EP4241301A2 - Hermetically connected arrangement, enclosure and method for the production thereof - Google Patents

Abstract

The invention discloses a hermetically connected arrangement comprising a first metallic substrate, a second substrate, at least certain regions of which and/or at least parts of which are designed to be transparent in respect of at least one wavelength range, wherein the first substrate is arranged with a contact surface adjacent to a contact surface of the second substrate, and also having at least one laser-joining line or a plurality of points of attachment for joining the first metallic substrate directly to the second substrate, on or in the contact surfaces, wherein the laser-joining line or the plurality of points of attachment, on the one hand, extends/extend into the first substrate and, on the other hand, extends/extend into the second substrate and fuses/fuse the at least two substrates directly to one another.

Description

Hermetically bonded assembly, housing and method of making same

description

field of invention

The present invention relates to a hermetically bonded assembly, a housing, a method of making a hermetically sealed assembly, and the hermetically bonded assembly made with the method.

Background and general description of the invention

In principle, it is known to join several parts together using different laser processes. For example, hermetically bonded glass-glass transitions are known from the applicant's European patent specification EP 3 012 059 B1. There, a method for producing a transparent part for protecting an optical component is shown. A novel laser process is presented.

Connections in which different materials are connected to one another are increasingly coming into focus. Among these, the metal-glass transition is particularly interesting, since the combination of metal and glass has a wide range of possible applications. Improvements and new applications in the field of biophysics and technical medicine, in particular with regard to bioprocessors and applications in space travel, can thus be implemented.

When a hermetically sealed enclosure is constructed, a component or components inside the enclosure can be protected from adverse environmental conditions. Sensitive electronics, circuits or sensors, for example, can be arranged in a hermetically sealed housing in order to construct and use medical implants, for example in the area of the heart, in the retina or generally for bioprocessors. Areas of application can also be for MEMS (microelectromechanical systems), in sensor technology, such as for a barometer, a blood gas sensor or a glucose sensor, etc., as well as for electronics applications, such as in particular in the field of watch production or in general in the field of wearables and devices that are waterproof, for example or are to be set up pressure-protected. Also in aviation, in high-temperature applications, in the context of electromobility, For example, for the production of flow cells, as well as in the field of micro-optics, there are many areas of application.

In contrast to the connection of two components of the same type, the use of different materials poses the problem that the two parts to be joined do not adhere well to one another or have to be brought together at all.

The present invention has therefore set itself the task of providing a hermetically connected arrangement between two components made of different materials, although this has hitherto not been able to be successfully implemented, in particular with metal. The object has also been set to also provide housings, in which case two parts made of different materials are to be connected to one another. In particular, a partial aspect of the present task results from the fact that the hermetically connected arrangement or the housing can be made sufficiently resistant to particularly ensure that the two parts do not become detached from one another or are already detached from one another under the application of little force. A further partial aspect of the present invention is that possible damage to the material can be examined by using a joining method and can be made accessible for checking how such possible damage is to be avoided or reduced. A possible aim of the present invention is thus to provide more reliable and durable hermetically connected assemblies or housings.

A hermetically connected arrangement according to the invention comprises a first metallic substrate and a second substrate, which is transparent at least in regions and/or at least partially for at least one wavelength range. The first substrate is arranged with a contact surface adjacent to a contact surface of the second substrate.

Contact surface within the meaning of this application is an area or a part of a surface, or also an entire side of the respective substrate, with which the respective substrate comes to lie or is arranged adjacent to the respective other substrate. Typically, the substrates are arranged side by side or one on top of the other. When the two substrates touch each other directly and immediately, a touch pad is formed. The touch contact area is therefore, for example, a partial area of the contact area in which the distance between the two substrates is so small that it can no longer be measured optically. The at least two substrates are typically initially arranged next to one another for their connection, that is to say stacked on top of one another, for example. Gravity can then press the typically second substrate lying on top against the typically first metallic substrate lying below. The orientation above or below is merely descriptive, since the arrangement of the substrates can of course assume any orientation in space and even an arrangement next to one another does not leave the scope of protection. The two substrates are typically placed abutting one another on a major side of their extent.

For example, the two substrates are disc-shaped or flat and therefore each have at least one larger flat side, which is preferably aligned in the direction of the other substrate.

The hermetically connected arrangement also includes at least one laser joining line or a plurality of tacking points for direct and immediate joining of the first metallic substrate to the second substrate at or in the contact areas. The laser joining line or the plurality of bonding points extends into the first substrate on the one hand and into the second substrate on the other hand and joins the at least two substrates directly to one another by melting them. In other words, the two substrates are joined to one another in the laser joining line.

The respective substrate is flat on the contact surfaces. An absolutely flat surface can only be achieved theoretically, since, depending on the viewing scale, depressions, elevations or curvatures or everything together can also be found on polished surfaces. A full-area touch contact is therefore difficult to implement. Rather, substrates are curved, inclined, curved, provided with depressions or elevations, even if only to a very small extent.

For example, a touch contact area can be defined if the first substrate has an average distance from the second substrate of less than or equal to 1 μm, preferably less than or equal to 0.5 μm and more preferably less than or equal to 0.2 μm.

In the context of the present invention, it has turned out to be advantageous if the distance between the first substrate and in the second substrate is smaller. It is thus advantageous if the surface on the contact area of the first substrate and/or the surface on the contact area of the second substrate is/are before the substrates are arranged is polished against each other in order to further reduce the average distance between the substrates. In the case of the first metallic substrate, it can be advantageous if absolute elevations over a mean surface of the metallic substrate do not exceed 0.5 μm.

This is surprising because a polished surface of the metallic substrate is fundamentally disadvantageous for a laser joining process, since an increased amount of reflection occurs on a polished surface and therefore precise positioning and power deposition for the joining process is made more difficult or the joining process may not be carried out in this way can be. Nevertheless, it was possible to realize good connected arrangements that strongly adhere to one another, especially with polished contact surfaces of the metallic first substrates.

In the laser joining line or in the plurality of tacking points there is a mixing zone, in which material of the second substrate and material of the first substrate are mixed.

In the intermixing zone, metal material of the first substrate can have entered the second substrate. Material of the second substrate can also have entered the first metallic substrate in the intermixing zone. Particularly preferably, both metal material of the first substrate has entered the second substrate and material of the second substrate has entered the metallic substrate in the intermixing zone.

The intermixing zone can have a thickness measured in a direction perpendicular to the contact surfaces, where the thickness of the intermixing zone can have a thickness of preferably at least 1 μm, more preferably 2 μm or more, more preferably 5 μm or more.

The intermixing zone preferably extends more than or equal to 1 μm into the second substrate. The intermixing zone preferably extends 5 μm into the second substrate. More preferably, the intermixing zone extends as far into the second substrate as the resolidified zone, so that the intermixing zone overlays the resolidified zone. For example, the intermixing zone extends approximately as far into the second substrate as into the first substrate. This is surprising at first sight since, for example, in the case of a metal-glass composite, the GTE of the first substrate is 3 to 10 times higher than the GTE of a glass. Also, the heat capacity and thermal conductivity of the metal is typically significantly higher than that of the second substrate. However, it has been shown that it is possible to use the mixing zone so advantageously in the laser joining line or the Adjust tacking points that this extends approximately as far into the first substrate as in the second substrate and thus to improve the bonded connection.

The intermixing zone has a width, the width of the intermixing zone preferably being greater than the thickness of the intermixing zone in the second substrate. The width of the mixing zone can also be 50% or more greater than the thickness of the mixing zone, more preferably 100% or more greater than the thickness of the mixing zone.

In this case, the width can be measured, for example, at the contact surface between the first and the second substrate and in a direction parallel to the contact surface and perpendicular to the laser joining line.

The at least one laser joining line or the plurality of bonding points can also include a resolidified zone, the resolidified zone having a thickness measured in the direction perpendicular to the contact surfaces. The thickness of the resolidified zone can preferably be less than or equal to 20 μm, preferably less than or equal to 10 μm and more preferably less than or equal to 5 μm.

The resolidified zone can also extend into a depth of the second substrate by less than or equal to 20 μm, preferably less than or equal to 10 μm and even more preferably less than or equal to 5 μm.

The resolidified zone of the at least one laser joining line or the plurality of tacking points can extend along the laser joining line or be arranged in the respective tacking points. The resolidified zone may have a width of 10 µm, for example +/- 5 µm, at the interface between the first and second substrates and in a direction parallel to the interface. This width can preferably be 20 μm +/- 10 μm, more preferably 30 μm +/- 10 μm.

The resolidified zone may also have a width greater than the thickness of the resolidified zone in a direction parallel to the contact surface and perpendicular to the laser bond line.

The resolidified zone is particularly advantageously as small as possible, that is to say the parameters of the irradiation with the joining laser can be selected in such a way that the resolidified zone is as small as possible. The resolidified zone is of no use for the joining process, since no material mixes there in such a way that an interlocking or adhesion occurs between the first substrate and the second substrate. The Refrozen Zone thus absorbs laser energy without improving the aim of adhesion. At the same time, cracks and/or holes or cavities appear in the resolidified zone as it cools, which can possibly be explained by the fact that the material of the respective substrate expands when heated, thereby generating stresses, and contracts again when it cools down.

The mixing zone should therefore be set as large as possible, whereas the resolidified zone should be set as small as possible. The mixing zone preferably has a height of at least 1/5 of the height of the resolidified zone, more preferably! the level of the resolidified level, more preferably the mixing zone is as high as the resolidified zone. For example, with a height of the intermixing zone of 5 μm, the height of the resolidified zone above the intermixing zone is 25 μm if the height of the intermixing zone is 1/5 of the height of the resolidified zone. If the height of the intermixing zone is 10 μm, and above that the height of the resolidified zone of the second substrate is also 10 μm, then the height of the resolidified zone corresponds to the height of the intermixing zone. The intermixing zone can also have a greater thickness than the resolidified zone, for example 1.5 times as thick or more, for example 5 times as thick as the resolidified zone.

The first metallic substrate also typically has a resolidified zone below the intermixing zone. So far it has not been found that the size of the resolidified zone of the first substrate would be detrimental to the joining process, as it is in the case of the second substrate. On the contrary, it could be shown that material of the second substrate can penetrate into the resolidified zone of the first substrate and dendrite formation can be provoked there, i.e. an anchoring connection of the second substrate to the first substrate can take place via one or more dendrites, whereby the Dendrites can reach into the resolidified zone of the first substrate.

Material of the first substrate and material of the second substrate can be arranged in the intermixing zone in such a way that a form-fitting interlocking between the material of the first substrate and the material of the second substrate is brought about. The hermetically bonded assembly may include a fused interlocking structure between the first metallic and second substrates. Material of the respective other substrate can protrude, invert or reach behind in the interlocking structure that has been fused together, so that the adhesive bond of the hermetically connected arrangement is considerably strengthened as a result. Such with each other The fused interlocking structure provides a form-fitting bond between the two substrates, which is particularly advantageous when the material bond between different materials is only able to provide a low adhesive force or a low material bond. The interlocking structure between the first and second substrate acts like a microscopic zipper.

Metal material of the metallic substrate can be present in the intermixing zone in the form of droplets and/or dendrites, the arrangement as droplets and/or dendrites causing a strengthening of the bond between the first and second substrate.

It is even more remarkable that metal material of the metallic substrate and/or material of the second substrate can also have penetrated into at least one of the resolidification zones, in particular in the form of droplets, ablation and/or dendrites, and causes a strengthening of the bond between the first and second substrate. In other words, the joining partners, i.e. the material of the first substrate and/or the material of the second substrate, are selected and/or the beam generator is set and/or prepared in such a way that the joining process is set in such a way that metal material of the metal substrate and/or material of the second substrate penetrates into the resolidification zone associated with the other substrate.

For example, the material of the first and/or second substrate can have an amorphous area or zone as a result of or after the introduction of the laser joining line. Such an amorphous area, ie, for example, amorphous metal material, can further improve the interlocking.

The contact surface of the first substrate can have at least one touch contact region, in which the first substrate is in areal touch contact with the second substrate. The touch contact area can in particular have an average distance between the first and second substrate of less than or equal to 1 μm, preferably less than or equal to 0.5 μm and more preferably less than or equal to 0.2 μm. For technical reasons or other reasons, the smallest gas inclusions or impurities, such as dust particles or unevenness from a polishing process, between the substrate layers may possibly be unavoidable. This can also result from any unevenness down to the micro level between the substrate layers or on the surfaces of the substrate layers. The touch contact area can correspond to the contact area if full-area contact can be established between the two substrates. The laser joining line can connect the first substrate to the second substrate in such a way that the two substrates can only be separated from one another by applying a holding force. The joint between the two substrates can also be achieved so strongly that the two substrates can only be separated from one another by destroying the second substrate if the holding force is greater than the force required to destroy the second substrate. The holding force of the second substrate on the first substrate can, for example, be greater than 10 N/mm ² , preferably greater than 25 N/mm ² , more preferably greater than 50 N/mm ² , even more preferably greater than 75 N/mm ² and finally most preferably greater than 100 N/mm ² .

The first substrate can be characterized in that the contact side is flat, ie in particular planar. The contact side of the first substrate can be polished.

The contact side of the first substrate can have an average roughness value Ra of less than or equal to 0.5 μm, preferably less than or equal to 0.2 μm, more preferably less than or equal to 0.1 μm, even more preferably less than or equal to 50 nm and finally preferred less than or equal to 20 nm.

The second substrate can be characterized in that it is flat on the contact side, in particular planar and more particularly has an average roughness value Ra of less than or equal to 0.5 μm.

The laser joining line is introduced using a joining laser. For example, the joining laser has a wavelength of preferably 1030 nm if it is an infrared laser. An ultra-short pulse laser with pulse lengths in the range of 50 ps or less, preferably 20 ps or less, more preferably 10 ps or more preferably 1 ps or less can be used, for example.

The joining laser has a beam focus. The beam focus can have a beam waist width 2w0. Furthermore, the joining laser has a beam width 2Wi.aser for the joining process, which can be greater than or equal to the beam waist width 2w0. The focal plane for the penetration of the laser joining line can be shifted distally relative to the joining plane. The beam width 2Wi.aser is greater than the beam waist width 2w0 in particular when the focal plane for the penetration of the laser joining line is shifted distally. In particular, the focal plane lies in the first substrate when the laser joining line is introduced. The focal plane is preferably shifted 10 μm +/- 10 μm distally into the first substrate, more preferably 20 μm +/- 10 μm. The beam width 2Wlaser at the joining plane is preferably 4 pm±1 pm, more preferably 4 pm±2 pm, more preferably 4 pm±3 pm. This can be achieved, for example, if the focal plane lies in the first substrate when the laser joining line is introduced, ie is shifted distally, for example, 10 μm +/-10 μm or 20 μm +/-10 μm into the first substrate. Alternatively or cumulatively, the laser beam can be widened or narrowed in front of the writing objective, for example by means of a diaphragm or a telescope, in order to adjust the beam width 2Wi.aser to the desired width.

The first substrate is preferably made entirely of metal material. In this case, the first substrate comprises metal in the sense of the definition of the periodic table.

The first substrate may include or consist of at least one of molybdenum, tungsten, silicon, platinum, silver, or gold. The first substrate may also include an alloy.

In particular, the first substrate can comprise or consist of at least one of carbon, copper, manganese, chromium, magnesium, cobalt, nickel, tin, zinc, niobium, palladium, rhenium, indium, tantalum, titanium or iridium.

The second substrate is preferably a transparent substrate. The second substrate can comprise or consist of glass, glass ceramic, silicon, sapphire or a combination of the aforementioned materials. The second substrate can also include or consist of ceramic material, in particular oxide ceramic material.

The second substrate may comprise or consist of at least one of quartz glass, borosilicate glass, aluminosilicate glass, a glass ceramic such as Zerodur, Ceran or Robax, an optoceramic such as alumina, spinel, pyrochlore or aluminum oxynitrite, calcium fluoride crystal or chalcogenide glass.

In a further development or alternative embodiment, the hermetically connected arrangement can comprise the first metallic substrate and the second substrate, which is designed to be transparent at least in regions and/or at least partially for at least one wavelength range. In this case, the first substrate is arranged with the contact surface adjacent to the contact surface of the second substrate. The hermetically bonded assembly further includes at least one spacer for defining a distance between the first and second substrates.

The spacer may be interposed or comprised between the first metallic substrate and the second substrate. For example, the first substrate can then have the ok

Spacers are in contact with the second substrate. In other words, the spacer can be arranged in areas on one of the contact surfaces, for example, so that the other substrate in each case comes into contact with the spacer or comes into physical contact, but between the contact surface of the first substrate and the contact surface of the second substrate outside of the spacer there is a distance , for example in the size of the thickness of the spacer, remains.

The first substrate can therefore be in contact or in physical contact with the second substrate via the spacer. The spacer can accordingly be arranged between the first substrate and the second substrate.

The spacer can be made of metal material. For example, the spacer can be formed as a coating on the first or the second substrate. The spacer can also be formed in one piece with the first substrate.

The spacer can be formed in one piece with the surface of the first substrate and/or the second substrate, ie it can form a shoulder or an elevation there, for example. For example, the spacer can be produced during polishing if areas of the contact surface of the first substrate or of the second substrate are not polished and elevations therefore remain there. Especially in the case of sapphire as the second substrate, such as in particular as a watch glass, in which the sapphire glass is typically already polished in a complex manner, an additional or modified polishing of the sapphire glass can also be carried out in the polishing step, so that no additional work step is required in the production will.

The spacer can be made as a thin foil of aluminum, for example, which can be adhered to the first or second substrate. The spacer can be sputtered on. The spacer may comprise a directly deposited lithographic glass layer. The spacer can also be printed onto the first or second substrate, for example using an inkjet printing process. The spacer can also result from 3D printing.

The spacer can extend at least along the laser joining line or in the area of the tacking points. The spacer can extend outside the laser joining line or outside the areas of the tacking points. The spacer can also be formed over the entire surface. In one example, the spacer is formed by the fact that the first metallic substrate is polished on its contact surface, but is not polished planar over the entire surface, but instead a web-shaped spacer, for example, remains on the contact surface of the first substrate. This spacer is therefore formed in one piece with the first substrate as an elevation from the contact surface of the first substrate. The spacer can preferably be arranged where the laser joining line(s) is/are introduced. This can further reduce the remaining distance between the substrates in the area of the laser joining line(s) and/or improve the joining result or the adhesion of the two substrates to one another.

The spacer can have a thickness of at least 5 μm, more preferably a thickness of at least 10 μm and even more preferably a thickness of at least 20 μm. This is particularly interesting when the spacer is used in the area of the laser joining line.

If the spacer is not used in the area of the laser joining line(s) to be set, but for example adjacent to it, it is advantageous if the spacer does not exceed a thickness of 5 μm. For example, the spacer can have a thickness of preferably greater than 1 μm, preferably 2 to 3 μm or more.

Within the scope of the invention, a hermetically connected arrangement is also shown, comprising a first metallic substrate, a second substrate which is transparent at least in certain areas and/or at least partially for at least one wavelength range, the first substrate having a contact surface adjacent to a contact surface of the second substrate, and having at least one avoidance zone for receiving molten material from a laser joining line or a tacking point, the laser joining line or a plurality of tacking points being used for the direct and immediate melting joining of the first metallic substrate to the second substrate.

The at least one avoidance zone is preferably arranged adjacent to the laser joining line or the plurality of tacking points. In other words, the escape zone is arranged in such a way that molten material can escape into the escape zone, in particular at the moment when the laser joining line is produced. For example, the avoidance zone can be arranged around the laser joining line and communicate with it, so that material that is heated to become molten in the laser joining line can flow slightly into the avoidance zone can avoid. The molten material can follow a pressure gradient during the evasion process.

For example, when introducing the laser joining line of the first substrate and/or the second substrate, an expansion can occur, for example thermal expansion. Since the laser only heats material locally, i.e. material remains in the solid state around the laser joining line, enormous stresses can arise between the material of the laser joining line and the material surrounding the laser joining line, which may cause cracks, such as stress cracks, or cavities. By providing the escape zone, molten material can escape into the escape zone, so that the formation of cracks or cavities is reduced.

The at least one avoidance zone, or also buffer zone or relaxation zone, is also preferably arranged between the first and the second substrate, for example there on the contact surface.

The at least one avoidance zone can be formed, for example, when arranging the second substrate on the first substrate on the contact surface, for example if one of the two substrates or both substrates does not have a planar surface in the area of the contact surface or on the side facing the other substrate.

The avoidance zone is particularly preferably formed in that a spacer is included, which allows the two contact surfaces to come to rest against one another at a defined distance from one another when the second substrate is arranged on the first substrate. The cavities that form between the first and second substrates in the areas in which there is no spacer can be designed or arranged in advance in such a way that they can be used as an escape zone for material that escapes during laser joining. As a result, the resulting laser joining line becomes less stressed and thus possibly stronger or provides a higher adhesive force, while at the same time stresses can be kept out of the second substrate, ie fewer stress cracks or cavities form in the second substrate.

If the zone in which the molten material of the two substrates is mixed with one another is referred to as the mixing zone and the adjacent zones of the laser joining line as the resolidification zones, then the resolidification zones are problematic in that cracks or cavities can form there due to the entry of the Laser joining line can arise. This is particularly disadvantageous when the second substrate for example, a single crystal such as a sapphire, in which damage caused by the introduction of a laser joining line cannot be healed by the subsequent introduction of a subsequent laser joining line that is offset in terms of coverage. With the present ideas, in particular the avoidance zone and/or the spacer, it is therefore possible to keep the resolidification zone as small as possible, but at the same time to let the mixing zone protrude as large as possible or as far as possible into the two substrates. In the ideal case, the intermixing zone is as large as the resolidification zone, so that the intermixing zone completely overlaps the resolidification zone and no resolidification zone remains recognizable as such. The adhesion of the two substrates to one another is then particularly good, but at the same time the formation of cracks or cavities is minimized.

A hermetically connected arrangement comprises a first metallic substrate, a second substrate which is transparent at least in certain areas and/or at least partially for at least one wavelength range, the first substrate being arranged with a contact surface adjacent to a contact surface of the second substrate, a first laser joining line or a first set of tacking points for direct and immediate joining of the first metallic substrate to the second substrate, on or in the contact surfaces, with the first laser joining line or the first set of tacking points extending into the first substrate on the one hand and into the second substrate on the other hand and which joins at least two substrates directly to one another by melting, and a second laser joining line or a second set of tacking points for directly and immediately joining the first metallic substrate to the second substrate, on or in the contact surfaces, the second laser f Glue line or the second set of tacking points extends into the first laser joining line or the first set of tacking points and changes or improves the material mixing achieved with the first laser joining line or the first set of tacking points.

Such a second laser joining line can be achieved by setting the same laser again to a previous or similar joining position, ie overlapping the new laser focus with a focal point that has already been set or has already been approached. The introduction of a second laser joining line, in particular in the still warm or hot first laser joining line, can also be produced by using a double focus on the laser generator. For example, a beam splitter or a diffraction grating can be used for this purpose, or even two Laser generators can be used. The second laser joining line is introduced into material of the first and second substrate that is still warm, in particular still molten.

Such an effect, i.e. the introduction of laser energy into material that is still warm or even still molten, can also be achieved, for example, if the laser generator has a burst function, and in this way a plurality of laser points overlapping and in quick succession into the Arrangement can be introduced. In other words, at a focal point of the first laser joining line, a further focal point is approached or a second laser joining line is introduced at a defined time interval and/or a defined spatial interval.

Within the scope of the invention, a hermetically sealed housing is also shown, in particular having a hermetically connected arrangement, as has already been described in detail above. The hermetically sealed housing comprises a metallic first substrate, a second substrate which is at least partially and/or at least partially transparent for at least one wavelength range, the first substrate being arranged with a contact surface adjacent to a contact surface of the second substrate.

Furthermore, the housing comprises at least one functional area arranged between the first and the second substrate, in particular a cavity. The housing also includes at least one laser joining line or a plurality of tacking points for direct and immediate joining of the first substrate to the second substrate on or in the contact surfaces, in particular around the functional area for hermetically sealing the functional area. The laser joining line or the plurality of bonding points extends into the first substrate on the one hand and into the second substrate on the other hand and the at least two substrates are directly melted together by means of the laser joining line or the plurality of bonding points.

In the hermetically sealed housing, the laser bonding line of the housing can be designed to be completely closed around the functional area. Furthermore or alternatively, a spacing of the first substrate from the second substrate in the laser bonding line can be consistently less than 0.75 μm, preferably less than 0.5 μm and more preferably less than 0.2 μm. The functional area of the housing can have a hermetically sealed accommodation cavity for accommodating an accommodation object, such as an electronic circuit, a sensor or MEMS.

The hermetically connected arrangement or hermetically sealed housing can also have a first covering or coating on the metallic first substrate at least in the area of the laser joining line or the plurality of bonding points on a side facing the second substrate. The laser joining line or the plurality of tacking points is provided in particular for the direct and immediate joining of the first metal substrate to the second substrate. The first covering or coating on the metallic first substrate can preferably be applied to one another by direct joining of the at least two substrates before the hermetically sealed connection of the at least two substrates.

In the case of the hermetically connected arrangement or hermetically sealed housing, material of the first substrate and material of the first occupancy or coating can also be mixed in the intermixing zone and/or at least in a region of the first substrate close to the surface.

Furthermore, in the case of the hermetically connected arrangement or hermetically sealed housing, the morphology of the structure in the intermixing zone can be changed by the material of the first covering or coating. An alloy can be formed at least in regions in the intermixing zone, which alloy comprises at least material of the metallic first substrate and the first occupancy or coating.

The alloy explained above can preferably form a eutectic.

The metallic first substrate of the hermetically bonded arrangement or the hermetically sealed housing can also comprise or consist of iron, steel or an iron-containing alloy. The first occupancy or coating can also include carbon or consist of carbon.

In the case of the hermetically connected arrangement or hermetically sealed housing, the mixed-in material of the first covering or coating can also be used to strengthen the bond between the first and second substrate. In the case of the hermetically connected arrangement or hermetically sealed housing, in particular before the hermetically sealed connection of the at least two substrates to one another by direct joining of the at least two substrates, a second covering or coating can also be applied to the second substrate at least in the area of the laser joining line or the plurality of Tacking points can be arranged on a side facing the first substrate, in particular for the direct and immediate joining of the first metallic substrate to the second substrate.

The first or second occupancy or coating on the second substrate, as described above, can comprise or consist of a composition by means of which compressive stress is applied in a near-surface zone of the second substrate, which extends at least to a depth DoL, perpendicular to the surface of the second substrate extending within the second substrate is formable.

In the intermixing zone and/or at least in a region of the second substrate close to the surface, material of the second substrate and material of the second covering or coating can be mixed in or introduced.

The second substrate of the hermetically connected arrangement or hermetically sealed housing can also include or consist of a material into which at least near-surface compressive stresses can be introduced in a compressive stress zone Ds and the first covering or coating includes or consists of a material by means of which, compressive stresses can be introduced into the material of the second substrate, in particular by ion exchange,

The material of the second substrate can include or consist of a glass, in particular a soda-lime or borosilicate glass. Furthermore, the material of the second covering or coating can comprise a compound which is suitable for releasing exchangeable ions, in particular a potassium and/or lithium compound, in particular potassium nitrate and/or lithium nitrate.

The mixed or introduced material of the second layer or coating can be used to strengthen the bond between the first and second substrate.

The invention also includes a method for producing a hermetically sealed composite of at least two parts with the steps: planar arrangement of at least one first metallic substrate on a second substrate, wherein the at least two substrates are arranged next to one another or on top of one another, so that a contact surface is formed between the at least two substrates, at which the first substrate is in contact with the second substrate, and the second substrate comprises a transparent material. The method also includes the hermetically sealed connection of the at least two substrates to one another by directly joining the at least two substrates to one another in the area of the at least one contact surface, so that an intermixing zone is formed which extends into the first substrate on the one hand and into the second substrate on the other hand and which at least two substrates are directly melted together.

In this method, the arrangement of a first covering or coating on the first substrate can take place before the areal arrangement of the at least one first metallic substrate on the second substrate,

Arranging a second occupancy or coating on the second substrate is also advantageously possible before the planar arrangement of the at least one first metallic substrate on the second substrate. Here, the designation first occupancy or coating and second occupancy or coating is not restricted to two occupancies or coatings limited. Within the scope of the present disclosure, the respective embodiments can also comprise either only a first occupancy or coating or a second occupancy or coating.

A contact surface can be understood as a plane made up of the inclined surfaces of the two substrates to be brought into contact. The touch contact area means a partial area of the contact area in which the distance between the two substrates is so small that it can no longer be measured optically. Finally, within the meaning of the present invention, a good surface is defined in which the distance between the substrates is sufficiently small, as will be described in detail below, or in which the two substrates actually come into contact. In general, the contact surface is larger than or equal to the good surface and the good surface is in turn larger than or equal to the physical contact surface. Both the first substrate and the second substrate can each have at least one contact area. The contact area can also be understood as the plane in which the contact between the first and second substrate takes place.

In other words, two substrates are first arranged next to one another, that is, for example, stacked one on top of the other, with gravity pulling the top typically first Substrate presses against the second substrate. The orientation above or below is only intended to be descriptive, since the substrates can, of course, assume any orientation in space and even an arrangement next to one another should not leave the scope of protection. The two substrates are typically placed abutting one another on a major side of their extent.

If both substrates are absolutely flat, ie have no indentations, elevations or curvatures at all, which can only be achieved theoretically, the first and second substrates would be in full-surface contact with one another. The two substrates would therefore touch at all points on the mutually aligned surfaces. This is not achievable in general and in structural reality. Rather, substrates are, even if only to a very small extent, arched, inclined, curved, provided with indentations or elevations, so that complete physical contact is only achieved at all in absolutely exceptional cases. In this way, touch contact areas are formed where the substrates touch or where the distance between the substrates is smaller than a certain amount (e.g. defined as “good area”, as will be explained below).

If the substrates are arranged directly next to one another or on top of one another, this means that the at least two substrates are arranged or attached to one another in such a way that they come to lie flat against one another, in particular without other materials or layers being present or inserted between the at least two substrates . For technical reasons, the slightest gas inclusions or impurities such as dust particles between the substrate layers may be unavoidable. This can also result from any unevenness, even in the micro range, between the substrate layers or on the surfaces of the substrate layers. If the joining zone or laser bonding line produced by the laser preferably provides a height HL of between 4 - 25 m, for example, a hermetic seal can be ensured using the laser bonding line, since the distance that may occur between the two substrates can be bridged.

One of the laser bonding lines can enclose the functional area circumferentially at a distance DF. The distance DF surrounding the functional area can be constant, so that the laser bonding line is arranged at approximately the same distance around the functional area on all sides. The distance DF can also vary depending on the application, what can possibly be more favorable in terms of production technology if, for example, a plurality of housings is joined in a common work step, or if the functional area has a round or any shape and the laser bonding line is drawn in a straight line. Even if the cavity has optical properties, for example in the form of a lens, such as a converging lens, the laser bonding line can be formed around the cavity and optionally have different distances from the cavity. A housing can also include several cavities.

The method can also include the step of checking the hermetic connection of the at least two substrates by determining a distance profile between the at least two substrates. The step can also be included: determination of a first bond quality index Q1 for checking the mechanical strength or the hermeticity of the bond.

The first Bond Quality Index Q1 can be determined as Q1=1-(A-G)/A. A represents the area of the contact surface and G represents a good surface. The good area G corresponds in particular to the touch contact area, the good area G can describe a part of the contact area in which the distance between the substrates is less than 5 μm, preferably less than 1 μm and more preferably less than 0.5 μm, most preferably finally less than 0.2pm. The bond quality index Q1 can be greater than or equal to 0.8, preferably greater than or equal to 0.9 and more preferably greater than or equal to 0.95.

The contact surface can have a useful area N, and the useful area can be used to calculate the first bond quality index Q1. Q1 is then found to be Q1 = 1 - (N - G)/N.

For this purpose, within the framework of the method, a return radiation can be detected, which arises as a result of the irradiation of the substrate stack with radiation on at least one contact surface of the substrate stack. In other words, the substrate stack is irradiated or illuminated, so that reflection from the irradiation is generated on the surfaces of the substrates. In this case, the return radiation can be the reflected radiation, which is reflected to a certain extent on one of the surfaces. In the case of two substrates, with the first substrate being metallic, three surfaces on which such a reflection can already occur can be considered for this purpose. These are the upper side of the first metallic substrate, the inside of the second, in particular transparent, substrate and the outside of the second substrate. In other words, the first substrate has an outside or outer flat side which is oriented towards the environment and which is of essentially planar or flat design. Adjacent to the outer flat side and typically oriented at a right angle to the outer flat side, for example designed to run around the edge of the outer flat side, is a peripheral narrow side. In one example, the first substrate can be written on as a plate or cuboid, having two large sides (i.e. the outside and the inside) and four smaller sides arranged between the large sides, which are in particular perpendicular to the two large sides and adjoin the large sides . Then the four smaller sides together form the circumferential narrow side and the upper side forms the outer flat side of the first substrate. The upper side typically has a larger surface than the smaller sides of the peripheral narrow side together. These statements regarding sizes and size ratios can also apply analogously to the second substrate.

In an area in which the two substrates are in touching contact, there is no or no significant reflection on the insides of both substrates, so that this proportion is comparatively small. However, if the two substrates fall apart, i.e. there is a distance between the two substrates, i.e. the two substrates are not in physical contact in this partial area, the radiation is reflected on all three surfaces of the two substrates to a certain extent. In the case of more substrates, such as three substrates, correspondingly more surfaces may have to be considered.

A first bond quality index Qi of the contact surface of the substrate stack is determined from the reflection that falls from the substrate stack into a measuring or observation device.

For example, the first bond quality index Q1 is determined before the first and second substrates are joined to one another.

The method can also include the step of determining a second bond quality index Q2 of the contact surface of the hermetically tightly joined assembly, with Q2 in particular being greater than Q1. Furthermore, in particular, Q2/Q1 is greater than 1.001.

The reflection preferably generates a pattern, in particular an interference pattern; more particularly, this pattern is generated from the superimposition of the irradiation with the backscatter on the at least one contact surface of the housing. It is then possible to design the measuring or observation device in such a way that it Detects or detects interference patterns and can use this to calculate or derive the distance between the two substrates.

The pattern from the retroreflection may have an arrangement in which the pattern extends around one or more defects. In other words, the pattern can be arranged particularly around such locations where the at least two substrates are not in physical contact. It is then particularly easy to use the measuring or observation device to localize the points at which the at least two substrates are not in physical contact. A defect can be characterized in that the distance between the substrates at these defects is greater than 5 μm, preferably greater than 2 μm and more preferably greater than 1 μm, greater than 0.5 μm, or also preferably greater than 0.2pm. In other words, a defect is particularly preferably present exactly where the criteria for a good surface G are not met. In this case, the contact area between the at least two substrates can be completely divided into a good area G and a defect F.

In one example, the corresponding area assignment can be identified using an interference pattern in the form of Newton's rings. If the irradiation is set in the visible light range, for example with A = 500 nm, each Newton ring shows a height difference of A/2 = 250 nm is present, is set, then in an optical image analysis of a reflection from the housing that area can be defined as a good area in which the distance between the substrates is less than or equal to 3* A 12 =750 nm.

The method can also include the step of igniting a plasma discharge in the mixing zone by means of a laser to prepare for the laser joining process.

The scope of the invention also includes the housing produced using the method presented above. An arrangement connected according to the invention or a housing closed according to the invention can be used in such a way that it is used in contact or physical contact with biological material, in particular plant, human or animal cells. For example, the housing can grow together with the biological material. Because the hermetically connected arrangement can advantageously be designed in such a way that it does not contain any toxic and/or allergy-causing substances, it does not release them either. The hermetically connected arrangement or housing is therefore preferably prepared and designed in such a way that it does not have any harmful effect on biological material. The arrangement according to the invention advantageously has a reduced allergy potential when it comes into contact with the human or animal body or plant material, for example when it is introduced into it and/or attached to it.

The arrangement according to the invention is used, for example, as a medical implant, in particular as a medical intracorporeal sensor and/or as a wearable, which is attached or arranged in the operating state on or in the human or animal body or plant material. Typical wearables are fitness trackers and smartwatches, i.e. electronic devices that can measure or monitor the body condition or physiological (body) parameters in particular. Other applications are of course possible and also covered by the invention, such as those wearables that can influence physiological (body) parameters, or other applications.

The invention is explained in more detail below using exemplary embodiments and with reference to the figures, in which identical and similar elements are sometimes provided with the same reference symbols and the features of the various exemplary embodiments can be combined with one another.

Brief description of the figures

Show it:

1 shows a first embodiment of a hermetic composite,

2 plan view of a hermetic composite, designed here as a housing with a functional area,

Fig. 3 Side sectional view of a hermetic compound with a functional area as a cavity, Fig. 4 Side sectional view of a detail of the joining zone in one embodiment, Fig. 4a Side sectional view of a detail of the joining zone in a further embodiment, Fig. 5 Side sectional view of a Details of a further joining zone, Fig. 6 side sectional view of a hermetic compound with joining zone, Fig. 7 side sectional view of a substrate stack with spacers, 8 side sectional view of a hermetic composite with spacer, FIG. 9 digital photograph of a joined hermetic composite, FIG. 10 side sectional view of a hermetic composite with a plurality of laser spots, FIG laser spots and spacers,

12 laser arrangement for producing the laser joint,

figs 13 to 17 Microscopic images of each joined substrate stack, Fig. 18 Photographic representation of a sample for evaluating the achievable hermeticity, Fig. 19 Schematic illustration of the measurement of the quality factor, Fig. 20 Flowchart for measuring the quality factor, Fig. 21 Flowchart for individual steps in the Determination of the figure of merit.

Detailed description of the invention

Referring to FIG. 1 , a first embodiment of a hermetic composite 1 according to the invention is shown, a metallic first substrate 3 being arranged under a dielectric 4 . The dielectric 4 or second substrate 4 is placed on the metallic substrate 3 so that its inside 11 comes to rest on the inside 12 of the first substrate 3 . The two substrates 3, 4 are therefore in contact with one another. Depending on the specific surface condition (cf. e.g. FIG. 6), the contact surface can make up the entire respective inner side 11, 12, and/or the substrates 3, 4 can be in physical contact with one another. The substrates 3, 4 can also be in physical contact only partially or in certain areas. If the substrates 3, 4 are stacked on top of each other, there is already a minimum of physical contact between the two substrates 3, 4 due to the gravitation, unless they are kept at a distance, for example by means of spacers 35 (cf. e.g. Fig. 7) .

In the example of FIG. 1, three laser joining lines 6a, 6b, 6c or tacking points 6a, 6b, 6c are introduced in order to join the two substrates 3, 4 to one another. The joining points/lines 6a, 6b, 6c are set along the sides of the substrates 3, 4, with the joining points being injected from above (in relation to the drawing) by means of a laser (cf. FIG. 12). The focal plane is set in the area of the inner surfaces 11 , 12 . The focal plane is preferably set in such a way that it already lies in the metallic substrate 3, for example 10 to 20 m is offset into the metallic substrate 3, ie 10 to 20 pm below the inner surface 12 of the metallic substrate 3. This can cause the laser beam 6a, 6b, 6c at the contact plane 15 to have the desired width of preferably 4pm +/-1 pm, more preferably 4pm +/- 2pm, more preferably 4pm +/- 3pm. This width can also be achieved by appropriate beam shaping in front of the lens.

If, in the case as shown in FIG shown in Figure 1.

1 already shows three laser joining lines 6a, 6b, 6c, which are interlaced so that the laser joining lines 6a, 6b, 6c also interact with one another. Various effects can be provoked or achieved depending on the objective. For example, the laser joining lines cannot be set warm-in-warm, but the successive laser joining line 6b is only shot in when the previous laser joining line 6a has already cooled down. The cooling process of the laser joining line takes place extremely quickly, since only extremely small total amounts of thermal energy are injected and the metal material of the metal substrate 3 predominantly has excellent thermal conductivity. With the first laser joining line 6a, the material of the two substrates 3, 4 is already mixed with one another and possible unevenness and distances (air gaps 26) are bridged by melting. Depending on the surface quality, for example in the case of large air gaps 26 of up to 5 μm in the area of the contact surface 15 to be joined, the joining with the first laser joining line 6a may possibly be inadequate. However, since the area of the contact surface 15 to be joined is closed with the introduction of the first laser joining line 6a, the air gaps 26, if previously present, are closed and the material is already at least "mixed", a second laser joining line 6b and possibly In a third laser joining line 6c, an optimal further mixing of the two materials of the substrates 3, 4 can be achieved.

FIG. 2 shows a plan view of a hermetic composite 1, with the laser joining lines 6a, 6b, 6c running around a functional area 2. For the sake of simplicity, three laser joining lines 6a, 6b, 6c are typically shown in the figures, but fewer or more laser joining lines 6, 6a, 6b, 6c can also be used. The laser joining lines 6a, 6b, 6c are completely guided around the functional area 2 around the To seal functional area 2 hermetically. The melted zone around the laser joining lines has a width w. An accommodation object 5 such as electronic circuits can be arranged in the functional area 2, for example (cf. FIG. 3).

3 shows a hermetic housing 9 with a hermetic composite 1, with a cavity 2 being hermetically sealed. Three laser joining lines 6a, 6b, 6c are introduced all around the cavity 2, which completely hermetically join the second substrate 4 to the first substrate 3 and produce an inseparable bond. The same reference symbols designate the same parts as in FIG.

FIG. 4 shows a detailed section of a laser joining point of a laser joining line 6 or a stapling point 6 with meaningful details that can explain a wide variety of developments of the present invention. Against the background of the known joining method already traditional in the applicant's company, the present invention deals with the consistent further development and optimization of various joining processes between substrates 3, 4. The focus of the present invention is on the stapling or joining of two different substrates 3 , 4, in particular a metallic substrate 3 with a dielectric 4, ie in particular a glass, glass ceramic, sapphire or the like. Here, the widely differing CTE values of the different materials, but also the different brittleness, among other things, must be taken into account. Thus, it can be the case that undesirable cracks or even holes or pores occur in the dielectric 4 when the materials are joined. These arise partly as a result of the thermal expansion in the laser joining line 6, which occurs with the ultra-rapid introduction of heat into the dielectric 4 by the laser. These can have such a significant impact that the second substrate 4 can easily be broken off from the first substrate 3, ie the material of the second substrate 4 breaks “next to the joining line”. In addition to the mechanical properties, such cracks can also impair the optical properties and also call into question the hermeticity that has been produced. It is therefore particularly advantageous to avoid these cracks 67 and pores 68 .

The laser joining point 6 shown in the side section in FIG. 4 has an intermixing zone 62 which extends into the metallic substrate 3 and the dielectric 4 and in the process also bridges the air gap 26 outlined. For example, the air gap 26 in the area of the laser joining point 6 should be less than or equal to 5 m in order to ensure that the laser joining point 6 is generated sufficiently. For this purpose, it is important, for example, that a plasma is initially ignited in the laser joining point 6 when the laser is injected which may not be able to bridge larger clearances. The plasma ignition, in turn, is a prerequisite for the laser to be able to apply a significant punctiform amount of heat to the laser joining point 6 . The example in FIG. 4 shows a resolidified zone 64 in the dielectric 4 (second substrate), which extends far into the second substrate 4 . Therefore, this represents an unfavorable case which has caused numerous cracks 67 and pinholes 68 . The edge 66 of the resolidified zone is then to be verified, for example microscopically, as the edge of the material change in the second substrate 4 in the finished product as well.

In the example in FIG. 4, no resolidified zone is shown below the intermixing zone 62, ie in the first substrate 3, since the influence in the dielectric 4 is to be explained first (but cf. FIG. 5 for this). In the mixing zone 62, material of the first substrate 3 is mixed with material of the second substrate 4 when both are put into a molten state at the same time. In a simple case, the two materials of the substrates 3, 4 have sufficient affinity for one another, so that sufficient adhesion and thus sufficient holding power of the second substrate 4 to the first substrate 3 (and vice versa) is already produced by the mixing in the mixing zone 64 .

The first substrate 3 can include, for example, copper, silver, gold, iron, aluminum, titanium or also alloys such as steel, as a non-exhaustive list.

The air gap 26 that may be present in the area of the (later) laser joining zone 6 is less than or equal to 0.5 μm. If the distance in the contact surface 15 is less than or equal to 0.5 μm, the contact surface 15 is also marked as a good surface G, for example.

With only one laser joining line 6, 6a, 6b, 6c or tacking point, the width W of the laser joining line corresponds approximately to the beam width 2wi.aser on the contact surface (15), which is generated by the laser generator (see FIG. 12). With N laser joining lines 6, 6a, 6b, 6c arranged in parallel, the width W of the laser joining line achieved is usually less than or equal to N times the beam width 2wlaser at the contact surface (15), since, for example, an overlapping of the laser effective range is sought. H _m describes the height of the mixing zone 62, H _r the height of the resolidified area 64. Ideally, H _m is greater than or equal to Hr. However, this is clearly not the case in the example in FIG. 4 in order to show the relationships clearly.

Fig. 4a shows the side sectional view of a detail of the joining zone in a further embodiment in which, in particular before the hermetically sealed connection of the at least two substrates 3, 4 to one another by directly joining the at least two substrates 3, 4, a first covering or coating 70 on the metallic first substrate 3 at least in the area of the laser joining line 6, 6a, 6b, 6c, 6d or the plurality of gluing points a side facing the second substrate 4, in particular for the direct and immediate joining of the first metal substrate to the second substrate.

This occupancy or coating 70 can be applied by various methods, which include, for example, physical and/or chemical deposition methods, such as physical vapor deposition (pVD), chemical vapor deposition methods or an ALD method (atomic layer deposition ), and can in particular also alternatively be applied by printing techniques, such as screen printing or 3D printing, preferably locally structured. Another form of application can be done while the substrate is floating on liquid metal.

With the joining method described here, material of the first substrate 3 and material of the first occupancy or coating can be mixed in the mixing zone 62 and/or at least in a region of the first substrate 3 close to the surface.

In this case, the morphology of the structure in particular in the intermixing zone can advantageously be changed by the material of the first covering or coating.

In certain embodiments, an alloy can be formed at least in regions in the intermixing zone, which alloy comprises at least material of the metallic first substrate 3 and the first occupancy or coating.

This alloy can form a eutectic in a particularly advantageous manner if the coating or covering is provided in an appropriate quantity for the joining process. This amount can be done by choosing the thickness Di of the first covering or coating. This thickness Di can be between 0.1 and 5 m, for example.

The metallic first substrate 3 can preferably include or consist of iron, steel or an iron-containing alloy and the first covering or coating can include carbon or consist of carbon. With this choice of material, areas with a higher local carbon content can be provided in or on the mixing zone 62 .

Without restricting the generality and without being restricted by the example disclosed above, by means of the mixed-in material of the first occupancy or Coating causes a solidification of the bond between the first and second substrate.

Here, as well as within the scope of the present disclosure, an increase in the forces that are required to separate the joined substrates 3, 4 from one another after joining is referred to as hardening. These forces can be introduced perpendicularly to the respective surface of the substrates 3, 4 on which they touch, in which case the pull-out strength can then be determined and indicated, or transversely to this surface, in which case the strength against proportional shear forces is then additionally determined and can be specified.

In connection with the first and second occupancy or coating disclosed here, strengthening is defined as the increase in these above-mentioned forces in a joint using this first and/or second occupancy or coating compared to a joint in which no first and/or second occupancy or coating is used was used, understood.

Alternatively or additionally, in particular prior to the hermetically sealed connection of the at least two substrates 3, 4 to one another by direct joining of the at least two substrates 3, 4, a second covering or coating 71 can be applied to the second substrate 4 at least in the area of the laser joining line 6, 6a, 6b , 6c, 6d or the plurality of tacking points on a side facing the first substrate 3, in particular for the direct and immediate joining of the first metallic substrate 3 to the second substrate 4.

The occupancy or coating 71 on the second substrate 4 can comprise or consist of a composition by means of which a compressive stress in a compressive stress zone is generated in a zone close to the surface of the second substrate 4, which extends at least to a depth DoL perpendicular to the surface of the second substrate Ds extends within the second substrate 4, can be formed.

In preferred embodiments, material of the second substrate 3 and material of the second occupancy or coating 71 are mixed or introduced in the intermixing zone 62 and/or at least in a region of the second substrate 4 close to the surface, whereby a correspondingly localized compressive stress zone can be formed. In this case, the second substrate 4 comprises or consists of a material into which at least near-surface compressive stresses can be introduced in a compressive stress zone Ds, and the first covering or coating comprises a material or consists of this by means of in which compressive stresses can be introduced into the material of the second substrate 4, in particular by ion exchange /0166478 A1, US 9.908.811 B2, US 2016/012240 A1, US 2016/012239 A1, US 2017/0295657 A1, US 8,312,739 B2, US 9.359.727 B2, US 2012/005271 A1, US 2015/00308 A1 or also DE 10 2010 009 584 B4 and CN 102690059 A.

For example, the material of the second substrate can generally comprise or consist of a glass, in particular a soda-lime or borosilicate glass, and the material of the second covering or coating 71 can be a compound which is suitable for emitting exchangeable ions, in particular a potassium and/or lithium compound, in particular potassium nitrate and/or lithium nitrate.

Here, too, the thickness of the second layer or coating 71 can preferably be from 0.1 to 5 m, and the mixed or introduced material of the second layer or coating 71 can also be used to strengthen the bond between the first and second substrate.

FIG. 5 shows a further embodiment of a detailed view of a laser joining line 6, again the same reference symbols used in other figures are also assigned to the same features. In this embodiment, the laser joining line 6 also has a resolidified region 69 in the first substrate 3 , which extends below the intermixing zone 62 . It can be assumed that the mixing zone 62 merges directly into the respective resolidified zone 64, 69. The intermixing zone 62 is characterized in that a material mix is present here, ie the intermixing zone 62 includes material of the first substrate 3 and includes material of the second substrate 4 . However, it is also possible and has also already been observed and adjusted that material from one substrate 3, 4 can be introduced into the respective other substrate, for example in the form of splinters 4a or dendrites 4b. Metal material of the first substrate 3 can also be introduced into the second substrate 4, for example in the form of droplets 3a. Such droplets 3a can be “thrown” into the second substrate 4 by several micrometers.

The dendrite 4b shown in FIG. 5 can be of particular interest because with such formations a significantly improved adhesion of the two substrates 3, 4 to one another can be achieved. A dendrite 4b possibly functions as an anchor or nail, if it interlocks with the material of the other substrate or is injected at an angle to the vertical. The two materials of the different types of substrates 3, 4 have little affinity for one another, for example, and do not cause any adhesive effect on one another even in the molten state. Such a dendrite 4b or a toothing in the mixing zone 62 can then be the best option for setting an adhesive effect or holding force between the two substrates 3, 4.

Referring to FIG. 6, a composite 1 is shown with a laser bond line 6 on one side. In this example, the air gap 26 in the contact area 15 of the laser joining line 6 is just small enough to introduce the laser joining line 6, but larger in other areas of the inner sides 11, 12 due to unevenness 31, 32 of the surface. Both a depression 31 and an elevation 32 can be disadvantageous for the introduction of the laser joining line 6 . In principle, it has turned out that it is advantageous if the surfaces 11, 12 are smooth, for example with a mean roughness value of 0.1 μm or better. First of all, this is surprising since a particularly smooth surface reflects well and it is therefore difficult to be able to introduce energy deposition into the composite at all using a laser.

7 shows an embodiment of a substrate stack 1 that is still to be joined, with spacers 35 being inserted between the substrates 3, 4 in order to set a defined distance between the substrates 3, 4. In the context of the present invention, it has been shown that air gaps 26 can be tolerated as long as the distance between the substrates 3, 4 in the area of the contact area 15 to be joined is small enough, for example less than 5 μm, better less than 2 μm, preferably less than 0. 5 p.m. The example in FIG. 7 also shows that with the use of spacers 35, even coarser unevenness of the substrates 3, 4 can be easily compensated for, since the substrate spacing no longer has to be produced by full-area contact of the inner sides 11, 12. Furthermore, the air gap 26 can take on a further task by creating an alternative zone 40 there, into which material of the substrates 3, 4, material of the substrate 4 being of particular importance, can penetrate if this is molten. In this way, cracks and holes in the second substrate 4 can be reduced or even completely avoided.

FIG. 8 shows the exemplary embodiment of FIG. 7, with a laser spot 6 being introduced on the left-hand side in the area of the contact area 15. Material of the second substrate 4 has now entered the avoidance zone 40 here. In the mixing zone 62 is material of the first Substrate 3 mixed with material of the spacer 35 and material of the second substrate 4 together. The intermixing zone 62 extends both into the first substrate 3 and into the second substrate 4 . With a suitable choice of material for the spacer 35, the adhesion property can be increased even further if, for example, material is selected which is somewhat affinity to the material of the first substrate 3 as well as to the material of the second substrate 4.

An alternative zone 40 can also be provided as a recess in one of the substrates 3, 4 (not shown). The avoidance zone 40 extends advantageously along the laser joining zone provided, so that material can constantly escape into the avoidance zone 40 in order to absorb pressure peaks or prevent them from occurring in the first place and thus reduce the formation of cracks and holes 67, 68.

FIG. 9 shows a photographic representation of a hermetic composite 1 corresponding to FIG. 6. Unevenness such as scratches 31 or burrs 32, which may impair the hermeticity of the composite 1, are resolved.

Referring to FIG. 10, another aspect of the present invention is to be explained in further detail. The sequence of a plurality of laser spots for the consecutive production of a laser joining line 6 is shown, with the spots 1, 2, 3, 4, 5 being injected one after the other. The spots are shot warm-in-warm and partially overlap because the width w of the beam focus is greater than the distance d between the target points or the laser spots. As a result, a further improvement in the mixing in the mixing zone 62 and thus in the adhesion can be achieved.

A similar effect is achieved if the laser spots shown in FIG. 10 are not intended to belong to a specific laser joining line 6, but rather to 5 different laser joining lines 6, 6a, 6b, 6c, 6d that are injected into the material next to one another. In both cases, the hermeticity and/or the holding force of the substrates 3, 4 on one another can be increased.

11 now shows a further embodiment, a plurality of laser spots 6 also being shot into the contact surface 15, the two substrates 3, 4 being arranged at a distance from one another with spacers 35. If the spacer(s) 35 are small enough, for example, i.e. thinner than 5 m (e.g. as foil, metal foil, or vapor-deposited, sputtered-on, or as a lithographic glass layer), then the remaining air gap 26 can be bridged directly with the laser. At the subsequent Laser spots that partially overlap with the respective previous laser spot, the air gap is no longer an obstacle, since the air gap is partially already bridged or closed. If the distance is to be set larger, a spacer 35 can serve as the "starting point" of the laser joining process and this can be fused (as shown in FIG. 6). The other laser spots partially overlap with the first "starting spot" and can therefore also be shot at larger substrate distances. In this way, distances can also be bridged which are greater than 5 μm from the substrate, for example also greater than 10 μm from the substrate or even up to 20 μm from the substrate and more. The height of the laser spot can be adjusted by 50 pm, up to 100 pm, for example. For example, the distance d from one laser spot to the next can be set to d<10 pm, preferably d<6 pm, more preferably d<4 pm.

In the example of FIG. 11, the interaction zone 62 is kept further out of the second substrate 4 thanks to the spacer 35, so the intermixing zone 62 extends only slightly into the second substrate 4. The penetration of the intermixing zone 62 can be adjusted to only 1 μm±0.8 μm, for example. The resolidified zone 64 in the second substrate 4 can then in particular disappear completely or for the most part and the intermixing zone 62 can nevertheless reach sufficiently deep into the second substrate 4 to ensure a bond.

On the left-hand side, Fig. 12 sketches a laser generator 80 for generating the laser spots 6 in the hermetic compound 1. In this embodiment option, the processing head 801 includes a 45° tilted mirror 802 and the inscription lens 803. Here the processing head is parallel to the laser beam of the laser source 806 moved in the direction x, 804 . Relative thereto, the arrangement 1 or the substrate stack is moved perpendicularly thereto in direction y, 805 on a separate processing table. In addition, an intensity profile 82 of the heat output is sketched on the right-hand side in FIG. The flanking laser joining lines 6a, 6c can thus bring about a further intensified mixing in the middle joining line 6b.

13 shows a microscopic image of a hermetic composite 1 that has been produced, aluminum being used as the first substrate 3 and sapphire as the second substrate 4 . It has already been successfully implemented that the intermixing zone 62 occurs practically exclusively in the second substrate 4 and cracks or holes in the second substrate 4 can occur be largely prevented. A dentrite 4b can be clearly seen, with sapphire 4 penetrating or mixing into the metal of the first substrate 3 and there into the resolidification zone 69 . This can significantly increase the holding power of the sapphire 4 to the aluminum 3. A particle 4a of the sapphire could also be identified in the resolidification zone 69 of the first substrate 3.

FIG. 14 shows a further microscopic image, the assembly shown in FIG. 13 being shown in a larger enlargement and again in a false-color representation. The generation of dendrite 4b is quite surprising and can possibly be described as groundbreaking. For this reason alone, this pleasing new development should be presented as completely as possible and with different representations at the applicant's premises. However, the overall quality of the bond made and the significant reduction in the resolidified zone 64 in the second substrate 4 are strong indicators that the present invention can pave the way for a wide range of products.

FIG. 15 shows a further micrograph, steel being selected as the first substrate 3 and sapphire as the second substrate 4 . In this example, a clear resolidified zone 64 can be seen above the mixing zone 62 in the sapphire 4, also with clear cracks 67. The sapphire has not penetrated the steel in this example. With the beam settings, it was possible to produce such a rough, toothed surface with the laser spot 6 on the first substrate 3 that a toothed structure 37 was created, which also increases the adhesion of the hermetic composite 1.

FIG. 16 shows a further microscopic image, titanium being selected as the first substrate 3 and sapphire as the second substrate 4 . In this example, it has also already been possible to ensure that there is no significantly pronounced resolidified zone 64 in the second substrate 4 , so that hardly any stresses or cracks 67 are introduced into the second substrate 4 . The material of the first substrate 3 is flung surprisingly far into the second substrate 4 in the mixing zone 62 and forms comb-like structures there, which also causes an extraordinary interlocking of the hermetic composite 1 .

Finally, FIG. 17 shows another microscopic image, copper being selected as the first substrate 3 and sapphire as the second substrate 4 . In this example, too, the resolidified zone 64 in the second substrate 4 could be practically eliminated. In this example, droplets 3a can be seen, which penetrate a few micrometers into the second substrate 4 have penetrated, but also dendrites 4b and ablation 4a of the second substrate 4, which have penetrated into the first substrate 3. In this example, too, the adhesion could already be significantly improved.

A series of measurements to determine the hermeticity were also carried out as part of the disclosure. A leak rate (mbar×liter/sec.) was determined for each sample 1a of 61 samples 1a. 18 shows an example of a copper sample 1a for determining the leakage rate, a sapphire disc 4 being laser-joined to a metal component 3 .

The leak rate was determined using the spraying technique. For example, in a standard pressure or low-pressure environment (vacuum), a helium gas is suitable in order to spray the sample with the gas and to measure possible diffusion into the interior of the sample 1 . A pressure difference of 1 bar between the outside and inside of sample 1a has proven to be advantageous. Various metal samples 1a were measured, with a particularly hermetic composite 1 being realized by arranging a sapphire disc 4 on a metal component 3 and joining it with a laser. Aluminum samples, titanium samples, steel samples and copper samples were measured as the metal component 3 and were each laser-joined to a sapphire substrate 4 . The lower measurement limit of the apparatus used to check the hermeticity was a leak rate of 1 x 10 ⁹ mbar l/s. It can be assumed that complete hermeticity is achieved using the spray test and achieving a leak rate of 1 x 10 ⁷ mbar x Is ¹ or less, preferably 1 x 10 ⁸ mbar x Is ¹ or less, more preferably 1 x 10 ⁹ x Is ¹ or less. The table below shows 12 samples 1a as an example, with the metal component 3 used to produce the hermetic compound 1 consisting (essentially) of aluminum in the three samples marked “AI”, in the samples marked “Ti” (in Essentially) titanium, the samples marked “St” (essentially) iron and the samples marked “Cu” (essentially) copper. All samples 1a reproduced here can therefore be described as hermetically sealed in the sense of the previous definition. It was particularly noteworthy that the samples with aluminum and steel showed such a low leak rate that it could no longer be resolved with the equipment used at a lower measuring range limit of 1 x 10 ⁹ x Is ¹ . The hermeticity actually achieved is therefore better than the lower limit of the measuring range, and thus smaller than 1 x 10 ⁹ x Is ¹ .

If necessary, the quality of the hermetic composites 1 produced should be made verifiable. For this it can be advisable to create a distance profile at least in the area of the laser joint before it is introduced. For better understanding, FIG. 19 shows a detailed section of a substrate stack 9, wherein the faulty area 17, the touching contact area 18 and the good area 19 can be seen. The double arrow 21 describes the point of greatest height of the defect 17.

The irradiation 22 is directed onto the substrate stack 9 , with the irradiation being reflected both on the inside 11 of the first substrate 3 and on the inside 12 of the second substrate 4 in the region of the fault location 17 . The reflection 24, 24a can be detected with the detector 30. In this case, the path difference between the reflection 24 and the reflection 24a leads to an interference pattern which is generated by the two reflections relative to one another. The transparent substrate (4) involves Fresnel effects, ie reflections, for example. In the case of glass without an anti-reflective coating, these reflections can each amount to around 4% per interface, for example. In the case of the metallic substrate (3), the reflection occurs through the polished surface. In this case, the irradiation 22 comprises monochromatic light. Interference patterns can thus be read, in particular Newton rings, and from this a measure of the distance between the substrates can be obtained.

20 shows steps of the method for producing or checking the hermetic bond of a substrate stack. In a first step 100, a first substrate is arranged flat on a second substrate. In a second step 110, a height profile of the gap within the substrate stack 9 is determined from the detection of a return radiation, which arises as a result of the irradiation of the substrate stack with radiation 22 at at least one contact surface of the substrate stack 9. In a step 120, the bond quality index Qi is determined from the height profile. In a decision step 130, it is determined if the bond quality index Qi, which was determined in step 120, is greater than a specified allowable one Threshold value Q-ithr that the substrate stack can then be released for further processing, ie in particular laser joining using laser joining lines 6. However, should Qi be smaller than the achieved or desired Q-ithr, then in step 135 the substrate stack 9 is, for example, reprocessed, ie it is detached from one another, possibly cleaned again or recycled in some other way.

In step 140 the laser joining of the substrate stack 1 to the housing or housings then takes place. A second height profile of the gap within the substrate stack of the attached substrate stack 1 is then determined in step 150 and Q2 is calculated therefrom in section 160 . It is determined in step 170 whether Q2 is greater than a threshold value Ctethr set for Q2. For example, Ctethr is less than or equal to Q-ithr. Step 170 preferably also determines or checks whether Q2 is in any case equal to or greater than Qi. If both conditions are met, the further processing of the joined housing 1 or housings 1 can take place in a step 180, for example the separation of the plurality of housings 1 from the wafer stack 9 at the dividing line 8. However, if one of the two or both conditions specified in step 170 are not fulfilled, an alternative further treatment of the substrate stack 9 can be introduced in a step 175; in this case, for example, defect areas F, 17 can be marked or the wafer stack 9 can be recycled.

FIG. 21 describes some steps that can be performed to calculate the bond quality index Qi and/or Q2. In a step 121, image data of the detector 30 are first obtained, for example by means of a workstation designed for this purpose. The image data obtained in step 121 is converted to a gray scale pattern in step 122 or the red channel is extracted from the image data. This can be processed with an image processing functionality that runs, for example, on the same computer on which the image data are obtained with step 121 . In step 123, the physical edges of the substrate stack 3, 4, 9 are determined in the recorded image of the detector 30, for example in the form of corner detection. In a step 124, the perspective can be corrected or rectified if this should be necessary. In a step 125, a contrast improvement can be carried out, for example in the area of the substrate stack. For example, the darkest gray background value can simply be subtracted here and a grayscale image can be generated from a black and white image. Finally, in a step 126, a height profile is calculated from the detector 30 image data obtained, for example based on detected Newton rings. In a step 127, regions in which critical heights or profiles have been determined can then be marked and integrated. This applies in particular to areas which have been identified as error areas F, 17. Finally, in a step 128, the respective Q-factor Qi or Q2 is calculated from the improved or corrected image data as described above.

Thus, with the present description, a method could be shown in a complete and comprehensible manner as to how two different substrates can be joined together by means of laser joining methods, in particular a metal substrate with a dielectric such as a glass substrate or crystal. The corresponding hermetically joined composite could also be presented in detail and explained in a comprehensible manner. The present description includes a large number of descriptions that may conflict with "conventional" knowledge or that could be found surprisingly. For this reason too, the results were further documented with microscopic images in order to show that the invention presented could already be translated into actual results.

It is apparent to those skilled in the art that the embodiments described above are to be understood as examples and that the invention is not limited to these, but can be varied in many ways without departing from the scope of protection of the claims. Furthermore, it is evident that the features, regardless of whether they are disclosed in the description, the claims, the figures or otherwise, also individually define essential components of the invention, even if they are described together with other features. In all figures, the same reference symbols designate the same features, so that descriptions of features that may only be mentioned in one or at least not with regard to all figures can also be transferred to these figures with regard to which the feature is not described in the description. Reference character list

1 composite or substrate stack

1 a sample

2 Functional area or cavity

2a, 2b cavities in the area of a defect 17

3 first substrate (metallic)

3a droplets

4 second substrate (dielectric, e.g. glass)

4a Melting or droplet of the second substrate

4b dendrite of the second substrate

5 accommodation facility

6, 6a, 6b, 6c joining zone or laser bonding line

8 dividing line

9 enclosure

11 contact surface or inside of the first substrate

12 contact surface or inside of the second substrate

15 contact surface

17 error area or void F

18 touch pad B

19 good area G

20 radiation source

21 maximum distance between the two substrates

22 insolation

24, 24a retroreflection

26 Possible air gap

30 detector

31 deepening

32 elevation

35 spacers

37 gear structure

40 Dodge Zone Melting zone or mixing zone resolidified zone

Edge of the refrozen zone

cracks, cracks

pores resolidified zone first coating or coating second coating or coating

laser generator

intensity profile

arrangement step

determination step of the height profile

Calculation step for the first bond quality index Qi

data provision

conversion step

detection step

correction step

contrast enhancement

Calculation step for the height profile

marking step

Calculation step for the Q-factor Qi or Q2

Evaluation step for Qi

feedback step

Further processing step, in particular laser joining

Determination of the second height profile

Calculation step for Q2

Evaluation step for Q2

Marking step in the event of an error, final treatment, in particular isolation of the arrangement 1 or housings 9

Processing head of the laser generator

deflection mirror 803 laser lens

804 Direction of movement of the machining head

805 direction of movement of the substrate

806 Laser beam of the laser beam source d Distance between two laser joining lines or two tacking points

N protection area

W width of the laser joining line 6

The thickness of the first covering or coating 70

D ₂ Thickness of the second covering or coating 71

Ds compressive stress zone

DoL depth of the compressive stress zone

Claims

Patent Claims:

1 . Hermetically connected arrangement (1) comprising: a first metallic substrate (3), a second substrate (4) which is transparent at least in regions and/or at least partially for at least one wavelength range, the first substrate being adjacent to a contact surface (11). is arranged to a contact surface (12) of the second substrate, at least one laser joining line (6, 6a, 6b, 6c, 6d) or a plurality of tacking points for direct and immediate joining of the first metallic substrate to the second substrate, on or in the contact surfaces (11, 12, 15), wherein the laser joining line or the plurality of gluing points extends into the first substrate on the one hand and into the second substrate on the other hand and joins the at least two substrates directly to one another by melting.

2. Hermetically bonded arrangement (1) according to the preceding claim, wherein in the laser joining line (6, 6a, 6b, 6c, 6d) or the plurality of bonding points there is an intermixing zone (62), in which material of the second substrate (4th ) And material of the first substrate (3) is mixed.

3. Hermetically connected arrangement (1) according to the preceding claim, wherein in the intermixing zone (62) metal material of the first metallic substrate (3) has entered the second substrate (4), and/or wherein in the intermixing zone (62) material of the second substrate (4) has entered the first substrate (3).

4. Hermetically connected arrangement (1) according to one of the preceding claims, wherein the intermixing zone (62) has a thickness measured in a direction perpendicular to the contact surfaces (11, 12, 15), and wherein the intermixing zone has a thickness of preferably at least 1 μm has, preferably 2 μm or more, more preferably 5 μm or more, and/or wherein the intermixing zone (62) is more than or equal to 1 μm in the second substrate reaches in.

5. Hermetically connected arrangement (1) according to one of the two preceding claims, wherein the intermixing zone (62) has a width and the width of the intermixing zone is greater than the thickness of the intermixing zone in the second substrate (4) and/or the width of the Intermixing zone (62) is 50% or more larger than the thickness of the intermixing zone, more preferably 100% or more larger than the thickness of the intermixing zone, the width of the intermixing zone (62) being in particular at the contact surface (15) between the first and the second substrate (3, 4) and is measured in a direction parallel to the contact surface and perpendicular to the laser joining line (6, 6a, 6b, 6c, 6d).

6. Hermetically connected arrangement (1) according to one of the preceding claims, the at least one laser joining line (6, 6a, 6b, 6c, 6d) or the plurality of tacking points further comprising a resolidified zone (64, 69), the resolidified zone has a thickness measured in the direction perpendicular to the contact surfaces (11, 12, 15), and the thickness of the resolidified zone is preferably less than or equal to 20 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 5 pm, and/ or wherein the resolidified zone (64, 69) extends less than or equal to 20 µm into a depth of the second substrate, preferably less than or equal to 10 µm, more preferably less than or equal to 5 µm.

7. Hermetically bonded arrangement (1) according to the preceding claim, wherein the resolidified zone (64, 69) extends along the laser joining line (6, 6a, 6b, 6c, 6d), and/or wherein the resolidified zone (64, 69 ) at the contact surface (11, 12, 15) between the first and the second substrate (3, 4) and in a direction parallel to the contact surface has a width of 10 μm ± 5 μm, preferably 20 μm ± 10 μm, more preferably 30 pm ± 10 pm and / or wherein the resolidified zone (64, 69) at the contact surface (11, 12, 15) between the first and second substrates (3, 4) and has a width in a direction parallel to the contact surface and perpendicular to the laser bonding line, which is greater than the thickness of the resolidified zone.

8. Hermetically connected arrangement (1) according to one of the preceding claims, wherein in the intermixing zone (62) material of the first substrate (3) and material of the second substrate (4) is arranged such that a form-fitting toothing between the material of the first substrate with the material of the second substrate, and/or having an interlocking structure (37) fused to one another between the first metallic (3) and the second substrate (4).

9. Hermetically connected arrangement (1) according to one of the preceding claims, wherein in the mixing zone (62) and/or the resolidification zones (64, 69)

Metal material of the metallic substrate (3) is present in the form of droplets (3a) and/or dendrites and/or material of the second substrate (4) is present in the form of ablations (4a) and/or dendrites (4b), the arrangement being droplets and/or dendrites causes a strengthening of the bond between the first and second substrate.

10. Hermetically connected arrangement (1) according to one of the preceding claims, wherein metal material of the metal substrate (3) and/or material of the second substrate (4) has penetrated into at least one of the resolidification zones (64, 69), in particular in the form of droplets (3a), ablation (4a) and/or dendrites (4b), and causes a solidification of the bond between the first and second substrate.

11 . Hermetically connected arrangement (1) according to any one of the preceding claims, wherein the contact surface (11) of the first substrate (3) at least one

Touch contact area, in which the first substrate is in surface touch contact with the second substrate (4), the touch contact area in particular having an average distance between the first and second substrate of less than or equal to 1 μm, preferably less than or equal to 0.5 μm preferably less than or equal to 0.2 pm, and/or wherein the touch contact surface corresponds in particular to the contact surface (15).

12. Hermetically connected arrangement (1) according to any one of the preceding claims, wherein the laser joining line (6, 6a, 6b, 6c, 6d) connects the first (3) to the second substrate (4) with one another, so that the two substrates only under application of a holding force, or only with the destruction of the second substrate if the holding force is greater than the force required to destroy the second substrate, and/or where a holding force of the second substrate on the first substrate is greater than 10 N/mm ² , preferably greater than 25 N/mm ² , more preferably greater than 50 N/mm ² , even more preferably greater than 75 N/mm ² and even more preferably greater than 100 N/mm ² .

13. Hermetically connected arrangement (1) according to any one of the preceding claims, wherein the first substrate (3) is characterized in that the contact surface (11) is flat, in particular planar, and / or wherein the contact surface (11) of the first substrate (3) is polished, and/or wherein the contact surface (11) of the first substrate (3) has an average roughness value Ra of less than or equal to 0.5 μm, preferably less than or equal to 0.2 μm, more preferably less than or equal to 0, 1 μm, even more preferably less than or equal to 50 nm and finally preferably less than or equal to 20 nm and/or wherein the second substrate (4) is characterized in that it is flat on the contact surface (12), in particular planar, further in particular has an average roughness value Ra of less than or equal to 0.5 μm.

14. Hermetically connected arrangement (1) according to the preceding claim, wherein the joining laser has a beam focus, and wherein the focal plane for the

Introduction of the laser joining line (6, 6a, 6b, 6c, 6d) is shifted distally, in particular in the first substrate (3), and wherein the focal plane is preferably shifted 10 pm ± 10 pm distally in the first substrate (3), more preferably 20pm ± 10pm.

15. Hermetically connected arrangement (1) according to one of the preceding claims, wherein the beam width (2W laser) at the contact plane (11, 12, 15) is 4 pm ± 1 pm, preferably 4m ± 2m, more preferably 4m ± 3pm.

16. Hermetically connected arrangement (1) according to any one of the preceding claims, wherein the first substrate (3) consists of metal material, and / or wherein the first substrate (3) comprises metal within the meaning of the definition of

periodic table.

17. Hermetically connected arrangement (1) according to any one of the preceding claims, wherein the first substrate (3) at least one of molybdenum, tungsten, silicon, platinum,

Includes or consists of silver or gold, and/or wherein the first substrate (3) includes an alloy, in particular at least one of carbon, copper, manganese, chromium, magnesium, cobalt, nickel, tin, zinc, niobium, palladium, rhenium, includes or consists of indium, tantalum, titanium or iridium.

18. Hermetically connected arrangement (1) according to any one of the preceding claims, wherein the second substrate (4) is a transparent substrate, and / or wherein the second substrate (4) comprises glass, glass ceramic, silicon, sapphire or a combination of the aforementioned materials or consists of it, and/or wherein the second substrate (4) comprises or consists of ceramic material, in particular oxide-ceramic material.

19. Hermetically connected arrangement (1) according to the preceding claim, wherein the second substrate (4) consists of at least one of quartz glass, borosilicate glass,

Alumnosilicate glass, a glass ceramic such as Zerodur, Ceran or Robax, an optoceramic such as aluminum oxide, spinel, pyrochlore or aluminum oxynitrite, calcium fluoride crystal or chalcogenide glass.

20. Hermetically connected arrangement (1), in particular according to one of the preceding claims, comprising a first metallic substrate (3), a second substrate (4), which is at least partially and/or at least partially transparent for at least one wavelength range, said first substrate having a contact pad (11) adjacent to a contact pad

(12) of the second substrate is arranged, at least one spacer (35) for defining a distance between the first and the second substrate.

21 . Hermetically connected arrangement (1) according to the preceding claim, further comprising at least one laser joining line (6, 6a, 6b, 6c, 6d) or a plurality of tacking points for direct and immediate joining of the first metallic substrate (3) to the second substrate (4 ), wherein the laser joining line or the plurality of bonding points extends into the first substrate on the one hand and into the second substrate on the other hand and joins the at least two substrates directly to one another by melting.

22. Hermetically connected arrangement (1) according to one of the two preceding claims, wherein the first substrate (3) via the spacer (35) with the second substrate (4) is in contact, and / or wherein the spacer (35) between the first substrate (3) and the second substrate (4) is arranged.

23. Hermetically connected arrangement (1) according to one of the three preceding claims, wherein the spacer (35) extends at least along the laser joining line (6, 6a, 6b, 6c,

6d) or in the area of the tacking points, or the spacer (35) extends outside the laser joining line (6, 6a, 6b, 6c, 6d) or outside the areas of the adhesion points, or the spacer (35) is formed over the entire surface , and/or wherein the spacer (35) has a thickness of at least 5 μm, more preferably a thickness of at least 10 μm, more preferably a thickness of at least 20 μm.

24. Hermetically connected assembly (1) according to any one of the three preceding claims, wherein the spacer (35) consists of metal material, and/or wherein the spacer (35) as a coating on the first (3) or the second Substrate (4) is formed, and / or wherein the spacer (35) is formed in one piece with the first substrate (3) and / or the second substrate (4).

25. Hermetically connected arrangement (1), in particular according to one of the preceding claims, comprising a first metallic substrate (3), a second substrate (4) which is transparent at least in certain areas and/or at least partially for at least one wavelength range, the first substrate is arranged with a contact surface (11) adjacent to a contact surface (12) of the second substrate, and at least one avoidance zone (40) for receiving molten material from a laser joining line (6, 6a, 6b, 6c, 6d) or a bonding point , wherein the laser joining line or a plurality of tacking points is used for direct and immediate fusion joining of the first metallic substrate to the second substrate.

26. Hermetically connected arrangement (1) according to the preceding claim, wherein the at least one avoidance zone (40) is arranged adjacent to the laser joining line (6, 6a, 6b, 6c, 6d) or the plurality of tacking points, and/or wherein the at least an escape zone (40) is arranged between the first (3) and the second substrate (4), and/or wherein the at least one escape zone (40) when arranging the second substrate (4) on the first substrate (3) at the contact surface (11, 12, 15) is formed.

27. Hermetically connected arrangement (1), in particular according to one of the preceding claims, comprising a first metallic substrate (3), a second substrate (4) which is transparent at least in regions and/or at least partially for at least one wavelength range, wherein the first substrate having a contact surface (11) adjacent to a contact surface (12) of the second substrate, a first laser bonding line (6, 6a, 6b, 6c, 6d) or a first set of bonding points for direct and immediate joining of the first metal substrate to the second substrate, on or in the contact surfaces (11, 12, 15), the first laser joining line or the first set of bonding points extending into the first substrate on the one hand and into the second substrate on the other and the at least two substrates are joined directly by melting, a second laser joining line (6a, 6b, 6c, 6d) or a second set of tacking points for direct and immediate joining of the first metallic substrate to the second substrate, on or in the contact surfaces, the second laser joining line or the second set of tacking points extends into the first laser joining line or the first set of tacking points and changes or improves the material mixing achieved with the first laser joining line or the first set of tacking points.

28. Hermetically sealed housing (9), in particular with a hermetically connected arrangement (1) according to one of the preceding claims, comprising a metallic first substrate (3), a second substrate (4) which is at least partially and/or at least partially for at least transparent in a wavelength range, the first substrate being arranged with a contact surface (11) adjacent to a contact surface (12) of the second substrate, at least one functional region (2) arranged between the first and the second substrate, in particular a cavity, at least one Laser joining line (6, 6a, 6b, 6c, 6d) or a plurality of bonding points for direct and immediate joining of the first substrate to the second substrate, on or in the contact surfaces, in particular around the functional area for hermetically sealing the functional area, the laser joining line or the plurality of tacking points on the one hand in the first substrate and others on the other hand extends into the second substrate and joins the at least two substrates directly to one another by melting.

29. Hermetically sealed housing (9) according to the preceding claim, wherein the laser bond line (6, 6a, 6b, 6c, 6d) of the housing completely around the

Functional area (2) is designed to be closed and/or wherein a spacing of the first substrate (3) from the second substrate (4) in the Laser bonding line (6, 6a, 6b, 6c, 6d) is continuously smaller than 0.75 μm, preferably smaller than 0.5 μm, more preferably smaller than 0.2 μm.

30. Hermetically sealed housing (1) according to one of the preceding claims, wherein the functional area (2) comprises a hermetically sealed accommodation cavity for accommodating an accommodation object (5), such as an electronic circuit, a sensor or MEMS.

31 . Hermetically connected arrangement (1) or hermetically sealed housing (1), in particular according to one of Claims 1 to 30, in which, in particular before the hermetically sealed connection of the at least two substrates to one another by direct joining of the at least two substrates, a first coating or coating on the metallic first substrate (3) at least in the area of the laser joining line (6, 6a, 6b, 6c, 6d) or the plurality of bonding points on a side facing the second substrate, in particular for direct and immediate joining of the first metallic substrate to the second substrate is arranged.

32. Method for producing a hermetically sealed composite (1) from at least two parts, with the steps: arranging at least one first metallic substrate (3) over a large area on a second substrate (4), the at least two substrates being arranged on one another or on top of one another, so that a contact surface (11, 12, 15) is formed between the at least two substrates, at which the first substrate is in contact with the second substrate, and wherein the second substrate comprises a transparent material, hermetically sealed connection of the at least two substrates to one another by direct joining of the at least two substrates to one another in the area of the at least one contact surface, so that a mixing zone (62) is formed, which extends into the first substrate on the one hand and into the second substrate on the other hand and joins the at least two substrates directly to one another by melting.

33. The method according to the preceding claim, in which the arrangement of a first covering or coating on the first substrate (3) before the areal arrangement of the 50 takes place at least one first metallic substrate (3) on the second substrate (4),

34. The method according to any one of the preceding claims 32 or 33, further comprising the step of

Checking the hermetic connection of the at least two substrates (3, 4) by determining a distance profile between the at least two substrates, and/or

Determination of a first bond quality index Qi to check the mechanical strength and/or the hermeticity of the bond (1).

35. The method according to the preceding claim, wherein the first bond quality index Qi to Qi = 1 - (A - G) / A is determined, where

A represents the area of the contact surface (11, 12, 15) and G represents a good surface, wherein the good surface G corresponds in particular to the physical contact surface, and/or wherein the good surface G describes a part of the contact surface (11, 12, 15) in which the The distance between the substrates (3, 4) is less than 5 pm, preferably less than 1 pm, more preferably less than 0.5 pm, more preferably less than 0.2 pm, and/or wherein the bond quality index is Qi is greater than or equal to 0.8, preferably greater than or equal to 0.9, more preferably greater than or equal to 0.95.

36. The method according to any one of the preceding claims 32 to 35, wherein the contact surface (11, 12, 15) has a useful area N and the useful area N is used to calculate the first bond quality index Qi, and/or

Qi is found to be Qi = 1 - (N - G) / N.

37. The method according to the preceding claim, wherein the first bond quality index Qi is determined before the first and the second substrate (3, 4) are joined together, and/or with the step of determining a second bond quality index Q2 the contact surface (11, 12, 15) of the hermetically tightly joined composite (1), with Q2 in particular being greater than Qi, more particularly with Q2/Q1>1.001.

38. The method according to any one of the preceding claims 32 to 37, with the step

Ignition of a plasma discharge in the mixing zone (62) by means of a laser 51

Preparation of the laser joining process.

39. Housing (9) or hermetically connected arrangement (1) produced with the method according to one of the preceding claims 32 to 38.

40. Use of a hermetically connected arrangement (1) according to any one of claims 1 to 27 or a hermetically sealed housing (9) according to any one of claims 28 to 31 in contact with human, animal or plant cells, in particular as a medical implant, in particular as a medical intracorporeal sensor, or as a wearable.