Technical field

[0001] The present disclosure relates to the field of high-frequency communication. In particular, the present disclosure relates to the integration of array antenna elements and driving circuits for enabling such communication.

Background

[0002] Array antennas are believed to form a major part of both present and future communication and sensing technologies, such as for example in Base Stations (BS) and/or User equipment (UE) of fifth generation (5G), and/or sixth generation (6G), mobile communication systems, and e.g. in technologies for various radar applications. In high-frequency applications, primarily between 10-300 GHz, so called Antenna-in-Packages (AiPs) provide an attractive way of creating both modular and scalable array antennas. [0003] Integration of both beam forming functionality and antenna structures in the same component may reduce signal losses compared with other designs where the beam forming functionality and antenna structure are provided separated in different components, or separated in component and printed circuit board (PCB). Including frequency conversion functionality, beam forming functionality and antenna structures in the same component may also reduce e.g. a need to route high- frequency signals via the PCB.

[0004] In an AiP, the radiating elements (of the antenna) are positioned on one side of the component and must not be covered by other structures that may disturb or even block the radio signal. For this reason, the heat transfer from the component are normally designed to occur from one or more sections of the AiP that does not include any radiating elements of the antenna. As AiPs in the high-frequency range (e.g. 10-300 GHz) have a relatively small surface area and generate a substantial amount of heat, the heat transfer in such components and circuits thus presents a design challenge. Summary

[0005] To at least partially solve the above identified problem with heat transfer in AiPs, the present disclosure provides an AiP and a circuit assembly as defined in the accompanying independent claims. Various alternative embodiments of the AIP and circuit assembly are defined in the dependent claims.

[0006] According to a first aspect of the present disclosure, an Antenna-in- Package (AiP) is provided. The AiP includes one or more integrated circuits (ICs) and an array antenna integrated in a same package. The array antenna includes a plurality of radiating elements, and the one or more ICs are configured to control a radio signal emitted by the plurality of radiating elements. The AiP further includes a routing arrangement including a plurality of electric contacting elements for electrically connecting the AiP and the one or more ICs to a printed circuit board (PCB). The one or more ICs are arranged at a first side of the package. The plurality of radiating elements is arranged at a second side of the package opposite to the first side of the package. The plurality of electric contacting elements is arranged around at least a part of the plurality of radiating elements also on the second side (of the package).

[0007] Within the present disclosure, unless explicitly stated to the contrary, an AiP and a so called “Antenna-on-Package” (AoP) are considered as being equivalent to each other. Thus, in what remains of the description of the present disclosure and in the claims, only the term AiP is used.

[0008] With “electric contacting elements”, it is meant any type of element which may be connected to a corresponding element on for example a PCB, in order to form an electrical connection between the AiP and the PCB. In addition to electrically connecting the AiP and PCB together, such electric contacting elements may also provide a mechanical interface between the two objects.

[0009] In one or more embodiments of the AiP, the electric contact elements may be selected from the group consisting of solder balls/ spheres, solder pads, or contacting pins. Solder pads may also be referred to as e.g. “solder lands”, or similar. With “solder balls” or “solder spheres”, it is envisaged that spheres of solder may be provided together with e.g. solder pads on the AiP such that, during soldering, the solder in the solder balls may melt and form the electrical and mechanical interface between the AiP and the PCB. If using solder balls, the AiP may for example be provided as a Ball Grid Array (BGA) package. If using solder pads/lands, the AiP may for example be provided as a Land Grid Array (LGA) package. If using contacting pins, the AiP may for example be provided as a Pin Grid Array (PGA) package. Other variants are also envisaged, as long as an electric connection between the AiP and the PCB may be formed using e.g. soldering or similar technology.

[ooio] In one or more embodiments of the AiP, the one or more ICs may include at least one beamforming integrated circuit (BFIC) for controlling a shape and/or direction of the radio signal emitted by the plurality of radiating elements. A BFIC, as envisaged herein, may for example also include an analog beamformer (ABF).

[oon] In one or more embodiments of the AiP, the one or more ICs may include at least one frequency converter for altering a frequency content of the radio signal emitted by the plurality of radiating elements. Herein, a frequency converter may for example be an up/ down converter (UDC), or similar.

[0012] In one or more embodiments of the AiP, the package may be of a fan-out wafer-level packaging (FOWLP) type.

[0013] In one or more embodiments of the AiP, the package may be of a substrate-based type, and the one or more ICs may e.g. be so called flip-chips. [0014] In one or more embodiments of the AiP, the AiP may further include a metal lid/heat spreader. The metal lid (or heat spreader) may cover e.g. the one or more ICs on the first side, and help to enhance the transport of heat away from the one or more ICs.

[0015] In one or more embodiments of the AiP, the plurality of electric contacting elements may surround the plurality of radiating elements along all edges of the second side of the package.

[0016] In one or more embodiments of the AiP, at least part of the plurality of radiating elements maybe arranged adjacent to one or more edges of the second side of the package (i.e., without any electric contacting elements arranged between the radiating element and the edge of the package). The plurality of electric contacting elements may only surround the plurality of radiating elements along one or more other edges of the second side of the package, such that if two or more such AiPs are arranged adjacent to each other, the combined radiating elements of their respective array antennas thereby together form a combined array antenna.

[0017] In one or more embodiments of the AiP, at least part of the plurality of radiating elements maybe arranged adjacent to exactly one edge of the second side of the package. The plurality of electric contacting elements may only surround the plurality of radiating elements on at least three other edges of the second side of the package.

[0018] In one or more embodiments of the AiP, at least part of the plurality of radiating elements maybe arranged adjacent to exactly two edges of the second side of the package. The plurality of electric contacting elements may only surround the plurality of radiating elements on at least one or more other edges of the second side of the package.

[0019] According to a second aspect of the present disclosure, a circuit assembly is provided. The circuit assembly include a printed circuit board (PCB) having an opening therein, and a plurality of electric contacting elements arranged around at least part of the opening. The circuit assembly further includes at least one AiP according to the first aspect of the present disclosure, or any embodiment described herein as related thereto, and a heatsink. The at least one AiP is arranged with its/the second side facing towards the PCB (e.g. the side of the PCB on which the electric contacting elements for the AiP are located), and the plurality of electric contacting elements of the at least one AiP are aligned with and connected to the plurality of electric contacting elements of the PCB to form an electrical/mechanical connection interface. The heatsink is arranged on the first side of the at least one AiP to provide cooling of the one or more ICs (of the AiP). The at least one AiP is further aligned such that the array antenna is at least partly exposed through the opening of the PCB. As used herein, “at least partly exposed through the PCB” is to be understood as the at least one AiP being aligned such that if there are no other components blocking the opening through the PCB, a radio beam emitted by at least some of the radiating elements has a free line-of-sight through the opening/hole in the PCB, or at least such that the opening in the PCB provides less attenuation or blocking of the radio beam than would be the case if the opening in the PCB was absent.

[0020] In one or more embodiments of the circuit assembly, the circuit assembly may further include a thermal interface material (TIM) provided between the first side of the at least one AiP (i.e. the side of the AiP at/on which the one or more ICs are located) and the heatsink.

[0021] In one or more embodiments of the circuit assembly, the at least one AiP may include at least two AiPs according to the first aspect (or according to any embodiment described herein as being related thereto). The at least two AiPs may be arranged such that their combined array antenna is exposed through the opening of the PCB.

[0022] In general, providing at least some radiating elements of the array antenna adjacent to one or more edges of the (second side of the) package may allow to form a combined array antenna by placing several such AiPs adjacent to each other on a PCB. This can provide a more flexible system, wherein the exact size, shape and function of the array antenna can be expanded in a modular fashion.

[0023] In one or more embodiments of the circuit assembly, the connection interface may further include an underfill material (in addition to e.g. solder joints connecting the electric contacting elements of the PCB to those of the at least one AiP). Providing an underfill may for example enhance the reliability of the solder joints (or similar), and provide additional mechanical stability to the circuit assembly.

[0024] The present disclosure improves upon existing technology by placing the radiating elements of the array antenna on a same side of the AiP as the soldering interface towards the PCB. This provides a plurality of advantages, including allowing for the AiP to be cooled from the top (and not through e.g. the PCB), and from a same side as where the various ICs are located. Consequently, as neither the radiating elements of the array antenna, nor the soldering interface, occupy any surface area on the same side as the various ICs, the heat transfer from the ICs may be increased and the overall cooling of the AiP component improved. In addition, by providing an opening in the PCB between the soldering pads, the radiating elements maybe exposed through the PCB and thus result in less blocking or attenuation by the PCB of a radio beam emitted from the antenna elements.

[0025] Other objects and advantages of the present disclosure will be apparent from the following detailed description, the drawings and the claims. Within the scope of the present disclosure, it is envisaged that all features and advantages described with reference to e.g. the AiP of the first aspect are relevant for, apply to, and maybe used in combination with also the circuit assembly of the second aspect, and vice versa.

Brief description of the drawings [0026] Exemplifying embodiments will be described below with reference to the accompanying drawings, in which:

[0027] Figures la-id schematically illustrate various embodiments of AiPs according to the present disclosure;

[0028] Figures le-ih schematically illustrate various configurations of radiating elements and electric contacting elements in various embodiments of modular AiPs according to the present disclosure; and

[0029] Figures 2a and 2b schematically illustrate various embodiments of a circuit assembly according to the present disclosure.

[0030] In the drawings, like reference numerals will be used for like elements unless stated otherwise. Unless explicitly stated to the contrary, the drawings show only such elements that are necessary to illustrate the example embodiments, while other elements, in the interest of clarity, may be omitted or merely suggested. As illustrated in the Figures, the sizes (absolute or relative) of elements and regions may be exaggerated or understated vis-a-vis their true values for illustrative purposes and, thus, are provided to illustrate the general structures of the embodiments.

Detailed description

[0031] Exemplifying embodiments of an Antenna-in-Package (AiP) and a circuit assembly including such an AiP according to the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings. The drawings show currently preferred embodiments, but the invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the present disclosure to the skilled person. [0032] Various embodiments of one or more AiPs according to the present disclosure will now be described with reference to Figures la-ii.

[0033] Figure la schematically illustrates one embodiment of an AiP 100. The AiP 100 includes a plurality 120 of ICs 122. Examples of ICs may e.g. include beamforming ICs (BFICs) for controlling a shape and/or direction of a radio (signal) beam 134, frequency converters (such as up/down converters, UDCs) for altering a frequency content of the radio beam 134, or other types of ICs such that the combined ICs achieves a desired functionality of the AiP 100 as a whole. In particular, it is envisaged that ICs that operate at higher frequency (including e.g. ten to hundreds of GHz) can benefit from being integrated within the AiP 100 such that their signals do not need to be routed via a PCB (which routing via the PCB would possibly cause unwanted signal attenuation or similar), and that other ICs operating at lower frequencies can instead, if so desired, be positioned as separate components on a PCB. This reasoning applies to all embodiments discussed herein. [0034] The AiP 100 further includes an array antenna 130 which is also integrated in the same package no as the plurality 120 of ICs 122. The array antenna 130 in turn includes a plurality of radiating elements 132, and the ICs 120, 122 are configured to control the radio signal 134 emitted by the plurality of radiating elements 132 of the array antenna 130. Here, “controlling the radio signal” may for example include adjusting a relative phase between the radiating elements (i.e. beamforming), such that a direction and/or shape of the radio signal 134 maybe controlled, using e.g. one or more BFICs or similar. As also mentioned above, controlling the radio signal 134 may also include using e.g. an UDC (or other frequency converter) to alter a frequency content of the radio signal before it is provided to the various radiating elements 132, or similar.

[0035] The AiP 100 further includes a plurality of electric contacting elements in form of solder balls or solder pads 142 (which may also be referred to as “solder lands”). These are for connecting the AiP 100 and the ICs 122 to the PCB, once the AiP 100 is mounted to the PCB using e.g. soldering. The solder balls or solder pads 142 form part of a routing arrangement (not shown) of the AiP 100, which is envisaged as containing e.g. all the internal traces/routings, wire bondings, etc., needed to transfer signals e.g. between the ICs 122, the radiating elements 132 of the array antenna 130, and similar, and to/from the solder balls or solder pads 142, thereby forming a connection/soldering interface 140 through which the AiP 100 may communicate with other separate components located e.g. on the PCB to which the AiP 100 is to be mounted.

[0036] The ICs are arranged at a first side 111 of the package 110, while the plurality of radiating elements 132 are arranged at a second side 112 of the package

110. As can be seen in Figure la, the first side 111 of the package 110 is opposite to the second side 112 of the package 110. The plurality of solder balls or solder pads 142 is arranged around at least part of the plurality of radiating elements 132 also on the second side 112 of the package 110. [0037] The AiP 100 may for example be of a fan-out wafer-level packing (FOWLP) type. Other packing types are also envisaged, such as e.g. substrate based (FCBGAs) with ICs in form of flip-chips, with/without mold and/or heat spreaders, metal lids, etc., of which examples will be described later herein.

[0038] A solution as envisaged by the present disclosure (e.g. the embodiment described with reference to Figure la, or any of the embodiments described with reference to the other Figures herein) provides at least the following advantages:

[0039] Ai) As the radiating elements 132 of the array antenna 130 are arranged on a same side 112 of the package as the connection/soldering interface 140, the other side 111 of the package 110, at which the ICs 122 are located, maybe cooled directly without the cooling equipment blocking or attenuating the radio signal 134. As no surface area on the first side 111 needs to be reserved for the radiating elements 132, the cooling of the package no and especially of the ICs 122 may thus be made more efficient, as a larger (e.g. all of the) surface area of the first side 111 may be used for the cooling and to extract heat from the ICs 122 located on/at the first side 111. [0040] A2) The radiating elements 132 can, when the AiP 100 is mounted to the

PCB, be more protected from mechanical damage, as they are protected from the top by the package 110 and thereby not visible from the side of the PCB on which the AiP 100 is mounted. It is also envisaged that the radiating elements 132 can be protected from mechanical damage by the PCB itself. [0041] A3) Cooling (using e.g. a heatsink, as will be described later herein) is provided “from the top”, and not through the PCB, and a varying thickness of the PCB (which may have a tolerance of e.g. +/- 10%) does not influence how e.g. such a heatsink is to be mounted. In one conventional solution different from the solution(s) envisaged by the present disclosure, the AiP would instead contain the radiating elements on its top side and the various ICs on its bottom side (facing towards the PCB), and a heatsink would have to be mounted through the PCB in order to reach the side of the various ICs without blocking the radio signals emitted by the radiating elements. A varying thickness of the PCB would then have to be compensated for e.g. adding a deformable layer between the side of the AiP containing the various ICs and the heatsink. This deformable layer may for example be a thermal interface material (TIM). If the variation in thickness of the PCB is large, the thickness of the deformable layer would need to be increased in order to compensate for such a large tolerance in PCB thickness. This would reduce the heat transfer capability through the deformable layer and lead to a reduced cooling. Making the deformable layer thinner would improve the cooling, but would at the same time risk the heatsink sometimes being pushed directly against the AiP, thus reducing the reliability of the AiP or even damaging the AiP directly during assembly of the heatsink. In another conventional solution different from the solution(s) envisaged by the present disclosure, mounting the heatsink through the PCB could be avoided by, instead of e.g. routing a hole through the PCB for the heatsink, adding one or more pieces of metal in the PCB right below the AiP (so called “metal coins”). This would allow to mount the heat sink on the underside of the PCB (i.e. the side facing away from the AiP), but would at the same time e.g. make it harder or impossible to use e.g. solder balls to mount the AiP to solder pads of the PCB. Such a PCB would in either way be more complex to make, and the assembly of the AiP to the PCB would be more difficult. In addition, achieving a good coefficient of thermal expansion (CTE) matching between e.g. the AiP mold/package, the AiP dies, the PCB laminate and the PCB metal coin may also be difficult to achieve, and the temperature cycling reliability of the assembly would likely be reduced. A third conventional solution also different from the solution(s) envisaged by the present disclosure, would for example include soldering the heat sink directly to exposed die of the various ICs, through the PCB, and such an option would also risk damaging the AiP. In summary, it is concluded that all such conventional solutions different from the solution(s) as envisaged by the present disclosure would likely suffer from problems related to both assembling, thermal efficiency and/ or reliability. In a solution as envisaged by the present disclosure, fewer mechanical tolerances would need to be accounted for, and a thermal interface material could be made thinner and result in a more efficient heat transfer from and cooling of the AiP.

[0042] A4) As the heatsink can be mounted “on top” of the AiP, solder joints connecting the AiP to the PCB would only experience compressive forces from the heatsink itself. This may avoid or at least reduce a negative influence of the heatsink on the lifetime of the solder joints.

[0043] A5) As the heatsink does not need to be mounted from a different side of

(and e.g. through) the PCB after the AiP has first been mounted, the possibility to enable a single-sided frontend board assembly is increased, implying a lower assembly cost.

[0044] A6) A radome, potentially covering part or a whole of the circuit assembly

(i.e., the AiP plus the PCB) can be placed closer to the PCB, thus allowing for an overall thinner assembly.

[0045] Although described so far only with reference to the AiP 100 illustrated in Figure la, the above listed advantages Ai)-A6) apply also to all other embodiments described herein, such as those that will be described later with reference to e.g. Figures lb-ii and Figures 2a and 2b.

[0046] Figure lb schematically illustrates another embodiment of an AiP 101, wherein the AiP 101 is of a substrate-based type. The AiP 101 includes a substrate 113 and a plurality 120 of ICs 122 of flip-chip type which are mounted and soldered on a first side 111 and mechanically strengthened by using an underfill 124. On a second side 112, the package no includes an array antenna 130 including a plurality of radiating elements 132, and a plurality of electric contacting elements in form of solder balls or solder pads 142 are arranged around at least a part of the plurality of radiating elements 132 also on the second side 112 of the package 110. Except for the different packaging type, the details of the AiP 101 and e.g. the AiP 100 described earlier with reference to Figure la are the same, and the same advantages as described for the AiP 100 apply also to the AiP 101.

[0047] Figure IC schematically illustrates another embodiment of an AiP 102 that has a configuration equal to that of the AiP 101 described with reference to Figure lb, except that a metal lid 150 is provided on top of the various ICs 122. The metal lid 150 may for example be in thermal contact with exposed die of the ICs 122, or with an area of the package no on the first side in below which the die of the ICs 122 are located, and help to further enhance thermal transfer from the ICs 122 and thus enhance cooling of the AiP 102.

[0048] Figure id schematically illustrates another embodiment of an AiP 103 that is also similar to e.g. the AiPs 101 and 102 described with reference to Figures lb and lc, respectively, but in the AiP 103 the underfill 114 is molded, and a heat spreader 152 (of e.g. metal) is provided over the whole surface of the first side 111 of the package no.

[0049] In summary, Figures la through id all illustrate various embodiments of an AiP all having the radiating elements 132 of the array antenna 130 located at a side 112 of the package no opposite to a side 111 of the package no on/at which the various ICs 132 are located. This enables the top-side cooling described above, and the advantages which, as also described earlier herein, follows therewith.

[0050] With reference to Figures le-ii, various envisaged configurations of radiating elements and electric contacting elements of AiPs according to the present disclosure will now be described in more detail.

[0051] Figure le schematically illustrates two AiPs 104 and 104’, wherein, on each AiP, at least part of the plurality of radiating elements 132 of the array antenna 130 are located adjacent to an edge 116 of the second side 112 of the package no, and where a plurality of electric contacting elements in form of solder pads or solder balls 142 are located at one or more other edges of the first side 112 of the package 110. More details about and advantages of such a configuration will be described later herein with reference to e.g. Figures lg, lh and 11.

[0052] Figure if schematically illustrates a top view (left) and a bottom view (right) of an AiP 105, showing the first side 111 and the second side 112, respectively, of the package. The various ICs 122 in the plurality of 120 of ICs are distributed across the first side 111. On the second side 112, the radiating elements 132 of the array antenna 130 are arranged in a symmetric pattern in the middle, while the plurality of electric contacting elements in form of solder pads or solder balls 142 are arranged around the radiating elements 132 along the edges of the second side 112. Here, the AiP 105 is made as a single package, and the solder pads or solder balls 142 are arranged along a maximum of four sides/edges of the package. When mounted to a PCB, one such AiP 105 may for example cover one opening in the PCB.

[0053] Figure lg schematically illustrates a top view (left) and a bottom view (right) of two AiPs 106 and 106’, showing the first sides 111 and the second sides 112, respectively, of their packages. The various components of the AiPs 106 and 106’ are arranged such that if the two AiPs 106 and 106’ are mounted adjacent to each other on a PCB, their combined appearance and functioning is similar to that of e.g. the single AiP 105 described with reference to Figure if. This is achieved by e.g. arranging the plurality of radiating elements 132 such that at least some radiating elements 132 are located adjacent to an edge 116 of the second side (along which edge 116 there are no solder pads or solder balls 142), and such that the solder pads or solder balls 142 are arranged along the other edges of the second side. In the particular example shown in Figure lg, the AiPs 106 and 106’ each have a total of four sides/edges, and there are radiating elements 132 adjacent to one such side, and there are solder pads or solder balls 142 arranged along the other, remaining three sides. It may, however, be envisaged also that an AiP has fewer or more sides than four, but that the radiating elements 132 maybe arranged such that at least some radiating elements 132 are arranged adjacent to one or more edges/sides of the AiP and the second side 112, and such that the plurality of solder pads or solder balls 132 are arranged along one or more other sides. In this configuration, the AiPs 106 and 106’ will together cover a single opening in a PCB.

[0054] Figure lh schematically illustrates a top view (top) and a bottom view

(bottom) of a three-package configuration of AiPs 106, 106’ and 107. The AiPs 106 and 106’ maybe similar or equal to those described with reference to Figure lg. The AiP 107, however, is configured such that plurality of radiating elements 132 of the array antenna 130 are positioned adjacent to two edges 116 and 117 on the second side 112 of the package, and such that there are electric contacting elements in form of solder pads or solder balls 132 only along the other two edges of the second side 112 of the package. In the configuration shown in Figure lh, the three AiPs 106, 107 and 106’ will together cover a single opening in a PCB. The configuration formed by the three AiPs 106, 106’ and 107 further form a basis of a modular system that maybe extended by adding more AiPs, similar or equal to e.g. the AiP 107. For example, it maybe envisaged that one or more additional AiPs (similar to the AiP 107) is/are inserted between e.g. the AiP 106 and the AiP 107, which would extend the length of the combined array antenna formed by all AiPs in one direction.

[0055] Figure 11 schematically illustrates a top view (top) and a bottom view (bottom) of another three-package configuration of AiPs 107. Just as the configuration described with reference to Figure lh, the configuration of Figure li can also be extended further by adding more AiPs 107. In contrast, however, the configuration of Figure li uses only a single AiP type. The configuration may also for example be extended as desired by adding more such AiPs 107.

[0056] In e.g. the AiPs described with reference to Figures le, lg, lh and li, it is preferable if the radiating elements are arranged such that when two AiPs are mounted adjacent to each other, the spacing between a radiating element on one side of the gap between the two AiPs (e.g. at the edge 116 of one AiP) and a radiating element on the other side of the same gap (e.g. at the edge 116 of the other AiP) is equal or at least approximately equal to a spacing between two radiating elements belonging to a same AiP. By so doing, a seamless construction of a combined array antenna from multiple smaller array antennas may be created. It is of course envisaged that it may not always be possible to arrange the various radiating elements such that the above referred to distance between radiating elements belonging to different AiPs is exactly equal to the distance between radiating elements belonging to a same AiP. However, as long as the difference in distance is small enough to have a negligible effect on the performance of the combined array antenna, it is envisaged that the construction is still “seamless”.

[0057] Applying to all embodiments of configurations of multiple AiPs forming combined array antennas disclosed herein, it is envisaged that some or all AiPs may have different configurations of for example the number of various ICs, the types of various ICs, the individual positions of the various ICs, the size of array antennas, the number of radiating elements, the exact positions of each radiating element, etc. A total number of beamforming ICs may for example be decided based on a desired number of radiating elements. If, for example, each beamforming IC is configured to control e.g. 2x2 or 4x4 radiating elements, or similar, another beamforming IC may be added for each additional such number of radiating elements. In the examples of AiPs provided in Figures lf-ii, all AiPs each include one beamforming IC 122 for each 4x4 radiating elements 132. For illustrative purposes, Figures lf-ii also illustrate each AiP as including one additional IC. Such an additional IC may for example be a frequency converter (e.g. an UDC), or similar. It is also envisaged that in other embodiments as envisaged by the present disclosure, such additional ICs may not form part of the various AiPs and, if still needed, may instead be placed e.g. as separate components on the PCB.

[0058] As described earlier herein, it is envisaged also that the various electric contacting elements maybe other than solder pads or solder balls, such as for example contacting pins or similar.

[0059] With reference to Figures 2a and 2b, a circuit assembly according to the present disclosure will now be described in more detail.

[0060] Figure 2a schematically illustrates (a side view of) a circuit assembly 200, including an AiP 100 mounted on/to a PCB 210. The various ICs 120 of the AiP 100 are arranged on/at a first side 111 of the package of the AiP 100. The circuit assembly 200 further includes a thermal interface material (TIM) 220 which is arranged on top of the first side 111, and in thermal contact with the various ICs 120. In turn, on top of the TIM 220, the circuit assembly 200 includes a heatsink 230 in thermal contact with the TIM 220. Phrased differently, the heatsink 230 is arranged such that it can extract heat generated by the various ICs 120 through the TIM 220. It is envisaged that the TIM 220 is optional, such that, in this or other embodiments of the circuit assembly 200, the TIM 220 is not present. The heatsink 230 may then, for example, instead be mounted directly to the first side 111 of the package of the AiP 100. It is envisaged that the heatsink 230 may have other forms than the one illustrated in Figure 2a. For example, in addition to being of a different size and overall shape, the heatsink may also e.g. form an integrated part in an end product frame or chassis, or similar, in which the AiP is to be installed. For example, it is envisaged that a casing of such a product maybe used as the heatsink 230, and/or that e.g. a single heatsink may be used to cool several components, including the AiP.

[0061] The AiP 100 further has an array antenna 130 arranged on a second side 112 opposite to the first side 111. The AiP 100 is mounted with its second side facing towards the PCB 210, and the plurality of electric contacting elements in form of solder pads or solder balls 142 of the AiP 100 are aligned with corresponding electric contacting elements (such as e.g. solder pads; not shown) of the PCB 210, and are connected to the electric contacting elements of the PCB 210 to form an electrical connection interface 140 between the AiP 100 and the PCB 210. As a result, signals to/from the AiP 100 maybe routed via the PCB 210 via the connection interface 140 (e.g. in form of solder joints), while the connection interface 140 at the same time may provide a mechanical fastening of the AiP 100 to the PCB 210. It is envisaged that the exact form of the electric contacting elements of the PCB can be selected to match those of the AiP 100 which is (or is to be) mounted to the PCB.

[0062] The PCB 210 further has an opening 212 (e.g. a routed hole) through it.

The AiP 100 is aligned such that the array antenna 230 is in the opening 212 of the PCB 210. Consequently, the array antenna 130 is exposed through the opening 212 of the PCB 210 such that a radio signal 134 emitted from one or more radiating elements of the array antenna 230 are not blocked or attenuated by the PCB 210. At least part of the array antenna 130 is exposed through the opening 212 of the PCB 210.

[0063] To further strengthen the mechanical connection between the AiP 100 and the PCB 210, the connection interface 140 may, in some embodiments, include an underfill material 244.

[0064] Figure 2b schematically illustrates (a top view of) an embodiment of a PCB 210 as used in the circuit assembly 200 described above with reference to Figure 2a. The opening 212 extends through the PCB 210 and is configured to be sufficiently large for an array antenna of an AiP that is to be mounted to the PCB 210 to at least partly, or fully, be exposed through the opening 212. Around the opening 212, the PCB 210 includes a plurality of electric contacting elements in form of solder pads 242. It is envisaged that total size of the solder pads 242 and opening 212 is such that it matches a size of one or more AiPs that are to be mounted on the PCB 210.

[0065] Although Figure 2a shows the AiP 100 being equal or similar to the AiP 100 described earlier with reference to Figure la, it is of course envisaged that the AiP

100 of the circuit assembly 200 may also be any other AiP described herein, such as e.g. the AiPs 101, 102, 103 and 105 described with reference to Figures lb, IC, id and if, respectively, and/ or a combination of multiple AiPs (together, when mounted on the PCB 210, forming a combined array antenna in a modular fashion), such as e.g. any combination of the AiPs 104, 104’, 106, 106’ and 107 described with reference to Figures le, lg, lh and 11, respectively. [0066] The circuit assembly 200 provides the same advantages as those already described earlier herein, e.g. with reference to the advantages Ai)-A6) described with reference to Figure la.

[0067] Although features and elements may be described above in particular combinations, each feature or element may be used alone without the other features and elements or in various combinations with or without other features and elements.

Additionally, variations to the disclosed embodiments may be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the words

“comprising” and “including” does not exclude other elements, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.