Abstract
An auxiliary structure for embedding a component in a component carrier is disclosed. The auxiliary structure has a solid state transition piece for at least partially, in particular substantially fully circumferentially, enclosing the component, wherein the solid-state transition piece consists of a material being or becoming adhesive in a liquid state and being liquefiable by heat and/or pressure so as to fill a gap between the component and surrounding component carrier material by applying heat and/or pressure.
Claims
1. An auxiliary structure for embedding a component in a component carrier, the auxiliary structure comprising: a solid state transition piece for at least partially enclosing the component; wherein the solid-state transition piece comprises or consists of a material being or becoming adhesive in a liquid state and being liquefiable by heat and/or pressure so as to fill a gap between the component and surrounding component carrier material by applying heat and/or pressure.
2. The auxiliary structure according to claim 1, further comprising one of the following features: the transition piece is a single integral body; the transition piece comprises a plurality of separate transition piece constituents configured to at least partly enclosing a component.
3. The auxiliary structure according to claim 1, further comprising at least one of the following features: the solid-state transition piece comprises a curable material; the solid-state transition piece comprises at least one of: at least partially uncured resin; a thermoplastic material; a hot melt adhesive; and a precursor of an adhesive foam; the transition piece has an irregular perimeter or a polygonal perimeter.
4. The auxiliary structure according to claim 1, wherein the component is integrally formed with the at least partially surrounding transition piece.
5. The auxiliary structure according to claim 1, further comprising: component carrier material integrally formed with and at least partially surrounding the transition piece.
6. The auxiliary structure according to claim 1, wherein the transition piece is a circumferentially closed frame.
7. The auxiliary structure according to claim 1, wherein the transition piece is an open structure which has free ends.
8. The auxiliary structure according to claim 1, further comprising at least one of the following features: a material of the solid state transition piece is selected so as to reduce mechanical load in a transition region between the component carrier material and the component; a material of the solid state transition piece is selected so as to reduce a thermal expansion mismatch between the component carrier material and material of the component.
9. The auxiliary structure according to claim 1, further comprising at least one of the following features: a material of the solid state transition piece is selected to provide a thermal conductivity higher than the thermal conductivity of the component carrier material and/or the component; a material of the solid state transition piece is selected to provide a high frequency compatibility better than a high frequency compatibility of the component carrier material and/or the component.
10. The auxiliary structure according to claim 1, wherein the auxiliary structure is manufactured by one of the group consisting of molding, punching or thermoforming.
11. A semifinished product obtainable during manufacturing a component carrier, the semifinished product comprising: a component carrier with a recess; an auxiliary structure having a solid-state transition piece for at least partially a component, wherein the solid-state transition piece is formed from a material being or becoming adhesive in a liquid state and being liquefiable by one of heat or pressure, the material filling a gap between the component and a surrounding component carrier, wherein the solid-state transition piece is located within the recess so as to define at least part of an accommodation volume for arranging a component therein.
12. The semifinished product according to claim 11, further comprising at least one of the following features: the semifinished product comprises the component in the accommodation volume; the transition piece is formed by one of: a single annular structure; a plurality of separate strips; and a granulate.
13. The semifinished product according to claim 11, further comprising: a further auxiliary structure having a further solid-state transition piece located within the component carrier material so as to define at least part of a further accommodation volume for arranging a further electronic component therein.
14. The semifinished product according to claim 11, further comprising one of the following features: the auxiliary structure and the further auxiliary structure are located in separate recesses in the component carrier material; the auxiliary structure and the further auxiliary structure are located in a common recess in the component carrier material to thereby delimit at least part of different accommodation volumes for different electronic components.
15. The semifinished product according to claim 11, further comprising at least one of the following features: the component carrier material comprises a core; at least part of at least one main surface of the component carrier material, the component and/or material of the transition piece is covered with at least one electrically insulating layer structure and/or at least one electrically conductive layer structure.
16. A method of manufacturing a component carrier, comprising: arranging a component in a recess of a component carrier material; at least partially surrounding the component by a solid state transition piece; transferring the transition piece into an adhesive state, so as to at least partially adhesively fill a gap between the component and the surrounding component carrier material.
17. The method according to claim 16, further comprising: laminating at least one electrically conductive layer structure and/or at least one electrically insulating layer structure on the component and the component carrier material.
18. The method according to claim 16, further comprising at least one of the following steps: arranging at least one further electronic component in the recess; at least partially surrounding the plurality of electronic components by the solid state transition piece; arranging at least one further electronic component in at least one further recess of the component carrier material; at least partially surrounding the at least one further electronic component by at least one further solid state transition piece; transferring the at least one further transition piece into an adhesive state, so as to at least partially adhesively fill a gap between the at least one further electronic component and the surrounding component carrier material.
19. The method according to claim 18, further comprising: singularizing an obtained structure into a plurality of separate component carriers, each comprising a portion of the component carrier material, and at least one of the components at least partially surrounded by at least one of the transition pieces.
20. The method according to claim 16, further comprising at least one of the following features: the component carrier is shaped as a plate; the component carrier is configured as one of the group consisting of a printed circuit board and a substrate; the component carrier is configured as a laminate-type component carrier.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] FIG. 1, FIG. 2 and FIG. 3 illustrate plan views of auxiliary structures for embedding a component in a component carrier according to exemplary embodiments.
[0056] FIG. 4 illustrates a plan view of a semifinished product of a batch procedure of manufacturing a plurality of component carriers according to an exemplary embodiment.
[0057] FIG. 5, FIG. 6 and FIG. 7 illustrate plan views of a procedure of embedding electronic components in a recess of component carrier material using an auxiliary structure according to exemplary embodiments.
[0058] FIG. 8, FIG. 9 and FIG. 10 illustrate plan view of semifinished products according to exemplary embodiments.
[0059] FIG. 11, FIG. 12, FIG. 13, FIG. 14, FIG. 15 and FIG. 16 illustrate cross-sectional views of component carriers manufactured by methods of manufacturing component carriers according to exemplary embodiments.
[0060] FIG. 17, FIG. 18, FIG. 19, FIG. 20 and FIG. 21 illustrate cross-sectional views of structures obtained during carrying out methods of manufacturing component carriers according to exemplary embodiments.
[0061] FIG. 22, FIG. 23, FIG. 24 and FIG. 25 illustrate further cross-sectional views of further structures obtained during carrying out the method described referring to FIG. 17 to FIG. 21.
[0062] FIG. 26, FIG. 27, FIG. 28 and FIG. 29 illustrate alternative further cross-sectional views of further structures obtained during carrying out the method described referring to FIG. 17 to FIG. 21.
[0063] FIG. 30, FIG. 31, FIG. 32, FIG. 33 and FIG. 34 illustrate cross-sectional views of structures obtained during carrying out methods of manufacturing component carriers according to other exemplary embodiments.
[0064] FIG. 35, FIG. 36 and FIG. 37 illustrate further cross-sectional views of further structures obtained during carrying out the method described referring to FIG. 30 to FIG. 34.
[0065] FIG. 38 shows a three-dimensional view of a semifinished product on batch level obtained during manufacturing component carriers according to an exemplary embodiment.
[0066] FIG. 39 shows a plan view of a component carrier in which a transition piece unifies component carrier material and a component to be connected thereto according to another exemplary embodiment.
[0067] FIG. 40 shows a plan view of a component carrier in which a freely shaped transition piece is arranged between surrounding component carrier material and a component to be recessed or embedded in the component carrier material according to another exemplary embodiment.
[0068] FIG. 41 shows a plan view of a component carrier in which a transition piece is arranged between component carrier material and multiple components to be recessed or embedded in the component carrier material according to another exemplary embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0069] The illustrations in the drawings are presented schematically. In different drawings, similar or identical elements are provided with the same reference signs.
[0070] According to an exemplary embodiment, an architecture and method for embedding a component in a component board using one or more transition pieces is provided which is or are preferably shaped as a frame. In particular, such a concept allows component integration in a printed circuit board (PCB) or any other component carrier using tailored transition pieces.
[0071] Embedding (or integrating) a component in a printed circuit board may lead to several advantages, such as device miniaturization, signal performance, heat management, hardware security, etc. However, the embedding (or integration) process is challenging. Many challenges have to be overcome, for instance warpage issues and issues related to material mismatch between component and printed circuit board (PCB) base substrates. In order to overcome such challenges, it may be beneficial to introduce an appropriate material positioned between the component to be integrated and the surrounding component carrier material. Exemplary embodiments provide geometry and physical properties of transition piece structures being appropriate for framing an integrated component into the component carrier material.
[0072] An advantageous gist of an exemplary embodiment is the placement of a transition piece surrounding a component which is going to be integrated within component carrier material. The transition piece can be pre-cut from many different kinds of materials. Appropriate materials for the transition piece can be composed of the same material as the main board (i.e. materials being identical or similar to materials of the component carrier material, such as prepreg) or even a different one. Particularly, this latter mentioned option may be beneficial, since it enables a proper mismatch reduction concerning the different physical properties of the component to be embedded and the component carrier material (such as a main PCB). One or more of the properties which may be compensated between the embedded electronic component and the component carrier material are coefficient of thermal expansion (CTE) and elastic module (or stiffness), etc. Additionally, depending on the component to be integrated, the transition piece material can be characterized also by low dielectric constant and/or low losses, supporting high frequency devices. The transition piece material can be advantageously in a pre-cured status, allowing the proper gap-filling between integrated component and component carrier material/main PCB during a lamination process.
[0073] Exemplary products resulting from such an integration strategy are represented in FIG. 11 to FIG. 16 described below in further detail. It has to be mentioned that, while in FIG. 12, FIG. 14 and FIG. 16 the components are contacted on both sides, they can also be contacted only on one surface. Furthermore, a sequential buildup of the products shown in FIG. 11 to FIG. 16 can be executed in order to add further layers of dielectric and structured copper layers, or proceeding with multiple core build ups.
[0074] Processes according to exemplary embodiments leading to products according to exemplary embodiments may follow different paths, but one advantageous measure which can be taken according to exemplary embodiments is the positioning of a pre-cut transition piece within a hole and a component within such a transition piece.
[0075] Processes which can be carried out according to exemplary embodiments can be divided in particular into the following two categories:
[0076] (i) integration of a component into a dielectric material cladded (for instance copper clad laminate) in both sides by a copper foil, or
[0077] (ii) uncladded dielectric material.
[0078] In particular, the dielectric material can be glass reinforced and either cured or partially cured. An exemplary procedure according to (i) is represented in FIG. 17 to FIG. 21. For simplicity, a possible process continuation has been represented uniquely for a component as thick as the core (see FIG. 22 to FIG. 25, and FIG. 26 to FIG. 29), but it is the same for all three described possibilities. On the other hand, FIG. 30 to FIG. 34 show procedures which may be taken in process (ii). Also in this case, for the sake of simplicity, the process continuation has been represented uniquely for a component as thick as the core (see FIG. 35 to FIG. 37), but it is the same for all three described possibilities.
[0079] The transition piece geometry of exemplary embodiments is not limited, and it can be chosen according to the geometry of the component to be inserted. Moreover, the processes hereby described are scalable and can be used on panel level (compare for example FIG. 38).
[0080] However, a gist of an exemplary embodiment is based on the use of a pre-cut transition piece in order to embed a component in a component carrier such as a printed circuit board (PCB). Such a transition piece may be made of another (in particular dielectric) material than that (in particular dielectric) material characterizing the component carrier material.
[0081] Just as examples, the component to be enclosed can be: [0082] a passive component (for instance a resistor, a capacitor, etc.) [0083] an active component (for instance an integrated circuit, a microchip, etc.) [0084] in a board-in-board configuration, another component carrier (for instance another PCB) with different complexity, or properties (for example high frequency compatibility), compared to the surrounding one [0085] a battery (for example a solid state lithium ion battery) [0086] a magnetic core (for example a ferrite block)
[0087] The embedding architecture of an exemplary embodiment relies on the use of materials in form of transition pieces, capable of mitigating stress by introducing for example plastic deformation or by being able to compensate for volumetric shrinkage. These materials may exhibit one or more of tailored CTE, glass temperature, Young modulus, etc., depending on their final use. Warpage may also be reduced by using a fully cured dielectric with pre-cut holes giving the stability, while the material surrounding the component may be an uncured dielectric, which homogeneously fills a gap between electronic component and cured dielectric component carrier material.
[0088] Stress mitigation may be obtained by the capability of the material to compensate temperature induced mechanical deformation of prepreg as well as of an embedded electronic component (such as a semiconductor die). Materials that can be applied provide a relatively high compressibility, i.e. materials capable to perform volumetric changes without generating high stress, and also relatively high plasticity. The range of the Young modulus may be advantageously relatively low, for instance lower than 1000 MPa.
[0089] Materials appropriate for the transition piece according to exemplary embodiments are chemically crosslinked materials (such as loosely linked thermosets, elastomers) as well as thermoplastic materials, for instance with homogenous bulk, multi-phase (material featuring a second plasticity phase, similar to the butadiene fraction in High Impact Polystyrene), or foam structured.
[0090] Furthermore, in case the embedded inner state electronic component requires the use of high frequency, it is possible to choose a proper transition piece characterized by very low dielectric constant and low losses. In this way, such high performance material may be only locally integrated instead of being used over the whole board or component carrier.
[0091] Another advantage of exemplary embodiments is that, for large components, a proper material can be pre-cut in a transition piece and positioned in the gap between component carrier material and electronic component, thereby reducing the time required to fill such a gap by dispensing, ink-jetting, screen printing, etc.
[0092] Handling of the transition piece can be accomplished according to an exemplary embodiment by a pick-and-place machine. Another possibility is to position the pre-cut transition pieces on a vacuum plate, align such a vacuum plate over the component carrier material with pre-cut holes and interrupt the vacuum, letting fall by gravity the transition pieces into the holes. In this way all gaps may be filled by the transition pieces simultaneously. Such a procedure is compatible with a batch manufacturing process.
[0093] In another embodiment, it is possible to firstly fix the component (for instance a die) into the transition piece, and then assemble both into the hole. In another embodiment, the transition piece can be produced directly around the die too. This may allow exploitation of the component as a carrier for the transition piece. Taking such a measure may allow to further reduce or mitigate the risk of transition piece failure compared to first placing or locating the transition piece into the hole, and subsequently the die into the transition piece (which is however possible according to another exemplary embodiment).
[0094] Exemplary embodiments are applicable to all embedding and board-in-board concepts. Exemplary embodiments promote further miniaturization and high integration.
[0095] Furthermore, depending of the component to be integrated, adding functionality to the component carrier beyond conducing electricity, is also enabled by exemplary embodiments. An exemplary embodiment may integrate a solid state battery as a component, which can be sustained by an energy harvester enabling autonomous energy systems. Another exemplary embodiment may use component carriers or boards having different properties (for example a high frequency compatible board and an ordinary board) and use transition pieces unifying such boards or component carriers.
[0096] One exemplary embodiment is a battery device, which may supply power directly from the component carrier. Furthermore, boards with different properties can be combined in a kind of PCB construction set or puzzle, fulfilling different requirements in terms of CTE, dielectric constant, loss factors, etc., in one unique platform.
[0097] FIG. 1 to FIG. 3 illustrate plan views of auxiliary structures 100 for embedding a component 102 in a component carrier 104 according to exemplary embodiments.
[0098] Referring to FIG. 1, an auxiliary structure 100 is shown which comprises a rectangular solid state transition piece 106 for fully circumferentially enclosing a component 102 (compare FIG. 4). According to FIG. 1, the transition piece 106 is advantageously configured as a circumferentially closed annular frame. The solid-state transition piece 106 is made of a material becoming adhesive in a liquid state and being liquefiable by heat and/or pressure so as to fill a gap between the component 102 and surrounding component carrier material 108 (compare FIG. 4) by applying heat and/or pressure. According to FIG. 1, the transition piece 106 is configured as a single integral body. The solid-state transition piece 106 is made of an uncured or curable material. In the shown embodiment, the solid-state transition piece 106 is made of B-stage prepreg. By providing the solid-state transition piece 106 from prepreg or any other B-stage material, this material may re-melt during lamination so that resin (or the like) may flow for interconnecting the various elements and for closing gaps or voids and may therefore contribute to a stable intrinsic interconnection within the component carrier 104 under manufacture. Advantageously, the auxiliary structure 100 may be manufactured with low effort by molding at a molding temperature below the curing temperature of the material of the solid-state transition piece 106.
[0099] Referring to FIG. 2, the transition piece 106 shown there is composed of four strip shaped separate transition piece constituents which are here arranged to form a rectangle for substantially fully circumferentially enclosing a component 102. Only in the four edge portions, very small gaps remain at which a component 102 which is placed in an interior of the transition piece 106 is not completely enclosed by transition piece material. According to FIG. 2, the strip shaped separate transition piece constituents have tapering end portions matched to one another. However, alternatively, the entire transition piece constituents may be provided with homogeneous width over their entire length. For instance, the material of the transition piece 106 may be a thermoplastic material or a hot melt adhesive.
[0100] Referring to FIG. 3, a transition piece 106 is shown which is formed by a granulate of solid particles arranged in a rectangular arrangement. According to FIG. 3, the material of the transition piece 106 may be a grit and may be dispersed into a gap between a component 102 and component carrier material 108. For example, the material of the transition piece 106 according to FIG. 3 may be a precursor of an adhesive foam. For instance, the material of the transition piece 106 may be a microcapsule-based two component system. Microcapsules may be filled with a precursor for a polyurethane (PU) foam or the like. If desired, the material of the transition piece 106 may further comprise a foaming agent. For instance by the application of mechanical pressure and/or heat, the microcapsules may break and the foaming reaction may be triggered. The consequence may be the generation of an adhesive foam gluing or adhering component carrier material 108 and electronic component 102 together. At the same time, the formed foam is properly compressible and is therefore capable of balancing out mechanical tensions (which may for instance occur due to different coefficients of thermal expansion between the material of the component 102 and the component carrier material 108.
[0101] FIG. 4 illustrates a plan view of a semifinished product 177 obtained during carrying out a batch procedure of manufacturing a plurality of component carriers 104 (compare FIG. 11 to FIG. 16, for example) according to an exemplary embodiment.
[0102] The illustrated semifinished product 177 comprises component carrier material 108 (for instance a PCB material, for example dielectric material such as FR4 or prepreg and/or electrically conductive material such as copper) with a plurality of recesses 110, and a plurality of auxiliary structures 100 (for instance as described referring to any of FIG. 1 to FIG. 3). The solid-state transition piece 106 of each of the auxiliary structures 100 is located within a corresponding one of the recesses 110 so as to define a respective accommodation volume for arranging a respective one of the plurality of electronic components 102 therein. As can be taken from FIG. 4, each of the components 102 is accommodated in a respective one of the accommodation volumes. For instance, the components 102 may be semiconductor chips, batteries, or further component carriers (for manufacturing board-in-board devices). Since the adhesion between a respective electronic component 102 and the component carrier material 108 may be accomplished by material of the auxiliary structure 100 upon laminating the batch-type panel-size semifinished product 177 according to FIG. 4 with at least one electrically conductive layer structure and/or with at least one electrically insulating layer structure (not shown in FIG. 4), it is also possible that the component carrier material 108 is a fully cured core (for instance consisting of FR4 and copper).
[0103] In order to manufacture component carriers 104 based on the semifinished product 177, it is possible to temporarily liquefy the material of the transition pieces 106 by heat and/or pressure so as to fill the gaps between the components 102 and the surrounding component carrier material 108 and thereby adhere them together by the now adhesive transition piece material. As mentioned above, one or more further electrically insulating layer structures and/or one or more electrically conductive layer structures may be laminated on top and/or bottom of the semifinished product 177 shown in FIG. 4. This lamination and the curing of the transition piece material may be advantageously carried out in a single common simultaneous procedure in which pressure and/or heat is applied.
[0104] In order to complete the formation of the component carriers 104, it is subsequently possible to singularize a so obtained structure into a plurality of separate component carriers 104, each comprising a portion of the component carrier material 108, one of the components 102 and one of the transition pieces 106 (however now in a fully cured state). Upon singularization or separation, it is optionally possible to remove at least part of the material of the former auxiliary structure 100 from the manufactured component carrier 104.
[0105] FIG. 5 to FIG. 7 illustrate plan views of showing three different procedures of embedding electronic components 102 in a recess 110 of component carrier material 108 using an auxiliary structure 100 according to exemplary embodiments.
[0106] Referring to FIG. 5, the component 102 is integrally formed with the surrounding transition piece 106, so that the integral component-transition piece-body may be placed (compare reference numeral 151) as a single piece into the recess 110 (for instance by a pick and place apparatus).
[0107] Referring to FIG. 6, the component carrier material 108 is integrally formed with and surrounds the transition piece 106 in the recess 110. According to FIG. 6, the component 102 alone is placed (compare reference numeral 153) into the recess 110 which is already surrounded by the auxiliary structure 100.
[0108] Referring to FIG. 7, yet another mounting procedure is shown. As shown, the auxiliary structure 100, the component 102 and the component carrier material 108 are provided as three separate bodies. Consequently, it is possible to firstly place the auxiliary structure 100 into the recess 110 (compare reference numeral 157) and to subsequently insert the component 102 into the through hole of the transition piece-type auxiliary structure 100 (compare reference numeral 155), or vice versa.
[0109] FIG. 8 to FIG. 10 illustrate plan view of semifinished products 177 according to exemplary embodiments.
[0110] Referring to FIG. 8, only a single electronic component 102 is embedded within component carrier material 108 by means of an auxiliary structure 100 in between.
[0111] Referring to FIG. 9, two electronic components 102 are embedded within component carrier material 108 by means of two separate, spaced and unconnected auxiliary structures 100 according to another exemplary embodiment. According to FIG. 9, one of the transition pieces 106 is configured as a frame fully circumferentially surrounding one of the components 102 in an interior of the component carrier material 108. The other one of the transition pieces 106 shown in FIG. 9 is configured as an open structure with two free ends which only partially surrounds the other one of the components 102 in an edge portion (here a corner portion) of the component carrier material 108.
[0112] Referring to FIG. 10, one auxiliary structure 100 and a further auxiliary structure 100 are located in a common recess 110 in the component carrier material 108 to thereby delimit two different accommodation volumes for two different electronic components 102. As shown, the auxiliary structure 100 and the further auxiliary structure 100 together substantially fully circumferentially surround the common recess 110. The auxiliary structures 100 moreover run through an interior of the recess 110 and hence divide the recess 110 into the two different accommodation volumes. Each of two electronic components 102 is placed in a respective one of the accommodation volumes or compartments defined by the auxiliary structures 100 in combination.
[0113] As an alternative to the configuration shown in FIG. 10, it is also possible that the two auxiliary structures 100 are not inserted into a common recess 110 but are inserted into two separate recesses separated by a thin web of component carrier material 108 (for example similar as in FIG. 9 but with the geometry according to FIG. 10).
[0114] FIG. 11 to FIG. 16 illustrate cross-sectional views of component carriers 104 manufactured by methods of manufacturing component carriers 104 according to exemplary embodiments. Hence, FIG. 11 to FIG. 16 show schematic representations of end products resulting from framing a component 102 by an auxiliary structure 100 using different processes. In contrast to FIG. 1 to FIG. 10, the material of the auxiliary structure 100 has meanwhile been fully cured according to any of FIG. 11 to FIG. 16 under the influence of mechanical pressure and heat applied during the lamination with at least one electrically insulating layer structure 112 and at least one electrically conductive layer structure 114. The fact, that the material of the former auxiliary structure 100 is fully cured according to FIG. 11 to FIG. 16, is indicated by reference numeral 100.
[0115] In FIG. 11, FIG. 13 and FIG. 15, the component 102 is facing out (i.e. is exposed to an environment), while in FIG. 12, FIG. 14 and FIG. 16 it is embedded in an interior the main PCB. Furthermore, in FIG. 11 and FIG. 12, the component 102 has the same height as the component carrier material 108 (particular a core). In FIG. 13 and FIG. 14, the component 102 is thinner than the component carrier material 108 (which also may be denoted as main PCB), whereas in FIG. 15 and FIG. 16, the component 102 is thicker than the component carrier material 108. In FIG. 11, FIG. 13 and FIG. 15, the upper main surfaces of the component 100 and the component carrier material 108 are covered by an electrically insulating layer structure 112 and an electrically conductive layer structure 114, whereas only an electrically conductive layer structure 114 is provided at the bottom surface. In FIG. 12, FIG. 14 and FIG. 16, the upper main surfaces of the component 100 and the component carrier material 108 are covered by an electrically insulating layer structure 112 and an electrically conductive layer structure 114, and an electrically conductive layer structure 114 and an electrically insulating layer structure 112 are provided at the bottom surfaces as well.
[0116] Substantially H-shaped plated through holes are shown as electrically conductive layer structures 114 on the right hand side of each of FIG. 12, FIG. 14 and FIG. 16. Although corresponding plated through holes are not shown in FIG. 11, FIG. 13 and FIG. 15, also these embodiments may be equipped with one or more of such substantially H-shaped plated through holes (not illustrated in these figures for the sake of simplicity).
[0117] FIG. 17 to FIG. 21 illustrate cross-sectional views of structures obtained during carrying out methods of manufacturing component carriers 104 according to exemplary embodiments.
[0118] In FIG. 18 to FIG. 21, three different embodiments of the manufacturing method are shown. The component 102 to be embedded or integrated may be as thick as the component carrier material 108 (see left hand side of any of FIG. 18 to FIG. 21), thinner than the component carrier material 108 (see middle of any of FIG. 18 to FIG. 21) or thicker than the component carrier material 108 (see right hand side of any of FIG. 18 to FIG. 21). For simplicity, the dielectric component carrier material 108 is only shown as a single layer. However, the dielectric component carrier material 108 can also be embodied as an N-layer PCB, where 2<N<20.
[0119] Referring to FIG. 17, processing starting from a pre-cut core (compare reference numeral 171) as component carrier material 108 fixed on a base 165 composed of a support 161 covered with a glue layer 163.
[0120] Referring to FIG. 18, one or more precut transition pieces, as auxiliary structure 100, is/are put into the recess 110, which is here a through hole. On the left hand side and on the right-hand side, three transition pieces are stacked. In the middle, two transition pieces are stacked. Hence, the number of transition pieces stacked in a recess 110 can be freely selected, in particular depending on the thickness of the component 102 to be embedded. Thereby, a board designer is enabled to configure the auxiliary structure 100 from one or more transition pieces 106 in an appropriate way.
[0121] Apart from its non-adhesive property in the solid state and its adhesive property in the liquid state, the material of the auxiliary structure 100 can be selected for improving or adjusting the properties of the component carrier 104 to be manufactured. For instance, a material of the auxiliary structure 100 may be selected so as to: [0122] reduce mechanical load in a transition region between the component carrier material 108 and the component 102; and/or [0123] reduce a thermal expansion mismatch between the component carrier material 108 and material of the component 102; and/or [0124] provide a thermal conductivity higher than the thermal conductivity of the component carrier material 108 and the component 102; and/or [0125] provide a high frequency compatibility better than a high frequency compatibility of the component carrier material 108 and the component 102.
[0126] Referring to FIG. 19, a respective electronic component 102 is inserted in the respective recess 110 in the component carrier material 108 in such a way that the component 102 is fully circumferentially surrounded by the solid auxiliary structure 100 having a non-adhesive property in the solid state and having a sticky or adhesive property in the liquid state. In other words, the component 102 is inserted into the central through hole of the transition pieces 106 so as to interpose the transition pieces 106 between the component carrier material 108 and the component 102.
[0127] Referring to FIG. 20, one or more electrically insulating layer structures 112 (for instance prepreg layers) and an electrically conductive layer structure 114 (for instance a copper foil) are attached to an upper main surface of the structures shown in FIG. 19. In other words, electrically insulating material (which may be the same material as or another material than the material of the transition piece 106 and/or the core-type component carrier material 108) and electrically conductive material may be positioned on the whole PCB surface.
[0128] Referring to FIG. 21, the various layer structures shown in FIG. 20 (including the at least one electrically conductive layer structure 114 and the at least one electrically insulating layer structure 112, as well as the auxiliary structure 100) are laminated together by the application of pressure, if desired supported by heat. During this lamination procedure, the material of the auxiliary structure 100 is temporarily liquefied by the pressure and/or heat applied in terms of the lamination. Thereby, gaps between the component 102 and the surrounding component carrier material 108 are filled with the now liquid, flowable and adhesive material of the transition pieces 106. The material of the auxiliary structure 100 is thereby cured and, after re-solidification, bridges the gap between the component 102 with regard to the component carrier material 108.
[0129] FIG. 22 to FIG. 25 illustrate further cross-sectional views of further structures obtained during carrying out the method described referring to FIG. 17 to FIG. 21. Hence, FIG. 22 to FIG. 25 show the continuation of the process described referring to FIG. 17 to FIG. 21. Two different routes can be pursued starting from the structure shown in FIG. 21, leading to the component facing out (compare FIG. 22 to FIG. 25) or being integrated in the inner layers (compare FIG. 26 to FIG. 29). The processes hereby described are valid for all three cases (component thinner than, thicker than and as thick as the core).
[0130] Referring to FIG. 22, openings 169 are formed from the surface to the component 102 or contact pads in the inner layers.
[0131] Referring to FIG. 23, contacts are formed at the surface and in the inner layers up to the component 102.
[0132] Referring to FIG. 24, the outermost electrically conductive layer is structured or patterned on the surface.
[0133] Referring to FIG. 25, the support 165 may be optionally removed.
[0134] FIG. 26 to FIG. 29 illustrate alternative further cross-sectional views of further structures obtained during carrying out the method described referring to FIG. 17 to FIG. 21. In other words, the procedure described referring to FIG. 26 to FIG. 29 is an alternative to the procedure described referring to FIG. 22 to FIG. 25.
[0135] Referring to FIG. 26, the support 165 is optionally removed. An electrically insulating layer structure 112 and an electrically conductive layer structure 114 are laminated onto a lower main surface of the shown structure.
[0136] Referring to FIG. 27, openings 169 are formed to/from both opposing main surfaces to the component 102 or contact pads in the inner layers.
[0137] Referring to FIG. 28, contacts are formed at the surfaces and in the inner layers up to the component 102.
[0138] Referring to FIG. 29, the outermost electrically conductive layers are structured or patterned on the surface.
[0139] Plated through holes are shown as electrically conductive layer structures 114 on the right hand side of each of FIGS. 27 to 29. Although corresponding plated through holes are not shown in FIGS. 22 to 26, also these embodiments may be equipped with one or more of such plated through holes (not illustrated in these figures for the sake of simplicity).
[0140] FIG. 30 to FIG. 34 illustrate cross-sectional views of structures obtained during carrying out methods of manufacturing component carriers 104 according to other exemplary embodiments.
[0141] Referring to FIG. 30, processing starts from a pre-cut, uncoated dielectric layer as component carrier structure 108 fixed on an electrically conductive layer structure 114 (here embodied as a copper foil) by glue layer 163. Thereby, a recess 110 is formed as a blind hole.
[0142] In FIG. 31 to FIG. 34, three different embodiments of the manufacturing method are shown. The component 102 to be embedded or integrated may be as thick as the component carrier material 108 (see left hand side of any of FIG. 31 to FIG. 34), thinner than the component carrier material 108 (see middle of any of FIG. 31 to FIG. 34) or thicker than the component carrier material 108 (see right hand side of any of FIG. 31 to FIG. 34).
[0143] Referring to FIG. 31, one or more prefabricated transition pieces 106, as auxiliary structure 100, is/are put into the recess 110, which is here a blind hole (rather than a through hole). On the left hand side and on the right-hand side, three transition pieces 106 are stacked. In the middle, two transition pieces 106 are stacked. Hence, the number of transition pieces 106 stacked in a recess 110 can be selected depending on the thickness of the component 102 to be embedded, thereby configuring the auxiliary structure 100 in an appropriate way.
[0144] Referring to FIG. 32, a respective electronic component 102 is inserted in the respective recess 110 in the component carrier material 108 in such a way that the component 102 is fully circumferentially surrounded by the solid auxiliary structure 100. The respective electronic component 102 is adhered on its bottom surface on the glue layer 163.
[0145] Referring to FIG. 33, an electrically insulating layer structure 112 (for instance a prepreg layer) and an electrically conductive layer structure 114 (for instance a copper foil) are attached to an upper main surface of the structures shown in FIG. 32.
[0146] Referring to FIG. 34, the various layer structures shown in FIG. 33 are laminated together by the application of pressure, if desired supported by heat. During this lamination procedure, the material of the auxiliary structure 100 is temporarily liquefied by the pressure and/or heat applied in terms of the lamination. Thereby, gaps between the component 102 and the surrounding component carrier material 108 are filled with the now liquid and adhesive material of the transition pieces 106. The material of the auxiliary structure 100 is thereby cured and, after re-solidification, bridges the gap between the component 102 with regard to the component carrier material 108 (compare reference numeral 100).
[0147] FIG. 35 to FIG. 37 illustrate further cross-sectional views of further structures obtained during carrying out the method described referring to FIG. 30 to FIG. 34.
[0148] Thus, FIG. 35 to FIG. 37 show the continuation of the process described in FIG. 30 to FIG. 34. The processes hereby described are valid for all three cases (electronic component 102 thinner than, thicker than and as thick as the dielectric layer in form of the component carrier material 108).
[0149] Referring to FIG. 35, openings 169 are formed to/from both opposing main surfaces to the component 102 or contact pads in the inner layers.
[0150] Referring to FIG. 36, contacts are formed at the surfaces and in the inner layers up to the component 102.
[0151] Referring to FIG. 37, the outermost electrically conductive layers are structured or patterned on the surface.
[0152] FIG. 38 shows a three-dimensional view of a semifinished product 177 on batch level obtained during manufacturing component carrier 104 according to an exemplary embodiment. The component carrier material 108 is provided with pre-cut holes, see recesses 110. The dielectric transition pieces 106, as auxiliary structures 100, are inserted in these holes, as well as the components 102. Reference numerals 181 represents gaps which will be filled during lamination by the curing of the dielectric transition pieces 106.
[0153] FIG. 39 shows a plan view of a component carrier 104 in which an open ends-type transition piece 106 unifies component carrier material 108 and a component 102 to be connected thereto according to another exemplary embodiment. According to FIG. 39, the transition piece 106 is angled or is substantially L-shaped so as to form an interface between component carrier material 108 and component 102 at a rectangular recess in a corner region of the rectangular component carrier 104.
[0154] FIG. 40 shows a plan view of a component carrier 104 in which a freely shaped transition piece 106 is arranged between surrounding component carrier material 108 and a component 102 to be recessed or embedded in the component carrier material 108 according to another exemplary embodiment. FIG. 40 illustrates that one or both of the component 102 and the transition piece 106 may have a free form or shape. In the shown embodiment, the frame type transition piece 106 has a wave shape which therefore increases the length of the transition piece 106 around component 102. This length increase also improves the mechanical robustness of the transition piece 106 and as a consequence of the component carrier 104.
[0155] FIG. 41 shows a plan view of a component carrier 104 in which a transition piece 106 is arranged between component carrier material 108 and multiple components 102 to be recessed or embedded in the component carrier material 108 according to another exemplary embodiment. FIG. 41 therefore illustrates that multiple components 102 (in the shown embodiment four components 102) can be connected to component carrier material 108 by a transition piece 106 having a number of interior recesses shaped and dimensioned to correspond to the shape and dimensions of the components 102.
[0156] It should be noted that the term comprising does not exclude other elements or steps and the a or an does not exclude a plurality. Also elements described in association with different embodiments may be combined.
[0157] Implementation is not limited to the preferred embodiments shown in the figures and described above. Instead, a multiplicity of variants are possible which use the solutions shown and the principle according to the invention even in the case of fundamentally different embodiments.
