Method for structuring glass components and structured glass components manufactured thereby

Abstract

To provide a method of structuring a glass element that at least partially solves the need for extensive process control.SOLUTION: The invention relates to a method of structuring a glass element (1), wherein a pulsed laser beam (5) of an ultrashort pulse laser (7) is directed onto the glass element (1), wherein the glass element is transparent for the laser beam and wherein at least one filament-shaped flaw (9) is produced in the glass element, the filament-shaped flaw extending transversely to the side faces (14, 15) of the glass element (1), the filament-shaped flaw being produced with a laser beam that is concentrated by means of a focusing optics (70) to form a focus line in the glass element, wherein the intensity of the laser beam within the focus line is sufficient to produce the filament-shaped flaw, and wherein the focus line is adjusted so that the filament-shaped flaw ends within the glass element.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to a method for structuring glass members. A further aspect of the present invention relates to structured glass members, particularly glass members that have been manufactured or can be manufactured by the method according to an embodiment of the present invention, and the use of such glass members. In particular, the present invention relates to a method for structuring glass members using a pulsed laser beam of an ultrashort pulsed laser, and glass members that have been manufactured or can be manufactured by such a method, and their use.

Background Art

[0002] A method for processing a workpiece using an ultrashort pulsed laser is frequently used, for example, in preparation for separating a workpiece.

[0003] For example, International Publication No. 2012 / 006736 (WO2012 / 006736 A2) discloses a preparation method for separating a substrate by using an ultrashort pulsed laser, that is, a laser having a pulse length shorter than 100 ps. In the method disclosed by International Publication No. 2012 / 006736, several spaced-apart filaments are generated along a separation line intended, by utilizing the self-focusing non-linear effect.

[0004] International Publication No. 2017 / 009379 (WO2017 / 009379 A1) describes a further development of the method of International Publication No. 2012 / 006736. In the method according to International Publication No. 2017 / 009379, modification is brought about in a workpiece that extends obliquely with respect to the surface of the substrate to be processed. This is achieved by directing the laser pulses obliquely onto the surface of each workpiece.

[0005] From European Patent Specification No. 2931467 (EP\,2931467 B1), it is known to include an ambient atmosphere as a further process parameter to prevent premature self-cleavage due to crack growth below the critical level.

[0006] Furthermore, German Patent Application Publication No. 102015116848 (DE102015116848 A1) describes introducing a defined region of intensity by generating a filament using the spherical aberration of a lens, where a Gaussian beam of an ultrashort pulse laser is transformed into a linear focus having a non-uniform intensity distribution along the optical axis.

[0007] Furthermore, German Patent Application Publication No. 102018126381 (DE102018126381 A1) relates to a method for introducing separation lines into a transparent brittle material and a member obtained in the same manner.

[0008] However, all of these methods are aimed at separating a workpiece. That is, in a workpiece using an ultrashort pulse laser layer, several material modifications are introduced, and these modifications are arranged along a predefined path along the intended separation line. Preferably, the material modification leads to holes formed within the workpiece. The workpiece can then be exposed to an etching medium or etching bath to widen the holes and merge adjacent holes or channels, thereby advantageously achieving separation. In this way, the workpiece can be separated along the predefined path of the material modifications (or filaments) formed within it.

[0009] However, in some applications, such as when a glass component is used as an interposer, it may be preferable to structure the glass component rather than separate it. Furthermore, known methods for generating filaments at an oblique angle to the surface of a workpiece require extensive process control to precisely adjust and monitor, for example, laser parameters and / or workpiece positioning, by preparing special focusing optics that can correct astigmatism distortion of the beam profile.

[0010] Therefore, there is a demand for manufacturing methods and glass components that can at least partially eliminate the shortcomings of conventional technology. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] International Publication No. 2012 / 006736 [Patent Document 2] International Publication No. 2017 / 009379 [Patent Document 3] European Patent No. 2931467 [Patent Document 4] German Patent Application Publication No. 102015116848 [Patent Document 5] German Patent Application Publication No. 102018126381 [Overview of the project] [Problems that the invention aims to solve]

[0012] The object of the present invention is to provide a method for structuring glass members that at least partially eliminates the known drawbacks of the prior art, namely methods that require extensive process control. Further aspects of the present invention are directed toward structured glass members and the use of such glass members. [Means for solving the problem]

[0013] Summary of the Invention This problem is solved by the subject matter of the independent claim. Advantageous embodiments and improvements are identified in the dependent claims, drawings, and specification.

[0014] Accordingly, the present invention relates to a method for structuring a glass member. According to this structuring method, a pulsed laser beam of an ultrashort pulse laser is directed onto a glass member. The glass member is transparent to the laser beam, and at least one filamentous crack is generated within the glass member, the filamentous crack extending to intersect the side surface of the glass member. The filamentous crack is generated using a laser beam focused by a focusing optical instrument to form a focal line within the glass member, where the intensity of the laser beam within the focal line is sufficient to generate the filamentous crack. The focal line is adjusted so that the filamentous crack terminates within the glass member. The glass member is exposed to an etching medium or an etching bath that removes glass by etching, causing the filamentous crack to expand and form a wall extending between opposing side surfaces of the glass member, the wall having a tapered boundary line at the apex between the wall and the adjacent side surface at a taper angle with respect to the perpendicular of the side surface, the taper angle being adjusted by at least one of the position, length, and intensity distribution of the focal line. By combining these parameters, the geometric shape of the filamentous crack, such as the crack depth in the form of a blind hole, can be adjusted.

[0015] This method offers several advantages.

[0016] According to the method of this disclosure, a structured glass member is obtained, in which filamentous cracks terminating within the glass member are formed. In a further step, these filamentous cracks are widened by using an etching medium or etching bath to form walls extending between opposing surfaces of the glass member. In other words, etching yields holes within the glass member, which at least essentially conform to the shape of the pre-formed filamentous cracks. Since the filamentous cracks terminate within the glass member, blind holes are obtained within the glass member.

[0017] Here, the expression "the hole follows, at least essentially, the shape of the crack" is understood to mean that the hole extends along the length of the original filamentous crack and is therefore formed as an elongated hole, but can be wider and longer than the crack itself.

[0018] The filamentous cracks extend intersecting the sides, meaning that the filamentous cracks and the sides of the glass member are at an angle. In other words, the filamentous cracks are not parallel to any of the sides of the glass member. Preferably, the cracks may be perpendicular to at least one of the sides of the glass member, or oriented essentially perpendicular to at least one of the sides of the glass member. Here, "oriented essentially perpendicular" is understood to mean that the crack and the normal to each side are at an angle of ±5° or less.

[0019] However, and quite surprisingly, when etching a glass component to widen filamentous cracks and form walls (or holes with walls) within the glass component, the walls (or holes with walls) are obtained with tapered boundaries. That is, the holes are at an oblique angle to at least one of the sides. In particular, the angles between the cracks and the sides may differ from the angles between the holes (or boundary lines of the holes' walls).

[0020] This can be achieved, quite unexpectedly, by adjusting the position of the focal line of the laser beam and / or at least one of the intensity distribution. However, it is not essential to control the orientation of the substrate relative to the laser beam with great precision by providing, for example, an additional optical device, such as a cylindrical lens or the like. Accordingly, the present disclosure provides a simple method for forming a structured glass member having at least one blind hole formed within the glass member, wherein the boundary line between the wall of the hole and the side of the glass member into which the hole is formed is at an oblique angle.

[0021] Within the scope of this invention, the following definitions apply: A filament is understood to be an elongated structure, that is, a structure in which the dimension along the first direction of the Cartesian coordinate system is at least one order of magnitude greater than the dimensions of the structure along two further directions perpendicular to the first direction of the Cartesian coordinate system.

[0022] According to the present disclosure, a crack can be understood as a region that has changed within a workpiece (or a glass member). That is, in that region, the properties are different from those of the workpiece (or glass member) before the crack is formed.

[0023] Therefore, a filamentous crack can be understood as an elongated region that has changed within a glass member.

[0024] A plate-like member (or body) is understood to be a body in which its dimension along the first direction of the Cartesian coordinate system is one order of magnitude smaller than the dimensions along two further directions perpendicular to the first direction of the Cartesian coordinate system. For example, a plate-like glass member can also be represented as a glass plate or a glass ribbon. The plate-like member according to the present disclosure can be formed as a flat or curved member. Further, in the case of a flat member, the side surfaces can preferably be substantially parallel to each other, that is, the normal lines or perpendicular lines of the side surfaces can preferably form an angle of 10° or less, particularly 5° or less.

[0025] An ultrashort pulse laser is understood to be a laser having a pulse length of 100 ps or less. Preferably, the pulse length is 10 ps or less, more preferably 1 ps or less, or even less than 1 ps.

[0026] According to one embodiment, a channel is generated by etching and widening a filamentous crack, wherein the channel is open with respect to both opposing side surfaces. That is, in other words, according to one embodiment, a through hole is formed. Such an embodiment can be advantageous when the glass member is used as an interposer in, for example, printed circuit applications.

[0027] In a further embodiment, a filamentous crack terminating within a glass member is generated by using a focusing optical device that superimposes at least two partial beams of a laser beam, causing the interference of the partial beams to produce an intensity variation along the focal line. This is a very simple but effective method for inducing a crack (or material modification) within a workpiece. In this regard, the crack may also be referred to as a “dead crack.” Furthermore, when superimposing two partial beams to thereby produce an intensity variation along the focal line, the angle between the side of the glass member and the wall boundary can be adjusted in a very simple manner.

[0028] According to one embodiment, a number of filamentous cracks are generated that are distributed in a predefined pattern across the glass member. Furthermore, these filamentous cracks may be formed by the expansion of the cracks during etching. In this way, a number of channels are generated that correspond to cracks originally generated within the glass member and are distributed in a predefined pattern across the glass member.

[0029] The disclosure further relates to glass members, in particular glass members manufactured, or at least manufacturable, by the method according to embodiments of the disclosure, preferably in the form of a plate. The glass member comprises two opposing sides and a number of etched channels, the channels extending through the glass member, with the walls of the channels connecting the sides. The boundary lines of the channel walls are tapered at the vertices between the walls and adjacent sides. Preferably, at the vertices between the walls and sides, at least two tapered angles between the boundary line and the perpendicular to the side are different from each other. [Brief explanation of the drawing]

[0030] [Figure 1] This figure shows the structuring of a glass component by the method disclosed herein. [Figure 2] This figure shows a glass member 1 according to one embodiment. [Figure 3] This is a diagram showing the etching tank 80. [Figure 4] This diagram shows that etching causes the filamentous cracks 9 to expand and form a wall 6. [Figure 5] This figure shows a suitable crack for obtaining a channel. [Figure 6] This diagram schematically shows a laser beam 5 including two partial beams 50 and 51. Figure 6a) shows the laser beam 5 along the beam direction, and Figure 6b) shows a side view of the laser beam 5. [Figure 7] This figure shows the intensity distribution along the focal line 8 of the laser beam 5 according to the embodiments of Figures 6a) and 6b). [Figure 8] This figure shows cracks 9 of various shapes formed within the glass component 1. [Figure 9] This figure shows a glass member 1 containing a channel 10 having different taper angles at different vertices 16, 17, 18, and 19. [Figure 10] This figure shows an embodiment having regions 100 and 101. [Figure 11] This figure shows the outer glass area 101 with the opening 102 remaining after the inner glass area 100 has been removed. [Figure 12] An example of a glass component 1 containing only a single filamentous crack is shown. [Figure 13] The glass member 1 is shown containing multiple individual filament-like cracks distributed throughout the glass member 1. [Figure 14] This figure shows graphs of four taper angle measurements obtained using basic etching baths of various molar concentrations. [Figure 15] This figure shows measured taper angles and fitted lines for various etching depths and various molar concentrations of the etching bath 81. [Figure 16] This figure shows a graph of the taper angle value as a function of etching removal at the wall formed by widening the filamentous crack 9. [Modes for carrying out the invention]

[0031] The present invention will now be further described with reference to the drawings. In the drawings, similar reference numerals refer to the same or corresponding elements.

[0032] Figure 1 schematically illustrates, and not to scale, the structuring of a glass member by the method of the present disclosure. A pulsed laser beam 5 is generated using an ultrashort pulse laser 7 and directed onto the glass member 1. The glass member 1 is transparent to the laser beam 5. Here, the glass member 1 is a plate-shaped, flat glass member, but it should be understood that according to the present disclosure, any glass member, such as a plate-shaped, curved glass member, can be structured. The glass member 1 has two sides 14, 15. Within the scope of the present disclosure, these sides can be understood as the main surfaces of the body, i.e., surfaces that together constitute more than 50% of the total surface area of ​​each body.

[0033] Furthermore, in addition to glass components, processed products containing or made of materials other than glass can also be structured by the method of this disclosure.

[0034] At least one filamentous, or elongated, crack 9, such as a material modification section, is formed within the glass member 1. The crack 9 extends so as to intersect with the sides 14 and 15 of the glass member 1, that is, it forms an angle with either the crack 9 or either of the sides 14 or 15. In other words, the crack 9 is not parallel to either of the sides 14 or 15.

[0035] The laser beam 5 used to generate the crack 9 is focused by a focusing optical device 70 to form a focal line 8 (not shown here) within the glass member 1. The intensity of the laser beam 5 within the focal line 8 (not shown here) is sufficient to generate the filamentous crack 9. Furthermore, the focal line 8 (not shown here) is adjusted so that the filamentous crack 9 terminates within the glass member 1.

[0036] Figure 1 further illustrates positioning means 20 and computer processing means 71. The position of the glass member 1 can be controlled by adjusting the output of the laser 5 and / or by controlling the positioning means 20 using the computer processing means 71. The positioning means 20 can be advantageously used when a number of filamentous cracks 9 are to be generated within the glass member 1, for example, along a predetermined path. However, it is certainly possible to use multiple computer processing means 71.

[0037] Figure 2 schematically illustrates a glass member 1 according to one embodiment, but not to scale. Here, a number of filamentous cracks 9 are generated within the glass member 1 by advancing a laser beam 5 relative to the glass member 1 along a predetermined path 11. In this way, a number of cracks 9 are formed along the path 11, i.e., arranged in a predetermined pattern. The predetermined pattern may be a grid, or it may be a series of cracks forming circles, ellipses, or any other suitable shape, such as a spiral. As already described with respect to Figure 1 illustrating the positioning means 20, advancing the laser beam 5 along the path 11, and thereby resulting in the formation of a number of cracks 9 distributed across the glass member 1 in a predetermined pattern, can be achieved by the positioning means 20.

[0038] After the laser treatment described above, the glass member 1, which contains at least one filamentous crack 9, is then transferred to an etching bath 80, as schematically and not to scale, as shown in Figure 3, where the glass member 1 is exposed to an etching bath 81 (etching medium 81) that removes the material of the glass member 1, i.e., the glassy material or altered glassy material, such as the material that forms the filamentous crack 9, by etching. The etching bath 81 may be an acid etching bath or a basic etching bath. However, for environmental and safety reasons, a basic etching bath may be preferred. According to the example schematically and not to scale shown in Figure 3, the glass member 1 contains a number of filamentous cracks 9 arranged along the path 11. However, it is generally understood that the glass member 1 may contain only a single filamentous crack 9, without being limited to the example shown in Figure 3. An example of a glass member 1 containing only a single filamentous crack is schematically and not to scale shown in a top view in Figure 12. Furthermore, the glass member 1 may include multiple individual filamentous cracks 9 distributed across the glass member 1, as schematically and not to scaled in Figure 13. It should also be noted that while Figures 2, 12, and 13 show a glass member 1 containing at least one crack 9, the locations of one or more cracks 9 correspond to the locations of blind holes 91 or channels 10 obtained through etching, so Figures 2, 12, and 13 can also be understood to show a glass member having holes 91 or channels 10 instead of cracks 9. Furthermore, in the case of the glass member 1 in Figure 13 containing multiple cracks 9 (or channels or holes), it is conceivable to arrange the cracks 9 such that the resulting holes are arranged in a grid or pattern. This may be particularly preferable when the glass member 1 is used as an interposer.

[0039] Through etching, the filamentous crack 9 expands to form a wall 6, as schematically and not to scale, as shown in Figure 4. That is, the material of the crack 9 is removed more easily by etching than the unchanged material of the glass member 1, so that a hole 91 is formed corresponding to the original crack 9, where the hole 91 has a wall 6. In the case shown in Figure 4, the wall 6 has a tapered boundary line 12 at the vertex 16 between the wall 6 and the adjacent side surface 14. Thus, a taper angle 94 is formed between the perpendicular 13 of the side surface 14 and the wall 6. This taper 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 the filamentous crack in the form of a blind hole can be adjusted. As shown in Figure 4, the resulting hole 91 is a blind hole, i.e., a hole that terminates within the glass member 1. It should be noted here that the dimensions of the hole 91 are exaggerated for better visibility. Etching creates holes 91, and the lateral dimension of the holes 91 decreases towards the bulk region of the glass member 1. This is because the etching bath changes (or ages) during etching, resulting in a higher etching rate on the surface 14 of the glass member 1 than in the bulk region.

[0040] An advantage of the method according to this disclosure is that the taper angle 94 can be controlled and adjusted in a very simple and efficient manner according to a predetermined value by adjusting the position and intensity of the focal line 8, preferably using a suitable focusing optical instrument 70.

[0041] A suitable focusing optical instrument 70 may include lenses, such as spherical or aspherical lenses, or axicones, or spatial light modulators, or a suitable combination thereof.

[0042] According to the embodiment schematically shown in Figure 5, not to scale, a channel (or through-hole) 10 is generated by etching and widening a crack 9, and the channel 10 opens to both opposing sides 14, 15 of the glass member 1. Such a through-hole or channel 10 is obtained by etching a blind hole extending from one surface of the glass member 1, in this case surface 15, and substantially through the glass member 1. A crack suitable for obtaining a channel as shown in Figure 5 is schematically shown, not to scale, as crack 9f in Figure 8, for example. Such an embodiment may be preferred when the glass member 1 is used in printed circuit applications. As schematically shown in Figure 5, not to scale, a number of channels 10 distributed across the glass member 1 in a predefined pattern can be generated by introducing a filamentous crack 9 across the glass member 1. However, it is generally possible to generate only one channel 10 within the glass member 1, without being limited to the example shown herein.

[0043] A significant advantage is that, according to one embodiment, a filamentous crack 9 terminating within the glass member 1 is generated using a focusing optical instrument 70, in which the focusing optical instrument 70 superimposes at least two partial beams 50, 51 of the laser beam 5, and the interference of the partial beams 50, 51 results in an intensity variation along the focal line 8. In this way, the taper angle 94 can be adjusted quickly and easily. Figure 6 schematically illustrates a laser beam 5 including two partial beams 50, 51. In Figure 6a), the laser beam 5 is illustrated along the beam direction. As understood in Figure 6a), partial beam 51 is the central beam, while partial beam 50 is an annular beam in the exemplary embodiment of Figure 5. In Figure 6b), the laser beam 5 is a side view. The partial beams 50, 51 interfere in a region 52 having a length 53. In this interference region 52, a filamentous crack can be advantageously generated within the glass member 1. It should be noted that, according to exemplary embodiments, as illustrated in Figures 6a) and 6b), the annular partial beam 50 can be a Bessel beam or a Bessel-Gauss beam. Such a partial beam can be produced using a suitable focusing optical instrument 70 (not shown here), such as an axicon.

[0044] Figure 7 illustrates the intensity distribution along the focal line 8 of the laser beam 5 according to the embodiments of Figures 6a) and 6b). Along the focal line 8, several intensity maxima 54 are caused by the interference of partial beams 50 and 51.

[0045] Figure 8 schematically and not to scale shows, as an example, various shapes of cracks 9 formed within the glass member 1 according to embodiments of the present disclosure.

[0046] According to an embodiment schematically and not to scale illustrated in Figure 8, two coaxially oriented filamentous cracks 9a and 9b are produced by irradiation with a laser beam 5 (not shown). The two coaxially oriented cracks 9a and 9b can be produced, for example, by irradiating the glass member 1 at different depths using the method described in German Patent Application Publication No. 102018126381 (DE102018126381 A1) or by the chromatic filamentation method described in German Patent Application Publication No. 102017208290 (DE102017208290 A1). In the chromatic filamentation method, the laser beam is focused using a lens with chromatic aberration. Next, the laser beam is focused at different depths using different wavelength bands to produce coaxially oriented filaments. A suitable laser light source may be a white laser, such as a white fiber laser, or any suitable multicolor laser can be used. In particular, using such a multicolor pulsed laser beam having a specific pulse duration and a specific wavelength of the laser beam, it is possible to generate a focal line of a workpiece, such as a glass member 1, along the beam direction by an optical arrangement having chromatic aberration for wavelength-dependent focusing of the laser beam and at least one filter for wavelength-dependent filtering of the laser beam, thereby selectively and precisely adjusting the processing depth of the workpiece. In particular, the length of the focal line can be adjusted by producing different focal points. Furthermore, it is also possible to filter the multicolor light to use a suitable wavelength range. Since the filter can selectively filter at least one wavelength of the laser beam, a focal point is not selectively formed at at least a specific position within the focal line. In particular, the start or end point of the focal line can be defined by restricting one or both sides of the optical spectrum (introduction of a band-edge filter or band-pass filter). In another embodiment, the end point (above the opposite side of the laser) can be adjusted in a defined manner to avoid processing, for example, the support on which the workpiece rests.

[0047] As illustrated in Figure 8, coaxially oriented cracks 9a and 9b begin from opposing end faces 14 and 15, respectively, and terminate facing each other within the glass member 1. This can be achieved, for example, by first irradiating a first side, e.g., side 14, to create a first crack, and then by subsequently irradiating a second side, e.g., side 15, to create a second crack. However, this requires very precise control of the position of the member relative to the position of the laser beam 5 in two different process stages, where the position of the member changes between stages, i.e., the orientation of sides 14 and 15 with respect to the laser 7 changes. Therefore, it may be preferable to use the method according to German Patent Application Publication No. 102018126381 (DE102018126381 A1), which allows both cracks to be generated in a single process stage. In such a method, for example, a suitable focusing optical instrument 70, e.g., an axicon (e.g., an axicon without a tip), can be used. Furthermore, in this case, it is possible to select an axicon so that the interference angle 55 (shown in Figure 6) of the partial beam 50 can be adjusted. For example, when an Nd:YAG laser (oscillation wavelength 1064 nm) is used as the laser 7, periodicity, i.e., the distance between the maxima 54 of the laser beam 5, can be obtained to be 10 μm, or even less than 10 μm, 100 μm or less, or even 200 μm or less. Therefore, the method according to this disclosure is suitable for creating holes or channels with tapered walls in very thin glass members, i.e., glass members having 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 cracks can be generated by subsequently irradiating them with laser beams at different focal positions or focal lengths, respectively.

[0048] In a further embodiment, coaxially oriented cracks 9c and 9d are formed within the glass member, each having a different length. The filamentous cracks 9c and 9d are etched and expanded to form a wall 6 connecting opposing sides 14 and 15 of the glass member 1, where the boundary line 12 is formed with different taper angles relative to the sides 14 and 15 at its vertices 16, 17, 18, and 19. In other words, the taper angle 94 can be adjusted simply by adjusting the length and / or position of the cracks 9. For example, for cracks 9e, 9g, and 9h in Figure 8, their positions relative to the surfaces 14 and 15 of the glass member 1 are different, so the resulting taper angles of the holes 91 or channels 10 are different from each other as a result of the etching bath aging. Accordingly, the present invention also relates to a method for generating a channel 10 within a plate-shaped glass member 1, particularly according to any of the embodiments described above, wherein a pulsed laser beam 5 of an ultrashort pulse laser 7 is directed onto the glass member 1, the glass member 1 being transparent to the laser beam 5, and at least one filamentous crack 9 (for example, crack 9g in Figure 8) is generated within the glass member 1, the filamentous crack 9 (here, filamentous crack 9g) extending to intersect the sides 14, 15 of the glass member 1, the filamentous crack 9 (here, crack 9g) is generated using a laser beam 5 focused by a focusing optical instrument 70 to form a focal line 8 within the glass member 1, the intensity of the laser beam 5 within the focal line 8 is sufficient to generate the filamentous crack 9, and the focal line 8 is adjusted so that both ends of the filamentous crack 9 are located within the glass member 1. Next, the glass member 1 is exposed to an etching bath 81 that removes glass by etching, so that the glass material on the sides 14 and 15 is removed, exposing at least one end of the filamentous crack 9 (crack 9g as noted above), and etching is continued so that the filamentous crack 9 expands, forming a channel 10 having a predetermined diameter.

[0049] According to one embodiment, at least two filamentous cracks 9 are introduced into the glass member 1 (cracks 9g and 9h in Figure 8). Here, the ends of the filamentous cracks 9g and 9h are at different distances from one of the sides 14 and 15 of the glass member 1, so that during etching, one of the filamentous cracks 9g and 9h, i.e., crack 9g in the exemplary embodiment shown in Figure 8, is exposed earlier than the other filamentous crack, crack 9h in this case, and cracks 9g and 9h are exposed to the etching bath 81 for different periods of time, thus creating channels 10 of different diameters.

[0050] Furthermore, it is conceivable to adjust the diameter of the crack 9 introduced into the glass member 1 according to a predefined value. For example, as can be understood in the schematic and non-scale depiction of Figure 8, it is possible to generate cracks 9 with different diameters, which can be achieved by adjusting the laser parameters and / or by irradiating the crack for a longer or more repeated time to achieve a larger diameter crack.

[0051] Furthermore, the channel 10 can be formed such that the angles between the channel 10 (or rather the boundary line 12 of the wall 6 of the channel 10) and the sides 14, 15 are different from each other. A glass member 1 such as this, which includes channels 10 having different taper angles at different vertices 16, 17, 18, and 19, is schematically and not to scale shown in Figure 9. In the exemplary plate-shaped glass member 1 schematically and not to scale shown in Figure 9, the three channels 10a, 10b, and 10c all differ from each other in terms of their respective shapes and taper angles. For example, since the boundary line 12 of the wall 6 of the channel 10 is a straight line, channel 10a can also be understood to have the shape of a frustoconical oblique cone.

[0052] Channel 10b has an inclined boundary line 12, meaning that the diameter of channel 10b is wider at the openings 60 and 61 than in the central region of channel 10b.

[0053] The diameter of channel 10c also widens towards the openings 60, 61, but in contrast to channel 10b, channel 10c has a boundary line 12 that curves concavely in at least one cross-section with respect to a perpendicular line 13 (not shown here) to the sides 14, 14.

[0054] Furthermore, the channel 10d has a straight section 62, that is, a section where the wall is parallel to the perpendicular, while near the surfaces 14, 15 of the glass member 1, the wall 12 is tapered, and the section of channel 10d between section 62 and surfaces 14, 15 exhibits a truncated cone shape. Such a channel 10d including the straight section 62 can be obtained, for example, by etching a series of filamentous cracks 9, for example, the row 90 shown in Figure 8.

[0055] In a further embodiment schematically and not to scale shown in Figure 8, a filamentous crack 9e is generated by irradiation with a laser beam 5, where the crack 9e begins and ends within the glass member 1.

[0056] In a further embodiment, the laser beam 5 is advanced relative to the glass member 1 along a predetermined path 11. In this way, a number of cracks 9 are created that are aligned along the path 11. In this case, etching is continued until at least adjacent channels 10 merge and the glass member 1 is divided along the path 11 into regions 100, 101 (shown schematically and not to scale in Figure 10), and in this way the walls 6 created by etching form the end faces 105 of regions 100, 101. Such an embodiment is preferred because, in this way, the removal of regions can be achieved much more easily, especially if the predetermined path 11 is a closed line within the glass member 1. Furthermore, the resulting end faces 105 are chamfered, thereby increasing the mechanical strength of regions 100, 101. Thanks to the etching process, defects that could degrade the strength of the glass, such as microcracks, have already been eroded, so the resulting end faces 105 can be obtained with a predetermined shape and high strength, i.e., higher strength than that obtained in a normal cleavage or cutting process. Accordingly, according to a further embodiment, the laser beam 5 is guided relative to the glass member 1 along a closed path 11, and subsequent etching separates the inner glass area 100 from the outer glass area 101, leaving an opening 102 within the outer glass area 101. This is illustrated schematically and not to scale in Figures 10 and 11, where Figure 11 shows the outer glass area 101 with the opening 102 remaining after the inner glass area 100 has been removed.

[0057] In a further embodiment, the taper angle 94 between the boundary line 12 and the side 14 and / or 15 of the wall 6 is adjusted by selecting the molar concentration of the etching bath (or etching medium) 81. That is, the taper angle can be changed by carefully selecting the etching conditions, in particular by adjusting the molar concentration of the etching bath. Preferably, a basic etching bath (or etching medium), for example, an etching bath (or etching medium) containing KOH as the main component, is used. Such etching baths or etching media are well suited for etching glass commonly used in technical applications, such as glass for interposers. In particular, borosilicate glass can be etched using a basic etching bath (or basic etching medium) containing KOH. In this way, it is not necessary to use acid etching media commonly used for glass, which are usually based on HF or related compounds. This is preferred because etching media containing HF and similar substances are harmful, especially in terms of safety and environmental issues.

[0058] Preferably, the taper angle of 94 is adjusted by increasing the molar concentration of the basic etching bath (or the molar concentration of the basic etching medium). This is preferred because it increases the overall reaction rate.

[0059] Generally, the dependence of the taper angle on the molar concentration of the etching bath allows for the generation of a predefined taper angle. Similarly, the taper angle can generally depend on parameters such as the viscosity of the etching bath, and even further, on the etching depth or etching removal. Etching removal depends on the etching time. Therefore, in a further embodiment, to achieve a desired taper angle, the following steps are taken: • A step in defining the taper angle 94 at the ends of regions 100 and 101 to be achieved after etching. - A step of determining at least one of the molar concentration of the etching bath 81, the viscosity of the etching bath 81, the etching removal, and the etching time, depending on the defined taper angle 94. • The step of preparing an etching bath 81 having a specified molar concentration or viscosity, and • The stage of etching the glass component in the etching bath 81. An improved method is provided which includes the following: In this way, the taper angle typically achieved after etching differs from a predefined or desired taper angle by less than 0.5°, preferably less than 0.3°, and more preferably less than 0.2°.

[0060] In general, determining at least one of the molar concentration and viscosity of the etching bath 81 depending on a defined taper angle 94 may involve extrapolation from one or more reference points related to the taper angle to at least one of the parameters of the etching bath's molar concentration or viscosity, or interpolation between one or more reference points. In this regard, it has been found that the taper angle 94, for example, the taper angle at the ends of areas 100, 101, can be increased by at least 0.1° by increasing the molar concentration of the basic etching bath or etching medium 81 by 2 mol / l. Therefore, the step of determining the molar concentration may involve extrapolation from one or more reference points using a coefficient of at least 0.1° / 2 mol / l.

[0061] According to a further embodiment, the taper angle 94, for example, at the ends of areas 100, 101, can be increased in the range of 0.3° to 0.7° by increasing the molar concentration of the etching bath 81 (or etching medium 81) from 4 mol / l to 8 mol / l, preferably by increasing the molar concentration of KOH by 6 mol / l. Thus, according to this embodiment, determining the molar concentration of the etching bath may include increasing the molar concentration of the etching bath 81 (or etching medium 81) from 4 mol / l to 8 mol / l relative to a reference point for molar concentration and taper angle, preferably by increasing the molar concentration of KOH by 6 mol / l, thereby increasing the taper angle in the range of 0.3° to 0.7°. Preferably, the reference point that can be used for adjusting the parameters of the etching bath according to the embodiments described above is derived from measurements, i.e., from the taper angle measured in areas of glass etched in an etching bath having a known molar concentration or viscosity. Naturally, the values ​​of one or more reference points can be corrected, for example, by averaging or linear regression.

[0062] In general, the determination of molar concentration or viscosity can be achieved using a reference function of taper angle that depends on molar concentration or viscosity. The function returns the molar concentration or viscosity for each taper angle to be achieved. This function can also be shown in a table. For example, the embodiment using the coefficient of at least 0.1° / 2mol / l described above actually uses a linear reference function having a slope given by this coefficient. In general, the reference function is obtained by regression, in particular by linear regression of multiple measurements, i.e., by multiple measured reference points. The coefficient may reach at least 0.2° / (mol / l), for example, about 0.25° / (mol / l).

[0063] Figure 14 shows a graph of four measurements of taper angle obtained with basic etching baths of various molar concentrations. The measurements are shown as filled circles. Furthermore, the regression line for the measurements is shown as a dotted line. Using the regression line as a reference function, the molar concentration of the etching bath for obtaining the desired taper angle of the wall between the sides of the glass member can be determined. In fact, linear regression also represents extrapolation from one or more reference points or interpolation between one or more reference points regarding the taper angle with respect to the molar concentration of the etching bath.

[0064] It should be understood that there are other parameters that affect the taper angle. Therefore, other adaptations of etching parameters can be selected, either alternatively or additionally, to the molar concentration or viscosity of the etching bath to obtain the desired taper angle. Specifically, as mentioned above, other etching parameters, including etching depth and etching removal, or etching time corresponding to etching removal, can affect the taper angle for specific molar concentrations and temperatures, and can therefore be used to adjust the taper angle to a desired value. Furthermore, etching depth can be taken into consideration when adjusting parameters to achieve a desired taper angle. If a filamentous crack 9 extends from one side to the opposite side throughout the entire glass member, the etching depth corresponds to the depth of the channel in the glass member, and therefore to the thickness of the glass. Figure 15 shows measured taper angles and fitted lines for various etching depths and various molar concentrations of the etching bath 81 (i.e., 6, 9, 12, and 15 mol / l as shown in the legend). As can be seen, the taper angle generally increases with both etching depth and molar concentration.

[0065] Similarly, Figure 16 shows a graph of the taper angle value as a function of etching removal at the wall formed by widening the filamentous crack 9. As shown in Figure 15, etching experiments were performed with etching baths 81 of various molar concentrations, namely 6, 9, 12, and 15 mol / l. Figure 16 shows that the taper angle increases with both etching removal and the molar concentration of the etching bath 81. Thus, the taper angle can also be adjusted by adjusting the etching removal or etching time.

[0066] The dependence of the taper angle on the etching rate and the molar concentration of the etching bath typically also depends on the type of glass. The example disclosed herein regarding the change in taper angle in relation to molar concentration relates to glass type D263. However, the range shown herein may also apply to other glasses. In general, the change in taper angle with respect to the molar concentration of the etching bath disclosed herein typically applies to glasses having an SiO2 content in the range of 30 to 85 mass percent.

[0067] The present invention further relates to a plate-shaped glass member 1. In particular, the plate-shaped glass member 1 can be manufactured, manufactured or can be manufactured by the method according to embodiments of the present disclosure. Figure 5 shows, as an example, a plate-shaped glass member 1 having two opposing sides 14, 15 and a number of etched channels 10. The channels 10 extend through the glass member 1, and the walls 6 of the channels 10 connect the sides 14, 15. The boundary line 12 of the wall 6 is tapered at the vertices 16, 17, 18, 19 between the wall 6 and the adjacent sides 14, 15. That is, there is a taper angle 94 (not shown in Figure 5) between the wall 6 (or the boundary line 12 of the wall 6) and the perpendiculars 13 (not shown) of the sides 14 and 15, respectively. The taper angle 94 can be controlled by the method according to embodiments of the present disclosure.

[0068] Preferably, according to one embodiment, at least two taper angles 94 between the boundary line 12 and the perpendicular 13 of the side surfaces 14, 14 are different from each other.

[0069] According to a further embodiment, at least one of the channels 10 has a wall 6 having a boundary line 12 at the openings 60, 61 of the channel 10 to the respective sides 14 and 15, with respect to the perpendiculars 13 of the sides 14 and 15 having different taper angles.

[0070] According to a further embodiment, the boundary lines 12 of the wall 6 at the openings 60, 61 of the channel 10 on the sides 14, 15 are different from each other.

[0071] In a further embodiment, in at least one section, the wall 6 is curved concavely with respect to the perpendicular direction 13 to the sides 14, 15.

[0072] In a further embodiment, a number of channels 10 are distributed across the glass member 1 in a predefined pattern. For example, the predefined pattern may constitute a grid, circles, or helices.

[0073] In a further embodiment, the glass member 1 has a thickness of up to 200 μm, preferably at least 3 μm, more preferably at least 5 μm, and most preferably 10 μm.

[0074] Such glass member 1 and / or regions 100, 101 can be used, for example, in printed circuit applications, microfluidic elements, or for liquid lenses. [Explanation of Symbols]

[0075] 1. Glass component 5. Laser beam 6 walls 7. Ultrashort pulse lasers, lasers 8. Focal line of laser beam 5 9, 9a, 9b, 9c, 9d, 9e, 9f, 9g, 9h Filament cracks, cracks 90 rows of cracks 10, 10a, 10b, 10c, 10d Channels 11 routes 12 Boundaries 13 Perpendicular line 14, 15 Side view of glass member 1 Vertices 16, 17, 18, 19 20 Positioning means 50, 51 Partial beam of laser 5 52 Interference Region 53 Length of the interference region 54 Maximum strength 55 Interference angle 60, 61 Aperture of channel 10 62 Channel 10d Straight Section 70 Focusing optics 71 Computer processing means 80 Etching tanks 81 Etching medium, etching bath 91 Blind Hole 94 taper angle Areas of glass member 1 100, 101 102 Openings within Area 100 105 The edges of areas 100 and 101

Claims

1. A method for structuring a glass component (1), - The pulsed laser beam (5) of the ultrashort pulse laser (7) is directed onto the glass member (1), - The glass member (1) is transparent to the laser beam (5), and - At least one filamentous crack (9) is formed in the glass member (1), the filamentous crack (9) extends so as to intersect with the sides (14, 15) of the glass member (1), the filamentous crack (9) is formed using a laser beam (5) that is focused by a focusing optical device (70) to form a focal line (8) within the glass member (1), the intensity of the laser beam (5) within the focal line (8) is sufficient to form the filamentous crack (9), and - The focal line (8) is adjusted so that the filamentous crack (9) terminates within the glass member (1), and - The glass member (1) is exposed to an etching bath (81) in which glass is removed by etching. - The filamentous crack (9) expands, forming a wall (6) that extends between the opposing sides (14, 15) of the glass member (1), and the wall (6) has a tapered boundary line (12) at the vertices (16, 17, 18, 19) between the wall (6) and the adjacent sides (14, 15), with a taper angle (94) to the perpendicular (13) of the sides (14, 15). - The taper angle (94) is adjusted by at least one of the position, length, and intensity distribution of the focal line (8). Two coaxially oriented filamentous cracks (9) are created by irradiation with a laser beam (5), and these coaxially oriented filamentous cracks (9) begin on opposing sides (14, 15) and end facing each other within the glass member (1). The aforementioned method.

2. The method according to claim 1, wherein a channel (10) is generated by etching and widening the filamentous crack (9), and the channel (10) is open to both opposing sides (14, 15).

3. The method according to claim 1 or 2, wherein a number of channels (10) distributed across the glass member (1) in a predefined pattern are generated by introducing filamentous cracks (9) that cross the glass member (1).

4. The method according to any one of claims 1 to 3, wherein a filamentous crack (9) terminating within the glass member (1) is generated using a focusing optical device (70), the focusing optical device (70) superimposes at least two partial beams (50, 51) of a laser beam (5) so that the interference of the partial beams (50, 51) causes an intensity variation along the focal line (8).

5. The method according to any one of claims 1 to 4, wherein a filamentous crack (9) is generated by irradiation with a laser beam (5), and the filamentous crack (9) starts and ends within the glass member (1).

6. The method according to any one of claims 1 to 5, wherein at least two coaxially oriented filamentous cracks (9) are generated by irradiation with a laser beam (5), the filamentous cracks (9) having different lengths, and the filamentous cracks (9) are etched and widened to form a wall (6) connecting opposing sides (14, 15) of the glass member (1), having a boundary line (12) at its apex (16) that has different taper angles with respect to the sides (14, 15).

7. The method according to any one of claims 1 to 6, wherein the laser beam (5) is advanced relative to the glass member (1) along a predetermined path (11) so that a number of adjacent filament-like cracks (9) are generated along the path (11), and etching is continued until at least adjacent channels (10) merge and the glass member (1) is divided into regions (100, 101) along the path (11), and the walls (6) generated by etching form the end faces (105) of the regions (100, 101).

8. The method according to any one of claims 1 to 7, wherein the laser beam (5) is guided relative to the glass member (1) along a closed path (11), and subsequent etching separates the inner glass area (100) from the outer glass area (101), leaving an opening (102) within the outer glass area (101).

9. The method according to any one of claims 1 to 8, characterized in that a predetermined taper angle (94) between the boundary line (12) of the wall (6) and the side surfaces (14, 15) is adjusted by selecting the molar concentration of the etching bath (81).

10. The method according to claim 9, wherein the etching bath (81) is a basic etching bath.

11. The following stages: - A step in defining the taper angle (94) at the end of the area (100, 101) to be achieved after etching, - A step of determining at least one of the molar concentration of the etching bath (81), the viscosity of the etching bath (81), the etching removal, and the etching time, depending on a defined taper angle (94). - A step of preparing an etching bath (81) having a specified molar concentration or viscosity, and - The step of etching the glass component in the etching bath (81) The method according to any one of claims 1 to 10, including the method described in any one of claims 1 to 10.

12. 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 with respect to the taper angle for at least one parameter of the molar concentration or viscosity of the etching bath. - The step of determining the molar concentration or viscosity of the etching bath includes using a reference function for the taper angle that depends on the molar concentration or viscosity, wherein the function returns the molar concentration or viscosity for each taper angle to be achieved. - The step of determining the molar concentration must include extrapolation from one or more reference points using a coefficient of at least 0.1° / 2 mol / l. The method according to claim 11, comprising at least one of the following.

13. The method according to claim 11, preferably by increasing the molar concentration of KOH by 6 mol / l, thereby increasing the molar concentration of the etching bath (81) from 4 mol / l to 8 mol / l, thereby increasing the taper angle (94) at the end of the area (100, 101) in the range of 0.3° to 0.7°.

14. A method for generating a channel in a plate-shaped glass member by the method described in any one of claims 1 to 13, - The pulsed laser beam (5) of the ultrashort pulse laser (7) is directed onto the glass member (1), - The glass member (1) is transparent to the laser beam (5), and - At least one filamentous crack (9) is formed within the glass member (1), the filamentous crack (9) extends so as to intersect with the sides (14, 15) of the glass member (1), the filamentous crack (9) is generated by a laser beam (5) that is focused by a focusing optical device (70) to form a focal line (8) within the glass member (1), the intensity of the laser beam (5) within the focal line (8) is sufficient to generate the filamentous crack (9), and - The focal line (8) is adjusted so that both ends of the filamentous crack (9) are located within the glass member (1), and the glass member (1) is exposed to an etching bath (81) that removes glass by etching so that the glass material on the side surface is removed and at least one end of the filamentous crack (9) is exposed, and etching is continued so that the filamentous crack (9) expands and a channel (10) having a predetermined diameter is formed. The aforementioned method.

15. The method according to claim 14, wherein at least two filamentous cracks (9) are introduced into the glass member (1), the ends of the filamentous cracks (9) are at different distances from the sides (14, 15) of the glass member (1), and during etching, one of the filamentous cracks (9) is exposed earlier than the other filamentous cracks (9), so that the cracks (9) are exposed to the etching bath (81) for different periods of time, and channels (10) of different diameters are generated.

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