Multilayer printed circuit board module

Abstract

The invention relates to a multilayer printed circuit board module, in particular for high-frequency and / or radar applications. The multilayer circuit board module has at least five layers, namely a first conductive layer, followed by a first substrate layer, followed by a second conductive layer, followed by a second substrate layer, followed by a third conductive layer, wherein a substrate-integrated waveguide is formed in the second substrate layer. The first and the second conductive layer each have a window in order to couple in and / or decouple modes, which are capable of propagating in the substrate-integrated waveguide, through the first substrate layer transversely to the main extension plane of the second substrate layer.

Description

[0001] Multilayer PCB module

[0002] The present invention relates to a multilayer printed circuit board module, in particular for high-frequency and / or radar applications, as well as a system comprising a multilayer printed circuit board module.

[0003] For the purposes of the present invention, high-frequency or radar applications are preferably applications, particularly in the industrial sector, in which high-frequency signals, in particular radar signals, are transmitted and / or received. High-frequency or radar signals for the purposes of the present invention are particularly preferably signals with frequencies in the gigahertz range, i.e., greater than 1 GHz and / or less than 1 THz, preferably greater than 20 GHz and / or less than 500 GHz.

[0004] Particularly preferably, the multilayer printed circuit board module is used in a radar system, or the system comprising the multilayer printed circuit board module is a radar system, particularly for use in the industrial sector. In this context, the multilayer printed circuit board module or (radar) system is used, for example, for level determination, flow determination, thickness measurement, distance measurement, scattering parameter measurement, millimeter-wave spectroscopy, or for monitoring purposes of industrial plants or production processes. Although the present invention is preferably used in corresponding areas, it can also be advantageous in other areas.

[0005] DE 10 2019 217 736 A1 discloses a radar chip with a waveguide coupling. The waveguide coupling consists of three layers, namely two copper layers with a dielectric layer between them, in which a substrate-integrated waveguide is integrated, extending into a circular waveguide. The radar chip is arranged on the outside of the waveguide coupling and is connected via bond wires to a stripline formed in the upper copper layer. The radar chip can excite electromagnetic waves in the waveguide, which are fed directly into the waveguide via an excitation patch at the end of the waveguide.

[0006] To protect against mechanical stress, dust, or other contaminants, the radar chip in DE 10 2019 217 736 A1 must be embedded in a potting compound, such as GlobTop. This is particularly disruptive at high frequencies above 100 GHz, as it leads to losses and reflections. Furthermore, the bandwidth of the signal coupled into the waveguide via the patch is severely limited.

[0007] CN 110739514 A relates to a structure, particularly for anti-collision radar systems in motor vehicles, for coupling millimeter waves from a substrate-integrated waveguide into a rectangular waveguide, also using patches. For this purpose, a recess is formed in the uppermost conductive layer, over which a rectangular waveguide can be placed. Four excitation patches are arranged in the recess, forming an electromagnetic dipole. Electromagnetic waves propagating in the substrate-integrated waveguide are deflected at the end of the waveguide through a slot in the conductive layer bounding the waveguide toward the recess to excite the patches.

[0008] The structure of CN 110739514 A, particularly the dimensions of the recess, the patches, and the slot, is designed for a frequency range below 100 GHz, particularly around 80 GHz. Even for this frequency range, the dimensions are extremely small; for example, the spacing between the excitation patches is approximately 0.1 mm. Slots of up to 0.15 mm can be produced using conventional etching processes; more complex etching processes allow for slots as small as 0.1 mm. Thus, the production of the structure shown in CN 110739514 A is already very complex and expensive for a frequency range around 80 GHz. For higher frequencies above 100 GHz, the dimensions would have to be reduced even further, which is not feasible, or at least not feasible, as a series product.

[0009] CN 115332766 A relates to an array of millimeter-wave radar antennas, particularly for mounting on vehicles, wherein each antenna has a substrate-integrated waveguide. CN 115332766 A features recesses in the uppermost conductive layer, each of which contains cross-shaped excitation patches. The array operates in the frequency range from 75 to 81 GHz.

[0010] Although CN 115332766 A provides for larger dimensions, in particular larger slot widths, than CN 110739514 A, for applications with higher frequencies, especially above 100 GHz, the dimensions of CN 115332766 A would have to be reduced so significantly that production is not practical, or at least not feasible as a series product. The technical article by S. Bu et al., "A Millimeter-Wave Broadband Transition of Air-Filled Rectangular Waveguide to Differential Substrate Integrated Waveguide", 2019 IEEE MTT-S International Wireless Symposium (IWS), IEEE, 2019, concerns a rectangular broadband transition between a rectangular waveguide and differential substrate-integrated waveguides, with a substrate-integrated waveguide terminating on opposite sides of a cavity. The transition thus has three ports.A signal fed through the rectangular waveguide is split into two signals 180° out of phase. The transition is designed for a frequency range of 25.5 to 40.7 GHz.

[0011] In particular, if the transition is to be used to feed a signal into the rectangular waveguide, it is necessary to couple two signals 180° out of phase into the cavity on opposite sides via the respective substrate-integrated waveguides. This is complex, as it requires additional circuit components. It also requires more space.

[0012] US 2012 / 0050125 A1 relates to millimeter-wave systems, in particular for coupling waveguide antennas to PCBs. A millimeter-wave signal can be generated by a chip on a PCB and fed into a stripline via bonding wires. The signal is transmitted via the stripline to a probe, where it is radiated as a millimeter wave and guided out of the PCB. The chip is arranged in a first cavity, and a second cavity can be formed above the chip so that the bonding wires are not directly covered by additional layers. The second cavity is sealed by a cover layer.

[0013] The present invention is based on the object of specifying a multilayer printed circuit board module, in particular for high-frequency and / or radar applications, as well as a system with a multilayer printed circuit board module, wherein a precise and / or versatile coupling and decoupling of electromagnetic signals is achieved, in particular with a high bandwidth, a defined transmission direction, a defined and frequency-stable phase center and / or few losses or reflections, preferably even at high frequencies, and / or wherein simple and cost-effective production is enabled.

[0014] The object underlying the invention is achieved by a multilayer printed circuit board module according to claim 1 or 17 or a system according to claim 21, 22 or 24. Advantageous further developments are the subject of the dependent claims. The proposed multilayer printed circuit board module has at least five plies or layers, namely a first conductive layer, followed by a first substrate layer, followed by a second conductive layer, followed by a second substrate layer, followed by a third conductive layer. In other words, the multilayer printed circuit board module preferably has a sandwich structure of alternating conductive layers and substrate layers, wherein at least three conductive layers and at least two substrate layers are provided.

[0015] In the proposed multilayer printed circuit board module, a substrate-integrated waveguide is formed in the second substrate layer, in which electromagnetic waves or modes, in particular with a frequency in the GHz range or a wavelength in the millimeter range, can propagate.

[0016] According to one aspect of the present invention, the first conductive layer has a first window and the second conductive layer has a second window in order to couple in and / or out waves or modes propagable in the substrate-integrated waveguide transversely, in particular at least substantially perpendicularly, to the main extension plane of the second substrate layer through the first substrate layer.

[0017] In particular, the propagation direction or transmission direction of the electromagnetic wave between the windows or in the first substrate layer runs transversely, in particular at least substantially perpendicularly, to the propagation direction or transmission direction of the electromagnetic wave in the substrate-integrated waveguide or in the second substrate layer.

[0018] The proposed multilayer printed circuit board module enables particularly precise coupling and decoupling of modes and is versatile in its application.

[0019] Through the proposed arrangement of the windows, the modes radiate in and out transversely, in particular at least substantially orthogonally, to the main extension of the multilayer printed circuit board module. Furthermore, higher modes are effectively suppressed. Both are advantageous for precise measurement and / or versatility. In particular, a waveguide can be placed particularly easily on the multilayer printed circuit board module, in particular the first conductive layer or the first window, whereby the transmission direction of the modes during coupling in and out already corresponds to the main extension of the waveguide, thus enabling transmission with as little loss as possible.

[0020] Preferably, precise alignment of the waveguide is possible in a particularly simple manner. For this purpose, corresponding alignment structures, such as dowel pin holes, can be formed on the multilayer printed circuit board module.

[0021] In addition, the outer side of the multilayer printed circuit board module, which is in particular a flat side of the first conductive layer, can be formed at least substantially flat due to the coupling / decoupling via the window, which enables precise application of the waveguide.

[0022] Particularly preferably, the proposed multilayer printed circuit board module can also be used without a waveguide. For example, modes could be coupled directly into an antenna, in particular a dielectric antenna and / or drop antenna, or coupled from such an antenna into the multilayer printed circuit board module. This is made possible in particular by the fact that the transmission direction of the modes during coupling or decoupling is preferably already at least substantially orthogonal to the main extension plane of the multilayer printed circuit board module. Aligning the transmission direction using a waveguide is therefore not absolutely necessary.

[0023] The transmission direction of the waves or modes can be adjusted or defined, in particular, by the proposed provision of the first and second windows and the propagation of the modes through the first substrate layer. This preferably enables coupling or decoupling of the modes in a defined direction, in particular transversely or orthogonally to the main extension plane of the multilayer printed circuit board module or its layers.

[0024] In addition, the modes radiated by the proposed multilayer printed circuit board module have a defined and frequency-stable phase center.

[0025] Furthermore, the proposed multilayer printed circuit board module makes it possible to transmit and / or receive particularly broadband signals. Within the meaning of the present invention, broadband signals contain, in particular, frequency components in a frequency range that, relative to a center frequency, has a bandwidth of more than 5%, preferably more than 10%, in particular more than 15%, of the center frequency.

[0026] Furthermore, the proposed multilayer printed circuit board module can be manufactured particularly easily, compactly and / or cost-effectively in production.

[0027] The proposed layer structure enables production by pressing or laminating the various layers together using standard manufacturing steps. The multilayer printed circuit board module can thus preferably be manufactured by laminating or pressing the layers together and / or be designed or considered a laminate. In particular, when using printed circuit boards as the "PCB core material," no complex fusion bonding of the layers or similar processes is necessary during module production. This contributes to simple and cost-effective production.

[0028] Structuring the multilayer printed circuit board module, in particular the formation of the windows and / or the sidewalls of the substrate-integrated waveguide, is preferably possible by laser processing, especially of the corresponding prepregs or core materials. Structuring can also be achieved via etching processes and / or metallization. However, complex milling or the like is preferably not necessary. This contributes to simple and cost-effective production.

[0029] The first and / or second window is / are preferably slot-shaped or shaped as a slot and / or has / has a main extension which is transverse, in particular perpendicular, to the main extension or to the course of the substrate-integrated waveguide.

[0030] The first and / or second window preferably has / has a rectangular basic shape or is / is formed as an at least substantially rectangular opening in the (respective) conductive layer.

[0031] Preferably, the two windows are designed differently. In particular, the first window has a larger opening area than the second window and / or the first window has a greater length and / or greater width than the second window.

[0032] The ratio of the side lengths of the first window is preferably greater than 3:1, in particular greater than 4:1, and / or the ratio of the side lengths of the second window is preferably greater than 5:1, in particular greater than 6:1.

[0033] In other words, the first window and / or the second window are preferably (each) formed as an elongated slot. In particular, the main extension / longitudinal extension of the (respective) window, in particular the extension transversely or perpendicularly to the main extension of the substrate-integrated waveguide, is many times, in particular more than three times, larger than the transverse extension / width of the (respective) window, in particular the extension in the direction of the main extension of the substrate-integrated waveguide.

[0034] The two windows preferably have a common axis, which runs through the centers of the windows and transversely, in particular perpendicularly, to the opening planes of the windows or to the layer planes or to the main extension plane of the first substrate layer. Particularly preferably, the windows are aligned with one another or extend at least substantially parallel to one another.

[0035] The preferred design of the windows is advantageous for further improving the coupling and / or decoupling of modes, in particular for more precisely defining the transmission direction and / or the phase center and / or reducing losses or reflections. Preferably, the shapes, dimensions, orientations, and / or positions of the windows are adapted to the desired modes, particularly with regard to the desired frequencies.

[0036] The first window is preferably constricted in the middle. In other words, the first window, in particular a slot-shaped and / or rectangular one, has a smaller width or is narrower in its center. The width here is understood to be the shorter of the two side lengths of the window. This preferably allows higher modes to be suppressed. This is advantageous for maximizing the usable frequency range or bandwidth, which in turn is beneficial for versatility and / or precise measurements. In the region of the first window, the first conductive layer preferably does not have any conductive material. In particular, the first window is free of patches or antennas and / or completely filled with dielectric.

[0037] In the region of the second window, the second conductive layer preferably has no conductive material. In particular, the second window is free of patches or antennas and / or completely filled with dielectric.

[0038] Surprisingly, it was found that the proposed multilayer printed circuit board module does not require the formation of patches or other conductive structures in the windows, yet still achieves very precise coupling and decoupling of modes with a defined and frequency-stable phase center.

[0039] The patch-free design of the first and / or second window advantageously allows for a wider bandwidth. Furthermore, the windows, and thus the multilayer PCB module, are simpler and more cost-effective to manufacture, as the formation of (delicate) structures such as patches is eliminated. This allows the multilayer PCB module to be mass-produced even for high frequencies, especially above 100 GHz.

[0040] Particularly preferably, the entire multilayer printed circuit board module is designed to be patch-free.

[0041] Preferably, a (first) cavity is formed between the windows in the first substrate layer, which at least substantially projects beyond the windows. The (first) cavity is delimited or defined in particular by conductive structures that extend through the first substrate layer or from the first to the second conductive layer. Mode propagation is preferably limited by the conductive structures.

[0042] The conductive structures are preferably spaced from the windows such that the (first) cavity delimited by the conductive structures projects beyond the windows, preferably on all sides. Particularly preferably, the windows are arranged centrally to the first cavity and / or each form an entrance or exit for modes into or out of the (first) cavity. Preferably, the substrate-integrated waveguide ends or opens into a (second) cavity that at least substantially projects beyond the second window. The (second) cavity is delimited or defined in particular by conductive structures that extend through the second substrate layer or from the second to the third conductive layer. Mode propagation is preferably limited by the conductive structures.

[0043] The conductive structures are preferably spaced apart from the second window, so that the (second) cavity defined by the conductive structures projects beyond the second window, preferably on all sides. Particularly preferably, the second window is arranged centrally relative to the (second) cavity and / or forms an entrance or exit for modes into or out of the (second) cavity.

[0044] The projection of the second cavity or the distance of the propagation-limiting structures from the second window is preferably at least 5%, in particular at least 10%, and / or at most 25% of the (clear) width of the substrate-integrated waveguide. These values ​​have proven particularly advantageous, so that the modes propagate through the second window in a defined direction, in particular the opening direction of the second window or at least substantially perpendicular to the layer plane or the propagation direction in the substrate-integrated waveguide.

[0045] The cavities are preferably substrate-filled spaces, volumes, or regions delimited by conductive structures in which the waves or modes can propagate. A cavity within the meaning of the present invention therefore does not have to be hollow, but can also be filled with a substrate or dielectric, provided that modes can propagate therein.

[0046] The cavities are preferably regions of the respective substrate layer delimited by conductive structures and / or the cavities are preferably produced by introducing the conductive structures into the respective substrate layer. A "filled cavity" is therefore preferably to be understood as meaning that the substrate or dielectric (completely) fills the cavity. In particular, the term "filled" is not intended to imply a manufacturing process in which an initially empty cavity is filled. The terms "first cavity" and "second cavity" preferably serve merely to distinguish the cavities. However, it is possible to form only the second cavity or only the first cavity. The terms "first" and "second" can also be understood as referring solely to the substrate layer in which the cavity is formed.A “second cavity” is therefore a cavity in the second substrate layer, but this does not necessarily imply the presence of a first cavity in the first substrate layer and vice versa.

[0047] The preferred design of the first and / or second cavity and / or the position of the windows relative to the first and / or second cavity is advantageous for further improving the coupling and / or decoupling of modes, in particular for more precisely defining the transmission direction and / or the phase center and / or for reducing losses or reflections. Preferably, the shape, dimensions, orientation, position, and / or permittivity of the first and / or second cavity are / are adapted to the desired modes, in particular with regard to the desired frequencies. The specific lengths and dimensions of the cavities preferably depend on the material of the respective substrate layer and / or the frequency range for which the multilayer printed circuit board module is to be designed.

[0048] Particularly preferably, the length and dimensions of the first cavity are selected so as to realize, together with the first window, an impedance matching to free space conditions, to an antenna and / or to a waveguide, for example a WR-6 waveguide.

[0049] Most preferably, the first and / or second cavity (each) forms a (cavity) resonator, wherein the dimensions, in particular the length, width and height, of the cavity(ies) are adapted to the desired resonance frequencies or modes.

[0050] The first cavity is preferably at least substantially cuboid-shaped. In one spatial dimension, the first cavity is preferably constricted in the center, or the distance between the structures delimiting the cavity is reduced there. Particularly preferably, the first cavity is constricted where the first window is also constricted. The constriction preferably continues from the first window through the first cavity. Particularly preferably, the first cavity has the shape of a so-called ridged waveguide, in particular a double-ridged waveguide. However, solutions without constriction are also possible. Due to this preferred shape of the first cavity, higher modes are preferably suppressed already in the first cavity, which achieves corresponding advantages, in particular maximizing the usable frequency range or bandwidth.

[0051] Preferably, a conductive structure, in particular a series of vias, extending transversely or orthogonally to the waveguide path is provided in the second substrate layer opposite the substrate-integrated waveguide, forming a boundary for the propagation of the modes. In particular, this conductive structure forms a boundary for the second cavity. A mode propagating in the substrate-integrated waveguide preferably cannot propagate beyond said conductive structure.

[0052] Preferably, the second cavity forms a two-port structure or has (only) two ports. A port is a structure through which modes can be coupled into and out of the second cavity. A first port is preferably formed where the substrate-integrated waveguide opens into the second cavity. A second port is preferably formed by the second window.

[0053] The first cavity also preferably has (only) two ports, namely the first and second windows. In particular, modes cannot propagate beyond the first cavity into the first substrate layer.

[0054] In the second and / or the third conductive layer, a coupling structure is preferably formed, via which modes capable of propagation in the substrate-integrated waveguide can be coupled into and / or decoupled from the substrate-integrated waveguide.

[0055] Preferably, the coupling structure is formed in the third conductive layer. This is advantageous for a simple construction. In particular, the coupling structure can be introduced into the third conductive layer only after the layers have been bonded together.

[0056] Preferably, the electromagnetic wave is coupled into the third conductive layer, in particular via the coupling structure, and decoupled into the first conductive layer, in particular via the first window, or conversely, coupled into the first conductive layer, in particular via the first window, and decoupled into the third conductive layer, in particular via the coupling structure. In other words, the coupling and decoupling takes place on opposite (flat or outer) sides of the multilayer printed circuit board module. This represents a further aspect of the present invention, which can also be implemented independently and be advantageous.

[0057] In this sense, the structures following the substrate-integrated waveguide, in particular the two windows and / or the first and / or second cavity, can be understood as a further coupling structure. Thus, the multilayer printed circuit board module preferably has a (first) coupling structure for coupling / decoupling modes at the third conductive layer and a further (second) coupling structure for coupling / decoupling modes at the first conductive layer.

[0058] The first coupling structure preferably couples the modes in / out parallel to the main extension of the layers. The second coupling structure preferably couples the modes in / out transversely, in particular perpendicularly, to the main extension of the layers.

[0059] A particular advantage of providing the coupling and decoupling on opposite sides of the multilayer printed circuit board module, or of forming the coupling structures on different sides or on opposite flat sides, is that the side of the multilayer printed circuit board module that couples electromagnetic waves out of the module or into the module, i.e., in particular, the side with the first window, can be at least substantially completely planar or flat. In particular, no structures such as a chip receptacle, a chip, conductor tracks, and the like are necessary on this side. This also allows, for example, a large-area application of a waveguide flange or an antenna to the multilayer printed circuit board module.

[0060] A further advantage is that the side with the first coupling structure faces the radiation / incoming radiation direction and can therefore be concealed or covered or does not have to be exposed. In particular, the multilayer printed circuit board module can be integrated into a system in such a way that the first coupling structure and any other structures such as a chip holder, a chip, bonding wires, conductor tracks, striplines and the like face or are covered by a PCB or other component of the system. As a result, these structures are preferably protected or shielded. Potting or embedding in a potting compound can therefore be dispensed with. This is conducive to a simpler and more compact design and leads to fewer losses and reflections, particularly at high frequencies above 100 GHz.

[0061] The multilayer printed circuit board module preferably has a chip receptacle. The chip receptacle is preferably formed at least by a recess in the third conductive layer. Particularly preferably, the chip receptacle extends at least partially into the second substrate layer, preferably completely through the second substrate layer. Accordingly, the second substrate layer also preferably has a recess, which, together with the recess in the third conductive layer, forms the chip receptacle.

[0062] The chip receptacle is preferably formed directly adjacent to the coupling structure, so that a chip arranged or capable of being arranged in the chip receptacle can be conductively connected to the coupling structure, in particular via one or more bond wires. This enables a particularly simple, compact, and cost-effective design, in which, in particular, the bond wires can be kept short. This is conducive to particularly low-loss coupling and decoupling.

[0063] Preferably, a chip, in particular an MMIC chip (Monolithic Microwave Integrated Circuit Chip), is arranged or secured, in particular glued, in the chip receptacle. The chip is preferably conductively connected to the third conductive layer, in particular the coupling structure, in particular via one or more bond wires.

[0064] By means of the chip, electromagnetic waves can be generated (coupled) in the substrate-integrated waveguide, preferably via the coupling structure, and / or electrical signals corresponding to an electromagnetic wave can be received, in particular for further evaluation.

[0065] The coupling structure is preferably designed to convert received modes into signals that can be further processed by the chip and / or to couple signals from the chip as modes into the substrate-integrated waveguide.

[0066] Particularly preferably, the chip is at least substantially flush with the third conductive layer. In other words, the third conductive layer forms an at least substantially flat surface with the chip. The chip therefore preferably does not protrude beyond the third conductive layer. In particular, the depth of the chip receptacle corresponds to the height of the chip. This is conducive to a particularly simple, compact, and cost-effective design. Furthermore, the chip is completely covered or encapsulated in the preferred, previously described installation of the multilayer printed circuit board module.

[0067] Preferably, the (first) window for coupling modes into or out of the multilayer printed circuit board module and the chip holder or the chip are formed or arranged on opposite sides of the multilayer printed circuit board module.

[0068] In the region of the chip receptacle, thermal vias preferably extend through the first conductive layer, first substrate layer, and second conductive layer, more preferably up to the chip receptacle. In particular, the thermal vias also extend through the second substrate layer if the chip receptacle is not also completely formed in the second substrate layer. Waste heat from a chip arranged in the chip receptacle can preferably be dissipated to the outside via the thermal vias, in particular through the first conductive layer, which preferably forms an outer side of the multilayer printed circuit board module.

[0069] Preferably, the multilayer printed circuit board module has—in addition to the first, second, and third conductive layers and the first and second substrate layers—at least one further layer, in particular a further substrate layer, which follows the third conductive layer or is arranged on the side of the third conductive layer facing away from the second substrate layer. Particularly preferably, the multilayer printed circuit board module has several further layers, in particular further conductive layers and / or substrate layers. The further conductive and substrate layers preferably follow the third conductive layer and are preferably arranged alternately or alternately.

[0070] The further layer(s) preferably each have a recess in the region of the coupling structure or form a recess in the region of the coupling structure, so that the coupling structure is exposed. In other words, none of the further layers extends over the coupling structure. This reduces or prevents losses during coupling and decoupling via the coupling structure.

[0071] The recess preferably extends beyond the coupling structure, in particular beyond the chip receptacle or the chip. The chip receptacle is therefore preferably arranged in the recess or formed as a (further) depression in the recess, and / or the chip is arranged within the recess. This is beneficial to the previously described shielding or encapsulation of the chip during the preferred assembly of the multilayer printed circuit board module on a PCB with the first conductive layer facing away from the PCB or with the recess or the chip facing toward the PCB.

[0072] In embodiments where the chip extends beyond the chip receptacle or protrudes beyond the chip receptacle, the chip is preferably still completely arranged within the recess or does not protrude beyond it. Thus, in this case, too, the chip is completely shielded or encapsulated in the preferred assembly.

[0073] Furthermore, the recess allows the third conductive layer, the coupling structure, the chip holder and / or the chip to be accessible, for example for subsequent assembly of the multilayer printed circuit board module with further electronic components, such as blocking capacitors and / or temperature sensors.

[0074] Preferably, the (first) window for coupling or decoupling modes into or out of the multilayer printed circuit board module and the recess are formed on opposite (flat or outer) sides of the multilayer printed circuit board module.

[0075] The proposed multilayer printed circuit board module is preferably a (chip) module that can be mechanically attached and / or electrically connected to a (main) PCB (printed circuit board). For this purpose, the multilayer printed circuit board module preferably has several pads or contacts for mechanically attaching and / or electrically connecting the multilayer printed circuit board module to a (main) PCB.

[0076] The pads are preferably formed on the side facing away from the first window or the first conductive layer, in particular on / at the outermost layer of the additional layers. In particular, the pads are arranged on the (flat or outer) side of the multilayer printed circuit board module on which the recess, the chip receptacle, the chip, and / or the (first) coupling structure are / are also formed.

[0077] This arrangement of the pads is conducive to the previously mentioned advantageous integration of the multilayer printed circuit board module, so that the first coupling structure, the chip holder, the chip and / or other structures such as bonding wires face or are covered by a PCB or other component of the system.

[0078] Preferably, the (first) window for coupling or decoupling modes into or out of the multilayer printed circuit board module and the pads are formed on opposite (flat or outer) sides of the multilayer printed circuit board module.

[0079] The substrate-integrated waveguide preferably forms a channel for electromagnetic waves in the multilayer printed circuit board module with the windows and / or cavities. In particular, the channel extends from one end of the substrate-integrated waveguide, in particular the end facing the coupling structure or the end facing away from the second cavity, to the first window, in particular across the second and / or first cavity.

[0080] The first conductive layer preferably has a plurality of windows for coupling and / or decoupling modes. In this case, the multilayer printed circuit board module preferably has a plurality of substrate-integrated waveguides, each of which is assigned to one of the plurality of windows of the first conductive layer. Preferably, a plurality of windows are formed in the second conductive layer and / or a plurality of cavities in the first substrate layer and / or a plurality of cavities in the second substrate layer and / or a plurality of coupling structures in the third conductive layer, wherein each window, each cavity and / or each coupling structure is assigned (precisely) to a substrate-integrated waveguide or window in the first conductive layer. Accordingly, a plurality of waveguiding or wave-coupling channels are preferably formed in the multilayer printed circuit board module.

[0081] The features described above preferably also apply to the additionally formed waveguiding or wave-coupling channels. In particular, these can be of identical or similar design. However, it is also possible for the channels to be designed differently, for example, to have different dimensions to accommodate different frequencies and / or to be arranged at different angles to each other to enable polarization measurements or ellipsometry. This allows for a particularly versatile multilayer printed circuit board module to be achieved.

[0082] Particularly preferably, the channels are formed identically or of a similar type. The multiple channels thus allow a signal to be received multiple times or from different directions I at different angles, which allows for an estimation of the angle or direction and / or an investigation of the signal's polarization. This is beneficial for a multilayer printed circuit board module that is versatile and / or enables precise measurements.

[0083] Preferably, even in the case of multiple channels, the multilayer printed circuit board module has only a single chip receptacle or only a single chip. The channels are preferably arranged such that their respective first coupling structures are located directly adjacent to the chip receptacle or chip. In this way, one chip can advantageously be used for multiple channels, in particular, while keeping the respective bonding wires short.

[0084] Preferably, the recess of the multilayer printed circuit board module extends over all first coupling structures of the respective channels, so that these coupling structures are exposed. In other words, only a single recess is formed in the multilayer printed circuit board module to expose the first coupling structures and preferably the chip receptacle or chip. This contributes to a particularly simple, compact, and / or cost-effective design.

[0085] As already mentioned above, the coupling and decoupling on opposite (flat or outer) sides of the multilayer printed circuit board module represents an aspect of the present invention that can also be implemented independently. Likewise, the formation of the pads and the exposed coupling structure or the (exposing) recess on the same flat or outer side of the multilayer printed circuit board module can also represent an independent aspect.

[0086] Particularly preferably, according to an independently realizable aspect, the present invention also relates to a multilayer printed circuit board module, in particular for high-frequency and / or radar applications, with an optional first conductive layer, followed by a first substrate layer, followed by a second conductive layer, followed by a second substrate layer, followed by a third conductive layer, wherein a coupling structure, in particular comprising a stripline, is formed in the second and / or third conductive layer, wherein the multilayer printed circuit board module has one or more further layers that follow the third conductive layer, wherein the one or more further layers have a recess in the region of the coupling structure, so that the coupling structure is exposed, wherein the multilayer printed circuit board module has a chip receptacle that is formed in the recess by a cutout in the third conductive layer and, preferably,at least parts of the second substrate layer, wherein a substrate-integrated waveguide is formed in the second substrate layer, wherein propagable modes can be coupled into and / or decoupled from the substrate-integrated waveguide via the coupling structure in the substrate-integrated waveguide, and / or wherein the multilayer printed circuit board module has pads for electrically connecting the multilayer printed circuit board module to a PCB, wherein the pads are formed on the side facing away from the first conductive layer or first substrate layer, in particular on / at the outermost layer of the additional layers.

[0087] In the first alternative, the coupling structure exposed by the recess is advantageously used to couple modes into or out of a substrate-integrated waveguide.

[0088] According to the second alternative, the pads are arranged on the same flat or outer side of the multilayer printed circuit board module as the recess. This allows the multilayer printed circuit board module to be arranged on a PCB using the pads in such a way that the recess or the structures arranged in the recess, in particular the coupling structure, are covered by the PCB, thus achieving the advantages described above.

[0089] In the two variants mentioned above, the formation of the first window is purely optional. Accordingly, the formation of the first conductive layer is also purely optional.

[0090] A further aspect of the present invention relates to a system, in particular for high-frequency and / or radar applications, comprising the proposed multilayer printed circuit board module. The system can be, in particular, a radar system and / or measuring system, for example, for level measurement, flow determination, thickness measurement, distance measurement, scattering parameter measurement, millimeter-wave spectroscopy, or for monitoring purposes of industrial plants or production processes, or a part of such a radar or measuring system.

[0091] The proposed system comprises the proposed multilayer printed circuit board module and an antenna, in particular a dielectric antenna, or a waveguide, in particular a rectangular waveguide, and / or a PCB (Printed Circuit Board).

[0092] The antenna or waveguide is arranged on the first conductive layer above the first window. In this way, modes generated by the multilayer printed circuit board module can be coupled (directly) into the antenna or waveguide or emitted by the antenna, and / or modes received by the antenna or propagating in the antenna or waveguide can be coupled into the multilayer printed circuit board module.

[0093] This results in corresponding advantages. In particular, it enables precise measurements using electromagnetic signals, especially high-frequency and / or radar signals, particularly with a defined transmission direction and / or defined phase center and / or few losses or reflections.

[0094] The multilayer printed circuit board module is attached or mounted on the PCB, preferably by means of pads, wherein the third conductive layer faces the PCB, in particular such that a chip receptacle formed in the third conductive layer or a chip arranged therein is completely covered by the PCB.

[0095] This results in corresponding advantages. In particular, the chip is completely shielded or encapsulated in the installed state, meaning it is not exposed. One advantage of this is that the chip or the bonding wires do not need to be covered with a potting compound, which promotes more precise coupling and decoupling with fewer losses and reflections. Partial potting, for example, of the edges of the module, is possible. In this case, an air-filled space forms beneath the module around the chip and the bonding wires, preferably small enough to meet explosion protection requirements.

[0096] If the recess and / or pads are provided, they preferably face the PCB. In particular, the recess is closed by the PCB and / or the multilayer printed circuit board module is electrically connected to the PCB via the pads. This achieves the corresponding advantages described above.

[0097] Preferably, the multilayer printed circuit board module is at least partially, in particular completely, embedded or countersunk into the PCB. For this purpose, the PCB preferably has a corresponding module receptacle. This promotes a compact and as flat as possible design. A design that is as flat as possible facilitates the attachment of the antenna, in particular a dielectric antenna, or the waveguide, in particular a rectangular waveguide. Most preferably, the multilayer printed circuit board module is embedded flush in the PCB.

[0098] Preferably, a "waveguide" within the meaning of the present invention is an elongated cavity or comprises an elongated cavity with electrically conductive boundary structures, such as plates, platings, walls, and / or vias, laterally surrounding the cavity. Electromagnetic waves or modes can propagate along the cavity and the boundary structures, preferably in frequency bands between 1 GHz and 1 THz.

[0099] The multilayer printed circuit board module is particularly preferably designed for frequency ranges from 57 GHz to 64 GHz, 75 GHz to 85 GHz, or 116 GHz to 260 GHz. However, other frequency ranges are also possible.

[0100] In a “substrate-integrated waveguide” (SIW), the cavity is preferably filled with a substrate or dielectric in which the electromagnetic waves or modes can propagate.

[0101] A "substrate" or "substrate layer" within the meaning of the present invention preferably refers to an insulating material, an insulator, and / or a dielectric, or a layer formed therefrom. In particular, it is a dielectric suitable for the high-frequency range, especially for frequencies above 10 GHz. This can be PTFE, ceramic, a PTFE-ceramic composite material, or a composite material made of fiberglass fabric and epoxy resin, in particular one or more FR-4 prepregs. In principle, however, other materials can also be used.

[0102] A “conductive layer” is preferably understood to mean an electrically conductive layer, in particular a so-called copper cladding or conductor track layer. The conductive layer is particularly preferably a mechanically or chemically structured or structurable metal layer, preferably comprising or consisting of copper, with which, for example, conductor tracks or striplines, in particular microstrip lines, can be or are produced by structuring. A conductive layer is preferably thin compared to the substrate layer. While the conductive layers usually have a material thickness of between 5 and 35 pm, the substrate layers can have a material thickness of more than five or ten times this, for example 100 pm to 300 pm, wherein the thickness depends in particular on the frequency range for which the multilayer printed circuit board module is designed.

[0103] A "window" within the meaning of the present invention is preferably a non-conductive or insulating region in a conductive layer through which electromagnetic waves or modes capable of propagating in the substrate-integrated waveguide can penetrate the conductive layer. The window is therefore preferably an opening in the conductive layer. This opening can be hollow or filled with a dielectric.

[0104] The proposed multilayer printed circuit board module is preferably designed or provided as a (chip) module that is used with or can be mounted on a (main) PCB. In particular, the proposed multilayer printed circuit board module is an integrated circuit package.

[0105] The aforementioned aspects and features as well as the aspects and features of the present invention resulting from the claims and the following description can in principle be implemented independently of one another, but also in any desired combination.

[0106] Further aspects, advantages, features, properties, and advantageous developments of the present invention will become apparent from the claims and the following description of preferred embodiments with reference to the figures. They show, in a schematic representation, not to scale:

[0107] Fig. 1 is a perspective view of the proposed multilayer printed circuit board module according to a first embodiment; Fig. 2A is a section through the multilayer printed circuit board module according to Fig. 1;

[0108] Fig. 2B the section according to Fig. 2A without dielectrics in a perspective

[0109] Opinion;

[0110] Fig. 3 shows the section according to Fig. 2A without dielectrics in a side view;

[0111] Fig. 4 is an exploded perspective view of the multilayer printed circuit board module according to the first embodiment;

[0112] Fig. 5 is a front view of a proposed multilayer printed circuit board module according to a second embodiment;

[0113] Fig. 6 is a rear view of the multilayer printed circuit board module according to the second embodiment;

[0114] Fig. 7 is a perspective view of the front side of the multilayer printed circuit board module according to the second embodiment;

[0115] Fig. 8 is a perspective view of the back of the multilayer printed circuit board module according to the second embodiment;

[0116] Fig. 9 is a plan view of a third conductive layer of the multilayer printed circuit board module according to the second embodiment;

[0117] Fig. 10 shows a section through the multilayer printed circuit board module according to the second embodiment in a perspective view;

[0118] Fig. 11 is a front view of a proposed multilayer printed circuit board module according to a third embodiment;

[0119] Fig. 12 shows a proposed system with the multilayer printed circuit board module according to the third embodiment, a PCB and a waveguide; and

[0120] Fig. 13 shows a proposed system with the multilayer printed circuit board module according to the second embodiment, a PCB, and an antenna. In the figures, some of which are not to scale and are merely schematic, the same reference numerals are used for identical, identical, or similar parts and components, whereby corresponding or comparable properties or advantages are achieved, even if repetition is omitted.

[0121] For better clarity, not all parts / components of the same part or component within a figure are provided with a reference symbol.

[0122] Fig. 1 to Fig. 4 show a proposed layer arrangement or a proposed multilayer printed circuit board module 1 according to a first embodiment. Fig. 1 shows the multilayer printed circuit board module 1 in a schematic, perspective view.

[0123] The multilayer printed circuit board module 1 is constructed from or comprises multiple layers. In the illustrated example, the multilayer printed circuit board module 1 comprises at least five layers, namely three conductive layers 2, 3, 4 and two substrate layers 5, 6. For clarity, the layers are referred to below as the first conductive layer 2, the second conductive layer 3, the third conductive layer 4, the first substrate layer 5, and the second substrate layer 6.

[0124] The conductive layers and substrate layers are arranged alternately. Specifically, a conductive layer is followed by a substrate layer, and a substrate layer is followed by a conductive layer.

[0125] The multilayer printed circuit board module 1 accordingly preferably has a sandwich structure of alternately arranged conductive layers and substrate layers.

[0126] The first conductive layer 2 is (immediately) followed by the first substrate layer 5. The first substrate layer 5 is (immediately) followed by the second conductive layer 3. The second conductive layer 3 is (immediately) followed by the second substrate layer 6. The second substrate layer 6 is (immediately) followed by the third conductive layer 4.

[0127] The first conductive layer 2 preferably forms an outer side, or flat side, or front side of the multilayer printed circuit board module 1. The third conductive layer 4 can form a further outer side, or flat side, or rear side of the multilayer printed circuit board module 1, in particular opposite the outer side formed by the first conductive layer, as shown in Figs. 1 to 4. However, it is also possible and preferred for the third conductive layer 4 to be followed by one or more further layers, in particular alternating further substrate layers and conductive layers. This will be discussed in more detail later with reference to the preferred second embodiment.

[0128] The conductive layers and / or substrate layers are preferably at least substantially planar layers with flat sides that run at least substantially parallel to their main plane of extension, with the layers more preferably running parallel to one another. The conductive layers and substrate layers are therefore preferably arranged parallel or in parallel planes to one another. The main planes of extension of the layers are also referred to below as layer planes.

[0129] Preferably, each layer has an at least substantially constant thickness or material thickness. However, the layers can each have different thicknesses.

[0130] The conductive layers 2, 3, 4 are preferably thinner than the substrate layers 5, 6. Preferably, the substrate layers 5, 6 are each at least five times, in particular at least eight times, and / or at most 12 times thicker than a respective conductive layer 2, 3, 4.

[0131] The conductive layers 2, 3, 4 preferably have a thickness of at least 10 pm, in particular at least 15 pm or 17.5 pm, and / or of at most 50 pm, in particular at most 40 pm or 35 pm.

[0132] Particularly preferably, the first and second conductive layers 2, 3 have the same thickness. The third conductive layer 4 can also have the same thickness, but may optionally be only half the thickness of the first and / or second conductive layers 2, 3.

[0133] The substrate layers 5, 6 preferably have a thickness of at least 100 pm, in particular at least 125 pm, and / or at most 200 pm, in particular at most 180 pm. However, the thickness of the substrate layers 5, 6 may depend on the frequency range for which the multilayer printed circuit board module 1 is to be designed. The aforementioned values ​​preferably apply to a frequency range of, for example, 100 GHz to 200 GHz, particularly preferably from 126 GHz to 182 GHz. For other frequency ranges, the layer thicknesses can preferably be scaled up or down accordingly.

[0134] The substrate layers 5, 6 preferably have different thicknesses. In particular, the first substrate layer 5 is thicker than the second substrate layer 6, preferably at least 1.2 times as thick and / or at most twice as thick.

[0135] The conductive layers 2, 3, 4 and / or the substrate layers 5, 6 preferably consist of a homogeneous material.

[0136] The conductive layers 2, 3, 4 are preferably electrically conductive or consist of or comprise an electrically conductive material, in particular copper. Preferably, the conductive layers 2, 3, 4 consist of the same material. Particularly preferably, the conductive layers 2, 3, 4 are copper layers.

[0137] The substrate layers 5, 6 preferably consist of or comprise an insulating material, an insulator, and / or a dielectric. Particularly preferably, the dielectric is suitable for the high-frequency range, in particular for frequencies above 10 GHz.

[0138] Preferably, the substrate layers 5, 6 consist of different (insulating) materials.

[0139] The first and second substrate layers 5, 6 are preferably suitable for high frequencies or have good RF properties. The first substrate layer 5 is preferably suitable for high frequencies or has good RF properties, at least in the direction transverse or orthogonal to its main extension direction. The second substrate layer 6 is preferably suitable for high frequencies or has good RF properties, at least in the direction of its main extension direction.

[0140] The first substrate layer 5 preferably consists of or comprises a dimensionally stable, electrically insulating material, in particular high-frequency FR-4 process-compatible FR-4 or Thermoset polymer material. FR-4 refers to a class of flame-resistant and flame-retardant composite materials consisting of epoxy resin and fiberglass fabric. Thermoset polymer material refers to a class of substrate materials with good RF properties and, preferably, FR-4 process compatibility.

[0141] The second substrate layer 6 particularly preferably consists of PTFE (polytetrafluoroethylene), ceramic (particularly aluminum oxide and / or aluminum nitride), PTFE-ceramic composite, or comprises PTFE, ceramic, PTFE-ceramic composite, or other RF-compatible materials such as Thermoset polymer. The PTFE-ceramic composite is preferably an at least substantially homogeneous mixture of PTFE and ceramic particles.

[0142] Alternatively or additionally, the second substrate layer 6 can (also) consist of or comprise FR-4. Furthermore, it is also possible for the first substrate layer 5 to be formed from PTFE, ceramic, or a PTFE-ceramic composite, or for the first substrate layer 5 to comprise the latter.

[0143] The materials of the substrate layers 5, 6 are preferably so-called "low-Dk materials" and / or "low-Df materials." This preferably refers to materials or dielectrics that have a lower dielectric constant (low-Dk) and / or a lower loss factor / dissipation factor (low-Df) than silicon dioxide.

[0144] The Dk value is also called the permittivity number, dielectric constant or relative permittivity. The symbol s is commonly used. r . This is preferably the (dimensionless) ratio of the (absolute) permittivity s to the permittivity so of the vacuum, s r=s / so.

[0145] Preferably, in the first and / or second substrate layer 5, 6, the Dk value (at 10 GHz) is less than 3.5, in particular less than 3.1 and / or the Df value (at 10 GHz) is less than 0.005, in particular less than 0.002.

[0146] Preferably, the Dk value of the first and / or second substrate layer 5, 6 is at least substantially uniform or constant.

[0147] The first substrate layer 5 can also have a higher loss factor, in particular higher than the second substrate layer 6 and / or higher than silicon dioxide, in particular since the wave W only has to travel a short path through the first substrate layer 5 compared to the second substrate layer 6.

[0148] The loss factor of the second substrate layer 6 is preferably low at least in the direction of its main extension.

[0149] The conductive layers 2, 3, 4 are preferably bonded to the adjacent substrate layers 5, 6. In particular, the first substrate layer 5 is bonded on one side to the first conductive layer 2 and on the opposite side to the second conductive layer 3, in particular on opposite flat sides, and / or the second substrate layer 6 is bonded on one side to the second conductive layer 3 and on the opposite side to the third conductive layer 4, in particular on opposite flat sides. The same preferably applies to possible additional conductive and substrate layers.

[0150] Particularly preferably, the conductive layers 2, 3, 4 are produced by coating the substrate layers 5, 6. In particular, the conductive layers 2, 3, 4 are preferably copper laminations of the substrate layers 5, 6.

[0151] The first conductive layer 2 is preferably formed by a coating or (copper) lamination of the first substrate layer 5. The third conductive layer 4 is preferably formed by a coating or (copper) lamination of the second substrate layer 6. The second conductive layer 3 can optionally be formed by a coating or (copper) lamination of the first substrate layer 5 or the second substrate layer 6, preferably the second substrate layer 6.

[0152] The layers or the layer composites formed by the respective coatings, for example on the one hand the composite of first conductive layer 2 and first substrate layer 5 and on the other hand the composite of second conductive layer 3, second substrate layer 6 and third conductive layer 4, are preferably bonded to one another, in particular laminated or glued, particularly preferably by pressing.

[0153] Particularly preferably, at least the first substrate layer 5 forms a self-adhesive or self-adhesive layer or comprises an adhesion promoter. The composite formed from the first conductive layer 2 and the first substrate layer 5 can thus be laminated with its uncoated side or the side opposite the first conductive layer 2 to the second conductive layer 3 or the composite consisting of the second conductive layer 3, the second substrate layer 5, and the third conductive layer 4, or can be bonded thereto in a materially bonded manner.

[0154] Preferably, the layer composites are pressed together, wherein the first substrate layer 5, in particular its epoxy resin, has adhesive properties under pressure.

[0155] In principle, however, it is also possible to use an additional adhesive or adhesion promoter to bond the layer composites or the individual layers together in a material-to-material manner if the conductive layers were produced separately from the substrate layers. In this sense, a conductive layer and a substrate layer are (directly) adjacent to one another even if an adhesive layer / bonding layer or similar is arranged between the conductive layer and the substrate layer for the purpose of bonding. Such adhesives or adhesion promoters are assigned to the substrate layer or form part of the substrate layer, in particular due to their generally electrically insulating properties. In this respect, the substrate layer can be multi-layered and, in addition to a main layer with a central cross-sectional area, have adhesive layers / bonding layers facing the respective conductive layers.

[0156] The first conductive layer 2 preferably has a first window 2A, as shown in Fig. 1.

[0157] The window 2A is preferably an opening in the first conductive layer 2. In particular, the first conductive layer 2 does not have any conductive material in the region of the window 2A. However, the window 2A can be filled with a non-conductive or insulating material, for example, the material of the first substrate layer 5.

[0158] The first window 2A is preferably designed to be patch-free or antenna-free, i.e., it has no patches, antennas, or other conductive structures. In particular, the first window is completely / continuously filled with non-conductive material or a dielectric, in particular the material / dielectric of the first substrate layer 5.

[0159] Preferably, the first window 2A is produced by etching the first conductive layer 2. Alternatively, the first window 2A can also be introduced into the first conductive layer 2 by other methods, for example, lasers. The first window 2A is preferably slit-shaped and / or has a rectangular shape.

[0160] The ratio of the side lengths (length divided by width) of the first window 2A is preferably greater than 3 or 4 and / or less than 6 or 5.

[0161] The dimensions of structures of the multilayer printed circuit board module 1 described above and below—here, the first window 2A—preferably apply to a multilayer printed circuit board module 1 designed for a frequency range of, for example, 100 GHz to 200 GHz, particularly preferably from 126 GHz to 182 GHz. However, this is only an example. In particular, the multilayer printed circuit board module 1 can also be designed for other frequency ranges, with the dimensions of the first window 2A being adapted accordingly. In particular, the specified dimensions can be scaled up or down accordingly for other frequency ranges. The same preferably applies to dimensions of other structures of the multilayer printed circuit board module 1.

[0162] The length of the first window 2A is preferably greater than 0.7 mm, in particular greater than 1.0 mm, and / or less than 2 mm, in particular less than 1.5 mm or 1.4 mm. The length of the first window 2A is particularly preferably approximately 1.1 mm.

[0163] The width of the first window 2A is preferably greater than 0.1 mm, in particular greater than 0.2 mm, and / or less than 0.6 mm, in particular less than 0.5 mm. The width of the first window 2A is particularly preferably approximately 0.3 mm.

[0164] The opening area of ​​the first window 2A is preferably greater than 0.2 mm 2 , especially larger than 0.3 mm 2 , and / or smaller than 1 mm 2 or 0.8 mm 2 , especially smaller than 0.5 mm 2 .

[0165] The window 2A preferably has a constriction 2B. The constriction 2B is preferably formed centrally on the window 2A. In other words, the width (the smaller of the two side lengths) of the window 2A is preferably reduced in a central region of the window 2A. The width of the window 2A is preferably reduced in the region of the constriction 2B by more than 0.05 mm and / or less than 0.15 mm, preferably by approximately 0.1 mm. The width of the window 2A in the region of the constriction 2B is preferably more than 0.1 mm and / or less than 0.3 mm, preferably approximately 0.2 mm.

[0166] The constriction 2B is preferably formed by two opposite curves extending into the window 2A.

[0167] Fig. 2A shows a perspective section through the proposed multilayer printed circuit board module 1. The section runs perpendicular to the longitudinal extent of the window 2A and perpendicular to the layer planes. Fig. 2B shows the multilayer printed circuit board module 1 in the same view as Fig. 2A, but the substrate layers 5, 6 are not shown here in order to illustrate the structures located therein. Fig. 3 is a side view of the section according to Figs. 2A and 2B, also the substrate layers 5, 6 are not shown here. Fig. 4 is a perspective exploded view of the five layers 2-6.

[0168] Preferably, a substrate-integrated waveguide 7 is formed in the second substrate layer 6. Certain electromagnetic waves or modes W can propagate in the substrate-integrated waveguide 7.

[0169] The substrate-integrated waveguide 7 is preferably delimited or defined by conductive structures. In the illustrated example, the substrate-integrated waveguide 7 is preferably delimited by vias 7A. Furthermore, the substrate-integrated waveguide 7 is preferably delimited by the second conductive layer 3 and the third conductive layer 4.

[0170] The vias 7A preferably extend from the second conductive layer 3 to the third conductive layer 4, in particular at least substantially perpendicular to the layer planes, and / or connect the second conductive layer 3 and third conductive layer 4 to one another in a conductive / electrical manner.

[0171] The vias 7A are preferably microvias and / or have been created using a laser or laser drilling. A microvia is preferably a via with a diameter in the micrometer range, in particular between 50 pm and 100 pm. A laser-drilled via has the advantage that the target position is not changed. In contrast, a mechanically drilled via is partially drilled into the target position due to the drill bit.

[0172] The vias 7A can be completely filled with conductive material, in particular copper, or can be formed as holes coated with conductive material, in particular copper.

[0173] The vias 7A are preferably arranged in rows, preferably with two adjacent vias 7A being spaced apart by a distance less than or equal to the via diameter. It is also possible to choose larger spacings, provided the waveguiding properties of the waveguide 7 are ensured.

[0174] Preferably, the substrate-integrated waveguide 7 is defined by two opposing via rows. The via rows can be arranged in a straight line, as shown in Fig. 4, but can also be curved if required. The distance between the two via rows, or the (clear) width of the substrate-integrated waveguide 7, is preferably at least substantially constant.

[0175] It is understood that, as an alternative to the via rows or vias 7A, other conductive structures can also be used, which preferably electrically connect the second and third conductive layers 3, 4 and / or form lateral electrically conductive boundary surfaces for the substrate-integrated waveguide 7. Examples include the use of slots or grooves filled with conductive material or coated with conductive material. The features described in connection with the vias 7A can also be implemented with other corresponding conductive or mode propagation-limiting structures.

[0176] The dimensions of the substrate-integrated waveguide 7, in particular its length and / or width, are preferably selected such that (only) modes of specific or desired wavelengths / frequencies can propagate in the substrate-integrated waveguide 7.

[0177] The (clear) width of the substrate-integrated waveguide 7 or the spacing of the via rows is preferably greater than 0.5 mm, in particular greater than 0.8 mm, and / or less than 1.2 mm, in particular less than or equal to 1.0 mm. The dimensions here again preferably relate to the frequency range from 100 GHz to 200 GHz, in particular from 126 GHz to 182 GHz. For other frequency ranges, the (clear) width must be scaled accordingly.

[0178] Preferably, the fundamental mode or lowest mode M that can propagate in the waveguide 7 has a wavelength that corresponds (approximately or ideally) to twice the (clear) width of the waveguide 7.

[0179] The second conductive layer 3 preferably has a second window 3A.

[0180] The second window 3A is preferably an opening in the second conductive layer 3. In particular, the second conductive layer 3 does not have any conductive material in the region of the window 3A. However, the window 3A can be (completely / continuously) filled with a non-conductive or insulating material. This can, for example, be the material of the first substrate layer 5, which can enter the second window 3A, in particular through pressing, or at least substantially fill the second window 3A.

[0181] Alternatively, the second window 3A can be filled with the material of the second substrate layer 6. In any case, the second window 3A is preferably designed to be patch-free or antenna-free, i.e., it does not have any patches, antennas, or other conductive structures.

[0182] Particularly preferably, the second window 3A is introduced into the second conductive layer 3 by means of a laser, in particular before lamination or pressing of the layers. Alternatively, the second window 3A can be produced by etching the second conductive layer 3.

[0183] The second window 3A is preferably slit-shaped and / or has a rectangular shape.

[0184] The ratio of the side lengths (length divided by width) of the second window 3A is preferably greater than 5 or 6 and / or less than 10 or 9 and / or about 8.

[0185] The (explicit) dimensions of the second window 3A described below preferably refer to the frequency range from 100 GHz to 200 GHz, in particular from 126 GHz to 182 GHz, as already explained for the first window 2A. For other frequency ranges, the dimensions must be scaled accordingly.

[0186] The length of the second window 3A is preferably greater than 0.5 mm, in particular greater than 0.7 mm, and / or less than 1 mm, in particular less than 0.8 mm.

[0187] The width of the second window 3A is preferably greater than 0.05 mm, in particular greater than 0.07 mm and / or less than 0.2 mm, in particular less than 0.15 mm.

[0188] The second window 3A is preferably designed without constrictions or has no constriction. The width of the second window 3A is therefore preferably at least substantially constant.

[0189] The opening area of ​​the second window 3A is preferably greater than 0.05 mm 2 , especially larger than 0.07 mm 2 , and / or less than 0.15 mm 2 or 0.1 mm 2 , in particular smaller than 0.08 mm 2 .

[0190] Preferably, the first window 2A has a larger opening area than the second window 3A, in particular at least four times and / or at most six times larger.

[0191] Preferably, the first window 2A is longer and / or wider than the second window 3A, in particular also in the region of the constriction 2B. Preferably, the length of the first window 2A is at least 1.5 times and / or at most twice the length of the second window 3A and / or the width of the first window 2A is at least 1.5 times or twice and / or at most three times or four times the length of the second window 3A.

[0192] Preferably, the windows 2A, 3A have the same main direction of extension and / or are aligned with each other and / or are located one above the other. In particular, the second window 3A is aligned or oriented centrally to the first window 2A in a plan view.

[0193] Particularly preferably, the centers of the windows 2A, 3A lie on a common axis A, which runs transversely, in particular orthogonally, to the opening planes of the windows 2A, 3A and / or the layers 2-6 or layer planes. The axis A is shown in Fig. 3.

[0194] The centre points are to be understood in particular as the intersection points of the diagonals of the at least substantially rectangular or slit-shaped windows 2A, 3A.

[0195] "Transverse" here means that axis A does not have to be exactly orthogonal to the layer planes, but can also be slightly oblique, particularly at an angle between 80° and 100°. However, "transverse" preferably does not mean angles that deviate significantly from 90°, such as 45° or 60°.

[0196] The second window 3A is preferably arranged at one end of the substrate-integrated waveguide 7, i.e. in front of or behind the substrate-integrated waveguide 7, depending on the propagation direction or transmission direction T of the waves / modes W.

[0197] The first and / or second window 2A, 3A preferably extend / extends at least substantially transversely, in particular orthogonally, to the course or the longitudinal extent of the substrate-integrated waveguide 7 or to the rows of vias 7A.

[0198] Preferably, a first cavity 8 is formed in the first substrate layer 5 and / or a second cavity 9 is formed in the second substrate layer 6.

[0199] The first cavity 8 and / or the second cavity 9 are / are preferably delimited or defined by conductive structures. The conductive structures form, in particular, propagation barriers for the W modes.

[0200] In the illustrated example, the first cavity 8 is preferably defined by through-contacts or vias 8A. Furthermore, the first cavity 8 is preferably defined by the first conductive layer 2 and the second conductive layer 3.

[0201] In the illustrated example, the second cavity 9 is preferably defined by through-contacts or vias 9A. Furthermore, the second cavity 9 is preferably defined by the second conductive layer 3 and the third conductive layer 4. The vias 8A preferably extend from the first conductive layer 2 to the second conductive layer 3, in particular at least substantially perpendicular to the layer planes, and / or conductively / electrically connect the first conductive layer 2 and the second conductive layer 3 to one another.

[0202] The vias 9A preferably extend from the second conductive layer 3 to the third conductive layer 4, in particular at least substantially perpendicular to the layer planes, and / or conductively / electrically connect the second conductive layer 3 and third conductive layer 4 to one another.

[0203] The vias 8A, 9A are preferably microvias and / or have been introduced using a laser or laser drilling. The vias 8A, 9A can be completely filled with conductive material, in particular copper, or can be formed as holes coated with conductive material, in particular copper.

[0204] It is understood that, as an alternative to vias 8A and / or 9A, other conductive structures may also be used, such as slots or grooves filled or coated with conductive material. The features described in connection with vias 8A, 9A may also be implemented with corresponding other conductive or mode propagation-limiting structures.

[0205] The substrate-integrated waveguide 7 preferably ends or opens into the second cavity 9.

[0206] The transition region from the substrate-integrated waveguide 7 to the second cavity 9 can be constricted or narrowed compared to the substrate-integrated waveguide 7. This is illustrated by way of example in Fig. 4, where the two vias in the transition region are spaced closer together than the vias 7A of the via rows delimiting the substrate-integrated waveguide 7.

[0207] Opposite the substrate-integrated waveguide 7, the second cavity 9 or a row of vias 9A extending transversely or orthogonally to the course of the waveguide 7 preferably forms a boundary for the propagation of waves / modes W. In particular, waves / modes W cannot propagate beyond this boundary through the second substrate layer 6 or parallel to the layer planes. As already mentioned, a corresponding boundary can also be achieved with other conductive structures instead of a row of vias.

[0208] Preferably, the second cavity 9 has only two openings or ports for coupling and decoupling modes W, namely, on the one hand, an opening or port to the substrate-integrated waveguide 7 and, on the other hand, the second window 3A. In particular, only a single substrate-integrated waveguide 7 opens into the second cavity 9.

[0209] The first and / or second cavities 8, 9 are preferably at least substantially cuboid-shaped. In particular, the vias 8A, 9A are arranged at least substantially on a rectangle.

[0210] The first cavity 8 is preferably open to the outside via the first window 2A and / or to the second cavity 9 via the second window 3A.

[0211] The second cavity 9 is preferably open via the second window 3A to the first cavity 8 and / or via an opening to the substrate-integrated waveguide 7.

[0212] Preferably, modes W can be coupled into the first cavity 8 via the first window 2A and coupled out of the first cavity 8 via the second window 3A, in particular in the direction transverse or perpendicular to the layer plane, or vice versa.

[0213] Preferably, modes W can be coupled into the second cavity 9 via the second window 3A, in particular in the direction transverse or perpendicular to the layer plane, and coupled out of the second cavity 9 via an opening to the substrate-integrated waveguide 7, in particular in the direction of the layer plane, or vice versa.

[0214] The first cavity 8 is preferably arranged between the windows 2A, 3A. In particular, the vias 8A are arranged around the windows 2A, 3A.

[0215] Modes W coupled into the first cavity 8 via one of the windows 2A, 3A can preferably propagate only within the first cavity 8.

[0216] The second cavity 9 is preferably arranged in the region of the second window 3A. In particular, the vias 9A are arranged around the window 3A. The cavity(ies) 8, 9 preferably have / have at least substantially the same main direction of extension as the windows 2A, 3A, in particular at least substantially transverse or orthogonal to the course of the substrate-integrated waveguide 7.

[0217] Particularly preferably, the first cavity 8 projects beyond the windows 2A, 3A or extends beyond the windows 2A, 3A in the layer plane. In particular, the propagation-limiting structures or vias 8A are arranged at a distance from the windows 2A, 3A.

[0218] Particularly preferably, the second cavity 9 projects beyond the second window 3A or extends beyond it in the layer plane. In particular, the propagation-limiting structures or vias 9A are arranged at a distance from the second window 3A.

[0219] Particularly preferably, the projections / distances of the first and / or second cavities 8, 9 or of the structures delimiting them are adapted to the desired modes W or those capable of propagation in the waveguide 7 or are selected / designed accordingly.

[0220] The projection of the cavity 8 and / or 9 or the distance of the propagation-limiting structures or vias 8A and / or 9A from the window 2A or 3A is preferably at least 5%, in particular at least 10%, and / or at most 25% of the (clear) width of the substrate-integrated waveguide 7.

[0221] The projection of the cavity 8 and / or 9 or the distance of the propagation-limiting structures or vias 8A and / or 9A from the window 2A or 3A is preferably at least 1.5 times, in particular at least twice, the window width of the second window 3A and / or at least half the window width of the first window 2A.

[0222] Preferably, the projection or distance is greater than 25 pm or 50 pm, in particular greater than 75 pm, and / or less than 250 pm, at least in a multilayer printed circuit board module 1 for a frequency range from 100 GHz to 200 GHz, in particular from 126 GHz to 182 GHz. For other frequency ranges, the projection or distance must be scaled accordingly. Due to the projection or distance, the modes W in the second cavity 9 can preferably propagate beyond the second window 3A to the propagation-limiting structures or vias 9A.

[0223] This preferably ensures that the modes W propagate in a defined direction through the second window 3A, in particular the opening direction of the second window 3A or the direction of the axis A or at least substantially perpendicular to the layer plane or to the propagation direction in the substrate-integrated waveguide 7.

[0224] In particular, the modes W would radiate obliquely through the second window 3A into the first cavity 8 due to a missing or insufficient projection / distance. This is preferably avoided here.

[0225] The same preferably applies to the first cavity 8. In particular, in the first cavity 8, too, the modes W are emitted or radiated in the defined direction from the first window 2A due to its projection or the distance of the propagation-limiting structures or vias 8A, or propagate at least substantially in the defined direction through the first cavity 8.

[0226] The cavities 8, 9 preferably each form a resonator, in particular a cavity resonator. "Cavity" here preferably means that W modes can be formed in the cavities 8, 9, i.e., they are only "hollow" for an electromagnetic wave. However, the cavities 8, 9 or cavity resonators are preferably filled with a dielectric.

[0227] The dimensions of the cavities 8, 9 preferably depend on the dielectric with which they are filled, in particular the material of the first or second substrate layer 5, 6, and / or on the frequency range for which the multilayer printed circuit board module 1 is to be designed.

[0228] Preferably, the following mathematical relationship exists for a cavity with length L, width B and height H: Here, p denotes the magnetic permeability and s the permittivity of the dielectric with which the cavity is filled. The positive, integer parameters m, n, and p denote the order of the modes in the respective directions (m is the order number in the direction of length L; n is the order number in the direction of width B; p is the order number in the direction of height H), whereby one of these parameters can also be zero (e.g., p=0 for modes without a height component). f mn p then denotes the respective resonance frequency of the mode with order m, n, p.

[0229] Instead of the absolute permittivity s and permeability p, the relative permittivity or permittivity number s can also be used. r and the relative permeability or permeability number p r The formula then becomes where c is the speed of light in vacuum (about 3*10 8m / s). For non-ferromagnetic materials (paramagnetic or diamagnetic materials), the permeability p r approximately equal to 1 and can therefore preferably be neglected or set equal to 1 in the above formula.

[0230] The first cavity 8 is preferably formed in the first substrate layer 5 or filled with the material of the first substrate layer 5. The second cavity 9 is preferably formed in the second substrate layer 6 or filled with the material of the second substrate layer 6. For s r This preferably results in the permittivity number or the Dk value of the respective substrate layer 5 or 6.

[0231] Preferably s r greater than 1 , in particular greater than 2, and / or less than 3.5. It is also possible that the cavity 8 and / or 9 is filled with air. In this case, s r preferably about 1.

[0232] Using the above formula, it is possible, for a given dielectric (known values ​​for p r and s r ) and desired resonance frequency(ies) f mn p of the order m, n, p (in particular for the lowest orders fno, fioi and / or fon) to specify or determine the dimensions L, B and H of the cavity(ies) 8, 9. Particularly preferably, the multilayer printed circuit board module 1 can be designed for a desired frequency range, in particular by adapting the cavities 8, 9 or their dimensions according to the above formula to the desired frequency range.

[0233] In particular, the explicit dimensions or values ​​of the waveguiding structures mentioned in this application, in particular of the waveguide 7, the windows 2A, 3A and / or the cavities 8, 9, which preferably relate to the frequency range from 100 GHz to 200 GHz, in particular from 126 GHz to 182 GHz, are scalable by means of the above formula or corresponding formulas, and can therefore preferably be scaled up or down for other frequency ranges.

[0234] The height H preferably corresponds to the thickness of the respective substrate layer 5, 6. It is possible that the height H cannot be adjusted arbitrarily, especially when standard prepregs with a given thickness are used. However, according to the above formula, even with a fixed height H, it is preferably possible to achieve any desired resonance frequency f by appropriately selecting the length L and width B. mnp, in particular to be able to design the multilayer printed circuit board module 1 for any frequency range.

[0235] In Figs. 2A to 4, the preferred transmission path or the preferred transmission direction T of electromagnetic modes or waves W propagating in the multilayer printed circuit board module 1 is shown.

[0236] The modes W are coupled into the waveguide 7 at one end of the substrate-integrated waveguide 7, in particular the end facing away from the cavity 9.

[0237] In the substrate-integrated waveguide 7, the modes W propagate preferably along the course of the waveguide 7 or in the second substrate layer 6 or in a direction parallel to the layer plane.

[0238] Behind the substrate-integrated waveguide 7, the modes W are preferably coupled out or radiated through the second window 3A and the first substrate layer 5 or first cavity 8 via the first window 2A. Conversely, modes W can preferably be coupled into the substrate-integrated waveguide 7 via the first window 2A and through the first substrate layer 5 or first cavity 8 and the second window 3A.

[0239] The transmission path T therefore preferably runs through the substrate-integrated waveguide 7, the second cavity 9, the second window 3A, the first cavity 8 and the first window 2A, or vice versa.

[0240] Preferably, the modes W or their transmission direction T are deflected in front of or behind the substrate-integrated waveguide 7 (depending on the propagation direction), in particular in the second cavity 9, preferably by approximately 90°. In particular, a mode W, in particular a fundamental mode, is excited in the second cavity 9, whose E-field is transverse, in particular perpendicular, to the second substrate layer 6 or layer plane.

[0241] The transmission direction T of the modes W through the windows 2A, 3A and / or the first cavity 8 or through the first substrate layer 5 preferably runs transversely, in particular at least substantially orthogonally, to the transmission direction T in the substrate-integrated waveguide 7 or to the course of the waveguide 7 and / or transversely, in particular at least substantially orthogonally, to the layer planes and / or at least substantially parallel to the axis A.

[0242] Preferably, the cavities 8, 9 are filled with a dielectric, in particular the substrates of the respective substrate layer 5, 6. Thus, the cavity 8 is preferably filled with the substrate of the first substrate layer 5 and / or the cavity 9 is filled with the substrate of the second substrate layer 6.

[0243] However, it is also possible to fill the first and / or second cavity 8, 9 with a different dielectric or to form it without a dielectric or hollow.

[0244] Preferably, the first cavity 8 has a constriction, in particular in the center or in the region where the first window 2A also has the constriction 2B. In other words, the width of the cavity 8 or the distance between opposing vias 8A is preferably reduced or narrowed in a central region of the cavity 8.

[0245] The constriction of the cavity 8 preferably extends over the entire layer thickness of the first substrate layer 5 or over the entire height of the cavity 8. The constriction of the cavity 8 is in particular a continuation of the constriction 2B of the first window 2A.

[0246] In the illustrated example, the cavity 8 is constricted in that the two opposite, central vias 9A are spaced apart by a smaller distance than their immediately adjacent vias 9A, as shown in particular in Fig. 4.

[0247] Particularly preferably, the first cavity 8 forms a ridged waveguide, in particular a double-ridged waveguide.

[0248] The multilayer printed circuit board module 1 is preferably designed or the geometries and / or dimensions of the substrate-integrated waveguide 7, the first cavity 8, the second cavity 9, the first window 2A and / or the second window 3A are preferably selected such that (only) modes of specific or desired wavelengths / frequencies can propagate therethrough.

[0249] Particularly preferably, the multilayer printed circuit board module 1 is designed for a frequency range of at least 24 GHz and / or at most 500 GHz, preferably from 51 GHz to 71 GHz or from 75 GHz to 85 GHz or more than 116 GHz.

[0250] Figures 5 to 10 show a second, particularly preferred, embodiment of the proposed multilayer printed circuit board module 1. Fig. 5 shows a schematic front view of the multilayer printed circuit board module 1. Fig. 6 shows a corresponding schematic rear view. Figs. 7 and 8 show the front and rear of the multilayer printed circuit board module 1, respectively, in perspective views. Fig. 9 shows a plan view of the multilayer printed circuit board module 1 starting from the third conductive layer 4. Layers lying above the third conductive layer 4 are not shown here. Fig. 10 shows a perspective section through the multilayer printed circuit board module, which essentially corresponds to the section according to Fig. 2A for the first embodiment.

[0251] The second embodiment preferably differs from the first embodiment essentially in that the second embodiment has further or additional structures. The aspects and features explained in connection with the first embodiment therefore preferably also apply to the second embodiment in a supplementary or corresponding manner, in particular without repetition.

[0252] The first embodiment can also be considered as part of the second embodiment.

[0253] In particular, the second embodiment also has the layer structure explained in connection with the first embodiment, comprising three conductive layers 2, 3, 4 and two substrate layers 5, 6. Furthermore, the second embodiment also has the substrate-integrated waveguide 7, the two windows 2A, 3A, and preferably the two cavities 8, 9. The transmission path T of modes W is shown as an example in Fig. 10 and corresponds or is similar to the transmission path T of the first embodiment.

[0254] As an example, Fig. 10 shows the cavity 8 without a substrate or filled with air. Of course, it is also possible in Fig. 10 to form the cavity 8 with a substrate, in particular the material of the first substrate layer 5.

[0255] In the second embodiment, the multilayer printed circuit board module 1 or its first conductive layer 2 preferably has a plurality of (first) windows 2A, in the illustrated example three (first) windows 2A, as shown in particular in Fig. 5 and Fig. 7.

[0256] Accordingly, the multilayer printed circuit board module 1 preferably has several, here three, substrate-integrated waveguides 7, or several, here three, substrate-integrated waveguides 7 are formed in the second substrate layer 6. This is particularly evident in Fig. 9, which shows how the vias 7A end in the third conductive layer 4. The substrate-integrated waveguides 7 are correspondingly formed in the underlying second substrate layer 6, which is concealed by the third conductive layer 4.

[0257] Furthermore, the multilayer printed circuit board module 1 preferably has a plurality of, here three, (first) cavities 8, a plurality of, here three, (second) cavities 9 and / or a plurality of, here three, (second) windows 3A.

[0258] The plurality of cavities 8, 9 are indicated by the corresponding vias 8A in Fig. 5, 7 and vias 9A in Fig. 9. The cavities 8, 9 are each located (hidden) below the layers shown in the figures (first conductive layer 2 in Fig. 5, 7 and third conductive layer 4 in Fig. 9).

[0259] Thus, in the multilayer printed circuit board module 1, several, here three, waveguiding channels are preferably formed, each having a substrate-integrated waveguide 7, a first window 2A, a second window 3A and preferably a first cavity 8 and / or a second cavity 9.

[0260] The first windows 2A are preferably designed identically or have the same shape and / or the same dimensions. The same preferably applies to the second windows 3A, first cavities 8, and / or second cavities 9. In general, however, the first windows 2A, second windows 3A, first cavities 8, and / or second cavities 9 can also be designed differently, for example, to enable different modes W to be transmitted and / or received with the multilayer printed circuit board module 1.

[0261] The substrate-integrated waveguides 7 are preferably identical or of similar design. In the illustrated example, the central waveguide 7 is shorter than the two outer waveguides 7 (see Fig. 9). However, the lengths are preferably selected such that the same modes W can propagate in the waveguides 7. In particular, the longer waveguides 7 are an integer multiple longer than the shorter waveguides 7. In general, however, the waveguides 7 can also be designed for different modes W, if necessary.

[0262] In the illustrated example, the windows 2A are preferably arranged in a triangle, as shown in Fig. 5. The same preferably applies to the underlying cavities 8, 9 or second windows 3A.

[0263] The windows 2A are preferably arranged with the same main extension direction or parallel to each other, as shown in particular in Fig. 5. The same preferably applies to the underlying cavities 8, 9 or second windows 3A.

[0264] However, other solutions are also possible here. For example, one of the windows 2A could be rotated by 45° and / or another of the windows 2A could be rotated by 90°. The same preferably applies to the underlying cavities 8, 9 or second windows 3A. This arrangement preferably enables polarization measurements. This will be explained in more detail later in connection with Fig. 11.

[0265] In the illustrated example with three windows 2A or three waveguiding channels, one of the channels, in particular the middle one, is used for transmitting and receiving signals, and / or two of the channels, in particular the outer ones, are used (exclusively) for receiving signals. By providing three receiving channels, direction determination and / or polarization determination can preferably be performed.

[0266] In general, it is also possible to form the multilayer printed circuit board module 1 of the second embodiment with only one window 2A and correspondingly only one channel or only one substrate-integrated waveguide 7, only one cavity 8, only one cavity 9 and / or only one second window 3A.

[0267] Preferably, the multilayer printed circuit board module 1 has a coupling structure 10 for coupling modes W into and / or out of the substrate-integrated waveguide 7, in particular at the end of the substrate-integrated waveguide 7 facing away from the second window 3A or the second cavity 9.

[0268] In the illustrated example with multiple waveguides 7, the multilayer printed circuit board module 1 preferably has a corresponding number of, in particular similar, coupling structures 10, here three coupling structures 10. One coupling structure 10 is explained in more detail below. The explanations preferably apply accordingly to the other coupling structures 10.

[0269] The coupling structure 10 is preferably formed in the third conductive layer 4. Particularly preferably, the third conductive layer 4 is structured in certain areas or has been removed in certain areas, in particular by means of lasers and / or etching, to form the coupling structure 10. This is illustrated in particular in Fig. 9, which is a plan view of the third conductive layer 4, with the underlying second substrate layer 6 partially visible and shown in dotted lines.

[0270] In general, the coupling structure 10 can also be formed in the second conductive layer 3 or in both the second and third conductive layers 3, 4. The coupling structure 10 is preferably designed to couple and / or decouple electromagnetic waves or modes W into the substrate-integrated waveguide 7 or to excite them in the substrate-integrated waveguide 7, in particular at its end opposite the second window 3A or the second cavity 9.

[0271] The coupling structure 10 is preferably designed to convert an electrical signal into an electromagnetic wave or mode W and / or to convert an electromagnetic wave or mode W into an electrical signal, in particular at least substantially loss-free.

[0272] The multilayer printed circuit board module 1 preferably comprises a chip 11, in particular a microchip or an integrated circuit. The chip 11 is particularly preferably an MMIC chip (Monolithic Microwave Integrated Circuit).

[0273] The chip 11 is preferably designed to generate and / or receive high-frequency electrical signals.

[0274] The coupling structure 10 is preferably electrically connected to the chip 11, in particular to its outputs for transmitting and / or inputs for receiving signals.

[0275] Particularly preferably, the chip 11 is bonded by means of bond wires 12. For this purpose, the chip 11 preferably has bond pads 11A. However, solutions other than (wire) bonding are generally also possible for electrically connecting the chip 11 to the coupling structure 10, for example, by means of flip-chip assembly.

[0276] In the case of several coupling structures 10, three in the illustrated example, the chip 11 is preferably electrically connected to all coupling structures 10, in particular bonded by means of bond pads 11A or bond wires 12.

[0277] For better clarity, the bonding wires 12 are only shown in Fig. 9 and omitted in Figs. 8 and 10. Preferably, however, the chip 11 is also bonded in Figs. 8 and 10. Fig. 6 shows an example of the multilayer printed circuit board module 1 without the chip 11 and thus also without the bonding wires 12. Signals generated by the chip 11 are preferably converted via the coupling structure 10 into modes W in the substrate-integrated waveguide 7. Conversely, modes W from the substrate-integrated waveguide 7 can preferably be converted into electrical signals via the coupling structure 10 and fed to the chip 11.

[0278] The signals can form the electromagnetic wave / mode W by coupling into the substrate-integrated waveguide 7 or, conversely, the signals can be generated from the electromagnetic wave / mode W from the substrate-integrated waveguide 7 in the coupling structure 10.

[0279] Particularly preferably, the coupling structure 10 is formed by or comprises a stripline, in particular a microstripline. Preferably, a corresponding conductive strip 10A is formed in the third conductive layer 4. Preferably, the second substrate layer 6 forms a substrate and / or the second conductive layer 3 forms a ground plane for the stripline.

[0280] The stripline, in particular the conductive strip 10A, is preferably electrically connected to the chip 11, in particular a bond pad 11A, in particular via one or more bond wires 12.

[0281] The stripline, in particular the conductive strip 10A, preferably ends at the substrate-integrated waveguide 7. Here, the strip 10A preferably transitions into a large-area section of the third conductive layer 4 that delimits the substrate-integrated waveguide 7 and can be considered, in particular, as ground. Consequently, at this transition, signals propagating in the stripline are preferably converted into modes W in the substrate-integrated waveguide 7, or vice versa.

[0282] The coupling structure 10 is preferably designed to convert a differential signal into a single-ended signal or vice versa. In particular, the coupling structure can preferably receive a differential signal from the chip 11 and / or supply a differential signal to the chip 11. For this purpose, the coupling structure 10 or the stripline preferably comprises a differential stripline and a single-ended stripline. In the illustrated example, the coupling structure 10 or stripline preferably comprises a balun 10B, in particular a lambda / 2 balun, to combine differential signals into a single-ended signal. Other solutions are generally also possible.

[0283] In general, it is also possible for chip 11 to directly feed single-ended signals into coupling structure 10 or receive them from coupling structure 10. Differential structures may therefore be omitted.

[0284] The third conductive layer 4 preferably has further conductor structures 13, in particular conductor tracks, for contacting the chip 11. The conductor structures 13 are preferably electrically connected, in particular bonded, to the chip 11. The conductor structures 13 are preferably etched and / or lasered into the third conductive layer 4.

[0285] The multilayer printed circuit board module 1 preferably has a chip receptacle 14 for the chip 11. The proposed multilayer printed circuit board module 1 can also have only the chip receptacle 14 and be capable of being populated with a chip (only subsequently). Fig. 6 shows the multilayer printed circuit board module 1 according to the second embodiment without a chip as an example.

[0286] The chip receptacle 14 is preferably formed at least in the third conductive layer 4, in particular by a corresponding recess in the third conductive layer 4. Preferably, the chip receptacle 14 is also formed at least partially in the second substrate layer 6, in particular by a corresponding recess in the second substrate layer 6. Particularly preferably, the chip receptacle 14 extends completely through the second substrate layer 6 or up to the second conductive layer 3.

[0287] Preferably, the chip holder 14 is introduced into the third conductive layer 4 and optionally the second substrate layer 6 by means of lasers.

[0288] The chip holder 14 is preferably arranged or formed directly adjacent to the coupling structure(s) 10. This allows the bond wires 12 to be short, which reduces losses.

[0289] The chip 11 is preferably arranged or mounted, for example, glued, in the chip receptacle 14. Particularly preferably, the chip 11 is aligned with the third conductive layer 4. In other words, the depth of the chip receptacle 14 preferably corresponds at least substantially to the thickness or height of the chip 11. In particular, the chip 11 does not protrude beyond the chip receptacle 14 and / or is not located deeper in the chip receptacle 14. This also allows the bonding wires 12 to be particularly short to reduce losses.

[0290] The multilayer printed circuit board module 1 preferably has thermal vias 15 that extend from the chip receptacle 14 or from the chip 11 to an outer side of the multilayer printed circuit board module 1, formed in particular by the first conductive layer 2. In particular, the thermal vias 15 extend through the first conductive layer 2, the first substrate layer 5, and the second conductive layer 3. If necessary, the thermal vias also extend (partially) through the second substrate layer 6 if the chip receptacle 14 is not completely formed in the second substrate layer 6.

[0291] Waste heat from the chip 11 can preferably be transported away or dissipated via the thermal vias 15. For this purpose, the thermal vias 15 are preferably completely filled with a thermally conductive material, in particular copper.

[0292] In addition to the five layers described, the multilayer printed circuit board module 1 preferably has one or more further layers 16 following the third conductive layer 4. In particular, the multilayer printed circuit board module 1 preferably has at least one further substrate layer, preferably followed by a further conductive layer, which directly adjoins the third conductive layer 4 or is integrally connected to it.

[0293] In the illustrated example, the multilayer printed circuit board module 1 preferably has six additional layers 16, namely three additional conductive layers and three additional substrate layers, as particularly illustrated in Fig. 10. However, other solutions are also possible.

[0294] The additional layers 16 are preferably bonded to each other and to the third conductive layer 4 by lamination or pressing, as already described for the conductive layers 2-4 and substrate layers 5, 6. The conductive layers of the additional layers 16 are preferably formed by coatings, in particular copper cladding. The thickness preferably corresponds to the thickness of the conductive layers 2-4.

[0295] The substrate layers of the additional layers 16 are preferably made of FR-4. This can be a different FR-4 than the first substrate layer 5, in particular a more cost-effective FR-4 with fewer requirements for RF compatibility. The thickness preferably corresponds to the thickness of the substrate layers 5 and / or 6.

[0296] Preferably, the further layers 16 have a recess 17. The recess 17 is preferably formed by corresponding cutouts in the layers 16.

[0297] The recess 17 is preferably formed at least in the region of the coupling structure(s) 10 and / or borders the chip receptacle 14, so that the coupling structures 10 are exposed. This is illustrated in particular in Figs. 6, 8, and 10.

[0298] Particularly preferably, the recess 17 extends beyond the region of the coupling structure(s) 10, in particular beyond the chip 11 or the chip receptacle 14.

[0299] Preferably, the chip 11 and / or the chip receptacle 14 are / is (completely) arranged or formed in the recess 17.

[0300] In order to be able to recognize the vias 7A of the substrate-integrated waveguide 7, the further (substrate) layer 16 directly adjacent to the third conductive layer 4 is partially omitted from Fig. 10. However, this layer, like the overlying layers 16, preferably extends to the edge of the recess 17 or just before the coupling structure 10.

[0301] The multilayer printed circuit board module 1 preferably has one or more alignment aids 18 for positioning the multilayer printed circuit board module 1 on a PCB (printed circuit board) and / or for aligning a waveguide and / or an antenna. In the illustrated example, the alignment aids 18 are formed by one or more holes and / or (edge-side) recesses, which preferably extend through all layers. Corresponding locating pins of a waveguide flange, PCB, or the like can be inserted into the holes.

[0302] If the multilayer printed circuit board module 1 has several alignment aids 18, these can be of the same or different design, for example they can have the same or different diameters.

[0303] The multilayer printed circuit board module 1 preferably has pads 19 for mechanically fastening and / or electrically connecting the multilayer printed circuit board module 1 to a (carrier) PCB. For example, the pads 19 can be designed as or form an LGA (Land Grit Array) system.

[0304] The pads 19 are, in particular, electrical contacts for electrically connecting to or contacting a PCB. Preferably, the multilayer printed circuit board module 1 can also be mechanically attached to a PCB using the pads 19, for example, by paste soldering or solder balls.

[0305] The pads 19 are preferably formed on the back of the multilayer printed circuit board module 1, or on the side facing away from the windows 2A or the first conductive layer 2. In particular, the pads 19 are formed on / at the outermost layer of the additional layers 16.

[0306] It is also possible that the pads 19 are embedded in the outermost (substrate) layer of the additional layers 16, in particular in alignment.

[0307] Preferably, the pads 19 are arranged at equal distances from one another and / or form an array.

[0308] Preferably, the pads 19 or the array of pads 19 extend substantially over the entire (outer or flat) side of the multilayer printed circuit board module 1.

[0309] The pads 19 are preferably formed on the same outer or flat side of the multilayer printed circuit board module 1 as the recess 17. In particular, the pads 19 are arranged around the recess 17. The first window(s) 2A is / are preferably formed on the outer side or flat side of the multilayer printed circuit board module 1, which is opposite the outer side or flat side that has the recess 17 and / or pads 19. In other words, the first window(s) 2A, on the one hand, and the recess 17 and / or the pads 19, on the other hand, are located on opposite outer sides or flat sides of the multilayer printed circuit board module 1.

[0310] Accordingly, structures arranged in the recess 17, in particular the coupling structure(s) 10, the chip 11, the bonding wires 12 and / or the chip receptacle 14, are preferably located on a side of the multilayer printed circuit board module 1 opposite the side with the window(s) 2A.

[0311] The multilayer printed circuit board module 1 is preferably a flat, compact module, in particular a high-frequency and / or radar module.

[0312] The thickness of the multilayer printed circuit board module 1, in particular including the further layers 16, is preferably less than 2 mm, in particular less than 1.5 mm, and / or more than 0.5 mm, particularly preferably about 1 mm.

[0313] The length of the multilayer printed circuit board module 1 is preferably less than 20 mm and / or more than 10 mm, particularly preferably about 14 mm.

[0314] The width of the multilayer printed circuit board module 1 is preferably less than 15 mm and / or more than 5 mm, particularly preferably about 10 mm.

[0315] Fig. 11 shows a third embodiment of the proposed multilayer printed circuit board module 1 in a schematic front view.

[0316] In the following, only essential differences between the third embodiment and the first and second embodiments are described. In particular, the features and explanations of the first and second embodiments also apply to the third embodiment, unless explicitly stated otherwise.

[0317] The third embodiment differs from the second embodiment in the arrangement of the windows 2A relative to one another. The (longitudinal extensions of the) windows 2A each run obliquely to one another, form an angle, or are not parallel.

[0318] In the illustrated example, the multilayer printed circuit board module 1 preferably has three windows 2A, wherein one of the further windows 2A is rotated by +45° and / or the other of the further windows 2A is rotated by -45° relative to a first window 2A.

[0319] The main directions of extension of the windows 2A preferably enclose an isosceles triangle, preferably wherein the triangle has a right angle at its apex or the angles at the base are each 45°.

[0320] Other solutions are also possible in which only two or more than three windows 2A are formed and / or in which the windows 2A enclose other angles.

[0321] The windows 2A arranged at an angle to each other preferably enable polarization measurements or ellipsometry.

[0322] The structures located beneath the windows 2A, in particular the cavities 8, 9 and / or the windows 3A, are preferably arranged at an angle to each other. In Fig. 11, this is indicated for the cavities 8 by the vias 8A.

[0323] The substrate-integrated waveguides 7 are preferably shaped or have a corresponding course to lead into the inclined cavities 9 (not shown). With windows 2A arranged as in Fig. 11, the two outer waveguides 7 can, for example, form the shape of a heart.

[0324] Preferably, as in the second embodiment, one of the windows 2A is used for transmitting and receiving signals and the other two (exclusively) for receiving.

[0325] Fig. 11 further shows, by way of example, two (additional) alignment aids 18, which are open at the edges and / or have a different, in particular larger, diameter than the other two alignment aids 18. The alignment aids 18 are preferably formed as, in particular semicircular, notches or recesses at the edge of the multilayer printed circuit board module 1 and / or are arranged laterally relative to the chip 11 or the thermal vias 15.

[0326] The edge-side alignment aids 18 also preferably serve to position the multilayer printed circuit board module 1 on a PCB and / or to position a waveguide or an antenna on the multilayer printed circuit board module 1.

[0327] The (additional) alignment aids 18 shown in Fig. 11 can also be designed or provided in the second embodiment.

[0328] Furthermore, the multilayer printed circuit board module 1 of the third embodiment is preferably designed like the multilayer printed circuit board module 1 of the second embodiment, in particular with regard to the waveguiding structures, the layer structure, the coupling structures 10, the chip 11 or the chip receptacle 14 and / or the recess 17.

[0329] Fig. 12 and 13 show two embodiments of a proposed system 100, in particular a high-frequency and / or radar system.

[0330] In both embodiments, the system 100 comprises the proposed multilayer printed circuit board module 1. By way of example, Fig. 12 shows the multilayer printed circuit board module 1 according to the third embodiment, and Fig. 13 shows the multilayer printed circuit board module 1 according to the second embodiment. Of course, it is also possible to configure the system 100 with the multilayer printed circuit board module 1 according to the first embodiment or with further embodiments according to the invention.

[0331] In both embodiments, the system 100 comprises a PCB 101 (Printed Circuit Board) on which the multilayer printed circuit board module 1 is mounted, in particular electrically connected, preferably by means of the pads 19.

[0332] The multilayer printed circuit board module 1 is mounted on the PCB 101 such that the windows 2A or the first conductive layer 2 face away from the PCB 101, or the third conductive layer 4, the chip 11, the chip receptacle 14, the recess 17, and / or the pads 19 face the PCB. Particularly preferably, the recess 17 is closed by the PCB 101 and / or the chip 11 is completely encapsulated.

[0333] For explosion protection, the recess 17 can be cast at the edge.

[0334] Preferably, the recess 17 is not completely encapsulated or has an air-filled space, particularly in the area of ​​the coupling structures 10, the chip 11, and / or the bonding wires 12. The air-filled space is preferably small enough to ensure explosion protection. In principle, however, it is also possible to completely encapsulate the recess 17.

[0335] If no recess 17 is provided, the chip 11 is preferably still completely encapsulated by the PCB 101 and the chip receptacle 14.

[0336] The multilayer printed circuit board module 1 is preferably at least partially, in particular completely, embedded or countersunk into the PCB 101. For this purpose, the PCB 101 preferably has a module receptacle 101A. In principle, however, it is also possible for the multilayer printed circuit board module 1 to merely rest on the PCB 101.

[0337] By way of example, Fig. 12 shows an (at least partially) recessed multilayer printed circuit board module 1 and Fig. 13 shows a multilayer printed circuit board module 1 lying on top. Of course, the multilayer printed circuit board module 1 can also be (partially) recessed in the embodiment shown in Fig. 13 or the multilayer printed circuit board module 1 can lie on top in the embodiment shown in Fig. 12.

[0338] The PCB 101 preferably has corresponding connection contacts for the multilayer printed circuit board module 1, in particular the pads 19. The connection contacts are provided in particular in the module receptacle 101A. Particularly preferably, the multilayer printed circuit board module 1, in particular the pads 19, are electrically and / or mechanically connected to the connection contacts, for example by paste soldering or by means of solder balls.

[0339] For positioning or aligning the multilayer printed circuit board module 1 on the PCB 101 or in the module receptacle 101A, one or more of the alignment aids 18 can preferably be used. For example, the PCB 101, particularly in the module receptacle 101A, can have one or more positioning pins (not shown) that engage with the corresponding alignment aid(s) 18 of the multilayer printed circuit board module 1.

[0340] The two embodiments of Figs. 12 and 13 preferably differ at least essentially (only) in how the signals are routed from / to the multilayer printed circuit board module 1.

[0341] In the first embodiment according to Fig. 12, the system 100 preferably has a waveguide 102.

[0342] The waveguide 102 may preferably be a standard waveguide, in particular a rectangular waveguide (WR waveguide).

[0343] The dimensions or the specification of the waveguide 102 are or are preferably adapted to the frequency range for which the multilayer printed circuit board module 1 is designed.

[0344] For example, waveguide 102 can be a WR6 waveguide, WR10 waveguide, WR12 waveguide, or WR15 waveguide. These are standardized rectangular waveguides, where the number indicates the width of the waveguide opening (rounded to the nearest whole number) in inches per 100. For example, a WR10 waveguide has an opening width of 0.1 inches or 2.54 mm.

[0345] The lowest mode that can propagate in the waveguide 102 has (ideally) a wavelength that corresponds to twice the aperture width of the waveguide 102. For a WR10 waveguide, for example, this is a maximum wavelength (cutoff wavelength) of 0.2 inches or a minimum frequency (cutoff frequency) of approximately 59 GHz.

[0346] The waveguide 102 is mounted on the PCB 101 and / or the multilayer printed circuit board module 1, in particular adjacent to the first conductive layer 2 or its window 2A. For this purpose, the waveguide 102 preferably has a waveguide flange 102A.

[0347] For fastening, the waveguide flange 102A preferably has one or more openings 102B and / or fastening elements 102C or is fastened to the PCB 101 and / or to the multilayer printed circuit board module 1 by means of fastening elements 102C. In the illustrated example, only two of the four openings 102B shown here are used for fastening.

[0348] The waveguide flange 102A is preferably fixed or attached to the PCB 101. For this purpose, the PCB 101 preferably has one or more mounting holes 101B, into which a mounting element 102C engages (each).

[0349] In the illustrated example, the waveguide flange 102A is screwed to the PCB 101. In particular, the fastening elements 102C, designed as screws, penetrate the openings 102B of the waveguide flange 102A and / or are screwed into the fastening holes 101B. In principle, however, other fastening solutions are also possible.

[0350] Furthermore, it is also possible, additionally or alternatively, to fix, in particular screw, the waveguide 102 or waveguide flange 102A to the multilayer printed circuit board module 1. For this purpose, the multilayer printed circuit board module 1 can have corresponding fastening holes or the like, or the alignment aids 18 can be designed for this purpose, for example, by having an internal thread.

[0351] The waveguide 102 or waveguide flange 102A is preferably arranged on the multilayer printed circuit board module 1 by means of the alignment aids 18 such that the waveguide 102 is aligned with at least one of the windows 2A.

[0352] For the (most precise) positioning of the waveguide 102, the waveguide 102 or waveguide flange 102A preferably has one or more positioning pins 102D, in the example shown (exactly) four positioning pins 102D.

[0353] The positioning pins 102D preferably engage in the alignment aids 18 and / or positioning holes 101C formed in the PCB 101.

[0354] The waveguide 102 preferably extends at least substantially in the opening direction of the window 2A and / or in the direction of the axis A and / or in the transmission direction of electromagnetic waves W emerging from the window 2A and / or transversely or perpendicularly to the layer planes or the main extension plane of the multilayer printed circuit board module 1. In the illustrated example, only one window 2A is used. If multiple windows 2A are provided, they are preferably covered, in particular by the waveguide flange 102A.

[0355] Of course, it is also possible to use several or all windows 2A. In this case, each (used) window 2A is preferably connected to a waveguide 102. The waveguides 102 can have a common flange 102A.

[0356] It is also possible that the waveguide 102 is not a standard waveguide, but a waveguide adapted to the multilayer printed circuit board module 1.

[0357] The waveguide 102 can, for example, be formed by several conductive discs stacked one above the other, which have (slot-shaped) recesses at corresponding locations (not shown). In particular, when using several windows 2A and / or for a short waveguide 102, a suitable waveguide 102 can be formed in this way in a simple manner.

[0358] In the second embodiment according to Fig. 13, the system 100 preferably has an antenna 103, in particular a dielectric antenna and / or drop antenna.

[0359] The antenna 103 is mounted on the PCB 101 and / or the multilayer printed circuit board module 1, in particular adjacent to the first conductive layer 2 or its window 2A. It is also possible for the antenna 103 to be connected to a waveguide 102.

[0360] The antenna 103 preferably extends at least substantially in the opening direction of the window 2A and / or in the direction of the axis A and / or in the transmission direction of electromagnetic waves W emerging from the window 2A and / or transversely or perpendicularly to the layer planes or the main extension plane of the multilayer printed circuit board module 1.

[0361] Preferably, the antenna 103 extends over several or all windows 2A. Consequently, the antenna 103 preferably radiates into the multilayer printed circuit board module 1 over several or all windows 2A. Of course, it is also possible to use only certain windows 2A or only one window 2A with the antenna 103.

[0362] In general, it is also possible to design or operate the system 100 without waveguide 102 and / or antenna 103.

[0363] Individual aspects and / or features of the present invention can be implemented independently, but also in any combination.

[0364] Further aspects of the present invention, which can be implemented independently or combined with the aforementioned aspects, relate to:

[0365] 1. Multi-layer printed circuit board module 1, in particular for high-frequency and / or radar applications, with at least five layers, namely a first conductive layer 2, followed by a first substrate layer 5, followed by a second conductive layer 3, followed by a second substrate layer 6, followed by a third conductive layer 4, wherein a substrate-integrated waveguide 7 is formed in the second substrate layer 6, characterized in that the first conductive layer 2 has a first window 2A and the second conductive layer 3 has a second window 3A in order to couple in and / or out propagable modes W in the substrate-integrated waveguide 7 transversely to the main extension plane of the second substrate layer 6 through the first substrate layer 5.

[0366] 2. Multilayer printed circuit board module according to aspect 1, wherein a first cavity 8 is formed between the windows 2A, 3A in the first substrate layer 5, which first cavity 8 projects at least substantially beyond the windows 2A, 3A.

[0367] 3. Multilayer printed circuit board module according to aspect 1 or 2, wherein the substrate-integrated waveguide 7 ends in a second cavity 9 which projects at least substantially beyond the second window 3A.

[0368] 4. Multilayer printed circuit board module according to one of the preceding aspects, wherein the windows 2A, 3A have a common axis A which extends through the centers of the windows 2A, 3A and transversely, in particular perpendicularly, to the opening plane.

[0369] 5. Multilayer printed circuit board module according to one of the preceding aspects, wherein the first window 2A is slot-shaped and / or wherein the second window 3A is slot-shaped, preferably wherein the first and / or second window 2A, 3A has / has a longitudinal extension transverse to the course of the substrate-integrated waveguide 7.

[0370] 6. Multilayer printed circuit board module according to one of the preceding aspects, wherein the first window 2A has a rectangular basic shape, preferably wherein the rectangular basic shape is constricted in the middle of its longitudinal extent.

[0371] 7. Multilayer printed circuit board module according to one of the preceding aspects, wherein the first window 2A has a larger opening area than the second window 3A, in particular at least four times and / or at most six times larger, and / or wherein the first window 2A is longer and / or wider than the second window 3A, in particular wherein the length of the first window 2A is at least 1.5 times and / or at most twice the length of the second window 3A and / or the width of the first window 2A is at least 1.5 times or double and / or at most three times or four times the length of the second window 3A.

[0372] 8. Multilayer printed circuit board module according to one of the preceding aspects, wherein the multilayer printed circuit board module 1, in particular the geometries and / or dimensions of the substrate-integrated waveguide 7, the windows 2A, 3A, of cavities 8, 9 formed in the first and / or second substrate layer 5, 6 and / or of coupling structures 10 for coupling and / or decoupling modes, is / are designed for a frequency range of at least 24 GHz and / or at most 500 GHz, preferably from 57 GHz to 71 GHz or from 75 GHz to 85 GHz or of more than 116 GHz.

[0373] 9. Multilayer printed circuit board module according to one of the preceding aspects, wherein a coupling structure 10, in particular comprising a stripline, is formed in the second and / or third conductive layer 3, 4, via which modes W capable of propagation in the substrate-integrated waveguide 7 can be coupled into and / or decoupled from the substrate-integrated waveguide 7.

[0374] 10. Multilayer printed circuit board module according to aspect 9, wherein the multilayer printed circuit board module 1 has one or more further layers 16 following the third conductive layer 4, wherein the one or more further layers 16 have a recess 17 in the region of the coupling structure 10, so that the coupling structure 10 is exposed.

[0375] 11. Multilayer printed circuit board module according to one of the preceding aspects, wherein the multilayer printed circuit board module 1 has a chip receptacle 14 formed by a recess in the third conductive layer 4 and, preferably, at least parts of the second substrate layer 6.

[0376] 12. Multilayer printed circuit board module according to aspect 11, wherein in the region of the chip receptacle 14, thermal vias 15 extend through the first conductive layer 2, first substrate layer 5 and second conductive layer 3, preferably up to the chip receptacle 14.

[0377] 13. Multilayer printed circuit board module according to aspect 11 or 12, wherein a chip 11 is arranged, in particular bonded, in the chip receptacle 14, wherein the chip 11 is at least substantially aligned and / or connected to the third conductive layer 4.

[0378] 14. Multilayer printed circuit board module according to one of the preceding aspects, wherein the first conductive layer 2 has a plurality of windows 2A for coupling and / or decoupling modes W, preferably wherein the second conductive layer 3 has a plurality of windows 3A and / or a plurality of substrate-integrated waveguides 7 are formed in the second substrate layer 6, wherein each window 2A of the first conductive layer 2 is assigned one of the windows 3A of the second conductive layer 3 and / or one of the substrate-integrated waveguides 7.

[0379] 15. System 100, in particular for high-frequency and / or radar applications, with a multilayer printed circuit board module 1 according to one of the preceding aspects, wherein the system 100 has an antenna 103, in particular a dielectric antenna, or a waveguide 102, in particular a rectangular waveguide, which is arranged on the first conductive layer 2 and covers the first window 2A, and / or wherein the system 100 has a PCB 101 on which the multilayer printed circuit board module 1 is mounted, such that the third conductive layer 4 faces the PCB 101, in particular such that a chip receptacle 14 formed in the third conductive layer 4 or a chip 11 arranged therein is completely covered by the PCB 101.

[0380] List of reference symbols:

[0381] Multilayer PCB module 14 Chip holder first conductive layer 15 Thermal vias A first window 16 Further layer B Constriction 17 Recess second conductive layer 18 Alignment aid A second window 19 Pad third conductive layer

[0382] 100 System first substrate layer

[0383] 101 PCB second substrate layer

[0384] 101 A module holder substrate-integrated waveguide

[0385] 101 B Positioning hole A Vias

[0386] 101C Mounting hole first cavity

[0387] 102 Waveguide A Vias

[0388] 102A Waveguide flange second cavity

[0389] 102B Opening A Vias

[0390] 102C Fastening element0 Coupling structure

[0391] 102D Positioning pin 03 Antenna 0A Stripline 0B Balun A Axis 1 Chip T Transmission direction 1A Bond pad W Electromagnetic wave 2 Bond wire 3 Conductor structures

Claims

Patent claims:

1. Multi-layer printed circuit board module (1), in particular for high-frequency and / or radar applications, with at least five layers, namely a first conductive layer (2), followed by a first substrate layer (5), followed by a second conductive layer (3), followed by a second substrate layer (6), followed by a third conductive layer (4), wherein a substrate-integrated waveguide (7) is formed in the second substrate layer (6), and wherein the first conductive layer (2) has a first window (2A) and the second conductive layer (3) has a second window (3A) in order to couple in and / or couple out propagable modes (W) in the substrate-integrated waveguide (7) transversely to the main extension plane of the second substrate layer (6) through the first substrate layer (5).

2. Multilayer printed circuit board module according to claim 1, wherein a first cavity (8) is formed between the windows (2A, 3A) in the first substrate layer (5), which first cavity (8) projects at least substantially beyond the windows (2A, 3A), wherein the first cavity (8) forms a ridged waveguide, in particular a double-ridged waveguide.

3. Multilayer printed circuit board module according to claim 1 or 2, wherein the substrate-integrated waveguide (7) ends in a second cavity (9) which projects at least substantially beyond the second window (3A), wherein opposite the substrate-integrated waveguide (7) a conductive structure extending transversely or orthogonally to the course of the waveguide (7), in particular a series of vias (9A), forms a boundary for the propagation of the modes (W).

4. Multilayer printed circuit board module according to claim 3, wherein the distance of the conductive structure from the second window (3A) is at most 25% of the width of the substrate-integrated waveguide (7).

5. Multilayer printed circuit board module according to one of the preceding claims, wherein cavities (8, 9) formed in the first and / or second substrate layer (5, 6), in particular the first cavity (8) and / or the second cavity (9), each have a Resonator, and wherein the dimensions (L, B, H) of the cavities (8, 9) are determined according to the formula are defined, where fmnp are the desired resonance frequencies of order m, n, p, where p denotes the magnetic permeability and s the permittivity of the dielectric with which the cavity (8, 9) is filled, and where L denotes the length, B the width and H the height of the cavity (8, 9).

6. Multilayer printed circuit board module according to one of the preceding claims, wherein the multilayer printed circuit board module (1) is designed for a frequency range of more than 116 GHz or for a frequency range of 100 GHz to 200 GHz, in particular of 126 GHz to 182 GHz.

7. Multilayer printed circuit board module according to claim 5 and 6, wherein the dimensions (L, W, H) of the cavities (8, 9), in particular of the first cavity (8) and / or the second cavity (9), are adapted according to the formula of claim 5 to the frequency range of more than 116 GHz or to the frequency range from 100 GHz to 200 GHz, in particular from 126 GHz to 182 GHz.

8. Multilayer printed circuit board module according to one of the preceding claims, wherein the first conductive layer (2) has no conductive material in the region of the window (2A).

9. Multilayer printed circuit board module according to one of the preceding claims, wherein the first window (2A) is slit-shaped and wherein the ratio of the side lengths of the first window (2A) is greater than 3 or 4.

10. Multilayer printed circuit board module according to one of the preceding claims, wherein the first and / or second window (2A, 3A) has / has a longitudinal extension transverse to the course of the substrate-integrated waveguide (7).

11. Multi-layer printed circuit board module according to one of the preceding claims, wherein a coupling structure (10), in particular comprising a stripline, is formed in the second and / or third conductive layer (3, 4), via which coupling structure modes (W) capable of propagation in the substrate-integrated waveguide (7) can be coupled into and / or decoupled from the substrate-integrated waveguide (7), wherein the multi-layer printed circuit board module (1) has one or more further layers (16) which follow the third conductive layer (4), wherein the one or more further layers (16) have a recess (17) in the region of the coupling structure (10), so that the coupling structure (10) is exposed.

12. Multilayer printed circuit board module according to one of the preceding claims, wherein the multilayer printed circuit board module (1) has pads (19) for mechanically fastening and / or electrically connecting the multilayer printed circuit board module (1) to a PCB, wherein the pads (19) are formed on the side facing away from the first window (2A) or the first conductive layer (2), in particular on / at the outermost layer of the additional layers (16).

13. Multilayer printed circuit board module according to one of the preceding claims, wherein the multilayer printed circuit board module (1) has a chip receptacle (14) which is formed by a recess in the third conductive layer (4) and, preferably, at least parts of the second substrate layer (6), in particular wherein the chip receptacle (14) is formed in the recess (17).

14. Multilayer printed circuit board module according to claim 13, wherein a chip (11) is arranged, in particular bonded, in the chip receptacle (14), wherein the chip (11) is at least substantially aligned and / or connected to the third conductive layer (4).

15. Multilayer printed circuit board module according to one of the preceding claims, wherein the first conductive layer (2) has a plurality of windows (2A) for coupling and / or decoupling modes (W).

16. Multilayer printed circuit board module according to claim 15, wherein the second conductive layer (3) has a plurality of windows (3A) and / or a plurality of substrate-integrated waveguides (7) are formed in the second substrate layer (6), wherein each window (2A) of the first conductive layer (2) is assigned one of the windows (3A) of the second conductive layer (3) and / or one of the substrate-integrated waveguides (7).

17. Multilayer printed circuit board module (1), in particular for high-frequency and / or radar applications, with an optional first conductive layer (2), followed by a first substrate layer (5), followed by a second conductive layer (3), followed by a second substrate layer (6), followed by a third conductive layer (4), wherein a coupling structure (10), in particular comprising a stripline, is formed in the second and / or third conductive layer (3, 4), wherein the multilayer printed circuit board module (1) has one or more further layers (16) following the third conductive layer (4), wherein the one or more further layers (16) have a recess (17) in the region of the coupling structure (10), so that the coupling structure (10) is exposed, wherein the multilayer printed circuit board module (1) has a chip receptacle (14) which is formed in the recess (17) by a cutout in the third conductive layer (4) and, preferably, at least parts of the second substrate layer (6). is formed,wherein a substrate-integrated waveguide (7) is formed in the second substrate layer (6), wherein propagable modes (W) can be coupled into and / or decoupled from the substrate-integrated waveguide (7) via the coupling structure (10), and / or wherein the multilayer printed circuit board module (1) has pads (19) for electrically connecting the multilayer printed circuit board module (1) to a PCB, wherein the pads (19) are formed on the side facing away from the first conductive layer (2) or first substrate layer (6), in particular on / at the outermost layer of the additional layers (16).

18. Multilayer printed circuit board module according to claim 17, wherein a chip (11) is arranged, in particular bonded, in the chip receptacle (14), wherein the chip (11) is at least substantially aligned and / or connected to the third conductive layer (4).

19. Multilayer printed circuit board module according to claim 17 or 18, wherein the multilayer printed circuit board module (1) has the first conductive layer (2) and wherein the first conductive layer (2) has a first window (2A) for coupling and / or decoupling modes (W), so that the window (2A) and the recess (17) or the pads (19) are arranged on opposite sides of the multilayer printed circuit board module (1).

20. Multilayer printed circuit board module according to one of claims 17 to 19, wherein the multilayer printed circuit board module (1) is designed according to one of claims 1 to 16.

21. System (100), in particular for high-frequency and / or radar applications, with a multilayer printed circuit board module (1) according to one of the preceding claims, wherein the system (100) has an antenna (103), in particular a dielectric antenna, or a waveguide (102), in particular a rectangular waveguide, which is arranged on the first conductive layer (2) and covers the first window (2A).

22. System (100), in particular for high-frequency and / or radar applications, with a multi-layer printed circuit board module (1) according to one of claims 1 to 16, wherein the system (100) comprises a PCB (101) on which the multi-layer printed circuit board module (1) is mounted and electrically connected, so that the third conductive layer (4) faces the PCB (101).

23. System according to claim 22, wherein a chip receptacle (14) formed in the third conductive layer (4) or a chip (11) arranged therein is completely covered by the PCB (101).

24. System (100), in particular for high-frequency and / or radar applications, with a multi-layer printed circuit board module (1) according to one of claims 17 to 20, wherein the system (100) comprises a PCB (101) on which the multi-layer printed circuit board module (1) is mounted and electrically connected, so that the third conductive layer (4), the chip receptacle (14), the recess (17) and / or the pads (19) face the PCB (101).

25. System according to claim 24, wherein the chip receptacle (14) or a chip (11) arranged therein is completely covered by the PCB (101).

26. System according to claim 24 or 25, wherein the recess (17) is closed by the PCB (101).

27. System according to one of claims 24 to 26, wherein the multilayer printed circuit board module (1) is electrically connected to the PCB (101) by means of the pads (19).

28. System according to one of claims 23 to 27, wherein the multilayer printed circuit board module (1) is at least partially, in particular completely, embedded or countersunk in the PCB (101).

29. System according to one of claims 23 to 28, wherein the system (100) comprises an antenna (103), in particular a dielectric antenna, or a waveguide (102), in particular a rectangular waveguide, which is arranged on the first conductive layer (2) and covers the first window (2A).

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