METHOD FOR MATERIALLY JOINING A GLASS ELEMENT TO A SUPPORT ELEMENT AND OPTICAL DEVICE

Description

[0001] The present approach relates to a method for the material-to-material bonding of a glass element to a carrier element and to an optical device.

[0002] DE 10 2016 213 561 A1 describes a process in which materials with similar expansion coefficients are joined by means of gluing, soldering or welding.

[0003] JP2005300976A discloses a method for bonding an optical component to a carrier element. A disadvantage is that the process stability of the method cannot be guaranteed for certain material combinations.

[0004] WO2006 / 034775A1 discloses a composite structure made of zero-expansion material and a method for producing such a structure. The disadvantage is the use of an adhesive layer, which can lead to component failure due to aging.

[0005] US 2003 / 221854 A1 discloses an arrangement with two binding elements, wherein one of the binding elements has a recess into which the other binding element is inserted and connected to the first element by means of a binding agent. Disclosure of the invention

[0006] Against this background, the present approach presents a method for bonding a glass element to a support element and an optical device according to the main claims. Advantageous embodiments emerge from the respective subclaims and the following description.

[0007] For tasks such as positioning devices or high-precision length or angle measuring devices, flat glass surfaces firmly bonded to a ceramic substrate are required. At the same time, the components can be exposed to temperature fluctuations during processing, manufacturing, and transport. The approach presented here enables a solid, adhesive-free bond between glass and ceramic, which can maintain a flat surface even after process- or transport-related heating during operation at room temperature or another predetermined operating temperature.

[0008] A method for the material-to-material bonding of a glass element to a carrier element is presented, wherein the method comprises a step of introducing at least one contact element into a contact recess in a surface of the carrier element. The method also comprises a step of placing the glass element onto a portion of the contact element projecting above the surface and a step of locally heating the contact element in order to bond the glass element to the carrier element via the contact element. For example, the glass element can be a titanium-doped quartz glass, which can have, for example, a TiO2 content of approximately 20 wt.% or less. Furthermore, the mean linear thermal expansion coefficient (CTE) of the glass element can be, for example, 0 ± 30 ppb / °C from 5°C to 35°C with a confidence level of 95% (ppb parts per billion). This is the case, for example, with a so-called ultra-low expansion glass.The carrier element can be, for example, a ceramic carrier, for example made of silicon carbide (SiC), or a metal carrier. Other materials of the carrier element can be, for example, monocrystalline or polycrystalline solids, such as silicon (Si), germanium, sapphire, diamond or quartz glass, or a mixture of silicon and silicon carbide (Si / SiC), in particular a reaction-bonded, silicon-infiltrated silicon carbide material, or boron carbide B4C or silicon-infiltrated boron carbide (SiB4C) or AlN or Al2O3. When joining the glass element to the carrier element, for example by gluing or soldering, any organic adhesive could bring its material-typical shrinkage and thermal expansion properties to the rigid and low-expansion structure of silicon carbide and glass.Direct welding, particularly of glass with a very low thermal expansion coefficient, for example ultra-low expansion glass, and Si / SiC ceramic can be problematic or even impossible due to the formation of carbon monoxide and, additionally or alternatively, carbon dioxide formation. Therefore, the insertion step presented in this method first involves inserting a contact element, which can be made of glass, for example, and can accordingly also be referred to as a glass dowel, into a contact recess in the carrier element. For example, the contact element can be made of the same material as the glass element or of a material with a lower melting point than the glass element. For example, the contact element can also be designed as a glass solder body, i.e. a shaped piece made of glass solder, advantageously a low-melting solder glass, wherein a stable glass solder can advantageously be used.Stable glass solders, in contrast to crystallizing glass solders, can behave like conventional glasses. When the solder joint is reheated, its softening can exhibit the same temperature dependence as in the previous soldering process. Advantageously, the contact element can have a lower softening temperature than the glass element. In the method presented here, such or a similar contact element is used to connect the carrier element to the glass element. For this purpose, in the placement step, the glass element is placed onto the portion of the contact element(s) (if several contact elements are present) that protrudes above the surface of the carrier element, while maintaining an air gap between the surface of the carrier element and the glass element.The glass element can thus be firmly bonded to the carrier element in the local heating step via the contact element alone, or, if multiple contact elements are provided, via the contact elements. This advantageously creates a strong, firmly bonded, and adhesive-free connection, for example, between glass and ceramic. In the local heating step, molten material from the contact element can wet the glass element to create a connection similar to a soldering process. It is also possible for molten material from the contact element to bond with locally molten material from the glass element to create a connection similar to a welding process. If multiple contact elements are provided, the local heating step can be performed sequentially for each of the contact elements.Alternatively, it is possible for several contact elements to be locally heated simultaneously, for example, using several laser beams. During the local heating step, the support element and the glass element, with the exception of the locally heated area, can be at room temperature. Alternatively, during the local heating step, the support element and the glass element, with the exception of the locally heated area, can be at a predetermined temperature, which can correspond to the intended operating temperature of the finished assembly.

[0009] Advantageously, several such contact elements, particularly advantageously at least three, can be provided, arranged at a distance from one another. Particularly advantageously, more than ten contact elements can be provided.

[0010] According to one embodiment, the method can comprise a step of forming the contact recess before the insertion step. For example, the contact recess can be introduced in the form of a pit during the forming step, for example, through a bore. Alternatively, the carrier element, which may be made of ceramic, can already be formed with corresponding recesses during the manufacturing process. The forming step has the advantage that the contact recesses can be optimally matched to the contact element to be inserted in the subsequent insertion step.

[0011] The method comprises a step of coating at least a portion of the contact recess with a separating layer prior to the insertion step. For example, the entire surface of the contact recesses into which the contact element is inserted in the insertion step can be coated with the separating layer. The separating layer, which can also be referred to as a barrier layer, can be formed, for example, with silicon (Si) or germanium (Ge) or a refractory metal and, additionally or alternatively, an oxide of the aforementioned substances and, additionally or alternatively, a refractory metal silicide, in order to advantageously keep the carrier element, formed, for example, from silicon carbide, chemically separated from the glass of the contact element.The separating layer can be provided to improve the adhesion and additionally or alternatively to prevent a chemical reaction of the glass solder with the carrier element, which could, for example, lead to foaming of the glass solder when it is melted.

[0012] According to a further embodiment, the method can comprise a step of heating the contact element in order to connect the contact element to the carrier element, wherein the heating step can be carried out after the insertion step. For example, the contact element can be used in a similar way to a glass solder, which can form a material connection with the carrier element upon increasing the temperature. The contact element can be heated, for example, above the melting temperature of the contact element, which can also be called the glass transition temperature, transformation temperature, or softening temperature, wherein the softened glass can wet the carrier element or the barrier layer covering the carrier element. Advantageously, the carrier element and the contact element, or all of the provided contact elements, can be heated together.The heating step can be carried out, for example, as a furnace process using a normal melting furnace, for example an industrial furnace with air or protective gas, or a vacuum furnace, or by means of a laser beam. The carrier element equipped with the intended contact elements, or several carrier elements equipped with contact elements of this type, can be introduced into the furnace together. Alternatively, the step of heating the contact element in order to connect the contact element to the carrier element can be carried out by local heating, with the carrier element otherwise remaining at room temperature. Advantageously, the heating step described in this section can produce a time- and cost-effective connection between the carrier element and the contact element. Advantageously, after this step, the carrier element with the connected contact elements can be cooled to room temperature.The step of reducing the thickness of the section and, additionally or alternatively, the step of placing the glass element at room temperature can then be carried out.

[0013] According to a further embodiment, in the heating step, the portion of the contact element projecting above the surface can be expanded to form a collar and additionally or alternatively shaped as a rounded cap projecting in the direction of the glass plate normal. For example, after the insertion step, the contact element can be inserted into the carrier element, for example, three-quarters of its length, while one quarter can project above the surface of the carrier element. In the heating step, the contact element can be heated, in particular at the portion projecting above the surface, whereby the portion can expand to form a collar and, as a result, can have a radius that can be larger than a radius of the contact recesses. This advantageously allows a materially bonded connection to be produced between the contact element and the surface of the carrier element.Additionally or alternatively, the section can be formed into a rounded cap during heating. This advantageously prevents or limits the radius of the contact element from extending beyond the edge of the contact recess, and if necessary, the connection between the carrier element and the glass element can be locally limited to a minimum.

[0014] According to a further embodiment, the method can comprise a step of reducing the thickness of the section prior to the attachment step. For example, the section of the contact element projecting above the surface of the carrier element can be at least partially melted by the preceding heating step, as a result of which a contact surface of the section can have irregularities. Therefore, the contact surface of the section can be leveled in the reduction step. Advantageously, such an irregular section can be leveled in the reduction step, for example by grinding. In this case, a projection of the contact element(s) above the surface of the carrier element of advantageously between 10 µm and 200 µm can be achieved. This can subsequently create a gap of a specific thickness between the carrier element and the glass element.Residual deformations of the surface of the contact elements in the range of up to a few micrometers, for example down to 0.1 µm, can be removed, for example, through a grinding and polishing process. Advantageously, the contact element can be machined in the reduction step such that the glass element can be placed on a flat surface in the subsequent placement step. Furthermore, if multiple contact elements are provided, these can be leveled so that their flat surfaces lie in a common plane. This allows the glass element to rest flat on the contact element, or on the contact elements if multiple contact elements are provided. This allows the connection process and, additionally or alternatively, the strength of the subsequent connection between the carrier element and the glass element to be optimized.The flatness of both the leveled surface of each contact element and the deviation from the common plane can advantageously be less than 1µm.

[0015] According to a further embodiment, the contact element can be inserted in the insertion step using a reactive welding process. For example, reactive welding can be performed as an alternative to an additional heating step, advantageously saving time and costs.

[0016] According to a further embodiment, the contact element can be heated using a laser beam in the local heating step. For example, a localized thermal joining method such as localized laser welding can be used in the local heating step, wherein the glass dowel (contact element) can be irradiated with a laser beam in a locally limited manner, for example through the glass element, in order to melt the contact element and join it to the glass element. The contact element can advantageously be heated above its melting temperature, whereby the softened glass of the glass dowel can wet the glass element. During the joining of the glass element to the contact element, the temperature of the carrier element can advantageously remain at room temperature using a laser beam in order to avoid bending during subsequent cooling to room temperature.For example, the glass element can be connected to the contact element using a short pulse. This has the advantage of heating only very locally, avoiding the need to heat the entire component, as occurs with welding, soldering, or adhesive curing. Accordingly, the use of laser welding is particularly advantageous, as this method, using short laser pulses, enables a locally sufficient temperature increase for the welding process while maintaining a nearly constant temperature of the carrier element. Alternatively, a laser can be used, for example, to initiate a reactive bonding process.

[0017] According to a further embodiment, the contact element can be cylindrical, spherical, partially spherical, ellipsoidal, or toroidal during the insertion step. For example, the contact element can be shaped as a glass cylinder, which can be inserted into the contact recess of the carrier element in a form-adapted manner and firmly connected to the carrier element. Advantageously, such a cylinder or one of the aforementioned shapes can be manufactured and stored cost-effectively.

[0018] According to a further embodiment, the glass element and the support element can be bonded in the local heating step to produce an optical device. For example, the optical device can be used as part of a positioning device, for example, as an encoder for an xy stage or as an angle encoder for a goniometer. The integral connection between the support element and the glass element can advantageously expand the application range of the optical device and increase its load-bearing capacity.

[0019] According to a further embodiment, the method can comprise a step of providing the carrier element in the form of a ceramic element and additionally or alternatively providing the glass element in the form of an ultra-low expansion glass and additionally or alternatively providing the contact element in the form of a borosilicate glass element. For example, the carrier element can be made of silicon carbide (SiC) or silicon-infused silicon carbide (Si / SiC), whereby it can advantageously have a particularly high degree of hardness and high temperature resistance. The glass element, as so-called ultra-low expansion glass, can advantageously have a very low coefficient of thermal expansion and can therefore be used in various devices, for example as a support for large telescope mirrors in reflecting telescopes.For example, borosilicate glass can be used as a contact element for connecting a carrier element to the glass element. The borosilicate glass can, for example, form a material bond with both the carrier element and the glass element, similar to a glass solder. The contact element can have a higher thermal expansion coefficient than the carrier element, which can lead to mechanical stresses when temperatures change, for example, during cooling after the contact element has been connected to the carrier element, which could lead to the contact element being torn off the carrier element. To minimize mechanical stresses to an insignificant level, contact elements with small dimensions can be used. For example, the largest linear dimension of each contact element can be less than 1 mm.To ensure the required strength of the connection between the glass element and the support element, a corresponding number of contact elements can be provided. Advantageously, the contact element can have a lower thermal expansion coefficient than the support element. Then, in addition to the integral connection, a clamping effect of the contact element in the support element can be achieved, particularly when a cylindrical contact element and a cylindrical recess in the support element are provided. Alternatively, the contact element can have a similar thermal expansion coefficient to the support element, which means that it can experience similar stress changes to the support element when exposed to temperature changes, for example, during a welding process or during heating of the contact element to connect the contact element to the support element.When cooled together to room temperature, for example, 20°C, the contact element and the support element remain mechanically stress-free. Advantageously, the use of borosilicate glass for both the support element and the contact element eliminates the need for a separating layer. For the purposes of this section, the thermal expansion coefficient can be assumed to be the average value between the softening temperature of the contact element and room temperature.

[0020] According to a further embodiment, in the insertion step, a plurality of contact elements can be introduced into a plurality of contact recesses in the surface of the carrier element. The plurality of contact recesses can be arranged in a line. For example, the plurality of contact recesses can be arranged in the form of a linear seam along a closed curve, such as a circle, or along a rectangular shape. The stability of the connection can advantageously be increased by the plurality of introduced contact elements.

[0021] According to a further embodiment, in the local heating step, a pressing force can be exerted on the glass element at least temporarily to press the glass element against the contact element. For example, mechanical pressure can be exerted locally or over the entire surface of the glass element. Advantageously, this can accelerate the bonding of the glass element to the contact element. Furthermore, it can be ensured that the glass element touches the contact element. It can be ensured that the material of the contact element melted during the local heating step can wet the glass element. After wetting the glass element with the locally melted material of the contact element, the pressing force can be reduced or eliminated to avoid mechanical stress.

[0022] Furthermore, an optical device is presented comprising a carrier element having a contact recess and a glass element, wherein the carrier element and the glass element are integrally connected to one another using a contact element inserted into the contact recess. The optical device can, for example, be manufactured using a variant of the method described above. Such an optical device can advantageously be used in light engines or sensor modules such as optical encoders or other high-precision optical modules. Such a component unit may be required there to ensure the required properties without bending or thermal drift.

[0023] According to one embodiment, the optical device can comprise an optical sensor device for detecting lengths and, additionally or alternatively, geometric positions. For example, the glass element can comprise a geometric measuring embodiment, such as position marks or a scale marking, for this purpose. The optical device can thus advantageously be used as a sensor device or as part of such a device, for example, as part of an encoder in an xy stage or as an angle encoder for a goniometer.

[0024] Examples of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows: Fig. 1 a flow diagram of an embodiment of a method for materially connecting a glass element to a carrier element; Fig. 2a flow diagram of an embodiment of a method for materially connecting a glass element to a carrier element; Fig. 3 a schematic representation of an embodiment of a carrier element with an inserted contact element; Fig. 4 a schematic representation of an embodiment of a carrier element with an inserted contact element; Fig. 5 a schematic representation of an embodiment of a carrier element with an inserted contact element Fig. 6 a schematic representation of an embodiment of a support element with a glass element attached; Fig. 7 a schematic representation of an embodiment of a support element with a glass element attached; Fig. 8 a schematic representation of an embodiment of an optical device; and Fig. 9a schematic plan view of an embodiment of a carrier element with an arrangement of a plurality of contact recesses.

[0025] In the following description of advantageous embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of these elements is omitted.

[0026] Fig. 1shows a flow diagram of an embodiment of a method 100 for materially bonding a glass element to a carrier element. By way of example only, the carrier element is a ceramic carrier made of silicon-infiltrated silicon carbide (Si / SiC) and the glass element is a glass plate made of so-called ultra-low expansion glass. The Si / SiC can have a thermal expansion coefficient of, by way of example only, 4 ppm / K between room temperature and 1000°C. The method 100 comprises a step 105 of introducing at least one contact element into a contact recess in a surface of the carrier element. In this embodiment, the contact element is introduced by way of example only using a reactive welding process. In a modification of the embodiment, a furnace process can be used.Furthermore, the method 100 comprises a step 110 of placing the glass element onto a section of the contact element projecting above the surface of the carrier element, wherein, merely by way of example, the glass plate is aligned parallel to the surface of the carrier element and brought into mechanical contact with the contact element. This creates an air gap between the surface of the carrier element and the glass element. In the subsequent step 115 of local heating, the contact element is heated in order to connect the glass element to the carrier element via the contact element. In this exemplary embodiment, the mechanical connection of the glass element and the contact element is realized merely by way of example by spot welding using a laser beam, thereby indirectly creating a connection between the glass element and the carrier element.The laser beam used here is set to short pulses with a duration of, for example, 10 nanoseconds, to locally heat the contact element and the glass element. The use of short pulses enables heating to be carried out only very locally, rather than the entire component being heated, as is the case with regular welding, soldering, or adhesive stamping. In this exemplary embodiment, the glass element and the carrier element are bonded in the local heating step to produce an optical device.

[0027] Fig. 2 shows a flowchart of an embodiment of a method 100 for bonding a glass element to a carrier element. The method 100 shown here corresponds to or is similar to the method described in the previous figure, with the difference that the method 100 shown here includes additional optional steps.

[0028] In one embodiment, method 100 comprises a step 200 of providing the carrier element in the form of a ceramic element, the glass element in the form of an ultra-low expansion glass, and the contact element in the form of a borosilicate glass element. The contact element is selected from borosilicate glass, and the carrier element from Si / SiC ceramic. In this embodiment, the borosilicate glass has a different thermal expansion coefficient between a welding temperature and room temperature than the carrier element made of Si / SiC. For example only, the thermal expansion coefficient of the borosilicate glass is 3.25 ppm / K between room temperature and 300°C, and that of the Si / SiC is 4.0 ppm / K. In this embodiment, the contact element has relatively small dimensions so that the difference in thermal expansion does not lead to the contact element being torn off from the carrier element upon cooling.

[0029] In one embodiment, step 200 of providing is followed by a step 205 of forming the contact recess. The contact recess is introduced into the carrier element, for example, by means of a bore and adapted to the dimensions of the contact element.

[0030] Following the molding process, in one embodiment, the contact recess is coated with a separating layer in the subsequent coating step 210. For example only, the separating layer, which may also be referred to as a barrier layer, is formed from silicon in this embodiment in order to chemically separate the carrier element from the contact element. In another embodiment, the separating layer may, for example, additionally or alternatively comprise germanium (Ge) or a refractory metal or an oxide of the aforementioned substances and additionally or alternatively a refractory metal silicide. In this embodiment, step 105 of introducing the contact element into the coated contact recess of the carrier element follows step 210 of coating.In one embodiment, a plurality of contact recesses can also be formed in the surface of the carrier element during the molding step, into which a plurality of contact elements can be inserted during the insertion step. The plurality of contact recesses can be arranged in a line. For example, the plurality of contact recesses can be arranged in the form of a linear seam along a closed curve, such as a circle, or along a rectangular shape.

[0031] In one embodiment, step 105 of insertion is followed by a step 215 of heating the contact element in order to connect the contact element to the carrier element. For example only, the contact element and optionally also the carrier element are heated to a joining temperature that enables a materially bonded connection between the contact element and the carrier element. For example only, step 215 of heating is carried out as a furnace process using a normal melting furnace. In another embodiment, the heating can be carried out using a vacuum furnace or by means of a laser beam. In this embodiment, a section of the contact element that projects above the surface of the carrier element is expanded as a collar by heating, in which it is melted, for example only.Subsequently, in this exemplary embodiment, the component is cooled to permanently connect the contact element to the carrier element. Since the borosilicate glass element and the Si / SiC ceramic element in this exemplary embodiment have different thermal expansion coefficients, step 215 of heating, including cooling to, for example, a room temperature of, for example, 20°C, can nevertheless be carried out with essentially low mechanical stress by using contact elements of small dimensions. In another exemplary embodiment, mechanical stresses or unevenness can be caused by soldering. During soldering, for example, the entire component can be heated to the soldering temperature.Upon cooling to room temperature, the joining position can be fixed at the solidification temperature of the solder, so that, if the soldered parts have different expansion coefficients, a thermally induced stress is created by the cooling, which can lead to surface distortion. The effect is equivalent to bonding, whereby the solidification temperature of the solder can correspond to the glass transition temperature of the adhesive.

[0032] In one embodiment, in the method 100 shown here, step 215 of heating is followed by a step 220 of reducing. By way of example only, a thickness of the portion of the cooled contact element that projects above the surface of the carrier element is ground and polished, resulting in a flat surface of the contact element. Any remaining deformations of the surface of the contact element are thereby eliminated. In one embodiment with a plurality of contact elements, the surfaces of several existing contact elements can also be leveled into a common plane. By way of example only, a flatness of less than 1 µm is achieved. In the subsequent step 110 of placing, the glass element is placed on this flat surface facing away from the carrier element.

[0033] This is followed by step 115 of local heating in order to connect the glass element to the carrier element via the contact element. In this exemplary embodiment, step 115 of local heating is carried out using a laser beam. Here, the laser beam is merely guided over the surface of the contact element in order to securely connect the contact element to the glass element. At the same time, in step 115 of local heating, merely by way of example, a pressing force is exerted on the glass element in order to press the glass element against the contact element. The pressing force can be exerted over the entire surface, for example by placing another glass element on the glass element, or only locally in the region of the contact element(s).In this embodiment, the glass element has a lower thermal expansion coefficient than the support element, which, however, does not lead to any mechanical stress due to the point-like connection between the glass element and the support element, which is only created by local heating.

[0034] Fig. 3shows a schematic representation of an embodiment of a carrier element 300 with an inserted contact element 305. For example only, the carrier element is an element made of Si / SiC ceramic, and the contact element 305 is a cylindrical element made of borosilicate glass, which can also be referred to as glass solder. In another embodiment, the contact element can also be spherical, partially spherical, ellipsoidal, or toroidal. In this embodiment, the cylindrical contact element 305 is adapted to the shape of the contact recess 310, in which the contact element 305 is inserted. In this embodiment, the contact recess 310 is coated with a separating layer 315 to chemically separate the contact element 305 from the carrier element 300.In this exemplary embodiment, the carrier element 300 also comprises a further contact recess 320, which is coated with a further separating layer 325 and into which a further contact element 330 is inserted. The further contact element 330 is configured equivalently to the contact element 305.

[0035] Fig. 4A and Fig. 4B show a schematic representation of an embodiment of a carrier element 300 with introduced contact element 305. The carrier element 300 and the contact element 305 shown here correspond to or are similar to the one shown in the previous Figure 3described carrier element and contact element. Different shaping options for the contact element are illustrated in sub-figures 4A and 4B. In both sub-figures 4A and 4B, the carrier element 300 in this exemplary embodiment also comprises, in addition to the contact element 305 arranged in the contact recess 310, a further contact element 330 introduced into a further contact recess 320. The contact element 305 and the further contact element 330 are shown in the illustration shown here after a heating step. In this exemplary embodiment, in sub-figure 4A, due to the heating, a section 405 of the contact element 305 projecting beyond the surface 400 of the carrier element 300 is widened as a collar and is integrally connected to the surface 400. Accordingly, a further section 410 of the further contact element 330 is also widened and integrally connected to the surface 400.In sub-figure 4B, however, both section 405 of contact element 305 and the further section 410 of the further contact element 330 are shaped as a rounded cap. In other words, the two dowels in the embodiment shown here are fused and firmly connected to the support element 300.

[0036] Fig. 5 shows a schematic representation of an embodiment of a carrier element 300 with introduced contact element 305. The carrier element 300 and the contact element 305 shown here correspond to or are similar to the one shown in the previous Figures 3 and 4 described carrier element and contact element, wherein the carrier element 305 also has, in this embodiment, a further contact element 330 in addition to the contact element 305. In the illustration shown here, the contact element 305 and the further contact element 330 are shown after a reduction step, as described in the previous Figure 2described. Accordingly, section 405 of contact element 305, as well as further section 410 of further contact element 330, is flattened to optimize the reception of the glass element.

[0037] Fig. 6 shows a schematic representation of an embodiment of a carrier element 300 with attached glass element 600. The carrier element 300 shown here corresponds to or is similar to the one shown in the previous Figures 3, 4 and 5described carrier element. Contact elements 305, 330 are arranged in the carrier element 300, which were melted in a previous heating step and leveled in a reduction step. In the illustration shown here, a glass element 600 is placed on the sections 405, 410 of the contact elements 305, 330 that protrude above the surface 400 of the carrier element 300. The glass element 600, which can also be referred to as a glass chip or glass plate, is merely an example of a so-called ultra-low expansion glass, which has an expansion coefficient that differs from that of the carrier element 300. The glass element is aligned parallel to the surface 400 of the carrier element 300. Due to the thickness of the sections 405, 410, an air gap 605 is created between the carrier element 300 and the glass element 600.

[0038] Fig. 7shows a schematic representation of an embodiment of a carrier element 300 with attached glass element 600. The carrier element 300 and the glass element 600 shown here correspond to or are similar to the one shown in the previous Figure 6described carrier element and glass element. The carrier element 300, the contact elements 305, 330, and the glass element 600 are shown during a local heating step. The sections 405, 410 function as a joining surface for joining the glass element 600. A laser beam 700 is directed through the glass element 600 onto the further contact element 330 in order to heat it locally. Accordingly, the contact element 305 is heated with another laser beam or subsequently by means of the newly aligned laser beam 700. By heating the contact elements 305, 330 connected to the carrier element 300, the glass element 600 can be indirectly connected to the carrier element 300, wherein the air gap 605 between the carrier element 300 and the glass element 600 remains. During the local heating, the glass element 600 is pressed onto the contact elements 305, 330 according to one embodiment.

[0039] Fig. 8shows a schematic plan view of an embodiment of optical device 800. The optical device 800 in this embodiment comprises a carrier element 300, which corresponds to the one described in the preceding Figures 3, 4 , 5, 6 and 7 described carrier element. The carrier element 300 of the device 800 is formed by a method as described in the preceding Figures 1 and 2 described, is integrally connected to a glass element 600. In this exemplary embodiment, a sensor device 805 is arranged on the glass element 600, which, by way of example only, are position marks for determining a geometric position. By way of example only, the optical device 800 is an xy encoder.

[0040] Fig. 9shows a schematic plan view of an embodiment of a carrier element 300 with an arrangement 900 of a plurality of contact recesses 310. The carrier element 300 shown here corresponds to or is similar to the one shown in the previous Figures 3, 4 , 5, 6 , 7 and 8 described carrier element and has a plurality of contact recesses, all of which correspond to those described in the preceding Figures 3, 4 and 6 The arrangement 900 comprises more than twenty, for example 26, contact recesses 310 in this exemplary embodiment and is rectangular in shape only by way of example. In another exemplary embodiment, for example, twenty or more contact recesses 310 can be arranged along several rings. For example, an inner ring can have a diameter of 20 mm, a middle ring a diameter of 40 mm, and an outer ring a diameter of 60 mm.

Claims

1. A method (100) of integrally bonding a glass element (600) to a carrier element (300), wherein the method (100) comprises the following steps (105, 110, 115): inserting (105) at least one contact element (305) into a contact recess (310) in a surface (400) of the carrier element (300); placing (110) the glass element (600) on a portion (405) of the contact element (305) projecting above the surface (400); and local heating (115) of the contact element (305) in order to connect the glass element (600) to the carrier element (300) via the contact element (305); wherein the method (100) further comprises a step (210) of coating at least a part of the contact recess (310) with a separating layer (315) prior to the step (105) of insertion.

2. The method (100) according to claim 1, comprising a step (205) of molding the contact recess (310) prior to the step (105) of insertion.

3. The method (100) according to any of the preceding claims, characterized in that the separating layer (315) is designed from silicon (Si) or germanium (Ge) or a refractory metal or an oxide of said substances or a refractory metal silicide.

4. The method (100) according to any of the preceding claims, comprising a step (215) of heating the contact element (305) to connect the contact element (305) to the carrier element (300), wherein the step (215) of heating is performed after the step (105) of insertion.

5. The method (100) according to claim 4, wherein in the step (215) of heating the portion (405) of the contact element (305) protruding above the surface (400) is widened as a collar and / or formed as a rounded cap protruding in the direction of the glass plate normal.

6. The method (100) according to any of the preceding claims, comprising a step (220) of reducing a thickness of the portion (405) prior to the step (110) of placing, for leveling a surface of the portion (405).

7. The method (100) according to any of the preceding claims, wherein in the step (105) of insertion, the contact element (305) is inserted using a reactive welding process.

8. The method (100) according to any of the preceding claims, wherein in the step (115) of locally heating the contact element (305) is heated using a laser beam (700).

9. The method (100) according to any of the preceding claims, wherein in the step (105) of insertion the contact element (305) is shaped cylindrical or spherical or partially spherical or ellipsoidal or toroidal.

10. The method (100) according to any of the preceding claims, wherein in the step (115) of local heating, the glass element (600) and the support element (300) are joined to produce an optical device (600).

11. The method (100) according to any of the preceding claims, comprising a step (200) of providing the carrier element (300) in the form of a ceramic element and / or the glass element (600) in the form of an ultra low expansion glass and / or the contact element (305) in the form of a borosilicate glass element.

12. The method (100) according to any of the preceding claims, wherein in the step (105) of insertion, a plurality of contact elements (305) are inserted into a plurality of contact recesses (310) in the surface (400) of the carrier element (300), wherein the plurality of contact recesses (310) are arranged on a line.

13. The method (100) according to any of the preceding claims, wherein in the step (115) of local heating, a pressing force is exerted on the glass element (600) to press the glass element (600) against the contact element (305).

14. An optical device (800) having a carrier element (300) consisting of silicon carbide (SiC) or diamond or a mixture of silicon and silicon carbide (Si / SiC) and having a contact recess (310), particularly a reaction-bonded, silicon-infiltrated silicon carbide material, or of boron carbide (B4C) or of silicon-infiltrated boron carbide (Si / B4C) or of AIN and a glass element (600), wherein the carrier element (300) and the glass element (600) are firmly connected to one another using a contact element (305) formed from a glass and inserted into the contact recess (310), wherein the contact recess (310) is coated with a separating layer (315).

15. The optical device (800) according to claim 14, comprising an optical sensor apparatus (805) for detecting lengths and / or geometric positions.