Imager assembly and associated visualization system

Abstract

For the mass production of a highly compact imager assembly (1), a novel approach is proposed which allows at least a large part of the production to be automated, in particular the insertion and electrical contacting of several electrical cables (8), more precisely of their inner conductors (1)3. For this purpose, the invention provides a support structure (7) which has several insertion openings (10) on its rear side (11), into which each of the cables (8) can be inserted after stripping.The respective inner conductor (13) of the respective cable (8) is automatically guided through a via (39) formed on the front side (12) of the carrier structure (7) with a very small diameter of typically less than 150 µm or even less than 100 µm up to the front side (12) of the carrier structure (7), so that a respective electrical connection (16, 15) can be formed there, in particular using an integrated heating element (5), in order to electrically contact an image sensor chip (2) of the assembly (1) using the cable (8) and the carrier structure (7).

Description

[0001] The invention relates to an imager assembly (i.e. an assembly comprising an image sensor chip as an “imager”), an endoscope comprising such an imager assembly, and an associated method for the automated and thus cost-effective (mass) production or assembly of an imager assembly.The imager assembly can be used in particular in a single-use chip-in-tip endoscope and comprises the following components: an image sensor chip, which can be designed in particular in the form of a CMOS image sensor chip and / or which can deliver analog or digital output signals; an associated imaging optics (this can preferably be manufactured / designed as a wafer-level optic using microsystem technology; moreover, 3D-printed optics can also form at least part of this imaging optics); at least two or more electrical cables for electrically contacting the image sensor chip; and finally, a carrier structure that carries the image sensor chip.

[0002] The endoscope according to the invention comprises an imager assembly according to the invention as described and / or claimed here, and this imager assembly is arranged at a distal end of a shaft of the endoscope. In other words, this endoscope is a so-called chip-in-tip endoscope, since the image sensor is arranged in a distal tip segment of the endoscope.

[0003] The method according to the invention can be used for the automated assembly of an imager module comprising an image sensor chip, a plurality of electrical cables for electrically contacting the image sensor chip and a support structure carrying the image sensor chip.

[0004] Of course, it is particularly advantageous if this method is used to assemble an imager module designed according to the invention, because the advantages according to the invention can then be realized particularly easily.

[0005] The invention is concerned, among other things, with enabling an industrial solution for the efficient, large-scale production of a so-called imager assembly of a disposable endoscope. Said imager assembly comprises a miniaturized image sensor (typically implemented using CMOS technology), which is preferably arranged within a compact imaging module, which, in addition to the image sensor, can also include associated imaging optics that generate an image on the active sensor surface of the image sensor.

[0006] Such imaging modules are already used in the prior art, with the electronic connection of the image sensor typically being realized by means of a cable that can be connected to a corresponding connector. Such imaging modules are very small and can, for example, have edge lengths of less than 1 mm. Furthermore, the cables to be connected are also extremely thin, with strand diameters in the range of 50 µm. Until now, it has been common practice to manually solder the cables to the respective contacts of the image sensor, which is challenging due to the small size of the imaging module and therefore requires a high level of manual labor. This makes the production of large quantities of such disposable endoscopes with such imaging modules economically unfeasible.The current state of the art also includes so-called pick-and-place systems (i.e., automated manufacturing robots that can pick up individual electronic components and place them at a desired location) for the production of electronic assemblies. However, to date, such systems are not suitable for the assembly of complex cable assemblies, for example, and therefore have not been used for such purposes.

[0007] For example, it is already known in the art to use so-called reflow ovens to form solder joints between electronic components, particularly those assembled using SMD technology. However, such processes are generally unsuitable for enabling electrical contact with a cable because the polymer materials used as electrical insulators in the cable are generally not designed for such high temperatures. With regard to an imaging module, which, for example, features polymer optics manufactured using wafer-level optics approaches, high-temperature processes are also considered critical because the polymer lenses can deform, thus resulting in a potential impairment of image quality.

[0008] Based on this, the object of the invention is to propose a new approach for an ideally fully automated manufacturing process for imager assemblies of miniaturized imaging systems, in particular endoscopes, so that such systems can be manufactured economically in large quantities. In this case, the process and the associated imager assembly should in particular be designed such that it is fundamentally suitable for the production of disposable endoscopes with very small diameters, for example a shaft diameter of less than 2.5 mm. However, an imager assembly according to the invention can also be used in optical image recording systems with significantly larger diameters, in which case, for example, a large-volume working channel can also be implemented.

[0009] If limiting, then preferably smaller than 6mm. Furthermore, the invention is also intended to propose a corresponding design for such an imager assembly.

[0010] To achieve this object, the features of claim 1 are provided according to the invention for an imager assembly. In particular, to achieve the object, the invention proposes that the image sensor chip be arranged on a front side of the carrier structure. This front side can be aligned in particular towards a tip of the associated endoscope shaft, in which the imager assembly is to be installed, or obliquely laterally thereto. It is further provided that the carrier structure has rear insertion openings on a rear side opposite this front side, into each of which one of the cables is inserted. Furthermore, each of the insertion openings opens into a respective front-side via, each of these vias forming a feedthrough from the front to the rear of the carrier structure.Finally, it is provided that an electrical inner conductor of the respective cable is inserted into the respective via and is electrically connected to a respective associated rear electrical contact of the image sensor chip by means of a respective electrical connection.

[0011] Such an electrical connection can be realized directly, for example by a direct solder connection between the respective inner conductor and the rear contact of the image sensor chip.

[0012] However, it is also possible for at least one interposer to be arranged between the image sensor chip and the carrier structure. In this case, the respective electrical connection can be established only indirectly, namely mediated by electrical connections in the interposer. In other words, a respective rear contact of the interposer is then electrically connected, for example, directly to the respective inner conductor, while the rear contacts of the image sensor chip can be electrically connected, in particular soldered, to the front contacts of the interposer.

[0013] Furthermore, it is preferred if only one electrical inner conductor is inserted into the respective via of the support structure, i.e., not a shield or insulation of the cable. In other words, the stripped and shield-free inner conductor protrudes from the front of the cable, and only this part of the inner conductor is inserted into the respective via.

[0014] With the inventive approach, the cable to be connected to the image sensor can be provided during assembly, for example, as a prefabricated module with an associated connector or as a continuous material (e.g., using a cable drum). Furthermore, it can be provided to insert the cable into a stripping machine, in which the cable is automatically stripped. Such stripping machines are already commercially available. In this way, the cable, in particular its inner conductor, can be prepared for insertion into the support structure.

[0015] According to the invention, it can further be provided that at least one cable harness, but preferably several cable harnesses, are automatically guided to the support structure. For this purpose, the support structure can form a cable receptacle that is optimized for the respective cable shape.

[0016] A carrier structure according to the invention can preferably be manufactured from a wafer using microsystem technology methods or from another material. This approach allows, in particular, efficient parallel production of identical carrier structures in large quantities, as is necessary for single-use endoscopes in order to comply with the stringent specifications regarding manufacturing costs. The approach according to the invention thus enables pre-assembly of the image sensors or the described imaging module with an associated cable. Known pick-and-place technologies / robots can be used for this purpose to assemble the image sensor, in particular the image sensor module, on the carrier structure and to electrically connect it to it.

[0017] According to the invention, it can further be provided that the support structure has a heating element which is designed such that a soldered connection can be established between the respective contact of the image sensor and the cable to be soldered thereto. For this purpose, it is provided to arrange smaller deposits of solder material in the support structure, which can then be heated with the (in particular respective) heating element to such an extent that the solder material begins to melt and thus forms the soldered connection. Via this electrical connection, raw analog signals or digital image signals already processed by the image sensor itself can later be derived from the image sensor with the aid of the cables, for example to a camera control unit of a visualization system in which the imager assembly is used as part of an endoscope for imaging.

[0018] The heating element can preferably be configured as an electrical heating element, so that by applying a sufficient electrical voltage to electrical contacts of the support structure (which are electrically connected to the heating element), an electrical current can be conducted through the heating element. The heating element can therefore be configured, for example, as a resistive heating element / heating resistor, thus converting electrically supplied energy into thermal energy (heat), which must be generated locally to form the soldered connection.

[0019] A particular advantage of the inventive approach is that the described manufacturing process can be fully automated. This allows miniaturized imaging systems, in particular single-use endoscopes, to be built in large quantities at low manufacturing costs. The manufacturing process, which will be presented in more detail below, is therefore particularly suitable for the cost-effective production of low-cost disposable endoscopes. These can have diameters of less than 4.50 mm or even less than 2.10 mm; however, larger diameters are also conceivable, especially if a separate working channel must be designed.

[0020] According to the invention, the object can also be achieved by further advantageous embodiments according to the subclaims.

[0021] For example, it can be provided that the respective via is closed towards the front side of the carrier structure by means of a metallization (in the fully assembled state), and that the respective inner conductor is electrically connected, preferably soldered, to this metallization. The metallization can in particular be formed by an alloy.

[0022] Alternatively, it can also be provided that the respective inner conductor is led through the respective via to the front side of the carrier structure and that the respective electrical connection is thus designed on the front side of the carrier structure, preferably as a soldered connection.

[0023] In contrast to previously known approaches, which often use so-called interposers with electrical vias to form electrical connections between an image sensor and several wires of a cable, according to the invention, the respective inner conductors of the cable are not merely soldered onto the front face of the carrier structure, but are inserted into a volume defined by the carrier structure, namely through the respective insertion opening into a respective inner conductor receptacle of the carrier structure. This inner conductor receptacle opens into the previously described front-side vias of the carrier structure. These vias are therefore not completely metallized / filled with metal, as is usual with interposers, but at most have an electrically conductive inner wall layer, in particular an inner wall metallization.Therefore, the front-side vias together with the inner conductor receptacle form a recess into which the respective inner conductor can be inserted up to the front side of the carrier structure.

[0024] The respective via preferably has an inner-walled electrically conductive layer. This can be configured, for example, as an inner-walled metallization or by means of other suitable conductive layers (e.g., ITO or electrically conductive pastes). Furthermore, it can then be provided that an end-side outer surface of the respective electrical inner conductor is electrically connected to this inner-walled electrically conductive layer or metallization of the associated via, whereby this electrical connection can also be achieved by soldering.

[0025] A maximum inner diameter of the respective via can preferably be selected to be smaller than a diameter of the respective cable. This is because it can be prevented that the respective cable is inserted into the via unintentionally. It is particularly preferred if the said maximum inner diameter of the respective via is smaller than a maximum diameter of the respective insertion opening. On the other hand, the maximum inner diameter of the respective via should be at least as large as a thickness of the respective inner conductor so that the inner conductor can actually be inserted into the via in an automated manner. The cable preferably has a respective electrical insulation and / or a respective electrical shielding for each inner conductor. In such a case, the respective electrical insulation and / or the respective electrical shielding of the respective cable can be inserted into the insertion opening.However, these parts of the cable are not passed through the respective via, so that only the respective inner conductor is inserted into the respective via, in particular up to the front of the carrier structure.

[0026] As already mentioned, the respective electrical connection between the respective rear-side electrical contact of the image sensor chip and the associated electrical inner conductor of the respective cable can be configured as a soldered connection. In such a case, the invention proposes that the carrier structure can comprise at least one integrated and electrically operable heating element with which such soldered connections can be or have been formed. The formation of the respective soldered connection can be achieved by directly or at least indirectly heating a respective solder mass with the at least one integrated heating element.In technical terms, a “solder mass” can be understood as any form of flowable material (including, in particular, conductive thermoplastic adhesives, which flow when heated but solidify when cooled) that provides sufficient electrical conductivity to transmit signals from the image sensor.

[0027] The support structure can (particularly when manufactured from a wafer) comprise an electrically conductive material such as doped silicon, i.e., in particular, a bulk material. An electrical current for operating the at least one integrated heating element can be injected or introduced via such a material. For example, the electrical current required to operate the heating element can be introduced into the support structure via a side wall of the support structure, which runs between the front and back sides.

[0028] Another embodiment, however, provides for the support structure to be made of an electrically insulating material, such as plastic, glass, or ceramic. In such a case, however, electrical conductor tracks can be provided and formed in and / or on the support structure, which can then be configured to supply the at least one integrated heating element with an (externally supplied) electrical operating current.

[0029] According to these concepts, the heating device used to form the soldering structure, namely the at least one heating element, remains in the imager assembly thus produced and thus possibly also in the later fully assembled endoscope.

[0030] As already mentioned, the carrier structure can be manufactured using a parallel manufacturing process. This can preferably be done using microsystem technology and / or at the wafer level. Etching processes can also be used to form the vias.

[0031] A bulk material of the support structure, in particular the one mentioned above, can be, for example, silicon or, as explained above, glass or a ceramic.

[0032] Depending on the design of the support structure, it may also be advantageous if the bulk material of the support structure has a thermal conductivity of at least 50 W / mK. In such a case, the front-side electrical connections can be formed, for example, by indirect heating. As mentioned, this can be achieved using at least one integrated heating element, with the heat then being transferred via the bulk material to the solder mass.

[0033] Parallel manufacturing can be understood here in particular as meaning that the carrier structure was obtained together with other identically formed carrier structures from a panel or wafer by singulation. Therefore, the carrier structure may exhibit traces of this singulation, such as saw chipping, on its outer edges, for example, on its side walls.

[0034] The presented manufacturing process is particularly suitable for producing support structures with a very small footprint of less than 1.2 × 1.2 mm 2Such very delicate dimensions of the carrier structure can be easily managed, particularly in wafer-level manufacturing, using conventional separation methods such as wafer sawing. The respective diameter of each via of the carrier structure can be less than 150 µm, preferably even less than 100 µm. On the other hand, it is preferred if the respective rear insertion opening has a diameter of at least 200 µm, preferably even at least 250 µm. Such dimensions have proven suitable, on the one hand, for inserting suitable cables, including insulation and shielding, into the carrier structure from the rear and, on the other hand, for feeding the stripped inner conductors through such delicate vias all the way to the front.

[0035] Each of the cables used in the imager assembly can therefore have a respective electrical shield. It is therefore preferred if the cables are each designed as coaxial cables and / or if the respective shield is electrically separated from the respective inner conductor by means of electrical insulation.

[0036] It is particularly advantageous for the electrical properties of the imager assembly if the respective shielding is electrically connected to an electrically conductive part of the carrier structure by means of a respective electrical contact. For example, the respective shielding can be connected to an electrically conductive bulk material of the carrier structure, in particular the aforementioned one, or to a metallization, such as a conductor track, of the carrier structure. In such cases, it is further preferred if an electrical GND potential can be applied to the shielding via the carrier structure.

[0037] Furthermore, the respective cable can also be mechanically firmly coupled to the support structure via this respective electrical contact. Preferably, a total of at least four cables can be provided in this way, via which 1) a supply voltage, 2) a GND potential, and 3) a clock signal can be transmitted to the image sensor chip. Furthermore, with the fourth cable, 4) analog output signals from the image sensor chip can be derived. The four cables can of course also be configured as stranded wires of a larger multi-core cable, preferably each electrically shielded.

[0038] As already mentioned at the beginning, the rear contacts of the image sensor chip can each be electrically connected to an associated inner conductor via an interposer. In such a case, it is preferred if the respective electrical connection, in particular the respective solder connection, is formed between a rear electrical contact of the interposer and the respective inner conductor. The interposer can further contact the rear electrical contacts of the image sensor chip using electrically conductive vias (in the interposer). Such vias can be configured, for example, by means of electroplated metallizations in a volume of the interposer in a manner known per se, wherein the vias are then completely filled with the metallization or at least the side surfaces of the vias are metallized.

[0039] The image sensor chip can be configured as part of a compact imaging module. Such an imaging module can have an edge length of less than 1.2 mm. The imaging module can also include the imaging optics and, if appropriate, an interposer (as previously explained). In such configurations, it is advantageous for the robustness of the imager assembly if the imaging module is firmly connected to the support structure, which can be achieved in particular by means of a solder connection (particularly as previously described).

[0040] Between the respective insertion opening (on the rear side of the support structure) and the adjoining via (on the front side of the support structure), a step or other contact surface can be formed, against which electrical insulation or shielding of the cable can rest. Such a configuration is advantageous for defining a desired insertion depth of the respective cable into the support structure, which can then significantly simplify automated assembly. In particular, the insertion depth of a stripped end of the respective inner conductor into the support structure can be specified in this way; for example, if this end is already formed at a predetermined desired distance from the end of the respective shielding / insulation of the cable, which can be achieved with high precision using automated stripping machines.

[0041] The multiple cables can be used in particular as cores of a multi-core imaging cable (or also: image transmission cable).

[0042] Furthermore, the support structure can form a rear receptacle into which such an imaging cable can then be plugged.

[0043] The support structure can, for example, be designed in the form of a sleeve that is plugged onto the imaging cable.

[0044] To achieve this objective, as already mentioned, an endoscope is proposed which comprises an imager assembly configured according to the invention, i.e., as described above or according to one of the claims directed to an imager assembly. The imager assembly is arranged at a distal end of a shaft of the endoscope, so that the endoscope is configured as a chip-in-tip endoscope. To reduce manufacturing costs, it can be advantageous if the endoscope, in particular the aforementioned imager assembly, comprises at least one material that is not autoclavable. In such a case, the endoscope can therefore only be used as a single-use / disposable endoscope in a medical application (once); however, it can then be manufactured significantly more cheaply.

[0045] As already explained, the shaft at the distal end, i.e., where the imager assembly is located, can have a diameter of less than 4.50 mm or even less than 2.10 mm. Such extreme miniaturization can be reliably manufactured thanks to the inventive design of the imager assembly. However, as already mentioned, imager assemblies according to the invention can also be effectively used in endoscopes with significantly larger shaft diameters of 5 mm or even 6 mm or more.

[0046] The finished endoscope, i.e., in particular its imager assembly, preferably even the support structure as described above, can comprise at least one electrically operable heating element (even after the assembly has been fully assembled). As explained, the electrical connections can be established with this at least one integrated heating element, which can be achieved in particular by melting a respective soldering compound.

[0047] To achieve this objective, a method for the automated assembly of an imager assembly, in particular as previously explained, is also proposed. In other words, the imager assembly to be produced using the method can be configured as previously described and / or according to one of the claims directed to an imager assembly. The method is characterized in that, with the aid of an assembly machine (this can in particular be a pick-and-place robot), the plurality of already stripped cables are automatically inserted into respective rear insertion openings in a carrier structure, wherein in this way the respective inner conductors of the respective cable are automatically guided through respective front vias, which are designed as feedthroughs on a front side of the carrier structure.Furthermore, it is provided that the image sensor chip, in particular as part of a compact imaging module, is automatically placed on the front side of the carrier structure. The image sensor chip can preferably be glued or soldered onto the front side of the carrier structure. It is further provided that, in the region of the front side of the carrier structure, a respective electrical connection between the respective inner conductor and a respective associated rear electrical contact of the image sensor chip is automatically formed, which, as explained, can occur at least indirectly or directly.

[0048] Such a fully assembled imager assembly can then be inserted into the distal end of an endoscope shaft to form a chip-in-tip endoscope (particularly as described above).

[0049] The stripping of the cables can also be carried out automatically using a stripping machine (even before the cables are automatically inserted into the rear insertion openings).

[0050] It has also already been explained that the respective electrical connection can be formed by melting a respective solder mass. This can, of course, be done, as has been common practice in the prior art, for example, using an external heating device, which then melts the respective solder mass to form the respective electrical connection. Optical radiation, a hot air stream, and / or a magnetic field can be used, for example, to generate the required amount of heat.

[0051] According to the invention, the respective solder mass can also be melted by electrically operating at least one heating element integrated into the support structure, thus forming the respective electrical connection. This approach can therefore, in particular, provide for the at least one heating element to remain in the support structure and thus in the assembly. Configurations are also conceivable in which the heating element is no longer functional after operation. The only decisive factor is that the respective electrical connection can be formed at the correct location with the aid of the heating element during initial operation.

[0052] The invention will now be described in more detail using exemplary embodiments, but is not limited to these examples. Further developments of the invention can be derived from the following description of the examples in conjunction with the general description, the claims, and the drawings. In the following description of various embodiments of the invention, elements that correspond in function are given the same reference numerals, even if they have different designs or shapes.

[0053] It shows: Fig. 1 a cross-sectional view, in highly schematic form, through an imager assembly designed according to the invention, Fig. 2 a detailed view of the imager assembly Fig. 1, illustrating the insertion of a cable 8 into a rear insertion opening, Fig. 3 a perspective view of a support structure as part of an imager assembly according to the invention, wherein a total of four cables are inserted into rear insertion openings of the support structure in order to electrically connect them to rear contacts of an image sensor chip, Fig. 4 the situation Fig. 3 after all four cables 8 have been fully inserted, Fig. 5 shows a highly schematic side view of the fully assembled imager assembly of the Fig. 3 and Fig. 4, and finally Fig. 6 schematically shows the components of a visualization system which comprises an endoscope designed according to the invention.

[0054] The Fig. 6 shows a visualization system 1 with an endoscope 6 according to the invention, which is read out by a camera control unit 34, which transmits corresponding video image signals to a monitor 33 in order to display a live video image thereon. The endoscope 6 comprises an endoscope shaft 22, at the distal end 30 of which an imager assembly 1 according to the invention is arranged, which in particular comprises an image sensor chip 2 for imaging / generating the video image signals, so that the endoscope 6 is designed as a chip-in-tip endoscope. The image sensor chip 2 is part of a compact imaging module 4, which is also arranged in the endoscope tip.

[0055] Fig. 1 shows details of the imager assembly 1 according to the invention, as arranged in the endoscope tip: The imager assembly 1 comprises, as mentioned, an image sensor chip 2 with associated imaging optics 3, which is designed as a wafer-level optics, wherein these two components are combined into a compact imaging module 4. On the rear side, the image sensor chip 2 has a plurality of rear-side electrical contacts 14, which are then to be electrically contacted using respective cables 8 in order to be able to derive analog image signals generated by the image sensor chip 2 along the endoscope shaft 22 to a handpiece and from there to the camera control unit 34.Each of the several cables 8 used in the imager assembly 1 has an outermost electrical insulation 19, an underlying electrical shield 18, then a further (inner) electrical insulation 19 and finally an electrically conductive inner conductor 13 inside, which is electrically connected to the respective contact 14 of the image sensor chip 2 via the interposer 9 shown.

[0056] The cross-sectional view of the Fig. 1, it is good that the support structure 7 forms 12 front-side vias 39 on its front side. Each of these vias 39 is connected to an insertion opening 10 on the rear side 11 of the support structure 7, wherein each of the cables 8 is inserted into a respective one of the insertion openings 10. Based on the dotted circle in Fig. 1 clearly shows a step 41 or a contact surface 42 on the inner wall of the respective insertion opening 10, with the inner insulation 19 resting against this step 41 / contact surface 42, thereby determining the insertion depth of the respective cable 8 into the support structure 7. Since the inner conductors 13 are stripped to a specific stripping length compared to the end of the inner insulation 19, the front ends of the respective inner conductors 13 can be precisely inserted through the vias 39 up to the front side 12 of the support structure 7 in an automated manner using a pick-and-place robot. In this case, only one electrical inner conductor 13 of the respective cable 8 is inserted into the respective via 39.

[0057] By means of a first solder connection 16 between the interposer 9 and the carrier structure 7, the respective inner conductor 13 is electrically connected to a respective rear-side electrical contact of the interposer 9 (cf. Fig. 1). The interposer 9 has electrically conductive vias 29 as well as electrical connections 15 within it, which thus electrically connect the respective inner conductor 13 to the respective contact 14 of the image sensor chip 2. For this purpose, additional solder connections 15 are formed between the front-side electrical contacts 31 of the interposer 9 and the electrical contacts 14 on the rear side of the image sensor chip 2. Depending on the arrangement of the rear contacts 14, however, an interposer 9 does not necessarily have to be used; if the rear contacts 14 of the image sensor chip 2 are sufficiently spaced, the inner conductors 13 can also be electrically connected directly to them by means of a respective solder connection 15.

[0058] In the Fig. 2 shows further details of the carrier structure 7 according to the invention as part of the assembly 1 according to the invention: The carrier structure 7 was manufactured by means of etching processes and wafer sawing from a silicon wafer using microsystem technology methods in parallel together with other identically formed carrier structures 7. The bulk material 24 of the silicon carrier structure 7 has a sufficiently high electrical conductivity, with an electrical passivation layer 25 in the form of a silicon oxide layer being grown on the outside of the carrier structure 7. At the upper edge of the insertion opening 10, an electrically conductive layer 36 can be seen in the form of a metallization 40, which is electrically insulated from the bulk material of the carrier structure 7 by means of an additional electrical insulation 19. This rear-side metallization 40 at the entrance of the insertion opening 10 serves, as can be clearly seen in Fig. 1, an electrical contact 27 is formed between the electrical shielding 18 of the cable 8 and the support structure 7, more precisely the said metallization 40. In this way, an electrical GND potential can be applied to the shielding 18 via the support structure 7.

[0059] By looking at the Fig. 1 and Fig. 2 further shows that the respective inner conductors 13 of the respective coaxial cable 8 are not only soldered to the contacts 17 of the interposer 9 by means of the respective front-side solder connection 16, but that this solder connection also extends into the respective front-side via 39 of the carrier structure 7. As the Fig. 2 shows, metallizations 40 are formed on the inside of the front side of the respective via 39, via which the inner conductor 13 can be firmly soldered to the carrier structure 7. This achieves a robust mechanical anchoring of the respective inner conductor 13 in the respective via 39. The respective via 39 is closed by means of the metallization 40. In Fig. 2 it can also be clearly seen that this front-side metallization 40 on the inner wall of the via 39 is electrically insulated from the bulk 24 of the carrier structure 7 by means of an additional electrically insulating layer 37, i.e. in addition to the passivation layer 25.

[0060] Based on the cross-sectional view of the Fig. 2 it can also be seen that the diameter of the cable 8, in particular the outer diameter of the shielding 18 and the inner insulation 19, exceeds the remaining inner diameter of the via 39, so that only the stripped inner conductor 13 can be inserted into the via 39 with its front end, but not the shielding 18 or the inner insulation 19 (the outer insulation 19 of the cable 8 is in Fig. 2 not shown).

[0061] In the Fig. 1 and Fig. 2, reference numeral 5 merely indicates that, according to a preferred embodiment, an electrically operable heating element 5 can be integrated into the support structure 7, for example in the form of a resistive heating element on the surface of the support structure 7, in order to form the respective solder connection 16 by operating this heating element with an electric current. In this way, the respective cable 8 can be particularly reliably connected both mechanically to the support structure 7 and electrically to the image sensor chip 2.

[0062] In the Fig. 1 and Fig. 2, for example, such an electrical operating current for operating the integrated heating element 5 could be introduced into the carrier structure 7 via the bulk material 24, wherein for this purpose the carrier structure 7 can be contacted very easily via the electrically non-insulated side wall 26 (cf. Fig. 1).

[0063] The Fig. 1 and Fig. The stepped shape of the insertion opening 10 with the illustrated step 41 shown in Figure 2 can be produced particularly precisely using etching processes such as dry etching. Fig. 1 and in Fig. However, the support structures 7 shown in Figure 2 can also be manufactured cost-effectively using other parallel manufacturing processes for other purposes, whereby non-conductive materials such as glass can also be used for this purpose. The advantage of these approaches is that the support structure can occupy an area that can be only slightly larger or even smaller than that of the image sensor chip 2. This allows the required highly compact design of the assembly 1 to be achieved.

[0064] Based on the Fig. 3-5, which illustrate in a highly schematic form another imager assembly 1 according to the invention, this time without using an interposer 9, the inventive method for the automated assembly of such an assembly 1 can also be understood: For this purpose, firstly, by means of a stripping machine, the Fig. 3, a total of four cables 8 are automatically stripped, so that the electrical shields 18 as well as the respective inner conductors 13 are exposed. The thus prepared cables 8 are then automatically inserted by a robot into the respective rear insertion opening 10 of the support structure 7, as shown in the Fig. 3 and Fig. 4. The respective inner conductor 13 is guided through the respective front-side via 39 to the front side 12 of the carrier structure 7. The image sensor chip 2, however, is also automatically placed on the front side 12 of the carrier structure 7 and initially glued there. Solder masses 21 were already applied to the front and back sides of the carrier structure 7 before the cables 8 were inserted. Alternatively, equivalent metallic alloys can also be used (e.g., at the location of the metallization 40 in Fig. 2).

[0065] An electric current is then introduced via the side walls 26 to operate the integrated heater 5 provided and formed in the support structure 7, with one integrated heating element 5 being formed for each insertion opening 10. The heat generated locally by means of the respective heating element 5 thus melts the solder masses 21, whereby the (already in Fig. 1 and Fig. 2) are formed on the one hand between the support structure 7 and the electrical shielding 18 of the respective cable 8 and on the other hand between the respective inner conductor 13 and the respective rear electrical contact 14 of the image sensor chip 2. It is understood that the Fig. 3-5 could also be applied analogously to an imaging module 4 with an interposer 9, which then provides the respective rear electrical contacts 17 which are to be connected to the respective inner conductor 13.

[0066] The result is the situation of the side view of the Fig. 5: On the left side, one can see the cables 8, which are inserted into the back of the support structure 7, and the respective electrical connections 15 formed between the front of the support structure 7 and the back of the image sensor chip 2 in the form of respective solder connections 16, through which the respective inner conductor 13 is electrically connected to the respective contact 14 of the image sensor chip 2. The automated formation of these solder connections can be achieved—in a manner known per se—for example, with the aid of external heating devices such as laser radiation sources or a hot air stream, or, as previously explained, with the aid of an integrated heating element 5.

[0067] In summary, a novel approach is proposed for the mass production of a highly compact imager assembly 1, which allows at least a large part of the production to be automated, in particular the insertion and electrical contacting of several electrical cables 8, more precisely of their inner conductors 13. For this purpose, according to the invention, a support structure 7 is provided which has on its rear side 11 several insertion openings 10 into which a respective one of the cables 8 can be inserted after stripping.The respective inner conductor 13 of the respective cable 8 is automatically guided through a via 39 formed on the front side 12 of the carrier structure 7 with a very small diameter of typically less than 150 µm or even less than 100 µm up to the front side 12 of the carrier structure 7, so that a respective electrical connection 16 / 15 can be formed there, in particular using an integrated heating element 5, in order to electrically contact an image sensor chip 2 of the assembly 1 with the aid of the cable 8 and the carrier structure 7 (cf. Fig. 1). List of reference symbols 1 imager assembly 2 Image sensor chip (has active sensor area on its front side and rear contacts 14) 3 Imaging optics 4 Imaging module heating element 5 6 Endoscope 7 Support structure 8 cables (for electrical contacting of 2, in particular for deriving analog signals from 2 and / or for electronic control of 2) 9 Interposer (provides electrical contact between the rear contacts of 2 and 8; can be part of 4) 10 Insertion opening (formed in 7, for insertion of 8) 11 Back (of 7) 12 front (of 7) 13 inner conductors (of 8) 14 rear electrical contact (of 2) 15 electrical connection 16 Solder connection 17 rear electrical contact (of 9) 18 electrical shielding 19 electrical insulation 20 Substrate (e.g. isolated chip from a wafer; forms 7) 21 Solder mass 22 shafts (of 6) 23 assembly machine 24 Bulk material (of 7, for example doped silicon, in particular such that an electric current can be injected via side walls of the support structure 7) 25 electrical passivation layer (especially oxide layer) 26 Sidewall (of 7, runs between 11 and 12) 27 electrical contacts (between 18 and 7) 28 outer edge 29 electrically conductive (especially metallically lined or metallically filled) vias (of 9) 30 distal end (of 6 / 22) 31 front electrical contacts (of 9) 32 Visualization system 33 monitors 34 Camera control unit 35 objects 36 electrically conductive layer, in particular metallization 37 electrically insulating layer, in particular oxide layer 38 insertion direction (from 8 to 10) 39 front via (in 7) 40 Metallization 41 level 42 contact surface

Claims

[1] Imager assembly (1), in particular for use in a single-use chip-in-tip endoscope (6), the imager assembly (1) comprising: - an image sensor chip (2), - in particular in the form of a CMOS image sensor chip (2) and / or which provides analog output signals, - an associated imaging optics (3), preferably designed as a wafer-level optics, - electrical cables (8) for electrical contacting of the image sensor chip (2) and - a support structure (7) for supporting the image sensor chip (2), characterized by , - that the image sensor chip (2) is arranged on a front side (12) of the carrier structure (7), - that the support structure (7) has rear insertion openings (10) on a rear side (11) opposite the front side (12), into each of which one of the cables (8) is inserted, - that furthermore each of the insertion openings (10) opens into a respective front-side via (39), each via (39) forming a passage from the front side (12) to the rear side (11) of the support structure (7), and - that, preferably exclusively, one electrical inner conductor (13) of the respective cable (8) is inserted into the respective via (39) and is electrically connected to a respective associated rear-side electrical contact (14) of the image sensor chip (2), directly or at least indirectly, by means of a respective electrical connection (15). [2] Imager assembly (1) according to claim 1, - wherein the respective via (39) is closed towards the front side (12) of the carrier structure (7) by means of a metallization (40) and the respective inner conductor (13) is electrically connected, preferably soldered, to this metallization (40) or - wherein the respective inner conductor (13) is guided through the respective via (39) to the front side (12) of the carrier structure (7) and the respective electrical connection (15) is thus configured on the front side (12) of the carrier structure (7), preferably as a soldered connection (16). [3] Imager assembly (1) according to one of the two preceding claims, wherein the respective via (39) has an inner-walled electrically conductive layer (36), preferably an inner-walled metallization (40), and wherein an end-side outer surface of the respective electrical inner conductor (13) is electrically connected, preferably soldered, to this inner-walled layer (36) / metallization (40) of the associated via (39). [4] Imager assembly (1) according to one of the preceding claims, - wherein a maximum inner diameter of the respective via (39) is smaller than a diameter of the respective cable (8), preferably and smaller than a maximum diameter of the respective insertion opening (10), in particular and at least as large as a thickness of the respective inner conductor (13) and / or - wherein a respective electrical insulation (19) and / or a respective electrical shielding (18) of the respective cable (8) is inserted into the insertion opening (10) but not guided through the respective via (39), so that only the respective inner conductor (13) is inserted into the respective via (39), in particular up to the front side (12) of the carrier structure (7). [5] Imager assembly (1) according to one of the preceding claims, wherein the respective electrical connection (15) is designed as a soldered connection (16) and wherein the carrier structure (7) comprises at least one integrated and electrically operable heating element (5) with which the soldered connections (16) were formed, preferably by directly or at least indirectly heating a respective solder mass (21) with the at least one integrated heating element (5). [6] Imager assembly (1) according to the preceding claim, wherein the carrier structure (7) comprises an electrically conductive material, in particular a bulk material (24), via which an electrical current for operating the at least one integrated heating element (5) can be injected / introduced, in particular mediated via a side wall (26) which runs between the front side (12) and the rear side (11), or - wherein the support structure (8) is made of an electrically insulating material, for example of a plastic, of glass or of ceramic, but preferably has electrical conductor tracks which are designed to supply the at least one integrated heating element (5) with an externally supplied electrical operating current. [7] Imager assembly (1) according to one of the preceding claims, wherein the support structure (7) is produced by means of a parallel manufacturing process, - preferably using microsystem technology methods and / or at wafer level, - particularly preferably using an etching process to form the vias (11), was / is manufactured, - in particular wherein one, in particular the, bulk material (24) of the carrier structure (7) is silicon or glass or a ceramic and / or - wherein a, in particular the, bulk material (24) of the support structure (7) has a thermal conductivity of at least 50 W / mK, in order to enable indirect heating of the front-side electrical connections (15), preferably with the aid of the at least one integrated heating element (4). [8] Imager assembly (1) according to one of the preceding claims, wherein the carrier structure (7) was obtained together with other identical carrier structures (7) from a panel or a wafer by singulation and therefore shows traces, for example sawing breaks, of this singulation on respective outer edges (28), in particular on side walls (26). [9] Imager assembly (1) according to one of the preceding claims, wherein the support structure (7) has a footprint of less than 1.2 × 1.2 mm 2 and / or - wherein a respective diameter of the respective via (11) of the carrier structure (7) is smaller than 150 µm, preferably smaller than 100 µm, - preferably wherein the respective rear insertion opening (10) has a diameter of at least 200 µm, preferably of at least 250 µm. [10] Imager assembly (1) according to one of the preceding claims, wherein each of the cables (8) has a respective electrical shield (18), - preferably wherein the cables (8) are each designed as coaxial cables and / or the respective shielding (18) is electrically separated from the respective inner conductor (13) by means of an electrical insulation (19), and - wherein the respective shielding (18) is connected to an electrically conductive part of the support structure (7), - in particular an electrically conductive bulk material (24) of the carrier structure (7) or a metallization, in particular a conductor track, of the carrier structure (7), is electrically connected by means of a respective electrical contact (27), - preferably so that, mediated via the support structure (7), an electrical GND potential can be applied to the shielding (18) and / or so that the respective cable (8) is mechanically firmly coupled to the support structure (7) via the respective electrical contact (27). [11] Imager assembly (1) according to one of the preceding claims, wherein the rear contacts (14) of the image sensor chip (2) are electrically connected to a respective one of the inner conductors (13) via an interposer (9), - preferably wherein the respective electrical connection (15), in particular the respective soldered connection (16), is formed between a rear electrical contact (17) of the interposer (9) and the respective inner conductor (13) and / or - wherein the interposer (9) contacts the rear electrical contacts (14) of the image sensor chip (2) by means of electrically conductive vias (29). [12] Imager assembly (1) according to one of the preceding claims, wherein the image sensor chip (2) is designed as part of a compact imaging module (4), in particular with an edge length of less than 1.2 mm, wherein the imaging module (4) also comprises the imaging optics (5), preferably and an interposer (9), - particularly preferably wherein the imaging module (4) is firmly connected, in particular by means of a soldered connection, to the carrier structure (7). [13] Imager assembly (1) according to one of the preceding claims, wherein a step (41) or another contact surface (42) is formed between the respective insertion opening (10) and the adjoining via (39), against which step (41) / contact surface (42) an electrical insulation (19) or a shielding (18) of the cable (8) can rest in order to define an insertion depth of the respective cable (8) into the support structure (7). [14] Imager assembly (1) according to one of the preceding claims, wherein the plurality of cables (8) are designed as wires of a multi-wire imaging cable and the support structure (7) forms a rear receptacle into which the imaging cable is plugged, - preferably wherein the support structure (7) is designed in the form of a sleeve which is plugged onto the imaging cable. [15] Endoscope (6) comprising an imager assembly (1) according to one of the preceding claims, - wherein the imager assembly (1) is arranged at a distal end (30) of a shaft (22) of the endoscope (6) and thus the endoscope (6) is designed as a chip-in-tip endoscope, - preferably wherein the endoscope (6), in particular its imager assembly (1), comprises a material which is not autoclavable, so that the endoscope (6) can only be used as a single-use endoscope in a medical application. [16] Endoscope (6) according to the preceding claim, wherein the finished endoscope (6), in particular the imager assembly (1), preferably the support structure (7), still comprises at least one electrically operable heating element (5), with the aid of which the electrical connections (15), in particular by melting a respective solder mass (21), were produced or at least is / would be produced. [17] Method for the automated assembly of an imager module (1), with - an image sensor chip (2), - several electrical cables (8) for electrically contacting the image sensor chip (2) and - a support structure (7) carrying the image sensor chip (2), - preferably wherein the imager assembly (1) is designed according to one of claims 1 to 14, characterized by , - that with the aid of an assembly machine (23), in particular with the aid of a pick-and-place robot, the plurality of already stripped cables (8) are automatically inserted into respective rear insertion openings (10) of a support structure (7), - that in this way respective inner conductors (13) of the respective cable (8) are automatically guided through respective front-side vias (39), which are designed as feedthroughs on a front side (12) of the carrier structure (7), - that the image sensor chip (2), in particular as part of a compact imaging module (4), is automatically placed on the front side (12) of the carrier structure (7), preferably glued or soldered there, and - that in the region of the front side (12) of the carrier structure (7) a respective electrical connection (15) between the respective inner conductor (13) and a respective associated rear-side electrical contact (14) of the image sensor chip (2) is formed automatically, at least indirectly or directly. [18] Method according to the preceding claim, wherein the stripping of the cables (8) is carried out automatically by means of a stripping machine. [19] Method according to one of the two preceding claims, wherein the respective electrical connection (15) is formed by melting a respective solder mass (21). [20] Method according to the preceding claim, wherein the respective solder mass (21) is melted by means of an external heating device, in particular using optical radiation or a hot air stream or a magnetic field, in order to form the respective electrical connection (15). [21] Method according to the preceding claim 19, wherein the respective solder mass (21) is melted by electrically operating at least one heating element (5) which is integrated into the carrier structure (7) in order to form the respective electrical connection (15), - in particular wherein the at least one heating element (5) remains in the carrier structure (7).

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