Pressure sensor, glass wafer, and manufacturing method

Abstract

The present invention relates to a glass article and its use in a pressure sensor. The present invention also relates to a method for producing said glass article.

Description

[Technical Field]

[0001] This invention relates to glass articles and their use in pressure sensors. The invention also relates to a method for manufacturing the glass articles. [Background technology]

[0002] As digitalization progresses, the use of intelligent and networked systems that rely on sensor data is increasing. For example, improved analytical methods using artificial intelligence enable the evaluation of large amounts of data and open up the possibility of using even small changes in measurements for automation and control. To further this development, increasingly accurate sensors are desirable. An example of such a sensor is a pressure sensor.

[0003] Pressure sensors are used in many fields, particularly for controlling machinery and industrial plants, for example in food manufacturing or the petrochemical industry. They are also used in the automotive sector, for example, to measure oil and tire pressure.

[0004] Microelectromechanical (or MEMS) pressure sensors include a thin film made of silicon that can be elastically deformed by pressure. This silicon film is typically mounted on an insulating or semiconductor material, such as a silicon base. The base includes an opening through which a fluid, such as a gas, can enter the measuring cavity of the pressure sensor. Here, pressure acts on the film from both sides, with a defined or variable reference pressure acting on one side and a variable pressure acting on the side of the film facing the measuring cavity. Some sensors operate without a reference pressure, meaning the reference pressure can be variable. If the pressures on both sides of the film are different from each other, the film is deformed. Measuring resistors are incorporated into the film, and their resistance changes when deformed (so-called piezoresistive resistors). They are electrically arranged in the form of a so-called Wheatstone bridge circuit. The deformation of the film results in a change in the voltage of the bridge circuit. This measurable change in the bridge voltage is approximately proportional to the pressure difference.

[0005] Glass articles are suitable as components for pressure sensors. An exemplary structure of such a pressure sensor is shown in Figure 1. The film deforms in response to the applied pressure. The deformation, and thus the pressure, is measured by the change in the resistance of the piezoresistive element in the film. [Overview of the project] [Problems that the invention aims to solve]

[0006] A pressure sensor with better measurement accuracy is desired. [Means for solving the problem]

[0007] Description of the present invention In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and is 2 × 2 mm 2 The mean level of damage near the surface (ONSL) in the sample is less than 2000 damages and / or 2 × 2 mm 2 The present invention relates to a glass article in which the normalized average positional thickness variation (ODS) with respect to the thickness is less than 10 nm per 1 μm of thickness, and the ODS is the difference between the highest and lowest thicknesses within a specified measurement area.

[0008] The glass articles of the present invention are suitable for use as components in pressure sensors. One function of such glass components is to thermally isolate the film used for measurement from the base material and the environment. As the desired measurement becomes more accurate, good, rapid, and above all, uniform thermal isolation becomes more important. Pressure sensors are also trending toward miniaturization. Components are becoming smaller and thinner. One advantage of glass is that it can be manufactured with good surface quality, especially at thin thicknesses. However, as pressure sensors as a whole become smaller, even small deviations can have a significant impact. For example, even the effect of certain vibration frequencies on the glass during shaping in the down-draw method can lead to thickness variations over small areas, which contribute to localized deviations in heat transfer.

[0009] During the handling and post-processing of glass articles, such as polishing, grinding, and lapping, small damage can be introduced into the glass, and it can penetrate surprisingly deep. Due to the extremely thin thickness of glass articles used in pressure sensors, even cracks a few micrometers deep can significantly affect the properties of the glass article, including heat transfer.

[0010] Thickness variations, cavities, cracks, and similar defects can impair the connection between the glass article and other components of the pressure sensor. For example, it may become more difficult to bond the components together, or more adhesive may be required to compensate for unevenness or cracks. The use of additional adhesive or inorganic frit will impair the uniformity of thermal separation.

[0011] The provision of glass articles according to the present invention can be achieved, for example, by taking specific measures in the glass forming and optionally in the surface treatment. For example, it has been proven beneficial to keep certain areas free of vibrations in the frequency range of 0.01 to 500 Hz, such as 0.05 to 400 Hz, 0.1 to 300 Hz, 0.5 to 250 Hz, 0.8 to 200 Hz, 1 to 100 Hz, 4 to 75 Hz, or 5 to 50 Hz during the drawing process. Preferably, during the drawing process, certain areas are kept free of vibrations having frequencies of at least 0.01 Hz, at least 0.05 Hz, at least 0.1 Hz, at least 0.5 Hz, at least 0.8 Hz, at least 1 Hz, at least 4 Hz, or at least 5 Hz. Preferably, during the drawing process, a specific area is kept free from vibrations having frequencies of up to 500 Hz, 400 Hz, 300 Hz, 250 Hz, 200 Hz, 100 Hz, 75 Hz, or 50 Hz. In surface treatment, it may be reasonable to follow specific parameters described herein regarding the particle size used.

[0012] In one embodiment, the present invention relates to the use of a glass article described herein as a component in a pressure sensor. For example, the glass article can be used as a component that serves to thermally separate a measuring film.

[0013] The aforementioned glass articles can be used for pressure sensors that enable higher measurement accuracy. For use in pressure sensors, the glass articles may be perforated. This solution is based on the idea that, for high measurement accuracy, the thermal separation of the silicon film of the pressure sensor from the medium being measured should be as uniform as possible. It has been found that variable positional thickness variation (ODS) and near-surface damage level (ONSL) are important for uniform thermal separation. Such glass articles can be obtained through appropriate manufacturing means.

[0014] In one embodiment, the present invention is a method for manufacturing a glass article, comprising the following steps: • The stage in which molten glass is manufactured, • The step of clarifying the aforementioned glass molten material, - A step of drawing the molten glass into a glass ribbon having a target thickness in the range of less than 3.0 mm, particularly using a drawing roll. • The step of dividing the glass ribbon into glass articles. The glass ribbon, including the above, passes through region Z, where the glass ribbon is less than 10% above the target thickness, but its viscosity is still 10 10 It is less than dPas, The glass is drawn out in region Z at a drawing speed of at least 0.5 m / min and a maximum of 50 m / min, for example, 2-10 m / min, 10-25 m / min, or 25-50 m / min, and The method relates to a method in which appropriate measures are taken to ensure that the region Z is free from interference in the frequency range of 0.01 to 500 Hz, for example, 0.05 to 400 Hz, 0.1 to 300 Hz, 0.5 to 250 Hz, 0.8 to 200 Hz, 1 to 100 Hz, 4 to 75 Hz, or 5 to 50 Hz.

[0015] The glass can be drawn out in region Z at, for example, a drawing speed of at least 0.5 m / min, at least 2 m / min, at least 10 m / min, or at least 25 m / min. It can be drawn out in region Z at, for example, a maximum drawing speed of 50 m / min, a maximum drawing speed of 25 m / min, or a maximum drawing speed of 10 m / min.

[0016] For example, suitable measures may be taken to preserve region Z so as not to be affected by interference having frequencies of at least 0.01 Hz, at least 0.05 Hz, at least 0.1 Hz, at least 0.5 Hz, at least 0.8 Hz, at least 1 Hz, at least 4 Hz, or at least 5 Hz. For example, suitable measures may be taken to preserve region Z so as not to be affected by interference having frequencies of up to 500 Hz, up to 400 Hz, up to 300 Hz, up to 250 Hz, up to 200 Hz, up to 100 Hz, up to 75 Hz, or up to 50 Hz.

[0017] In particular, frequencies above 1 Hz were found to be associated with the appearance of related positional and thickness variations. Therefore, appropriate measures should be taken to preserve region Z so as not to be affected by interference in the frequency ranges of 1-500 Hz, 2-400 Hz, 3-300 Hz, 4-250 Hz, 5-200 Hz, 10-100 Hz, 15-75 Hz, or 20-50 Hz. For example, appropriate measures can be taken to preserve region Z so as not to be affected by interference having frequencies of at least 1 Hz, at least 2 Hz, at least 3 Hz, at least 4 Hz, at least 5 Hz, at least 10 Hz, at least 15 Hz, or at least 20 Hz. For example, appropriate measures can be taken to preserve region Z so as not to be affected by interference having frequencies up to 500 Hz, up to 400 Hz, up to 300 Hz, up to 250 Hz, up to 200 Hz, up to 100 Hz, up to 75 Hz, or up to 50 Hz.

[0018] The drawing of the glass melt may particularly include down-drawing or overflow fusion. In both cases, the glass melt exits the tank and is then drawn into a glass ribbon. The viscosity of the glass melt at the point where it exits the tank is related to the occurrence of position and thickness variations. In particular, the viscosity should not be too high for the glass melt to be properly drawn. However, if the viscosity is too low, the glass ribbon becomes too long in the viscosity range that tends to generate position and thickness variations during drawing. Therefore, the viscosity of the glass melt when it exits the tank should be 10 2.20 dPas or more, 10 2.30 dPas or more, 10 2.40 dPas or more, 10 2.50 dPas or more, 10 2.60 dPas or more, 10 2.70 dPas or more, 10 2.80 dPas or more, 10 2.90 dPas or more, 10 3.00 dPas or more, 10 3.10 dPas or more, 10 3.20 dPas or more, or 10 3.30 dPas or more. The viscosity of the glass melt when it exits the tank is, for example, at most 10 4.00 dPas, at most 10 3.90 dPas, at most 10 3.80 dPas, at most 10 3.70 dPas, at most 10 3.60 dPas, or at most 10 3.50 dPas. The viscosity of the glass melt when it exits the tank is, for example, 10 2.20 dPas to 10 4.00 dPas, 10 2.30 dPas to 10 4.00 dPas, 10 2.40 dPas to 10 3.90 dPas, 10 2.50 dPas to 10 3.90 dPas, 10 2.60 dPas to 10 3.80 dPas, 10 2.70 dPas to 10 3.80 dPas, 10 2.80 dPas to 10 3.70 dPas, 102.90 dPas~10 3.70 dPas, 10 3.00 dPas~10 3.60 dPas, 10 3.10 dPas~10 3.60 dPas, 10 3.20 dPas~10 3.50 dPas, or 10 3.30 dPas~10 3.50 It can be within the dPas range.

[0019] In the down-draw process, the tank has a long, narrow nozzle from which molten glass flows downward. The point where the molten glass exits the tank is provided by the opening of the nozzle or by the end of a blade inserted into the nozzle, at which point the glass flows down. In the overflow fusion process, this point is provided by the bottom of the tank, where the glass flows collide and merge and flow downward.

[0020] A rapid increase in viscosity after exiting the tank is also advantageous. The abruptness of the viscosity increase can be influenced by the selection of the glass composition and / or by the application of a suitable cooling regime.

[0021] Detailed description of the invention The Near Surface Damage Level (ONSL) describes the degree of superficial damage to the surface of a glass article. “Damage” is a volume with an extent of at least 1.0 μm that is not filled with glass but exists within the glass article as an open or closed cavity resulting from scratches, grooves, striations, gas inclusions, delaminations, conchoidal fractures, or similar factors. The “extent” of the damage is its maximum diameter. The “extent” of the damage may also be referred to as the “length” of the damage. The “width” of the damage means the diameter of the damage in a direction perpendicular to the length of the damage. In this context, “superficial” means that the damage reaches the surface of the article at least regionally, or that they are at least regionally 1.0 μm or less below the surface. A region of the glass article's surface is considered undamaged if it contains no damage whatsoever, i.e., no damage at the surface and no damage to a depth of 1.0 μm below the surface.

[0022] ONSL can be identified as Area Coverage ONSL in percentage, where it is the area portion of the surface area under consideration that includes damage. Where ONSL is referred to in this disclosure, unless otherwise stated, ONSL is based on a specific area size, typically 2 × 2 mm, rather than area coverage percentage. 2 This refers to a numerical ONSL that defines the number of near-surface damages based on the area.

[0023] The average ONSL in a specific area is determined by identifying the number of surface-near-surface damages, particularly in several different test areas, and then calculating the average value from these. The area of ​​the area being inspected does not need to be the same as the area of ​​the area specified as the basis for ONSL. For example, if ONSL is 2 × 2 mm 2 When identified based on area, the number of damages near the surface is calculated based on an area of ​​2 × 2 mm². 2 It can be identified in a different test area. In particular, the area of ​​individual test areas and / or the total area of ​​test areas is 2 × 2 mm 2 It is possible to make it even smaller. In this embodiment of the present invention, the area of ​​each test region is, for example, at least 0.05 mm². 2 at least 0.1 mm2 , or at least 0.15 mm 2 The total area of ​​the test region is, for example, at least 0.2 mm². 2 at least 0.5 mm 2 at least 0.7 mm 2 , or at least 1.0 mm 2 This may be the case. In embodiments of the present invention, the test areas are arranged to be uniformly distributed. In particular, the individual test areas may be equally spaced from each other and / or from the edges of the glass article. For example, if four or nine test areas are to be inspected, they may be arranged in a square shape. In the case of nine test areas, naturally, the test area located in the center of the square will not have the same distance from the edges. The same distance from the edges applies especially to the outer test areas. The test areas may also be arranged in a rectangular or circular shape. The shape of the arrangement of the test areas may correspond in particular to the shape of two main sides. A substantially uniform distribution of test areas is advantageous, in particular, for identifying a representative ONSL.

[0024] ONSL can be identified using a microscope with a magnification of 40x, preferably a confocal laser scanning microscope, particularly a Zeiss LSM 800.

[0025] The calculation of the average ONSL will be explained using an example. For a glass item, the area is 2 x 2 mm. 2 It is assumed that the average ONSL should be determined based on the following. For this purpose, the number of near-surface damages can be determined in several test areas, usually 2 to 10 (e.g., 7). The area of ​​each test area is, for example, 0.1 mm². 2 ~0.2mm 2 It can be 0.1 mm each. 2 When 10 test areas with a certain area are inspected and a total of 200 surface-near-surface damages are detected overall, the average ONSL is 1 mm 2 That's 200 damages per unit, or in other words, 2 x 2 mm. 2 There are 800 damages in the area.

[0026] Alternatively or additionally to the average ONSL, the maximum level of damage near the surface (ONSL) max It is also possible to define ). For example, in the above example, if 40 near-surface damages are detected in one of the 10 test areas, and this number is the highest among all 10 test areas, then ONSL max The number of damages and ONSL max It can be calculated as the product of the quotient between the area content of the area area to be based on and the area content of the test area. Therefore, in this example, it is as follows:

number

[0027] ONSL should be distinguished from surface roughness. Surface roughness essentially describes smaller structures on the surface, their extent significantly less than 1.0 μm. Exemplary roughness is typically less than 5 nm for polished / treated glass and even lower for thermoformed surfaces. Glass articles, for example, particularly 2 × 2 mm 2 or 5 x 5 mm 2 In the area, particularly preferably on the entire surface of one or both main sides of the glass article, the roughness R of less than 2 nm is a It may have.

[0028] In particular, 2 x 2 mm 2 An average of less than 2000 ONSLs in the area is favorable, for example, a maximum of 1500, 1250, 1000, 750, 500, 400, 300, 200, 150, 125, 100, 90, 80, 70, 60, or 50 damages. 2×2mm 2 The average ONSL in the area may be, for example, at least 1, at least 2, at least 5, at least 10, or at least 20 damages.

[0029] In particular, 2 x 2 mm 2 ONSL in the area maxIt is advantageous to have up to 4000 damages, for example, up to 3000, 2500, 2000, 1500, 1000, 800, 600, 400, 300, 250, 200, 180, 160, 140, 120, or up to 100 damages. 2×2mm 2 ONSL in the area max For example, these may be at least 2, at least 4, at least 10, at least 20, or at least 40 damages.

[0030] The glass article has a thin thickness of less than 3.0 mm. In a preferred embodiment, it is even more remarkably thin, where in particular the article may have a thickness of less than 2.0 mm, less than 1.0 mm, or less than 500 μm. In a particular embodiment, the article may have a thickness of less than 350 μm, less than 250 μm, less than 150 μm, less than 100 μm, or even less than 50 μm. In particular, thin glass articles have the advantage that (apart from the reduction in thickness as a contribution to miniaturization) they contribute only slightly to the weight of the pressure sensor. Low weight is important, especially in the automotive field or in portable electronic devices. However, very thin glass is also more difficult to handle. For example, with very thin glass, damage can occur very easily, and the effort based on the equipment required to handle very thin glass is great. In some embodiments, the thickness of the glass article is greater than 5.0 μm, preferably even greater than 10.0 μm, or greater than 20.0 μm. A particularly preferred glass article of the present invention has a thickness greater than 250 μm, for example, at least 300 μm, at least 350 μm, at least 400 μm, at least 450 μm, or at least 500 μm. The thickness may be in the range of >250 μm to <3.0 mm, 300 μm to 2.75 mm, 350 μm to 2.5 mm, 400 μm to 2.25 mm, 450 μm to 2.0 mm, or 500 μm to 1.5 mm. The thickness may be, for example, up to 2.75 mm, up to 2.5 mm, up to 2.25 mm, up to 2.0 mm, up to 1.5 mm, or up to 1.0 mm.

[0031] Therefore, the glass article is preferably a flat article in the form of a plate, disk, wafer, sheet or the like. The article has two main sides that have the longest extent compared to the other sides of the article. The shortest distance between these two sides corresponds to the thickness of the glass article. The two main sides are particularly parallel planes.

[0032] Preferably, the ONSL described herein corresponds to areas on at least both main sides of the glass article. Where the ONSL is specified herein for an area of ​​the glass article, this value preferably also corresponds to a corresponding area on the opposite main side of the glass article.

[0033] Portable technical devices are becoming increasingly smaller, requiring the highest possible packing or integration density. The same applies to automobiles, where the available space for pressure sensor modules and systems is shrinking (e.g., in-valve pressure sensors for measuring tire pressure). These trends are driving development toward smaller components, which also applies to pressure sensors. To achieve high measurement accuracy, the quality of the glass article must be achieved in an area sufficient for manufacturing the pressure sensor, particularly with respect to ONSL and / or ODS. Preferably, this area is 2 × 2 mm². 2 The above, especially 4x4mm 2 For example, 5 x 5 mm 2 That's all.

[0034] The glass articles themselves can be significantly larger. Typically, glass articles are at least 100 mm. 2 , at least 200mm 2 , at least 400mm 2 , at least 600mm 2 , at least 800mm 2 , at least 2000mm 2 (Especially in diameter of 2 inches (approximately 50 mm)), at least 4400 mm 2 (especially in diameter of 3 inches (approximately 75 mm)), and / or at least 74,000 mm2 (It may have a size of particularly 12 inches (about 300 mm) in diameter). From such a large glass article, for example, by cutting out (dicing) components from the glass article with a saw, a number of components for manufacturing a pressure sensor can be manufactured. Larger or smaller sheets or wafers than those mentioned above can also be used. The glass article may have a round or angled bottom surface.

[0035] In a preferred embodiment, the glass article is at least 100 mm 2 , for example at least 200 mm 2 , at least 400 mm 2 , at least 600 mm 2 , at least 800 mm 2 , at least 2000 mm 2 (particularly 2 inches (about 50 mm) in diameter), at least 4400 mm 2 (particularly 3 inches (about 75 mm) in diameter), and / or at least 74000 mm 2 (particularly 12 inches (about 300 mm) in diameter). The "size" of the glass article particularly means the area content of one of both main surfaces of the glass article. In particular, both main surfaces of the glass article have the same area content.

[0036] <000042​​​​is substantially filled at approximately 100% of the total area of each of the two major surfaces, particularly of each of the two major surfaces. In one embodiment, the ODS normalized with respect to thickness avg the ODS max and / or the ODS is substantially filled over the entire area of the glass article, particularly at 100% of said area.

[0037] Position - thickness variation (ODS) describes the difference between the highest thickness a measured within the area region of the glass article and the lowest thickness b measured. The following applies: ODS i = a i - b i where i = 1, 2,..., n (n = the number of area regions of the glass article). The maximum position - thickness variation (ODS max ) of the glass article is the highest ODS i value of this glass article. The minimum position - thickness variation (ODS min ) of the glass article is the lowest ODS i value of this glass article. The average position - thickness variation (ODS avg ) of the glass article is the average value of the ODS i values of this glass article. In the present disclosure, ODS avg is often abbreviated and referred to as ODS. When referred to as ODS in the present disclosure, unless otherwise specified, ODS avg is meant.

[0038] For the measurement, for example, an interferometer, particularly a Precitec Sensor Interferometric - K interferometer, can be used. The sampling rate can particularly be 4 kHz. The scanning speed can particularly be 500 mm / second. The interval between measurement points can particularly be 0.125 mm.

[0039] The ODS can be normalized with respect to thickness and thus determined based on the average thickness of the area under consideration, or the average thickness of the glass article, or the nominal thickness of the glass article. The difference between the average thickness of the glass article and the nominal thickness of the glass article is usually negligible. Therefore, the nominal thickness is a good measure of the average thickness of the glass article and is preferably used for thickness normalization.

[0040] In particular, ODS normalized with respect to thickness, with a density of less than 10 nm per 1 μm of glass article thickness, is advantageous. A preferred ODS normalized with respect to thickness, with a density of less than 10 nm per 1 μm of glass article thickness, is 2 × 2 mm. 2 The above area, especially 4 x 4 mm 2 The above area, or even 5 x 5 mm 2 This is achieved in the above area. Preferably, 2 × 2 mm 2 The normalized ODS for the thickness in the area is less than 5 nm / μm or less than 2 nm / μm. More preferably, 5 × 5 mm 2 The ODS normalized to thickness in the area is less than 5 nm / μm or less than 2 nm / μm. Depending on the manufacturing method, a specific ODS normalized to thickness cannot always be avoided, so in one embodiment, the glass article, particularly in the 2 × 2 mm area, is... 2 For example, 5 x 5 mm 2 In the area region, the ODS normalized to the thickness may be 0.001 nm / μm or more, for example, at least 0.01 nm / μm, or at least 0.05 nm / μm. For example, the present invention is 2 × 2 mm 2 The present invention relates to a glass article having an ODS normalized to thickness in the range of 0.001 to 10 nm / μm, 0.01 to 5 nm / μm, or 0.05 to 2 nm / μm in an area region. 2 The same applies to glass articles having an ODS normalized to thickness in the area range of 0.001 to 10 nm / μm, 0.01 to 5 nm / μm, or 0.05 to 2 nm / μm.

[0041] ODS can also be specified without normalizing to thickness. In this case, the unit "μm" is used, not "nm / μm" as in the case of ODS normalized to thickness. If normalization to thickness is not mentioned, it usually means ODS that is not normalized to thickness.

[0042] In one embodiment, the ODS is 2 x 2 mm 2 In the area, the ODS is less than 10 μm, particularly less than 5 μm, or less than 2 μm. In one embodiment, the ODS is 5 × 5 mm 2 The area is less than 10 μm, particularly less than 5 μm, or less than 2 μm. Depending on the manufacturing method, certain ODS cannot always be avoided, so in one embodiment, the glass article is particularly 2 × 2 mm 2 For example, 5 x 5 mm 2 In the area, the ODS may be 0.001 μm or larger, for example 0.01 μm or larger, and particularly at least 0.05 μm. For example, the present invention is 2 × 2 mm 2 The present invention relates to glass articles having ODS in the range of 0.001 to 10 μm, 0.01 to 5 μm, or 0.05 to 2 μm in an area. 2 This also applies to glass articles having ODS in the range of 0.001 to 10 μm, 0.01 to 5 μm, or 0.05 to 2 μm within the area.

[0043] In one embodiment, the maximum positional thickness variation (ODS) is shown. max ) is 2 x 2 mm 2 In the area, the area is less than 50 μm, particularly less than 25 μm, or less than 10 μm. In one embodiment, the ODS is 5 × 5 mm 2 The area is less than 50 μm, particularly less than 25 μm, or less than 10 μm. Depending on the manufacturing method, certain ODS cannot always be avoided, so in one embodiment, the glass article is particularly 2 × 2 mm 2 For example, 5 x 5 mm 2 In the area, ODS of 0.005 μm or larger, for example 0.05 μm or larger, and especially at least 0.25 μm maxIt may have. For example, the present invention is 2 × 2 mm 2 ODS in the area range of 0.005 to 50 μm, 0.05 to 25 μm, or 0.25 to 10 μm max The present invention relates to glass articles having 5 x 5 mm 2 ODS in the area range of 0.005 to 50 μm, 0.05 to 25 μm, or 0.25 to 10 μm max This also relates to glass articles having [a certain characteristic].

[0044] The aforementioned glass article should enable good, rapid, and above all, uniform thermal separation between the semiconductor and the medium to be measured in the pressure sensor. 2×2mm 2 Uniform thermal separation is achieved when the glass article over the above area exhibits a variation in thermal conductivity of 0.2 W / (m·K) or less, particularly at room temperature, and therefore at temperatures in the range of 20°C to 25°C, for example at 22°C, with a maximum of 0.15 W / (m·K), a maximum of 0.1 W / (m·K), a maximum of 0.05 W / (m·K), a maximum of 0.02 W / (m·K), or a maximum of 0.01 W / (m·K). Preferably, this value applies to the entire glass article. In this regard, “variation” means the maximum difference in thermal conductivity, and therefore the difference between the highest and lowest thermal conductivity over the corresponding area. In some embodiments, the variation in thermal conductivity may be, for example, at least 0.0001 W / (m·K), or at least 0.001 W / (m·K), particularly at room temperature, and therefore at temperatures in the range of 20°C to 25°C, for example at 22°C. The thermal conductivity can be measured, for example, using the so-called laser flash method. Here, the method conforms to ASTM E1461, and the specific heat capacity (C) is calculated from the measured thermal diffusivity α. p Calculate the thermal conductivity (λ) using the density (ρ):

number

[0045] It is also possible to determine the thermal conductivity of a glass object at a specific location through calculation. At an undamaged location, the effective thermal conductivity λ effThis corresponds to the thermal conductivity λ of the glass. At the location where heat conduction occurs through damage, the effective thermal conductivity can be calculated according to the following equation (2):

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[0046] In equation (2), λ ガラス λ is the thermal conductivity of glass. 空気 λ is the thermal conductivity of air, d is the thickness of the glass article, and Δx is the extent of damage in the direction of heat conduction. In particular, heat conduction occurs from one main surface of the glass article, perpendicularly through the glass article to the other main surface of the glass article. Conductivity λ 空気 λ is a suitable parameter for heat conduction through damage, because damage is a volume not filled with glass. At approximately room temperature, λ 空気 The thermal conductivity is approximately 0.0262 W / (m·K), which is therefore significantly different from the typical thermal conductivity of glass, which is approximately 1.0 W / (m·K) at a given temperature. According to equation (2), if the thickness d of the glass article is 500 μm, damage with a spread of Δx = 1 μm in the direction of heat conduction will already result in a decrease in thermal conductivity of approximately 7%.

[0047] Temperature range 20℃ to 300℃, 2.5 to 11 × 10 -6 / K, especially 3.0~9.5×10 -6 It has been shown to be advantageous when glass articles with a mean coefficient of thermal expansion (CTE) in the range of / K are used. The CTE is specified in accordance with DIN ISO 7991:1987.

[0048] Preferably, the glass article is 1 mm 3 Contains several gaseous inclusions with a value of less than 1.0 per unit.

[0049] Viscosity and temperature profiles The present invention is not limited to the fact that only glasses having a specific viscosity-temperature profile are suitable for the glass articles of the present invention. However, it has been shown that a specific viscosity-temperature profile is advantageous. Particularly for economical manufacturing, glasses that can be manufactured well by a draw method, such as a down-draw method or an overflow fusion method, are preferred, and therefore particularly, a liquidus viscosity (above which crystals can be formed) of 10 3 dPas or higher, preferably 10 3.5 Above dPas, especially preferably 10 4 Glass can be formed that has a value exceeding dPas.

[0050] In the down-draw process of overflow fusion, it is particularly advantageous for the glass to have a viscosity-temperature profile such that the viscosity is relatively high at the temperature when the molten glass exits the bath, in order to reduce positional and thickness variations. Furthermore, it is advantageous for the glass to have a viscosity-temperature profile such that the increase in viscosity with decreasing temperature is relatively rapid. Any of the above means, individually or in combination, substantially reduces the likelihood of substantial positional and thickness variations occurring in the glass.

[0051] Typically, the Vogel-Fulcher-Tammann (VFT) formula is used to calculate the temperature required to achieve a specific viscosity of glass (see also DIN ISO 7884-2:1998-2):

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[0052] In the VFT equation, η is viscosity, A and B are temperature-independent material parameters, T is temperature, and T0 is the Vogel temperature. For a given glass, A, B, and T0 are constant.

[0053] Preferably, the glass has a value of at least 3500K, at least 4000K, or at least 4500K for B. In a particularly preferred embodiment, the glass has a value of at least 5000K, at least 5500K, or at least 6000K for B. Preferably, B is up to 12000K, up to 11000K, up to 10500K, up to 10000K, up to 9500K, or up to 9000K. Parameter B may be in the range of, for example, 3500-12000K, 4000-11000K, 4500-10500K, 5000-10000K, 5500-9500K, or 6000-9000K.

[0054] T0 is preferably at least 25°C, at least 50°C, at least 75°C, at least 100°C, or at least 120°C. Preferably, T0 is up to 300°C, up to 275°C, up to 250°C, up to 225°C, or up to 215°C. T0 may be in the range of, for example, 25°C to 300°C, 50°C to 275°C, 75°C to 250°C, 100°C to 225°C, or 120°C to 215°C.

[0055] The value for A is preferably less than 0, less than -0.5, less than -0.75, less than -1.0, or less than -1.5. The value for A is preferably at least -5.5, at least -5.0, or at least -4.5. The value for A may be in the range of, for example, -5.5~<0, -5.5~<-0.5, -5.0~<-0.75, -4.5~<-1.0, or -4.5~<-1.5.

[0056] Glasses having these VFT constants can be manufactured particularly well using drawing methods, such as the down-draw method or the overflow fusion method.

[0057] Particularly preferably, the glass has the following VFT constants: A is in the range of -5.5 to <0.0, B is in the range of 3500 to 12000K, and / or T0 is in the range of 25°C to 300°C. Even more preferably, the glass has the following VFT constants: A is in the range of -5.0 to <-0.75, B is in the range of 4000 to 10000K, and / or T0 is in the range of 75°C to 270°C. Even more preferably, the glass has the following VFT constants: A is in the range of -4.5 to <-1.5, B is in the range of 4500 to 9000K, and / or T0 is in the range of 120°C to 250°C. Even more preferably, the glass has the following VFT constants: A is in the range of -4.5 to less than -1.5, B is in the range of 5000 to 10000K, and / or T0 is in the range of 100°C to 225°C. This is particularly advantageous for achieving a rapid increase in viscosity with decreasing temperature, thus reducing the likelihood of substantial positional and thickness variations.

[0058] The viscosity of the glass molten material at the point where it exits the tank is also relevant. This viscosity is determined by two independent factors: on the one hand, the temperature at which the glass molten material exits the tank, and on the other hand, the glass composition. The first factor is a process parameter that a person skilled in the art can appropriately select. For example, if the viscosity of the glass molten material at the relevant point is too low, a person skilled in the art can increase the viscosity by selecting a lower temperature. However, this is reasonably done only within certain limitations. Therefore, it is advantageous if the glass has a composition such that the viscosity at the relevant temperature is relatively high. In particular, if the glass has a viscosity η10 at T=1400℃ according to the VFT formula... 2.20 dPas or higher, 10 2.30 dPas or higher, 10 2.40 dPas or higher, 10 2.50 dPas or higher, 10 2.60 dPas or higher, 10 2.70 dPas or higher, 10 2.80 dPas or higher, 10 2.90 dPas or higher, 10 3.00 dPas or higher, 10 3.10 dPas or higher, 10 3.20dPas or higher, or 10 3.30 Having a viscosity of dPas or higher is advantageous. The viscosity η at T=1400℃ according to the VFT formula is, for example, up to 10 4.00 dPas, up to 10 3.90 dPas, up to 10 3.80 dPas, up to 10 3.70 dPas, up to 10 3.60 dPas, or up to 10 3.50 It may be dPas. The viscosity η at T=1400℃ according to the VFT formula is, for example, 10 2.20 dPas~10 4.00 dPas, 10 2.30 dPas~10 4.00 dPas, 10 2.40 dPas~10 3.90 dPas, 10 2.50 dPas~10 3.90 dPas, 10 2.60 dPas~10 3.80 dPas, 10 2.70 dPas~10 3.80 dPas, 10 2.80 dPas~10 3.70 dPas, 10 2.90 dPas~10 3.70 dPas, 10 3.00 dPas~10 3.60 dPas, 10 3.10 dPas~10 3.60 dPas, 10 3.20 dPas~10 3.50 dPas, or 10 3.30 dPas~10 3.50 It can be within the dPas range.

[0059] In light of the VFT equation shown above, it can be seen that increases in A, B, and / or T0 are associated with increases in viscosity η at a given temperature T. However, increases in the values ​​of A and / or B are also associated with less abrupt viscosity changes in the relevant temperature range.

[0060] Therefore, it is advantageous when the glass components are selected in a balanced manner to obtain a desired viscosity-temperature profile. For example, to obtain an optimized viscosity-temperature profile, components that decrease a particular VFT constant are preferably balanced by components that increase each VFT constant or one of two other VFT constants, and vice versa.

[0061] The choice of glass components affects the temperature dependence of the refractive index. For example, the addition of SiO2 decreases the value A in the VFT equation and increases the values ​​B and T0. The following table summarizes the effects of glass components on the VFT constants, where "+" indicates an increasing effect, and "++" means that the value of the constant mentioned above is strongly increased. "-" indicates a decreasing effect, and "--" means that the value of the constant under consideration is strongly decreased by the increase in the amount of glass component.

[0062] [Table 1]

[0063] Preferred glass composition The composition of the glass articles is not limited to a specific type of glass. However, for economical manufacturing in particular, glass that can be well manufactured by a draw method, such as a down-draw or overflow fusion method, is preferred. In one embodiment, the glass is a silicate glass, particularly borosilicate glass or aluminosilicate glass. Furthermore, keeping the glass composition within certain limitations can be particularly advantageous for optimizing the viscosity-temperature profile to reduce the likelihood of variability in the position and thickness of the glass. This is especially true for glass that has a relatively high viscosity at the point of leaving the vat and / or a rapid increase in viscosity with decreasing temperature.

[0064] With the help of the glass composition, for example, the thermal conductivity (W / (m·K)) and, consequently, the heat transfer coefficient (W / (m 2K)) can also be affected. Certain oxides, such as SiO2, Al2O3, B2O3, MgO, CaO, SrO, BaO, or K2O, are associated with an increase in thermal conductivity. Other oxides, such as TiO2, Li2O, or Na2O, are associated with a decrease in thermal conductivity.

[0065] In this disclosure, the sum of alkali metal oxides, particularly the sum of Li2O + Na2O + K2O, is also referred to as "R2O". Similarly, the sum of MgO + CaO + SrO + BaO + ZnO is also referred to as "RO".

[0066] In one embodiment, the glass contains at least 60.0 mol% of SiO2. Optionally, the SiO2 content can be up to 87.0 mol% or up to 85.0 mol%. Silicon dioxide substantially contributes to the glass's resistance. However, it increases the glass's processing temperature, thus reducing the economics of production. In one embodiment, the glass contains at least 67.0 mol%, or at least 75.0 mol%, more preferably at least 77.5 mol%, and more preferably at least 80.0 mol% of SiO2.

[0067] In some embodiments, the optional component in the glass is B2O3.

[0068] For example, the glass may contain the following components in proportions specified in mole percent: [Table 2]

[0069] Glass articles containing the following components in mass% or manufactured from such glass are particularly preferred to provide glass articles that can be manufactured in the embodiments and / or by the methods thereof: Composition range 1: SiO260~65 B2O36~10.5 Al2O3 14~25 MgO 0~3 CaO 0-9 BaO 3~8 ZnO 0~2, The following applies here: The total content of MgO, CaO, and BaO is in the range of 8 to 18% by mass.

[0070] Composition range 2: SiO260~85 B2O35~20 Al2O3 2~15 Na2O 3~15 K2O 3-15 ZnO 0~12 TiO2 0.5~10 CaO 0-0.1.

[0071] Composition range 3: SiO275~85 B2O38~15 Al2O3 2~4.5 Na2O 1.5~5.5 K2O 0-2.

[0072] Composition range 4: SiO2 20-70, preferably 50-60, particularly preferably 52-58 B2O3 0.5-14, preferably 2-12, particularly preferably 2-4 Al2O3 15-41, preferably 16-24, particularly preferably 18-23 MgO 0.5-15, preferably 2-12, particularly preferably 3-5 CaO 0-5, preferably 0-3 BaO 0-7, preferably 0-6 ZnO 0-20, preferably 2-12, particularly preferably 8-10 Na2O 0-7, preferably 1-6, particularly preferably 3-5

[0073] Composition range 5: SiO250~81 B2O30~5 Al2O30~5 R2O 5~28 RO 5~25 TiO2 + ZrO20~6 P2O50~2.

[0074] Composition range 6: SiO252~66 B2O30~8 Al2O3 15~25 R2O 4~30 RO 0~6 TiO2 + CeO2 0~2.5 ZrO20 ~2.5.

[0075] Within the entire composition range described above, there are small amounts of components and / or trace components, for example, in the form of colorants and / or clarifying agents, such as SnO2, CeO2, As2O3, Cl - F - It may also contain sulfates.

[0076] In general, it may be advantageous if the glass has a form that is anodically bondable (or joinable), not limited to the embodiments described herein. For this purpose, it may be advantageous if the glass contains a certain proportion of alkali and / or alkali oxides, particularly sodium and / or sodium oxides. In such embodiments, the Na2O content should be at least 0.5% by mass, but preferably not exceeding 6% by mass.

[0077] Furthermore, the average coefficient of thermal expansion is relevant when using glass as a pressure sensor. In the temperature range of 20°C to 300°C, it is 2.5 to 11 × 10⁻⁶. -6 / K, especially 3.0~9.5×10 -6 It has been shown to be advantageous to use glass articles having a mean coefficient of thermal expansion (CTE) in the range of / K. The CTE is specified in accordance with DIN ISO 7991:1987. In certain embodiments of the present invention, this is in the range of 3.1 to 3.3 ppm / K, which corresponds to the coefficient of expansion of silicon.

[0078] In the best case, across all temperatures in the temperature range of 20 to 400°C, the relative change over length ΔL / L is similar to the change in silicon, and in the best case, it coincides.

[0079] Manufacturing method The glass articles of the present invention can be manufactured, for example, by a drawing method. Exemplary drawing methods include downdraw, overflow fusion, and redraw. Downdraw and / or overflow fusion are particularly preferred.

[0080] Depending on the surface quality, post-treatment may be required. Typical post-treatment steps include polishing, grinding, and lapping. Grinding and optionally subsequent polishing are particularly advantageous. Grinding with bonded abrasive grains, especially diamond abrasives, is particularly preferred.

[0081] Typically, drawing methods yield glass articles already characterized by a very good level of near-surface damage. However, without more targeted methods, drawn glass can have a high ODS. Glass articles manufactured as ingots by casting methods, rather than drawing methods, and subsequently sawn and polished, often have a very low ODS but a high degree of near-surface damage. The method according to the present invention provides glass characterized by both low ODS and low ONSL, and therefore particularly well-suited as a component in pressure sensors. The method described below can be performed in a continuous manner, and is therefore also advantageous from an economic standpoint.

[0082] In one embodiment, the present invention is a method for manufacturing a glass article, comprising the following steps: • The stage in which molten glass is manufactured, • The step of clarifying the aforementioned glass molten material, - A step of drawing the molten glass into a glass ribbon having a target thickness in the range of less than 3.0 mm, particularly using a drawing roll. • The step of dividing the glass ribbon into glass articles. The glass ribbon passes through region Z, where it has already reached the target thickness, but its viscosity is still 10. 10 It is less than dPas, The glass is drawn out in region Z at a drawing speed of at least 0.5 m / min and a maximum of 50 m / min, for example, 2-10 m / min, 10-25 m / min, or 25-50 m / min, and The method relates to a method in which appropriate measures are taken to ensure that the region Z is free from interference in the frequency range of 0.01 to 500 Hz, for example, 0.05 to 400 Hz, 0.1 to 300 Hz, 0.5 to 250 Hz, 0.8 to 200 Hz, 1 to 100 Hz, 4 to 75 Hz, or 5 to 50 Hz.

[0083] In particular, frequencies above 1 Hz were found to be associated with the appearance of related positional and thickness variations. Therefore, appropriate measures should be taken to preserve region Z so as not to be affected by interference in the frequency ranges of 1-500 Hz, 2-400 Hz, 3-300 Hz, 4-250 Hz, 5-200 Hz, 10-100 Hz, 15-75 Hz, or 20-50 Hz. For example, appropriate measures can be taken to preserve region Z so as not to be affected by interference having frequencies of at least 1 Hz, at least 2 Hz, at least 3 Hz, at least 4 Hz, at least 5 Hz, at least 10 Hz, at least 15 Hz, or at least 20 Hz. For example, appropriate measures can be taken to preserve region Z so as not to be affected by interference having frequencies up to 500 Hz, up to 400 Hz, up to 300 Hz, up to 250 Hz, up to 200 Hz, up to 100 Hz, up to 75 Hz, or up to 50 Hz.

[0084] The interference effects in the aforementioned frequency range can be achieved, for example, by the drawing equipment and / or the acoustic housing in region Z. Optionally, the interference effects in the equipment can already be minimized by adjusting the distance of the drawing rolls (particularly in the drawing direction).

[0085] In this way, the natural vibrations of the glass can be suppressed. The natural vibrations of the glass occur particularly at the natural frequency EF and its multiples (frequency f = n × EF). These natural vibrations can be suppressed by appropriately arranging the drawing rolls or rollers. For example, by arranging a second drawing roll between a first drawing roll and the HFG zone (hot forming zone), such that the distance of the second drawing roll relative to the first drawing roll is less than 1 / n of the distance of the first drawing roll relative to the HFG zone, natural vibrations with n × EF can be suppressed.

[0086] The relevant natural frequencies can be evaluated, for example, if the glass ribbon is considered as a string, according to the following formula:

number

[0087] L is the length of the string, Ψ is the tension, and μ is the mass coverage. If the glass ribbon is considered as a two-dimensional object (a membrane instead of a string), further natural frequencies can be identified.

[0088] To minimize the effects of interference, isolation of vibrations can be provided, particularly in the range of 0.01 to 500 Hz, for example, 0.05 to 400 Hz, 0.1 to 300 Hz, 0.5 to 250 Hz, 0.8 to 200 Hz, 1 to 100 Hz, 4 to 75 Hz, or 5 to 50 Hz, or in the frequency range of 1 to 500 Hz, 2 to 400 Hz, 3 to 300 Hz, 4 to 250 Hz, 5 to 200 Hz, 10 to 100 Hz, 15 to 75 Hz, or 20 to 50 Hz.

[0089] It is advantageous to exclude a specific frequency range and / or to create detuning with respect to the natural frequencies.

[0090] It is also advantageous to mitigate convection in the cooling region to prevent the glass from vibrating. This can be achieved, for example, with the help of panels (shielding of the pressure cascade). Sealing, particularly hermetic sealing, may also be provided.

[0091] Furthermore, if the drawing equipment and the molding process are separated, vibration can be avoided. Therefore, it is possible to prevent vibration from being transmitted to the molding process.

[0092] The drawing of molten glass can include downdraw or overflow fusion. In both cases, the molten glass exits the tank and is then drawn into a glass ribbon. The viscosity of the molten glass at the point where it exits the tank is particularly relevant to the appearance of positional and thickness variations. In particular, for the molten glass to be properly drawn, the viscosity must be 10 4 It must be less than dPa. However, if the viscosity is too low, the glass ribbon will become too long in the viscosity range that makes it easy for positional and thickness variations to occur during drawing. Therefore, the viscosity of the glass molten material at the point where it exits the tank should be 10 2.20 dPas or higher, 10 2.30 dPas or higher, 10 2.40 dPas or higher, 10 2.50 dPas or higher, 10 2.60 dPas or higher, 10 2.70 dPas or higher, 10 2.80 dPas or higher, 10 2.90 dPas or higher, 10 3.00 dPas or higher, 10 3.10 dPas or higher, 10 3.20 dPas or higher, or 10 3.30 It should be greater than or equal to dPas. The viscosity of the molten glass at the point where it exits the tank should be, for example, a maximum of 10 4.00 dPas, up to 10 3.90 dPas, up to 10 3.80 dPas, up to 10 3.70 dPas, up to 10 3.60 dPas, or up to 10 3.50 It may be dPas. The viscosity of the molten glass at the point where it exits the tank is, for example, 10 2.20 dPas~10 4.00 dPas, 10 2.30 dPas~10 4.00 dPas, 10 2.40 dPas~10 3.90 dPas, 10 2.50dPas~10 3.90 dPas, 10 2.60 dPas~10 3.80 dPas, 10 2.70 dPas~10 3.80 dPas, 10 2.80 dPas~10 3.70 dPas, 10 2.90 dPas~10 3.70 dPas, 10 3.00 dPas~10 3.60 dPas, 10 3.10 dPas~10 3.60 dPas, 10 3.20 dPas~10 3.50 dPas, or 10 3.30 dPas~10 3.50 It can be within the dPas range.

[0093] The viscosity of the glass molten material at the point of exiting the tank is determined primarily by two independent factors: firstly, the temperature at which the glass molten material exits the tank, and secondly, the glass composition. The first factor is a process parameter that a person skilled in the art can appropriately select. For example, if the viscosity of the glass molten material at the relevant point is too low, a person skilled in the art can increase the viscosity by selecting a lower temperature.

[0094] A rapid increase in viscosity after exiting the tank is also advantageous. The abruptness of the viscosity increase can be influenced by the selection of the glass composition and / or by the application of a suitable cooling regime.

[0095] advantageous mechanism In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2 The present invention relates to a glass article wherein the mean level of damage near the surface (ONSL) is less than 2000 damages having an extent of at least 1.0 μm.

[0096] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2The present invention relates to a glass article in which the normalized average positional-thickness variation (ODS) with respect to the thickness is less than 10 nm per 1 μm of thickness.

[0097] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, wherein the ODS is 2 × 2 mm 2 or 5 x 5 mm 2 The glass article relates to a glass article whose area is less than 10 μm.

[0098] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and ONSL max 2 x 2 mm 2 The glass articles relating to a maximum of 4,000 pieces in the area.

[0099] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, wherein the maximum positional thickness variation (ODS) is less than 3.0 mm. max ) is 2 x 2 mm 2 or 5 x 5 mm 2 This relates to the glass article having a surface area of ​​less than 50 μm.

[0100] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm and having a thermal conductivity variation of 2 × 2 mm 2 The glass article relates to a glass article having a temperature of 0.2 W / (m·K) or less over its area.

[0101] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm and having a viscosity-temperature profile characterized by the following VFT parameters: A is in the range of -5.5 to <0.0, B is in the range of 3500 to 12000 K, and / or T0 is in the range of 25°C to 300°C.

[0102] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2The mean near-surface damage level (ONSL) in the sample is less than 2000 damages with an extent of at least 1.0 μm, and the ODS is 2 × 2 mm. 2 The glass article relates to a glass article whose area is less than 10 μm.

[0103] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2 The mean level of damage near the surface (ONSL) is less than 2000 damages with an extent of at least 1.0 μm, and the maximum positional and thickness variation (ODS) is low. max ) but 2 x 2 mm 2 This relates to the glass article having a surface area of ​​less than 50 μm.

[0104] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2 The mean level of damage near the surface (ONSL) is less than 2000 damages with an extent of at least 1.0 μm, and the variation in thermal conductivity is 2 × 2 mm. 2 The glass article relates to a glass article having a temperature of 0.2 W / (m·K) or less over its area.

[0105] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2 The present invention relates to a glass article having a viscosity-temperature profile characterized in that the mean damage level near the surface (ONSL) is less than 2000 damages having an extent of at least 1.0 μm, and the following VFT parameters: A is in the range of -5.5 to <0.0, B is in the range of 3500 to 12000K, and / or T0 is in the range of 25°C to 300°C.

[0106] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2 The normalized average position-thickness variation (ODS) for thickness is less than 10 nm per 1 μm of thickness, and ONSL max However, 2 x 2 mm2 The glass articles relating to a maximum of 4,000 pieces in the area.

[0107] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2 The normalized average positional thickness variation (ODS) for thickness is less than 10 nm per 1 μm of thickness, and the variation in thermal conductivity is 2 × 2 mm. 2 The glass article relates to a glass article having a temperature of 0.2 W / (m·K) or less over its area.

[0108] In one embodiment, the present invention relates to a glass article having a thickness of less than 3.0 mm, and 2 × 2 mm 2 The present invention relates to a glass article having a viscosity-temperature profile characterized in that the normalized mean position-thickness variation (ODS) with respect to the thickness is less than 10 nm per 1 μm of thickness, and the following VFT parameters: A is in the range of -5.5 to <0.0, B is in the range of 3500 to 12000 K, and / or T0 is in the range of 25°C to 300°C. [Brief explanation of the drawing]

[0109] [Figure 1] This is a diagram illustrating an example of a pressure sensor. [Figure 2] This diagram shows damage near the surface in a side view. [Figure 3] This figure shows an exemplary image of the sample according to Example 1. [Figure 4A] This is a box plot of the ODSi distribution normalized with respect to the nominal thickness d for a glass article manufactured using the downdraw method, for an area (2×2) mm2. [Figure 4B] This is a box plot of the ODSi distribution normalized with respect to the nominal thickness d for a glass article manufactured using the downdraw method, for an area (5×5) mm2. [Examples]

[0110] The present invention will now be described in more detail using the following examples.

[0111] 1. Example 1 Glass articles were subjected to various post-processing stages. Example 1A was post-processed by lapping and polishing. Example 1B was post-processed by grinding and polishing. In detail, the post-processing protocols were as follows.

[0112] [Table 3]

[0113] In Examples 1A and 1B, the same polishing step was performed. The only difference between the two examples is that Example 1A was subjected to the lapping process described above, while Example 1B was subjected to the grinding process described above.

[0114] The effects of different post-treatment stages on the near-surface damage level (ONSL) were observed under a 40x magnification microscope (Zeiss LSM 800) with 65% illumination at 120V. Exemplary images are shown in Figure 3. Each black dot was interpreted as a single damage point. To avoid counting errors due to surface contamination, the sample surface was cleaned before microscopic evaluation.

[0115] The results are summarized in the table below, where ONSL represents the average number of surface-near-surface damages in a specified area. For each of Examples 1A and 1B, seven samples were examined.

[0116] [Table 4]

[0117] Comparing Examples 1A and 1B, it is shown that grinding achieves better results (lower ONSL) compared to lapping.

[0118] The nominal thicknesses of Examples 1A and 1B after appropriate post-processing were in the range of approximately 400 μm to 450 μm, respectively. In the method described in Example 2, 2 × 2 mm 2 and 5×5mm 2 For the area, the location-thickness variation (ODS) was identified. No difference in the correlation of ODS values ​​was observed between Example 1A and Example 1B.

[0119] 2 x 2 mm 2 For the area zone, the individual ODS of Example 1A and 1B i The average positional and thickness variation (ODS) is identified as the arithmetic mean of the values. avg Each of these was approximately 0.05 μm. Correspondingly, 2 × 2 mm 2 The ODS per nominal thickness in the area was in the range of 0.11 to 0.13 nm / μm.

[0120] 5 x 5 mm 2 For the area zone, the individual ODS of Example 1A and 1B i The average positional and thickness variation (ODS) is identified as the arithmetic mean of the values. avg Each of these was approximately 0.13-0.14 μm. Correspondingly, 5 × 5 mm 2 The ODS per nominal thickness in the area ranged from 0.27 to 0.34 nm / μm.

[0121] 2. Example 2 Glass articles having a nominal thickness of 700 μm or 250 μm were manufactured by the down-draw method. Each of the articles had a length of 510 mm and a width of 430 mm.

[0122] The location-dependent thickness of a glass article was optically determined using interferometry. To achieve this, light was focused onto the glass article, and the interference resulting from the difference in reflection paths at the front and back of the article was used to determine its local thickness.

[0123] A Precitec Sensor Interferometric-K interferometer was used for the measurements. The sampling rate was 4 kHz. The scanning speed was 500 mm / second. The measurement point spacing was 0.125 mm.

[0124] Measurement tracks were taken in a direction perpendicular to the direction in which the glass was pulled. The distance between the two measurement tracks was 10 mm. Therefore, the spatial resolution measured in the direction in which the glass was pulled was only 10 mm. Linear interpolation was performed to increase the resolution in the pulling direction. As a result, the spatial resolution in the direction in which the glass was pulled could be increased to 1 mm. The error introduced by the interpolation was estimated to be <0.05 μm. Therefore, the interpolation does not result in any discrepancy in the relevant results.

[0125] Based on the thickness value obtained in this way, 2 × 2 mm 2 and 5×5mm 2 For the area zones, the positional and thickness variation (ODS) was identified. The area zones were selected so that one of the measurement points was always in the center of one of the area zones. Therefore, for each measurement point, one area zone was calculated and evaluated in terms of ODS. The position was too close to the edge of the glass article, 2×2mm 2 and 5×5mm 2 The only exceptions were measurement points that did not serve as the center of the area zone. With a resolution of 1 mm in the direction of pulling out the glass article and in the direction perpendicular to the pulling direction, this results in approximately 200,000 evaluated area zones per glass article.

[0126] Four glass articles with a nominal thickness of 250 μm (e.g., "V1") were examined using a different series of tests (hereinafter referred to as V1 to V6). Furthermore, ten glass articles with a nominal thickness d = 700 μm (e.g., "V2 to V6") were examined (two glass articles per test). (2 × 2) mm 2 The number of area regions considered using this method is 204,408 per glass article, and (5×5) mm 2The number of area regions considered using this method was 202,905 per glass item.

[0127] Interestingly, for a nominal thickness of 700 μm, the identified ODS value did not change within the test, but it was found to change significantly between tests (V2 to V6). However, for a nominal thickness of 250 μm, no discrepancies in the correlation of ODS values ​​were observed for different samples. Therefore, below, only one ODS value is specified for a nominal thickness of 250 μm, while for a nominal thickness of 700 μm, its upper and lower limits are the highest and lowest ODS values ​​of the samples examined in all tests, respectively. avg Defines a range corresponding to the value.

[0128] The ODS values ​​shown are, for each individual ODS i The average positional and thickness variation (ODS) is identified as the arithmetic mean of the values. avg ) (2×2)mm 2 Regarding the area, ODS is 204,408 ODS i It is calculated as the average value. (5 x 5) mm 2 For the area, the ODS is 202,905 per test. i This is the average value.

[0129] The results are summarized in the table below: [Table 5]

[0130] The data on which the above summary is based is ODS per nominal thickness d i The values ​​are shown in the form of a box plot in Figure 4. Here, Figure 4A represents the area (2 × 2) mm. 2 Regarding this, Figure 4B shows the area (5×5) mm 2 Regarding.

[0131] Description of the drawing Figure 1 schematically, but not to scale, shows an exemplary pressure sensor. The pressure sensor is shown in cross-section and includes a base 60, which may be manufactured from, for example, a ceramic material. A glass member 100 is fixed onto the base 60 using an adhesive layer 63, which may be formed from, for example, an epoxy resin. The glass member 100 includes an opening. The pressure sensor includes a silicon MEMS chip 61 as a central sensing unit. In its central region, it includes a thinned portion (filament). The piezoresistive function is incorporated into this filament. The MEMS chip 61 is anodized to the glass member to form a measuring cavity 600. A reference pressure cavity 601 is formed by a locally thinned portion 62. This component may be manufactured from either silicon or glass and is hermetically connected to the MEMS chip 61, for example, by anodizing or thermal fusion.

[0132] Figure 2 shows a side view of damage near the surface. The resolution is 1000x.

[0133] Figure 3 shows an exemplary image of the sample from Example 1 for analysis of the near-surface damage level (ONSL) at 40x magnification. Figures 3A and 3B correspond to the samples from Example 1A and 1B, respectively. It can be seen that the ONSL in Example 1A (Figure 3A) is higher than that in Example 1B (Figure 3B).

[0134] Figure 4 shows the area (2×2) mm for a glass article manufactured using the down-draw method. 2 (Figure 4A) and (5×5) mm 2 (Figure 4B) shows the ODS normalized with respect to the nominal thickness d for nominal thicknesses of 250 μm (V1) and 700 μm (V2~V6). i The box plot of the distribution is shown. Each box is defined by the lower and upper quartiles. The median is shown as a horizontal line within the box. The mean is shown as a horizontal line extending beyond the horizontal limit of the box.

Claims

1. A glass article having two parallel main surface planes, wherein the glass article has a thickness of less than 3.0 mm, and each of the main surface planes of the glass article has 2 × 2 mm 2 The mean level of damage near the surface (ONSL) is less than 2000 damages having an extent of at least 1.0 μm, and the glass article is 2 × 2 mm 2 The normalized average positional-thickness variation (ODS) with respect to thickness is less than 10 nm per 1 μm of glass article thickness, and the ODS is 2 × 2 mm 2 The glass article is the difference between the maximum thickness and the minimum thickness within the specified measurement area.

2. 2 x 2 mm 2 The glass article according to claim 1, wherein the average positional and thickness variation in the glass is less than 10 μm.

3. 2 x 2 mm 2 Maximum positional and thickness variation (ODS) max The glass article according to claim 1 or 2, wherein the thickness is less than 50 μm.

4. The glass article has a 2 x 2 mm dimension on both main sides. 2 Maximum near-surface damage level in ONSL max The glass article according to any one of claims 1 to 3, wherein there are up to 4,000 damages having an extent of at least 1.0 μm.

5. A glass article according to any one of claims 1 to 4, having a thickness of less than 2.0 mm, less than 1.0 mm, or less than 0.5 mm.

6. 2 × 2 mm 2 having a roughness R less than 2 nm in a the glass article according to any one of claims 1 to 5.

7. Number of gaseous inclusions: 1 mm 3 A glass article according to any one of claims 1 to 6, wherein the amount per unit is less than 1.

0.

8. The following VFT parameters: A is in the range of -5.5 to <0.0, B is in the range of 3500 to 12000K, and / or T 0 A glass article according to any one of claims 1 to 7, wherein the viscosity-temperature profile is characterized by being in the range of 25°C to 300°C.

9. 2 x 2 mm 2 A glass article according to any one of claims 1 to 8, wherein the maximum difference in thermal conductivity in is a maximum of 0.2 W / (m·K).

10. At least 400 mm 2 A glass article according to any one of claims 1 to 9, having the area of ​​the above.

11. A glass article according to any one of claims 1 to 10, having an area of ​​1 to 10 mm².

12. Use of the glass article according to claim 11 in a pressure sensor.

13. A pressure sensor comprising a glass article as described in claim 11.

14. A method for manufacturing a glass article according to any one of claims 1 to 11, the following steps: - The stage in which molten glass is manufactured, - The step of clarifying the aforementioned molten glass, - The step of drawing the molten glass into a glass ribbon having a target thickness of less than 3.0 mm. - The step of dividing the glass ribbon into glass articles. The glass ribbon passes through region Z, where it has already reached the target thickness, but its viscosity is still 10. 10 It is less than dPas, The glass is drawn out in region Z at a drawing speed of at least 0.5 m / min and a maximum of 50 m / min, and The method wherein appropriate means are taken to keep the region Z free from interference in the frequency range of 1 to 500 Hz.

15. The method according to claim 14, wherein the method is a downdraw method or an overflow fusion method.

16. The molten glass exits the tank and is then drawn into a glass ribbon, where the viscosity of the molten glass at the point where it exits the tank is 10 2.20 dPas-10 4.00 The method according to claim 15, wherein the range is dPas.

17. The means described above, - Pulling equipment and / or acoustic housing of area Z, - Separation of the drawing equipment from the molding process. - Adjusting the distance of the pull-out roll - One or more panels to reduce convection in the cooling area - Sealing, and • Those combinations The method according to any one of claims 14 to 16, selected from the following.

18. The following stages: - The stage of grinding glass articles using bonded abrasive grains, The method according to any one of claims 14 to 17, including the method described in any one of claims 14 to 17.

19. The method according to claim 18, further comprising a polishing step following the grinding step.

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