Light module for motor vehicle signal transmission device and motor vehicle signal transmission device incorporating same

Abstract

The invention relates to a lighting module (1) for a signal transmission device of a motor vehicle, comprising an array of light sources (2) mounted on an interconnection substrate (3) comprising a stack of insulating layers (33) alternating with electrically conductive layers (34) and interconnected by vias (35). The lighting module (1) comprises at least one electronic component (4) for controlling and powering the array of light sources (2), said electronic component being buried in the inner layer of the interconnection substrate (3). This 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 arranged to power and selectively control each of the light sources (2) of the array through said plurality of control vias (35a).

Description

[0001] The present invention relates to the field of automotive lighting and / or luminous signaling. More precisely, the present invention relates to the field of displays integrated into luminous motor vehicle lighting or luminous signaling modules.

[0002] It is known practice to integrate displays into luminous motor vehicle equipment, for example into taillights, headlights, bumpers or even into other parts of the front of the vehicle. These displays are produced, for example, by means of an array of a large number of selectively controllable light sources, the dimensions of which are small enough to be able to display information, for example in the form of messages or pictograms, on these displays with a satisfactory resolution. Such information thus makes it possible to improve the signalling given by the motor vehicle, for example by contextualizing a given signalling function or displaying an accompanying message.

[0003] These light sources are usually mounted on a substrate, such as a printed circuit board, on the back of which one or more controllers are mounted, each of which allows selective control of some of these light sources. This controller is usually an integrated circuit enclosed in a package, allowing the integrated circuit to be mechanically and electrically interfaced with the substrate and ensuring the dissipation of the heat generated by the integrated circuit. The package of modern controllers is usually equipped with an array of connectors, such as a ball grid array (BGA) or a land grid array (LGA), which is optimized from the point of view of heat dissipation only on one side of the face used to mount the package on the substrate.

[0004] Therefore, these encapsulated controllers have various disadvantages.

[0005] From a thermal point of view, a large amount of heat is generated by the light source and must therefore be dissipated in order not to adversely affect its performance. It goes without saying that this heat cannot be dissipated on one side of the light source and that it must therefore be transferred to the back side of the substrate. However, the presence of the controller on this side of the substrate reduces the space available for heat exchange and in particular for mounting a radiator. Likewise, a large space must be maintained on this side of the substrate not only for solutions allowing the mechanical assembly of the display and the light emitting device, but also for solutions allowing the display to be connected to a control unit and / or a power supply unit of this display.

[0006] From a manufacturing point of view, these controllers must be soldered to the substrate, which complicates the production of the light emitting devices combined with the display, thereby reducing their reliability and increasing their cost. In addition, a cable harness must be provided between the display and its control unit and / or power supply unit, which further complicates the assembly and correspondingly increases the cost of the light emitting device.

[0007] From an electromagnetic compatibility point of view, the package in which the controller is enclosed must be shielded in order to prevent the controller from emitting electromagnetic interference that could easily affect the operation of another electronic component of the lighting device or even the motor vehicle, and vice versa.

[0008] Finally, from a reliability perspective, the greater the distance between the light sources and their controllers, the more likely it is that the control signals sent by the controller to those light sources will be attenuated or affected by interference during their transmission to the light sources, potentially creating reliability issues relative to the display instructions given to it while the display is displaying an image.

[0009] There is therefore a need for a lighting module capable of forming a display for a signalling device for a motor vehicle, provided with light sources and with one or more controllers for these light sources, and which solves the disadvantages of the lighting devices mentioned above.

[0010] The present invention falls within this background and is intended to meet this need.

[0011] To this end, a subject of the present invention is a light-emitting module for a signal transmission device of a motor vehicle, the light-emitting module comprising a first array of selectively controllable light sources mounted on a first interconnected substrate, the first interconnected 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 passing through the insulating layer, characterized in that the light-emitting module comprises at least a first electronic component for controlling and powering the light sources of the first array, the first electronic component being buried in the inner layer of the first substrate, and characterized in that the first substrate comprises a plurality of first control vias electrically connecting the first electronic component to the light sources of the first array, the first electronic component being arranged to power and selectively control each of the light sources of the first array through the plurality of first control vias.

[0012] The invention and in particular the fact that one or more electronic components capable of controlling and powering the light sources of the first array are buried in the interconnection substrate give the light module various advantages. On the one hand, due to the conductive layer, the interconnection substrate forms a shield with respect to electromagnetic interferences that are easily transmitted or received by said electronic components. On the other hand, no operation of soldering or assembling the controller to the substrate is required, and thus installation is facilitated, the reliability of the light module is improved and the cost of the light module is reduced. In addition, the distance between the light sources and the electronic components that control these light sources is reduced, and thus the integrity of the light source control signals sent by these electronic components is improved. Finally, the face of the interconnection substrate opposite to the face for receiving the light sources is freed up, and thus it is possible to obtain a large space (which may in particular correspond to more than 90% of this receiving face) for example for heat dissipation solutions, for components for mounting the light module on a signal transmission device or even a control and / or power supply unit. In the latter case, in addition to reducing the overall volume of the signal transmission device, it is also possible to avoid the use of cable harnesses between the light module and the control and / or power supply unit, which makes it possible to further reduce the volume and cost of the signal transmission device.

[0013] In the present invention, a "via" is a metallized hole, for example a metallized hole having a metal plating or filled with a metal, such as copper, on its inner surface and in particular provided with a pad for connection to a conductive layer at each end thereof. Advantageously, the problem may be microvias, i.e. vias having a diameter substantially less than or equal to 350 micrometers or even substantially less than or equal to 150 μm and in particular equal to 90 μm.

[0014] In the present invention, the interconnect substrate will likely be a printed circuit board in which two successive conductive layers are separated by an insulating layer. Where appropriate, each conductive layer will potentially be etched and drilled to define interconnection tracks that are connected to interconnection tracks of another conductive layer by vias. Each conductive layer will potentially be interconnected with the conductive layer immediately above and / or below and / or with one or more conductive layers. Therefore, the vias will potentially be buried vias (i.e., vias that extend through the substrate without appearing on either the bottom and top of the substrate), blind vias (i.e., vias that extend through the substrate and appear on only one of the bottom and top of the substrate), or through-type vias, particularly thermal vias (i.e., vias that extend through the substrate and appear on each top or bottom of the substrate). Similarly, the vias will potentially be arranged in the substrate in a layered and / or stacked configuration.

[0015] In the present invention, "electronic component" means one or more integrated circuits, which are optionally associated with one or more passive components necessary for the operation of the one or more integrated circuits. The passive components will potentially be electronic components, such as multilayer ceramic capacitors, or silicon capacitors or resistors or inductors, or will potentially be formed by a specific arrangement of parts of one or more conductive layers (such as two continuous conductive layers partially overlapping to form a capacitor). Where appropriate, the electronic component or each electronic component will potentially be a bare component, that is, a component that is not enclosed in a package, or as a variant, enclosed in a package equipped with electrical connection elements.

[0016] Advantageously, the first electronic component is arranged in a cavity left in an internal insulating layer (i.e., a layer different from the layer of the substrate exposed to the air) and is electrically connected to a conductive layer immediately above and / or below this insulating layer. Thus, the cavity can be formed during the manufacture of the substrate, so that the first electronic component can be buried in the substrate during this 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 these light sources includes at least one light emitting semiconductor chip having a size between 150 μm and 400 μm. Such a chip is particularly referred to as a mini-LED. Where appropriate, the light sources may be arranged on the first side of the substrate so as to be spaced apart from each other by a distance of less than 1 mm. As a variant, each of these light sources includes at least one light emitting semiconductor chip having a size between 5 μm and 150 μm. Such a chip is particularly referred to as a micro-LED. Where appropriate, the light sources may be arranged on the first side of the substrate so as to be spaced apart from each other by a distance between 200 μm and 400 μm or even less than or equal to 300 μm. Here, the “distance between two light sources” refers to the distance separating the center of one of these light sources from the center of another of these light sources.

[0019] In one embodiment of the present invention, the light sources of the first array are mounted on a first face of the first interconnected substrate. Where appropriate, the light emitting module comprises a control unit and / or a power supply unit, the control unit being capable of generating control instructions for the first electronic component for selectively controlling each of the light sources of the first array, the power supply unit being capable of supplying power to the first electronic component for powering the light sources of the first array, the control unit and / or the power supply unit being mounted on a second face of the first interconnected substrate opposite to the first face. Thus, the space freed up on the second face of the first substrate can be utilized to arrange such a control unit or such a power supply unit thereon.

[0020] By "control unit" is meant a unit capable of receiving from a connector of a lighting module instructions for displaying an image using the light sources of the first array (the instructions potentially containing in particular said image) and arranged to generate control instructions for each of these light sources based on said set points. By "power supply unit" is meant a unit capable of receiving from a connector of a lighting module an external power supply and arranged to convert this external power supply into a power supply suitable for powering the light sources of the first array and the first electronic component.

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

[0022] Advantageously, the light sources of the first array form a passive array and the first electronic component is arranged to control the passive array through the plurality of first control vias according to control instructions received from the control unit. For example, each control via will be able to control a row or column of the light sources of the first array.

[0023] In an alternative or cumulative embodiment, the light sources of the first array are mounted on a first face of the first interconnected substrate, and the light module comprises a heat sink for the light module, which is mounted on a second face of the first interconnected substrate opposite to the first face. Thus, the space vacated on the second face of the first substrate is utilized to arrange the heat sink thereon, allowing the heat generated by the light sources and the first electronic component to be dissipated. It should further be noted that this heat can be distributed over the entire surface area of ​​this second face in order to optimize the dissipation. The heat sink will potentially be equipped with heat dissipation fins and / or made of a material exhibiting high thermal conductivity.

[0024] According to an example of an embodiment of the present invention, the light emitting module comprises a second array of light sources that can be selectively controlled and mounted on a first interconnected substrate, and at least a second electronic component for controlling and powering the light sources of the second array, the second electronic component being buried in the first substrate in an inner layer of the first substrate. Where appropriate, the first substrate comprises a plurality of second control vias electrically connecting the second electronic component to the light sources of the second array, the second electronic component being arranged to power and selectively control each of the light sources of the second array through the plurality of second control vias. In this example, it is therefore proposed to produce a display having a plurality of arrays of light sources mounted on the same substrate, each array being independently controlled and powered by an electronic component buried in the substrate.

[0025] According to another example of an embodiment of the present invention, the light emitting module comprises a second array of light sources that can be selectively controlled and mounted on a second interconnected substrate, and at least a second electronic component for controlling and powering the light sources of the second array, wherein the second electronic component is buried in the second substrate in an inner layer of the second substrate, and the first substrate is arranged adjacent to the second substrate. In this example, the display is thus divided into a plurality of juxtaposed submodules, each of which is formed by an array of light sources mounted on a substrate in which the electronic components for controlling and powering the light sources of this array are buried. Preferably, the second substrate has substantially the same properties as the first substrate. This type of architecture enables the manufacturing yield of the display to be increased, the submodules to be standardized, while providing a high degree of freedom regarding the shape and size of the display, and facilitating its repairability.

[0026] In particular, it would potentially be envisaged that the lighting module comprises more than two submodules, and in particular at least 10 submodules, which are juxtaposed to each other to form a display.

[0027] Advantageously, one edge of the first substrate abuts one edge of the second substrate in a connected or unconnected manner, so that the light sources of the first array abut against the light sources of the second array. Preferably, the distance separating the first light source of the first array located on the edge of the first substrate and the second light source of the second array located on the edge of the second substrate and as close to the first light source as possible is substantially less than or equal to the distance between two light sources of the first array and / or the second array. Thus, the space between the submodules of the display can be masked.

[0028] Advantageously, the light sources of the first array and the light sources of the second array are mounted on first faces of the first and second interconnected substrates, respectively, and the first and second interconnected substrates are mounted via a second face opposite to their first faces on the same carrier, in particular the same printed circuit board. Thus, this carrier can serve on the one hand as a carrier for control and / or power supply units for the various submodules and on the other hand as a member for mechanically fastening the display formed by the submodules to the signal transfer device.

[0029] Advantageously, the second face of each of these substrates carries an electrical connector mechanically coupled to the carrier and capable of transmitting control instructions and / or power to the electronic components buried in the substrate. In other words, each substrate is mechanically carried by the electrical connector. For example, the electrical connector carried by each substrate may be connected to a distribution layer through vias, which distribution layer is connected to the electronic components buried in the substrate.

[0030] According to an example of an embodiment, the module will potentially include a control unit and / or a power supply unit, the control unit is capable of generating control instructions for each electronic component for selectively controlling each of the light sources of each array, the power supply unit is capable of supplying power to each electronic component for powering the light sources of each array, the control unit and / or the power supply unit are mounted on the carrier. Where appropriate, the light emitting module will potentially include an input connector for delivering display instructions and / or external power supply, the input connector being mounted on the carrier.

[0031] For example, control instructions generated by the control unit based on display instructions and / or power supply converted from an external power supply will potentially be transmitted to the submodules through the carrier and in particular via electrical tracks formed on this carrier, and the control instructions and the power supply are distributed to these submodules, for example via connectors.

[0032] According to another example, the electronic components of each substrate are connected to at least one electronic component of another substrate so that all the electronic components together form a network, and at least one substrate, in particular the electronic components of each substrate, can transmit control instructions to the electronic components of another substrate of the network to which this electronic component is connected. For example, it will be potentially proposed that this control instruction is dedicated to this other electronic component and contains an address associated with this other electronic component, or as a variant this control instruction is included in the global instruction and is associated with the address of this other electronic component. The electronic components will potentially be interconnected to form a network with a daisy chain topology, or a network with a mesh topology or any other topology. In this example, for example, power supply can be transmitted to each submodule via a carrier, while control instructions are distributed by another means, such as by connecting wires, cables or cable harnesses that interconnect the submodules or even by wireless communication.

[0033] Advantageously, each substrate comprises a wireless data receiver. Where appropriate, the receiver may be buried in an internal layer of the substrate or, as a variant, mounted on the first face of the substrate. Where appropriate, the control unit may comprise a wireless data transmitter capable of transmitting the control instructions for the electronic components to the receiver of the substrate in which these components are buried, the receiver of each substrate being connected, for example via a distribution layer, to the electronic components buried in this substrate for transmitting the control instructions received from the transmitter of the control unit to the electronic components.

[0034] In one example of an embodiment of the present invention, each substrate and in particular the first face of each substrate has a square or rectangular shape. Where appropriate, the light source of each array will potentially include 64, 144, 256, 576 or 1024 light sources, which are arranged in 8 rows by 8 columns, or 12 rows by 12 columns, or 16 rows by 16 columns, or 24 rows by 24 columns or 32 rows by 32 columns. For all arrays of light sources, the distance between two light sources will potentially be the same, or different between light source arrays as a variant.

[0035] According to another example of an embodiment of the present invention, each substrate and in particular the first face of each substrate has a triangular or hexagonal shape. As a variant, each substrate will potentially be rhombus-shaped. More generally, it will be potentially proposed that each substrate can have a shape without right angles. This type of configuration makes it possible to increase the density of light sources on the first face of the substrate relative to a square or rectangular configuration and therefore reduce the distance between the light sources.

[0036] Where appropriate, the light sources of each array will potentially be organized in rows and columns in a checkerboard pattern, or as a variant in staggered rows and columns. Preferably, the rows and columns will potentially be placed parallel to the edges of the substrate. This feature makes it possible to avoid aliasing effects in particular at the edges of the substrate, which would make the abutment of the submodules of the display visible. As a variant, it will potentially be proposed to organize the light sources of each array in a grid with square or triangular unit cells.

[0037] It will potentially be proposed, without departing from the scope of the invention, to combine the various embodiments described above, in particular by providing a plurality of submodules, each submodule being equipped with a plurality of arrays of light sources each controlled by an electronic component buried in the substrate of the submodule.

[0038] Another subject of the invention is a signaling device for a motor vehicle, characterized in that it comprises a lighting module according to the invention, which forms a display of the device.

[0039] The present invention will now be described using examples, which are for illustration purposes only and in no way limit the scope of the invention, and with reference to the accompanying drawings, in which the various figures show:

[0040] [ Figure 1 ] schematically and partially shows a cross-sectional view of a light emitting module according to an example of an embodiment of the present invention;

[0041] [ Figure 2 ] schematically and partially shows a side view of a light emitting module according to another example of an embodiment of the present invention; and

[0042] [ Figure 3 ] schematically and partially shows [ Figure 2 ] front view of the module.

[0043] Throughout the following description, elements that are identical in structure or function and appear in the various figures are labeled with the same reference numerals unless otherwise specified.

[0044] [ Figure 1 ] shows a cross-sectional view of a light module 1 according to one embodiment of the invention. In the example described, this light module 1 is intended to be integrated into a rear light of a motor vehicle, the light module 1 forming a display. It will potentially be proposed to integrate the light module 1 into another element of a motor vehicle, such as a headlight or a front light or a bumper or another element at the front of the vehicle, without departing from the scope of the invention.

[0045] The lighting module 1 comprises an array of light sources 2 mounted on a substrate 3 .

[0046] In the example described, each of the light sources 2 comprises at least one light emitting semiconductor chip, a so-called micro-LED, of a size 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 being spaced apart from one another by a distance less than or equal to 300 μm. It should be noted that other sizes of light sources, other distances between the light sources, other numbers of light sources or even other distributions of the light sources are conceivable without departing from the scope of the present invention.

[0047] The substrate 3 is a printed circuit board or PCB having a first face 31 and a second face 32 opposite to the first face. The light source 2 is mounted on the first face 31 of the substrate, which faces the outside of the signal transmission device into which the light emitting module 1 is integrated.

[0048] It should be noted that, in the example described, the substrate 3 is a so-called multilayer PCB comprising a stack of insulating layers 33 alternating with conducting layers 34 between a first face 31 and a second face 32 .

[0049] 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 interconnection tracks, which are connected to the interconnection tracks of another conductive layer 34 by vias 35. It should be noted that the first face 31 and the second face 32 are formed by the faces of the insulating layers 33 that are oriented toward the outside of the substrate 3 and are open so as to be able to access the first conductive layer and the last conductive layer 34, respectively, and thus mount electronic components on the surface of the substrate 3.

[0050] Thus, the light source 2 is surface mounted on the substrate 3 flush with the opening or hole formed in the first face 32 and is electrically connected to the first conductive layer 34 by soldering or wire bonding so as to be interconnected with the substrate 3 .

[0051] The lighting module 1 comprises electronic components 4 for controlling and powering the array of light sources 2. This electronic component 4 is buried in the substrate 3 in an internal insulating layer 33 of this substrate 3.

[0052] More specifically, during the manufacture of the internal insulating layer 33, a cavity 33a is left in this internal insulating layer 33, and the electronic component 4 is placed in this cavity, and then the electronic component is electrically connected to the conductive layer 34 immediately below this insulating layer, so as to continue the manufacture of the substrate 3. It will be potentially proposed that the electronic component 4 is electrically connected to the conductive layer 34 immediately above without departing from the scope of the present invention.

[0053] The electronic components 4 include an integrated circuit associated with passive components. It should be noted that the integrated circuit may be bare, as opposed to being enclosed in a package. It will be potentially proposed to enclose the integrated circuit in a package without departing from the scope of the present invention.

[0054] A plurality 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, wherein each row and each column of light sources 2 can be controlled by the electronic component 4 by means of a control via addressed to this row or this column, in particular for controlling the power supply delivered to the light sources of this row or this column. Thus, the electronic component 4 can power and selectively control each of the light sources 2 through the plurality of control vias 35a, for example by successively scanning the rows and then the columns of the array in order to control the power supply delivered to each of the light sources 2.

[0055] The lighting module 1 comprises a connector (not shown) for receiving display instructions for the display performed by the plurality of light sources 2. The problem may consist in instructions sent by a computer or signaling device of the motor vehicle for displaying a sign, a message, a pattern or a pictogram. By way of example, the problem may consist in the display of an instruction intended to inform an external observer that a door of the motor vehicle is opening, a pictogram intended to inform a car driver following the motor vehicle of the presence of black ice on the road, or even traffic-related information or indeed a pictogram intended to inform pedestrians whether they can cross the road. The display instructions will potentially include a representation of the pictogram.

[0056] The lighting module 1 further comprises a connector (not shown) for receiving an external power supply, for example from a battery of a motor vehicle.

[0057] The lighting module 1 comprises a power supply and a control unit 5 connected to a connector for receiving display commands and external power supply. The unit 5 is carried by a printed circuit board mounted on the second face 32 of the substrate 3, perpendicular to an opening or hole formed in the second face 32, in which a connector 51 electrically connected to the unit 5 and the last conductive layer 34 is arranged, so as to interconnect the unit 5 with the substrate 3.

[0058] On the one hand, the unit 5 is capable of generating control instructions for the electronic components 4 based on the display instructions it receives, for selectively controlling each of the light sources 2 so as to cause the array to display the pictogram of the display instruction. In addition, the unit 5 is capable of converting the external power supply into a power supply suitable for powering the array of light sources 2 and the electronic components 4. The control instructions and the converted power supply are thus distributed to the electronic components 4 via the connector 51, followed by the vias 35 and the conductive layers 34, which are called distribution layers.

[0059] The controller 4 is thus arranged to control each of the passive array of light sources 2 in dependence on control instructions received from the unit 5 and to power these light sources 2 using the power supply converted by the unit 5 .

[0060] Furthermore, the lighting 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 part made of a thermally conductive material, in particular aluminum, and is provided with heat dissipation fins. The face 32 may be partially covered with a gold layer or a nickel layer so that the heat sink 6 can be soldered to the substrate 3.

[0061] It should be noted that the second face 32 of the substrate 3 thus provides a space allowing the unit 5 and the heat sink 6 to be arranged thereon, so as to improve the thermal performance of the lighting module 1, to avoid the need to use a cable harness to connect to a control or power supply unit remote from the substrate 3, and to reduce the distance between the unit 5, the electronic component 4 and the array of light sources 2. It should be noted that the second face 32 of the substrate also provides a solution as to the arrangement of the means for fastening the lighting module 1 to the backlight or any other element into which the lighting module must be integrated. Furthermore, the fact that the electronic component 4 is buried makes it possible to simplify the design of the lighting module 1 and to shield the electronic component 4 with the conductive layer 34.

[0062] [ Figure 2 ] shows a cross-sectional view of a light emitting module 10 according to another embodiment of the present invention.

[0063] In this example, the light module 10 includes a plurality of submodules 11, each of which includes an array of light sources 2 that are selectively controllable and mounted on an interconnected substrate 3; and electronic components 4 that are buried in the substrate 3 and are used to control and power the array of light sources 2. The structure of each substrate 3 is similar to [ Figure 1 ] is not related to the structure of module 1 shown in the drawings and will therefore not be described further.

[0064] The submodules 11 are arranged adjacent to each other so as to form together a display for a rear light or another element of a motor vehicle. Figure 2 ] only three submodules 11 are shown, but a substantially larger number of submodules could potentially be proposed without departing from the scope of the present invention.

[0065] In the example described, the substrates 3 of the submodules 11 are mounted on a common carrier 7 , in the present 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 board 7 .

[0066] In addition, plate 7 bears the Figure 1 ] is similar to the control and power supply unit 5 of the module 1, except that this unit is capable of sending control instructions to the various sub-modules 11 and distributing power supplies thereto via electrical connectors 8, which transmit the control instructions and converted power supplies they receive to the electronic components 4 buried in the substrates 3 of these sub-modules 11.

[0067] For example, it can be imagined that the control unit subdivides the pictogram of the display instruction into sub-images, each of which is intended to be displayed by the array of light sources 2 of one of the sub-modules 11, so that the display of all sub-images together forms this pictogram; and then generates control instructions for the electronic components 4 of this sub-module 11 for each of the sub-modules 11 for displaying this sub-image.

[0068] In an example not shown, it is conceivable that only the power supply converted by the unit 5 is transmitted to the connector 8 through the board 7, and the control instructions generated by the unit 5 are distributed to the submodules 11 through another connection device (such as a wired connection connecting the unit 5 to each of the submodules 11) so as to form a star network; or distributed by a wired connection connecting the unit 5 to the submodules 11, each submodule 11 being then connected to another submodule 11 to form a daisy chain; or distributed by a wireless connection, wherein the unit 5 and the submodules 11 include wireless data transmitters and receivers.

[0069] [ Figure 3 ] shows a front view of an example of the arrangement of the submodule 11.

[0070] Each base plate 3 has a triangular shape. Other shapes may be adopted without departing from the scope of the invention, in particular a rhombus or hexagonal shape.

[0071] It can be observed that, for each submodule 11, the array of light sources 2 is organized into rows and columns placed parallel to the edge of the substrate 3. The distance between the light sources 2 of a given submodule 11 is the same between submodules.

[0072] One edge 3a of the substrate 3 of each submodule 11 abuts against, but is not connected to, one edge 3a of the substrate 3 of an adjacent submodule 11. It can therefore be seen that the arrays of light sources 2 of two adjacent submodules 11 are substantially abutted, and the distance separating the adjacent light sources 2 on the edge 3a of these submodules 11 is substantially less than or equal to the distance between the two light sources 2 of a given submodule 11.

[0073] Thus, each submodule 11 forms a standard submodule, so that, due to the triangular shape, the submodules can be organized to form a display of any shape, the resolution of which is satisfactory in terms of the distribution and density of the light sources 2 on the triangular substrate and the abutment of the array, and which is easy to repair considering that the display is divided into submodules 11.

[0074] The above description clearly explains how the invention enables the objects set for it to be achieved by proposing to bury the controllers of the light sources of a display of a lighting device of a motor vehicle in the substrate carrying these light sources so as to free up the back side of this substrate.

[0075] In any case, the invention is not limited to the embodiments specifically described in this document, and in particular extends to all equivalent devices and to any technically operable combination of these devices. In particular, a substrate of another organization with an inner layer and / or vias will potentially be proposed, regardless of whether the substrate is rigid or flexible, straight or curved. Other types of light sources than the types described may also be used, in particular light sources of larger size (for example, between 150 μm and 400 μm), such as micro-LEDs. Types of electronic components other than the types described may be envisaged. Types of heat dissipation members other than the types described may also be envisaged, and in particular heat dissipation members combined with fan members.

Claims

1. A light emitting module (1, 10) for a signal transmission device of a motor vehicle, the light emitting module comprising a first array of light sources (2) capable of being selectively controlled and mounted on a first interconnection substrate (3), the first interconnection substrate comprising a stack of insulating layers (33) alternating with conductive layers (34), each conductive layer being interconnected to another conductive layer by at least one via (35) passing through the insulating layer, characterized in that The light emitting module comprises at least a first electronic component (4) for controlling and powering the light sources of the first array, the first electronic component being buried in the first substrate in an inner layer of the first substrate, and the first substrate comprising a plurality of first control vias (35a) for electrically connecting the first electronic component to the light sources of the first array, the first electronic component being arranged to power each of the light sources of the first array through the plurality of first control vias and selectively control each of the light sources of the first array.

2. The lighting module (1, 10) according to the preceding claim, characterized in that The light sources (2) of the first array are mounted on a first surface (31) of the first interconnected substrate (3); the light emitting module comprises a control unit (5) and / or a power supply unit (5); the control unit is capable of generating control instructions for the first electronic component (4) for selectively controlling each of the light sources of the first array; the power supply unit is capable of supplying power to the first electronic component for powering the light sources of the first array; the control unit and / or the power supply unit are mounted on a second surface (32) of the first interconnected substrate opposite to the first surface.

3. The lighting module (1, 10) according to the preceding claim, wherein: The light sources (2) of the first array form a passive array, and wherein the first electronic component (4) is arranged to control the passive array through the plurality of first control vias (35a) according to control instructions received from the control unit (5).

4. The lighting module (1, 10) according to one of the preceding claims, characterized in that The light sources (2) of the first array are mounted on a first surface (31) of the first interconnected substrate (3), and the light emitting module comprises a heat sink (6) for the light emitting module, the heat sink being mounted on a second surface (32) of the first interconnected substrate opposite to the first surface.

5. The lighting module (1, 10) according to one of the preceding claims, characterized in that The light-emitting module comprises a second array of light sources (2) that can be selectively controlled and mounted on the first interconnect substrate (3), characterized in that the light-emitting module comprises at least a second electronic component (4) for controlling and powering the light sources of the second array, the second electronic component being buried in the first substrate in an inner layer (33) of the first substrate, and characterized in that the first substrate comprises a plurality of second control vias (35a) for electrically connecting the second electronic component to the light sources of the second array, the second electronic component being arranged to power and selectively control each of the light sources of the second array through the plurality of second control vias.

6. The lighting module (1, 10) according to any one of claims 1 to 4, characterized in that: The light-emitting module comprises a second array of light sources (2) which can be selectively controlled and mounted on a second interconnected substrate (3), characterized in that the light-emitting module comprises at least a second electronic component (4) for controlling and powering the light sources of the second array, the second electronic component being buried in the second substrate in an inner layer (33) of the second substrate, and the first substrate being arranged adjacent to the second substrate.

7. The lighting module (1, 10) according to the preceding claim, characterized in that The light sources of the first array and the light sources (2) of the second array are mounted on first surfaces (31) of the first interconnected substrate and the second interconnected substrate (3), respectively, and the first interconnected substrate and the second interconnected substrate are mounted on the same carrier (7) via a second surface (32) opposite to their first surfaces.

8. The lighting module (1, 10) according to the preceding claim, characterized in that The second face (32) of each of the substrates (3) carries an electrical connector (8) mechanically coupled to the carrier (7) and capable of transmitting control instructions and / or electrical power to the electronic components (4) buried in the substrate.

9. The lighting module (1, 10) according to any one of claims 6 to 8, characterized in that The electronic component (4) of each substrate (3) is connected to at least one electronic component of another substrate so that all the electronic components together form a network, and the electronic component of each substrate can transmit control instructions to the electronic component of another substrate of the network to which this electronic component is connected.

10. The lighting module (1, 10) according to any one of claims 6 to 9, characterized in that: Each substrate (3) includes a wireless data receiver.

11. The lighting module (1, 10) according to any one of claims 6 to 10, wherein: Each base plate (3) has a triangular or hexagonal shape.

12. A signal transmission device for a motor vehicle, characterized in that: The signal transmission device comprises a lighting module (1, 10) according to one of the preceding claims, which forms a display of the device.

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