JP2023549138A - Substrate with improved electrostatic performance - Google Patents

Abstract

The substrate includes a glass sheet and a deposited layer deposited on a major surface of the glass sheet. The deposited layer includes inorganic particles and provides a major surface roughness in the range of about 0.4 nanometers to about 50 nanometers.

Description

Cross-reference of related applications

This application is filed under United States Provisional Patent Application No. 63/110,548, filed November 6, 2020, 35 U.S.C. 35 U.S.C. 119(e), which is hereby incorporated by reference in its entirety. ).

TECHNICAL FIELD This disclosure relates generally to substrates and, more particularly, to substrates with improved electrostatic performance.

Thin glass substrates are commonly utilized in flat panel display (FPD) devices such as liquid crystal displays (LCD) and organic light emitting diode (OLED) displays. Substrates used in FPD devices generally have a functional A-side surface on which thin film transistors are fabricated, and a non-functional back or B-side surface opposite the A-side surface. During the manufacture of FPD devices, the B-side surface of the glass substrate may come into contact with various material transport and handling equipment, such as metal, ceramic, and polymeric materials. The interaction between the substrate and these materials often results in charging due to triboelectric effects or contact charging. As a result, charge can migrate to the glass surface and accumulate on the substrate. When charges accumulate on the surface of the glass substrate, the surface potential of the glass substrate also changes.

Electrostatic charging (ESC) on the B-side surface of a glass substrate used in an FPD device can degrade the performance of the glass substrate and/or damage the glass substrate. For example, electrostatic charging on the B-side surface can cause gate damage to thin film transistor (TFT) devices deposited on the A-side surface of a glass substrate due to dielectric breakdown or field-induced charging. Additionally, the electrical charge on the B-side surface of the glass substrate may attract particles such as dust or other particulate debris, which may damage the glass substrate or degrade the surface quality of the glass substrate. There is sex. In either situation, electrostatic charging of the glass substrate can reduce the manufacturing yield of FPD devices, thereby increasing the overall cost of the manufacturing process.

Furthermore, frictional contact between the glass substrate and handling and/or transport equipment can wear out such equipment, thereby shortening its useful life. Repairing or replacing worn equipment causes process downtime, reduces manufacturing yield, and increases the cost of the entire FPD device manufacturing process.

Therefore, there is a need for a method of processing glass substrates that reduces charge generation and reduces friction between the glass substrate and the equipment utilized in the fabrication of FPD devices.

Embodiments disclosed herein include a substrate. The substrate includes a first major surface and an opposite second major surface extending in a direction substantially parallel to the first major surface. The substrate also includes a glass sheet and a deposited layer extending between the glass sheet and the second major surface. The deposited layer includes inorganic particles and provides a surface roughness on the second major surface of the substrate in the range of about 0.4 nanometers to about 50 nanometers.

Embodiments disclosed herein also include a method of manufacturing a substrate. The method includes depositing a deposited layer on a glass sheet. The deposited layer extends between the glass sheet and the second major surface of the substrate, and the glass sheet extends between the deposited layer and the first major surface of the substrate. The first major surface extends in a direction substantially parallel to the second major surface. The deposited layer includes inorganic particles and provides a surface roughness on the second major surface of the substrate in the range of about 0.4 nanometers to about 50 nanometers.

Additional features and advantages of the embodiments disclosed herein are set forth in, and in part will be readily apparent to, those skilled in the art from the following detailed description, or will be described in the following detailed description. The embodiments disclosed may be practiced by practicing the disclosed embodiments as described herein, including the description, claims, and accompanying drawings.

It is to be understood that both the foregoing summary and the following detailed description are intended to provide an overview or framework for understanding the nature and features of the claimed embodiments. It is. The accompanying drawings are included to provide a further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure and, together with the description, serve to explain the principles and operation thereof.

Schematic diagram of exemplary fusion downdraw glass manufacturing equipment and process Perspective view of glass sheet Side cross-sectional view of a glass sheet with a liquid-dispersed deposit layer deposited on it Side cross-sectional view of a glass sheet with a deposited layer Side cross-sectional view of the lift test device during the first stage of operation Side cross-sectional view of the lift test device during the second stage of operation Side cross-sectional view of the lift test device in the third stage of operation

Reference will now be made in detail to the preferred embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or similar parts. However, this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Ranges can be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, eg, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. Furthermore, it will be appreciated that each endpoint of the range is significant both in relation to the other endpoints and independently of the other endpoints.

Directional terms used herein (e.g., top, bottom, right, left, front, back, top, bottom) are made only with reference to the depicted figures and are meant to refer to absolute directions. It is not intended to.

Unless stated otherwise, any method described herein is to be construed as requiring its steps to be performed in a particular order or requiring a particular orientation of the apparatus. That was never my intention. Thus, if a method claim does not actually recite the order in which its steps are to be followed, or an apparatus claim does not actually recite the order or orientation for the individual components, or if the steps are not in a particular order, Unless it is expressly stated otherwise in the claims or specification that a limitation is to be imposed, or unless a specific order or orientation of the components of the device is recited, , order or direction is in no way intended to be inferred. This applies to any implicit basis for interpretation, such as: logical considerations regarding the arrangement of steps, flow of action, order of components, or direction of components; derived from grammatical organization or punctuation. and the number or type of embodiments described in the specification.

As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a" component includes embodiments having more than one such component, unless the context clearly indicates otherwise.

As used herein, the term "surface roughness" refers to the measured roughness on the major surface of a substrate as determined by the surface roughness measurement techniques described herein.

As used herein, the term "electrostatic charge" refers to the measured charge on the major surface of a substrate as determined by the surface potential measurement techniques described herein.

An exemplary glass manufacturing apparatus 10 is shown in FIG. In some examples, glass manufacturing apparatus 10 can include a glass melting furnace 12 that can include a melting vessel 14. In addition to the melting vessel 14, the glass melting furnace 12 optionally includes one or more additional heating elements (e.g., combustion burners or electrodes) that heat the feedstock to convert the feedstock into molten glass. Can contain components. In a further example, glass melting furnace 12 may include a thermal management device (eg, an insulating component) to reduce heat loss from the vicinity of the melting vessel. In yet another example, glass melting furnace 12 may include electronic and/or electromechanical devices that facilitate the melting of raw materials into a glass melt. Additionally, glass melting furnace 12 may include support structures (eg, support chassis, support members, etc.) or other components.

Glass melting vessel 14 is typically constructed of a refractory material, such as a refractory ceramic material, such as a refractory ceramic material containing alumina or zirconia. In some examples, glass melting vessel 14 may be constructed from a refractory ceramic brick. Certain embodiments of glass melting vessel 14 are described in more detail below.

In some examples, a glass melting furnace can be incorporated as a component of glass manufacturing equipment to produce glass sheets, such as continuous lengths of glass ribbon. In some examples, the glass melting furnace of the present disclosure can be applied to a slot draw device, a float bath device, a downdraw device such as a fusion process, an updraw device, a press rolling device, a tube drawing device, or any of the methods disclosed herein. It may be incorporated as a component of glass manufacturing equipment, including any other glass manufacturing equipment that would benefit from the embodiments. By way of example, FIG. 1 schematically depicts a glass melting furnace 12 as a component of a fusion downdraw glass manufacturing apparatus 10 for melt-drawing a glass ribbon for subsequent processing into individual glass sheets. .

Glass manufacturing apparatus 10 (eg, fusion downdraw apparatus 10) may optionally include an upstream glass manufacturing apparatus 16 positioned upstream with respect to glass melting vessel 14. In some examples, a portion or all of upstream glass manufacturing equipment 16 may be incorporated as part of glass melting furnace 12 .

As shown in the illustrated example, upstream glass manufacturing apparatus 16 may include a storage bin 18, a feedstock delivery device 20, and a motor 22 connected to the feedstock delivery device. Storage bin 18 may be configured to store a quantity of raw material 24 that can be fed to melting vessel 14 of glass melting furnace 12, as shown by arrow 26. Feedstock 24 typically includes one or more glass-forming metal oxides and one or more modifiers. In some examples, raw material delivery device 20 may be powered by motor 22 such that raw material delivery device 20 delivers a predetermined amount of raw material 24 from storage bin 18 to melting vessel 14 . In a further example, motor 22 can power feedstock delivery device 20 to introduce feedstock 24 at a controlled rate based on a sensed level of molten glass downstream of melting vessel 14. Thereafter, raw material 24 within melting vessel 14 may be heated to form molten glass 28.

Glass manufacturing apparatus 10 may also optionally include a downstream glass manufacturing apparatus 30 positioned downstream with respect to glass melting furnace 12 . In some examples, a portion of downstream glass manufacturing equipment 30 may be incorporated as part of glass melting furnace 12 . In some cases, the first connecting conduit 32, discussed below, or other portions of the downstream glass manufacturing apparatus 30 may be incorporated as part of the glass melting furnace 12. The elements of the downstream glass manufacturing apparatus, including the first connecting conduit 32, may be formed from precious metals. Suitable noble metals include platinum group metals selected from the group of metals consisting of platinum, iridium, rhodium, osmium, ruthenium, and palladium, or alloys thereof. For example, downstream components of glass manufacturing equipment can be formed from a platinum-rhodium alloy containing from about 70% to about 90% by weight platinum and from about 10% to about 30% by weight rhodium. However, other suitable metals may include molybdenum, palladium, rhenium, tantalum, titanium, tungsten, and alloys thereof.

Downstream glass production apparatus 30 includes a first conditioning (i.e., processing) vessel, such as a fining vessel 34 , located downstream of melting vessel 14 and coupled to melting vessel 14 by said first connecting conduit 32 . may include. In some examples, molten glass 28 may be gravity fed from melting vessel 14 to fining vessel 34 by first connecting conduit 32 . For example, gravity can cause molten glass 28 to pass from melting vessel 14 to fining vessel 34 through the internal passage of first connecting conduit 32 . However, it should be understood that other conditioning vessels may be placed downstream of melting vessel 14, such as between melting vessel 14 and fining vessel 34, for example. In some embodiments, a conditioning vessel that further heats the molten glass from the primary melting vessel to continue the melting process or cools it to a temperature below the temperature of the molten glass in the melting vessel before entering the fining vessel. can be used between the melting vessel and the fining vessel.

Air bubbles can be removed from molten glass 28 within finer vessel 34 by a variety of techniques. For example, feedstock 24 may include a polyvalent compound (i.e., a fining agent), such as tin oxide, that undergoes a chemical reduction reaction and releases oxygen when heated. Other suitable fining agents include, but are not limited to, arsenic, antimony, iron, and cerium. The fining vessel 34 is heated to a temperature above the melting vessel temperature, thereby heating the molten glass and fining agent. Oxygen bubbles produced by the temperature-induced chemical reduction of the fining agent rise through the molten glass in the fining vessel, where the gases in the molten glass produced in the melting furnace are It can diffuse or integrate into oxygen bubbles. The enlarged air bubbles can then rise to the free surface of the molten glass within the fining vessel and then be discharged from the fining vessel. Oxygen bubbles can also cause mechanical mixing of the molten glass within the finer vessel.

Downstream glass manufacturing apparatus 30 may further include another conditioning vessel, such as a mixing vessel 36 for mixing molten glass. A mixing vessel 36 may be located downstream of the fining vessel 34. Mixing vessel 36 is used to provide a homogeneous glass melt composition, thereby reducing codes of chemical or thermal non-uniformity that may otherwise exist within the fined molten glass exiting the finer vessel. be able to. As shown, fining vessel 34 may be connected to mixing vessel 36 by a second connecting conduit 38 . In some examples, molten glass 28 may be gravity fed from finer vessel 34 to mixing vessel 36 by second connecting conduit 38 . For example, gravity can cause molten glass 28 to pass from the fining vessel 34 to the mixing vessel 36 through the internal passage of the second connecting conduit 38 . Although mixing vessel 36 is shown downstream of fining vessel 34, it should be noted that mixing vessel 36 may be positioned upstream of fining vessel 34. In some embodiments, downstream glass manufacturing apparatus 30 may include multiple mixing vessels, such as a mixing vessel upstream of fining vessel 34 and a mixing vessel downstream of fining vessel 34 . These multiple mixing vessels may be of the same design or of different designs.

Downstream glass manufacturing apparatus 30 may further include another conditioning vessel, such as delivery vessel 40 , which may be located downstream of mixing vessel 36 . Delivery container 40 can condition and feed molten glass 28 into downstream forming equipment. For example, delivery container 40 can function as an accumulator and/or flow control device to regulate and/or provide a constant flow of molten glass 28 to compact 42 via outlet conduit 44 . As shown, mixing container 36 may be connected to delivery container 40 by a third connecting conduit 46 . In some examples, molten glass 28 may be gravity fed from mixing vessel 36 to delivery vessel 40 by third connecting conduit 46 . For example, gravity can drive molten glass 28 from mixing vessel 36 to delivery vessel 40 through the internal path of third connecting conduit 46 .

The downstream glass manufacturing apparatus 30 may further include a forming apparatus 48 that includes the formed body 42 and inlet conduit 50 described above. Outlet conduit 44 may be positioned to deliver molten glass 28 from delivery container 40 to inlet conduit 50 of forming device 48 . For example, outlet conduit 44 is nested within and spaced from the inner surface of inlet conduit 50, thereby providing a free surface of molten glass positioned between the outer surface of outlet conduit 44 and the inner surface of inlet conduit 50. can do. The compact 42 of the fusion downdraw glass manufacturing apparatus may include a trough 52 located on the top surface of the compact and a converging forming surface 54 that converges in the drawing direction along a bottom edge 56 of the compact. Molten glass delivered to the compact trough via delivery vessel 40, outlet conduit 44, and inlet conduit 50 overflows the sidewalls of the trough and descends along converging forming surface 54 as separate streams of molten glass. do. The separate streams of molten glass meet below and along the bottom edge 56, and by applying tension to the glass ribbon, such as by gravity, edge rolls 72, and pull rolls 82, the glass cools and the glass A single glass ribbon 58 is produced that is drawn from the bottom edge 56 in the draw or machine direction 60 to control the dimensions of the glass ribbon as the viscosity increases. Therefore, the glass ribbon 58 undergoes a viscoelastic transition and acquires mechanical properties that give the glass ribbon 58 stable dimensional properties. Glass ribbon 58 may be separated into individual glass sheets 62 by glass separation apparatus 100 in the elastic regions of the glass ribbon in some embodiments. The individual glass sheets 62 can then be transferred by the robot 64 using the grippers 65 to a conveyor system, after which the individual glass sheets can be further processed.

FIG. 2 shows a first major surface 162, a second major surface 164 (on the opposite side of the glass sheet 62 from the first major surface) extending in a direction substantially parallel to the first major surface 162, and , a glass having an edge surface 166 extending between a first major surface 162 and a second major surface 164 and extending in a direction generally perpendicular to the first and second major surfaces 162, 164. A perspective view of the sheet 62 is shown.

FIG. 3 shows a side cross-sectional view of a glass sheet 62 with a liquid dispersed deposition layer 202 deposited thereon. Specifically, a liquid dispersed deposition layer 202 is deposited on the second major surface 164 of the glass sheet 62 to form the substrate precursor 62'. Liquid dispersed deposited layer 202 is deposited onto glass sheet 62 via disperser 300 according to methods known to those skilled in the art, including, but not limited to, at least one of spin coating, flow coating, or spray coating. can be deposited.

In certain exemplary embodiments, the deposited layer can be dispersed in water such that liquid-dispersed deposited layer 202 includes an aqueous dispersion. The deposited layer can also be dispersed in other liquids, including organic solvents such as, for example, alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, amines, esters, ethers, and/or ketones.

The weight percent (wt%) of solids in the liquid-dispersed deposited layer 202 can be, for example, but not limited to, about 0.1 wt% to about 10 wt%, such as about 0.5 wt% to about 5 wt%, and even can range, for example, from about 1% to about 3% by weight.

In certain exemplary embodiments, liquid-dispersed deposited layer 202 can include a solid material that includes inorganic particles. Such particles may include, for example, at least one of aluminum oxide, aluminum hydroxide, and/or colloidal silica. Prior to incorporation into the liquid dispersed deposited layer 202, such particles may be, for example, at least about 100 square meters per gram, such as at least about 200 square meters per gram, even from about 100 square meters per gram to about 500 square meters per gram, It can include a Brunauer-Emmett-Teller (BET) specific surface area of at least about 300 square meters/gram, including, for example, from about 200 square meters/gram to about 400 square meters/gram. The BET specific surface area is calculated by observing the physical adsorption of a gas onto a solid surface and using the Brunauer-Emmett-Teller (BET) adsorption isotherm known to those skilled in the art to calculate the adsorbed gas equivalent to a monolayer on the surface. determined by calculating the amount of

When the inorganic particles include aluminum oxide, aluminum hydroxide, and/or colloidal silica, they may be in amorphous or crystalline form. Examples of aluminum oxide and/or aluminum hydroxide that can be used in the liquid-dispersed deposit layer 202 include amorphous aluminum oxide, alpha alumina, beta alumina, gamma alumina, gibbsite, bayerite, nordstrandite, boehmite, Examples include, but are not limited to, diaspore or todite.

After being deposited on the glass sheet 62, the liquid-dispersed deposited layer 202 may be subjected to a drying process to evaporate the liquid, such as by using an air knife and/or high temperature drying, as is known to those skilled in the art. Can be done. For example, high temperature drying can be carried out at a temperature of at least about 100°C, such as at least about 200°C, such as from about 100°C to about 500°C, for at least about 10 seconds, such as from about 10 seconds to about 20 minutes. Air knife drying can be performed, for example, for at least about 30 seconds, such as from about 30 seconds to about 30 minutes.

FIG. 4 shows a side cross-sectional view of a glass sheet 62 with a deposited layer 204 deposited thereon. Specifically, the deposited layer 204 is deposited on the second major surface 164 of the glass sheet 62 to form the substrate 62''. As a result of drying, it can be deposited on the second major surface 164 of the glass sheet 62.

The deposited layer 204 has a substrate 62'' in the range of about 0.4 nanometers to about 50 nanometers, such as about 0.6 nanometers to about 20 nanometers, and even such as about 0.8 nanometers to about 10 nanometers. The first major surface 162 of the substrate 62'' may have a surface roughness of, for example, from about 0.05 nanometers to about 0.5 nanometers, such as about 0.1 nanometers. It can have a surface roughness of less than about 0.5 nanometers, including from nanometers to about 0.25 nanometers, such as less than about 0.25 nanometers.

The surface roughness of the second main surface 206 may be at least partially due to the deposited layer 204 containing inorganic particles. Such particles may include, for example, at least one of aluminum oxide, aluminum hydroxide, and/or colloidal silica. In addition, such particles may contain, for example, at least about 100 square meters per gram, such as at least about 200 square meters per gram, even from about 100 square meters per gram to about 500 square meters per gram, such as from about 200 square meters per gram to about It can include a Brunauer-Emmett-Teller (BET) specific surface area of at least about 300 square meters/gram, including 400 square meters/gram.

When the inorganic particles include aluminum oxide, aluminum hydroxide, and/or colloidal silica, they may be in amorphous or crystalline form. Examples of aluminum oxide and/or aluminum hydroxide that can be used in the deposited layer 204 include amorphous aluminum oxide, alpha alumina, beta alumina, gamma alumina, gibbsite, bayerite, nordstrandite, boehmite, diaspore, or todite, but is not limited to these.

In certain exemplary embodiments, the substrate 62'' may be subjected to a cleaning process following the drying process described above. Specifically, the first major surface 162 or the second major surface of the substrate 62'' At least one of the major surfaces 206 can be cleaned with a liquid cleaning solution that includes a solvent, such as water or an organic solvent, and at least one solute. In certain exemplary embodiments, the solute may include at least one detergent and/or surfactant. In certain exemplary embodiments, the solvent comprises water (e.g., deionized water) and the solute comprises an alkaline detergent, such as a detergent comprising at least one of potassium hydroxide (KOH) or sodium hydroxide (NaOH). commercially available examples include Semi Clean KG and PK-LCG225X. In certain exemplary embodiments, the solute is at least about 0.1% by weight, including at least about 1%, such as from about 0.1% to about 10%, even such as from about 1% to about 5%. % in solution. In certain exemplary embodiments, the cleaning liquid may be applied at a temperature of at least about 20°C, such as from about 20°C to about 80°C, for at least about 10 seconds, such as from about 10 seconds to about 10 minutes. Additionally, cleaning fluids can be applied according to methods known to those skilled in the art, including, but not limited to, spraying, brushing, and dipping.

In certain exemplary embodiments, substrate 62'' may be subjected to a drying process following the cleaning process described above. For example, following the cleaning process, as is known to those skilled in the art, An air knife and/or high temperature drying may be used to dry the substrate 62''. For example, high temperature drying can be carried out at a temperature of at least about 100°C, such as at least about 200°C, such as from about 100°C to about 500°C, for at least about 10 seconds, such as from about 10 seconds to about 20 minutes. Air knife drying can be performed, for example, for at least about 30 seconds, such as from about 30 seconds to about 30 minutes.

In certain exemplary embodiments, the substrate 62'' may also be subjected to an etching process, such as an acid etching process, such as spraying, dipping, etc. It can be applied to at least the second major surface 206 of the substrate 62'' according to methods known to those skilled in the art, such as, or brushing. The acid etchant is, for example, present in solution at a concentration ranging from about 0.1% to about 10% by weight and at a temperature ranging from about 20°C to about 60°C for about 10 seconds to about 10 minutes. time, can be applied.

Embodiments disclosed herein include embodiments in which the etching process does not significantly affect the surface roughness of the second major surface 206 of the substrate 62''. The second major surface 206 has a diameter in the range of about 0.4 nanometers to about 50 nanometers, such as about 0.6 nanometers to about 20 nanometers, and even such as about 0.8 nanometers to about 10 nanometers. It may have surface roughness.

In certain exemplary embodiments, the absolute electrostatic charge (ESC) of the second major surface 206 of the substrate 62'' is less than about 200 volts (V), such as less than about 150 volts (V), and is less than 100 volts (V), even less than about 50 volts (V), such as from about 0 volts (V) to about 200 volts (V), further such as from about 1 volt (V) to about 150 volts (V), Further, for example, from about 2 volts (V) to about 100 volts (V), and further, for example, from about 5 volts (V) to about 50 volts (V).

In certain exemplary embodiments, the thickness between the first major surface 162 and the second major surface 206 of the substrate 62'' in a wavelength range of between about 400 nanometers and about 850 nanometers is 0.0. The total light transmittance per 5 millimeters is at least about 90%, including from about 90% to about 99%, such as at least about 95%. Transmittance was determined by placing a 0.5 mm thick substrate sample in a Hitachi U-4000 spectrophotometer and measuring the percent transmittance (T%) in the wavelength range between about 400 and about 850 nanometers. Decided.

Embodiments disclosed herein may include embodiments in which deposited layer 204 is not sintered. Embodiments disclosed herein may further include embodiments in which the deposited layer 204 does not melt. Additionally, embodiments disclosed herein may include embodiments in which no compressive stress is applied to the deposited layer 204. Embodiments disclosed herein also provide embodiments in which the deposited layer 204 does not include a substantial amount (e.g., greater than 1% by weight) of glass, metal, and/or organic compounds (e.g., binders, etc.). may also be included. Additionally, embodiments disclosed herein include embodiments in which a wet or dry etching step (such as a wet or dry acid etching step) is not performed on the glass sheet 62 prior to application of the deposited layer 204. sell.

In certain exemplary embodiments, the thickness of the substrate 62'' between the first major surface 162 and the second major surface 206 includes, for example, between about 0.1 mm and about 1 mm. , even less than about 1 mm, such as less than about 0.5 mm, including about 0.2 mm and about 0.5 mm.

Embodiments disclosed herein can be used with a variety of glass compositions. Such a composition may contain, for example, 58-65 weight percent (wt.%) SiO ₂ , 14-20 wt. % Al ₂ O ₃ , 8-12 wt. % B ₂ O ₃ , 1-3 wt. % Glass compositions such as alkali-free glass compositions containing MgO, 5-10% by weight CaO, and 0.5-2% by weight SrO can be included. Such compositions also contain 58-65% by weight SiO ₂ , 16-22% by weight Al ₂ O ₃ , 1-5% by weight B ₂ O ₃ , 1-4% by weight MgO, 2-6% by weight Glass compositions may also be included, such as alkali-free glass compositions containing % by weight CaO, 1-4% by weight SrO, and 5-10% by weight BaO. Such a composition further comprises 57-61% by weight SiO ₂ , 17-21% by weight Al ₂ O ₃ , 5-8% by weight B ₂ O ₃ , 1-5% by weight MgO, 3 Glass compositions may also be included, such as alkali-free glass compositions containing ~9% by weight CaO, 0-6% by weight SrO, and 0-7% by weight BaO. Such a composition contains 55-72% by weight SiO ₂ , 12-24% by weight Al ₂ O ₃ , 10-18% by weight Na ₂ O, 0-10% by weight B ₂ O ₃ , 0-10% by weight B 2 O 3 5% by weight K ₂ O, 0-5% by weight MgO, and 0-5% by weight CaO, and in certain embodiments, 1-5% by weight K ₂ O and 1-5% by weight. It may further include a glass composition, such as an alkali-containing glass composition, which may also include MgO.

Surface Roughness Measurement Techniques As described herein, including in the examples below, surface roughness is measured by atomic force microscopy roughness (AFM Ra) analysis using a Hitachi High-Tech AFM5400L. refers to For each sample to be analyzed, an AFM surface morphology image was obtained using a cantilever SI-DF20P2 (spring constant = 9 N/m, resonance frequency: 100-200 kHz, tip radius: 7 nm, tip height: 14 μm, lever length: 160 μm, lever width: 40 μm, lever thickness: 3.5 μm) and scanned in dynamic force mode (DFM). For each sample analyzed, the substrate surface was irradiated with soft X-rays during the measurement using the following analysis parameters: integral gain (0.2), proportional gain (0.05), Z limit (500 nm), Scan area (10 μm x 10 μm), image quality X axis (256) and Y axis (256). The difference (PV value) between the highest "mountain" and the deepest "valley" on the surface was also determined.

Surface Potential Measurement Technique The electrostatic charge (ESC) of the second major surface of the substrates described herein, including in the examples below, was measured using a lift test apparatus as schematically illustrated in FIGS. This was determined by placing the substrate sample on the substrate. Specifically, as shown in FIG. 5, in the first stage of operation, a substrate sample 62'' of approximately 10 x 10 ^cm2 is placed such that the sample is located approximately 30 mm above the anodized aluminum table 404. , on the three lift pins 408a, 408b, and 408c of the lift test apparatus 400. During this step, the ion generator 410 increases the air gap between the second major surface of the substrate sample 62'' and the table by approximately 30 mm. Process for seconds. Then, in the second stage of operation, as shown in FIG. is turned on for approximately 70 seconds between table 404 and substrate sample 62''. Then, in the third stage of operation, the vacuum 406 is turned off and the substrate sample 62'' is lifted by three lift pins 408a, 408b, and 408c, as shown in FIG. 402 for approximately 30 seconds to determine the electrostatic charge (ESC) in volts (V). During this step, the gap between the first major surface of the substrate sample 62" and the ESFM 402 is approximately 10 millimeters. , and the gap between the second major surface of the substrate sample 62'' and the table 404 is about 30 mm.

The embodiments disclosed herein will be further described with reference to the following non-limiting examples.

Example 1:
Amorphous aluminum oxide particles having a BET specific surface area of about 300 m ² /g were combined with water to form an aqueous dispersion with a solids content of about 1% by mass, and coated with a thickness of about It was applied to the main surface of 0.5 mm Corning Lotus™ NXT glass. The surface was then dried at about 200° C. for about 15 seconds. The obtained substrate exhibited a total light transmittance of about 91.4% between its main surfaces in a wavelength range of about 400 nanometers to about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 11.4 nanometers, and the PV value was determined to be approximately 209 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately +49V. The substrate was then heated at about 590° C. for about 30 minutes as a simulation of the TFT process, after which the ESC measured between the coated main surface and the lift test device was about −9V. Next, as a further TFT process simulation, the substrate was immersed in an aqueous solution containing about 1% by mass of HF at about 23°C for about 45 seconds, and then measurements were taken between the coated main surface and a lift test device. The ESC applied was approximately +69V.

Example 2:
Boehmite particles having a BET specific surface area of about 220 m ² /g were combined with water to form an aqueous dispersion with a solids content of about 1% by mass, and coated with a thickness of about 0.5 mm via a spin coater rotating at about 1,000 rpm. of Corning Lotus™ NXT glass. The surface was then dried at about 200° C. for about 15 seconds. The resulting substrate is then cleaned with an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 60 seconds, rinsed with deionized (DI) water at about 40°C for about 60 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.6% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 6.37 nanometers, and the PV value was determined to be approximately 166 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately -42V. The substrate was then heated at about 590° C. for about 30 minutes as a simulation of the TFT process, after which the ESC measured between the coated main surface and the lift test device was about −1V. Next, as a further TFT process simulation, the substrate was immersed in an aqueous solution containing about 1% by mass of HF at about 23°C for about 45 seconds, and then measurements were taken between the coated main surface and a lift test device. The ESC applied was approximately +114V.

Example 3:
Boehmite particles having a BET specific surface area of about 220 m ² /g were combined with water to produce an aqueous dispersion with a solids content of about 3% by mass, and coated with a thickness of about 0.5 mm via a spin coater rotating at about 4,000 rpm. of Corning Lotus™ NXT glass. The surface was then dried at about 150° C. for about 15 minutes. The resulting substrate is then cleaned with an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 60 seconds, rinsed with deionized (DI) water at about 40°C for about 60 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.4% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 7.4 nanometers, and the PV value was determined to be approximately 99 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately -1V.

Example 4:
Amorphous aluminum oxide particles having a BET specific surface area of about 300 m ² /g are combined with water to form an aqueous dispersion with a solids content of about 1% by mass, and coated with a thickness of about It was applied to the main surface of 0.5 mm Corning Lotus™ NXT glass. The surface was then dried using an air knife for approximately 10 minutes at room temperature. The resulting substrate is then cleaned using an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 90 seconds, rinsed with deionized (DI) water at about 40°C for about 90 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.3% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 11.0 nanometers, and the PV value was determined to be approximately 193 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately +52V.

Example 5:
Boehmite particles having a BET specific surface area of about 220 m ² /g were combined with water to form an aqueous dispersion with a solids content of about 1% by mass, and coated with a thickness of about 0.5 mm via a spin coater rotating at about 2,000 rpm. of Corning Lotus™ NXT glass. The surface was then dried using an air knife for approximately 10 minutes at room temperature. The resulting substrate is then cleaned using an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 90 seconds, rinsed with deionized (DI) water at about 40°C for about 90 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.5% in a wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 4.6 nanometers, and the PV value was determined to be approximately 166 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately +19V.

Example 6:
Amorphous aluminum oxide particles with a BET specific surface area of about 300 m ² /g were combined with water to form an aqueous dispersion with a solids content of about 1% by weight and coated with Corning powder with a thickness of about 0.5 mm via a flow coater. It was applied to the main surface of Lotus™ NXT glass. The surface was then dried using an air knife for approximately 10 minutes at room temperature. The resulting substrate is then cleaned using an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 90 seconds, rinsed with deionized (DI) water at about 40°C for about 90 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.4% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 15.9 nanometers, and the PV value was determined to be approximately 253 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately +106V.

Example 7:
Boehmite particles with a BET specific surface area of about 220 m ² /g were combined with water to form an aqueous dispersion with a solids content of about 1% by weight and coated with Corning Lotus™ with a thickness of about 0.5 mm via a flow coater. It was applied to the main surface of NXT glass. The surface was then dried using an air knife for approximately 10 minutes at room temperature. The resulting substrate is then cleaned using an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 90 seconds, rinsed with deionized (DI) water at about 40°C for about 90 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.3% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 8.1 nanometers, and the PV value was determined to be approximately 105 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately -26V.

Example 8:
Amorphous silicon oxide (colloidal silica) particles having a BET specific surface area of about 110 m ² /g were combined with water to produce an aqueous dispersion with a solid content of about 1% by mass, and a spin coater rotating at about 2,000 rpm was used. The solution was applied to the main surface of Corning Lotus™ NXT glass approximately 0.5 millimeters thick. The surface was then dried using an air knife for approximately 10 minutes at room temperature. The resulting substrate is then cleaned using an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 90 seconds, rinsed with deionized (DI) water at about 40°C for about 90 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.5% in a wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 1.5 nanometers, and the PV value was determined to be approximately 74 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately -21V.

Example 9:
A 70:30 mass % mixture of boehmite and amorphous silicon oxide (colloidal silica), each having a BET specific surface area of approximately 220 m ² /g, is combined with water to form an aqueous dispersion with a solid content of approximately 1 mass %. was produced and applied to the major surface of Corning Lotus™ NXT glass approximately 0.5 millimeters thick via a spin coater rotating at approximately 2,000 rpm. The surface was then dried using an air knife for approximately 10 minutes at room temperature. The resulting substrate is then cleaned using an aqueous solution containing 1% Parker 225X detergent at about 40°C for about 90 seconds, rinsed with deionized (DI) water at about 40°C for about 90 seconds, and then washed at about 150°C. It was dried in an oven for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.7% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 13.6 nanometers, and the PV value was determined to be approximately 162 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately +73V.

Example 10:
Boehmite particles having a BET specific surface area of about 220 m ² /g were combined with water to produce an aqueous dispersion with a solid content of about 0.2% by mass, and then coated with Corning Lotus (about 0.5 mm thick) via a flow coater. Trademark) NXT was applied to the main surface of the glass. The aqueous dispersion was drained by sheet tilting for 20 seconds, and the resulting substrate was then washed with an aqueous solution containing 4% Parker 225X detergent at about 50° C. for about 10 minutes and with deionized (DI) water for about 10 minutes. Rinsed at 40°C for about 10 minutes and then dried in an oven at about 150°C for about 20 minutes. The substrate exhibited a total light transmission between its major surfaces of about 91.7% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of the coated major surface was determined to be approximately 0.50 nanometers, and the PV value was determined to be approximately 17 nanometers. In contrast, the surface roughness of the opposite, uncoated major surface was approximately 0.2 nanometers. The ESC measured between the coated major surface and the lift test apparatus was approximately -94V.

Comparative example:
Corning Lotus(TM) NXT glass approximately 0.5 mm thick cleaned with an aqueous solution containing 1% Parker 225X detergent at approximately 40°C for approximately 20 minutes and deionized (DI) water at approximately 40°C for approximately 20 minutes. Rinsed and then dried in an oven at about 150° C. for about 20 minutes. The glass exhibited a total light transmission between its major surfaces of about 91.8% in the wavelength range between about 400 nanometers and about 850 nanometers. The surface roughness (AFM Ra) of both major surfaces was determined to be approximately 0.2 nanometers, and the PV value was determined to be approximately 16 nanometers. The ESC measured between the main surface of the glass and the lift test apparatus was approximately -350V.

Embodiments disclosed herein can significantly reduce the surface potential of a glass substrate, resulting in reduced gate damage to TFT devices deposited on the A-side surface of the glass substrate, It may be possible to reduce particles and debris on the B-side surface, increase the yield of FPD device manufacturing, and increase the useful life of glass substrate handling and/or transport equipment.

Embodiments disclosed herein also include electronic devices that include any of the substrates disclosed herein.

Although the above embodiments are described with reference to a fusion downdraw process, such embodiments may be used with other processes such as float processes, slot draw processes, updraw processes, tube draw processes, and press rolling processes. It should be understood that it is also applicable to glass forming processes.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Accordingly, it is intended that this disclosure cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.

Preferred embodiments of the present invention will be described below.

Embodiment 1
A substrate,
a first main surface, an opposite second main surface extending in a direction substantially parallel to the first main surface, a glass sheet, and a connection between the glass sheet and the second main surface; a deposited layer extending therebetween, the deposited layer comprising inorganic particles and providing a surface roughness of the second major surface of the substrate in the range of about 0.4 nanometers to about 50 nanometers;
substrate.

Embodiment 2
The substrate of embodiment 1, wherein the first major surface has a surface roughness of less than about 0.5 nanometers.

Embodiment 3
2. The substrate of embodiment 1, wherein the inorganic particles have a Brunauer-Emmett-Teller (BET) specific surface area of at least about 100 square meters per gram.

Embodiment 4
4. The substrate of embodiment 3, wherein the inorganic particles include at least one of aluminum oxide, aluminum hydroxide, and/or colloidal silica.

Embodiment 5
The total light transmittance per 0.5 mm thickness between the first major surface and the second major surface in a wavelength range of about 400 nanometers to about 850 nanometers is at least about 90%. The substrate according to Embodiment 1, which is.

Embodiment 6
2. The substrate of embodiment 1, wherein the second major surface has an absolute electrostatic charge (ESC) of less than about 200 volts (V).

Embodiment 7
2. The substrate of embodiment 1, wherein the substrate thickness between the first major surface and the second major surface is between about 0.1 mm and about 1 mm.

Embodiment 8
The glass sheet contains 58-65% by weight of SiO ₂ , 14-20% by weight of Al ₂ O ₃ , 8-12% by weight of B ₂ O ₃ , 1-3% by weight of MgO, 5-10% by weight of The substrate according to embodiment 1, comprising an alkali-free glass composition containing CaO and 0.5 to 2% by mass of SrO.

Embodiment 9
The glass sheet contains 58-65% by weight of SiO ₂ , 16-22% by weight of Al ₂ O ₃ , 1-5% by weight of B ₂ O ₃ , 1-4% by weight of MgO, 2-6% by weight of The substrate of embodiment 1, comprising an alkali-free glass composition comprising CaO, 1-4 wt% SrO, and 5-10 wt% BaO.

Embodiment 10
The glass sheet contains 57-61% by weight of SiO ₂ , 17-21% by weight of Al ₂ O ₃ , 5-8% by weight of B ₂ O ₃ , 1-5% by weight of MgO, 3-9% by weight of The substrate of embodiment 1, comprising an alkali-free glass composition comprising CaO, 0-6% by weight SrO, and 0-7% by weight BaO.

Embodiment 11
The glass sheet contains 55-72% by weight of SiO ₂ , 12-24% by weight of Al ₂ O ₃ , 10-18% by weight of Na ₂ O, 0-10% by weight of B ₂ O ₃ , 0-5% by weight % K ₂ O, 0-5% MgO, and 0-5% CaO, 1-5% K ₂ O, and 1-5% MgO. The substrate according to Form 1.

Embodiment 12
An electronic device comprising the substrate according to embodiment 1.

Embodiment 13
A method of manufacturing a substrate, the method comprising:
depositing a deposited layer on a glass sheet, the deposited layer extending between the glass sheet and a second major surface of the substrate, and the glass sheet extending between the deposited layer and the first major surface of the substrate. and extends in a direction substantially parallel to the first major surface, the deposited layer includes inorganic particles, and has a diameter of about 0.4 nanometers to about 50 nanometers. providing a surface roughness of the second major surface of the substrate in the range of meters;
Method.

Embodiment 14
14. The method of embodiment 13, wherein the method further comprises forming the glass sheet from molten glass.

Embodiment 15
14. The method of embodiment 13, wherein the deposited layer is deposited on the glass sheet in a dispersion.

Embodiment 16
16. The method of embodiment 15, wherein the dispersion is deposited on the glass sheet by at least one of spin coating, flow coating, or spray coating.

Embodiment 17
16. The method of embodiment 15, wherein the dispersion is subjected to a drying step after being deposited on the glass sheet.

Embodiment 18
18. The method of embodiment 17, wherein the substrate is subjected to a cleaning step after the drying step.

Embodiment 19
14. The method of embodiment 13, wherein the inorganic particles have a Brunauer-Emmett-Teller (BET) specific surface area of at least about 100 square meters per gram.

Embodiment 20
20. The method of embodiment 19, wherein the inorganic particles include at least one of aluminum oxide, aluminum hydroxide, and/or colloidal silica.

10 glass manufacturing equipment 12 glass melting furnace 14 melting vessel 16 upstream glass manufacturing equipment 18 storage bin 20 raw material delivery device 22 motor 24 raw material 28 molten glass 30 downstream glass manufacturing equipment 32 first connecting conduit 34 fining vessel 36 mixing vessel 38 Second connecting conduit 40 Delivery container 42 Formed body 44 Outlet conduit 46 Third connecting conduit 48 Forming device 50 Inlet conduit 54 Convergent forming surface 56 Bottom edge 58 Glass ribbon 62 Glass sheet 62' Substrate precursor 62'' Substrate 72 Edge roll 82 pull roll 100 glass separation device 162 first main surface 164 second main surface 166 edge surface 202 liquid dispersed deposited layer 204 deposited layer 206 second main surface 300 disperser 400 lift test device 402 electrostatic force microscope (ESFM)
404 Anodized aluminum table 406 Vacuum 408a, 408b, 408c Lift pin 410 Ion generator

Claims (13)

A substrate,
a first main surface, an opposite second main surface extending in a direction substantially parallel to the first main surface, a glass sheet, and a connection between the glass sheet and the second main surface; a deposited layer extending therebetween, the deposited layer comprising inorganic particles and providing a surface roughness of the second major surface of the substrate in the range of about 0.4 nanometers to about 50 nanometers;
substrate. The substrate of claim 1, wherein the first major surface has a surface roughness of less than about 0.5 nanometers. 2. The substrate of claim 1, wherein the inorganic particles have a Brunauer-Emmett-Teller (BET) specific surface area of at least about 100 square meters per gram. The total light transmittance per 0.5 mm thickness between the first major surface and the second major surface in a wavelength range of about 400 nanometers to about 850 nanometers is at least about 90%. The substrate according to claim 1. 2. The substrate of claim 1, wherein the second major surface has an absolute electrostatic charge (ESC) of less than about 200 volts (V). 2. The substrate of claim 1, wherein the substrate thickness between the first major surface and the second major surface is between about 0.1 millimeter and about 1 millimeter. An electronic device comprising the substrate according to any one of claims 1 to 6. A method of manufacturing a substrate, the method comprising:
depositing a deposited layer on a glass sheet, the deposited layer extending between the glass sheet and a second major surface of the substrate, and the glass sheet extending between the deposited layer and the first major surface of the substrate. and extends in a direction substantially parallel to the first major surface, the deposited layer includes inorganic particles, and has a diameter of about 0.4 nanometers to about 50 nanometers. providing a surface roughness of the second major surface of the substrate in the range of meters;
Method. 9. The method of claim 8, wherein the method further comprises forming the glass sheet from molten glass. 9. The method of claim 8, wherein the deposited layer is deposited on the glass sheet in a dispersion. 11. The method of claim 10, wherein the dispersion is subjected to a drying step after being deposited on the glass sheet. 12. The method of claim 11, wherein the substrate is subjected to a cleaning step after the drying step. 9. The method of claim 8, wherein the inorganic particles have a Brunauer-Emmett-Teller (BET) specific surface area of at least about 100 square meters per gram.

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