the first layer and/or component and the second layer and/or component. [0095] FIG.1A shows a cross-section of a laminate glass 100 according to some embodiments. Laminate glass 100 may include at least two layers—a first glass layer 150 and a second glass layer 110. In some embodiments, laminate glass 100 may be a fusion- drawn laminate. In some embodiments laminate glass 100 may include a plurality of layers bonded together using an adhesive. Fusion-drawn laminates are distinguishable from adhesively bonded laminates because no adhesive is present between layers of the laminate. In some embodiments, laminate glass 100 may include a plurality of layers bonded together using a hydroxide catalyst bonding technique. [0096] First glass layer 150 has a first surface 152, a second surface 154 opposite first surface 152, and a thickness 156 measured from first surface 152 to second surface 154. First glass layer 150 may be formed of a first glass composition. First glass layer 150 is formed of a first glass composition and second glass layer 110 is formed of a second glass composition different from the first glass composition. In other words, the glass composition of first glass layer 150 is different from the glass composition of second glass layer 110. Also, for a given set of etch conditions, the etch rate of the glass composition of first glass layer 150 is different from the etch rate of the glass composition of second glass layer 110. In some embodiments, first glass layer 150 may instead be a polymer layer formed of a polymeric material, such as Poly(methyl methacrylate) (PMMA). [0097] Second glass layer 110 is disposed over first surface 152 of first glass layer 150. In some embodiments, second glass layer 110 may be disposed on first surface 152 of first glass layer 150. In some embodiments, second glass layer 110 may be directly adjacent to first surface 152 of first glass layer 150. In such embodiments, an interior surface 114 of second glass layer 110 is in direct contact with first surface 152 of first glass layer 150. In some embodiments, second glass layer 110 may be bonded to first glass layer 150 with an adhesive layer. In such embodiments, interior surface 114 of second glass layer 110 may be bonded to first surface 152 of first glass layer 150 with an adhesive layer. [0098] As shown in FIG.1A, second glass layer 110 may include a plurality of etched through holes 120 (i.e., etched vias). These etched through holes 120 have a maximum effective diameter 122 and a depth 124. In some embodiments, depth 124 of etched through holes 120 may be equal to thickness 116 of second glass layer 110. In other words, the etchant used to etch through holes 120 does not etch first glass layer 150 adjacent to through holes 120. In some embodiments, during etching, it is possible that a small amount of first glass layer 150 is etched at interface 102 between second glass layer 110 and first glass layer 150. In some embodiments, depth 124 of etched through holes 120 may be equal to the thickness 116 of second glass layer 110 +/- 5% of thickness 156 of first glass layer 150. [0099] Through holes 120 may have any suitable maximum effective diameter 122. As non-limiting examples, maximum effective diameter 122 may be 10 µm, 20 µm, 30 µm, 40 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 120 µm, 140 µm, 160 µm, 180 µm, 200 µm, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, maximum effective diameter 122 may be in a range of 20 µm to 180 µm, 30 µm to 160 µm, 40 µm to 140 µm, 50 µm to 120 µm, 60 µm to 100 µm, 70 µm to 90 µm, or 70 µm to 80 µm. In some embodiments, maximum effective diameter 122 may be 10 µm to 200 µm, or 40 µm to 60 µm. [0100] Through holes 120 may have any suitable aspect ratio. As non-limiting examples, the aspect ratio of through holes 120 may be 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 40, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, the aspect ratio may be 0.1 to 40, 0.25 to 30, 0.5 to 25, 0.75 to 20, 1 to 15, 2 to 14, 3 to 13, 4 to 12, 5 to 11, 6 to 10, 7 to 9, or 8 to 9. In some embodiments, the aspect ratio may be 0.1 to 10. An “aspect ratio” for a through hole 120 is the ratio of second glass layer thickness 116 to maximum effective diameter 122 of the through hole 120. For purposes of determining an “aspect ratio” for a set of through holes 120, the average aspect ratio for the set of through holes 120 is measured. [0101] First glass layer 150 and second glass layer 110 may have any suitable thickness. In some embodiments, each layer of laminate glass 100 may have the same thickness. In some embodiments, different layers of laminate glass 100 may have a thickness different from others. As non-limiting examples, the thicknesses of individual layers (i.e., thicknesses 116 and 156) may be 0.1 µm, 1 µm, 5 µm, 10 µm, 60 µm, 120 µm, 180 µm, 240 µm, 300 µm, 360 µm, 420 µm, 480 µm, 540 µm, 600 µm, 720 µm, 840 µm, 960 µm, 1080 µm, or 1500 µm, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, the thickness of individual layers may be in a range of 0.1 µm to 1500 µm, 1 µm to 1080 µm, 5 µm to 960 µm, 10 µm to 840 µm, 60 µm to 720 µm, 120 µm to 600 µm, 180 µm to 540 µm, 240 µm to 480 µm, 300 µm to 420 µm or 300 µm to 360 µm. [0102] In some embodiments, the glass composition of first glass layer 150 has a first etch rate in an etching solution and the glass composition of second glass layer 110 has a second etch rate in the etching solution. The etching solution may include an acid such as, but not limited to, nitric acid, hydrochloric acid (HCl), or phosphoric acid. Fluorine containing etchants such as hydrofluoric (HF) acid, ammonium bifluoride, sodium fluoride, and mixture thereof may also be used. In some embodiments, the etching solution may include hydrofluoric acid. An etch rate for first glass layer 150 may be described herein as a “core etch rate.” An etch rate for second glass layer 110 may be described herein as a “clad etch rate.” [0103] The differential etch rates between the glass composition of first glass layer 150 (first etch rate) and the glass composition of second glass layer 110 (second etch rate) are tailored such that interface 102 between first glass layer 150 and second glass layer 110 acts as an etching barrier, thus controlling the depth 124 of through holes 120. In some embodiments, the second etch rate may be three times or more higher than the first etch rate. In some embodiments, the second etch rate may be five times or more higher than the first etch rate. In some embodiments, the second etch rate may be ten times or more higher than the first etch rate. In some embodiments, the second etch rate may be fifteen times or more higher than the first etch rate. In some embodiments, the second etch rate may be twenty times or more higher than the first etch rate. [0104] In some embodiments, first glass layer 150 may include electromagnetically modified regions that extend into a portion of first glass layer 150. In such embodiments, the electromagnetically modified regions 160 may extend into first glass layer 150 to a depth equal to a portion of the thickness 156 of first glass layer 150. In some embodiments, electromagnetically modified regions 160 may be modified tracks. In some embodiments, electromagnetically modified regions 160 may be pilot holes. In some embodiments, the pilot holes may have a diameter in a range of 1 micron to 15 microns, including subranges. For example, a pilot hole may have a diameter of 1 micron, 2.5 microns, 5 microns, 7.5 microns, 10 microns, 12.5 microns, or 15 microns, or within a range having any two of these values as endpoints, inclusive of the endpoints. In some embodiments, a pilot hole may have a diameter in a range of 2.5 microns to 12.5 microns, or diameter in a range of 5 microns to 10 microns, or a diameter in a range of 1 micron to 10 microns. [0105] By allowing electromagnetically modified regions 160 to extend into first glass layer when forming regions 160 prior to etching, precise positioning and length of a modified track or pilot hole can be relaxed. Precise positioning is expensive. So, by ending the modified track or pilot hole somewhere in first glass layer 150, the cost of a process for forming blind through holes as described herein can be minimized. [0106] In some embodiments, the electromagnetically modified regions 160 may extend into first glass layer 150 to a depth equal to 1%, 5%, 10%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 75% of thickness 156, or within a range having any two of these values as endpoints, inclusive of the endpoints. In some embodiments, the electromagnetically modified regions 160 may extend into first glass layer 150 to a depth equal to 1% to 75%, 5% to 70%, 10% to 60%, 20% to 50%, 25% to 40%, or 30% to 40% of thickness 156. In some embodiments, electromagnetically modified regions 160 may extend into first glass layer 150 to a depth equal to 1% or more of thickness 156. In some embodiments, electromagnetically modified regions 160 may extend into first glass layer 150 to a depth equal to 5% or more of thickness 156. In some embodiments, electromagnetically modified regions 160 may extend into first glass layer 150 to a depth equal to 10% or more of thickness 156. [0107] After the formation of etched through hole(s) 120 as described herein, electromagnetically modified region(s) 160 are located on first surface 152 of the first glass layer 150 exposed to an etched through hole 120 in second glass layer 110. Since electromagnetically modified regions(s) 160 extend into first glass layer 150, a portion of electromagnetically modified region(s) 160 remain in laminate glass 100 after formation of through holes 120. First glass layer 150 may be devoid of etched through holes at locations corresponding to electromagnetically modified regions 160. [0108] In some embodiments, second glass layer 110 of laminate glass 100 may be formed of a glass composition having a cladding coefficient of thermal expansion (CTE) and first glass layer 150 may be formed of a glass composition having a core coefficient of thermal expansion. In some embodiments, the cladding coefficient of thermal expansion and the core coefficient of thermal expansion may be the same or substantially the same. For example, in some embodiments, the cladding coefficient of thermal expansion may be equal to the core coefficient of thermal expansion +/- 10%, +/- 5%, or +/- 2%. Cladding and core coefficients of thermal expansion that are the same or substantially the same facilitates fusion bonding between glass layers. [0109] In some embodiments, the glass composition of second glass layer 110 and /or first glass layer 150 may have a liquidus viscosity of 20 kiloPoise (kPoise) or more. In some embodiments, the glass composition of second glass layer 110 and /or first glass layer 150 may have a liquidus viscosity of 250 kPoise or less. In some embodiments, the glass composition of second glass layer 110 and /or first glass layer 150 may have a liquidus viscosity of about 50 kPoise or more, about 80 kPoise or more, or about 100 kPoise or more. [0110] Liquidus viscosities reported herein are the shear viscosity of a glass composition at the liquidus temperature of the glass composition. Unless specified otherwise, the liquidus viscosities are determined by the following method. First the liquidus temperature of the glass is measured in accordance with ASTM C829-81 (2015), titled “Standard Practice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method.” Next the viscosity of the glass at the liquidus temperature is measured in accordance with ASTM C965-96(2012), titled “Standard Practice for Measuring Viscosity of Glass Above the Softening Point.” [0111] Liquidus temperatures reported herein are the highest temperature at which devitrification occurs in a glass composition. The liquidus temperatures were measured in accordance with ASTM C829-81 (2015), titled “Standard Practice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method.” [0112] FIG.1B shows a cross-section of a laminate glass 100 according to some embodiments. Laminate glass 100 may include at least three layers—second glass layer 110, a third glass layer 130, and first glass layer 150. In such embodiments, first glass layer 150 may be referred to as a “core layer,” and second glass layer 110 and third glass layer 130 may be referred to as a “first clad layer” and a “second clad layer,” respectively. In some embodiments, laminate glass 100 may be a fusion-drawn laminate. In some embodiments laminate glass 100 may include a plurality of layers bonded together using an adhesive. Fusion-drawn laminates are distinguishable from adhesively bonded laminates because no adhesive is present between layers of the laminate. In some embodiments, laminate glass 100 may include a plurality of layers bonded together using a hydroxide catalyst bonding technique. [0113] Third glass layer 130 is disposed over second surface 154 of first glass layer 150. Third glass layer 130 is formed of a third glass composition different from the first glass composition of first glass layer 150. In some embodiments, the glass composition of third glass layer 130 may be the same as the glass composition of second glass layer 110. In some embodiments, the glass composition of third glass layer 130 may be different than the glass composition of second glass layer 110. In some embodiments, third glass layer 130 may be disposed on second surface 154 of first glass layer 150. In some embodiments, third glass layer 130 may be directly adjacent to second surface 154 of first glass layer 150. In such embodiments, an interior surface 134 of third glass layer 130 is in direct contact with second surface 154 of first glass layer 150. In some embodiments, third glass layer 130 may be bonded to first glass layer 150 with an adhesive layer. In such embodiments, interior surface 134 of third glass layer 130 may be bonded to second surface 154 of first glass layer 150 with an adhesive layer. [0114] Second glass layer 110, third glass layer 130, and first glass layer 150 may have any suitable thickness. In some embodiments, each layer of laminate glass 100 may have the same thickness. In some embodiments, different layers of laminate glass 100 may have a thickness different from others. As non-limiting examples, the thicknesses of individual layers (i.e., thicknesses 116, 136, and 156) may be 0.1 µm, 1 µm, 5 µm, 10 µm, 60 µm, 120 µm, 180 µm, 240 µm, 300 µm, 360 µm, 420 µm, 480 µm, 540 µm, 600 µm, 720 µm, 840 µm, 960 µm, 1080 µm, or 1500 µm, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, the thickness of individual layers may be in a range of 0.1 µm to 1500 µm, 1 µm to 1080 µm, 5 µm to 960 µm, 10 µm to 840 µm, 60 µm to 720 µm, 120 µm to 600 µm, 180 µm to 540 µm, 240 µm to 480 µm, 300 µm to 420 µm or 300 µm to 360 µm. [0115] In some embodiments, the glass composition of first glass layer 150 has a first etch rate in an etching solution, the glass composition of second glass layer 110 has a second etch rate in the etching solution, and the glass composition of third glass layer 130 has a third etch rate in the etching solution. The second etch rate and the third etch rate may be the same or different. In some embodiments, the second etch rate may be substantially the same as the third etch rate. The etching solution may include an acid such as, but not limited to, nitric acid, hydrochloric acid (HCl), or phosphoric acid. Fluorine containing etchants such as hydrofluoric acid, ammonium bifluoride, sodium fluoride, and mixture thereof may also be used. In some embodiments, the etching solution may include hydrofluoric acid. An etch rate for first glass layer 150 may be described herein as a “core etch rate.” An etch rate for a second and third glass layers 110, 130 may be described herein as a “clad etch rate.” [0116] As discussed above in regards to FIG. 1A, first glass layer 150 may be devoid of etched through holes at locations corresponding to electromagnetically modified regions 160. In some embodiments, third glass layer 130 may be devoid of etched through holes. In some embodiments, third glass layer 130 may be devoid of electromagnetically modified regions. [0117] In some embodiments, one or more modified tracks or pilot holes (electromagnetically modified regions) may be formed in laminate glass such that the track(s) or hole(s) extend through third glass layer 130 and into a portion of the first glass layer 150. In such embodiments, these modified track(s) or pilot hole(s) may be used to form through holes in third glass layer 130 (e.g., through holes 140) in the same manner as through hole(s) 120 are formed in second glass layer 110. In such embodiments, third glass layer 130 may be formed of a third glass composition different from the first glass composition of first glass layer 150. And etching conditions may etch the third glass composition at a third etch rate that is higher than the first etch rate such that the etching conditions etch one or more through hole(s) 140 in the third glass layer 130 at the location(s) of the modified track(s) or pilot hole(s), but do not form an etched through hole in the first glass layer 150 at the location(s) of the modified track(s) or pilot hole(s). In such embodiments, the track(s) or hole(s) may extend into first glass layer 150 to a depth equal to a portion of the thickness 156 of first glass layer 150. In some embodiments, the third etch rate may be three times or more higher than the first etch, five times or more higher than the first etch rate, ten times or more higher than the first etch rate, or twenty times or more higher than the first etch rate. [0118] In some embodiments, second glass layer 110 and /or third glass layer 130 of laminate glass 100 may be formed of a glass composition having a cladding coefficient of thermal expansion (CTE) and first glass layer 150 may be formed of a glass composition having a core coefficient of thermal expansion. In some embodiments, the cladding coefficient of thermal expansion and the core coefficient of thermal expansion may be the same or substantially the same. For example, in some embodiments, the cladding coefficient of thermal expansion may be equal to the core coefficient of thermal expansion +/- 10%, +/- 5%, or +/- 2%. Cladding and core coefficients of thermal expansion that are the same or substantially the same facilitates fusion bonding between glass layers. [0119] In some embodiments, the glass composition(s) of second glass layer 110, third glass layer 130, and /or first glass layer 150 may have a liquidus viscosity of 20 kiloPoise (kPoise) or more. In some embodiments, the glass composition(s) of second glass layer 110, third glass layer 130, and /or first glass layer 150 may have a liquidus viscosity of 250 kPoise or less. In some embodiments, the glass composition(s) of second glass layer 110, third glass layer 130, and /or first glass layer 150 may have a liquidus viscosity of about 50 kPoise or more, about 80 kPoise or more, or about 100 kPoise or more. [0120] FIGS. 2A–2C illustrate a method for forming through holes (blind vias) 120 in a laminate glass 100 according to some embodiments. First, as illustrated in FIG.2A, one or more electromagnetically modified regions 160 may be formed in laminate glass 100 such that they extend through second glass layer 110 and into a portion of first glass layer 150. In other words, electromagnetically modified region(s) 160 may extend from exterior surface 112 of second glass layer 110 to interior surface 114 of second glass layer 110 and into a portion of first glass layer 150. As discussed above, electromagnetically modified region(s) 160 may extend into first glass layer 150 to a depth equal to a portion of the thickness 156 of first glass layer 150. Each electromagnetically modified region 160 may be a modified track or a pilot hole. [0121] Electromagnetically modified region(s) 160 may be formed in second glass layer 110 by controlling the focus position of the laser used to create the electromagnetically modified region(s) 160. The effective line focus of the laser can be positioned such that it spans the entire thickness of second glass layer 110 and only a portion of the thickness of first glass layer 150. In some embodiments, selective positioning of laser modification may additionally or alternatively be accomplished by truncating the incoming laser beam through the use of an iris or other optics to selectively omit portions of the line focus. [0122] In some embodiments, a high energy laser pulse or pulses may be applied to create an electromagnetically modified region(s) 160 in laminate glass 100. In some embodiments, an electromagnetically modified region(s) 160 may be a line (track) of laser- induced modification formed by a pulsed laser. The pulsed laser may form the modified track by non-linear multi-photon absorption, for example. When subsequently etched, the modified track allows etchant to penetrate laminate glass 100. Exemplary ways for performing the laser modification and subsequent etching are disclosed in U.S. Patent No.9,278,886, US Pub. No. 2015/0166393, U.S. Pub. No.2015/0166395, and US Application 62/633,835, “Alkali-Free Borosilicate Glasses with Low Post-HF Etch Roughness,” filed February 22, 2018, each of which is hereby incorporated by reference in its entirety. In some embodiments, a laser may be used to form an ablated hole instead of modified regions, and the ablated hole may be widened by etching. Any suitable method of forming a pilot hole or modified track in laminate glass 100 may be used. [0123] After forming electromagnetically modified region(s) 160, region(s) 160 are etched to form through holes 120. As illustrated in FIGS.2B and 2C, electromagnetically modified region(s) 160 allow etchant to preferentially etch therein during an etching process. As etchant begins to preferentially etch electromagnetically modified regions 160, partially etched holes 121 are formed in second glass layer 110 at the location of electromagnetically modified region(s) 160. The rate of material removal within an electromagnetically modified region 160 is faster than the rate of material removal outside the electromagnetically modified region 160. Once through holes 120 having desired dimensions and morphologies are formed, the etching process is stopped, leaving through holes 120 in second glass layer 110, as shown in FIG.2C. While FIGS.2A–2C illustrate the formation of etched through holes 120 in a three-layer glass laminate, etched through holes 120 may be formed in a two- layer glass laminate having first glass layer 150 and second glass layer 110 (e.g., laminate glass 100 illustrated in FIG.1A) in the same fashion. [0124] The etching conditions for forming through holes 120 and the glass compositions of second glass layer 110 and first glass layer 150 may be selected such that through holes 120 are formed in second glass layer 110 without formation of through holes in first glass layer 150. In other words, etching conditions may be selected such that the etching conditions etch a first through hole 120 in second glass layer 110 at the location of an electromagnetically modified region 160, but do not form a through hole in first glass layer 150 at the location of an electromagnetically modified region 160. [0125] Etching laminate glass 100 may include exposing laminate glass 100 to etching conditions that (i) etch a glass composition of first glass layer 150 at a first etch rate and etch a glass composition of second glass layer 110 at a second etch rate. In some embodiments, the second etch rate may be three times or more higher than the first etch rate. In some embodiments, the second etch rate may be five times or more higher than the first etch rate. In some embodiments, the second etch rate may be ten times or more higher than the first etch rate. In some embodiments, the second etch rate may be fifteen times or more higher than the first etch rate. In some embodiments, the second etch rate may be twenty times or more higher than the first etch rate. In some embodiments, the first etch rate may be zero. In such embodiments, the second etch rate may be described as infinity times higher than the first etch rate. [0126] Etching processes for forming through holes 120 may include any suitable method for applying etchant solution(s) to laminate glass 100. Suitable etchant solution application processes include, but are not limited to, submerging laminate glass 100 in an etchant bath, spraying etchant solution(s) onto laminate glass 100, or a combination thereof. [0127] Non-limiting examples of etchant solutions for forming through holes 120 include, but are not limited to, aqueous solutions including strong mineral acids such as nitric acid, hydrochloric acid (HCl), or phosphoric acid. Fluorine containing etchants such as hydrofluoric acid, ammonium bifluoride, sodium fluoride, and mixture thereof may also be used. In some embodiments, the etchant solution may include hydrofluoric acid. In some embodiments, the etchant solution can be a mixture of hydrofluoric acid and hydrochloric acid. Exemplary etchant solutions are shown below in Table 1. [0128] In some embodiments, the etching solution may be an aqueous solution including one or more acids at a volume percent (vol%) in the range of 5 vol% to 60 vol% total, including subranges. For example, the etching solution may include one or more acids having a total volume percent of 5 vol%, 10 vol%, 15 vol%, 20 vol%, 25 vol%, 30 vol%, 35 vol%, 40 vol%, 45 vol%, 50 vol%, 55 vol%, or 60 vol%, or a volume percentage having any two of these values as endpoints, including the endpoints. In some embodiments, the etching solution may include one or more acids having a total volume percent in a range of 10 vol% to 55 vol%, 15 vol% to 50 vol%, 20 vol% to 45 vol%, 25 vol% to 40 vol%, or 30 vol% to 35 vol%. In some embodiments, etching may be performed 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 40°C, 50°C, or 60°C. In some embodiments, etching may be performed at room temperature (23°C). [0129] In some embodiments, the etching solution may be an aqueous solution including HF and / or HCl. In some embodiments, the etching solution may include 5 vol% to 30 vol% HF, including subranges. For example, the etching solution may include 5 vol% HF, 10 vol% HF, 15 vol% HF, 20 vol% HF, 25 vol% HF, or 30 vol% HF, or a volume percentage having any two of these values as endpoints. In some embodiments, the etching solution may include HF in a range of 10 vol% to 25 vol%, or 15 vol% to 20 vol%. [0130] In some embodiments, the etching solution may include 1 vol% to 5 vol% HCl, including subranges. For example, the etching solution may include 1 vol% HCl, 2 vol% HCl, 2.5 vol% HCl, 3 vol% HCl, 4 vol% HCl, or 5 vol% HCl, or a volume percentage having any two of these values as endpoints, including the endpoints. In some embodiments, the etching solution may include HCl in a range of 2 vol% to 4 vol%, or 1 vol% to 3 vol%. [0131] In some embodiments, an etching solution may include a masking surfactant. As used herein, a “masking surfactant” means a surfactant that adheres to a glass surface during etching to act as a dynamic surface masking layer. Such a surfactant may facilitate preferential etching of an electromagnetically modified region. In some embodiments, the etching solution may include 0.01 vol% to 2 vol% of a masking surfactant, including subranges. For example, the etching solution may include 0.01 vol% masking surfactant, 0.1 vol% masking surfactant, 1 vol% masking surfactant, or 2 vol% masking surfactant, or a volume percentage having any two of these values as endpoints, including the endpoints. Suitable masking surfactants include, but are not limited to, polyelectrolyte (PE) surfactants, such as poly (diallyldimethylammonium chloride) (PDADMAC). In some embodiments, the etching solution may include 0.01 vol% to 1 vol% of a masking surfactant [0132] In some embodiments, after etching through holes 120, laminate glass 100 including through holes 120 may be plated with a metallic material. As illustrated, for example in FIG. 3A, plating laminate glass 100 with a metallic material may form a metal plating 170 disposed within through holes 120. Plating laminate glass 100 with a metallic material may include plating a sidewall 126 of one or more through holes 120 with the metallic material. [0133] In some embodiments, the metal plating 170 may partially fill the one or more through holes 120. In other words, a portion of the volume defined by the sidewalls 126 of through holes 120 may remain open after plating of the metallic material. In some embodiments, the metal plating 170 may fill one or more through holes 120. In other words, the metallic material may completely fill the volume defined by the sidewalls 126 of through holes 120. [0134] In some embodiments, plating laminate glass 100 with a metallic material may include an electroplating process. In some embodiments, the metal plated in the electroplating process may include copper. Other metallic materials that may be electroplated include, but are not limited to, silver, gold, ruthenium, rhodium, palladium, osmium, iridium, and platinum. [0135] In some embodiments, plating laminate glass 100 with a metallic material may include an electroless plating process. The electroless plating process may partially fill the one or more through holes 120 with a metallic material. In some embodiments, the metal plated in the electroless plating process may include copper. Other metallic materials that may be electroless plated include, but are not limited to, silver, gold, ruthenium, rhodium, palladium, osmium, iridium, and platinum. In some embodiments, after the electroless plating process, an electroplating process may be performed to further fill the one or more through holes 120 with metallic material. [0136] In some embodiments, after plating laminate glass 100 including through holes 120 formed in second glass layer 110, first glass layer 150 and/or third glass layer 130 may be removed. For example, as shown in FIG.3B, first glass layer 150 and third glass layer 130 may be removed from second glass layer 110 after plating laminate glass 100 with metallic material to form a glass article 180 including through vias 182 fully or partially filed with the metallic material. In some embodiments, removal of first glass layer 150 and/or third glass layer 130 may be performed using an etching process that etches away the material of first glass layer 150 and/or third glass layer 130, leaving only second glass layer 110. In some embodiments, removal of first glass layer 150 and/or third glass layer 130 may alternatively or additionally include a mechanical grinding or polishing process. [0137] In some embodiments, prior to an electroless and/or electroplating process, the sidewall 126 of a through hole 120 may be coated with a material to improve the effective adhesion between a metallic material and the glass composition defining sidewall 126. In some embodiments, the coating may be a metal-oxide interlayer. Suitable metal-oxides for the interlayer include, but are not limited to, aluminum oxide, silicon oxide, titanium oxide, cerium oxide, zirconium oxide, or a combination of two or more of these types of metal- oxides. In some embodiments, the coating may be a nanoporous metal-oxide interlayer. In some embodiments, the nanoporous metal-oxide interlayer may be a nanoporous aluminum oxide (alumina, Al₂O₃) interlayer. [0138] Such an interlayer may increase the adhesion of a metallic material to a sidewall 126 by creating a mechanical interlock between the glass surface of sidewall 126 and a plated metallic material. In particular, the structure of the metal-oxide interlayer with re-entrant geometries can serve to create a mechanical interlock between the plated metallic material and the glass surface of sidewall 126. An interlayer may be made by coating all or a portion of second glass layer 110 with a slurry including colloidal metal-oxide precursor particles and metal-oxide particles (e.g., alumina particles) followed by calcination at a high temperature. These coating and calcination processes can create sufficient adhesion between the interlayer and second glass layer 110. In some embodiments, the metal-oxide particles may be nanoparticles. [0139] As used herein, “nanoporous” means a porous material having an average pore size in the range of 1 nanometer (nm) to 100 nanometers. A nanoporous structure includes a plurality of interconnected tunnels or “nanopores.” As used herein, a “nanoparticle” means a particle having at least one dimension in the range of 1 nanometer to 100 nanometers in size. The size of a nanoparticle may be measured by scanning electron microscopy or a dynamic light scattering (DLS) particle size analyzer. An average particle size of a batch of particles may be measured by measuring a sample of the particles using scanning electron microscopy or a DLS particle size analyzer, or may be calculated from the Brunauer–Emmett–Teller (BET) surface area of the sample. Unless indicated otherwise, the size of a nanoparticle discussed herein is measured by scanning electron microscopy and an average particle size of a batch of particles discussed herein is calculated from the Brunauer–Emmett–Teller (BET) surface area of the sample. [0140] In some embodiments, a metal-oxide interlayer may be catalyzed to improve adhesion between a metallic plating material and the interlayer. For example, palladium complexes may be adsorbed on the metal-oxide layer. This palladium complex adsorption step may include treatment of the metal-oxide layer with K2PdCl4 (potassium tetrachloropalladate), ionic palladium, and/or a Sn/Pd (tin/palladium) colloidal solution. If K2PdCl4 or ionic palladium are used, catalyzing may include reduction of the K2PdCl4 or ionic palladium into metallic palladium. In such embodiments, the reduction of K₂PdCl₄ or ionic palladium forms palladium particles. Such a reduction may be performed by reacting the K₂PdCl₄ or ionic palladium with dimethylaminoborane (DMAB). If a Sn/Pd colloidal solution is used, the palladium is already in Pd⁰ form with a tin shell around it. The tin shell can be removed by acid etching. [0141] In some embodiments, the metal-oxide interlayer may be charged prior to catalyzing. For example, charging the metal-oxide layer may include treating the nanoporous metal-oxide layer with an aminosilane, such as aminopropyltriethoxysilane (APTES). [0142] FIG.4 shows a cross-section of a laminate glass 100 according to some embodiments. Laminate glass 100 may include at least three layers—a second glass layer 110, a third glass layer 130, and a first glass layer 150. In some embodiments, laminate glass 100 may be a fusion-drawn laminate. In some embodiments laminate glass 100 may include a plurality of layers bonded together using an adhesive. Fusion-drawn laminates are distinguishable from adhesively bonded laminates because no adhesive is present between layers of the laminate. In some embodiments, laminate glass 100 may include a plurality of layers bonded together using a hydroxide catalyst bonding technique. [0143] First glass layer 150 has a first surface 152, a second surface 154 opposite first surface 152, and a thickness 156 measured from first surface 152 to second surface 154. First glass layer 150 may be formed of a first glass composition. The glass composition of first glass layer 150 is different from glass composition(s) of second glass layer 110 and third glass layer 130. Also, for a given set of etch conditions, the etch rate of the glass composition of first glass layer 150 is different from the etch rate of the glass composition(s) of second glass layer 110 and third glass layer 130. In some embodiments, first glass layer 150 may be formed of a polymeric material, such as Poly(methyl methacrylate) (PMMA). [0144] Second glass layer 110 is disposed over first surface 152 of first glass layer 150. Second glass layer 110 is formed of a second glass composition different from the first glass composition of first glass layer 150. In some embodiments, second glass layer 110 may be disposed on first surface 152 of first glass layer 150. In some embodiments, second glass layer 110 may be directly adjacent to first surface 152 of first glass layer 150. In such embodiments, an interior surface 114 of second glass layer 110 is in direct contact with first surface 152 of first glass layer 150. In some embodiments, second glass layer 110 may be bonded to first glass layer 150 with an adhesive layer. In such embodiments, interior surface 114 of second glass layer 110 may be bonded to first surface 152 of first glass layer 150 with an adhesive layer. [0145] Third glass layer 130 is disposed over second surface 154 of first glass layer 150. Third glass layer 130 is formed of a third glass composition different from the first glass composition of first glass layer 150. In some embodiments, the glass composition of third glass layer 130 may be the same as the glass composition of second glass layer 110. In some embodiments, the glass composition of third glass layer 130 may be different than the glass composition of second glass layer 110. In some embodiments, third glass layer 130 may be disposed on second surface 154 of first glass layer 150. In some embodiments, third glass layer 130 may be directly adjacent to second surface 154 of first glass layer 150. In such embodiments, an interior surface 134 of third glass layer 130 is in direct contact with second surface 154 of first glass layer 150. In some embodiments, third glass layer 130 may be bonded to first glass layer 150 with an adhesive layer. In such embodiments, interior surface 134 of third glass layer 130 may be bonded to second surface 154 of first glass layer 150 with an adhesive layer. [0146] As shown in FIG.4, second glass layer 110 may include a plurality of etched through holes 120 (i.e., etched vias). These etched through holes 120 have a maximum effective diameter 122 and a depth 124. In some embodiments, depth 124 of etched through holes 120 may be equal to thickness 116 of second glass layer 110. In other words, the etchant used to etch through holes 120 does not etch first glass layer 150 adjacent through holes 120. In some embodiments, during etching, it is possible that a small amount of first glass layer 150 is etched at interface 102 between second glass layer 110 and first glass layer 150. In some embodiments, depth 124 of etched through holes 120 may be equal to the thickness 116 of second glass layer 110 +/- 5% of thickness 156 of first glass layer 150. [0147] Through holes 120 may have any suitable maximum effective diameter 122. As non-limiting examples, maximum effective diameter 122 may be 10 µm, 20 µm, 30 µm, 40 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 120 µm, 140 µm, 160 µm, 180 µm, 200 µm, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, maximum effective diameter 122 may be in a range of 20 µm to 180 µm, 30 µm to 160 µm, 40 µm to 140 µm, 50 µm to 120 µm, 60 µm to 100 µm, 70 µm to 90 µm, or 70 µm to 80 µm. In some embodiments, maximum effective diameter 122 may be 10 µm to 200 µm, or 40 µm to 60 µm. [0148] Through holes 120 may have any suitable aspect ratio. As non-limiting examples, the aspect ratio of through holes 120 may be 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 40, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, the aspect ratio may be 0.1 to 40, 0.25 to 30, 0.5 to 25, 0.75 to 20, 1 to 15, 2 to 14, 3 to 13, 4 to 12, 5 to 11, 6 to 10, 7 to 9, or 8 to 9. In some embodiments, the aspect ratio may be 0.1 to 10. An “aspect ratio” for a through hole 120 is the ratio of second glass layer thickness 116 to maximum effective diameter 122 of the through hole 120. For purposes of determining an “aspect ratio” for a set of through holes 120, the average aspect ratio for the set of through holes 120 is measured. [0149] Similarly, third glass layer 130 may include a plurality of etched through holes 140. These etched through holes 140 have a maximum effective diameter 142 and a depth 144. In some embodiments, depth 144 of etched through holes 140 may be equal to thickness 136 of third glass layer 130. In other words, the etchant used to etch through holes 140 does not etch first glass layer 150 adjacent through holes 140. In some embodiments, during etching, it is possible that a small amount of first glass layer 150 is etched at interface 104 between third glass layer 130 and first glass layer 150. In some embodiments, depth 144 of etched through holes 140 may be equal to the thickness 136 of third glass layer 130 +/- 5% of thickness 156 of first glass layer 150. [0150] Through holes 140 may have any suitable maximum effective diameter 142. As non-limiting examples, maximum effective diameter 142 may be 10 µm, 20 µm, 30 µm, 40 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 120 µm, 140 µm, 160 µm, 180 µm, 200 µm, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, maximum effective diameter 142 may be in a range of 20 µm to 180 µm, 30 µm to 160 µm, 40 µm to 140 µm, 50 µm to 120 µm, 60 µm to 100 µm, 70 µm to 90 µm, or 70 µm to 80 µm. In some embodiments, maximum effective diameter 142 may be 10 µm to 200 µm, or 40 µm to 60 µm. [0151] Through holes 140 may have any suitable aspect ratio. As non-limiting examples, the aspect ratio of through holes 140 may be 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 40 or any range having any two of these values as endpoints, including the endpoints. In some embodiments, the aspect ratio may be 0.1 to 40, 0.25 to 30, 0.5 to 25, 0.75 to 20, 1 to 15, 2 to 14, 3 to 13, 4 to 12, 5 to 11, 6 to 10, 7 to 9, or 8 to 9. In some embodiments, the aspect ratio may be 0.1 to 10. In some embodiments, the aspect ratio may be 0.1 to 10. An “aspect ratio” for a through hole 140 is the ratio of third glass layer thickness 136 to maximum effective diameter 142 of the through hole 140. For purposes of determining an “aspect ratio” for a set of through holes 140, the average aspect ratio for the set of through holes 140 is measured. [0152] Second glass layer 110, third glass layer 130, and first glass layer 150 may have any suitable thickness. In some embodiments, each layer of laminate glass 100 may have the same thickness. In some embodiments, different layers of laminate glass 100 may have a thickness different from others. As non-limiting examples, the thicknesses of individual layers (i.e., thicknesses 116, 136, and 156) may be 0.1 µm, 1 µm, 5 µm, 10 µm, 60 µm, 120 µm, 180 µm, 240 µm, 300 µm, 360 µm, 420 µm, 480 µm, 540 µm, 600 µm, 720 µm, 840 µm, 960 µm, 1080 µm, or 1500 µm, or any range having any two of these values as endpoints, including the endpoints. In some embodiments, the thickness of individual layers may be in a range of 0.1 µm to 1500 µm, 1 µm to 1080 µm, 5 µm to 960 µm, 10 µm to 840 µm, 60 µm to 720 µm, 120 µm to 600 µm, 180 µm to 540 µm, 240 µm to 480 µm, 300 µm to 420 µm or 300 µm to 360 µm. [0153] In some embodiments, the glass composition of first glass layer 150 has a first etch rate in an etching solution, the glass composition of second glass layer 110 has a second etch rate in the etching solution, and the glass composition of third glass layer 130 has a third etch rate in the etching solution. The second etch rate and the third etch rate may be the same or different. In some embodiments, the second etch rate may be substantially the same as the third etch rate. The etching solution may include an acid such as, but not limited to, nitric acid, hydrochloric acid (HCl), or phosphoric acid. Fluorine containing etchants such as hydrofluoric acid, ammonium bifluoride, sodium fluoride, and mixture thereof may also be used. In some embodiments, the etching solution may include hydrofluoric acid. An etch rate for first glass layer 150 may be described herein as a “core etch rate.” An etch rate for second or third glass layers 110, 130 may be described herein as a “clad etch rate.” [0154] The differential etch rates between the glass composition of first glass layer 150 (first etch rate) and the glass composition(s) of second glass layer 110 (second etch rate) and third glass layer 130 (third etch rate) are tailored such that the interfaces 102, 104 between first glass layer 150 and second and third glass layers 110, 130 act as an etching barrier, thus controlling the depth 124, 144 of through holes 120, 140, respectively. In some embodiments, the second etch rate and the third etch rate may each be three times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be five times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be ten times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be fifteen times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be twenty times or more higher than the first etch rate. [0155] In some embodiments, a plurality of etched through holes 120 in second glass layer 110 may be disposed directly opposite a plurality of etched through holes 140 in third glass layer 130. In such embodiments, respective through holes 120, 140 may be located at the same location on opposing sides of first glass layer 150. In some embodiments, respective through holes 120, 140 disposed directly opposite each other may be disposed in a co-axial relationship such that they share a common central vertical axis (e.g., vertical axis 106 shown in FIG. 1). The common central vertical axis of through holes 120, 140 disposed directly opposite each other may extend on or parallel to an electromagnetically modified region 160 located between respective opposing through holes 120, 140. [0156] First glass layer 150 is devoid of etched through holes. In some embodiments, first glass layer 150 may include electromagnetically modified regions 160 located between respective opposing through holes 120, 140 in second glass layer 110 and third glass layer 130, respectively. In some embodiments, electromagnetically modified regions 160 may be modified tracks. In some embodiments, electromagnetically modified regions 160 may be pilot holes. [0157] In some embodiments, second glass layer 110 and /or third glass layer 130 of laminate glass 100 may be formed of a glass composition having a cladding coefficient of thermal expansion (CTE) and first glass layer 150 may be formed of a glass composition having a core coefficient of thermal expansion. In some embodiments, the cladding coefficient of thermal expansion and the core coefficient of thermal expansion may be the same or substantially the same. For example, in some embodiments, the cladding coefficient of thermal expansion may be equal to the core coefficient of thermal expansion +/- 10%, +/- 5%, or +/- 2%. Cladding and core coefficients of thermal expansion that are the same or substantially the same facilitates fusion bonding between glass layers. [0158] In some embodiments, the glass composition(s) of second glass layer 110, third glass layer 130, and /or first glass layer 150 may have a liquidus viscosity of 20 kiloPoise (kPoise) or more. In some embodiments, the glass composition(s) of second glass layer 110, third glass layer 130, and /or first glass layer 150 may have a liquidus viscosity of 250 kPoise or less. In some embodiments, the glass composition(s) of second glass layer 110, third glass layer 130, and /or first glass layer 150 may have a liquidus viscosity of about 50 kPoise or more, about 80 kPoise or more, or about 100 kPoise or more. [0159] FIGS. 5A–5C illustrate a method for forming through holes (blind vias) 120, 140 in layers of laminate glass 100 according to some embodiments. First, as illustrated in FIG. 5A, one or more electromagnetically modified regions 160 may be formed through laminate glass 100 between an exterior surface 112 of second glass layer 110 and an exterior surface 132 of third glass layer 130. In other words, electromagnetically modified region(s) 160 may extend from exterior surface 112, through second glass layer 110, through first glass layer 150, through third glass layer 130, to exterior surface 132. Electromagnetically modified region(s) 160 may be a modified track or a pilot hole. [0160] In some embodiments, an electromagnetically modified region(s) 160 may extend through only a portion of laminate glass 100 between exterior surface 112 of second glass layer 110 and exterior surface 132 of third glass layer 130. For example, in some embodiments, an electromagnetically modified region(s) 160 may extend through only second glass layer 110 or third glass layer 130. Electromagnetically modified region(s) 160, and thus through holes 120,140 may be formed in second glass layer 110, third glass layer 130, or both second glass layer 110 and third glass layer 130 by controlling the focus position of the laser used to create the electromagnetically modified region(s) 160. The effective line focus of the laser can be positioned such that it spans the entire thickness of laminate glass 100, only the thickness of second glass layer 110, or only the thickness of third glass layer 130. In some embodiments, selective positioning of laser modification may additionally or alternatively be accomplished by truncating the incoming laser beam through the use of an iris or other optics to selectively omit portions of the line focus. [0161] In some embodiments, a high energy laser pulse or pulses may be applied to create an electromagnetically modified region 160 through the laminate glass 100. In some embodiments, an electromagnetically modified region 160 may be a line (track) of laser- induced modification formed by a pulsed laser. The pulsed laser may form the modified track by non-linear multi-photon absorption, for example. When subsequently etched, the modified track allows etchant to penetrate laminate glass 100. Exemplary ways for performing the laser modification and subsequent etching are disclosed in U.S. Patent No.9,278,886, US Pub. No. 2015/0166393, U.S. Pub. No.2015/0166395, and US Application 62/633,835, “Alkali-Free Borosilicate Glasses with Low Post-HF Etch Roughness,” filed February 22, 2018, each of which is hereby incorporated by reference in its entirety. In some embodiments, a laser may be used to form an ablated hole instead of modified regions, and the ablated hole may be widened by etching. Any suitable method of forming a pilot hole or modified track through laminate glass 100 may be used. [0162] After forming electromagnetically modified region(s) 160, region(s) 160 are etched to form through holes. As illustrated in FIGS. 5B and 5C, electromagnetically modified region(s) 160 allow etchant to preferentially etch therein during an etching process. As etchant begins to preferentially etch electromagnetically modified region(s) 160, partially etched holes 121, 141 are formed in second glass layer 110 and third glass layer 130, respectively. The rate of material removal within an electromagnetically modified region 160 is faster than the rate of material removal outside the electromagnetically modified region 160. Once through holes 120, 140 having desired dimensions and morphologies are formed, the etching process is stopped, leaving through holes 120, 140 in second glass layer 110 and third glass layer 130, as shown in FIG.5C. [0163] The etching conditions for forming through holes 120, 140 and the glass compositions of second glass layer 110, third glass layer 130, and first glass layer 150 may be selected such that through holes are formed in the second and / or third glass layer(s) without formation of through holes in first glass layer 150. In other words, etching conditions may be selected such that the etching conditions etch a first through hole 120 in second glass layer 110 and a second through hole 140 in third glass layer 130 at the location of an electromagnetically modified region 160, but do not form a through hole in first glass layer 150 at the location of an electromagnetically modified region 160. [0164] Etching laminate glass 100 may include exposing laminate glass 100 to etching conditions that (i) etch a glass composition of first glass layer 150 at a first etch rate, (ii) etch a glass composition of second glass layer 110 at a second etch rate, and (iii) etch a glass composition of third glass layer 130 at a third etch rate. The second etch rate and the third etch rate may be the same or different. In some embodiments, the second etch rate and the third etch rate may be substantially the same. However, both of the second etch rate and the third etch rate are significantly higher than the first etch rate such that through holes are not formed in first glass layer 150 during the etching process. [0165] In some embodiments, the second etch rate and the third etch rate may each be three times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be five times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be ten times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be fifteen times or more higher than the first etch rate. In some embodiments, the second etch rate and the third etch rate may each be twenty times or more higher than the first etch rate. In some embodiments, the first etch rate may be zero. In such embodiments, the second and third etch rate may be described as infinity times higher than the first etch rate. [0166] Etching processes for forming through holes 120, 140 may include any suitable method for applying etchant solution(s) to laminate glass 100. Suitable etchant solution application processes include, but are not limited to, submerging laminate glass 100 in an etchant bath, spraying etchant solution(s) onto laminate glass 100, or a combination thereof. [0167] Non-limiting examples of etchant solutions for forming through holes 120, 140 include, but are not limited to, aqueous solutions including strong mineral acids such as nitric acid, hydrochloric acid (HCl), or phosphoric acid. Fluorine containing etchants such as hydrofluoric acid, ammonium bifluoride, sodium fluoride, and mixture thereof may also be used. In some embodiments, the etchant solution may include hydrofluoric acid. In some embodiments, the etchant solution can be a mixture of hydrofluoric acid and hydrochloric acid. Exemplary etchant solutions are shown below in Table 1. [0168] In some embodiments, the etching solution may be an aqueous solution including one or more acids at a volume percent (vol%) in the range of 5 vol% to 60 vol% total, including subranges. For example, the etching solution may include one or more acids having a total volume percent of 5 vol%, 10 vol%, 15 vol%, 20 vol%, 25 vol%, 30 vol%, 35 vol%, 40 vol%, 45 vol%, 50 vol%, 55 vol%, or 60 vol%, or a volume percentage having any two of these values as endpoints, including the endpoints. In some embodiments, the etching solution may include one or more acids having a total volume percent in a range of 10 vol% to 55 vol%, 15 vol% to 50 vol%, 20 vol% to 45 vol%, 25 vol% to 40 vol%, or 30 vol% to 35 vol%. In some embodiments, etching may be performed 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 40°C, 50°C, or 60°C. In some embodiments, etching may be performed at room temperature (23°C). [0169] In some embodiments, the etching solution may be an aqueous solution including HF and / or HCl. In some embodiments, the etching solution may include 5 vol% to 30 vol% HF, including subranges. For example, the etching solution may include 5 vol% HF, 10 vol% HF, 15 vol% HF, 20 vol% HF, 25 vol% HF, or 30 vol% HF, or a volume percentage having any two of these values as endpoints. In some embodiments, the etching solution may include HF in a range of 10 vol% to 25 vol%, or 15 vol% to 20 vol%. [0170] In some embodiments, the etching solution may include 1 vol% to 5 vol% HCl, including subranges. For example, the etching solution may include 1 vol% HCl, 2 vol% HCl, 2.5 vol% HCl, 3 vol% HCl, 4 vol% HCl, or 5 vol% HCl, or a volume percentage having any two of these values as endpoints, including the endpoints. In some embodiments, the etching solution may include HCl in a range of 2 vol% to 4 vol%, or 1 vol% to 3 vol%. [0171] In some embodiments, an etching solution may include a masking surfactant. As used herein, a “masking surfactant” means a surfactant that adheres to a glass surface during etching to act as a dynamic surface masking layer. Such a surfactant may facilitate preferential etching of an electromagnetically modified region. In some embodiments, the etching solution may include 0.01 vol% to 2 vol% of a masking surfactant, including subranges. For example, the etching solution may include 0.01 vol% masking surfactant, 0.1 vol% masking surfactant, 1 vol% masking surfactant, or 2 vol% masking surfactant, or a volume percentage having any two of these values as endpoints, including the endpoints. Suitable masking surfactants include, but are not limited to, polyelectrolyte (PE) surfactants, such as poly (diallyldimethylammonium chloride) (PDADMAC). In some embodiments, the etching solution may include 0.01 vol% to 1 vol% of a masking surfactant. [0172] In some embodiments, after etching through holes 120 and / or through holes 140, laminate glass 100 including through holes 120 and / or through holes 140 may be plated with a metallic material. As illustrated, for example in FIG.6, plating laminate glass 100 with a metallic material may form a metal plating 170 disposed within through holes 120 and /or through holes 140. Plating laminate glass 100 with a metallic material may include plating a sidewall 126 of one or more through holes 120 with the metallic material and plating a sidewall 146 of one or more through holes 140 with the metallic material. [0173] In some embodiments, the metal plating 170 may partially fill the one or more through holes 120 and partially fill the one or more through holes 140. In other words, a portion of the volume defined by the sidewalls 126, 146 of through holes 120, 140 may remain open after plating of the metallic material. In some embodiments, the metal plating 170 may fill one or more through holes 120 and one or more through holes 140. In other words, the metallic material may completely fill the volume defined by the sidewalls 126, 146 of through holes 120, 140. [0174] In some embodiments, plating laminate glass 100 with a metallic material may include an electroplating process. In some embodiments, the metal plated in the electroplating process may include copper. Other metallic materials that may be electroplated include, but are not limited to, silver, gold, ruthenium, rhodium, palladium, osmium, iridium, and platinum. [0175] In some embodiments, plating laminate glass 100 with a metallic material may include an electroless plating process. The electroless plating process may partially fill the one or more through holes 120 and partially fill the one or more through holes 140 with a metallic material. In some embodiments, the metal plated in the electroless plating process may include copper. Other metallic materials that may be electroless plated include, but are not limited to, silver, gold, ruthenium, rhodium, palladium, osmium, iridium, and platinum. In some embodiments, after the electroless plating process, an electroplating process may be performed to further fill the one or more through holes 120 with metallic material and further fill the one or more through holes 140 with metallic material. In some embodiments, prior to an electroless and/or electroplating process, sidewalls 126, 146 may be coated with a metal- oxide interlayer to improve the effective adhesion between a metallic material and the glass composition defining sidewalls 126, 146, as discussed above. [0176] By using methods described herein, the shape of through holes 120 and/or through holes 140 can be controlled by one or more of: (i) laser conditions used to form electromagnetically modified regions 160, (ii) the etch chemistry for glass compositions and etching solutions, and (iii) the etching process time. Various samples of a fusion-drawn laminate glass having 1 mm total thickness and clad layers having a 0.1 mm thickness were etched under various etch conditions A–D shown below in Table 1. The core layer had a composition consistent with sample 1-2 in Table 2 and the clad layers had a composition consistent with the composition of sample 2-69 in Table 4. The polyelectrolyte (PE) surfactant used was poly (diallyldimethylammonium chloride) (PDADMAC). The positively charged surfactant adheres to the glass surface and acts as a dynamic surface masking layer, further adding to the preferential etching of the modified region. [0177] The Bessel laser beam utilized to form electromagnetically modified regions for the test samples had a focal line length of approximately 0.7 mm, which can be adjusted for different glass thicknesses. The laser source also has the ability to vary the “burst” number, i.e. the number of pulses incident at one spot. A burst (B) is a series of laser pulses separated by burst time, and a burst number is the number of pulses within a burst. For purposes of the tests described here, a burst has one or a series of pulses with 12 ps (picoseconds) duration and consecutive pulses are spaced apart by 20 ns (nanoseconds). For example, a burst of “B8” would correspond to eight consecutive pulses each of 12 ps duration and spaced 20 ns apart. The laser burst number and pulse energy can be varied. The laser was operated at 100 kHz repetition rate for each test. The etch time (duration) for each test was set for a target of 100 micron removal (also referred to as “t1”), unless stated otherwise. Targeting for a 100 micron removal means that the etch time was selected to etch opposing vias isotropically and target a total thickness removal of 100 microns with 50 microns being removed from opposing surfaces of the laminate, respectively, and such that the radius of a via at the surface(s) is 50 microns (i.e., a diameter of 100 microns). Table 1

[0178] Samples 700, 710, 720, and 730 in FIG.7A illustrate how varying the laser energy of the laser source can change the via morphology. Sample 700 includes blind vias 702 formed in a clad layer 704 adjacent a core layer 706. The laser energy used to form electromagnetically modified regions for sample 700 was set at 60 µJ (microjoules) with a burst number of B8. Sample 710 includes blind vias 712 formed in a clad layer 714 adjacent a core layer 716. The laser energy used to form electromagnetically modified regions for sample 710 was set at 80 µJ with a burst number of B8. Sample 720 includes blind vias 722 formed in a clad layer 724 adjacent a core layer 726. The laser energy used to form electromagnetically modified regions for sample 720 was set at 120 µJ with a burst number of B15. Sample 730 includes blind vias 732 formed in a clad layer 734 adjacent a core layer 736. The laser energy used to form electromagnetically modified regions for sample 730 was set at 100 µJ with a burst number of B20. Each sample 700, 710, 720, and 730 was etched under Etch Condition A. [0179] At B860 µJ, blind vias 702 having a pyramid shape were formed. A B880 µJ, blind vias 712 having a less tapered pyramid shape were formed. This indicates that a lower energy produces a more angular blind via. At higher burst number conditions of B15120 µJ, blind vias 722 had an even less tapered shape than blind vias 712. At high burst and lower energy conditions of B20100 µJ, blind vias 732 with a relatively smoother pyramid shape were formed. [0180] Samples 740 and 750 in FIG. 7B illustrate how etching conditions can be tailored to produce different via shapes. Sample 740 includes blind vias 742 formed in a clad layer 744 adjacent a core layer 746. Sample 740 was etched under Etch Condition A. Sample 750 includes blind vias 752 formed in a clad layer 754 adjacent a core layer 756. Sample 750 was etched under Etch Condition B. The laser energy used to form electromagnetically modified regions for both sample 740 and sample 750 was set at 60 µJ with a burst number of B8. The relatively slow etch rate of Etch Condition B (2.8 µm/min) created blind vias 752 having a more rounded shape than blind vias 742 formed using Etch Condition A (9.2 µm/min etch rate). [0181] Samples 760a/b, 770a/b, and 780a/b in FIG. 7C illustrate how etching time can be utilized to produce different via shapes. Blind vias 762 formed in clad layer 764 adjacent core layer 766 of sample 760a were formed using the following process conditions: Etch Condition A, B860 µJ laser energy, and etch time of t1. Blind vias 762 formed in clad layer 764 adjacent core layer 766 of sample 760b were formed using the following process conditions: Etch Condition A, B860 µJ laser energy, and etch time of 1.5*t1 (i.e., a target 150 µm removal). Blind vias 772 formed in clad layer 774 adjacent core layer 776 of sample 770a were formed using the following process conditions: Etch Condition C, B860 µJ laser energy, and etch time of t1. Blind vias 772 formed in clad layer 774 adjacent core layer 776 of sample 770b were formed using the following process conditions: Etch Condition C, B8 60 µJ laser energy, and etch time of 1.5*t1. Blind vias 782 formed in clad layer 784 adjacent core layer 786 of sample 780a were formed using the following process conditions: Etch Condition D, B1080 µJ laser energy, and etch time of t1. Blind vias 782 formed in clad layer 784 adjacent core layer 786 of sample 780b were formed using the following process conditions: Etch Condition D, B1080 µJ laser energy, and etch time of 1.5*t1. [0182] By increasing the etch time, more cylindrical blind vias 762, 772, and 782 with a more distinct boundary at the clad/core interface were formed in samples 760b, 770b, and 780b. Once the via reaches the depth of the clad, the shape is relatively independent of etch and laser conditions. Thus, cylindrical blind vias with consistent depths can be created very reproducibly by controlling the clad thickness and using a lower burst energy. [0183] FIG.8 illustrates a laminate fusion-draw apparatus 800 for forming a laminate glass 100 according to some embodiments. Apparatus 800 may include an upper isopipe 802 that is positioned over a lower isopipe 804. Upper isopipe 802 may include a trough 810, into which a molten glass cladding composition 806 may be fed from a melter. Molten glass cladding composition 806 has an appropriately high liquidus viscosity to run over upper isopipe 802. Similarly, lower isopipe 804 may include a trough 812, into which a molten glass core composition 808 may be fed from a melter. Molten glass core composition 808 has an appropriately high liquidus viscosity to run over lower isopipe 804. [0184] As molten glass core composition 808 fills trough 812, it overflows trough 812 and flows over outer forming surfaces 816, 818 of lower isopipe 804. Outer forming surfaces 816, 818 of lower isopipe 804 converge at a root 820. Accordingly, molten glass core composition 808 flowing over outer forming surfaces 816, 818 rejoins at root 820 of lower isopipe 804, thereby forming core layer 150 of laminate glass 100. [0185] Simultaneously, molten glass cladding composition 806 overflows trough 810 of upper isopipe 802 and flows over outer forming surfaces 822, 824 of upper isopipe 802. During operation, molten glass cladding composition 806 is outwardly deflected by upper isopipe 802 such that the molten glass cladding composition 806 flows around lower isopipe 804 and contacts molten glass core composition 808 flowing over outer forming surfaces 816, 818 of lower isopipe 804, thereby fusing to molten glass core composition 808 and forming second and third glass layers 110, 130 on opposing sides of first glass layer 150. [0186] In some embodiments, thickness 116 and /or thickness 136 may be significantly thinner than thickness 156 so that second glass layer 110 and / or third glass layer 130 goes into compression and first glass layer 150 is under a tensile stress. In such embodiments, the small CTE difference may results in the magnitude of the tensile stress in first glass layer 150 being relatively low (for example, on the order of 10 MPa or lower). This will allow for the production of a laminated sheet that will be relatively easy to cut off the draw due to its low levels of tensile stress in first glass layer 150. Sheets can thus be cut from the laminate structure of laminate glass 100 that is drawn from laminate fusion-draw apparatus 200. After the sheets are cut, the cut product can then be subjected to etching processes as discussed herein. [0187] In some embodiments, laminate glass 100 according to some embodiments herein may be formed by a fusion lamination process as described in U.S. Patent No.4,214,886, which is incorporated herein by reference. As a non-limiting example, the processes for forming glass structures by fusion lamination described herein with reference to FIGS.1 and 2 and in U.S. Pat. No.4,214,886 may be used for preparing laminate glass 100 in which second glass layer 110 and third glass layer 130 have the same glass composition. As another non-limiting example, suitable processes for forming laminate glass 100 having a second glass layer 110 and a third glass layer 130 formed of different compositions are described in U.S. Pat. No.7,514,149, which is incorporated herein by reference in its entirety. [0188] A plurality of core glass compositions and clad glass compositions suitable for forming first glass layers (core layers), and second and third glass layers (clad layers) disclosed herein are reported below in Tables 2 and 4. Compositions shown in Table 2 and Table 4 below are suitable for use in a fusion-draw process described herein. For example, they have a glass transition temperature (Tg) and a viscosity profile suitable for a fusion- draw process. Any suitable combination of core and clad glass compositions may be used, so long as the clad glass composition has an etch rate higher than that of the core glass composition under the etch conditions to be used to form the blind vias in a clad layer. [0189] Batches of the oxide constituents were mixed, melted, and formed into glass plates. The properties of the glass melt and the resultant glass article were measured and the results are reported in Tables 3 and 5. The degradation rates reported in Tables 3 and 5 are expressed in terms of weight loss per surface area relative to the original weight of the sample after contact with a 50 vol% aqueous HCl solution at 60°C in an ultrasonic bath for 30 minutes. A degradation rate is similar to an etch rate, but is not the same. The degradation rates listed can be used as a baseline to select a combination of core and clad compositions that have desirable comparative etch rates as described herein (e.g., a clad etch rate that is three times or more higher than a core etch rate). [0190] For glass compositions described herein, the concentration of constituent components (e.g., SiO₂, Al₂O₃, Li₂O, and the like) are given in mole percent (mol%) on an oxide basis, unless otherwise specified. Components of the glass compositions according to embodiments are discussed individually below. As used herein, a trailing 0 in a number is intended to represent a significant digit for that number. For example, the number “1.0” includes two significant digits, and the number “1.00” includes three significant digits. As used herein, a composition described as including an oxide within a range defined by 0 mol% as the lower bound means that the composition includes the oxide at any amount above 0 mol% (e.g., 0.01 mol% or 0.1 mol%) and up to the upper bound of the range. Table 2: Exemplary Core Glass Compositions (mol%)

Table 3: Properties of Exemplary Core Glass Compositions

Table 4: Exemplary Clad Glass Compositions (mol%)

Table 5: Properties of Exemplary Clad Glass Compositions

[0191] In some embodiments, a core glass composition may include from about 62 mol % to about 77 mol % SiO₂. Additionally, or alternatively, the core glass composition may include from about 2 mol % to about 13 mol % Al₂O₃. Additionally, or alternatively, the core glass composition may include from about 0 mol % to about 10 mol % B₂O₃. Additionally, or alternatively, the core glass composition may include an alkali metal oxide selected from the group consisting of Na2O, K2O, and combinations thereof. For example, the core glass composition may include from about 0 mol % to about 15 mol % Na2O and/or from about 0 mol % to about 16 mol % K2O. Additionally, or alternatively, the core glass composition may include an alkaline earth oxide selected from the group consisting of CaO, MgO, SrO, BaO, and combinations thereof. For example, the core glass composition may include from about 0 mol % to about 1.1 mol % CaO, from about 1 mol % to about 7 mol % MgO from about 0 mol % to about 7 mol % SrO, and/or from about 0 mol % to about 1 mol % BaO. Additionally, or alternatively, the core glass composition may include from about 0 mol % to about 1 mol % SnO2. [0192] Although exemplary embodiments of the core glass composition are described herein, the core glass composition can include suitable components in suitable amounts such that the core glass composition is compatible with a clad glass composition for formation of laminate glasses as described herein. For example, the liquidus viscosity, liquidus temperature, and/or CTE of the core glass composition relative to those of the clad glass composition can enable formation of a laminate glass article using a fusion-draw process as described herein. In some embodiments, a core glass composition may be defined a range of one or more oxides listed in Table 2, wherein the upper and lower bounds of the ranges are defined by the maximum and minimum values for each oxide listed in Table 2. [0193] In the embodiments, a clad glass composition may include SiO2, which can serve as a glass network former. For example, the clad glass composition may include from about 45 mol % to about 60 mol % SiO₂. If the concentration of SiO₂ is too low, the clad glass composition can be incompatible with Zr (zirconium), which is a common component found in fusion-draw equipment (e.g., in refractory). If the concentration of SiO2 is too high, the clad glass composition can have an undesirably high durability and can have a sufficiently high melting point to adversely impact the formability of the glass. [0194] In the embodiments, a clad glass composition may include Al2O3, which can serve as a glass network former. For example, the clad glass composition may include from about 8 mol % to about 19 mol % Al₂O₃. The presence of Al₂O₃ can reduce the liquidus temperature of the clad glass composition, thereby increasing the liquidus viscosity of the clad glass composition. If the concentration of Al2O3 is too low, the clad glass composition can be undesirably soft (e.g., the strain point can be undesirably low) and can have an undesirably high CTE. If the concentration of Al2O3 is too high, the clad glass composition can be incompatible with Zr and can have an undesirably high durability. [0195] In some embodiments, a clad glass composition may include B₂O₃, which can serve as a glass network former. For example, the clad glass composition may include from about 0 mol % to about 25 mol % B₂O₃. The presence of B₂O₃ can reduce the durability of the clad glass composition. Additionally, or alternatively, the presence of B2O3 can reduce the viscosity and the liquidus temperature of the clad glass composition. For example, increasing the concentration of B2O3 by 1 mol % can decrease the temperature required to obtain an equivalent viscosity by about 10° C to about 14° C, depending on the glass composition. However, increasing the concentration of B₂O₃ by 1 mol % can lower the liquidus temperature by about 18° C to about 22° C, depending on the glass composition. Thus, B₂O₃ can reduce the liquidus temperature of the glass composition more rapidly than it decreases the liquidus viscosity. If the concentration of B2O3 is too low, the clad glass composition can have an undesirably high durability. If the concentration of B2O3 is too high, the clad glass composition can be undesirably soft. [0196] In some embodiments, a clad glass composition may include an alkali metal oxide selected from the group consisting of Li2O, Na2O, K2O, Rb2O, CS2O, and combinations thereof. For example, the clad glass composition may include from about 0 mol % to about 8 mol % Li₂O. Additionally, or alternatively, the clad glass composition may include from about 0 mol % to about 21 mol % Na₂O. Additionally, or alternatively, the clad glass composition may include from about 0 mol % to about 12 mol % K₂O. The alkali metal oxide can serve as a modifier. For example, the presence of Na2O can reduce the melting temperature of the clad glass composition, which can enhance the formability of the clad glass composition. In embodiments comprising Na2O, if the concentration of Na2O is too low, the clad glass composition can have an undesirably high durability. If the concentration of Na₂O is too high, the core glass composition can have an undesirably high CTE. [0197] In some embodiments, a clad glass composition may include an alkaline earth oxide selected from the group consisting of CaO, MgO, SrO, and combinations thereof. For example, the clad glass composition may include from about 0 mol % to about 10 mol % CaO. Additionally, or alternatively, the clad glass composition may include from about 0 mol % to about 2 mol % MgO. Additionally, or alternatively, the clad glass composition may include from about 0 mol % to about 2 mol % SrO. [0198] In some embodiments, a clad glass composition may include a fining agent selected from the group consisting of SnO₂, Sb₂O₃, Ce₂O₃, Cl (e.g., derived from KCl or NaCl), and combinations thereof. For example, the clad glass composition may include from about 0 mol % to about 0.1 mol % SnO2. [0199] In some embodiments, a clad glass composition may include P2O5. For example, the clad glass composition may include from about 0 mol % to about 10 mol % P2O5. [0200] In some embodiments, a clad glass composition may include trace amounts of ZrO₂. For example, the clad glass composition may include from about 0 mol % to about 0.02 mol % ZrO₂. [0201] In some embodiments, a clad glass composition may be defined by a range of one or more oxides listed in Table 4, wherein the upper and lower bounds of the ranges are defined by the maximum and minimum values for each oxide listed in Table 4. [0202] In some embodiments, a clad glass composition may be substantially free of any or all of Pb, As, Cd, and Ba (i.e., constituents comprising the listed elements). For example, the clad glass composition may substantially free of Pb. Additionally, or alternatively, the clad glass composition may be substantially free of As. Additionally, or alternatively, the clad glass composition may be substantially free of Cd. Additionally, or alternatively, the clad glass composition may be substantially free of Ba. [0203] As used herein, the term “substantially free” means that a component is not added as a component of the batch material even though the component may be present in the final glass in very small amounts as a contaminant. As a result of the raw materials and/or equipment used to produce a glass composition, certain impurities or components that are not intentionally added, can be present in the final glass composition. Such materials are present in the glass composition in minor amounts, referred to “tramp materials.” A composition that is “substantially free” of a component means that the component was not purposefully added to the composition, but the composition may still comprise the component in tramp or trace amounts. A composition that is “substantially free” of an element means that the element is present at an amount less than or equal to 0.1 mol%, for example 0 mol% to 0.1 mol%. [0204] In some embodiments, the CTE of a clad glass composition is less than or equal to the CTE of a core glass composition. For example, the CTE of a clad glass composition may be from about 0×10⁻⁷/°C to about 50×10⁻⁷/°C less than the CTE of the core glass composition, from about 0×10⁻⁷/°C to about 30×10⁻⁷/°C less than the CTE of the core glass composition, or from about 0×10⁻⁷/°C to about 10×10⁻⁷/°C less than the CTE of the core glass composition. In some embodiments, a clad glass composition may have a CTE of from about 50×10⁻⁷/°C to about 95×10⁻⁷/°C. [0205] While various embodiments have been described herein, they have been presented by way of example, and not limitation. It should be apparent that adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It therefore will be apparent to one skilled in the art that various changes in form and detail can be made to the embodiments disclosed herein without departing from the spirit and scope of the present disclosure. The elements of the embodiments presented herein are not necessarily mutually exclusive, but may be interchanged to meet various situations as would be appreciated by one of skill in the art. [0206] Embodiments of the present disclosure are described in detail herein with reference to embodiments thereof as illustrated in the accompanying drawings, in which like reference numerals are used to indicate identical or functionally similar elements. References to “one embodiment,” “an embodiment,” “some embodiments,” “in certain embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. [0207] The examples are illustrative, but not limiting, of the present disclosure. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the field, and which would be apparent to those skilled in the art, are within the spirit and scope of the disclosure. [0208] The term “or,” as used herein, is inclusive; more specifically, the phrase “A or B” means “A, B, or both A and B.” Exclusive “or” is designated herein by terms such as “either A or B” and “one of A or B,” for example. [0209] The indefinite articles “a” and “an” to describe an element or component means that one or at least one of these elements or components is present. Although these articles are conventionally employed to signify that the modified noun is a singular noun, as used herein the articles “a” and “an” also include the plural, unless otherwise stated in specific instances. Similarly, the definite article “the,” as used herein, also signifies that the modified noun may be singular or plural, again unless otherwise stated in specific instances. [0210] As used in the claims, “comprising” is an open-ended transitional phrase. A list of elements following the transitional phrase “comprising” is a non-exclusive list, such that elements in addition to those specifically recited in the list may also be present. As used in the claims, “consisting essentially of” or “composed essentially of” limits the composition of a material to the specified materials and those that do not materially affect the basic and novel characteristic(s) of the material. As used in the claims, “consisting of” or “composed entirely of” limits the composition of a material to the specified materials and excludes any material not specified. [0211] The term “wherein” is used as an open-ended transitional phrase, to introduce a recitation of a series of characteristics of the structure. [0212] Where a range of numerical values is recited herein, comprising upper and lower values, unless otherwise stated in specific circumstances, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the claims be limited to the specific values recited when defining a range. Further, when an amount, concentration, or other value or parameter is given as a range, one or more preferred ranges or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether such pairs are separately disclosed. Finally, when the term “about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not a numerical value or end-point of a range recites “about,” the numerical value or end-point of a range is intended to include two embodiments: one modified by “about,” and one not modified by “about.” [0213] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. [0214] The terms “substantial,” “substantially,” and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, “substantially” is intended to denote that two values are equal or approximately equal. In some embodiments, “substantially” may denote values within about 10% of each other, such as within about 5% of each other, or within about 2% of each other. [0215] The present embodiment(s) have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. [0216] It is to be understood that the phraseology or terminology used herein is for the purpose of description and not of limitation. The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined in accordance with the following claims and their equivalents.

Claims

WHAT IS CLAIMED IS: 1. A method, comprising: forming a modified track or a pilot hole in a laminate glass with a laser, the laminate glass comprising a first glass layer and a second glass layer disposed over the first glass layer, wherein: the modified track or the pilot hole extends through the second glass layer and into a portion of the first glass layer, the first glass layer is formed of a first glass composition, the second glass layer is formed of a second glass composition different from the first glass composition; and after forming the modified track or the pilot hole, exposing the laminate glass to etching conditions that etch the first glass composition at a first etch rate and etch the second glass composition at a second etch rate, wherein: the second etch rate is three times or more higher than the first etch rate, and the etching conditions etch a through hole in the second glass layer at a location of the modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the modified track or pilot hole.

2. The method of claim 1, further comprising removing the first glass layer after forming the etched through hole in the second glass layer.

3. The method of claim 1 or claim 2, wherein the second glass layer is disposed on the first glass layer.

4. The method of any of claims 1-3, wherein the second etch rate is five times or more higher than the first etch rate.

5. The method of any of claims 1-3, wherein the second etch rate is ten times or more higher than the first etch rate.

6. The method of any of claims 1-5, wherein the laminate glass is a fusion-drawn laminate.

7. The method of any of claims 1-6, wherein the etching conditions comprise an etching solution comprising hydrofluoric acid.

8. The method of any of claims 1-7, further comprising plating the laminate glass with a metallic material after etching the through hole in the second glass layer.

9. The method of claim 8, wherein the plating comprises plating a sidewall of the through hole with the metallic material.

10. The method of claim 8 or claim 9, wherein the plating fills the through hole with the metallic material.

11. The method of any of claims 8-10, wherein the plating the laminate glass comprises an electroplating process.

12. The method of any of claims 8-11, wherein the metallic material comprises copper.

13. The method of any of claims 8-12, further comprising removing the first glass layer after plating the laminate glass with the metallic material.

14. The method of any of claims 1-13, wherein the laminate glass comprises a third glass layer, the second glass layer is disposed over a first surface of the first glass layer, and the third glass layer is disposed over a second surface of the first glass layer opposite the first surface.

15. The method of claim 14, wherein the second glass layer is disposed on the first surface of the first glass layer and the third glass layer is disposed on the second surface of the first glass layer.

16. The method of claim 14 or claim 15, further comprising removing the first glass layer and the third glass layer after forming the etched through hole in the second glass layer.

17. The method of any of claims 14-16, further comprising forming another modified track or pilot hole in the laminate glass with the laser, wherein the another modified track or pilot hole extends through the third glass layer and into a portion of the first glass layer.

18. The method of claim 17, wherein: the third glass layer is formed of a third glass composition different from the first glass composition, the etching conditions etch the third glass composition at a third etch rate that is three times or more higher than the first etch rate, and the etching conditions etch a through hole in the third glass layer at a location of the another modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the another modified track or pilot hole.

19. The method of any of claims 14-16, wherein the modified track or pilot hole extends through the second glass layer, the first glass layer, and the third glass layer of the laminate glass.

20. The method of claim 19, wherein the etching conditions etch the through hole in the second glass layer and another through hole in the third glass layer at the location of the modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the modified track or pilot hole.

21. A method, comprising: forming a modified track or a pilot hole in a laminate glass with a laser, wherein the laminate glass comprises: a first glass layer formed of a first glass composition, a second glass layer disposed over a first surface of the first glass layer and formed of a second glass composition different from the first glass composition, and a third glass layer disposed over a second surface of the first glass layer opposite the first surface and formed of a third glass composition different from the first glass composition, and wherein the modified track or the pilot hole extends through the second glass layer and into a portion of the first glass layer; and after forming the modified track or the pilot hole, exposing the laminate glass to etching conditions that etch a through hole in the second glass layer at a location of the modified track or pilot hole, but do not form an etched through hole in the first glass layer at the location of the modified track or pilot hole.

22. The method of claim 21, wherein: the etching conditions are configured to etch the second glass layer at a second etch rate, the etching conditions are configured to etch the first glass layer at a first etch rate, and the second etch rate is three times or more higher than the first etch rate.

23. The method of claim 21 or claim 22, further comprising plating the laminate glass with a metallic material to at least partially fill the through hole with the metallic material.

24. The method of any of claims 21-23, further comprising removing the first glass layer and the third glass layer after forming the etched through hole in the second glass layer.

25. A laminate glass article, comprising a first glass layer formed of a first glass composition; a second glass layer disposed over a first surface of the first glass layer and formed of a second glass composition, the second glass composition being different from the first glass composition; an etched through hole in the second glass layer; and an electromagnetically modified region located on the first surface of the first glass layer exposed to the etched through hole in the second glass layer.

26. The laminate glass article of claim 25, wherein the electromagnetically modified region comprises a modified track or a pilot hole.

27. The laminate glass article of claim 25 or claim 26, further comprising a metal plating disposed in the etched through hole of the second glass layer.

28. The laminate glass article of any of claims 25-27, wherein the second glass layer is disposed on the first glass layer.

29. The laminate glass article of any of claims 25-28, wherein: the first glass composition comprises a first etch rate in an etching solution comprising hydrofluoric acid, the second glass composition comprises a second etch rate in the etching solution comprising hydrofluoric acid, and the second etch rate is three times or more higher than the first etch rate.

30. The laminate glass article of any of claims 25-29, further comprising a third glass layer disposed over a second surface of the first glass layer opposite the first surface.

31. The laminate glass article of claim 30, wherein the second glass layer is disposed on the first surface of the first glass layer and the third glass layer is disposed on the second surface of the first glass layer opposite the first surface.