Sealed glass enclosure

Abstract

The present invention relates to an enclosure for thermally sealing a functional area, the enclosure comprising a base substrate, a cover substrate, the base substrate together with the cover substrate forming at least a part of the enclosure or the enclosure, and at least one functional area, in particular a cavity, which is sealed by the enclosure, the enclosure having at least one laser joining line by which the substrates of the enclosure are joined to each other in an airtight seal, the laser joining line having a height HL perpendicular to the joining plane, in which heat may be generated in the functional area of ​​the enclosure, and in which at least the base substrate and / or the cover substrate are formed as a thermal insulator.

Description

[Technical field]

[0001] The present invention particularly relates to a multi-sealed glass enclosure as well as a method for providing a hermetically sealed glass enclosure.

[0002] Background and Summary of the Invention The sealed enclosure can be used, for example, to protect delicate electronics, circuits or, for example, sensors. This can be applied to medical implants, for example in the area of ​​the heart, the retina or bioprocessors. Bioprocessors made from and used from titanium are well known.

[0003] Sensors can be protected by the inventive housing from particularly adverse environmental conditions, for example in the field of MEMS (Mikro-Elektro-Mechanische-Systeme), barometers, blood gas sensors, glucose sensors, etc.

[0004] Further fields of use of the housing according to the invention are found in the fields of smartphone covers, virtual reality glasses and similar devices. The housing according to the invention can also be used, for example, in the manufacture of flow batteries in the context of electric vehicles. However, the housing according to the invention can also be used in aerospace, in high-temperature applications and in the field of micro-optics.

[0005] Common to the above mentioned applications, high demands are placed on the electronics in terms of their robustness. In order to enable the use of electronics that would not be expected to withstand such external influences, the housing must be protected from these adverse environmental influences. In some cases, furthermore, the requirement is imposed that exchange with the interior area of ​​the housing, i.e. the cavity formed by the housing, i.e. with electromagnetic radiation, for example, in particular in the visible range and / or microwave radiation range, is guaranteed, i.e. the housing is at least partially - i.e. at least in a range and / or for at least one wavelength range - transparent. This transparency allows communication methods, data transmission or energy transmission, measurements from electronics or sensors arranged in the cavity using them. In particular, optical communication methods or optical data transmission or energy transmission may be made possible.

[0006] Basically, it is known to combine several components and arrange them in such a way that an intermediate space results in a receiving area capable of receiving a component. For example, EP 3012059 describes a method for producing a transparent component for protecting an optical component, which is incorporated herein by reference. Here, a novel laser method is used.

[0007] This can be problematic if relatively large amounts of heat energy are released from the inside of the housing, either for a short time or for a relatively long time, i.e., for example in bioimplant applications, where the heat from the housing can potentially cause damage to the surroundings. There are already studies on the effect of heat on various tissue morphologies, starting from which it has been found that typically local damage already occurs when the local temperature exceeds 43° C., and this damage can already lead to cell death, depending on the localization of the damage. For example, in the case of malfunctions such as short circuits in semiconductor components or batteries, temperatures of more than 100° C. can be reached in a short time.

[0008] The present invention therefore works within the framework of an improved, in particular more durable, construction of the housing, i.e. the problem underlying the invention is to provide an improved housing, which reduces the thermal load on the surroundings and thus prevents, for example, damage to cells.

[0009] This can be achieved by reducing, delaying or influencing the heat dissipation from the housing to the surroundings. In some cases, the housing according to the invention allows the use of more advantageous components in the housing due to the protective effect it provides. In particular, components with a relatively high fault tolerance can be used, which are more advantageous in production, since the invention makes it possible to tolerate component failures, provided that their failure no longer results in peak temperatures, particularly in the tissue.

[0010] One further aspect of the invention is based on the realization that in the case of a sealed housing configuration, special precautions may have to be taken to dissipate heat, in particular from power semiconductors, possibly generated inside the housing over a relatively long period of time.

[0011] The housing according to the invention is therefore designed to thermally seal the functional area. In other words, the housing is thermally insulated, so that the escape of heat from the housing to the surroundings is prevented, in particular heat peaks that may occur, for example, in the event of a failure of an electronic component in the housing. For this purpose, the housing has at least one base substrate and a cover substrate, the base substrate forming together with the cover substrate at least a part of the housing or the housing. Furthermore, at least one functional area (12, 13, 13a), in particular a cavity, sealed by the housing is arranged in the housing.

[0012] The housing has at least one laser joining line, whereby the substrates of the housing are hermetically joined to one another by at least one laser joining line. In this case, each laser joining line has a height HL perpendicular to its joining plane. Preferably, the laser joining line with the height HL reaches into the material of the substrate located above the laser joining line. On the opposite side, the laser joining line reaches into the material of the substrate located below the laser joining line. For example, the cover substrate and the base substrate are fused and joined to one another. In other words, during the joining step or within the laser joining line, the material of one substrate is fused and mixed with the material of the other substrate, so that a solid, inseparable, hermetic composite is formed between the one substrate and the other substrate.

[0013] In one other example, at least one intermediate substrate is disposed between the base substrate and the cover substrate, and in this example the base substrate is bonded to the intermediate substrate by at least one first laser bond line in a first bonding plane, and the cover substrate is bonded to the intermediate substrate by at least one second laser bond line in a second bonding plane.

[0014] Heat may be generated within the functional area of ​​the housing, for example, due to power electronic components being located therein that generate heat during operation, or when an electronic component within the housing experiences a component failure with a heat peak.

[0015] Such peak thermal loads, i.e. high thermal energy within a short time, will result in spot or localized elevated temperatures around the housing if the housing were to dissipate the heat freely to the outside. If the housing is, for example, placed inside the body, i.e., for example, in tissue, this elevated temperature may also lead to cell damage and cell death. Thus, it is generally accepted that cell damage and cell death may occur from a threshold temperature of, for example, 43° C. in human tissue (see, for example, “Thresholds for thermal damage to normal tissues: an update”, P. Yarmolenko et al., Int. J. Hyperthermia 2011, pp. 320-343).

[0016] On the other hand, if a power semiconductor fails, local temperatures can be reached in the semiconductor component that can significantly exceed 100° C. and even exceed the melting temperature of the semiconductor component. In order to protect the human tissue from cell damage in this failure example of a semiconductor component that is intended for application in human tissue, for example as a bioimplant, the housing can for example be designed in such a way that the generated heat is dissipated into the surrounding tissue over a relatively long period of time, thereby reducing the peak temperature to no more than a critical temperature of 43° C.

[0017] In the most general case, this can be achieved by at least the base substrate and / or the cover substrate being formed as a thermal insulator, so that heat generated inside the housing is not released to the surroundings or is released at a relatively significantly slower rate.

[0018] The housing may preferably have at least one intermediate substrate, on which one or more functional areas may be arranged.

[0019] The base substrate, the intermediate substrate(s) and the cover substrate may all be formed as thermal insulators, preferably such that the entire outer cover of the housing acts as a thermal insulator.

[0020] The base substrate is preferably made of a material with low thermal conductivity. The base substrate, the intermediate substrate or substrates and / or the cover substrate may comprise a glass-like material, for example glass, glass ceramic, silicon, sapphire or a combination of said materials. In particular glass or glass-like materials have been found to be particularly advantageous, since they have a very good biocompatibility, are chemically compatible with the human body and have no known interactions with it, while at the same time glass offers excellent thermal insulation properties. Furthermore, glass can be manufactured to be transparent to radiation, so that wireless information exchange, for example via radiation or radio wave information or contactless charging of electronic devices or batteries, which may possibly be arranged in the housing, can be ensured. If the substrate, in particular the cover substrate, is a substrate that is transparent in the light wavelength range, i.e. for example an optically transparent substrate, the energy supply into the housing can be realized by optical means, for example via a photovoltaic cell arranged in the housing or another type of photoreceptor for supplying electrical energy. In this case, the housing can be described as a self-sufficient housing.

[0021] In particular, in order to create a hermetic seal around the functional area, one of the laser joining lines may surround the functional area with a distance DF. In one example, the distance DF is constant around the functional area, so that the laser joining lines surround the functional area with approximately the same distance on all sides. However, the distance DF may also vary depending on the application. This may be more advantageous in terms of manufacturing technology if several housings are joined simultaneously in one work step, for example, a straight joining line or laser joining line is guided to each contact surface of the individual housings. This may also be the case when the functional area or the housing is, for example, circular or has any shape and the laser joining line sealing the functional area is drawn in a straight line. In one special example, the functional area may be formed as a cavity, which may also have optical properties and may be processed in the form of a lens, such as a convex lens, and the laser joining line may be drawn around the cavity in a different pattern than the cavity.

[0022] The functional area of ​​the housing is configured to accommodate at least one object, such as an electronic circuit, a sensor, or a MEMS, and thus at least one object is arranged in the housing. The at least one object may include a power semiconductor chip, such as a GaN-LED, a SiC power transistor, a GaAs power transistor, or a GaN power transistor.

[0023] In this case, the contents are arranged in a cavity that is preferably surrounded on all sides or completely by the housing. The functional area or cavity may be formed in the base substrate, i.e., for example, by grinding a recess out of the base substrate, so that the functional area and / or at least one content is surrounded below and laterally by the material of the base substrate. The functional area or cavity may be arranged on the upper side of the base substrate. The cavity has a lower surface, a laterally surrounding edge and an upper surface. Alternatively, the upper surface can be described as a first side, the lower surface as a second side located opposite the first side, and the edge as an intermediate area between the first side and the second side, in which case the edge typically lies substantially perpendicular to the first and / or second side. Furthermore, the height of the edge may be zero, in which case the upper surface is directly supported by the lower surface, for example if the functional area only has one thin functional layer.

[0024] The housing may have several cavities, in particular for housing at least one container in each cavity. In other words, several containers may be divided into different cavities in one housing, which results in a spatial separation of the components from one another in the same housing. For example, this allows a battery or memory cell, which may be installed, to be housed in the housing isolated from the other components. This can improve the situation where the other components are damaged or destroyed by the heat generated in the case of a component failure, for example. In this way, the battery or memory cell can be protected in the event of overheating of the power transistor, so that the battery or memory cell does not also overheat and release heat. In this case, therefore, less heat is stored or released to the surroundings overall, which in particular keeps the overall temperature of the housing lower, which can reduce or avoid cell damage in the case of a bioimplant.

[0025] That is, the reduction of heat dissipation from the housing to the environment can be improved by dividing the components or contents into several different cavities, thereby preventing a "chain reaction" in which, for example, if a first component fails, other components also fail and release additional heat. One other aspect is that by dividing the contents into different cavities, each component is also additionally protected. In this way, memory components can be arranged in their own cavities, so that even if a component, such as a power transistor, fails in the housing, it can still possibly still be read or removed safely.

[0026] Alternatively or additionally, a heat insulating medium may be placed in one or more cavities to improve the heat insulation. In other words, the cavities are filled with a heat insulating medium of a different kind than glass. In this case, the heat insulating medium is in particular a fluid, for example a heat insulating liquid or a heat insulating gas. Heat insulating medium also means that the one or more cavities are evacuated, i.e. that the cavities are "filled with vacuum", since vacuum is also well suited as a heat insulating medium. In this case, it can be ensured that the filling of the cavities with the heat insulating medium or vacuum can be maintained continuously due to the sealing of the cavities, particularly preferably by laser welding.

[0027] In other words, a plurality of containers are disposed within the housing, and in this case, it is preferable that the containers are each divided into different cavities.

[0028] The hermetically sealed housing preferably comprises a glass feedthrough, in particular in an intermediate substrate separating the at least two cavities, which is provided for electrically connecting the contents arranged in the different cavities, in particular a "Through Glass Via" (TGV), in which case the via is filled with a conductive material.

[0029] The housing may have at least one electrical connection layer on at least one of the intermediate substrates, which makes it particularly easy to arrange components or components in each cavity and electrically connect them. The electrical connection layer is arranged, for example, on the underside of one or more or all of the cavities and is contact-connected to one or more glass feed-throughs.

[0030] It is certainly a preferred design form for the housing to have a cavity in which, in particular, one or more components can be arranged. However, the housing according to the invention is not limited to a design form with a cavity, since a functional area can have or perform a function, and in this case it is not necessary to have a cavity in the sense of a hollow space. An example of such a functional area is the application of an electrical connection layer onto a substrate, whereby a functional area is already formed without a hollow space. Such an electrical connection layer can, for example, electrically connect two further functional areas, for example two cavities.

[0031] A substrate may have several layers and thus may be a multi-layer composite, which may then be bonded to another substrate as one of the layers of the housing by a laser bonding method, which means that the multi-layer composite is prepared in advance, for example by applying a coating to the substrate, thus resulting in a two-layer composite, and this two-layer or the entire multi-layer composite is bonded to another layer during the manufacturing process of the housing to produce the housing.

[0032] The use of a multi-layer composite in the housing can add additional material properties to the housing. For example, the multi-layer composite may already have internal stresses or preloads or preload directions, so that the amount of internal stresses can be improved when the multi-layer composite is laser bonded to at least one other layer of the housing. For example, this can improve the resistance capabilities of the housing when a pre-cured multi-layer composite is used. This can result in the entire housing taking on the properties of the cured housing. Additionally or alternatively, the multi-layer composite can have one or more coating layers, i.e., coatings that can cause complications if, for example, this layer has to be bonded by a laser bonding method. In other words, the substrate prepared as the multi-layer composite is prepared with multiple layers already bonded to each other as a "pack" or "stack". It may also include optical coatings.

[0033] To bond the substrates together, a laser bonding method is used, which can be locally controlled so that the bonding operation introduces only a small or negligible amount of heat into the functional areas or cavities, and thus the laser bonding is carried out at approximately room temperature, i.e. the housing is bonded at approximately room temperature.

[0034] The laser joining line, in particular with a height HL, extends into the material of the substrate arranged above the laser joining line. At the laser joining line, a local melting process in the material takes place, so that when the laser joining line reaches, on the one hand, into the first substrate and, on the other hand, into the second substrate, the two substrates are fused together and joined. In other words, the laser joining line fusedly joins the base substrate to the one or more intermediate substrates and the cover substrate.

[0035] The laser joint line is arranged or formed in such a way that, for example, two components are fused together and joined by the laser joint line, thereby bridging the gap of the enclosure. If the enclosure only has a base substrate and a cover substrate to completely enclose the functional area, the contact areas between the base substrate and the cover substrate, i.e. the points, areas or surfaces where the cover substrate and the base substrate meet, are bridged or joined by the laser joint line. As a result, an enclosure is formed as if it were molded in one piece, in which the separations between the components are also sealed by the laser joint line.

[0036] In other words, to provide the housing, a first step is provided with a first substrate (base substrate) and at least one second substrate (cover substrate), the at least one second substrate (cover substrate) comprising a transparent material, i.e. at least in an area or partially transparent for at least one wavelength range. The cover substrate is preferably arranged directly on the base substrate, i.e. the cover substrate covers, for example, the cavity to be sealed, and the base substrate forms the respective underside of each housing. At least one contact surface is formed between the at least two substrates, so that each housing has at least one contact surface. The cavity is then hermetically sealed by bonding the at least two substrates along the contact surfaces of each housing, in particular along a line at the edge of each housing at the contact surface. Advantageously, from one common starting substrate, for example in the form of wafers of a wafer stack, a number of housings can be produced together, or only the base substrate can be provided as a wafer. The method for producing the housings may then continue with the individualization of each housing by a cutting or separation step.

[0037] In this case, the substrate layers or base substrate and the cover substrate are directly stacked in direct contact with each other, i.e. arranged adjacent to each other. Preferably, foreign materials are excluded as much as possible between the substrate layers, so that the most intimate and surface-like contact of one substrate layer with the adjacent substrate layer occurs. In the case of two substrates, for example, the base substrate is arranged opposite to the cover substrate so that it is in direct contact with the cover substrate, in particular without any additional material or space between the base substrate and the cover substrate. In the case of three or more substrates, the base substrate is arranged immediately adjacent to the first or first intermediate substrate layer, and the cover layer is also arranged immediately adjacent to the first or last intermediate substrate layer.

[0038] The substrates are then joined to one another using the novel laser joining method. In this case, one area-shaped substrate layer is directly joined to the area-shaped substrate layer arranged immediately adjacent to one another, without the provision or need for a foreign or non-area-shaped material or intermediate layer for this purpose. That is, the substrates are directly joined to one another. The laser joining line generated in the area-shaped contact area between the two substrate layers inseparably joins the substrate layers arranged directly adjacent to one another. That is, the melted area of ​​the laser joining line is located in the two substrates and seamlessly transitions from the first substrate to the second substrate arranged immediately adjacent to one another, for example from the base substrate to the cover substrate. In this case, the novel laser joining method is also in contrast to previous methods of joining substrates to one another by laser, in particular because the method according to the invention generates a significantly smaller amount of heat energy in the substrate stack or the housing, so that only very little heat energy is dissipated into the remaining housing and only very little temperature rise of the components / components arranged in the functional area occurs. This is even more important. In the present invention, at least one of the substrates of the housing has particularly good thermal insulation properties, so that the thermal energy applied to the housing during laser joining possibly remains there for a relatively long time before being released to the surroundings. The use of thermal insulation materials for housings in which components are or may be located close to the laser joining line is therefore only possible in this combination by using the novel laser joining method according to the present invention.

[0039] That is, a direct, planar or even complete transition is formed from one substrate layer to the next, for example a substrate-substrate transition or a glass-glass transition. A locally restricted volume is formed as a bonding zone or laser bonding line, in which there is a material transfer or material mixing between adjacent substrate layers, which is formed in particular planar. In other words, the material of the first substrate, for example the cover substrate, penetrates into the adjacently arranged substrate, for example the intermediate substrate or the base substrate, and vice versa, i.e. the material of the adjacently arranged substrate also penetrates into the first substrate, so that in the bonding zone there is a complete material mixing between the adjacently arranged substrates. The bonding zone may therefore also be called a convection zone.

[0040] In this case, the new laser bonding technology for forming an inseparable glass-glass transition or substrate-substrate transition is particularly advantageous in that it does not require intermediate layers, glass frits, films or adhesives that must be placed between the substrates in previously known methods. Instead, the inseparable bond can be produced without correspondingly cumbersome intermediate layers or additional materials. This saves on the use of additional materials, increases the hardness that the final product can achieve, and allows for reliable sealing of functional areas or cavities. In this case, the laser bonding zone is detected in the finished final product, for example, based on a specific local refractive index change of the material in a small or localized melted area.

[0041] In one advantageous refinement, at least one of the substrates may incorporate a marker.

[0042] The housing is preferably at least partially and / or area-transparent for one wavelength range. In one simple example, the cover substrate of the housing is optically transparent, i.e. transparent, in the visible wavelength range. However, transparency, for example in the X-ray range, may also be advantageous. In other words, for example, the cover substrate preferably comprises a glass-like material. The cover substrate is thereby preferably transparent or transmissive, for example optically transparent, for at least one wavelength range. Depending on the application, it may be advantageous if the cover is opaque, i.e. optically opaque and formed like milky glass. Reduced or partial transparency may also be sufficient for the function. For example, the cover substrate may comprise glass, glass ceramic, silicon, sapphire or a combination of said materials. In one preferred embodiment, the cover substrate is a glass sheet, for example made of hardened glass, special glass or high-temperature resistant glass, for example from the product portfolio of the applicant.

[0043] The housing may be formed such that at least one functional area of ​​the housing can be configured to accommodate at least one object having a size of 10 mm x 10 mm or less, preferably 5 mm x 5 mm or less, more preferably 2 mm x 2 mm or less or 1 mm x 1 mm or less. In this case, the size of the housing is adapted to the size and number of objects in the functional area or cavity of the housing. For example, if one object having a size of about 5 mm x 5 mm is arranged in each of four cavities of the housing, when two cavities are arranged side by side and two cavities are arranged one above the other, the housing will typically have a size of 13 mm x 13 mm or more, thereby ensuring the accommodation of the object in the cavity.

[0044] The size of the wafers to be cut has a practical size specification based on the preferred manufacturing method, which should be understood as not being a size limitation per se. However, the use of wafers in the manufacturing should be understood as an example only. It is quite possible to use, for example, glass sheets to manufacture a transparent housing, which may have dimensions larger than the typical wafer size.

[0045] The invention also focuses on a method for providing a hermetically sealed housing, which encloses a functional area, in particular a cavity, comprising the steps of providing at least one base substrate and a cover substrate, the cover substrate being at least partially or regionally transparent for at least one wavelength range and thus a transparent cover substrate, arranging at least one container in the functional area, in particular in the cavity, arranging the cover substrate on the base substrate above the at least one container, forming at least one contact surface between the base substrate and the cover substrate, so that each housing has at least one contact surface, and hermetically sealing the cavity by forming at least one laser joining line on at least one contact surface of each housing, forming at least one of the base substrate or the cover substrate in a thermally insulated manner.

[0046] The cover substrate and the base substrate are preferably joined together by a laser joining line. In other words, the cover substrate is placed on or in the base substrate without an intermediate layer and is immediately joined directly to the base substrate by one or more common laser joining lines. In this case, the cover substrate forms a complete housing together with the base substrate. In other words, no additional or separate components are required to form or close the housing, but the base substrate, at least one laser joining line and the cover substrate together completely hermetically seal the functional area or cavity. On the other hand, it may be advantageous to use one or more intermediate substrates, for example to isolate multiple cavities from each other.

[0047] At least two substrates or a base substrate and a cover substrate are arranged or attached adjacent to each other, so that they are located adjacent to each other in a planar manner, and no other films, layers or inclusions are present between the at least two substrates or a base substrate and the cover substrate and possibly an intermediate substrate. For technical reasons, very small amounts of gas inclusions between the layers in the area of ​​the contact surfaces may be unavoidable, which may also result from unevenness. For example, the amount of gas inclusions in the area of ​​the planarly supported contact surfaces can be significantly reduced by pressure increase, especially by pressing, or by surface treatment, such as a grinding process of the substrate layers, especially the contact surfaces. Prior evacuation is advantageous. It may also be advantageous to fill with a type of gas or liquid depending on the process parameters and the materials to be used.

[0048] It is particularly preferred that possible gaps between the substrates are less than 5 μm thick, more preferably less than 1 μm thick. Such gaps arise, for example, due to manufacturing errors during the production of the substrates, due to thermal effects or due to inclusions of particles such as dust. In the case of such permissible distances, which are also considered to be immediately adjacent within the scope of the present invention, it is also possible to join them by laser, so that the joining zone has a thickness of 10 to 50 μm and thus hermetic sealing is guaranteed. In this case too, the joining zone extends from the first substrate to the inside of the second substrate arranged adjacent to the first substrate. The joining zone is thus brought to the contact area between the first substrate and the second substrate, directly fusing the substrates to each other and forming one inseparable composite. In other words, by joining the substrates arranged adjacently in the joining zone, the material located in the joining zone of the two substrates is directly melted, the material of the first substrate mixes with the material of the second substrate and one inseparable integral composite is formed. That is to say, the housing thus produced in any case has an integral, i.e. monolithic, composite between the substrates in the joining zone.

[0049] The contact surface does not have to be optically transparent. It is even more advantageous if the substrate, which is transparent in the visible wavelength range, is made opaque. Only the substrate, which passes the laser to reach the contact surface, has at least one spectral "window", so that at least the wavelength of the laser used can be at least partially or at least regionally transmitted through the substrate. The contact surface is such that the laser can deposit energy at the contact surface. For example, the surfaces of the two substrates, which are located adjacent to each other, may be optically contact bonded and may even preferably have a roughness in the nm range. At this surface, the laser is at least partially absorbed and can therefore bring energy there. Overall, the contact surface in the sense of the present application can be understood as a surface at which the incident laser beam can deposit energy, i.e. along which the bonding process can be carried out.

[0050] Additionally, the present invention includes within its scope a housing manufactured or formed by the above method.

[0051] To form the laser joint line, in particular the laser beam is guided in a circular manner around the functional area, whereby the functional area is sealed in an annular manner along at least one contact surface. Optionally, the laser beam may be circulated in an annular manner multiple times and / or optionally multiple laser joint lines may be formed.

[0052] Also included within the scope of the present invention is the use of a housing containing a sealed functional area or cavity produced by the above-described method as a medical implant or bioimplant or sensor.

[0053] The invention will now be explained in more detail on the basis of an embodiment with reference to the drawings, in which identical and partially similar parts are provided with the same reference numerals and the features of different embodiments may be combined with one another. [Brief description of the drawings]

[0054] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] Detail view showing the bonding zone. [Figure 4] FIG. 4 is a side cross-sectional view showing a functional area of ​​the housing. [Diagram 5] FIG. 2 is a side cross-sectional view showing the functional area of ​​a housing with two cavities. [Figure 6a] 1 is an example showing steps for manufacturing a housing. [Figure 6b] 1 is an example showing steps for manufacturing a housing. [Figure 6c] 1 is an example showing steps for manufacturing a housing. [Figure 6d] 1 is an example showing steps for manufacturing a housing. [Figure 6e] 1 is an example showing steps for manufacturing a housing. [Figure 7] FIG. 2 is another cross-sectional side view showing the functional areas of the two housings. [Figure 8] FIG. 2 is another cross-sectional side view showing the functional areas of the two housings. [Figure 9] 4 is an example showing another step of manufacturing the housing.

[0055] Detailed Description of the Invention In Fig. 1 a plan view of a housing 1 according to the invention is shown, in which a circumferentially extending laser-bonded zone 8 surrounds a functional area 13. The functional area 13 may be configured in various ways. Examples of various configurations of the functional area 13 can also be seen in the further Figs. 3 to 8, which show cross-sections and thus allow the vertical structure of the functional area 13 to be elucidated. In this case, all plan views can be shown diagrammatically as well, so that the various configurations of the functional area 13 are summarized in the diagram of Fig. 3.

[0056] The functional area 13 can fulfill various roles. For example, the functional area 13 may be configured as a photoreceptor or may have technical, electromechanical and / or electronic components 2 arranged in the functional area 13. Several of these roles may be fulfilled in the functional area 13. The housing 1 is covered on the top side by a top substrate 5, for example a cover 5, into the interior of which the laser bonding zone 8 or at least one laser bonding zone 8 reaches.

[0057] With reference to Fig. 2, a first cross-sectional view of a first embodiment of a housing 1 having a base substrate 3 and a cover substrate 5 is shown. In other words, the housing 1 is composed or assembled from two layers, namely the base layer 3 and the cover layer 5. Fig. 3 further shows the configuration of a laser bond line 8 consisting of a series of laser pulse impingement areas 16 arranged in close contact with one another, so that the materials of the base substrate 3 and the cover substrate 5 are fused together without any gaps and thus sealing the functional area 13 or cavity 12 (located behind the laser bond line 8 in this figure).

[0058] 3 shows a part of the bonding area in detail, in this case the interface zone, i.e. the contact surface 25 and the laser bonding zone 8. The laser bonding zone 8 is arranged in the area of ​​the contact surface 25 for bonding the two substrates 3, 5 to one another.

[0059] In Fig. 4, a cross-section of one embodiment of the housing 1 is shown along the line C→D shown in Fig. 1. Fig. 4 thus shows a cross-section of the functional area 13, 13a, which extends, for example, as a consistent hollow space or cavity in the housing 1. In other words, the cavity extends from the base substrate 3 into the cover substrate 5 and is present, for example, in the form of a recess consisting of the base substrate 3 and / or the cover substrate 5. Here, the functional area 13 is formed as a recess in the cover substrate 5 and the functional area 13a is formed as a recess in the base substrate 3, for example by means of a polishing method, such as a sandblasting method. In other words, the base substrate 3 has a recess 13a and the cover substrate has a recess 13 into which the content 2 is inserted.

[0060] For example, the functional area 13a may include an active layer, for example a conductive layer 34. The active layer of the functional area 13a may include a photoreceptor, for example in the form of a photovoltaic cell, which is arranged to generate electrical power. In this case, the housing 1 may be a self-contained housing 1. The functional area 13, arranged in the area of ​​the cover substrate 5 thereon, may include a cavity 12.

[0061] A laser-bonding zone 8 is arranged around the functional area 13, 13a, which closes the periphery of each side of the functional area 13, 13a. It is conceivable that in the laser-bonding zone 8, the functional area 13, 13a is not closed all around, but leaves open areas, which for example leave spaces for communication passages or electrical connections, which for example can also form fluid connections with the surroundings. In other words, it is conceivable that preplanned places or positions are not closed by the focused laser beam 9, but are instead sealed there by other means, such as an adhesive. It is preferable to close the functional area 13, 13a on all sides without gaps, so that a hermetic seal of the functional area 13, 13a can be guaranteed. In the cavity 12, the contents 2, i.e. for example electronic components, are arranged on the functional area 13a, i.e. for example on the conductive layer 34.

[0062] 5, a further cross-section is shown in the region of the functional areas 13, 13a of the housing 1. The housing 1 has five substrate layers, namely a base substrate 3, three intermediate substrates 4a, 4b, 4c and a cover substrate 5. The intermediate substrates 4a and 4c each have a cavity 12 for receiving a component 2. The intermediate substrate 4b has electrical through contacts or glass feed-throughs 32, so-called through-glass vias, so that the components of the functional area 13 can be electrically connected to components arranged in the functional area 13a.

[0063] The functional area 13 is formed as a cavity 12 in which several components 2 are arranged. The components 2 are also arranged on the conductive partial layer 34, which is also electrically contacted to the glass lead-through 32. The components 2 of the functional area 13 are thus isolated by the intermediate layer 4b from the components 2 arranged in the functional area 13a. If a component 2 arranged in the functional area 13 for example fails, if a liquid leaks out or if thermal overheating occurs, the components 2 arranged in the functional area 13a are isolated from it. This reduces or even prevents failures of further components 2 that may follow as a result of the failure of the first component. A heat insulating medium is accommodated in the two cavities 12 in order to further improve the thermal insulation.

[0064] With reference to Figs. 6a to 6e, an example for the manufacture of a housing 1 according to the invention is shown. Starting from Fig. 6a, a middle intermediate substrate 4b is first provided, which already has a glass feed-through 32 or in which a glass feed-through 32 is to be provided. The manufacturing process is carried out in this example in such a way that for economic reasons two housings 1 are produced from one wafer 4b. The subsequent separation of the two housings 1 can be carried out, for example by a laser cutting method, along a separation line 10. Alternatively, it is also conceivable to form a common housing with the cavities 12 arranged side by side, i.e. corresponding to the example shown in Fig. 6e, without separating the two partial areas along the separation line 10. In this case, horizontal glass feed-throughs 32 (not shown) corresponding to the illustrated vertical glass feed-throughs 32 may be provided to connect the adjacent cavities 12.

[0065] 6b shows the partial application of an electrical contact layer 34 on both sides of the middle intermediate layer 4b. The electrical contact layer 34 is divided into contact areas, which may be electrically contacted to one of the glass feedthroughs 32, as shown. Some of the contact areas 34 may also be applied without contacting the glass feedthroughs 32, if this is advantageous, for example, to connect two components 2 in one cavity to each other but not to a component 2 arranged in another cavity 12 in the housing 1.

[0066] 6c shows the application of the fillers 2 in the areas which will later correspond to the cavities 12, in particular in the contact areas 34. These components 2 can be electrically connected to further components 2 arranged in the same cavity 12 and / or to further components 2 arranged in other cavities 12, in particular via glass feedthroughs 32. The components 2 can be contact-connected, for example, by soldering, welding, epoxy conductive paste or in the manner of wire bonding.

[0067] Fig. 6d clearly shows that one spacer wafer 4a and one spacer wafer 4c are attached to the upper or lower side of the intermediate layer 4b. The spacer wafers 4a and 4c are laser bonded to the intermediate layer 4b, i.e. a laser bond line 8 is formed in each case. Finally, Fig. 6e clearly shows the application of the base substrate 3 to the lower side of the housing 1 and the application of the cover substrate 5 to the upper side of the housing 1, where the substrates are again bonded by the laser bond line 8.

[0068] That is, the laser pulse impingement 16 creates a laser bonding zone 8 along the contact surface 25 where the cover substrate 5 is welded or bonded to the base substrate 3 .

[0069] 7 shows an embodiment of a housing 1 with a first glass interlayer 4a applied to a base substrate 3, a component carrier layer 4b on which the component 2 is arranged, a further glass interlayer 4c and a cover substrate 5. The functional areas 12, 13, 13a are arranged in this embodiment such that the functional areas 12, 13, 13a are respectively arranged below and above the component carrier layer 4b. A bonding line 8 is arranged around each cavity 12, so that each cavity 12 is sealed on all sides. The housing 1 may be circular or rectangular and can have any basically free shape.

[0070] The contents 2, for example sensors or actuators or processors, are arranged on the underside and on the top side of the component carrier layer 4b, for example glued or soldered thereto. On both sides of the contents, metal pads 34 are arranged for electrical contact-connection of the contents 2. The contents 2 are electrically contact-connected to the further components 2 via contact conductors 32, for example bonding wires. The metal pads 34 may also refer to metal contact surfaces. The substrates are respectively directly connected to each other by laser bonding lines 8. In this case, the laser 9 was guided twice around the cavity 12 along the contact surface 25 or along the outer edge of the cavity 12, but on a path that is not identical, so that two closed annular laser bonding zones 8 are formed. Instead, the laser 9 was guided on a path that was laterally offset each time around the cavity 12, resulting in two laser bonding zones 8 located next to each other. The microbonding zones 8 in the present example have dimensions of, for example, 5 μm×10 μm or 10 μm×50 μm.

[0071] In one embodiment of the housing 1 shown in FIG. 8, the cavity 12 is formed in the intermediate substrate or component carrier layer 4b. For example, the cavity 12 can be formed in the intermediate substrate 4b by sandblasting, i.e. generally cut out from the intermediate substrate 4b by grinding. Chemical etching is also possible to form the cavity 12 in the component carrier layer 4b. This configuration is advantageous in that the cover substrate 5 can be formed as a simple glass plate, which is joined to the component carrier layer 4b, for example by microbonding and laser bonding lines 8. This configuration is advantageous in that the components arranged in the upper cavity 12, i.e. in the cavity cut out from the intermediate substrate 4b, are arranged protected by the intermediate substrate 4b already during the manufacturing process. Furthermore, one substrate layer is saved. In all embodiments, the same reference numerals indicate the same features in the figures.

[0072] Referring to Fig. 9, another embodiment of a method for manufacturing multiple housings 1 is shown. The manufacturing of a housing such as that shown in Fig. 8 is described. It is clear to those skilled in the art that only a single housing can be manufactured depending on the process requirements.

[0073] In step A, a common component carrier substrate 4b is provided with a number of recesses 12 which correspond to the future cavities 12 and are formed in the component carrier substrate 4b, for example by a grinding method. An object 2 is placed in each of the recesses 12 and is soldered, for example, to a contact 34 (see FIGS. 6a to 6e) which is provided or which is already attached thereto. In step B, a common cover substrate 5 is attached to the component carrier substrate 4b, i.e. each recess has its own cavity 12. A number of objects 2 can be placed in each common cavity 12.

[0074] It may then be envisaged to attach a further component 2 to the underside of the component carrier substrate 4b and to form a further cavity 12 (see Figures 6c to 6e and 8). For this purpose, it is conceivable to arrange a further glass interlayer 4a on the underside of the component carrier substrate 4b and underneath that a base substrate 3. This is optional in the sense of the manufacturing method.

[0075] In step C, the completed substrate stack is laser-bonded, thereby sealing each receiving cavity 12, i.e. closing the cavity 12 on all sides along the contact surface 25 and forming at least one laser bonding line 8 for each housing 1. For this purpose, a laser unit 15 is guided over the cover substrate 5 and across the surface of the cover substrate 5, directing a point-like focused laser beam 9 onto the zone to be bonded, i.e. in particular onto the contact surface 25. After completion of step C of the manufacturing method, all cavities 12 are sealed. After step C, it is possible to singulate the individual housings 1 by a cutting process and thus obtain a number of individually separated housings 1.

[0076] In step D, the components are separated from one another along parting or cutting lines 10. Optionally, the same laser can be used for this as for the laser joining in step C. However, conventional cutting methods can also be used if advantageous.

[0077] It is clear to those skilled in the art that the above-mentioned embodiments are exemplary, and the present invention is not limited to these embodiments, and may be varied in various ways without departing from the scope of protection of the claims. Moreover, it is also clear that each feature, even if described together with other features, alone defines a main component of the present invention, regardless of whether they are disclosed in the specification, claims, drawings or otherwise. In all figures, the same symbols represent the same features, and the description of a feature that is sometimes mentioned only in one figure or in any case not mentioned in all figures may also be transferred to the figures in which this feature is not explicitly described in the specification. [Explanation of symbols]

[0078] 1. Sealed enclosure 2. Contents and functional devices 3 Lower substrate, layer or wafer, base substrate or lower cover 4,4a,4b,4c,4d,4e,4f Middle layer 5 Top substrate, layer or wafer, cover substrate or top cover 8 Laser Bonding Zone 9 Focused laser beam 10 Parting or cutting lines 12. Storage cavity 13 Functional Areas 13a Second Functional Area 14 Edge 15 Laser unit for joining and / or cutting 16 Laser pulse collision region 18 Board Stack 21 Cavity edge 22 Underside of cavity 23 Top of cavity 25 Contact surface 32 Glass through guide, through glass via 34 Electrical Contact Layer

Claims

1. A housing (1) for thermally sealing a functional area, comprising: A base substrate (3), a cover substrate (5), said base substrate (3) forming together with said cover substrate (5) at least a part of said housing (1) or said housing (1); at least one functional area (12, 13, 13a), in particular a cavity (12), enclosed by said housing (1), Heat can be generated in the functional area (12, 13, 13a) of the housing (1); At least the base substrate (3) and / or the cover substrate (5) are formed as a thermal insulator, The housing (1) further includes at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) disposed between the base substrate (3) and the cover substrate (5); The housing (1) has at least one laser joining line (8), Adjacent substrates among the base substrate (3), the at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) are hermetically sealed and joined together by corresponding ones of the at least one laser joining line (8); The laser bond line (8) has a height (HL) perpendicular to its bonding plane, The functional areas (12, 13, 13a) are configured to accommodate a plurality of contents (2), such as electronic circuits, sensors, or MEMS, thereby disposing a plurality of the contents (2) within the housing (1); the functional areas (12, 13, 13a) are present inside an area of ​​the base substrate (3), the at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) that is surrounded by the at least one laser joining line (8); The functional area (12, 13, 13a) of the housing (1) includes a plurality of cavities (12), The housing (1) further includes a glass through-passage (32) in the intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f, 4g) isolating at least two of the cavities (12) for electrically connecting contents (2) arranged in different cavities (12). Housing (1).

2. the base substrate (3), the at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and / or the cover substrate (5) are made of a material with low thermal conductivity, and / or the base substrate (3), the intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) are formed as thermal insulating materials; The housing (1) according to claim 1.

3. The housing (1) according to claim 1 or 2, wherein the base substrate (3), one or more of the intermediate substrates (4, 4a, 4b, 4c, 4d, 4e, 4f) and / or the cover substrate (5) comprise a glass-like material, such as glass, glass ceramic, silicon, sapphire or a combination of said materials.

4. 4. The housing (1) according to claim 1, wherein at least one of the laser joining lines (8) surrounds the functional area (12, 13, 13a) with a distance (DF) therebetween.

5. The plurality of containers (2) include power semiconductor chips, such as GaN-LEDs, SiC power transistors, GaAs power transistors or GaN power transistors; and / or The plurality of containers (2) are part of the housing (1); The housing (1) according to any one of claims 1 to 4.

6. The housing (1) according to any one of claims 1 to 5, wherein an insulating medium is placed in one or more of the cavities (12) to improve the insulating effect, the insulating medium being in particular a fluid, for example an insulating liquid or an insulating gas or a vacuum.

7. The housing (1) according to any one of the preceding claims, further comprising at least one electrical connection layer on at least one of the intermediate substrates (4, 4a, 4b, 4c, 4d, 4e, 4f, 4g).

8. The housing (1) according to any one of claims 1 to 7, wherein at least one of the base substrate (3), the one or more intermediate substrates (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) is provided as a multi-layer composite, e.g. having one or more coating layers or preload zones and / or e.g. having one or more substrates.

9. 9. The housing (1) according to claim 1, wherein the laser joining line (8) having the height (HL) extends into the interior of the material of the intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) arranged above the laser joining line, and the base substrate (3), the intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) are fused and joined to one another.

10. The housing (1) according to any one of claims 1 to 9, wherein at least one of the base substrate (3), the one or more intermediate substrates (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) is provided with a marker.

11. The housing (1) according to any one of the preceding claims, wherein the housing (1) is at least partially and / or area-transparent to a given wavelength range.

12. The housing (1) according to any one of claims 1 to 11, wherein the cavities (12) of the housing (1) are configured to accommodate the contents (2) having a size of 10 mm x 10 mm or less, preferably 5 mm x 5 mm or less, more preferably 2 mm x 2 mm or less or 1 mm x 1 mm or less.

13. A method for providing a hermetically sealed enclosure (1) enclosing a functional area (12, 13, 13a) including a cavity (12), comprising the steps of: - providing a base substrate (3), at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and a cover substrate (5), the cover substrate (5) being at least partially or regionally transparent for at least one wavelength range and thus a transparent cover substrate (5); placing at least one container (2) in said cavity (12); placing said cover substrate (5) on said base substrate (3) above said at least one container (2), forming at least one contact surface (25) between said base substrate (3) and said cover substrate (5), so that each housing (1) has at least one contact surface (25); forming at least one laser bond line (8) on said at least one contact surface (25) of each housing (1) to hermetically seal said cavity (12), while forming at least one of said base substrate (3) or said cover substrate (5) in a thermally insulated manner; having The method further comprises the step of disposing at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) between the base substrate (3) and the cover substrate (5), bonding adjacent substrates among the base substrate (3), the at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) to each other by a corresponding one of the at least one laser bonding line (8) so as to form an airtight seal; the functional areas (12, 13, 13a) are present inside an area of ​​the base substrate (3), the at least one intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f) and the cover substrate (5) that is surrounded by the at least one laser joining line (8); The housing (1) includes a plurality of cavities (12) and a plurality of contents (2); The housing (1) further includes a glass through-passage (32) in the intermediate substrate (4, 4a, 4b, 4c, 4d, 4e, 4f, 4g) isolating at least two of the cavities (12) for electrically connecting contents (2) arranged in different cavities (12). method.

14. 14. The method according to claim 13, for forming a housing (1) according to any one of claims 1 to 12.

15. 15. The method according to claim 13 or 14, wherein to form the laser joining line (8), a laser beam (9) is guided in a circular manner around the functional area (12, 13, 13a), whereby the functional area (12, 13, 13a) is sealed in an annular manner along the contact surface (25), and optionally the laser beam (9) may be circulated in an annular manner several times and / or optionally several laser joining lines (8) may be formed.

16. Use of a housing (1) enclosing an internally sealed cavity (12) manufactured by the method according to any one of claims 13 to 15 as a medical implant or sensor.

Images