Printed circuit board, metal-ceramic substrate as insert and method for manufacturing such a printed circuit board

Abstract

Printed circuit board (100) for electrical components (5) and / or conductor tracks (4), comprising - a basic body (2) extending along a principal extension plane (HSE), and - an insert (1) which is integrated into the base body (2), wherein the insert (1) comprises a metal-ceramic substrate (15), an electrical and / or electronic component (5) and an encapsulation (10) which encloses at least the electrical and / or electronic component (5), characterized in that the insert (1) has a round profile or a rounded corner in the main extension plane.

Description

[0001] The present invention relates to a printed circuit board, a metal-ceramic substrate as an insert for such a printed circuit board and a method for manufacturing such a printed circuit board.

[0002] Printed circuit boards (PCBs) are well known from the prior art. These boards serve as carriers for electrical circuits, which are formed or assembled from conductive traces, electrical components, and / or connections. The electrical circuits are preferably located on one side of the PCB. Typically, such PCBs are made of a plastic, in particular a fiber-reinforced plastic, an epoxy resin, and / or hard paper. The use of such materials proves to be particularly cost-effective and easy to handle during the manufacturing process. However, it has been found that the aforementioned materials for PCBs have limited thermal conductivity, which is necessary to dissipate heat generated by electrical components during operation. Furthermore, their insulating properties are limited.With the increasing performance of electronic components, printed circuit boards made from conventional materials are therefore unsuitable for permanently withstanding the stresses that arise during operation and for providing good insulation properties.

[0003] On the other hand, printed circuit boards (PCBs) made from metal-ceramic substrates are characterized by high insulation properties and typically exhibit higher thermal conductivity compared to those made from the materials mentioned above. However, the production of metal-ceramic substrates is more complex and expensive than the production of PCBs made from plastic, epoxy resin, and / or hard paper.

[0004] A multilayer printed circuit board structure is known from DE 10 2005 032 489 B3. DE 10 2017 200 128 A1 describes an electronic module with an antenna. DE 10 2013 104 739 A1 describes a filling of a stepped flank profile of a metal layer. US 2003 / 0 189 246 A1 shows encapsulated components.

[0005] Starting from the state of the art, the present invention aims to provide printed circuit boards that meet the high demands for heat dissipation and insulation of electronic components and can be produced at a lower cost.

[0006] This problem is solved by the printed circuit board according to claim 1, an insert according to claim 8 and a method according to claim 9. Further embodiments can be found in the dependent claims and the description.

[0007] According to a first aspect of the present invention, a printed circuit board for electrical components and / or conductor tracks is provided, comprising - a basic body extending along a principal extension plane, and - an insert that is integrated into the main body, wherein the application comprises a metal-ceramic substrate, an electrical and / or electronic component and an encapsulation that at least encloses the electrical and / or electronic component.

[0008] In contrast to printed circuit boards known from the prior art, the invention provides that the base body of the printed circuit board is not entirely made of one of the common materials, such as plastic, hard paper and / or epoxy resin, but rather only a section of the printed circuit board is formed from at least the insert according to the claim. In particular, the metal-ceramic substrate with the encapsulated component is embedded or inserted into the base body of the printed circuit board in order to provide targeted, localized increased thermal conductivity. This makes it possible, for example, to insert or embed inserts in the printed circuit board in areas where increased heat generation is expected.At the same time, it is possible to manufacture the majority of the basic body from a material such as a plastic, in particular a fiber-reinforced plastic, epoxy resin or hard paper, which is inexpensive and easy to process.

[0009] In particular, it proves advantageous to provide electrical or electronic components that exhibit increased heat generation during operation in an environment specifically tailored to the heat output of the respective component. This is advantageously achieved with the claimed application, in which the design of the metal-ceramic substrate, for example, with regard to the dimensioning of the component metallization and / or backside metallization and / or ceramic element along a stacking direction perpendicular to the main extension plane, takes into account the respective heat generation emanating from the electrical component. For example, it is conceivable that the thickness of the component metallization of the metal-ceramic substrate is adapted to the respective heat generation of the component in order to provide the fastest possible heat dissipation for the respective component.The individual inserts then simply need to be placed into the base of the printed circuit board. An electrical connection is provided between the component and the outside of the insert to supply and control the component. Preferably, only a single component is provided for each insert, or the insert comprises several components. Furthermore, those skilled in the art understand a complete encapsulation of the component to mean that the component is not exposed on any side, i.e., no outside.

[0010] Furthermore, encapsulation allows for external protection of the electrical and electronic components. It also simplifies component integration into the base body, requiring only the connection between the insert's terminals and the corresponding traces and / or connections on the circuit board. Additionally, the encapsulated components no longer protrude from the circuit board's surface, thus providing further protection from the surrounding environment.

[0011] Preferably, the insert, particularly one with a suitably profiled side wall, is designed to interlock with the base body in a direction parallel to the stacking direction when installed. Additionally, it is conceivable that the positive-locking connection between the base body and the insert is reinforced by a material-bonded and / or force-fit connection.

[0012] Furthermore, it is specifically provided that the proportion of the insert(s) to the printed circuit board is less than 30%, preferably less than 20%, and particularly preferably less than 10%. It is further provided that the insert extends from the component side of the base plate to the rear side of the printed circuit board body. In other words, the insert is flush with the base plate body in a direction perpendicular to the main plane of extension on both sides, i.e., on the component side and the rear side. The positive locking mechanism between the base plate body and the metal-ceramic substrate serving as the insert creates a particularly durable bond between the metal-ceramic substrate and the base plate body, preventing the insert from detaching from the printed circuit board. Preferably, the positive locking mechanism acts in both possible directions perpendicular to the main plane of extension of the base plate body.Furthermore, it is conceivable that additional inserts are arranged within the base body. It is also possible that the insert is flush with the base body only on the component side, while the back of the metal-ceramic substrate is enclosed by the base body. In other words, the metal-ceramic substrate or the insert is recessed or inserted into a recess in the base body of the printed circuit board. This also results in a positive fit parallel to the main plane of extension.

[0013] In particular, the metal-ceramic substrate and the base body are designed such that their coefficients of thermal expansion are as similar as possible. In other words, the difference between the coefficient of thermal expansion of the insert and the base body is kept as small as possible. This is achieved, for example, by adjusting the thickness of the ceramic element within the metal-ceramic substrate. It is also conceivable that a stabilizing layer is provided to adjust the thermomechanical expansion coefficient, or that several metal layers and / or different metallizations (e.g., component metallizations and back-metallizations made of different metals or materials) are used to achieve the desired adaptation.This ensures that expansions occurring during operation do not create significant mechanical stresses between the base body and the metal-ceramic substrate, which could, for example, lead to cracking. It is also preferably conceivable that different ceramic elements are used within a metal-ceramic substrate.

[0014] It has proven advantageous if, in addition to the positive locking, a material bond is achieved between the side surface of the insert and the base body.

[0015] According to a preferred embodiment, it is provided that, in order to form the positive locking interaction, - the insert, preferably the metal-ceramic substrate and / or the encapsulation, is profiled on a side surface that is not parallel to the main extension plane and / or - a ceramic element of the metal-ceramic substrate and / or a part of it protrudes in a direction parallel to the main extension plane opposite a component metallization and / or the backside metallization of the metal-ceramic substrate.

[0016] For example, it is envisaged that a side surface, in particular a side surface of the encapsulation, the component metallization, and / or the back surface metallization, is concavely and / or convexly curved or bent. Alternatively, it is also conceivable that the insert has a stepped design on its side wall or side surface. In particular, it is envisaged that the base body engages in the recessed or projecting sections on the side surfaces of the encapsulation, the metallization, and / or the back surface metallization in order to create a positive fit in one or both directions perpendicular to the main extension plane. For example, it is conceivable that the outermost edge of the encapsulation or the component metallization is stepped, in particular stepped such that the open area of ​​the step is formed on the side facing the component side and / or the back surface.A component can be arranged on the component metallization in such a way that, considering isotropic heat transfer, the heat spread is completely absorbed by the component metallization. The sections of the component metallization that do not contribute to heat transfer are removed in this stepped arrangement and replaced by the base body. Preferably, a protruding section of the ceramic element is used to form the positive connection. This is particularly the section known as the pullback, which ensures sufficient insulation between the component metallization and the backside metallization.

[0017] Preferably, the insert has a maximum dimension in a plane parallel to the main extension plane, with a value between 1 mm and 200 mm, preferably between 4 mm and 60 mm, and most preferably between 6 mm and 30 mm. This provides comparatively small inserts that can be used as needed to locally increase the thermal conductivity in the printed circuit board. In particular, a relatively large number of individual inserts can be provided from a single large card. Such a large card is defined by the format immediately after the component metallization is bonded to the backside metallization, which is achieved via a suitable bonding method.

[0018] In particular, the side surface is profiled to achieve a modulation depth or height of between 1 µm and 200 µm, preferably between 20 µm and 100 µm, and most preferably between 25 µm and 60 µm. Modulation depth or height is defined as a deviation, measured in a direction parallel to the main plane of extension, from an imaginary cylindrical outer profile associated with the narrowest point of the metal-ceramic substrate (measured in planes parallel to the main plane of extension). The imaginary cylindrical outer profile extends perpendicular to the main plane of extension. It is also conceivable that the modulation depth is caused by the component metallization and / or the ceramic element projecting beyond the backside metallization in a direction parallel to the main plane of extension.For example, it is also conceivable that the side surface in the area of ​​the ceramic element has an inclined course relative to the stacking direction (in other words: the top and bottom of the ceramic element have different diameters).

[0019] For example, it is conceivable that the profile of the side surface(s) in the area of ​​encapsulation, component metallization, and / or backside metallization extends parallel to the stacking direction (i.e., the cross-section of the component metallization and / or backside metallization is essentially constant in the stacking direction). The modulation depth is then preferably achieved by a step at the level of the ceramic element. The modulation depth can be generated by profiling or modulation in the area of ​​the ceramic element, whereby the profiling in the stacking direction can be continuous across the thickness of the ceramic element or discrete or abrupt at the level of the ceramic element.

[0020] Furthermore, it is conceivable that the insert has one or more projections that extend in a direction parallel to the main plane of extension relative to the general contour of the insert's outer circumference. This projection, preferably nose-shaped, can advantageously provide an additional positive fit in the circumferential direction along the outer circumference, supporting a rotationally fixed arrangement in the base body. It has proven advantageous that such a projection can be created by separating the metal-ceramic substrates from a large sheet using laser light and / or waterjet cutting.

[0021] According to a preferred embodiment, the insert has at least one insert-side connection, wherein the at least one insert-side connection is formed on a component side of the insert and is connected to the electrical or electronic component via a through-hole, in particular to a component-side connection on the electrical or electronic component on the side facing away from the metal-ceramic substrate. The connections advantageously make it possible to control and electrically supply the encapsulated, in particular embedded, electrical or electronic components from the outside of the insert by means of conductor tracks and / or insert-side connections. The through-holes extend through the encapsulation and thus establish a connection between the outside of the insert and the embedded or encapsulated electrical or electronic component.By using appropriate electrical or electronic components that have a component-side connection on their upper side, a shortened via can be provided, which establishes an electrical connection with an outer surface of the insert. In particular, it is intended that such an insert is advantageous if the insert integrated into the printed circuit board is flush with the component side of the circuit board on its upper surface, i.e., on the side facing away from the ceramic substrate.

[0022] This results in a common plane for the conductor tracks on the outside of the printed circuit board, and the electrical or electronic component can be recessed into the interior of the printed circuit board, in particular into the interior of the insert, relative to this component side.

[0023] Preferably, the metal-ceramic substrate comprises a component metallization, a ceramic element, and a backside metallization. A backside metallization is particularly advantageous for counteracting thermomechanical stresses that would otherwise arise in a metal-ceramic substrate due to the different coefficients of thermal expansion of the ceramic on one side and the metal on the other. A corresponding symmetrical arrangement of the component metallization, ceramic element, and backside metallization effectively counteracts this stress development. This is advantageous for the service life of the component and, consequently, for the service life of the printed circuit board.

[0024] Preferably, the component metallization is structured, with the space between two metal sections of the component metallization preferably filled with encapsulation material. The two metal sections are electrically insulated from each other by the structuring. This allows each metal section to be used individually for different electrical components and their control. To electrically connect the respective metal sections to the outside of the insert and / or the printed circuit board, further vias are provided, extending from an outer surface of the encapsulation, particularly on the component side of the printed circuit board, through the encapsulation to the component metallization.

[0025] Preferably, the encapsulation surrounds the electrical and / or electronic component and at least a portion of the metal-ceramic substrate. For example, it is conceivable that, in addition to the electrical or electronic component, the component metallization, the ceramic element, and / or the backside metallization are also surrounded by the encapsulation, particularly on the insert side. This advantageously allows for a side wall that is formed as largely as possible by the encapsulation material. This can prove advantageous if it simplifies the connection of the insert to the base body. For example, it is conceivable that a more effective bond between the encapsulation and the base body can be achieved using suitable adhesives than between the metal-ceramic substrate and the base body.Furthermore, it is conceivable to incorporate a corresponding profile into the side wall to facilitate a positive fit between the base body and the insert. Additionally, the encapsulation could be designed to act as a buffer between the base body and the metal-ceramic substrate, compensating for the expansion of the base body and / or the metal-ceramic substrate. This could improve the service life of the insert and / or the circuit board.

[0026] Preferably, one side wall of the insert is shaped to form a profile, wherein, for example, the ceramic element projects in a direction parallel to the main extension plane relative to the component metallization and / or the backside metallization. The ceramic element may, for example, protrude from or project beyond the encapsulation.

[0027] Preferably, the insert has additional vias embedded in the encapsulation, connecting the component metallizations of the metal-ceramic substrate to an insert-side connection. Preferably, the distance between the component-side connection and the insert-side connection, measured in the stacking direction, is between 100 µm and 500 µm. This advantageously allows for the smallest possible distance between the component-side connection and the insert-side connection, which is beneficial for lossless communication between the electrical component and the outside of the insert, particularly without losses due to parasitic inductances.

[0028] Furthermore, it is conceivable that the insert has rounded or rounded corner areas on its perimeter in a plane parallel to the main extension plane. This proves advantageous because it counteracts a core effect.

[0029] Another aspect of the present invention is an insert for a printed circuit board according to the invention. All the advantages and properties described for the printed circuit board can be transferred analogously to the insert and vice versa.

[0030] A further object of the present invention is a method for manufacturing a printed circuit board according to the present invention, wherein an insert and a base body are provided, the insert is inserted into the base body, and the insert and base body are joined together by a material bond, a force bond, and / or a form bond. All advantages and features described for the printed circuit board can be transferred analogously to the method and vice versa.

[0031] Preferably, the insert is profiled to create a positive fit between the insert and the base of the printed circuit board in the stacking direction. In particular, profiling can be achieved, for example, by etching, by mechanical processing such as milling, by laser processing, and / or by a water jet.

[0032] Furthermore, it is planned that bores will be incorporated into the encapsulation to create corresponding vias that connect the outside of the insert to the electrical or electronic component. Alternatively, it is conceivable that free areas for the subsequent vias are created during the manufacturing process of the encapsulation. For example, it is planned that, through a suitable design of the mold, in particular the mold halves, in an injection molding or casting process, such as injection molding, it will be ensured that such free areas for the subsequent vias are provided.It is particularly preferred that slidably mounted punch elements are embedded in the mold to ensure that these punch elements are moved before a cavity is filled and, in particular, are placed onto the electrical or electronic components embedded in the metal-ceramic substrate. This advantageously prevents damage to the electrical and / or electronic component during the encapsulation process due to slight displacement or positional changes of the component bonded to the metal-ceramic substrate.

[0033] Essential components of the metal-ceramic substrates are an insulating layer, preferably made entirely of ceramic, and at least one metal layer bonded to the insulating layer. Due to their comparatively high insulating strength, ceramic insulating layers have proven particularly advantageous in power electronics. Conductive tracks and / or connection pads for the electrical components can then be created by structuring the metal layer. Preferably, the component metallization of the metal-ceramic substrate intended for use is not structured, but forms a closed surface. A prerequisite for providing such a metal-ceramic substrate is a permanent bond between the metal layer and the ceramic layer. Besides a so-called direct metal bonding method, i.e.,In addition to a DCB or DAB process, bonding via an active soldering process, a thick film layer process, diffusion bonding and / or hot isostatic bonding is also conceivable.

[0034] Suitable materials for the metal layer or metallization include copper, aluminum, molybdenum, tungsten, and / or their alloys such as CuZr, AlSi, or AlMgSi, as well as laminates such as CuW, CuMo, CuAl, and / or AlCu or MMC (metal matrix composite), such as CuW, CuMo, or AlSiC. Furthermore, it is preferred that the metal layer or metallization on the manufactured metal-ceramic substrate, particularly as component metallization, is surface-modified.

[0035] Surface modifications could include sealing with a precious metal, especially silver; and / or gold, or (electroless) nickel or ENIG ("electroless nickel immersion gold"), or edge sealing of the metallization to suppress cracking or propagation. For example, the metal of the component metallization could also differ from the metal of the reverse side metallization.

[0036] Preferably, the ceramic element comprises Al₂O₃, Si₃N₄, AlN, an HPSX ceramic (i.e., a ceramic with an Al₂O₃ matrix containing an x ​​percent proportion of ZrO₂, for example, Al₂O₃ with 9% ZrO₂ = HPS₅ or Al₂O₃ with 25% ZrO₂ = HPS₅), SiC, BeO, MgO, high-density MgO (> 90% of the theoretical density), or TSZ (tetragonally stabilized zirconia) as the ceramic material. It is also conceivable that the ceramic element is designed as a composite or hybrid ceramic, in which several ceramic layers, each differing in their material composition, are arranged one above the other and joined together to form a ceramic element in order to combine various desired properties.

[0037] According to the invention, the insert, in particular the metal-ceramic substrate, has a round profile or a rounded corner in its main plane. A corresponding design of the insert's cross-section in a plane parallel to the main plane proves particularly advantageous because it reduces the notch effect on the printed circuit board's substrate. This, in turn, extends the service life of the printed circuit board with the insert.

[0038] Preferably, the metal-ceramic substrate has a ceramic element, wherein a component metallization is attached to the ceramic element, wherein - one of the component metallizations is provided or formed in a backside metallization opposite a stacking direction running perpendicular to the main extension plane, and / or - a stabilizing layer, for example in the form of a further ceramic element, is provided or formed, wherein a metallic intermediate layer is arranged between the ceramic element and the stabilizing layer, and / or - the component metallization and / or the backside metallization comprises a first metal layer and / or a second metal layer, wherein the first metal layer and the second metal layer are arranged one above the other.

[0039] In particular, the thermal expansion coefficient of the insert can be influenced by appropriately designing the metal-ceramic substrate, in order to match it to the thermal expansion coefficient of the base body. For example, it is conceivable to design the stabilizing layer from a different material or to dimension it accordingly. The thickness of the ceramic element can also be used to optimize the thermomechanical expansion coefficient of the insert in such a way as to reduce mechanical stresses between the base body and the insert. Preferably, the first metal layer differs from a second metal layer with regard to its grain size, wherein preferably a grain size in the first metal layer is smaller than a grain size in the second metal layer and / or, more preferably, the thickness of the first metal layer is thinner than that of a second metal layer.Furthermore, it is conceivable that the thickness of the component metallization differs from the thickness of the backside metallization. This advantageously allows for influencing the height of the ceramic element within the printed circuit board substrate and, in particular, ensuring that the insulating ceramic element is positioned offset towards the backside and away from the component side of the substrate, or vice versa.

[0040] In particular, it is intended that the insert is placed into the base body and that the insert and base body are connected to each other by material bonding, force bonding and / or form bonding.

[0041] Further advantages and features will become apparent from the following description of preferred embodiments of the invention with reference to the accompanying figures. Individual features of the individual embodiments can be combined with one another within the scope of the invention.

[0042] It shows: Fig. 1: Schematic representation of a printed circuit board according to a first preferred embodiment of the present invention in a top view (above) and a sectional view (below) Fig. 2a - 2c Examples of preferred embodiments of the inserts according to the present invention Fig. 3a , Fig. 3b Further embodiments of inserts according to the present invention Fig. 4a - 4c Further embodiments of inserts according to the present invention Fig. 5a - 5d Further embodiments of inserts according to the present invention Fig. 6a - 6d Further embodiments of inserts according to the present invention Fig. 7a, Fig. 7b Exemplary embodiments of printed circuit boards according to the present invention

[0043] In Fig. Figure 1 shows a printed circuit board 100 according to a first preferred embodiment of the present invention in a top view (top) and a sectional view (bottom). Such printed circuit boards 100 serve in particular as carriers for circuits formed from electrical or electronic components 5, terminals 7, and / or conductive traces 4. The electrical or electronic components 5, the conductive traces 4, and / or the terminals 7, for example in the form of solder pads or solder lugs, are preferably arranged or connected to a component side BS of the printed circuit board 100. For particularly cost-effective production of such printed circuit boards 100, it has become established to use plastics, in particular fiber-reinforced plastics, epoxy resin, and / or hard paper, as materials for a base body 2, which extends essentially along a main extension plane HSE and on whose component side BS electronic components 5 are formed or connected.are connected. Preferably, the electrical or electronic components 5 are power components. Electrical conductors 4 can also be considered electrical components 5.

[0044] Due to continuous advancements in electronics, particularly regarding the performance of electrical components 5, it has become apparent that the materials used for the base body 2 cannot withstand the new challenges, especially concerning the heat generated during operation. This is primarily because the materials used for the base body 2 of a printed circuit board 100 have a comparatively low thermal conductivity, which prevents sufficient dissipation of the heat generated by the electrical components during operation.

[0045] Printed circuit boards 100, which are designed as metal-ceramic substrates, can, however, dissipate the generated heat to a sufficient extent due to their increased thermal conductivity, especially compared to printed circuit boards made of substrates 2 from the above-mentioned materials, i.e. plastics, especially fiber-reinforced plastics, epoxy resin and / or hard paper, but are more complex to produce and costly.

[0046] In order to utilize the positive properties of a printed circuit board 100 made of a plastic, an epoxy resin or a hard paper and the positive properties of a metal-ceramic substrate, in particular its thermal conductivity, it is preferably provided that the printed circuit board 100 is designed according to the specifications in Fig. In the embodiment shown in Figure 1, a base body 2 extends along the main extension plane HSE and into which an insert 1 is integrated, the insert 1 comprising a metal-ceramic substrate 15. Preferably, the insert 1 is arranged in the printed circuit board 100 at locations where increased heat generation is expected.

[0047] Preferably, at least one insert 1, and preferably several inserts 1, are integrated into the base body 2 of the printed circuit board 100. A component side BS of the insert 1 preferably terminates substantially flush with a component side BS of the base body 2 and / or a rear side RS of the insert 1 terminates flush with the rear side RS of the base body 2. Furthermore, it is preferably provided that the volume fraction of the insert 1 or the multiple inserts 1 in relation to the volume of the base body 2 or the entire printed circuit board 100 is less than 30%, preferably less than 20%, and particularly preferably less than 10%.It has been shown that with such low proportions it is already possible to effectively improve the thermal properties of the printed circuit board 100 and at the same time to work predominantly with materials for the base body 2 that are easy to process and less expensive than metal-ceramic substrates 15.

[0048] Preferably, the insert 1, which is flush with the component side BS and the rear side RS of the base body 2 in a stacking direction S perpendicular to the main extension direction HSE, interacts with the base body 2 in a form-fit, force-fit, and / or material-fit direction perpendicular to the main extension direction HSE. This ensures or supports a secure hold of the insert 1 in the printed circuit board 100. In particular, it is provided that the insertion is achieved through both material-fit and form-fit connections.Preferably, the selection of materials, whether a material of the base body 2 on the one hand or one or more materials of the ceramic element 30, is carried out such that the differences in the coefficients of thermal expansion are kept as small as possible in order to prevent thermomechanical stresses from leading to cracks and / or damage to the printed circuit board 100 and / or the metal-ceramic substrate 15. Preferably, the coefficient of thermal expansion of the insert 1 does not deviate from the coefficient of thermal expansion of the base body 2 by more than 30%, preferably by more than 15%, and particularly preferably by more than 10%. To select the suitable inserts, the person skilled in the art uses, for example, simulations for the respective compositions of the inserts 1 and compares these with the values ​​for the base body 2.

[0049] In particular, the insert 1 comprises a metal-ceramic substrate 15 and an electrical and / or electronic component 5. Specifically, the electrical and / or electronic component 5 is already integrated into the insert 1 by being connected to a component metallization 20 of the metal-ceramic substrate 15, for example, by soldering. In addition to the metal-ceramic substrate 15 and the electrical and / or electronic component 5, the insert 1 also includes an encapsulation 10 that surrounds the electronic and / or electrical component 5, preferably completely sealing and thus encapsulating it on the component side BS. This allows an electrical and / or electronic component 5, which generates heat during operation, to be advantageously integrated into the base body 2 of the circuit board 100 together with a metal-ceramic substrate 15 as the insert 1.This allows such electrical and / or electronic components 5, which emit increased heat energy during operation, to be installed directly in the appropriate environment, thus ensuring adequate heat dissipation.

[0050] Preferably, the insert 1 is provided to have a side wall SW which has a general orientation perpendicular to the main extension plane HSE and connects the component side BS and the rear side RS of the insert. Preferably, the side wall SW is profiled to form a positive fit with the base body 2 of the printed circuit board 100 in the installed state, for example, concave and / or convex.

[0051] In the Fig. Figures 2a-2c are examples of preferred embodiments of the inserts 1 according to the present invention. Fig. 2a An insert 1 is provided in which an encapsulation 10 surrounds the electrical and / or electronic component 5, i.e., surrounds the electrical and / or electronic component 5 on at least three different sides, so that the component 5 is not exposed on any side. In particular, the electrical and / or electronic component 5 is embedded in the encapsulation 10, which is solid, i.e., free of cavities. In particular, the encapsulation 10 is manufactured by means of a pressing, casting, or injection molding process. Such encapsulations 10 are solid and can be manufactured relatively easily. Furthermore, it is preferably provided that insert-side connections 8 are provided on an outer side, in particular on an outer side facing the component side BS in the installed state, of the encapsulation 10. A connection or... can be made via these insert-side connections 8 in the installed state.Contact can be made, for example, to other conductor tracks 4 or external lines. The insert-side connections 8 are preferably connected to component-side connections 7 via vias 9 in the encapsulation 10. In particular, these component-side connections 7 are located on a top side, i.e., on a side of the component 5 facing away from the metal-ceramic substrate 15. Furthermore, it is preferably provided that the encapsulation 10 has a first thickness D1 along a stacking direction S and the metal-ceramic substrate 15 has a second thickness D2. Preferably, the ratio of the first thickness D1 to the second thickness D2 is such that it assumes a value between 0.1 and 0.7, preferably between 0.15 and 0.4, and most preferably between 0.18 and 0.23.Furthermore, it is preferably provided that the encapsulation 10 is dimensioned such that the distance D between the component-side connection 7 and the insert-side connection 8 in the stacking direction S assumes a value between 100 µm and 500 µm. This advantageously allows for a connection with minimal electrical loss between the external insert-side connections 8 and the encapsulated component-side connections 7 on the component 5.

[0052] Furthermore, it is particularly preferred that the metal-ceramic substrate 15 comprises a component metallization 20, a ceramic element 30, and a back-side metallization 20'. It is conceivable that a third thickness D3 of the component metallization 20, measured in the stacking direction S, is the same as a fourth thickness D4 of the back-side metallization 20', also measured in the stacking direction S. This provides symmetry between the front and back sides of the metal-ceramic substrate, which counteracts deflection.

[0053] Furthermore, it is preferably provided that, in the stacking direction S, the ceramic element 30 has a fifth thickness D5, which has a value between 0.07 mm and 0.4 mm, preferably between 0.15 mm and 0.4 mm, and particularly preferably between 0.22 mm and 0.28 mm. Due to the insertion of the insert 1 into the base body 2, the base body 2 also has a stabilizing effect on the insulating ceramic element 30, thus increasing the mechanical stability of the insert 1 in the installed state. This also allows, for example, the use of a comparatively thin ceramic element 30. Preferably, the third thickness D3 and / or fourth thickness D4 has a value between 0.1 mm and 0.8 mm, more preferably between 0.15 mm and 0.7 mm, and particularly preferably between 0.3 mm and 0.7 mm. It is also conceivable that the third thickness D3 takes on a value greater than 1.3 mm, preferably greater than 1.8 mm and particularly preferably greater than 2 mm.

[0054] Furthermore, it is particularly preferred in the embodiment of the Fig. 2a, that a first extension A1 of the encapsulation 10, measured in a direction parallel to the principal extension plane HSE, is smaller than a second extension A2 of the metal-ceramic substrate 15 measured parallel to it. As a result, the metal-ceramic substrate 15 projects in the direction of the principal extension plane HSE towards the outermost edge of the encapsulation 10.

[0055] In the exemplary embodiment of the Fig. 2b, it is provided that the insert 1 comprises, in addition to the electrical and / or electronic component 5, a second electrical and / or electronic component 5, which are together connected to the component metallization 20, with the electrical and / or electronic components 5 being in electrical contact with each other via the component metallization 20. The projection of the metal-ceramic substrate 1 beyond the outermost edge of the encapsulation 10 in a direction parallel to the main extension plane HSE is particularly advantageous because it allows direct contact with the component metallization 20, especially from the component side BS. This also allows the component metallization 20 to be used for controlling the encapsulated or embedded component 5.

[0056] In the Fig. In the embodiment shown in Figure 2c, the component metallization 20 is structured such that two mutually insulated metal sections 21 are realized in the metal-ceramic substrate 15. The space between the two metal sections 21 is filled with an encapsulation material 10. For example, it is further provided that conductive traces 4 are formed on the outside of the insert 1, particularly on an outside of the insert 1 facing component side BS, which create an electrical connection between the electrical component 5 of one metal section 21 and the metal section 21 of the other electrical component 5. In particular, it is provided that a further via 19 is provided, which connects the insert-side terminals 8 to the component metallization 20.

[0057] In the Fig. 3a and Fig. 3b shows further embodiments of inserts 1 according to the present invention.

[0058] The stakes differ from the Fig. 3a and Fig. 3b from the one from the Fig. 2a essentially only in that the metal-ceramic substrates 15 are designed differently. In particular, in the exemplary embodiment of Fig. 3a provided that a third extension A3 of the ceramic element along a direction parallel to the principal extension plane HSE is larger than a fourth extension A4 of the component metallization 20 and / or the backside metallization 20'. In particular, in the exemplary embodiment of Fig. 3a provides that a fourth extension A4 of the component metallization 20 corresponds to the fourth extension A4 of the backside metallization 20'. The ceramic element 30 projecting from the side wall SW, in particular the ceramic element 30 projecting relative to the component metallization 20 and / or the backside metallization 20', forms, firstly, a so-called pullback, which contributes to the electrical and / or electronic insulation between the component metallization 20 and the backside metallization 20'. Furthermore, the projecting section of the ceramic element 30 provides a section suitable for forming a positive fit between the base body 2 of the printed circuit board 100 and the insert 1, thereby further improving the bond between the insert 1 and the printed circuit board 100 in the assembled state.In particular, the protrusion relative to the component metallization 20 and the back side metallization 20' allows for a positive locking mechanism to be realized, which interacts both in the direction of the component side BS and in the direction of the back side RS, i.e. on both sides, in a direction essentially perpendicular to the main extension plane HSE.

[0059] In the Fig. In the embodiment shown in 3b, it is different from the embodiment shown in the Fig. 3a provides that the fourth dimension A4 of the backside metallization 20' is larger than the fourth dimension A4 of the component metallization 20 and larger than the third dimension A3 of the ceramic element 30. This creates an insert 1 that tapers from the backside RS to the component side BS, in particular in a stepped manner. Specifically, by appropriately dimensioning the fourth dimension A4 of the component metallization 20 and the backside metallization 20' and the third dimension A3 of the ceramic element 30, an external shape of the metal-ceramic substrate 15 can be realized which, in accordance with a key-and-lock principle, can be used, for example, to allow only the insertion of suitable inserts into the corresponding holes in the base body 2, which are defined accordingly by the circuit board 100 or the base body.This prevents, for example, incorrect inserts 1 from being accidentally inserted into the circuit board 100.

[0060] Alternatively, it is conceivable that the fourth extension A4 of the backside metallization 20' is larger than the fourth extension A4 of the component metallization 20 and smaller than the third extension A3 of the ceramic element 30.

[0061] In the Fig. Figures 4a - 4c show further embodiments of inserts 1 according to the present invention.

[0062] In particular, it is in the exemplary embodiments of the Fig. 4a - 4c provides that the first extension A1 of the encapsulation 10 corresponds to the fourth extension A4 of the component metallization 20. In particular, it is therefore provided that the encapsulation 10 is oriented such that it forms a common plane with the side wall SW of the component metallization 10 on the outer circumference or side wall SW of the insert 1. To establish electrical contact with the component metallization 20, it is particularly preferred that a further via 19 is provided, which electrically connects an insert-side terminal 8 to the component metallization 20. Accordingly, such a further via 19 is also embedded in the encapsulation 10, with the further via 19 extending from the outside of the encapsulation 10 to the component metallization 20.

[0063] The exemplary embodiment of the Fig. 4b differs essentially from the embodiment of the Fig. 4a such that the third extension A3 of the ceramic element 30 forming a pullback is larger than a fourth extension A4 of the component metallization 20 and the backside metallization 20'.

[0064] In the exemplary embodiment of the Fig. 4c is as in the embodiment of the Fig. 3b the fourth extension A4 of the backside metallization 20' larger than the third extension A3 of the ceramic element 30 and the fourth extension A4 of the component metallization 20.

[0065] In the Fig. Figures 5a-5d show further embodiments of inserts 1 according to the present invention. Fig. In each of the embodiments 5a - 5d, the encapsulation 10 is designed to also enclose or surround the component metallization 20. In other words, in the embodiments of Fig. In sections 5a-5d, both the electrical and / or electronic component 5 and the component metallization 20 are embedded in the encapsulation 10, with the side walls SW of the component metallization 20 also being surrounded or enclosed by the encapsulation 10. This allows for additional insulation in the component metallization 20 from the base body 2 of the printed circuit board 100. Fig. In the embodiment shown in 5a, it is provided that the fourth extension A4 of the backside metallization 20' essentially corresponds to the fourth extension A4 of the component metallization 20.

[0066] In the Fig. In the embodiment shown in Figure 5b, the fourth extension A4 of the backside metallization 20' essentially corresponds to the first extension A1 of the encapsulation 10 and / or the third extension A3 of the ceramic element 30. This ensures a common seal between the encapsulation 10, the ceramic element 30, and the backside metallization 20 at the side within the insert 1.

[0067] In Fig. In section 5c, it is provided that the fourth extension A4 of the backside metallization 20' is larger than the first extension A1 of the encapsulation 10 and the third extension A3 of the ceramic element 30. This provides a corresponding protruding feature of the backside metallization 20 relative to the outermost extent of the encapsulation 10 and the ceramic element 30.

[0068] In the exemplary embodiment of the Fig. In addition to the electrical component 5 and the component metallization 20, the ceramic element 30 is also enclosed or surrounded by the encapsulation 10. Specifically, the side walls SW of the ceramic element 30 are surrounded and enclosed by the encapsulation 20. This ensures that the ceramic element 30 is spaced apart from the base body 2 of the circuit board 100 when installed.

[0069] Furthermore, it is preferably provided that in the exemplary embodiment of the Fig. 5d the fourth extension A4 of the backside metallization 20' essentially corresponds to the first extension A1 of the encapsulation 10, while the fourth extension A4 of the component metallization 20 is smaller than the fourth extension A4 of the backside metallization 20'.

[0070] In the Fig. Figures 6a-6d show further embodiments of inserts 1 according to the present invention. In these embodiments, Fig. 6a - 6d provides that the encapsulation 10 surrounds the electrical and / or electronic component 5, the component metallization 20 and the backside metallization 20'. In the Fig. In the embodiment shown in Figure 6a, the encapsulation 10 completely covers the side walls SW of the insert 1. This proves particularly advantageous if the appropriate design of the encapsulation 10 facilitates the connection to the base body 2, for example, by means of a suitable adhesive. Furthermore, in the embodiment shown in Figure 6a, the encapsulation 10 completely covers the side walls SW of the insert 1. Fig. 6a provides that the third extension A3 of the ceramic element 30 corresponds to the fourth extension A4 of the component metallization 20 and the backside metallization 20'. In particular, it is provided that the encapsulation 10 is designed such that the side walls SW of the electrical and / or electronic component 5, the component metallization 20, the ceramic element 30 and the backside metallization 20' are sealed by the encapsulation 10.

[0071] The exemplary embodiment of the Fig. 6b differs from the embodiment of the Fig. 6a merely insofar as the ceramic element 30 has a third extension A3 to form a pullback, which is larger than the fourth extension A4 of the component metallization 20 and / or the backside metallization 20', but smaller than the first extension A1 of the encapsulation.

[0072] In the exemplary embodiment of the Fig. In section 6c, it is provided that the fourth extension A4 of the backside metallization 20' is larger than the third extension A3 of the ceramic element 30 and the fourth extension A4 of the component metallization 20. In the exemplary embodiments of Fig. 6b and Fig. 6c also include the electrical component 5, the component metallization 20, the ceramic element 30, and the backside metallization 20', each enclosed on their side walls SW by the encapsulation 10, so that the side walls SW of the insert 1 are formed exclusively from the material of the encapsulation 10. In the Fig. 6d it is provided that the third extension A3 essentially corresponds to the first extension A1 of the encapsulation 10. In other words: the ceramic element 30 in the insert 1 extends to the side wall of the insert 1 and is flush with the encapsulation 10, preferably forming a section of the side wall SW.

[0073] In the Fig. 7a and Fig. Figure 7b shows printed circuit boards 100 according to a preferred embodiment of the present invention. In particular, it is provided that in Fig. 7a Two inserts 1 are embedded in a base body 2 to form a printed circuit board 100. It is conceivable that the printed circuit board 100, in particular the base body 2, comprises further conductor elements 27 which are integrated into the base body 2 in order, for example, to laterally contact the component metallization 20 and / or backside metallization 20' of the insert 1.

[0074] Furthermore, it is conceivable that, in the assembled state, conductor tracks 5 on the base body 2 of the printed circuit board 100 are connected to the insert-side connections 8, for example via corresponding conductor tracks 4. It is also particularly preferred that, on the component side BS and / or back side RS of the printed circuit board 100, the outer surface of the base body 2 is largely flush with the outer surface of the encapsulation 10 and / or the back-side metallization 20'. This allows the connections and / or conductor tracks 4 on the outer surface of the insert 1 and on the base body 2 to be arranged on the same plane. In other words, it is preferred that, in the printed circuit boards 100, the electrical or electronic components 5 of the inserts 1 are recessed into the interior of the printed circuit board 100, namely within the insert 1, relative to an outer surface of the base body 2.In other words, the electrical or electronic components 5 are set inwards relative to the outside, in particular the component side BS of the printed circuit board 100, and are integrated into the printed circuit board 100.

[0075] In the exemplary embodiment of the Fig. 7b provides for an insert 1 which has a structured component metallization 20. The metal sections 21 of the component metallization 20 of this insert 1 can be electronically connected to each other, for example, via conductor tracks 4 on the base body 2 and / or on the insert 1.

[0076] Furthermore, it is conceivable that the backside metallization 20 protrudes from the base body 2 to ensure good thermal contact with a cooling element. Reference symbol: 1 deployment 2 basic shapes 4 conductor track 5 components 7. Component-side connection 8. Insert-side connection 9. Through-hole plating 10 Encapsulation 15 Metal-ceramic substrate 19 vias 20 Component metallization 20' Backside metallization 21 Metal section 27 conductor element 30 ceramic elements 100 printed circuit boards HSE Main Extension Level A1 first extension A2 second extension A3 third extension A4 fourth extension D1 first thickness D2 second thickness D3 third thickness D4 fourth thickness D5 fifth thickness D distance S Stacking direction RS back BS component page

Claims

Printed circuit board (100) for electrical components (5) and / or conductor tracks (4), comprising: a base body (2) extending along a principal extent plane (HSE), and an insert (1) integrated into the base body (2), wherein the insert (1) comprises a metal-ceramic substrate (15), an electrical and / or electronic component (5) and an encapsulation (10) enclosing at least the electrical and / or electronic component (5), characterized in that the insert (1) has a round profile or a rounded corner in the principal extent plane. Printed circuit board (100) according to claim 1, wherein the insert (1) has at least one insert-side connection (8), wherein the at least one insert-side connection (8) is formed on a component side (BS) of the insert (1) and is connected via a through-contact (9) in the encapsulation (10) to the electrical and / or electronic component (5), namely to a component-side connection (7) on the electrical and / or electronic component (5) on its side facing away from the metal-ceramic substrate (15). Printed circuit board (100) according to one of the preceding claims, wherein the metal-ceramic substrate (15) comprises a component side metallization (20), a ceramic element (30) and preferably a back side metallization (20'). Printed circuit board (100) according to claim 3, wherein the component metallization (20) is structured and wherein preferably an intermediate space between two metal sections (21) of the structured component metallization (20) is filled with encapsulation material (10). Printed circuit board (100) according to one of the preceding claims, wherein the encapsulation (10) surrounds the electrical and / or electronic component (5) and at least a part of the metal-ceramic substrate (15). Printed circuit board (100) according to claim 3 or 4, wherein a side wall (SW) of the insert (1) is modulated to form a profile, wherein, for example, the ceramic element (30) projects towards the component metallization (20) and / or the back side metallization (20') in a direction parallel to the main extension plane (HSE). Printed circuit board (100) according to one of claims 2 to 6, wherein a distance (D) measured in the stacking direction (S) between the component-side connection (7) and the insert-side connection (8) assumes a value between 100 µm and 500 µm. Insert (1) for a printed circuit board (100) according to any one of the preceding claims 1 to 7 . Method for manufacturing a printed circuit board (100) according to one of claims 1 to 7, wherein - an insert (1) and a base body (2) are provided, - the insert (1) is inserted into the base body (2) and - the insert (1) and base body (2) are joined together by material bonding, force bonding and / or form bonding.

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