Optical module for a signaling device for a motor vehicle and a signaling device for a motor vehicle incorporating said module

Abstract

The present invention relates to a light emitting module (1) for a motor vehicle signaling system comprising an array of selectively controllable light sources (2) mounted on an interconnection substrate (3) comprising a stack of insulating layers (33) alternating with conductive layers (34) interconnected by vias (35). The light emitting module (1) comprises at least one electronic component (4) for controlling and powering the array of light sources, the electronic component being embedded within an internal layer of the interconnection substrate (3). The substrate (3) comprises a plurality of control vias (35a) electrically connecting the electronic component (4) to the array of light sources (2), the electronic component (4) being configured to power and selectively control each of the light sources of the array (2) through the plurality of control vias (35a).

Description

[Technical field]

[0001] The present invention relates to the field of motor vehicle lighting and / or light signaling. More precisely, the invention relates to the field of displays integrated into light-emitting motor vehicle lighting and / or light signaling modules. [Background technology]

[0002] It is a known practice to incorporate displays into light-emitting motor vehicle devices, such as rear lights, front headlamps, bumpers, or even other parts of the front of the vehicle. These displays are created, for example, by an array of multiple selectively controllable light sources. The dimensions of the light sources are small enough to allow information (e.g., in the form of messages or pictograms) to be displayed on these displays with sufficient resolution. Such information thus makes it possible to improve the cues provided by the motor vehicle, for example by explaining the background of a given cuing function or by displaying an accompanying message.

[0003] These light sources are typically mounted on a substrate (e.g. a printed circuit board) on the back of which one or more controllers are mounted, each allowing some of these light sources to be selectively controlled. The controllers are typically integrated circuits encapsulated in a package that allows the integrated circuit to be mechanically and electrically connected to the substrate and ensures the dissipation of heat generated by the integrated circuit. Modern controller packages are typically equipped with an array of connectors (e.g. ball grid array (BGA) or land grid array (LGA)), which are optimized in terms of heat dissipation only on the side used to mount the package on the substrate.

[0004] These encapsulated controllers thus suffer from various drawbacks.

[0005] From a thermal point of view, a considerable amount of heat is generated by each light source, which must be dissipated in order to avoid adversely affecting their performance. It goes without saying that this heat cannot be dissipated at the light source side, but must therefore be transferred to the rear side of the board. However, the presence of the controller on this side of the board reduces the space available for heat exchange (in particular for the placement of a heat sink). Likewise, a large amount of space must be left on this side of the board for solutions that allow the mechanical assembly of the display and the light-emitting device, but also for solutions that allow this display to be connected to a control and / or power supply unit of the display.

[0006] From a manufacturing point of view, these controllers must be soldered to a substrate, which complicates the manufacture of light emitting devices incorporating the display, reducing the reliability and increasing the cost of such devices. Moreover, a cable harness must be provided between the display and its control and / or power unit, which further complicates the assembly and correspondingly increases the cost of the light emitting device.

[0007] From an electromagnetic compatibility standpoint, the package in which the controller is encapsulated must be shielded to prevent the controller from generating electromagnetic interference that could adversely affect the operation of other electronic components in the lighting device (or even the motor vehicle) and vice versa.

[0008] Finally, from a reliability standpoint, the greater the distance between each light source and its controller, the more likely the control signals sent by the controller to those light sources will be weakened or subject to interference during transmission to the light sources, which can lead to reliability problems during the display of images by a display command given to the display. Summary of the Invention [Problem to be solved by the invention]

[0009] Thus, there is a need for a lighting module that can form a display for a motor vehicle signaling system, including light sources and one or more controllers for those light sources, that overcomes the drawbacks of the lighting devices discussed above.

[0010] The present invention is within this context and aims to meet this need. [Means for solving the problem]

[0011] To these ends, one subject of the present invention is a light-emitting module for a signaling system of a motor vehicle, comprising a first array of selectively controllable light sources mounted on a first interconnection substrate, the first interconnection substrate comprising a stack of insulating layers alternating with conductive layers, each conductive layer being interconnected with another conductive layer by at least one via penetrating one of the insulating layers, the light-emitting module comprising at least a first electronic component for controlling and powering the first array of light sources, the first electronic component being embedded in the first substrate within an internal layer of the first substrate, and the first substrate comprising a first plurality of control vias electrically connecting the first electronic component to the first array of light sources, the first electronic component being configured to power and selectively control each of the light sources of the first array through the first plurality of control vias.

[0012] The invention, and in particular the fact that one or more electronic components capable of controlling and powering each light source of the first array are embedded in the interconnection board, gives the light emitting module various advantages. On the one hand, the interconnection board forms a shield against electromagnetic interferences that may be transmitted or received by said electronic components (thanks to the conductive layers). On the other hand, the absence of the need for soldering or assembly of a controller to the board facilitates the implementation, increases the reliability of the light emitting module and reduces its costs. Furthermore, the reduced distance between each light source and the electronic components controlling them improves the quality of the light source control signals sent by said electronic components. Finally, the freeing of the surface of the interconnection board opposite to that intended for receiving the light sources makes available a large amount of space (which may in particular amount to more than 90% of this receiving surface), for example for solutions for heat dissipation, for components for mounting the light emitting module to a signaling device, or even for a control and / or power supply unit. In the latter case, apart from reducing the overall bulk of the signalling device, it is possible to avoid the use of cable harnesses between the light emitting modules and the control and / or power supply units, thereby further reducing the bulk and cost of the signalling device.

[0013] By "via" in the present invention is meant a metallized hole, for example one having a metal plating on its inner surface, filled with a metal such as copper, and in particular one provided at each of its two ends with a land for connection to a conductive layer. It may be particularly advantageous to concern microvias, i.e. vias with a diameter of approximately 350 microns or less, or even approximately 150 μm or less, in particular 90 μm.

[0014] In the present invention, the interconnection substrate is alternatively a printed circuit board in which two adjacent conductive layers are separated by an insulating layer. Where appropriate, each conductive layer could be etched and drilled to define interconnection tracks connected by vias to the interconnection tracks of another conductive layer. Each conductive layer could be interconnected with the conductive layer immediately above and / or below, and / or with one or more conductive layers. Thus, each via could be a buried via (i.e. a via that extends through the substrate without appearing on either the bottom or top surface of the substrate), a blind via (i.e. a via that extends through the substrate and appears on only one of the bottom or top surfaces of the substrate), or a through via, in particular a thermal via (i.e. a via that extends through the substrate and appears on the top or bottom surface, respectively). Similarly, each via could be arranged in a stepped and / or stacked configuration within the substrate.

[0015] In the present invention, an "electronic component" means one or more integrated circuits, optionally associated with one or more passive elements necessary for the operation of the one or more integrated circuits. The passive elements could be electronic components, such as multilayer ceramic capacitors, silicon capacitors, resistors, inducers, or could be formed by a specific arrangement of parts of one or more conductive layers (e.g. two adjacent conductive layers partially overlapping to form a capacitor). Where appropriate, the or each electronic component could be an exposed component (i.e. not encapsulated in a package) or alternatively encapsulated in a package provided with electrical connection elements.

[0016] The first electronic component is disposed in a cavity provided in an internal insulating layer (i.e. a layer separate from the layers of the substrate exposed to air) and is electrically connected to the conductive layers immediately above and / or below said insulating layer, such that said cavity can be formed during the manufacture of the substrate, so that the first electronic component can be embedded in the substrate during said manufacture.

[0017] Advantageously, the first array of light sources comprises at least 50 light sources, or even at least 200 light sources, or even at least 500 light sources.

[0018] In one embodiment of the invention, each of the light sources comprises at least one light-emitting semiconductor chip with dimensions between 150 μm and 400 μm. Such chips are known in particular as mini-LEDs. Where appropriate, the light sources may be arranged on the first side of the substrate such that they are separated from each other by a distance of less than 1 millimeter. As a variant, each of the light sources comprises at least one light-emitting semiconductor chip with dimensions between 5 μm and 150 μm. Such chips are known in particular as micro-LEDs. Where appropriate, the light sources may be arranged on the first side of the substrate such that they are separated from each other by a distance of between 200 and 400 μm, or even 300 μm or less. Here, "distance between two light sources" means the distance that separates the center of one of the light sources from the center of the other of the light sources.

[0019] In one embodiment of the invention, a first array of light sources is mounted on a first side of a first interconnection substrate. Where appropriate, the light emitting module comprises a control unit capable of generating control instructions for a first electronic component to selectively control each of the light sources of the first array and / or a power supply unit capable of supplying power to the first electronic component to power each of the light sources of the first array, the control unit and / or the power supply unit being mounted on a second side opposite to the first side of the first interconnection substrate. Such a control unit and / or power supply unit can thus be arranged on the second side of the first substrate, taking advantage of the space available on the second side of the first substrate.

[0020] "control unit" means a unit capable of receiving (from a connector of the light emitting module) instructions to display an image on a first array of light sources (which instructions may in particular include said image) and configured to generate control instructions for each of the light sources based on said settings. "power supply unit" means a unit capable of receiving (from a connector of the light emitting module) an external power supply and configured to convert said external power supply into a power supply suitable for powering the first array of light sources and the first electronic component.

[0021] The control unit and / or the power supply unit may preferably be connected to the first electronic component by at least one via of the substrate connected (directly or indirectly) to at least one conductive layer (called power distribution layer) of the substrate. If appropriate, the power distribution layer may be connected to one or more connection pins of the first electronic component. If desired, the control unit and the conversion unit may be implemented on the same circuit board, which is attached to the second side of the first substrate.

[0022] Advantageously, the first array of light sources forms a passive array, and the first electronic component is configured to control said passive array through said first plurality of control vias in response to control instructions received from the control unit, for example each control via being capable of controlling one row or column of the first array of light sources.

[0023] In an alternative or cumulative embodiment, the first array of light sources is mounted on a first surface of the first interconnection substrate, the light emitting modules are provided with a heat sink for the light emitting modules, and the heat sink is mounted on a second surface of the first interconnection substrate opposite the first surface. Thus, the heat sink, which allows the heat generated by the light sources and the first electronic components to be dissipated, is placed on the second surface of the first substrate, taking advantage of the space left on the second surface. It should be noted that furthermore, this heat can be distributed over the entire surface area of ​​the second surface in order to optimize the heat dissipation. The heat sink could be equipped with heat dissipation fins and / or made of a material exhibiting high thermal conductivity.

[0024] According to one embodiment of the invention, the light emitting module comprises a second array of selectively controllable light sources mounted on a first interconnection substrate and at least a second electronic component for controlling and powering the second array of light sources, the second electronic component being embedded in the first substrate within an internal layer of the first substrate. Where appropriate, the first substrate comprises a second plurality of control vias electrically connecting the second electronic component to the second array of light sources, the second electronic component being configured to power and selectively control each of the light sources of the second array through the second plurality of control vias. In this example, a display is thus created with multiple arrays of light sources mounted on the same substrate, each array being independently controlled and powered by one electronic component embedded in the substrate.

[0025] According to another embodiment of the invention, the light emitting module comprises a second array of selectively controllable light sources mounted on a second interconnection substrate and at least second electronic components for controlling and powering the second array of light sources, the second electronic components being embedded in the second substrate within an inner layer of the second substrate, the first substrate being disposed adjacent to the second substrate. In this example, the display is thus divided into a number of sub-modules arranged side by side, each of which is formed by an array of light sources mounted on a substrate, with electronic components embedded in the substrate for controlling and powering the array of light sources. The second substrate preferably has substantially the same characteristics as the first substrate. This type of architecture allows to increase the manufacturing yield of the display and standardize the sub-modules, while at the same time providing a high degree of freedom in the shape and size of the display and facilitating its repairability.

[0026] In particular, it could be envisaged that a light emitting module comprises more than two sub-modules, in particular at least ten sub-modules, arranged juxtaposed to one another to form a display.

[0027] Advantageously, an edge of the first substrate is close (in contact or not) to an edge of the second substrate, so that the first array of light sources is adjacent to the second array of light sources. Preferably, the distance separating a first light source of the first array located on said edge of the first substrate and a second light source of the second array located as close as possible to the first light source on said edge of the second substrate is substantially equal to or smaller than the distance between two light sources in the first and / or second array. It is thus possible to hide gaps between the sub-modules of the display.

[0028] Advantageously, each of the first and second arrays of light sources is mounted on a first side of a first and second interconnection substrate, respectively, which are mounted on the same support (in particular the same printed circuit board) via their second sides opposite to their first sides, which support can thus serve on the one hand as a support for the control and / or power supply units of the various sub-modules and on the other hand as a member for mechanically fixing the display formed by the sub-modules to the signalling device.

[0029] Advantageously, the second surface of each of the substrates carries an electrical connector that is mechanically coupled to the support and capable of transmitting control commands and / or power to electronic components embedded in the substrates. In other words, each substrate is mechanically supported by the electrical connector. For example, the electrical connector supported by each substrate may be connected (by vias) to a power distribution layer that is connected to electronic components embedded in the substrates.

[0030] According to an example of embodiment, the module could comprise a control unit capable of generating control instructions for the respective electronic components for selectively controlling each of the light sources of each array, and / or a power supply unit capable of powering the respective electronic components for supplying power to the light sources of each array, the control unit and / or the power supply unit being mounted on the support. Where appropriate, the light emitting module could comprise input connectors for delivering display instructions and / or an external power supply, the input connectors being mounted on the support.

[0031] For example, control commands generated by the control unit based on the display commands and / or power supplies converted from an external power supply could pass through the support (in particular via respective electrical tracks formed on this support) to each submodule (where, for example, they would be distributed via respective connectors).

[0032] According to another embodiment, the electronic components of each board are connected to at least one electronic component of another board, so that all of the electronic components together form a network, and the electronic components of at least one board (in particular each board) can transmit control instructions to the electronic components of the other boards in the network to which they are connected. For example, the control instructions could be dedicated to the other electronic components and include an address associated with the other electronic components, or, as a variant, the control instructions could be included in a global instruction, while being associated with the address of the other electronic components. The electronic components could be interconnected to form a network with a daisy-chain topology, or a mesh topology, or any other topology. In this example, for example, power can be transmitted to the sub-modules via the support, while the control instructions can be distributed by other means (for example, by connecting wires, cables or cable harnesses interconnecting the sub-modules, or even by wireless communication).

[0033] Advantageously, each board comprises a wireless data receiver, which, if appropriate, may be embedded in an internal layer of the board or, alternatively, may be mounted on the first side of the board. If appropriate, the control unit may comprise a wireless data transmitter capable of transmitting the control commands for each electronic component to a receiver of each board in which these components are embedded. The receiver of each board is connected, for example via a power distribution layer, to the electronic components embedded in this board in order to transmit the control commands received from the transmitter of the control unit to the electronic components.

[0034] In one embodiment of the invention, each substrate, in particular the first side of each substrate, has a square or rectangular shape. Where appropriate, each array of light sources could comprise 64, 144, 256, 576 or 1024 light sources arranged in 8 rows and 8 columns, 12 rows and 12 columns, 16 rows and 16 columns, 24 rows and 24 columns or 32 rows and 32 columns. The distance between two light sources could be the same for all of the array of light sources or, alternatively, could be different for each array of light sources.

[0035] According to another embodiment of the invention, each substrate (in particular the first surface of each substrate) has a triangular or hexagonal shape. Alternatively, each substrate could be rhomboidal. More generally, each substrate could have a shape that does not have right angles. This type of configuration allows to increase the density of light sources on the first surface of the substrate relative to a square or rectangular configuration, and thus to reduce the distance between the light sources.

[0036] Where appropriate, the arrays of light sources could be arranged in rows and columns in a checkerboard pattern or, as a variant, in staggered rows and columns. The rows and columns could preferably be arranged parallel to the edges of the substrate. This feature makes it possible in particular to avoid aliasing effects at the edges of the substrate, which would cause the abutments of sub-modules in the display to be visible. As a variant, the light sources of the arrays could be arranged in a grid with square or triangular unit cells.

[0037] It would be possible to combine the various embodiments described above without departing from the scope of the invention, in particular by resulting in a number of sub-modules each equipped with a number of arrays of light sources, each controlled by an electronic component embedded in the substrate of the respective sub-module.

[0038] Another subject of the invention is a signalling device for a motor vehicle, characterised in that it comprises a light-emitting module according to the invention, said light-emitting module forming a display of the device.

[0039] The invention will now be described by way of examples which are merely illustrative and in no way limiting of the scope of the invention, and with reference to the accompanying drawings in which various figures are shown. [Brief description of the drawings]

[0040] [Figure 1] FIG. 2 is a schematic partial cross-sectional view of a light-emitting module according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic partial side view of a light emitting module according to another embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic partial front view of the module of FIG. 2; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] Throughout the following description, elements that are structurally or functionally identical and that appear in different figures are designated by the same reference numerals unless otherwise specified.

[0042] 1 shows a cross-sectional view of a light emitting module 1 according to an embodiment of the present invention. In the example described, the light emitting module 1 is intended to be integrated into a rear light of a motor vehicle, the light emitting module 1 forming a display. Without departing from the scope of the invention, the light emitting module 1 could also be adapted to be integrated into other elements of the motor vehicle, such as a headlamp, a front light, a bumper or other elements in the front of the vehicle.

[0043] The light emitting module 1 comprises an array of light sources 2 mounted on a substrate 3 .

[0044] In the example described, each of the light sources 2 comprises at least one light-emitting semiconductor chip (i.e. a so-called micro LED) with dimensions between 5 μm and 150 μm. The light-emitting module 1 comprises 64 light sources 2 arranged in an array of 8 columns and 8 rows. The light sources 2 are spaced apart from each other by a distance of 300 μm or less. It is noted that other dimensions, other distances between the light sources, other numbers of light sources or even other distributions of the light sources are foreseeable without departing from the scope of the invention.

[0045] The substrate 3 is a printed circuit board, or PCB, having a first side 31 and an opposite second side 32. Each light source 2 is mounted on the first side 31 of the substrate, which faces the exterior of the signaling device in which the light emitting module 1 is incorporated.

[0046] It should be noted that in the example described, the substrate 3 is a so-called multi-layer PCB, comprising between a first side 31 and a second side 32 a stack of insulating layers 33 alternating with conductive layers 34 .

[0047] Each conductive layer 34 is interconnected with another conductive layer 34 by at least one via 35 passing through one insulating layer 33. Each conductive layer 34 is etched and drilled to define interconnect tracks which are connected by vias 35 to the interconnect tracks of another conductive layer 34. The first side 31 and the second side 32 are formed by the sides of the insulating layers 33 facing towards the outside of the substrate 3. The sides are perforated to provide access to the first and last conductive layers 34 respectively and thus to allow mounting of electronic components on the surface of the substrate 3.

[0048] Thus, each light source 2 is surface mounted on the substrate 3 near an opening (or hole) formed in the first surface 32 and electrically connected (by soldering or wire bonding) to the first conductive layer 34 for interconnection with the substrate 3.

[0049] The light emitting module 1 comprises electronic components 4 for controlling and powering the array of light sources 2. The electronic components 4 are embedded in the substrate 3 within one of its internal insulating layers 33.

[0050] More precisely, during the manufacture of the inner insulating layer 33, a cavity 33a is reserved in this layer 33, and the electronic component 4 is placed in this cavity and electrically connected to the conductive layer 34 immediately below this insulating layer in order to continue the manufacture of the substrate 3. It would be possible for the electronic component 4 to be electrically connected to the conductive layer 34 immediately above without departing from the scope of the invention.

[0051] The electronic component 4 comprises an integrated circuit associated with passive elements. The integrated circuit may be exposed as opposed to an integrated circuit encapsulated in a package. It would be possible for the integrated circuit to be encapsulated in a package without departing from the scope of the invention.

[0052] A number of control vias 35a electrically connect the electronic component 4 to the array of light sources 2. The array of light sources 2 forms a passive array in which each row and each column of light sources 2 can be controlled by the electronic component 4, using the control vias that address this row or this column in order to control the power supply to the light sources of that row or this column in particular. The electronic component 4 can thus supply power to and selectively control each of the light sources 2 through said number of control vias 35a, for example by successively scanning each row and then each column of the array in order to control the power supply to each of the light sources 2.

[0053] The light-emitting module 1 is provided with a connector (not shown) for receiving display commands regarding the display by the plurality of light sources 2. It may be a matter of commands sent by the computer of the motor vehicle or the signaling device for the purpose of displaying a logo, a message, a pattern or a pictogram. For example, it may be a matter of a pictogram intended to inform an outside observer that the door of the motor vehicle is open, a pictogram intended to inform a driver following the motor vehicle of the presence of black ice on the road, or even traffic-related information or even a pictogram intended to inform a pedestrian whether or not he can cross the road. The display command could include a representation of the pictogram.

[0054] The light emitting module 1 also comprises a connector (not shown) for receiving an external power supply (eg from an electric battery of the motor vehicle).

[0055] The light-emitting module 1 includes a power supply and control unit 5 connected to each connector for the purpose of receiving display commands and an external power supply. The unit 5 is supported by a printed circuit board mounted on the second surface 32 of the substrate 3 perpendicular to an opening (or hole) formed in the second surface 32. A connector 51 is arranged in the opening and electrically connected to the unit 5 and the last conductive layer 34 for interconnecting the unit 5 with the substrate 3.

[0056] On the one hand, the unit 5 can generate, based on a received display command, control commands for the electronic component 4 in order to selectively control each of the light sources 2 so as to cause the array to display a pictogram of the display command. Furthermore, the unit 5 can convert an external power supply into a power supply suitable for powering the array of light sources 2 and the electronic component 4. The control commands and the converted power supply are thus distributed to the electronic component 4 through the connector 51, then through the respective vias 35 and the respective conductive layers 34, referred to as power distribution layers.

[0057] The controller 4 is thus configured to control each of the light sources 2 of the passive array in response to control commands received from the unit 5 and to power these light sources 2 using the power supply converted by the unit 5 .

[0058] Furthermore, the light emitting module 1 comprises a heat sink 6 mounted on the second face 32 of the substrate 3. In the example described, this heat sink 6 is a component made of a thermally conductive material, in particular aluminum, and provided with heat dissipation fins. The face 32 may be partially covered with a layer of gold or nickel so that the heat sink 6 can be soldered to the substrate 3.

[0059] It should thus be noted that the second side 32 of the substrate 3 provides a space on which the unit 5 and the heat sink 6 can be placed, so as to improve the thermal performance of the light-emitting module 1, to avoid the need to use cable harnesses to connect to a control or power supply unit far away from the substrate 3, and to reduce the distance between the unit 5, the electronic components 4 and the array of light sources 2. It should also be noted that the second side 32 of the substrate provides a solution for the placement of the components for fixing the module 1 to the rear light or to any other element in which it must be integrated. Furthermore, the fact that the electronic components 4 are embedded makes it possible to simplify the design of the light-emitting module 1 and to shield the electronic components 4 by means of the conductive layer 34.

[0060] FIG. 2 shows a cross-sectional view of a light emitting module 10 according to another embodiment of the present invention.

[0061] In this example, a light emitting module 10 comprises a number of sub-modules 11. Each sub-module 11 comprises an array of selectively controllable light sources 2 mounted on an interconnection substrate 3, and electronics 4 embedded within the substrate 3 for controlling and powering the array of light sources 2. The structure of each substrate 3 is similar to that of the module shown in Figure 1 and will not be described again.

[0062] The sub-modules 11 are arranged next to each other so as to together form a display for the rear light (or other element) of the motor vehicle. Although only three sub-modules 11 are shown in Figure 2, there could be a much larger number of sub-modules without departing from the scope of the invention.

[0063] In the example described, the substrates 3 of the submodules 11 are mounted on a common support 7, in this case the same printed circuit board. More precisely, the second face 32 of each substrate 3 carries an electrical connector 8 which is mechanically coupled to the substrate 7.

[0064] The substrate 7 further supports a control and power unit 5, which is similar to that of the module 1 of Fig. 1, except that it is able to send control commands and distribute power to the various sub-modules 11 via respective electrical connectors 8. The electrical connectors 8 transmit the received control commands and converted power to the electronic components 4 embedded in the substrate 3 of these sub-modules 11.

[0065] For example, it is possible to envisage a control unit which subdivides the pictogram of the display command into sub-images each intended to be displayed by the array of light sources 2 in one of the sub-modules 11 (such that the display of all the sub-images together forms this pictogram) and then generates, for each of the sub-modules 11, control commands for the electronic components 4 of this sub-module 11 in order to display this sub-image.

[0066] In an example not shown, it can be envisaged that only the power supply converted by the unit 5 travels through the board 7 to the connector 8, the control commands generated by the unit 5 being distributed to each of the sub-modules 11 by other connection means, for example a wired connection connecting the unit 5 to each of the sub-modules 11 to form a star circuit, a wired connection connecting the unit 5 to one sub-module 11 and then each sub-module 11 to another sub-module 11 to form a daisy chain, or else a wireless connection in which the unit 5 and each sub-module 11 are equipped with a wireless data transceiver.

[0067] FIG. 3 shows a front view of an example of the arrangement of the sub-modules 11. In FIG.

[0068] Each substrate 3 has a triangular shape, although other shapes could be adopted without departing from the scope of the invention, in particular rhombic or hexagonal shapes.

[0069] It will be noted that the array of light sources 2 is arranged (for each submodule 11) into rows and columns that are arranged parallel to each edge of the substrate 3. The distance between the light sources 2 in a given submodule 11 is the same for every submodule.

[0070] An edge 3a of the substrate 3 in each submodule 11 is adjacent, but does not contact, an edge 3a of the substrate 3 in an adjacent submodule 11. Thus, it will be seen that the arrays of light sources 2 in two adjacent submodules 11 are substantially adjacent, and the distance separating adjacent light sources 2 located at the edges 3a of those submodules 11 is substantially less than or equal to the distance between two light sources 2 in a given submodule 11.

[0071] Thus, thanks to the triangular shape, each sub-module 11 forms a standard sub-module, which can be arranged to form a display of any shape, with sufficient resolution in terms of distribution and density of light sources 2 based on the adjacency of the triangular substrates and arrays, and which is easily reversible given the division of the display into sub-modules 11.

[0072] The above description clearly explains how the present invention is able to achieve its set objectives: by embedding the controllers of each light source in the display of an automotive lighting device into the substrate that supports these light sources, leaving the back surface of this substrate free.

[0073] In any case, the invention is not limited to the embodiments specifically described in this document, but in particular extends to all equivalent means and any technically functional combination of these means. In particular, the substrate could be with a different organization of the internal layers and / or vias, whether it is rigid or flexible, straight or curved. Other types of light sources than those described may be employed, in particular light sources with larger dimensions (for example comprised between 150 μm and 400 μm), such as micro LEDs. Other types of electronic components than those described are possible. Other types of heat dissipation elements than those described are also possible, in particular heat dissipation elements incorporating fan elements.

Claims

1. 1. A light emitting module (1, 10) for a signaling system of a motor vehicle comprising a first array of selectively controllable light sources (2) mounted on a first interconnection substrate (3), the first interconnection substrate (3) comprising a stack of insulating layers (33) alternating with conductive layers (34), each conductive layer being interconnected with another conductive layer by at least one via (35) passing through an insulating layer, the light emitting module (1, 10) comprising at least a first electronic component (4) for controlling and powering the first array of light sources, the first electronic component being embedded in the first substrate within an internal layer thereof, and the first substrate comprising a first plurality of control vias (35a) electrically connecting the first electronic component to the first array of light sources, the first electronic component being configured to power and selectively control each of the light sources of the first array through the first plurality of control vias.

2. A light-emitting module (1, 10) according to the preceding claim, comprising a first array of light sources (2) mounted on a first side (31) of the first interconnection substrate (3), a control unit (5) capable of generating control instructions for the first electronic component (4) for selectively controlling each of the light sources of the first array and / or a power supply unit (5) capable of supplying power to the first electronic component for supplying power to each light source of the first array, the control unit and / or the power supply unit being mounted on a second side (32) of the first interconnection substrate opposite to the first side.

3. The light emitting module (1, 10) according to the preceding claim, wherein the first array of light sources (2) forms a passive array, and the first electronic component (4) is configured to control the passive array through the first plurality of control vias (35a) in response to the control commands received from the control unit (5).

4. A light emitting module (1, 10) according to any one of the preceding claims, comprising a first array of light sources (2) mounted on a first side (31) of the first interconnection substrate (3) and a heat sink (6) for the light emitting module, the heat sink being mounted on a second side (32) of the first interconnection substrate opposite the first side.

5. 13. A light emitting module (1, 10) according to any one of the preceding claims, comprising a second array of selectively controllable light sources (2) mounted on the first interconnection substrate (3), comprising at least a second electronic component (4) for controlling and powering the second array of light sources, the second electronic component being embedded in the first substrate in an internal layer (33) of the first substrate, and the first substrate comprising a second plurality of control vias (35a) electrically connecting the second electronic component to the second array of light sources, the second electronic component being configured to power and selectively control each of the light sources of the second array through the second plurality of control vias.

6. 5. A light emitting module (1, 10) according to claim 1, characterized in that it comprises a second array of selectively controllable light sources (2) mounted on a second interconnection substrate (3), comprising at least second electronic components (4) for controlling and powering the second array of light sources, the second electronic components being embedded in the second substrate within an internal layer (33) of the second substrate, and the first substrate being arranged adjacent to the second substrate.

7. A light-emitting module (1, 10) according to the preceding claim, wherein each of the first and second arrays of light sources (2) is mounted on a first side (31) of the first and second interconnection substrates (3), respectively, and wherein the first and second interconnection substrates are mounted on the same support (7) via their second sides (32) opposite to their first sides.

8. The light-emitting module (1, 10) according to the preceding claim, wherein the second surface (32) of each of the substrates (3) supports an electrical connector (8) that is mechanically coupled to the support (7) and capable of transmitting control commands and / or power to the electronic components (4) embedded in the substrate.

9. A light-emitting module (1, 10) as claimed in any one of claims 6 to 8, wherein the electronic components (4) of each board (3) are connected to at least one electronic component of another board so that all of the electronic components (4) together form a network, and the electronic components of each board are capable of transmitting control commands to the electronic components of the other boards in the network to which they are connected.

10. A light emitting module (1, 10) according to any one of claims 6 to 9, wherein each substrate (3) is provided with a wireless data receiver.

11. A light emitting module (1, 10) according to any one of claims 6 to 10, wherein each substrate (3) has a triangular or hexagonal shape.

12. A signalling device for a motor vehicle, comprising a light-emitting module (1, 10) according to any one of the preceding claims, said light-emitting module forming a display of the device.

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