Component carrier with through-holes filled with additional plated structures and bridge structures

Abstract

A component carrier (100) and a method of manufacturing a component carrier (100) are provided. The component carrier comprises: an electrically insulating layer structure (102) having a first main surface (104) and a second main surface (106); a through hole (108) extending through the electrically insulating layer structure (102) between the first main surface (104) and the second main surface (106) and having a first tapered portion (114) extending from the first main surface (104) and a second tapered portion (116) extending from the second main surface (106); a first plated structure (180) located on at least a portion of a side wall (112) of the electrically insulating layer structure (102), the side wall (112) defining the through hole (108); and a second plated structure (182) formed separately from the first plated structure (180) and arranged on the first plated structure, wherein the second plated structure (182) comprises a conductive bridge structure (110) connecting opposite side walls (112).

Description

Technical Field

[0001] The invention relates to a component carrier and a method for producing a component carrier. Background Art

[0002] Against the background of increasing product functionality of component carriers equipped with one or more electronic components and the increasing miniaturization of such components as well as the increasing number of components to be mounted on component carriers such as printed circuit boards, more powerful array-like components or packages with several components having a plurality of contacts or connections with decreasing spacing between these contacts are increasingly being used. Removing the heat generated by such components and the component carriers themselves during operation is becoming an increasingly prominent problem. At the same time, the component carriers should be mechanically strong and electrically reliable so that they can operate even under harsh conditions. All these requirements are closely related to the continuous miniaturization of component carriers and their construction.

[0003] Furthermore, it may be advantageous to effectively contact conductive layer structures and / or components embedded in the component carrier with suitable quality.The formation of mechanical vias and laser vias that can be filled with copper may be advantageous for this and other purposes. Summary of the invention

[0004] It may be necessary to manufacture the component carrier with suitable electrical reliability.

[0005] According to an exemplary embodiment of the present invention, a component carrier is provided, which includes: an electrically insulating layer structure having a first main surface and a second main surface; a through hole (especially a laser through hole), which extends through the electrically insulating layer structure between the first main surface and the second main surface and has a first tapered portion extending from the first main surface and a second tapered portion extending from the second main surface; a first plating structure, which is located on at least a portion of the side wall of the electrically insulating layer structure, and the side wall defines the through hole; and a second plating structure, which is formed separately from the first plating structure and is arranged on the first plating structure, wherein the second plating structure includes (as an integral part of the second plating structure) a conductive bridge structure connecting the opposite side walls.

[0006] According to another exemplary embodiment of the present invention, a method for manufacturing a component carrier is provided, wherein the method includes: forming a through hole (especially a laser through hole) extending between a first main surface and a second main surface of an electrically insulating layer structure, so that the through hole has a first tapered portion extending from the first main surface and a second tapered portion extending from the second main surface; performing a first plating procedure to thereby form a first plated structure on at least a portion of a side wall of the electrically insulating layer structure, the side wall defining the through hole; and subsequently performing a separate second plating procedure to thereby form a second plated structure on the first plated structure, wherein the second plated structure is formed with a conductive bridge structure connecting the opposite side walls.

[0007] In the context of the present application, the term "component carrier" may specifically denote any support structure capable of accommodating one or more components thereon and / or therein for providing 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. Specifically, 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 component carriers of the above-mentioned types of component carriers.

[0008] In the context of the present application, the term "layer structure" may particularly denote a continuous layer, a patterned layer or a plurality of non-continuous islands in a common plane.

[0009] In the context of the present application, the term "through hole" may particularly denote a hole that extends completely through the entire electrically insulating layer structure and may in particular and preferably be formed by laser processing. Thus, the through hole may be a laser through hole. Such a through hole may have, for example, two opposite tapered portions extending from two opposite main surfaces of the electrically insulating layer structure. The through hole may be manufactured, for example, by a combination of laser irradiation from the front side and the back side of the electrically insulating layer structure, i.e. from two opposite main surfaces. One or more laser irradiations may be performed from each of these sides. The through hole may also be formed by laser processing from only one main surface. In addition, the formation of the through hole may also be performed by other methods than laser processing, for example by plasma treatment.

[0010] In the context of the present application, the term "plating structure" can particularly represent a physical structure formed by plating, i.e., by a surface covering process, wherein metal is deposited on the surface, particularly on a conductive surface. In particular, the plating structure can be formed by electroplating. In electroplating, electrons are supplied to ionic metals to form a non-ionic coating on a conductive surface. The corresponding system can be related to a chemical solution with an ionic form of a metal, can correspond to the anode (i.e., an electrode with negative charge) of the metal to be plated and the cathode (i.e., an electrode with positive charge) provided with electrons to produce a non-ionic metal film on a conductive surface. For the current deposition or electroplating of a metal such as copper, a water-based solution comprising a metal (particularly a dissolved metal salt) to be deposited as an ion can be used. The electric field between the anode and the workpiece as the cathode (such as a preform of a component carrier with a through hole, which has a sidewall to be covered by the plating structure) can force the positively charged metal ions to move to the cathode, where they give up their charge and deposit themselves as metal on the surface of the sidewall of the through hole in the electrical insulating layer structure. In addition to pure metal deposition, electroplating or galvanic deposition processes may also involve the preparation and / or post-treatment of preforms of the component carriers to be coated.

[0011] In the context of the present application, the term "plated structure formed individually" can particularly represent the physically separated and visually distinguishable plating structures formed in different plating processes. As known to those skilled in the art, if independent plating structures are performed one by one, when the cross-sectional view of the inspection component carrier, the interface between these plating structures is visible. Different plating manufacturing equipment can be used, different plating chemistries are utilized and / or different plating structures are manufactured in different time periods.

[0012] In the context of the present application, the term "bridge structure" may particularly denote a conductive structure that extends substantially horizontally between the opposite side walls of the electrically insulating layer structure and that delimits the through-hole in particular at or near the narrowest portion of the through-hole. For example, such a bridge structure may be formed by plating after the through-hole is formed. After such a plating procedure, the previously formed through-hole is only partially filled with the conductive material constituting the bridge structure, so that the bridge structure may be delimited in an upward direction by a first interface surface and at a lower side by a second interface surface. Both the first interface surface and the second interface surface may have a concave shape.

[0013] According to an exemplary embodiment of the present invention, a component carrier is provided, which has a through hole (preferably a laser through hole) that is at least partially filled with a conductive filling medium such as copper. In order to properly fill the through hole, i.e., there are no reliability issues, no crack formation, no light penetration issues, and / or no inclusions or voids in the interior of the filling medium, it has been shown that it is very advantageous to first form a first plating structure on the side walls that define the through hole, and then only form a bridge structure that forms a horizontal connection between the side walls and is deposited on the first plating structure in a separate additional plating procedure. It has been shown that when a double plating procedure is performed for filling the through hole with a sidewall cover layer and forming a horizontal bridge structure, the quality of the copper-filled laser via can be significantly improved. Therefore, the yield can be increased and the electrical, mechanical and thermal reliability of the component carrier can be enhanced.

[0014] In the following, further exemplary embodiments of the component carrier and of the method will be explained.

[0015] In one embodiment, the first plated structure is a plated layer covering the sidewall with a substantially uniform thickness. Although it is not always possible to ensure an absolutely identical thickness of the first plated structure on different portions of the sidewall delimiting the laser via, the deviation between the thickest and thinnest areas of the first plated structure may be less than 30%, preferably less than 15%. With such a substantially uniform coating of the sidewalls (which delimit the laser via with respect to the electrically insulating layer structure) formed with conductive material before the bridge is formed, the reliability of the component carrier obtained can be significantly improved.

[0016] It should be said that the first plating structure can be applied directly on the dielectric material of the electrically insulating layer structure defining the sidewalls. However, it is also possible and sometimes even preferred that the first plating structure is formed on a very thin seed layer (which can be formed by electroless deposition), which can first be formed on the dielectric sidewalls of the electrically insulating layer structure to appropriately prepare for the subsequent formation of the first plating structure (in particular by electroplating or galvanic plating). In the latter mentioned embodiment, the first plating structure on the sidewall is spaced apart relative to the sidewall by the thin seed layer.

[0017] In one embodiment, the minimum horizontal thickness of the first plated structure is in the range between 3 μm and 30 μm, in particular in the range between 5 μm and 15 μm. For example, the first plated structure with such a minimum thickness (i.e., the thickness at the thinnest part of the first plated structure in the entire laser via) may fill 10% to 50% of the entire width of the laser via. Such a relatively thick first plated structure has been shown to have a very positive impact on the reliability of the laser via filled with conductive material.

[0018] In one embodiment, the minimum vertical thickness of the bridge structure is in the range between 10 μm and 60 μm, in particular between 20 μm and 40 μm. In addition, it has been shown that the reliability of the laser via filled with the conductive filling medium can be significantly improved when the thickness of the bridge structure in the vertical direction becomes not too small. The most preferred thickness is at least 20 μm. However, when the thickness of the bridge structure becomes too large, this may have an undesirable effect on the shape of the pits or recesses above and below the bridge structure in the laser via, so that the upper limit of 60 μm of the minimum thickness of the bridge structure (i.e. the thickness of the narrowest part of the bridge structure) should not be exceeded.

[0019] In one embodiment, outside or in addition to the bridge structure, the minimum horizontal thickness of the second plated structure may be in the range of 2 μm to 20 μm, in particular in the range of 4 μm to 10 μm. In particular, the minimum horizontal thickness of the second plated structure at the portion of the sidewall of the electrically insulating layer structure covering the second plated structure in addition to the bridge structure may be less than the minimum thickness of the first plated layer. However, the minimum horizontal thickness of the second plated structure may be greater than the thickness of the optional seed layer.

[0020] In one embodiment, in a cross-sectional view according to a viewing plane including the main extension direction of the laser via, the first plated structure is formed as two angled legs. The term "viewing plane including the main extension direction of the laser via" may correspond to Figure 7 plane of the paper. Thus, the cross-sectional view mentioned corresponds to an observation plane including the central axis of the through hole and a further axis perpendicular to the central axis of the through hole. In this observation plane, the first plated structure appears as two connected straight legs with a (particularly obtuse) angle between them. In other words, the first plated structure can follow the shape of the side walls defining the laser through hole and be defined by two tapered portions on opposite main surfaces of the electrically insulating layer structure.

[0021] In one embodiment, in a cross-sectional view according to a viewing plane including the main extension direction of the laser via (see Figure 7 ), the second plated structure is substantially H-shaped. When a second separate plating procedure is performed after forming the first plating procedure, this results in the formation of a substantially horizontal bridge structure, but also results in the use of additional conductive material of the second plated structure to cover the exposed sidewalls of the first plated structure. As a result, the second plating procedure can result in the formation of a substantially H-shaped conductive structure on the first plated structure.

[0022] In one embodiment, the thickness of the electrical insulating layer structure is not more than 100 μm, particularly in the range between 40 μm and 60 μm. As described above, the double plating architecture according to an exemplary embodiment of the present invention significantly improves the reliability of laser vias filled with a conductive filling medium such as copper. It should also be mentioned that the thinner the electrical insulating layer structure (particularly the fully cured core) becomes, the more serious this reliability problem becomes. If the thickness of the electrical insulating layer structure is less than 100 μm and particularly in the range between 40 μm and 60 μm, the electrical reliability problem caused by cracks, gaps or delamination tendencies becomes particularly significant. Using the double plating architecture according to an exemplary embodiment of the present invention, this reliability problem can be overcome or at least significantly reduced.

[0023] In one embodiment, the conductive bridge structure is defined by a first boundary surface, in particular a concave first boundary surface, facing the first main surface and a second boundary surface, in particular a concave second boundary surface, facing the second main surface. In many cases, the central part of the bridge structure has the smallest thickness in the vertical direction. In the region of the minimum thickness, the two boundary surfaces have the smallest mutual distance.

[0024] In one embodiment, the component carrier comprises a first conductive bulk structure, which fills at least a portion between the first interface surface and the first main surface. Thus, an additional conductive filling medium can be filled into the recess or pit above the first interface surface. This can further improve the electrical reliability of the component carrier.

[0025] In one embodiment, the component carrier includes a second conductive bulk structure that fills at least a portion between the second interface surface and the second main surface. Accordingly, the pit or recess below the second interface surface may also be partially or completely filled with a conductive filling medium such as copper. This filling procedure also further improves the electrical reliability of the component carrier.

[0026] In one embodiment, at least one of the first conductive mass structure and the second conductive mass structure is an additional plated structure, i.e., formed by an additional additional separate plating procedure. The filling degree of the pits above the corresponding interface surface of the bridge structure and / or the pits below the corresponding interface surface of the bridge structure can be defined by designing additional plating procedures and by adjusting the number of additional plating procedures, which are performed after completing the formation of the second plated structure that integrally includes the bridge structure. As known to those skilled in the art, a cross-sectional view of the component carrier will allow visually distinguishing the various additional plated structures that constitute the first or second conductive mass structure.

[0027] In one embodiment, the component carrier comprises a (e.g. patterned) first conductive layer structure (in particular a first metal foil having a first window aligned with a first tapered portion of a through hole through the electrically insulating layer structure) on a first main surface and / or a (e.g. patterned) second conductive layer structure (in particular a second metal foil having a second window aligned with a second tapered portion of a through hole through the electrically insulating layer structure) on a second main surface. Thus, a respective conductive layer can be attached to each of the two opposite main surfaces of the electrically insulating layer structure. Preferably, the conductive layer structure can be a copper foil. By performing a first laser irradiation from the first main surface of the electrically insulating layer structure, a first window can be formed in the first conductive layer structure. Accordingly, a second window can be formed in the second conductive layer structure by performing a second laser irradiation from the second main surface of the electrically insulating layer structure.

[0028] In another embodiment, the method comprises: forming a through hole in the electrically insulating layer structure when one or both main surfaces of the electrically insulating layer structure are not covered by the conductive layer structure. In such an embodiment (where the conductive layer structure on one or both of the opposite main surfaces of the electrically insulating layer structure may be unnecessary), the through hole may be drilled directly through the electrically insulating layer structure.

[0029] In one embodiment, at least a portion of the laser via is substantially X-shaped. Accordingly, forming the laser via may include performing a first laser drilling from the first main surface using one laser shot and performing a second laser drilling from the second main surface using only one laser shot. Figure 2 As shown in , forming a laser via having a substantially X-shape can be performed by a combination of a first laser irradiation from the front side or first main surface of the electrically insulating layer structure, followed by a single second laser irradiation from the back side or second main surface of the electrically insulating layer structure. Such a procedure for manufacturing a laser via is very simple and fast.

[0030] In one embodiment, the laser via includes a central connecting portion connecting the first tapered portion and the second tapered portion, and wherein the bridge structure is at least partially located in the central connecting portion. Accordingly, forming the laser via may include performing a first laser drilling from the first main surface using one laser shot and performing a second laser drilling from the second main surface using two laser shots. Figure 3 As shown in , such a structure can be obtained by first performing a single laser irradiation from the front side or first main surface of the electrically insulating layer structure, followed by two subsequent laser irradiations from the back side or second main surface of the electrically insulating layer structure. By performing such a procedure for manufacturing laser vias, reliability can be further improved by preventing too narrow a central portion of the laser via.

[0031] In one embodiment, the electrically insulating layer structure is a core, in particular a fully cured core. Therefore, when the laser via is formed, the material of the electrically insulating layer structure may have been fully cured. This means that the material of the electrically insulating layer structure may not be further cross-linked in a subsequent lamination process, during which additional layer structures may be laminated to the front side and / or back side of the stack through which the laser via is formed. For example, the core may include a resin such as an epoxy resin and reinforcing particles such as glass fibers or glass balls. In particular, the core may be made of FR4 material.

[0032] In one embodiment, the component carrier includes a seed layer, which is directly located on at least a portion of the sidewall so as to be arranged or sandwiched between the electrical insulation layer structure and the first plating structure. Accordingly, the formation of the first plating structure can be performed after the seed layer is formed directly on the sidewall. Electroplating (for forming the first plating structure) can be promoted by a conductive surface, and the conductive material of the first plating structure is deposited on the conductive surface. In order to utilize the dielectric sidewall of the electrical insulation layer structure to be covered by a thin metal film on which the first plating structure can be formed by electroplating, it is advantageous to form a chemical copper seed layer with a small thickness. The seed layer may have a thickness higher than 1 μm and / or provide several cumulative seed layers. For example, the thickness of the seed layer or the cumulative thickness of multiple seed layers can be in the range between 0.5 μm and 5 μm. If multiple seed layers are provided, they may include an organic (e.g., polymer) layer, a palladium layer, and / or a copper layer. The formation of such a seed layer can be performed by a chemical reaction to obtain a conductive surface preferably comprising copper. After formation of this seed layer, a first plated structure can then be formed by galvanic plating, by which a significantly thicker layer (e.g., copper with a thickness of, for example, 15 μm) can be plated in the laser vias and on the chemical copper surface by applying an electric current to the component carrier to be manufactured.

[0033] In one embodiment, the component carrier comprises a patterned first conductive layer structure on a first main surface and / or a patterned second conductive layer structure on a second main surface. For example, a metal layer such as a copper foil can be formed on two opposite main surfaces of the electrically insulating layer structure. Each conductive layer structure can have windows aligned with the laser vias, wherein laser irradiation from its front and back sides can form these windows in a previous continuous metal layer to form the patterned conductive layer structure.

[0034] In one embodiment, the component carrier comprises a stack of 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 one or more electrically insulating layer structures and the one or more electrically conductive layer structures, in particular formed by applying mechanical pressure and / or thermal energy. Such a stack can provide a plate-shaped component carrier that can provide a large mounting surface for additional components but is still very thin and compact.

[0035] In one embodiment, the component carrier is formed in the form of a plate. This contributes to a compact design, but wherein the component carrier provides a large base for mounting components thereon. Furthermore, due to the small thickness of the bare wafer, the bare wafer, in particular as an example of an embedded electronic component, can be conveniently embedded in a thin board such as a printed circuit board.

[0036] In an embodiment, the component carrier is configured as one of the group consisting of a printed circuit board and a substrate, in particular an IC substrate.

[0037] In the context of the present application, the term "printed circuit board" (PCB) may specifically refer to a plate-shaped component carrier (which may be plate-shaped (i.e., flat), three-dimensionally curved (e.g., when manufactured using 3D printing) or it may have any other shape) formed by laminating several conductive layer structures with several electrically insulating layer structures, the above-mentioned forming process being formed, for example, by applying pressure and / or by the supply of thermal energy. As a preferred material for PCB technology, the conductive layer structure is made of copper, while the electrically insulating layer structure may include resin and / or glass fiber, so-called prepreg such as FR4 material. The various conductive layer structures can be connected to each other in a desired manner by forming through holes through the laminate (e.g., by laser drilling or mechanical drilling) and by filling these through holes with conductive material (in particular copper) to form vias as through-hole connections. 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 or two opposite surfaces of the plate-shaped printed circuit board. These components can be connected to the corresponding main surfaces by welding. The dielectric part of the PCB can be composed of a resin with reinforcing fibers (e.g., glass fibers).

[0038] In the context of the present application, the term "substrate" can specifically refer to a small component carrier having substantially the same size as the component (particularly electronic component) to be mounted thereon. More specifically, a substrate can be understood as a carrier for electrical connection or electrical network and a component carrier comparable to a printed circuit board (PCB), but with significantly higher density of horizontal and / or vertically arranged connectors. The horizontal connectors are, for example, conductive paths, and the vertical connectors can be, for example, drill holes. These horizontal and / or vertical connectors are arranged in the substrate and can be used to provide electrical and / or mechanical connections between the accommodated components or unaccommodated components (e.g., bare wafers) of, in particular, IC chips and a printed circuit board or an intermediate printed circuit board. Thus, the term "substrate" also includes an "IC substrate". The dielectric portion of the substrate can be composed of a resin with reinforcing particles (such as glass particles, particularly glass balls).

[0039] In one embodiment, at least one electrically insulating layer structure comprises at least one of the group consisting of: resins (such as reinforced or non-reinforced resins, for example epoxy resins or bismaleimide-triazine resins), cyanate esters, polyphenylene derivatives, glass (particularly glass fibers, multilayer glass, glass-like materials), prepreg materials (such as FR-4 or FR-5), polyimides, polyamides, liquid crystal polymers (LCP), epoxy-based laminates, polytetrafluoroethylene (Teflon), ceramics, and metal oxides. Reinforcement materials such as meshes, fibers or spheres made of glass (multilayer glass) may also be used. Although prepregs, especially FR4, are generally preferred for rigid PCBs, other materials may also be used, especially epoxy-based laminates for substrates. For high-frequency applications, high-frequency materials such as polytetrafluoroethylene, liquid crystal polymers and / or cyanate ester resins, low temperature co-fired ceramics (LTCC) or other low, very low or ultra-low DK materials may be implemented as electrically insulating layer structures in component carriers.

[0040] In one embodiment, at least one of the conductive layer structures comprises at least one of the group consisting of copper, aluminum, nickel, silver, gold, palladium and tungsten. Although copper is generally preferred, other materials or their coated forms are also possible, in particular the above materials coated with superconducting materials such as graphene.

[0041] In one embodiment, at least one component may be surface mounted on and / or embedded in a component carrier. The at least one component may be selected from the group consisting of: a non-conductive inlay, a conductive inlay (such as a metal inlay, preferably comprising copper or aluminum), a heat transfer unit (such as a heat pipe), a light-conducting element (such as an optical waveguide or optical conductor connector, an electronic component, or a combination thereof). For example, the component may be an active electronic component, a passive electronic component, an electronic chip, a storage device (such as a DRAM or another data storage device), a filter, an integrated circuit, a signal processing component, a power management component, an optoelectronic interface element, a light emitting diode, an optical coupler, a voltage converter (such as a DC / DC converter or an AC / DC converter), an encryption component, a transmitter and / or a receiver, an electromechanical transducer, a sensor, an actuator, a microelectromechanical system (MEMS), a microprocessor, a capacitor, a resistor, an inductor, a battery, a switch, a camera, an antenna, a logic chip, and an energy harvesting unit. However, other components may be embedded in the component carrier. For example, a magnetic element may be used as the component. Such a magnetic element may be a permanent magnetic element (such as a ferromagnetic element, an antiferromagnetic element, a multiferroic element or a ferrimagnetic element, for example a ferrite core), or may be a paramagnetic element. However, the component may also be a substrate, an insert or another component carrier, for example in a board-in-board configuration.

[0042] In one embodiment, the component carrier is a laminated component carrier. In such an embodiment, the component carrier is a composite of multilayer structures that are stacked and connected together by applying pressure and / or heat.

[0043] The substrate or interposer may be composed of at least one layer of glass, silicon (Si), or a photoimageable or dry-etchable organic material (such as an epoxy-based build-up material) or a polymer composite (such as polyimide, polybenzoxazole, or benzocyclobutene).

[0044] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figures 1 to 7 A method of fabricating a laser via by performing multiple laser irradiation processes from opposite sides and then at least partially filling the laser via with a conductive filling medium according to an exemplary embodiment of the present invention is shown. Figure 7 4. A cross-sectional view of a structure obtained during the method for producing a component carrier with a laser through-hole is shown in FIG.

[0046] Figure 2A A cross-sectional view of a preform of a component carrier according to another exemplary embodiment is shown, which is similar to Figure 2 This embodiment is related, but differs in that no electrically conductive layer structure is provided on the opposite main surface of the electrically insulating layer structure when the through hole is formed. DETAILED DESCRIPTION

[0047] The illustrations in the drawings are schematic. In different drawings, similar or identical elements are provided with the same reference numerals.

[0048] Before describing the exemplary embodiments in further detail with reference to the accompanying drawings, some basic considerations upon which the exemplary embodiments of the present invention were developed will be outlined.

[0049] According to an exemplary embodiment of the present invention, a two-layer bridge plating procedure can be performed to ensure a complete and reliable bridge in the narrowest area of ​​the laser via. At the same time, high or even maximum capacity can be ensured using this manufacturing procedure.

[0050] When forming laser vias with very thin electrically insulating layer structures, such as cores with a thickness of no more than 60 μm or even no more than 50 μm, it is crucial to fill the laser vias with a conductive filling medium, such as copper. Reliable filling with such a conductive filling medium can be problematic, especially in the region of the narrowest portion of the laser via, since it is difficult to form a bridge connecting the opposing side walls in such a narrowest region. At the same time, a large number of laser vias, such as more than 100,000 laser vias per panel, must be formed in component carrier technology.

[0051] Surprisingly, it has been shown that two-layer plating is particularly advantageous for reliably filling laser vias without forming voids or cracks in the conductive filling medium. In particular, reliable formation of a substantially horizontal bridge structure can be effectively promoted by two-layer plating. This allows ensuring good bridge formation and sufficient capacity. Thus, exemplary embodiments of the present invention can provide a simple laser via bridging process.

[0052] Figures 1 to 7 Shows the execution of manufacturing Figure 7 100 is a cross-sectional view of the structure obtained during the method of the component carrier 100 shown in FIG. The manufacturing process involves forming a laser through hole 108 (compare Figures 1 to 4 ). Subsequently, by performing a plurality of plating procedures according to an exemplary embodiment of the present invention, such laser vias 108 may be partially or completely filled with a conductive filling medium such as copper (compare Figures 5 to 7 ).

[0053] like Figure 1 The starting point of the production method is a stack 159 which comprises a first electrically conductive layer structure 152 on a first main surface 104 of the electrically insulating layer structure 102. The stack 159 also comprises a second electrically conductive layer structure 154 on a second main surface 106 of the electrically insulating layer structure 102.

[0054] To obtain Figure 1 1 , the front side or first main surface 104 of the electrically insulating layer structure 102 covered with the first conductive layer structure 152 can be the object of a first laser treatment. For this purpose, a first laser irradiation 111 can be performed to form a through hole or window in the first conductive layer structure 152 and a blind hole 113 in the electrically insulating layer structure 102. The blind hole 113 is bounded by the side wall 112 and the bottom wall 161 of the electrically insulating layer structure 102.

[0055] It should be noted that the laser energy and duration during the first irradiation 111 are not excessive so that the blind hole 113 does not extend all the way to the second conductive layer structure 154. Otherwise, undesirable effects such as reflection of the laser light may occur. Descriptively speaking, the blind hole 113 may be formed later. Figure 2 or Figure 3 The first tapered portion 114 of the laser via 108 is shown in FIG.

[0056] refer to Figure 2 , according to Figure 1 After the first laser drilling is performed from the first main surface 104 using one laser irradiation, the formation of the laser via 108 can be completed by performing a second laser drilling from the second main surface 106 using one laser irradiation. As a result of this backside laser drilling, a through hole or window is formed in the second conductive layer structure 154, and the blind hole 113 is extended until it forms a laser via 108 extending between the first main surface 104 and the second main surface 106 of the electrically insulating layer structure 102. Figure 2 As shown in FIG. 1 , the laser via 108 has a first tapered portion 114 extending from the first major surface 104 and has a second tapered portion 116 extending from the second major surface 106. The first tapered portion 114 and the second tapered portion 116 meet each other at the narrowest portion in the center of the laser via 108.

[0057] To obtain Figure 2 The structure shown in the reference Figure 1 The structure obtained after the described procedure can be subjected to a second laser irradiation 115 from the rear side or second main surface 106 of the electrically insulating layer structure 102. As a result, a through hole is formed through the second electrically conductive layer structure 154 and additional material of the electrically insulating layer structure 102 is removed by the laser energy until the previously formed blind hole 113 extends from the bottom side into the laser through hole 108. Figure 2 This laser via 108 has a substantially X-shaped shape and can be directly subsequently subjected to a filling procedure with a conductive filling medium such as copper (see Figures 4 to 7 ).according to Figure 2 The formation of the laser through-hole 108 is efficient and thus particularly suitable for industrial-scale processing, since it is sufficient to form it using only two laser shots.

[0058] Alternatively, an additional laser drilling process may be performed from the back side before filling the laser via 108 with a conductive filling medium such as copper. Figure 3 The latter mentioned embodiments are described.

[0059] refer to Figure 3 , according to Figure 1After performing the first laser drilling from the first main surface 104 using a single laser irradiation and according to Figure 2 After the second laser drilling is performed from the second main surface 106 , the shape of the laser via hole 108 , particularly the shape of the central portion thereof, is modified by performing a third laser irradiation from the rear side of the laser via hole 108 .

[0060] Therefore, as a reference Figure 2 As an alternative to the procedure described above, an additional third laser irradiation 117 may also be performed from the back side or second main surface 106 of the electrically insulating layer structure 102 to improve the shape of the laser via 108. Such a third laser irradiation 117 may remove material in the central portion of the electrically insulating layer structure 102 so as to form a substantially cylindrical central portion 134 sandwiched between the two tapered portions 114, 116. Figure 3 The manufacturing process of the laser via 108 of the shape of Figure 2 Although an additional third laser irradiation 117 is required, this shape can further improve the reliability of the manufactured component carrier 100 .

[0061] The laser via filling procedure according to an exemplary embodiment of the present invention will be referred to below. Figures 4 to 7 is described, and based on Figure 2 The geometry of the laser through hole 108 of the type shown in FIG. A person skilled in the art will appreciate that according to another exemplary embodiment of the present invention, it is also possible to Figure 3 The geometry shown in FIG. 1 is used to initiate the filling of the laser via 108 .

[0062] like Figure 4 As shown in , depending on the parameters of the first and second laser shots 111 , 115 , the narrowest portion of the laser via 108 having a horizontal width w may be displaced in the vertical direction. Figure 4 , the position of the minimum width w is lower than the vertical center position of the electrical insulation layer structure 102. Figure 4 As shown in FIG. 1 , the main extension direction 184 of the laser via 108 is vertical.

[0063] refer to Figure 5 , first a thin seed layer (seed layer, seed layer) 144 (especially made of copper) is directly formed on the dielectric sidewall 112 of the electrically insulating layer structure 102, for example by electroless deposition. Subsequently, a first electroplating procedure can be performed to thereby form a first plating structure 180 on the seed layer 144 on the sidewall 112 of the electrically insulating layer structure 102. Therefore, the first plating structure 180 (which can also be expressed as a first electroplating structure) is formed on the seed layer 144 and can also be made of copper. For example, the first electroplating procedure can be a current plating procedure.

[0064] Descriptively, the electroless deposition process is performed to form a seed layer 144 of chemical copper. Figure 5 The structure shown in FIG. The thickness b of the seed layer 144 may be, for example, 0.5 μm. The chemical copper of the seed layer 144 may be formed by chemical reaction to obtain a conductive surface on the sidewall 112 for facilitating the subsequent formation of the first plating structure 180. Optionally, a procedure for forming the seed layer 144 may be performed after a previous decontamination procedure, during which the laser via 108 may be cleaned and its resin may be expanded to obtain an improved surface roughness. Such a procedure may further improve the reliability of the manufactured copper-filled laser via.

[0065] After forming the seed layer 144, the first current plating or electroplating procedure mentioned above may be performed for forming the first plated structure 180. For this purpose, a current may be applied to the conductive seed layer 144. During this current plating procedure, Figure 5 The preform of the component carrier shown in FIG. 1 can be immersed in a bath with a copper source. Due to the current applied between the cathode and the anode, metallic copper will be deposited on the seed layer 144, thereby forming a first plated structure 180.

[0066] The first plating structure 180 is implemented as a plating layer covering the seed layer 144 on the sidewall 112 with a substantially uniform thickness I (see Figure 5 ). The minimum value of the horizontal thickness I of the first plating structure 180 may be 10 μm. Figure 5 In the cross-sectional view of , ie according to a viewing plane including the main extension direction 184 of the laser via 108 , the first coating structure 180 is formed as two angled legs on the left-hand side and the right-hand side, wherein the angle α between the legs is obtuse here.

[0067] refer to Figure 6, a separate second plating procedure may then be performed (i.e., after the first electroplating procedure for forming the first plating structure 180), thereby forming a second plating structure 182 (which may also be represented as a second electroplating structure) on the first plating structure 180. As shown, a second plating structure 182 is formed, which includes a conductive bridge structure 110 connecting opposite side walls 112. In other words, the bridge structure 110 forms an integral part of the second plating structure 182 together with the inclined legs of the second plating structure 182 that are integrally connected to the bridge structure 110. The inclined legs of the second plating structure 182 are formed on the inclined legs of the first plating structure 180. More specifically, the second plating structure 182 is substantially H-shaped and covers the lateral sidewalls of the first plating structure 180 and forms a substantially horizontal bridge structure 110. The minimum thickness D of the bridge structure 110 may be 25 μm. The minimum horizontal thickness s of the vertical or inclined legs of the second plating structure 182 may be 8 μm. Figure 6 In the cross-sectional view of , the second plated structure 182 is substantially H-shaped.

[0068] Therefore, in obtaining Figure 5 After the structure shown in , a separate additional plating procedure of the same or different kind, such as current plating, can be performed. By taking such measures, a second plated structure 182 is obtained, for example, by current deposition or electroplating. It has been shown that adding a separate procedure for forming the first plated structure 180 before forming the second plated structure 182 including the bridge structure 110 can improve the reliability of the component carrier 100 obtained.

[0069] Still reference Figure 6 When performing a plating process, the geometry of the through hole 108 may cause the formation of a bridge structure 110 that laterally connects opposite side walls 112 of the electrically insulating layer structure 102 that delimit the through hole 108 at a vertical level, where the distance to the first main surface 104 is different from the distance to the second main surface 106. This may promote the formation of a free-hanging, asymmetric bridge structure 110 that is located outside the vertical center of the through hole 108.

[0070] refer to Figure 7 The method includes forming a first conductive block structure 148 filling the recess above the bridge structure 110. In addition, the method includes forming a second conductive block structure 150 filling the recess below the bridge structure 110. After the second electroplating process of forming the bridge structure 110, the first conductive block structure 148 and the second conductive block structure 150 can be formed by another electroplating process (in particular, another current plating process). Figure 6 and Figure 7As shown in FIG. 1 , the conductive bridge structure 110 is formed to be defined by an upper first interfacing surface 183 oriented upward or toward the first major surface 104 and a lower second interfacing surface 185 oriented downward or toward the second major surface 106 .

[0071] In the illustrated embodiment, the small depressions 190, 192 remain respectively on the upper or lower side of the illustrated component carrier 100. In other embodiments, the block structures 148, 150 almost completely fill the remaining depressions above the first interface surface 183 and below the second interface surface 185. It should be noted that it is well known to those skilled in the art that when imaging a cross section of the component carrier 100, the interface surfaces 183, 185 are clearly visible.

[0072] As a result of the described production method, the illustrated component carrier 100 according to the exemplary embodiment of the invention is obtained. The vertical thickness d of the electrically insulating layer structure 102 may be 60 μm.

[0073] The remaining recesses above the first boundary surface 183 and below the second boundary surface 185 can be partially or completely filled with a further single or multiple plating process, for example by carrying out a further galvanic plating process / electrodeposition process. Figure 7 A partial filling is shown, by which small depressions 190, 192 appear in the laser via 108, which remain unfilled with the conductive filling medium. As can be seen in detail 194, the conductive mass structure 150 can consist of individual plated layers 195, 196, 197, which can be produced in a separate process. In a corresponding manner, detail 193 shows that the conductive mass structure 148 can also consist of a plurality of individual plated layers 198, 199, 200 formed in a subsequent plating process.

[0074] Figure 2A A cross-sectional view of a preform of a component carrier 100 according to another exemplary embodiment is shown, which is similar to Figure 2 This embodiment is related, but differs in that, when forming the through-hole 108 , no electrically conductive layer structures 152 , 154 are arranged on the opposite main surfaces 104 , 106 of the electrically insulating layer structure 102 .

[0075] Figures 1 to 7 Implementation plan and Figure 2A The main difference between the implementations of Figure 2A , when forming the through hole 108, the main surfaces 104, 106 of the electrically insulating layer structure 102 are not covered by the conductive layer structures 152, 154. Figure 2AThe manufacturing method of an embodiment of the invention comprises forming a through hole 108 in the electrically insulating layer structure 102 while the main surfaces 104 , 106 of the electrically insulating layer structure 102 are not covered by an electrically conductive layer structure 152 , 154 , such as a copper foil.

[0076] With regard to the subsequent filling of the through hole 108 and covering the major surfaces 104, 106 with the conductive filling medium, this can be performed by forming an optional seed layer 144, then forming a first plated structure 180 covering the major surfaces 104, 106 and at least a portion of the sidewalls 112 of the through hole 108, then forming a second plated structure 182 covering the first plated structure 180, and forming a bridge structure 110 bridging the opposing sidewalls 112 and having, for example, a substantially H-shape with the second plated structure 182. It is also possible to optionally fill one or both volumes above and / or below the bridge structure 110 by one or more block structures 148, 150 (which may be further plated structures or a series of plated structures). Reference Figures 5 to 7 The corresponding description.

[0077] Apart from this distinction, Figures 1 to 7 The above disclosure also applies to Figure 2A Moreover, according to Figure 3 The through-hole formation may also be performed on the electrically insulating layer structure 102 without a copper foil.

[0078] It should be noted that the term "comprising" does not exclude other elements or steps and "a" or "an" does not exclude a plurality. Also, elements described in connection with different embodiments may be combined.

[0079] It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

[0080] The implementation of the invention is not limited to the preferred embodiments shown in the drawings and described above. Instead, various modifications using the solutions shown and according to the principle of the invention are possible, even in fundamentally different embodiments.

Claims

1. A component carrier (100), wherein: The component carrier (100) comprises: An electrically insulating layer structure (102) having a first main surface (104) and a second main surface (106); a through hole (108) extending through the electrically insulating layer structure (102) between the first major surface (104) and the second major surface (106) and having a first tapered portion (114) extending from the first major surface (104) and a second tapered portion (116) extending from the second major surface (106); a first plated structure (180) located on at least a portion of a sidewall (112) of the electrically insulating layer structure (102), the sidewall (112) defining the through hole (108); a second plated structure (182) formed separately from the first plated structure (180) and arranged on the first plated structure, wherein the second plated structure (182) and the first plated structure (180) are two physically separated and visually distinguishable plated structures formed in different plating procedures in a double plating procedure, and wherein the second plated structure (182) includes a conductive bridge structure (110) connecting opposite side walls (112) and extending horizontally, so that in a cross-sectional view according to a viewing plane including a main extension direction (184) of the through hole (108), the second plated structure (182) is H-shaped; wherein the conductive bridge structure (110) forms an integral part of the second plated structure (182); wherein the minimum vertical thickness (D) of the conductive bridge structure (110) of the second plating structure (182) is in the range of 10 μm to 60 μm; A seed layer (144) is directly located on at least a portion of the sidewall (112), the seed layer being arranged between the electrically insulating layer structure (102) and the first plated structure (180).

2. The component carrier (100) according to claim 1, wherein: The first plating structure (180) is a plating layer covering the side wall (112) with a uniform thickness (I).

3. The component carrier (100) according to claim 1 or 2, wherein: The minimum horizontal thickness of the first plated structure (180) is in the range of 3 μm to 30 μm.

4. The component carrier (100) according to claim 1 or 2, wherein: The minimum horizontal thickness of the first plated structure (180) is in the range of 5 μm to 15 μm.

5. The component carrier (100) according to claim 1 or 2, wherein: The minimum horizontal thickness of the second plated structure (182) excluding the conductive bridge structure (110) is in the range of 2 μm to 20 μm.

6. The component carrier (100) according to claim 1 or 2, wherein: The minimum horizontal thickness of the second plated structure (182) excluding the conductive bridge structure (110) is in the range of 4 μm to 10 μm.

7. The component carrier (100) according to claim 1 or 2, wherein: In a cross-sectional view according to a viewing plane including a main extension direction (184) of the through hole (108), the first plated structure (180) is shaped as two angled legs.

8. The component carrier (100) according to claim 1 or 2, wherein: The vertical thickness (d) of the electrical insulation layer structure (102) is not greater than 100 μm.

9. The component carrier (100) according to claim 1 or 2, wherein: The vertical thickness (d) of the electrically insulating layer structure (102) is in the range of 40 μm to 60 μm.

10. The component carrier (100) according to claim 1 or 2, wherein: The conductive bridge structure (110) is defined by a first interface surface (183) facing the first main surface (104) and a second interface surface (185) facing the second main surface (106).

11. The component carrier (100) according to claim 10, wherein: The first boundary surface (183) is concave.

12. The component carrier (100) according to claim 10, wherein: The second boundary surface (185) is concave.

13. The component carrier (100) according to claim 10 comprises a first conductive block structure (148) and / or comprises a second conductive block structure (150), wherein the first conductive block structure fills at least a portion of the volume above the first boundary surface (183), and the second conductive block structure fills at least a portion of the volume below the second boundary surface (185).

14. The component carrier (100) according to claim 13, wherein: At least one of the first conductive bulk structure (148) and the second conductive bulk structure (150) is an additional plated structure.

15. The component carrier (100) according to claim 13, wherein: At least one of the first conductive bulk structure (148) and the second conductive bulk structure (150) is an additional plated structure consisting of one or more additional plated layers.

16. The component carrier (100) according to claim 1 or 2, wherein: The conductive bridge structure (110) is at least partially located in the narrowest portion of the through hole (108).

17. The component carrier (100) according to claim 1 or 2, wherein: The electrically insulating layer structure (102) is a core.

18. The component carrier (100) according to claim 17, wherein: The core is a fully cured core.

19. The component carrier (100) according to claim 1 or 2, comprising a patterned first electrically conductive layer structure (152) on the first main surface (104) and / or a patterned second electrically conductive layer structure (154) on the second main surface (106).

20. The component carrier (100) according to claim 1 or 2, wherein: At least a portion of the through hole (108) is X-shaped.

21. The component carrier (100) according to claim 1 or 2, wherein: At least a portion of the through hole (108) has a central cylindrical portion (134) between two opposing tapered portions.

22. The component carrier (100) according to claim 1 or 2, comprising at least one of the following features: The component carrier (100) comprises at least one component embedded in the component carrier (100), wherein: The at least one component is selected from the group consisting of: an active electronic component, a passive electronic component and a further component carrier; wherein at least one conductive layer structure of the component carrier (100) comprises at least one of the group consisting of: copper, aluminum, nickel, silver, gold, palladium and tungsten; Wherein, the electrical insulating layer structure (102) comprises at least one of the group consisting of: resin; polyphenylene derivative; glass; prepreg material; ceramic; and metal oxide; wherein the component carrier (100) is formed as a plate; Therein, the component carrier (100) is configured as a laminated component carrier (100).

23. The component carrier (100) according to claim 22, wherein: The resin is epoxy resin, bismaleimide-triazine resin, cyanate, polyimide, polyamide, liquid crystal polymer, epoxy-based laminated material or polytetrafluoroethylene.

24. The component carrier (100) according to claim 22, wherein: The prepreg material is FR-4 or FR-5.

25. The component carrier (100) according to claim 22, wherein: The component carrier (100) is configured as one of a printed circuit board and a substrate.

26. The component carrier (100) according to claim 1, wherein The through hole (108) is a laser through hole.

27. A method of manufacturing a component carrier (100), wherein: The method comprises: forming a through hole (108) extending between a first major surface (104) and a second major surface (106) of the electrically insulating layer structure (102), such that the through hole (108) has a first tapered portion (114) extending from the first major surface (104) and a second tapered portion (116) extending from the second major surface (106); performing a first plating process to thereby form a first plated structure (180) on at least a portion of a sidewall (112) of the electrically insulating layer structure (102), the sidewall (112) defining the through hole (108); Subsequently performing a separate second plating procedure to thereby form a second plated structure (182) on the first plated structure (180), wherein the second plated structure (182) and the first plated structure (180) are two physically separated and visually distinguishable plated structures formed in different plating procedures of the dual plating procedure, and wherein the second plated structure (182) is formed with a conductive bridge structure (110) connecting the opposite side walls (112) and extending horizontally, so that in a cross-sectional view according to a viewing plane including a main extension direction (184) of the through hole (108), the second plated structure (182) is H-shaped; wherein the conductive bridge structure (110) forms an integral part of the second plated structure (182); wherein the minimum vertical thickness (D) of the conductive bridge structure (110) of the second plating structure (182) is in the range of 10 μm to 60 μm; Wherein, forming the first plating structure (180) is performed after forming a seed layer (144) directly on the side wall (112).

28. The method according to claim 27, wherein: Forming the through hole (108) includes performing a first laser drilling from the first main surface (104) using one laser shot and performing a second laser drilling from the second main surface (106) using only one additional laser shot.

29. The method according to claim 27, wherein: Forming the through hole (108) includes performing a first laser drilling from the first main surface (104) using one laser shot and performing a second laser drilling from the second main surface (106) using two additional laser shots.

30. The method of claim 27, wherein: The method includes forming the seed layer (144) by electroless deposition.

31. The method according to any one of claims 27 to 30, wherein: The method includes forming a first conductive block structure (148) and / or a second conductive block structure (150), wherein the first conductive block structure fills at least a portion of a recess between the conductive bridge structure (110) and the first main surface (104), and the second conductive block structure fills at least a portion of a recess between the conductive bridge structure (110) and the second main surface (106).

32. The method according to claim 31, wherein: The method includes forming at least one of the group consisting of the first conductive bulk structure (148) and the second conductive bulk structure (150) by at least one additional plating procedure after the second plating procedure for forming the conductive bridge structure (110).

33. The method of claim 32, wherein: At least one of the first plating procedure, the second plating procedure and the at least one further plating procedure is configured as a galvanic plating procedure.

34. The method according to any one of claims 27 to 30, wherein: The method comprises: before forming the through hole (108), providing a first conductive layer structure (152) on the first main surface (104); and / or A second electrically conductive layer structure (154) is provided on the second major surface (106).

35. The method according to any one of claims 27 to 30, wherein: The method comprises forming the through hole (108) in the electrically insulating layer structure (102) while one or both main surfaces of the electrically insulating layer structure (102) are not covered by an electrically conductive layer structure.

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