Component carrier and method for manufacturing a component carrier

Abstract

A component carrier (100) is described wherein the component carrier (100) comprises: a stack (102) comprising at least one electrically conductive layer structure (104) and at least one electrically insulating layer structure (106); a through cavity (108) extending vertically through the stack (102) and delimited by the side wall (100); and an electrically insulating coating material portion (112) covering portions of the two opposite main surfaces (114, 116) of the stack (102) and at least portions of the side walls (110) of the through-cavity (108) of the stack (102), in which the through-cavity (108) extends in at least one main planar direction (150) of the through-cavity (108). A change in the cavity width (155) is provided at a middle portion (151) of at least one side wall (110) with respect to the remaining extension of the respective side wall (110), preferably a straight remaining extension. A method of manufacturing a component carrier (100) is also described.

Description

Technical Field

[0001] The present invention relates to a component carrier having an electrically insulating coating and a method for producing a component carrier. The present invention may therefore relate to the technical field of component carriers such as printed circuit boards or IC substrates and the production of component carriers. Background Art

[0002] Against the backdrop of the ever-increasing product functionality of component carriers equipped with one or more components, the increasing miniaturization of such components, and the increasing number of components to be mounted on component carriers, such as printed circuit boards, increasingly powerful array-like components or packages are being used, comprising a plurality of components with a plurality of contacts or connections, wherein the spacing between these contacts is increasingly smaller. In particular, component carriers must be mechanically robust and electrically reliable in order to be able to operate even under harsh conditions.

[0003] To implement or integrate components, a cavity into which the component is inserted may be provided in a component carrier. To reliably integrate the component in the cavity of the component carrier, the dimensions of the cavity must be manufactured with high precision and with minimal dimensional variation. However, if electrically insulating materials are applied to component carriers having cavities, it is difficult to manufacture such cavities with minimal dimensional variation or tolerance. Summary of the Invention

[0004] It may be necessary to provide cavities in a component carrier in a fault-robust and high-precision manner.

[0005] A component carrier and a method of manufacture are described.

[0006] According to one aspect of the present invention, a component carrier (e.g. a printed circuit board or an IC substrate) is described, comprising: a (multi-layer) stack comprising at least one electrically conductive layer structure (e.g. a metal layer) and at least one electrically insulating layer structure (e.g. a reinforced / unreinforced resin layer).

[0007] The component carrier includes a through cavity (eg, a through hole produced by laser machining / plasma treatment) extending vertically through the stack and defined by side walls.

[0008] The component carrier further comprises an electrically insulating coating material (e.g. an electrically insulating ink) which covers a portion of the two opposite main surfaces of the stack and at least a portion of the side walls of the through cavity of the stack, wherein a change in cavity width is provided in the middle portion of at least one side wall relative to the preferably straight remaining extension of the corresponding side wall along at least one main plane direction of the cavity.

[0009] At least one sidewall of the through-going cavity of the component carrier has an irregular shape. The sidewall includes a central portion, where the cavity width is different from the cavity width at other portions of the sidewall. Preferably, the cavity width at the central portion of the sidewall is greater than the cavity width at other portions of the sidewall outside the central portion.

[0010] According to another aspect of the invention, a method for producing a component carrier, such as described above, is described, the method comprising:

[0011] providing a stack comprising at least one electrically conductive layer structure and at least one electrically insulating layer structure,

[0012] forming a through cavity extending vertically through the stack and delimited by side walls, wherein, along at least one main plane of the cavity, a change in cavity width is provided at a middle portion of at least one side wall relative to the, preferably straight, remaining cavity extension of the corresponding side wall; and

[0013] An electrically insulating coating material is applied to portions of the two opposing major surfaces of the stack and at least portions of the sidewalls of the through-cavities of the stack.

[0014] In the context of the present application, the term "component carrier" may particularly denote any supporting structure capable of accommodating one or more components on and / or in the component carrier to provide mechanical support and / or electrical connection. In other words, the component carrier may be configured as a mechanical carrier and / or an electronic carrier for the components. In particular, the component carrier may be one of a printed circuit board, an organic interposer and an IC (integrated circuit) substrate. In particular, the component carrier may be embodied as a flexible or semi-rigid substrate. The component carrier may also be a hybrid board combining different types of component carriers of the types mentioned above.

[0015] In the context of the present application, the term "stack" may particularly denote an arrangement of multiple planar layers mounted in parallel on top of one another. For example, the stack may be a laminate stack, i.e. comprising multiple layers connected by applying heat and / or pressure.

[0016] 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 of a common plane.

[0017] In the context of the present application, the term "through cavity" or "cavity" may particularly denote a cavity or opening extending through the stack such that a central axis or axis of symmetry of the cavity is perpendicular or substantially perpendicular to a main surface of the stack that is parallel to the main surface of the stack. A "through cavity" or "cavity" connects two opposite main surfaces of a component carrier to one another.

[0018] In the context of the present application, the term "sidewall" may particularly denote a sidewall bordering a through-hole cavity within a stack. The sidewall may be straight or curved (e.g., in a concave and / or convex manner). Preferably, the through-hole cavity delimited by the sidewalls of the stack may be formed by laser drilling, i.e., by treating the stack with a drilling laser beam.

[0019] In the context of the present application, the term "electrically insulating coating material" may specifically refer to a non-electrically conductive filling medium that fills only a portion of a corresponding through-cavity while maintaining a void portion of the through-cavity. The electrically insulating coating material may laterally, partially, or completely cover or line the sidewalls defined by the internal aperture of the stack. Such a filling medium may be a dielectric (e.g., electrically insulating ink).

[0020] In the context of this application, the term "major surface" of a body (such as a stack) may specifically refer to one of the two largest opposing surfaces of the body. The major surfaces may be connected by a circumferential sidewall. The thickness of a body such as a stack may be defined by the vertical distance between the two opposing major surfaces.

[0021] In the context of the present application, the term "main plane direction" may particularly denote a direction in the plane of one of the main surfaces of the component carrier. For example, if the through-hole has a rectangular shape when viewed from above on the main surface, the main plane direction may be along the length or width of the rectangle.

[0022] In the context of the present application, the term "cavity width" may particularly denote the distance between two opposite side walls of a through cavity. The cavity width is the width of the cavity without the electrically insulating coating material.

[0023] In the context of the present application, the term "middle portion" may particularly denote a portion of a side wall that is within the length of the side wall and overlaps the middle of the length of the respective side wall. The side wall also extends in both directions in the middle portion of the side wall.

[0024] According to an exemplary embodiment, a component carrier (e.g., a printed circuit board or an integrated circuit substrate) includes a (preferably laminated) stack of layers having one or more through-cavities. The formation of at least one through-cavity can be performed (e.g., by laser drilling using appropriate laser operating parameters). After the cavity is formed, an electrically insulating coating material is applied to the cavity, wherein the electrically insulating coating material covers at least a portion of the sidewalls of the through-cavity. Unfortunately, the thickness of the electrically insulating coating material on the sidewall (one or more) is not constant over the length or width of the through-cavity or along the sidewalls. There may be multiple reasons for the non-constant thickness of the electrically insulating coating material. One reason may be that the coating is affected by the surface tension of the electrically insulating coating material when applied in a liquid or viscous state. The surface tension or strain of the electrically insulating coating material may be higher at the corners of the cavity and cause the thickness at the corners to increase. Another reason may be the way in which the electrically insulating coating material is applied to the component carrier. During the coating process, the component carrier may be oriented perpendicular to the ground. Therefore, due to gravity, the electrically insulating coating material may slowly flow down and accumulate in the middle before the electrically insulating coating material solidifies (through a baking process). When the component carrier is turned 180 degrees and then subjected to a second coating process, the uneven thickness of the electrically insulating coating material becomes even more pronounced.

[0025] As a result, the shape of the through cavity without the electrically insulating coating material is different from the shape of the remaining opening after the electrically insulating coating material is applied. This shape of the remaining opening can also be expressed as the final contour of the cavity. The non-constant thickness of the electrically insulating coating material along the side walls makes it difficult to provide the exact dimensions of the final contour of the cavity of the final component carrier. For example, in Figure 3 and Figure 4 The problems resulting from the difference between the shape of the through-cavity without electrically insulating coating material and the shape of the remaining opening after application of the electrically insulating coating material, which occurs in component carriers according to the prior art, are shown in FIG.

[0026] A component carrier according to an exemplary embodiment of the present invention provides a variation in cavity width within the through-cavity to compensate for the non-constant thickness of the electrically insulating coating material on the sidewalls. It has been found that the thickness of the electrically insulating coating material is greater in the middle portion of a sidewall than at the ends of that sidewall. Advantageously, a through-cavity with a variation in cavity width in the middle portion proves to be a suitable basis for depositing or applying the electrically insulating coating material, particularly with regard to the precise dimensions of the final cavity profile. The cavity extends along at least one principal plane direction. This means that the final cavity profile should follow this principal plane direction as precisely as possible. Advantageously, providing a variation in cavity width in the middle portion of at least one sidewall relative to the rest of the corresponding sidewall allows for compensation for variations in the thickness of the electrically insulating coating material along the sidewall. This significantly improves the precision of the final profile of the through-cavity with the electrically insulating coating material. Furthermore, by providing a variation in cavity width, variations in the shape of the final profile during the manufacture of multiple component carriers with through-cavities can be significantly reduced. The change in cavity width at the middle portion of the side wall provides improved process stability for the production of component carriers with through-going cavities and improves the quality of the shape and dimensions of the final contour of the cavity.

[0027] Advantageously, exemplary embodiments of the present invention can achieve a relatively uniform final shape for the through-hole cavity of the component carrier. Furthermore, by varying the cavity width, the final shape and dimensions of the through-hole cavity of the component carrier can be precisely controlled, thereby enabling any desired shape to be achieved, such as a square, a circle, a regularly stepped shape, and the like.

[0028] Exemplary embodiments

[0029] In one embodiment, the change in cavity width (at the mid-portion) comprises at least one recess disposed in at least one sidewall of the cavity of the stack, wherein at least a portion of the electrically insulating coating material partially fills the recess. The term "recess" may refer to any cutout or portion that completely penetrates the component carrier and is positioned adjacent to the cavity. The recess communicates with the cavity. The recess provides space for receiving / storing the electrically insulating coating material. Preferably, the recess is located in the mid-portion of the sidewall and provides an increased cavity width relative to the remaining extension of the sidewall.

[0030] In one embodiment, the recess is oriented away from the center of the cavity, wherein the recess defines a portion of the contour of the cavity in a plan view on at least one of the main surfaces of the stack, in particular wherein the recess has a rectangular shape in a plan view on at least one of the main surfaces of the stack. The recess is oriented away from the center of the cavity. The cavity extends in the opposite direction of the cavity with respect to the remaining extension of the side wall. The recess is part of the contour of the cavity. The term "contour" may refer to the shape of the circumference of the cavity in a plan view or top view without the electrically insulating coating material. The shape of the cavity in a plan view on one of the main surfaces may be rectangular. The shape of the cavity may also be at least partially curved, circular, triangular, trapezoidal, such as a parallelogram, or a combination of such shapes.

[0031] In one embodiment, the recess includes at least two portions, one larger than the other, specifically defining a stepped recess. The recess may include two or more portions connected to one another. This allows for a variety of recess shapes. Different portions of the recess may have different shapes. For example, a first portion of the recess may have a rectangular shape, while a second portion of the recess may be curved or arc-like.

[0032] In one embodiment, a first portion of the recess is located in the middle portion and adjacent to the remaining extension of the side wall, and a second portion of the recess, which is smaller than the first portion, is adjacent to the side of the first portion and opposite the center of the cavity, wherein the two portions are connected to each other. In this embodiment, the recess includes two parts. The larger first portion is directly connected to the cavity and is in place adjacent to the remaining extension of the side wall. The first portion can extend along the entire length of the middle portion in the direction of the main plane. The smaller second portion of the recess is in place adjacent to the first portion and connected to the first portion. The second portion extends away from the center of the cavity. The first and second portions can together form a stepped recess. The first and second portions can have the same shape or can be shaped in different ways.

[0033] In an embodiment, the recess includes a length defined along the main plane direction of the cavity, wherein the length is symmetrically distributed relative to the central axis of the cavity in the main plane direction. In order to achieve a precise shape of the cavity using the applied electrically insulating coating material, it is advantageous to have the length of the recess distributed symmetrically relative to the middle of the length of the cavity. In the event that the width of the recess perpendicular to the main plane direction is not constant along the length of the recess in a plan view, the width along the main plane direction may also be distributed symmetrically relative to the central axis of the cavity. For example, if the recess has an arcuate or partially circular shape, this shape may be positioned symmetrically relative to the central axis of the cavity.

[0034] In one embodiment, the cavity has at least one sidewall that is at least partially tilted relative to the stacking direction. In this embodiment, the cavity or recess at least partially has tilted sidewalls. The term "tilted" may refer to the orientation of at least a portion of the sidewall that deviates from a plane perpendicular to one of the major surfaces of the component carrier. For example, a portion of the sidewall may be oriented at an angle of 15° relative to a plane perpendicular to the major surface. This tilted orientation of the sidewall may provide increased sidewall surface area, thereby improving adhesion of the applied electrically insulating coating material.

[0035] In an embodiment, the cavity width change portion includes a gradient change portion of the cavity width along the main plane direction, with the gradient in the middle portion being different from the corresponding gradient along the rest of the sidewall. In this embodiment, the cavity width changes according to a gradient in the middle portion. The term "gradient" can refer to a gradual change (evolution, progression) of the cavity width along the main plane direction. This change can be continuously distributed. The gradient change of the cavity width can be achieved by a recess having an arcuate shape in a top view. The gradient in the middle portion is different from the gradient of the remaining extension along the rest of the sidewall. In an alternative embodiment, the cavity width change portion can include one or more steps or transitions, at which the cavity width changes discontinuously. The change in cavity width according to the gradient can expand design flexibility while ensuring improved quality of the shape and size of the final contour portion of the cavity. The gradient change of the cavity width allows for more complex forms of the final contour portion of the cavity. Such complex forms may be required to accommodate components with complex forms within the component carrier.

[0036] In an embodiment, the cavity comprises a shape that defines at least one planar extension along a principal planar direction, in particular along two perpendicular principal planar directions, wherein the second principal planar direction is perpendicular to the first principal planar direction, preferably, for example, a square or rectangular recess or a more complex shape with a length and height, such as a hexagon, wherein the cavity width is defined by the distance between two opposing side walls. The cavity can extend along two principal planar directions oriented perpendicular to each other. For example, the shape of the cavity can be rectangular, wherein the length of the rectangle extends along the first principal planar direction and the height (or width) of the rectangle extends along the second principal planar direction. However, the cavity can also have a more complex shape that essentially extends to dimensions along the first principal planar direction and the second principal planar direction. For example, the shape of the cavity in a top view can be hexagonal, polygonal, circular, elliptical, or a combination of different shapes. A cavity having a shape along two perpendicular principal directions can create corners in which the electrically insulating coating material flows. As a result, the electrically insulating coating material portion can have better adhesion to the side walls of the cavity near the corners.

[0037] In an embodiment, the cavity includes rounded or inclined corners. The corners can connect side walls that are perpendicular to each other and arranged adjacently. The cavity can include corners that include a continuous or stable shape. This shape improves the adhesion of the electrically insulating coating material portion at the corners and also prevents cracks at the connecting portion during stress dispersion. In an alternative embodiment, the cavity can include sharp corners or corners. In this case, an unstable connection is provided between two adjacent side walls. Such sharp corners can include a 90° angle between two adjacent side walls.

[0038] In an embodiment, the electrically insulating coating material portion defines a lateral final profile that is more uniform than the cavity profile without the electrically insulating coating material portion, and the deviation of the final profile defined by the electrically insulating coating material portion in the main plane direction of the side wall is within the range of + / - 5%, preferably the deviation is 1%. The term "final profile" can refer to the shape of the cavity after the electrically insulating coating material portion is applied. This final profile defines the dimensions of the cavity after the component carrier is manufactured. The final profile can be adapted to the external dimensions of the component that can be integrated into the cavity. Due to the change in the cavity width in the middle part before the electrically insulating coating material portion is applied, the final profile deviates very little from its designed optimal shape. Along the main plane direction, the tolerance of the shape of the final profile is preferably within the range of + / - 1% of the shape of the final profile.

[0039] In an embodiment, the electrically insulating coating material portion defines a lateral final profile that is straighter than the profile of a cavity without the electrically insulating coating material portion, wherein the width of the resulting coated cavity between two opposing sidewalls coated by the insulating coating material portion has a deviation of at most + / - 10%, preferably at most + / - 2%. Due to the change in cavity width in the middle portion, the straightness of the linear portion of the final profile is significantly improved compared to the prior art. The resulting coated cavity width between the two opposing linear portions of the final profile can have very low deviation along the main plane direction, preferably at most + / - 2%.

[0040] In an embodiment, the thickness of the electrically insulating coating material portion varies in a circumferential direction around the cavity, wherein the thickness of the electrically insulating coating material portion is greater in the middle portion of the side wall than in the remaining extension of the corresponding side wall. The thickness of the insulating coating material portion around the cavity is not continuous, but varies. Preferably, the thickness of the electrically insulating coating material portion is greatest in the middle portion of the side wall where the recess is located, and decreases indirectly towards the ends of the remaining extension of the corresponding side wall. The variation in the thickness of the electrically insulating coating, combined with the straighter lateral final profile, can create a larger surface / interface area between the electrically insulating coating and the cavity, thereby achieving better adhesion compared to a combination of a constant thickness of the electrically insulating coating and a straighter lateral profile.

[0041] In one embodiment, the electrically insulating coating material portion completely fills at least one recess in at least one side wall, and / or the electrically insulating coating material portion coating at least one side wall compensates for the width of at least one recess in the side wall when viewed from a plan view of at least one major surface of the stack. After application of the electrically insulating coating material portion, changes in the cavity width and / or one or more recesses in the at least one side wall are no longer visible when viewed from a top view of the major surface of the component carrier. The electrically insulating coating material portion has different thicknesses in different areas around the perimeter of the cavity, compensating for the increased cavity width after cutting. As a result of this compensation, a very high degree of precision is achieved in the final contour of the cavity.

[0042] In one embodiment, the distance between the final cavity contour and the contour without the electrically insulating coating material is greater in the middle portion of at least one side wall relative to the remaining, preferably straight, extension of the corresponding side wall. The deviation between the cavity contour after cutting and the final contour after application of the electrically insulating coating material is greatest in the middle portion of one or more side walls, providing a change in cavity width in the middle portion of one or more side walls. Preferably, this deviation between the two contours decreases in the direction of the main plane at the ends of the remaining extension of the corresponding side wall. By providing an adapted shape of the middle portion with the maximum cavity width in the middle of the length of the side wall, a very precise straight extension of the final contour can be achieved.

[0043] In an embodiment, the shape of the electrically insulating coating material portion, in particular the final contour portion, defines rounded or tilted corners. The final contour portion may include stable corners or at least rounded corners. After cutting and before applying the electrically insulating coating material portion, the corners of the cavity contour portion may also define rounded or tilted corners. Alternatively, the shape of the rounded or tilted corners of the final contour portion may be formed by applying the electrically insulating coating material portion on the cavity contour portion that includes a sharp edge after cutting. Therefore, applying the electrically insulating coating material portion can define the shape of the corners of the final contour portion.

[0044] In an embodiment, the electrically insulating coating material covers the entire sidewalls defined by the cavity. The entire surface of all sidewalls can be covered with the electrically insulating coating material. In this way, the component carrier and the cavity are well protected from environmental influences, and the conductive layer structure of the stack can be effectively insulated from components that may be introduced into the cavity.

[0045] In an embodiment, the electrically insulating coating material portion has a planar thickness along the side wall of the cavity, and the planar thickness changes along the final contour portion of the cavity contour portion, in particular changes continuously along the final contour portion. The term "planar thickness" may refer to the thickness of the electrically insulating coating material portion in a direction perpendicular to the side wall surface of the cavity. The planar thickness changes in the circumferential direction of the final contour portion of the cavity. Preferably, the planar thickness along the side wall changes continuously. However, in the area where the recess is provided, the planar thickness of the electrically insulating coating material portion does not change continuously, but is unstable. Unstable means that the planar thickness changes abruptly at the position where the recess begins and / or ends. The thickness change of the planar thickness of the electrically insulating coating material portion is preferably associated with the change portion of the cavity width. Therefore, an unstable change of the planar thickness of the electrically insulating coating material portion can be provided by providing an unstable extension portion of the cavity width. In this way, the design flexibility of the final contour portion of the cavity can be increased.

[0046] In embodiments, the greater thickness of the electrically insulating coating material portion corresponds to the greater width of the cavity, particularly within the recessed portion. The electrically insulating coating material portion has a greater thickness at locations where the cavity width along the principal plane is greater. Correspondingly, the electrically insulating coating material portion has a lower thickness at locations where the cavity width is less, or at locations that are not in the middle of the sidewalls along the principal plane but at the end portions of the sidewalls. In embodiments including one or more recessed portions, the electrically insulating coating material portion has a highest thickness in the region of the recessed portion.

[0047] In one embodiment, the electrically insulating coating material portion defines additional sidewalls of the stack. The electrically insulating coating material portion may also be applied to sidewalls other than the cavity, such as lateral sidewalls of the stack. Furthermore, the electrically insulating coating material portion may be partially or fully applied to one or both major surfaces of the component carrier. This may provide additional mechanical and / or chemical protection for the component carrier.

[0048] In one embodiment, the recess has a length, defined along the main plane of the cavity, between 1 mm and 20 mm, and a width, perpendicular to the length, between 0.005 mm and 5 mm. The length of the recess can be in the range of several millimeters, with the corresponding width being significantly lower. The absolute size of the recess depends on the overall dimensions of the component carrier and the cavity. Even when the component carrier has a length greater than 10 mm, an improved quality of the shape and dimensions of the final cavity profile can be ensured.

[0049] In an embodiment, the recess has a length corresponding to 40% to 80% of the length of the side wall defined along the main plane of the cavity. Preferably, the length of the recess is adapted to the length of the corresponding side wall adjacent to the recess. The adaptation of the length of the recess to the length of the corresponding side wall has the effect of achieving a very precise final contour of the cavity. The longer the side wall, the greater the thickness variation of the electrically insulating coating material portion along the side wall. Therefore, in the case of a longer (total) length of the side wall, the longer the recess, the better it is possible to compensate for the thickness variation of the electrically insulating coating material portion.

[0050] In one embodiment, the changes in cavity width are mirrored along at least one main planar direction, in particular along two perpendicular main planar directions. The term "mirror-imaged" may mean that the cavity width distribution is symmetrical with respect to a plane that is perpendicular to one of the main planar directions and perpendicular to the main surface of the component carrier. The symmetrical distribution of the cavity width changes provides a precisely straight extension of the final profile along the main planar direction of the corresponding side wall.

[0051] In one embodiment, the mirror-image changes in the cavity width have the same dimensions and position on corresponding, particularly opposing, side walls. In this embodiment, the mirror-image changes in the cavity width are also symmetrical for both opposing side walls relative to a plane located in the middle of the cavity width and perpendicular to one of the main surfaces of the component carrier. In other words, the shape of the middle portions of the two opposing side walls of the cavity is identical. This configuration provides a very precise, symmetrical shape for the two opposing portions of the final contour.

[0052] In an embodiment, the cavity width varies along all four sidewalls of the cavity. If high precision of the final contour of the cavity is required on four or more sides, variations in the cavity width between all opposing sidewalls can be provided. For example, if the final contour of the cavity is to have a precisely rectangular shape, variations in the cavity along the first and second principal planes can be provided. In this configuration, prior to application of the electrically insulating coating material, all four sidewalls of the cavity have a shape that deviates from a linear shape to provide the necessary variations in cavity width.

[0053] In one embodiment, the cavity width changes have the same size and position on corresponding, particularly opposing, sidewalls. The size and position of the cavity width changes result in the shape of the central portion of the corresponding sidewall in a top view. Preferably, this shape of the central portion is the same for opposing sidewalls. Furthermore, this shape of the central portion can also be the same for sidewalls that are connected to or positioned adjacent to each other.

[0054] In an embodiment, the component carrier is a printed circuit board or a substrate. The component carrier may also be a panel. The component carrier may be rigid or flexible.

[0055] In embodiments, the electrically insulating coating material may include ink or resin. For example, the electrically insulating coating material may be a solid or liquid synthetic or natural organic polymer. An example is epoxy resin. In another example, the resin forming at least a portion of the electrically insulating coating may include polyimide and / or polytetrafluoroethylene and / or cyanate ester resin.

[0056] In an embodiment, the method comprises forming a through-hole cavity in the stack by laser processing. In an embodiment, the cavity may be a laser cavity. The cavity may be formed in particular and preferably by laser processing. In order to obtain the described shape, the cavity may preferably be formed by laser processing only from one main surface of the electrically insulating layer structure. Advantageously, when the cavity is formed by laser processing, substantially no glass fibers from the prepreg material of the stack extend into the through-hole due to the impact of the laser beam. This can improve the accuracy of the obtained geometry and can suppress artifacts. However, the formation of the cavity can also be carried out by other methods than laser processing, for example by plasma treatment, by wet etching, etc.

[0057] In an embodiment, the method includes applying the electrically insulating coating material portion on the side wall and on a portion of the main surface using a roller. For example, such a roller can be a cylindrical body that rotates around its central symmetric axis during operation, for example, during coating. Such a roller can move longitudinally along the corresponding main surface of the stack while rotating. Surprisingly, it has been found that by forming the coating member using a roller (rather than a scraper (scarper)), it is possible to achieve an enhanced balance of the side wall thickness. This can keep the center of the cavity in a consistent position before and after coating. However, an alternative method for forming the coating member is also possible, such as spraying, screen printing, etc.

[0058] In an embodiment, the method includes applying the electrically insulating coating material portion to the sidewalls and portions of the main surface using a pair of rollers rolling along opposing main surfaces of the stack, preferably rolling simultaneously along opposing main surfaces of the stack (the pair of rollers can be implemented as described above for the rollers). By taking this approach, excellent coating accuracy and high-precision characteristics of the coated through-holes can be achieved.

[0059] In an embodiment, a component carrier stack includes 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 one or more electrically insulating layer structures and one or more electrically conductive layer structures, formed, in particular, by applying mechanical pressure and / or heat. The stack can provide a plate-like component carrier that can provide a large mounting surface for additional components while still being very thin and compact.

[0060] In one embodiment, the component carrier is formed as a plate. This facilitates a compact design, while still providing a large base for components mounted thereon. Furthermore, bare dies, in particular, as an example of embedded electronic components, can be easily embedded in thin boards, such as printed circuit boards, due to their relatively low thickness.

[0061] In an embodiment, the component carrier is configured as one of the group consisting of a printed circuit board, a substrate (in particular an IC substrate) and an interposer.

[0062] In the context of the present application, the term "printed circuit board" (PCB) may particularly denote a plate-like component carrier formed by laminating a plurality of electrically conductive layer structures with a plurality of electrically insulating layer structures, for example by applying pressure and / or by supplying heat. As a preferred material for PCB technology, the electrically conductive layer structures are made of copper, while the electrically insulating layer structures may comprise resin and / or glass fiber, so-called prepreg materials or FR4 materials. The individual electrically conductive layer structures can be connected to one another in a desired manner by forming through-holes through the laminate, for example by laser drilling or mechanical drilling, and by partially or completely filling these through-holes with electrically conductive material, in particular copper, thereby forming vias or any other through-hole connections. A filled hole connecting the entire stack (the through-hole connection extending through several layers or the entire stack) or a filled hole connecting at least two electrically conductive layers is referred to as a via. Similarly, optical interconnections can be formed through the individual layers of the stack to receive an optoelectronic circuit board (EOCB). In addition to one or more components that can be embedded in the printed circuit board, the printed circuit board is generally configured to accommodate one or more components on one surface or two opposing surfaces of the plate-shaped printed circuit board. The one or more components can be connected to the corresponding main surface by soldering. The dielectric portion of the PCB may include a resin with reinforcing fibers (such as glass fiber).

[0063] In the context of this application, the term "substrate" can particularly refer to a small component carrier, particularly an IC substrate. Relative to a PCB, an IC substrate can be a relatively small component carrier on which one or more components can be mounted and which can serve as a connection medium between one or more chips and another PCB. For example, an IC substrate can have approximately the same dimensions as the components (particularly electronic components) to be mounted on the substrate (for example, in the case of a chip-scale package (CSP)). More specifically, an IC substrate can be understood as a component carrier that serves as a carrier for electrical connectors or an electrical network, as well as a component carrier with a relatively high density of lateral and / or vertical connectors comparable to a printed circuit board (PCB). Lateral connectors can be, for example, conductive channels, while vertical connectors can be, for example, drilled holes. These lateral and / or vertical connectors can be particularly arranged within the IC substrate and can be used to provide electrical, thermal, and / or mechanical connections between accommodated or unaccommodated components (such as bare wafers)—particularly IC chips—and a printed circuit board or intermediate printed circuit board. In the context of this application, a "substrate" is particularly useful for electrical connections and / or heat dissipation and / or providing mechanical strength. Therefore, the term "substrate" is particularly used in the context of this application as a synonym for "IC substrate." It should be noted that the term "substrate" should not be confused with the term "substrate" commonly used in the context of wafers, where "substrate" generally refers to a substrate material used in wafer manufacturing as a base material—a base material on which devices or circuits are built and which forms the foundation layer that supports the electronic or photonic structures integrated into the wafer. This is not the meaning of "substrate" in the context of this application.

[0064] In the context of this application, the term "inorganic layer structure" may particularly refer to a layer structure comprising an inorganic material, such as an inorganic compound. In particular, the dielectric material of the inorganic layer structure, or even the entire inorganic layer structure, may be made exclusively or at least substantially exclusively of an inorganic material. In another embodiment, the inorganic layer structure may comprise an inorganic dielectric material and an additional dielectric material. The inorganic compound may be a compound lacking carbon-hydrogen bonds or a compound that is not an organic compound. In an example, the inorganic layer structure may comprise glass, such as silicon-based glass, particularly soda-lime glass, and / or borosilicate glass and / or aluminosilicate glass and / or lithium silicate glass and / or alkali-free glass. In another example, the inorganic layer structure may comprise a ceramic material, such as aluminum nitride and / or aluminum oxide and / or silicon nitride and / or boron nitride and / or a tungsten-containing ceramic material. However, in another example, the inorganic layer structure may comprise a semiconductor material, such as silicon and / or germanium and / or silicon oxide and / or germanium oxide and / or silicon carbide and / or gallium nitride. In another embodiment, the inorganic layer structure may comprise (elemental) metals and / or metal alloys, such as copper and / or tin and / or bronze. In yet another embodiment, the inorganic layer structure may comprise inorganic materials not listed in the above examples, such as MoS2, CuGaO2, AgAlO2, LiGaTe2, AgInSe2, CuFeS2, BeO.

[0065] The substrate or interposer may include or be composed of at least one layer of glass, silicon (Si) and / or a photosensitive or dry-etchable organic material, such as an epoxy-based laminate material (e.g., an epoxy-based laminate film) or a polymer compound (the polymer compound may or may not include photosensitive and / or heat-sensitive molecules) such as polyimide or polybenzoxazole.

[0066] In an embodiment, the at least one electrically insulating layer structure (and / or curable dielectric element) comprises at least one of the following: a resin or polymer, such as an epoxy resin, a cyanate resin, a benzocyclobutene resin, a bismaleimide-triazine resin, a polyphenylene derivative (e.g. based on polyphenylene ether, PPE), a polyimide (PI), a polyamide (PA), a liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) and / or a combination thereof. Reinforcement structures such as meshes, fibers, spheres or other types of filler particles made of glass (multilayer glass) may also be used to form a composite. Semi-cured resins combined with reinforcing agents, such as fibers impregnated with the above resins, are called prepregs. These prepregs are usually named after their properties, such as FR4 or FR5, which describe their flame retardant properties. Although prepregs, especially FR4, are generally preferred for rigid PCBs, other materials, especially epoxy-based laminates (such as laminate films) or photosensitive dielectric materials may also be used. For high-frequency applications, high-frequency materials such as polytetrafluoroethylene, liquid crystal polymers and / or cyanate resins may be preferred. In addition to these polymers, low-temperature co-fired ceramics (LTCC) or other low, very low or ultra-low DK materials can be applied as electrically insulating layer structures in the component carrier.

[0067] In an embodiment, the at least one electrically conductive layer structure comprises at least one of the following: copper, aluminum, nickel, silver, gold, palladium, tungsten, carbon, platinum, (doped) silicon, and magnesium. Although copper is generally preferred, other materials or coated variants thereof, in particular coated with superconducting materials or conductive polymers such as graphene or poly (3,4-ethylenedioxythiophene) (PEDOT) are also possible.

[0068] At least one component can be embedded in the component carrier and / or surface-mounted on the component carrier. Such a component can be selected from the following: a non-electrically conductive inlay, an electrically conductive inlay (e.g., a metal inlay, preferably comprising copper or aluminum), a heat transfer unit (e.g., a heat pipe), a light-guiding element (e.g., an optical waveguide or optical conductor connector), an electronic component, or a combination thereof. The inlay can be, for example, a metal block with or without an insulating material coating (IMS-inlay), which can be embedded or surface-mounted to promote heat dissipation. Suitable materials are defined by their thermal conductivity, which should be at least 2 W / mK. Such materials are typically based on, but not limited to, metals, metal oxides, and / or ceramics, such as copper, aluminum oxide (Al2O3), or aluminum nitride (AlN). Other geometries with increased surface area are also often used to increase the heat exchange capacity. Furthermore, the component may be an active electronic component (implementing at least one pn junction), a passive electronic component such as a resistor, an inductor or a capacitor, an electronic chip, a memory device (e.g., a DRAM or other data memory), a filter, an integrated circuit (such as a field programmable gate array (FPGA), a programmable array logic (PAL), a general array logic (GAL) and a complex programmable logic device (CPLD)), a signal processing component, a power management component (such as a field effect transistor (FET), a metal oxide semiconductor field effect transistor (MOSFET), a complementary metal oxide semiconductor (CMOS), a junction field effect transistor (JFET), a transistor (MOSFET ... ) or insulated gate field effect transistors (IGFETs), all based on semiconductor materials such as silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), gallium oxide (Ga2O3), indium gallium arsenide (InGaAs) and / or any other suitable inorganic compound), optoelectronic interface elements, light emitting diodes, optocouplers, voltage converters (e.g., DC / DC converters or AC / DC converters), cryptographic components, transmitters and / or receivers, electromechanical transducers, sensors, actuators, microelectromechanical systems (MEMS), microprocessors, capacitors, resistors, inductors, batteries, switches, cameras, antennas, logic chips and energy harvesting units. However, other components may also be embedded in the component carrier. For example, a magnetic element may be used as a component. Such a magnetic element may be a permanent magnetic element (e.g., a ferromagnetic element, an antiferromagnetic element, a multiferroic element or a ferrimagnetic element, such as a ferrite core) or may be a paramagnetic element. However, the component may also be an IC substrate, an interposer, or another component carrier, for example in a board-in-board configuration. The component can be surface-mounted on a component carrier and / or embedded in the interior of a component carrier.In addition, other components, in particular those that generate and emit electromagnetic radiation and / or are sensitive to electromagnetic radiation propagating from the environment, can also be used as components.

[0069] In an embodiment, the component carrier is a laminated component carrier. In this embodiment, the component carrier is a composite of multiple layers that are stacked and connected together by applying pressure and / or heat.

[0070] After the internal layer structure of the component carrier has been treated, one or both main surfaces of the treated layer structure can be covered symmetrically or asymmetrically with one or more further electrically insulating and / or electrically conductive layer structures (in particular, by lamination). In other words, the stacking can be continued until the desired number of layers is obtained.

[0071] After the formation of the stack having the electrically insulating layer structure and the electrically conductive layer structure has been completed, the resulting layer structure or component carrier can be subjected to a surface treatment.

[0072] In particular, regarding surface treatment, an electrically insulating solder mask can be applied to one or both major surfaces of a laminate or component carrier. For example, such a solder mask can be formed over the entire major surface, and the solder mask layer can then be patterned to expose one or more electrically conductive surface portions that will be used to electrically couple the component carrier to an electronic peripheral. Surface portions of the component carrier that remain covered with the solder mask, particularly those containing copper, can be effectively protected from oxidation or corrosion.

[0073] In terms of surface treatment, a surface treatment can also be selectively applied to exposed electrically conductive surface portions of the component carrier. This surface treatment can be an electrically conductive covering material on exposed electrically conductive layer structures (e.g., pads, conductive traces, etc., particularly comprising or consisting of copper) on the surface of the component carrier. If such exposed electrically conductive layer structures are not protected, the exposed electrically conductive component carrier material (particularly copper) can oxidize, thereby reducing the reliability of the component carrier.

[0074] The surface treatment can then be formed, for example, as a joint between a surface-mounted component and a component carrier. The surface treatment has the function of protecting the exposed electrically conductive layer structure (particularly copper circuits) and enables a joint process with one or more components, for example, by soldering. Examples of suitable materials for the surface treatment are organic solderability preservatives (OSP), electroless nickel immersion gold (ENIG), electroless nickel immersion palladium immersion gold (ENIPIG), gold (particularly hard gold), chemical tin, nickel gold, nickel palladium, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The aspects defined above and further aspects of the invention are apparent from the examples of embodiment described hereinafter and are explained with reference to these examples of embodiment.

[0076] Figure 1 A top view of a component carrier without an electrically insulating coating material according to an exemplary embodiment of the present invention is shown.

[0077] Figure 2 A top view of a component carrier having an electrically insulating coating material according to an exemplary embodiment of the present invention is shown.

[0078] Figure 3 A top view of a component carrier according to the related art without an electrically insulating coating material portion is shown.

[0079] Figure 4 A top view of a component carrier having an electrically insulating coating material portion according to the related art is shown.

[0080] Figure 5 A plan view of a component carrier without an electrically insulating coating material according to another exemplary embodiment of the present invention is shown.

[0081] Figure 6 A plan view of a component carrier having an electrically insulating coating material according to another exemplary embodiment of the present invention is shown.

[0082] Figure 7 A plan view of a component carrier without an electrically insulating coating material according to another exemplary embodiment of the present invention is shown.

[0083] Figure 8 A plan view of a component carrier having an electrically insulating coating material according to another exemplary embodiment of the present invention is shown.

[0084] Figure 9 A plan view of a component carrier without an electrically insulating coating material according to another exemplary embodiment of the present invention is shown.

[0085] Figure 10 A plan view of a component carrier without an electrically insulating coating material according to another exemplary embodiment of the present invention is shown.

[0086] Figure 11 A perspective view of a component carrier without an electrically insulating coating material according to another exemplary embodiment of the present invention is shown.

[0087] Figure 12 A schematic cut-away side view of a side wall of a cavity is shown according to an exemplary embodiment of the present invention.

[0088] Figure 13 A schematic cut-away side view of a side wall of a cavity according to another exemplary embodiment of the present invention is shown.

[0089] Figure 14 A plan view of a component carrier without an electrically insulating coating material according to another exemplary embodiment of the present invention is shown. DETAILED DESCRIPTION

[0090] Figure 1 A top view of a component carrier 100 without an electrically insulating coating material portion 112 according to an exemplary embodiment of the present invention is shown. The top view is directed to a main surface 114 of the component carrier 100. The component carrier includes a through cavity 108 that extends vertically at least partially, preferably completely, through the stack 102. A first main plane direction 150 is oriented along the length of the cavity 108. The cavity 108 is bounded by four side walls 110. Alternatively, the cavity can be bounded by at least five side walls 110, in particular by six side walls 110. Two of these side walls extend along the main plane direction 150. The other two side walls 110 are oriented perpendicular to the main plane direction 150 and perpendicular to the stack thickness direction. Both side walls 110 extending along the main plane direction 150 include a middle portion 151. At this middle portion 151, a change in cavity width 155 is provided relative to the straight remaining extension of the respective side wall 110 of the cavity. The change in cavity width 155 is achieved by providing two recesses 160 arranged in the middle portion 151 of each side wall 110. Consequently, cavity width 155 in the middle portion 151 is greater than cavity width 155 at the end portions of each side wall 110. Due to the two recesses 160, the shape of cavity 108 in a top view deviates from a rectangle. In this example, middle portion 151 can be located in the center portion of the corresponding side wall 110. Furthermore, middle portion 151 can be positioned symmetrically, for example, if component carrier 100 includes at least one imaginary mirror surface. Alternatively, middle portion 151 can be located in the outer periphery of the corresponding side wall 110. In another example, middle portion 151 can be positioned asymmetrically. Alternatively, at least two middle portions 151 can be arranged on a corresponding side wall 110.

[0091] Figure 2 A top view of a component carrier 100 with an electrically insulating coating material portion 112 according to an exemplary embodiment of the present invention is shown. Figure 2 Shown with Figure 1 The same component carrier 100. However, in Figure 2In the embodiment shown, electrically insulating coating material portion 112 has been applied to component carrier 100 and cavity 108. In the illustrated embodiment, electrically insulating coating material portion 112 covers all side walls 110 of cavity 108. Furthermore, electrically insulating coating material portion 112 is located on the exposed main surface of component carrier 100. After application of electrically insulating coating material portion 112, the remaining opening of cavity 108 is represented as final contour portion 158 of cavity 108. Due to electrically insulating coating material portion 112, the coated cavity width 157 is smaller than the uncoated cavity width 155. Final contour portion 158 has a very precise rectangular shape. This precise rectangular shape is achieved by varying cavity width 155, particularly due to the introduction of intermediate portion 151. Electrically insulating coating material portion 112 completely fills both recesses 160. Therefore, the thickness of the electrically insulating coating material portion 112 extending along the main plane direction 150 at the middle portion 151 of the two side walls 110 is greater than the thickness of the electrically insulating coating material portion 112 at the end portion of the corresponding side wall 110. The change in the cavity width 155 at the middle portion 151 compensates for the change in the thickness of the electrically insulating coating material portion 112 along the extension direction of the side wall 110. In one example, the electrically insulating coating material portion 112 includes an organic (polymer) material, such as epoxy resin, poly (meth) acrylate, polyethylene terephthalate. In another example, the electrically insulating coating material portion may include an inorganic material, in particular particles less than 300 μm, such as glass and / or ceramics. In a preferred example, the electrically insulating coating material portion 112 can be applied to the side walls and portions of the main surface by using a roller. For example, such a roller can be a cylinder that rotates around its central symmetry axis during operation, such as a cylinder that rotates around its central symmetry axis during coating application. Such rollers can be moved longitudinally along the respective main surfaces of the stack while rotating. In another example, the electrically insulating coating material portion 112 can be applied by printing, in particular screen printing or 3D printing, screen coating and / or dispensing. The electrically insulating coating material portion 112 can have an electrical conductivity of less than 10^-10 S / m. In one example, the electrically insulating coating material portion 112 can be optically reflective. To ensure optical reflectivity, the electrically insulating coating material portion can contain metal particles, in particular Al, Ag, Rh.

[0092] Figure 3 A top view of a component carrier 100 according to the related art without an electrically insulating coating material portion is shown. Figure 3 A component carrier 100 according to the related art is shown. The component carrier 100 comprises a cavity 108 having a rectangular shape. The cavity width 155 is constant along the extension of the side wall 110. No intermediate portion is provided at which the cavity width 155 changes.

[0093] Figure 4 A top view of a component carrier 100 having an electrically insulating coating material portion 112 according to the related art is shown. Figure 4 Shown after applying the electrically insulating coating material portion 112 Figure 3 The component carrier 100 of the electrically insulating coating material portion 112 is not constant in the (longer) extension direction of the vertical side wall 110. Therefore, the coated cavity width 157 is not constant in the (longer) extension direction of the vertical side wall 110. In the related art, the final shape of the cavity 108 is significantly different from the shape of the cavity 108 after cutting. Therefore, the final shape of the cavity 108 after coating with the electrically insulating coating material portion 112 is not accurate because it is not formed into a rectangle. For example, inserting a component with a precise rectangular shape into a cavity according to Figure 4 This would be a problem in the cavity 108 of the illustrated related art component carrier 100 .

[0094] Figure 5 A top view of a component carrier 100 according to another exemplary embodiment of the present invention is shown without an electrically insulating coating material portion 112 . Figure 5 The embodiment shown is similar to Figure 1 The embodiment shown is similar. Figure 5 Also shown in Figure 1 For components in Figure 1 Description of . Figure 5 In the embodiment shown, the cavity width 155 also varies in the second main plane direction 152. Figure 5 In one embodiment, all four sidewalls 110 include recesses 160 to vary the cavity width 155 at the middle portion 151 of the corresponding sidewall 110. The changes in cavity width are mirrored along the first main planar direction 150 and the second main planar direction 152. In an example, the length and / or width of the recess 160 along the first main planar direction 150 can be the same as the length and / or width of the recess 160 along the second main planar direction 152. In another example, the length and / or width of the recess 160 along the first main planar direction 150 can be different from the length and / or width of the recess 160 along the second main planar direction 152. This can provide freedom in adjusting the length and / or width of the recess to ensure a planar final profile 158 after applying the electrically-insulative coating material portion 112.

[0095] Figure 6 A top view of a component carrier 100 with an electrically insulating coating material portion 112 according to another exemplary embodiment of the present invention is shown. Figure 6 The embodiment shown in Figure 2 The implementation shown in is similar. Figure 6 Also in Figure 2For components shown in the reference Figure 2 Description of . Figure 2 The embodiment shown is similar, Figure 6 The contour of the cavity 108 in the embodiment includes a final contour 158 having a precise rectangular shape. Figure 3 and Figure 4 Compared to the illustrated embodiment according to the related art, the accuracy of the shape of the final contour portion 158 is significantly improved.

[0096] Figure 7 A top view of a component carrier 100 according to another exemplary embodiment of the present invention is shown without an electrically insulating coating material portion 112 . Figure 7 The embodiment shown in Figure 5 The implementation is similar to that shown in , see reference Figure 5 Furthermore, the manufacturing steps for producing the component carrier 100 having the cavity 108 are similar to Figure 5 and Figure 7 The embodiment shown is the same. However, Figure 7 The embodiment shown in FIG can be coated with a thickness ratio Figure 6 In the embodiment shown in FIG, the electrically insulating coating material portion 112 is larger. Figure 8 The component carrier 100 is shown after application of an electrically insulating coating material portion 112 having a greater thickness.

[0097] Figure 8 A top view of a component carrier 100 with an electrically insulating coating material 112 according to another exemplary embodiment of the present invention is shown. Figure 8 Shown according to Figure 7 The component carrier 100 of the illustrated embodiment after applying an electrically insulating coating material 112 having a higher thickness (caused by a larger amount of electrically insulating coating material 112 applied) to cover all surfaces of all side walls 110 of the cavity 108. The electrically insulating coating material 112 having a higher thickness can be applied by, for example, repeated roller processing. The higher thickness of the electrically insulating coating material 112 can be caused by the higher total thickness of the component carrier 100. At component carriers 100 having a higher total thickness, the electrically insulating coating material 112 may pile up higher at the corners between the two side walls due to strain or surface tension. The higher thickness of the electrically insulating coating material 112 can also be caused by a higher roller spacing, which results in an increased volume of the applied electrically insulating coating material 112. This increased volume of the applied electrically insulating coating material 112 and therefore the higher thickness after application can also be achieved by increasing the pressure on the rollers during application. In addition, the increased viscosity of the applied electrically insulating coating material 112 can result in a higher thickness after application. The electrically insulating coating material 112 fills Figure 7 All recesses 160 are shown. In addition, the electrically insulating coating material 112 fills all corners of the cavity 108, for example, the final contour portion 158 has an (irregular) elliptical shape. Therefore, the shape of the electrically insulating coating material 112, in particular the shape of the final contour portion 158, defines a rounded vertex or an inclined vertex. Figure 8 In the embodiment shown, the coated cavity width 157 varies in a gradient manner along the first main planar direction 150 and the second main planar direction 152. Figure 8 As shown in the embodiment of FIG. , the final contour 158 of the component carrier 100 according to the present invention can have different shapes. It is also possible to provide a component carrier 100 with a final contour 158 of the cavity 108 that has, for example, a precise elliptical shape. Providing a change in the cavity width 155 of the cavity 108 before applying the electrically insulating coating material 112 can also provide a precise shape of the final contour 158 that differs from a rectangle. The desired shape of the final contour 158 depends, for example, on the shape of the component to be inserted into the component carrier 100.

[0098] Figure 9 A top view of a component carrier 100 without an electrically insulating coating material 112 according to another exemplary embodiment of the present invention is shown. Figure 9 The embodiment of the component carrier 100 shown is similar to Figure 1 The embodiment shown is similar. However, in Figure 9 , the main plane direction 150 is from left to right. The cavity 108 includes a change in cavity width 155 along the main plane direction 150. Each of the side walls 110 that delimit the cavity 108 on two opposite sides includes a recess 160. Both recesses 160 are directed away from the center of the cavity 108. In a plan view on the main surface 114, each of the recesses 160 has a rectangular shape. The recesses can also have a square shape or a trapezoidal shape. Each recess 160 has a length that extends along the main plane direction 150. The length of each recess 160 is symmetrically distributed with respect to the center axis of the cavity 108, wherein the center axis is at Figure 9 In vertical direction. Figure 9 In the embodiment shown, the end of the recess 160 in the main plane direction 150 comprises a chamfer connecting the recess 160 to the remaining extension of its corresponding side wall 110 .

[0099] Figure 10 A top view of a component carrier 100 without an electrically insulating coating material 112 according to another exemplary embodiment of the present invention is shown. Figure 10 The embodiment shown in Figure 9 The implementation shown in is similar. Figure 10 In Figure 9Elements also shown in the reference Figure 9 Description of . Figure 10 In the embodiment shown, each of the recesses 160 includes a first portion 160a and a second portion 160b. The first portion 160a is larger than the second portion 160b. The two portions 160a, 160b together define a stepped recess 160. The first portion 160a of the recess 160 is located adjacent to the remaining extension of the corresponding side wall 110 in the middle portion 151, and the second portion 160b of the recess 160 is located adjacent to the side of the first portion 160b opposite to the center of the cavity 108, wherein the two portions 160a, 160b are connected to each other. The recess 160 may also include more than two portions. The shape and size of the recess 160 are not limited to Figure 9 and Figure 10 In addition, the remaining sidewalls 110 that bound the cavity 108 on the left and right sides may also include recesses 160 having one or more portions to provide a change in the cavity width 155 in the horizontal direction.

[0100] Figure 11 A perspective view of a component carrier 100 without an electrically insulating coating material 112 according to another exemplary embodiment of the present invention is shown. Figure 11 The component carrier 100 is shown before application of an electrically insulating coating material 112. The component carrier 100 comprises a stack 102. The stack 102 comprises two conductive layer structures 104 and three electrically insulating layer structures 106 which are sandwiched relative to each other. Figure 11 The upwardly pointing surface in the stack 102 may be defined as a first major surface 114 and the downwardly pointing surface may be defined as a second major surface 116. A cavity 108 is provided that extends from the first major surface 114 to the second surface 116 and penetrates the entire stack 102. The cavity 108 may be formed in the stack 102 by laser processing, the cavity 108 being defined by side walls 110 that are oriented perpendicular to the major surfaces 114. In an example, the side walls 110 may be inclined in the stacking direction. The cavity 108 extends from left to right in a first major plane direction 150 and from front to back in a second major plane direction 152. The first major plane direction 150 and the second major plane direction 152 extend perpendicular to each other. Figure 11 In the embodiment shown, a change in the cavity width 155 along the first main plane direction 150 is provided. Two opposite side walls 110 delimiting the cavity 108 in the front and rear directions comprise a middle portion 151. The middle portions 151 each comprise a recess 160. Due to these recesses 160, the cavity width 155 in the middle portion 151 is greater than the cavity width 155 at the remaining extension of the corresponding side wall 110. The recesses 160 are directed away from the center of the cavity 108. The length of the recesses 160 in the first main plane direction 150 is distributed symmetrically with respect to the center axis of the cavity 108. With reference to Figure 11 , the central axis extends from front to back. Figure 11 In the illustrated embodiment, each recess 160 has a rectangular shape in a plan view on the first major surface 114. However, the shape of the recess 160 is not necessarily a rectangle. The shape of the recess 160 in a top view on the major surfaces 114, 116 may also be curved, trapezoidal, triangular, parallelogram-like, or a combination of these shapes.

[0101] It should be noted that the term "comprising" does not exclude other elements or steps, and the singular form does not exclude a plurality. Likewise, elements described in conjunction with different embodiments may be combined.

[0102] It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

[0103] The implementation of the invention is not limited to the preferred embodiments shown in the drawings and described above. On the contrary, several variations using the solutions shown and according to the principle of the invention are possible, even in the case of fundamentally different embodiments.

[0104] Figure 12 A schematic cut-away side view of a sidewall 110 of a cavity 108 is shown, according to an exemplary embodiment of the present invention. Figure 12 Only a cross section of the component carrier 100 is shown with the cavity 108. The component carrier comprises a stack 102 having a plurality of electrically insulating layer structures 106 and a plurality of electrically conductive layer structures 104. The cavity 108 is located on the right side of the illustration. Figure 12 In FIG. 1 , the cavity 108 is limited on the left side by a side wall 110 coated with an electrically insulating coating material 112. The side wall 110 is inclined relative to the stacking direction. The stacking direction is Figure 12 The vertical direction of the component carrier 100 is oriented in the stacking direction, and the stacking direction is perpendicular to the two opposing main surfaces 114 and 116 of the component carrier 100. The inclined configuration of the sidewalls 110 can be achieved by laser cutting (from the main surface 114 of the component carrier). Compared to a configuration in which the sidewalls 110 are oriented perpendicular to the main surfaces 114, 116, the inclined orientation of the sidewalls 110 increases the surface area to which the electrically insulating coating material 112 is applied. However, the final contour 158 of the cavity 108 with the applied electrically insulating coating material 112 is oriented perpendicular to the main surfaces 114, 116. The inclined orientation of the sidewalls 110 improves the adhesion of the electrically insulating coating material 112 by increasing the contact surface. However, the electrically insulating coating material 112 compensates for the inclined orientation of the sidewalls 100, and a precise orientation of the final contour 158 perpendicular to the main surfaces 114, 116 can be achieved.

[0105] Figure 13A schematic cut-away side view of a sidewall 110 of a cavity 108 is shown according to another exemplary embodiment of the present invention. Figure 13 The embodiment shown is similar to Figure 12 The embodiments shown are very similar. As far as the differences are not explicitly explained, Figure 13 , please refer to Figure 12 Description of . Figure 12 different, Figure 13 The embodiment in FIG has a side wall 110 that is partially inclined in two different directions relative to the stacking direction. The upper portion of the side wall 110 is inclined to the left, and the lower portion is inclined to the right. Such a configuration can be achieved by laser cutting from two opposite sides in the vertical direction. In addition, the side wall 110 that is partially inclined in two different directions provides an increased contact surface with the electrically insulating coating material 112 and improved adhesion thereto. Figure 12 In the illustrated embodiment, the electrically insulating coating material 112 compensates for the tilted orientation of the sidewalls 100 and allows for a precise orientation of the final profile 158 perpendicular to the major surfaces 114 , 116 .

[0106] Figure 14 A top view of a component carrier 100 without an electrically insulating coating material 112 according to another exemplary embodiment of the present invention is shown. Figure 14 The embodiment shown in Figure 1 Insofar as there are no explicitly explained differences, Figure 14 , please refer to Figure 1 Description of . Figure 1 different, Figure 14 The embodiment shown comprises a gradient change in the cavity width 155 along the main plane direction 150, which gradient differs in the middle portion 151 from the rest of the cavity extension of the side wall 110. This gradient change in the cavity width 155 is provided by two recesses 160, which have an arcuate shape and are located at two opposite side walls 110, as shown in FIG. Figure 14 As shown in the top view. Figure 14 ), this gradient change in cavity width 155 results in a very precise final contour 158 of cavity 108 . Figure 14 The embodiment shown in Figure 1 Another difference of the embodiment shown in is that Figure 14 In the embodiment, the change in cavity width 155 is not mirrored along the main plane direction 150. Figure 14In the embodiment, the change in cavity width 155 and / or the middle portion 151 is not symmetrical relative to a plane oriented perpendicular to the main surface 114 and located in the middle of the cavity 108 in the main plane direction 150. Figure 14 In the embodiment, the asymmetric development of the cavity width 155 with a gradient allows for expanded design flexibility while ensuring an improved quality of the shape and size of the final contour of the cavity.

[0107] Reference Signs List

[0108] 100 component carriers

[0109] 102 stacked pieces

[0110] 104 Electrically conductive layer structure

[0111] 106 Insulation layer structure

[0112] 108 cavity

[0113] 110 sidewall

[0114] 112 Electrical Insulation Coating Materials Department

[0115] 114 main surface

[0116] 116 main surface

[0117] 150 Principal plane direction

[0118] 151 middle part

[0119] 152 principal plane direction

[0120] 155 cavity width

[0121] 157 Coated cavity width

[0122] 158 Final outline

[0123] 160 recess

[0124] Section 160a

[0125] Section 160b.

Claims

1. A component carrier (100), wherein: The component carrier (100) comprises: a stack (102) comprising at least one electrically conductive layer structure (104) and at least one electrically insulating layer structure (106); a through cavity (108) extending vertically through the stack (102) and defined by the sidewalls (100); and an electrically insulating coating material portion (112) covering portions of two opposing major surfaces (114, 116) of the stack (102) and at least a portion of the sidewall (110) of the through cavity (108) of the stack (102), Wherein, along at least one main plane direction of the through cavity (108), a cavity width (155) changing portion is provided at the middle portion (151) of at least one side wall (110) relative to the remaining extended portion of the corresponding side wall (110); preferably, along at least one main plane direction of the through cavity (108), a cavity width (155) changing portion is provided at the middle portion (151) of at least one side wall (110) relative to the remaining straight extended portion of the corresponding side wall (110).

2. The component carrier (100) according to claim 1, wherein The cavity width (155) changing portion includes at least one recess (160) arranged at at least one side wall (110) of the through cavity (108) of the stack (102), wherein at least a portion of the electrically insulating coating material portion (112) is partially filled in the recess (160).

3. The component carrier (100) according to claim 2, wherein The recess (160) is oriented away from a central portion of the through cavity (108), wherein, in a plan view on at least one of the main surfaces (114, 116) of the stack (102), the recess (160) defines a portion of a contour portion of the through cavity (108), and in particular, wherein, in a plan view on at least one of the main surfaces (114, 116) of the stack (102), the recess (160) has a rectangular shape.

4. The component carrier (100) according to claim 2, wherein The recess (160) comprises at least two portions, one of which is larger than the other, thereby defining a stepped recess.

5. The component carrier (100) according to claim 4, wherein A first portion (160a) of the recess (160) is located in the middle portion (151) and adjacent to the remaining extension of the side wall (110), and a second portion (160b) of the recess (160) that is smaller than the first portion (160a) is adjacent to a side portion of the first portion (160a) opposite to the central portion of the through cavity (108), wherein the first portion (160a) and the second portion (160b) are connected to each other.

6. The component carrier (100) according to any one of claims 2 to 4, wherein The recess (160) includes a length portion defined along the main plane direction of the through cavity (108), wherein the length portion is symmetrically distributed about a middle axis of the through cavity (108) in the main plane direction.

7. The component carrier (100) according to claim 1, wherein The through cavity (108) has at least one side wall (110) that is at least partially inclined relative to the stacking direction of the stacked pieces (102).

8. The component carrier (100) according to claim 1, wherein The cavity width (155) change portion includes a gradient change portion of the cavity width (155) along the main plane direction, and the gradient of the cavity width (155) at the middle portion (151) is different from the corresponding gradient along the remaining portion of the side wall (110).

9. The component carrier (100) according to claim 1, wherein The through cavity (108) comprises a shape defining at least one planar extension along a main plane direction, in particular, the through cavity (108) comprises a shape defining at least one planar extension along two main plane directions, wherein the second main plane direction is perpendicular to the first main plane direction, preferably, the two main plane directions are the length and height of a square or rectangular recess or the length and height of a more complex shape such as a hexagon, wherein the cavity width (155) is defined by the distance between two opposite side walls (110).

10. The component carrier (100) according to any one of claims 1 to 9, wherein The through cavity (108) includes rounded or beveled corners.

11. The component carrier (100) according to claim 1, wherein Compared to the shape of the through cavity (108), the electrically insulating coating material portion (112) defines a more regular shape and is more aligned with the main planar direction.

12. The component carrier (100) according to claim 1, wherein The electrically insulating coating material portion (112) coating at least one of the side walls (110) of the through cavity (108) defines a final contour portion (158) of the through cavity (108), wherein the final contour portion (158) is smaller than the contour portion of the through cavity (108) in the absence of the electrically insulating coating material portion (112).

13. The component carrier (100) according to claim 1, wherein Compared to the contour portion of the through cavity (108) in the absence of the electrically insulating coating material portion (112), the electrically insulating coating material portion (112) defines a more uniform lateral final contour portion (158), and the deviation of the final contour portion (158) defined by the electrically insulating coating material portion (112) in the main plane direction of the side wall (110) is within the range of + / -5%, preferably, the deviation of the final contour portion (158) defined by the electrically insulating coating material portion (112) in the main plane direction of the side wall (110) is within the range of + / -1%.

14. The component carrier (100) according to claim 9, wherein The electrically insulating coating material portion (112) defines a straighter lateral final contour portion (158) than the contour portion of the through cavity (108) in the absence of the electrically insulating coating material portion (112), and the coated cavity width (157) formed by the final contour portion (158) between the two opposite side walls (110) coated by the electrically insulating coating material portion (112) has a deviation of at most + / -10%, preferably, the coated cavity width (157) formed by the final contour portion (158) between the two opposite side walls (110) coated by the electrically insulating coating material portion (112) has a deviation of at most + / -2%.

15. The component carrier (100) according to claim 1, wherein The thickness of the electrically insulating coating material portion (112) varies in a circumferential direction around the through cavity (108), wherein the thickness of the electrically insulating coating material portion (112) is greater at the middle portion (151) of the side wall (110) than at the remaining extension of the corresponding side wall (110).

16. The component carrier (100) according to any one of claims 2 to 15, wherein The electrically insulating coating material portion (112) completely fills at least one recess (160) of at least one of the side walls (110), and / or wherein, In a plan view on at least one of the main surfaces (114, 116) of the stack (102), the electrically insulating coating material portion (112) coating at least one of the side walls (110) compensates for the width of at least one recess (160) of the side wall (110).

17. The component carrier (100) according to claim 12, wherein The distance between the final contour portion (158) and the contour portion of the through cavity (108) in the absence of the electrically insulating coating material portion (112) is greater in the middle portion of at least one side wall (110) than in the remaining extension of the corresponding side wall (110). Preferably, the distance between the final contour portion (158) and the contour portion of the through cavity (108) in the absence of the electrically insulating coating material portion (112) is greater in the middle portion of at least one side wall (110) than in the remaining straight extension of the corresponding side wall (110).

18. The component carrier (100) according to claim 1, wherein The shape of the electrically insulating coating material portion (112) defines rounded or inclined corners, and in particular, the final contour portion (158) defines rounded or inclined corners.

19. The component carrier (100) according to claim 1, wherein The electrically insulating coating material portion (112) covers the entire side wall (110) defined by the through cavity (108).

20. The component carrier (100) according to claim 1, wherein The electrically insulating coating material portion (112) has a planar thickness along the side wall (110) of the through cavity (108), and the planar thickness changes along the final contour portion (158) of the through cavity (108), and in particular, the planar thickness changes continuously along the final contour portion (158).

21. The component carrier (100) according to claim 1, wherein Corresponding to the larger width of the through cavity (108), the thickness of the electrically insulating coating material portion (112) is larger, and in particular, the thickness of the electrically insulating coating material portion (112) is larger in the recess (160).

22. The component carrier (100) according to claim 1, wherein The electrically insulating coating material portion (112) defines a further side wall of the stack (102).

23. The component carrier (100) according to claim 1, wherein The recess (160) has a length between 1 mm and 20 mm defined along the main plane direction of the through cavity (108), and has a width between 0.005 mm and 5 mm perpendicular to the length.

24. The component carrier (100) according to claim 1, wherein The change portion of the cavity width (155) is distributed in a mirror image along at least one main plane direction, and in particular, the change portion of the cavity width (155) is distributed in a mirror image along two perpendicular main plane directions.

25. The component carrier (100) according to claim 16, wherein The mirror-image changes of the cavity width (155) have the same size and the same position on the corresponding sidewall (110), and in particular, the mirror-image changes of the cavity width (155) have the same size and the same position on the opposite sidewall (110).

26. The component carrier (100) according to claim 16, wherein The cavity width (155) varies along four side walls (110) surrounding the through cavity (108).

27. The component carrier (100) according to claim 16, wherein The changing portion of the cavity width (155) has the same size and the same position on the corresponding side wall (110), and in particular, the changing portion of the cavity width (155) has the same size and the same position on the opposite side wall (110).

28. The component carrier (100) according to claim 1, wherein The component carrier (100) is a printed circuit board or substrate.

29. A method of manufacturing a component carrier (100), wherein: The method comprises: Providing a stack (102) comprising at least one electrically conductive layer structure (104) and at least one electrically insulating layer structure (106); forming a through cavity (108) extending vertically through the stack (102) and defined by side walls (100), wherein, along at least one main plane direction of the through cavity (108), a change in cavity width (155) is provided at a middle portion (151) of at least one side wall (110) relative to the remaining cavity extension of the corresponding side wall (110), preferably, along at least one main plane direction of the through cavity (108), a change in cavity width (155) is provided at a middle portion (151) of at least one side wall (110) relative to the remaining straight cavity extension of the corresponding side wall (110); and An electrically insulating coating material portion (112) is applied to portions of two opposing major surfaces (114, 116) of the stack (102) and to at least portions of the sidewalls (110) of the through cavity (108) of the stack (102).

30. The component carrier (100) according to claim 29, wherein The method includes forming the through cavity (108) in the stack (102) by laser processing.

31. The component carrier (100) according to claim 29 or 30, wherein The method includes applying the electrically insulating coating material portion (112) on the sidewall (110) and on portions of the major surfaces (114, 116) using a roller.

32. The component carrier (100) according to claim 29 or 30, wherein The method comprises applying the electrically insulating coating material portion (112) on the side wall (110) and on portions of the major surfaces (114, 116) using a pair of rollers rolling along opposite major surfaces (114, 116) of the stack (102); preferably, applying the electrically insulating coating material portion (112) on the side wall (110) and on portions of the major surfaces (114, 116) using a pair of rollers rolling simultaneously along opposite major surfaces (114, 116) of the stack (102).

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