Method and system for substrate etching, and substrate holder

Abstract

The invention relates to a method (100) and a system (1) for substrate etching, and a substrate holder (30). A substrate blank (2) is arranged in a substrate holder (30) (S2), and a substrate blank surface (4) is treated with an etching medium (41) (S3). According to the invention, the substrate blank (2) is irradiated (S1) with laser radiation (3) along the outer contour (6) of the target substrate (5) before the treatment with the etching medium (41), such that the target substrate (5) is separated from the substrate blank (2) during the treatment with the etching medium (41).

Description

Technical Field

[0001] The present invention relates to a method and system for etching a substrate, and a substrate holder. Background Art

[0002] Known etching processes are used to produce substrates with desired surface properties and / or to change substrate dimensions, particularly thickness. Typically, a large number of substrates (e.g. made of glass (SiO2)) are fixed in a substrate holder (carrier) and then exposed to an acidic and / or alkaline etching medium.

[0003] The problem with this etching process is the etching marks that usually appear. These etching marks, also called shadows, are caused by fixing the substrate on the substrate holder. In order to obtain a substrate without etching marks, complex post-processing steps are required, such as trimming or grinding the etched substrate. Summary of the invention

[0004] An object of the present invention is to improve the etching of substrates, in particular to enable efficient production of substrates without etching marks. This object is achieved by a method and a system for etching substrates and a substrate holder according to the independent claims. Preferred embodiments of the invention are the subject of the dependent claims and the following description.

[0005] In a substrate etching method according to a first aspect of the invention, a substrate blank is arranged on a substrate holder and the surface of the substrate blank is treated with an etching medium. According to the invention, before the treatment with the etching medium, the substrate blank is irradiated with laser radiation along the outer contour of the target substrate, so that during the treatment with the etching medium, the target substrate is separated from the substrate blank, in particular automatically.

[0006] One aspect of the invention is based on a method for pre-treating a substrate blank using laser radiation, which method causes an enhanced or accelerated etching effect of an etching medium on the substrate blank in one or more predetermined areas on the surface of the substrate blank. Advantageously, the substrate blank is irradiated in such a way that a portion of the substrate blank corresponding to a target substrate is etched away or can be etched away during the etching process. The separation of the target substrate from the substrate blank caused by this etching enables the substrate blank to be fixed on a substrate holder without obstructing the target substrate. In other words, the substrate blank can be arranged on the substrate holder in such a way that the area of ​​the substrate blank corresponding to the target substrate to be separated later does not contact the substrate holder.

[0007] Preferably, the laser radiation is irradiated onto the substrate blank along the outer contour of the target substrate. For example, areas on the surface of the substrate blank that are located on the expected outer contour of the target substrate or areas that together form the outer contour in a discrete manner can be irradiated. It has been shown that molecular bonds of the substrate can be weakened or loosened using laser irradiation. This can make it easier for the etching medium to dissolve the substrate material or its components in these areas. For example, by selecting appropriate laser parameters such as wavelength, power or pulse energy, pulse duration, focus position, etc., a modified intensity of the substrate material and thus a (local) etching effect of the etching medium can be easily achieved.

[0008] Advantageously, the substrate blank is arranged on the substrate holder in such a way that the area enclosed by the outer contour does not come into contact with the substrate holder. In this way, etching marks on the target substrate can be reliably and easily avoided. Preferably, the substrate blank remains on the substrate holder until the target substrate is separated from the substrate blank. It is advantageous to end the etching process immediately after the target substrate is separated. This prevents the target substrate from being in contact with the substrate holder for a long time in the etching medium, which contact could lead to etching marks on the target substrate.

[0009] In the following, preferred embodiments of the invention and developments thereof are described, which, unless explicitly excluded, can be combined with one another and with the aspects of the invention described below.

[0010] In a preferred embodiment, the substrate blank is irradiated with laser radiation before it is placed in the substrate holder.This may facilitate the irradiation of the substrate blank and / or increase the accuracy of the irradiation.

[0011] In another preferred embodiment, the substrate blank is irradiated with laser radiation along the outer contour of the target substrate in such a way that through holes are generated in the substrate blank along the outer contour of the target substrate when the substrate blank is treated with the etching medium. In other words, the substrate blank can be irradiated in such a way that through holes are formed in the substrate blank during the etching process, which through holes are arranged along the outer contour, in particular arranged in rows. For this purpose, it is advantageous to irradiate the substrate blank with laser pulses. This is also advantageous in that it enables a particularly high energy input per unit time. During the etching process, through holes can continue to form. In particular, through holes can grow, that is, their diameter can increase. Advantageously, the etching process is continued until adjacent through holes are connected together, that is, the material layer between two through holes is essentially completely etched away, so that the target substrate is separated from the substrate blank. The formation of through holes during the etching process, in particular the growth of through holes, allows a particularly reliable and gentle separation of the target substrate.

[0012] In a further preferred embodiment, the substrate blank is irradiated with laser radiation along the outer contour of the target substrate in such a way that, when the substrate blank is treated with the etching medium, through holes are formed in the substrate blank along the outer contour of the target substrate at predetermined distances from one another. Advantageously, adjacent through holes are connected to one another after a predetermined treatment time of the substrate blank with the etching medium. By selecting the distance between adjacent impact points in the region in which the laser radiation irradiates the substrate blank surface and through holes are generated in the etching process, the desired treatment duration can be determined particularly easily.

[0013] In another preferred embodiment, the target substrate is separated from the substrate blank without etching marks, in particular substantially without etching marks. In particular, the substrate blank can be held, for example, by means of a correspondingly designed substrate holder and / or the substrate blank surface can be irradiated and / or treated with an etching medium, so that the target substrate is separated from the substrate blank without etching marks. This eliminates the need for post-processing aimed at removing such etching marks.

[0014] In a preferred manner, the treatment duration is adapted to the speed of etching on the non-irradiated portions of the substrate blank surface. In particular, the treatment duration can be adapted to the desired intensity of the etching process on the non-irradiated portions of the substrate blank surface. This allows the target substrate to be detached from the substrate blank when the etching process on the non-irradiated substrate blank surface is also completed. In other words, the detachment of the target substrate and the end of a "conventional" etching process, such as surface preparation, can thereby be substantially synchronized.

[0015] In another preferred embodiment, a substrate holder is placed in an etching medium bath to treat the substrate blank surface with the etching medium. After the target substrate is separated from the substrate blank, the substrate holder is advantageously removed from the etching medium bath immediately. For example, after reaching a specified treatment time, the substrate holder can be removed from the etching medium bath immediately. This prevents the surface of the target substrate from being etched more than expected and / or prevents etching marks from being formed on the separated target substrate, which may now be in contact with the substrate holder.

[0016] In another preferred embodiment, a substrate holder is used to capture the separated target substrate. For this purpose, the substrate holder advantageously has a capture device for this purpose. For example, the substrate holder can have one or more capture elements, which are located next to and / or below the substrate blank arranged in the substrate holder. For example, these capture elements can be designed as pins. Thus, the target substrate can fall from the substrate blank after separation, wherein it is safely captured and guided by the capture element.

[0017] In another preferred embodiment, the substrate blank is held by an arrangement in a substrate holder such that when the substrate holder is aligned horizontally, the substrate blank surface is inclined relative to the vertical. In other words, the substrate blank is held at an angle in the substrate holder so that the target substrate can fall out of the substrate blank after removal. Such an arrangement of the substrate blank in the substrate holder can significantly facilitate the separation process. In particular, it can be ensured in this way that the separation is automatic and directed. This increases the efficiency of the process.

[0018] In another preferred embodiment, due to the arrangement of the substrate blank in the substrate holder when aligned horizontally, the substrate blank surface is tilted relative to the vertical direction at an angle between 0° and 90° (inclusive), preferably between 10° and 90° (inclusive). Tests have shown that this enables a particularly reliable separation of the target substrate from the substrate blank. In particular, when the tilt angle is 10° or more, tilting of the target substrate on the remaining substrate blank (i.e., the remaining "frame") can be reliably avoided, or at least the risk of such tilting can be reduced.

[0019] In another preferred embodiment, the laser radiation is irradiated in such a way that the target substrate is separated from the substrate blank after a predetermined treatment time with the etching medium. It is advantageous to select a treatment time that is shorter than or substantially equal to the time required to achieve the desired etching effect on the surface of the substrate blank in the unirradiated portion. This ensures that the target substrate is separated from the substrate blank at the end of the desired etching treatment (e.g. for surface modification).

[0020] In a further preferred embodiment, the substrate blank is irradiated only on one side with laser radiation essentially perpendicular to the surface of the substrate blank. By selecting the laser parameters, the penetration depth of the laser radiation into the substrate blank and thus also the depth to which the substrate material is modified by the etching medium can be set. Irradiating the substrate blank only on one side can speed up the process and / or reduce the laser irradiation effort.

[0021] In a further preferred embodiment, the substrate blank is irradiated on two opposite sides with laser radiation essentially perpendicular to the surface of the substrate blank. Here, too, the penetration depth of the laser radiation can be set on both sides, if desired independently of one another. Irradiating the substrate blank on both sides enables targeted etching along the outer contour of the front and back sides of the substrate blank, thereby allowing faster separation of the target substrate during treatment with the etching medium.

[0022] In another preferred embodiment, the two opposite sides are irradiated with different laser parameters. For example, the laser parameters can be selected such that the penetration depth of the laser radiation on one side is greater than the penetration depth of the laser radiation on the opposite side of the substrate blank. This can be used to influence the process time required to trigger the target substrate with the etching medium. In particular, this makes it possible to control the required process time. For example, by performing the etching process on both sides of the substrate, the required process time can be shortened.

[0023] In a further preferred embodiment, when the substrate blank is irradiated with laser radiation along the outer contour of the target substrate, the laser pulses strike the substrate blank surface at least partially in the region of regularly spaced impact points. The spacing can be selected here depending on the material. For example, the distance between adjacent impact points can be 1 μm to 15 μm, preferably 2 μm to 10 μm, particularly preferably 3 μm to 5 μm. Ideally, the impact points are at least partially in a straight line. This makes it possible to achieve uniform etching along the outer contour.

[0024] In principle, however, other arrangements of the impact points, even irregular arrangements, are also possible. For example, the impact points can also be arranged partially along a curve. In particular, the arrangement of the impact points can depend on the substrate and / or the geometry requirements.

[0025] In another preferred embodiment, when the substrate blank is irradiated with laser radiation along the outer contour of the target substrate, the laser pulses hit the substrate blank surface in the area of ​​the impact points, which are preferably at least partially regularly spaced. Advantageously, the impact points are at least partially located on two or more lines parallel to each other. Irradiating the substrate blank in this way allows the effect of the substrate material relative to the etching medium to be modified in a larger area around the area of ​​the target substrate. In particular, the effect of the etching medium can be enhanced or accelerated along a wide "band" around the target substrate. During the etching process, this will produce a wider gap between the target substrate and the remaining substrate blank. This is particularly advantageous in the case of thick substrate blanks, because this can prevent the target substrate from tilting during the separation process, or at least reduce the risk of tilting. In addition, the processing time required to completely release the target substrate can also be affected by providing this method.

[0026] In another preferred embodiment, the substrate surface is treated with an etching medium containing alkaline compounds, such as potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH), sodium hydroxide (NaOH) and / or lithium hydroxide (LiOH). This enables a particularly reliable separation of the target substrate. In particular, such an etching medium allows a particularly controlled etching and thus a controlled separation of the target substrate.

[0027] In another preferred embodiment, the substrate blank surface is treated with an etching medium at a temperature of 90° C. or higher, preferably 110° C. or higher, in particular 120° C. or higher. Particularly preferably, the substrate blank surface is treated with an etching medium at a temperature of about 120° C. For this purpose, for example, an etching medium bath can be brought to such a temperature and the substrate blank can be immersed in the etching medium bath. At such a temperature, the etching medium can act reliably and in a controlled manner on the irradiated areas on the substrate blank surface. By selecting a high temperature for the etching medium, such as 110° C. or even 120° C., the etching process can be accelerated if necessary, in particular compared to conventional etching processes.

[0028] It may be advantageous to treat the substrate blank surface with an etching medium at a temperature of 90° C. to 190° C., preferably between 110° C. and 170° C., in particular between 120° C. and 150° C. When working within these temperature ranges, excessive evaporation of the etching medium can be avoided. Furthermore, further heating of the etching medium is too energy-intensive in terms of improving the etching effect.

[0029] The temperature range selected may be application or substrate specific. For example, conventional display glass can be etched well at around 120° C. However, certain ceramic glasses that etch more slowly may require correspondingly higher temperatures.

[0030] According to a second aspect of the invention, a system for etching substrates, in particular for carrying out the method according to the first aspect of the invention, has a laser device which is arranged to irradiate a substrate blank with laser radiation along the outer contour of a target substrate, so that during the treatment with an etching medium, the target substrate is separated from the substrate blank, in particular automatically. Furthermore, the system advantageously comprises a substrate holder in which the substrate blank can be arranged and an etching device, which is used to treat the irradiated substrate blank arranged in the substrate holder with the etching medium. Such a system can be used to produce substrates, for example substrates obtained by etching, with desired surface properties, without etching marks thereon.

[0031] For example, the laser device may have one or more solid-state lasers, such as a fiber laser. Advantageously, the laser device is arranged to repeatedly generate one or several laser pulses synchronously. Preferably, the laser device is also arranged to change the position of the region in which one or more synchronously generated laser pulses strike the surface of the substrate blank, so that the outer contour of the target substrate can be "scanned". To this end, for example, at least a part of an optical system of the laser device can be arranged to be displaceable relative to the target substrate, or can be arranged to influence the propagation direction of the laser radiation.

[0032] The etching device advantageously has an etching medium bath, in which the substrate holder and the substrate blank can be placed. According to a third aspect of the invention, a substrate holder for holding a substrate blank, in particular a substrate holder for use in a method according to the first aspect of the invention, has a capture device; the capture device is arranged to capture a target substrate separated from the substrate blank during treatment of the held substrate blank with the etching medium. Using such a substrate holder, the separated target substrate can be safely and reliably removed from the etching medium bath and subjected to post-processing, such as cleaning and / or rinsing and drying.

[0033] The invention is explained in more detail below with the aid of the accompanying drawings. Where appropriate, elements having the same effect are given the same reference numerals. The invention is not limited to the embodiments shown in the drawings, nor even to the functional features. The previous description and the following description of the drawings contain many features, some of which are included in the dependent claims. However, those skilled in the art will also consider these features and all other features disclosed in the above and following descriptions of the drawings separately and combine them to form useful further combinations. In particular, all of the features described can be combined separately and in any suitable combination with the method according to the first aspect of the invention, the system according to the second aspect of the invention and the substrate holder according to the third aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings show, at least in part, schematically:

[0035] Figure 1 is an example of a substrate etching method using a corresponding system;

[0036] Figure 2 is a plan view of an example of a substrate blank irradiated with laser radiation;

[0037] Figure 3 yes Figure 2 A cross-sectional view of an example of a substrate blank irradiated with laser radiation;

[0038] Figure 4 is an example of etching a substrate blank using an etching medium; and

[0039] Figure 5 is an example of a substrate holder. DETAILED DESCRIPTION

[0040] Figure 1 An example of a system 1 for performing a substrate etching method 100 is shown. The system 1 has a laser device 20, a substrate holder 30, an etching device 40 and an optional post-processing device 50.

[0041] In the method 100 that can be performed with the system 1, in method step S1 a substrate blank 2, for example a glass plate, is irradiated with laser radiation 3. A laser device 20 is advantageously used for this purpose. The laser device 20 can have any suitable laser, for example a fiber laser, to generate the laser radiation 3. The laser radiation 3 preferably comprises a plurality of laser pulses that successively irradiate the substrate blank surface 4.

[0042] Along the outer contour of the target substrate 5 (see Figure 2 ) The substrate blank 2 is irradiated with laser radiation 3, in particular laser pulses. Advantageously, the outer contour is successively "scanned" with the laser radiation 3, in particular laser pulses. In other words, it is preferred that the laser radiation 3 impinges on the substrate blank surface 4, for example in the region of regularly spaced impact points (see Figure 4 ), wherein the position of the impact point corresponds to the outer contour. Thus, the area where the laser radiation 3 irradiates the substrate surface 4 can discretely correspond to the outer contour.

[0043] Advantageously, the substrate blank 2 is irradiated with the laser radiation 3 such that the target substrate 5 is detached from the substrate blank 2 during the treatment with the etching medium 41. To this end, it may be necessary to adapt the laser parameters to the properties of the substrate blank 2, for example by configuring the laser device 20. For example, it is conceivable to adapt the laser parameters to the material and / or thickness of the substrate blank 2. For example, these laser parameters may relate to power, in particular energy per laser pulse, pulse duration, distance between impact points, wavelength, etc.

[0044] By irradiating the substrate blank 2 accordingly, the substrate material can be modified along the outer contour, in particular in the region of the impact point of the laser radiation 3, thereby enhancing and / or accelerating the effect of the etching medium 41. For example, in the case of a substrate made of quartz glass (SiO2), when irradiated with an appropriate frequency, the atomic bonds between silicon atoms (Si) and oxygen atoms (O) can be at least partially broken and / or weakened, so that the material in this region can be dissolved more quickly by a subsequent wet-chemical etching process. In particular, irradiation can promote the process of the following reactions:

[0045] SiO 2 +2NaOH->Na 2 SiO 3 +H 2 O

[0046] SiO 2 +6HF->H 2 SiF 6 +2H 2 O.

[0047] In a further method step S2, the substrate blank 2 is arranged in a substrate holder 30. For example, the substrate blank 2 can be inserted into the substrate holder 30. For this purpose, the substrate holder 30 can have a holding device, for example in the form of a groove (see Figure 5 ).

[0048] like Figure 1 As shown, the substrate blank 2 is preferably held by being arranged in the substrate holder 30 such that when the substrate holder 20 is horizontally placed, the substrate blank surface 4 is inclined relative to the vertical. This can facilitate the separation of the target substrate 5 from the substrate blank 2 in a further method step S3.

[0049] In this method step S3, the substrate blank surface 4 is treated with an etching medium 41, preferably using an etching device 40. For this purpose, the etching device 40 can have an etching medium bath containing the etching medium 41. Preferably, the substrate holder 30 is immersed in the etching medium bath together with the substrate blank 2.

[0050] The etching medium 41 may be an alkaline or acidic liquid. For example, potassium hydroxide (KOH), sodium hydroxide (NaOH) or hydrofluoric acid (HF) may be used to process the glass substrate.

[0051] Preferably, the substrate blank 2 remains in the etching medium 41 for at least a predetermined treatment time. After this treatment time has elapsed, the etching medium 41 advantageously dissolves the substrate material along the outer contour, in particular in the region of the impact point of the laser radiation 3, until a gap is formed between the target substrate 5 and the remaining substrate blank 2, the so-called “frame”. As a result, the target substrate 5 can be separated from the substrate blank 2.

[0052] Preferably, in another optional method step S4, the separated target substrate 5 is captured by the substrate holder 30. For this purpose, the substrate holder 30 may have a capture device (see Figure 5 ).

[0053] In a further optional method step S5, the substrate holder 30 can be removed from the etching medium 41 together with the remaining substrate blank 2 and the separated target substrate 5. Advantageously, the target substrate 5 is then cleaned, for example by rinsing with a rinsing medium. The target substrate 5 can then be dried.

[0054] Cleaning and / or drying can be performed by means of a post-processing device 50. To this end, the post-processing device 50 advantageously comprises a cleaning and drying chamber in which the substrate holder 30 can be accommodated.

[0055] Figure 2 A first example of a substrate blank 2 irradiated with laser radiation is shown in plan view, with the substrate blank surface 4 being visible.

[0056] The substrate blank 2 is irradiated with laser radiation along an outer contour 6 of the target substrate 5, so that the target substrate 5 can be separated from the substrate blank 2 when treated with the etching medium. The outer contour 6 is shown in hatched lines.

[0057] During the irradiation, the laser radiation preferably impinges on the substrate blank surface 4 in the region of the impact point (see Figure 4 ). The impact points are preferably arranged at least partially one after the other in a linear manner, corresponding to the outer contour 6. The etching effect of the etching medium is advantageously intensified or accelerated when the laser radiation impinges on the substrate blank surface 4 and changes the substrate material accordingly.

[0058] In the example shown, the impact points are located on three different lines 7a, 7b, 7c, which are parallel to each other in some parts. Advantageously, all impact points on the same straight line 7a, 7b, 7c are evenly spaced. The lines 7a, 7b, 7c are shown in dotted lines, where each point can be understood as an impact point.

[0059] like Figure 2 As shown, the lines 7a, 7b, 7c are preferably arranged in a nested manner, i.e. one inside the other. In other words, an outer line 7a and an inner line 7c can be provided. The inner line 7c delimits the (subsequent) target substrate 5, while the position of the outer line 7a relative to it determines the width of the gap generated between the target substrate 5 and the remaining substrate blank 2 during the etching process. Depending on the required gap width, it is also possible to allow the laser radiation to irradiate the substrate blank surface 4 between the outer line 7a and the inner line 7c, as shown in the present example, so that the gap can be formed uniformly. As shown in the present example, the corresponding impact point can be located on the line 7b or on several other lines. In principle, however, it is also possible to irradiate the substrate blank 2 in such a way that the laser radiation only irradiates the substrate blank surface 4 in the area of ​​the impact points located on only two different lines 7a, 7c or even on only one line 7a.

[0060] Figure 3 Shows Figure 2 2 is an example of a cross section of a substrate blank 2 irradiated with laser radiation. Various irradiation options are described here for explanation purposes only.

[0061] On the one hand, the substrate blank 2 can be irradiated with laser radiation only on one side. This is indicated by the dashed line, which shows the penetration depth of the laser radiation in the region of the impact point located on the inner line 7c defining the target substrate 5.

[0062] The term "penetration depth" here particularly refers to the depth or depth range at which the laser radiation interacts particularly strongly with the substrate material. In other words, "penetration depth" advantageously refers to the depth or depth range at which the substrate is modified so as to enhance or accelerate the etching effect of the etching medium.

[0063] The penetration depth can be adjusted by selecting appropriate laser parameters, for example by adjusting the wavelength, power or pulse energy, pulse duration etc., in particular the focus position or focus depth relative to the substrate blank surface 4 .

[0064] On the other hand, it is possible to irradiate the substrate blank 2 on two opposite sides, namely the front side and the back side. This double-sided irradiation is indicated by the dashed lines which indicate the penetration depth of the laser radiation in the region of the impact point located on the center line 7b or the outer line 7a on the one hand and on the corresponding opposite lines 7b', 7a' on the other hand.

[0065] By means of double-sided illumination, symmetrical illumination is usually possible (see lines 7b, 7b'). However, asymmetrical illumination is also possible (see lines 7a, 7a'). By means of such asymmetrical illumination, the penetration depth of the laser radiation on one side can be greater than on the other (opposite) side.

[0066] like Figure 3 As shown, the various irradiation options can be used together. However, it is also conceivable to irradiate only on one side or both sides, and in the case of bilateral irradiation, to irradiate only symmetrically or asymmetrically.

[0067] By irradiating along two or more lines 7a, 7b, 7c extending at least partially in parallel, the treatment time required to release the target substrate can be influenced in particular. In principle, at least within certain limits, by increasing the number of lines, i.e. a wider gap, a faster separation of the target substrate from the substrate blank can be achieved. Alternatively or additionally, the treatment time may also be influenced by the selected penetration depth of the laser radiation.

[0068] Figure 4 An example of an etching process of a substrate blank using an etching medium is shown. Prior to the etching process, the substrate blank is irradiated with laser radiation. As a result, the substrate material in the shaded region 8, where the laser radiation irradiates the substrate blank surface 4, is appropriately modified to enhance or accelerate the etching effect of the etching medium. During the etching process, the substrate material in the region 8 is dissolved to a correspondingly greater extent. In this way, a through hole 9 can be formed in the substrate blank in the region 8.

[0069] As the substrate blank is treated with the etching medium, the size of the through hole 9 increases. In other words, the through hole 9 may gradually expand. Figure 4 In the figure, the adjacent through holes 9 are connected together sooner or later in the region 8 where the laser radiation hits the substrate blank surface 4, depending on the distance between adjacent impact points. In other words, as the etching process proceeds, the material layer between adjacent through holes 9 is substantially completely dissolved.

[0070] This mechanism advantageously results in a gap being formed between the remaining substrate blank and the target substrate, the outer contour of the target substrate corresponding to the arrangement of the impact points. Thus, the target substrate can be separated from the substrate blank.

[0071] exist Figure 4 In the example shown, the impact points are regularly arranged on the substrate blank surface 4. In particular, the impact points are located on the dashed lines 7 and have a predetermined distance from the respective adjacent impact points. The areas 8 around the impact points irradiated by the laser radiation onto the substrate blank surface 4 are correspondingly regularly arranged, and the through holes 9 are also correspondingly regularly formed.

[0072] In particular, the treatment duration required for connecting the through-holes 9 and the associated separation of the target substrate can be determined by selecting the distance between adjacent impact points or areas 8. In this regard, the treatment duration can be adjusted to the desired effect of the etching medium on the portions of the substrate blank surface 4 that are not irradiated by the laser radiation (i.e., the portions that are not modified). In other words, the treatment duration can be adjusted by determining the distance between adjacent impact points or areas 8 so that the target substrate is substantially dissolved in the unmodified portions of the substrate blank while achieving the desired etching effect.

[0073] Figure 5 A side view of an example of a substrate holder 30 is shown. The substrate holder 30 has a holding device 31 for holding a substrate blank 2 and a catching device 32 for catching a target substrate 5 separated from the substrate blank 2 during treatment with an etching medium. For the sake of clarity, only one substrate blank 2 and one target substrate 5 are shown.

[0074] The holding device 31 is preferably designed so that the held substrate blank 2 is not contacted in the area corresponding to the target substrate 5 to be separated. To this end, the holding device 31 advantageously has a plurality of grooves 33 into which the substrate blank 2 can be inserted. As a result, the contact of the substrate holder 30 with the substrate blank 2 can be limited to a narrow strip at the edge of the substrate blank 2. For example, the substrate blank 5 can be inserted into the groove in such a way that the contact of the substrate holder (30) with the substrate blank (2) is limited to a portion located outside the area corresponding to the target substrate (5) to be separated. The area corresponding to the target substrate 5 to be separated is not affected (see Figure 2 ). For the sake of clarity, in this example only some of the grooves 33 are provided with reference symbols.

[0075] In the present example, the slots 33 are advantageously provided in at least one crossbeam 34, which is arranged between two side walls 36 of the substrate holder 30. In the case of two or more crossbeams 34, two slots 33 in different crossbeams 34 are aligned with each other, so that only one substrate blank 2 can be arranged in these two slots.

[0076] The holding device 31 is advantageously designed to hold the substrate blank 2 in such a way that the substrate blank surface 4 is inclined relative to the vertical direction when the substrate holder 30 is arranged horizontally. To this end, the grooves 33 can be arranged at a corresponding angle on the crossbeam 34. Preferably, the grooves 33 are arranged in such a way that the inclination of the substrate blank surface 4 relative to the vertical direction is greater than 0°, preferably 10° or more, but at most 90°.

[0077] The substrate holder 30 also has a bridge 35, on which the lower end of the substrate blank 2 (in particular, held in the groove 33 of the holding device 31) can be placed. The bridge 35 also connects the side walls 36. Preferably, the bridge 35 also has a groove 33, such as Figure 5 As shown, the ends of the substrate blank 2 can also be fixed when arranged in the groove 33 of the beam 34. If necessary, several bridges 35 and beams 34 can also be arranged one after another in a direction perpendicular to the plane of the figure to increase the capacity of the substrate holder 30.

[0078] The catch device 32 preferably has a plurality of catch elements 37, only some of which are provided with reference symbols for the sake of clarity. In the present example, the catch elements 37 are designed as pins which protrude horizontally from at least one, in the present case two, crossbars 34. The catch elements 37 are advantageously arranged in the vicinity of the slots 33. Each slot 33 and crossbar 34 can be equipped with a catch element 37. In other words, a catch element 37 can be assigned to each slot 33 in the crossbar 34. In principle, however, each slot 33 can also have several catch elements 37.

[0079] After being separated from the substrate blank 2 , one lower end of the target substrate 5 may fall onto the bridge 35 while being laterally held by the capture element 37 .

[0080] Advantageously, the bridge 35 has a plurality of recesses 38, each of which is designed to fix a separated target substrate 5. Fixing here is in particular stabilization of the position of the separated target substrate 5 in a horizontal plane. In other words, the fixation can prevent or at least hinder a movement along the bridge 35, in particular such a movement of the end of the target substrate 5 facing the bridge 35. The recesses 38 can be designed, in particular arranged, such that the target substrate 5 separated from the substrate blank 2 slides, in particular automatically, into one of the recesses 38. For this purpose, the respective recess 38 can be arranged near the groove 33 in the bridge 35.

[0081] Reference numerals list

[0082] 1 System

[0083] 2 substrate blanks

[0084] 3 Laser radiation

[0085] 4Substrate blank surface

[0086] 5 Target substrate

[0087] 6 Outer contour

[0088] 7 lines

[0089] 7a External line

[0090] 7a' outside line

[0091] 7b midline

[0092] 7b' Center Line

[0093] 7c Inside

[0094] 8 Regions

[0095] 9 Through Holes

[0096] 20Laser device

[0097] 30 substrate holder

[0098] 31 Holding device

[0099] 32 Capture Device

[0100] 33 slots

[0101] 34 beam

[0102] 35 Bridge

[0103] 36 Sidewall

[0104] 37 Capture Elements

[0105] 38 concavity

[0106] 40 Etching device

[0107] 41 Etching medium

[0108] 50 Post-processing device

[0109] 100 Methods

[0110] S1-S5 Method Steps

Claims

1. A method (100) for substrate etching, wherein a substrate blank (2) is arranged in a substrate holder (30) (S2), and a substrate blank surface (4) is treated with an etching medium (41) (S3), Features: Prior to treatment with an etching medium (41), the substrate blank (2) is irradiated with laser radiation (3) along an outer contour (6) of a target substrate (5) (S1), so that during treatment with the etching medium (41), the target substrate (4) is separated from the substrate blank (1).

2. The method (100) according to claim 1, Features: The substrate blank (2) is irradiated with laser radiation (3) along the outer contour (6) of the target substrate (5), so that when the substrate blank (2) is treated with an etching medium (41), a through hole (9) is produced in the substrate blank (2) along the outer contour (6) of the target substrate (5).

3. The method (100) according to any one of the preceding claims, Features: The substrate blank (2) is irradiated with laser radiation (3) along the outer contour (6) of the target substrate (5), so that during the treatment of the substrate blank (2) with an etching medium (41), through holes (9) are generated in the substrate blank (2) along the outer contour (6) of the target substrate (5) at a predetermined distance from each other, and after the substrate blank (1) is treated with the etching medium (41) for a predetermined time, adjacent through holes (9) are connected to each other.

4. The method (100) according to any one of the preceding claims, characterized in that: The target substrate (5) is separated from the substrate blank (2) substantially without any etching marks.

5. The method (100) according to any one of the preceding claims, characterized in that: A substrate holder (30) for treating a substrate blank surface (4) with an etching medium (41) is placed in an etching medium bath and is taken out of the etching medium bath immediately after a target substrate (5) is separated from the substrate blank (2).

6. The method (100) according to any one of the preceding claims, Features: The separated target substrate (5) is captured (S4) by means of the substrate holder (30).

7. The method (100) according to any one of the preceding claims, Features: The substrate blank (2) is held by means in the substrate holder (30) in such a way that when the substrate holder (30) is placed horizontally, the substrate blank surface (4) is inclined relative to the vertical.

8. The method (100) according to claim 7, characterized in that: The substrate blank surface (4) is inclined at an angle from 0° to 90° relative to the vertical direction, preferably 10° or more.

9. The method (100) according to any one of the preceding claims, characterized in that: The substrate blank (2) is irradiated on one side with laser radiation (3) essentially perpendicularly to the substrate blank surface (4).

10. The method (100) according to any one of the preceding claims, characterized in that: The substrate blank (2) is irradiated with laser radiation (3) on two opposite sides substantially perpendicularly to the substrate blank surface (4).

11. The method (100) according to any one of the preceding claims, characterized in that: Irradiation was performed on two opposite sides with different laser parameters.

12. The method (100) according to any one of the preceding claims, characterized in that: When the substrate blank (2) is irradiated with laser radiation (3) along the outer contour (6) of the target substrate (5), at least part of the laser pulses impinge on the substrate blank surface (4) in a region (8) of regularly spaced impact points, wherein the impact points are located on a line (7; 7a, 7b, 7c).

13. The method according to any one of the preceding claims, characterized in that: When a substrate blank (2) is irradiated with laser radiation (3) along an outer contour (6) of a target substrate (5), the laser pulses impinge on the substrate blank surface (4) in the region of impact points, wherein the impact points are at least partially located on two or more lines (7a, 7b, 7c) parallel to one another.

14. The method according to any one of the preceding claims, Features: When the substrate blank (2) is irradiated with laser radiation (3) along the outer contour (6) of the target substrate (5), the laser pulses impinge on the substrate blank surface (4) in the region of an impact point, wherein the impact point is at least partially located on two or more lines (7a, 7b, 7c) arranged in a nested manner and on an inner line (7c) delimiting the target substrate (5).

15. The method (100) according to one of the preceding claims, Features: The substrate surface (4) is treated with an etching medium (41) containing potassium hydroxide, tetramethylammonium hydroxide, sodium hydroxide and / or lithium hydroxide.

16. The method according to any one of the preceding claims, Features: The substrate blank surface (4) is treated with an etching medium (41) at a temperature of 90°C or higher.

17. A substrate holder (30) for holding a substrate blank (2), in particular for use in a method (100) according to any one of claims 1 to 16, comprising a capture device (32) for capturing a target substrate (5) separated from the substrate blank (2) during treatment of the held substrate blank (1) with an etching medium (41).

18. The substrate holder (30) according to claim 17 comprises a holding device (31) for holding a substrate blank (2), wherein the holding device has a plurality of grooves (33) for inserting the substrate blank (3), so that the contact portion between the substrate holder (30) and the substrate blank (2) is limited to a portion located outside the area corresponding to the target substrate (5) to be separated.

19. The substrate holder (30) according to any one of claims 17 or 18, wherein the catch device (32) comprises a plurality of catch elements (37) formed as pins.

20. The substrate holder (30) according to claims 18 and 19, wherein The capture elements (37) are arranged adjacent to the slots (33), and at least one capture element (37) is associated with a corresponding slot (33) so as to capture a target substrate (5) separated from a substrate blank (2) held by the corresponding slot (33).

21. The substrate holder (30) according to any one of claims 17 to 20, having two side walls (36) and a bridge (35) located between the two side walls (36), wherein: The lower end of the substrate blank (2) may be placed on the bridge (35) and / or the lower end of the separated target substrate (5) may fall on the bridge.

22. The substrate holder (30) according to claim 21, wherein the bridge (35) comprises a plurality of recesses (38), each recess being used to stabilize a separated target substrate (5).

23. The substrate holder (30) according to claim 22, wherein the recesses (38) are formed in such a manner that a lower end of a target substrate (5) separated from the substrate blank (2) automatically slides into one of the recesses (38).

24. A system (1) for substrate etching, in particular for performing the method (100) according to any one of claims 1 to 16, comprising a laser device (20) for irradiating the substrate blank (2) with laser radiation (3) along an outer contour (6) of a target substrate (5), A substrate holder (30), in particular a substrate holder (30) according to any one of claims 17 to 23, for arranging a substrate blank (2) therein, and An etching device (40) is provided for treating an irradiated substrate blank (2) arranged in a substrate holder (30) with an etching medium (41).

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