CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application No. 63/417,731 filed October 20, 2022, the content of which is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

[0002] The present disclosure pertains to laminate articles that hold display stacks or semiconductor components.

BACKGROUND

[0003] Flat panel displays sometimes include an array of microscopic light emitting diodes ("microLEDs"). Each microLED forms an individual pixel of the flat panel display. MicroLEDs are sometimes grown in a substrate such as sapphire and then transferred to a display backplane, which may further include electronic circuitry to control the microLEDs. Sometimes, microLEDs are transferred to both sides of the display backplane. The microLEDs and the display backplane are heated together to bond the microLEDs to the display backplane. The display backplane with the microLEDs is then incorporated into the flat panel display. Further, there is a general desire among manufactures of flat panel displays for thinner products, which entails thinner display backplanes. The manufacture of semiconductors encounters the same problem, where semiconductors are temporarily deposited on a backplane.

[0004] However, there is a problem in that, the bonding process that utilizes heat (and subsequent cooling) may cause the display backplane to warp. The propensity of the display backplane to warp increases as the thickness of the thereof decreases.

SUMMARY

[0005] The present disclosure addresses the aforementioned problem with a laminate article with a core layer having a glass-ceramic composition sandwiched by clad layers having a glass composition. The glass-ceramic composition of the laminate article has a higher coefficient of thermal expansion than the glass composition of the core layers, which allows the laminate article to exhibit an effective coefficient of thermal expansion that is the same or closer to an effective coefficient of thermal expansion of a display stack (or some other component) to be disposed upon the laminate article. The difference in coefficients of thermal expansion of the laminate article and the display stack is one facilitator of warp. Thus, lessening the difference can decrease the warp. Further, the glass compositions of the clad layers of the laminate article reduce or prevent leaching of potentially deleterious constituents from the glassceramic composition of the core layer into the display stack. A glass composition of the clad layers can be fused to a glass composition of the core layer via a fusion forming process and then subsequently heat treated to transform the glass composition of the core layer into a glass-ceramic composition.

[0006] According to a first aspect of the present disclosure, a laminate article comprises: (a) a core layer comprising a glass-ceramic composition, a first core surface, and a second core surface, the first core surface and the second core surface facing in generally opposite directions; (b) a first clad layer comprising a glass composition disposed on the first core surface of the core layer; and (c) a second clad layer comprising a glass composition disposed on the second core surface of the core layer; wherein (i) the core layer comprises a thickness within a range of from 150 pm to 200 pm; (ii) the core layer exhibits a coefficient of thermal expansion within a range from 2.5xlO ^-5 /°K to 4.5xlO ^-5 /°K; and (iii) the laminate article comprises an effective coefficient of thermal expansion within a range of from 8.0xl0 ^-5 /°K to 2.0X107°K.

[0007] According to a second aspect of the present disclosure, the laminate article of the first aspect further comprises a thickness that is less than 3.0 mm.

[0008] According to a third aspect of the present disclosure, the laminate article of any one of the first through second aspects is presented, wherein each of the first clad layer and the second clad layer comprises a thickness within a range of from 50 pm to 150 pm.

[0009] According to a fourth aspect of the present disclosure, the laminate article of any one of the first through third aspects is presented, wherein the glass-ceramic composition of the core layer comprises from 20 wt% to 70 wt% of a petalite ( LiAISiziO io) crystalline phase.

[0010] According to a fifth aspect of the present disclosure, the laminate article of any one of the first through third aspects is presented, wherein the glass-ceramic composition of the core layer is a LizO-ZnO-MgO-SiCh system glass-ceramic with from 20 wt% to 70 wt% of one or more crystalline phases. [0011] According to a sixth aspect of the present disclosure, the laminate article of any one of the first through fifth aspects is presented, wherein the glass composition of the first clad layer is at least substantially the same as the glass composition of the second clad layer.

[0012] According to a seventh aspect of the present disclosure, the laminate article of any one of the first through sixth aspects is presented, wherein the glass compositions of the first clad layer and the second clad layer each comprise S iO 2 within a range of from 35 wt% to 80 wt%.

[0013] According to an eighth aspect of the present disclosure, the laminate article of any one of the first through seventh aspects is presented, wherein the first clad layer and the second clad layer are fused to the core layer without the aid of an adhesive.

[0014] According to a ninth aspect of the present disclosure, an electronic device comprises: (I) a laminate article comprising: (a) a core layer comprising a glass-ceramic composition, a first core surface, and a second core surface, the first core surface and the second core surface facing in generally opposite directions; (b) a first clad layer comprising a glass composition disposed on the first core surface of the core layer; and (c) a second clad layer comprising a glass composition disposed on the second core surface of the core layer; and (II) a display stack disposed on the first clad layer of the laminate article; wherein (i) the core layer exhibits a thickness within a range of from 150 pm to 200 pm; (ii) the core layer exhibits a coefficient of thermal expansion within a range from 2.5xlO ^-5 /°K to 4.5xlO ^-5 /°K; (iii) both the display stack and the laminate article exhibit an effective coefficient of thermal expansion within a range of from 8.0xl0 ^-5 /°K to 2.0xl0 ^-5 /°K; and (iv) the effective coefficient of thermal expansion that the laminate article exhibits differs from the effective coefficient of thermal expansion the display stack exhibits by less than 5%.

[0015] According to a tenth aspect of the present disclosure, the laminate article of the ninth aspect further comprises a second display stack disposed on the second clad layer of the laminate article, wherein (i) the second display stack exhibits an effective coefficient of thermal expansion within the same range of from 8.0xl0 ^-5 /°K to 2.0xl0 ^-5 /°K, and (ii) the effective coefficient of thermal expansion that the laminate article exhibits differs from the effective coefficient of thermal expansion the second display stack exhibits by less than 5%.

[0016] According to an eleventh aspect of the present disclosure, the laminate article of any one of the ninth through tenth aspects is presented, wherein (i) the laminate article further comprises a thickness that is less than or equal to 3.0 mm; and (ii) each of the first clad layer and the second clad layer comprises a thickness within a range of from 50 pm to 150 pm.

[0017] According to a twelfth aspect of the present disclosure, the laminate article of any one of the ninth through eleventh aspects is presented, wherein (i) the glass composition of the first clad layer is substantially the same as the glass composition of the second clad layer; and (ii) the glass compositions of the first clad layer and the second clad layer each comprise SiCh within a range of from 35 wt% to 80 wt%.

[0018] According to a thirteenth aspect of the present disclosure, the laminate article of any one of the ninth through twelfth aspects is presented, wherein the laminate article exhibits a warp of less than 100 pm.

[0019] According to a fourteenth aspect of the present disclosure, the laminate article of any one of the ninth through thirteenth aspects is presented, wherein the first clad layer and the second clad layer are fused to the core layer without the aid of an adhesive.

[0020] According to a fifteenth aspect of the present disclosure, the laminate article of any one of the ninth through fourteenth aspects is presented, wherein the electronic device is a microLED display.

[0021] According to a sixteenth aspect of the present disclosure, the laminate article of any one of the ninth through fifteenth aspects is presented, wherein the effective coefficient of thermal expansion that the laminate article exhibits is greater than the effective coefficient of thermal expansion that the display stack exhibits.

[0022] According to a seventeenth aspect of the present disclosure, a method of manufacturing a laminate article for an electronic device comprises: (a) fusing a first clad layer and a second clad layer to opposite core surfaces of a core layer, thus forming a laminate article; and (b) heat treating a glass composition of the core layer into a glass-ceramic composition that exhibits a coefficient of thermal expansion that is within a range from 2.5X10 ^-5 /°K to 4.5X10 ^-5 /°K, wherein (i) the first clad layer and the second clad layer each comprise a glass composition and exhibit a coefficient of thermal expansion that is less than 2.0X10 ^-5 /°K, and (ii) the laminate article exhibits an effective coefficient of thermal expansion that is within a range of from 8.0xl0 ^-5 /°K to 2.0xl0 ^-5 /°K.

[0023] According to an eighteenth aspect of the present disclosure, the method of the seventeenth aspect further comprises second heat treating the laminate article, wherein the effective coefficient of thermal expansion that the laminate article exhibits is different than the effective coefficient of thermal expansion that the laminate article exhibits after the heat treating that occurs before the second heat treating.

[0024] According to a nineteenth aspect of the present disclosure, the method of any one of the seventeenth through eighteenth aspects further comprises determining a target effective coefficient of thermal expansion for the laminate article as a function of (i) a measured warp of a substrate or article with a display stack disposed thereupon and (ii) an effective coefficient of thermal expansion of the substrate or article, wherein, the effective coefficient of thermal expansion that the laminate article exhibits is within 5% of the target effective coefficient of thermal expansion for the laminate article.

[0025] According to a twentieth aspect of the present disclosure, the method of any one of the seventeenth through eighteenth aspects further comprises determining a target effective coefficient of thermal expansion for the laminate article as a function of an effective coefficient of thermal expansion of a display stack to be disposed upon the laminate article.

[0026] According to a twenty-first aspect of the present disclosure, the method of any one of the seventeenth through twentieth aspects is presented, wherein (a) the fusing occurs before the ceramming, and (b) the heat treating is at a temperature or range of temperatures below (i) a glass transition temperature of the first clad layer and (ii) a glass transition temperature of the second clad layer.

[0027] According to a twenty-second aspect of the present disclosure, the method of any one of the seventeenth through twenty-first aspects is presented, wherein the fusing occurs during a fusion lamination process.

[0028] According to a twenty-third aspect of the present disclosure, the method of the twenty-second aspect is presented, wherein at least a portion of the heat treating occurs during the fusing.

[0029] According to a twenty-fourth aspect of the present disclosure, the method of the twenty-second aspect is presented, wherein (i) the core layer comprises a thickness within a range of from 150 pm to 200 pm; and (ii) the laminate article further comprises a thickness that is less than 3.0 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In the drawings: [0031] FIG. 1 is a perspective view of a laminate article of the present disclosure, illustrating a core layer sandwiched between a first clad layer and a second clad layer;

[0032] FIG. 2 is an elevation view of the laminate article of FIG. 1, illustrating the core layer, the first clad layer, the second clad layer, and the laminate article each having a thickness;

[0033] FIG. 3 is a flow chart of a method of forming the laminate article of FIG. 1, including the step of heat treating a glass composition of the core layer into a glass-ceramic composition, which increases the effective coefficient of thermal expansion of the laminate article;

[0034] FIG. 4 is cross-sectional elevation view of an apparatus used to fusion form glass compositions of the first clad layer, second clad layer, and the core layer between the first clad layer and the second clad layer;

[0035] FIG. 5 is a perspective view of an electronic device that includes the laminate article of FIG. 1, illustrating a display stack on the first clad layer of the laminate article and a second display stack on the second clad layer of the laminate article;

[0036] FIG. 6, pertaining to Example 1, is a graph plotting the effective coefficient of thermal expansion of the laminate article as a function of (i) the coefficient of thermal expansion of the glass-ceramic composition of the core layer and (ii) the thickness of the core layer;

[0037] FIG. 7A, pertaining to Example 2A, is a graph plotting warp as a function of position along a laminate article having a set coefficient of thermal expansion; and

[0038] FIG. 7B, pertaining to Example 2B, is a graph plotting warp as a function of position along a laminate article having a higher coefficient of thermal expansion than the laminate article of FIG. 7A.

DETAILED DESCRIPTION

[0039] Referring now to FIGS. 1 and 2, a laminate article 10 includes a core layer 12, a first clad layer 14, and a second clad layer 16. The core layer 12 includes a first core surface 18 and a second core surface 20. The first core surface 18 and the second core surface 20 of the core layer 12 face in generally opposite directions 22, 24, respectively. The first clad layer 14 is disposed on the first core surface 18 of the core layer 12. The second clad layer 16 is disposed on the second core surface 20 of the core layer 12. The first clad layer 14 provides a first article surface 26. The second clad layer 16 provides a second article surface 28. The first article surface 26 and the second article surface 28 face in the opposite directions 22, 24, respectively.

[0040] The core layer 12 of the laminate article 10 has a glass-ceramic composition. A glassceramic composition is the polycrystalline product of uniform, internal, in situ crystallization of a precursor glass composition via heat treatment. Depending on the size of the crystals developed, the glass-ceramic composition may be transparent or opaque. Crystal size is influenced, among other things, by the nature of the nucleating agent, the crystal phase(s) formed, and the degree and extent of heat treatment. Aspects of forming the glass-ceramic composition are discussed further below.

[0041] In embodiments, the glass-ceramic composition of the core layer 12 includes a petalite (LiAISizjOio) crystalline phase. Petalite, LiAISi40io, is a monoclinic crystal possessing a three- dimensional framework structure with a layered structure having folded SizOs layers linked by Li and Al tetrahedra. The Li is in tetrahedral coordination with oxygen. The mineral petalite is a lithium source and is used as a low thermal expansion phase to improve the thermal downshock resistance of glass-ceramic or ceramic parts. In embodiments, the glass-ceramic composition of the core layer 12 includes 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, or 70 wt% petalite (LiAISi40io) crystalline phase, or any range bound by any two of those values (e.g., from 20 wt% to 70%, from 35 wt% to 55 wt%) petalite (LiAISi40io) crystalline phase.

[0042] In embodiments, the glass-ceramic composition of the core layer 12 is or includes a LizO-ZnO-MgO-SiOz system glass-ceramic. A LizO-ZnO-MgO-SiOz system glass-ceramic is a glass-ceramic formed from a precursor glass that includes at least LizO, ZnO, MgO, and SiOz. The LizO-ZnO-MgO-SiOz system glass-ceramic may include one or more crystalline phases. In embodiments, the glass-ceramic composition of the core layer 12 is a LizO-ZnO-MgO-SiOz system glass-ceramic that includes 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, or 70 wt% of one or more crystalline phases, or any range bound by any two of those values (e.g., from 20 wt% to 70%, from 35 wt% to 55 wt%) of one or more crystalline phases.

[0043] In embodiments, the glass-ceramic composition of the core layer 12 is or includes a lithium alumino silicate glass-ceramic composition. Such glass-ceramics are formed from a LizO— AlzOs— SiOz System (i.e., LAS-System) precursor glass composition. The LAS-System may generally provide highly crystallized glass-ceramics which include a predominant crystalline phase of: i) a transparent beta-quartz solid solution; or ii) an opaque betaspodumene solution, depending on the heat treatment utilized including the ceramming temperature.

[0044] In embodiments, the glass-ceramic composition of the core layer 12 includes one or more of YPO4 (xenotime), LaPC (monazite), and RE(PC>4) crystalline phases, where RE means a rare earth element. In such embodiments, the precursor glass composition used to form the glass-ceramic composition of the clad layer includes Y2O3, LazCh and/or RE2O3, and the orthophosphates of these elements are present in the resulting glass-ceramic composition. The presence of such crystalline phases may enhance the transparency of the core layer 12.

[0045] The core layer 12 of the laminate article 10 has a thickness 30. The thickness 30 is the straight-line distance between the first core surface 18 and the second core surface 20 measured perpendicular to the first core surface 18. In embodiments, the thickness 30 is 150 pm, 155 pm, 160 pm, 165 pm, 170 pm, 175 pm, 180 pm, 185 pm, 190 pm, 195 pm, or 200 pm, or within any range bound by any two of those values (e.g., from 150 pm to 200 pm, from 155 pm to 180 pm, and so on). In other embodiments, the thickness 30 of the core layer 12 is less than 150 pm or greater than 200 pm.

[0046] The core layer 12 exhibits a coefficient of thermal expansion. The coefficient of thermal expansion that the core layer 12 exhibits is within a range of from 2.5xlO ^-5 /°K to 4.5X10 ^-5 /°K. In embodiments, the coefficient of thermal expansion that the core layer 12 exhibits is 2.5xlO- ⁵ /°K, 3.0xl0- ⁵ /°K, 3.5xlO-7°K, 4.0xl07°K, 4.5xlO- ⁵ /°K or within any range bound by any two of those values (e.g., from 3.5xlO ^-5 /°K to 4.0xl0 ^-5 /°K, from 3.5xlO ^-5 /°K to 4.5X10 ^-5 /°K, and so on). The coefficient of thermal expansion is an average over a temperature range of from about 20 °C to about 300 °C determined according to ASTM E228 (and its progeny, all herein incorporated by reference) "Standard Test Method for Linear Thermal Expansion of Solid Materials with a Push-Rod Dilatometer," ASTM International, Conshohocken, Pa., US.

[0047] Whereas the core layer 12 has a glass-ceramic composition, the first clad layer 14 and the second clad layer 16 each have a glass composition. In embodiments, the glass compositions of the first clad layer 14 and the second clad layer 16 are the same or at least substantially the same (e.g., made from the same source of molten glass). The particular glass composition is not particularly important as long as the first clad layer 14 and the second clad layer 16 serve the functions described herein and have a coefficient of thermal expansion that is sufficiently lower than the coefficient of thermal expansion of the core layer 12 so that a target effective coefficient of thermal expansion for the laminate article 10 can be achieved. As further discussed below, the first clad layer 14 and the second clad layer 16 can be formed from the same batch of molten glass.

[0048] In embodiments, the glass composition of the first clad layer 14 and the second clad layer 16 includes SiCh within a range of from 35 wt% to 80 wt%. Examples of suitable glass compositions can include alkaline-earth aluminoborosilicate glasses, zinc borosilicate glasses, and soda-lime glass. In embodiments, the glass composition is substantially free of alkali oxides, while in other embodiments, the glass composition includes one or more alkali oxides. In embodiments, the glass composition of the first clad layer 14 and the second clad layer 16 is substantially free of lithium. "Substantially free" here means that the component, if present, is present in the glass composition as a contaminant in a trace amount of less than 1 mol%.

[0049] The glass composition of the first clad layer 14 and the second clad layer 16 may generally include a combination of SiC , AI2O3, at least one alkaline earth oxides such as BeO, MgO, CaO, SrO and BaO, and/or alkali oxides, such as U2O, Na2O, K2O, Rb20 and CS2O. In some embodiments, the glass composition may further include minor amounts of one or more additional oxides, such as, by way of example and not limitation, SnC>2, Sb2C>3, ZrC>2, ZnO, or the like. These components may be added as fining agents and/or to further modify the coefficient of thermal expansion of the glass composition.

[0050] As mentioned, in embodiments, the glass composition generally includes SiC>2 in an amount greater than or equal to 35 wt% and less than or equal to 80 wt%. When the content of SiO ₂ is too small, the glass may have poor chemical and mechanical durability. On the other hand, when the content of SiO2 is too large, melting ability of the glass decreases and the viscosity increases, so forming of the glass becomes difficult. In some embodiments, SiO2 is present in the glass composition in an amount of 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, or 80 wt%, or within any range bound by any two of those values (e.g., from 25 wt% to 75 wt%, from 45 wt% to 80 wt%, and so on).

[0051] The glass composition may also include AI2O3. AI2O3, in conjunction with alkali oxides present in the glass composition, such as Na2O or the like, improves the susceptibility of the glass to ion exchange strengthening. Moreover, increased amounts of AI2O3 may also increase the softening point of the glass, thereby reducing the formability of the glass. If included, the glass compositions described herein may include AI2O3 in an amount of 1.5 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, or 27 wt%, or within any range bound by any two of those values (e.g., from 1.5 wt% to 27 wt%, from 4 wt% to 10 wt%, and so on).

[0052] In embodiments, the glass composition includes boron, for example as a flux to make the viscosity-temperature curve less steep, as well as lowering the entire curve, thereby improving the formability of the glass and softening the glass. In embodiments, the glass composition includes B2O3 in an amount of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, or 18 wt%, or within any range bound by any two of those values (e.g., from 0 wt% to 18 wt%, from 2 wt% to 5 wt%, and so on). In some embodiments, the glass composition may be substantially free of boron.

[0053] In embodiments, the glass composition further includes one or more alkali oxides (e.g., Na2O, K2O, U2O, or the like). The alkali oxides facilitate the melting of the glass composition, lower the 200 Poise temperature, and lower the softening point of the glass, thereby offsetting the increase in the softening point due to higher concentrations of SiCh and/or AI2O3 in the glass composition. The alkali oxides also assist in improving the chemical durability of the glass composition and tuning the CTE to a desired value. In embodiments, the one or more alkali oxides are present in the glass composition in a combined amount of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, or 14 wt%, or within any range bound by any two of those values (e.g., from 0 wt% to 14 wt%, from 2 wt% to 5 wt%, and so on).

[0054] In order to achieve the desired coefficient of thermal expansion for the glass composition of the first clad layer 14 and the second clad layer 16, embodiments of the glass compositions include Na2O in an amount of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, or 18 wt%, or within any range bound by any two of those values (e.g., from 0% to 18 wt%, from 1 wt% to 8 wt%, and so on).

[0055] The concentration of K2O in the glass also influences the coefficient of thermal expansion of the glass composition. Accordingly, in embodiments, the glass composition includes K2O in an amount of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, or 14 wt%, or within any range bound by any two of those values (e.g., from 0% to 14 wt%, from 1 wt% to 7 wt%, and so on).

[0056] In embodiments, the glass compositions include U2O in an amount of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4wt%, 5 wt%, 6 wt%, 6.5 wt%, or 7.5 wt%, or within any range bound by any two of those values (e.g., from 0% to 7.5 wt%, from 1 wt% to 7 wt%, and so on).

[0057] As mentioned, the glass composition may further include one or more alkaline earth oxides. The alkaline earth oxides may include, for example, MgO, CaO, SrO, BaO, or combinations thereof. Alkaline earth oxides improve the meltability of the glass batch oxides and increase the chemical durability of the glass composition, in addition to influencing the coefficient of thermal expansion. In embodiments, the glass composition includes one or more alkaline earth oxides in an amount of 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, or 22 wt%, or within any range bound by any two of those values (e.g., from 1 wt% to 22 wt%, from 3 wt% to 8 wt%, and so on). MgO may be present in an amount of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, or 12 wt%, or within any range bound by any two of those values (e.g., from 1 wt% to 12 wt%, from 3 wt% to 8 wt%, and so on). However, in embodiments, the glass composition is substantially free of MgO. As another example, CaO may be present in the glass composition in an amount of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or 8.5 wt%, or within any range bound by any two of those values (e.g., from 0 wt% to 8.5 wt%, from 3 wt% to 8 wt%, and so on). However, in embodiments, the glass composition is substantially free of CaO.

[0058] In embodiments, SrO may be included in the glass composition in an amount of 0.5 wt%, 1 wt%, 2 wt%, or 3 wt%, or within any range bound by any two of those values (e.g., from 0.5 wt% to 3 wt%, from 1 wt% to 2 wt%, and so on). However, in embodiments, the glass composition is substantially free of SrO.

[0059] In embodiments, BaO may be included in the glass composition in an amount of 0 wt%, 1 wt%, 2 wt%, or 3 wt%, or within any range bound by any two of those values (e.g., from 0 wt% to 3 wt%, from 1 wt% to 2 wt%, and so on). However, in embodiments, the glass composition is substantially free of BaO.

[0060] In addition to the SiO?, AI2O3, alkali oxides and alkaline earth oxides, the glass composition of the first clad layer 14 and the second clad layer 16 can include one or more fining agents, such as, by way of example and not limitation, SnC , SbzCh, AS2O3, and/or halogens, such as F“, and/or Cl“ (from NaCI or the like). When a fining agent is present in the glass composition, the fining agent may be present in an amount less than or equal to 1 wt% or even less than or equal to 0.5 wt%. When the content of the fining agent is too large, the fining agent may enter the glass structure and affect various glass properties. However, when the content of the fining agent is too low, the glass may be difficult to form. For example, in some embodiments, SnC is included in the glass composition as a fining agent in an amount greater than or equal to 0.25 wt% to less than or equal to 0.50 wt%.

[0061] In embodiments, the glass composition includes one or more other metal oxides. For example, the glass composition may further include ZnO or ZrCh, each of which improves the resistance of the glass composition to chemical attack. In such embodiments, the additional metal oxide may be present in an amount of 0 wt%, greater than 0 wt%, 1 wt%, 2 wt%, 3 wt%,

4 wt%, 5 wt%, or 6 wt%, or within any range bound by any two of those values (e.g., from greater than 0 wt% to 6 wt%, from 3 wt% to 5 wt%, and so on). For example, the glass composition may include ZrC in an amount of 0 wt%, greater than 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, or 6 wt%, or within any range bound by any two of those values (e.g., from greater than 0 wt% to 6 wt%, from 3 wt% to 5 wt%, and so on). If the content of ZrCh is too high, it may not dissolve in the glass composition, may result in defects in the glass composition, and may drive the Young's modulus up. In embodiments, the glass composition may include ZnO in an amount of 0 wt%, greater than 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, or

5 wt%, or within any range bound by any two of those values (e.g., from greater than 0 wt% to 5 wt%, from 3 wt% to 4 wt%, and so on). The ZnO may be included as a substitute for one or more of the alkaline earth oxides, such as a partial substitute for MgO or in addition to or in place of at least one of CaO, BaO, or SrO. Accordingly, the content of ZnO in the glass composition can have the same effects as described above with respect to alkaline earth oxides if it is too high or too low.

[0062] In embodiments, the glass composition is substantially free of transition metals, such as iron and lanthanides (such as cerium). Without being bound by theory, it is believed that by avoiding the use of such elements in the glass composition, the optical transmission of the glass across near UV wavelengths can be increased. The increased UV transmission can enable or improve the use of UV-debonding. [0063] In embodiments, the glass composition includes (on an oxide basis): from 60 mol% to 75 mol% SiCh; from 5 mol% to 15 mol% B2O3; from 5 mol% to 15 mol% AI2O3; from 0.5 mol% to 5 mol% MgO; from 5 mol% to 15 mol% CaO; and from 0.1 mol% to 1 mol% SrO.

[0064] In embodiments, the glass compositions of the first clad layer 14 and the second clad layer 16 each have a liquidus viscosity suitable for forming the laminate article 10 using a fusion forming process as described below. For example, the glass composition may have a liquidus viscosity of at least about 70 kP, at least about 100 kP, at least about 200 kP, or at least about 300 kP. Additionally or alternatively, each of the glass compositions comprises a liquidus viscosity of less than about 3000 kP, less than about 2500 kP, less than about 1000 kP, or less than about 800 kP.

[0065] The first clad layer 14 and the second clad layer 16 of the laminate article 10 both have a thickness 32, 34, respectively. In embodiments, the thicknesses 32, 34 are the same, or at least substantially the same (e.g., within 10% of each other). In embodiments, one or both of the thicknesses 32, 34 are 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, 100 pm, 110 pm, 120 pm, 130 pm, 140 pm, or 150 pm, or within any range bound by any two of those values (e.g., from 50 pm to 150 pm, from 70 pm to 100 pm, and so on). In embodiments, one or both of the thicknesses 32, 34 are less than 50 pm or greater than 150 pm. The thickness 32 of the first clad layer 14 is the straight-line distance between the first article surface 26 and the first core surface 18. The thickness 34 of the second clad layer 16 is the straight-line distance between the second article surface 28 and the second core surface 20.

[0066] In embodiments, the first clad layer 14 and the second clad layer 16 are fused to the core layer 12 without the aid of an adhesive. In other words, in embodiments, the laminate article 10 does not include an adhesive disposed between the first clad layer 14 and the core layer 12 to secure the first clad layer 14 and the core layer 12 together, or an adhesive disposed between the second clad layer 16 and the core layer 12 to secure the second clad layer 16 and the core layer 12 together. Thus, the core layer 12 is directly adjacent the first clad layer 14 without any material disposed therebetween, and the core layer 12 is directly adjacent the second clad layer 16 without any material disposed therebetween.

[0067] The laminate article 10 comprises an effective coefficient of thermal expansion that is within a range of from 8.0xl0 ^-5 /°K to 2.0xl0 ^-5 /°K. In particular, the effective coefficient of thermal expansion of a laminate, such as the laminate article 10, can be calculated according to the following equation (I): (I) where a is the CTE, E is Young's modulus, v is Poisson's ratio, t is the thickness of the layer, and R is the total core/clad thickness ratio. In the above equation, it is assumed that the first clad layer 14 and the second clad layer 16 have the same composition and thus the same Young's modulus and Poisson's ratio. In some instance, the equation can be simplified to be the following equation (II):

CD

[0068] The laminate article 10 has a thickness 36. The thickness 36 of the article is the straight-line distance between the first article surface 26 and the second article surface 28. In embodiments, the thickness 36 is less than 3.0 mm. In embodiments, the thickness 36 is 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, or 3.0 mm, or within any range bound by any two of those values (e.g., from 0.4 mm to 1.1 mm, from 0.5 mm to 0.7 mm, or from 0.5 mm to 2.0 mm, and so on).

[0069] Referring now to FIG. 3, a method 100 of manufacturing the laminate article 10 includes, at a step 102, fusing the first clad layer 14 and the second clad layer 16 to opposite surfaces (e.g., the first core surface 18 and the second core surface 20) of the core layer 12. The step 102 of fusing forms the laminate articles 10.

[0070] In embodiments, the step 102 of fusing occurs during a fusion lamination process. The fusion lamination process can be that described in U.S. Pat. No. 4,214,886, which is incorporated herein by reference in its entirety. Referring now to FIG. 4 by way of example, a laminate fusion draw apparatus 104 for forming a laminated glass article includes an upper overflow distributor 106, which is positioned over a lower overflow distributor 108. The upper overflow distributor 106 includes a trough 110 into which a molten glass clad composition 112 is fed from a melter (not shown). Similarly, the lower overflow distributor 108 includes a trough 114 into which a molten glass core composition 116 is fed from a melter (not shown).

[0071] As the molten glass core composition 116 fills the trough 114, it overflows the trough 114 and flows over the outer forming surfaces 118 of the lower overflow distributor 108. The outer forming surfaces 118 of the lower overflow distributor 108 converge at a root 120. Accordingly, the molten glass core composition 116 flowing over the outer forming surfaces 118 rejoins at the root 120 of the lower overflow distributor 108 thereby forming the core layer 12 of the laminate article 10.

[0072] Simultaneously, the molten glass clad composition 112 overflows the trough 110 formed in the upper overflow distributor 106 and flows over outer forming surfaces 122 of the upper overflow distributor 106. The molten glass clad composition 112 is outwardly deflected by the upper overflow distributor 106, such that the molten glass clad composition 112 flows around the lower overflow distributor 108 and contacts the molten glass core composition 116 flowing over the outer forming surfaces 118 of the lower overflow distributor 108, fusing to the molten glass core composition 116 and forming the first clad layer 14 and the second clad layer 16 around the core layer 12.

[0073] The thicknesses 30, 32, 34 of the core layer 12, the first clad layer 14, and the second clad layer 16, and therefore, the ratio of the thickness 30 of the core layer 12 to the combined thicknesses 32, 34 of the first clad layer 14 and the second clad layer 16, can be adjusted by controlling the flow of the molten glass core composition 116 and/or the molten glass clad composition 112 from the overflow distributors 108, 106, or other methods of controlling the thickness of a glass sheet as known to those skilled in the art. Alternatively, in some embodiments, the ratio of the thickness 30 of the core layer 12 to the combined thicknesses 32, 34 of the first clad layer 14 and the second clad layer 16 can be adjusted or controlled by etching or polishing.

[0074] Aside from the fusion draw process, the first clad layer 14, the second clad layer 16, and the core layer 12 can all be separately formed and then fused via reformation at an elevated temperature. Among other options, each of the first clad layer 14, the second clad layer 16, and the core layer 12 can be formed via, slot draw processes, thin rolling processes, float processes, or a combination thereof.

[0075] At a step 124, the method 100 further includes heat treating the (precursor) glass composition of the core layer 12 into the glass-ceramic composition that exhibits the coefficient of thermal expansion that is within a range of from 2.5xlO ^-5 /°K to 4.5xlO ^-5 /°K. The step 124 of heat treating can include the sub-steps (i) heating the glass composition of core layer 12 at a rate within a range of from 1 °C/min to 10 °C/min to a nucleation temperature (Tn) in the range from about 600 °C to about 810 °C (e.g., from 630 °C to 725 °C); (ii) maintaining the core layer 12 at nucleation temperature for a time in the range from about % hr to about 4 hrs to produce a nucleated crystallizable glass composition; (iii) heating the nucleated crystallizable glass composition at a rate in the range of from about 1° C./min to about 10° C./min to a crystallization temperature (Tc) in the range of from about 675° C. to about 1000° C. (e.g., from about 700° C. to about 850° C.); (iv) maintaining the core layer 12 at the crystallization temperature for a time in the range of from about % hr to about 4 hrs to produce the glass-ceramic composition described herein; and (v) cooling the core layer 12 with the glass-ceramic composition to room temperature. The heat treatment can occur in a resistance-heated furnace.

[0076] Temperature-temporal profile of heat treatment sub-steps (iii) and (iv), in addition to the glass composition of the core layer 12 as formed, are judiciously prescribed so as to generate the desired coefficient of thermal expansion of the core layer 12 and, thus, the effective coefficient of thermal expansion of the laminate article 10. In addition, the temperature-temporal profile of the heat treatment sub-steps, in addition to the glass composition of the core layer 12 as formed, are judiciously prescribed to produce one or more of the following desired attributes: crystalline phase(s) of the glass-ceramic composition, proportions of one or more major crystalline phases and/or one or more minor crystalline phases and residual glass, crystal phase assemblages of one or more predominate crystalline phases and/or one or more minor crystalline phases and residual glass, and grain sizes or grain size distributions among one or more major crystalline phases and/or one or more minor crystalline phases, which in turn may influence the final integrity, quality, color, and/or opacity of the resultant formed glass-ceramic composition.

[0077] Despite the ceramming of the core layer 12 that occurs during the step 124 of heat treating, the glass compositions of the first clad layer 14 and the second clad layer 16 remain glass compositions. The glass compositions of the first clad layer 14 and the second clad layer 16 allow the first clad layer 14 and the second clad layer 16 to remain chemically compatible with components that may be added thereto, such as a display stack as described further below. [0078] In embodiments, the step 102 of fusing of the first clad layer 14 and the second clad layer 16 to the core layer 12 occurs before the step 124 of heat treating. As explained, when the fusion forming process is utilized, the first clad layer 14 and the second clad layer 16 are fused to the core layer 12 while the glass compositions thereof are molten. Thus, the step 102 of fusing, in some embodiments, occurs before the step 124 of heat treating to transform the glass composition of the core layer 12 into a glass-ceramic composition. When the step 102 of fusing occurs before the step 124 of heat treating, the temperature or range of temperatures of the step 124 of heat treating can be below the glass transition temperature(s) of the first clad layer 14 and the second clad layer 16. Doing so reduces potential warping and other deformation of the first clad layer 14 and the second clad layer 16 and, thus, the laminate article 10.

[0079] In embodiments, at least a portion of the step 124 of heat treating occurs during the step 102 of fusing. For example, in the fusing formation process, the temperatures involved can at least partially nucleate the core layer 12.

[0080] At a step 126, in embodiments, the method 100 further includes second heat treating the laminate article 10. The step 126 of second heat treating the laminate article 10 can further tweak the effective coefficient of thermal expansion that the laminate article 10 exhibits. Increasing the percentage of crystalline phase of the core layer 12 via such second heat treatment tends to increase the coefficient of thermal expansion of the core layer 12 and thus increase the effective coefficient of thermal expansion of the laminate article 10.

[0081] As mentioned, after the steps 102, 124, 126, the glass compositions of the first clad layer 14 and the second clay layer 18 both exhibit a coefficient of thermal expansion that is less than 2.0xl0 ^-5 /°K, while the laminate article 10 exhibits a coefficient of thermal expansion that is within a range of from 8.0xl0 ^-5 /°K to 2.0xl0 ^-5 /°K.

[0082] At a step 128, in embodiments, the method 100 further includes determining the target effective coefficient of thermal expansion for the laminate article 10. The step 128 may occur before the steps 124 and 126 (first and second heat treating) of the method 100, as well as before the step 102 (fusing). In some embodiments, the target effective coefficient of thermal expansion for the laminate article 10 is determined as a function of (i) a measured warp of a substrate or article with a display stack disposed thereupon and (ii) an effective coefficient of thermal expansion of the substrate or article. The display stack is typically an arrangement of several or numerous different components, each having their own coefficient of thermal expansion. The display stack thus exhibits its own effective coefficient of thermal expansion. The substrate or article on which the display stack is disposed likewise has its own effective coefficient of thermal expansion. A difference between the coefficient of thermal expansion of the display stack and the coefficient of thermal expansion of the substrate or article upon which the display stack is disposed is one driver the substrate or article warping. Thus, by correlating measured warp of the substrate or article with the effective coefficient of thermal expansion of the substrate or article, the coefficient of thermal expansion of expansion of the substrate or article that minimizes or sufficiently reduces the measured warp can be determined. That coefficient of thermal expansion of expansion of the substrate or article that minimizes or sufficiently reduces the measured warp can be determined and can be utilized as a target effective coefficient of thermal expansion of expansion for the laminate article 10 produced via the method 100. In embodiments, the effective coefficient of thermal expansion that the laminate article 10 exhibits, as produced via the method 100, is within 5% of the target effective coefficient of thermal expansion as determined at the step 128. In some embodiments, the target coefficient of thermal expansion is the effective coefficient of thermal expansion of the display stack that is to be disposed on the laminate article 10 manufactured via the method 100.

[0083] Referring now to FIG. 5, an electronic device 200 includes the laminate article 10 and a display stack 202 disposed on the first clad layer 14. The display stack 202 can include a multitude of components, substrates, layers, and so on. As mentioned, the effective coefficient of thermal expansion that the laminate article 10 exhibits is within the range of from 8.0X10 ^-5 /°K to 2.0xl0 ^-5 /°K. Similarly, the display stack 202 exhibits an effective coefficient of thermal expansion within the same range of from 8.0xl0 ^-5 /°Kto 2.0xl0 ^-5 /°K. In addition, the effective coefficient of thermal expansion that the laminate article 10 exhibits differs from the effective coefficient of thermal expansion that the display stack 202 exhibits by less than 5%.

[0084] In embodiments, the electronic device 200 further includes a second display stack 204 disposed on the second clad layer 16 of the laminate article 10. Again, the second display stack 204 can include a multitude of components, substrates, layers, and so on. The second display stack 204 exhibits an effective coefficient of thermal expansion within the same range of from 8.0xl0 ^-5 /°K to 2.0xl0 ^-5 /°K. In addition, the effective coefficient of thermal expansion that the laminate article 10 exhibits differs from the effective coefficient of thermal expansion that the second display stack 204 exhibits by less than 5%.

[0085] Warpage can result from the laminate article 10 and the display stack 202 (and, in embodiments, the second display stack 204) expanding and/or contacting at different rates in response to temperature changes. Reducing the difference between the effective coefficient of thermal expansion of the laminate article 10 and the display stack 202 can reduce the warp that can occur in response to temperature change of the electronic device 200. As the size of the electronic device 200 increases, the warpage increases as well.

[0086] In embodiments, the effective coefficient of thermal expansion that the laminate article 10 exhibits is greater than the effective coefficient of thermal expansion that the display stack 202 exhibits. The difference between the effective coefficient of thermal expansion of the laminate article 10 and the effective coefficient of thermal expansion of the display stack 202 may not be the only driver of warpage. In addition to the difference, sintering of the display stack 202 upon the laminate article 10 may drive warpage. Sintering of the display stack 202 typically cancels out a portion of the warpage that the disparity in coefficient of thermal expansion between the laminate article 10 and the display stack 202 causes. In such instances, minimizing the warpage may include the feature that the effective coefficient of thermal expansion that the laminate article 10 exhibits is not exactly the same as (e.g., is deliberately different than) the effective coefficient of thermal expansion that the display stack 202 exhibits. Rather, to minimize the warpage, the effective coefficient of thermal expansion of the laminate article 10 is greater than (but still within 5%, 10%, or 15% of) the effective coefficient of thermal expansion of the display stack 202. Manufacturing the laminate article 10 so that the effective coefficient of thermal expansion that the laminate article 10 exhibits is close to but greater than the effective coefficient of thermal expansion of the display stack 202 accounts for both drivers of warpage (CTE difference and sintering) and thus minimizes the warpage that the laminate article 10 will exhibit.

[0087] The laminate article 10 of the present disclosure addresses and reduces potential warpage without the need to compensate for such warpage via pre-warping or making the laminate article 10 thicker than desired. Pre-warping is the structural inducement of a counter-warpage in a laminate article 10 using asymmetric clad layers. The counter-warpage levels out as the laminate article 10 warps in response to attachment of the display stack 202. In addition, the thicker the laminate article 10 is, the less the laminate article 10 warps. However, pre-warping and increasing the thickness 36 of the laminate article 10 increases manufacturing costs and might not meet customer specifications.

[0088] In embodiments, the laminate article 10 exhibits a warp of less than 100 pm. In embodiments, the laminate article 10 exhibits a warp of 0 pm, greater than 0 pm, 10 pm, 20 pm, 30 pm, 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, or 100 pm, or within any range bound by any two of those values (e.g., from 0 pm to 100 pm, from 20 pm to 80 pm, and so on). Warp can be measured using a Tropel Flatmaster FM200 interferometer, taking the least squares fit from a flat plate.

[0089] The presence of the core layer 12 helps the glass laminate 10 exhibit the desired effective coefficient of thermal expansion. The presence of the first clad layer 14 and the second clad layer 16 sandwiching the core layer 12 helps prevent constituents of the glassceramic composition of the core layer 12 leaching to the display stack 202. The glass compositions of the first clad layer 14 and the second clad layer 16 do not react with typical constituents of the display stack 202.

[0090] In embodiments, the electronic device 200 is a microLED display. The electronic device 200 can be any electronic device 200 that includes the laminate article 10 and the display stack 202.

[0091] EXAMPLES

[0092] Example 1 - Example 1 demonstrates a model for determining various parameters of a laminate article to minimize warpage based on the assumption that the difference in effective coefficient of thermal expansion is the only driver of warpage. In such a scenario, warpage is reduced or minimized by forming the laminate article so that the effective coefficient of thermal expansion of the laminate article is the same as the effective coefficient of thermal expansion of the display stack. The model of Example 1 assumes that the coefficient of thermal expansion of the display stack is 12xl0 ^-5 /°K. Thus, in this scenario, the effective coefficient of thermal expansion for the laminate article is targeted to be 12xl0 ^-5 /°K, as well.

[0093] Formula II above was utilized to estimate the effective coefficient of thermal expansion for the laminate article as a function of (i) the coefficient of thermal expansion of the core layer and (ii) the thickness of the core layer. The model assumes that the coefficient of thermal expansion of the glass composition of both the first clad layer and the second clad layer is 3.5xlO ^-5 /°K. In addition, the model assumes that the thickness of the laminate article is 500 pm (0.5 mm). Thus, as the thickness of the core layer is varied, the combined thickness of the first clad layer and the second clad layer changes as well to equalize the thickness of the laminate article at 500 pm.

[0094] The results are graphically illustrated at FIG. 6. The graph reveals that the thicker the core layer is, the less the coefficient of thermal expansion of the glass-ceramic composition of the core layer can be to achieve the target effective coefficient of thermal expansion for the laminate article. When the thickness of the core layer is within a range of from 100 pm to 200 pm, the coefficient of thermal expansion for the core layer can be within a range of from about 2.5xlO ^-5 /°K to about 4.5xlO ^-5 /°K and can achieve the target effective coefficient of thermal expansion for the laminate article. For example, if the thickness of the core layer is 100 pm, then the coefficient of thermal expansion for the core layer needs to be about 4.5X10 ^-5 /°K to cause the effective coefficient of thermal expansion of the laminate article to be the target of 12xl0 ^-5 /°K. As another example, if the thickness of the core layer is 150 pm, then the coefficient of thermal expansion for the core layer needs to be about 3.2xl0 ^-5 /°K to cause the effective coefficient of thermal expansion of the laminate article to be the target of 1 X10 ^-5 /°K. The thickness of the core layer of 150 pm and a coefficient of thermal expansion of 3.2xlO ^-5 /°K for the glass-ceramic composition of the core layer are achievable with a fusion forming process and an appropriate heat treatment. Thicknesses of the core layer greater than 200 pm were not evaluated because such greater thicknesses may be difficult for a fusion forming process to achieve together with the first and second clad layers each having a thickness of less than 150 pm.

[0095] Examples 2A and 2B - For Examples 2A and 2B, a finite-element program was utilized to model the warp that placement of a display stack would generate due to a difference between the effective coefficient of thermal expansion of the display stack and the effective coefficient of thermal expansion in the laminate article. Both examples assumed that the laminate article had dimensions of 6 inches by 9 inches (e.g., ~15.24 cm by "'22.86 cm) and a thickness of 0.5 mm. For Example 2A, the effective coefficient of thermal expansion of the laminate article was set to be 3.5xlO ^-5 /°K and the effective coefficient of thermal expansion of the display stack was set to a particular value. The model calculated that the warp would be 328 pm. The warp, at a top-right quadrant of the glass substrate, is graphically illustrated at FIG. 7A. Only the top-right quadrant is illustrated, because the warp is symmetric. [0096] For Example 2B, the effective coefficient of thermal expansion of the laminate article was set to be lxlO ^-5 /°K, which is closer to the effective coefficient of thermal expansion of the display stack so assigned. That value for the effective coefficient of thermal expansion of the laminate article is achievable with the laminate articles of the present disclosure. The model calculated that the warp would be reduced to 77 pm. The warp, at a top-right quadrant of the glass substrate, is graphically illustrated at FIG. 7B.'