EP3537541B1 - Electromagnetic decoupling - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to the field of antennas and more particularly that of miniature antennas used by all kinds of portable and mobile electronic equipment to receive and transmit signals, typically in a range of frequencies currently up to about ten gigahertz ( GHz = 10 ⁹ Hertz), so that they can communicate freely within the limits of a geographical area covered by a so-called “wireless” network or even “wireless”, a widely used English expression having the same meaning.

STATE OF THE ART

So-called “wireless” communicating systems, which are used more and more daily, and often almost permanently, by an ever-growing population of users, all have antennas to receive and, most often also, to transmit signals in the frequency band defined by the technical standard which governs them. These are mainly portable telephones, in particular those obeying the so-called GSM standard, an acronym for “global system for mobile communications” which defines a communication standard with global geographic coverage.

Another communicating system, very widely used, which requires a very sensitive receiving antenna, is the GPS acronym for “global positioning system”. By decoding the signals coming from a network of satellites, this system makes it possible to obtain, over the extent of the terrestrial globe, a very precise geographical positioning of the receiver. GPS receivers are more and more often present in mobile phones and in all kinds of so-called smart phones or "smart phones" which also include all the functions of a personal digital assistant and the possibility of connecting to the global network of the Internet.

The wireless network can, on the contrary, be designed to cover only a restricted geographical area such as Wi-Fi, or even a very restricted one, such as the so-called “Bluetooth®” standard which allows communication up to ten meters from terminals between terminals. them.

Despite their necessary miniaturization to adapt to the dimensional constraints imposed by housings of ever smaller sizes, in particular of thicknesses that have become very small, the antennas of the above devices must nevertheless be able to maintain optimum efficiency throughout the entire band. frequencies where they must operate. This efficiency depends on losses which are intrinsic to the antenna and which are most commonly measured using the so-called “S” parameters, standing for “scattering parameters” which make it possible to qualify the behavior of the antenna between the propagation medium on the one hand and the electronic control circuit on the other hand. In general, the S parameters have been designed and are used to measure and qualify the behavior of passive or active linear circuits operating in the range of frequencies mentioned above often referred to as microwave or radio frequencies (RF) in the technical literature. on these topics. They make it possible to evaluate the electrical properties of these circuits such as their gain, the loss of efficiency or the voltage standing wave ratio resulting from an impedance mismatch observed between the control circuit and the antenna. The adaptation of the antenna is defined in particular by the parameter S11 which represents the losses by reflection of the antenna. It is expressed in decibels (dB). The lower the value of S11, the better the adaptation and therefore the better the overall efficiency of the antenna.

The parameter S11, which is dependent on the frequency, makes it possible to define the passband of the antenna, that is to say the band of frequencies in which S11 remains below a given threshold which is typically defined at a level of - 6dB. Under these conditions, a quarter of the power delivered by the electronic control circuit is lost by reflection and three quarters are therefore usefully radiated by the antenna.

The bandwidth of an antenna can be more or less wide. It is often expressed as a percentage of its center frequency. An antenna with a bandwidth of a few percent is considered to have a narrow band of operation. This type of antenna is well suited for certain applications. For example, for a GPS receiver, an antenna with a bandwidth of the order of 2% is sufficient.

An antenna with a bandwidth equal to or greater than 15% is considered to have a wide operating band. Those whose bandwidth is greater than or equal to 20% benefit from a very wide bandwidth. It will be noted here that to qualify this type of antenna, the acronym “UWB”, standing for “ultra wide band”, is also often used.

The use of a very wideband antenna potentially offers many advantages. A single broadband antenna can then simultaneously cover several radio frequency standards. This makes it possible to reduce the number of antennas that must be able to be installed in multiservice wireless devices such as smart phones, which not only gives a definite advantage in terms of cost but also allows to overcome technical problems that are difficult to solve otherwise, such as parasitic couplings that can occur between the different antennas of the same smart phone.

However, faced with the versatility of UWB antennas, there is still sometimes a need to have a second antenna, for example for communications using the “Bluetooth®” protocol. Thus, even though UWB antennas are used in order to restrict the number of antennas and thereby the problems of electromagnetic coupling between two antennas close to each other, it appears that, in certain cases of miniaturized devices, electromagnetic coupling problems remain between UWB antennas and other antennas present at the level of the microelectronic circuit carrying them.

We know the document US 2017/018975 A1 or the patent publication US 2014/085158 A1 which discloses an antenna device with a part used for decoupling between two antennas placed in a plane. This device can have different shapes, depending on the folding configuration of the metallic element which constitutes it. The methods of manufacturing such a decoupling part are very rudimentary.

It is therefore an object of the invention to offer a solution to this electromagnetic coupling problem by allowing the reduction in size of antennas intended to be installed in the same box as their control circuit can however be done in preserving sufficient operating performance.

The present invention aims to resolve at least in part the problems set out above. The other objects, features and advantages of the present invention will become apparent on examination of the following description and the accompanying drawings. It is understood that other advantages can be incorporated.

SUMMARY OF THE INVENTION

• un circuit microélectronique s'étendant dans un plan principal d'extension et selon une direction principale d'extension ;
• une première antenne, de préférence à large bande, portée par une première zone dudit circuit microélectronique et s'étendant selon un premier plan d'extension, de préférence parallèle audit plan principal d'extension, de préférence disposée au regard d'une portion du circuit microélectronique ;
• une deuxième antenne portée par une deuxième zone dudit circuit microélectronique s'étendant selon un deuxième plan d'extension, de préférence parallèle audit premier plan d'extension ;

The present invention relates to a device for transmitting and / or receiving radiofrequency signals comprising at least:

• a microelectronic circuit extending in a main extension plane and in a main extension direction;
• a first antenna, preferably broadband, carried by a first zone of said microelectronic circuit and extending along a first extension plane, preferably parallel to said main extension plane, preferably disposed facing a portion of the microelectronic circuit;
• a second antenna carried by a second zone of said microelectronic circuit extending along a second extension plane, preferably parallel to said first extension plane;

The device is further characterized in that it further comprises an electromagnetic decoupling module of the first antenna and of the second antenna, carried by a third zone of said microelectronic circuit arranged between the first zone and the second zone, the module of electromagnetic decoupling being disposed between the first antenna and the second antenna;

The electromagnetic decoupling module comprises at least one structure raised relative to said microelectronic circuit and at least one element for connecting said structure raised to said microelectronic circuit.

Compared to the decoupling technique implemented in American prior art US 2014/0085158 A1 above. The structural and manufacturing methods of the device of the invention are markedly improved. In particular, the decoupling part is raised relative to the main plane of the microelectronic circuit and is supported by an overmolding, a connecting element in the form of a plurality of vias passing through the overmolding so as to connect the decoupling part raised to the rest of the device, and advantageously to the mass. The arrangements of the invention make it possible to use a deposition technique, in particular a metallic deposition, to form the raised structure, offering great flexibility of shape, with a potentially very low thickness. However, the assembly is mechanically coherent and more resistant than the prior art due to the presence of the overmolding element.

In one embodiment, the manufacture of the decoupling module can be widely shared with the manufacture of at least one of the antennas. Indeed, the overmolding phase and, potentially, the overmolding polishing phase, can be pooled. Preferably, this common overmolding then defines a single plane for producing an electrically conductive deposit to form antenna parts of the decoupling parts.

The present invention makes it possible to have a device for transmitting and / or receiving radiofrequency signals comprising two antennas having no or very little electromagnetic coupling with one another.

Indeed, the present invention comprises an electromagnetic decoupling module between each of the first and second antennas of the device for transmitting and / or receiving radiofrequency signals.

This electromagnetic decoupling module advantageously has an electrically conductive surface electrically connected by means of electrically conductive vias to the device for transmitting and / or receiving radiofrequency signals.

In a particularly advantageous manner, this electromagnetic decoupling module is arranged between the first antenna and the second antenna. The use of an electrically conductive surface accompanied by a plurality of electrically conductive vias extending in a direction orthogonal to said electrically conductive surface makes it possible to reinforce the electromagnetic decoupling between the first and the second antenna. This makes it possible to form an electromagnetic shield comprising two parts, a first part consisting of the electrically conductive surface and a second part consisting of the plurality of electrically conductive vias.

The present invention also makes it possible to have an electromagnetic decoupling module having an electrically conductive surface facing a portion of the microelectronic circuit and preferably raised relative to the microelectronic circuit by means of electrically conductive vias. This thus allows greater compactness of the device for transmitting and / or receiving radiofrequency signals.

Advantageously, the use of electrically conductive vias for the heightening of the raised structure of the electromagnetic decoupling module offers a surface gain at the level of the microelectronic circuit which can be exploited to place microelectronic components, for example below the electromagnetic decoupling module. .

• Fourniture du circuit microélectronique présentant un plan principal d'extension ;
• Formation de la première antenne au niveau à la première zone dudit circuit microélectronique ;
• Formation de la deuxième antenne au niveau de la deuxième zone dudit circuit microélectronique ;
• Formation du dispositif de découplage électromagnétique au niveau de la troisième zone dudit circuit microélectronique, cette étape de formation comprenant au moins les étapes suivantes :
  1. i. Formation d'au moins un élément de raccordement au niveau de la troisième zone dudit du circuit microélectronique ;
  2. ii. Surmoulage du circuit microélectronique de manière à recouvrir en partie au moins l'au moins un élément de raccordement et le circuit microélectronique de sorte à définir une surface, de préférence plane, s'étendant sensiblement selon le troisième plan d'extension ;
  3. iii. Formation de la structure surélevée du module de découplage électromagnétique au niveau de ladite surface, de préférence par dépôt d'au moins un élément conducteur électrique.

The present invention also relates to a method of manufacturing a device for transmitting and / or receiving radiofrequency signals according to the present invention.

• Supply of the microelectronic circuit having a main extension plan;
• Forming the first antenna at the first area of said microelectronic circuit;
• Forming the second antenna at the second zone of said microelectronic circuit;
• Formation of the electromagnetic decoupling device at the level of the third zone of said microelectronic circuit, this formation step comprising at least the following steps:
  1. i. Formation of at least one connection element at the level of the third zone of said microelectronic circuit;
  2. ii. Overmolding of the microelectronic circuit so as to partially cover at least one connection element and the microelectronic circuit so as to define a surface, preferably flat, extending substantially along the third extension plane;
  3. iii. Formation of the raised structure of the electromagnetic decoupling module at said surface, preferably by depositing at least one electrically conductive element.

BRIEF DESCRIPTION OF THE FIGURES

• La figure 1 illustre un dispositif d'émission et/ou de réception de signaux radiofréquences comprenant deux antennes distinctes présentant un couplage électromagnétique non souhaité, réduisant ainsi leurs performances respectives.
• Les figures 2a et 2b illustrent un dispositif d'émission et/ou de réception de signaux radiofréquences selon un mode de réalisation de la présente invention et comprenant un module de découplage électromagnétique.
• Les figure 3a, 3b, 3c, 3d et 3e illustrent des paramètres S d'un dispositif d'émission et/ou de réception de signaux radiofréquences comprenant deux antennes distinctes, en fonction des figures considérées le dispositif d'émission et/ou de réception de signaux radiofréquences comprend ou non un module de découplage électromagnétique selon un mode de réalisation de la présente invention.
  • La figure 3a représente le coefficient de transmission inverse avec et sans module de découplage.
  • La figure 3b représente le coefficient de réflexion de la première antenne sans le module de découplage.
  • La figure 3c représente le coefficient de réflexion de la première antenne avec le module de découplage.
  • La figure 3d représente le coefficient de réflexion de la deuxième antenne sans le module de découplage.
  • La figure 3e représente le coefficient de réflexion de la deuxième antenne avec le module de découplage.
• Les figures 4a à 4e représentent différentes étapes d'un procédé de fabrication d'un élément antennaire surélevée selon un mode de réalisation de la présente invention.
• Les figures 5a à 5c représentent différentes étapes d'une technique de formation d'un via conducteur électrique vertical selon un mode de réalisation de la présente invention.
• La figure 6 représente un art antérieur d'une antenne UWB surélevée.

The aims, objects, as well as the characteristics and advantages of the invention will emerge better from the detailed description of an embodiment of the latter which is illustrated by the following accompanying drawings in which:

• The figure 1 illustrates a device for transmitting and / or receiving radiofrequency signals comprising two distinct antennas exhibiting undesired electromagnetic coupling, thus reducing their respective performances.
• The figures 2a and 2b illustrate a device for transmitting and / or receiving radiofrequency signals according to one embodiment of the present invention and comprising an electromagnetic decoupling module.
• The figure 3a , 3b , 3c , 3d and 3rd illustrate parameters S of a device for transmitting and / or receiving radiofrequency signals comprising two distinct antennas, depending on the figures considered, the device for transmitting and / or receiving radiofrequency signals may or may not include an electromagnetic decoupling module according to one embodiment of the present invention.
  • The figure 3a represents the inverse transmission coefficient with and without decoupling module.
  • The figure 3b represents the reflection coefficient of the first antenna without the decoupling module.
  • The figure 3c represents the reflection coefficient of the first antenna with the decoupling module.
  • The 3d figure represents the reflection coefficient of the second antenna without the decoupling module.
  • The figure 3e represents the reflection coefficient of the second antenna with the decoupling module.
• The figures 4a to 4e represent different steps of a method of manufacturing a raised antenna element according to an embodiment of the present invention.
• The figures 5a to 5c represent different steps of a technique for forming a vertical electrical conductor via according to an embodiment of the present invention.
• The figure 6 shows a prior art of an elevated UWB antenna.

The accompanying drawings are given by way of examples and do not limit the invention. These drawings are schematic representations and are not necessarily to the scale of practical application.

DETAILED DESCRIPTION OF THE INVENTION

In the context of the present invention, two planes parallel to each other are described as two planes not exhibiting any coplanar deviation or exhibiting a negligible deviation with regard to industrial tolerances, in particular less than 10 degrees and preferably less than 10 degrees. less than 5 degrees.

In the present application, a wide bandwidth antenna, also called “UWB”, means an antenna configured to operate on a frequency band ranging from a few megahertz to a few tens of gigahertz, for example between 3000 MHz and 11000. MHz.

• Avantageusement, ladite structure surélevée comprend au moins une surface conductrice électrique s'étendant selon un troisième plan d'extension coplanaire à au moins l'un parmi le premier plan d'extension et le deuxième plan d'extension.
  Cela permet d'accroître le découplage électromagnétique entre la première antenne et la deuxième antenne en diminuant le couplage électromagnétique entre la première antenne et la deuxième antenne, et de préférence en augmentant le couplage électromagnétique entre la surface conductrice électrique du module de découplage électromagnétique et l'une parmi la première antenne et la deuxième antenne.
• Avantageusement, l'élément de raccordement comprend une pluralité de vias conducteurs électriques électriquement connectés à ladite structure surélevée et audit circuit microélectronique et s'étendant depuis ladite structure surélevée vers ledit circuit microélectronique.
• Avantageusement, la surface conductrice électrique du module de découplage électromagnétique s'étend selon un troisième plan d'extension parallèle au plan principal d'extension.
  Cela permet d'accroître la compacité du dispositif tout en disposant d'un module découplage situé entre la première antenne et la deuxième antenne.
• Avantageusement, la pluralité de vias conducteurs électriques est disposée sur une partie au moins de la troisième zone du circuit microélectronique.
• Avantageusement, le premier plan d'extension et le deuxième plan d'extension sont décalés relativement à une direction perpendiculaire au premier plan d'extension et au deuxième plan d'extension.
  Cela permet de réduire le couplage électromagnétique entre la première antenne et la deuxième antenne tout en augmentant la compacité du dispositif.
• Avantageusement, au moins l'un parmi le premier plan d'extension et le deuxième plan d'extension sont coplanaires au plan principal d'extension.
  Cela permet de réaliser aisément la connexion électrique du circuit microélectronique avec l'une parmi la première antenne et la deuxième antenne.
• Avantageusement, le module de découplage électromagnétique est mécaniquement solidaire de la première antenne et de la deuxième antenne uniquement via le circuit microélectronique.
• Avantageusement, la structure surélevée du module de découplage électromagnétique est en partie au moins au-dessus d'une partie au moins des composants microélectroniques du circuit microélectronique, de préférence la structure surélevée du module de découplage électromagnétique recouvre au moins 15%, de préférence au moins 20% et avantageusement au moins 30% du circuit microélectronique.
• Avantageusement, la structure surélevée du module de découplage électromagnétique est en partie au moins au-dessus d'une partie au moins des composants microélectroniques du circuit microélectronique, de préférence la structure surélevée du module de découplage électromagnétique recouvre au moins 10%, de préférence au moins 20% et avantageusement au moins 30% du circuit microélectronique.
• Avantageusement, la structure surélevée du module de découplage électromagnétique présente au moins une extension transversale, perpendiculaire à ladite direction principale d'extension, supérieure ou égale à l'extension transversale, perpendiculaire à ladite direction principale d'extension, de la première surface conductrice électrique et à l'extension transversale, perpendiculaire à ladite direction principale d'extension, de la deuxième surface conductrice électrique.
• Avantageusement, la structure surélevée du module de découplage électromagnétique présente au moins une extension transversale perpendiculaire à ladite direction principale inférieure ou égale à la l'extension transversale dudit circuit microélectronique relativement à ladite direction principale d'extension.
• Avantageusement, le potentiel électrique de la structure surélevée du module de découplage électromagnétique est contrôlé, de préférence au travers dudit élément de raccordement.
  Le contrôle du potentiel électrique de la surface conductrice électrique permet un ajustement du découplage électromagnétique entre la première antenne et la deuxième antenne afin de l'améliorer et/ou de répondre à des conditions de fonctionnement ou des paramètres extérieurs.
• Avantageusement, le circuit microélectronique comprend une masse et la structure surélevée du module de découplage électromagnétique est électriquement connectée à ladite masse, de préférence au travers dudit élément de raccordement.
  Cela permet de réaliser un bouclier électromagnétique entre la première antenne et la deuxième antenne afin de limiter le couplage électromagnétique entre ces deux antennes.
• Avantageusement, la première antenne comprend une première surface conductrice électrique s'étendant selon le premier plan d'extension, la deuxième antenne comprend une deuxième surface conductrice électrique s'étendant selon le deuxième plan d'extension et la structure surélevée du module de découplage électromagnétique présente au moins une extension transversale, perpendiculaire à ladite direction principale d'extension, supérieure ou égale à l'extension transversale, perpendiculaire à ladite direction principale d'extension, de la première surface conductrice électrique et à l'extension transversale, perpendiculaire à ladite direction principale d'extension, de la deuxième surface conductrice électrique.
• Avantageusement, la première antenne comprend au moins une première structure surélevée relativement audit circuit microélectronique et au moins un premier élément de raccordement de ladite première structure surélevée audit circuit microélectronique, ladite première structure surélevée s'étendant dans le premier plan d'extension, le premier plan d'extension étant disposé en regard d'une partie au moins de ladite première zone dudit circuit microélectronique.
• Avantageusement, le premier élément de raccordement de ladite première structure surélevée audit circuit microélectronique comprend une première pluralité de vias conducteurs électriques électriquement connectés à ladite première structure surélevée et audit circuit microélectronique et s'étendant depuis ledit circuit microélectronique vers ladite première structure surélevée.
• Avantageusement, la première antenne est configurée pour fonctionner dans une bande de fréquences comprise entre 3000 MHz et 11000 MHz, et la deuxième antenne est configurée pour fonctionner dans une bande de fréquences comprise entre 2000 MHz et 3000 MHz.
• De préférence, la première antenne et la deuxième antenne sont configurées pour fonctionner dans des bandes de fréquences distinctes, de préférence séparée l'une de l'autre.
• Avantageusement, la première antenne est configurée pour fonctionner à une fréquence comprise entre 3000 MHz et 11000 MHz, et la deuxième antenne est configurée pour fonctionner dans une bande de fréquences comprise entre 2200 MHz et 2600 MHz, de préférence entre 2300 MHz et 2500 MHz et avantageusement entre 2400 MHz et 2 483.5 MHz.
  Cela permet de disposer d'une antenne à large bande ainsi que d'une antenne de type Bluetooth® afin d'accroître les fonctionnalités du dispositif d'émission et/ou de réception de signaux radiofréquences tout en conservant une compacité réduite et tout en limitant, voire évitant, le couplage électromagnétique entre ces deux antennes.
• Avantageusement, la structure surélevée du module de découplage électromagnétique présente une aire comprise entre 15% et 75%, avantageusement entre 25% et 50% de l'aire de l'une parmi la surface de la première antenne dans le premier plan d'extension et la surface de la deuxième antenne dans le deuxième plan d'extension.
  Cela permet d'améliorer le découplage électromagnétique entre la première antenne et la deuxième antenne.
• Avantageusement, la structure surélevée présente une forme identique à au moins une forme d'au moins l'une parmi la première antenne et la deuxième antenne.
  Cela permet d'améliorer le découplage électromagnétique entre la première antenne et la deuxième antenne.
• Avantageusement, le rapport entre l'aire de la surface conductrice électrique du module de découplage électromagnétique et l'aire de la surface du circuit microélectronique s'étendant dans le plan principale d'extension est compris entre 10% et 50%, de préférence entre 20% et 40% et avantageusement entre 25% et 35%.
  Cela permet d'améliorer le découplage électromagnétique entre la première antenne et la deuxième antenne.
• Avantageusement, le rapport entre l'aire de la surface conductrice électrique du module de découplage électromagnétique et l'aire de la surface de la première antenne dans le premier plan d'extension est compris entre 50% et 100%, de préférence entre 70% et 90% et avantageusement entre 75% et 85%.
  Cela permet d'améliorer le découplage électromagnétique entre la première antenne et la deuxième antenne.
• Avantageusement, le rapport entre l'aire de la surface conductrice électrique du module de découplage électromagnétique et l'aire de la surface de la deuxième antenne dans le deuxième plan d'extension est compris entre 50% et 100%, de préférence entre 70% et 90% et avantageusement entre 75% et 85%.
  Cela permet d'améliorer le découplage électromagnétique entre la première antenne et la deuxième antenne.
• Avantageusement, l'étape de formation de la structure surélevée du module de découplage électromagnétique est réalisée par dépôt d'au moins un élément conducteur électrique, de préférence par pulvérisation sélective de plasma.
• Avantageusement, l'étape de formation de l'au moins un élément de raccordement comprend la formation d'une pluralité de vias conducteurs électriques.
• Avantageusement, l'étape de formation d'au moins un élément de raccordement au niveau de la troisième zone dudit du circuit microélectronique comprend au moins les étapes suivantes :
  • ∘ Soudure d'une extrémité d'au moins un fil conducteur électrique au niveau d'une partie de la troisième zone dudit circuit microélectronique ;
  • ∘ Coupure d'une partie au moins dudit fil conducteur électrique soudé au niveau d'une partie de la troisième zone dudit circuit microélectronique ;
  • ∘ Disposition dudit fil conducteur électrique soudé au niveau d'une partie de la troisième zone dudit circuit microélectronique de sorte à ce qu'il présente une direction d'extension orthogonale au plan principal d'extension dudit circuit microélectronique.
• Avantageusement, l'étape de formation de la première antenne comprend au moins les étapes suivantes :
  • ∘ Former une première pluralité de vias conducteurs électriques au niveau de la première zone du circuit microélectronique ;
  • ∘ Surmouler le circuit microélectronique de manière à recouvrir en partie au moins lesdits vias conducteurs électriques de la première pluralité de vias conducteurs électriques de sorte à définir une première surface, de préférence plane, s'étendant sensiblement selon le premier plan d'extension ;
  • ∘ Former une première surface conductrice électrique de la première antenne au niveau de ladite première surface, de préférence par dépôt d'au moins un élément conducteur électrique.
  • ∘ De préférence, mais non limitativement, on protège la première surface conductrice électrique par un film isolant électrique, par exemple par un masque isolant électrique relativement fin par rapport à l'épaisseur de la première surface conductrice électrique et généralement dénommé « vernis de protection ».
• Selon un mode de réalisation, l'étape de formation de la première antenne comprend au moins les étapes suivantes :
  • ∘ Fourniture d'un circuit microélectronique ;
  • ∘ Formation d'une première pluralité de pistes conductrices électriques au niveau de la première zone du circuit microélectronique ;
  • ∘ Formation d'une troisième pluralité de vias conducteurs électriques au niveau de ladite première zone du circuit microélectronique ;
  • ∘ Surmoulage du circuit microélectronique de manière à recouvrir en partie au moins lesdits vias conducteurs électriques de la troisième pluralité de vias conducteurs électriques de sorte à définir une première surface, de préférence plane, s'étendant sensiblement selon le premier plan d'extension.
  • ∘ Formation d'une deuxième pluralité de pistes conductrices électriques au niveau de ladite première surface, de préférence par dépôt d'au moins un élément conducteur électrique.
• Avantageusement, l'étape de formation du module de découplage électromagnétique est réalisée en même temps que l'étape de formation de la première antenne.

Before starting a detailed review of embodiments of the invention, the following are characteristics which can optionally be used in combination or alternatively:

• Advantageously, said raised structure comprises at least one electrically conductive surface extending along a third extension plane coplanar with at least one of the first extension plane and the second extension plane.
  This makes it possible to increase the electromagnetic decoupling between the first antenna and the second antenna by reducing the electromagnetic coupling between the first antenna and the second antenna, and preferably by increasing the electromagnetic coupling between the electrically conductive surface of the electromagnetic decoupling module and the 'one of the first antenna and the second antenna.
• Advantageously, the connection element comprises a plurality of electrically conductive vias electrically connected to said raised structure. and said microelectronic circuit and extending from said raised structure to said microelectronic circuit.
• Advantageously, the electrically conductive surface of the electromagnetic decoupling module extends along a third extension plane parallel to the main extension plane.
  This makes it possible to increase the compactness of the device while having a decoupling module located between the first antenna and the second antenna.
• Advantageously, the plurality of electrically conductive vias is arranged on at least part of the third zone of the microelectronic circuit.
• Advantageously, the first extension plane and the second extension plane are offset relative to a direction perpendicular to the first extension plane and to the second extension plane.
  This makes it possible to reduce the electromagnetic coupling between the first antenna and the second antenna while increasing the compactness of the device.
• Advantageously, at least one of the first extension plane and the second extension plane are coplanar with the main extension plane.
  This makes it possible to easily achieve the electrical connection of the microelectronic circuit with one of the first antenna and the second antenna.
• Advantageously, the electromagnetic decoupling module is mechanically secured to the first antenna and to the second antenna only via the microelectronic circuit.
• Advantageously, the raised structure of the electromagnetic decoupling module is partly at least above a part at least of the microelectronic components of the microelectronic circuit, preferably the raised structure of the electromagnetic decoupling module covers at least 15%, preferably at least. less 20% and advantageously at least 30% of the microelectronic circuit.
• Advantageously, the raised structure of the electromagnetic decoupling module is in part at least above a part at least of the microelectronic components of the microelectronic circuit, preferably the raised structure of the electromagnetic decoupling module covers at least 10%, preferably at least. less 20% and advantageously at least 30% of the microelectronic circuit.
• Advantageously, the raised structure of the electromagnetic decoupling module has at least one transverse extension, perpendicular to said main direction of extension, greater than or equal to the transverse extension, perpendicular to said main direction of extension, of the first electrically conductive surface. and the transverse extension, perpendicular to said main direction of extension, of the second electrically conductive surface.
• Advantageously, the raised structure of the electromagnetic decoupling module has at least one transverse extension perpendicular to said main direction less than or equal to the transverse extension of said microelectronic circuit relative to said main direction of extension.
• Advantageously, the electric potential of the raised structure of the electromagnetic decoupling module is controlled, preferably through said connection element.
  The control of the electric potential of the electrically conductive surface allows an adjustment of the electromagnetic decoupling between the first antenna and the second antenna in order to improve it and / or to respond to operating conditions or external parameters.
• Advantageously, the microelectronic circuit comprises a ground and the raised structure of the electromagnetic decoupling module is electrically connected to said ground, preferably through said connection element.
  This makes it possible to produce an electromagnetic shield between the first antenna and the second antenna in order to limit the electromagnetic coupling between these two antennas.
• Advantageously, the first antenna comprises a first electrically conductive surface extending along the first extension plane, the second antenna comprises a second electrically conductive surface extending along the second extension plane and the raised structure of the electromagnetic decoupling module has at least one transverse extension, perpendicular to said main direction of extension, greater than or equal to the transverse extension, perpendicular to said main direction of extension, of the first electrically conductive surface and to the transverse extension, perpendicular to said main direction of extension, of the second electrically conductive surface.
• Advantageously, the first antenna comprises at least a first raised structure relative to said microelectronic circuit and at least a first connection element of said first raised structure to said microelectronic circuit, said first raised structure extending in the first extension plane, the first extension plane being disposed facing at least part of said first zone of said microelectronic circuit.
• Advantageously, the first connection element of said first raised structure to said microelectronic circuit comprises a first plurality of electrically conductive vias electrically connected to said first raised structure and to said microelectronic circuit and extending from said microelectronic circuit towards said first raised structure.
• Advantageously, the first antenna is configured to operate in a frequency band between 3000 MHz and 11000 MHz, and the second antenna is configured to operate in a frequency band between 2000 MHz and 3000 MHz.
• Preferably, the first antenna and the second antenna are configured to operate in distinct frequency bands, preferably separate from each other.
• Advantageously, the first antenna is configured to operate at a frequency between 3000 MHz and 11000 MHz, and the second antenna is configured to operate in a frequency band between 2200 MHz and 2600 MHz, preferably between 2300 MHz and 2500 MHz and advantageously between 2400 MHz and 2483.5 MHz.
  This makes it possible to have a broadband antenna as well as a Bluetooth® type antenna in order to increase the functionalities of the device for transmitting and / or receiving radiofrequency signals while maintaining reduced compactness and while limiting or even avoiding electromagnetic coupling between these two antennas.
• Advantageously, the raised structure of the electromagnetic decoupling module has an area of between 15% and 75%, advantageously between 25% and 50% of the area of one of the surface of the first antenna in the first extension plane. and the surface of the second antenna in the second extension plane.
  This makes it possible to improve the electromagnetic decoupling between the first antenna and the second antenna.
• Advantageously, the raised structure has a shape identical to at least one shape of at least one of the first antenna and the second antenna.
  This makes it possible to improve the electromagnetic decoupling between the first antenna and the second antenna.
• Advantageously, the ratio between the area of the electrically conductive surface of the electromagnetic decoupling module and the area of the surface of the microelectronic circuit extending in the main extension plane is between 10% and 50%, preferably between 20% and 40% and advantageously between 25% and 35%.
  This makes it possible to improve the electromagnetic decoupling between the first antenna and the second antenna.
• Advantageously, the ratio between the area of the electrically conductive surface of the electromagnetic decoupling module and the area of the surface of the first antenna in the first extension plane is between 50% and 100%, preferably between 70% and 90% and advantageously between 75% and 85%.
  This makes it possible to improve the electromagnetic decoupling between the first antenna and the second antenna.
• Advantageously, the ratio between the area of the electrically conductive surface of the electromagnetic decoupling module and the area of the surface of the second antenna in the second extension plane is between 50% and 100%, preferably between 70% and 90% and advantageously between 75% and 85%.
  This makes it possible to improve the electromagnetic decoupling between the first antenna and the second antenna.
• Advantageously, the step of forming the raised structure of the electromagnetic decoupling module is carried out by depositing at least one electrically conductive element, preferably by selective plasma spraying.
• Advantageously, the step of forming the at least one connection element comprises forming a plurality of electrically conductive vias.
• Advantageously, the step of forming at least one connection element at the level of the third zone of said microelectronic circuit comprises at least the following steps:
  • ∘ Welding of one end of at least one electrical conductor wire at the level of a part of the third zone of said microelectronic circuit;
  • ∘ Cutting at least part of said soldered electrical conductor wire at part of the third zone of said microelectronic circuit;
  • ∘ Arrangement of said soldered electrical conductor wire at the level of a part of the third zone of said microelectronic circuit so that it has an extension direction orthogonal to the main extension plane of said microelectronic circuit.
• Advantageously, the step of forming the first antenna comprises at least the following steps:
  • ∘ Forming a first plurality of electrically conductive vias at the level of the first zone of the microelectronic circuit;
  • ∘ Overmolding the microelectronic circuit so as to partially cover at least said electrically conductive vias of the first plurality of electrically conductive vias so as to define a first surface, preferably flat, extending substantially along the first extension plane;
  • ∘ Forming a first electrically conductive surface of the first antenna at the level of said first surface, preferably by depositing at least one electrically conductive element.
  • ∘ Preferably, but not limited to, the first electrically conductive surface is protected by an electrically insulating film, for example by an electrically insulating mask that is relatively thin with respect to the thickness of the first electrically conductive surface and generally referred to as "protective varnish" .
• According to one embodiment, the step of forming the first antenna comprises at least the following steps:
  • ∘ Supply of a microelectronic circuit;
  • ∘ Formation of a first plurality of electrically conductive tracks at the level of the first zone of the microelectronic circuit;
  • ∘ Formation of a third plurality of electrically conductive vias at said first zone of the microelectronic circuit;
  • ∘ Overmolding of the microelectronic circuit so as to partially cover at least said electrically conductive vias of the third plurality of electrically conductive vias so as to define a first surface, of preferably flat, extending substantially along the first plane of extension.
  • ∘ Formation of a second plurality of electrically conductive tracks at said first surface, preferably by depositing at least one electrically conductive element.
• Advantageously, the step of forming the electromagnetic decoupling module is carried out at the same time as the step of forming the first antenna.

The present invention finds, as its preferred field of application, antennas in a package or AIP, the acronym for “antenna in package”. This field covers all the solutions which make it possible to implement in a single device: the radiofrequency chip for transmitting and receiving radiofrequency signals; the antenna (s) and their matching networks as well as other radio frequency components.

For this type of device, one of the main requirements is efficiency combined with compactness. The present invention, as presented below, makes it possible to meet these two requirements jointly.

Technique possible pour la réalisation d'un élément antennaire surélevé :We will first of all describe a process for manufacturing an elevated antenna using vertical vias formed by a technique called the “Bond Via Array” technique.

Possible technique for the realization of a raised antenna element :

The present invention is based at least in part on a manufacturing technique which, surprisingly, is found to be in perfect harmony with the requirements demanded by this technical field. In general, vias are manufactured to form conductive elements between a part raised above the substrate and the surface of the latter.

Thus, according to a preferred embodiment, the present invention advantageously takes advantage of the Bond Via Array (BVA ™) technique (see in particular the article "BVA: Molded Cu Wire Contact Solution for Very High Density Package-on-Package ( PoP) Applications, Vern Solberg and Ilyas Mohammed Invensas Corporation, 02/06/2013) which allows the construction of vias connected on a circuit microelectronics extending perpendicular to the extension plane of the microelectronic circuit.

We will now describe the steps of a method in this context for forming one or more elevated antennas relative to a microelectronic circuit according to a preferred embodiment of the present invention.

• Fourniture d'un circuit microélectronique 2 ;
  Ce circuit microélectronique peut comprendre des composants microélectroniques, des pistes mais également un plan de masse.
• Formation d'un ou d'une pluralité d'éléments de raccordement mécanique et électrique d'au moins un élément antennaire à former ;
  • De manière préférée, cette pluralité d'éléments de raccordement comprend une pluralité de vias conducteurs électriques 12, 32.
  • Cette étape de formation peut nécessiter le masquage d'une partie au moins du circuit microélectronique 2 de sorte à ce que l'intégralité du circuit microélectronique ne soit pas exposée aux étapes que peut comprendre la formation des éléments de raccordement.
• Surmoulage d'une partie au moins du circuit microélectronique 2 de manière à recouvrir en partie au moins lesdits éléments de raccordement.
  Selon un mode de réalisation, le circuit microélectronique 2 est surmoulé d'un matériau polymère, par exemple une résine.
• De manière optionnelle, réalisation d'un polissage du surmoulage, via une étape de CMP (de l'anglais « chemical mechanical polishing ») par exemple, de sorte à définir au moins une surface s'étendant sensiblement selon un plan d'extension et de sorte à exposer une partie desdits éléments de raccordement 12, 32 ;
• Formation d'une ou de plusieurs surfaces conductrices électriques au niveau de ladite surface, de préférence par dépôt d'au moins un élément conducteur électrique.
  Pour cette étape, un masquage d'une partie de ladite surface peut être nécessaire afin de ne pas réaliser la ou les surfaces conductrices électriques sur l'ensemble de ladite surface, ou bien afin de réaliser une surface conductrice électrique présentant une géométrie particulière, comme par exemple des pistes ou bien des structures polygonales complexes.
• Optionnellement, retrait du surmoulage.

This method can thus comprise at least the following steps:

• Supply of a microelectronic circuit 2;
  This microelectronic circuit can include microelectronic components, tracks but also a ground plane.
• Formation of one or a plurality of mechanical and electrical connection elements of at least one antenna element to be formed;
  • Preferably, this plurality of connection elements comprises a plurality of electrically conductive vias 12, 32.
  • This training step may require the masking of at least part of the microelectronic circuit 2 so that the entire microelectronic circuit is not exposed to the steps that may include the formation of the connection elements.
• Overmolding at least part of the microelectronic circuit 2 so as to partially cover at least said connection elements.
  According to one embodiment, the microelectronic circuit 2 is overmolded with a polymer material, for example a resin.
• Optionally, polishing the overmolding, via a CMP (standing for “chemical mechanical polishing”) step for example, so as to define at least one surface extending substantially along an extension plane and so as to expose a part of said connecting elements 12, 32;
• Formation of one or more electrically conductive surfaces at said surface, preferably by depositing at least one electrically conductive element.
  For this step, a masking of part of said surface may be necessary in order not to produce the electrically conductive surface (s) over the whole of said surface, or else in order to produce an electrically conductive surface having a particular geometry, such as for example tracks or complex polygonal structures.
• Optionally, removal of the overmolding.

In order to illustrate this manufacturing process, the figures 4a to 4e will now be described.

The figure 4a shows a microelectronic circuit 2 in a sectional view. This microelectronic circuit 2 comprises a substrate 3 and a plurality of microelectronic components 4.

The figure 4b illustrates the formation of the mechanical and electrical connection elements 12, 32. These connection elements are electrically conductive vias 12, 32.

Advantageously, the connecting elements are conductive wires. They are preferably formed from an electrically conductive micro-wire advantageously soldered to a part of the microelectronic circuit 2 and then rectified in a vertical position, that is to say in a direction orthogonal to the main extension plane of the substrate 3.

According to one embodiment, the electrically conductive vias 12, 32 have a diameter, according to their transverse dimension, of between 10 μm and 500 μm, preferably between 20 μm and 250 μm and advantageously equal to 50 μm.

Advantageously, the spacing between two electrically conductive vias 12, 32 is between 150 μm and 50,000 μm, preferably between 300 μm and 3000 μm and advantageously between 250 μm and 1000 μm.

Advantageously, the height dimension of the conductive vias 12, 32 is between 100 μm and 5000 μm, preferably between 750 μm and 3000 μm and advantageously equal to 1500 μm.

Preferably, the electrically conductive vias 12, 32 comprise at least one electrically conductive material which is taken from at least: Copper, Gold, Silver, Aluminum, or an alloy formed by all or part of these elements.

The connection elements then form electrically conductive vias 12, 32 extending from the substrate 3 in a direction orthogonal to the main extension plane of the substrate 3.

This step of forming the electrically conductive vias 12, 32 will be described at greater length below through the figures 5a to 5c .

Each electrically conductive via 12, 32 has a proximal end 12a, 32a integral with the substrate 3 and a distal end 12b, 32b intended to be integral with at least one metallized surface to be formed.

The figure 4c represents the step of overmolding the microelectronic circuit 2. This overmolding is advantageously carried out from one or more polymers 5 of resin type commonly used in microelectronics.

According to an embodiment not shown, this resin 5 is deposited in a height dimension less than the height dimension of the connecting elements 12, 32.

According to a preferred embodiment and presented in figure 4c , the overmolding is carried out so that the resin 5 covers the connecting elements 12, 32, that is to say that the resin 5 used for the overmolding is preferably deposited in a dimension in height greater than the dimension in height of the connecting elements 12, 32. According to this embodiment, the distal end 12b, 32b of the electrically conductive vias 12, 32 is then embedded in the resin 5.

Advantageously, the height dimension of the resin 5 is between 100 μm and 5000 μm, preferably between 750 μm and 3000 μm and advantageously equal to 1500 μm.

It is understood that the use of an overmolding technique, in particular with a resin, makes it possible to take advantage of a liquid phase for the establishment of the overmolding element at the appropriate places and by surrounding the vias, then, after solidification of the overmolding material (typically by polymerization of the resin) to have a solid element serving in fact to construct the portions of the upper plane of the overmolding, in particular by depositing a conductive material.

According to this embodiment, illustrated in figure 4d , a mechanical-chemical polishing step of the CMP type may be necessary in order to reduce the height dimension of the resin 5 at least to the height dimension of the connecting elements 12, 32 in order to expose at least the end distal 12b, 32b of the electrically conductive vias 12, 32.

Cleverly, this polishing step makes it possible on the one hand to define a raised flat surface relative to the microelectronic circuit 2 and on the other hand to expose the connection elements 12, 32, and preferably by locally spreading the distal end. 12b, 32b of the electrically conductive vias 12, 32 relative to said flat surface. This spreading phenomenon comes from the polishing of the distal end 12b, 32b of the connecting elements 12, 32. As we will see below, this local spreading of the material of which the connecting elements 12, 32 are made participates in the mechanical and mainly electrical connection of the electrically conductive vias 12, 32 with the electrically conductive surface or surfaces to be formed.

The figure 4e represents the formation of two electrically conductive surfaces 11, 31. The formation of each of these electrically conductive surfaces 11, 31 comprises at least the deposition of at least one electrically conductive material.

According to one embodiment, this deposit can be a deposit by selective plasma spraying, for example, or by any other type of deposit allowing the formation of said electrically conductive surfaces.

In a particularly advantageous manner, the deposition technique used is configured to allow the electrical connection between the distal end 12b, 32b of the electrically conductive vias 12, 32 and the electrically conductive material deposited.

Preferably, the electrically conductive material deposited is taken from at least: Copper, Nickel, Gold, Silver, Aluminum, Palladium or an alloy formed by all or part of these elements.

According to a preferred embodiment, the two electrically conductive surfaces 11, 31 are formed at the same time and preferably from the same deposit of one or more electrically conductive materials. In addition, a mask can be used to form from the same deposit two electrically conductive surfaces 11, 31 separate, that is to say not integral with each other in their respective extension plane. .

Advantageously, one or more masks can be used in order to form one or more electrically conductive surfaces 11, 31 distinct from each other and / or having particular geometries, such as for example tracks, discs, circles, etc. ...

We will now describe more precisely, according to one embodiment, the step of forming one or a plurality of mechanical and electrical connection elements through the figures 5a to 5b .

The figure 5a shows a substrate 3 comprising an electrically conductive zone 62 and an electrically non-conductive zone 63.

By means of a wiring tool 60, an electrically conductive wire 61 is soldered at the level of the electrically conductive zone 61 as illustrated in figure 5a .

Then the wiring tool 60 unwinds part of the electrically conductive wire 61 before cutting it at the level of the non-electrically conductive zone 62 as illustrated in figure 5b . These previous steps are common when microwelds are carried out by the ultrasonic cabling technique also called “wire bonding” in English.

Finally, by means of the same tool or of another, the electrically conductive wire 61 cut is arranged in an orthogonal position relative to the main plane of the substrate 3 so as to define an electrically conductive via 12, as illustrated in figure 5c .

As will be presented hereinafter, the present invention thus advantageously takes advantage of the BVA ™ construction technique to, on the one hand, increase the compactness of the device for transmitting and / or receiving radiofrequency signals and, on the other hand, to reduce the number of steps in the manufacturing process.

This manufacturing process also allows better dimensional accuracy in the production of electrically conductive surfaces which is an essential factor in the operation of electromagnetic elements given that the resonance frequencies and electromagnetic couplings are directly affected by the dimensional aspect of the electromagnetic elements. electromagnetic elements.

In addition, this allows great flexibility in the design of the antenna element (s), in particular the possibility of placing one or more antenna (s) in one or more optimal positions relative to their functions.

This also allows better reproducibility of the characteristics, which represents a definite advantage in mass production.

Exemple d'antenne à large bande passante (UWB) :Finally, this process is compatible with electronic mass production processes, it has the advantage of being integrable into the assembly flow and industrial packaging, therefore the cost is significantly reduced and reliability increased.

Example of a wide bandwidth antenna (UWB) :

With regard to the double problem of compactness and efficiency, we will now describe a high bandwidth antenna, called “UWB”, as well as its manufacturing process using the technique of forming vias previously introduced.

For the question of compactness, we know for example devices according to the figure 6 which include a UWB type antenna raised relative to the microelectronic circuit 2 in order to increase the compactness of the device. However, this type of solution still presents problems of compactness and efficiency.

In fact, this type of device has a first drawback relative to the efficiency of this UWB 10 antenna. Due to its electrical connection with the microelectronic circuit 2 only at the level of the 11th carrying flanks of the UWB 10 antenna, parts remain. of the UWB antenna 10 electrically relatively distant from the microelectronic circuit 2, implying an increase in the electrical resistance of the UWB antenna 10 in certain places.

In addition, the 11th carrying flanks of the UWB antenna 10 occupy a non-negligible space on the microelectronic circuit 2 involving non-negligible design constraints.

The present invention proposes a method of manufacturing a raised UWB type antenna which at least partially resolves these drawbacks and makes it possible to at least partially respond to the dual problem of efficiency and compactness.

According to one aspect, the present invention therefore relates to the production of a so-called “UWB” wide bandwidth antenna raised relative to a microelectronic circuit.

Advantageously taking advantage of the previously introduced BVA ™ technique, the present invention allows the formation of a UWB antenna above a microelectronic circuit so as to reduce the bulk that this type of antenna can represent and so as to increase its efficiency via a greater distribution of mechanical and electrical connections of said UWB antenna with the microelectronic circuit.

Thus, according to a preferred embodiment, the present invention relates to a device for transmitting and / or receiving radiofrequency signals comprising at least one microelectronic circuit extending in a main extension plane and in a main direction of extension. .

Advantageously, this device for transmitting and / or receiving radiofrequency signals is further characterized in that it comprises a first antenna, preferably broadband UWB type, carried by a first zone of said microelectronic circuit and s 'extending along a first extension plane, preferably parallel to said main extension plane and preferably disposed opposite a portion of the microelectronic circuit.

Preferably, the first antenna comprises at least a first structure raised relative to said microelectronic circuit and at least a first connection element of said structure raised to said microelectronic circuit.

We will now describe, through the figure 1 , a device for transmitting and / or receiving radiofrequency signals comprising a first antenna 10 of the UWB type.

This device for transmitting and / or receiving radiofrequency signals traditionally has a microelectronic circuit 2 arranged on a substrate 3 and comprising a plurality of microelectronic components 4. This microelectronic circuit 2 extends along a main extension plane and has a main extension dimension along a main direction.

The first antenna 10, for example of the UWB type, has a first electrically conductive surface 11 raised by means of a first plurality of electrically conductive vias 12 electrically connecting this first electrically conductive surface 11 to the microelectronic circuit 2 and arranged above a first zone of the microelectronic circuit 2. This first electrically conductive surface 11 extends along a first extension plane preferably parallel to the main extension plane of the microelectronic circuit 2.

According to one embodiment, the first zone represents at least 25%, preferably at least 50% and advantageously at least 65% of the surface of the microelectronic circuit 2.

Advantageously, the first plurality of electrically conductive vias 12 is arranged mainly on a part of the periphery of the microelectronic circuit 2 and in particular mainly on one side of the microelectronic circuit 2.

According to one embodiment, the first plurality of electrically conductive vias 12 can be arranged at a distance from the periphery of the microelectronic circuit 2, for example in an internal zone of the microelectronic circuit 2, that is to say at the level of microelectronic components. 4, for example between microelectronic components 4.

This can make it possible to bring the electrically conductive vias 12 closer to certain parts of the microelectronic circuit 2 such as, for example, certain microelectronic components 4 in particular. This can also make it possible to optimize the lengths of radiofrequency paths, in other words to optimize the distance between the antenna element and the part of the microelectronic circuit 2 intended to process the radiofrequency signal (s).

Advantageously, the number of electrically conductive vias of the first plurality of electrically conductive vias 12 is between 4 and 80, preferably between 8 and 40 and advantageously between 12 and 20.

It should be noted that in this figure the first plurality of electrically conductive vias 12 may comprise electrically conductive vias 12 grouped together in several groups so as for example to electrically connect certain portions of the first electrically conductive surface 11 at different points of the microelectronic circuit 2 .

Advantageously, the spacing between two groups of electrically conductive vias 12 is between 150 μm and 50,000 μm, preferably between 200 μm and 10000 μm and advantageously between 250 μm and 3000 μm.

According to one embodiment, the number of electrically conductive vias of the first plurality of electrically conductive vias 12 is greater at one side of the first antenna 10.

According to one embodiment, the first antenna 10 comprises at least one electrically conductive via of the first plurality of electrically conductive vias 12 at each corner of its geometric shape.

In a nonlimiting manner, but as illustrated in figure 1 , the first antenna 10 can be placed in a cantilever manner, that is to say not carried by a plurality of electrically conductive vias 12 at the level of one or two contiguous sides. Thus, in this figure, the first antenna 10 is integral with the microelectronic circuit 2 at the level of two contiguous sides, thus placing it in a cantilever manner. This is particularly practical when the microelectronic component (s) 4 located under the first electrically conductive surface 11 prevent the provision of electrically conductive vias12, or when the dimensions of the first electrically conductive surface 11 are such that one or more microelectronic components 4 make it impossible to provide additional electrically conductive vias 12.

Advantageously, this cantilevered arrangement allows a distribution of the planar currents, for example as in an antenna element of the PIFA type, that is to say a planar antenna device called “inverted F”.

In this figure, and according to one embodiment, it will be noted that the first electrically conductive surface 11 has a first portion 11a and a second portion 11b which are mechanically and electrically connected to one another via a third portion 11c so as to define a slot 11d. Preferably, the second portion 11b has a surface smaller than that of the first portion 11a, and a transverse extension, perpendicular to the main direction of extension of the microelectronic circuit 2, greater than that of the first portion 11a.

The presence of the first 11a and of the second 11b portions having distinct geometries and forming the first electrically conductive surface 11 allows the first antenna 10 to have several resonant frequencies.

Indeed, it should be noted that the resonance frequencies of the different modes governing an antenna depend on the dimensions (width and length) of the latter and / or of its different parts.

Thus, the realization of this first antenna 10 in cantilever allows a precise and easy adjustment of the dimensions of the first electrically conductive surface 11 and therefore of the resonant frequencies of said first antenna 10 and this preferably without being concerned with the mechanical rigidity of the first antenna 10 given that the first electrically conductive surface 11 is supported by the overmolding, that is to say by the resin 5.

In addition, the electromagnetic coupling between the resonance modes of the same antenna characterizes the bandwidth thereof. Therefore, the geometry of the antenna directly influences its electromagnetic characteristics.

Therefore, the electromagnetic coupling between the different resonance modes of the first antenna 10 varies according to the width of the slot 11d separating the first 11a and second 11b portions of the first electrically conductive surface 11.

In particular, the narrower the slot 11d, the greater the electromagnetic coupling between the first portion 11a and the second portion 11b, which may prove to be particularly advantageous in certain applications.

According to one embodiment, the slot 11d has a width dimension of between a few tens of micrometers and a few hundreds of micrometers, and preferably being of the order of 100 μm.

Advantageously, the slit 11d has a width dimension of between 1 μm and 1000 μm, preferably between 25 μm and 500 μm and advantageously between 50 μm and 150 μm.

In comparison with the techniques of the state of the art, the present invention makes it possible to create one or more slits 11d of controlled width. In fact, it is the process of forming the first electrically conductive surface 11 by physicochemical deposition which makes it possible to achieve this control and this precision.

According to this embodiment, a first group of electrically conductive vias 12 mechanically and electrically connects the first portion 11a of the first electrically conductive surface 11 to the microelectronic circuit 2, and a second group of electrically conductive vias 12 mechanically and electrically connects the second portion 11b from the first electrically conductive surface 11 to the microelectronic circuit 2.

It should be noted that here again the use of electrically conductive vias 12 makes it possible to improve the performance of the first antenna 11 by electrically connecting each of the first 11a and second 11b portions of the first electrically conductive surface 11 to the microelectronic circuit 2.

As illustrated in figure 1 , the first electrically conductive surface 11 covers at least 25%, preferably at least 50% and advantageously at least 65% of the microelectronic circuit 2.

As previously indicated, the present invention finds for its preferred field of application package antennas or AIP, acronym for “antenna in package”, and this field is confronted with problems of efficiency and compactness.

Thus, in order to resolve this problem, the present invention advantageously takes advantage of the technique of forming vias previously presented. Indeed, this technique allows the realization of the first antenna 10 raised above the microelectronic circuit. This advantageous arrangement allows a significant gain in compactness. As for efficiency, this manufacturing process allows very good reproducibility of the characteristics of the first antenna, a criterion necessary for the mass production of this type of device.

• Fourniture d'un circuit microélectronique 2 ;
• Formation d'une première pluralité de vias conducteurs électriques 12 destinée à raccorder mécaniquement et électriquement la première antenne 10 au niveau d'une première zone du circuit microélectronique 2 ;
• Surmoulage du circuit microélectronique 2 de manière à recouvrir en partie au moins lesdits vias conducteurs électriques de la première pluralité de vias conducteurs électriques 12.
• Réalisation d'un polissage du surmoulage via une étape de CMP de sorte à définir une première surface s'étendant sensiblement selon le premier plan d'extension et de sorte à exposer la première pluralité de vias conducteurs électriques 12 au niveau de ladite première surface ;
• Formation de la première surface conductrice électrique 11 de la première antenne 10 au niveau de ladite première surface, de préférence par dépôt d'au moins un élément conducteur électrique.

Regarding the manufacturing process of this raised UWB antenna, the process described above can be adapted as follows:
This process can comprise at least the following steps:

• Supply of a microelectronic circuit 2;
• Formation of a first plurality of electrically conductive vias 12 intended to mechanically and electrically connect the first antenna 10 at the level of a first zone of the microelectronic circuit 2;
• Overmolding of the microelectronic circuit 2 so as to partially cover at least said electrically conductive vias of the first plurality of electrically conductive vias 12.
• Carrying out polishing of the overmolding via a CMP step so as to define a first surface extending substantially along the first extension plane and so as to expose the first plurality of electrically conductive vias 12 at said first surface;
• Formation of the first electrically conductive surface 11 of the first antenna 10 at said first surface, preferably by depositing at least one electrically conductive element.

Module de découplage électromagnétique :Thus, surprisingly, this method allows the resolution of the problem of compactness and efficiency by allowing the formation of a plurality of electrically conductive vias, rather than continuous sections, electrically connecting to the microelectronic circuit an antenna of the type. UWB raised relative to said microelectronic circuit.

Electromagnetic decoupling module :

As previously indicated, the present invention relates to the resolution of a dual problem of efficiency and compactness.

Indeed, AIP devices often have a plurality of antennas, and in particular in the case where the latter has a UWB antenna, it may be necessary to use a second antenna, of the Bluetooth® type for example, in order to increase the functionality of the device and extend its modularity. It is in this type of situation that the present invention mainly finds application.

Due to the ever decreasing size of microelectronic devices, the presence of a plurality of antennas leads to electromagnetic coupling problems causing performance losses relative to each antenna.

In order to solve this problem, among other things, the present invention relates to a device for transmitting and / or receiving radiofrequency signals comprising an electromagnetic decoupling module cleverly arranged between a first antenna and a second antenna.

This electromagnetic decoupling module, as will be explained later, is designed both to allow each antenna to present performance whose characteristics tend to be independent of the presence of another antenna, and while having a bulk. reduced, this through among other things, a clever positioning and design.

Typically, the electromagnetic decoupling module comprises a raised structure, formed for example of an electrically conductive surface, disposed above a part of a microelectronic circuit between a first antenna and a second antenna, preferably in the same plane. only one of the two antennas. In order to thus dispose this raised structure, the present invention may resort to the use of at least one connecting element, for example a plurality of vias electrically connected to the electrically conductive surface and to the microelectronic circuit, for example making it possible to raise said electrically conductive surface of the electromagnetic decoupling module.

According to one embodiment, the use of electrically conductive vias brings to the present invention on the one hand the possibility of raising the electrically conductive surface relative to the components of the microelectronic circuit, like one of the first and the second. antenna, and on the other hand to reinforce the phenomenon of electromagnetic shield relative to each of the first and second antennas. Indeed, the electrically conductive vias participate in the electromagnetic shield phenomenon between each of the first and second antennas.

The figure 1 previously presented illustrates the case of a device for transmitting and / or receiving radiofrequency signals comprising a first antenna 10 of UWB type and a second antenna 20 but not having an electromagnetic decoupling module. This type of device for transmitting and / or receiving radiofrequency signals generally has an efficiency limited by the electromagnetic coupling between its various antennas.

As previously described, this device for transmitting and / or receiving radiofrequency signals has a microelectronic circuit 2 arranged on a substrate 3 and comprising a plurality of microelectronic components 4.

In a manner similar to what has been described above, this device comprises the first antenna 10 which may for example be of the UWB type produced as previously indicated.

The second antenna 20, for example an antenna configured for Bluetooth® applications, is arranged at a second zone of the microelectronic circuit and in a second extension plane preferably different from the first extension plane of the first antenna 10. , but preferably parallel to it. This second extension plane corresponds for example to the main extension plane of the microelectronic circuit 2. This second antenna 20 has a second electrically conductive surface 21 electrically connected to the microelectronic circuit 2.

According to one embodiment, the second zone represents at least 15%, preferably at least 20% and advantageously at least 25% of the surface of the microelectronic circuit 2.

As illustrated in figure 1 , this second antenna 20 may have the shape of a coil extending mainly from the microelectronic circuit 2 according to a direction substantially collinear with the main direction of extension of the microelectronic circuit 2.

According to one embodiment, the second antenna 20 has a cross section, relative to its main dimension of extension, increasing as it extends from the microelectronic circuit 2.

Advantageously, the second antenna 20 has a mainly two-dimensional geometric shape.

Preferably, the second antenna 20 is directly electrically and mechanically connected to the microelectronic circuit 2.

According to one embodiment, the transverse extension of the second antenna 20 perpendicular to the main direction of extension of the microelectronic circuit 2 is less than or equal to the transverse extension of the microelectronic circuit 2, and the longitudinal extension of the second antenna 20 relative to the main direction of extension of microelectronic circuit 2 is less than or equal to the longitudinal extension of microelectronic circuit 2.

According to a particular embodiment not shown, the second antenna 20 may comprise a second electrically conductive surface 21 raised relative to the microelectronic circuit 2 by means for example of a second connection element of the type of electrically conductive vias for example and / or of the type solid vertical walls.

In the configuration of this type of device for transmitting and / or receiving radiofrequency signals, there is an electromagnetic coupling between the first antenna 10 and the second antenna 20. This electromagnetic coupling therefore disturbs the performance of each of the first 10 and the second antenna. second 20 antennas.

In order to highlight this electromagnetic coupling, the figure 3a illustrates the variation of the reverse transmission coefficient S12 40 of this device for transmitting and / or receiving radiofrequency signals when no electromagnetic decoupling module is provided.

In this same figure, the curve 41 corresponds to the case where an electromagnetic decoupling module 30 between the first antenna 10 and the second antenna 20 is produced. In particular, the strong influence of this electromagnetic decoupling module 30 will be noted in the frequency band located between 4GHz and 7 GHz by way of example.

Thus, in this frequency band which serves us here as an example of highlighting part of the advantages of the present invention, the presence of an electromagnetic decoupling module 30 allows the device 1 to transmit and / or to reception of radiofrequency signals to exhibit enhanced radiofrequency characteristics, while limiting, and preferably eliminating, the electromagnetic coupling between the first 10 and the second 20 antennas.

This electromagnetic decoupling module 30 is shown, according to one embodiment, in the figures 2a and 2b which have a device 1 for transmitting and / or receiving radiofrequency signals 1.

As previously, this device 1 for transmitting and / or receiving radiofrequency signals comprises a microelectronic circuit 2, a first zone of which carries a first antenna 10 and of which a second zone carries a second antenna 20.

In addition, this device 1 for transmitting and / or receiving radiofrequency signals has a third zone carrying an electromagnetic decoupling module 30. This electromagnetic decoupling module 30 advantageously comprises a structure raised relative to said microelectronic circuit 2.

This third zone is preferably arranged between the first zone and the second zone according to the main direction of extension of the microelectronic circuit 2.

This raised structure advantageously comprises an electrically conductive surface 31 arranged in a third extension plane.

According to one embodiment, the electromagnetic decoupling module 30 comprises at least one connection element extending from the microelectronic circuit 2, preferably from a part of the third zone of the microelectronic circuit 2, towards said raised structure.

According to one embodiment, the connection element may comprise a substantially vertical solid wall extending from the microelectronic circuit 2 towards said raised structure.

Advantageously, and as previously indicated, it may be preferred to use electrically conductive vias 32 in order to form this connection element so as to electrically connect the raised structure, in particular the electrically conductive surface 31, to the microelectronic circuit 2, for example to its ground plane.

In addition, the use of electrically conductive vias 32 makes it possible to form at least one electromagnetic shielding for the microelectronic components 4 arranged between the electrically conductive surface 31 and the substrate 3 of the microelectronic circuit 2, in other words for the microelectronic components 4 arranged. at the level of the third zone of the microelectronic circuit 2 with regard to the raised structure, preferably with regard to the electrically conductive surface 31.

Advantageously, the number of electrically conductive vias of the plurality of electrically conductive vias 32 is between 4 and 100, preferably between 10 and 80 and advantageously between 20 and 40.

Preferably, the electrically conductive surface 31 is supported by the electrically conductive vias 32 at the level of at least 2 corners, preferably at the level of at least three corners and advantageously at the level of each of its corners.

According to one embodiment, the number of electrically conductive vias of the plurality of electrically conductive vias 32 is greater at the level of one side of the electromagnetic decoupling module 30.

According to a preferred embodiment, the third extension plane corresponds to the extension plane of one or other of the first 10 and second 20 antennas, that is to say to the extension plane of their surfaces. respective electrical conductors 11 and 21.

Advantageously, the electrically conductive surface 31 has a transverse extension perpendicular to the main direction of extension of the microelectronic circuit 2 less than or equal to the transverse extension of the microelectronic circuit 2.

According to one embodiment, the third zone represents at least 15%, preferably at least 25% and advantageously at least 35% of the surface of the microelectronic circuit 2.

Advantageously, the electrically conductive surface 31 of the electromagnetic decoupling module 30 has an area at least equal to 25%, preferably to 50% and advantageously to 75% of the area of one of the surface of the first antenna 10 according to the first extension plane and the surface of the second antenna 20 according to the second extension plane.

Preferably, the electrically conductive surface 31 of the electromagnetic decoupling module 30 has an area at least equal to 10%, preferably 20% and advantageously 30% of the area of the microelectronic circuit 2.

Advantageously, as visible at the figure 2b in particular, the electrically conductive surface 31 may be polygonal, and preferably rectangular. Preferably, the connecting element has vias on at least two sides of the polygonal structure; it can present via at each intersection between sides.

Advantageously, the electrically conductive surface 31 is a surface resulting from a metal deposit.

It should be noted, and this will be described more precisely below, that the electromagnetic decoupling module 30 and the first antenna 10 may at least partly comprise similar structural characteristics given that they can be formed via the same method and preferably simultaneously.

In the figures 3a and 3b , and this advantageously, the electrically conductive surface 31 of the electromagnetic decoupling module 30 is arranged in the extension plane of the first electrically conductive surface 11 of the first antenna 10. This arrangement is particularly advantageous because it makes it possible to use the area of the microelectronic circuit 2 not covered by the first electrically conductive surface 11 of the first antenna 10 and thus the electrically conductive surface 31 has a very small footprint.

Advantageously, the use of a plurality of electrically conductive vias 32 extending from the microelectronic circuit 2 towards the electrically conductive surface 31 makes it possible to connect them electrically. These electrically conductive vias 32 therefore participate in electromagnetic decoupling by playing a role complementary to that of the electrically conductive surface 31.

According to a preferred embodiment, the electrically conductive surface 31 is mechanically independent of the first electrically conductive surface 11 and of the second electrically conductive surface 21. Otherwise formulated this means that the electrically conductive surface 31 has no physical contact point. direct neither with the first electrically conductive surface 11 nor with the second electrically conductive surface 21.

The figures 3b and 3c present the reflection coefficient S11 of the first antenna 10 as a function of the frequency. The curve 42 of the figure 3b corresponds to the situation of the figure 1 , that is to say in the absence of an electromagnetic decoupling module.

Conversely, the curve 43 of the figure 3c corresponds to the situation of figures 2a and 2b , i.e. the presence of an electromagnetic decoupling module 30.

Note that on the figure 3c , a frequency band for which the reflection coefficient S11 of the first antenna 10, of the UWB type for example, has widened and for which its amplitude is reduced.

This modification of the reflection coefficient S11 of the first antenna 10 is a marker of the electromagnetic decoupling effect allowed by the electromagnetic decoupling module 30.

About the figures 3d and 3e , these relate to the reflection coefficient S22 of the second antenna 20 as a function of the frequency. Curve 44 of the 3d figure corresponds to the situation of the figure 1 , that is to say in the absence of an electromagnetic decoupling module. Curve 44 of the figure 3e corresponds to the situation of figures 2a and 2b , that is to say in the presence of an electromagnetic decoupling module 30. It will be noted that the presence of an electromagnetic decoupling module 30 has very little influence on the performance of the second antenna 20, for example. Bluetooth® type.

Indeed, relative to the positioning of the electromagnetic decoupling module 30 relative to the first 10 and to the second 20 antennas in the figures 2a and 2b , electromagnetic decoupling has a more marked effect on the electromagnetic properties of the first antenna 10 than of the second antenna 20.

In fact, relative to the respective operating frequency bands of the first 10 and of the second 20 antennas, the electromagnetic decoupling module 30 allows an improvement in the electromagnetic performance of the first antenna 10 having the largest operating frequency band.

We will now describe the steps of a method of manufacturing a device 1 for transmitting and / or receiving radiofrequency signals comprising an electromagnetic decoupling module according to a preferred embodiment. This manufacturing method repeats many steps of the previously described method of manufacturing a raised antenna from the technique of forming vias described above.

• Fourniture du circuit microélectronique 2 ;
• Formation d'un premier élément de raccordement mécanique et électrique de la première antenne 10 au niveau de la première zone du circuit microélectronique 2 ;
  • De manière préférée, ce premier élément de raccordement comprend une première pluralité de vias conducteurs électriques 12.
  • Pour cette étape, il peut être avantageux de recourir à la technique précédemment décrite et illustrée au travers des figures 5a à 5c.
  • Cette étape de formation peut nécessiter le masquage d'une partie au moins du circuit microélectronique 2, par exemple la deuxième zone et/ou la troisième zone du circuit microélectronique 2 peuvent être masquées de sorte à ne pas être exposées aux étapes que peut comprendre la formation du premier élément de raccordement.
• Formation de l'élément de raccordement de la structure surélevée du module de découplage électromagnétique 30 au niveau de la troisième portion du circuit microélectronique 2 ;
  • De préférence, ledit élément de raccordement comprend la pluralité de vias conducteurs électriques 32. Pour cette étape, il peut être avantageux également de recourir à la technique précédemment décrite.
  • De manière préférée, cette étape de formation des vias conducteurs électriques 32 est réalisée simultanément à l'étape de formation de la première pluralité de vias conducteurs électriques 12.
  • Cette étape de formation peut également nécessiter le masquage d'une partie au moins du circuit microélectronique 2, comme par exemple la deuxième zone destinée à accueillir la deuxième antenne 20.
• Surmoulage du circuit microélectronique 2 de manière à recouvrir en partie au moins lesdits vias conducteurs électriques de la première pluralité de vias conducteurs électriques 12 et lesdits vias conducteurs électriques de la pluralité de vias conducteurs électriques 32. Selon un mode de réalisation, le circuit microélectronique 2 est surmoulé d'un matériau polymère ;
• De préférence, réalisation d'un polissage du surmoulage via une étape de CMP ( de l'anglais « chemical mechanical polishing ») par exemple de sorte à définir une première surface s'étendant sensiblement selon le premier plan d'extension et une surface s'étendant sensiblement selon le troisième plan d'extension, de préférence coplanaire au premier plan d'extension et de sorte à exposer la première pluralité de vias conducteurs électriques 12 et la pluralité de vias conducteurs électriques 32 au niveau respectivement de la première surface et de ladite surface ;
• Formation de la première surface conductrice électrique 11 de la première antenne 10 au niveau de ladite première surface, de préférence par dépôt d'au moins un élément conducteur électrique. Pour cette étape, un masquage de ladite surface destinée à accueillir la structure surélevée du module de découplage électromagnétique 30 peut être réalisé afin de la protéger de ce dépôt. De même, un masquage de la deuxième zone peut être nécessaire.
• Formation de la surface conductrice électrique 31 du module de découplage électromagnétique 30 au niveau de ladite surface, de préférence par dépôt d'au moins un élément conducteur électrique. Ici également pour cette étape, un masquage de la première surface conductrice électrique 11 peut être réalisé afin de la protéger de ce dépôt. Selon un autre mode de réalisation préféré, la formation de la surface conductrice électrique 31 est réalisée simultanément à la formation de la première surface conductrice électrique 11.
• Optionnellement, retrait du surmoulage ;
• Formation de la deuxième antenne 20 au niveau de la deuxième zone du circuit microélectronique 2. Cette formation pouvant comprendre des étapes de gravure, masquage et de dépôts de matériaux conducteurs électriques.

Thus, this method can comprise at least the following steps:

• Supply of microelectronic circuit 2;
• Formation of a first mechanical and electrical connection element of the first antenna 10 at the level of the first zone of the microelectronic circuit 2;
  • Preferably, this first connection element comprises a first plurality of electrically conductive vias 12.
  • For this step, it may be advantageous to use the technique described above and illustrated through the figures 5a to 5c .
  • This formation step may require the masking of at least part of the microelectronic circuit 2, for example the second zone and / or the third zone of the microelectronic circuit 2 can be masked so not to be exposed to the steps that may include the formation of the first connecting element.
• Formation of the connection element of the raised structure of the electromagnetic decoupling module 30 at the level of the third portion of the microelectronic circuit 2;
  • Preferably, said connecting element comprises the plurality of electrically conductive vias 32. For this step, it may also be advantageous to have recourse to the technique described above.
  • Preferably, this step of forming the electrically conductive vias 32 is carried out simultaneously with the step of forming the first plurality of electrically conductive vias 12.
  • This training step may also require the masking of at least part of the microelectronic circuit 2, such as for example the second zone intended to receive the second antenna 20.
• Overmolding of the microelectronic circuit 2 so as to partially cover at least said electrically conductive vias of the first plurality of electrically conductive vias 12 and said electrically conductive vias of the plurality of electrically conductive vias 32. According to one embodiment, the microelectronic circuit 2 is overmolded from a polymeric material;
• Preferably, polishing of the overmolding via a CMP step (standing for “chemical mechanical polishing”), for example so as to define a first surface extending substantially along the first extension plane and a surface s 'extending substantially along the third extension plane, preferably coplanar with the first extension plane and so as to expose the first plurality of electrically conductive vias 12 and the plurality of electrically conductive vias 32 respectively at the first surface and at said surface;
• Formation of the first electrically conductive surface 11 of the first antenna 10 at said first surface, preferably by depositing at least one electrically conductive element. For this step, said surface intended to receive the raised structure of the electromagnetic decoupling module 30 may be masked in order to protect it from this deposit. Likewise, masking of the second zone may be necessary.
• Formation of the electrically conductive surface 31 of the electromagnetic decoupling module 30 at said surface, preferably by depositing at least one electrically conductive element. Here also for this step, a masking of the first electrically conductive surface 11 can be carried out in order to protect it from this deposit. According to another preferred embodiment, the formation of the electrically conductive surface 31 is carried out simultaneously with the formation of the first electrically conductive surface 11.
• Optionally, removal of the overmolding;
• Formation of the second antenna 20 at the level of the second zone of the microelectronic circuit 2. This formation can include steps of etching, masking and deposits of electrically conductive materials.

Thus, surprisingly, the technique of forming vias and the method of manufacturing an elevated antenna from this technique of forming vias present a synergy with the resolution of the problem of electromagnetic decoupling between the first antenna 10 and the second. antenna 20. This technique and method in fact make it possible to have the electrically conductive surface 31 in the same extension plane as the first electrically conductive surface 11, thus allowing better electromagnetic decoupling between the first 10 and the second 20 antennas.

The present invention thus makes it possible, in a nonlimiting embodiment, to increase the efficiency of the AIP devices without affecting their compactness via, among other things, the use of an original method of forming an elevated antenna system advantageously used for the production of 'an electromagnetic decoupling module for example and an antenna then located in the same extension plane.

The invention is not limited to the embodiments described, but extends to any embodiment falling within the scope of the claims.

REFERENCES

1.

Device for transmitting and / or receiving radiofrequency signals

2.

Microelectronic circuit

3.

Substrate

4.

Microelectronic components

5.

Resin

10.

First antenna

11.

First electrically conductive surface

11a.

First portion

11b.

Second portion

11c.

Third portion

11d.

Slot

11th.

Electrically conductive sidewall

12.

First plurality of electrically conductive vias

12a.

Proximal end of a via of the first plurality of electrically conductive vias

12b.

Distal end of a via of the first plurality of electrically conductive vias

20.

Second antenna

21.

Second electrically conductive surface

22.

Second plurality of electrically conductive vias

22a.

Proximal end of a via of the second plurality of electrically conductive vias

22b.

Distal end of a via of the second plurality of electrically conductive vias

30.

Electromagnetic decoupling module

31.

Electrically conductive surface

32.

Plurality of electrically conductive vias

32a.

Proximal end of a via of the plurality of electrically conductive vias

32b.

Distal end of a via of the plurality of electrically conductive vias

40.

Inverse transmission coefficient between the first antenna and the second antenna in the absence of the electromagnetic decoupling module

41.

Inverse transmission coefficient between the first antenna and the second antenna in the presence of the electromagnetic decoupling module

42.

Reflection coefficient of the first antenna in the absence of the electromagnetic decoupling module

43.

Reflection coefficient of the first antenna in the presence of the electromagnetic decoupling module

44.

Reflection coefficient of the second antenna in the absence of the electromagnetic decoupling module

45.

Reflection coefficient of the second antenna in the presence of the electromagnetic decoupling module

60.

Wiring tool

61.

Electric conductor wire

62.

Electrically conductive zone

63.

Electrically non-conductive area

Claims (15)

1. Radiofrequency signal transmission and/or receiving device (1) comprising at least:

   • a microelectronic circuit (2) extending over a main extension plane defined by a main extension direction and another direction;

   • a first antenna (10) borne by a first zone of said microelectronic circuit (2) and extending along a first extension plane;

   • a second antenna (20) borne by a second zone of said microelectronic circuit (2) extending along a second extension plane;

   the device (1) further comprising an electromagnetic decoupling module (30) between the first antenna (10) and the second antenna (20), borne by a third zone of said microelectronic circuit (2) disposed between the first zone and the second zone; the electromagnetic decoupling module (30) comprising at least one raised structure relative to said microelectronic circuit (2) and at least one connection element of said raised structure to said microelectronic circuit (2),

   the device being characterised in that:

   - it comprises an overmoulding (5) of the microelectronic circuit (2) configured in such a way as to cover at least partially the at least connection element and the microelectronic circuit (2) so as to define a surface, preferably planar, extending substantially along a third extension plane;

   - the connection element comprises a plurality of electric conductive vias (32) electrically connected to said raised structure and to said microelectronic circuit (2) and extending from said microelectronic circuit (2) to the raised structure;

   - the raised structure is a deposition of at least one metallic conductive element of the electromagnetic decoupling module (30) located on said surface.
2. Device (1) according to the preceding claim, wherein the raised structure is supported by the electric conductive vias (32) at the level of at least two of the corners thereof, preferably at the level of at least three of the corners thereof and more preferably at the level of each of the corners thereof.
3. Device (1) according to one of the preceding claims, wherein said raised structure comprises at least one electric conductive surface (31) extending along the third extension plane coplanar with at least one from the first extension plane and the second extension plane.
4. Device according to any one of the preceding claims, wherein the overmoulding is made of at least one polymer material.
5. Device according to any one of the preceding claims, wherein the diameter of the electric conductive vias (32), along the transverse dimension thereof, is between 10 µm and 500 µm.
6. Device (1) according to one of the preceding claims, wherein the plurality of electric conductive vias (32) is disposed on a portion at least of the third zone of the microelectronic circuit (2).
7. Device (1) according to any one of the preceding claims, wherein the first extension plane and the second extension plane are offset relative to a perpendicular direction to the first extension plane and to the second extension plane.
8. Device (1) according to any one of the preceding claims, wherein the electromagnetic decoupling module (30) is mechanically connected to the first antenna (10) and the second antenna (20) only via the microelectronic circuit (2).
9. Device (1) according to any one of the preceding claims, wherein the first antenna (10) comprises a first electric conductive surface (11) extending along the first extension plane, the second antenna (20) comprises a second electric conductive surface (21) extending along the second extension plane and the raised structure (31) of the electromagnetic decoupling module (30) has at least one transverse extension, perpendicular to said main extension direction, greater than or equal to the transverse extension, perpendicular to said main extension direction, of the first electric conductive surface (11) and to the transverse extension, perpendicular to said main extension direction, of the second electric conductive surface (21).
10. Device according to any one of the preceding claims, wherein the microelectronic circuit (2) comprises a ground and wherein the raised structure of the electromagnetic decoupling module (30) is electrically connected to said ground, preferably via said connection element.
11. Method for manufacturing a radiofrequency signal transmission and/or receiving device (1) according to any one of the preceding claims, comprising at least the following steps:

    • Providing the microelectronic circuit (2) extending along the main extension plane and the antenna called the second antenna (20) at the level of the second zone of said microelectronic circuit (2);

    • Forming the first antenna (10) at the level of the first zone of said microelectronic circuit (2);

    • Forming the electromagnetic decoupling device (30) at the level of the third zone of said microelectronic circuit (2), this forming step comprising at least the following successive steps:

    i. Forming said at least one connection element at the level of said microelectronic circuit (2), the connection element comprising the plurality of electric conductive vias (32) electrically connected to said raised structure and to said microelectronic circuit (2) and extending from said microelectronic circuit (2) to the raised structure;

    ii. Overmoulding the microelectronic circuit (2) in such a way as to cover at least partially the at least one connection element and the microelectronic circuit (2) so as to define the surface, preferably planar, extending substantially along the third extension plane;

    iii. Forming the raised structure of the electromagnetic decoupling module (30) by depositing said at least one metallic conductive element at the level of said surface.
12. Method according to the preceding claim wherein the step of forming the raised structure (31) of the electromagnetic decoupling module (30) by depositing said at least one electric conductive element is carried out by selective plasma sputtering.
13. Method according to any one of the preceding claims wherein the step of forming said at least one connection element at the level of the third zone of said microelectronic circuit (2) comprises at least the following steps:

    • Welding one end of at least one electric conductive wire (61) at the level of a portion of the third zone of said microelectronic circuit (2);

    • Cutting at least a portion of said electric conductive wire (61) welded at the level of a portion of the third zone of said microelectronic circuit (2);

    • Disposing said electric conductive wire (61) welded at the level of the third zone of said microelectronic circuit (2) such that it has an extension direction orthogonal to the main extension plane of said microelectronic circuit (2).
14. Method according to any one of the three preceding claims wherein the step of forming the first antenna (10) comprises at least the following steps:

    • Forming the first plurality of electric conductive vias (12) at the level of the first zone of the microelectronic circuit (2);

    • Overmoulding the microelectronic circuit (2) in such a way as to cover partially at least said electric conductive vias of the first plurality of electric conductive vias (12) so as to define a first surface, preferably planar, extending substantially along the first extension plane;

    • Forming a first electric conductive surface (11) of the first antenna at the level of said first surface, preferably by depositing at least one electric conductive element.
15. Method according to any one of the four preceding claims wherein the step of forming the electromagnetic decoupling module (30) is carried out at the same time as the step of forming the first antenna (10).

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