Method for structuring a glass element and structured glass element produced thereby

Abstract

The invention relates to a method of structuring a glass element, in which a laser beam of an ultrashort pulse laser is directed onto a glass element, which is transparent to the laser beam, at least one filament-like defect is produced in the glass element, which extends transversely to the side of the glass element, the filament-like defect is produced by the laser beam, which is focused by means of focusing optics to form a focal line in the glass element (1), wherein the intensity of the laser beam within the focal line is sufficient to produce the filament-like defect, the focal line is adjusted so that the filament-like defect ends within the glass element (1), the glass element is exposed to an etching bath, the glass is removed by etching, so that the filament-like defect widens to form a wall which extends between the opposite sides of the glass element, the wall has a boundary line, which tapers at the apex between the wall and the adjacent side, has a taper angle with respect to the perpendicular of the side, the taper angle is adjusted by at least one of the position and the intensity profile of the focal line.

Description

Technical Field

[0001] This invention generally relates to a method for structuring a glass element. Further aspects of the invention relate to a structured glass element, particularly a glass element produced or producible by a method according to embodiments of the invention, and the use of such a glass element. Specifically, the invention relates to a method for structuring a glass element using a pulsed laser beam with an ultrashort pulse layer, and to a glass element produced or producible by this method, and the use of such a glass element. Background Technology

[0002] The method of using ultrashort pulse layers to process workpieces is often used, for example, to prepare workpieces for separation.

[0003] For example, WO2012 / 006736A2 discloses a method for preparing a substrate for separation using an ultrashort pulse laser, i.e., a laser with a pulse length of less than 100 ps. In the method disclosed in WO2012 / 006736A2, a number of spaced filaments are generated along a desired separation line by utilizing the nonlinear effect of self-focusing.

[0004] WO2017 / 009379A1 describes a further development of the method in WO2012 / 006736A2. In the method according to WO2017 / 009379A1, a surface extension inclined to the workpiece is produced as a modification. This is achieved by obliquely guiding a laser pulse onto the surface of the corresponding workpiece.

[0005] As is known from EP 2 931 467 B1, environmental atmosphere is included as a further process parameter to prevent premature self-cracking due to subcritical defect propagation.

[0006] In addition, DE 10 2015 116 848 A1 describes the introduction of a region of defined intensity by using the spherical aberration of a lens to generate a filament, wherein a Gaussian beam of an ultrashort pulse laser is converted into a line focal point with a non-uniform intensity distribution along the optical axis.

[0007] In addition, DE 10 2018 126 381 A1 relates to a method for introducing a separation line into a transparent brittle material and the element obtained therefrom.

[0008] However, all these methods are aimed at separating workpieces. That is, several material modifications are generated in the workpiece using an ultrashort pulse layer, wherein the modifications are arranged along a predetermined path along a desired separation line. Preferably, the material modification results in the formation of pores within the workpiece. Separation can then be advantageously achieved by exposing the workpiece to an etching medium or etching bath so that the pores are widened until adjacent pores or channels merge. In this way, the workpiece can be separated along a predetermined path of the material modification (or filaments) formed in the workpiece.

[0009] However, for some applications, it may be preferable to structure the glass element rather than separate it, for example, if the glass element is used as an interposer. Furthermore, known methods for generating filaments at an angle to the workpiece surface require extensive process control to precisely adjust and monitor, for example, laser parameters and / or workpiece positioning, by providing specialized focusing optics that can compensate for astigmatic distortions in the beam profile.

[0010] Therefore, there is a need for methods that at least partially overcome the shortcomings of the prior art, and for glass components that can be produced from them. Summary of the Invention

[0011] The object of this invention is to provide a method for structuring glass elements that at least partially overcomes the known drawbacks of prior art, namely methods requiring extensive process control. Another aspect of this invention relates to structured glass elements and their uses.

[0012] This objective is achieved through the subject matter of the independent claims. Advantageous embodiments and improvements are described in detail in the dependent claims, drawings, and description.

[0013] Therefore, the present invention relates to a method for structuring a glass element. According to this structuring method, a pulsed laser beam from an ultrashort pulse laser is guided onto a glass element. The glass element is transparent to the laser beam and at least one filamentary defect is generated within the glass element, the filamentary defect extending laterally to the side of the glass element. The filamentary defect is generated by the laser beam, which is converged by a focusing optics to form a focal line within the glass element, wherein the intensity of the laser beam within the focal line is sufficient to generate the filamentary defect. The focal line is adjusted such that the filamentary defect terminates within the glass element. The glass element is exposed to an etching medium or etching bath, which removes glass by etching, causing the filamentary defect to widen to form a wall extending between opposing sides of the glass element, the wall having a boundary line tapering at the apex between the wall and the adjacent side, having a taper angle relative to the perpendicular line of the side, the taper angle being adjusted by at least one of the position, length, and intensity distribution of the focal line. These parameters can be combined to adjust the geometry of the filamentary defect, such as the depth of a defect in the form of a blind hole.

[0014] This method offers several advantages.

[0015] A structured glass element is obtained according to the method of the invention, wherein filamentary defects terminating within the glass element are formed. In a further method step, the filamentary defects are widened by using an etching medium or etching bath to form walls extending between opposite sides of the glass element. In other words, a hole is obtained within the glass element by etching, which at least substantially follows the form of the previously formed filamentary defects. Since the filamentary defects terminate within the glass element, blind holes are thus formed within the glass element.

[0016] Here, the statement "the hole at least substantially follows the form of the defect" is understood as the hole extending along the length of the preceding filamentous defect and thus forming an elongated hole, however, it can also be wider and longer than the defect itself.

[0017] The filamentary defect extends laterally to the side, meaning it forms an angle with the side of the glass element. In other words, the filamentary defect is not parallel to either side of the glass element. Preferably, the defect may be perpendicular to at least one side of the glass element or may be oriented substantially perpendicular to at least one side of the glass element. Here, "at least substantially perpendicular" is understood to mean that the angle formed by the defect and the normal to the corresponding side does not exceed ±5°.

[0018] However, quite unexpectedly, when etching the glass element to widen the filamentary defect to form a wall (or a hole with a wall) within the glass element, a wall (or a hole with a wall) with a tapered boundary line is obtained. That is, the hole is at an angle to at least one side. In particular, the angle formed between the defect and the side may be different from the angle formed between the hole (or the boundary line of the hole's wall).

[0019] This can be achieved quite unexpectedly by adjusting at least one of the position of the focal line of the laser beam and / or the intensity distribution. However, it is not necessary to precisely control the position of the substrate orientation relative to the laser beam, for example by providing supplementary optical devices, such as cylindrical lenses. Therefore, the present invention provides a simple method for forming a structured glass element having at least one blind hole formed within the glass element, wherein the boundary line of the hole wall is at an angle to a side surface of the glass element, and the hole opens toward that side surface.

[0020] Within the scope of this invention, the following limitations apply.

[0021] The term "filament" can be understood as a slender structure, that is, a structure whose dimension along the first direction of the Cartesian coordinate system is at least an order of magnitude larger than its dimensions along the other two directions perpendicular to the first direction of the Cartesian coordinate system.

[0022] According to the present invention, a defect can be understood as a region within a workpiece (or glass element) that has changed. That is, the characteristics in this region are different from the characteristics of the workpiece (or glass element) before the defect was formed.

[0023] Therefore, filamentous defects can be understood as elongated, altered regions within a glass element.

[0024] A plate-like element (or object) is understood to be an object whose dimension along a first direction in the Cartesian coordinate system is an order of magnitude smaller than its dimensions along the other two directions perpendicular to the first direction in the Cartesian coordinate system. For example, a plate-like glass element can also be represented as a glass plate or glass strip. The plate-like element according to the invention can be formed as a flat or curved element. Furthermore, in the case of a flat element, the sides can preferably be substantially parallel to each other, that is, the angle formed by the normals or perpendiculars of the sides is preferably no more than 10°, and particularly no more than 5°.

[0025] An ultrashort pulse laser is understood as a laser with a pulse length not exceeding 100 ps. Preferably, the pulse length is not longer than 10 ps, ​​more preferably not longer than 1 ps or even less than 1 ps.

[0026] According to an embodiment, channels are created by etching and widening filamentary defects, wherein the channels open to two opposite sides. In other words, through-holes are formed according to the embodiment. This embodiment may be advantageous when the glass element is used as an interposer, for example, in printed circuit applications.

[0027] According to another approach, a filamentary defect terminating in the glass element is generated by using a focusing optics. The focusing optics superimpose at least two portions of a laser beam, causing the interference of these portions to produce an intensity variation along the focal line. This is a very simple yet effective method for generating defects (or modifying materials) in a workpiece. In this respect, the defect can also be referred to as a "blind defect." Furthermore, once the two portions of the beam are superimposed, resulting in an intensity variation along the focal line, the resulting angle between the sidewall and the wall boundary of the glass element can be adjusted in a very simple manner.

[0028] According to an embodiment, a large number of filamentary defects are generated and distributed on the glass element in a predetermined pattern. Furthermore, these filamentary defects may be formed during etching by widening the defects. In this way, multiple channels corresponding to previously generated defects within the glass element and distributed on the glass element in a predetermined pattern are generated.

[0029] The present invention also relates to a glass element, particularly a glass element produced or at least producible by a method according to embodiments of the invention, preferably a plate-shaped glass element. The glass element includes two opposing sides and a plurality of etched channels extending through the glass element, such that the walls of the channels connect to the sides. The boundary lines of the channel walls are tapered at the apex between the wall and the adjacent side. Preferably, at the apex between the wall and the side, at least two tapered angles between the boundary line and the perpendicular line of the side are different from each other. Attached Figure Description

[0030] The invention will now be further described with reference to the accompanying drawings. In the drawings, the same reference numerals refer to the same or corresponding elements.

[0031] Figure 1 The structure of the glass element according to the method of this disclosure is shown schematically and not to scale.

[0032] Figure 2 The glass element 1 according to the embodiment is shown schematically and not to scale.

[0033] Figure 3 The transfer of glass element 1 into etching tank 80 is shown schematically and not to scale.

[0034] Figure 4 The widening of the filamentary defect 9 by etching is shown schematically and not to scale.

[0035] Figure 5 The embodiments of the invention are shown schematically and not to scale.

[0036] Figure 6a A laser beam 5 along the beam direction is shown; Figure 6b The laser beam 5 is shown in a side view.

[0037] Figure 7 It shows the following according to Figure 6a , 6b The intensity distribution of the focal line 8 of the laser beam 5 in the embodiment.

[0038] Figure 8 The defects 9 of different shapes formed in the glass element 1 according to an embodiment of the invention are shown schematically and not to scale.

[0039] exist Figure 9 An embodiment of glass element 1 is shown schematically and not to scale.

[0040] Figure 10 An embodiment of glass element 1 is shown.

[0041] Figure 11 An embodiment of a glass element 1 with an opening 102 left in the outer glass portion 101 is shown.

[0042] Figure 12 An embodiment of a glass element 1 having a single filamentary defect 9 is shown.

[0043] Figure 13 An embodiment of a glass element 1 having multiple filamentary defects 9 is shown.

[0044] Figure 14 Four measurements of the cone angle obtained at different molar concentrations in an alkaline etching bath are shown.

[0045] Figure 15 The measured cone angle and fitted lines for different etching depths and different molar concentrations of etching bath 81 are shown.

[0046] Figure 16 The graph shows the value of the cone angle as a function of etching removal at the wall formed by widening the filamentary defect 9. Detailed Implementation

[0047] Figure 1 The glass element structuring according to the method of the present invention is shown schematically and not to scale. A pulsed laser beam 5 is generated by an ultrashort pulse laser 7 and guided onto the glass element 1. The glass element 1 is transparent to the laser beam 5. Here, the glass element 1 is a plate-shaped glass element; however, it is understood according to the present invention that any glass element, such as a plate-shaped curved glass element, can be structured. The glass element 1 has two sides 14, 15. Within the scope of the present invention, a side can be understood to refer to the main surface of an object, i.e., the surface that together accounts for more than 50% of the total surface area of ​​the corresponding object.

[0048] In addition to glass components, the method of the present invention can also be used to structure workpieces comprising materials other than glass or composed of materials other than glass.

[0049] At least one filamentous, elongated defect 9 is generated in the glass element 1, for example, as a material modification. The defect 9 extends transversely to the sides 14 and 15 of the glass element 1, i.e., an angle is formed between the defect 9 and any one of the sides 14 and 15. In other words, the defect 9 is not parallel to any one of the sides 14 and 15.

[0050] The laser beam 5 used to generate defect 9 is focused by focusing optics 70 to form a focal line 8 (not shown here) in the glass element 1. The intensity of the laser beam 5 within the focal line 8 (not shown here) is sufficient to generate the filamentary defect 9. Furthermore, the focal line 8 (not shown here) is adjusted so that the filamentary defect 9 terminates within the glass element 1.

[0051] Figure 1 The positioning device 20 and the computing device 71 are further illustrated. The computing device 71 can be used to adjust the power output of the laser 7 and / or to control the position of the glass element 1 by controlling the positioning device 20. The positioning device 20 can be advantageously used in cases where a large number of filamentary defects 9 are generated in the glass element 1, for example, along a predetermined path. However, multiple computing devices 71 can certainly be used.

[0052] Figure 2The glass element 1 according to the embodiment is shown schematically and not to scale. Here, by causing the laser beam 5 to travel relative to the glass element 1 along a predetermined path 11, a large number of filamentary defects 9 are generated within the glass element 1. In this way, a large number of defects 9 are generated along the path 11, i.e., arranged side by side in a predetermined pattern. The predetermined pattern may be a grid or a series of defects forming circles, ellipses, or any other suitable shape, such as a spiral. As already mentioned... Figure 1 As illustrated by the positioning device 20, the laser beam 5 can be propelled along the path 11 to result in the formation of a large number of defects 9 distributed in a predetermined pattern on the glass element 1.

[0053] After laser processing as described above, the glass element 1, including at least one filamentary defect 9, is transferred to a process such as... Figure 3 In the illustrative and not to scale etching bath 80, the glass element 1 is exposed to an etching bath 81 (etching medium 81), which removes the material of the glass element 1, i.e., the glass material or a modified glass material, such as the material forming the filamentary defects 9, by etching. The etching bath 81 can be an acidic etching bath or an alkaline etching bath. However, an alkaline etching bath may be preferred due to environmental and safety concerns. Figure 3 In an illustrative and not scaled example, glass element 1 includes a plurality of filamentary defects 9 arranged along path 11. However, it is generally not limited to... Figure 3 The example shown should be understood to mean that glass element 1 only needs to include a single filamentary defect 9. An example of glass element 1 including only a single filamentary defect is shown in... Figure 12 The diagram is schematic and not shown to scale, but is presented as a top view. Furthermore, the glass element 1 may include multiple single filamentary defects 9 distributed on the glass element 1, such as... Figure 13 Indicative and not shown to scale. Furthermore, it should be noted that even... Figure 2 , 12 Figures 1 and 13 show a glass element 1 including at least one defect 9, since the location of one or more defects 9 corresponds to the location of blind holes 91 or channels 10 obtained by etching. Figure 2 , 12 13 can also be understood as a glass element with a hole 91 or channel 10 rather than defect 9. Furthermore, in Figure 13 In the case of a glass element 1 comprising several defects 9 (or channels or holes), it is conceivable that the defects 9 are arranged in such a way that the resulting holes are arranged in a grid or pattern. This may be particularly preferred when the glass element 1 is used as an intermediate layer.

[0054] Through etching, the filamentary defects 9 are widened to form walls 6, such as Figure 4This is schematic and not shown to scale. Specifically, through etching, the material of defect 9 is more easily removed than the unaltered material of glass element 1, thus forming a hole 91 corresponding to the previous defect 9, wherein hole 91 has a wall 6. Figure 4 In the illustrated case, wall 6 has a tapered boundary line 12 at its vertex 16 between wall 6 and adjacent wall surface 14. Therefore, a cone angle 94 is formed between the perpendicular line 13 of side surface 14 and wall 6. The cone angle 94 is adjusted by at least one of the position, length, and intensity distribution of the focal line 8. For example, by adjusting the position and length of the focal line 8, the depth of a filamentary defect in the form of a blind hole can be adjusted. Figure 4 As shown, the resulting hole 91 is a blind hole, i.e., a hole terminating within the glass element 1. Note that the diameter of hole 91 has been exaggerated for better visibility. Hole 91 is formed due to etching, where its lateral dimensions decrease towards the volumetric region of the glass element 1. This is because the etching bath changes (or ages) during etching, resulting in a higher etching rate at the surface 14 of the glass element 1 compared to the volumetric region.

[0055] As an advantage of the method according to the invention, the cone angle 94 can be controlled and adjusted in a very simple and effective manner by means of a suitable focusing optics 70 by adjusting the position and intensity of the focal line 8 according to a predetermined value.

[0056] Suitable focusing optics 70 may include lenses, such as spherical or aspherical lenses, or axonal prisms, or spatial light modulators, or suitable combinations thereof.

[0057] according to Figure 5 In an illustrative, not scaled-out embodiment, a channel (or via) 10 is created by etching and widening defect 9, opening onto two opposing sides 14, 15 of the glass element 1. Such a via or channel 10 can be obtained by etching extending from one surface of the glass element 1, in this case surface 15, and almost through a blind hole in the glass element 1. Suitable for achieving... Figure 5 The defects of the channel shown are, for example... Figure 8 Defect 9f is shown schematically and is not drawn to scale. Such an embodiment may be advantageous when the glass element 1 is used in a printed circuit application. For example... Figure 5 In a schematic and non-scale drawing, multiple channels 10 distributed in a predetermined pattern on the glass element 1 can be created by introducing filamentary defects 9 through the glass element 1. However, generally not limited to the example shown here, only one channel 10 can be created within the glass element 1.

[0058] Advantageously, according to an embodiment, a focusing optics 70 is used to generate a filamentary defect 9 terminating in the glass element 1, wherein the focusing optics 70 superimposes at least two partial beams 50, 51 of the laser beam 5, such that the interference of the partial beams 50, 51 produces an intensity variation along the focal line 8. In this way, the cone angle 94 can be adjusted quickly and easily. Figure 6 schematically illustrates the laser beam 5 comprising two partial beams 50, 51. Figure 6a In the image, the laser beam 5 is depicted along the beam direction. (As shown in...) Figure 6a As can be seen, part of beam 51 is a central beam, while part of beam 50 is a ring beam in the exemplary embodiment of FIG6. Figure 6b In the image, laser beam 5 is shown as a side view. Parts of the beams 50 and 51 interfere in region 52, which has a length of 53. Within this interference region 52, filamentary defects can advantageously be generated within the glass element 1. It should be noted that, according to... Figure 6a , 6b In the exemplary embodiment shown, the annular partial beam 50 can be a Bessel beam or a Bessel-Gaussian beam. Such a partial beam can be generated using suitable focusing optics 70 (not shown here), such as an axonometric prism.

[0059] Figure 7 It shows the following according to Figure 6a , 6b The intensity distribution of the laser beam 5 along the focal line 8 in this embodiment. Along the focal line 8, interference of portions of the beam 50 and 51 causes several intensity maximum values ​​54.

[0060] Figure 8 The defects 9 of different shapes formed in the glass element 1 according to an embodiment of the invention are shown schematically and not to scale by way of example.

[0061] According to the embodiments and as in Figure 8The diagram, shown schematically and not to scale, illustrates the generation of two coaxially oriented filamentary defects 9a and 9b by irradiation with a laser beam 5 (not shown). The two coaxially oriented defects 9a and 9b can be generated, for example, by using the method described in DE 10 2018 126 381 A1 or by the multicolor filament method as described in DE 10 2017 208 290 A1, through irradiation of the glass element 1 at different depths. In the multicolor filament method, a lens with chromatic aberration is used to focus the laser beam. Using different wavelengths, the laser beam can be focused at different depths to generate coaxially oriented filaments. A suitable laser source can be a white laser, such as a white fiber laser, or any suitable multicolor laser. Using a pulsed multicolor laser beam, particularly one with a specific pulse duration and wavelength, a focal line can be generated along the beam direction of a workpiece, such as a glass element 1, by means of an optical assembly having chromatic aberration for wavelength-dependent focusing of the laser beam and at least one filter for wavelength-dependent filtering of the laser beam. The processing depth of the workpiece can be selectively and accurately adjusted by the focal line. Specifically, the length of the focal line can be adjusted by generating different focal points. Furthermore, multicolor light can be filtered to allow for the use of a suitable wavelength range. By means of the filter, at least one wavelength of the laser beam can be selectively filtered, resulting in selective defocusing at least at specific locations within the focal line. In particular, the start or end point of the focal line can be defined by unilateral or bilateral spectral restriction (introducing a band-edge filter or a bandpass filter). In individual embodiments, the endpoint is particularly adjusted in a defined manner (on the side facing away from the laser), for example, to avoid processing supports on which the workpiece is placed.

[0062] like Figure 8 As shown, coaxially oriented defects 9a and 9b begin at opposite end faces 14 and 15, respectively, and end relative to each other within the glass element 1. This can be achieved, for example, by first irradiating a first side face, such as side face 14, to produce a first defect, followed by irradiating a second side face 15 to produce a second defect. However, this requires very precise control of the element position relative to the laser beam 5 in two different process steps, where the element position changes between steps, i.e., changing the orientation of sides 14 and 15 relative to the laser 7. Therefore, it may be preferable to use the method according to German patent application DE 10 2018 126 381 A1, which allows the production of two defects in a single process step. In such a method, a suitable focusing optics 70, such as an axial prism (e.g., an axial prism without a tip), can be used, for example. Furthermore, the axial prism can be selected in this case so that the interference angle 55 of a portion of the beam 50 can be adjusted. Figure 6a and 6b(As shown). For example, if an Nd:YAG laser (emission wavelength 1064 nm) is used as laser 7, the periodicity, i.e., the distance between the maximum values ​​54 of the laser beam 5, can be obtained as 10 μm or even less than 10 μm, at most 100 μm or even at most 200 μm. Therefore, the method according to the invention is suitable for producing holes or channels with tapered walls in very thin glass elements, i.e., glass elements with a thickness of 1 mm or less, preferably 0.5 mm or less, particularly preferably 300 μm or less, more particularly preferably 200 μm or less, for example 100 μm or less or even 50 μm or less or 30 μm or less. Similarly, coaxially oriented defects can be produced by subsequently irradiating with laser beams with different focal positions or focal lengths.

[0063] According to another embodiment, coaxially oriented defects 9c, 9d are generated in the glass element, each defect 9c, 9d having a different length, thereby forming a wall 6 connecting the opposing sides 14, 15 of the glass element 1 by etching and widening the filamentary defects 9c, 9d, wherein boundary lines 12 with different cone angles from the sides 14, 15 are formed at vertices 16, 17, 18, 19. That is, the cone angle 94 can be adjusted simply by adjusting the length and / or position of the defects 9. For example, regarding Figure 8 The defects 9e, 9g, and 9h in the glass element 1, due to their different positions relative to surfaces 14 and 15, result in different cone angles of the obtained holes 91 or channels 10 due to etch bath aging. Therefore, the invention also relates to a method for generating channels 10 in a plate-shaped glass element 1, particularly according to any of the foregoing embodiments, wherein a pulsed laser beam 5 of an ultrashort pulse laser 7 is directed onto the glass element 1, wherein the glass element 1 is transparent to the laser beam 5, and wherein at least one filamentary defect 9 is generated in the glass element 1 (e.g., and regarding...). Figure 8 A filamentary defect 9 (hereinafter, filamentary defect 9g) extends laterally to the sides 14 and 15 of the glass element 1. The filamentary defect 9 (hereinafter, defect 9g) is generated using a laser beam 5, which is focused by a focusing optics 70 to form a focal line 8 within the glass element 1. The intensity of the laser beam 5 within the focal line 8 is sufficient to generate the filamentary defect 9, and the focal line 8 is adjusted so that both ends of the filamentary defect 9 are located within the glass element 1. Subsequently, the glass element 1 is exposed to an etching bath 81, where glass is removed by etching, thereby removing the glass material from the sides 14 and 15 and exposing at least one end of the filamentary defect 9 (hereinafter, as indicated above, defect 9g). Etching continues, causing the filamentary defect 9 to widen to form a channel 10 with a predetermined diameter.

[0064] According to the embodiment, at least two filamentary defects 9 are present here. Figure 8Defects 9g and 9h are introduced into glass element 1. Here, the ends of the filamentous defects 9g and 9h are at different distances from one of the sides 14 and 15 of glass element 1, such that when etching one of the filamentous defects 9g and 9h, i.e., during etching... Figure 8 In the exemplary embodiment shown, defect 9g is exposed earlier than other filamentary defects, such as defect 9h, so that defects 9g and 9h are exposed to the etching bath 81 for different time spans, resulting in channels 10 of different diameters.

[0065] Furthermore, the diameter of the defect 9 generated within the glass element 1 can be adjusted according to a predetermined value. For example, as illustrated and not drawn to scale... Figure 8 As can be seen from the image, it is possible to specify the generation of defects 9 with different diameters, which can be achieved by adjusting the laser parameters and / or by irradiating the defects for a longer or repeated period to achieve a larger diameter of the resulting defects.

[0066] Furthermore, the channel 10 can be formed in such a way that the angles formed between the channel 10 (or the boundary line 12 of the wall 6 of the channel 10) and the sides 14, 15 are different from each other. Figure 9 The image schematically shows, but not to scale, a glass element 1 comprising channels 10 with different cone angles at different vertices 16, 17, 18, 19. Figure 9 In the exemplary plate-shaped glass element 1 shown schematically and not to scale, the three channels 10a, 10b, and 10c differ from each other in their respective shapes and cone angles. For example, the boundary line 12 of the wall 6 of channel 10a is a straight line, so channel 10a can also be understood as having the shape of a truncated oblique cone.

[0067] Channel 10b has a sloping boundary line 12, meaning that the diameter of channel 10b is wider at the openings 60 and 61 than in the middle region of channel 10b.

[0068] The diameter of channel 10c also widens toward openings 60, 61; however, unlike channel 10b, channel 10c has a boundary line 12, at least a portion of which is concavely curved toward sides 14, 15 relative to the vertical line 13 (not shown here).

[0069] Furthermore, the channel 10d has a straight portion 62, i.e., a portion in which the walls are parallel to a vertical line, while near the surfaces 14, 15 of the glass element 1, the walls 12 are tapered, such that the portion of the channel 10d between the portion 62 and the surfaces 14, 15 is truncated conical. This channel 10d, including the straight portion 62, can be constructed, for example, by etching a series of filamentary defects 9, for example... Figure 8 The series 90 shown is obtained.

[0070] according to Figure 8In another embodiment, which is illustrative and not shown to scale, filamentary defects 9e are generated by irradiation with a laser beam 5, wherein the defects 9e begin and terminate within the glass element 1.

[0071] According to another embodiment, the laser beam 5 travels relative to the glass element 1 along a predetermined path 11. In this manner, numerous defects 9 are generated side-by-side along the path 11. In this case, etching continues at least until adjacent channels 10 are joined, such that the glass element 1 is divided into portions 100, 101 (illustrated and not to scale) along the path 11. Figure 10 (As shown in the diagram), and in this manner, the wall 6 produced by etching forms the edge surfaces 105 of portions 100, 101. Such an embodiment is advantageous because, in this way, the removal of portions can be achieved more easily, especially when the predetermined path 11 is a closed line within the glass element 1. Furthermore, the resulting edge surfaces 105 are angled, which increases the mechanical strength of portions 100, 101. Due to the etching process, any defects that might reduce the strength of the glass, such as micro-defects, have been eroded, making it possible to obtain the resulting edge surfaces 105 with a predetermined shape and high strength, i.e., higher strength than that obtained by ordinary cutting or dicing processes. Therefore, according to another embodiment, the laser beam 5 is guided relative to the glass element 1 along the closed path 11, such that by subsequent etching, the inner glass portion 100 separates from the outer glass portion 101, leaving an opening 102 in the outer glass portion 101. This is illustrative and not to scale. Figure 10 and 11 As shown in the figure, Figure 11 The outer glass portion 101 is shown, with the inner glass portion 100 removed, leaving an opening 102.

[0072] According to another embodiment, the cone angle 94 between the boundary line 12 of the wall 6 and the side surfaces 14 and / or 15 is adjusted by selecting the molar concentration of the etching bath (or etching medium) 81. That is, the cone angle can be changed by carefully selecting the etching conditions, particularly by adjusting the molar concentration of the etching bath. Preferably, an alkaline etching bath (or etching medium), such as one containing KOH as a main component, is used. This etching bath or etching medium is well-suited for glass commonly used in etching technology applications, such as glass used as an interlayer. In particular, borosilicate glass can be etched using an alkaline etching bath (or alkaline etching medium) containing KOH. In this way, it is not necessary to use acidic etching media typically used for glass, usually based on HF or related compounds. This is advantageous because etching media containing HF, etc., are harmful, especially in terms of safety and environmental issues.

[0073] Preferably, the cone angle 94 is adjusted by setting, in particular increasing, the molar concentration of the alkaline etching bath (or the molar concentration of the alkaline etching medium). This is advantageous because it increases the overall reaction rate.

[0074] Typically, the dependence of the cone angle on the molar concentration of the etching bath allows for the production of a predetermined cone angle. Similarly, the cone angle also typically depends on the viscosity of the etching bath and other parameters, such as etching depth or etching removal. Etching removal depends on the etching time. Therefore, in another embodiment, an improved method is provided to achieve the desired cone angle, comprising the following steps:

[0075] -The cone angle of the edges of the portions 100 and 101 to be implemented after etching is limited to 94 degrees.

[0076] - Determine at least one of the following based on the defined cone angle 94: molar concentration of etching bath 81, viscosity of etching bath 81, etching removal, and etching time.

[0077] - Prepare an etching batch 81 with the determined molar concentration or viscosity, and

[0078] - The glass element is etched in etching bath 81. In this way, the cone angle achieved after etching is typically less than 0.5°, preferably less than 0.3°, and more preferably less than 0.2° from the predetermined or desired cone angle.

[0079] Typically, determining at least one of the molar concentration and viscosity of the etching bath 81 based on a defined cone angle 94 may include extrapolation from one or more reference points or interpolation between one or more reference points, which correlates the cone angle with at least one of the parameter etching bath molar concentration or viscosity parameters. In this regard, it has been found that by increasing the molar concentration of the alkaline etching bath or etching medium 81 by 2 mol / L, the cone angle 94, for example, the cone angle of the edges of portions 100, 101, can be increased by at least 0.1°. Therefore, the step of determining the molar concentration may include extrapolation from one or more reference points using a factor of at least 0.1° / 2 mol / L.

[0080] According to another embodiment, by increasing the molar concentration of etching bath 81 (or etching medium 81) by 4 mol / L to 8 mol / L, preferably by increasing the molar concentration of KOH by 6 mol / L, the cone angle 94, for example, the cone angle 94 of the edge of portions 100, 101, can be increased in the range of 0.3° to 0.7°. Therefore, according to this embodiment, determining the molar concentration of the etching bath may include the step of increasing the molar concentration of etching bath 81 (or etching medium 81) by 4 mol / L to 8 mol / L, preferably by increasing the molar concentration of KOH by 6 mol / L, so that the cone angle is increased in the range of 0.3° to 0.7° relative to a reference point for the molar concentration and the cone angle. Preferably, the reference point used in the embodiment explained above for adjusting the parameters of the etching bath is derived from a measurement, i.e., from a measured cone angle at a glass portion etched in an etching bath having a known molar concentration or viscosity. Of course, the values ​​of one or more reference points can be corrected, for example, by averaging or linear regression.

[0081] Typically, the determination of molar concentration or viscosity can be accomplished using a reference function that depends on the cone angle of the molar concentration or viscosity. This function returns the molar concentration or viscosity at the corresponding cone angle to be achieved. This function can also be represented tabularly. For example, the above embodiment using a factor of at least 0.1° / 2 mol / L actually uses a linear reference function with a gradient given by that factor. Typically, the reference function can be obtained through regression, particularly linear regression of multiple measurements (i.e., multiple measurement reference points). This factor can even reach at least 0.2° / (mol / L), for example, about 0.25° / (mol / L).

[0082] Figure 14 A graph showing four measurements of the cone angle obtained at different molar concentrations in an alkaline etching bath is presented. The measurements are represented as solid circles. Furthermore, the regression lines of the measurements are shown as dashed lines. The regression lines can be used as a reference function to determine the molar concentration of the etching bath to obtain the desired cone angle of the glass element's walls between the sides. In fact, linear regression also represents extrapolation from one or more reference points or interpolation between one or more reference points, which correlates the cone angle with the molar concentration of the etching bath.

[0083] It should be understood that other parameters also affect the cone angle. Therefore, alternatively, or in addition to the molar concentration or viscosity of the etching bath, other adjustments to the etching parameters can be selected to obtain the desired cone angle. Specifically, as mentioned above, other etching parameters, including etching depth and etching time corresponding to etching removal at a given molar concentration and temperature, can affect the cone angle and can therefore be used to adjust the cone angle to its desired value. Furthermore, etching depth can be considered when adjusting parameters to achieve the desired cone angle. Etching depth corresponds to the depth of the channel in the glass element and therefore to the glass thickness if the filamentary defect 9 extends from one side through the entire glass element to the opposite side. Figure 15 The figures show the measured cone angle and the fitted lines for different etching depths and different molar concentrations of etching bath 81 (i.e., 6, 9, 12, and 15 mol / L as shown in the figure). As can be seen in the figure, the cone angle generally increases with etching depth and molar concentration.

[0084] Similarly, Figure 16 The graph shows the cone angle as a function of etching removal at the wall formed by widening the filamentary defect 9. (See figure) Figure 15 As shown, etching experiments were conducted at different molar concentrations in etching bath 81, namely 6, 9, 12 and 15 mol / L. Figure 16 The diagram shows that the cone angle increases with the etch removal and the molar concentration of the etch bath 81. Therefore, the cone angle can also be adjusted by adjusting the etch removal or the etch time.

[0085] The dependence of etching rate and cone angle on the molar concentration of the etching bath also generally depends on the glass type. The example disclosed herein regarding the variation of cone angle with molar concentration refers to glass type D263. However, the ranges given herein may also apply to other glasses. Generally, the variation of cone angle with molar concentration of the etching bath as disclosed herein is typically suitable for glasses with SiO2 content ranging from 30 to 85% by weight.

[0086] The present invention also relates to a plate-shaped glass element 1. In particular, the plate-shaped glass element 1 can be produced or is producible by a method according to an embodiment of the present invention. Figure 5 An exemplary diagram illustrates a plate-shaped glass element 1 having two opposing sides 14, 15 and a plurality of etched channels 10. The channels 10 extend through the glass element 1 such that the walls 6 of the channels 10 connect to the sides 14, 15. The boundary line 12 of the wall 6 is tapered at vertices 16, 17, 18, 19 between the wall 6 and the adjacent sides 14, 15. That is, a tapered angle 94 is formed between the wall 6 (or the boundary line 12 of the wall 6) and the perpendicular lines 13 (not shown) of the sides 14 and 15. The tapered angle 94 can be controlled by a method according to an embodiment of the invention.

[0087] Preferably, according to an embodiment, at least two cone angles 94 between the boundary line 12 and the perpendicular line 13 of the sides 14, 15 are different from each other.

[0088] According to another embodiment, at least one channel 10 has a wall 6 with a boundary line 12, which has a different taper angle from the perpendicular line 13 of the side 14, 15 at the openings 60, 61 of the channel 10 to the corresponding side 14, 15.

[0089] According to another embodiment, the boundary lines 12 of the walls 6 at the openings 60 and 61 of the channels 10 on the sides 14 and 15 are different from each other.

[0090] According to another embodiment, in at least one portion, the wall 6 is concavely curved relative to the direction of the perpendicular line 13 of the sides 14, 15.

[0091] According to another embodiment, a plurality of channels 10 are distributed on the glass element 1 in a predetermined pattern. For example, the predetermined pattern may form a grid, or a circle, or a spiral.

[0092] According to another embodiment, the glass element 1 has a thickness of up to 200 μm and preferably at least 3 μm, more preferably at least 5 μm and most preferably at least 10 μm.

[0093] Such glass elements 1 and / or portions 100, 101 can be used, for example, in printed circuit applications, microfluidic devices, or for liquid lenses.

[0094] List of reference numerals

[0095] 1. Glass components

[0096] 5 laser beams

[0097] 6 walls

[0098] 7. Ultrashort pulse lasers

[0099] 8. Focal line of laser beam 5

[0100] 9, 9a, 9b, 9c, 9d, 9e, 9f, 9g, 9h: Filamentous defects

[0101] 90 series defects

[0102] Channels 10, 10a, 10b, 10c, and 10d

[0103] 11 Path

[0104] 12 Boundary Line

[0105] 13 Perpendicular lines

[0106] 14, 15 Side view of glass element 1

[0107] Vertices 16, 17, 18, and 19

[0108] 20 Positioning devices

[0109] Partial beams of laser beam 50 and 51

[0110] 52 Interference Region

[0111] 53. Length of the interference region

[0112] 54 Maximum Strength

[0113] 55° interference angle

[0114] Openings of channel 10, 60 and 61

[0115] 62-channel 10d linear portion

[0116] 70 Focusing Optics

[0117] 71 Computing device

[0118] 80 Etching Tank

[0119] 81 Etching medium, etching bath

[0120] 91 Blind Hole

[0121] 94 cone angle

[0122] Parts 100 and 101 of glass element 1

[0123] 102. Opening within 100.

[0124] 105 The edges of parts 100 and 101

Claims

1. A method for structuring a glass element (1), wherein - The pulsed laser beam (5) of the ultrashort pulse laser (7) is guided onto the glass element (1), wherein - The glass element (1) is transparent to the laser beam (5), wherein - At least one filamentary defect (9) is generated in the glass element (1), the filamentary defect (9) extending transversely to the sides (14, 15) of the glass element (1), the filamentary defect (9) is generated by a laser beam (5), the laser beam (5) is focused by a focusing optics (70) to form a focal line (8) in the glass element (1), wherein, The intensity of the laser beam (5) within the focal line (8) is sufficient to produce filamentary defects (9), in which - Adjust the focal line (8) so that the filamentary defect (9) terminates within the glass element (1), wherein - The glass element (1) is exposed to an etching bath (81), which removes the glass by etching, so that - The filamentary defects (9) widen to form a wall (6) extending between the opposite sides (14, 15) of the glass element (1), the wall (6) having a boundary line (12) tapering at the apex (16, 17, 18, 19) between the wall (6) and the adjacent sides (14, 15), and having a cone angle (94) relative to the perpendicular line (13) of the sides (14, 15). - Adjust the cone angle (94) by at least one of the position, length, and intensity distribution of the focal line (8), wherein Etching parameters are selected to adjust the cone angle, and the etching parameters include at least one of the molar concentration of the etching bath (81), the viscosity of the etching bath (81), the amount of material removed by etching, and the etching time.

2. The method according to claim 1, wherein, Channels (10) are created by etching and widening filamentary defects (9), wherein the channels (10) open to two opposite sides (14, 15).

3. The method according to claim 1 or 2, wherein, Multiple channels (10) are generated on the glass element (1) in a predetermined pattern by introducing filamentous defects (9) that pass through the glass element (1).

4. The method according to claim 1 or 2, wherein, A filamentary defect (9) terminating in a glass element (1) is generated using a focusing optics (70). The focusing optics (70) superimposes at least two partial beams (50, 51) of the laser beam (5), such that the interference of the partial beams (50, 51) produces an intensity variation along the focal line (8).

5. The method according to claim 1 or 2, wherein, Two coaxially oriented filamentary defects (9) are generated by irradiation with a laser beam (5). The coaxially oriented filamentary defects (9) start from opposite sides (14, 15) and terminate within the glass element (1).

6. The method according to claim 1 or 2, wherein, Fine filamentary defects (9) are generated by irradiation with a laser beam (5), and the fine filamentary defects (9) begin and terminate within the glass element (1).

7. The method according to claim 1 or 2, wherein, At least two coaxially oriented filamentary defects (9) are generated by irradiation with a laser beam (5), wherein the filamentary defects (9) have different lengths, such that walls (6) connecting opposite sides (14, 15) of the glass element (1) are formed by etching and widening the filamentary defects (9), the walls (6) having boundary lines (12) with different cone angles from the apex (16) to the sides (14, 15).

8. The method according to claim 1 or 2, wherein, The laser beam (5) travels along a predetermined path (11) relative to the glass element (1), causing a plurality of filamentary defects (9) arranged side by side to be generated along the path (11), and wherein etching continues at least until adjacent channels (10) are joined, causing the glass element (1) to be divided into an inner glass portion (100) and an outer glass portion (101) along the path (11), and causing the wall (6) generated by etching to form the edge surface (105) of the inner glass portion (100) and the outer glass portion (101).

9. The method according to claim 1 or 2, wherein, A laser beam (5) is guided along a closed path (11) relative to the glass element (1) so that the inner glass portion (100) is separated from the outer glass portion (101) by subsequent etching, leaving an opening (102) in the outer glass portion (101).

10. The method according to claim 1 or 2, characterized in that, The predetermined cone angle (94) between the boundary line (12) and the sides (14, 15) of the wall (6) is adjusted by selecting the molar concentration of the etching bath (81).

11. The method according to claim 10, wherein, The etching bath (81) is an alkaline etching bath.

12. The method according to claim 1 or 2, comprising the following steps: - Define the cone angle (94) between the edges of the inner glass portion (100) and the outer glass portion (101) of the glass element (1) to be realized after etching. - Determine at least one of the following based on the defined cone angle (94): molar concentration of etching bath (81), viscosity of etching bath (81), amount of material removed by etching, and etching time. - Prepare an etching bath with a defined molar concentration or viscosity (81), and - Etch the glass element in the etching bath (81).

13. The method of claim 12, comprising at least one of the following features: The step of determining the molar concentration or viscosity of the etching bath includes extrapolation from one or more reference points or interpolation between one or more reference points, which correlates the cone angle with at least one of the parameters of the etching bath: molar concentration or viscosity. The step of determining the molar concentration or viscosity of the etching bath includes using a reference function that depends on the molar concentration or viscosity of the cone angle, where the function returns the molar concentration or viscosity for the corresponding cone angle to be achieved. - The steps for determining molar concentration involve extrapolation from one or more reference points using a factor of at least 0.1° / 2 mol / L.

14. The method of claim 10, wherein, By increasing the molar concentration of the etching bath (81) by 4 mol / l to 8 mol / l, the cone angle (94) of the edges of the inner glass portion (100) and the outer glass portion (101) of the glass element (1) to be realized after etching is increased in the range of 0.3° to 0.7°.

15. The method according to claim 10, wherein, By increasing the molar concentration of KOH by 6 mol / l, the cone angle (94) of the edges of the inner glass portion (100) and the outer glass portion (101) of the glass element (1) to be realized after etching is increased in the range of 0.3° to 0.7°.

16. The method according to claim 1 or 2, wherein the focal line (8) is adjusted such that both ends of the filamentous defect (9) are located within the glass element (1), exposing the glass element (1) to an etching bath (81) which removes glass by etching, thereby removing side glass material and exposing at least one end of the filamentous defect (9), and wherein, Etching continues, causing the filamentous defects (9) to widen to form channels (10) with a predetermined diameter.

17. The method according to claim 16, wherein, At least two filamentary defects (9) are introduced into the glass element (1), wherein the ends of the filamentary defects (9) are at different distances from the sides (14, 15) of the glass element (1), so that the filamentary defects (9) are exposed earlier than other filamentary defects (9) during etching, and the defects (9) are exposed to the etching bath (81) for different time spans, thereby producing channels (10) of different diameters.

18. A plate-shaped glass element (1) produced by the method according to any one of the preceding claims, the glass element (1) having two opposing sides (14, 15) and a plurality of etched channels (10) extending through the glass element (1) such that the walls (6) of the channels (10) connect to the sides (14, 15), and wherein, The boundary line (12) of the wall (6) is conical at the vertices (16, 17, 18, 19) between the wall (6) and the adjacent side (14, 15).

19. The plate-shaped glass element (1) according to claim 18, wherein, At least two cone angles (94) between the boundary line (12) and the perpendicular line (13) of the side (14, 15) are different from each other at the vertices (16, 17, 18, 19) between the wall (6) and the side (14, 15).

20. The glass element (1) according to claim 19, characterized in that... At least one of the following characteristics: - At least one channel (10) has a wall (6) with a boundary line (12), the boundary line (12) and the perpendicular line (13) of the side (14, 15) having different cone angles (94) at the openings (60, 61) from the channel (10) to the side (14, 15). - The boundary lines (12) of the wall (6) are different from each other at the openings (60, 61) of the passage (10) to one of the sides (14, 15).

21. The glass element (1) according to any one of claims 19-20, wherein, In at least one part, the wall (6) is concavely curved in the direction of the perpendicular (13) to the side (14, 15).

22. The glass element (1) according to claim 20, comprising at least one of the following features: - Multiple channels (10) are distributed on the glass element (1) in a predetermined pattern. - The thickness of the glass element (1) is up to 200µm.

23. The glass element (1) according to claim 20, wherein, Multiple channels (10) are distributed on the glass element (1) in a predetermined pattern that forms a grid.

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