Airtight Connection Assembly

Abstract

A hermetic connection assembly is shown, which comprises a first substrate, which is at least in some areas and / or at least partially made transparent for at least one wavelength range, a metal foil, which is arranged so as to have a contact area 5 adjacent to the contact area of ​​the first substrate, and at least one laser bond line or a number of bond points for directly and without mediation bonding the metal foil to the first substrate on or in the contact area. The laser bond line or the number of bond points penetrates into the first substrate on the one hand and into the metal foil on the other hand and directly bonds the two bonding partners to each other by melting. Here, the metal foil is prepared to be flexible so that irregularities in the contact area of ​​the first substrate can be flattened.

Description

[Technical field]

[0001] The present invention relates to a hermetic connection assembly, an enclosure, a method of making a hermetically sealed connection, and a hermetic connection assembly made by the method.

[0002] 2. Background and General Description of the Invention The joining of components by various laser processes to form hermetically sealed connections or enclosures is known in principle. Hermetically connected glass-glass connections are known, for example, from EP 3012059 by the applicant. In said document a method for producing a transparent component for protecting an optical component is presented. In this method a novel laser process is presented.

[0003] Connections where different materials are joined to one another are constantly being developed. Among them, metal-glass joints are of particular interest, since the combination of metal and glass in particular allows for a wide range of applications, for example in the fields of biophysics and technical medicine, and in particular for improved and new applications in bioprocessors and aerospace applications.

[0004] The construction of a hermetically sealed enclosure allows one or more components therein to be protected from adverse environmental conditions. For example, sensitive electronics, circuits or sensors can be placed in the hermetically sealed enclosure for the construction and use of medical implants, for example in the area of ​​the heart, in the retina or generally for bioprocessors. Also possible are applications such as MEMS (Micro-Electro-Mechanical Systems) in sensor technology, such as barometers, blood gas sensors or glucose sensors, and electronics applications, such as providing antennas, applying conductor strips to glass components, etc. The invention also allows for the provision of a "CTE bridge" by applying and rigidly fixing a material having a significantly different CTE (Coefficient of Thermal Expansion) to a substrate. Potential applications can likewise be found in particular in the field of watchmaking and generally in the field of wearables and devices, where for example waterproofing and pressure resistance are required. In particular, covers for smart watches and the like can be improved by the invention. Wide ranges of fields of use for the present invention can also be found in aviation, high temperature applications, in the area of ​​electromobility, for example in the manufacture of fuel cells, analytics, for example in the form of optical access and flow cells, and in the field of micro-optics.

[0005] Unlike connecting two similar components to each other, the problem when using dissimilar materials is that the two joining partners often do not adhere well to each other or even can not be connected in particular. Here, the invention is based on preliminary investigations carried out in-house by the applicant. In this respect, reference is made to the unpublished German patent application DE102020129380.1, which is incorporated herein by reference in its entirety.

[0006] The present invention has set itself the task of providing a hermetic connection assembly between two components made of different materials, i.e. a first substrate comprising, for example, a glass or glass-like material with a metal, and furthermore, an enclosure in which two components of different materials are connected to each other.

[0007] In particular, it is an aspect of the subject matter that the hermetic connection assembly or enclosure can be made to be sufficiently durable, particularly so that the two members do not separate from one another or do not separate under the action of a small force. Accordingly, it is an object of the present invention to provide a more reliable and durable hermetic connection assembly or enclosure.

[0008] The gas-tight connection assembly according to the present invention comprises a first substrate, which is formed to be transparent in at least some areas and / or at least partially to at least one wavelength range. The first substrate is arranged to have a contact area adjacent to the contact area of ​​the metal foil. In other words, the metal foil is arranged on the first substrate, for example, the metal foil is attached to the first substrate, pressed onto it, or temporarily bonded thereto.

[0009] The substrate and the metal foil are usually first placed in contact with each other for their connection, thus for example stacked on each other. Gravity can then force the upper substrate onto the lower metal foil. Here, the up or down orientation is merely illustrative, and the assembly can of course be in any orientation in space, even a side-by-side assembly does not depart from the scope of protection. The metal foil is usually placed with its larger extension side adjacent to the substrate. For example, the substrate and / or the metal foil are formed in a disk-like or flat shape, so that each has at least one large flat surface. However, it is typically not possible or desirable to apply a force to "press" the substrate and the metal foil together, since this can cause various stresses (e.g. shear stresses) to be permanently "baked" into the substrate during the joining process. If the joining process is carried out under stress, the gas-tight connection or enclosure can show reduced strength and increased tendency to break. Therefore, the substrate may not be placed in close enough contact with the metal member to obtain good quality and reproducible results in the laser joining process. Therefore, a metal foil is included to further improve the joining result. The use of the metal foil according to the invention can increase the final strength of the enclosure or substrate, and the metal foil and the substrate can be joined together without stress. The absence of stress distinguishes the method from "high temperature" coating processes, especially sputtering of metal coatings, which can leave the coated substrate with stress after cooling. The use of metal foils also allows for more cost-effective production, especially compared to sputtering of metal coatings on substrates, the metal foils can be provided thicker and more robust than such coatings, and the metal foils can easily smooth or fill irregularities on the substrate surface. This allows for the intermediate step of sputtering the substrate to be completely omitted, which further shortens the process run time and reduces costs.

[0010] The gas-tight connection assembly further comprises at least one laser bond line or a number of bond points for directly and without mediation bonding the metal foil to the first substrate on or in the contact area, the laser bond line or the number of bond points penetrating the first substrate on the one hand and the metal foil on the other hand and bonding the first substrate directly to the metal foil by melting, in other words the first substrate and the metal foil are bonded to each other at the laser bond line.

[0011] In the context of this application, a contact area is a region or part of the surface or the entire surface of the respective substrate or metal foil where the respective substrate is adjacent or arranged so as to be adjacent to the other substrate or metal foil. Typically, the substrate is arranged next to or on the metal foil. A contiguous contact area is formed when the substrate and the metal foil are in direct and unmediated contact. Thus, a contiguous contact area is, for example, a partial area of ​​the contact area where the gap between the two substrates is so small that it cannot be measured optically.

[0012] The first substrate is formed as flat as possible in the contact area. However, in this case, an absolutely flat surface can only be achieved theoretically, since depressions, ridges, curvatures or the aforementioned variations may be observed even on a polished surface, depending on the scale of observation. Thus, it is difficult to achieve full contact, especially when placing a substrate such as glass on a metal member. The substrate has bulges, inclinations, curvatures, depressions or ridges, even if only to a very small extent. For example, the interfacial contact area can be defined when the first substrate has an average gap of 1 μm or less, preferably 0.5 μm or less, more preferably 0.2 μm or less, with respect to the metal foil.

[0013] Further reduction of the variation of the surface of the substrate may be very laborious. For some substrates, a sufficiently large reduction of the variation may not be possible or desirable at all. For example, polishing the surface may in turn change the optical properties of the first substrate or change the surface stress of the first substrate. The substrate may also begin to swell or deform upon further reduction, which further increases the distance to the desired joining partner, i.e. the resulting air gap. Polished surfaces, especially of metal objects, may also be disadvantageous for laser joining processes under certain circumstances, because polished surfaces may cause an increased amount of reflection or scattering, making accurate positioning and power deposition for the joining process difficult or even impossible to carry out in this way.

[0014] It has now been surprisingly found within the scope of the present invention that the use of a metal foil can result in a particularly good adhesion between the metal foil or metal object and the first substrate, where the metal foil is flexible and in close contact with the contact area of ​​the first substrate. In particular, the metal foil can flatten its own irregularities, i.e. the irregularities of the metal foil surface, in this case. By flattening these irregularities (usually curved), the gap between the metal foil and the first substrate can be narrowed. For example, an aluminum foil can be used, which is pressed against one side of the first substrate. In this case, the aluminum foil remains in the shape obtained by pressing or adhering to the first substrate. In other words, the metal foil is deformed, for example flexed, twisted or curved, and hits the contact area, thereby assuming a shape complementary to the contact area. The metal foil thus becomes a complementary metal foil, since it complements the contact area of ​​the first substrate so that the interfacing contact area between the metal foil and the first substrate is increased and / or the gap is reduced.

[0015] In particular, the deformation of the metal foil for adhesion to the contact area is inelastic, so that the metal foil retains the modified shape without the application of significant forces. This is important, for example, in the case of glass or glass-like substrates, since the bonding process under the application of external forces introduces a stress field into the substrate under certain circumstances. Thus, when using metal foils, the bonding process can be carried out particularly preferably without the application of external forces, since the metal foil remains in the modified shape and does not return to its original shape by itself. The modified shape is therefore essentially stable or irreversible, and the deformation is particularly inelastic. For example, the self-weight of the first substrate is sufficient when it is placed on the metal foil, so that the metal foil adheres to the first substrate, providing an improved contact area without significant substrate stresses in the first substrate that would otherwise be "burned" into the substrate by the bonding process.

[0016] The metal foil is preferably arranged along the peripheral region of the first substrate. In other words, the metal foil extends along the peripheral region, for example in the form of an open square or rectangle. For example, the metal foil only partially or partially covers the contact area of ​​the first substrate, i.e. in particular does not cover it completely. The metal foil may form one or more contact points on the contact area of ​​the first substrate. The purpose of the metal foil may be to establish an improved connection of the first substrate to the metal member, where the metal foil is first welded to the first substrate by the laser joining process presented herein, and then the metal member can be joined to the first substrate by a conventional joining process with the metal foil connected to the first substrate.

[0017] Additionally or alternatively, the metal foil can have vertical sections, which allow fusion welding to be introduced at the laser joining line not only in horizontal planes but also in some sections of the vertical region.Furthermore, additionally or alternatively, the side joining by conventional joining processes can extend to the side peripheral regions, so that the joined parts, in particular the metal parts, provide a frame or enclosure for the gas-tight assembly.

[0018] The metal foil may further have vertical structures, which may be introduced, for example, by punching or embossing with a profile, which may act as alignment or centering aids when aligning the parts to be joined with the substrate.

[0019] Instead of metal components, for example plastic or crystalline components can also be bonded to the first substrate via metal foils. Examples of crystalline components are, inter alia, silicon or germanium wafers, sapphire, yttrium oxide (Y2O3), zirconium oxide (ZrO2), aluminum oxide (Al2O3), yttrium-doped zirconium oxide, yttrium-doped aluminum oxide, lanthanum-doped yttrium oxide, aluminum-doped aluminum nitride, magnesium-doped aluminum oxide.

[0020] In the bonding area, i.e. the area including the laser bond line or multiple laser bond lines, the metal foil may not (anymore) be flexible due to its attachment to the first substrate after the introduction of the laser bond line by the bonding process. Since the foil is inseparably connected to the first substrate in the bonding area, the metal foil can only remain flexible in this area if the first substrate is also flexible. However, the metal foil can remain flexible outside the bonding area including the laser bond line even after the introduction of the laser bond line.

[0021] At the laser bond line or at a number of bond points, a fusion zone is present in which the material of the first substrate and the material of the metal foil intermingle. In the fusion zone, the metal material of the metal foil may penetrate into the first substrate. In the fusion zone, the material of the first substrate may penetrate into the metal foil. Particularly preferably, in the fusion zone, not only the metal material of the first substrate penetrates into the metal foil, but also the material of the metal foil penetrates into the first substrate. The fusion zone may have a thickness measured in a direction perpendicular to the contact area, and the thickness of the fusion zone may preferably be at least 1 μm, more preferably 2 μm or more, even more preferably 5 μm or more.

[0022] The metal foil is formed to be sufficiently flexible so that it can be adhered to the contact area. This depends on the material, among others. To still be sufficiently flexible, the metal foil can have a thickness of 500 μm or less, preferably 250 μm or less, more preferably 100 μm or less, more preferably 50 μm or less. On the other hand, it is advantageous if the metal foil has a minimum thickness that still allows the metal foil to be reliably welded to the first substrate. The minimum thickness of the metal foil can be 10 μm or more, preferably 20 μm or more, more preferably 40 μm or more.

[0023] The underside of the metal foil, located opposite the contact area, may be shaped to provide advantageous surface properties for subsequent conventional welding processes. In some processes, the underside is shaped as a very low roughness surface. However, in other processes, a high roughness in the μm range may be advantageous or groove- or rut-like structures may be required.

[0024] The metal foil can have a weld rib on the underside opposite the contact area. This weld rib can be generated during the joining process. For example, if the metal foil is strongly heated at certain points during laser welding and the material of the metal foil escapes from the joining zone, a nose or weld rib can be formed on the underside. This weld rib can be advantageous, since the presence of a weld rib on the underside in this case can simplify subsequent conventional welding with the metal part. Such a metal part can be inseparably connected, i.e. for example bonded, to the metal foil welded to the first substrate.

[0025] The metal component is preferably material-connected to the metal foil by conventional joining processes, i.e. by means of heat and / or pressure, with or without a weld filler, in particular by molten metal welding, such as arc welding. The use of such welding processes for connecting a metal component, such as a watch casing for a smartwatch, with an assembly, such as a watch glass or watch cover, is thus only possible with the use of the metal foil according to the invention, since metal-to-metal joining is now possible.

[0026] Thus, for example, the airtight assembly can be delivered for further processing with the metal foils already bonded, so that the watch manufacturer in some cases does not need to have any additional equipment for performing a laser bonding process; when the airtight assembly is delivered in a completed state, the watch manufacturer (or for example the manufacturer of the final enclosure of the watch) can produce an airtight and permanent connection by conventional bonding processes, which may mean a significant simplification of the manufacturing process on the part of the manufacturer of the final enclosure - for example the watch manufacturer.

[0027] The fusion zone preferably penetrates into the first substrate by at least 1 μm. Preferably, the fusion zone penetrates into the first substrate by 5 μm. More preferably, the fusion zone penetrates into the first substrate as far as the resolidification zone, so that the fusion zone overlaps with the resolidification zone. For example, the fusion zone penetrates into the first substrate to approximately the same distance as the metal foil. This is surprising at first glance, because, for example, in the case of a metal-glass connection, the CTE of the metal foil is 3 to 10 times higher than the CTE of the glass (first substrate). Also, the heat capacity and thermal conductivity of the metal are usually much higher than those of the first substrate. However, it has been found that by advantageously adjusting the fusion zone at the laser bond line or joint, the fusion zone can be made to penetrate into the metal foil to approximately the same distance as the first substrate, thus improving the bonded connection.

[0028] The fusion zone has a width, and the width of the fusion zone is preferably greater than the height of the fusion zone on the first substrate, and may be at least 50% greater than the height of the fusion zone, and more preferably at least 100% greater than the height of the fusion zone.

[0029] Here, the width can be measured, for example, at the contact area between the first substrate and the second substrate in a direction parallel to the contact area and perpendicular to the laser bond line.

[0030] At least one of the laser bond lines or the plurality of bond points may further include a re-solidified zone, the re-solidified zone having a height measured in a direction perpendicular to the contact area, the height of the re-solidified zone may be preferably 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less.

[0031] The resolidification zone may extend into the first substrate to a depth of preferably 20 μm or less, preferably 10 μm or less, even more preferably 5 μm or less.

[0032] The resolidification zone of at least one laser bond line or of a plurality of bond points may extend along the laser bond line or may be located within each bond point. The resolidification zone may have a width in the contact area between the first substrate and the metal foil, in a direction parallel to the contact area, of e.g. 10 μm±5 μm. Preferably, this width may be 20 μm±10 μm, more preferably 30 μm±10 μm.

[0033] The resolidification zone can also have a width, parallel to the contact area and perpendicular to the laser bond line, that is greater than the height of the resolidification zone.

[0034] It is particularly advantageous for the resolidification zone to be as small as possible, i.e. the irradiation parameters of the joining laser can be selected in such a way that the resolidification zone is as small as possible. The resolidification zone does not have any significant utility for the joining process, since there is no intermixed material between the first substrate and the metal foil that would cause interlocking and adhesion. The resolidification zone therefore absorbs the laser energy without improving the purpose of adhesion. At the same time, cracks and / or holes or cavities may form in the resolidification zone upon its cooling, which may be explained by stresses caused by the expansion of the joining material upon heating, which then contracts again upon cooling.

[0035] Therefore, it is preferable to set the fusion zone as large as possible, while the resolidification zone can be set as small as possible. Preferably, the fusion zone has a height of at least 1 / 5 of the height of the resolidification zone, more preferably 1 / 2 of the resolidification height, and more preferably, the fusion zone has the same height as the resolidification zone. Here, for example, if the height of the fusion zone is 5 μm, and the height of the fusion zone is 1 / 5 of the height of the resolidification zone, the height of the resolidification zone is 25 μm above the fusion zone. If the height of the fusion zone is 10 μm and the height of the resolidification zone of the first substrate is also 10 μm, the height of the resolidification zone will match the height of the fusion zone. The fusion zone can also have a thickness larger than the resolidification zone, for example, 1.5 times or more thicker than the resolidification zone, for example 5 times thicker.

[0036] The metal foil may also have a resolidification zone below the fusion zone. It is not determined whether the size of the resolidification zone of the metal foil is detrimental to the joining process, as in the case of the first substrate. On the contrary, the material of the first substrate may penetrate into the resolidification zone of the metal foil and induce the formation of dendrites there, i.e. an anchor-like connection between the first substrate and the metal foil is made via one or more dendrites, which may penetrate into the resolidification zone of the metal foil.

[0037] In the fusion zone, the material of the first substrate and the material of the metal foil may be arranged such that a form-locking interlock occurs between the material of the first substrate and the material of the metal foil. The gas-tight connection assembly may include interlocking structures fused to each other between the first substrate and the metal foil. In the interlocking structures fused to each other, there may be an inversion, indentation or intrusion of the material, which may strengthen the connection of the gas-tight connection assembly. Such interlocking structures fused to each other provide a form-locking connection, which is particularly advantageous when the material connection between different materials may possibly provide only a small adhesion or a small material connection. Here, the interlocking structures act like fine fasteners.

[0038] In the fusion zone, the metal material of the metal foil can be present in the form of droplets and / or dendrites, the assembly of which as droplets and / or dendrites results in a strengthening of the connection.

[0039] It should further be noted that the metallic material of the metal foil and / or the material of the first substrate may also penetrate into at least one of the resolidification zones, in particular in the form of droplets, melts and / or dendrites, which causes a strengthening of the connection. In other words, the joining partners, i.e. the material of the first substrate and / or the material of the metal foil, are selected and / or the beam generator is set and / or prepared in order to adjust the joining process in such a way that the metallic material of the first substrate and / or the material of the metal foil, respectively, penetrates into the resolidification zone belonging to the other component.

[0040] For example, the material of the first substrate may have amorphous regions or zones due to or after the introduction of a laser bond line. Such amorphous regions, i.e., for example, amorphous metal material, may further improve the interlocking.

[0041] The contact area of ​​the first substrate comprises at least one coplanar contact area, where the first substrate is in planar contact with the metal foil. The coplanar contact area may in particular have an average gap of 1 μm or less, preferably 0.5 μm or less, more preferably 0.2 μm or less. Here, for technical or other reasons, it may be unavoidable to have very slight gas inclusions or impurities at the contact surface, such as dust or irregularities due to the grinding process. This may also be caused by irregularities, possibly even down to the micro range, present on the contact surface or on the component surface. The coplanar contact area may coincide with the contact area, provided that the establishment of a full-surface contact is possible.

[0042] The laser bond line can connect the first substrate and the metal foil together such that they cannot be separated from each other without overcoming the holding forces. The bond can also be achieved with such strength that separation cannot be achieved without destroying the first substrate, if the shear strength is greater than the material strength, e.g., edge strength, of the first substrate. For example, the shear strength can be determined using the ISO 13445:2003 standard. The shear strength of the connection between the metal foil and the first substrate can be, for example, 10 N / mm 2 Greater than 25N / mm 2 Greater than 50N / mm 2 Greater, and even more preferably 75N / mm 2 Larger, and finally most preferably 100N / mm 2 It can be made larger.

[0043] It is preferred that the contact area of ​​the first substrate is formed flat, i.e. particularly flat. The contact area of ​​the first substrate may be polished if the metal foil is in intimate contact with the contact area. The contact area of ​​the first substrate may have an average roughness value Ra of, for example, 0.5 μm or less, preferably 0.2 μm or less, more preferably 0.1 μm or less, even more preferably 50 nm or less, and finally preferably 20 nm or less. The metal foil is in intimate contact with the contact area of ​​the first substrate, possibly following the irregularities of the contact area. In the case where the metal foil itself is not provided in a flat state, for example because it is deformed by warping (i.e. bending) and, for example, rolled, the intimate contact of the metal foil may implicitly refer to the metal foil being in intimate contact with the flat contact area of ​​the first substrate.

[0044] The laser bonding line is introduced by means of a bonding laser, for example with a wavelength in the range of 1000 nm to 1100 nm, preferably 1030 nm to 1060 nm for infrared lasers, or even with a wavelength of 500 nm to 550 nm. For example, an ultrashort pulse laser with a pulse length in the range of 50 ps or less, preferably 10 ps, ​​more preferably 1 ps, or even more preferably 500 fs or less can be used.

[0045] The bonding laser has a beam focus. The beam focus can have a beam waist width 2w0. Further, the bonding laser has a beam width 2w レーザ , which may be equal to or greater than the beam waist width 2w0. The focal plane for the penetration of the laser bond line may be shifted distally relative to the bond plane. レーザ is greater than the beam waist width 2w0, in particular if the focal plane for the penetration of the laser bond line is shifted distally. In particular, the focal plane is located within the metal foil when the laser bond line is introduced. The focal plane is shifted distally into the metal foil by preferably 10 μm±10 μm, more preferably 20 μm±10 μm.

[0046] Beam width 2w レーザ is preferably 4 μm±1 μm, more preferably 4 μm±2 μm, even more preferably 4 μm±3 μm at the joining surface. This can be achieved, for example, if the focal plane is located within the metal foil when the laser joining line is introduced, i.e., shifted, for example, by 10 μm±10 μm or 20 μm±10 μm distal to the metal foil. レーザ Alternatively or cumulatively, the laser beam can be widened or narrowed in front of the inscribed lens, for example by means of an aperture or a telescope, in order to adjust the width of the inscribed lens to the desired width.

[0047] The metal foil preferably consists entirely of metallic or semi-metallic materials, where the metal foil preferably comprises a metal or semi-metal within the meaning of the periodic table definition. The metal foil may comprise or consist of at least one of aluminum, molybdenum, tungsten, silicon, platinum, silver or gold. The metal foil may also comprise an alloy. In particular, the metal foil may 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.

[0048] The first substrate is preferably a transparent substrate. The first substrate can comprise or consist of glass, glass ceramic, silicon, germanium, sapphire or a combination of the aforementioned materials. One example of a glass with good transparency in the IR range is the Ca-aluminate glass available from SCHOTT AG under the name IRG11A.

[0049] The first substrate may also be or consist of a fiber plate or a fiber rod. Such a fiber plate or fiber rod comprises a plurality of optical fibers, each fiber having an elongated glass core. The core is surrounded by a glass cladding, so that the cladding forms together with the core a rigid continuous glass element. The core has a higher refractive index than the cladding, so that the light can be guided along the glass core by total internal reflection. The light can also be guided by Anderson localization, as in the waveguides known, for example, from DE 102020116444 A1. In this case, cylinders of high and low refractive index glass with different diameters are arranged randomly or unevenly according to a clearly predetermined rule. The glass element of the multi-fiber light guide has two adjacent faces, where the core is terminated at both end faces, so that the light can be guided along the core from one end face to the other end face.

[0050] The first substrate may also comprise or consist of a ceramic material, in particular an oxide ceramic material. The first substrate may also comprise or consist of a crystalline material or crystal, in particular crystalline quartz, yttrium oxide (Y2O3), zirconium oxide (ZrO2), aluminum oxide (Al2O3), yttrium-doped zirconium oxide, yttrium-doped aluminum oxide, lanthanum-doped yttrium oxide, aluminum-doped aluminum nitride and magnesium-doped aluminum oxide, where the dopants are preferably the respective metal oxides.

[0051] The first substrate may comprise or consist of at least one of quartz glass, borosilicate glass, aluminosilicate glass, glass ceramics such as Zerodur, Ceran or Robax, opto-ceramics such as aluminum oxide, spinel, pyrochlore or aluminum oxynitride, calcium fluoride crystals or chalcogenide glasses.

[0052] In one development, the gas-tight connection assembly can include a spacer for defining a gap between the first substrate and the metal member. The spacer can be introduced or included horizontally between the metal foils, i.e. in areas recessed from the metal foils, such as windows bordered by the metal foils. For example, the first substrate can be in contact with the metal member via the spacer. In other words, the spacer can be arranged, for example, in some areas on the contact area of ​​the first substrate, so that the substrate is in contact with the spacer, but a gap remains between the contact area of ​​the first substrate and the contact area of ​​the metal member outside the spacer, for example with the size of the thickness of the spacer and / or the thickness of the metal foil.

[0053] The spacer can fill the area between the substrate and the component, in particular the metal component, to be joined to the substrate. This allows the substrate to stand on the metal component in the joined state. For example, the spacer can be formed as a coating on the first substrate or as a metal foil. The spacer can also be formed integrally with the first substrate, for example in the form of a protrusion forming a projection or bump there. For example, the spacer can be produced during polishing of the contact area of ​​the first substrate, if the area of ​​the contact area of ​​the first substrate is not polished and thus bumps remain there. In particular, when sapphire is used as the first substrate, for example as a watch glass, where already a laborious polishing of the sapphire glass is generally performed, additional polishing or corrective polishing of the sapphire glass can be carried out together with the polishing process, so that no additional work steps are required during production.

[0054] The spacer can be sputtered. The spacer can comprise a directly deposited lithographic glass layer. The spacer can also be printed, for example, using an inkjet printing method. The spacer can also be manufactured using 3D printing. In this case, the spacer can extend along the laser bond line, the spacer being arranged outside the laser bond line or outside the area of ​​the bond point. The spacer can support the first substrate, for example, against the metal member. However, preferably, the spacer is not intended to connect the first substrate to the metal member in such a way that it cannot be separated. The spacer can have a thickness of at least 5 μm, more preferably at least 10 μm, even more preferably at least 20 μm. The spacer preferably has the same thickness as the metal foil.

[0055] The spacer can also have structure in the form of ridges, bulges and / or recesses, which can act as alignment or centering aids and can facilitate accurate positioning of the substrate relative to the member to which it is connected.

[0056] In one development of the invention, at least one avoidance zone may be provided to accommodate the molten material from the laser joining line or the joining point. Here, preferably, the at least one avoidance zone is arranged adjacent to the laser joining line or the joining points. In other words, the avoidance zone is arranged in such a way that the molten material can escape to the avoidance zone, especially at the moment when the laser joining line is generated. For example, the avoidance zone may be arranged around the laser joining line and thus in communication with it, so that the material that is melted and heated at the laser joining line can escape slightly to the avoidance zone. In this case, the molten material can follow the pressure gradient in the process of avoidance.

[0057] For example, the first substrate and / or the metal foil may exhibit expansion, e.g. thermal expansion, when the laser bond line is introduced. Since the laser only heats the material locally, i.e. the material remains in a solid state around the laser bond line, in some cases significant stresses may be generated between the material of the laser bond line and the material surrounding the laser bond line, which may result in cracks or cavities, such as stress cracks. With the avoidance zone maintained, the molten material can escape to the avoidance zone, thus reducing the formation of cracks or cavities. At least one avoidance zone, or even a buffer zone or a relief zone, is further preferably arranged between the first substrate and the metal foil, e.g. in the contact area there.

[0058] The avoidance zone can also be formed by the inclusion of a spacer, which places the two contact areas with a predefined gap from each other when the first substrate is placed on the metal foil. The cavities formed in this case in the areas without the spacer can be pre-configured or pre-positioned to be used as an avoidance zone for material to escape during laser bonding. This results in a laser bond line that is less stressed, potentially resulting in a stronger or higher adhesion, while at the same time allowing stress to escape from the first substrate, reducing the formation of stress cracks or cavities in the first substrate.

[0059] If the zone where the molten materials are fused together is called the fusion zone and the adjacent zone of the laser joining line is called the resolidification zone, then the resolidification zone in particular is problematic in that the introduction of the laser joining line can lead to the formation of cracks or cavities there. This is particularly disadvantageous when the first substrate is a single crystal, such as sapphire, and the damage caused by the introduction of the laser joining line cannot be repaired by the subsequent introduction of a subsequent laser joining line with an offset cover. The concept of the invention, in particular the avoidance zone and / or the spacer, therefore allows the resolidification zone to be kept as small as possible while at the same time making the fusion zone as large as possible or protruding as far as possible into the substrate or metal foil. In the ideal case, the fusion zone is made the same size as the resolidification zone, so that it completely overlaps the resolidification zone and the resolidification zone itself remains unrecognized. In that case, the mutual adhesion is particularly good and at the same time the occurrence of cracks and cavities is minimized.

[0060] The second laser joining line can be achieved by realigning the same laser to the previous or similar joining position, i.e. the new laser focus overlaps with the already set or already close focus. The introduction of the second laser joining line into the first laser joining line, which is in particular still warm or hot, can also be achieved by using a double focus of the laser generator. For example, for this purpose, a beam splitter or a diffraction grating can be used or two laser generators can be used. Here, the second laser joining line is introduced into the still warm, in particular still molten, material of the joining partners.

[0061] Such an effect, i.e. the introduction of laser energy into still warm or even still molten material, can also be achieved, for example, if the laser generator has a burst function and thus multiple laser points can be introduced into the assembly in an overlapping and short temporal sequence. In other words, at the focus of the first laser joint line, a further focus is approached at a predefined time interval and / or a predefined spatial interval, or a second laser joint line is introduced. The second laser joint line can possibly further improve the connection and thus increase the holding force of the metal foil on the first substrate.

[0062] In the scope of the present invention, a hermetically sealed enclosure is also provided, in particular with a hermetically connected assembly as described in detail above. The hermetically sealed enclosure comprises a first substrate, which is formed at least in some areas and / or at least partially transparent to at least one wavelength range, and a metal foil, the metal foil being arranged to have a contact area adjacent to the contact area of ​​the first substrate. The metal foil is prepared to be flexible, so that irregularities in the contact area of ​​the first substrate can be flattened. Furthermore, a functional area is provided. The functional area may be arranged between the metal foil and the first substrate. The functional area may be arranged on the contact area of ​​the first substrate, for example surrounded by the metal foil.

[0063] The enclosure has at least one laser bond line or a number of bond points for directly and without mediation bonding the metal foil to the first substrate on or in the contact area, in particular around the periphery of the functional area for hermetically sealing the functional area, the laser bond line or the bond points penetrating into the first substrate on the one hand and into the metal foil on the other hand and bonding them directly to each other by melting.

[0064] In a hermetically sealed enclosure, the laser bond line of the enclosure may be designed to completely close the periphery of the functional area. Additionally or alternatively, the potential void at the laser bond line, i.e., the distance between the first substrate and the metal foil, may be consistently less than 0.75 μm, preferably less than 0.5 μm, and more preferably less than 0.2 μm.

[0065] The functional area of ​​the enclosure may have a hermetically sealed containment cavity for containing an electronic circuit, a sensor, a MEMS, etc. However, one or more contents may also be arranged in the area of ​​the metal member, if appropriate. The functional area may be an optical coating of the first substrate, a layer containing one or more light emitting diodes (LEDs), a polarizer.

[0066] The scope of the invention also includes a method for producing a hermetically sealed connection consisting of at least two parts, comprising the steps of providing a first substrate and a metal foil, pressing the metal foil against the first substrate to form a contact area between the metal foil and the first substrate, where the metal foil is in contact with the first substrate and the metal foil adheres to the projections and recesses of the contact area of ​​the first substrate by pressing and is permanently deformed, followed by hermetically connecting the metal foil and the first substrate to each other by directly bonding them to each other in the area of ​​at least one contact area, so that a fusion zone is formed which penetrates into the first substrate on the one hand and into the metal foil on the other hand, and which directly bonds them to each other by melting.

[0067] A contact area can be understood as a plane consisting of the opposing surfaces of the two components to be brought into contact. A contiguous contact area refers to a partial area of ​​the contact area where the gap between the two substrates is so small that it cannot be measured optically. Finally, within the meaning of the present invention, a good area is defined as one in which the gap between the substrates is sufficiently small or the two substrates are in actual contact, as will be described in more detail below. In general, the contact area is larger than or equal to the good area, and the good area is larger than or equal to the contiguous contact area. The first substrate as well as the metal foil can each have at least one contact area. A contact surface can be understood as a surface where contact between the first substrate and the metal foil takes place. If the metal foil is permanently deformed or is in close contact with the contact area of ​​the first substrate, the contact surface is also "deformed" accordingly, i.e. the contact area follows the overlapping contact structure.

[0068] In other words, the metal foil is first placed below or above the first substrate, thus e.g. stacked on top of each other, and gravity presses the upper, typically first, substrate onto the metal foil. Here, the up or down orientation is merely illustrative, since of course the components can be oriented in any way in space, and even a side-by-side assembly does not depart from the scope of protection. The two components are usually arranged with their larger extensions adjacent to each other.

[0069] In particular, no other materials or layers, such as, for example, adhesives or glass frits, are present or introduced between the first substrate and the metal foil. For technical reasons, slight gas inclusions or impurities, such as dust, may not be avoided. This may also be caused by irregularities, possibly even reaching the micro range, between the substrate layers or on the substrate layer surface. If the bonding zone or laser bonding line produced by the laser preferably provides a height HL of, for example, 4 to 25 μm, it is possible to close any gaps that may occur between the two substrates, so that the laser bonding line ensures an airtight seal.

[0070] The laser bonding line or lines can surround the functional area with a distance DF. The distance DF around the functional area can be constant, so that the laser bonding lines are arranged at approximately the same distance around the functional area on all sides. The distance DF can also be varied depending on the application, which may be advantageous in terms of production technology, for example, when joining several enclosures in one common work step, or when the functional area has a circular or any shape and the laser bonding lines are drawn in a straight line. If the cavity has optical properties and is formed in the shape of a lens, such as a focusing lens, the laser bonding lines can still be formed around the cavity, possibly at different distances from the cavity. One enclosure can also include several cavities.

[0071] The method may further include the step of testing the hermetic connection of at least two substrates by determining a spacing profile between the at least two substrates, and may include the step of determining a first bond quality index Q1 for testing the mechanical strength or hermeticity of the connection.

[0072] The first bonding quality index Q1 can be determined as Q1=1-(AG) / A, where A represents the area of ​​the contact area and G represents the good area. The good area G corresponds in particular to the area of ​​the intimate contact and can represent the part of the contact area where the gap between the constituent first substrate and the metal foil is less than 5 μm, preferably less than 1 μm, more preferably less than 0.5 μm and most preferably finally less than 0.2 μm. The bonding quality index Q1 can be 0.8 or more, preferably 0.9 or more and more preferably 0.95 or more.

[0073] The contact area may have an available area N, which may be used to calculate a first bond quality index Q1, where Q1 is determined as Q1=1-(NG) / N.

[0074] Within the scope of the method, for this purpose, it is possible to detect reflected radiation generated by illuminating the assembly so that it is incident on at least one contact area of ​​the assembly. In other words, the assembly is irradiated or illuminated in such a way that reflected radiation is generated from the incident radiation at the surface. Here, the reflected radiation may be a reflector of the incident radiation, which is reflected to some extent at one of the surfaces. In the case of two substrates with a further substrate arranged on the opposite side of the metal foil, for this purpose, three surfaces can be considered where such reflection may already occur. These are the top surface of the first substrate, the inner surface of the second substrate and the outer surface of the second substrate.

[0075] In other words, the first substrate has an outer surface facing the periphery and formed substantially planar or flat, or even flat. Adjacent to the flat outer surface, there is a peripheral narrow surface that is typically oriented perpendicular to the flat outer surface, for example configured to go around the periphery of the flat outer surface. In one example, the first substrate can be represented as a plate or a rectangular parallelepiped having two large surfaces (i.e., an outer surface and an inner surface) and four small surfaces arranged between the large surfaces, in particular perpendicular to the two large surfaces and adjacent to the large surfaces. The four small surfaces then together form a peripheral narrow surface, and the top surface forms the flat outer surface of the first substrate. Here, the top surface typically has a larger surface area than the sum of the small surfaces of the peripheral narrow surfaces. These indications regarding size and size ratios are equally applicable to other substrates.

[0076] This percentage is relatively low, since in the region where the substrate is in contact with the metal foil, no reflection or no reflection worth mentioning occurs on the inner surface. If there is a gap there, i.e. if the substrate is not in contact with the metal foil in this partial region, the incident light is reflected to some extent on all three surfaces respectively. In the case of multiple substrates, e.g. three, it may be necessary to take into account a correspondingly larger number of surfaces.

[0077] A first bond quality index Q1 of the contact area of ​​the assembly is determined from reflected radiation entering a measurement or observation device from the substrate stack. For example, the first bond quality index Q1 is determined before the first substrate is bonded to the metal foil. Further, a step of determining a second bond quality index Q2 of the contact area of ​​the hermetically sealed bonded connection may be included, in particular, Q2 is greater than Q1. In particular, Q2 / Q1 is greater than 1.001.

[0078] The reflected radiation preferably produces a pattern, in particular an interference pattern, more particularly produced from the superposition of the backscattered and incident radiation on at least one contact area of ​​the enclosure, whereby it is possible to design a measuring or observation device to recognise or detect the interference pattern and to calculate or derive therefrom the gap between the substrate and the metal foil.

[0079] The pattern from the reflected radiation can have an arrangement in which the pattern extends around one or more defects. In other words, the pattern can be arranged in particular around the places where the substrate is not in contact with the metal foil. In that case, it is particularly easy to identify the places where the substrate is not in contact with the metal foil with a measuring or observation device. Here, the defects can be characterized in that the spacing between these defects is greater than 5 μm, preferably greater than 2 μm, more preferably greater than 1 μm, greater than 0.5 μm or preferably greater than 0.2 μm. In other words, the defects are particularly preferably present exactly where the criteria for the good area G are not met. In this case, the contact area between the substrate and the metal foil can be completely divided into the good area G and the defects F.

[0080] The allocation of the corresponding regions can be determined, for example, by using an interference pattern in the form of Newton's rings. If the incident radiation is in the visible light range, e.g. λ=500 nm, then each Newton's ring exhibits a height difference of λ / 2=250 nm. If the occurrence of, for example, three Newton's rings is the limit criterion for determining whether a good region exists, then in the optical image analysis of the reflected radiation from the enclosure, a good region can be defined as one in which the gap between the substrate and the metal foil is less than or equal to 3λ / 2=750 nm.

[0081] The scope of the present invention also includes an enclosure manufactured using the above-described method.

[0082] The proposed enclosure is particularly suitable for use as a watch casing. Further fields of application relate in particular to devices for optical analysis, for example in endoscopy, optical access to sampling or reaction vessels and flow cells.

[0083] The invention will now be described in more detail with reference to the drawings based on embodiments, in which identical and similar elements are partly given the same reference symbols and in which the features of the various embodiments can be combined with one another. [Brief description of the drawings]

[0084] [Figure 1] FIG. 1 is a diagram showing a first embodiment of an airtight connection body. [Figure 1a] FIG. 2 is a partial detailed view of the bonding zone before laser bonding. [Figure 1b] FIG. 2 is a partial detailed view of the bond zone where the laser bond line has been introduced. [Diagram 2] 1 shows a top view of the gas-tight connection, which here is designed as an enclosure with functional areas. [Diagram 3] FIG. 2 is a side cross-sectional view of one embodiment of an airtight connection. [Figure 4] FIG. 2 is a side cross-sectional view of an airtight connection body to which a metal member is joined. [Diagram 5]FIG. 2 is a side cross-sectional view of an airtight connection body to which a metal member is joined. [Figure 6] FIG. 2 is a perspective view of an airtight connection having a window portion. [Figure 7] FIG. 2 is a cross-sectional side view of an airtight connection that is only partially covered with metal foil. [Figure 8a] 1 illustrates an embodiment of an enclosure. [Figure 8b] 13A-13C show further embodiments of an enclosure having lateral frames. [Figure 9a] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 9b] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 9c] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 9d] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 9e] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 9f] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 9g] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 9h] 1A-1C illustrate an embodiment of a process for manufacturing an airtight connection or enclosure. [Figure 10] 13A-13C show further embodiments of a gas tight connection with edge bonding. [Figure 11] FIG. 11 shows the embodiment of FIG. 10 with metal members bonded thereto. [Figure 11a] FIG. 11 shows a further embodiment of FIG. 10 with metal members bonded to the sides. [Figure 12] 13A and 13B show further embodiments of the gas-tight connection. [Figure 13] FIG. 1 shows a fiber rod welded to a flange. [Figure 14]FIG. 1 shows an airtight enclosure with a crystal member. [Figure 15] FIG. 1 illustrates the fabrication of multiple hermetic enclosures on a wafer.

[0085] Detailed Description of the Invention With reference to FIG. 1, a first embodiment of the gas-tight connection 1 according to the invention is illustrated, in which a dielectric 4 or a first substrate 4 is arranged on the entire surface of a metal foil 3. The dielectric 4 or the first substrate 4 is placed on the metal foil 3 in such a way that its inner surface 11 abuts on the inner surface 12 of the metal foil 3. The two joint partners 3, 4 are thus in contact with each other. Depending on the particular surface characteristics, the joint partners 3, 4 can be in contact with each other in an area-wise manner. If the surface of the first substrate 4 is rough, the joint partners 3, 4 may be in contact only partially or in some areas at first. If the joint partners 3, 4 are superimposed on each other, gravity already brings the joint partners 3, 4 into minimal contact. In this case, the metal foil 3 can be pressed against the inner surface 11 of the first substrate 4 and permanently deformed, thereby smoothing out any irregularities that may be present on the inner surface 11 of the first substrate 4.

[0086] In the example of FIG. 1, three laser joining lines 6a, 6b, 6c or bonding points 6a, 6b, 6c are introduced to join two joining partners 3, 4 together. The joining points / joining lines 6a, 6b, 6c are arranged along the sides of the joining partners 3, 4, and the joining points are introduced from above (in the drawing) by means of a laser 80 (see for example FIG. 9c). Here, the focal plane is preferably set below the area of ​​the inner surfaces 11, 12. Advantageously, the focal plane is arranged to be located within the metal foil 3, for example 10-20 μm into the metal foil 3, i.e. 10-20 μm below the inner surface 12 of the metal foil 3. This allows the laser beam 82 to achieve the desired width at the contact surface 15, preferably 4 μm±1 μm, more preferably 4 μm±2 μm, even more preferably 4 μm±3 μm. This width can also be achieved by suitable beam shaping in front of the lens.

[0087] In the case shown in FIG. 1, if the two joining partners 3, 4 are directly adjacent to each other with their inner surfaces 11, 12, i.e. in particular are in face-to-face contact, then the contact surface 15 is also the same as the two inner surfaces 11, 12, as shown in FIG. 1.

[0088] FIG. 1 further shows three laser joining lines 6a, 6b, 6c, which overlap each other so that they also interact with each other. Here, different effects can be induced or achieved depending on the purpose. For example, the laser joining lines cannot be set warm-in-warm, but the successive laser joining line 6b is introduced only after the previous laser joining line 6a has already cooled down. Since only a very small amount of heat energy is introduced here and the metallic material of the metal foil 3 mainly has a good thermal conductivity, the cooling process of the laser joining line takes place very quickly. The first laser joining line 6a already mixes the materials of the two joining partners 3, 4 and fills possible irregularities and gaps (voids) in a slightly molten state. Here, depending on the surface quality, if large voids, for example up to 5 μm, are present in the area of ​​the contact area 15 to be joined, the first laser joining line 6a may possibly only produce an insufficient bond. However, since the area of ​​the contact region 15 to be joined has been closed by the introduction of the first laser joining line 6a, and if any voids are present they are closed and the materials are already at least "mixed", the introduction of the second laser joining line 6b and possibly the third laser joining line 6c only makes it possible to bring about an optimal further fusion of the two materials of the joining partners 3, 4.

[0089] 1a shows a partial detailed view of the bonding zone before laser bonding. Since the metal foil 3 adheres to the first contact area 11 along its irregularities, the metal foil 3 may no longer have its original flat shape, but may have a curved or complex surface shape. The contact area 12 of the metal foil 3 can follow the geometrical definition of the contact area 11. This ensures that the metal foil 3 follows the contour of the first contact area 11 without exceeding the maximum gap of the contact surface 15 between the first substrate 4 and the metal foil 3.

[0090] FIG. 1b shows a detailed view of a part of FIG. 1a in which a laser joining line 6 has been introduced. The metal foil 3 is seamlessly attached to the contact area 11 of the first substrate along the irregularities of the contact area 11, so that the gap between the two contact areas 11, 12 can be kept small, so that the laser joining line 6 can also be introduced reliably at the intended position of the joining process. If the gap between the two contact areas 11, 12 is too wide, a reliable joining and therefore the gap cannot be filled or only an insufficient connection can be obtained. By using the metal foil 3, the gap between the joining partners 3, 4 remains small, and the introduction of the joining line 6 is guaranteed. The joining line 6 has a melting zone 62, in which the material of the first substrate 4 and the material of the metal foil 3 melt and mix with each other. Within the bond line 6, one (or more) bubbles 64 may occur, which typically (in the illustrated aspect, but also typically in practice) face the direction of the laser 80, which is emitted from above. A bulge 32 or arch may remain on the underside, which may be advantageous in some cases for the subsequent normal welding process with the metal part, acting like a weld rib.

[0091] FIG. 2 shows a top view of the gas-tight connection 1, in which the laser joining lines 6a, 6b, 6c surround the periphery of the functional area 2. For simplicity, only one laser joining line 6 is shown in the following figures, but in the respective embodiments several laser joining lines 6, 6a, 6b, 6c can also be used. In the embodiment of FIG. 2, the laser joining lines 6a, 6b, 6c completely surround the periphery of the functional area 2 in order to hermetically seal the functional area 2 all around. In principle, the hermetic sealing of the functional area 2 can already be achieved with a single laser joining line 6. The use of several laser joining lines 6, 6a, 6b, 6c increases the shear strength, and furthermore, the use of several laser joining lines 6, 6a, 6b, 6c can possibly ensure or improve the gas-tightness by redundancy.

[0092] For example, a gas leak test using, for example, helium as a leak gas can be applied to test or determine the airtightness of the enclosure or the airtight connection 1. The airtightness is particularly determined by a gas leak rate between the inside of the airtight connection 1 and the surroundings of 10 at a pressure difference of 1 bar. -7 mbar ls -1 Below 10, preferably -8 mbar ls -1 More preferably, 10 -9 ·ls -1 It is obtained if:

[0093] Here, the melt zone 62 around the laser bond lines 6a, 6b, 6c has a width W. In the functional area 2, a content 5, for example an electronic circuit, may be arranged (see for example FIG. 9g).

[0094] 3 shows a further embodiment of the gas-tight connection 1, which comprises a first substrate 4, which is typically transparent in the range of the laser wavelength used. The substrate 4 has a functional area 2a on its outer surface, which is for example an optical coating, such as an anti-reflection coating, a layer containing a light-emitting element, in particular a layer containing a light-emitting diode, a polarizer, or even a layer with electrical or electronic functions.

[0095] A functional layer 2 is applied to the inner surface 11 of the first substrate 4. The functional area or layer 2, 2a can be applied to the first substrate as a coating or can be placed or glued thereon. It may be advantageous if the functional layer or layer 2 can be irradiated with a laser joining line 6. In that case, the functional area can be applied, for example, to the entire surface of the inner surface 11 of the first substrate 4, but still be able to carry out the laser joining process. This is the case in the embodiment of FIG. 3, in which the entire functional layer 2 is shown, the laser joining line running along the outer side of the substrate 4 and forming a closed line (see FIG. 2). In order to make the illustration less complicated, a not very high resolution has been chosen. In this respect, in all the embodiments, implicit reference is made to FIG. 1a and FIG. 1b, which show the corresponding details, and thus also the important advantage of the use of a metal foil is taken over, namely that the metal foil can follow all the contours of the inner surface 11 of the first substrate 4.

[0096] With reference to FIG. 4, an airtight connection 1 is shown, where the underside 14 of the metal foil has a clearly uneven or rough shape for the sake of clarity. The metal member 44 can also have a rough shape, since there is no need for a flat or polished surface. This is a considerable advantage over previous tests, where a direct contact between the metal member 44 and the substrate 4 had to be established. By equivalently using the metal foil 3 as an intermediate between the metal member 44 and the substrate 4, the manufacturing costs can be significantly reduced while at the same time a strong, load-bearing and / or airtight connection can be achieved.

[0097] FIG. 5 shows the embodiment of FIG. 3, where the metal element 44 is attached in a conventional manner, i.e. by introducing a joining seam 42. Due to the metal content of the metal foil 3, in this case a metal-to-metal connection is made, so that conventional joining processes, such as in particular welding, can be used. A particular advantage here is that the demands of conventional joining processes, for example in terms of surface quality or surface finish, are lower than those of laser joining. It may therefore not be necessary to process or polish the underside of the metal foil 3 facing away from the substrate and / or the contact area 18 of the metal body 44. The intermediate step of applying the metal foil 3 thus significantly simplifies all further process steps, if at all. This is because the metal foil 3 first serves to fill critical gaps at the contact surface 15, and then the metal element can finally be connected to the metal foil 3 at its contact area 18 using conventional joining processes, such as in particular metal welding, in which case rather large gaps can be filled and a stable and reliable connection can be produced, even if the inner surface 18 of the metal element 44 or plastic element 44a of various sizes is rough or uneven, in that it is possible. It is therefore not a problem if the metal foil 3 possibly also has irregularities on its outer surface, for example, which pick up irregularities formed on the inner surface 12 of the metal foil 3, since conventional metal welding processes are more tolerant or robust to roughness or irregularities.

[0098] 6, one embodiment of the airtight connection body 1 is shown, in which the metal foil 3 is disposed in an annular portion surrounding the outside of the base material 4, and a window portion remains in the central region of the base material 4 where the metal foil 3 is not disposed. In other words, the metal foil 3 is disposed only in a partial region on the base material 4.

[0099] 7 shows a cross section of such an embodiment in which the metal foil 3 is only arranged in a partial area, the metal foil 3 being joined to the substrate 4 by a laser joining line 6. Corresponding to the partial arrangement of the metal foil 3, an arrangement of some sections of the metal foil may be provided, for example for providing an electrical contact on the substrate 4. Such contact in the partial section by application of the metal foil 3 may, for example, have at least the size of the laser joining point. The width W of the metal foil 3 ccan typically correspond to 1.5 times or more the width W of the laser joining line 6. In other words, the metal foil can have a relatively small extension, for example 50 μm, 100 μm or more, 200 μm or more or even several hundred μm. In order to hermetically join the substrate 4 to the metal foil 3 resulting in an inseparable connection, the laser joining lines 6, 6a, 6b, 6c are typically introduced in a completely hermetic manner. The invention also deals with the consistent further development of different parameters or joining processes between the objects to be joined 3, 4 on the background of known joining processes already established in-house by the applicant. Here, within the scope of the invention, one focus is on the connection of the substrate 4 via the joining partner of the metal foil 3 and the freely designable metal member 42. Here, the substrate 4 is usually provided as a dielectric, in particular glass, glass ceramic, sapphire, etc. For example, the hermetic assembly 1 is provided as a watch glass for a smart watch. In this case, the significantly different CTE values ​​and possibly different brittleness etc. of the various materials involved in the joining process must be taken into account. In particular, it has been found that the gap remaining between the substrate 4 and the first joining partner of the metal foil 3 can be critical and that this gap should be kept as narrow as possible in the entire area of ​​the introduced laser joining line 6. Such possible, possibly undesirable gaps in the area of ​​the laser joining point of the formed laser joining line 6 are advantageously designed to be as narrow as possible, at least initially so narrow that a plasma can be ignited at the laser joining point upon exiting the laser. Plasma ignition is a prerequisite for being able to apply a sufficient spot-like heat quantity along the laser joining line 6 with the laser 80. For this purpose, it is also advantageous to be able to confine the resolidification zone as far as possible to the area of ​​the laser joining line 6. It has now been found that, within the scope of the present invention, the advantageous use of a metal foil 3 can further narrow the gap or can be made sufficiently narrow continuously over the extension of the planned laser joining line 6, which can help to reduce undesirable optical disturbances and / or cracks or pores that affect the mechanical stability.This allows to provide further improved products, which are desired or required, especially in very high quality products. Examples of this are the aforementioned smart watches, but also in some embodiments in aerospace and medical technology applications. In that case, the material of the substrate 4 can be fused with the material of the metal foil 3 in the fusion zone 62, which is the case when both are mixed in the molten state at the same time. For example, already by fusion in the fusion zone 64, sufficient adhesion and thus sufficient holding power of the connection 1 can be generated. For example, it may be desirable to leave a gap at the contact surface 15, which is continuously 0.5 μm or less in the area of ​​the introduced laser joint line 6, due to the permanent deformation of the metal foil 3 and the adhesion of the substrate 4 to the contact area 11. For example, when the laser 82 is projected on the laser joint line 6, dendrites and / or droplets can be formed in the fused area of ​​the material, which provides or improves the interlocking between the substrate 4 and the metal foil 3. Here, the droplets are projected into the respective other joint partner material, and the dendrites act as anchors or pegs from the respective joint partner material into the respective other joint partner material.

[0100] The metal foil 3 is brought into close contact with the contact area 11, which allows the metal foil 3 to be at an ideal distance from the contact area 11 of the substrate 4, thereby allowing an ideal size of the gap between the contact area 11 and the contact area 12. In this case, it is advantageous if this ideal size is not zero, but is maintained at a very short distance, since this allows forming or providing an avoidance zone into which the material of the joining partners 3, 4 can escape if it is in the molten liquid state during the introduction of the laser joining line 6. In this way, cracks or cavities in the joining partners 3, 4 can possibly be reduced. This also applies if the metal foil 3 is arranged on the substrate 4 only in some areas or in some sections, since in this case a gap area is automatically formed into which the molten material can flow during the joining process. In this case, the gap between the contact areas 11, 12 can be completely omitted and a perfect contact of the metal foil 3 with the substrate 4 can be set up.

[0101] With reference to FIG. 8a, an airtight enclosure 9 is shown, in which a first substrate 4 is first joined to a metal foil 3 by a laser joining line 6. A functional area 2 is arranged on the entire underside of the substrate 4, and the laser joining line 3 penetrates the functional area 2. Nevertheless, a completely continuous part of the functional area 2 is arranged in an internal area 50, which forms the upper surface of a cavity 50. A layer 2, which contains, for example, LEDs, can be provided here, for example to form a display surface of a smartwatch. A joining seam 42 is applied to the metal foil 3 by conventional metal welding, by means of which a metal element 44 is attached and is connected firmly and airtight to the assembly 1.

[0102] FIG. 8b shows a further embodiment of the enclosure 9, with which the cavity 50 is hermetically sealed. The assembly 1 comprises a substrate 4 and a metal foil 3 joined to the substrate 4 by a laser joining line 6. The metal foil 3 is inseparably connected to the metal element 44 by a joining seam 42. The metal element 44 surrounds the assembly 1, so that the substrate 4 is also protected and held in an improved manner on its sides. Thus, the corners 46 of the substrate stack are also held laterally by the metal element 44. Here, the laser joining seam 6 and the joining seam 42 can in principle overlap and also be fused together, since metal material is present over the entire fusion zones 62, 64 (see FIG. 1b) and therefore metal welding can also take place there. Thus, both directly and by the laser joining line 6, the substrate 4 can be used to be joined to the metal element 44 by conventional joining processes. In other words, a continuous fusion weld is formed from the substrate 4 through the metal foil 3 to the metal element 44.

[0103] With reference to Figures 9a to 9h the production of the gas-tight connection 1 or enclosure 9 is explained in individual steps. In the step shown in Figure 9a a functional layer 2 is applied to the inner surface 11 of the substrate 4 by thermal spraying or sputtering. The layer 2 may be an optically active layer or a layer with electrical or electronic properties and may for example comprise a light emitting diode (LED).

[0104] In Fig. 9b, the metal foil 3 is arranged in the region of the contact surface 15 of the inner surface 11 of the substrate 4. In this case, the metal foil 3 is arranged only in a partial area on the substrate 4, i.e. only in the area surrounding the outside. The step shown in Fig. 9c shows the introduction of a laser joining line 6 for gas-tight connection of the metal foil 3 to the substrate 4 by means of a focused laser beam 82 delivered by a laser generator 80. For example, the gas-tight assembly 1 is moved relative to the laser generator 80 on a movable table below the laser generator 80 to form a laser joining seam in the gas-tight connection 1.

[0105] The process shown in Fig. 9d produces a finished laser bond line 6, forming an edge 74 which is post-processed, for example by edge grinding or milling processes. Optionally, the process shown in Fig. 9e can also involve abrasive grinding 72 of the outer surface of the first substrate 4 or the application of a further functional layer 2a (Fig. 9e), for example a coating or an optical coating, to the outer surface of the substrate 4.

[0106] FIG. 9f additionally illustrates the hermetic assembly around a functional layer 52, which for example comprises an LED.

[0107] With reference to Fig. 9g, the arrangement of the gas-tight assembly 1 on the metal member 44 is shown. In the formed cavity 50, the content 5 is arranged. The content 5 may be a power source such as a battery or an accumulator, a computing device, an electronic component, etc. The metal foil 3 is arranged adjacent to the protruding portion 45 of the metal member 44, such that the metal foil 3 is at least partially in contact with the protruding portion 45. This ensures electrical conductivity between the metal foil 3 and the metal member 44, which provides a prerequisite for carrying out a metal welding process.

[0108] 9h, there is shown the introduced metal bonding seam 42, by which the gas-tight assembly 1 is inseparably connected to the metal member 44. Overall, the cavity 50 is now hermetically sealed from the outside and is therefore hermetically sealed.

[0109] With reference to FIG. 10, an alternative arrangement of the metal foil 3 is presented, which has a vertical section 3a, and if the focused laser beam 82 is introduced sufficiently close to the peripheral region of the substrate 4, then fusion welding can be introduced at the laser joint line 6 not only in the horizontal plane but also in some sections of the vertical region. In this case, it is particularly advantageous that the metal foil 3, 3a is not so close to the peripheral region of the substrate, since it is usually not possible to work, since not enough substrate material 4 remains to the side of the laser joint zone to achieve a stress-free or reliable joint result. The laser is deflected by the side edges of the substrate 4, and not enough energy reaches the focus to be able to realize the laser joint 6. However, by shading or surrounding the side edges of the substrate 4 with the metal foil 3, 3a, the laser joint seam 6 can be obviously introduced further to the periphery of the substrate 4, so that, overall, more area for the target region can be left between the laser joint seams 6 and at the same time the possibly unattractive outer peripheral edge of the laser joint seam 6 can be further reduced. This configuration can be very attractive, especially for smart watches. In some cases, it is also possible to make the modified metal joint seam 42a even smaller and thus reduce the unattractive peripheral area even further (see Figs. 11 and 11a). In this case, the metal member 44 can also provide a frame or enclosure for the airtight assembly 1, since the lateral joints can also be extended to the lateral peripheral areas using conventional joining processes.

[0110] Figures 11 and 11a show corresponding possible assemblies or configurations which can be combined with one another to produce a metal bond between the metal foils 3, 3a and the metal member 44, thus still further improving the substrate-metal bond.

[0111] Finally, referring to Fig. 12, an embodiment of the gas-tight assembly 1 is further illustrated, which shows a ridge or weld rib 32 on the underside of the laser joint line 6, which allows a reliable contact and thus a reliable conductive connection to be established and simplifies the introduction of the metal joint line 42, 42a by a subsequent metal joining process, thereby improving the conductive connection with the metal part 44 attached thereto. In some cases, the weld rib 32 can remain when the laser joint line is introduced, for example by the molten material forming the weld rib itself, or by the metal foil 3, 3a forming pleats in the area of ​​the laser joint line, which remain on the underside after the laser joining process. In some cases, the metal foil 3, 3a can be preconditioned or prepared in advance so that it is provided with the weld rib 32 on its underside from the beginning, thereby simplifying the subsequent metal joining process.

[0112] A plastic member (44a) may be attached in place of the metal member 44 and the enclosure 9 may be formed using conventional bonding processes between the metal foil 3, 3a and the plastic member.

[0113] It is also conceivable to use a fibre composite element instead of the metal element 44, which is connected in a conventional manner to the metal foil 3. Other possible materials for the attachment element are Teflon or PEEK.

[0114] In this way, by using an intermediate foil, i.e. a metal foil, a material connection to a plurality of components, particularly preferably metal components 44 or plastic components 44a or components made of fiber composites, can be established.

[0115] Finally, if only one laser bond line 6, 6a, 6b, 6c or bonding point is introduced, the width W of the laser bond line is equal to the beam width 2w on the contact area 15 generated by the laser generator (see FIG. 10). レーザIt should be noted that for N parallelly arranged laser bonding lines 6, 6a, 6b, 6c, the aim is, for example, to achieve an overlap of the laser action areas, so that the width W of the laser bonding line achieved is usually less than the beam width 2w on the contact area 15. レーザ H m represents the height of the fusion zone 62, and H r represents the height of the resolidification region. Ideally, H m is H r That's all.

[0116] FIG. 13 shows a flange 102, which is adapted for connection to, for example, a reaction vessel. It is envisaged to allow optical access and to connect an optical measuring instrument, such as a spectrometer, in order to carry out an optical test of the medium contained in the reaction vessel. Here, an adapter 104 is provided for connection to the spectrometer and the measuring head of the spectrometer, which adapter 104 is connected to the flange 102, for example by welding. For optical access, a bore 103 is arranged in the flange 102, into which a fiber rod 100 is introduced. Here, the fiber rod 100 serves as a light guide for directing light into the reaction vessel and out again from the reaction vessel. For a hermetically sealed connection between the light guide 100 and the flange 102, it is envisaged to weld the components together.

[0117] As shown in the enlarged partial view of Fig. 13, in this respect a metal foil 6 is arranged in the region of one end of the fiber rod 100 and is connected to the fiber rod 100 as the first substrate 4 by means of a laser weld or laser bonding line 6. Here, as shown in Fig. 13, the metal foil 3 preferably has a vertical portion 3a, which is provided to connect to the wall of the bore 103. The fiber rod 100 is then introduced into the bore 103 and is connected, for example by welding, to a flange 102, which is the metal member 44, via the metal foil 3 fixed to the fiber rod 100.

[0118] 14 and 15 respectively show an airtight enclosure 9 in which a substrate stack 1 is connected to a crystal element 106. In the embodiment shown in FIG. 14 and FIG. 15, the substrate stack 1 is formed from a first substrate 4 and a further substrate 4'. Here, the further substrate 4' forms the lid or bottom of the enclosure 9. The first substrate 4 forms the side walls of the enclosure 9. To join the first substrate 4 and the crystal element 106, a metal foil 3 is arranged on the end face of the first substrate 4 as described above and here is connected, for example, by a laser bonding wire 6. The crystal element 106 can then be arranged on the substrate stack 1 or vice versa and the enclosure 9 can be closed by a welded connection.

[0119] FIG. 15 shows a method for producing a number of enclosures 9 by processing the entire wafer, as already explained with reference to FIG. 14. For this purpose, a substrate stack 1 is formed by connecting a first substrate 4 formed as a spacer wafer to a further substrate 4′. Here, the spacer wafer comprises a recess or cavity for each enclosure 9 to be formed. Here, both the first substrate 4 and the spacer wafer can be made of semimetallic material, for example silicon or germanium, or made of glass, and can be hermetically joined to each other directly, i.e. without metal foil 3, by a laser bonding process. Then, the metal foils 3 punched for the individual recesses that will later form the interior of the enclosure 9 are placed on the substrate stack 1 and connected by laser bonding lines 6 or individual bonding points. Then, as illustrated in FIG. 15, individual disks, for example designed as crystal elements 106, are placed and welded to the metal foil 3. It is of course also possible to place and join the entire wafer as crystal elements 106. The formed enclosures 9 are then individually separated by separation of the substrate stack 1 along dicing lines 108.

[0120] Thus, it has been possible with this description to show in a complete and understandable way how two different joining partners can be joined together by a laser joining process, namely by using metal foils which allow even better control of the remaining gap dimensions or even increase the interfacial contact area and thus improve the quality of the laser joining line 6, 6a, 6b, 6c. The corresponding gas-tight connection has also been described in detail and reproducibly. The description contains many statements which may contradict "conventional" knowledge or which could be found unexpectedly. In this respect too, the invention represents a further development of the German patent application DE102020129380.1 (unpublished at the time of filing), the entire content of which is incorporated herein by reference and is incorporated in its entirety into the present application.

[0121] The above-described embodiments should be understood as illustrative, and the present invention is not limited thereto. It is obvious to those skilled in the art that various modifications may be made without departing from the scope of protection of the claims. Moreover, it is also clear that each feature individually defines a substantial component of the present invention, even if it is described together with other features, whether or not they are disclosed in the specification, claims, drawings, etc. Since the same reference signs in all drawings indicate the same features, the description of a feature that is only mentioned in one drawing, or at least not in all drawings, can be transferred to the drawings in which the feature is not described in the specification. [Explanation of symbols]

[0122] 1 Connector or substrate stack 2,2a Functional area 3 Metal foil 3a Permanent deformation of metal foil 4 First substrate (e.g., a dielectric material, e.g., glass) 4' Further substrates 5. Contents 6,6a,6b,6c Bonding zone or laser bonding line 9 Enclosure 10 Window 11 Contact area or inner surface of first substrate 12 Contact area or inner surface of metal foil 14 Underside of metal foil 15 Contact areas between mating partners 18 Contact area of ​​metal parts 32 Raised or welded ribs 42 Conventional or Metallic Bonding Wires 44 Metallic parts 44a Plastic parts 45 Protruding parts of metal parts 46 Corner of substrate stack 50 Cavity or internal space 52 Functional elements, e.g. LED layer 62 Melt or Fusion Zone 64 "Bubble" 70 Application means, e.g. sputter nozzle 72 Polishing means 74 Post-treated edge of first substrate 4 80 Laser Generator 82 Focused Laser Beam W: width of laser welded lines 6, 6a, 6b, 6c 100 Fiber Rod 102 Flange 103 Boa 104 Adapter 106 Crystal Materials 108 Dicing Line

Claims

1. An airtight connection assembly (1), comprising: a first substrate (4) that is made transparent in at least some areas and / or at least partially to at least one wavelength range; A metal foil (3), a metal foil (3), the metal foil being arranged to have a contact area (12) adjacent to a contact area (11) of the first substrate; at least one laser bond line (6, 6a, 6b, 6c) or a plurality of bond points for directly and without mediation bonding the metal foil to the first substrate on or in the contact area, the laser bond line or the plurality of bond points penetrate into the first substrate on the one hand and into the metal foil on the other hand, and are directly bonded to each other by melting; Equipped with The metal foil is prepared to have flexibility, thereby enabling the metal foil to be tightly attached to the contact area of ​​the first substrate.

2. the metal foil (3) is arranged along the peripheral edge region of the first substrate (4), and / or the metal foil (3) partially or only partially covers the contact area (11) of the first substrate (4), and / or 2. The gas-tight connection assembly (1) according to claim 1, wherein the metal foil (3) forms one or more contact points on the contact area (11) of the first substrate (4).

3. the metal foil (3) is inflexible in the joining area including the laser joining line (6, 6a, 6b, 6c) due to its adhesion to the first substrate (4) after the introduction of the laser joining line by the joining process; and / or 2. The gas-tight connection assembly (1) according to claim 1, wherein the metal foil (3) remains flexible outside the joining area including the laser joining lines (6, 6a, 6b, 6c) even after the introduction of the laser joining lines.

4. the presence of a fusion zone (62, 64) at the laser bond line (6, 6a, 6b, 6c) or at the bonding points, in which the material of the metal foil (3) and the material of the first substrate (4) are intermixed; and / or In the fusion zone (62, 64), the metal material of the metal foil (3) penetrates into the first substrate (4), and / or 2. The gas-tight connection assembly (1) of claim 1, wherein in the fusion zones (62, 64) the material of the first substrate (4) penetrates into the metal foil (3).

5. the fusion zones (62, 64) have a height measured in a direction perpendicular to the contact surface (15); and the fusion zone preferably has a height of at least 1 μm, preferably 2 μm or more, more preferably 5 μm or more; and / or The gas-tight connection assembly (1) of claim 1, wherein the fusion zone extends into the first substrate (4) by 1 μm or more.

6. the metal foil (3) has a thickness of 500 μm or less, preferably 250 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, and / or 2. The gas-tight connection assembly (1) according to claim 1, wherein the metal foil (3) has a thickness of 10 μm or more, preferably 20 μm or more, more preferably 50 μm or more.

7. 2. The airtight connection assembly (1) according to claim 1, wherein the metal foil (3) is permanently deformed by being pressed against the first substrate, so that the metal foil (3) adheres closely to the irregularities of the contact area (11) of the first substrate (4).

8. 2. The gas-tight connection assembly (1) according to claim 1, wherein the metal foil (3) has a welding rib (32) on its underside opposite the contact area (12).

9. The airtight connection assembly (1) further comprising a metal element (44) which is inseparably connected, in particular bonded, to said metal foil (3); and / or further comprising a plastic element (44a), said plastic element being inseparably connected, in particular bonded, to said metal foil (3); and / or 2. The gas-tight connection assembly (1) according to claim 1, further comprising a crystal element (106), said crystal element (106) being inseparably connected, in particular bonded, to said metal foil (3).

10. 10. The gas-tight connection assembly (1) according to claim 9, wherein the metal element (44), the crystal element (106) or the plastic element (44a) is material-connected to the metal foil (3) by a conventional joining process, i.e. by means of heat and / or pressure, with or without a welding filler, in particular by molten metal welding, such as arc welding.

11. The metal foil (3) has a vertical portion (3a), At the laser joining line (6), fusion welding is introduced not only on horizontal surfaces but also in some sections of vertical areas, or 10. The airtight connection assembly (1) of claim 9, wherein the metal member (44) provides a frame or enclosure for the airtight assembly (1) by extending the lateral joints by a conventional joining process to the lateral peripheral areas.

12. The contact area (11) of the first substrate (4) has at least one adjacent contact area, and the first substrate is in surface contact with the metal foil (3) in the adjacent contact area; the interfacial contact area has an average gap between the first substrate and the metal foil of, in particular, 1 μm or less, preferably 0.5 μm or less, more preferably 0.2 μm or less; and / or 2. The gas-tight connection assembly (1) according to claim 1, wherein the abutting contact area coincides in particular with the contact surface (15).

13. the metal foil (3) is made of a metal material, in particular an aluminum foil, and / or 2. The gas-tight connection assembly (1) of claim 1, wherein the metal foil (3) comprises a metal within the meaning of the definition of the periodic table.

14. the metal foil (3) comprises or consists of at least one of molybdenum, tungsten, silicon, aluminum, platinum, silver or gold; and / or 2. The gas-tight connection assembly (1) according to claim 1, wherein the metal foil (3) comprises an alloy, in particular comprising or consisting of at least one of carbon, copper, manganese, chromium, magnesium, cobalt, nickel, tin, zinc, niobium, palladium, rhenium, indium, tantalum, titanium or iridium.

15. The first substrate (4) is a transparent substrate, said first substrate (4) is a fiber plate or a fiber rod; and / or The first substrate (4) is made of the following material: glass, glass ceramic, silicon, germanium, sapphire or combinations thereof; Ceramic materials, in particular oxide ceramic materials, Crystals, especially crystalline quartz, yttrium oxide (Y ２ O ３ ), zirconium oxide (ZrO ２ ), aluminum oxide (Al ２ O ３ ), yttrium-doped zirconium oxide, yttrium-doped aluminum oxide, lanthanum-doped yttrium oxide, aluminum-doped aluminum nitride and magnesium-doped aluminum oxide, Quartz glass, borosilicate glass, aluminosilicate glass, glass ceramics such as Zerodur, Ceran or Robax, optoceramics such as aluminium oxide, spinel, pyrochlore or aluminium oxynitride, calcium fluoride crystals or chalcogenide glasses.

2. The gas-tight connection assembly (1) according to claim 1, comprising or consisting of at least one of:

16. A hermetically sealed enclosure (9) comprising a hermetic connection assembly (1) according to any one of claims 1 to 15, said hermetically sealed enclosure (9) comprising: a first substrate (4) that is made transparent in at least some areas and / or at least partially to at least one wavelength range; A metal foil (3), the metal foil is arranged to have a contact area (12) adjacent to a contact area (11) of the first substrate; A metal foil (3), which is prepared to have flexibility so that it can flatten unevenness in the contact area of ​​the first substrate; At least one functional area (2, 2a), at least one laser bonding line (6, 6a, 6b, 6c) or a plurality of bonding points, present around the functional area, for directly and without intermediary bonding the metal foil to the first substrate on or in the contact area, in particular for hermetically sealing the functional area, the laser bond line or the plurality of bond points penetrate into the first substrate on the one hand and into the metal foil on the other hand, and are directly bonded to each other by melting; A hermetically sealed enclosure (9).

17. 17. The hermetically sealed enclosure (9) according to claim 16, wherein the functional area (2, 2a) is an optical coating of the first substrate (4), a layer including one or more light emitting diodes (LEDs), a polarizer, or a hermetically sealed accommodating cavity for accommodating an electronic circuit, a sensor, a MEMS, or the like.

18. A method for manufacturing a hermetically sealed connection (1) consisting of at least two parts, said method comprising: Providing a first substrate (4) and a metal foil (3); pressing the metal foil against the first substrate to form a contact surface (15) between the metal foil and the first substrate, in which the metal foil is in contact with the first substrate at least partially or in a partial area; the metal foil is pressed against the first base material to adhere closely to the irregularities in the contact area, the first substrate comprises a transparent material; hermetically connecting said metal foil and said first substrate to each other by directly bonding them to each other in the region of said at least one contact area, so that fusion zones (62, 64) are formed which penetrate into said first substrate on the one hand and into said metal foil on the other hand, said fusion zones (62, 64) directly bonding them to each other by melting; A method comprising:

19. After the hermetically sealed connection, a metal member (44) is placed on the connection body; Joining the metal member to the connector using heat and / or pressure, with or without a weld filler material.

20. The method of claim 18, further comprising:

20. The metal foil (3) has a vertical portion (3a), Introduce fusion welding at the laser joining line (6) not only in horizontal planes but also in some sections of vertical areas, or 19. The method according to claim 18, wherein the metal member (44) provides a frame or enclosure for the gas-tight assembly (1) by extending the lateral joints by conventional joining processes to the lateral peripheral areas.

21. testing the gas-tight connection (1) by determining the spacing profile between the at least two joining partners (3, 4), and / or A first joint quality index Q for testing the mechanical strength and / or airtightness of the connection body (1) １ The process of determining 20. The method of claim 18, further comprising:

22. An enclosure (9) or gas-tight connection assembly (1) manufactured by the method of claim 18.

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