ELEMENT MADE OF BRITTLE MATERIAL HAVING A STRUCTURED EDGE, INTERMEDIATE BODY AND METHOD FOR MANUFACTURING SUCH ELEMENT - Patent application

Abstract

The invention is based on the problem of producing small components made of glass and glass-ceramics by laser-assisted etching in a consistent quality and at the same time simplifying their handling during production and for further processing. To this end, a plate-shaped element (10) made of a brittle material is provided, which has two opposing, in particular parallel, main faces (100, 101) and a peripheral end face (13) which defines the outer contour of the plate-shaped element (10), the end face (13) having at least one first region (15) and at least one second region (17), the first region (15) differing in its surface structure from the second region (17), the first region (15) having an etched surface and the second region (17) being a fracture surface, the area of ​​the at least one first region (15) being greater than the area of ​​the at least one second region (17), the first and second regions being arranged side by side in a direction along the end face (13).

Description

[Technical field]

[0001] The present invention relates generally to the manufacture of elements made of brittle materials, and in particular to the manufacture of such elements by forming a profile from a plate-shaped workpiece.

[0002] US Patent Application Publication No. 2018 / 215647 describes a method for introducing continuous channels into a plate-shaped glass element using an ultrashort pulsed laser, the pulse being formed by a focus expanding optical system, and in a subsequent etching process, mutually adjacent channels are removed together by etching away the material bridges between them, whereby structured elements with a defined geometry and specific end features ("cones") are separated and produced. In this way, glass or glass-ceramic elements, even with complex contours, can be obtained from the plate material.

[0003] US Pat. No. 1,094,069 describes a method for processing a plate-shaped workpiece having a layer of glass or glass ceramic, which workpiece is divided by selective laser etching into a number of incompletely separated subsegments, which initially remain connected to the remainder of the workpiece by a mesh-like connection, which is still realized with undercuts on the upper and lower sides, i.e. in a structured state (only in partial areas of the thickness).

[0004] US Patent No. 10,626,040 discloses a sheet glass product structured with two damage fields, the second of which has at least one interruption and is singulated after an etching process. The damage fields may overlap and are introduced into the material by a laser process, which may also include ultrashort pulses.

[0005] The method described in US 2018 / 215647 allows the structuring of transparent substrates made of glass or glass ceramic, generally made of brittle materials, in a two-step process, by first introducing a series of modifications laterally along the desired structure into the substrate by means of an ultrashort pulsed laser, and then expanding these modifications in a second step, preferably by means of an alkaline etching process, until the modifications are spatially connected and the inner and outer parts are separated from each other in the etching bath. However, when producing a number of products with small lateral dimensions from an initial substrate, handling problems arise, in that the separated micro-products float in the etching medium and accumulate in the bottom region of the etching tank, and therefore cannot be fed to further process steps in a controlled manner. This results in overlapping of glass elements, which leads to uncontrollable etching processes, damage during further handling, and generally leads to considerable quality variations in production. The invention is therefore based on the problem of producing glass and glass-ceramic miniature parts by laser-assisted etching in a consistent quality while at the same time simplifying their handling during production and for further processing. The basic idea of ​​the invention is that the miniature products produced after the laser contouring step and the subsequent etching remain connected to an adjacent holder or to another adjacent product by at least one web-like connection. The holder can fix one or more structured miniature products and can be realized in various geometries, such as one or more strips or a surrounding frame.

[0006] The invention therefore provides a plate-like element made of a brittle material, which has two opposing, in particular parallel, main faces and a peripheral end face defining the outer contour of the plate-like element, the end face having at least one first region and at least one second region, the first region differing in its surface structure from the second region. Here, the first region has in particular an etched surface. The second region is a fracture surface. The area of ​​the at least one first region is greater than the area of ​​the at least one second region. If there are a plurality of first and second regions, this condition applies to the total area. Thus, in this case, the total area of ​​the first regions is greater than the total area of ​​the second regions. In particular, the first and second regions are arranged side by side along the end faces or along a contour defined by the end faces. Particularly preferred brittle materials are glass ceramics, in particular glasses.

[0007] The elements made of brittle material are produced by separation from a larger intermediate body. The connection at the intermediate body greatly simplifies the handling of the elements.

[0008] The present invention therefore also provides a plate-shaped intermediate made of a brittle material for producing elements, the plate-shaped intermediate having a holding part and an element connected to the holding part by at least one connecting part, the element and the connecting part having an end face with an etched surface. The width of the connecting part at the transition to the element is smaller than the length of the contour formed by the end face with the etched surface, so that by separating the element by fracture of the brittle material at the connecting part, separated elements made of brittle material can be obtained, where the end face of the separated element has at least one first region and at least one second region, the first region differs from the second region in its surface structure, the first region has an etched surface and the second region is a fracture surface, the area of ​​the at least one first region is larger than the area of ​​the at least one second region, and the first and second regions are arranged side by side in a direction along the end face or along an outer contour defined by the end face. The present invention will be explained in more detail below with reference to the drawings. The intermediate body made of brittle material can be produced by a method in which a plate made of brittle material is provided and irradiated with a laser, where the brittle material of the plate is at least partially transparent to the laser, and the laser beam of the laser produces material modifications in the plate. The laser beam is guided along a path above the plate, so that the material modifications are aligned along the path. The plate is then subjected to an etching process, which expands the material modifications to form channels that eventually connect to separate the plate along the path. The path defines the contours of the elements connected to the holder by the connecting parts, resulting in a plate-like intermediate body according to the present disclosure. The connecting parts can then be separated to separate the elements from the holder to produce plate-like elements made of brittle material.

[0009] The invention will now be described in more detail with reference to the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1]FIG. 2 is a perspective view of a plate-shaped element made of brittle material. [Diagram 2] FIG. 2 is a diagram showing a cross section of a surface structure of a first region. [Diagram 3] 1A-1C show various variants of intermediate bodies each comprising an element made of brittle material connected to a retaining part; [Figure 4] FIG. 13 shows an embodiment in which several elements, each made of brittle material, are connected to a common retainer. [Diagram 5] FIG. 13 shows an embodiment in which several elements, each made of brittle material, are connected to a common retainer. [Figure 6] FIG. 13 shows an embodiment in which several elements, each made of brittle material, are connected to a common retainer. [Figure 7] 1 shows process steps for manufacturing an element 10 made of brittle material. [Figure 8] FIG. 13 illustrates an embodiment of an intermediate body subdivided into fields. [Figure 9] FIG. 1 is a diagram showing an apparatus for manufacturing an intermediate body made of a brittle material. [Figure 10] FIG. 1 shows a top view of an element made of brittle material. [Figure 11] 11 is a graph showing the distance from the end face position to the face midpoint for the element of FIG. 10 as a function of the path along the contour of the element. [Figure 12] FIG. 2 shows an example of an intermediate body with an element made of brittle material in the form of a gear wheel. [Figure 13] FIG. 13 is a diagram showing the height profile of the end face. [Figure 14] 1 is an optical microscope photograph of a glass element. [Figure 15] 1 is an optical microscope photograph of a glass element. [Figure 16] 1 is an electron microscope photograph of an end face of an element made of a brittle material. [Figure 17] 1 is an electron microscope photograph of an end face of an element made of a brittle material. [Figure 18] FIG. 2 is a diagram showing a camera module. [Figure 19] FIG. 2 shows a Weibull diagram of the breaking strength of glass elements. [Figure 20] FIG. 2 shows an intermediate body with a rectangular element made of brittle material. [Figure 21] FIG. 1 shows an example embodiment with elements made of brittle material. [Figure 22] FIG. 1 shows an example of an electro-optic assembly with an element. [Figure 23] FIG. 1 shows an assembly with an intermediate on a support for separating elements. [Figure 24] FIG. 13 shows a further assembly for separating the element from the holder.

[0011] Detailed Description of the Drawings FIG. 1 shows a perspective view of a plate-shaped element 10 made of brittle material. Brittle materials include, in particular, glasses and glass ceramics in general. These materials are characterized in particular by a generally high transmittance, for example, on average more than 80% in the range from 270 nm to 2700 nm, which facilitates their preferred manufacture by a laser-assisted etching process, which will be described in detail below. The plate-shaped element 10 made of brittle material has two opposing, in particular parallel, main faces 100, 101. The outer contour of the element 10 is formed by a peripheral end face 13. The end face 13 is subdivided into various sections or regions arranged side by side. Here, there is at least one first region 15 and at least one second region 17. These two types of regions differ in their surfaces. In particular, the first region 15 has an etched surface. On the other hand, the second region 17 is a fracture surface. Here, the area of ​​the first region 15 is greater than the area of ​​the second region 17. Here, these regions are not arranged one above the other as superimposed strips running parallel to the main faces 100, 101, but are lined up in a contoured direction, i.e. along the end face 13. The second region 17 of the end face 13 thus adjoins at least one of the ends 19, 20, at which the end face 13 transitions into the main faces 100, 101.

[0012] In the illustrated example, there are two second regions 17. The second regions 17 are spaced apart from one another so that between these two second regions 17 there is a first region 15 with an etched surface. Further first regions extend along the peripheral end face 13 of the element 10 and adjoin a second region 17 at two transitions facing away from one another. It is also possible to provide only one second region 17. If the end face is not otherwise treated, there is also only one first region 15. However, an embodiment with two or more spaced apart second regions 17, as in the illustrated example, is preferred. This is advantageous in order to allow a stable connection of the element 10 to the holder while still being easily separable. For the same reason, in an embodiment it is provided that at least one second region 17 or a plurality of second regions 17 together have a width of at least 0.5%, preferably at least 1%, of the maximum lateral dimension of the element 10. 1, where element 10 has a rectangular outline, the maximum lateral dimension is given by the length of the diagonal between two opposing corners. It is desirable for the width of a second region 17, or the sum of the widths of a plurality of second regions, to be at least 20 μm, preferably at least 50 μm, more preferably at least 100 μm.

[0013] It is generally advantageous for the etched surface of the first region to occupy the largest part of the end face 13, since such an end face 13 has a high stability, i.e. a high (mechanical) (end) strength. It is therefore generally provided in a preferred embodiment, without on the other hand being limited to the particular example shown, that the sum of all area percentages of the one or more first regions 15 to the total area of ​​the end face 13 is at least 90%, preferably at least 95%, particularly preferably at least 98%, in particular at least 99%.

[0014] Since the strength of a glass component is substantially determined by its surface characteristics, particularly the microcracks that run from the surface into the substrate, the strength of small components produced according to the present invention is characterized by a generally high strength over the majority of the surface exposed to the etching process (release process).

[0015] According to an embodiment, the strength of the element 10 against bending loads at the end face 13 can be higher, in particular significantly higher, in the first region than in the second region 17. By significantly higher strength is understood a strength that is on average at least 50 MPa higher. For example, according to one development, characteristic strengths of 80 to 200 MPa have been measured for glass elements with ends that have been previously damaged by filament formation with an ultrashort pulsed laser and then broken. In combination with an etching process, characteristic strengths of more than 150 MPa to 500 MPa have been measured when forming a surface similar to that in the first region. Here, the characteristic strength σ c is calculated by fitting a two-parameter Weibull distribution to the experimental data using the maximum likelihood method.

[0016] Thus, when elements 10 manufactured according to the present disclosure are tested for strength of the individual major surfaces / ends, for example by 3-point or 4-point bending or stepped rolling, there may be a significant difference in the characteristic strength between the end having the second region (i.e., the retaining web removed / broken) and the end not having the second region. The surface of the second region exposed by the removal of the web connections or retainers has lower mechanical strength and can be used or provided as the predetermined break point.

[0017] The small components retain their high strength even though the strength of the fracture surfaces of the surface areas exposed by the separation, i.e. the one or more second regions 17, is reduced. As already mentioned, it is also possible to use the one or more second regions 17 as predetermined fracture locations and take them into consideration in construction.

[0018] A further advantage of the subdivision of the end face 13 into at least one first region 15 and at least one second region 17 is that alignment is possible. The second region can thus serve as an orientation mark for the alignment of the part. For example, a robot can recognize this second region and use this to grasp or install the element 10 in the intended orientation. If the alignment of the second region 17 is asymmetric with respect to the axis of symmetry of the element, the robot can also determine how the main surface is oriented, for example which main surface is up. This is particularly important if one of the main surfaces is coated.

[0019] In a preferred embodiment, the number of such second regions 17 with modified strength, introduced as fracture surfaces, should be minimized. Overall, it is advantageous if the number of connections and thus the number of second regions is at most 50, preferably at most 10, more preferably at most 5 and very particularly preferably at most 3. In a particularly preferred configuration, the structuring is carried out in such a way that the small members are connected to the holder by one or two connections. As will be explained below with reference to FIG. 3, by means of several connections the small members can be fixed from different directions, in a preferred embodiment from the same direction for stability reasons, or even in parallel. In a preferred embodiment, the small members or elements 10 are connected to the holder by parallel connections, preferably two parallel connections.

[0020] The two types of regions 15, 17 can also differ in features other than the surface texture. For example, the end faces of both regions can have different angles relative to the main surface 100, 101. For example, one or more of the first regions 15 can have tapered angles at both ends 19, 29 due to an etching process. Furthermore, the second region 17 can have a slope such that one end is protruding and / or the other end is recessed due to a breaking process. In addition to different surface structures, the first and second regions 15, 17 can also have different end geometries or shapes.

[0021] In general, the taper angle of the end face of the first region can also be induced by the direction of incidence of the laser beam, whereby obliquely extending filamentary damage is introduced into the material, so that during etching an end face with a surface lying obliquely along the filament direction is generated accordingly.

[0022] The different surface structures of the first and second regions 15, 17 can be distinguished by one of the following characteristics, among others: roughness, reflectivity, visual appearance. According to one embodiment, both regions 15, 17 have the same, or at least indistinguishable visual appearance to the naked eye, although they are indeed distinguishable.

[0023] The element 10 is preferably realized as a miniature product for precision or micromechanical applications, such as, for example, design and functional elements for the watch industry, packaging (sealing) components for optoelectronic emitters or sealing components for optoelectronic sensors. In this respect, the element preferably has a maximum lateral dimension of at most 100 mm, preferably at most 80 mm, particularly preferably at most 50 mm. Smaller components can also be produced, with a maximum lateral dimension of 30 mm. Furthermore, a maximum lateral dimension of 0.3 mm or more, in particular 1 mm or more, preferably 3 mm or more, particularly preferably 5 mm or more is preferred.

[0024] FIG. 2 shows a cross section of the surface structure of the first region according to a preferred embodiment. It is generally preferred that the etched surface of the first region 15 has cone-shaped recesses 22. In particular, it is also possible for the cone-shaped recesses 22 to be more or less directly adjacent to one another, so that adjacent recesses 22 are separated by ridges 24. The depth of the cone-shaped or rounded recesses is preferably less than 5 μm. According to an embodiment, the lateral dimensions of the recesses 22 are on average in the range from 5 μm to 200 μm, preferably in the range from 5 μm to 100 μm, in particular in the range from 5 μm to 50 μm, particularly preferably in the range from 5 μm to 20 μm. Here, according to one development, the ridges 24 form the polygonal boundary of the cone-shaped recesses 22 when viewed from above the first region 15.

[0025] The average lateral dimension of the cone-shaped recesses can be influenced by the duration of the etching process. Cone-shaped recesses are typically formed at low removal rates, preferably using alkaline etching media, such as KOH or NaOH solutions. However, etching with acidic etching media is also possible. According to a preferred embodiment, the material is removed at a removal rate of less than 15 μm per hour, preferably less than 10 μm, particularly preferably less than 8 μm per hour. Depending on the amount of material removed after the integration of the channels formed along the filamentary damage, the channels at the ends of the plate-like element can still be recognized as laterally open adjacent channels or, conversely, as ribs. These ribs remain where the channels join during etching. If the etching is continued longer after the integration of the channels, these structures are flattened and, in addition to the cone-shaped recesses, a surface without superstructures in the form of semi-open channels or ribs is formed. Preferably, the polygons formed by the ridges have an average number of sides of less than 8, preferably less than 7. The ridges 24 are relatively steep compared to the curves of the cone-shaped recesses. Accordingly, the area ratio of the convexly curved portion that should be present on the ridge line at approximately the center is very small. The area ratio of the convexly curved portion of the etched surface is preferably less than 5%, in particular less than 2%.

[0026] The surface structure resulting from the particularly low etching rate is generally characterized by high edge strength, which is particularly advantageous for small components subjected to mechanical stress.

[0027] The properties of such surfaces and their production are described in U.S. Patent Application Publication No. 2018 / 215647, which is also incorporated herein in its entirety with respect to the laser-assisted etching method and the surface structures produced thereby.

[0028] FIG. 3 shows various embodiments of a structured plate-like intermediate body 1 made of brittle material in partial views (a) to (e). The intermediate body each comprises an element 10 as a separable material part, which is connected to a holding part 6 by a connection 2, preferably in the form of a web-like material bridge. Here, in all the embodiments shown, the holding part 6 is designed as a frame. Here, the element 10 is arranged in the frame 8 or in an opening 9 defined by the frame 8 and is connected to the frame 8 or more generally to the holding part 6 by one or more connections 2. In the example of partial view (a), the element 10 is connected to the frame 8 by a single connection 2 in the form of a web. Due to the manufacturing process, the inner end surface 80 of the opening 9 of the frame-like holding element 6 generally has the same surface structure, i.e. in particular a similar etched surface, as the first region 19 of the end surface 13 of the plate-like element 10. This is advantageous, since it also gives the frame 8 a high stability.

[0029] In order to increase the mechanical stability of the isolated element (10), according to one embodiment, the contour of the element 10 may be convexly configured adjacent the second region 17 or may be curved outwardly, as is also realized in the example of partial view (a) of Fig. 3. This geometry reduces the tensile forces occurring in the second region 17 under mechanical stress compared to a straight or arched contour.

[0030] In the example of partial view (b), there are two connections 2 which engage on opposite sides of the element 10 to hold the element 10. In the examples of partial views (c) and (d), two material bridges or connections 2 are also provided, respectively. Here, in the example of (c), the connections 2 hold the element 10 on two different sides. In other words, the longitudinal directions of the material bridges 2 are here transverse and, in particular, perpendicular to one another. In the example of (d), the connections or material bridges 2 are arranged side by side. The longitudinal directions of these connections 2 are therefore substantially parallel.

[0031] In order to provide the required mechanical stability to the manufactured element or to the small or ultra-small product, the holding part 6 is, according to a preferred embodiment, larger in at least one lateral dimension than the connecting part 2 and / or the element 10, without being limited to the particular example shown.

[0032] For reasons of mechanical stability, the connection part 2 according to the further embodiment generally has a width of, without being limited to a specific example, at least 0.5 percent (0.5%), preferably at least 1 percent, of the maximum lateral dimension of the connected microproduct or glass or glass ceramic element 10, but according to a further alternative or additional embodiment, at least 100 μm. In order to allow good separability of the element 10, it is further preferred in general that the width of the connection part is at most 50%, preferably at most 30%, particularly preferably at most 20%, and particularly preferably at most 10% of the maximum lateral dimension of the holding part 6 or of the glass or glass ceramic element 10 connected to the connection part 2.

[0033] In order to stably hold the element 10 while still being able to separate it well from the holding part 6, it is generally preferred according to a further embodiment if the mutual spacing between at least two connecting parts 2 holding the element 10 is at least half, preferably at least the same and particularly preferably at least twice the thickness of the intermediate body 1 or the element 10. By mutual spacing is meant here the distance between the ends of the connecting parts 2. Thus, according to this embodiment, the width of the first region 15 between the two second regions 17 in the example shown in FIG. 1 is also at least twice the thickness of the element 10. According to a further alternative or additional embodiment, the mutual spacing between the connecting parts is at least 20 μm.

[0034] Furthermore, more than two connections 2 can also be provided. In this respect, part (e) of FIG. 3 shows an embodiment example in which the element 10 is connected to the holding part 6 by three connections 2. Here too, it is preferable if the connections 2 run substantially parallel. However, as explained above, it is generally advantageous, without being limited to the illustrated example, if only a small number of connections are provided. As is the case in the illustrated example, it is advantageous if the number of connections is at most 50, in particular at most 10, preferably at most 5, particularly preferably 1 to 3. In many cases, a single connection 2 is sufficient.

[0035] If several elements 10 of different types and sizes are connected to the holding part 6, the aforementioned dimensions are preferably given for each element and the associated connecting part 2.

[0036] In the simplest case, the separation of the small pieces or elements 10 is purely mechanical, i.e. by applying mechanical stress at the transition from the element 10 to the connecting element 2. However, such a separation process can lead to tear cracks in the small pieces or connecting elements 2, leaving small material protrusions or shell-like depressions / cuts in the contour of the element 10. To avoid such defects, the transition area between the connecting element and the small pieces can be structured by targeted introduction of pre-damage in order to control the stress progression and thus the crack growth. For this purpose, methods known from the prior art can be used, for example mechanical scribing or even laser-based methods such as ablation, stealth dicing, laser thermal cutting or even filament formation along the desired separation line. Thus, according to an embodiment, as also shown in FIG. 3, a weakened structure 4 is provided which extends along the separation line provided between the connection 2 and the element 10.

[0037] In particular, the weakening structure 4 between the connection 2 and the small member or element 10 can be structured by a filamentation process, in which a series of through-holes, or filamentary damage, which may be designed as through-holes, typically with a diameter in the submicron range, is introduced at a predefined distance along the desired contour or separation line by means of a focused ultrashort pulsed laser. For this, according to an embodiment, the already structured intermediate body 1 with the holding part 6, the connection element 2 and the element 10 can be introduced into an ultrashort pulsed laser system and processed thereby. Such a broken end pretreated by filamentation is advantageous compared to a broken end provided without a weakening structure, for example, since it can be separated from the connection 2 with a lower force. Furthermore, the force required for separation is almost the same and the end is hardly visually noticeable. In contrast, a non-filamentation-formed end is prone to visible chipping on the surface. Furthermore, a significantly higher force must be applied, which also increases the risk of damage to the actual element 10.

[0038] In a preferred embodiment, these additional modifications are introduced perpendicular to the extension direction of the connecting element and in addition to the existing profile.

[0039] Further alternatively or additionally, the weakened structure 4 may comprise areas of reduced thickness. For example, such a reduction in thickness may be achieved by laser ablation.

[0040] Yet another method is the introduction of indentations using a scribing tool, such as a scribing wheel or a scribing diamond.

[0041] Advantageously, it is provided that the weakened structures 4 are manufactured in a separate process step after the contour of the intermediate body 1 has been formed, i.e. after the etching process. The weakened structures can be formed, for example, as continuous or discontinuous trenches (and thus as localized thinning) in at least one of the two surfaces, as perforations (for example by filament formation with an ultrashort pulsed laser) or by internal modification, as in the case of so-called stealth dicing. In general, the weakened structures can be detected using optical or electron microscopy.

[0042] 4 to 6 show an embodiment of an intermediate body 1 in the form of a structured plate made of brittle material, in which several elements 10 are connected to a common holding part 6. In the embodiment according to FIG. 4, the holding part 6 is designed in the form of a strip. The holding part 6 therefore does not surround the elements 10 in the form of a ring or frame here. As a result, at least one end of the elements 10 is exposed, without the holding part 6 hindering access. This can be advantageous, for example, if the glass or glass-ceramic element 10 is gripped with pliers and separated from the holding part 6. For example, a pliers-like tool can be provided as part of a robot in automated production.

[0043] In the example of FIG. 5, a number of glass or glass ceramic elements 10 are arranged in a matrix in a common opening 9 of a holding part 6 designed as a frame 8. According to one embodiment, the glass or glass ceramic elements 10 are arranged in rows on the holding part 6 in the form of a frame 8, in particular in a matrix with two or more rows of elements 10. As in the example shown, an arrangement with two rows in the opening 9 of the frame is particularly preferred. This allows the elements 10 to be attached separately to opposite sides of the opening by means of the connecting parts 2. As shown, a number of, in particular two, connecting parts 2 can be provided for each element 10 respectively. As in the example of partial view (d) of FIG. 3, two parallel connecting parts 2 are provided here. The embodiment shown here with two, in particular parallel web-like connecting parts 2 is exemplary, and it is also possible to use less than two or even more than two connecting elements for each small part. In the example of Figure 6, a general embodiment is realized in which at least two elements 10 are arranged in an opening 9 of a holding part 6 designed as a frame 8, the two elements 10 being connected to each other by at least one connecting part 20 extending from one element 10 to the other element 10.

[0044] Figure 7 shows the process steps for manufacturing an element 10 made of a brittle material according to the present disclosure as illustrated by way of example in Figure 1. In general, without being limited to the specific example shown, the method for manufacturing the intermediate 1 and the method for manufacturing the plate-like element 10 made of a brittle material are based on the following steps: A plate 3 made of a brittle material is provided, as shown in partial view (a) of Figure 7.

[0045] Suitable brittle materials are in particular glasses or glass ceramics, in particular alkali-free (AF) glasses, borosilicate glasses, glasses with the product names AF32, AF35, AS87, D263, D263T, B270, MEMPAX, Willow, G-Leaf, EN-A1, BDA-E.

[0046] Below is a list of glasses that are particularly suitable for a manufacturing method that involves laser irradiation, formation of filamentary damage, and then integration of expanded channels along the filamentary damage by etching.

[0047] According to a first embodiment, the composition of the glass comprises, in percentages by weight, the following components: [Table 1]

[0048] According to a further embodiment, the composition of the glass of element 10 comprises the following components: [Table 2]

[0049] In a further embodiment, the composition of the glass comprises the following components: [Table 3]

[0050] Another suitable composition of the glass of element 10 is given below: [Table 4]

[0051] According to yet another embodiment, the composition of the glass of element 10 comprises the following components: [Table 5]

[0052] For all the above glass compositions, coloring oxides such as Nd2O3, Fe2O3, CoO, NiO, V2O5, MnO2, CuO, Cr2O3, etc. can be added as needed. As fining agents, 0-2 wt.% of As2O3, Sb2O3, SnO2, SO3, Cl, F and / or CeO2 can be added, each of which totals 100 wt.% of the entire composition.

[0053] Overall, the thickness of the sheet material 3 is preferably in the range of 20 μm to 6000 μm, preferably up to 5000 μm, particularly preferably in the range of 20 μm to 3000 μm. In a first step, the contours of the holding and connecting elements and the small products or elements 10 are defined. For this purpose, the sheet material 3 made of a brittle material is irradiated with a laser, the brittle material of the sheet material 3 being at least partially transparent to the laser, and the laser beam of the laser produces material modifications 5 in the sheet material 3. The laser beam is guided above the sheet material 3 along a path 50, so that the material modifications are aligned on the path 50. In the partial view (b) of FIG. 7, the sheet material 3 with the material modifications aligned on the path 50 is shown. Modifications here may be understood to mean material changes such as refractive index changes (localized or continuous), localized material thinning in the form of trenches, wedges, cavities, internal damage to the substrate, e.g. microcracks, localized melting, through holes (cylindrical or more general shape), or filaments or filament-like damage.

[0054] In order to separate the unnecessary excess parts from the substrate parts necessary for the retaining parts 6, the connecting elements 2 and the small products or elements 10, in a next step, the existing modifications are reinforced, i.e. expanded, by an etching process, so that the modified areas come into contact or overlap, resulting in a continuous and uninterrupted weakening or even separation of the material along the intended target contour. Thus, the sheet material 3 is then subjected to an etching process, which expands the material modifications 5 to form channels, which eventually connect, separating the sheet material 3 along the path 50. The path 50 defines the contour of the elements 10 connected to the retaining parts 8 by the connecting parts 2. As a result, after separation along the path, a sheet-like intermediate body 1 according to the present disclosure is obtained.

[0055] The etching may be with an acidic etching medium, for example an aqueous solution of HF, HCl, H2SO4, HNO3 or other acids. It is preferred to etch with an alkaline etching medium, for example caustic potash, KOH or caustic soda, NaOH. According to one development, it is provided that the etching is carried out with an alkaline etching medium having a pH value of more than 12 and with a complexing agent, whereby at least one of the components of the brittle material is complexed by said complexing agent. According to one development, alkaline earth metal ions, preferably calcium ions (Ca 2+ ) is used. According to yet another development, the complexing agent is selected from the group of phosphates, preferably ATMP (nitrilotris(methylenephosphonic acid)), phosphonic acids, salts of hydroxycarboxylic acids, preferably alkali metal gluconates, EDTA and / or transition metal salts, in particular CrCl3. The above measures can advantageously counteract local inhibition of the etching process by complexation of the released components. On the contrary, a self-stabilizing or even self-strengthening effect on the etching rate can occur even in the structures produced.

[0056] Furthermore, etching solutions containing silicate, preferably alkali metal silicate, particularly preferably water glass, in solution can also be used. The use of etching solutions containing dissolved silicate allows the etching rate to be significantly increased. This effect is observed in particular at high silicate concentrations in the etching solution. In particular at high silicate concentrations, silicate also acts as an alkali carrier, thus increasing the mobility or ionic mobility of hydroxide ions. This is particularly advantageous in embodiments where the hydroxide concentration in the etching solution is very high. For example, the ionic mobility of hydroxide ions decreases with increasing concentration at very high concentrations of alkali, which also affects the etching rate. However, this effect can be at least partially counteracted by adding silicate as an alkali carrier.

[0057] The etching process separates the sheet 3 along a path 50 similar to the contour of the elements 10 and the connections 2, resulting in the elements 14 being cut off from the sheet 3, which are complementary to the elements 10 with their connections 2. Unnecessary substrate parts therefore fall off partly or entirely from the structured substrate during the etching process (for example if auxiliary cuts are introduced before etching). At the end of this step there is a member consisting of one or more retainers, one or more miniatures and one or more connections to their retaining elements or to each other. This member is characterised in particular by a surface structure resulting from the etching process.

[0058] By cutting off this element 14, the intermediate body 1 is obtained. This is illustrated in the partial view (c) of FIG. 7. Contrary to the illustration, the contour of the element 10 can be formed without cutting off the complementary element 14, for example by tracing the contour as a path with a laser beam and then etching away narrow slits along the path in an etching process. It is also possible to cut off a number of smaller pieces instead of a single complementary element 14 to form the element 10. At the end of the process sequence, there is a separation step, in which the small pieces or elements 10 are separated from their connecting elements along a predefined separation line. Thus, a method for producing the element 10 is also provided, in which, after the intermediate body 1 has been produced, the connecting parts 2 are separated, thereby separating the element 10 from the holding part 6. This step is illustrated in the partial view (d) of FIG. 7.

[0059] It is particularly advantageous if the step shown in FIG. 7(d) is carried out separately in time from the production of the intermediate, i.e. at a clearly later time and / or at a different location, for example after a storage or transport process, for example in order to incorporate the element 10 in an apparatus provided for this purpose. The advantage of the intermediate 1 produced in this way is that the position of the subsequent small products or elements 10 is stabilized and therefore it can be easily further processed, either by processing the intermediate as a whole directly or with additional handling aids. The further process steps can be, without claiming to be all-inclusive, coating, printing, restructuring of the surface or parts of the surface or a combination thereof. Furthermore, according to an embodiment, the intermediate 1 can be subjected to chemical strengthening. The connection of the element 10 to the holding part 6 also allows easy handling during this further processing. It is generally advantageous to use alkali-containing brittle materials for the chemical strengthening, such as glasses or glass ceramics with a sufficiently high Na2O content. Preferably, the Na2O content for this purpose is at least 5% by weight. In order to facilitate the separation of the element 10 from the holding part 6 at the connection 2 even in the chemically strengthened state, according to one development, it is advantageous here if the width of the connection 2 is smaller than twice the exchange depth (DoL). In this case, the connection 2 is chemically strengthened over its entire cross section, so that the risk of uncontrolled fracture due to stress variation along the fracture is reduced. According to another development, it is also possible for the width of the connection 2 to be smaller than four times the exchange depth (DoL), or preferably smaller than three times the exchange depth. This is particularly useful in thick glasses, in order, on the one hand, to still allow a non-breaking separation and, on the other hand, to limit the exchange depth. Furthermore, according to one embodiment, channels, for example 10 μm long, can be provided in the connection 2. By permeating these channels with an exchange bath, chemical strengthening can also occur around these channels. In this way, the transition region from the connection to the element 10 can likewise be chemically strengthened in its volume to such an extent that high stress differences at the fracture point are avoided. Analogous to the weakening structure 4 shown in FIG. 1, at least one channel can be introduced both on the main face and on the end face.

[0060] At the end of the separation process steps, the holding part with the connecting elements and the small parts or elements 10 are separated. The main faces 100, 101 may now be subjected to structuring or other forms of further processing.

[0061] As already explained with reference to FIG. 1, the surface exposed by the separation process has a second surface structure different from the first region exposed by the etching process, which is for example a smooth surface in the case of a preceding mechanical separation and an optically rough surface penetrated by open, vertically extending filamentation channels in the case of laser drilling by a filamentation process. For each original connection 2, the end face 13 of the element 10 has a second region 17 with an area corresponding to the cross section of the connection 2 in the contact area between the connection 2 and the element 10. As a result, the sum of the surface proportions of the second regions 17 in the total area of ​​the end face 13 is significantly smaller than the sum of the proportions of the first regions 15. Preferably, the proportion of the second regions 17 is less than 20%, preferably less than 10%, particularly preferably less than 5%. An area proportion of less than 2%, in particular less than 1%, is very particularly preferred.

[0062] FIG. 8 shows an embodiment example of an intermediate body 1 subdivided into fields. In this embodiment, the small parts or elements 10 present in the frame 8 can also be produced in a cascade manner, by first structuring or pre-damaging the plate material 3 according to the geometry of the holding part 6 in a first process step, and structuring the frame 8, the connecting element 2 and the subfields in the element 10 in a second process step. Here, by appropriately selecting the process parameters, for example the pitch, it can be ensured that only the elements 10 are exposed by the etching process, and not the perforations 26 between the frames 8. This embodiment of the intermediate body 1 is based on the fact that the intermediate body 1 has a plurality of holding parts 6 in the form of frames 8, in which at least one element 10 is arranged in each case, which are connected to the frame 8 by at least one connecting part 2, and which are connected to one another in a separable manner by one or more perforations 26.

[0063] In the example of Fig. 8, yet another embodiment is realized. The laser-assisted etching process that defines and forms the contours of the elements 10 can also produce alignment marks 28 in the form of through holes. As shown in Fig. 8, in frames 8 connected by several fields or perforations, all holding elements 6 in the form of frames can be provided with such alignment marks 28. This allows easy and precise alignment thereof after separation of the frames 8, for example for further processing processes.

[0064] According to an embodiment of the method, it is provided that the structuring by ultrashort pulsed laser is carried out inline in the manufacturing process of the substrate glass. In particular, it is envisaged to integrate the laser structuring inline in a continuous drawing process for producing a continuous glass ribbon. It is furthermore preferably provided to combine the laser structuring in the manufacture of thin and ultra-thin glass with a thickness of less than 400 μm, preferably at most 200 μm, in particular at most 100 μm, or even at most 50 μm or at most 30 μm. The manufacture of thin glass can be carried out by the downdraw or overflow fusion method. The structured glass ribbon can be directly etched inline. Alternatively or additionally, after the structuring by laser, the glass ribbon can be wound up on a roll or separated by a further process transversely to the feed direction of the glass ribbon, so that it can be cut to the desired length in the feed direction. In these variants, the structuring, the etching steps and, if necessary, the separation can be separated from one another in time and space. In this respect, FIG. 9 shows an apparatus 29 for the production of a glass ribbon, which is further developed into an apparatus for the production of an intermediate body 1 according to the disclosure. In the example shown, the apparatus 29 is designed to wind up an initially unstructured sheet material 3 on a roll 44 in the form of a continuous glass ribbon 30. First, the glass melt 32 is drawn through a nozzle 34 to obtain the glass ribbon 30, while a drawing roller 36 arranged below the nozzle 34 exerts a tensile force on the glass emerging from the nozzle 34. The illustrated variant shows a downdraw process, in which the glass emerges from a nozzle opening downwards. In the overflow fusion process, the glass flows over the edge of an elongated trough that opens at the top and then down the side wall of the trough. The glass ribbon is obtained by merging the partial flows below the trough.

[0065] As shown, the glass ribbon 30 is deflected, preferably horizontally, and moved by a conveying device 38, for example a belt conveyor. The structuring by introducing filamentary material modifications along a path 50, as shown in the partial view (b) of FIG. 7, is performed inline on the undivided glass ribbon 30 by an ultrashort pulsed laser 40. The laser beam 41 of the ultrashort pulsed laser 40 is focused on the glass ribbon 30 by beam optics 42 and guided along the desired path 50 above the glass ribbon 30. In the illustrated variant, the glass ribbon 30 is then wound on a roll core 46 to form a roll 44. Alternatively or additionally, the glass ribbon 30 can be passed through an etching bath in order to produce the contours of the elements 10, as shown in the partial view (c) of FIG. 7. Thus, the method and device 29 according to the present embodiment are based on the following facts: - as the non-structured plate material 3, a continuous glass ribbon 30 is produced from a hard and brittle material in a continuous drawing process, - During the drawing process, a material modification is introduced into the moving continuous glass ribbon 30 by an ultrashort pulsed laser 40 along a predetermined path 50.

[0066] Since the one or more second regions 17 of the end face 13 may be weaker than the first regions 15, it is advantageous to provide the second regions at locations where mechanical stresses are generally lower. In the ideal case, the second regions 17 can be located at locations where stresses are minimal in a given, for example symmetrical, case of loading. In this regard, preferred embodiments for the arrangement of the one or more second regions at the end face 13 are described below. According to a preferred embodiment, at least one second region 17 extends along a position on the end face 13 at a distance of at least 2 / 3 of the maximum distance from the face center point. For the same purpose, alternatively or additionally, it can be provided that at least one second region 17 extends along a portion of the end face 13 which is subjected to a mechanical load of at most 80%, preferably at most 60%, particularly preferably at most 40% of the maximum load when loaded.

[0067] For the purpose of explanation, FIG. 10 shows an example of an L-shaped element 10 with the main surface 100 viewed from above. The surface center point 103 is not necessarily located within the main surface 100 of the element 10. This is also the case for the illustrated element 10. The coordinates (p x ,p y For each point in m x ,m y The distance d to the surface center point 103 of the x -m x ) 2 +(p y -m y ) 2 ) 1 / 2 It can be found according to the following.

[0068] In this regard, FIG. 11 shows a graph of the distance d from the location of the end face or contour to the surface midpoint for the element of FIG. 10 as a function of the path s along the contour of the element 10. The point 104 at which the distance from the contour to the surface midpoint 103 is minimal is selected as the starting point. The arrows indicate the direction of movement of the contour. In FIG. 10, the corners of the contour are represented by the letters a, b, c, d, e, f. These points are also represented in the diagram of FIG. 11 and are easily recognizable as peaks. The maximum distance to the surface midpoint 103 is at the location of the corner e. A dashed line is drawn in FIG. 11, which indicates a value of 2 / 3 of the distance at point e. On the scale of FIG. 11, the distance of the corner e is approximately 51 (arbitrary units). The limit value of 2 / 3 of this value is therefore approximately 34. In the example shown, the preferred location of the connection to the connection 2 is therefore the end of the legs 105, 106. The preferred fastening area 107 is shown by a dashed line for clarity. As can be seen from the diagram in Fig. 11, the corner d is indeed also relatively far from the face midpoint 103, but it does not yet fulfill the condition of at least 2 / 3 of the maximum distance. In fact, this area is also less suitable for fastening by the connection 2, since the fracture surface in the area of ​​the corner d may be subjected to tensile stresses when the legs 105, 106 are subjected to a mechanical load.

[0069] FIG. 12 shows a further example in which the arrangement of the second regions or, in the case of the intermediate body 1, the connection positions of the element 10 to the holding part 6 by the connections 2, fulfill the design specifications explained above. Here, FIG. 12 shows an intermediate body 1 with a holding element 6 in the form of a frame. In an opening in the frame, an element 10 in the form of a gear is connected to the frame 8 by two connections 2. Here, the connections 2 are connected to the element 10 at the outer ends of the toothings 108. In these parts of the contour, the distance to the face center point 103 is greater than in the recesses between the toothings 108. These outer regions of the toothings 108 furthermore have a maximum distance to the face center point 103 of the gear center.

[0070] In general, it is not only possible to generate end faces with a straight profile, in particular a profile that extends substantially perpendicular to the main faces 100, 101. Instead, it is also possible to generate end faces with curved profiles or cross sections. In addition to inwardly curved, i.e. concave, profiles, in particular outwardly curved profiles, can also be generated. In this regard, FIG. 13 shows a height profile of the end face 13 of the element 10 in the first region 15. The steep drop in the height profile to local minima at x-positions of approximately -321 μm and +372 μm represents the location of the main faces 100, 101. As can be seen from this profile, the end face is outwardly curved by an amount in the range of 10 μm to 15 μm. Such profiling can be achieved in general by fully or partially introducing filamentary damage at an angle. Alternatively or additionally, the etch removal rate can be influenced by generating filamentary damage that terminates at least on one side within the material.

[0071] In this regard, without being limited to a particular embodiment, it is provided that the end face 13 having the etched surface of the first region has a profile that is curved outwardly or inwardly by at least 1% of the thickness of the element 10.

[0072] 14 and 15 are optical micrographs of a glass element. The end face 13 of the element 10 is curved outward as shown in the example of FIG. 13. As shown in FIG. 14, the element 10 has a ring-shaped portion to which a rod-shaped portion is connected, which is visible in the upper right corner of the image. Both regions 15, 17 are barely visually distinguishable in the photograph of FIG. 14. FIG. 15 shows a further enlarged photograph of the end face 13 with the regions 15 and 17. In particular, the transition 18 between the regions 15 and 17, which can be recognized as a line, is visible here. In any case, the broken end of the second region 17 is also barely visually distinguishable from the etched surface of the first region. This is due in particular to the fact that the roughness of both these regions can be adapted to each other. The roughness of the first region can therefore be influenced by the etching parameters. In the second region 17, the roughness can be influenced in particular by the type and configuration of the weakening structures 4, for example the spacing of the filamentary damage along the weakening line. Thus, in one embodiment, without being limited to the illustrated example, it is provided that the ratio of the average roughness Ra of the first region 15 to the average roughness Ra of the adjacent second region 17 is in the range of 0.75 to 1.25. Both regions 15, 17 have an appearance similar to a polished surface, as in the illustrated example according to a preferred embodiment. Thus, in particular, both regions can have the same overall visual appearance, without being limited to the illustrated example.

[0073] The second region 17 is typically formed flat, since it is preferably a broken end. However, even here, by certain measures, other forms, such as convex or concave curvatures, can be achieved. For this purpose, for example, multiple filamentary damages can be introduced at different angles as weakening structures.

[0074] In order for both regions 15, 17 to visually match one another, it is furthermore advantageous for the height deviation between the second region 17 and the adjacent first region 15 to be less than 20 μm. This characteristic is also fulfilled in the examples shown in figures 14 and 15. The second region 17 is neither protruding nor perceptibly recessed. This characteristic can be achieved in that at the connection 2 the weakened structure 4 ends close to or proceeds to the outer contour of the adjacent first region 15.

[0075] 16 and 17 show two electron microscope photographs of the end face 13 of an element 10 made of brittle material, here in particular an element made of glass, as in the example of FIGS. 14 and 15.

[0076] The example of FIG. 16 was taken at a magnification of 200 times. Here, the second region 17 is clearly visible, followed to the left and right by the first region 15. The cone-shaped recess 22 of the first region is also clearly visible. According to an embodiment, which is also realized in the illustrated example, there is a transition 18 between the first region 15 and the second region 17, respectively, with the transition 18 having a cone-shaped recess that is on average larger than the cone-shaped recess of the first region. The larger recess 22 extending along the transition 18 is clearly visible in the micrograph. The creation of the recess is due to a change in the etching rate at the transition between the connection 2 and the element 10 when the contour is formed in the etching bath. Such a large cone is advantageous in order to avoid uncontrollable breakage and scalloping when separating the element 10 from the connection 2.

[0077] FIG. 17 shows an end face magnified 500 times. At this magnification, the filamentary damage 39 introduced by the ultrashort pulsed laser on the fracture surface of the first region 17 can also be recognized as a thin dark line, since the fracture surface extends along the filamentary damage. The resulting damage is therefore present as a partially semi-open channel on the fracture surface. In the image of FIG. 17, the filamentary damage 39 extends from top to bottom, i.e. from one main surface of the element 10 to the opposite main surface. In the illustrated example, the filamentary damage 39 is spaced apart by about 6 μm. As explained above, the filamentation and etching preferably first form the contour of the plate-like intermediate body with the connections 2 and the elements 10. Only afterwards is the filamentary damage 39 introduced, which forms the weakened structure 4 and is therefore visible on the fracture surface of the second region. However, other variants are also conceivable, such as for example introducing all the filamentary damage and then masking the damage 39 of the link 2 to avoid etching this damage 39 .

[0078] In one embodiment, the intermediate body 1, as for example shown in figures 4 to 6, is coated after the structuring process (laser filamentation and subsequent etching process), so that the elements 10 separated from the intermediate body can then also be provided with a coating, in particular an optically active coating.

[0079] Various coating processes are possible in principle, such as sputtering and PVD, dip coating or printing on the entire component and carrier. Various types of applied layers are also conceivable, such as optically active layers (anti-reflection layers, filter layers, e.g. IR-cut filters), functional layers (anti-fingerprint, anti-microbial or anti-bacterial coatings, e.g. based on silver ions), anti-scratch coatings or even purely decorative coatings in the form of applied paints or lacquers. As anti-scratch coatings, layers with a high refractive index and a layer thickness of 1 μm or more, e.g. based on aluminum nitride / silicon nitride or zirconium oxide, are generally suitable.

[0080] For IR cut and bandpass filters, the desired optical properties can be achieved by combining a multi-layer system of suitable thicknesses consisting of alternating high refractive index coatings (usually TiO2, Ta2O5, Nb2O5, HfO2, ZrO2) and low refractive index coatings (preferably SiO2). Such multi-layer systems can also be used for other coatings, for example anti-reflection coatings. Thus, without being limited to a particular example, in one embodiment it is provided that the optically active coating comprises a number of layers with different refractive indices, in particular alternating layers of high refractive index and layers of relatively lower refractive index.

[0081] The method described here allows the production and handling of particularly small components, in particular with lateral dimensions in the range of 1 mm to a maximum of 10 mm and a substrate thickness of at least 50 μm, 70 μm to 400 μm. A possible application of such small elements is, for example, as IR cut filters for camera sensors in mobile phones or camera modules such as those found in other portable electronic devices, such as notebooks or tablet PCs. For this purpose, an optically active layer having the required optical properties is generally applied. The deposition of this layer is facilitated or even generally only possible due to the defined positioning of the element 10 by the connection 2 and the holding part 6.

[0082] Furthermore, the strength of the elements is also an important parameter, especially for this aforementioned field of application, whereby the production of high-strength filter elements is achieved by a suitable combination of a coating process following the structuring process with a reinforcement process that is carried out before or after.

[0083] The coating of the elements and the method for robotically identifying the orientation of the coated and separated elements 10 based on the regions 15, 17 and the reinforcement have already been described above.

[0084] Thus, according to an embodiment of the present invention, generally, a plate-shaped optical filter element is provided, in which an element 10 made of a brittle material is coated with an optical filter coating. Here, at least one of the main faces 100, 101 may be provided with an optical filter coating, and if necessary, both sides may also be provided with a coating. Here, each coating may be different. The optical filter coating may be an IR-cut coating, i.e. a coating that absorbs or reflects radiation, in particular in the near infrared range. Here, it is typical for such optical filter elements that the substrate or element 10 is transparent to infrared rays or, more generally, has a higher infrared transmittance than the filter coating. The near infrared range is understood to be the wavelength range between 0.7 μm and 2.5 μm in the sense of the function of the IR-cut coating. Furthermore, according to an embodiment, generally, a camera module is provided with a sensor covered with a plate-shaped element 10 according to the present disclosure, the plate-shaped element 10 forming an optical filter. In this respect, in particular, as described above, an optical filter coating may be provided on the element 10. Alternatively or additionally, the glass of the plate-like element 10 may be a filter glass.

[0085] Fig. 18 shows a camera module 52, which can be used for example in a mobile phone or other portable electronic device, according to this embodiment. The camera module 52 comprises a camera sensor 56 for capturing images, a lens 58 and possibly a housing 59 for receiving and fixing the sensor 56 and the lens 58. An optical filter element 60 is applied to the photosensitive layer of the sensor 56 and is, for example, bonded with a bonding layer 61. The optical filter element 60 is formed by the coated element 10. Here, the optical filter coating 54 is designed such that a large part of the radiation in the near infrared range is reflected or absorbed and substantially only visible light is incident on the sensor.

[0086] In a further embodiment, the coating process is preceded by a strengthening, preferably a chemical strengthening, of the substrate, for which purpose the brittle plate-like intermediate body 1 with the holding part 6 and the frame 8 as well as the connecting part 2, or alternatively with all the aforementioned parts, is subjected to a strengthening process in an exchange bath.

[0087] The strength of the component is very important not only when connected to the holder, but also after separation. Here, the strength is determined largely by the breaking strength of each edge. In this regard, the Weibull diagram in FIG. 19 shows typical values ​​of the edge strength of an ultra-thin glass sheet with a thickness of 100 μm, measured immediately after filament formation, i.e. immediately after the introduction of filamentary damage with an ultrashort pulsed laser (measurement "A", circular symbols). Furthermore, measurements of the glass sheet after a subsequent KOH etching process (measurement "B", triangular symbols) and after a chemical strengthening process following the etching process (measurement "C", diamond symbols) are shown. The glass sheet was produced from D263T type glass.

[0088] The line drawn in Figure 19 is based on the formula H=100%×(1-exp(-t / T) b ) function of failure rate H of the specimen fitted to the measurements. These lines therefore represent the cumulative density function of the probability of failure with shape parameter b and scale parameter T. For the measurement after filamentation "A", T=53.55, b=25.25, for the measurement after etching "B", T=826.35, b=1.69, and for the measurement after etching and strengthening "C", T=508.8, b=8.27.

[0089] The minimum break stress of the filamented edge of the ultra-thin glass substrate (measurement "A") is about 50 MPa, while the etched edge (measurement "B") achieves a minimum break stress of at least about 200 MPa, and the strengthened edge (measurement "C") achieves a minimum break stress of at least more than about 300 MPa. The strengthening process significantly narrows or makes the distribution of break stresses of the etched edge more distinct. The average break stress of the etched and strengthened edges is about 500 MPa.

[0090] The strength increase due to the tempering process is material dependent, but generally significantly higher strength values ​​can be achieved compared to untempered glass panes, as the example in FIG. 19 shows.

[0091] These values ​​are particularly important for the process of separating the small components or elements 10 from the holding frame 8 or the material bridge, i.e. the connection 2. If the weak structures 4 are introduced in the narrow material bridges, their strength corresponds approximately to the reference value of the filament-formed ends (measurement value "A"), so that their strength is approximately one-fourth (characteristic value of b10) of the strength of the etched ends. If this component is also subjected to a strengthening process, this distance is even wider, to one-sixth. Thus, during singulation, the material bridges in the region of the weak structures 4 are first broken, and the component 10 can be reliably separated from the holding part 6, in particular in the form of the frame 8. This effect allows the element 10 to be easily separated from the frame 8, even after chemical strengthening. In one advantageous configuration, therefore, a plate-shaped intermediate body 1 is provided, in which the weak structures 4 extend along a separation line provided between the connection 2 and the element 10, the weak structures 4 having a series of filament-shaped damages, and the intermediate body 1 is chemically strengthened. Here, both the elements 10 and the connections 2 at least in the region of the weakened structures 4 are chemically strengthened.

[0092] When the coated and / or reinforced intermediate body 1 according to the present disclosure is separated by the retaining part 6 or material bridge, the already mentioned second region 17 of the end face 13 is generated, which, as already explained, can differ from the first region 13 of the end face not only in terms of the roughness value but also in terms of its coating and its strength. Due to the possible decrease in the strength of the end face of the second region 17, it seems reasonable, especially in the case of reinforced and coated intermediate bodies 1, for the material bridge / connecting part 2 to come into contact with the end face of the element 10 in the region where a decrease in the strength of the element 10 is allowed during subsequent use. It is therefore preferred in the case of rectangular elements 10 that the connecting part or retaining part 6 is arranged in the region of the corner of the element 10 or directly at the corner, since the stresses occurring there when loaded are the lowest. An intermediate body 1 with the connecting part 2 arranged accordingly is shown in FIG. 20. In contrast to the embodiment examples of FIGS. 3 to 8, here the connecting part 2 is arranged here directly at the corner of the rectangular element 10. In this case, when the element 10 is separated from the holding part 6, the element 10 is generally, but not limited to the illustrated example, shaped with at least one corner, in which there is a second region 17 of the end face, one edge of which coincides with the corner of the element 10 or the second region 17 ends at this corner. The same effect can also be achieved with a small distance between the edge of the region 17 and the corner. Here, according to a more general embodiment, the distance from the edge of the second region to the corner is smaller than the width of the second region 17, preferably smaller than half the width of the second region 17.

[0093] An example embodiment with such an element 10 is shown in FIG. 21. In this example, the second regions 17 do not end directly at each corner 110, but at a distance therefrom. However, the distance is smaller than the width of the second regions 17, or even smaller than half the width of the second regions 17. A small distance, as in the example shown, can be advantageous to prevent material breakage at the corners 110 during separation, which would result in an uneven fracture surface of the second regions. As mentioned above, the intermediate body 1 can be coated before the separation of the element 10. The second regions 17 exposed by the separation process at the material bridge of the coated intermediate body 1 are thus free of a coating. This embodiment is also illustrated in FIG. 21. The coating 70 is illustrated here as hatching. As shown, the coating 70 can also be at least partially present on the end faces 13. Thus, generally, and not limited to the specific example shown, according to one embodiment, an element 10 made of a brittle material is provided, having a coating 70 applied to at least one of the main faces 100, 101 and at least partially to the end face 13, and the coating 70 being missing or shed in the second region 17.

[0094] Thus, in a further embodiment, the second area thus generated can be used for the input / output coupling of electromagnetic radiation, in particular visible (coherent or incoherent) electromagnetic radiation, after optionally post-treating the surface during further use. Such elements are for example used as light guides or also as microfluidic elements in biotechnology. Thus, according to a further embodiment, and without being limited to the presence of a particular coating, an electro-optical assembly is provided which generally comprises at least one radiation source and / or sensor, the radiation source and / or sensor being arranged such that radiation starting from the radiation source is input-coupled through at least one second area 17 of the end face 13 of the element 10 made of brittle material or output-coupled for detection by the sensor.

[0095] Overall, the already explained change in roughness values ​​of the second regions 17 of the end 13 of the intermediate body compared to the surrounding first regions 15, as well as the absence of a coating and a reduced strength in these second regions, are also indicative of the use of the method according to the invention. In a further embodiment, the transition region between the element 10 and the material bridge or link 2 with the weakened structure 4 is provided along the target contour of the element 10 and then coated, for example with Cr / CrO, by a sputtering process or another PVD process. In this case, due to the small thickness of the intermediate body, it is observed that not only the main faces 100, 101 of the intermediate body 10 are coated, but also, as mentioned above, at least partially its circumferential end faces 13 and, if the diameter of the weakened structure 4 is sufficiently large after the etching process, the inner faces of the individual elements of the weakened structure 4. After separation of the element 10 from the connection 2, the end face has the above-mentioned properties, i.e. an end face 13 divided into a first and a second part 15, 17 depending on the number of material bridges, which end face 13 has the above-mentioned coating at least outside the area of ​​the material web, i.e. in the first area 15, and possibly also in the second area 17, the remainder of the coating 70. In particular, different optical properties in terms of reflection / scattering can also be used to distinguish the first and second areas of the end face 13. With the element 10 produced in this way, electro-optical assemblies can be realised, in particular as described below.

[0096] FIG. 22 shows an example of an electro-optical assembly 71 with an element 10. The electro-optical assembly 71 comprises a radiation source 72 and a radiation sensor 74. The element 10 has a coating 70, which is also present on the end face 13, but which is blank in the second region 17 as described above. For example, the coating 70 may be designed to reflect radiation. The radiation of the radiation source 72 can then be coupled into the element 10 through the second region 17 and exit again through a further second region 17, so that it is detected by the radiation sensor 74. A possible radiation path is shown with an exemplary ray 76. Here, the radiation can interact with the medium, for example if one main face of the element 10 is also not coated.

[0097] A development of the method for producing an element 10 made of brittle material is described below. The basic idea of ​​the method is to simplify the handling of the element 10 by coupling to the holding part 6. The element 10 is in a singulated state at the latest when it is separated at the connection part 2, from which point on it may again become difficult to handle. In order to improve this further, according to an embodiment of the method, it is generally provided that the intermediate body 1 is fixed to a support. According to a first development, the separation of the element 10 from the holding part 6 takes place while the element 10 is fixed to the support, the element 10 in particular remaining connected to the support after the separation. This makes it possible to separate the element 10 from the support at a later time without having to cut the holding part 2 at this point. According to an alternative or additional development, the support is deformable, the separation of the element 10 from the connection part 2 taking place by the generation of mechanical stresses at the connection part 2 due to a deformation of the support. This deformation may involve stretching of the support and / or bending of the support. In the case of bending, the intermediate body 1 is also bent due to its fixation to the support, so that a bending stress is applied to the connecting portion 2. In the case of stretching the support, a tensile stress is generated in the connecting portion 2 in a direction along the surface of the intermediate body 1.

[0098] The above-mentioned developments are explained in more detail below with the aid of examples. In general, the support can be designed as a film. The intermediate 1 can then be applied to the support in the form of a strip of film, possibly avoiding the formation of air bubbles or other inclusions. This film can be fixed to a further holding frame (e.g. made of steel) so that the tape tension in the film is as constant as possible. The element 10 is thus fixed and stable also in the subsequent cutting process. The element 10 can now be separated from the holding part 6 by various process variations.

[0099] A) Film Stretching: The geometry of the film-holding frame depends on the geometry of the components and the required stretching direction during the separation process: for circular components, an isotropic, i.e. angle-independent, uniform stretching of the film in all directions is preferred, whereas for rectangular components, a directional uniaxial stretching of the film is preferred in order to transfer mechanical tensile stresses to the material-weakened areas or to the connection 2 in general, resulting in the separation of the element 10 from the holding part 2.

[0100] FIG. 23 shows the corresponding assembly. The intermediate 1 is fixed to a support 77 in the form of a stretchable film 78. The film 78 is tensioned by a tensioning device 82, which can comprise, for example, a suitable holding frame. The tensioning device 82 can then apply a force to the film 78, as represented by the arrow marked "F". As a result, the film 78 is stretched, which force is transferred to the intermediate as a tensile stress. The tensile stress is thus along the surface of the intermediate and causes separation at the connection 2. In particular, if the holding part 6 is in the form of a frame 8 surrounding the element 10, as in the illustrated example, separation can be facilitated if the frame 8 also has one or more weakening structures 4. In this way, it can be ensured that the frame 8 separates first when the film is stretched or stretched, so that the elongation is also transferred to the connection between the element 10 and the holding part 6.

[0101] B) Bending: Another option is to mechanically bend the support and / or the intermediate body 1 fixed to the support along the weakened structure or more generally at the connection 2. For example, a three-point bending process can be used, in which from one side of the assembly consisting of the support and the intermediate body, two support bars / blades support the left and right areas of the weakened structure 4 or the connection 2, and from the other side, a blade mechanically loads the connection itself, leading to a break at the connection 2, preferably at the weakened structure 4. Depending on the arrangement and fastening of the element 10 to the holding part, this process can also be carried out successively in different directions. A corresponding assembly is shown by way of example in FIG. 24. A support 77, for example again in the form of a film 78 or other deformable substrate, rests on two spaced apart support members 84, in such a way that the connection 2 of the intermediate body fixed to the support 77 is located between the support members 84. A blade 86 presses the support 77 together with the intermediate body from the other side of the support members, so that the support 77 together with the intermediate body is bent, resulting in bending stresses in the area of ​​the connection 2. Here, FIG. 24 shows a state in which the holding portion 6 and the element 10 have already been separated.

[0102] A further embodiment of mechanical bending may be to transmit mechanical stress to the connection between the element 10 and the retaining part 6 to induce the separation process, for example by a trough that is sucked with negative pressure or by guiding the member support film over a preferably raised, e.g. rounded, structure.

[0103] Suitable films 78 can be designed as single-layer or multi-layer films. In principle, suitable films 78 include at least one support film and a pressure-sensitive adhesive film, possibly even a further release film. As adhesive tape, so-called blue tape or, in the case of very finely structured elements 10, UV-curable tapes can also be used. The adhesion of the adhesive tape must be high enough so that the components or elements 10 are held during the processing process, but still the singulated components can be peeled off from the film without damage. In particular UV-curable films are particularly suitable here, since in the uncured state they have a high adhesion, which is reduced by the curing process, allowing the components to be peeled off. Another option is to fix the intermediate 1 to the support 77 electrostatically.

[0104] It is clear to those skilled in the art that the embodiments are not limited to the specific example embodiments shown and described, but can be modified and combined in various ways, for example the above-mentioned separation methods can also be combined with each other, in particular for separating the elements 10 at the connections 2 at different positions. [Explanation of symbols]

[0105] 1 Plate-shaped intermediate 2,20 Connection, material bridge 3 Unstructured board material 4 Weakened structure 5. Material Modification Department 6 Holding part 8 Frames 9 8 opening 10 Elements made of brittle materials 11 10 Contours 12 10 openings 13 10 end face 14 Complementary element to element 10 15 13th area 17 13th Region 18 Transition between 15 and 17 19,20 End of 10 22 Cone-shaped recess 24 Ridgeline 26 Perforations 28 Alignment Mark 29 Glass ribbon manufacturing equipment 30 Glass Ribbon 32 Glass melt 34 Nozzle 36 Stretching roller 38 Transport Equipment 39 Filamentous Lesion 40 Ultrashort Pulse Laser 41 Laser Beam 42 Beam optics 44 rolls 46 Roll Core 50 routes 52 Camera module 54 Optical Filter Coating 56 Sensors 58 Lens 59 Housing 61 Bonding layer 70 Coating 71 Electro-Optical Assembly 72 Radiation source 74 Radiation Sensor 76 Rays of light 77 Support 78 Film 80 8,9 inner end face 82 Tensioning device 84 Support member 86 Blade 100,101 10 major faces 103 10 face center points 104 The point with the smallest distance to 103 105,106 Legs 107 Fixed area 108 Teeth 110 10 corner

Claims

1. A plate-shaped element (10) made of a brittle material, in particular a glass or glass-ceramic, the plate-shaped element (10) having two opposing, in particular parallel, main surfaces (100, 101) and a peripheral end surface (13) defining the outer contour of the plate-shaped element (10), the end surface (13) having at least one first region (15) and at least one second region (17), the surface structure of the first region (15) being different from that of the second region (17), the first region (15) having an etched surface, the second region (17) being a fracture surface, the area of at least one of the first regions (15) being larger than the area of at least one of the second regions (17), and the first and second regions being arranged side by side in a direction along the end surface (13).

2. The following features: - The second region (17) of the end surface (13) is adjacent to at least one of the ends (19, 20), and the end surface (13) transitions to the main surfaces (100, 101) at the ends (19, 20). - The etched surface of the first region (15) has mortar-shaped recesses (22), and adjacent recesses (22) are separated by ridge lines (24) due to the adjacent mortar-shaped recesses (22) being adjacent to each other. The plate-shaped element (10) according to claim 1, characterized by at least one of the above.

3. The following features: - At least one of the second regions (17) has a width of at least 0.5%, preferably at least 1%, of the maximum transverse dimension of the element (10). - At least one of the second regions (17) has a width of at least 20 μm, preferably at least 50 μm, very particularly preferably at least 100 μm. - The total proportion of the area of at least one of the first regions (15) in the total area of the end surface (13) is at least 90%. - The maximum transverse dimension of the element (10) is at most 100 mm. - The maximum transverse dimension is at least 1 mm. - The contour of the element (10) is formed convexly adjacent to the second region (17). - The number of the second regions (17) is at most 50, preferably at most 10, particularly preferably at most 3. The plate-like element (10) according to claim 1, characterized by at least one of the following.

4. The following features: - At least one of the second regions (17) extends along a position on the end face (13) at a distance of at least 2 / 3 of the maximum distance from the surface center point (103). - At least one of the second regions (17) extends along a portion of the end face (13) that is subjected to a mechanical load of at most 80%, preferably at most 60% of the maximum load when a load is applied. The plate-like element (10) according to claim 1, characterized by at least one of the following.

5. The following features: - The second region (17) is flat. - The height deviation between the second region (17) and the adjacent first region (15) is less than 20 μm. - The ratio of the average roughness Ra of the first region (15) to the average roughness Ra of the adjacent second region (17) is in the range of 0.75 to 1.

25. - There is a transition portion (18) between the first region (15) and the second region (17), and the transition portion (18) has a mortar-shaped recess (22) that is on average larger than the mortar-shaped recess of the first region (15). - At least one of the first regions and at least one of the second regions have the same visual appearance. - The second region (17) of the end face (13) ends at a corner of the element (10). - The distance from the edge of the second region (17) to the corner of the element (10) is smaller than the width of the second region (17). - The strength of the element (10) against the bending load of the end face (13) is at least 20 MPa, preferably at least 50 MPa, particularly preferably at least 80 MPa or 150 MPa higher in the first region (15) than in the second region (17). The plate-like element (10) according to claim 1, characterized by at least one of the following.

6. The plate-like element (10) according to claim 1, wherein the element (10) is provided with a coating, particularly an optically active coating.

7. The following features: - At least one of the main surfaces (100, 191) of the element (10) is coated with an optical filter coating (54), the optical filter coating being preferably an IR cut coating that absorbs or reflects radiation in the near-infrared region, and the element (10) having a higher infrared transmittance than the filter coating (54), - The optically active coating includes a plurality of layers having different refractive indices, - At least one of the main surfaces (100, 101) and at least partially the end face (13) are coated with a coating (70), and the coating (70) is missing in the second region (17), The plate-shaped element (10) according to claim 6, characterized by at least one of the above.

8. A plate-shaped intermediate body (1) made of a brittle material for manufacturing the element (10) according to any one of claims 1 to 7, the plate-shaped intermediate body (1) having a holding part (6) and an element (10) connected to the holding part (6) by at least one connecting part (2), the element (10) and the connecting part (2) having end faces (13) with an etching surface, the width of the connecting part at the transition to the element (10) being smaller than the length of the contour formed by the end face (13) having the etching surface, so that the element (10) can be separated by breaking the brittle material at the connecting part (2) to obtain a separated element (10) made of a brittle material, where the end face (13) of the separated element (10) has at least one first region (15) and at least one second region (17), the surface structure of the first region (15) being different from that of the second region (17), the first region (15) having an etching surface, the second region (17) being a fracture surface, the area of at least one of the first regions (15) being larger than the area of at least one of the second regions (17), and the first and second regions being arranged side by side in a direction along the end face (13). Plate-shaped intermediate body (1).

9. The following features: - At least one lateral dimension of the holding part (6) is larger than that of the connecting part (2) or the element (10) made of the brittle material, - The connecting part (2) has a width of at least 0.5%, preferably at least 1 percent, of the maximum lateral dimension of the element (10) made of the brittle material. - The connecting part (2) has a width of at least 20 μm, preferably at least 50 μm, particularly preferably at least 100 μm. - The width of the connecting part (2) is at most 50%, preferably at most 30%, particularly preferably at most 20%, especially at most 10% of the maximum lateral dimension of the holding part (6) or of the maximum lateral dimension of the element (10) made of the brittle material. The plate-shaped intermediate body (1) according to claim 8, characterized by at least one of the above.

10. The plate-shaped intermediate body (1) according to claim 8, wherein a plurality of elements (10) made of the brittle material are arranged in a row, in particular in a matrix having two or more rows of elements (10) made of the brittle material.

11. In the opening (9) of the holding part (6) designed as a frame (8), there are at least two elements (10) made of the brittle material, and the two elements (10) made of the brittle material are connected to each other by at least one connecting part (20) extending from one element (10) to the other element (10). The plate-shaped intermediate body (1) according to claim 8.

12. One element (10) is connected to the holding part (6) by at least two connecting parts (2), with the following characteristics: - The mutual distance between the connecting parts (2) is at least 20 μm. - The mutual distance between the connecting parts (2) is at least half, preferably at least of the same order, particularly preferably at least twice the thickness of the intermediate body (1). - The element (10) is connected to the holding part (6) by two parallel connecting parts (2). The plate-shaped intermediate body (1) according to claim 8, characterized by at least one of the above.

13. The plate-shaped intermediate body (1) according to claim 8, characterized by a weakening structure (4) extending along a separation line provided between the connecting part (2) and the element (10).

14. The weakening structure (4) has the following characteristics: - Grooves. - A series of through-holes or filamentous damages. - A region with reduced thickness. The plate-shaped intermediate body (1) according to claim 13, having at least one of the above.

15. Characterized by a plurality of holding parts (6) in the form of a frame (8), wherein at least one element (10) is arranged in each of the frames (8), and the element (10) is connected to the frame (8) by at least one connecting part (2), and the frames (8) are connected to each other in a separable state by one or more perforations (26). The plate-shaped intermediate body (1) according to claim 8.

16. A method for manufacturing a plate-shaped element (10) made of a brittle material, comprising providing a plate material (3) made of a brittle material and irradiating the plate material (3) with a laser. Here, the brittle material of the plate material (3) is at least partially transparent to the laser, and a material modification part (5) is generated inside the plate material (3) by the laser beam (41) of the laser. By guiding the laser beam along a path (50) above the plate material (3), the material modification parts exist side by side on the path (50). Then, the plate material (3) is subjected to an etching process, and a channel is formed by expanding the material modification part (5) by the etching process. Finally, by connecting the channels, the plate material (3) is separated along the path (50). The plate-shaped intermediate body (1) according to claim 8 is obtained by defining the contour of the element (10) whose path (50) is connected to the holding part (8) by the connecting part (2). Next, a method of separating the connecting part (2) and separating the element (10) from the holding part (6).

17. The method according to claim 16, wherein a weakening structure (4) extending along a separation line provided between the connecting part (2) and the element (10) is introduced.

18. - As an unstructured plate material (3), a continuous glass ribbon (30) is manufactured from a hard brittle material by a continuous stretching process, wherein - During the stretching process, a material modification part is introduced into the moving continuous glass ribbon (30) by an ultrashort pulse laser (40) along a predetermined path (50). The method according to claim 16.

19. Fix the intermediate body (1) to a support, as follows: - Separating the element (10) from the holding part (6) while the element (10) is fixed to the support, and at this time, the element (10) remains connected to the support even after the separation. - A step in which the support is deformable, and in this case, separation of the element (10) from the connecting part (2) is performed by generating mechanical stress at the connecting part (2) due to deformation of the support. - A step of stretching the support to apply tensile stress to the connecting part (2). - A step of bending the support or the intermediate body (1) fixed to the support to apply bending stress to the connecting part (2). The method according to claim 16, characterized by one or more of the above.

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