Dielectric element in embedded waveguide of component carrier

Abstract

It is described a component carrier (100) comprising: i) a stack (101) comprising at least one electrically insulating layer structure (102) and / or at least one electrically conductive layer structure (104); ii) a cavity (120) which is at least partially arranged in the stack (101) and which is delimited by a plurality of side walls (121); iii) a metal shielding structure (125) located in the cavity (120), where the metal shielding structure (125) at least partially covers the plurality of side walls (121); and iv) a dielectric element (150) arranged within the cavity (120), where the dielectric element (150) comprises a material having a dielectric constant Dk of 2 or more.

Description

Technical Field

[0001] The invention relates to a component carrier having a cavity and a dielectric element which is arranged in the cavity. The invention also relates to a method for producing a component carrier. The invention also relates to the use of a dielectric element in a cavity of a component carrier.

[0002] Thus, the present invention may relate to the technical field of component carriers such as printed circuit boards and IC substrates, in particular in the context of signal transmission. Background Art

[0003] Against the background of the growing product functionality of component carriers equipped with one or more electronic components and the increasing miniaturization of such electronic components and the increasing number of electronic components mounted to component carriers such as printed circuit boards, more and more powerful array-like components or packages with a plurality of electronic components are being used, which have a plurality of contacts or connections with increasingly smaller spacings between these contacts. Removing the heat generated by these electronic components and the component carriers themselves during operation is becoming an increasingly important issue. At the same time, the component carriers should be mechanically robust and electrically and magnetically reliable in order to be able to operate even under adverse conditions.

[0004] In particular, it remains a challenge to provide component carriers with efficient and reliable electromagnetic signal transmission in a compact (robust) but still design-flexible manner. Channel structures (waveguides) with metal sidewalls are known for transmitting electromagnetic waves. However, these structures are optimized for high frequencies, and when the operating frequency decreases, the size of the waveguide needs to increase. Therefore, miniaturization may be attractive for recent and upcoming high-frequency applications. Summary of the invention

[0005] It may be desirable to provide a component carrier with efficient and reliable electromagnetic signal transmission in a compact (robust) yet design-flexible manner.

[0006] A component carrier, a manufacturing method and a use are provided.

[0007] According to a first aspect of the invention, a component carrier is described, the component carrier comprising:

[0008] i) a (layer) stack comprising at least one electrically insulating layer structure and / or at least one electrically conductive layer structure;

[0009] ii) a cavity which is at least partially arranged (embedded) in the stack and which is bounded by a plurality of side walls (particularly of stack material),

[0010] iii) a metal shielding structure (especially a copper layer) located in the cavity, wherein the metal shielding structure at least partially (especially completely) covers the plurality of side walls; and

[0011] iv) a dielectric element (e.g. a ceramic material) arranged in the cavity,

[0012] The dielectric element includes a material having a dielectric constant Dk of 2 or greater.

[0013] According to a second aspect of the invention, a method of manufacturing a component carrier, such as a component carrier as described above, is described, wherein the method comprises:

[0014] i) forming a stack comprising at least one electrically insulating layer structure and / or at least one electrically conductive layer structure;

[0015] ii) at least partially forming a cavity in the stack, wherein the cavity is bounded by a plurality of side walls;

[0016] iii) at least partially covering the sidewalls with a metal shielding structure; and

[0017] iv) Arranging a dielectric element in the cavity, wherein the dielectric element comprises a material having a dielectric constant Dk of 2 or more.

[0018] According to a third aspect of the invention, a use (method of use) of a dielectric element in a waveguide is described, wherein the dielectric element has a material with a dielectric constant Dk of 2 or more, and the waveguide is at least partially embedded in a component carrier (in particular to reduce the frequency, apply low frequencies, without substantially increasing the size).

[0019] In the context of the present document, the term "cavity" may particularly denote any opening in the component carrier material and / or the layer stack (in other words, a volume portion without component carrier material / stack material). The component carrier material / stack material may delimit the cavity here. In one example, the cavity may be completely embedded in the component carrier material and delimited by the component carrier material. In this example, the cavity may be arranged in the stack. In another example, the cavity may be only partially embedded in the component carrier material, in other words, the cavity is only partially formed in the stack. For example, a portion of the cavity may be formed outside the stack, and this portion may be delimited by an additional metal shielding structure.

[0020] In this context, the term "sidewall" may refer to any wall that bounds a cavity. While a cavity may include four sidewalls oriented parallel to a vertical (z) direction, a cavity may also include top and bottom sidewalls oriented parallel to horizontal (x, y) planes, respectively.

[0021] In the context of this document, the term "metal shielding structure" may particularly refer to any structure that is configured to at least partially delimit a cavity (and / or cover one or more sidewalls that delimit a cavity), and that includes a metal material. In one example, the metal shielding structure may include only a metal material. In another example, the main part of the metal shielding structure may include a metal, while non-metallic substances may also be present. The metal shielding structure may be particularly configured to shield electromagnetic radiation / waves from leaving the cavity. Here, the metal shielding structure may be configured to shield electromagnetic waves to remain in the cavity and move in a specific direction in the cavity. Thus, the metal shielding structure may cover the sidewalls of the cavity, thereby providing a waveguide within the stack. Although in one example, the metal shielding structure may be configured as a metal layer, preferably a continuous metal layer, in another example, the metal shielding structure may include a plurality of (metal) vias, such as rectangular columns or circular columns. In a specific example, the metal shielding structure may be configured as a copper layer that covers the electrically insulating stack material of the sidewalls. In an example, the metal shielding structure may be applied by electroplating or PVD / CVD. In an embodiment, the thickness of the metal shielding structure (layer) is in the range of 2 microns to 60 microns.

[0022] In the context of this document, the term "waveguide" may particularly refer to the following structure: the structure is configured to guide waves, especially electromagnetic waves. A waveguide may represent a physical constraint for a wave to maintain strength and avoid reduction due to expansion into space. In a basic example, a waveguide may be constructed as a hollow metal channel. In a more advanced example, a waveguide may include multiple (e.g., six) metal sidewalls. For example, by providing a cavity and covering the sidewalls with a metal shielding structure, such a waveguide structure may be (at least partially) embedded in a stack of component carriers. According to further definitions, a waveguide may be an electromagnetic feeder for high-frequency signals. A waveguide may conduct microwave energy with a lower loss than a coaxial cable, and may be used, for example, for microwave communications, radar, and other high-frequency applications. A waveguide may include the following shapes (in cross section): for example, rectangular, ridged, double-ridged, curved, L-shaped, Z-shaped, elliptical, or circular. The term "ridged form" is established and refers to a U-shaped cavity (observed in cross section). The term "double-ridged" is also established and refers to an H-shaped cavity (viewed in cross-section).

[0023] In the context of this document, the term "dielectric element" may particularly refer to any of the following elements: the element may be configured to interact with a signal in the form of an electromagnetic wave and include a dielectric material. Even if the dielectric element itself may include a dielectric material, a metal layer and / or a coating may be formed at the outer surface of the dielectric element. In an embodiment, the dielectric element may also provide an electromagnetic function, such as an antenna, a radar function, a filter function, an RF / HF coupling function. In one example, the dielectric material includes a polymer and / or a ceramic, such as a polymer-ceramic composite material. In another example, the dielectric element includes a low temperature co-fired ceramic (LTCC). In a preferred embodiment, the dielectric material is a non-laminated material, i.e., an electrically insulating material of a laminate that is different from a laminate of a component carrier in terms of its physical / chemical properties. The dielectric element is not limited in its shape and may, for example, be block-shaped, rectangular, circular and / or structured. For example, the dielectric element may be configured as a dielectric antenna, such as a dielectric resonator antenna. In another example, the dielectric element may be configured as a filter or an RF / HF coupling device. In one example, the dielectric element may be a completely dielectric element. In another example, the dielectric element may include a (thin) metal structure, such as a coating (eg a thin copper coating) on ​​at least one surface.

[0024] In the context of the present document, the term "component carrier" may particularly denote any supporting structure on which and / or in which one or more components can be accommodated to provide mechanical support and / or electrical connection. In other words, the component carrier may be configured as a mechanical and / or electronic carrier for the components. In particular, the component carrier may be one of a printed circuit board, an organic interposer and an IC (integrated circuit) substrate. The component carrier may also be a hybrid board combining different types of component carriers of the above-mentioned types of component carriers.

[0025] In an embodiment, the component carrier comprises a (layer) stack of at least one electrically insulating layer structure and at least one electrically conductive layer structure. For example, the component carrier may be a laminate of said one or more electrically insulating layer structures and one or more electrically conductive layer structures, the laminate being formed in particular by applying mechanical pressure and / or heat. The stack may provide a plate-like component carrier which is able to provide a large mounting surface for other components and yet is very thin and compact. The term "layer structure" may in particular denote a continuous layer, a patterned layer or a plurality of discontinuous islands in a common plane.

[0026] According to an exemplary embodiment, the present invention may be based on the following concept: when the side walls of a cavity in a stack of component carriers are covered with a metal shielding structure, and when a dielectric element (a material with a high dielectric constant) is arranged in the cavity, a component carrier with efficient and reliable electromagnetic signal transmission can be provided in a compact (robust) but still design-flexible manner.

[0027] The cavity with metal sidewalls can be used as a waveguide in the stack of embedded component carriers. The inventors were surprised to find that placing dielectric elements with high dielectric constant materials in waveguides can significantly improve the signal transmission quality. In particular, lower frequencies can be efficiently transmitted without further increasing the size of the waveguide. In other words, for microwave and millimeter wave applications such as antennas, filters, couplers or other (microwave) components / circuits, the operating resonant frequency can be reduced by embedding high dielectric constant materials in the waveguide embedded in the stack.

[0028] Conventional waveguides are suitable for microwaves and higher frequencies (e.g. 300 MHz to 1 THz). For lower frequencies (e.g. 100 MHz to 5 GHz), significantly increased space requirements must be considered.

[0029] However, the surprising beneficial effect of the dielectric element enables applications with lower frequencies by using the same size and dimensions of the waveguide as for high frequencies. In a specific example, a size reduction in the range of 30% to 40% can be achieved by the described architecture. In addition, the described component carrier with embedded waveguide can be manufactured with standard PCB manufacturing processes, making it possible to directly implement into existing production lines.

[0030] Exemplary embodiments

[0031] According to an embodiment, the metal shielding structure extends in a manner parallel to the layers of the stack. In this way, the cavity can be constructed as an elongated channel through the stack, wherein the channel wall is (at least partially) metal-covered. This can provide the following advantages: an efficient and stable waveguide structure is embedded in the component carrier. Electromagnetic waves can be efficiently and reliably transmitted in a specific direction (horizontal direction) along the component carrier. The metal layer parallel to the layers of the stack can be particularly stable. In an example, the electrically conductive layer structure of the stack can be at least partially used as a metal shielding structure.

[0032] In another embodiment, the metal shielding structure extends perpendicular to the layers of the stack, thereby providing a waveguide in the vertical direction (along z).

[0033] According to further embodiments, the material of the dielectric element comprises a dielectric constant (Dk) in the range of 2 to 100, in particular a dielectric constant (Dk) in the range of 2 to 80, more particularly a dielectric constant (Dk) in the range of 2 to 20, more particularly a dielectric constant (Dk) in the range of 4 to 20 (or a dielectric constant of 4 (in particular 4.5) or more). In other words, the dielectric element has a high dielectric constant, thereby allowing a reduction in size.

[0034] According to a further embodiment, the metal shielding structure comprises a metal layer and / or a metal-filled via. This can provide the following advantages: established materials and their manufacturing techniques in the field of PCB manufacturing can be directly applied. For example, there are a variety of effective methods of how to form a metal (copper) layer on the side walls of the component carrier material. In addition, (copper) vias, for example in the form of columns, can be formed as the boundaries of the cavity. In the example, two options, such as layers at the top and bottom of the cavity and vias at the sides, are combined.

[0035] According to further embodiments, the surface of the metal shielding structure is at least partially covered by a surface treatment (eg, gold, palladium, etc., see further examples below) Thus, oxidation may be prevented and / or signal transmission may be enhanced.

[0036] According to further embodiments, the dielectric element is configured as a discontinuous dielectric layer structure, in particular as an array of dielectric sub-elements. In a first example, exactly one dielectric element may be arranged in the cavity. In a further example, two or more dielectric elements, in particular three or more dielectric elements may be arranged in the cavity. In another example, a plurality of dielectric elements may be arranged in the cavity, for example in the form of an array (see Figure 6 ). In this case, the dielectric element may be considered as a discontinuous layer comprising a plurality of dielectric elements, in particular in a common plane. Such a discontinuous layer may be made from an original continuous layer which is then separated / patterned. Alternatively, the discontinuous layer may be considered as a dielectric element having dielectric element sub-portions. The dielectric elements and / or the dielectric element sub-portions may be adjacent to each other (side by side). Thus, the dielectric elements may not be in physical contact, but no other components are arranged between them. Preferably, the dielectric elements may have the same extension. Alternatively, the extensions of the dielectric elements may be different.

[0037] According to a further embodiment, the cavity and the metal shielding structure form a waveguide. As already discussed above, the metal shielding structure can define a channel within the component carrier through which electromagnetic waves can propagate in a specific direction. In this way, an efficient and reliable waveguide can be provided, which can be significantly improved by dielectric elements.

[0038] According to another embodiment, the cavity is filled with at least one of a fluid (particularly air), a vacuum, an electrically insulating component carrier material. Different media can be applied to partially or completely fill the cavity between the metal shielding structures. Depending on the desired application, the most suitable properties can be selected. The electrically insulating component carrier material can be an encapsulating medium, such as a resin. In an example, the material is the same as the stack material. In another example, the material is a typical component carrier material (see the list below), but a material different from the material of the stack.

[0039] According to a further embodiment, the dielectric element is embedded in the component carrier material (embedding material / encapsulation material, molding material) in the cavity. In a specific example, the dielectric element is embedded in the central part of the cavity with respect to the thickness direction (z) perpendicular to the extension of the layers of the stack. Additionally or alternatively, the dielectric element is embedded in the central part of the cavity with respect to the length / width (x, y) direction parallel to the extension of the layers of the stack.

[0040] According to a further embodiment, the dielectric element is at least partially covered by a coating, in particular by a metal coating, such as a copper layer. By taking this measure, specific properties of the dielectric element are advantageously provided in a selective manner.

[0041] According to a further embodiment, the operating frequency is in the range of 100 MHz to 5 GHz. The operating frequency may depend on the dimensions, in particular the width, of the waveguide. Due to the dielectric element, the size requirements may not increase for lower frequencies.

[0042] According to further embodiments, the dielectric element comprises at least one of the following materials: a polymer, a ceramic, a composite material of a polymer and a ceramic, a polymer resin, a thermoplastic material, a curable material, a photoresist, a photopolymer, a polymer with a filler material, a polymer with a ceramic powder filler material, a polymer with a fiber filler material.

[0043] According to a further exemplary embodiment, the dielectric element comprises a polymer and / or a ceramic. In particular, a composite material of a polymer and a ceramic (e.g. a polymer matrix with a ceramic filler such as powder, particles or fibers). This can provide the following advantages: industrially relevant materials can be directly provided in a cost-effective manner.

[0044] According to a further exemplary embodiment, the polymer comprises at least one of the following: a polymer resin, a thermoplastic material, a curable material, a photoresist, a photopolymer, a polymer with a filler material, in particular a (ceramic) powder material or a fiber material. This may also provide the advantage that industrially relevant materials may be provided directly in a cost-effective manner.

[0045] In an embodiment, a polymer resin such as polyimide, polystyrene (sulfonate) (PSS), a photoresist polymer such as polymethyl methacrylate (PMMA) as a positive photoresist, and SU-8 as an epoxy-based negative photoresist may be used. TM ). In an example, in order to balance the relatively low dielectric constant of the pure polymer material, a filler material with a relatively high dielectric constant can be mixed or added to the polymer to form a composite material with enhanced dielectric properties. In particular, ceramic powders can be effective filler materials, such as aluminum oxide, barium titanate oxide, zirconium oxide (other oxides of calcium, magnesium, titanium, bismuth, barium). The composite material can also include other fillers, such as fiber materials, carbon nanotubes, CdS nanowires, and active ferroelectric materials.

[0046] In a specific example, the dielectric element includes ECCOS-TOCKHiK material having a dielectric constant of 10 and a loss tangent of 0.002.

[0047] According to further exemplary embodiments, the dielectric element comprises at least one of the following features: a rectangular shape, a circular shape, at least one structured surface, a stack of a plurality of dielectric layers, at least one (cylindrical) hole in at least one surface, at least one protrusion, a central portion with a plurality of protrusions. Depending on the desired situation, an advantageous shape can be achieved.

[0048] According to a further exemplary embodiment, an electronic device is described, the electronic device comprising:

[0049] i) a component carrier as described above, and

[0050] ii) at least one of the following functions: 4G function, 5G function, 6G function, microwave function, millimeter waveguide function, WiFi function, antenna function, radar function, filter function, RF / HF coupling function.

[0051] The described component carrier can be integrated into the electronic device or can be arranged separately from the electronic device.

[0052] In the context of this document, the term "antenna" may particularly refer to an element connected to a receiver or transmitter, for example, by a transmission line. Thus, an antenna may refer to an electrical component that converts power into radio waves and / or converts radio waves into power. The antenna may be used with a controller (e.g., a control chip) such as a radio transmitter and / or a radio receiver. In transmission, the radio transmitter may provide the antenna with a current (i.e., a high-frequency alternating current) oscillating at a radio frequency, and the antenna may radiate the energy from the current as electromagnetic waves (in particular, radio waves). In receiving mode, the antenna may intercept some of the power of the electromagnetic wave to provide a small voltage, which may be applied to a receiver, for example, for amplification. In an embodiment, the antenna may be configured as a receiver antenna, a transmitter antenna, or a transceiver (i.e., a transmitter and a receiver) antenna. In an embodiment, the antenna structure may be used for radar applications. In one example, the antenna may be configured as a single antenna. In another example, the antenna may be configured as a (bonded, embedded) antenna array.

[0053] In the context of this document, the term "4G and / or 5G functionality" may refer to known wireless system standards. 4G (or LTE) is an established standard, while 5G is an upcoming technology that has been standardized and may be fully established in the near future. The electronic device may also be suitable for future developments, such as 6G. In addition, the electronic device may comply with WiFi standards, such as 2.4GHz, 5GHz, and 60GHz. The electronic device may, for example, include a so-called wireless combination (with integrated WiFi, Bluetooth, GPS...), a radio frequency front end (RFFE), or a low power wide area (LPWA) network module. The electronic device may, for example, be a laptop computer, a notebook computer, a smartphone, a portable WiFi dongle, a smart home appliance, or a machine-to-machine network.

[0054] In addition, the electronic device can be used for radar applications, such as in the industrial field (industrial radar) or in the automotive field for radar applications. Therefore, the antenna structure and / or the dielectric element can be configured to be used for radar applications. In the context of this document, the term "radar" can refer to object detection that uses electromagnetic waves to determine the range, angle or speed of one or more objects. The radar arrangement structure may include a transmitter that transmits electromagnetic waves (for example, in the radio or microwave range). The electromagnetic waves from the transmitter are reflected from the object and returned to the receiver. Therefore, an antenna structure can be used for transmitting and receiving. In addition, a processor such as an electronic component can be used to determine object properties, such as position and speed based on the received electromagnetic waves.

[0055] According to further embodiments, the waveguide has a length (x) greater than its width (y), and the width (y) greater than its height (z).

[0056] In an embodiment, the stack comprises at least one electrically insulating layer structure and at least one electrically conductive layer structure. For example, the component carrier can be a laminate of the mentioned one or more electrically insulating layer structures and one or more electrically conductive layer structures, the laminate being formed in particular by applying mechanical pressure and / or heat. The mentioned stack can provide a plate-like component carrier that can provide a large mounting surface for other elements and is still very thin and compact.

[0057] In an embodiment, the component carrier is formed as a plate-like element. This contributes to a compact design, wherein the component carrier still provides a large base for mounting components thereon. Furthermore, in particular bare wafers as an example of embedded electronic components can be conveniently embedded in thin plates such as printed circuit boards due to their small thickness.

[0058] In an embodiment, the component carrier is configured as one of a printed circuit board, a substrate (particularly an IC substrate) and an interposer.

[0059] In the context of the present application, the term "printed circuit board" (PCB) may particularly denote a plate-like component carrier formed by laminating a plurality of electrically conductive layer structures with a plurality of electrically insulating layer structures, for example by means of applying pressure and / or providing thermal energy. As a preferred material for PCB technology, the electrically conductive layer structures are made of copper, while the electrically insulating layer structures may comprise resin and / or glass fibers, so-called prepregs or FR4 materials. The individual electrically conductive layer structures may be connected to each other in the desired manner by forming holes through the laminate, for example by laser drilling or mechanical drilling, and partially or completely filling the holes with an electrically conductive material, in particular copper, to form vias or any other through-hole connections. The filled holes connect the entire stack (through-hole connections extending through a plurality of layers or the entire stack), or the filled holes connect at least two electrically conductive layers, so-called vias. Similarly, optical interconnects may be formed through the layers of the stack to accommodate an electro-optical circuit board (EOCB). In addition to one or more components that can be embedded in the printed circuit board, the printed circuit board is generally configured to accommodate one or more components on one surface or two opposite surfaces of the plate-shaped printed circuit board. The one or more components can be connected to the corresponding main surface by welding. The dielectric portion of the PCB may include a resin with reinforcing fibers (such as glass fibers).

[0060] In the context of the present application, the term "substrate" may particularly refer to a small component carrier. A substrate may be a relatively small component carrier relative to a PCB, one or more components may be mounted on the relatively small component carrier, and the relatively small component carrier may be used as a connection medium between one or more chips and another PCB. For example, a substrate may have approximately the same size as a component (particularly an electronic component) to be mounted thereon (for example, in the case of a chip-scale package (CSP)). In another embodiment, the substrate may be substantially larger than the assigned component (for example, in a flip chip ball grid array - FCBGA configuration). More specifically, a substrate may be understood as a carrier: a carrier for electrical connectors or electrical networks, and a component carrier for connectors that are comparable to a printed circuit board (PCB) but have a relatively high density of lateral and / or vertical arrangements. Lateral connectors are, for example, conductive paths, and vertical connectors may be, for example, drilled holes. These lateral connectors and / or vertical connectors may be arranged within the substrate and may be used to provide electrical, thermal and / or mechanical connection of accommodated components or unaccommodated components (such as bare wafers), in particular IC chips, to a printed circuit board or an intermediate printed circuit board. Therefore, "substrate" also includes "IC substrate". The dielectric part of the substrate may include a resin with reinforcing particles (such as reinforcing spheres, in particular glass spheres).

[0061] The substrate or interposer may include or be composed of a layer of at least one of the following: glass; silicon (Si); and / or a photosensitive or dry-etchable organic material, such as an epoxy-based laminate material (e.g., an epoxy-based laminate film); or a polymer compound (which may or may not include photosensitive and / or heat-sensitive molecules), such as polyimide or polybenzoxazole.

[0062] In an embodiment, the at least one electrically insulating layer structure comprises at least one of the following: a resin or polymer, such as an epoxy resin, a cyanate resin, a benzocyclobutene resin; a bismaleimide triazine resin; a polyphenylene derivative (e.g. based on polyphenylene ether, PPE), a polyimide (PI), a polyamide (PA), a liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE) and / or a combination thereof. A reinforcing structure, such as a mesh, a fiber, a sphere or other kinds of filler particles, made of glass (multilayer glass), for example, may also be used to form a composite material. A semi-cured resin combined with a reinforcing agent, such as a fiber impregnated with the above resin, is called a prepreg. These prepregs are usually named after their properties, such as FR4 or FR5, which describe their flame retardant properties. Although prepregs, especially FR4, are usually preferred for rigid PCBs, other materials, especially epoxy-based laminates (such as epoxy-based laminate films) or photosensitive dielectric materials may also be used. For high-frequency applications, high-frequency materials such as polytetrafluoroethylene, liquid crystal polymers and / or cyanate resins may be preferred. In addition to these polymers, low temperature co-fired ceramics (LTCC) or other low, very low or ultra-low DK materials can be used as electrically insulating structures in the component carrier.

[0063] In an embodiment, the at least one electrically conductive layer structure comprises at least one of the following: copper, aluminum, nickel, silver, gold, palladium, tungsten, magnesium, carbon, (particularly doped) silicon, titanium and platinum. Although copper is generally preferred, other materials or coatings thereof are also possible, in particular coatings with superconducting materials or conductive polymers, such as graphene or poly (3,4-ethylenedioxythiophene) (PEDOT), respectively.

[0064] At least one further component may be embedded in the stack and / or surface mounted on the stack. The component and / or the at least one further component may be selected from the following: a non-electrically conductive inlay, an electrically conductive inlay (such as a metal inlay, preferably comprising copper or aluminum), a heat transfer unit (such as a heat pipe), an optical element (such as an optical waveguide or optical conductor connector), an electronic component or a combination of the above. The inlay may be, for example, a metal block with or without a coating of insulating material (IMS inlay), which may be embedded or surface mounted for the purpose of promoting heat dissipation. Suitable materials are defined according to their thermal conductivity, which should be at least 2 W / mK. Such materials are typically based on, but not limited to, metals, metal oxides and / or ceramics, such as copper, aluminum oxide (Al2O3) or aluminum nitride (AlN). In order to increase the heat exchange capacity, other geometries with increased surface area are also often used. Furthermore, the component may be an active electronic component (having at least one realized pn junction), a passive electronic component (such as a resistor, an inductor, or a capacitor), an electronic chip, a memory device (e.g., a DRAM or another data storage), a filter, an integrated circuit (such as a field programmable gate array (FPGA), a programmable array logic (PAL), a general purpose array logic (GAL), and a complex programmable logic device (CPLD)), a signal processing component, a power management component (such as a field effect transistor (FET), a metal oxide semiconductor field effect transistor (MOSFET), a complementary metal oxide semiconductor (CMOS), a junction field effect transistor (JFET), or an insulated gate field effect transistor (IGFET). Transistors (IGFETs), all of which are based on semiconductor materials such as silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), gallium oxide (Ga2O3), indium gallium arsenide (InGaAs), indium phosphide (InP) and / or any other suitable inorganic compound), optoelectronic interface elements, light emitting diodes, optical connectors, voltage converters (e.g. DC / DC converters or AC / DC converters), cryptographic components, transmitters and / or receivers, electromechanical transducers, sensors, actuators, microelectromechanical systems (MEMS), microprocessors, capacitors, resistors, inductors, batteries, switches, cameras, antennas, logic chips and energy harvesting units. However, other components can be embedded in the component carrier. For example, a magnetic element can be used as a component. Such a magnetic element can be a permanent magnetic element (such as a ferromagnetic element, an antiferromagnetic element, a multiferroic element or a ferrimagnetic element, such as a ferrite core) or can be a paramagnetic element. However, the component can also be an IC substrate, an interposer or another component carrier, such as in a board-in-board configuration. The component can be surface mounted on the component carrier and / or can be embedded in the interior of the component carrier.In addition, other components, in particular components which generate and emit electromagnetic radiation and / or are sensitive to electromagnetic radiation propagating from the environment, can also be used as components.

[0065] In an embodiment, the component carrier is a laminated component carrier. In such an embodiment, the component carrier is a composite of multiple layers that are stacked and connected together by applying pressure and / or heat.

[0066] After the internal layer structure of the component carrier has been processed, one or both main surfaces of the processed layer structure can be covered symmetrically or asymmetrically with one or more further electrically insulating layer structures and / or electrically conductive layer structures, in particular by lamination. In other words, the layering can be continued until the desired number of layers is obtained.

[0067] After the formation of the stack of electrically insulating layer structures and electrically conductive layer structures has been completed, the resulting layer structure or component carrier can be subjected to a surface treatment.

[0068] In particular, with regard to surface treatment, an electrically insulating solder resist may be applied to one or both of the opposite main surfaces of a layer stack or component carrier. For example, such a solder resist may be formed over the entire main surface and the solder resist layer may be subsequently patterned to expose one or more electrically conductive surface portions that will be used to electrically couple the component carrier to an electronic peripheral. Surface portions of the component carrier that are still covered with the solder resist, in particular those containing copper, may be effectively protected from oxidation or corrosion.

[0069] As far as the surface treatment is concerned, a surface treatment can also be selectively applied to the exposed electrically conductive surface portion of the component carrier. Such a surface treatment can be an electrically conductive covering material on an exposed electrically conductive layer structure (such as a pad, a conductive trace, etc., in particular a pad, a conductive trace, etc. comprising or consisting of copper) on the surface of the component carrier. If such an exposed electrically conductive layer structure is not protected, the exposed electrically conductive component carrier material (in particular copper) may be oxidized, thereby making the reliability of the component carrier low. The surface treatment can then be formed, for example, as a joint between a surface mounted component and a component carrier. The surface treatment has the function of protecting the exposed electrically conductive layer structure (in particular a copper circuit) and can enable a connection process with one or more components, for example by welding. Examples of suitable materials for the surface treatment are organic solderability preservatives (OSP), electroless nickel immersion gold (ENIG), electroless nickel immersion palladium immersion gold (ENIPIG), electroless nickel immersion palladium immersion gold (ENEPIG), gold (in particular hard gold)), chemical tin (chemical and electroplating), nickel gold, nickel palladium, etc. Nickel-free materials for the surface treatment can also be used, especially for high-speed applications. Examples are ISIG (immersion silver, immersion gold) and EPAG (electroless palladium autocatalytic gold). BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment.

[0071] Figures 1 to 4 A side view of a component carrier according to an exemplary embodiment of the invention is shown in each case.

[0072] Figures 5 to 7 A plan view of a component carrier according to an exemplary embodiment of the invention is shown in each case. DETAILED DESCRIPTION

[0073] The illustrations in the drawings are schematic. In different drawings, similar or identical elements are provided with the same reference signs.

[0074] Before the exemplary embodiments will be described in more detail with reference to the accompanying drawings, some basic considerations will be summarized based on which the exemplary embodiments of the present invention were developed.

[0075] According to an exemplary embodiment, a dielectric element (e.g., a dielectric resonator) including one of the shapes listed above is included in an embedded waveguide cavity with metal walls within a PCB using PCB manufacturing techniques. The shape of the dielectric resonator may depend on the application and may be fixed using an attachment film. The dielectric resonator may be excited within the metal cavity / waveguide structure to have a high Q component at low frequencies compared to an empty cavity / waveguide structure.

[0076] Figure 1 A side view of a component carrier 100 according to an exemplary embodiment of the present invention is shown. The component carrier 100 comprises a stack 101 having a plurality of electrically insulating layer structures 102 and an electrically conductive layer structure 104. In the central part of the stack 101, a cavity 120 is embedded in the stack material. The cavity 120 is firstly an empty space bounded by a plurality of (six in this case) side walls 121 (the top wall and the bottom wall are also regarded as side walls here), which comprise the stack material (in the horizontal direction and in the vertical direction, the electrically insulating layer structures 102 of the stack 101 are arranged). The plurality of side walls 121 are completely covered by a metal shielding structure 125, which in this example is provided as a copper layer. Therefore, the metal shielding structure can also be regarded as the electrically conductive layer structure 104 of the stack 101.

[0077] The component carrier 100 also includes a dielectric element (e.g., a ceramic material) 150 arranged in the cavity 120. The dielectric element includes a material having a dielectric constant (Dk) of 2 or more, particularly between 4 and 20. A support structure 145 is arranged at the bottom of the cavity 120, and the support structure 145 is made of a component carrier material (a stacking material, particularly a resin, such as a prepreg). An attachment material 140 (e.g., an adhesive film, glue, etc.) is formed on the support structure to adhere to the dielectric element 150 and firmly hold the dielectric element in place at the central portion of the cavity 120. In this example, the dielectric element 150, the support structure 145, and the attachment material 140 have the same horizontal extension. In addition, the dielectric element 150 is located on top of the attachment material 140 without horizontal misalignment, and the attachment material 140 is located on top of the support structure 145 without horizontal misalignment. In addition, the height of the dielectric element 150 is different from the height of the attachment material 140 and the support structure 145. Furthermore, the height of the attaching material 140 is different from the height of the supporting material 145 .

[0078] In this example, the cavity 120 is filled with an electrically insulating embedding (potting) material 160. Also indicated with reference numeral 130, the cavity 120 and the metallic shielding structure 125 form a waveguide 130, wherein a dielectric element 150 is arranged in the cavity 120.

[0079] Figure 2 A side view of a component carrier 100 according to a further exemplary embodiment of the invention is shown. Figure 1 The example described is very similar. However, the support structure 145 is omitted, and the dielectric element 150 is directly attached to the bottom of the cavity 120 by the attachment material 140. Therefore, the dielectric element 150 is not arranged in the central part of the cavity with respect to the height (z) direction. However, in this example, with respect to the horizontal (x, y) direction, the dielectric element 150 is arranged in the middle.

[0080] Figure 3 A side view of a component carrier 100 according to a further exemplary embodiment of the invention is shown. Figure 1 The example described is very similar. However, in this example, the cavity 120 is not filled with an embedding material 160, but with a fluid 170, for example air. Furthermore, the support structure 145 of the component carrier material does not comprise a horizontal extension in the horizontal direction which is identical to the horizontal extension of the dielectric element 150 (see Figure 1 ), but rather covers the entire bottom of cavity 120.

[0081] Figure 4 A side view of a component carrier 100 according to a further exemplary embodiment of the invention is shown. Figure 1 The example described is very similar. However, the attachment structure 140 is omitted and the dielectric element 150 is arranged directly on the component carrier material 145, which is, for example, a prepreg (which may also include adhesive properties). In this example, Figures 1 to 3 In contrast to the example of FIG. 1 , the component carrier material 145 and the dielectric element 150 extend in a horizontal direction.

[0082] Figure 5 A top view of a cavity 120 of a component carrier 100 according to an exemplary embodiment of the present invention is shown. It can be seen that two dielectric elements 150 are arranged side by side (adjacent) to each other in the cavity 120. The dielectric elements 150 are close to each other (without other components in between), but are not in physical contact with each other.

[0083] Figure 6 A further top view of the cavity 120 of the component carrier 100 according to an exemplary embodiment of the present invention is shown. Figure 5 Compared to the example of , a plurality of dielectric elements 150 are arranged in the cavity 120 and are disposed in the form of an array.

[0084] Figure 7 A side view of a cavity 120 of a component carrier 100 according to an exemplary embodiment of the invention is shown. In this example, a dielectric element 150 is arranged in the vertical direction and in the horizontal direction directly in the center of the cavity 120. This is possible because the dielectric element 150 is completely embedded in the embedding material 160 and is held in place by the embedding material 160.

[0085] Reference numerals

[0086] 100 Component carriers

[0087] 101 stacked pieces

[0088] 102 Electrical insulation layer structure

[0089] 104 Electrically conductive layer structure

[0090] 120 chambers

[0091] 121 Sidewall

[0092] 125 Metal shielding structure

[0093] 130 Waveguide

[0094] 140 Attachment Materials

[0095] 145 Support structure

[0096] 150 Dielectric Components

[0097] 160 Embedded Materials

[0098] 170 Fluid, air.

Claims

1. A component carrier (100), the component carrier (100) comprising: A stack (101), the stack (101) comprising at least one electrically insulating layer structure (102) and / or at least one electrically conductive layer structure (104); a cavity (120), the cavity (120) being at least partially disposed in the stack (101), and the cavity (120) being bounded by a plurality of side walls (121), a metal shielding structure (125) located in the cavity (120), wherein the metal shielding structure (125) at least partially covers the plurality of side walls (121); and a dielectric element (150), the dielectric element (150) being arranged in the cavity (120), Wherein, the dielectric element (150) comprises a material having a dielectric constant Dk of 2 or greater.

2. The component carrier (100) according to claim 1, in, The metal shielding structure (125) extends in parallel with the layers (102, 104) of the stack (101).

3. The component carrier (100) according to claim 1 or 2, in, The material of the dielectric element (150) includes a dielectric constant Dk in the range of 2 to 80, and in particular, the material of the dielectric element (150) includes a dielectric constant Dk in the range of 4 to 20.

4. The component carrier (100) according to any one of the preceding claims, in, The metal shielding structure (125) includes a metal layer and / or a metal-filled via.

5. The component carrier (100) according to any one of the preceding claims, in, The dielectric element (150) is constructed as a discontinuous dielectric layer structure, and in particular, the dielectric element (150) is constructed as an array of dielectric sub-elements.

6. Component carrier (100) according to any one of the preceding claims in, The cavity (120) and the metal shielding structure (125) form a waveguide (130).

7. The component carrier (100) according to any one of the preceding claims, in, The cavity (120) is filled with at least one of the following: a fluid, a vacuum, an electrically insulating component carrier material (160), in particular the fluid is air.

8. The component carrier (100) according to any one of the preceding claims, in, The dielectric element (150) is embedded in a component carrier material (160) in the cavity (120), In particular, the dielectric element (150) is embedded in a central portion of the cavity (120) relative to a thickness direction (z) perpendicular to the extension of the layers (102, 104) of the stack (101).

9. The component carrier (100) according to any one of the preceding claims, in, The dielectric element (150) is at least partially covered by a coating, in particular, the dielectric element (150) is at least partially covered by a metal coating.

10. The component carrier (100) according to any of the preceding claims, in, The operating frequency is in the range of 0.3 GHz to 300 GHz, particularly, the operating frequency is 10 GHz or more, more particularly, the operating frequency is 20 GHz or more.

11. The component carrier (100) according to any one of the preceding claims, in, The dielectric element (150) comprises at least one of the following materials: polymer, ceramic, a composite material of polymer and ceramic, polymer resin, thermoplastic material, curable material, photoresist, photopolymer, polymer with filler material, polymer with ceramic powder filler material, polymer with fiber filler material.

12. The component carrier (100) according to any one of the preceding claims, in, The dielectric element (150) comprises at least one of the following features: a rectangular shape, a circular shape, at least one structured surface, a stack of multiple dielectric layers, at least one (cylindrical) hole in at least one surface, at least one protrusion, a central portion having multiple protrusions.

13. An electronic device, comprising: A component carrier (100) according to any one of the preceding claims; as well as At least one of the following functions: 4G function, 5G function, millimeter waveguide function, WiFi function, antenna function, radar function, filter function, RF / HF coupling function.

14. A method for manufacturing a component carrier (100), wherein: The method comprises: forming a stack (101), the stack (101) comprising at least one electrically insulating layer structure (102) and / or at least one electrically conductive layer structure (104); forming a cavity (120) disposed at least partially in the stack (101), wherein the cavity (120) is bounded by a plurality of side walls (121); at least partially covering the side wall (121) with a metal shielding structure (125); and A dielectric element (150) is disposed in the cavity (120), wherein the dielectric element (150) comprises a material having a dielectric constant Dk of 2 or more.

15. Use of a dielectric element (150) having a material with a dielectric constant Dk of 2 or more in a waveguide structure (130), the waveguide structure (130) being at least partially embedded in a component carrier (100).

Images