Glass composite device

Abstract

The present invention shows a substrate stack and an enclosure having at least one base substrate and a cover substrate that form at least a portion of the enclosure. Functional zones can be arranged so as to be circumferentially enclosed within the enclosure. At least the cover substrate preferably comprises glass or a glass-like material. The base substrate and the cover substrate are hermetically welded together by at least one laser weld line, the laser weld line having a height HL perpendicular to the joining surface, reducing mechanical stresses within the at least one laser weld line and thereby improving the mechanical stability of the enclosure.

Description

Technical Field

[0001] The present invention relates to a glass composite device, for example, a glass composite device for providing a hermetically sealed compartment in at least two layers of the glass composite device, and a manufacturing process for manufacturing the glass composite device.

[0002] Background and Summary of the Invention Glass and glassy enclosures can be used, for example, to protect electronic devices, circuits or sensors. For example, hermetically sealed embodiments of the aforementioned enclosures can be used for treating heart disease or for medical implants in, for example, the retina or any form of bioprocessor. A bioprocessor made of titanium is well known.

[0003] Sensors can be protected by the present invention, for example, for use in particularly harsh climatic conditions. Another example is Micro-Electro-Mechanic-Systems (MEMS), pressure sensors, blood gas sensors, and sugar measuring devices such as blood glucose meters.

[0004] Another field of use of the present invention can be found in the fields of mobile phones, protective sleeves for wearable devices, virtual reality and augmented reality goggles, and headsets and similar devices. For example, the present invention can also be used in the range of electric vehicles, in aviation and space environments, in high-temperature environments, and in the field of micro-optics.

[0005] All of the aforementioned applications are related to some form of electronic device that faces harsh environmental conditions and thus must be particularly robust or protected from these conditions. Thus, for example, the present invention can be used to protect devices such as electronic devices in order to enable the use of any electronic device that can be manufactured relatively inexpensively but is expected not to withstand the aforementioned environmental conditions, or the use of any electronic device where no robust electronic device that can withstand said conditions exists.

[0006] Furthermore, the present invention enables a certain degree of exchange or communication means between the device according to the present invention, for example, the internal region of an enclosure, or a cavity arranged within the enclosure. This exchange or communication means can be realized, for example, by electromagnetic radiation in the range of visible light and / or in the range of microwave radiation. To achieve this, the enclosure is transparent at least partially and / or over at least a plurality of wavelength ranges. This transparency enables a plurality of communication methods, any kind of data or energy transmission, as well as measurements by electronic devices or sensors arranged within the cavity. In particular, optical communication methods or optical data or energy transmission are possible.

[0007] However, providing a cavity in the enclosure is only one embodiment of the possible uses of the present invention. As will be understood hereinafter, the present invention is not limited to a cavity and can also be used to improve an enclosure having a cavity. In fact, the present invention can be implemented exactly in a substrate stack.

[0008] Primarily, it is known to arrange several components or layers such that components can be located in the inner region. For example, European Patent No. 3012059 shows a method for manufacturing a transparent component for protecting an optical component. A new laser welding method is used therein.

[0009] The present invention may be found in proximity to an improvement in the reliability and / or robustness of a substrate stack and / or an enclosure with respect to environmental conditions.

[0010] The object of the present invention is to enhance the mechanical stability of a substrate stack and / or an enclosure.

[0011] The object of the present invention is achieved by the subject matter of the independent claims. Preferred embodiments of the present invention are described in the dependent claims.

[0012] Based on the present invention, the hermetically sealed enclosure has at least one base substrate and a cover substrate that form at least part of the enclosure. A functional zone is arranged to be surrounded circumferentially within the enclosure, for example, surrounded by the base substrate and the cover substrate. The substrate may consist of various materials ranging from homogeneous ones such as glass or single crystal silicon wafers to more complex substrates such as chemically strengthened glass coated with a multilayer optical coating.

[0013] At least the cover substrate of the enclosure preferably comprises a glass or glass-like material, for example, a glass ceramic or a crystalline material. Further, a silicone-based substrate as the base and / or cover substrate can also be used in combination with a glass or glass-based substrate. The base substrate and the cover substrate are hermetically welded by at least one laser weld line. The laser weld line is typically obtained by irradiating the material with a short pulse laser beam having a predetermined wavelength and energy from a laser source such that a series of beam spots are arranged within the material of the enclosure at each laser focus set by the laser source.

[0014] To do this, the laser source can be set such that, for example, the sum of the cumulative thermal energies applied to several adjacent beam spots is an amount sufficient to melt the material within the melting zone. This can be achieved, for example, when several beam spots overlap each other, whereby thermal energy is continuously accumulated along the laser weld line and a limited area of the melting zone is sufficiently heated, resulting in melting of the material within the melting zone.

[0015] At the same time, heat dissipation from the laser welding line into the substrate stack (enclosure) during the welding process can be critical. For example, if several electrical or electronic devices or components are arranged within the functional zone (cavity) of the enclosure, they must be protected from overheating beyond a predetermined threshold and / or any heat transfer into the device or component. For this purpose, advantageously, during the formation of one laser welding line, the thermal energy introduced at one time is limited so that the substrate stack (enclosure) as a whole is not kept at a higher temperature level.

[0016] Based on the process shown herein, in the first operation process, a first laser welding line is formed, where only a limited amount of energy just sufficient to locally melt the material within the melting zone of each laser spot is introduced into the material. This thermal energy dissipates into the rest of the substrate stack (enclosure), but is extremely low, so that even near the laser welding line, the temperature rise is sufficiently low. After the formation of the first laser welding line, the substrate stack (enclosure) may be given sufficient cooling time and / or this heat can dissipate across the substrate stack (enclosure), so that little or no heat accumulation remains in the laser welding line.

[0017] Thereafter, optionally, after the cooling period between each step of forming two laser welding lines, a second laser welding line is formed. Also in this case, the thermal energy introduced by the second (or any successive) laser welding line is spatially limited to the welding line itself, where the heat dissipates into the substrate stack (enclosure), but does not promote a significant temperature rise in the remaining material and / or any object / device arranged within the functional zone (cavity).

[0018] Therefore, placing two laser weld lines in close proximity to each other, or even overlapping them, does not cause heat to accumulate, or at least accumulate in a critical amount, within the substrate stack (enclosure), and thus the device / component is protected from overheating.

[0019] For example, if only the substrate stack (enclosure), or rather only the area of the laser weld line, is preheated before the formation of the laser weld line, and / or if additional heat needs to be significantly introduced into the substrate stack (enclosure) after the formation of the laser weld line to slow down the cooling of the laser weld line, a critical amount of thermal energy may be introduced into the substrate stack (enclosure), and any device / component installed within the functional zone (cavity) may be damaged. Therefore, the method shown herein is advantageous even when attempting to attach any device / component in the vicinity of any laser weld line, but also enables a significant reduction or removal of stress within the substrate stack (enclosure) in this case.

[0020] As already outlined, by arranging a plurality of beam spots in proximity to each other within the same process step such that the resulting non-linear absorption zones at least contact or, rather, overlap with adjacent non-linear absorption zones of the same laser welding line, limited heat accumulation can be generated within the area to be welded, resulting in a continuous welding "line". In some embodiments, this can be seen as being rather similar to well-known welding methods for welding metals, for example, where even a point-by-point spot welding method can ultimately result in a substantially continuous welding line in the metal. In the point-by-point spot welding method, for example, the energy accumulation can be adjusted such that melting of the material is not initiated by a single beam spot, resulting in less energy being accumulated than is required for melting. However, by arranging a number of beam spots in sufficient proximity to each other, a sufficient amount of thermal energy is accumulated to melt the material within the melting zone. Any of these preferred embodiments can be implemented alone or in combination in the method to improve the protection of any device / component within the functional zone (cavity).

[0021] In other words, in a first step to form an enclosure, a first substrate (base substrate) and at least one second substrate (cover substrate) are provided, the at least one second substrate (cover substrate) preferably comprising a transparent material, i.e., the second substrate (cover substrate) is transparent at least in part of the second substrate or at least in one region and for at least one group of wavelengths. The at least one second substrate (cover substrate) is provided, for example, immediately above the first substrate (base substrate) such that the second substrate (cover substrate) covers the functional zone (cavity), in which case the first substrate may provide the lower surface of the functional zone (cavity).

[0022] Both the first and second substrates establish a contact region or contact zone located where the first substrate contacts the second substrate. Thus, each enclosure has at least one contact region. Thereafter, the functional zone (cavity) is hermetically sealed by introducing the laser welding line along the contact region, for example, along a line around the frame of the enclosure. For example, a plurality of enclosures can be manufactured within a shared substrate stack, such as a wafer stack, large enough to provide a plurality of enclosures. In this case, each enclosure can then be separated by a separation step.

[0023] The laser welding line has a height HL in a direction perpendicular to its connection surface. The connection surface is the direction in which adjacent or continuous beam spots are set. Typically, laser welding is performed from an "upper" perspective, that is, in this sense, the substrate stack is placed on a surface such as a - table, etc., and the laser is irradiated from above through at least the top substrate layer - or through two or more substrate layers - to the location of the beam focus. Thus, the height HL is measured in the direction of the laser beam, and the width of the laser welding line is measured perpendicular to the direction of the laser beam.

[0024] When defining a first laser welding line within a specific amount of material within the enclosure, for example, in the region around the laser welding line, there may be thermal stresses locally induced within the specific amount of material. Thus, when one laser welding line is defined, a specific amount of material may have lower mechanical stability. It has thus been found that even when only one laser welding line is provided for each contact surface, the enclosure as a whole may have lower mechanical stability.

[0025] Surprisingly, it has been found that when a second laser weld line is placed close to the first laser weld line, the same amount of material within the enclosure can achieve improved mechanical stability, even improved compared to a situation where no laser weld lines are provided at all. That is, by defining at least a second laser weld line that overlaps with the first laser weld line within the enclosure, it is possible to reduce the thermal stress within at least said amount of material.

[0026] In addition, when the second laser weld line is arranged to overlap with the first laser weld line, it is also possible to reduce the thermal stress throughout the enclosure.

[0027] The enclosure described in the present specification has improved mechanical stability. That is, the mechanical stability is preferably improved by introducing at least two laser weld lines for each contact surface, and one contact surface is located between each two adjacent substrate layers. In addition, when there is at least one laser weld line on both sides of each contact surface that overlaps with the laser weld line arranged on the other side of the same contact surface, the mechanical stability can be further improved.

[0028] Additionally, or in other words, the mechanical stress within at least one laser weld line can be reduced, and thus the mechanical stability of the hermetically sealed enclosure as a whole can be improved. This means that by introducing additional laser weld lines into the material and overlapping them with the "older" laser weld lines that have already been pre - arranged within the material, it is even possible to reduce or eliminate the mechanical stress within the material.

[0029] That is, the mechanical stress within at least one laser weld line, which is an "older" laser weld line already disposed within the material, is reduced by a stress reduction process step and / or by a crack reduction step. (Which may also include said crack reduction) During the stress reduction process step, any stress within the stress zone near the new laser spot can be varied. This may include, among other adjustable features, a reduction of stress within the material up to an increase or elimination of stress within the material, depending on where the new laser spot is set within the material.

[0030] The new laser spot may advantageously be set as another weld line, but is not necessarily limited thereto. In other words, stress can also be reduced by carefully placing the laser spot in a series of weld lines without the need to align a second laser spot. However, the enclosure may have at least one second laser weld line located adjacent to the first laser weld line and / or positioned such that stress reduction is achieved by the second laser weld line. This is one preferred embodiment. This is because in this case, when the second laser spot is set in the same arrangement as the first laser spot, i.e., when the second laser weld line is placed adjacent to the first laser weld line, it can be easily ensured that the stress introduced by the first laser weld line is eliminated throughout the material. However, several laser spots can also be dispersed and placed around or along the first laser weld line without establishing a continuous, for example, non-interrupted array of spots, and this is also understood to be the second laser weld line.

[0031] The first laser weld line may introduce a stress zone within the enclosure, in which case internal stress or tension remains in the solidified material within the stress zone.

[0032] Therefore, the second laser welding line is preferably located within or adjacent to the stress zone induced by the first laser welding line. Thereby, the second laser welding line interacts with the stress zone and can even eliminate the stress zone located adjacent to the second laser welding line. In other words, the second laser welding line removes the stress zone, thereby establishing a zone where the stress has been removed or substantially removed, and / or the stress has been removed or substantially removed from the laser-welded enclosure.

[0033] The enclosure may have a cavity therein, which may mean that the functional zone is the cavity enclosed within the enclosure. The residual stress within the area of the cavity of the package can be particularly critical. This is because package damage is most often observed in the area where the cavity reaches the package frame. For the reinforcement of the edge of the cavity, i.e., the reinforcement of the material located around the cavity, it is advantageous to arrange at least a two-dimensional laser welding line around the cavity. Thereby, the inner side of the enclosure surrounding the cavity or cavities within the enclosure can be strengthened and reinforced, and as a result, it can have higher durability against any force from the inside or outside. For example, the inside of the cavity may have a higher or lower pressure compared to the outside of the enclosure, thereby introducing additional tension based on the differential pressure. When the material surrounding the cavity / cavities within the enclosure is strengthened, the enclosure can withstand higher forces without breakage or loss of function.

[0034] At least one laser bonding line can be designed to surround the functional zone at a distance DF. This distance can be set to be equal around the functional zone. As an example, this distance can correspond to a height HF or less, or twice the height HF or less.

[0035] Each laser bonding wire can be arranged to extend into two different substrates of the enclosure. For example, the laser bonding wire extends from the base cover layer into its adjacent layer, such as the upper cover layer, and the laser bonding wire welds the two different substrates to each other.

[0036] The enclosure may have an elastic or flexible layer, especially as an intermediate layer between other layers, so that the hermetically sealed enclosure can be deformed, for example, by a pressure change or by a mechanical force. Such an elastic layer enables the enclosure to be used, for example, as an adjustable lens.

[0037] The enclosure can further be configured to have, for example, an inner coating zone arranged around the functional zone. For example, a welding process using a laser source can be controlled to change the material properties in the surface area directly surrounding the functional zone / cavity. This corresponds to applying a coating to the said surface area.

[0038] Furthermore, each substrate may include a plurality of layers and can be provided as a multi-layer composite. In other words, a plurality of multi-layer composites can be used and made adjacent by a laser welding process. This may include preparing the multi-layer composite in advance and welding the entire multi-layer composite to one or more other substrates in the manufacturing process to provide the enclosure.

[0039] By including a multilayer composite, additional material properties can be easily added to the enclosure. For example, such a multilayer composite may have prestress, or preferably a prestress direction, and thus, when such a multilayer composite is laser bonded, the internal stress level of the multilayer composite can, for example, improve the durability of the enclosure and can result in, for example, a cured multilayer composite. Consequently, a uniformly improved cure is obtained for the entire enclosure as a result. Additionally or alternatively, such a multilayer composite may have a coating layer, for example a coating layer that is difficult to weld by laser welding, whereby some or all of the intermediate composite layers will be provided as an already mutually bonded "pack" or "stack". Such coatings may include optical coatings.

[0040] A glass substrate or glass-like substrate with an optical coating added to the front surface or back surface or both surfaces may be welded to another (coated or uncoated) substrate and then cured. Preferably, the substrate including the coating is at least partially transparent at the emission wavelength of the welding laser when it extends within the planned beam line of the welding laser. For example, a substrate with a reflective coating in the VIS wavelength region is achieved by sputtering several alternately arranged thin layers composed of titanium oxide and silicon oxide. In this case, welding can be achieved by an NIR emission laser.

[0041] The enclosure may have any number of additional intermediate layers, for example three intermediate layers, arranged between the base layer and the cover layer.

[0042] The functional zone may be arranged within an intermediate layer or within one of the plurality of intermediate layers. In this configuration, the functional zone may be covered by the base layer on its bottom side and / or by the cover layer on its top side.

[0043] The functional zone can be designed as a cavity, and functional components such as electrical components can be arranged in the cavity so as to be protected by the enclosure.

[0044] The hermetically sealed enclosure may include one or more functional components including power semiconductors such as GaN-LEDs, SiC power transistors, GaAs power transistors, or GaN power transistors arranged in the cavity. Additionally or alternatively, the hermetically sealed enclosure may include through vias for establishing electrical contact connections from the inside to the outside of the enclosure, for example, for contact connection to contact pads outside the enclosure.

[0045] That is, at least one of the plurality of substrate layers, for example, the base cover layer, may have one or more through vias for making electrical contact connections with the contact pads on the outer periphery of the functional zone, for example, on the lower surface side of the base cover layer.

[0046] The substrate of the enclosure may have a thickness of less than 3 mm, preferably less than 1500 μm, preferably less than 500 μm, preferably less than 120 μm, and more preferably less than 80 μm. The base cover layer and / or the upper cover layer may be thinner than one or more intermediate layers, for example, may have a width of half or less of the width of the intermediate layer. The enclosure may have a size of 10 mm × 10 mm or less, preferably 5 mm × 5 mm or less, and more preferably 2 mm × 2 mm or 1 mm × 1 mm or less. Also, the enclosure may have a height greater than its width.

[0047] Also, the use of a hermetically sealed enclosure for manufacturing medical implants, microlens composites, micro-optical chips, drug packages, or LED devices is also based on the present invention.

[0048] Furthermore, a method of providing a hermetically sealed enclosure that encloses a functional zone such as a cavity, as will be described in detail above and below, is also based on the present invention, and the method includes providing a base substrate and aligning a cover substrate on the base substrate such that at least one contact surface is disposed between the base substrate and the cover substrate.

[0049] In other words, the substrate layers (e.g., the base substrate and the cover substrate) are laminated in direct contact with each other, i.e., the substrate layers are disposed adjacent to each other. By noting that no other materials and / or interfering materials are disposed between the substrate layers, the substrate layers are in planar / layered contact with each other in close proximity. For example, the base substrate is provided in direct contact with the cover substrate, and in particular, it is avoided that other materials or spaces or gaps remain between the base substrate and the cover substrate. For example, when attempting to provide three or more substrates, the base substrate is in direct contact in close proximity to the intermediate substrate, and the intermediate substrate is in direct contact in close proximity to the cover substrate on the other side. That is, the substrates are provided immediately adjacent to the next substrate respectively.

[0050] Thereafter, the substrates will be welded by a novel laser welding method, in which case the substrate layers are directly welded to the adjacent substrate layers without the need for additional and / or other and / or non-air materials or intermediate layers. Each substrate will be directly welded to each other, whereby the laser weld line irradiated in the air contact region / zone between the two substrate layers inseparably bonds these immediately adjacent substrate layers. Accordingly, the molten zone of the laser weld line is disposed simultaneously on both substrates to be welded and proceeds seamlessly from the first substrate (base substrate) to the second substrate (cover substrate).

[0051] Thus, proximal, aerial, or even fully aerial transfer is established, which may be, in some cases, a transfer from substrate to substrate or from glass to glass. A locally restricted volume is established as the welding zone (laser weld line), where there is movement or mixing of the material of the adjacent substrate layers, which may be flat. For example, the material of the first substrate (base substrate) penetrates into the second substrate (cover substrate), and conversely, the material of the second substrate (cover substrate) penetrates into the first substrate (base substrate), resulting in a complete material mixing of the adjacent substrates within the welding zone. Thus, the laser weld line may be referred to as the convection zone.

[0052] The novel laser welding technique is advantageously provided without the need for any intermediate layer or materials such as glass frit, foil, or adhesive, which were required in the previously well-known techniques. The novel inseparable bond between the substrate layers can advantageously be provided without restricting additional materials such as intermediate layers or bonding materials. This simplifies manufacturing, eliminates the need for such additional materials as described above, enhances the robustness and / or strength of the enclosure, and enables a safe airtight sealing of the functional zone (cavity). For example, the laser weld line can be identified in the final product by specific local changes in the refractive index of the material within the small melting zone.

[0053] For example, in the case where the substrate is not provided completely flat, which may be due to manufacturing errors, such a gap between the substrates (the base substrate and the cover substrate) can be tolerated if, for example, the gap is 5 μm or less, preferably 1 μm or less. Such a gap can occur from manufacturing errors of the substrate, or due to the influence of heat, or rather due to the inclusion of particles such as dust. Even when there is such an acceptable interval between substrates considered to be immediately adjacent to each other according to the present invention, it is possible to weld such that the welding zone (laser welding line) has a width of about 10 to 50 μm, thereby achieving a hermetic seal. Also in this case, the melting zone progresses seamlessly from the first substrate to the second substrate. That is, the laser welding line is brought into the contact region between the first substrate and the second substrate, directly fusing the substrates together to form an inseparable composite. By the welding process, the materials of both substrates located within the laser welding line are directly melted, and the material of the first substrate is mixed with the material of the second substrate to form an inseparable one-piece composite. Therefore, at least the enclosure manufactured with the laser welding line finally contains a monolithic composite.

[0054] Therefore, a method for hermetically sealing an enclosure includes the steps of hermetically sealing a functional zone by introducing a first laser welding line into the enclosure, introducing a second laser welding line at the same position as the first laser welding line or at a position close to or overlapping the first laser welding line, and removing stress in the region of the first laser welding line of the enclosure by introducing the second laser welding line.

[0055] In this method, a laser beam source can be used to introduce the laser welding line into the enclosure. The laser beam may be guided around the functional zone to form a laser welding line along the contact region between the base substrate (3) and its adjacent substrate, for example, the cover substrate.

[0056] The laser source may be a pulsed laser source, in which case several laser pulses are introduced along the laser welding line, whereby a single continuous or almost continuous welding line is formed from several laser pulses.

[0057] The present invention also provides an enhanced sealed enclosure manufactured by the methods shown above and below.

[0058] The present invention will be described in more detail below with reference to the preferred embodiments. Refer to the accompanying drawings in which like or similar components are labeled with the same reference numerals.

Brief Description of the Drawings

[0059]

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[0060] Detailed Description of the Invention FIG. 1a shows a cross-sectional view of one embodiment of the enclosure. An intermediate layer 4 is disposed on the base layer 3, and a functional zone 12 is disposed within the intermediate layer 4 of the enclosure 1. A cover layer 5 is disposed on the intermediate layer 4. All of the layers 3, 4, and 5 may be chemically strengthened glass with a dielectric coating that partially or entirely covers one or both sides of a multilayer component. This may apply to all of the following descriptions. The functional zone 12 is a cavity, and a functional component 2 such as an electrical component or a lens is disposed within the cavity 12. Contact surfaces 25 are disposed between the base layer 3 and the intermediate layer 4, and between the intermediate layer 4 and the cover layer 5, respectively. The base layer provides the bottom 22 of the cavity 12, the intermediate layer 4 has side walls 21, and the cover layer 5 includes the top 23 of the cavity 12.

[0061] Referring to FIG. 1b, details of the corner of the enclosure 1 are shown, where an interface zone 8 welded by a laser beam is shown in more detail. In this embodiment, there is one interface zone 8 for each contact surface 25, and in this case, each interface zone 8 is a laser weld line surrounding the perimeter of the cavity 12. In other words, each interface zone 8 forms a closed ring or closed line in the circumferential direction.

[0062] Figure 1c shows another example of an enclosure, in which case a plurality of intermediate layers 4a, 4b, 4c are used and a stack 18 consisting of layers 3, 4a, 4b, 4c, 5 is formed. Similarly in this case, each contact surface 25 has a respective laser weld line 8 disposed thereon. As a result of the laser welding, each layer or substrate is firmly bonded or fixed to the adjacent layer. The upper layer 5 in this example may be a glass layer. The intermediate layers 4a, 4b and 4c may be provided as a single multi-layer composite 4, and then the cavity 12 can be removed, for example, by a polishing method.

[0063] For example, the base substrate may be a wafer or a printed circuit board and may be formed, for example, from aluminum nitride. The functional zone 13 (or cavity 12) may be formed, for example, as a recess in the base layer 3 and may be formed by a polishing method such as sandblasting.

[0064] Figure 2 shows a top view of the enclosure 1 according to the invention, in which case the circumferential laser weld line 8 surrounds the functional zone 13. The functional zone 13 can be designed to meet different requirements according to needs, which may be, for example, an optical receptor disposed in the functional zone 13, or a technical and / or electromechanical device 2. For example, it is also possible that a plurality of different tasks are achieved by the functional zone 13 in that a plurality of different devices 2 are installed in a single functional zone 13.

[0065] Refer to FIG. 3, which is another cross-sectional view showing one embodiment of an enclosure 1 having both a base layer 3 and a cover layer 5 in the form of a substrate. In other words, the enclosure 1 has two layers, a base substrate 3 and a cover substrate 5. Further, FIG. 3 shows how a laser weld line 8 is typically configured, i.e., a number of laser pulses 16 are arranged in close proximity to each other and aligned in the form of a single line, whereby the materials of the base substrate 3 and the cover layer 5 are melted and fused together, preferably without any gaps, so that the functional zone 13 or the cavity 12 is hermetically sealed by the laser weld line 8 or by the laser weld lines 8 surrounding the functional zone 13 or the cavity 12.

[0066] Next, referring to FIGS. 4 and 5, it will be explained how the stress in the materials of various substrates 3, 4a, 4b, 5, etc. can be reduced by introducing a plurality of adjacent laser welding lines 8 in the method of the present invention. FIG. 4 shows a cross-section of a typical welding line 8, which is a cross-section showing the changes caused by a plurality of laser pulse shots 16. A large number of laser pulse shots 16 cause heat accumulation over overlapping non-linear absorption zones and produce one line that forms the laser welding line 8. Such a cross-section of the welding line is shown in FIG. 4 and has a plurality of distinguishable regions. The first is the non-linear absorption region 31, which corresponds more or less to the laser focus and has dimensions of several micrometers. When the laser 9 is irradiated from above the substrate stack 18, above the region 31, an elongated "bubble-like" region 32 (also typically referred to as "bubble 32" due to its rather characteristic shape comparable to an elongated bubble) with a width of only a few micrometers but typically a height of up to several tens of micrometers can be formed. Surrounding the bubble-like region 32 is a molten region 33 having a width w and a height h. In this molten region 33, a temperature above Tg can be reached, and thus the glass will be in a re-solidified state (after cooling or heat dissipation). The molten region 33 containing the elongated bubble 32 can usually be clearly identified, for example, using an optical microscope, from its density and the refractive index changed with respect to the surrounding glass along with the density. In some cases, the non-linear absorption region 31 may also be observed as an optical damage at the lower tip of the molten region 33.

[0067] Within the heating region 34 surrounding the molten region 33, the glass receives a certain amount of energy from the heat accumulation of a plurality of laser shots 9, whereby the temperature of the glass rises to a temperature lower than Tg (the melting temperature of each material) but still significantly higher than room temperature. Due to heat diffusion, this temperature is not the same at all corners of the heating region 34. The size of the heating region 34 is adjusted to the size of the molten region 33. Therefore, the dimensions of the molten region 33, especially the boundaries, can be used as an indicator of the dimensions of the heating region 34.

[0068] In the realization of the present invention, it has been found that any weld line 8 can also function doubly as a local heat source for strengthening the substrate material. Strengthening is typically known as a heat treatment of the glass to make the glass stronger and more durable against heat and breakage. This is the same as the strengthening presented in this disclosure, but it does not involve the multiple drawbacks of any strengthening method well-known in the art. In this case, when a predetermined profile of the weld line 8 characterized by the height h and width w of the molten region 33 is given, the heating region 34 can be arranged by the weld line 8 with respect to the region or feature to be strengthened. Such strengthening features can reduce stress or remove microcracks from the material in the conventional weld line 8.

[0069] Typical numerical values found to be useful as means for improving or strengthening the substrate layer material are shown in Table 1 below: Table 1: Typical Numerical Values of Strengthening

Table 1

[0070] Table 1 shows the respective advantages obtained when strengthening is performed for various purposes ("features"). The typical numerical values listed in the third and fourth columns are the typical widths that can be obtained for each zone improved by the "laser-induced strengthening" shown in this specification. The coordinates indicated by "X" and "Y" in Table 1 can be, for example, those shown with respect to the feature to be strengthened. W indicates the width of the molten region 33 of the laser weld line 8, and h indicates the height of the molten region 33. The molten region introduced by the laser weld line 8 can typically have dimensions of approximately w = 50 μm, optionally ±10 μm, and / or h = 100 μm, optionally ±20 μm.

[0071] For example, when one laser welding line 8 irradiates one substrate layer, the material of each substrate layer is in a state of receiving a predetermined amount of stress stored therein. By irradiating the second laser welding line 8 in proximity to the first laser welding line 8, the stress introduced by the first laser welding line 8 can be reduced and even eliminated as will be further described below. In another example shown in Table 1, improving the edge of the cavity 12 can eliminate microcracks, so that the cavity 12 becomes more stable and has higher durability against any force from the outside or inside.

[0072] In yet another example shown in Table 1, the tearing strength can be eliminated on the pre-scored surface, and at the same time, microcracks can also be reduced or eliminated. In a waveguide element, for example, a gradient refractive index can be set to reduce the loss of the waveguide.

[0073] At the interface between two layers, stress and microcracks can also be reduced. For example, at the glass coating - glass interface, hermetic sealing of the coated interface can be performed. When the surface or edge is hardened by another means, such as chemical hardening or thermal hardening, or hardened for any surface or edge, a local stress - conforming profile can be implemented within the material. When a metal is filled through a glass via, better metal retention within the hole can be achieved as shown in Table 1. Near any dicing line, the edge of the individualized chip can be strengthened. For any outer conductive layer, some harmful effects such as delamination or thinning can be avoided.

[0074] Referring to FIG. 5, first, the lower laser welding line 8 is carried out, and then the second laser welding line 8a for "repair" is carried out. Any distortion introduced by the first laser welding line 8 is neutralized by the implementation of the second laser welding line 8a. In this example, the two laser welding lines 8, 8a achieve the additional feature of substrates welded to each other. The first laser welding line 8 welds the base substrate 3 to the first intermediate layer 4a, and the second laser welding line 8a welds the first intermediate layer 4a to the second intermediate layer 4b along each contact region 25.

[0075] FIGS. 6 to 14 show one exemplary method of constructing the enclosure 1 according to the present invention, which is also a method of manufacturing the enclosure 1 according to the present invention. The enclosure 1 of this embodiment is covered on both sides by a cover substrate that may be thinner than the "inner" substrate, but this is merely for exemplary reasons. Introducing additional cover substrates on both sides of the template can be advantageous as will be explained in more detail below, and as found in the implementation of the present invention, introducing additional cover substrates can even eliminate greater stress in the material of the inner substrate.

[0076] It should be noted that it is not necessary to perform the steps as shown in FIGS. 6 to 14 separately. Rather, for each layer, it is possible to provide a complete stack 18 as shown in FIG. 14, for example, and laser weld each laser welding line 8 to the complete stack 18, rather than providing each layer after the next upper layer is provided.

[0077] In addition to this, it should be noted that in FIGS. 6 to 14, several enclosures 1 (in this case, two enclosures 1) are prepared, and the same are manufactured simultaneously in the same manufacturing process, and then the two enclosures 1 are separated from each other along the dicing line 10 shown in FIG. 6, for example. Of course, each enclosure 1 can also be prepared and manufactured separately.

[0078] In FIG. 6, a lower cover substrate 3 is provided, and a first intermediate layer 4a is disposed on the lower cover substrate 3. Therefore, it can be said that the intermediate product 1 is formed. In one simple embodiment, the enclosure 1 can further be formed by adjacent two layers and welding each enclosure 1 by at least one laser welding line 8.

[0079] FIG. 7 shows a stress region 35 of the first intermediate layer 4a introduced by forming a laser welding line 8 in the material of the enclosure 1. In this example, when a laser welding line 8 is formed in the material, residual stress and / or microcracks are caused as a result in the welding region 35, and this residual stress and / or microcracks are caused by rapid local heating and relaxation of the material and / or by a temperature difference in the material. For reasons of explanation, it should be added that such a structurally weak region 35 can even be worsened if there is a risk that cracks or incipient cracks will increase in the region under the next / second welding line.

[0080] The “physical” welding line 8 corresponding to the melting region 33 can be seen by a change in the refractive index at its outer periphery. Above this physical welding line 8, when the laser irradiates the material from above, a stress region 35 having an initial “strain pool” is generated. The strain pool is mainly caused by thermally induced stress in the welding implementation zone 35, but may also include initial microcracks and the like.

[0081] FIG. 8 shows the substrate stack 18 at the moment when the second and third welding lines 8a, 8b are arranged in the enclosure 1, and the second intermediate layer 4b is arranged above the first intermediate layer 4a. The second intermediate layer 4b constitutes the frame 21 or "frame" of the subsequent cavity 12. The stress zone 35 is shown in the same manner as in the embodiment shown in FIG. 7, and at the moment represented by the embodiment shown in FIG. 8, the stress zone 35 still remains, but then decreases as shown in FIG. 9. The first welding line 8 has already been cooled, but in the second and third "hot" welding lines 8a, 8b, a heating region 34, an elongated bubble 32, a melting region 33, and a non-linear absorption region 31 are still shown (see, for example, FIG. 4 for details). The contact surface 25 between the first intermediate layer 4a and the second intermediate layer 4b is mostly welded by the two welding lines 8a and 8b, and the left side portion of FIG. 8 shows how the material changes when only one welding line 8a is used.

[0082] Referring to FIG. 9, the enclosure 1 is cooled after the welding step shown in FIG. 8, and a plurality of stress regions 35 are generated. No stress is generated in the material of the first intermediate layer 4a as can be seen in the central and most of the right side where two welding lines 8a and 8b are provided in FIG. 8. It has been found that when the two welding lines 8a, 8b are close to each other, for example, one is provided below the contact surface 25 to be welded and one is provided above, the stress and even the microcracks that may exist can be "repaired" in the material around the welding zone. This is particularly important because the contact surface 25 between any substrate layer of the stack 18 / enclosure 1 typically constitutes one of the most important regions regarding its integral stability. Now, new stress zones 35 are generated in the second intermediate layer 4b surrounding the subsequent cavity 12. The stress can be removed from these stress zones 35 in subsequent steps (see FIG. 10).

[0083] Returning to the left - hand portion of FIG. 9, only one second weld line 8a is introduced into the material here. In this region, stress remains within the material of the first intermediate layer 4a, and as a result, a weaker material composition is produced, which deteriorates the durability against any bending force or impact and may even leave micro - cracks there.

[0084] FIG. 10 shows the following subsequent steps for manufacturing the enclosure 1 according to the present invention. A third intermediate layer 4c is disposed on top of the second intermediate layer 4b so as to close the cavity 12. When attempting to insert any electronic device or functional component 2 into the cavity 12 or functional zone 13, in this exemplary method of manufacturing the enclosure 1, this should be added before the steps shown in FIG. 10. For exemplary reasons, the functional component 2 is included in the left - hand cavity 12. The third and fourth laser weld lines 8c and 8d are irradiated onto the enclosure 1, leaving a relatively hot zone that must be further cooled. The stress zone 35 shown in this example corresponds to that shown in FIG. 9. This is because the laser weld zones are still hot and stress removal in each zone has not yet occurred. The contact surface 25 between the second and third intermediate layers 4b, 4c is welded by two laser weld lines 8c, 8d.

[0085] As can be seen from FIG. 11, in the central and right - hand portions of the drawing, the stress zone 35 has disappeared, which means that the stress within the material of the enclosure 1 has been reduced or eliminated. However, in the left - hand portion of FIG. 11, shown for comparative reasons only, where each contact surface 25 is welded only by one laser weld line 8b, 8d, stress remains within the material, as indicated by the remaining stress zone 35 in the first and second intermediate layers 4a, 4b.

[0086] Referring now to FIG. 12, subsequent steps for forming the enclosure 1 according to the present invention are shown, where the upper cover layer 5 is disposed on the third intermediate layer 4c and welded to the third intermediate layer 4c by one additional weld line 8e. Also in FIG. 12, the moment when the laser irradiates the material of the enclosure 1 is shown, and the stress zone 35 is the same as the situation shown in FIG. 11. One complete stack 18 consisting of a plurality of substrates is completed. In FIG. 13, the stress zone 35 no longer remains in the central and right portions, and the resulting stress removal can be observed. For easier understanding of the reason, only one laser weld line 8 is used for welding each contact surface 25, shown only for comparison purposes, and in the left portion, a stress zone 35 still remains in the material, thus weakening the stress zone 35. However, in the third intermediate layer 4c where two laser weld lines 8d and 8e are disposed, complete stress removal can be achieved. As is clear from FIG. 13 and the foregoing description, the enclosure can finally benefit from all the advantages of being laser welded by the bottom cover layer 3 and the upper cover layer 5, and moreover, no additional stress is added to the material. Since the material is strengthened, the microcracks are the same, but without the drawbacks of typical strengthening methods. For example, an electronic device or a functional component 2 may be attached within the enclosure 1, which would be impossible with normal strengthening due to the high temperatures required throughout the material of the enclosure 1. However, the outermost layers, the lower cover layer 3 and the upper cover layer 5, can be strengthened, for example, by a typical method of heating the layers 3, 5 above the melting temperature (which is the removal of stress).

[0087] Referring to FIG. 14 here, in one complete stack 18 consisting of substrates 3, 4a, 4b, 4c and 5 arranged stacked on top of each other, one embodiment is shown where laser weld lines 8, 8a, 8b, 8c, 8d and 8e are sequentially introduced into the material. Finally, two enclosures 1 are cut or separated along the dicing line 10, and a single enclosure 1 obtained by the manufacturing method of the enclosure 1 described above is shown in FIG. 15.

[0088] FIG. 16 shows another example of strengthening the periphery of the edge of the cavity 12. At least a two-dimensional weld line 8 is formed around the cavity 12. Here, not only are the previously separated substrates 3, 4 and 5 welded to each other by the laser weld line 8, but also any stress in the zone surrounding the cavity 12, including the elimination of the possibility of microcracks, is eliminated or at least significantly reduced. Such microcracks may continue to remain in the material or may be introduced into the material when, for example, cutting the material to form the cavity 12. The subsequent lines of laser shots 16 are set close to each other to form the laser weld line 8 around the cavity 12.

[0089] Referring to FIG. 17, a multi-layered example is shown. In this example, each enclosure 1 has three cavities 12. At the same time, three enclosures 1 are manufactured together in the same manufacturing process, but in the separation step after the laser welding is completed, they are separated, for example, along the dicing line 10 shown in FIG. 17. To eliminate or reduce the stress in the material of the enclosure 1, a plurality of laser weld lines 8 are introduced into the material as described above. Each cavity 12 typically contains one functional component 2, but such a functional component 2 is shown in only one cavity 12 for reasons of clarity.

[0090] FIG. 18 shows a side view of the details of the enclosure 1 having the cavity 12, with the upper substrate 5 and the lower substrate 3 and the cavity 12 being shown only partially. A laser welding line 8 surrounding or enclosing the cavity 12 is shown together with a safety margin 41 for the edges of layers 3 and 4. The safety margin 41 helps to ensure that the laser welding line 8 is properly formed within the material of the enclosure 1. The safety margin or pre-scored surface 41 can have a width of 0.5w to 2w.

[0091] As shown in FIG. 18, the lower substrate 3 has dimensions larger than the adjacent substrates 4, 5, and the lower substrate 3 extends further outwards with an extension 7. The extension 7 has a width 47, and generally, a somewhat smaller width 47 is desirable to reduce the overall size of the enclosure 1. Since the structural details are similar, FIGS. 18 to 21 can show the same embodiment such as a hermetic biomedical implant with electrical contacts.

[0092] The extension portion 7 can be used to position the contact pad 54 laterally with respect to the cavity 12 and can thus be accessible from above. For example, a metal-filled through-glass via 52 can connect the contact pad 54 to a conductive portion 56 such as a conductive strip provided below the base substrate 3. The through-glass via 52 is arranged at a margin 43 away from the laser welding line 8 so that the through-glass via 52 is not changed or obstructed when the laser welding line 8 is formed within the enclosure 1. The safety margin 43 between the welding lines 8, 8a, 8b, 8c, 8d, 8e and the through-glass via 52 can be, as shown, within a range of 1w to 1.5w, for example, in the horizontal direction. When the welding lines 8, 8a, 8b, 8c, 8d, 8e are located or arranged under the through-glass via 52, the corresponding safety margin can be within a range of 1h to 1.5h.

[0093] The conductive part 56 may have another electrical contact zone to establish an electrical contact connection with the contact pad 54. The safety margin 45 between the conductive part 56 and the welding lines 8, 8a, 8b, 8c, 8d, 8e can be selected to be about 1h - 2h in the vertical arrangement as shown in the figure and / or about 1w - 2w in the horizontal arrangement.

[0094] Referring to FIG. 19, a side cross-sectional view of the enclosure 1 having the cavity 12 shows the laser welding lines 8, 8a surrounding the cavity 12. The same reference numerals as those used with respect to FIG. 18 denote the same features. The enclosure 1 may be used as a hermetic biomedical implant having electrical contacts 54, 55 (see FIG. 20). The contact pad 54 located at the extension 7 of the lower substrate 3 is connected to the conductive part 56 via the through-glass via 52 and further connected to the functional component 2 disposed within the cavity 12 via the through-glass via 53. In other words, the electrical paths 52, 53, 54, 56 are defined from the inside to the outside of the enclosure 1. In this case, the contact pad 54 can be easily accessed, for example, from above or from the side.

[0095] FIG. 20 shows a top view of the enclosure 1, for example, a hermetic biomedical implant 1 having electrical contacts 54, 55 as also shown in FIG. 19, and two contact pads 54, 55 can be identified at the extension part 7 of the lower substrate 3. The laser welding lines 8, 8a are hermetically drawn around the functional zones 12, 13 having the functional components 2. The two contact pads 54, 55 can facilitate operation and electrical contact connection. Next, FIG. 21 shows a bottom view of the enclosure 1 having the electrical contact strips 56, 57. The electrical strips 56, 57 are separated from each other and are disposed below the lower substrate 3 to make contact connections with two electrically insulated electrical contacts. As outlined with respect to FIG. 18 or FIG. 19, for example, the through-glass vias 52, 52a, 53, 53a can be electrically connected to the contact strips 56, 57.

[0096] Referring to FIG. 22, an enclosure 1 is shown which is disposed below a base substrate 3 and encapsulated by a thin substrate 3a such as a cover glass 3a, particularly an electrically encapsulated conductive layer 58. Through-glass vias 52 and 53 are connected to each other via the conductive layer 58. The through-glass via 52 is in contact with a connection pad 54, and the through-glass via 53 is in contact with a functional component 2 within a cavity 12 of the enclosure 1.

[0097] On a side surface of the enclosure 1 where electrical contacts guided to the outside of the enclosure are not required, laser welding lines 8a can be disposed through the conductive layer 58. On the side including the extension 7, the laser welding line 8 ends near the conductive layer 58 so as not to extend into or through the conductive layer 58. For example, another laser welding line 8b can be disposed on the extension 7 to provide a hermetic seal of the enclosure there, and alternatively or additionally, at least one of the conductive layer 58 and the substrate 3a can be reliably mechanically connected to the remaining portion of the enclosure 1. Depending on the width of the conductive layer 58 and the arrangement of electrical contacts connected to the conductive layer 58, the laser welding line may be arranged such that portions other than near the edge of the enclosure 1 can be welded to the lower substrate 3.

[0098] FIG. 23 shows a bottom view of the enclosure 1, where individualized conductive strips 59, 60 separated from the conductive layer 58 are shown. Thus, for example, separate electrical contacts can be easily established within the conductive layer 58 even by guiding identification electrical contacts to different sides of the enclosure 1, including two or more sides of the enclosure 1 (see, for example, FIG. 26). The conductive layer 58 may have, for example, the same extension dimension as the lower substrate 3, but may be kept slightly smaller so that the encapsulating layer 3a can insulate the conductive layer 58 laterally thereof.

[0099] FIG. 24 shows a cross-sectional view of the enclosure 1, where upper and lower contacts 74, 76 are established in that electrical contacts are provided on the lower and upper surfaces of the enclosure 1. For example, the upper contact 76 may be brought into contact with the functional element 2 through an upper contact portion that contacts the upper contact 76 via the through-glass via 62 on one side and contacts the functional component 2 via contact means 65 such as solder droplets and the through-glass via 64 on the other side. A bay 68 for accommodating connectors such as plug-type connectors is provided on the side thereof. Two separate electrical contacts 74, 76 are provided on the upper and lower sides of the bay 68. One or more connector holding notches 70 may be provided to hold the connector in the bay 68, and when the force on the connector is released, a raised portion or any means that functionally couples with the connector holding notch 70 may press the connector holding means 72 to hold the connector in the bay 68. Arrow 80 indicates the possible insertion direction of the connector.

[0100] FIG. 25 shows another enclosure 1, and members having the same reference numerals as in other drawings indicate the same or similar members in this drawing. A clamping portion 82 is provided on one side of the enclosure 1, for example, on the contact pad 54, and any electrical conductor can be clamped onto the contact pad 54 through the clamping portion 82. For example, the nerve 85 can be brought into contact with the contact pad 54 and stimulated by an electrical pulse from the functional component 2 within the enclosure 1. All electrical means of the enclosure 1, or at least the parts that need to be protected, can be enclosed within the enclosure 1, and the interaction with the outside can be established in various embodiments. The clamping portion 82 can be structurally strengthened, for example, by another weld line 8b.

[0101] Figure 26 shows another enclosure 1, where electrical contacts 54, 55 are provided on both sides of the enclosure 1. Identifiable contact portions 56, 56a are provided under the lower substrate 3, where different sides of the enclosure 1 can be marked with different codings, for example colors, etc., in order to facilitate the electrical contact connection between the functional component 2 and the external contacts via the contact pads 54, 55.

[0102] Figure 27 shows a photograph of two substrates 3 and 5 laser welded to each other along the laser weld line 8, where changes in refractive properties and a reduction in stress within the material can be observed, which will be used to prove the method and the principle of the enclosure 1 described above.

[0103] It will be understood that the features defined herein in connection with any aspect of the present invention or any particular embodiment of the present invention may be utilized alone or in combination with any other feature or aspect of the present invention or embodiment. In particular, the present invention is intended to cover a method of manufacturing the enclosure 1 configured to include the enclosure 1 and / or any features described herein. It will always be understood that any feature disclosed herein may be an essential feature of the present invention, whether disclosed alone or in combination with other features, regardless of whether it is disclosed in the specification, the claims and / or the drawings.

[0104] Furthermore, the above-described embodiments of the present invention are described merely by way of example to illustrate its principles, and it will be understood that further modifications and changes of the present invention may be made without departing from the scope of the present invention. Finally, it is obvious that the features described in connection with a particular embodiment, for example an enclosure, can also be combined with any other embodiment, for example a substrate stack.

Explanation of Reference Numerals

[0105] 1 Enclosure 2 Device or functional component 3 Lower substrate, base layer or lower cover substrate 3a Substrate 4, 4a, 4b Intermediate layer or multilayer composite 4c Intermediate layer 5 Upper cover layer, cover substrate 7, 7a Extension 8, 8a, 8b, 8c, 8d, 8e Laser welding line 9 Focused laser beam 10 Dicing line 12 Cavity 13 Functional zone 14 Edge 15 Laser unit 16 Laser pulse 18 Stack of substrates; wafer stack 21 Edge / frame of the cavity 22 Bottom of the cavity 23 Top of the cavity 25 Contact surface 31 Non-linear absorption region 32 Elongated bubble 33 Melting region 34 Heating region 35 Stress region 41 Safety margin or pre-scored surface 43 Safety margin for the through-glass via 45 Safety margin for the conductive layer 47 Width of the extension 7 52, 52a Through-glass via 53, 53a Second through-glass via 54 Contact device or contact pad 55 Second contact part or contact pad 56, 56a Contact part or contact layer 57 Second contact part or contact layer 58 Conductive layer 59, 60 Conductive strip 62 Upper outer through-glass via 64 Upper inner through-glass via 65 Contact means such as solder droplets 66 Upper contact portion or contact layer 68 Socket (female connector) 70 Connector holding notch 72 Connector holding means 74 First electrical contact, bottom contact 76 Second electrical contact, upper contact 80 Plug-in direction of the connector 82 Flexible tightening portion 85 Nerve

Claims

1. A substrate stack (18) for an enclosure (1), comprising at least one base layer (3), a cover layer (5), and having, wherein at least said cover layer or said base layer preferably has a glass or glass-like material or a silicon-based material, at least one first laser welding line (8) is provided for welding said base layer and said cover layer, and said first laser welding line (8) introduces a stress zone (35) into said enclosure, at least one second beam spot or at least one second laser welding line (8a, 8b, 8c, 8d, 8e, 8f) is provided which is located adjacent to said first laser welding line (8) and / or by which a stress reduction in said at least one first laser welding line (8) is achieved, whereby the mechanical stability of said substrate stack (18) is improved, said first laser welding line (8) has a height HL in a direction perpendicular to its joint surface and a width w in said joint surface, said at least one second beam spot or at least one second laser welding line (8a, 8b, 8c, 8d, 8e, 8f) is i) arranged such that the distance in the direction perpendicular to said joint surface between said first laser welding line (8) and said at least one second beam spot or second laser welding line (8a, 8b, 8c, 8d, 8e, 8f) is less than 5HL and at least 1HL, and / or, ii) the distance in the direction within said joint surface between said first laser welding line (8) and said at least one second beam spot or second laser welding line (8a, 8b, 8c, 8d, 8e, 8f) is less than 5w and at least 0.5w A substrate stack (18).

2. An enclosure (1) having the substrate stack (18) according to claim 1, comprising said base layer (3) and said cover layer (5) which form at least a part of said enclosure, and a functional zone (13) arranged to be at least partially enclosed within said enclosure, An enclosure (1).

3. ​ The enclosure (1) according to claim 2, having at least one second laser welding line (8a, 8b, 8c, 8d, 8e, 8f) arranged adjacent to the first laser welding line and / or arranged such that stress reduction is achieved by the second laser welding line.

4. The second laser welding line (8a, 8b, 8c, 8d, 8e, 8f) is arranged inside or adjacent to the stress zone induced by the first laser welding line, and the second laser welding line removes the stress zone, thereby establishing a zone where stress has been removed or a zone where stress has been substantially removed, and / or in the laser-welded enclosure, stress has been removed or stress has been substantially removed. The enclosure (1) according to claim 3.

5. The enclosure (1) according to any one of claims 2 to 4, wherein the functional zone (13) is a cavity (12).

6. The at least one laser welding line (8, 8a, 8b, 8c, 8d, 8e, 8f) surrounds the functional zone (13) at a distance DF, and the distance corresponds to less than or equal to the height HL or less than or equal to twice the height HL. The enclosure (1) according to any one of claims 2 to 5.

7. Since the enclosure provides a hermetic seal for the functional zone, the enclosure is a hermetically sealed enclosure, and / or the functional zone (13) is enclosed circumferentially within the enclosure. The enclosure (1) according to any one of claims 2 to 6.

8. Further having an elastic layer or a flexible layer (4a, 4b, 4c, 4d), whereby the enclosure is deformable by a pressure change or by a mechanical force. The enclosure (1) according to any one of claims 2 to 7.

9. Further having an inner coating zone (36) arranged around the functional zone (13). The enclosure (1) according to any one of claims 2 to 8.

10. The enclosure (1) according to any one of claims 2 to 9, wherein at least one of the layers of the enclosure is provided as a multilayer composite (4) having one or more coating layers or prestress zones and / or providing one or more layers.

11. The enclosure (1) according to any one of claims 2 to 10, further comprising an intermediate layer (4, 4a, 4b, 4c, 4d, 4e) disposed between the base layer (3) and the cover layer (5), the intermediate layer being provided as a multilayer composite.

12. The enclosure (1) according to claim 11, wherein the functional zone (13) is a cavity (12), the cavity (12) being surrounded by the intermediate layer (4, 4a, 4b, 4c, 4d, 4e), covered by the base layer (3) on its bottom side and covered by the cover layer (5) on its top side.

13. The enclosure (1) according to any one of claims 2 to 12, wherein the functional zone (13) is a cavity (12), and a functional component (2) is disposed in the cavity protected by the enclosure.

14. The enclosure (1) according to claim 13, wherein the functional component (2) includes a power semiconductor disposed in the cavity (12).

15. The enclosure (1) according to claim 14, wherein the power semiconductor is a GaN-LED, a SiC power transistor, a GaAs power transistor, or a GaN power transistor.

16. Each of the first laser welding line (8) and the second laser welding lines (8a, 8b, 8c, 8d, 8e, 8f) is arranged to extend into two different layers (3, 4a, 4b, 4c, 4d, 4e, 4f, 5) of the enclosure, and each of the first laser welding line (8) and the second laser welding lines (8a, 8b, 8c, 8d, 8e, 8f) welds the two different layers to each other. The enclosure (1) according to any one of claims 2 to 15.

17. The layers (3, 4a, 4b, 4c, 4d, 4e, 4f, 5) have a thickness of less than 3 mm, preferably less than 1500 μm, preferably less than 500 μm, preferably less than 120 μm, more preferably less than 80 μm, and / or The base layer (3) and / or the cover layer (5) is thinner than one or more of the intermediate layers (4a, 4b, 4c, 4d, 4e, 4f) and has a width of half or less of the width of the intermediate layer. The enclosure (1) according to claim 11.

18. The enclosure (1) according to any one of claims 2 to 17, wherein at least one of the layers (3, 4a, 4b, 4c, 4d, 4e, 4f, 5) has a through via for electrically connecting the functional zone (13) to the outer periphery of the enclosure.

19. The enclosure has a size of 10 mm × 10 mm or less, preferably 5 mm × 5 mm or less, more preferably 2 mm × 2 mm or 1 mm × 1 mm or less, and / or the enclosure has a height greater than its width. The enclosure (1) according to any one of claims 2 to 18.

20. Use of the enclosure (1) according to any one of claims 2 to 19 for manufacturing a medical implant, a microlens complex, a micro-optical chip, a drug package, an LED or an optical assembly for an augmented reality device.

21. A method of providing an enclosure (1) according to any one of claims 2 to 20 for enclosing a functional zone (13), the method comprising: providing a base layer (3); aligning the cover layer (5) on the base layer such that at least one contact surface (25) is disposed between the base layer and the cover layer; introducing a first laser weld line (8) into the enclosure to hermetically seal the functional zone; introducing a second laser weld line (8a, 8b, 8c, 8d, 8e, 8f) at a position close to the first laser weld line; introducing the second laser weld line to remove stress in the region of the first laser weld line of the enclosure; comprising The first laser weld line (8) has a height HL in a direction perpendicular to its bonding surface and a width w in the bonding surface. The at least one second beam spot or at least one second laser weld line (8a, 8b, 8c, 8d, 8e, 8f) is i) The distance in the direction perpendicular to the joint surface between the first laser weld line (8) and the at least one second beam spot or second laser weld line (8a, 8b, 8c, 8d, 8e, 8f) is less than 5HL and at least 1HL, and / or ii) The distance in the direction within the joint surface between the first laser weld line (8) and the at least one second beam spot or second laser weld line (8a, 8b, 8c, 8d, 8e, 8f) is less than 5w and at least 0.5w are arranged so that A method of providing an enclosure (1). **Claim 22** using a laser beam source (9) to introduce the laser weld lines (8, 8a, 8b, 8c, 8d, 8e, 8f) into the enclosure, and guiding the laser beam around the functional zone (13) to form the laser weld line along the contact surface (25) between the base layer (3) and the cover layer (5). A method of providing an enclosure (1) according to claim 21. **Claim 23** The method according to claim 22, wherein the laser beam source (9) is a pulsed laser source and several laser pulses are introduced along the laser weld lines (8, 8a, 8b, 8c, 8d, 8e, 8f), thereby forming one continuous or substantially continuous weld line from the several laser pulses.

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