Method for producing a component carrier and component carrier

Abstract

The present invention relates to a method for manufacturing a component carrier (100) and a component carrier (100), wherein the method comprises: providing a stack (102), the stack comprising at least one electrically conductive layer structure (104) and / or at least one electrically insulating layer structure (106); embedding a component (108) in the stack (102); drilling a blind hole (110) in the stack (102) towards the embedded component (108); and thereafter extending the blind hole (110) by etching to expose a surface portion (112) of the embedded component (108).

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 increasing miniaturization of such components, as well as an increasing number of components to be mounted on component carriers, such as printed circuit boards, increasingly powerful array components or packages with several components are used, which have a plurality of contacts or connections with increasingly smaller spacings between them. Removing the heat generated by such components and the component carriers themselves during operation is becoming an increasingly serious problem. At the same time, the component carriers should be mechanically robust and electrically reliable in order to be operable even under adverse conditions.

[0003] It is still difficult to assemble the components on and / or in the component carrier with little effort and to reliably maintain the functionality of the components. Summary of the invention

[0004] It may be necessary to assemble components of a component carrier in a simple and compact manner while reliably ensuring proper function of the components.

[0005] According to an exemplary embodiment of the present invention, a method for manufacturing a component carrier is provided, wherein the method comprises: providing a stack comprising at least one electrically conductive layer structure and / or at least one electrically insulating layer structure; embedding a component in the stack; creating (e.g. drilling) a blind hole in the stack towards (but preferably not completely reaching) the embedded component; and thereafter extending the blind hole by etching (preferably reaching the embedded component), thereby partially exposing the surface of the embedded component.

[0006] According to another exemplary embodiment of the present invention, a component carrier is provided, wherein the component carrier comprises: a stack, the stack comprising at least one conductive layer structure and / or at least one electrically insulating layer structure; a component embedded in the stack; and a blind hole in the stack, the blind hole partially exposing a surface of the embedded component and having a side wall that is at least partially curved defined by the stack.

[0007] In the context of the present application, the term "component carrier" may particularly denote any supporting structure capable of accommodating one or more components thereon and / or therein to provide mechanical support and / or electrical connection. In other words, the component carrier may be configured as a mechanical and / or electrical carrier for the components. In particular, the component carrier may be one of a printed circuit board, an organic interposer and an integrated circuit (IC) 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 "stack" may particularly denote an arrangement of a plurality of planar layer structures mounted one on top of the other in parallel.

[0009] In the context of the present application, the term "layer structure" may particularly denote a plurality of non-continuous islands, a patterned layer or a continuous layer in a common plane.

[0010] In the context of the present application, the term "component" may particularly denote an inlay-type component. Such a component may be arranged inside a stack. The component may particularly have an optical and / or electronic function. For example, such a component may be a semiconductor die.

[0011] In the context of the present application, the term "blind hole" may particularly denote a hole in a stack which does not extend completely through the entire stack, but ends inside the stack with a closed bottom.

[0012] In the context of the present application, the term "partially curved sidewall" may particularly mean that the sidewall defining the blind hole does not have a completely straight (i.e. vertical or inclined) shape, but may be curved and thus may show a non-zero curvature at least along a certain subsection of the sidewall. For example, such a curved sidewall may include one or more concave sections and / or convex sections. However, it is not excluded that a certain subsection of the sidewall also has a straight section, as long as (the subsection of) the sidewall also has a curved section.

[0013] According to an exemplary embodiment of the present invention, a component carrier (such as a printed circuit board) is provided, having a preferably laminated (i.e. connected by pressure and / or heat) layer stack, including an embedded component, such as a sensor component. Access to the embedded component can be obtained by combining blind hole creation (e.g. drilling, preferably laser drilling) and etching processes. According to an exemplary embodiment of the present invention, an embedded package can thus be provided, which can be manufactured with high quality and less effort and has a compact construction considering the embedding aspect. Compared with conventional methods, an exemplary embodiment creates an embedded (especially optical sensor) package by: encapsulation (especially based on lamination); forming a layer stack; removing the stack material (e.g. during drilling (preferably by soft laser drilling)) to form a first part of the access hole close to the embedded component; and subsequently exposing the surface part of the embedded component by etching (especially by plasma treatment) (preferably in combination with cleaning the orifice window of the embedded component). Such a process can be implemented with little effort and at the same time reliably exposes the targeted surface portion of the embedded component without the risk of damaging the embedded component and in such a way that the exposed surface portion is reliably prevented from being covered with undesirable residues such as burnt stack material, dirt or dust. Advantageously, such a process can be implemented in a simple and rapid manner and can make the conventionally used and undesirable molding barriers, release layers, etc. unnecessary. As a result of such a process (particularly when laser drilling is implemented), blind holes having at least partially curved side walls can be formed in the stack.

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

[0015] Drilling is preferably performed to form the blind hole. However, the blind hole may also be created by other processes such as milling or cutting. Thus, a "drilling motion" to dig out the material to create the blind hole may be preferred and optional. However, other techniques for opening the blind hole may also be used.

[0016] In one embodiment, the method includes drilling a blind hole by laser drilling. The laser beam can be directed to the surface of the stack, thereby removing the laminated stack material by the strong energy impact of the laser beam. The power of the laser beam, the irradiation time, and the type of laser device used for laser drilling can be adjusted according to the target thickness of the blind hole to be drilled, the material of the stack, etc. It has been proven that laser drilling is a powerful and fast method for creating blind holes, even in the case of small sizes. It should be noted that laser drilling does not expose the above-mentioned surface portions of the embedded components, but maintains the embedded components covered by some residual material in the stack. This can ensure that sensitive surface portions of the embedded components will not be degraded or even damaged by excessive laser energy. The laser process for forming the blind hole can be implemented with a pulsed laser or with a continuous laser. The blind hole can be formed by a single laser irradiation or by multiple laser irradiations.

[0017] In one embodiment, the method includes exposing the surface portion by plasma etching. Plasma etching can be represented as a form of plasma process for processing component carriers. Plasma etching can involve irradiating (particularly in the form of pulses) a high-speed plasma stream (such as a glow discharge) of a suitable gas mixture at the stack near the hole to be formed near the embedded component. The plasma source or etching species can be charged (i.e., it can be provided in the form of ions) or can be electrically neutral (for example, in the form of atoms and / or free radicals). During the plasma process, the plasma can generate volatile etching products from chemical reactions between elements of the stack material to be etched and reactive species generated by the plasma. From the description, the stack with embedded components and blind holes can be subjected to plasma treatment to remove the remaining film of the laminated stack material that still covers the embedded components after the above-mentioned drilling process (particularly laser drilling process or mechanical drilling process). Because the plasma treatment may not be as aggressive as the previous laser treatment for the sensitive surface of the component to be exposed, plasma etching is a highly advantageous process for actually exposing the surface portion of the embedded component. At the same time, the plasma treatment can also clean the surface of the embedded component and optionally clean pores in the surface region of the embedded component.

[0018] In one embodiment, the method comprises performing the etching for extending the blind hole over the last few microns until the embedded component, in particular in the range of less than 5 μm. Thus, timely termination of the drilling (e.g. by switching off the laser or stopping the rotation of the mechanical drill) before reaching the surface of the component to be exposed ensures that the integrity of the component and its sensitive surfaces is maintained and is not negatively affected by excessive laser energy or mechanical abrasion of the drill. After this, the remaining few microns of the thickness of the stack can be removed by plasma etching, for example the remaining distance is in the range of between 1 μm and 5 μm, thereby exposing the above-mentioned surface portion of the component.

[0019] In one embodiment, the method includes performing etching for extending the blind via to less than 5 μm up to the embedded component. Etching may be less efficient for removing dielectric stack material than laser drilling. Thus, the etching process may be limited to the last less than 5 μm of dielectric stack material covering the embedded component in order to ensure that the blind via is formed quickly and efficiently. At the same time, stopping (particularly laser) drilling should be controlled so that it occurs early enough before the drilling process (e.g., laser beam) reaches the surface of the embedded component. The last few microns should be removed by processes other than drilling (preferably by etching) to protect the embedded component from damage (particularly caused by the laser).

[0020] In one embodiment, the method comprises cleaning the exposed surface portions and / or the blind holes by said etching. Further alternatively, the method may comprise cleaning the exposed surface portions and / or the blind holes by laser treatment. In other words, the etching process and the laser treatment (e.g., the same laser treatment used for drilling or an additional laser treatment) may also clean the exposed surface portions and / or the interior of the blind holes from residues of the material removal process, dust, dirt and / or any other contaminants. This may significantly improve the performance of component carriers with embedded components, in particular for sensor applications, and more particularly for optical sensor applications, where a reliable exposed sensor-enabled (active) surface is required.

[0021] In one embodiment, the component is an optical component, in particular an optical sensor, an optical emitter, a light emitting device and / or an optical receiving and / or emitting device. For example, the surface portion of the embedded optical component to be exposed may be a sensor-enabled surface of an optical sensor. In other words, the sensor-enabled surface may be capable of detecting electromagnetic radiation (such as optical light, infrared light, etc.) reaching the component from the environment. For example, the optical component may be a photodiode or a camera (such as a charge coupled device (CCD) camera or a complementary metal oxide semiconductor (CMOS) camera). In another embodiment, the optical component may be an electromagnetic radiation emitter, such as a laser diode or a light emitting diode. Reliably exposing enabled surface portions (e.g., photosensitive surfaces or light emitting surfaces) of such optical components without the risk of damage may be highly advantageous for ensuring proper functioning of the optical component.

[0022] In one embodiment, the component has an aperture in its exposed surface portion. In particular, such an aperture may be a recess in a major surface of the embedded component corresponding to an optically active area of ​​the optical component. In optics, an aperture may represent a hole or opening through which light propagates. More specifically, the aperture and the focal length of the optical system may determine the cone angle of a beam of light rays arriving at a focal point in an image plane. The exposed surface portion of the optical component may include the entire aperture and optionally also include an annular area surrounding the aperture.

[0023] In one embodiment, the component carrier comprises an optical element, in particular a lens, at least partially accommodated in the aperture. In other words, an optical element, such as a lens having one or two curved surfaces, in particular having a concave curvature and / or a convex curvature, can be mounted in the aperture and at least partially accommodated in the aperture. Such an optical element can be provided for manipulating electromagnetic radiation, such as light propagating between an embedded component and the environment of the component carrier, in a predetermined manner.

[0024] In one embodiment, the width of the exposed portion of the embedded component is less than 100 μm, in particular less than 70 μm. Correspondingly, the maximum diameter of the blind hole can be of the same order of magnitude, for example can be less than 150 μm, in particular less than 90 μm. Highly advantageously, even such small-sized exposed portions and corresponding blind holes can be created by laser drilling followed by etching of the last few microns up to the embedded component. Although mechanical drilling can be implemented in other embodiments of the invention, a preferred embodiment of the invention is blind holes by laser drilling, which makes the manufacturing process perfectly compatible with the continuous miniaturization of the embedded components and their enabled surface area.

[0025] In one embodiment, the at least partially curved sidewall is at least partially concavely curved. In particular, concave means curved inwards or hollowed out inwards, as opposed to convex. Such a curved sidewall can be obtained by performing a laser drilling process for forming the outer main part of the blind hole; a supplementary etching process can then be performed to reach the embedded component. In other words, the concavely curved sidewall can be considered as a fingerprint of the laser drilling process. The laser drilling process can be followed by an etching process to complete the formation of the blind hole extending to the embedded component in the laminated layer stack of the component carrier.

[0026] In one embodiment, the at least partially curved sidewall has a curved section and a step at the interface with the component. More specifically, the outer section of the blind hole (i.e., the section extending from the outer surface of the stack) can have a curved (especially concave) shape, while the inner section of the blind hole (i.e., the section adjacent to the embedded component) can have a vertical and essentially straight shape. The outer section can have a longer vertical extension than the inner section. Between the outer section and the inner section, a step can be formed. Such a step between the described outer section and the described inner section can be obtained by manufacturing the corresponding blind hole by laser drilling and subsequent plasma etching.

[0027] In one embodiment, the curved section is defined by a first electrically insulating layer structure in at least one electrically insulating layer structure, in particular by a first electrically insulating material. The step can be defined by a second electrically insulating layer structure in at least one electrically insulating layer structure, in particular by a second electrically insulating material different from the first electrically insulating material. For example, the first electrically insulating material of the first electrically insulating layer structure can be configured to be removed by laser drilling at a higher removal rate, while the second electrically insulating material of the second electrically insulating layer structure can be configured to be removed by laser drilling at a lower removal rate. In such an embodiment, the different materials of the corresponding electrically insulating layer structures themselves can define the stop position of the laser drilling. Preferably, the second electrically insulating material can be configured to be appropriately removed by etching, in particular by plasma etching, and more preferably, the etching rate is higher than the etching rate of the first electrically insulating material. Therefore, the selection of the dielectric material can support the appropriate formation of the blind hole and protect the embedded components from damage.

[0028] In one embodiment, the at least partially curved sidewall tapers toward the embedded component. For example, the sidewall may taper inwardly substantially conically, yet have a superimposed curvature. The tapered shape of the blind hole may be due to the fact that the impact of the laser energy at the outer surface of the stack may be stronger than the impact of the laser energy at a more internal portion of the stack.

[0029] In one embodiment, the exposed surface portion is a sensor-enabled surface of the component. Precise and reliable exposure of such a sensor-enabled surface is of greatest advantage for the embedded component to function as a sensor with a high signal-to-noise ratio.

[0030] 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 may be a laminate of the mentioned (one or more) electrically insulating layer structures and (one or more) electrically conductive layer structures, in particular formed by applying mechanical pressure and / or heat. The mentioned stack may provide a plate-like component carrier that is able to provide a large mounting surface for further components and yet is very thin and compact. The term "layer structure" may in particular denote a plurality of non-continuous islands, patterned layers or continuous layers lying in a common plane.

[0031] In one embodiment, the component carrier is formed as a plate. This facilitates a compact design, wherein the component carrier still provides a large base for mounting components on the component carrier. Furthermore, in particular bare dies as an example of embedded electronic components can be easily embedded in thin boards such as printed circuit boards due to their small thickness.

[0032] In one embodiment, the component carrier is designed as one of the group consisting of a printed circuit board, a substrate (in particular an IC substrate) and an interposer.

[0033] In the context of the present application, the term "printed circuit board" (PCB) may particularly denote a plate-shaped component carrier formed by laminating several conductive layer structures with several electrically insulating layer structures (e.g. by applying pressure and / or by supplying 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 fibers, so-called prepregs, or FR4 materials. The various conductive layer structures can be connected to each other in a desired manner by forming through holes that penetrate the laminate (e.g. by laser drilling or mechanical drilling); and filling these through holes with conductive material (in particular copper), thereby forming 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 surface 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 consist of a resin with reinforcing fibers (such as glass fibers).

[0034] In the context of the present application, the term "substrate" may particularly refer to a small component carrier. Compared to a PCB, a substrate may be a relatively small component carrier, on which one or more components may be mounted and the substrate may serve as a connection medium between (one or more) chips and another PCB. For example, a substrate may have substantially the same size as the size of the component (particularly an electronic component) to be mounted thereon (for example, in the case of a chip size package (CSP)). More specifically, a substrate may be understood as a carrier for electrical connection or electrical network, and a component carrier comparable to a printed circuit board (PCB), but with a relatively higher density of lateral and / or vertically arranged connections. The lateral connection is, for example, a conductive path, and the vertical connection may be, for example, a drill hole. These lateral connections and / or vertical connections are arranged in the substrate and may be used to provide electrical, thermal and / or mechanical connections between accommodated components (particularly IC chips) or unaccommodated components (such as bare dies) 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 may consist of a resin with reinforcing particles such as reinforcing spheres, particularly glass spheres.

[0035] The substrate or interposer may include at least layers of the following materials: glass, silicon (Si) or photoimageable or dry-etchable organic materials, such as epoxy-based laminated materials (such as epoxy-based laminated films) or polymer composites, such as polyimide, polybenzoxazole or benzocyclobutene; or the substrate or interposer may consist of at least layers of these materials.

[0036] In one embodiment, at least one electrically insulating layer structure comprises at least one of the group consisting of a resin (such as a reinforced resin or a non-reinforced resin, for example an epoxy resin or a bismaleimide triazine resin), a cyanate ester, a polyphenylene derivative, a glass (particularly glass fiber, multilayer glass, a glass-like material), a prepreg material (such as FR-4 or FR-5), a polyimide, a polyamide, a liquid crystal polymer (LCP), an epoxy-based laminated film, polytetrafluoroethylene (Teflon), a ceramic, and a metal oxide. Reinforced materials such as meshes, fibers, or balls, for example made of glass (multilayer glass) may also be used. Although prepregs (particularly FR4) are generally preferred for rigid PCBs, other materials, particularly epoxy-based laminated films or photoimageable dielectric materials may also be used. For high-frequency applications, high-frequency materials such as polytetrafluoroethylene, liquid crystal polymers and / or cyanate ester resins, low temperature cofired ceramics (LTCC) or other low, very low or ultra-low DK materials may be implemented in the component carrier as an electrically insulating layer structure.

[0037] In one embodiment, at least one conductive layer structure 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 coated with superconducting materials such as graphene.

[0038] At least one component that can be optically surface mounted on the stack and / or embedded in the stack can 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 guiding element (such as an optical waveguide or optical conductor connection), an optical element (such as a lens), an electronic component or a combination thereof. For example, the component can be an active electronic component, a passive electronic component, an electronic chip, a storage device (such as a DRAM or other data storage), 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), a cryptographic 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 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, for example a ferrite core) or can be a paramagnetic element. However, the component can also be a substrate, an intermediate layer or another component carrier, for example a board-in-board structure. 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 can also be used as components.

[0039] In one embodiment, the component carrier is a laminated component carrier. In such an embodiment, the component carrier is a composite of multiple layers stacked and connected together by applying pressure and / or heat.

[0040] After processing the internal layer structure of the component carrier, one or two opposite main surfaces of the processed layer structure can be covered (especially by lamination) symmetrically or asymmetrically with one or more further electrically insulating layer structures and / or electrically conductive layer structures. In other words, the layering can be continued until the desired number of layers is obtained.

[0041] 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.

[0042] In particular, with regard to surface treatment, an electrically insulating solder resist may be applied to one or both opposing major surfaces of a layer stack or component carrier. For example, a layer such as a solder resist may be formed over the entire major surface, and the layer of solder resist may then be patterned so as to expose one or more conductive surface portions that should be used to electrically couple the component carrier to an electronic peripheral. The remaining surface portions of the component carrier covered with the solder resist may be effectively protected from oxidation or corrosion, in particular surface portions containing copper.

[0043] As far as surface treatment is concerned, surface modification can also be selectively applied to the exposed conductive surface portion of the component carrier. Such surface modification can be a conductive covering material on the exposed conductive layer structure (such as a pad, a conductive track, etc., particularly including copper or consisting of copper) on the surface of the component carrier. If such an exposed conductive layer structure is not protected, the exposed conductive component carrier material (especially copper) may be oxidized, making the component carrier less reliable. The surface modification can then be formed, for example, as an interface between a surface-mounted component and a component carrier. The surface modification has the following functions: protecting the exposed conductive layer structure (especially the copper circuit) and enabling, for example, a bonding process with one or more components to be realized by welding. Examples of suitable materials for surface modification are organic solderability preservative (OSP), electroless nickel immersion gold (ENIG), gold (especially hard gold), chemical tin, nickel-gold, nickel-palladium, etc.

[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] Figure 1 A cross-sectional view of a preform of a component carrier during the implementation of a method for producing a component carrier according to an exemplary embodiment of the present invention is illustrated.

[0046] Figure 2 This example shows that Figure 1 sectional view of a component carrier according to an exemplary embodiment of the invention obtained from the preform shown in FIG.

[0047] Figure 3 Illustrated Figure 2 Detail of the blind hole of the component carrier.

[0048] Figure 4 An image of a component carrier manufactured according to an exemplary embodiment of the present invention is illustrated.

[0049] Figure 5 A cross-sectional view of a component carrier according to another exemplary embodiment of the present invention is illustrated. DETAILED DESCRIPTION

[0050] The illustrations in the drawings are schematic. In different drawings, similar or identical elements are provided with the same reference signs.

[0051] Before various exemplary embodiments will be described in further detail with reference to the accompanying drawings, some basic considerations based on which exemplary embodiments of the present invention have been developed will be summarized.

[0052] Conventionally, sensor packages are created using a complex mold packaging process flow with a low robustness mechanical mold barrier to protect the sensor aperture.Another conventional approach implements peeling layers to create access to the encapsulated component.

[0053] Exemplary embodiments of the present invention provide a method for manufacturing a component carrier with an embedded or encapsulated component, in particular an embedded sensor component, wherein the apertures of the embedded component are accessed and cleaned by laser and plasma processes. Preferably, the encapsulation is accomplished by laminating a multilayer structure, with the component located between them. By means of the combined laser and plasma processes, it is possible to form access blind holes for exposing the embedded component without the need for cumbersome molding processes or peeling layers. In addition, such a manufacturing method can allow the creation of micro access holes without the risk of damaging sensitive embedded components. This can be accomplished by stopping the laser drilling process early enough before reaching the embedded component and removing the remaining laminate material by etching (e.g. plasma etching) to finally expose the embedded component.

[0054] According to an exemplary embodiment of the present invention, a method of manufacturing a sensor package can be provided, which synergistically combines a laser cleaning process and a plasma cleaning process. This can ensure that the functionally enabled surface of the embedded component is partially exposed, preferably under the frame of the embedded sensor package.

[0055] Exemplary embodiments of the present invention provide a highly advantageous manufacturing architecture in which an embedded optical sensor package is created by encapsulation and additionally forming and cleaning the aperture window by laser and plasma treatment. Such a manufacturing technique provides multiple benefits in terms of reliability and greatly reduces manufacturing effort compared to conventional molded barrier concepts. In particular, exemplary embodiments of the present invention may allow smaller opening sizes to be achieved without the need to form additional molded barriers or peeling layers.

[0056] Exemplary applications of exemplary embodiments of the invention are sensor packages, in particular optical sensor packages, cameras (eg for mobile phones or automotive applications), light sources and optoelectronic packages (eg for optical data transmission).

[0057] Figure 1 In the implementation of the exemplary embodiment according to the present invention, the manufacturing method as shown in FIG. Figure 2 1 is a cross-sectional view of a preform of a component carrier 100 obtained during the method for manufacturing a component carrier 100 shown in FIG.

[0058] like Figure 1 As illustrated, component 108 is disposed within a cavity (not shown) formed in layer stack 102 .

[0059] The stack 102 may be a plate-like laminated stack consisting of a plurality of conductive layer structures 104 and a plurality of electrically insulating layer structures 106. For example, the conductive layer structure 104 may include patterned copper foil and vertical through-connections, such as copper-filled laser vias. The electrically insulating layer structure 106 may include a resin (e.g., epoxy resin) and optional reinforcing particles (e.g., glass fibers or glass balls) therein. For example, the electrically insulating layer structure 106 may be made of FR4 or ABF. In the illustrated embodiment, the thick central electrically insulating layer structure 106 may be a fully cured core.

[0060] The above-mentioned cavity can be defined by a through hole in the thick central electrically insulating layer structure 106 of the stack 102, which can be closed on the bottom side by attaching a temporary carrier (not shown) to the lower main surface of the core. The temporary carrier can be, for example, an adhesive tape. The component 108 with the pad 150 (protruding downward here) can be attached in the cavity, directly physically contacting the temporary carrier. The function of the temporary carrier is to provide stability as long as the component 108 has not yet been glued in place in the cavity.

[0061] The structure may be obtained by laminating one or more further electrically insulating layer structures 106 and one or more further electrically conductive layer structures 104 to the upper main surface of the electrically insulating layer structure 106 in the center of the receiving part 108. Figure 1 The structure shown. For example, a prepreg layer (as an additional electrical insulating layer structure 106) and one or more copper foils (as an additional conductive layer structure 104) can be laminated on top. During the lamination process, the uncured material of the additional electrical insulating layer structure 106 may become flowable or melted and may flow in the gap between the stack 102, the temporary carrier and the component 108. When the material of the additional electrical insulating layer structure 106 is cured (e.g., cross-linked, polymerized, etc.), the filling medium in the gap can become solid. In particular, the bottom filler 152 material can be formed in the gap by the currently cured resin material.

[0062] As an alternative to the lamination described, the components 108 can also be glued in place in the cavities formed in the stack 102 by filling the gaps between them with a liquid adhesive material and, when the adhesive material cures, gluing the components 108 in place in the cavities again.

[0063] After the component 108 has been glued in place within the cavity and thus provided with an integral connection to the stack 102, the temporary carrier can be removed. When the temporary carrier is a tape, it can be simply removed from the Figure 1 The tape is peeled off from the lower main surface of the structure shown. One or more further conductive layer structures 104 and electrically insulating layer structures 106 can be connected to the lower surface of the obtained structure, thereby obtaining a structure such as Figure 1 The stack 102 is shown.

[0064] By implementing the described manufacturing process, the illustrated laminated stack 102 of the electrically conductive layer structure 104 and the electrically insulating layer structure 106 with the embedded component 108 is obtained. In the illustrated embodiment, the embedded component 108 is an optical component, for example, an optical sensor, which is configured to detect visible light in the environment of the component carrier 100 currently being manufactured. For example, the embedded component 108 is a photodiode or a camera. Therefore, the described manufacturing method involves a sensor embedding encapsulation using lamination technology. Figure 1 It can also be seen that the bottom main surface of the component 108 has an aperture 114 in the form of a recess. The light-sensitive detection surface of the optical component 108 is located in the aperture 114 at the bottom side of the component 108. Therefore, the lower main surface of the embedded component 108 is provided with an aperture opening, where the sensor-enabled surface is located, which should be made accessible to the environment.

[0065] Figure 2 Illustrated based on the reference Figure 1 The described preform is a cross-sectional view of a component carrier 100 according to an exemplary embodiment of the present invention, which is obtained by carrying out the further production process described below. Figure 3 The further manufacturing process creates Figure 2 Detail 180 of the blind hole 110 of the component carrier 100 .

[0066] like Figure 2 As shown, a blind hole 110 is created in the lower major surface of the stack 102. More specifically, the blind hole 110 is formed from Figure 1 The bottom major surface of the structure is shown extending toward the embedded component 108 .

[0067] The main part of the blind hole 110 extends almost but not completely from the outer bottom main surface of the stack 102 to the lowest electrically insulating layer structure 106 to the component 108 and can be formed by laser drilling. By laser drilling, i.e. irradiating the central part of the lower main surface of the stack 102 with a laser beam (not shown), the dielectric material of the stack 102 can be effectively removed with a high removal rate and thus quickly. Highly advantageously, the laser drilling process can be stopped at a certain distance (preferably a few micrometers) from the surface portion 112 of the optical component 108 to be exposed. This ensures that the laser beam does not reach the sensor-enabled surface of the optical component 108, i.e. the surface portion 112, and thus reliably protects it from degradation or damage due to excessive laser energy. By taking this measure, the rapid formation of the blind hole 110 can be combined with the component 108 being reliably protected from damage. Highly advantageously, laser drilling is able to create blind holes 110 with a small maximum width D (e.g. 90 μm), see Figure 3 Details 180. Also as Figure 3 As illustrated, the width W of the exposed portion 112 can be even smaller, for example 60 μm. The width L of the aperture 114 in the lower main surface of the component 108 can be still smaller, for example 50 μm. Thus, the described manufacturing method is suitably compatible with the trend towards continued miniaturization of embedded components 108 and corresponding component carriers 100.

[0068] After the laser drilling process has been completed several microns from the surface portion 112 to be exposed (and currently still partially covered by the dielectric material of the stack 102), the method can extend the formed outer portion of the blind hole 110 by etching further into the stack 102, thereby exposing the above-mentioned sensor-enabled surface portion 112 of the embedded component 108. Highly preferably, the method may include exposing the surface portion 112 by plasma etching. Alternatively, other etching processes may be implemented (e.g., wet etching, in which an etchant is selected that leaves the surface portion 112 intact). Thus, the method may include etching for extending the blind hole 110 on the last few microns up to the embedded component 108, thereby exposing the embedded component. After laser drilling, extending the blind hole 110 by etching may occur within the remaining less than 5μm range up to the embedded component 108. The thickness of the portion of the stack 102 removed by plasma etching is in the range of Figure 3 denoted by "d", where d may for example be in the range between 1 μm and 5 μm. Highly advantageously, the described plasma etching process enables the formation of the blind vias 110 up to the surface portion 112 of the embedded component 108 to be exposed.

[0069] At the same time, the etching process cleans the blind hole 110, and in particular cleans the exposed bottom surface of the blind hole 110 defined by the exposed surface portion 112. A laser process may also be used to support the cleaning. After laser drilling, residues of the laser-burned dielectric material of the stack 102 may remain in the blind hole 110 and may interfere with the sensor function of the embedded sensor component 108. However, by performing etching, exposing the surface portion 112 can be combined synergistically and simultaneously with cleaning the blind hole 110 without damaging the component 108. More specifically, the cleaning of the exposed surface portion 112 and / or the blind hole 110 can be completed by the etching process that exposes the exposed surface portion 112. In addition or alternatively, effective cleaning of the exposed surface portion 112 and / or the blind hole 110 can be completed by laser processing. The laser processing can be the same as the laser processing used to drill the outer portion of the blind hole 110 or an additional laser processing. In particular, a synergistic combination of plasma etching and laser processing for exposing and cleaning the exposed surface portions 112 and blind vias 110 may have the greatest advantage.

[0070] As a result, it is possible to obtain Figure 2 and Figure 3 A blind hole 110 in the stack 102 of the shape shown. The blind hole 110 exposes a surface portion 112 of the embedded component 108 and has a partially curved sidewall 120. In other words, the blind hole 110 is defined by the inclined sidewall 120 of the stack 102.

[0071] More specifically, the partially curved sidewall 120 is partially concavely curved. This is a result of laser drilling, because the laser beam has a stronger impact on the outside of the stack 102 than the inside of the stack 102. More precisely, the partially curved sidewall 120 has an outer curved section 122 and a step 124 located at the interface with the component 108. The step 124 formed is a result of plasma etching. In addition, the partially curved sidewall 120 tapers toward the embedded component 108. This is a further result of the energy impact characteristics of the laser beam used to laser drill the outer main part of the blind hole 110.

[0072] Also like Figure 3 As shown, the curved section 122 is defined by the first electrically insulating layer structure in the electrically insulating layer structure 106, in particular by its first electrically insulating material 126. In contrast, the step 124 may be defined by the second electrically insulating layer structure in the electrically insulating layer structure 106, in particular by a second electrically insulating material 128 different from the first electrically insulating material 126. By selecting the materials of the electrically insulating materials 126, 128 accordingly, the following can be further facilitated. Figure 2 The characteristic shape of the blind hole 110 is shown. Figure 2The shape of the blind hole 110 shown is also highly advantageous for the sensor function of the embedded component 100, since its funnel shape promotes the propagation of the light with sensing between the exterior and the interior of the component carrier 100, while additionally providing adequate shielding from ambient light. Thus, the described geometry also promotes a high signal-to-noise ratio.

[0073] Also like Figure 2 As shown, the component carrier 100 may also include an optional optical element 116, such as a convex lens, which may, for example, be partially or fully accommodated in the aperture 114. Such an optical element 116 may further enhance the optical performance of the sensor package component carrier 100.

[0074] In short, the manufacturing process is characterized by a laser ablation process with ultra-soft parameters, followed by plasma etching. As a result, a component carrier 100 is obtained with embedded and exposed components 108, which are properly protected from damage and configured for detecting light with high accuracy.

[0075] Figure 4 An image of a component carrier 100 manufactured according to an exemplary embodiment of the present invention is illustrated.

[0076] Already passed and referenced Figures 1 to 3 A process similar to the one described manufactures the corresponding component carrier 100. The width of the windows formed in the stack 102 by laser processing followed by plasma etching may be slightly greater than 100 μm.

[0077] Figure 5 A cross-sectional view of a component carrier 100 according to another exemplary embodiment of the present invention is illustrated.

[0078] Figure 5 The implementation method and Figure 2 The embodiment differs in particular in that Figure 2 compared to, Figure 5 The outer portion of the blind hole 110 in the embodiment has different shapes. Figure 5 , the outer part of the blind hole 110 has straight walls, as obtained, for example, by mechanical drilling, for example using a drill (not shown) for removing material of the stack 102. The mechanical drilling process can be stopped at a distance of several micrometers (in particular between 1 μm and 5 μm) from the surface portion 112 to be exposed. By stopping the mechanical drilling process at a sufficient distance from the surface portion 112 to be exposed, damage to the embedded component 108 during drilling can be reliably prevented. After this, the exposure of the surface portion 112 and the cleaning of the blind hole 110 can be completed by a subsequent etching process (preferably plasma etching).

[0079] It should be noted that the term "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, elements described in association with different embodiments may be combined.

[0080] It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

[0081] The implementation of the invention is not limited to the preferred embodiments shown in the drawings and described above. On the contrary, numerous variants are possible using the principles according to the invention and the solutions shown, even in fundamentally different embodiments.

Claims

1. A method for manufacturing a component carrier (100), wherein: The method comprises: Providing a stack (102) comprising at least one electrically conductive layer structure (104) and / or at least one electrically insulating layer structure (106); embedding a component (108) into the stack (102); Drilling a blind hole (110) by laser drilling in the stack (102) toward but not completely reaching the embedded component (108); and Thereafter, the blind hole (110) is extended to reach the embedded component (108) by etching, thereby exposing a surface portion (112) of the embedded component (108).

2. The method according to claim 1, wherein: The method includes exposing the surface portion (112) by plasma etching.

3. The method according to claim 1 or 2, wherein: The method comprises carrying out the etching for extending the blind hole (110) on the last few micrometers until the embedded component (108).

4. The method according to claim 1 or 2, wherein: The method comprises: carrying out the etching for extending the blind hole (110) in a range of less than 5 μm up to the embedded component (108).

5. The method according to claim 1 or 2, wherein: The method comprises: cleaning the exposed surface portion (112) and / or the blind hole (110) by etching.

6. The method according to claim 1 or 2, wherein: The method comprises cleaning the exposed surface portion (112) and / or the blind hole (110) by laser processing.

7. A component carrier (100), wherein: The component carrier (100) comprises: A stack (102) comprising at least one electrically conductive layer structure (104) and / or at least one electrically insulating layer structure (106); a component (108) embedded in the stack (102); and A blind hole (110) in the stack (102), the blind hole exposing a surface portion (112) of the embedded component (108) and having an at least partially curved side wall (120) defined by the stack (102), the at least partially curved side wall (120) having a curved section (122) and a step (124) located at an interface with the component (108), the curved section (122) being defined by a first electrically insulating layer structure in the at least one electrically insulating layer structure (106); and the step (124) being defined by a second electrically insulating layer structure in the at least one electrically insulating layer structure (106).

8. The component carrier (100) according to claim 7, wherein: The component (108) is an optical component.

9. The component carrier (100) according to claim 7, wherein: The component (108) is at least one of an optical sensor and an optical transmitter.

10. The component carrier (100) according to claim 7, wherein: The component (108) is a light emitting device.

11. The component carrier (100) according to claim 7, wherein: The component (108) is an optical receiving and / or transmitting device.

12. The component carrier (100) according to any one of claims 7 to 11, wherein: The component (108) has an aperture (114) at the exposed surface portion (112).

13. The component carrier (100) according to claim 12, comprising an optical element (116) at least partially received in the aperture (114).

14. The component carrier (100) according to claim 13, wherein: The optical element is a lens.

15. The component carrier (100) according to any one of claims 7 to 11, wherein: The width (W) of the exposed surface portion (112) is less than 100 μm.

16. The component carrier (100) according to any one of claims 7 to 11, wherein: The width (W) of the exposed surface portion (112) is less than 70 μm.

17. The component carrier (100) according to any one of claims 7 to 11, wherein: The maximum width (D) of the blind hole (110) is less than 150 μm.

18. The component carrier (100) according to any one of claims 7 to 11, wherein: The maximum width (D) of the blind hole (110) is less than 90 μm.

19. The component carrier (100) according to any one of claims 7 to 11, wherein: The at least partially curved sidewall (120) is at least partially concavely curved.

20. The component carrier (100) according to any one of claims 7 to 11, wherein: The curved section (122) is defined by a first electrically insulating material (126); and the step (124) is defined by a second electrically insulating material (128) different from the first electrically insulating material (126).

21. The component carrier (100) according to any one of claims 7 to 11, wherein: The at least partially curved side wall (120) tapers toward the embedded component (108).

22. The component carrier (100) according to any one of claims 7 to 11, wherein: The surface portion (112) that is exposed is a sensor-enabled surface of the component (108).

23. The component carrier (100) according to claim 7, comprising at least one of the following features: in, The component (108) is selected from the group consisting of a non-conductive inlay and / or a conductive inlay, a heat transfer unit, a light guiding element, a bridge, an energy harvesting unit, a storage device, a filter, an integrated circuit, a signal processing component, a power management component, an optoelectronic interface component, a voltage converter, a cryptographic component, a transmitter and / or a receiver, an electromechanical transducer, an actuator, a micro-electromechanical system, a microprocessor, a capacitor, a resistor, an inductor, an accumulator, a switch, a camera, an antenna, a magnetic element, another component carrier and a logic chip; wherein the at least one conductive layer structure (104) comprises at least one of copper, aluminum, nickel, silver, gold, palladium and tungsten, any of the mentioned materials being coated with a superconducting material; Wherein, the at least one electrical insulating layer structure (106) comprises at least one of the following items: reinforced resin or non-reinforced resin; FR-4; FR-5; cyanate ester; polyphenylene derivative; Glass; Prepreg material; Polyimide; Polyamide; Liquid crystal polymer; Epoxy-based laminate film; Polytetrafluoroethylene; ceramics and metal oxides; wherein the component carrier (100) is formed as a plate; wherein the component carrier (100) is configured as a printed circuit board; Therein, the component carrier is configured as a laminated component carrier (100).

24. The component carrier (100) according to claim 7, wherein: The component (108) is an electronic component.

25. The component carrier (100) according to claim 7, wherein: The component (108) is an active electronic component.

26. The component carrier (100) according to claim 7, wherein: The component (108) is a passive electronic component.

27. The component carrier (100) according to claim 7, wherein: The component (108) is an electronic chip.

28. The component carrier (100) according to claim 23, wherein: The superconducting material is graphene.

29. The component carrier (100) according to claim 7, wherein: The at least one electrically insulating layer structure (106) comprises a resin.

30. The component carrier (100) according to claim 7, wherein: The at least one electrically insulating layer structure (106) comprises an epoxy resin or a bismaleimide triazine resin.

31. The component carrier (100) according to claim 7, wherein: The component carrier (100) is designed as a base plate.

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