METHODS FOR MANUFACTURING ULTRA-THIN GLASS PARTS AND GLASS PARTS PRODUCED BY THIS METHOD

Abstract

The invention relates to a method for the efficient production of ultrathin parts comprising glass-based material (2, 4) with a material thickness (d) from 5µm to 100µm, into which microfilament-like weakening elements (14) are inserted by irradiation with ultrashort laser pulses, where adjacent microfilament-like weakening elements (14) have a spacing (A) from 0.4µm to 4.0µm. This has the beneficial effect of achieving high edge strength. The invention also relates to such ultrathin parts comprising glass-based material (2, 4).

Description

[0001] Process for producing ultra-thin glass elements and glass element produced according to the process and their use

[0002] The present invention relates to the production of ultra-thin elements made of glass-based material, in particular glasses and / or glass-ceramics with a thickness of 5 μm to 100 μm, by laser filamentation for the insertion of separating lines. Examples of ultra-thin elements made of glass-based material include ultra-thin glass panes and so-called glass films.

[0003] Description

[0004] Laser filamentation for separating glass-based materials enables higher process efficiencies than a purely mechanical separation process. This improved efficiency affects both processing speeds and the avoidance or at least reduction of scrap.

[0005] For the purposes of the invention, glass-based materials are all materials that have a glass-like network at least in some areas and / or are derived from a glass material. Glass-based materials include, in particular, glasses as such, but also glass ceramics obtained by at least partial crystallization of glass material elements.

[0006] When cutting endless glass ribbons, for example, the border cut and the transverse separation of the glass ribbon, and possibly in combination with a subsequent cutting of the glass, allow for higher glass ribbon speeds or drawing speeds and cutting speeds in the cutting process than, for example, with wheel cutting, where the achievable cutting speeds for the border and transverse scoring are limited, particularly by the cutting and depositing processes carried out by a worker. Laser filamentation is also a low-particle process, so there is less contamination and scratches in the glass. The same applies to the cutting of ultra-thin glass panes that are processed individually. The cutting of glass panes by inserting filaments using ultrashort pulse lasers is known per se. Corresponding processes are described, among others, in WO 2018 / 020145 A1 and US 2018 / 0057390 A1.

[0007] The goal is to select processing speeds as fast as possible, as this enables particularly efficient production. For glass substrates, the distance A between adjacent filamentary damages, also called the pitch, is set in the range of 10 pm. For TFT glass substrates with a thickness of 0.5 to 7 mm, a pitch range of 5 to 10 pm is suggested. To increase processing speed, it is usually assumed that the pitch should be increased.

[0008] The distance A, or synonymously the pitch, between adjacent filamentary lesions is measured between their centers. The center of a filamentary lesion lies on its longitudinal axis. In the simplest case, the diameter of a filamentary lesion is circular.

[0009] A quality characteristic of a processing process is the edge strength K of the processed element, especially the edge of the desired element, from which an excess portion is usually removed. The goal is to achieve the highest possible edge strength. Unlike with thicker substrates, it is hardly possible to post-process the edge of ultra-thin elements.

[0010] Ultra-thin elements made of glass-based material are becoming increasingly important, for example, as substrates for electronic components or as covering materials for displays, especially hinged or foldable displays. Since such applications require particularly efficient manufacturing processes, the object of the invention is to provide a particularly economical method for producing ultra-thin elements made of glass-based material, as well as corresponding ultra-thin elements made of glass-based material and their use.

[0011] This object is achieved by the subject matter of the independent claims. Advantageous embodiments of the invention are specified in the respective dependent claims. The method for producing ultra-thin elements from glass-based material comprises the following steps:

[0012] - Providing an ultra-thin element made of glass-based material with a material thickness (d) of 5 to 100 pm,

[0013] - generating a focused laser beam by means of at least one ultrashort pulse laser with a laser wavelength in which the element made of glass-based material is at least substantially transparent,

[0014] - Inserting filament-shaped damage into the ultra-thin element made of glass-based material with the focused laser beam along a separation line,

[0015] - where adjacent filament-shaped lesions have a distance (A) of 0.4 to 3.8 pm,

[0016] - where the distance (A) is measured between the centers of adjacent filamentary lesions.

[0017] The described process is based on laser filamentation with ultrashort pulse lasers. For this purpose, the focused laser beam of a pulsed laser is directed onto the element to be processed, or synonymously, the workpiece. The laser emits the laser beam at a wavelength A, whereby the workpiece is at least essentially transparent to the laser wavelength A used, at least in the area of ​​incidence of the laser beam. This means that the transmission of the workpiece at this point is greater than 85%, advantageously greater than 90%, and particularly advantageously greater than 95% at wavelength A.

[0018] In order to nevertheless achieve interaction between the laser beam and the material of the workpiece, an ultrashort pulse laser is used according to the invention. In such a laser, the pulse width is very short, i.e. in the range of less than 1 ns, in particular in the range of a few ps to fs, in particular in the range from 100 ps or 10 ps to 100 fs or 10 fs. The interaction can generally be based on nonlinear optical effects, as described, for example, in WO 2012 / 006736 A2. Two nonlinear effects interact here: the self-focusing of the pulse due to the optical Kerr effect and its defocusing due to the plasma that the laser generates in the material. EP 3169635 A1 uses a Bessel beam with an axicon optics to extend the laser focal line during laser cutting.It is stated there that the difference from a process based on the Kerr effect is that refocusing the laser beam requires a modification of the refractive index of the workpiece material, in this case glass. This inevitably results in a different damage pattern, which can be undesirable.

[0019] Alternatively, and particularly advantageously within the meaning of the invention, it is also possible to focus the laser beam onto the ultra-thin element using beam-shaping optics. This is particularly advantageous because the ultra-thin element represents a length range for the laser focus, which can also be achieved using a simple convergent beam path, for example, using lenses in a telescopic arrangement.

[0020] A filament is generally understood to be an elongated, thread-like structure whose diameter is significantly smaller than its length. For the purposes of the present invention, the filament-like damage is a modification of the original material caused by the irradiation of the ultrashort laser pulses. This damage typically represents a mechanical weakening of the original material, or, particularly advantageously, a channel, which can in particular be a hollow channel. In the hollow channel, at least in some areas, no original material is present. The hollow channel thus represents a cavity.

[0021] A well-known application of filamentation is laser cutting. This involves introducing damage into the glass. If several damages are then placed next to one another, a separation line is created along which the glass can be separated by applying stress. A fundamental mechanism assumed here is that microcracks emanating from the filament weaken the material. If damages are located next to one another, the microcracks connect to form a connecting line, allowing separation along this connecting or separation line. The separation line can also be regarded as a predetermined breaking line, particularly if separation of the workpiece does not occur after the introduction of the filament-shaped damage and this is only carried out in a later process step and / or by the application of a mechanical force. The terms separation line and predetermined breaking line are used synonymously herein.The inventors have discovered that the applicable spacing A between adjacent filamentary damages for ultra-thin glass-based elements is surprisingly different from that known for thicker elements. Generally speaking, it was found that smaller spacings are more advantageous for ultra-thin elements than those used for elements of normal thickness. This is particularly surprising because it would be expected that ultra-thin elements have lower mechanical stability than thicker ones and that thus a smaller number of damages, in this case filamentary damages, would be necessary to efficiently separate the ultra-thin elements. However, the exact opposite is the case.

[0022] For ultra-thin elements made of glass-based material with a thickness d of 5 to 100 μm, a pitch A of 0.4 to 4.0 μm has proven particularly favorable. A pitch A of 0.5 to 3.8 μm is particularly advantageous.

[0023] The distance A is measured from the center of one filamentary damage to the center of the adjacent filamentary damage. The center lies on the longitudinal axis of the filament, which extends into the glass-based material element.

[0024] This distance A range represents the optimal compromise between processing speed and edge strength for the aforementioned ultra-thin elements made of glass-based material. As described in more detail below, the edge strength decreases with both larger and smaller distances A. It has been recognized that this range enables the best edge strength for ultra-thin elements made of glass-based material in the specified thickness range.

[0025] The reason for this maximum is unknown. It can be assumed that the ultra-thin material exhibits flexibility that reduces crack formation around a filament compared to a thicker and thus rigid material, so that a larger number of filaments on a separation line is necessary to create separability.

[0026] At this point, it should be noted that separability, as used in this description, refers to both the independent separation of parts of the element and separation by applying additional force, be it a mechanical breaking force and / or thermal stress. The latter can be advantageous for the efficient industrial processing of pre-separated elements.

[0027] An advantageous range for the material thickness d of the ultra-thin glass-based element is from 5 pm to 50 pm, particularly advantageous from 7 pm to 40 pm. Thus, particularly thin glass elements such as glass panes, glass ribbons and / or glass wafers can benefit from the invention. Equally advantageous lower limits for glass thicknesses are 18 pm, 20 pm or 22 pm or 24 pm or 26 pm or 28 pm or 30 pm. Advantageous upper limits are 42 pm or 44 pm or 46 pm or 48 pm. The upper and lower limits can of course be combined with one another. Particularly advantageous ranges are, for example, from 18 pm to 48 pm or from 24 pm to 38 pm.

[0028] It is particularly advantageous for the method according to the invention to select the distance A between adjacent filamentary damages in the range from 0.6 pm to 2.0 pm or in the range from 2.2 pm to 3.6 pm. The inventors have recognized that, surprisingly, two maxima for the edge strength of the aforementioned ultra-thin elements arise which lie in these ranges for the distance A. With the maximum in the smaller distance range A, somewhat higher edge strengths can be achieved, but the smaller pitch increases the processing time. With the maximum in the higher distance range A, the edge strengths are comparatively somewhat lower, but the processing time is shorter. The user is thus given the opportunity to advantageously select the distance according to the required compromise between edge strength and processing speed.This of course also applies analogously to the entire previously mentioned range for distance A.

[0029] Advantageous ranges for the distance A are also 0.5 pm to 2.0 pm or 0.6 to 2.0 pm or 1.1 pm to 2 pm or 1.2 pm to 2.0 pm or 1.2 pm to 1.9 pm. Also advantageous ranges are from 1.1 pm to 3.6 pm or from 1.2 pm to 3.5 pm. Equally advantageous ranges are from 2.4 pm to 3.6 pm or from 2.5 pm to 3.5 pm.

[0030] A method is advantageous in which the filamentary damage extends from a top side O to the opposite bottom side U of the glass element. Thus, the filaments advantageously extend completely through the thickness of the element made of glass-based material. Alternatively, it is of course also possible, and encompassed by the invention, for the filamentary damage to end within the volume of the element.

[0031] An advantageous embodiment of the method provides that the diameter F of the filament-shaped damage is from 0.2 pm to 1.2 pm, in particular from 0.4 pm to 1.0 pm. The filament diameter A is measured in this description on the side of the element facing the laser, which is referred to herein as the top side 0. As stated, the damage can be or contain a material modification. However, the filament-shaped damage is particularly advantageously a hollow channel. Such a hollow channel can be introduced in particular by a sequence of successive ultrashort laser pulses, a so-called burst. The burst used can advantageously consist of 2 to 6 individual pulses, in particular of 4 individual pulses. However, the inventors have recognized that it is particularly possible and advantageous if a single laser pulse produces a hollow channel-shaped filament.

[0032] A particularly advantageous embodiment of the method provides for adjusting the distance A between the filaments to match the diameter F of the filament-shaped damage. In such a particularly advantageous embodiment, a distance-filament relationship Q is set, where Q is determined by Q = A - F. Q lies in a range from -0.4 pm to 3.6 pm, in particular from -0.4 pm to 2.8 pm or from -0.2 pm to 2.0 pm.

[0033] The advantageous ranges for A and F were mentioned previously. This shows that Q can take on negative numerical values ​​if F is smaller than A. This means that if Q < 0 is selected, there is an overlap of the filamentary damage along the dividing line. Surprisingly, the edge strength decreases again if the overlap becomes too large. Therefore, these ranges are the most advantageous.

[0034] A further particularly advantageous embodiment of the method comprises that the element made of glass-based material is separated along the dividing line, wherein between filament-shaped damages along the dividing line a web with a web width g) of 0.1 pm to 3.6 pm is created or the web width g) is in the range 0.1 < g < 2 F, advantageously in the range 0.1 < g < F, particularly advantageously in the range 0.1 < g < F / 2.

[0035] A web within the meaning of the invention is an edge of the severed element, in particular of the finished part, which runs on and / or at least substantially parallel to the separating line. This web connects the filament-shaped damage, so to speak. It can be seen that this web is present when Q > 0 and thus there is no overlap of the filaments. It has proven particularly advantageous if the web width g is also adjusted depending on the diameter of the filaments F. This can be achieved by selecting the distance A. A web width of up to twice the filament diameter, i.e. up to 2-F, has proven advantageous. The range up to one filament diameter F is particularly advantageous, in particular up to half the filament diameter F / 2. Within these ranges, a high edge strength of the ultra-thin element can be achieved in the embodiment with a web on the separating line.

[0036] As already mentioned, the glass-based material of the ultra-thin element includes, in particular, glass and / or glass ceramic. In particular, it consists of these.

[0037] A particularly advantageous embodiment of the method comprises separating the element made of glass-based material along the dividing line, wherein the edge strength K of the element is more than 120 MPa at least on one side of the dividing line, advantageously from 120 to 400 MPa or from 125 to 300 MPa or from 125 to 250 MPa, particularly advantageously an edge strength K in the range of 4 d < K < 10 d. This inequality merely represents a correlation, the pure numerical value of which is applicable. The numerical values ​​are to be used dimensionlessly. As described, d denotes the material strength or thickness of the ultra-thin element. It has been found thatthat the edge strength increases, as expected, with the thickness or material strength d of the element. In the aforementioned range for the thickness d, it lies within the range specified in the inequality. The specified edge strength can be measured as described in DE 10 2014 110 855 A1. Accordingly, the testing of the fracture strength of flat specimens made of brittle material, in particular glass sheets, requires that the specimens have a first side surface and a second side surface, as well as at least one edge, with the first side surface being opposite the second side surface. The test relates to fractures originating from the edge of the specimen to be tested under a mechanical tensile stress s, in which the first side surface at the edge to be tested is subjected to a tensile stress s along the edge to be tested in a section of the specimen by bending the specimen in this section to be tested.so that it is bent along the edge to be tested by pressing the sample in the section to be tested against the gauge surface of a dimensionally stable gauge with a defined curvature, so that the curvature of the gauge surface is imposed on the section to be tested. A gauge surface with a first bending radius R is used, and the breaking strength of the sample is tested under the mechanical tensile stress s corresponding to this bending radius R. This test is repeated with successively reduced bending radius R and the associated increased tensile stress s until the sample breaks, and it is evaluated at which tensile stress s or at which bending radius the sample broke. In particular, it can also be determined whether the sample broke from the edge to be tested.

[0038] In the method according to the invention, the element made of glass-based material can advantageously be in the form of a flat substrate, in particular a glass and / or glass-ceramic pane. The dividing line is particularly advantageously inserted into the edge regions of the flat substrate.

[0039] This particularly applies to the processing of individual elements at corresponding processing stations. The individual elements are separated sequentially in the processing stations. This means that a glass element is fed to the processing station and processed. The processed element is transported further, and an unprocessed element is then fed to it. Of course, it is possible, and encompassed by the invention, for the separating line to be inserted at any point on the element. However, separating the edge area of ​​the elements, in particular the edge area of ​​ultra-thin glass panes, is particularly advantageous.

[0040] An alternative advantageous embodiment of the method comprises the element made of glass-based material being present as a continuous glass ribbon with a predetermined glass thickness d, and wherein at least one longitudinal dividing line is created at least along the glass ribbon with an edge having a thickened border. The border is severed along the longitudinal dividing line to form an edge, and / or at least one transverse dividing line is created transversely to the glass ribbon, wherein glass panes are severed along the transverse dividing line running transversely to the glass ribbon to form edges.

[0041] The method according to the invention thus makes it possible to separate one or both borders on the respective edge side of a continuous ultra-thin glass ribbon. Alternatively or additionally, the method according to the invention makes it possible to separate a continuous ultra-thin glass ribbon transversely into ultra-thin glass panes. The resulting edges exhibit improved edge strength.

[0042] In a further advantageous embodiment, the method provides that the at least one longitudinal dividing line is inserted in the hot area of ​​the glass ribbon.

[0043] Laser filamentation with the parameters mentioned here makes it possible to process the edge regions of the glass ribbon of ultra-thin glasses shortly after leaving the melting unit, thus in the hot area, especially at temperatures above the transformation temperature Tg of the glass.

[0044] Alternatively, it is possible for the at least one longitudinal parting line to be inserted in the cold region of the glass ribbon, wherein the glass ribbon is cooled at a cooling rate of equal to or greater than 10 Kelvin / s, preferably equal to or greater than 20 Kelvin / s, particularly preferably equal to or greater than 40 Kelvin / s. Within the meaning of the present description, the ultra-thin glass ribbon is drawn rapidly using a down-draw process, in particular at a speed in the range of 0.5 meters per minute to 50 meters per minute. However, the process is not limited to the down-draw process. Drawing using the overflow fusion process or other processes suitable for producing thin glass ribbons is also possible. According to one possible embodiment, the parting lines formed from filamentary damage can be inserted in the down-draw process after the glass ribbon has been deflected horizontally.In principle, the glass ribbon is cooled quickly; in particular, cooling rates as mentioned above can be applied.

[0045] To subsequently achieve reliable and easy separation of the borders from the glass ribbon and the separation of individual glass panes, the glass ribbon is particularly advantageously cooled before inserting the predetermined breaking lines in the range of the glass transition temperature, preferably at a temperature below the softening point, particularly preferably at a temperature below the glass transition temperature. To optimize the process, the glass ribbon can optionally also be cooled during and / or after inserting the predetermined breaking lines.

[0046] In one possible embodiment of the process, cooling takes place in a cooling furnace, in particular with heating elements, or by blowing or spraying a cooling fluid, in particular air, other gaseous media, or an aerosol. In the latter case, the cooling rate can be adjusted / determined to the process parameters of glass ribbon temperature and feed rate, for example, by controlling the flow rate of the cooling fluid, in order to prevent undesirable stresses in the glass ribbon.

[0047] In addition to the described beam-shaping optics, the laser beam can also be shaped as a Bessel beam, particularly with beam-shaping optics.

[0048] An advantageous method is further developed in such a way that the beam profile of the laser beam is shaped in such a way that the extension of the laser beam in the direction of the dividing line is greater than transversely thereto.

[0049] This creates a so-called preferred direction along the dividing line. In particular, the beam-shaping optics can generate a beam profile with a lateral preferred direction, for example, an elliptical, lancet-shaped, drop-shaped, with two spaced-apart beams (e.g., a double Bessel beam), a diamond-shaped, dumbbell-shaped, wedge-shaped, or spot-shaped beam profile, or even a beam profile with a main beam and a lower-intensity satellite beam. This allows virtually any contour to be created with particularly high edge quality or edge strength after the edges have been burned off and the ultra-thin glass panes have been separated.

[0050] In particular, the laser beam can be shaped such that in its focus area the extension of the laser beam in the direction along the predetermined breaking line is greater by a factor in the range from 1.3 to 5, in particular by a factor in the range from 1.5 to 4, than the extension in the direction perpendicular to the dividing line.

[0051] In one possible embodiment of the process for producing ultra-thin glass panes, the dividing line is inserted first transversely across the glass ribbon, creating the transverse dividing lines, and then along both sides of the glass ribbon, with edges each featuring a thickened border, to create the longitudinal dividing lines. In this way, after the transverse predetermined breaking lines have been inserted, the glass ribbon is still held together by the borders, thus providing mechanical stability.

[0052] In another possible embodiment, the movement device for moving the ultra-thin glass ribbon is preferably equipped with at least one pressure roller, a pressure edge, or a suction device for fixing the position of the glass ribbon within the laser's focus area. This fixes the glass ribbon with respect to the position of the focus of the ultrashort pulse laser and the arrangement of the dividing line formed by filament-like damage, preventing the glass ribbon from drifting out of the laser beam's focus area. In particular, the fixation can also increase the speed of the manufacturing process while avoiding the described disadvantages, which has a positive effect on the cost-effectiveness of the process.

[0053] The separation of the borders at the longitudinal break points and / or the separation of ultra-thin glass panes by cutting along the transverse break lines running perpendicular to the glass ribbon can advantageously be performed mechanically. It has been shown that separation along the break line generally requires little mechanical intervention. Often, the movement and tension during transport of the glass ribbon are sufficient to separate the break line.

[0054] With the method for producing ultra-thin glass panes according to this disclosure, particularly high cutting speeds, in particular up to 5 m / s, particularly preferably 3 m / s to 5 m / s, can also be achieved.

[0055] Thanks to laser filamentation, very little or no separation force is required for the border cutting and transverse separation of the ultra-thin glass ribbon, i.e., for separating the borders and separating individual glass panes, or the so-called full-body cut (FBC). In particular, no induction of thermal stresses by applying heat is necessary, for example, no so-called thermal cleaving process or thermal shock cutting through an abrupt drop in temperature, especially through a cold shock.

[0056] The process is particularly low in particle size and results in particularly stable edge strength, thus increasing predictable yields. The reduced manufacturing costs and the stable quality of the ultra-thin elements made of glass-based material achieved with the process also make the process particularly cost-effective.

[0057] Glass panes with a thickness of 5 pm to 100 pm, particularly 5 pm to 50 pm or 7 pm to 40 pm, were produced using this process. The glasses used had a thermal expansion coefficient of greater than 6 ppm / K.

[0058] In addition to the described method, the invention also encompasses ultra-thin elements made of glass-based material. An ultra-thin element made of glass-based material according to the invention is one with a thickness in the range from 5 pm to 100 pm, which has filamentary damage along at least one edge, the distance A being from 0.4 pm to 3.8 pm, in particular from 0.6 pm to 2.0 pm or from 2.2 pm to 3.6 pm. As described in connection with the method, the diameter F of the filamentary damage, measured at the top side 0 of the element, is from 0.2 pm to 1.2 pm. The aforementioned particularly advantageous ranges also apply here.

[0059] An advantageous ultra-thin element made of glass-based material has a pitch-filament relationship Q, where Q is determined by Q = A - F, and Q is in a range from - 0.4 pm to 3.6 pm, in particular from - 0.4 pm to 2.8 pm or from - 0.2 pm to 2.0 pm.

[0060] A particularly advantageous ultra-thin element made of glass-based material has, between filament-shaped damages along an edge, a web with a web width g of 0.1 pm to 3.6 pm or a web with the web width g in the range 0.1 < g < 2- F, advantageously in the range 0.1 < g < F, particularly advantageously in the range 0.1 < g < F / 2.

[0061] Descriptions of these designs have already been provided above in connection with the procedure and, of course, also apply to the element itself.

[0062] These ultra-thin glass panes, which can be produced by the process according to the invention, as well as the ultra-thin elements described herein, can be used for a wide variety of applications. They are particularly advantageously used as insulating intermediate substrates or spacers for electronic components, for encapsulating optoelectronic components, as supports for thin-film cells, such as thin-film batteries or thin-film solar cells, as cover elements for displays, particularly hinged and / or foldable displays, or as substrates or composite substrates for displays and for microfluidic cells.

[0063] The diverse applications benefit from properties such as chemical, thermal shock, and heat resistance, gas tightness, high electrical insulation capacity, adjusted expansion coefficients, flexibility, high optical quality and light transmission, as well as the high surface quality with very low roughness of the two ultra-thin glass sides, as well as the high edge strength achieved through the separation process. The invention is explained in more detail below with reference to the accompanying figures, but without limiting the invention. The figures and the associated description also represent exemplary embodiments.

[0064] Fig. 1 shows a schematic device for producing glass panes.

[0065] Fig. 2 shows schematic beam profiles of the beam-shaping optics.

[0066] Fig. 3 shows an arrangement for separating the glass ribbon into individual glass panes.

[0067] Fig. 4 is a graph of the cooling rate as a function of glass thickness.

[0068] Fig. 5a to 5d Filament-like damage in ultrathin elements.

[0069] Fig. 6a to 6b show the top view of the edge of a separated element.

[0070] Fig. 6c shows the top view of an element provided with filaments.

[0071] Fig. 7 is a graph of edge strength versus pitch.

[0072] Fig. 1 shows an exemplary embodiment of a device 1 for producing glass panes 2 with a predetermined glass thickness d in the range from 15 μm to 2 mm. A continuous glass ribbon 4 is drawn from a glass melt 10 through a downwardly directed slot-shaped nozzle 6, which is part of a hot-forming device 8. Here, the so-called down-draw process is preferably used as the hot-forming process for glass ribbons, and the insertion of separating lines 12 from filament-shaped defects 14, i.e., laser filamentation, preferably takes place directly during the down-draw process, particularly preferably after the glass ribbon 4 has been deflected horizontally. In principle, the process is also applicable to other glass-based materials.

[0073] Controlled predetermined breaking lines 12 consisting of filamentary damages 14 are introduced into the glass ribbon 4 using at least one ultrashort pulse laser 16. The laser pulse generates an approximately Bessel beam 20 through a beam-shaping optic 18, which creates a focal region 22 that passes through the glass ribbon 4. In particular, the beam-shaping optic 18 can focus the laser beam 20 to increase the power density in the glass. The intensity distribution and thus also the shape of the filamentary damages 14 can be specifically adjusted via the beam-shaping optic 18. The focus area is advantageously set longer than the glass thickness d in order to create deep - spaced apart - filament-shaped damages 14 in a predetermined volume of the glass ribbon 4, preferably from one side surface 51 to the opposite side surface 52 of the glass ribbon 4, that is to say preferably over the entire thickness d of the glass ribbon 4.

[0074] A suitable ultrashort pulse laser for the purposes of the invention is, for example, an Nd:YAG laser with a wavelength of 1064 nm, an average power of 12 W (at 1064 nm, 100 kHz, 1 pulse per burst), a repetition rate of 100 kHz, a burst frequency of 50 MHz, and a pulse duration of approximately 10 ps (at 1064 nm and 100 kHz). Other lasers, especially those with higher powers, are of course also applicable.

[0075] According to a further embodiment, a Yb:YAG laser operating at 1030 nm can be used. Generally, the lasers can be used as frequency-doubled (SHG) or frequency-tripled (THG) versions. According to one embodiment, the pulse lengths are in the range from 300 fs to 20 ps, ​​or in the range from 400 fs to less than 10 ps. The repetition rates can be in the range from 50 kHz to 1 MHz, preferably 100 kHz to 500 kHz. Pulse energies can be more than 100 pJ, more than 200 pJ, or even more than 400 pJ. The number of burst pulses was <2, <4, or <8. Particularly advantageously, no burst is used; instead, a single pulse is sufficient to cause damage in the ultrathin glass.

[0076] In addition, the device 1 for producing panes from glass-based material 2 preferably comprises a movement device 24, for example by means of transport rollers, in particular drawing rollers, for moving the glass ribbon 4, the ultrashort laser 16 and / or the beam-shaping optics 18 for positioning the laser beam 20 along a predetermined course of the predetermined breaking lines 12 on the glass ribbon 4.

[0077] The laser beam 20 can be guided over the glass ribbon 4, or the glass ribbon 4 can be guided past the laser beam 20. A combination of both variants is also possible. To move the laser beam 20 perpendicular to the direction of movement of the glass ribbon 4, a galvanometer scanner, for example, can be used, or a deflecting mirror can be transported on a movable axis transversely to the glass ribbon. In this case, transverse dividing lines 121 are formed transversely to the glass ribbon 4, and longitudinal dividing lines 122 are formed on both sides along the glass ribbon 4, each with a thickened border 13.

[0078] The finding that the scattering of the breaking force at the edges produced with the laser-assisted method according to this disclosure can be reduced with a cooling rate adapted to the glass thickness can also be used. The device 1 for producing glass panes 2 thus further comprises a cooling device 26, which is arranged and configured such that it cools the glass ribbon 4 before the filament-shaped defects 14 are introduced into the glass ribbon 4 at a cooling rate that is selected depending on the predetermined glass thickness d, wherein the cooling rate is increased as the glass thickness decreases. Advantageously, the cooling of the glass ribbon 4 before the parting lines 12 are introduced takes place in the range of the glass transition temperature, preferably at a temperature below the softening point, particularly preferably at a temperature below the glass transition temperature.

[0079] In an advantageous embodiment, the cooling of the glass ribbon 4 is carried out in a cooling furnace 27, in particular in a controlled manner using heating elements. If necessary, homogeneous cooling can also be assisted by blowing or spraying a cooling fluid, in particular air or an aerosol.

[0080] According to one embodiment, the device 1 for producing glass panes 2 further comprises a separating device 28, which is arranged and configured to preferably mechanically separate the borders 13 along the longitudinal predetermined breaking points 122, forming edges 30, and to separate the glass panes 2 by separating them along the transverse separating lines 121 running transversely to the glass ribbon 4, forming further edges 30. Thus, the separating device can comprise an arrangement with a spherical roller, which is guided over the predetermined breaking lines. A heat source, such as a laser, can also be provided to induce thermal stresses at the predetermined breaking line. However, mechanical action may no longer be required to separate the glass at the predetermined breaking lines. The beam-shaping optics 18 can also be used to specifically adjust the intensity distribution in the glass and thus also the shape of the filamentary damage 14.

[0081] In a further advantageous embodiment, the movement device 24 for moving the glass ribbon 4 is equipped with at least one pressure roller, a pressure edge, or a suction device for fixing the axial position, or the position of the glass ribbon 4 in the beam direction within the focus area, so that the glass ribbon 4 is not distorted with regard to the separation of the glass panes 2 and the separation of the borders 13, which could impair the shape and edge quality of the individual glass panes 2. In particular, the fixing can also increase the speed of the manufacturing process while avoiding the disadvantages described, which has a positive effect on the cost-effectiveness of the process. In the case shown in Fig.In the example shown in Figure 1, a pair of pressure rollers 15 is shown as a device for fixing the vertical position of the glass ribbon 4, which determine the position of the glass ribbon in the direction of incidence of the laser beam 20 near the point of impact of the ultrashort pulse laser 16.

[0082] In an advantageous embodiment of the method for producing glass panes 2, the beam profile is preferably adjusted by a corresponding beam-shaping optic 18 such that the intensity profile is formed in the form of a Bessel beam or approximately in the form of a Bessel beam with greatly increased intensity on the optical axis. The beam-shaping optic brings about focusing to a line focus. To achieve such focusing, one or more axicons or a diffractive optical element (DOE), or combinations thereof with other optical elements, are suitable as beam-shaping optical elements. Other optical structures, as described above, are also possible and encompassed by the invention.

[0083] In particular, the beam profile is preferably adjusted such that the extent of the laser beam is greater in the direction of the dividing lines 12 than transversely, particularly perpendicularly, thereto. In this way, the amount of radiation integrated along the dividing lines is greater than along a line perpendicular to the dividing line and crossing the center of the beam. In other words, the beam-shaping optics preferably generates a beam bundle with a cross-section that is more extensive in the direction of the linearly arranged filamentary damages 14 than transversely to this direction. The individual filamentary damages 14 extend transversely, preferably perpendicularly, to the surface of the glass ribbon 4 in their longitudinal direction, following the propagation direction of the laser beam 20.For this purpose, the beam-forming optics 18 is preferably adjustable with respect to a larger beam cross-sectional extent and the direction of the larger cross-sectional extent is preferably adjusted to the course of the linearly arranged filament-shaped damages 14.

[0084] In a further advantageous embodiment of the method, the beam-shaping optics 18 generates an asymmetric beam profile with a lateral preferred direction. Fig. 2 shows various possibilities for a beam profile. Partial image (a) shows an elliptical beam profile 32. This is aligned such that its long semi-axis is aligned along the respective predetermined breaking line. Accordingly, the extension A P of the beam profile along the predetermined breaking line is greater than the extension A sperpendicular to the separation line. Part (b) shows a drop-shaped beam profile 33. In the embodiment according to part (c), the laser beam is split into two beams. The beam profile 34 therefore has two spaced-apart beams in the form of a double beam. Part (d) shows a diamond-shaped beam profile 35. Fig. 2(e) shows a dumbbell-shaped beam profile 36 and Fig. 2(f) a wedge-shaped beam profile 37. Finally, Fig. 2(g) shows a beam profile 38 with a main beam and a weaker or smaller satellite. The embodiments of parts (b), (e), (f) and (g) have in common that they are not only more extensive in the feed direction than perpendicular to it, but are also asymmetrical with respect to a mirror axis perpendicular to the feed direction. Such a shape can be very advantageous in order to further facilitate separation and achieve higher edge strengths.This can be particularly advantageous because asymmetric conditions also exist during the insertion of the filaments. Unlike the portion of the predetermined breaking line already swept over by the beam, no filaments are present in front of the laser beam in the feed direction. In general, without limitation to the specific examples, it is therefore intended that the filamentary damage be inserted with a laser beam 20 that has an asymmetric beam profile with respect to a reflection perpendicular to the feed direction. This results in a controllable shape with greater geometric accuracy of the resulting dividing lines 12 from filamentary damage 14, coupled with greater edge strength after the edges 13 have been burned off and the glass panes 2 have been separated.

[0085] To promote gap formation along the dividing lines, it is advisable to select cross-sectional shapes for the laser beam that extend in the direction of the desired fracture. The elliptical cross-sectional shape 32 in Fig. 2 (a) can be obtained, for example, from an originally circular cross-sectional shape of the laser beam using a combination of cylindrical lenses. The other beam profiles can also be generated using suitable lenses, optionally also using diffractive optical elements (DOEs).

[0086] In an advantageous embodiment of the method for producing glass panes 4, the sequence of inserting the dividing lines 12 is, due to the process technology, first transversely to the glass ribbon, whereby the transverse dividing line 121 is produced, and then on both sides longitudinally to the glass ribbon with edges, each of which has a thickened border, to produce the longitudinal predetermined breaking lines 122, because the glass ribbon 4 is then held together by the borders 13 and is thus mechanically stabilized.

[0087] Fig. 3 shows an arrangement for separating the glass ribbon 4 into individual glass panes 2 and for separating the borders 3.

[0088] For this method, a movement device 24 for transporting the continuously drawn glass ribbon 4 is preferably provided, which in the example shown comprises a conveyor belt 240. To insert the separating lines 12, a plurality of ultrashort pulse lasers 16 can generally also advantageously be used, without limitation to the example shown, wherein at least a first ultrashort pulse laser 16 inserts the transverse predetermined breaking lines 121 and at least a second ultrashort pulse laser 16 inserts the longitudinal separating lines 122. In particular, two ultrashort pulse lasers 16 can also be used for two longitudinal separating lines 122, as in the example shown. The beam-shaping optics 18 of the ultrashort pulse lasers 16 are not shown in the figure for the sake of simplicity. The movement device 24 can also comprise beam deflection optics 241, as in the example shown.According to one embodiment, the transverse dividing lines 121 are inserted using a laser beam 20 moved across the glass ribbon 4 by a beam deflection optics 241. The beam deflection optics 241 can, for example, comprise a galvanometer scanner.

[0089] As shown, in a preferred embodiment, the said dividing lines 121, 122 are first inserted transversely and then longitudinally into the continuous glass ribbon 4.

[0090] The separation of individual glass panes 2, or the so-called full-body cut (FBC) by separating or breaking along the transverse predetermined breaking lines 121 running transversely to the glass ribbon 4, can be performed by a mechanical separation device 28, for which only very low or no separation forces are required after laser filamentation. The border cut, i.e. the separation of the borders 13 along the longitudinal predetermined breaking lines 122 of the glass ribbon 4, can also be performed using very low separation forces, for example by simply pulling and / or by moving along an acceleration belt 29. An acceleration belt 29, with which the individual glass panes 2 are separated in the direction of movement, can, for example, also be a component of a separation device 28 or represent the separation device 28.

[0091] After the glass panes 2 have been separated and separated, they can be transported to an inspection unit 39 by means of the transport device 24. The inspection unit 39 can be used, among other things, to check the dimensions of the glass panes and their edge quality.

[0092] In particular, in order to achieve good edge quality, no thermal separation of the glass ribbon 4 by introducing stress is necessary, or no induction of thermal stresses by introducing temperature, for example by a CO2 laser, i.e. no so-called thermal cleaving process, is necessary for the separation, and no thermal shock cutting, for example by an abrupt reduction in temperature, for example by a cold shock, is necessary.

[0093] The separation can be achieved, for example, by applying mechanical tension with spherical rollers or by guiding the separation lines over spherical rollers. The edges 13 separated from the remaining glass ribbon 4 can then be collected, for example, in a cullet container, possibly remote from the glass ribbon (in a cullet cellar or other room). The selected distance makes it possible for the glass ribbon to be separated along the separation line by the action of gravity. For this purpose, an overhang of the section of the glass ribbon to be separated can be provided, in particular, over a guide device, for example a rail or a roller.

[0094] In an advantageous method, the cooling of the glass ribbon 4 takes place at a cooling rate which is selected depending on the predetermined glass thickness d, wherein with a predetermined smaller glass thickness d the cooling rate is increased and with a predetermined larger glass thickness the cooling rate is reduced.

[0095] Fig. 4 is a graph of the selected cooling rate as a function of the glass thickness. In particular, Fig. 4 shows the cooling rate in the range from 40 K / s to 325 K / s as a function of the glass thickness d of the ultra-thin glass ribbon 4, using the example of AF32 glass from Schott AG in the range from 25 pm to 110 pm (curve (a)).

[0096] The glass offered by Schott AG under the designation AF32 is an alkali-free aluminum borosilicate thin glass from a class of alkali-free glasses well suited for the process and has the following components:

[0097] SiÜ2 58 to 65

[0098] B2O3 6 to 10.5

[0099] AI2O3 14 to 25

[0100] MgO 0 to 3

[0101] CaO 0 to 9

[0102] BaO 3 to 8

[0103] ZnO 0 to 2, whereby the sum of the contents of MgO, CaO and BaO is characterized by being in the range of 8 to 18 wt. / .

[0104] The glass on which the exemplary embodiment is based has the following composition in wt.%: SiO261

[0105] AI2O3 18

[0106] B2O3 10

[0107] CaO 5

[0108] BaO3

[0109] MgO3

[0110] The glass AF32 has a high optical transmission and a density p of 2430 kg / m 3 and a surface tension y of 0.3 N / m, a thermal conductivity A of 2 W / mK and a specific heat capacity c P of 1360 J / kgK. The transformation temperature T g The thermal expansion coefficient of AF32 glass is 713°C. AF32 glass has a low coefficient of thermal expansion, very close to that of silicon. The down-draw process also allows for the production of particularly smooth surfaces with a low roughness of less than 1 nm (RMS). The application temperature ranges up to approximately 600°C.

[0111] Another class of glasses suitable for the process described here contains the following components in wt%:

[0112] SiO250 - 70

[0113] AI2O3 10 - 20

[0114] B2O3 5 - 15,

[0115] CaO 4 - 8

[0116] BaO 0.5 - 5

[0117] SrO 4 - 8.

[0118] In one example, a glass is manufactured with the following components:

[0119] SiO2 60 wt%,

[0120] B2O3 10 wt%,

[0121] AI2O3 15 wt%

[0122] SrO 6 wt%

[0123] CaO 6 wt% BaO 2 wt%, and 1 wt% other components.

[0124] According to another embodiment, a glass ribbon with a thickness of preferably 32 pm ± 5 pm is drawn. An overflow fusion process, for example, is suitable.

[0125] Another class of glasses that are well suited for the invention because they can be processed into thin glass ribbons and easily divided by the insertion of dividing lines described here has the following components in wt.%:

[0126] SiÜ2 30 to 85

[0127] B2O3 3 to 20

[0128] AI2O3 0 to 15

[0129] Na2<3 3 to 15

[0130] K2O 3 to 15

[0131] ZnO O to 12

[0132] TiÜ2 0.5 to 10

[0133] CaO O up to 0.1.

[0134] An example of this class of glasses has the following composition:

[0135] SiO264.0

[0136] B2O3 8.3

[0137] AI2O3 4.0

[0138] Na2O 6.5

[0139] K2O 7.0

[0140] ZnO 5.5

[0141] TiO24.0

[0142] Sb2O30.6

[0143] CI-0.1

[0144] Glass panes with this composition generally have the following characteristics: CTE(20-300) 7.2-10-6 / K

[0145] Tg 557°C

[0146] Density 2.5 g / cm 3

[0147] Another class of glasses that can be chemically toughened and are particularly suitable for processing using the method described here have the following components in wt.%:

[0148] SiÜ2 50 to 65

[0149] AI2O3 15 to 20

[0150] B2O3 0 to 6

[0151] U2O 0 to 6

[0152] Na2<3 8 to 15

[0153] K2O 0 to 5

[0154] MgO 0 to 5

[0155] CaO 0 to 7, advantageously 0 to 1

[0156] ZnO 0 to 4, advantageously 0 to 1

[0157] ZrÜ2 0 to 4

[0158] TiO2 0 to 1, advantageously essentially TiO2-free

[0159] Furthermore, the glass may contain 0 to 1 wt.%: P2O5, SrO, BaO; as well as refining agents 0 to 1 wt.%: SnÜ2, CeÜ2 or AS2O3 or other refining agents.

[0160] According to one embodiment, ultra-thin glass sheets with one of the following thicknesses are produced from a glass having a composition from the above range: 20 pm ± 5 pm, 32 pm ± 5 pm, 40 pm ± 5 pm, 50 pm ± 5 pm, 75 pm ± 5 pm, 100 pm ± 10 pm. The glasses of the aforementioned class can be drawn into thin glass ribbons using both a down-draw and an overflow fusion process. These ribbons can be easily divided into glass sheets using the process described here by inserting predetermined breaking lines while achieving high strength. If necessary, the desired glass thickness can also be achieved by thinning, chemically or mechanically, if this is not possible or difficult in the drawing process. An example from this class of glasses has the following composition:

[0161] SiO260.7

[0162] AI2O3 16.9

[0163] Na2O 12.2

[0164] K2O 4.1

[0165] MgO 3.9

[0166] ZrO21.5

[0167] SnÜ2 0.4

[0168] CeÜ2 0.3.

[0169] All glasses mentioned here can be easily processed by down-draw into glass ribbons with a thickness in the range of 5 to 100 pm.

[0170] Without being limited to the example shown, a glass ribbon 4 with a predetermined glass thickness d in the range from 5 pm to 100 pm is cooled according to the method according to the invention preferably at a cooling rate of equal to or greater than (40 K / s because of Fig. 4) 50 K / s, preferably equal to or greater than 100 Kelvin / s, particularly preferably equal to or greater than 150 Kelvin / s or equal to or greater than 200 Kelvin / s.

[0171] As the diagram in Fig. 4 shows, with a glass ribbon thickness of 30 pm, a cooling rate in the range between 150 Kelvin / s and 300 Kelvin / s is preferably selected, with a glass ribbon thickness of 50 pm, a cooling rate in the range between 90 Kelvin / s and 180 Kelvin / s is preferably selected, and with a glass ribbon thickness of 100 pm, a cooling rate in the range between 45 Kelvin / s and 90 Kelvin / s is preferably selected.

[0172] Thus, without limitation to the example shown or the glass compositions described here, the glass ribbon is preferably cooled at a cooling rate in the range from 150 Kelvin / s ■ 30 pm / d to 300 Kelvin / s ■ 30 pm / d, where d denotes the thickness of the glass ribbon. Curve (b) in Fig. 4 denotes the upper limit of (1 / d) ■ 300 Kelvin / s ■ 30 pm, and curve (c) denotes the lower limit of (1 / d) ■ 150 Kelvin / s ■ 30 pm.

[0173] This preferred range can alternatively be expressed as follows: the glass ribbon is preferably cooled at a cooling rate which is in the range of (1 / d) ■ 4500 Kelvin ■ pm / s (curve (c)) to (1 / d) ■ 9000 Kelvin ■ pm / s (curve (b)), where d denotes the thickness of the glass ribbon.

[0174] This allows advantageous and particularly efficient glass panes with high edge strength to be achieved even at high cooling rates, taking the glass thickness into account.

[0175] 5a to 5c show cross-sections through filamented elements made of glass-based material 2, 4 in order to schematically illustrate possible forms of filamentary damage 14. In these examples, these are designed as hollow channels. Fig. 5a shows the simplest case when cylindrical hollow channels are introduced into the element 2, 4 as filamentary damage 14. The filament axis X passes through the center of the filamentary damage 14, also called filaments. The filament walls are axially symmetrical. In the example shown, the filaments 14 connect the top side O of the element 2 with its bottom side U. The hollow channel-shaped filament 14 thus represents a through-channel or a through-opening. As previously described, it is also possible for the filament not to form a hollow channel, but rather to be damage in the element 2, which is represented here by the reference numeral 144.The diameter of the filament, which includes both the hollow channel-shaped filament 14 and the filament-shaped damage 144, is designated F. The filament-shaped damages 14, 144, measured from the respective filament axis X, are spaced apart by the distance A. Between them is a web which, together with the separated filaments, forms the fracture edge in a severed element.

[0176] According to Fig. 5b, a truncated cone-shaped filament 14 can also be provided, which is synonymously referred to as a V-shaped filament. This can also be referred to as having a hollow channel. The truncated cone-shaped filament is, in particular, also axially symmetrical to the filament axis X. In the present illustration, the filament opens towards the underside of the workpiece. This means that the diameter (FO) of the filament 14 at the top of the element 14 is smaller than the diameter FU at the bottom. The widening of the filament 14 towards one side of the workpiece can be achieved in particular by adjusting the focus position of the beam-shaping optics, in particular by adjusting the convergence of the laser beam and the distance from the workpiece. Typical channel angles α for V- or X-shaped filaments are from 0.1° to approximately 30°, in particular from 0.1° to 10° or from 0.2° to 3°.This channel angle is measured between the perpendicular through element 2 and the inner wall of the filament and thus corresponds to half the opening angle.

[0177] Fig. 5c shows hourglass-shaped or synonymously x-shaped filaments (1), again designed as continuous hollow channels. This embodiment can be produced in particular by placing the area of ​​the narrowest focus of the laser in the volume of the workpiece. The same ranges as mentioned for the v-shaped filaments are advantageous for the channel and / or opening angle α. The x-shaped filaments are characterized by a constriction of the filament diameter in a region along the filament axis X. In the example shown, the constriction is in the middle of the element 2, i.e. at the same distance from its surfaces. There are also embodiments in which the constriction is arranged closer to one surface of the element 2 than to the opposite one.

[0178] Fig. 5d shows a top view of an element made of glass-based material 2, into which filament-shaped defects 14 have been introduced along dividing lines 12. However, the element 2 is not yet separated, i.e., not yet separated. This can be done in a subsequent step, as described. Element 2 essentially corresponds to a glass pane whose edges are being cut off. It is also possible for the inner contour to be removed.

[0179] Fig. 6a shows the top view of an element made of glass-based material that was separated along the separation line 12. The top view is of the upper side of the element, on which the filament diameter F is also measured as described. The upper side can also be identified on the filamented element, since the microstructure around the filament opening has features that allow a clear determination. The filaments 14 are arranged along the separation line 12 with the distance A. In the example shown here, A is greater than F. Between the filaments there is a web 60 that has a web width g. The web lies on the separation line or at least runs essentially parallel to it. The value for the distance-filament relationship Q, calculated as described by Q = A - F, is > 0. Fig. 6b shows an analogous top view, but the filament diameter F and the distance A between the filaments are chosen to be the same, so that Q = 0.Here, filament wall borders filament wall. In the true sense, no bridge 60 is formed as previously defined; instead, one filament merges into the adjacent filament at a sharp point.

[0180] Fig. 6b shows the top view of a described ultra-thin element made of glass-based material, into which the filaments 14 were inserted overlapping along the dividing line 12. This means that A was chosen to be smaller than F, so that Q < 0. Q takes on negative numerical values ​​here. Here, too, no bridge 60 can form, but rather a sharp transition occurs between the adjacent filaments, at least on the illustrated top side of the filament.

[0181] Fig. 7 is a diagram of edge strength as a function of pitch. The edge strength was determined as described above. As also described, the pitch is synonymous with the distance A between adjacent filamentary defects. These are usually located on the dividing line 12. The edge strengths of ultra-thin glasses are shown. The line marked 501 shows the edge strength as a function of pitch for an ultra-thin glass with a thickness of 40 pm, line 502 an ultra-thin glass with a thickness of 32 pm and line 503 an ultra-thin glass with a thickness of 20 pm. Thickness fluctuations and / or measurement inaccuracies can amount to approximately 3 pm to 5 pm in all of the examples shown. In this example, the edge strength as a function of pitch was measured for filament diameters of 0.6 pm, 0.8 pm and 1.0 pm.The curves do not differ in principle for these filament diameters and are largely superimposed, so that a separate representation was omitted.

[0182] Figure 7 shows that, quite surprisingly and remarkably, a maximum of edge strength occurs in the pitch range between 0.4 pm and 5 pm, with two local maxima at approximately 1.2 pm and 2.9 pm pitch. The position of these maxima is surprisingly independent of the material thickness or the thickness d of the ultra-thin glass-based material. Only the absolute values ​​of edge strength correlate with the thickness d; higher material thicknesses result in higher edge strengths than lower thicknesses d. The previously mentioned pitch ranges lie around these maxima, thus demonstrating their advantageous selection.

[0183] In the example underlying Fig. 7, the measurement was terminated at a pitch of 0.2 pm as the lower limit or minimum distance. The improvement in edge strength in the described pitch range is essentially independent of the diameter F of the filamentary damage 14.

[0184] The improvement in edge strength in the range shown is extremely significant; with a suitable pitch, an increase in edge strength of at least 30% is achieved for the main maximum at 1.2 pm, and more than 20% for the secondary maximum at approximately 2.9 pm. The inventors recognized that the existence of the two maxima allows the pitch to be selected within a relatively broad range to ensure high edge strength. This allows for high process stability, which ultimately contributes to reducing the amount of scrap and thus increasing resource efficiency.

[0185] The invention thus has the advantage of providing, for the first time, a processing window for the pitch, i.e., the distance A between adjacent filamentary damages 14, for ultra-thin elements made of glass-based material 2, 4, within which particularly good edge strengths can be achieved. The invention balances processing speed and manufacturing quality in such a way that a rational manufacturing process for ultra-thin elements made of glass-based material 2, 4 with a low reject rate is enabled. With its high edge strength reliably provided by the invention, the product can be transported further and / or further processed. This enables a more comprehensive application of ultra-thin elements made of glass-based material 2, 4, in particular of ultra-thin glass.

[0186] 1 Device for the production of glass panes 2

[0187] 2 glass panes

[0188] 4 glass band

[0189] 6 slot-shaped nozzle

[0190] 8 Device for hot forming

[0191] 10 glass melt

[0192] 12 dividing line(s)

[0193] 121 transverse dividing line(s)

[0194] 122 longitudinal dividing line(s)

[0195] 13 border

[0196] 14 filamentous lesion(s)

[0197] 15 Pressure roller

[0198] 16 ultrashort pulse lasers

[0199] 18 beam-shaping optics

[0200] 20 laser beam

[0201] 22 Focus area

[0202] 24 Movement device

[0203] 26 Cooling device

[0204] 27 Cooling oven

[0205] 28 Separator

[0206] 29 acceleration band

[0207] 30 edges

[0208] 32 - 38 beam profiles

[0209] 39 Inspection Unit

[0210] 60 bridge between filamentous lesions

[0211] 240 conveyor belt

[0212] 241 Deflection optics

[0213] 501 edge strength at pitch 40 pm

[0214] 502 edge strength at pitch 32 pm

[0215] 503 Edge strength at pitch 20 pm d Thickness of the element made of glass-based material

[0216] 0 Top

[0217] U bottom

[0218] A Distance between filamentary damages, synonym Pitch F Diameter of filamentary damages

[0219] Q Distance-filament relationship a Angle of the wall of a filamentary damage g Width of the web between filamentary damages

Claims

Patent claims 1. A method for producing ultra-thin elements made of glass-based material (2, 4) comprising the following steps: - providing an ultra-thin element made of glass-based material (2, 4) with a material thickness (d) of 5 to 100 pm, - generating a focused laser beam (20) by means of at least one ultrashort pulse laser (16) with a laser wavelength in which the element made of glass-based material is at least substantially transparent, - inserting filament-shaped damages (14) into the ultra-thin element made of glass-based material (2, 4) with the focused laser beam (20) along a dividing line (122), - wherein adjacent filament-shaped damages (14) have a distance (A) of 0.4 pm to 4.0 pm, - wherein the distance (A) between the centers of adjacent filamentary lesions (14) is measured.

2. The method according to claim 1, wherein the material thickness (d) is from 5 pm to 50 pm, preferably from 7 pm to 40 pm.

3. Method according to at least one of the preceding claims, wherein the distance (A) is from 0.5 pm to 3.8 pm, in particular from 0.6 pm to 2.0 pm or from 2.2 pm to 3.6 pm.

4. Method according to at least one of the preceding claims, wherein the filament-shaped damages (14) extend from an upper side (O) to the opposite lower side (U) of the element made of glass-based material (2, 4).

5. Method according to at least one of the preceding claims, wherein the diameter (F) of the filament-shaped damage measured on the side of the ultra-thin element made of glass-based material (2, 4) associated with the laser is from 0.1 pm to 1.2 pm, in particular from 0.4 pm to 1.0 pm.

6. Method according to at least one of the preceding claims, wherein the glass-based material (2, 4) comprises a glass or a glass ceramic.

7. Method according to at least one of the preceding claims, wherein a distance-filament relationship Q is set, wherein Q is determined by Q = A - F, and Q is in a range from - 0.4 pm to 3.6 pm, in particular from - 0.4 pm to 2.8 pm or from - 0.2 pm to 2.0 pm.

8. Method according to at least one of the preceding claims, wherein the element made of glass-based material (2, 4) is severed along the dividing line (122), wherein between filament-shaped damages (14) along the dividing line (122) a web with a web width (g) of 0.1 pm to 3.6 pm is formed or the web width (g) is in the range 0.1 < g < 2 F, preferably in the range 0.1 < g < F, particularly preferably in the range 0.1 < g < F / 2.

9. Method according to at least one of the preceding claims, wherein the element made of glass-based material (2, 4) is separated along the separating line (122), wherein the edge strength (K) of the element at least on one side of the separating line (122) is more than 120 MPa, preferably from 120 to 400 Mpa or from 125 to 300 Mpa or from 125 to 250 Mpa, particularly preferably an edge strength (K) in the range of 4 d < K < 10-d.

10. Method according to at least one of the preceding claims, wherein the element made of glass-based material is in the form of a flat substrate (2), in particular as Glass and / or glass-ceramic pane, and wherein the dividing line (122) is preferably inserted into edge regions of the flat substrate. 11 . Method according to at least one of the preceding claims, - wherein the glass-based material is present as a continuous glass ribbon (4) with a predetermined glass thickness (d), - wherein at least one longitudinal dividing line (122) is produced at least longitudinally to the glass ribbon (4) with an edge having a thickened border (13), and wherein the border (13) is severed along the longitudinal dividing line (122) to form an edge (30), and / or - wherein at least one transverse dividing line (121) is produced transversely to the glass ribbon (4) and wherein glass panes (2) are separated at the transverse dividing line (122) running transversely to the glass ribbon (4) to form edges (30).

12. The method according to claim 11, wherein the at least one longitudinal dividing line (122) is inserted in the hot region of the glass ribbon (4).

13. The method according to claim 11, wherein the at least one longitudinal dividing line (122) is inserted in the cold region of the glass ribbon (4), wherein the glass ribbon (4) is cooled at a cooling rate of equal to or greater than 40 Kelvin / s, preferably equal to or greater than 100 Kelvin / s, particularly preferably equal to or greater than 150 Kelvin / s or equal to or greater than 200 Kelvin / s, particularly preferably cooled at a cooling rate in the range of (1 / d) ■ 4500 Kelvin / (s ■ pm) to (1 / d) ■ 9000 Kelvin / (s ■ pm), where d denotes the thickness of the glass ribbon (4).

14. Method according to at least one of the preceding claims, wherein the beam profile of the laser beam (20) is shaped such that the extension of the laser beam (20) in the direction of the dividing line (12) is greater than transversely thereto.

15. Method according to at least one of the preceding claims, wherein the separation of the borders (13) at the longitudinal separation lines (122) and / or the separation of glass panes (2) by separation at the transverse separation lines (121) running transversely to the glass ribbon is carried out mechanically.

16. Ultra-thin element made of glass-based material (2, 4) with a thickness (d) in the range from 5 pm to 100 pm, which has filament-shaped damages (14) along at least one edge, which have a spacing (A) of 0.4 pm to 3.8 pm, in particular of 0.6 pm to 2.0 pm or of 2.2 pm to 3.6 pm.

17. Ultra-thin element made of glass-based material (2, 4) according to claim 16, wherein the diameter (F of the filamentary damages), measured at the top side (O) of the element, is from 0.2 pm to 1.2 pm.

18. Ultra-thin element made of glass-based material (2, 4) according to at least one of claims 16 to 17, with a distance-filament relationship Q, where Q is determined by Q = A - F, and Q is in a range from - 0.4 pm to 3.6 pm, in particular from - 0.4 pm to 2.8 pm or from - 0.2 pm to 2.0 pm.

19. Ultra-thin element made of glass-based material (2, 4) according to at least one of claims 16 to 18, wherein between filament-shaped damages (14) along an edge there is a web with a web width (g) of 0.1 pm to 3.6 pm or a web with the web width (g) in the range 0.1 < g < 2 F, preferably in the range 0.1 < g < F, particularly preferably in the range 0.1 < g < F / 2.

20. Ultra-thin element made of glass-based material (2, 4) according to at least one of claims 16 to 19, wherein an edge with filamentary damage (14) has an edge strength (K) of 120 MPa, preferably from 120 to 400 MPa or from 125 up to 300 Mpa or from 125 to 250 Mpa, particularly preferably an edge strength (K) in the range of 4 d < K < 10 d.

21. Use of an ultra-thin element made of glass-based material (2, 4) according to at least one of claims 16 to 20 or of an ultra-thin element made of glass-based material (2, 4) producible according to at least one of claims 1 to 15 for insulating intermediate substrates or spacers for electronic components, for encapsulating optoelectronic components, as a carrier for thin-film cells, such as thin-film batteries or thin-film solar cells, as a cover element for displays, in particular hinged and / or foldable displays, or as a substrate or composite substrate for displays and for microfluidic cells.

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