Imager assembly and associated visualization system

Abstract

Imager assembly (1), in particular for use in a single-use chip-in-tip endoscope (6), wherein the imager assembly (1) comprises: - 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 optic (3), preferably designed as a wafer-level optic, - electrical cables (8) for electrical contacting the image sensor chip (2) and - a support structure (7) for carrying the image sensor chip (2), wherein: - the image sensor chip (2) is arranged on a front side (12) of the carrier structure (7), - the support structure (7) has rear insertion openings (10) on one of the rear sides (11) opposite the front side (12), into which one of the cables (8) is inserted, - each of the insertion openings (10) opens into a respective front via (39), each via (39) forming a passage from the front (12) to the rear (11) of the support structure (7), and - wherein, preferably exclusively, each electrical inner conductor (13) of the respective cable (8) is inserted into the respective via (39) and is electrically connected, directly or at least indirectly, to a respective associated rear electrical contact (14) of the image sensor chip (2) by means of a respective electrical connection (15), wherein - the respective electrical connection (15) is designed as a soldered connection (16) and the support structure (7) comprises at least one integrated and electrically operable heating element (5) with which the soldered connections (16) were formed.

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 as a CMOS image sensor chip and / or which can provide analog or digital output signals; an associated imaging optic (this can preferably be manufactured / designed as a wafer-level optic using microsystems technology techniques; in addition, for example, 3D-printed optics can also form at least part of this imaging optic); at least two or more electrical cables for electrically contacting the image sensor chip; and finally a support structure that carries the image sensor chip.

[0002] The endoscope according to the invention comprises an imager assembly as described and / or claimed herein, 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, several electrical cables for electrically contacting the image sensor chip, and a support structure that carries the image sensor chip. Naturally, it is particularly advantageous if this method is used for assembling an imager module designed according to the invention, because the advantages of the invention can then be realized particularly easily.

[0004] The invention relates, among other things, to enabling an industrial solution for the efficient mass production of a so-called imager assembly for a disposable endoscope. This imager assembly comprises a miniaturized image sensor (typically implemented using CMOS technology), which is preferably arranged within a compact imaging module. This module may also include associated imaging optics that generate an image on the active sensor area of ​​the image sensor.

[0005] Such imaging modules are already used in the prior art, where the electronic connection of the image sensor is typically achieved via a cable that can be plugged into a corresponding connector. These 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 wire diameters in the range of 50 µm. Currently, it is 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 generates a high level of manual labor. Consequently, the production of large quantities of such disposable endoscopes with these imaging modules is not economically feasible.In the prior art, so-called pick-and-place systems (i.e., automated manufacturing robots that can pick up individual electronic components and place them at a desired position) are already used for the production of electronic assemblies. However, such systems are not yet suitable for the assembly of complex cable assemblies, for example, and have therefore not been used for such purposes.

[0006] It is already known in the art, for example, to use so-called reflow ovens to create solder joints on electronic components, especially those mounted using SMD technology. However, such processes are generally unsuitable for electrically contacting a cable because the polymer materials used as electrical insulators in the cable are usually not designed for such high temperatures. With regard to an imaging module, which, for example, incorporates polymer optics manufactured using wafer-level optics, high-temperature processes are also considered critical because the polymer lenses can deform, potentially impairing image quality.

[0007] US 2018 / 0325364A1 describes an imager assembly according to the invention, which is to be used in the tip of a flexible endoscope for imaging, wherein the electrical contacting of the image sensor is realized by means of blind holes which have an inner wall metallization which establishes contact with the respective conductor of an associated connecting cable.

[0008] DE 10 2016 122 436 A1 also proposes, for a similar purpose, perforations, which are designed in stages, with the electrical conduction of the signals taking place by means of conductors implanted in an insulating body.

[0009] DE 10 2010 047 288 A1 discloses a complex image sensor module comprising an image sensor, a first circuit board serving as an "interposer", and a second circuit board electrically connected to individual conductors of a multi-core cable. For this purpose, several bores 64 are provided in the second circuit board, with each bore through which one of the conductors passes through the second circuit board to the front side.

[0010] US 2015 / 0312457A1 also describes an imaging module; however, its approach to electrically contacting the image sensor involves using a 180° bent, flexible printed circuit board (PCB), allowing both the image sensor and the connecting cables to be electrically connected to the same PCB surface. US 2020 / 0046210A1 describes a similar approach, also using a bent, flexible PCB.

[0011] Starting from these numerous previously known solutions, the invention aims to propose a new approach for a manufacturing process, ideally fully automated, for imager assemblies of miniaturized imaging systems, particularly endoscopes, enabling the economical production of such systems in high volumes. The process and the associated imager assembly are designed to be 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 imaging systems with significantly larger diameters, where, for example, a large-volume working channel can also be implemented.

[0012] Furthermore, the invention is also intended to propose a corresponding design for such an imager assembly that enables such a manufacturing process.

[0013] To solve this problem, the features of claim 1 are provided according to the invention for an imager assembly. In particular, it is proposed according to the invention, to solve the problem in an assembly of the type described above, that the image sensor chip is arranged on a front side of the carrier structure. This front side can be oriented, in particular, towards a tip of the associated endoscope shaft in which the imager assembly is to be installed, or obliquely to the side therefrom. 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 via, each of these vias forming a passage from the front to the rear side of the carrier structure.Finally, it is provided that each 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.

[0014] Such an electrical connection can be implemented directly, for example, by a direct soldered connection between the respective inner conductor and the rear contact of the image sensor chip. For this purpose, it is further provided that the support structure includes at least one integrated and electrically operated heating element and that the respective electrical connection is designed as a soldered connection formed with the at least one integrated heating element.

[0015] However, it is also possible that at least one interposer is arranged between the image sensor chip and the support structure. In this case, the respective electrical connection can only be established indirectly, namely via electrical connections in the interposer, whereby, according to the invention, the respective solder joint forming the electrical connection can also be formed with the at least one integrated heating element. In other words, a respective rear contact of the interposer is then, for example, directly electrically connected to the respective inner conductor, while the rear contacts of the image sensor chip can be electrically connected, in particular soldered, to front contacts of the interposer.

[0016] Furthermore, it is preferred if only one electrical inner conductor is inserted into each via of the support structure, i.e., neither a shield nor an insulation of the cable. In other words, the stripped inner conductor, free of its shielding, protrudes from the front of the cable, and only this part of the inner conductor is inserted into the respective via.

[0017] In the inventive approach, the cable to be connected to the image sensor can be supplied during assembly, for example, as a pre-assembled module with an associated connector or as a continuous length of cable (e.g., on a cable reel). It can also be provided that the cable is fed into a stripping machine, in which the cable is automatically stripped. Such stripping machines are already commercially available. In this way, the cable, and in particular its inner conductor, can be prepared for insertion into the support structure.

[0018] According to the invention, it can further be provided that at least one cable strand, but preferably several cable strands, 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.

[0019] A support structure according to the invention can preferably be manufactured from a wafer using microsystems technology methods or from another substrate. This approach particularly allows for the efficient parallel production of identical support structures in high volumes, as is necessary for single-use endoscopes to comply with stringent manufacturing cost requirements. The approach according to the invention thus enables pre-assembly of the image sensors or the described imaging module with an associated cable, whereby known pick-and-place technologies / robots can be used to assemble the image sensor, in particular the image sensor module, onto the support structure and connect it electrically.

[0020] As explained above, the invention provides that the support structure includes a heating element designed to create a soldered connection between the respective contact of the image sensor and the cable to be soldered to it. For this purpose, the support structure incorporates smaller deposits of solder material, which can then be heated by the (in particular, the respective) heating element to such an extent that the solder material begins to melt, thus forming the soldered connection. Analog raw signals or digital image signals already processed by the image sensor itself can subsequently be derived from the image sensor via this electrical connection using 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.

[0021] The heating element is designed as an electrical heating element, such that applying a sufficient electrical voltage to electrical contacts of the support structure (which are electrically connected to the heating element) allows an electric current to flow through the heating element. The heating element can therefore be designed, for example, as a resistive heating element / heating resistor and thus convert electrically supplied energy into thermal energy (heat), which must be generated locally to form the solder joint.

[0022] A particular advantage of the inventive approach is that the described manufacturing process can be fully automated. This allows miniaturized imaging systems, especially single-use endoscopes, to be produced in large quantities at low manufacturing costs. The manufacturing process, described 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 needs to be incorporated.

[0023] According to the invention, the problem can also be solved by further advantageous embodiments according to the dependent claims.

[0024] For example, it can be provided that the respective via is closed towards the front of the support structure by means of a metallization (in the fully assembled state) and that the respective inner conductor is electrically connected to this metallization, preferably soldered. The metallization can in particular be formed by an alloy.

[0025] Alternatively, it can also be provided that the respective inner conductor is routed through the respective via to the front of the support structure and that the respective electrical connection is thus designed on the front of the support structure, preferably as a soldered connection.

[0026] Unlike previously known approaches, which often employ so-called interposers with electrical vias to create electrical connections between an image sensor and several conductors of a cable, the invention proposes that the respective inner conductors of the cable are not simply soldered to an end face of the support structure, but rather inserted into a volume defined by the support structure, namely through the respective insertion opening and into a corresponding inner conductor receptacle of the support structure. This inner conductor receptacle terminates in the previously described front-facing vias of the support structure. These vias are therefore not completely metallized / filled with metal, as is typical for interposers, but instead have at most an electrically conductive inner wall layer, in particular an inner wall metallization.Therefore, the front vias together with the inner conductor receptacle form a recess into which the respective inner conductor can be inserted up to the front of the support structure.

[0027] The respective via therefore preferably has an electrically conductive inner layer. This can be designed, for example, as an inner metallization or by means of other suitable conductive layers (e.g., ITO or electrically conductive pastes). Furthermore, it can be provided that an end-face of the respective electrical conductor is electrically connected to this electrically conductive inner layer or metallization of the associated via, whereby this electrical connection can also be achieved by soldering.

[0028] The maximum inner diameter of each via can preferably be smaller than the diameter of the respective cable. This prevents the cable from being unintentionally inserted into the via. It is particularly preferred that the maximum inner diameter of the via be smaller than the maximum diameter of the respective insertion opening. On the other hand, the maximum inner diameter of the via should be at least as large as the thickness of the respective inner conductor to ensure that the inner conductor can actually be inserted into the via automatically. Preferably, the cable has separate electrical insulation and / or electrical shielding for each inner conductor. In such a case, the respective electrical insulation and / or 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 support structure.

[0029] As already mentioned, the electrical connection between the respective rear electrical contact of the image sensor chip and the associated inner conductor of the respective cable can be configured as a soldered connection. In such a case, the invention proposes that the support structure can include at least one integrated and electrically operated heating element with which such soldered connections can be formed 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 this context, "solder mass" can technically refer to any form of flowable material (including, in particular, conductive thermoplastic adhesives that become flowable when heated and solidify when cooled) that provides sufficient electrical conductivity to transmit signals from the image sensor.

[0030] The support structure can (especially if it is made from a wafer) comprise an electrically conductive material such as doped silicon, i.e., in particular a bulk material. An electric current can be injected or introduced through such a material to operate the at least one integrated heating element. For example, the electric current required to operate the heating element can be introduced into the support structure via a side wall that runs between the front and back surfaces.

[0031] Another embodiment, however, provides that the support structure is made of an electrically insulating material, such as plastic, glass, or ceramic. In such a case, electrical conductors can be provided and formed in and / or on the support structure, which can then be configured to supply at least one integrated heating element with an externally supplied electrical operating current.

[0032] According to these concepts, the heating device used to form the solder structure, namely at least one heating element, remains in the imager assembly thus produced and therefore possibly also in the later fully assembled endoscope.

[0033] It has already been mentioned that the support structure can be manufactured using a parallel manufacturing process. Preferably, this can be done using methods from microsystems technology and / or at the wafer level. Etching processes can also be used to form the vias.

[0034] One of the bulk materials of the support structure, especially the one mentioned above, can be silicon, or, as explained previously, glass or a ceramic.

[0035] Depending on the design of the support structure, it can 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 the at least one integrated heating element, whereby the heat is then conducted via the bulk material to the solder mass.

[0036] Parallel manufacturing, in this context, refers specifically to the fact that the support structure, along with other identically designed support structures, was produced from a single panel or wafer through singulation. Therefore, the support structure may exhibit traces of this singulation process, such as saw marks, on its outer edges, for example, on its side walls.

[0037] The presented manufacturing process is particularly suitable for producing support structures with a very small footprint of less than 1.2 × 1.2 mm. 2to develop such a delicate structure. This is because such intricate dimensions of the support structure can be readily managed, especially during wafer-level manufacturing, using conventional singulation methods such as wafer sawing. The diameter of each via in the support structure can be less than 150 µm, preferably even less than 100 µm. However, it is preferable for the rear insertion opening to have a diameter of at least 200 µm, preferably even at least 250 µm. Such dimensions have proven suitable for both inserting suitable cables, including insulation and shielding, into the support structure from the rear and for guiding the stripped inner conductors through these delicate vias to the front side.

[0038] Each of the cables used in the imager assembly can therefore have its own electrical shielding. It is thus preferred if the cables are designed as coaxial cables and / or if the respective shielding is electrically separated from the respective inner conductor by means of electrical insulation.

[0039] It is particularly advantageous for the electrical properties of the imager assembly if the respective shield is electrically connected to an electrically conductive part of the support structure by means of an electrical contact. For example, the respective shield can be connected to an electrically conductive bulk material of the support structure, particularly the aforementioned one, or to a metallization, such as a conductor track, of the support structure. In such cases, it is further preferred if an electrical ground potential can be applied to the shield via the support structure.

[0040] Furthermore, the respective cable can also be mechanically coupled to the support structure via this electrical contact. Preferably, at least four cables can be provided in this way, via which 1) a supply voltage, 2) a ground potential, and 3) a clock signal can be transmitted to the image sensor chip, and furthermore, via the fourth cable, 4) analog output signals from the image sensor chip can be derived. The four cables can, of course, also be designed as strands of a larger multi-core cable, preferably each electrically shielded.

[0041] As mentioned at the outset, the rear contacts of the image sensor chip can be electrically connected to one of the corresponding inner conductors via an interposer. In such a case, it is preferred that the respective electrical connection, and in particular the respective solder joint, 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 by means of electrically conductive vias (within the interposer). Such vias can, for example, be formed by means of electroplated metallizations in a volume of the interposer in a manner known per se, wherein the vias are then completely filled by the metallization or at least side surfaces of the vias are metallized.

[0042] The image sensor chip can be designed 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 necessary, 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 substrate, which can be achieved in particular by means of a soldered connection (especially as previously described).

[0043] Between the respective insertion opening (on the back of the support structure) and the adjoining via (on the front of the support structure), a step or other contact surface can be provided against which the cable's electrical insulation or shielding can rest. This design is advantageous for defining a desired insertion depth of the cable into the support structure, which can then significantly simplify automated assembly. In particular, this allows for the predefined insertion depth of a stripped end of the respective inner conductor into the support structure; for example, if this end is already formed at a predetermined distance from the end of the cable's shielding / insulation, which can be achieved with high precision using automated stripping machines.

[0044] The multiple cables can be considered, in particular, as conductors of a multi-core imaging cable (or also: image transmission cable).

[0045] Furthermore, the support structure can form a rear receptacle into which such an imaging cable can then be plugged.

[0046] The support structure can, for example, be designed in the form of a sleeve that is plugged onto the imaging cable.

[0047] To solve this problem, as already mentioned, an endoscope is proposed which includes an imager assembly configured according to the invention, i.e., as previously described or according to one of the claims relating 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 save 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 only be used as a single-use / disposable endoscope in a medical application (once only); however, it can then be manufactured much more cheaply.

[0048] As already explained, the shaft at the distal end, 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 is reliably achievable through the inventive design of the imager assembly. However, as already mentioned, imager assemblies according to the invention can also be used effectively in endoscopes with significantly larger shaft diameters of 5 mm or even 6 mm or more.

[0049] The finished endoscope, i.e., in particular its imager assembly, or more precisely the support structure of the imager assembly, comprises, according to the invention, at least one electrically operated heating element, which is still present even after the assembly has been completely assembled. As explained, this at least one integrated heating element allows the electrical connections to be made by melting a respective solder compound.

[0050] To solve the problem, a method for the automated assembly of an imager assembly, particularly as previously described, is also proposed. In other words, the imager assembly to be manufactured using the method can be designed as previously described and / or according to one of the claims directed to an imager assembly. The method is characterized by the fact that, with the aid of an assembly machine (this can be, in particular, a pick-and-place robot), the several already stripped cables are automatically inserted into respective rear insertion openings in a support structure, whereby the respective inner conductors of each cable are automatically passed through respective front vias, which are designed as feedthroughs on a front side of the support structure.Furthermore, it is provided that the image sensor chip, particularly as part of a compact imaging module, is automatically placed on the front of the carrier structure. Preferably, the image sensor chip can be glued or soldered to the front of the carrier structure. It is also provided that an electrical connection is automatically formed on the front of the carrier structure between the respective inner conductor and a corresponding rear electrical contact of the image sensor chip, which, as explained, can be done either indirectly or directly.

[0051] Such a fully assembled imager module can then be inserted into the distal end of an endoscope shaft to form a chip-in-tip endoscope (especially as described above).

[0052] The stripping of the cables can also be carried out automatically using a cable stripping machine (even before the cables are automatically inserted into the rear insertion openings).

[0053] It has already been explained that the respective electrical connection is formed by melting a solder mass. This could, of course, be done, as is common practice in the prior art, for example, using an external heating device that melts the solder mass to form the electrical connection. Optical radiation and / or a hot air stream and / or a magnetic field could be used to generate the necessary amount of heat.

[0054] According to the invention, the respective solder mass is melted by electrically operating at least one heating element integrated into the support structure in order to form the respective electrical connection. This approach thus provides that the at least one heating element remains in the support structure and therefore in the assembly. It is also conceivable in which the heating element is no longer functional after operation. The crucial point is simply that the respective electrical connection can be formed at the correct location using the heating element during the initial operation.

[0055] The invention will now be described in more detail with reference to exemplary embodiments, but is not limited to these examples. Further embodiments 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 are functionally identical are assigned the same reference numerals even if they differ in design or shape.

[0056] 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 from Fig. 1, where the insertion of a cable 8 into a rear insertion opening is illustrated, 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 it to rear contacts of an image sensor chip, Fig. 4 the situation Fig. 3 after fully inserting all four cables 8, Fig. Figure 5 shows a highly schematic side view of the fully assembled imager assembly. Fig. 3 and Fig. 4, and finally Fig. 6 schematically the components of a visualization system which includes an endoscope designed according to the invention.

[0057] The Fig. Figure 6 shows a visualization system 32 with an endoscope 6 according to the invention, which is read out by a camera control unit 34 that transmits corresponding video image signals to a monitor 33 to display a live video image. 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 includes an image sensor chip 2 for imaging / for 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.

[0058] Fig. Figure 1 shows details of the imager assembly 1 according to the invention, as arranged in the endoscope tip: As mentioned, the imager assembly 1 comprises an image sensor chip 2 with an associated imaging optic 3, which is designed as a wafer-level optic, wherein these two components are combined to form a compact imaging module 4. On its rear side, the image sensor chip 2 has several rear electrical contacts 14, which are to be electrically connected by means of respective cables 8 in order to transmit 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 another (inner) electrical insulation 19 and finally an electrically conductive inner conductor 13, which is electrically connected to the respective contact 14 of the image sensor chip 2 via the interposer 9 shown.

[0059] In the cross-sectional view of the Fig. It is good that the support structure 7 forms 12 front-facing 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, with each of the cables 8 being inserted into a respective insertion opening 10. Based on the dotted circle in Fig. Figure 1 clearly shows a step 41 or a contact surface 42 on the inner wall of the respective insertion opening 10, whereby the inner insulation 19 rests against this step 41 / contact surface 42, thus defining an 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 to the front face 12 of the support structure 7 using a pick-and-place robot. Only one electrical inner conductor 13 of the respective cable 8 is inserted into the respective via 39 at a time.

[0060] By means of a first soldered connection 16 between the interposer 9 and the support structure 7, the respective inner conductor 13 is electrically connected to a respective rear electrical contact of the interposer 9 (cf. Fig. 1) The interposer 9 has electrically conductive vias 29 and electrical connections 15 inside, which electrically connect the respective inner conductor 13 to the respective contact 14 of the image sensor chip 2. For this purpose, further solder connections 15 are provided between the front electrical contacts 31 of the interposer 9 and the electrical contacts 14 on the back of the image sensor chip 2. Depending on the arrangement of the rear contacts 14, however, an interposer 9 is not necessarily required; if the rear contacts 14 of the image sensor chip 2 have sufficient spacing, the inner conductors 13 can also be directly connected to them by means of a respective solder connection 15.

[0061] In the Fig. Figure 2 shows further details of the support structure 7 according to the invention as part of the assembly 1 according to the invention: The support structure 7 was manufactured from a silicon wafer using microsystems technology methods by means of etching processes and wafer sawing in parallel with other identically designed support structures 7. The bulk material 24 of the silicon support 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 support structure 7. At the upper edge of the insertion opening 10, an electrically conductive layer 36 in the form of a metallization 40 can be seen, which is electrically insulated from the bulk material of the support structure 7 by means of an additional electrical insulation 19. This rear metallization 40 at the entrance of the insertion opening 10 serves, as can be clearly seen in Figure 2, to... Fig. 1 recognizes that an electrical contact 27 is formed between the electrical shielding 18 of the cable 8 and the support structure 7, more precisely the aforementioned metallization 40. In this way, an electrical ground potential can be applied to the shielding 18 via the support structure 7.

[0062] By combining the Fig. 1 and Fig. 2. It can also be seen 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 joint 16, but that this solder joint also extends into the respective front-side via 39 of the support structure 7. As the Fig. Figure 2 shows that metallizations 40 are formed on the inner front side of each via 39, via which the inner conductor 13 can be firmly soldered to the support 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. Fig. 2 it can also be clearly seen that this front-side metallization 40 on the inner wall of the vias 39 is electrically insulated from the bulk 24 of the support structure 7 by means of an additional electrically insulating layer 37, i.e. in addition to the passivation layer 25.

[0063] Based on the cross-sectional view of the Fig. 2. It can also be seen that the diameter of the cable 8, and in particular the outer diameter of the shielding 18 as well as the inner insulation 19, exceeds the remaining inner diameter of the via 39, so that only the stripped inner conductor 13 with its front end can be inserted into the via 39, but not the shielding 18 or the inner insulation 19 (the outer insulation 19 of the cable 8 is in Fig. 2 not shown).

[0064] In the Fig. 1 and Fig. Reference numeral 5 merely indicates that an electrically operated heating element 5 is 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 joint 16 by operating this heating element 5 with an electric current. In this way, the respective cable 8 can be connected to the support structure 7 both mechanically and electrically to the image sensor chip 2 in a particularly reliable manner.

[0065] During the Fig. 1 and Fig. In the embodiment shown, for example, such an electrical operating current for operating the integrated heating element 5 could be introduced into the support structure 7 via the bulk material 24, whereby the support structure 7 can be contacted very simply via the electrically non-insulated side wall 26 (compare Figure 2). Fig. 1).

[0066] The in the Fig. 1 and Fig. The stepped shape of the insertion opening 10 shown in Figure 2, with the illustrated step 41, can be produced with particular precision using etching processes such as dry etching. The [details of the step shown in Figure 2 are missing from the original text.] Fig. 1 and in Fig. The two support structures 7 shown can also be manufactured cost-effectively using other parallel manufacturing processes from an alternative application, whereby non-conductive materials such as glass can also be used. An advantage of these approaches is that the support structure can occupy an area that is 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.

[0067] Based on the Fig. Figures 3-5, which illustrate in a highly schematic form another imager assembly 1 according to the invention, this time without the use of an interposer 9, also allow the inventive method for the automated assembly of such an assembly 1 to be followed: For this purpose, the components are first stripped using a wire stripping machine. Fig. The four cables 8 shown in the diagram are automatically stripped, exposing both the electrical shielding 18 and the respective inner conductors 13. The pre-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 diagram. Fig. 3 and Fig. Figure 4 illustrates this. The respective inner conductor 13 is guided through the respective front-facing via 39 to the front surface 12 of the support structure 7. The image sensor chip 2, on the other hand, is also automatically placed on the front surface 12 of the support structure 7 and initially glued in place. Solder compounds 21 were applied to the front and back of the support 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).

[0068] An electric current is 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 the respective heating element 5 thus melts the solder masses 21, thereby melting the (already in Fig. 1 and Fig. The electrical connections shown in Figure 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 connections shown in the Fig. The embodiments shown in 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 that are to be connected to the respective inner conductor 13.

[0069] The result is the situation of the side view of the Fig. 5: On the left side, the cables 8, which are inserted into the rear of the support structure 7, and the respective electrical connections 15 formed between the front of the support structure 7 and the rear of the image sensor chip 2 in the form of solder joints 16, through which the respective inner conductor 13 is electrically connected to the respective contact 14 of the image sensor chip 2, can be seen. The automated formation of these solder joints could be generated – in a manner known per se – for example, using an external heating device such as laser radiation sources or a hot air stream; however, according to the invention, this is done, as explained above, using an integrated heating element 5.

[0070] 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 process 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, a support structure 7 is provided according to the invention, 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 support structure 7, with a very small diameter typically less than 150 µm or even less than 100 µm, to the front side 12 of the support structure 7, so that an electrical connection 16 / 15 can be formed there using a heating element 5 integrated into the support structure 7, in order to electrically contact an image sensor chip 2 of the assembly 1 using the cables 8 and the support structure 7 (compare . Fig. 1). Reference symbol list 1 Imager assembly 2 Image sensor chip (has active sensor area on its front and rear contacts 14) 3 Imaging optics 4 Imaging module 5 heating element 6 Endoscope 7 Support structure 8 cables (for electrical contacting 2, in particular for deriving analog signals from 2 and / or for electronically controlling 2) 9 Interposer (mediates electrical contacting of the rear contacts from 2 to 8; can be part of 4) 10 insertion opening (designed in 7, for insertion of 8) 11 Back side (of 7) 12 Front (of 7) 13 inner conductors (out of 8) 14 rear electrical contact (of 2) 15 electrical connection 16 soldered connections 17 rear electrical contacts (out of 9) 18 electrical shielding 19 electrical insulation 20 substrate (e.g., a single chip from a wafer; forms 7 with it) 21 Solder mass 22 shaft (of 6) 23 Assembling 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 Side wall (of 7, runs between 11 and 12) 27 Electrical contact (between 18 and 7) 28 outer edge 29 electrically conductive (especially metallically lined or metallically filled) via (of 9) 30 distal end (of 6 / 22) 31 front electrical contact (of 9) 32 Visualization system 33" Monitor 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 41st level 42 Plant area

Claims

[1] Imager assembly (1), in particular for use in a single-use chip-in-tip endoscope (6), wherein the imager assembly (1) comprises: - 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 optic (3), preferably designed as a wafer-level optic, - electrical cables (8) for electrical contacting the image sensor chip (2) and - a support structure (7) for carrying the image sensor chip (2), wherein: - the image sensor chip (2) is arranged on a front side (12) of the carrier structure (7), - the support structure (7) has rear insertion openings (10) on one of the rear sides (11) opposite the front side (12), into which one of the cables (8) is inserted, - each of the insertion openings (10) opens into a respective front via (39), each via (39) forming a passage from the front (12) to the rear (11) of the support structure (7), and - wherein, preferably exclusively, each electrical inner conductor (13) of the respective cable (8) is inserted into the respective via (39) and is electrically connected, directly or at least indirectly, to a respective associated rear electrical contact (14) of the image sensor chip (2) by means of a respective electrical connection (15), wherein - the respective electrical connection (15) is designed as a soldered connection (16) and the support structure (7) comprises at least one integrated and electrically operable heating element (5) with which the soldered connections (16) were formed. [2] Imager assembly (1) according to claim 1, - wherein the respective via (39) to the front (12) of the support structure (7) is closed by means of a metallization (40) and the respective inner conductor (13) is electrically connected to this metallization (40), preferably soldered, or - wherein the respective inner conductor (13) is passed through the respective via (39) to the front (12) of the support structure (7) and the respective electrical connection (15) is thus designed on the front (12) of the support 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 any 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 is not passed 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 (12) of the support structure (7). [5] Imager assembly (1) according to one of the preceding claims, wherein the solder joints (16) were formed 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 support structure (7) comprises an electrically conductive material, in particular a bulk material (24), through which an electric current can be injected / introduced for the operation of the at least one integrated heating element (5), in particular mediated via a side wall (26) which runs between the front (12) and the back (11), or - wherein the support structure (8) is made of an electrically insulating material, for example of a plastic, glass or ceramic, but preferably has electrical conductors 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 manufactured using a parallel manufacturing process, - preferably using methods of microsystems technology and / or at the wafer level, - was / is produced particularly preferably using an etching process to form the vias (11), - in particular wherein one, in particular the, bulk material (24) of the support structure (7) is silicon or glass or a ceramic and / or - wherein one, 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 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 support structure (7) together with other identical support structures (7) was obtained from a panel or a wafer by singulation and therefore shows traces, for example saw cutouts, 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 x 1.2 mm 2 exhibits and / or - wherein the respective diameter of the respective via (11) of the support structure (7) is designed to be 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 at least 250 µm. [10] Imager assembly (1) according to any 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 support structure (7) or a metallization, in particular a conductor track, of the support structure (7), is electrically connected by means of a respective electrical contact (27), - preferably such that, mediated via the support structure (7), an electrical GND potential can be applied to the shield (18) and / or such 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 each of the associated 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 to the support structure (7), in particular by means of a soldered connection. [13] Imager assembly (1) according to one of the preceding claims, wherein a step (41) or other contact surface (42) is provided between the respective insertion opening (10) and the via (39) adjoining thereto, on which step (41) / contact surface (42) an electrical insulation (19) or a shielding (18) of the cable (8) can be applied 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 multiple cables (8) are designed as conductors of a multi-core imaging cable and the support structure (7) forms a rear receptacle into which the imaging cable is inserted, - 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 any 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) by means of which the electrical connections (15) were made, in particular by melting a respective solder mass (21), or at least could be made. [17] Method for the automated assembly of an imager assembly (1), wherein the imager assembly (1) - an image sensor chip (2), - several electrical cables (8) for electrical contacting the image sensor chip (2) and - a support structure (7) that carries the image sensor chip (2), - preferably wherein the imager assembly (1) is configured according to any one of claims 1 to 14, characterized by , - that with the help of an assembly machine (23), in particular with the help of a pick-and-place robot, the several already stripped cables (8) are automatically inserted into the respective rear insertion openings (10) of the support structure (7), - that in this way the respective inner conductors (13) of the respective cable (8) are automatically guided through the respective front-side vias (39), which are designed as feedthroughs on a front side (12) of the support 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 area of ​​the front (12) of the support structure (7) a respective electrical connection (15) between the respective inner conductor (13) and a respective associated rear electrical contact (14) of the image sensor chip (2) is formed, at least indirectly or directly, automatically, - wherein the respective electrical connection (15) is formed by melting a respective solder mass (21) and the respective solder mass (21) is melted by electrically operating at least one heating element (5) which is integrated into the support structure (7) in order to form the respective electrical connection (15), and wherein the at least one heating element (5) remains in the support structure (7). [18] Method according to the preceding claim, wherein the stripping of the cables (8) is carried out automatically using a stripping machine.

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