DE102019121051A1 - Hermetically sealed, transparent cavity and its housing - Google Patents

Abstract

The invention relates to a hermetically sealed housing (1), comprising a functional area (12, 13, 13a) hermetically sealed by the housing (1), in particular a cavity, a cap (5) with an upper part (5b) and a circumferential flank ( 5a) for forming an upper side (23) and a laterally circumferential edge (21) of the functional area or the cavity (12), as well as a second part (3), in particular a base substrate, for forming an underside (22) of the functional area or the cavity (12), and a glass intermediate layer (4) deposited on the second part (3), which is arranged between the second part (3) and the flank of the cap (5), the cap (5) and the glass intermediate layer ( 4) are hermetically sealed with at least one laser bond line (8), the laser bond line (8) having a height (HL) perpendicular to its connection plane, the cap (5), the second part and the glass intermediate layer (4) jointly forming the functional area or the behe Completely enclose the hermetic cavity (12) so that the hermetically sealed housing (1) is formed.

Description

Field of invention

The invention relates to a method for providing a hermetically sealed housing and a transparent housing.

Background and general description of the invention

Hermetically sealed enclosures can be used to protect sensitive electronics, circuits or, for example, sensors. Medical implants can be used, for example, in the heart area, in the retina or for bio-processors. Bio-processors are known which are made from titanium and used.

Sensors can be protected with an enclosure in particularly adverse environmental conditions. This area also includes, for example, MEMS (micro-electro-mechanical systems), barometers, blood gas sensors, glucose sensors, etc.

Another field for the use of a housing can be found in a case for a smartphone, in the area of virtual reality glasses and similar devices. An enclosure can also be used for the production of flow cells, for example in the context of electromobility. But enclosures can also be used in the aerospace industry, in high-temperature applications and in the field of micro-optics.

It can be problematic if the sensitive electronics are to be connected to the outside with electrical connections. Or if the electronics to be protected have larger dimensions, for example comprise an entire printed circuit board. The protection of a larger area such as a printed circuit board is possible, but expensive and time-consuming.

The aforementioned uses have in common that high demands are made on the electronics with regard to their robustness. The electronics must therefore be protected from adverse environmental influences. In addition, the requirement is sometimes that an exchange with the inner area of the housing, i.e. the cavity formed by the housing, for example with electromagnetic radiation, in particular in the visible range and / or in the microwave radiation range, is guaranteed. The housing is expediently at least partially and / or at least partially transparent. The transparency for at least one wavelength range of electromagnetic radiation allows communication methods, data or energy transmission, measurements from and with the electronics or the sensor arranged in the cavity. In the case of optical transparency in the wavelength range of visible light, this also allows optical communication methods and optical measurements.

It is basically known to join several parts together and to arrange these parts in such a way that a receiving area is created in an intermediate space in which components can be accommodated. For example shows EP 3 012 059 B1 a method of manufacturing a transparent part for protecting an optical component. A new type of laser process is used here.

The present invention is to be seen in the context that housings are to be improved and, in particular, built to be more resistant. This increases the robustness against environmental influences and also the mechanical load capacity.

In other words, the invention is based on the object of making protection for sensitive electronics more flexible and cost-effective, and at the same time withstanding even more adverse environmental conditions and influences.

A further aspect of the present invention is to provide the improvement of the housing in a particularly reliable and durable manner. Overall, the improved housing also has to assert itself in the competitive situation on the market.

In the context of the invention, a method for providing a hermetically sealed housing is therefore presented. The method can also be changed in such a way that a plurality of housings are produced using the method in the same process sequence. Depending on the application, this is used under economic considerations to produce a plurality of housings in the same process sequence, since this can save time, effort and raw material material depending on the application.

The present invention shows a hermetically sealed housing comprising a functional area hermetically sealed by the housing, the functional area in particular being or including a cavity. The housing further comprises a cap with an upper part and a circumferential flank for forming an upper side and at least a part of a laterally circumferential edge of the functional area or the cavity. The housing further comprises a second part, in particular a base substrate, for forming an underside of the functional area or the cavity. On the second part is a deposited glass intermediate layer which is arranged between the second part and the flank of the cap. The cap and the intermediate glass layer are hermetically sealed with at least one laser bond line. The laser bond line has a height perpendicular to its connection plane.

The cap, the second part and the intermediate glass layer therefore together completely enclose the functional area or the accommodation cavity, so that the hermetically sealed housing is formed.

The functional area can include an accommodation cavity, which is prepared to accommodate an accommodation object in the housing. The accommodation object can comprise electronic circuits, in particular a sensor, a MOEMS or MEMS.

The second part of the housing is preferably a base substrate. Such a base substrate can be, for example, a printed circuit board (PCB), which is preferably cut to length or shortened to the corresponding dimensions of the housing for the production of the housing before or after the cap is applied to the second part.

The second part can have at least one first and at least one second electrical contact. For example, the first contact can be arranged on the underside of the functional area or the cavity. The underside of the functional area is that area or that area on an upper side of the second part which forms part of the inside of the area enclosed by the housing. In one example, the underside of the functional area is a defined area of the PCB on which an accommodation object can be arranged or a functional layer can be applied. In the example, this underside of the functional area is framed by the glass intermediate layer and the cap is placed on the frame-like glass intermediate layer.

A second contact is preferably arranged outside the underside of the functional area or the cavity and is electrically connected to the first contact. This means that the second part, that is to say in particular the base substrate, has a greater extent than the cap. In other words, the underside of the housing takes up only part of the base substrate or the second part and thus the base substrate, in particular the PCB, has a further area which can have electrical contacts on the same side of the second part as the cap, which can be connected to the interior of the housing. This embodiment has the advantage that the second part below the contact conductor or the conductor tracks can have a hermetically sealable layer and the electrical connections run above the hermetically sealable layer. In another example, the second part can have an upper side and a lower side and the second contacts can, for example, be arranged on the lower side of the second part, so that they can also be arranged directly below the lower side of the functional area. This has the advantage that the finished housing can be made even smaller, since the outwardly guided contacts on the same surface - but on the underside - of the second part do not take up any additional surface laterally. The cap is then arranged on the same surface - but on the upper side of the second part.

The cap preferably has a glass-like material. The vitreous material can be or comprise glass, glass ceramic, silicon or sapphire or a combination of the aforementioned materials. The second part can further comprise a material different from the cap. The intermediate glass layer preferably has a thickness of less than 50 μm, preferably less than 30 μm, more preferably between 15 and 25 μm. Furthermore, the glass intermediate layer can have a thickness of 5 μm or more, preferably of 10 μm or more.

The housing can, for example, have a size of 3 mm × 3 mm or less, preferably 2 mm × 2 mm, more preferably 1 mm × 1 mm or also 0.2 mm × 0.2 mm or smaller. Furthermore, the cap can have a height of 2 mm or less. More preferably, the flank of the cap can have a height of 2 mm or less.

The laser bond line of the housing protrudes in a special way on one side into the flank of the cap and on the other side into the glass intermediate layer. The glass intermediate layer is then joined to the cap by fusing the material of the glass intermediate layer with the material of the cap.

According to the invention, each housing comprises a functional area or a cavity, which is enclosed by a laterally circumferential edge, an underside and an upper side of the housing. In other words, the cavity is enclosed on all sides by the housing, so that the housing for the cavity forms the circumferential edge, the bottom and the top.

For the purposes of this application, the underside or the upper side is a geometric construct which, with regard to the final position of the housing, can also be any other side. Alternatively, the top side can be described as a first side the lower side as a second side opposite the first side and the edge as the intermediate region between the first and second side, the edge typically being essentially perpendicular to the first and / or second side. In order to facilitate understanding of the invention and to approximate the invention to a typical description, however, the terms top side, bottom side and circumferential edge are used below as explained.

The top of the cavity can then be formed by a top layer, such as a substrate, wafer or plate. The circumferential edge of the cavity can furthermore be formed, for example, by a second or middle substrate, disc or plate, the second substrate having a “hole” and this hole representing the subsequent cavity. The underside of the cavity can finally be formed by a sublayer, such as a substrate, disc or plate, by arranging the sublayer below the intermediate layer.

The cavities are designed in particular as accommodation cavities. This means that the housing is designed in such a way that accommodation objects, for example electronic circuits, sensors, MOEMS or MEMS, can be used in the respective cavities. These aforementioned devices, such as in particular electronic circuits, sensors or MEMS, are therefore enclosed on all sides by the housing, since they are arranged within the accommodation cavity.

In the method according to the invention, a substrate is provided, a portion of the substrate forming the underside of the accommodation cavity to be formed. The substrate can be, for example, a printed circuit board on which a plurality of circuits and electronic components are arranged. In one case, the partial area of the substrate can therefore include the accommodation object, and the remaining part of the substrate lies outside of the housing to be attached.

The accommodation object is positioned on the underside of the accommodation cavity. In other words, the accommodation object is positioned on the substrate within the partial area which will later form the underside of the accommodation cavity.

A cap made of transparent material is arranged on the substrate and above the accommodation object, the cap having a top part and a flank, so that the top side is formed from the top part of the cap and at least part of the edge of the accommodation cavity is formed from the flank , and so that a contact surface is formed on the face of the flank. The substrate forms the respective underside of the housing of the cavities to be sealed, and the cap forms at least part of the edge and the upper side of the respective housing. The edge of the housing is preferably completely formed from the cap and the glass intermediate layer.

The cap can be constructed in one piece, for example by introducing the cavity in the cap material by an etching process or an abrasive particle jet process. The cap can also be constructed in two parts, for example by joining two substrates with a laser, so that a first substrate forms a ring, i.e. the laterally circumferential edge of the cavity, and a second substrate forms a disk, i.e. the top of the cavity.

An areally delimited intermediate glass layer is preferably present on the substrate and the cap is placed on the intermediate glass layer. For example, the glass intermediate layer can be deposited at least in regions on the substrate by means of a glass lithography method. For example, this intermediate glass layer can be applied or deposited on the substrate in such a way that it defines a contour or a type of frame on which the cap can be placed. In this case, the contact surface is between the flank and the glass intermediate layer, so that the cap rests directly on the glass intermediate layer and the contact surface is formed there. In other words, the cap and the glass intermediate layer or substrate are arranged directly on one another or on top of one another, ie arranged or attached to one another in such a way that they lie flat against one another without other layers between the glass intermediate layer and the flank of the cap or between the substrate and the flank of the cap available. For technical reasons, it is possible that the slightest gas inclusions between the glass intermediate layer and the flank cannot be avoided, which can also result from possible unevenness and the like. For example, the amount of trapped gas can be further reduced by increasing the pressure, in particular by pressing the cap against the intermediate glass layer, or by treating the substrate layers on the surface, such as a grinding and polishing process. Prior evacuation is beneficial. Filling with a type of gas or a liquid can also be advantageous, depending on the process parameters and the materials to be used. The cap can be at least temporarily connected to the intermediate glass layer by means of wringing.

It is particularly preferred if the gap that may occur between the contact surfaces is less than or equal to 5 μm thick, furthermore preferably less than or equal to 1 μm. It is thus possible to join with the laser in such a way that the joining zone has a thickness between 10 µm and 50 µm and thus a hermetic seal is ensured.

It is preferred if the glass intermediate layer is only deposited in areas on the substrate, for example only where contact with the cap or caps to be placed is provided. The contact surface is formed on a part of the upper side of the glass intermediate layer and / or on a lower side of the flank of the cap. A contact area can optionally also extend over the entire surface of the substrate if this is deposited over the entire surface of the substrate, for example. Several housings, that is to say several caps, can be provided or arranged on the substrate. In this case, at least one contact surface is assigned to each housing. This means that even if the glass intermediate layer, viewed as a whole, should have a continuous optical interface that extends over the entire surface of the substrate or part of the surface of the substrate, this contact surface is divided or subdivided into each housing, so that a part of this contact surface is assigned to each housing.

In a simple case, the contact area is arranged between the substrate and the cap or between the glass intermediate layer and the flank of the cap, so that each housing has at least this contact area.

Finally, the cavity is hermetically sealed by joining along the contact surface of the housing by means of a laser joining process. During joining, a laser bond line is created that joins the glass intermediate layer with the flank of the cap in a hermetically sealed manner. In a preferred embodiment, the substrate can have at least a first and a second contact, the first contact being arranged on the underside of the accommodation cavity. The second contact can then advantageously be arranged outside the underside of the accommodation cavity and be electrically connected to the first contact. In this way, an electrical through-connection can be achieved, so that an accommodation object arranged in the interior of the cavity can establish an electrical connection with the remaining circuitry on the substrate.

The transparent cap is preferably made of glass, glass ceramic or sapphire or a combination of the aforementioned materials. The substrate preferably comprises a material different from the transparent cap, which in particular can also be inorganic. In the case of a transparent cap made of glass or predominantly made of glass, in particular made of borosilicate glass, it is particularly advantageous that this is chemically inert.

The substrate as well as the cap can have a coating. AR coatings, protective coatings, bioactive films, optical filters, conductive layers, e.g. made of ITO or gold, can be used, for example, as long as it is ensured that there is at least partial transparency for the laser wavelength used in the radiation area for the laser.

Before the cap is arranged on the substrate, an intermediate glass layer can be deposited at least in certain areas on the substrate by means of the lithography method. In particular, the deposited glass intermediate layer is hermetically sealed to the substrate. The top of the intermediate glass layer also forms a contact surface.

For joining, the laser beam can be guided all the way around the cavity, so that the cavity is hermetically sealed along the contact surface all the way around the cavity. In other words, energy can be deposited in the area of the contact surface by means of a laser, specifically so locally that it is in particular a cold joining process. The thermal energy provided for joining is therefore concentrated on the course of the contact surface and diffuses only comparatively slowly into the rest of the material of the housing, so that in particular no significant temperature rise occurs in the functional area or in the cavity. This protects the electronics arranged in the cavity from overheating.

By means of the laser, the two materials, here the glass intermediate layer and the flank of the cap, are melted locally in the area of the respective housing along the contact surfaces, so that the two materials connect locally. The person skilled in the art can, for example, refer to the EP 3 012 059 B1 which is hereby incorporated by reference.

A contact surface does not have to be optically transparent. It is also advantageous if the cap is opaque in the visible wavelength range. Only the material through which the laser passes to get to the contact surface preferably has at least one spectral window, so that at least the wavelength of the laser used can pass through the material or through the cap at least partially or at least in areas . The contact surface is designed so that the laser can perform an energy deposition on it. For example, the surfaces of the two adjacent contact surfaces can be crimped on, and further for example have a roughness in the nm range. The laser is at least partially absorbed at this contact surface, so that energy can be introduced there. In general, a contact surface in the sense of this application is to be understood as a surface on which the incident laser beam can deposit energy and thus a joining process can be carried out along the contact surface. A simple case of such a contact area is the contact area or the two contact areas between two mutually adjacent substrates or between cap and glass intermediate layer.

If necessary, the laser beam can be guided around the cavity several times, so that if necessary more than one seam is produced in the material along the contact surface and the cap is thus firmly welded to the glass intermediate layer.

The layer thickness of this glass intermediate layer can be set in such a way that a later laser joining process can be carried out. The glass intermediate layer can have a thickness of less than 50 μm, preferably less than 30 μm, more preferably between 15 μm and 25 μm. The intermediate glass layer can also have a thickness of 5 μm or more, preferably of 10 μm or more.

The accommodation object, which is arranged in the cavity of the housing, can comprise electronic circuits, in particular a sensor, a MOEMS or MEMS.

A plurality of undersides for a plurality of accommodation cavities to be formed can also be formed on the substrate, and a plurality of caps can be applied to the substrate in order to form a plurality of housings on the substrate. In other words, a single substrate, such as, in particular, a printed circuit board, can have sensitive electronics at different points in such a way that a plurality of caps, which can also be constructed differently with regard to shape, height and size, are applied to the same substrate around the sensitive electronics to protect and not to cover an excessive amount of the substrate. In this way, material can advantageously be saved and a cost-effective method for producing a housing can be provided, with which sensitive electronics can be protected from external environmental influences.

According to the invention, a transparent housing with a hermetically sealed accommodation cavity for receiving an accommodation object, comprising a transparent part for forming a laterally circumferential edge and an upper side of the accommodation cavity made in one piece from the same material, as well as a second part for forming an underside of the accommodation Cavity.

The transparent housing further comprises an intermediate glass layer deposited on the second part and arranged between the first part and the laterally circumferential edge of the transparent part. The first part, the second part and the intermediate glass layer and any metallizations that may be present, such as contact pads, then together completely enclose the accommodation cavity, with the at least two parts of the housing being joined to the hermetically sealed housing using a laser joining process. In other words, the presented housing with cap is then hermetically sealed if the laser joining method is used to join along the contact surface between the flank of the cap or contact surface of the cap and the glass intermediate layer by means of the high-energy laser, in particular the picosecond laser. If necessary, multiple joints can be made along the contact surface, for example several joint seams can be produced next to one another in order to increase the quality of the joint seam formed overall.

The housing can, for example, have a size of 3 mm × 3 mm or less, in particular the accommodation cavity has a diameter of less than or equal to 2 mm. For example, an enclosure can also have a size of 0.2 mm × 0.2 mm or smaller. On the other hand, depending on the area of use, the housing can also be made larger, several centimeters in length and more is possible. In a simple example, a size dimension results from the process practice, which is determined by the preferred production method, but which must not be understood as a size limitation per se, namely in the size of the wafers to be cut and used, which are available in large series. The use of wafers for production is only to be understood as an example. It is entirely possible, for example, to use glass plates to produce the housing, which can also have larger dimensions than typical wafer sizes.

The essence of the invention is the type of substrate that is coated with a glass, preferably litho glass. After the electronic components have been assembled, a local area of the substrate is hermetically sealed. There are two fundamentally different types of substrate for this, inorganic and organic, e.g. conventional printed circuit boards. Since organic materials are not hermetic per se and therefore a local hermetic area can only then arise, the surface according to the invention is either with glass or with a metallization - namely without gaps in between - covered. This is related to the gas permeability of the materials. Organic materials have a permeability several orders of magnitude higher than metals and other inorganic substances, eg ceramics. Inorganic substrates are chosen for materials that are not or only with great difficulty suitable for laser bonding, eg metals.

Figure list

• 1 a eine Draufsicht auf die geöffnete Beherbergungskavität,
• 1 b eine 3D-Ansicht einer geschlossenen Umhäusung,
• 1c eine alternative geöffnete Umhäusung,
• 1d eine Schnittansicht durch die Fügezone,
• 2 ein Verfahren zur Herstellung einer Mehrzahl von Umhäusungen auf einem Substrat,
• 3 eine Schnittansicht durch eine geschlossene Umhäusung,
• 3a ein Detail der Fügezone.

It show or illustrate:

• 1 a a top view of the opened accommodation cavity,
• 1 b a 3D view of a closed enclosure,
• 1c an alternative open enclosure,
• 1d a sectional view through the joining zone,
• 2 a method for producing a plurality of enclosures on a substrate,
• 3 a sectional view through a closed housing,
• 3a a detail of the joining zone.

Detailed description of the invention

1 a shows the accommodation object to be protected 2 embedded on a lower substrate 3 , for example a wafer, a metal plate or a ceramic plate, for example Si ₃ N ₄ , BN, AlN, metal, etc., but a printed circuit board can also be used. The accommodation object 2 is bordered by an intermediate glass layer 4th and to be covered by a top cap 5 . The three elements 3 , 4th , 5 thus together form the housing 1 around the accommodation object 2 which is in the cavity 12 is arranged. When putting on the cap 5 on the glass interlayer 4th in the example of 1a becomes a closed accommodation cavity 12 formed, which is to be hermetically sealed in a subsequent step. The glass intermediate layer can advantageously 4th be made of a different material than the substrate 3 and the cap 5 . The characteristic value of the coefficient of thermal expansion (CTE) can, however, be selected as desired, since this does not have to be coordinated between the layers in the room temperature bonding process.

1b shows the hermetically sealed housing formed in this way 1 , which was joined using a laser joining process. With this enclosure 1 exhibits the substrate 3 the sub-area 3a on, where the sub-area 3a the bottom of the enclosure 1 forms. In other words, it becomes the enclosure 1 with part of the substrate 3 as the bottom 3a formed, with the enclosure 1 firmly to the substrate 3 connected, preferably joined. The enclosure 1 further comprises the glass intermediate layer 4th and the cap 5 stacked on top of each other, with between the glass intermediate layer 4th and the cap 5 a contact area 25th is formed. Like that too 1a can be seen, is the intermediate glass layer 4th not consistently formed flat, but forms part of the laterally peripheral edge 21st the accommodation cavity 12 so that the accommodation cavity 12 partly between the glass interlayer 4th and in the cap 5 is formed.

1c shows another embodiment of the housing 1 , with the cap 5 the top 5b and a circumferential flank 5a having. The cap 5 becomes with the contact surface 25th on the face of the circumferential flank 5a on the substrate 3 set in the area of the bottom 3a the enclosure 1 .

1d shows a detail of the joining area, the interface zone, ie the contact area 25th , and the laser joining zone 8th clearly emerges. The laser joining zone 8th is in the area of the contact surface 25th arranged. From outside the enclosure 1 environmental influences can have an effect on the housing, especially on corners 6th the enclosure 1 . The laser joint 8th prevents chemical solutions from penetrating into the housing 1 by the flank 5a the cap 5 with the glass interlayer 4th is merged.

Referring to 2 Figure 3 is one embodiment of the method of making a plurality of enclosures 1 on the substrate 3 illustrated. It is clear to the person skilled in the art that only a single housing or a single cap 5 on a substrate 3 can be attached, depending on the process requirements. This method of applying a single cap 5 on a substrate 3 is ultimately a simplification of the process flow here with 2 procedure shown.

In a step A, the planned position of each accommodation object 2 around a thin layer of lithoglass on the intended glass deposition surface 17th deposited to form the intermediate glass layer 4th . In this example, the litho glass 4th each a round line-like structure made of lithoglass along the intended glass separation surface 17th formed around every lodging object 2 extends around fully encompassing. A round housing can be made from this, for example 1 are formed. Also a square or rectangular structure of the glass intermediate layer 4th - like any other shape - possible and shown in step B. Thus, with step A of the procedure is already the respective subpage 22nd and part of the edge 21st of the cavity to be formed 12 educated.

In a step B are on the substrate 3 each within the areas covered by a glass interlayer 4th are enclosed, a plurality of accommodation objects 2 arranged, for example at intended contacts 32 , 32a (see. 3 ) soldered on. It is provided on each accommodation object 2 a cap 5 to be attached, ie to every accommodation object 2 its own cavity 12 to create. But there can also be several accommodation objects 2 in a common cavity 12 from a common cap 5 be housed.

The formation of the glass interlayer 4th by means of deposition using lithoglass is a preferred embodiment, but only to be regarded as an example of the implementation. Optionally, a thin layer of glass can be used 4th on the substrate 3 arranged and fixed there using a laser joining process. The use of the litho glass for this purpose has, however, proven to be particularly easy to handle within the scope of the invention and also to be carried out quickly and particularly inexpensively. It is also particularly advantageous that the lithoglass can be applied, although the respective accommodation object 2 already on the substrate 3 is arranged. It is clear that the steps are applying the glass interlayer 4th and arranging the lodging objects 2 however, can also be done in reverse order, so that the glass intermediate layer 4th first on the substrate 3 is deposited and only then the respective accommodation object 2 on the substrate 3 is arranged.

With step C the glass caps 5 on the on the substrate 3 deposited glass interlayer 4th placed and thus the cavities 12 fully formed.

Step D shows the laser joining of the respective accommodation cavities 12 , i.e. closing the cavities 12 on all sides along the contact surfaces 25th . A laser unit is used for this 15th from above the caps 5 over the surface of the substrate 3 guided and a focused laser beam 9 directed towards the zones to be joined. After completing step D of the manufacturing process, all cavities are 12 hermetically closed.

It is possible to use the individual enclosures 1 to be separated after step D by means of known cutting processes, and thus to obtain individual separate housings.

Referring to 3 is a further embodiment of an enclosure 1 shown. The cap 5 is on the glass interlayer 4th arranged and joined there by means of a laser joining process. The cap 5 can be round or angular and can basically have a free shape. The glass interlayer 4th in turn is by means of lithography process on the glass deposition surface 17th (see. 3a) of the substrate 3 been deposited. The glass interlayer 4th has a thickness of approx. 20 µm in this example, but can be between 100 nm and 30 µm, for example. The enclosure 1 thus forms the completely hermetically sealed cavity 12 . The cavity 12 again in this example it is only encased by predominantly glass and by metal in the contact areas.

The accommodation object 2 , for example a sensor or actuator, is on a substrate residue 3b glued on, which in the sectional view of the 3 over the worn area of the metal pads 32 , 32a , 34 , 34a and the glass interlayer 4th protrudes upwards. By means of the substrate residue 3b can be the area below the accommodation object 2 be electrically isolated if required. By means of contact lines 36 , 36a , such as bond wires, is the lodging object 2 with contact points 32 , 32a electrically contacted. At the contact points 32 , 32a it can be metal contact surfaces. Via connector 35 , 35a the electrical contact to outside the cavity 12 arranged second contacts 34 , 34a made so that the lodging object on the substrate 3 , here a printed circuit board 3 , can be contacted from outside.

With the substrate 3 it can be an organic circuit board, for example as FR4.

The hermetic seal at the bottom of the cavity 12 can optionally be improved by adding the glass layers 3b and 4th are designed to overlap each other, and thus also the electrical bushings 32 , 32a be covered overlapping. For example, the intermediate glass layer can be used for this purpose 4th be executed in stages so that they extend over the layer 4th extends, or the glass interlayer 4th can be applied in two separate working steps, so that first the layer 4th as in 3 shown is applied and then another layer that covers the layers 3b and 4th bridged.

3a shows a detail of the 3 , in which the laser joining zones 8th , ie in particular the microbonding zones 8th , are recognizable. In this case there were three laser joining zones 8th formed by the laser 9 three times around the cavity along the glass deposition surface 17th or along the outer edges of the cap 5 or along the contact surface 25th was performed, but not on exactly identical path. Rather, it became the laser 9 with every revolution around the cavity 12 guided on a laterally offset path, so that three adjacent laser joining zones 8th arise. The microbonding zones 8th in this example have a dimension of typically 5 µm x 10 µm.

In summary, organic circuit boards, for example, can be used with the present invention 3 are refined so that hermetically sealed cavities 12 with electronics 2 can be equipped. Organic circuit boards 3 are not hermetic as water can diffuse through the polymers. So can on the circuit board 3 For example, metallic areas can be created, for example in the form of the contact pads 32 , 34 , their connections 36 inside the circuit board 3 and led to the outside world. A layer of litho glass 4th as a glass intermediate layer 4th is applied either additively, for example via a shadow mask, or subtractively, for example by full-area coating and subsequent lithographic structuring and wet chemical etching. This creates a surface on the circuit board 3 made of either glass or metal, but as far as possible no longer has any free areas made of the circuit board material. Then comes the cap 5 and forms the hermetically sealed seal.

Because organic circuit boards 3 can be particularly temperature-sensitive, it is particularly advantageous here that neither during the lithographic glass deposition for producing the glass intermediate layer 4th , still with the laser joining of the cap 5 with the glass interlayer 4th a harmful amount of heat in the substrate 3 is introduced.

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

List of reference symbols

1

Hermetically sealed, chemically hardened housing

2

Accommodation object

3

Substrate

3a

Underside of the enclosure

3b

Substrate part

4th

Glass interlayer

5

cap

5a

Flank

5b

Top of the cap

6

Corner of laser joining

8th

Laser joining zone

9

focused laser beam

12

Accommodation cavity

13

Functional area

13a

further functional area

15th

Laser unit for joining and / or cutting

17th

Glass separation surface

21st

edge

22nd

Underside of the cavity

23

Top of the cavity

25th

Contact area

32

first electrical contact inside

32a

second electrical contact inside

34

first electrical contact outside

34a

second electrical contact outside

35

electrical connector

35a

electrical connector

36

Contact line

36a

Contact line

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 3012059 B1 [0007, 0038]

Claims (15)

Hermetically sealed enclosure (1) comprising: a functional area (12, 13, 13a) hermetically sealed by the housing (1), in particular a cavity, a cap (5) with an upper part (5b) and a circumferential flank (5a) for forming an upper side (23) and a laterally circumferential edge (21) of the functional area or the cavity, and a second part (3), in particular a base substrate, for forming an underside (22) of the functional area or the cavity, and a glass intermediate layer (4) deposited on the second part (3) and arranged between the second part (3) and the flank of the cap (5), wherein the cap (5) and the intermediate glass layer (4) are hermetically sealed with at least one laser bond line (8), wherein the laser bond line (8) has a height (HL) perpendicular to its connection plane, wherein the cap (5), the second part and the intermediate glass layer (4) together completely enclose the functional area or the accommodation cavity (12), so that the hermetically sealed housing (1) is formed. Hermetically sealed housing (1) according to the preceding claim, wherein the functional area comprises an accommodation cavity (12) which is prepared to receive an accommodation object (2) in the housing (1), and / or wherein the second part (3) is a base substrate. Hermetically sealed housing (1) according to at least one of the preceding claims, wherein the second part (3) has at least one first (32, 32a) and at least one second electrical contact (34, 34a), and wherein the first contact (32, 32a) ) is arranged on the underside (22) of the functional area (13, 13a) or the cavity (12). Hermetically sealed housing (1) according to at least one of the preceding claims, wherein the second contact (34, 34a) is arranged outside the underside (22) of the functional area (13, 13a) or the cavity (12) and electrically with the first contact (32, 32a) is connected. Hermetically sealed housing (1) according to at least one of the preceding claims, wherein the cap (5) comprises a glass-like material, consists of glass, glass ceramic, silicon or sapphire or a combination of the aforementioned materials, and / or wherein the second part (3) comprises a material different from the transparent cap (5). Hermetically sealed housing (1) according to at least one of the preceding claims, wherein the glass intermediate layer (4) has a thickness of less than 50 µm, preferably less than 30 µm, more preferably between 15 and 25 µm, and / or wherein the glass intermediate layer (4) has a thickness Has a thickness of 5 µm or more, preferably 10 µm or more. Hermetically sealed housing (1) according to at least one of the preceding claims, wherein the accommodation object (2) comprises electronic circuits, in particular a sensor, a MOEMS or MEMS. Hermetically sealed housing (1) according to at least one of the preceding claims, wherein the housing (1) has a size of 3mm x 3mm or less, preferably 2mm x 2mm, more preferably 1mm x 1mm or also 0.2mm x 0.2mm or smaller, and / or wherein the cap (5) has a height of 2 mm or less, and / or wherein the flank (5a) of the cap (5) has a height of 2 mm or less. Hermetically sealed housing (1) according to at least one of the preceding claims, wherein the laser bond line (8) protrudes on one side into the flank (5a) of the cap (5) and on the other side into the glass intermediate layer (4) and the glass intermediate layer (4) ) with the cap (5) by fusing the material of the glass intermediate layer (4) with the material of the cap (5). Method for providing a hermetically sealed housing (1) on a substrate (3), the housing (1) enclosing a functional area (12, 13, 13a), in particular a cavity (12), which is surrounded by a laterally circumferential edge (21), an underside (22) and an upper side (23) of the housing (1) is enclosed, and wherein the cavity (12) is designed in particular as an accommodation cavity (12) for receiving an accommodation object (2) in the cavity (12), with the following steps: - Provision of the substrate (3), a portion of the substrate forming the underside of the accommodation cavity (12) to be formed, - Deposition of an intermediate glass layer (4) at least in some areas on the substrate by means of Lithography method such that a cap (5) can be arranged on the glass intermediate layer (4), in particular circumferentially around the underside of the accommodation cavity (12), - before or after the deposition of the glass intermediate layer (4) on the substrate Positioning the accommodation object on the underside of the accommodation cavity (12), - arranging the cap (5) on the intermediate glass layer (4) above the accommodation object, - wherein a contact surface (7, 25) is arranged between the glass intermediate layer (4) and a flank (5a) of the cap (5), so that each housing (1) has at least one contact surface, and - hermetically sealed sealing of the cavity (12) by joining along the contact surface of the housing (1) by means of a laser joining process and producing a laser bond line (8) around the functional area. Method according to the preceding claim, wherein the glass intermediate layer (4) is deposited at least in some areas on the substrate by means of the lithography method in a layer thickness such that the flank (5a) of the cap (5) comes to rest on the glass intermediate layer (4), and the contact surface (7, 25) ) is arranged on an upper side (23) of the glass intermediate layer (4). Method according to at least one of the preceding claims, wherein the cap (5) has an upper part (5b) and a flank (5a) so that the upper side (23) of the upper part (5b) of the cap (5) and the flank ( 5a) at least part of the edge (21) of the accommodation cavity (12) is formed, and so that the contact surface (7) is formed on the end face of the flank (5a). Method according to at least one of the preceding claims, wherein the laser beam (9) is guided circumferentially around the cavity (12) to form the laser bond line (8) so that the cavity (12) is hermetically sealed along the contact surface (7, 25) circumferentially around the cavity (12), if necessary the laser beam can be guided around the cavity (12) several times. Method according to at least one of the preceding claims, wherein a plurality of undersides (22) for a plurality of accommodation cavities (12) to be formed are formed on the substrate (3) and a plurality of caps (5) are applied to the substrate for Forming a plurality of housings (1) on the substrate. Housing (1) with hermetically sealed accommodation cavity (12) enclosed therein, produced according to one of the above processes.

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