Method for manufacturing a printed circuit board and printed circuit board with at least one embedded electronic component

Abstract

Method for manufacturing a printed circuit board (1) with at least one embedded electronic component (2), comprising the following steps: • Manufacturing a printed circuit board module (3) with at least one electrically conductive layer (4) and at least one electrically insulating layer (5), wherein the electrically insulating layer (5) surrounds the electronic component (2) and the contacts (6) of the electronic component (2) are conductively connected to contact pads (7) of the at least one electrically conductive layer (4), • Providing a substrate layer (8), • Providing a positioning layer (9) having a recess (10) slightly larger than the corresponding base area of ​​the printed circuit board module (3), • Placing the positioning layer (9) onto the substrate layer (8), • Inserting the printed circuit board module (3) into the recess (10) in the positioning layer (9), thereby positioning the printed circuit board module (2) without soldering or gluing,• Applying at least one electrically insulating layer (11) to the printed circuit board module (3) and the positioning layer (9) surrounding the printed circuit board module (3), • Applying an electrically conductive layer (12) to the at least one electrically insulating layer (11) covering the printed circuit board module (3), • Pressing the layer sequence thus produced (13), • Drilling holes (14) into the pressed layer sequence (13) in the area of ​​the contact pads (7) of the printed circuit board module (3) up to at least the contact pads (7), and • Metallizing the holes (14).

Description

[0001] The invention relates to a method for manufacturing a printed circuit board with at least one embedded electronic component and a printed circuit board with at least one embedded electronic component.

[0002] Printed circuit boards (PCBs), sometimes also called printed circuit boards, have been used for many decades in electrical devices, machines, systems, and motor vehicles as carriers for electronic components. These are typically rigid circuit boards that both electrically connect discrete components and highly integrated components and act as their carriers. The PCBs usually consist of one or more layers, which are copper-clad on one or both sides to form conductive traces or circuit patterns. In multilayer PCBs, the individual layers or the conductive traces arranged on the individual layers are electrically connected to each other by metallized holes in the circuit board.

[0003] As the number of electrical and electronic components to be arranged on a printed circuit board (PCB) steadily increases, and the available installation space for PCBs becomes increasingly limited, there has been a need for several years to enable ever higher integration and packing density on the boards. To increase the number of electronic components that can be arranged on a PCB of a given size, electronic components with ever smaller form factors and smaller pin pitches have been developed. However, even these measures are often no longer sufficient to accommodate all the necessary electronic components on the two outer layers of a PCB.

[0004] Therefore, for several years now, electrical and electronic components have been arranged or embedded not only on the two outer layers of a printed circuit board (PCB), but also within the PCB itself. These are active or passive electronic components, such as semiconductors, resistors, inductors, and capacitors, which are integrated into the PCB. Embedding electronic components in the PCB allows for a further increase in the number of electronic components per board. Furthermore, embedding components in a PCB offers the advantage of protecting them from environmental influences and high voltages. Additionally, embedding also provides improved thermal connectivity and shielding of the components, thus better meeting relevant EMC requirements.

[0005] However, arranging or embedding the electronic components in the printed circuit board involves increased effort in the manufacturing of the printed circuit board.

[0006] In a well-established process for manufacturing a printed circuit board (PCB) with an embedded electronic component, the component is first bonded to a structured PCB core using a conductive adhesive. The assembled PCB core is then pressed into a multilayer board before undergoing further standard manufacturing steps for multilayer PCBs. This process utilizes bare die electronic components whose pads are coated with a layer of gold to ensure adequate electrical contact.

[0007] A similarly constructed printed circuit board is known from US Patent 2009 / 0084596 A1. In this design, a core layer with a recess is first placed onto a substrate layer containing a resin layer. To fix the core layer to the substrate, the substrate is heated to a temperature of 40 to 60°C, at which point the resin softens. An unpackaged electronic component is then inserted into the recess of the core layer, and the substrate is again heated to a temperature of 40 to 60°C to fix the component to the substrate. Finally, an uncured resin layer is pressed onto the surface of the core layer, and this resin layer is heated to a temperature of up to 150 to 180°C, so that the electronic component in the recess is surrounded by resin.

[0008] To connect the embedded electronic component, holes are created from the top surface of the resin layer covering the core layer and the electronic component down to the electronic component using a laser, and then metallized. The top surface of the resin layer facing away from the core layer has a copper foil that can be structured by etching to create the necessary contact surfaces.

[0009] Another known method for embedding electronic components in printed circuit boards uses standard SMD components, which are first soldered onto a structured PCB core using a reflow process. This assembled core is then pressed into a multilayer board before further PCB manufacturing processes take place.

[0010] However, these known methods have the disadvantage that, in order to position the electronic component, the component must be glued or soldered, or the substrate layer must be heated before the assembly of the printed circuit board can continue.

[0011] The present invention aims to provide a method for the simple and reliable production of printed circuit boards with at least one embedded electronic component. Furthermore, it aims to provide a printed circuit board with at least one embedded electronic component that can be manufactured simply.

[0012] This problem is solved in a method according to claim 1 and in the printed circuit board according to claim 9, among other things, by the fact that the electronic component is already embedded in a prefabricated printed circuit board module during the assembly of the printed circuit board, which has at least one electrically conductive layer and at least one electrically insulating layer, wherein the electrically insulating layer surrounds the electronic component and the contacts of the electronic component are conductively connected to the contact surfaces of the at least one electrically conductive layer.

[0013] The method according to the invention is characterized by the following steps: • Provide a carrier layer, • Providing a positioning layer that has a recess larger than the corresponding footprint of the printed circuit board module, • Placing the positioning layer onto the carrier layer, • Inserting the printed circuit board module into the recess in the positioning layer, • Applying at least one electrically insulating layer to the printed circuit board module and the positioning layer surrounding the printed circuit board module, • Applying an electrically conductive layer to the at least one electrically insulating layer covering the printed circuit board module, • Pressing the resulting layer sequence, • Drilling holes into the pressed layer sequence in the area of ​​the connection surfaces of the printed circuit board module, extending at least to the connection surfaces and • Metallizing the bores.

[0014] The printed circuit board produced by the method according to the invention differs significantly from known printed circuit boards with embedded electronic components in that the electronic component is embedded in a printed circuit board module. The electronic component itself can be designed as an unpackaged electronic component (bare die) arranged in an insulating single layer, wherein an electrically conductive layer, for example a copper foil, is applied to the top and / or bottom of the single layer. The insulating layer or single layer can be a base material, for example a composite material consisting of a thermoset and a reinforcing material based on different types of glass fiber fabric. The base laminate can, for example, be an FR4 base laminate, which has been used extensively in the production of printed circuit boards for many years.

[0015] The electrical connection between the contacts of the electronic component and at least one electrically conductive layer, or the contact pads formed on the conductive layer, can be established in various ways. This includes contact via metallized holes or via individual conductors or wires embedded in the insulating middle layer. Such printed circuit board modules with embedded electronic components are offered by various electronic component manufacturers.

[0016] As previously explained, the printed circuit board module comprises at least one electrically conductive layer and at least one electrically insulating layer. Preferably, the printed circuit board module has two outer electrically conductive layers, between which the at least one electrically insulating layer is arranged as a middle layer. The electrically insulating layer itself can be composed of several electrically insulating individual layers, which are preferably joined together by compression during the manufacture of the printed circuit board module. However, the specific design of the printed circuit board module, and in particular the type of electrical connection within the printed circuit board module, is not of particular importance within the scope of this application.

[0017] The embedded printed circuit board module is contacted via metallized holes that extend at least to the module's contact pads. These contact pads can be located on either one or both sides of the module, even with two outer electrically conductive layers.

[0018] In the inventive method, soldering or gluing of the printed circuit board module inserted into the recess in the positioning layer is unnecessary. Heating the substrate layer before or during insertion of the printed circuit board module is also not required. Instead, the printed circuit board module can simply be positioned by inserting it into the corresponding recess in the positioning layer. For this purpose, the dimensions of the recess in the positioning layer are adapted to the outer dimensions of the printed circuit board module; that is, the recess is only slightly larger than the printed circuit board module in its unpressed state.

[0019] The recess in the positioning layer is dimensioned such that, after the printed circuit board module is inserted into the recess, the lateral distance *a* between the printed circuit board module and the surrounding positioning layer is as small as possible to enable precise positioning. For this purpose, a defined distance *a* exists between the inserted printed circuit board module and the at least one insulating layer surrounding it in the unpressed state. This distance is chosen to ensure both sufficiently easy insertion of the printed circuit board module into the recess and secure positioning of the printed circuit board module in the recess after pressing.

[0020] The distance is chosen to be just large enough to fill the gap between the edge of the recess and the electronic component during pressing. This distance is preferably less than 0.5 mm, and particularly less than 0.3 mm. To allow for sufficiently easy insertion of the printed circuit board module into the recess, the distance on the other side is preferably at least 0.1 mm, and particularly approximately 0.2 mm, thus fulfilling both criteria very well.

[0021] Inserting a printed circuit board module into the recess can be done manually or automatically, for example, when multiple circuit boards are manufactured simultaneously in a single panel. The individual circuit boards can be assembled, for instance, by positioning the individual layers on top of each other in a registration system. To ensure precise positioning of the individual layers, corresponding recesses can be formed in the edge area of ​​each layer or panel.

[0022] In the inventive method, the layers of the printed circuit board are stacked successively on top of each other. In an intermediate step, the printed circuit board module to be embedded is inserted into the recess of the positioning layer and placed onto the substrate layer. The inserted printed circuit board module is then covered by at least one electrically insulating layer before an outer, electrically conductive layer is applied as the top layer. The resulting layer sequence with the embedded printed circuit board module is then pressed together, thereby fixing the printed circuit board module in its position and simultaneously mechanically bonding the individual layers of the printed circuit board to one another. Naturally, more than one printed circuit board module can be embedded in a printed circuit board.The positioning layer then has a number of recesses corresponding to the number of printed circuit board modules to be embedded, each recess being adapted to the external dimensions of the individual printed circuit board modules.

[0023] To electrically contact the embedded electronic component, holes are subsequently drilled into the pressed layer sequence in the area of ​​the PCB module's contact pads. The holes are deep enough to penetrate the contact pads. This ensures a good electrical connection between the individual contact pads during the subsequent metallization of the holes.

[0024] The holes drilled into the printed circuit board are preferably blind holes that penetrate a few micrometers into the contact pads. Alternatively, the holes could also be designed as through holes, in which case the electrical connection of the contact pads to at least one outer electrically conductive layer is also achieved by metallizing the holes.

[0025] By embedding the electronic component within the printed circuit board module and thus within the circuit board itself, not only can a higher packing density be achieved, but improved heat dissipation from the component via the material immediately surrounding it is also possible. This leads to increased component performance. Furthermore, embedding the component has the advantage that the circuitry implemented by the circuit board is not immediately apparent, thus providing enhanced protection against counterfeiting.

[0026] In the printed circuit board according to the invention, the substrate layer initially serves as the bottom layer in the board's construction, and therefore should possess sufficient stability. The substrate layer can be an insulating layer, for example, a cured base material. A composite material consisting of a thermoset and a reinforcing material based on various types of glass fiber fabric can be used as the base material. If the substrate layer consists of an electrically insulating material, the holes are introduced into the layer sequence from the upper, electrically conductive layer, such that the holes extend through the electrically conductive layer and the at least one electrically insulating layer covering the printed circuit board module, reaching at least to the connection pads of the printed circuit board module.

[0027] According to a preferred embodiment of the inventive method and the inventive printed circuit board, the substrate layer comprises an electrically conductive layer and an electrically insulating layer. The electrically insulating layer is arranged between the electrically conductive layer and the printed circuit board module or the positioning layer, such that the electrically conductive layer forms the outer, lower layer. In this preferred embodiment, the printed circuit board thus has two electrically conductive layers as outer layers, which can in particular be copper foils.Even with this type of printed circuit board design, the holes can only be drilled into the layer sequence from one side. In this case, the holes can be drilled from either the top or the bottom, since both the top and bottom surfaces are formed by an electrically conductive layer. Therefore, in both cases, the connection of the pads via the metallized holes to an outer electrically conductive layer is possible. If the substrate layer has an electrically conductive layer, at least some of the holes can extend through the substrate layer.

[0028] In particular, if the printed circuit board module has an electrically conductive layer and at least one contact pad on both its top and bottom surfaces, it is provided that holes are drilled into the pressed layer sequence from both sides, i.e., from both the top and the bottom, in the area of ​​the contact pads, each extending at least to the contact pads. The holes are each deep enough to penetrate the top surface of the contact pads facing the respective electrically conductive layer. The individual contact pads are preferably made from the side of the layer sequence to which the contact pad is closest, so that the holes to be drilled have the shallowest possible depth.

[0029] In the printed circuit board according to the invention, the positioning layer serves to position a printed circuit board module during the manufacturing of the printed circuit board. The recess in the positioning layer, into which the printed circuit board module is inserted before pressing, determines the position of the printed circuit board module so precisely that, when the holes are drilled after pressing, it is ensured that the connection surfaces are indeed contacted by the holes. The positioning layer thus positions the inserted printed circuit board module and fixes it in its position.

[0030] In principle, the positioning layer can consist of a single electrically insulating layer, the thickness of which is then adapted to the thickness of the printed circuit board module. However, according to a preferred embodiment, the positioning layer has at least two electrically insulating layers, each of which has a recess for the printed circuit board module. By using at least two insulating layers for the positioning layer, it is possible to select the two layers such that both the positioning of the printed circuit board module during insertion and the fixation of the printed circuit board module during pressing can be optimized. In particular, two layers with different rigidities or curing levels can be used for this purpose.Preferably, a prepreg is used for at least one electrically insulating layer of the positioning layer and a cured base laminate is used for at least one electrically insulating layer of the positioning layer.

[0031] Prepreg is generally understood to be a resin-impregnated fiberglass fabric that has dried but not yet cured. By using at least one prepreg as an insulating layer, sufficient resin, usually epoxy resin, is available during the pressing of the finished layer sequence, thus fixing the printed circuit board module inserted into the recess of the positioning layer in its position. Furthermore, the use of at least one prepreg also improves the mechanical bond between the individual layers. According to a preferred embodiment, a prepreg is therefore also used for the insulating layer covering the printed circuit board module and, optionally, also for the insulating layer of the substrate layer.

[0032] The cured base laminate used for at least one additional insulating layer of the positioning layer, compared to the uncured prepreg, ensures sufficient stability of the printed circuit board (PCB) and guarantees secure positioning of the PCB module to be embedded in the recess of the positioning layer before pressing. A composite material consisting of a thermoset and a reinforcing material based on glass fiber fabrics can be used as the cured base laminate. For example, the base laminate could be an FR4 base laminate commonly used in PCB manufacturing.

[0033] For both the prepreg and the cured base laminate, in addition to epoxy-impregnated fiberglass fabrics, other suitable materials can be used, such as thermosets with a high Tg value (glass transition temperature). To achieve the advantages described above, at least one insulating layer should not yet be cured, and at least one insulating layer of the positioning layer should be cured.

[0034] If the positioning layer has several electrically insulating layers, each with a corresponding recess, these are placed sequentially onto the first, lower insulating layer during the manufacturing process. The recesses formed in the individual electrically insulating layers are adapted to the corresponding outer dimensions of the printed circuit board module, with the recess always being slightly larger than the corresponding outer dimensions. The uppermost insulating layer can have a larger recess than the electrically insulating layer below it. Alternatively, the recesses formed in the individual electrically insulating layers can also be of the same size.

[0035] The electrically insulating layers of the positioning layer do not need to consist entirely of insulating material. For example, it is possible for at least one electrically conductive section, in particular at least one conductor track, to be arranged on the underside and / or the top side of at least one electrically insulating layer. Standard printed circuit boards with corresponding conductor tracks on the underside and / or the top side can therefore also be used as electrically insulating layers.

[0036] If, as previously explained, several electrically insulating layers are arranged one above the other, each having a recess for the printed circuit board module, then preferably a prepreg is used for at least one of these electrically insulating layers and a cured base material for at least one other of the electrically insulating layers. When using, for example, three electrically insulating layers, each having a recess, the middle insulating layer can preferably consist of a prepreg, while a cured base material is used for each of the two outer insulating layers.

[0037] According to a manufacturing-advantageous embodiment of the inventive method, in a first step, corresponding recesses are created in the insulating layers of the positioning layer into which the printed circuit board module is inserted, so that these electrically insulating layers are prepared with the recess before the individual layers are stacked on top of each other. The recesses in the electrically insulating layers can be produced, in particular, by etching, milling, punching, or laser cutting. Depending on the design of the recess, a combination of the methods described above is also possible.

[0038] In the printed circuit board and the method according to the invention, the electrically conductive layers, which are typically copper foils, preferably have a thickness of at least 50 µm, preferably at least 75 µm, and particularly about 105 µm. The use of relatively thick copper foils for the electrically conductive layers has the advantage that it allows for the simple production of a printed circuit board with relatively thick conductor tracks on both outer surfaces. This enables even larger currents to flow easily through the conductor tracks without causing impermissible heating of the conductor tracks and thus of the printed circuit board as a whole. The desired final thickness of the conductor tracks can be further increased, for example, by electroplating with copper up to the target thickness.

[0039] Particularly in the production of a printed circuit board (PCB) where the finished conductor tracks have a thickness of at least 100 µm, the holes in the area of ​​the electronic component's contact connections are preferably created by mechanical drilling. In contrast, the methods otherwise used in PCB production for creating holes, such as lasers or etching, are less suitable for the method according to the invention. Preferably, the diameter of the holes corresponds at least to the depth of the holes. By selecting a ratio of hole diameter to hole depth equal to or greater than 1, good metallization of the holes can be achieved.

[0040] To electrically connect the terminal pads of the embedded circuit board module, located inside the circuit board, to corresponding terminal pads on the surface of the circuit board formed by the electrically conductive layer, holes are drilled into the circuit board, as described above. These holes extend at least to the terminal pads, and the hole walls are subsequently metallized. To create the terminal pads on the surface of the circuit board, the electrically conductive layer is preferably structured accordingly. Specifically, the following steps can be performed: • Printing a plating resist, • Electroplating with copper up to the target thickness, • Deposition of a metal resist, • Stripping of the plating surface and • Etching of the connection surfaces.

[0041] It is not necessary to carry out all of the aforementioned steps for creating the contact surfaces. For example, if the thickness of the electrically conductive layer is sufficiently large, the electroplating with copper and thus also the pressure of the plating resist can be omitted.

[0042] In detail, there are numerous possibilities for designing and further developing the inventive method or the printed circuit board. Reference is made to the claims subordinate to the independent claims, as well as to the following description of two preferred embodiments in conjunction with the drawing. The drawing shows Fig. 1 a schematic representation of individual steps of the inventive method for manufacturing a printed circuit board with an embedded printed circuit board module, and Fig. 2 a schematic representation of a second embodiment of a printed circuit board according to the invention.

[0043] In Fig. Figure 1 schematically depicts five consecutive steps of the process for manufacturing a printed circuit board 1 with an embedded electronic component 2. The electronic component 2, which may be a power semiconductor in particular, is an electronic component that has no housing, i.e., a so-called "bare die".

[0044] The electronic component 2 is embedded in a printed circuit board module 3, which consists of two outer electrically conductive layers 4 and an intermediate insulating layer 5. The electronic component 2 is surrounded by the electrically insulating layer 5, which can be a cured base laminate, in particular an FR4 base laminate. For electrical contacting of the electronic component 2, its contacts 6 are conductively connected to contact pads 7 of the electrically conductive layers 4, which are only indicated in the figures. However, the specific design of the printed circuit board module 3, and in particular the type of electrical connection between the contacts 5 of the electronic component 2 and the contact pads 7 on the conductive layers 4, can also be implemented differently.

[0045] The in Fig. A schematically depicted printed circuit board (PCB) is manufactured by first layering the individual layers, described in more detail below, on top of each other. The individual layers are positioned on a suitable table, which has devices that ensure precise positioning of the individual layers. For this purpose, upward-pointing pins can be arranged on the table, and corresponding recesses can be formed in the edge area of ​​the individual layers, so that the layers with the recesses can be slid over the pins on the table, thus allowing the individual layers to be positioned precisely.

[0046] In the method according to the invention, a carrier layer 8 is first positioned or provided accordingly, on which a positioning layer 9 is arranged, the positioning layer having a recess 10 that is larger than the corresponding base area of ​​the printed circuit board module 3. In the Fig. In the embodiment shown in Figure 1a, the carrier layer 8 itself consists of two layers, namely a lower, electrically conductive layer 12 and an electrically insulating layer 13 arranged above it. The positioning layer 9 consists of three electrically insulating layers 17, 18, 19, each of which has a recess 10, wherein the recesses 10 in the three insulating layers 17, 18, 19 are of the same size.

[0047] In the next procedural step, which takes place in Fig. As shown in Figure 1b, the printed circuit board module 3 is inserted into the recesses 10 in the positioning layer 9 or the individual electrically insulating layers 17, 18, 19. The lateral distance a between the inserted printed circuit board module 3 and the insulating layer 17, 18, 19 surrounding the printed circuit board module 3 is chosen such that the printed circuit board module 3 can be inserted securely into the recess 10, while also being positioned with sufficient accuracy. As shown in Figure 1b, the printed circuit board module 3 is inserted into the recess 10. Fig. As can be seen from 1b, this distance a is preferably at least approximately the same on all sides and is preferably less than 0.3 mm, in particular approximately 0.2 mm.

[0048] After the printed circuit board module 3 has been inserted into the recesses 10, according to Fig. 1c Next, another insulating layer 11 is applied to the printed circuit board module 3 and the uppermost electrically insulating layer 19 of the positioning layer 9 surrounding the printed circuit board module 3. This insulating layer 11 has no recess and its dimensions correspond to the insulating layer 16 of the carrier layer 8. An electrically conductive layer 12, whose dimensions correspond to the electrically conductive layer 15 of the carrier layer 8, is then applied as the uppermost layer to the insulating layer 11.

[0049] The two electrically conductive layers 12 and 15 are, in particular, copper foils with a thickness d of more than 50 µm, especially approximately 105 µm. After the upper electrically conductive layer 12 is applied, the resulting layer sequence 13 is pressed together, thereby bonding the individual layers and filling the gap laterally surrounding the embedded printed circuit board module 3. For the electrically insulating layers 11, 16, and 18, prepregs are used, i.e., a fiberglass fabric impregnated with reactive resin that has dried but not yet cured. During the pressing of the layer sequence 13, sufficient resin, particularly from the prepregs, flows into the gap surrounding the embedded printed circuit board module 3, thus securely fixing the printed circuit board module 3 in its position.

[0050] According to the illustration in Fig. In step 1d, the previously separate insulating layers 11, 16, and 17 to 19 are joined together by compression to form a common insulating layer 20. Next, holes 14 are drilled into the printed circuit board 1, which was previously produced by compression of the layer sequence 13, in the area of ​​the connection pads 7 of the printed circuit board module 3. The holes 14 extend through the upper electrically conductive layer 12 and the insulating layer 11 covering the printed circuit board module 3. In the illustrated embodiment, an additional hole 14 is also drilled into the layer sequence 13, extending from the carrier layer 8, i.e., from the lower electrically conductive layer 15, through the insulating layer 16 to a connection pad 7 on the lower conductive layer 4 of the printed circuit board module 3. The holes 14 are deep enough to penetrate the respective upper surfaces of the connection pads 7.

[0051] According to the in Fig. In the final step shown in Figure 1e, the holes 14 are metallized, thereby connecting the contact pads 7 of the embedded printed circuit board module 3 to the upper electrically conductive layer 12 and the lower electrically conductive layer 15, respectively. Because the surface of the contact pads 7 was drilled in the previous step, a reliable electrical connection to the contact pads 7 via the metallized holes 14 is ensured. Simultaneously with the metallization of the holes 14, corresponding contact pads are preferably created on the surface of the printed circuit board 1, i.e., the upper electrically conductive layer 12, for which purpose the electrically conductive layer 12 is appropriately structured.

[0052] If the thickness of the electrically conductive layer 12 does not correspond to the desired thickness of the pads or conductor tracks, it can be increased to the desired thickness by electroplating with copper. Similar to the upper electrically conductive layer 12, the electrically conductive layer 15 of the substrate layer 8, which forms the lower layer, can also be structured to create corresponding pads and conductor tracks. Here, too, the thickness of the pads and conductor tracks can be further increased if required. These are well-known processes in the manufacture of printed circuit boards, so they do not need to be explained further here.

[0053] In Fig. Figure 2 shows a second embodiment of a printed circuit board 1, which is almost identical to the one in Figure 2. Fig. The circuit board 1 shown is constructed and manufactured as shown. The only difference to circuit board 1 as shown in Fig. As shown in Figure 1e, the difference consists in the fact that, in addition to several metallized holes 14 designed as blind holes, a metallized hole 14' is now also provided in the circuit board 1, which is designed as a through hole. This metallized hole 14' extends through the electrically conductive layers 12 and 15 and the insulating layers 11, 16 and 17 to 19, as well as through the circuit board module 3, i.e., its two outer conductive layers 4 and its middle insulating layer 5. Reference symbol list 1 circuit board 2 components 3 printed circuit board module 4 conductive layers 5 insulating layer 6 contacts component 7 connection surfaces LP module 8 Carrier layer 9 Positioning layer 10 exceptions 11 insulating layer 12 conductive layer 13 shift sequence 14 bore 15 conductive layer 16 insulating layer 17-19 insulating layers 20 shared shift a distance d thickness QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2009 / 0084596 A1

[0007]

Claims

[1] Method for manufacturing a printed circuit board (1) with at least one embedded electronic component (2), comprising the following steps: • Manufacturing a printed circuit board module (3) with at least one electrically conductive layer (4) and at least one electrically insulating layer (5), wherein the electrically insulating layer (5) surrounds the electronic component (2) and the contacts (6) of the electronic component (2) are conductively connected to contact surfaces (7) of the at least one electrically conductive layer (4), • Provide a support layer (8), • Providing a positioning layer (9) having a recess (10) that is slightly larger than the corresponding base area of ​​the printed circuit board module (3), • Placing the positioning layer (9) onto the carrier layer (8), • Inserting the printed circuit board module (3) into the recess (10) in the positioning layer (9), thereby positioning the printed circuit board module (2) without soldering or gluing, • Applying at least one electrically insulating layer (11) to the printed circuit board module (3) and the positioning layer (9) surrounding the printed circuit board module (3), • Placement of an electrically conductive layer (12) onto the at least one electrically insulating layer (11) covering the printed circuit board module (3), • Pressing the resulting layer sequence (13), • Drilling holes (14) into the pressed layer sequence (13) in the area of ​​the connection surfaces (7) of the printed circuit board module (3) up to at least the connection surfaces (7) and • Metallizing the bores (14). [2] Method according to claim 1, characterized by, that the recess (10) in the positioning layer (9) is dimensioned such that, after the printed circuit board module (3) is inserted into the recess (10), the lateral distance (a) between the printed circuit board module (3) and the positioning layer (9) surrounding the printed circuit board module (3) is less than 0.5 mm, in particular less than 0.3 mm, preferably approximately 0.2 mm. [3] Method according to claim 1 or 2, characterized by , that the drilling of the holes (14) into the pressed layer sequence (13) in the area of ​​the connection surfaces (7) of the printed circuit board module (3) is carried out by means of mechanical drilling. [4] Method according to any one of claims 1 to 3, characterized by , that the carrier layer (8) has an electrically conductive layer (15) and an electrically insulating layer (16), wherein the electrically insulating layer (16) is arranged between the electrically conductive layer (15) and the printed circuit board module (3) or the positioning layer (9). [5] Method according to claim 4, characterized by , that at least part of the holes (14) extend through the electrically conductive layer (12) and the at least one electrically insulating layer (11) covering the printed circuit board module (3), and / or that part of the holes (14) extend through the carrier layer (8). [6] Method according to any one of claims 1 to 5, characterized by , that the positioning layer (9) has at least two electrically insulating layers (17, 18, 19), wherein the electrically insulating layers (17, 18, 19) each have a recess (10) for the printed circuit board module (3). [7] Method according to claim 6, characterized by , that for at least one electrically insulating layer (18) of the positioning layer (9) a prepreg is used and for at least one electrically insulating layer (17, 19) of the positioning layer (9) a cured base laminate is used. [8] Method according to any one of claims 1 to 7, characterized by , that in a first step recesses (10) are introduced into the electrically insulating layers (17, 18, 19) of the positioning layer (9), wherein the recesses (10) are preferably produced by etching, milling, punching or laser cutting. [9] Printed circuit board (1) with at least one embedded electronic component (2), wherein the electronic component (2) is arranged in a printed circuit board module (3) and wherein the printed circuit board module (3) has at least one electrically conductive layer (4) and at least one electrically insulating layer (5), wherein the electrically insulating layer (5) surrounds the electronic component (2) and the contacts (6) of the electronic component (2) are conductively connected to contact surfaces (7) of the at least one electrically conductive layer (4), wherein the printed circuit board (1) is manufactured in a method according to any one of claims 1 to 8 and has at least the following layer sequence (13): • a carrier layer (8), • a positioning layer (9) having a recess (10) that is larger than the corresponding base area of ​​the printed circuit board module (3), • an electrically insulating layer (11) and • an electrically conductive layer (12) wherein the printed circuit board module (3) is inserted into the recess (10) in the positioning layer (9), wherein bores (14) are provided in the area of ​​the contact surfaces (7) of the printed circuit board module (3) of at least one of the two outer layers (8, 12) of the layer sequence (13) up to at least the contact surfaces (7) and wherein the bores (14) are metallized. [10] Printed circuit board (1) according to claim 9, characterized by , that at least part of the bores (14) extend through the electrically conductive layer (12) and the at least one electrically insulating layer (11) covering the printed circuit board module (3). [11] Printed circuit board (1) according to claim 9 or 10, characterized by, that the carrier layer (8) has an electrically conductive layer (15) and an electrically insulating layer (16), wherein the electrically insulating layer (16) is arranged between the electrically conductive layer (15) and the printed circuit board module (3) or the positioning layer (9). [12] Printed circuit board (1) according to claim 11, characterized by , that at least part of the boreholes (14) extend through the support layer (8). [13] Printed circuit board (1) according to any one of claims 9 to 12, characterized by , that the positioning layer (9) consists of at least two electrically insulating layers (17, 18, 19), wherein the electrically insulating layers (17, 18, 19) each have a recess (10) for the printed circuit board module (3). [14] Printed circuit board (1) according to claim 13, characterized by, that on the underside and / or the top side of at least one electrically insulating layer (17, 19) of the positioning layer (9) at least one electrically conductive section, in particular at least one conductor track (21), is arranged. [15] Printed circuit board (1) according to claim 13 or 14, characterized by , that the electrically insulating layer (12) covering the printed circuit board module (3) and at least one electrically insulating layer (17, 19) of the positioning layer (9) is designed as a prepreg and / or at least one electrically insulating layer (18) of the positioning layer (9) is designed as a cured base laminate. [16] Printed circuit board according to any one of claims 9 to 15, characterized by , that the diameter of the bores (14) is at least equal to the depth of the bores (14). [17] Printed circuit board (1) according to any one of claims 9 to 16, characterized by, that at least one electrically conductive layer (8, 15) has a thickness (d) of at least 50 µm, preferably at least 75 µm, in particular about 105 µm.

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