This application claims priority to the French application 1458669 filed on Sep. 15, 2014, which application is incorporated herein by reference and made a part hereof.
1. Field of the Invention
The invention deals with the field of lighting and/or light indication, notably for a motor vehicle. More specifically, the invention deals with the field of the lighting and light indication by means of light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs).
2. Description of the Related Art
The patent document US 2005/0243558 A1, which is now issued as U.S. Pat. No. 7,044,620, discloses an LED diode support for an indication module of the motor vehicle rear light type. It consists of a plate with printed circuit and comprising a series of orifices through which are inserted LED diodes of the inverted mounting type. These LEDs comprise optical parts in the form of domes, these domes being visible from the side of the front face. The LEDs comprise fixing and electrical connection tabs soldered with electrical tracks on the rear face of the plate. This mounting provides an aesthetic support when observed from a viewpoint situated to the side of the front face, the electrical connections being exclusively on the rear face. Furthermore, it allows a heat sink to be placed on the rear face of the base of the LED. The electrical tracks extend to an edge of the plate in order to be able to ensure a connection with a power supply. The electrical tracks are terminated by typical circular solder link zones. Now, the soldering operations require particular care and constitute an additional step in the assembly of the support.
The published patent document FR 2 995 657 A1 discloses a light source with diodes of the OLED type, comprising a support with cavities filled by the diodes. The support comprises, on one of its faces, electrodes or electrical tracks intended to electrically contact the diodes for their electrical power supply. The diodes comprise a stacking of organic layers and a transparent substrate arranged on the stacking concerned. The substrate has a surface area of greater size than that of the organic layers in order to extend beyond the corresponding cavity and thus come into contact with the electrical tracks, around the cavity. The support is produced by the injection of insulating material such as thermoplastic or thermosetting plastic. It can be plane, with a dip or even of more complex form. The electrical tracks are limited to ensuring the powering of the diodes. This teaching does not address the issue of the connection to an electrical power supply.
The aim of the invention is to propose a support for light source(s) for a light module of which the electrical connection is simplified.
The subject of the invention is a support for light source(s) for a light module, notably for a motor vehicle, comprising: a substrate with at least one zone for receiving a light source; electrical tracks deposited on the substrate to the zone or zones for receiving light source(s), the tracks being intended to power the light source or sources; noteworthy in that the substrate comprises at least one protruding portion of a piece with the rest of the substrate and on which the electrical tracks extend from the reception zone or zones, the portion or portions being connection portions suitable for cooperating with an electrical connector, respectively.
Some of the electrical tracks can extend over at least a part of a front surface of the support. The front surface is a surface of the support which, when the support is mounted on a vehicle, is visible from the outside of the vehicle.
The tracks advantageously form a network of tracks, these tracks being able to be of the same width.
“Of a piece” should be understood to mean that the connection portion or portions are produced in the same material as the rest of the substrate and that their link with the rest of the substrate is produced when they are formed together, notably by molding.
According to an advantageous embodiment of the invention, the substrate is a rigid molded part having a three-dimensional form. Advantageously, the substrate consists essentially of a wall of an average thickness of between 0.5 and 3 mm.
According to an advantageous embodiment of the invention, the substrate is made of a thermoplastic material doped with metal particles so as to allow the bonding of the electrical tracks made of metal material.
Advantageously, the substrate can be produced in a thermoplastic material, the electrical tracks being printed on the substrate itself. The printing can be of the inkjet type with an ink that includes metal particles. As a variant, the tracks can be produced by printing or screen printing on a film of polyethylene terephthalate (PET) or of polyethylene naphthalate (PEN), the film being deposited on the substrate, for example by thermodeformation. Also as a variant, the tracks can also be produced by a two-step molding of the substrate, also called “two shot molding”. This is an injection molding process using two different resins in which only one of the two resins can be metallized. The substrate is then subjected to an autocatalytic deposition process in which butadiene is used to chemically roughen the surface and allow for the adhesion of a primary layer of copper.
According to an advantageous embodiment of the invention, least one of the connection portions has the form of a tongue with two opposing main faces, the electrical tracks extending preferentially on the two faces.
According to an advantageous embodiment of the invention, at least one of the connection portions in the form of a tongue has, on a distal zone intended to penetrate into the connector, a reduced thickness relative to the thickness of a proximal zone of the portion, the thickness of the distal zone being preferentially less than 50% of the thickness of the proximal zone. The distal and proximal zones extend from the substrate. More specifically, proximal zone should be understood to mean a zone of the connection portion which is closer to the support than a distal zone of the portion, the distal zone then being further away from the support. Advantageously, the transition between the two distal and proximal zones forms a dip. The dip is present on both main faces of the connection portion.
Advantageously, the electrical tracks extend essentially parallel to one another and on the main axis of the connection portion. In this case, the main axis of the connection portion corresponds to the optical and longitudinal axis of the module. The electrical tracks can extend essentially to the distal edge of the connection portion, so as to extend over all of the distal zone.
According to an advantageous embodiment of the invention, at least one of the connection portions comprises a notch serving as poka-yoke with the corresponding connector. The notch can be provided on just one of the two sides of the connection portion, the notch allowing a corresponding edge of the connector to advance until the connector is in the position of engagement on the connection portion.
According to an advantageous embodiment of the invention, the support comprises the light source or sources, the source or sources being of the light-emitting diode type and linked to the electrical tracks by a glue filled with metal particles, the glue being preferentially a polymer glue suitable for polymerizing after application. As a variant, the light source or sources can be linked to the electrical tracks by a solder based on tin, copper or other metals.
According to an advantageous embodiment of the invention, the substrate comprises a central portion and a cavity with a bottom and at least one lateral wall, at least one of the zones for receiving light source(s) being on the bottom of the cavity, the connection portion or portions protruding from the central portion in a direction opposite to the cavity. If so desired, at least one of the reception zones can also be arranged on a rear face of the lateral wall.
Advantageously, the light sources, preferably of the LED type, are arranged directly on the substrate and are powered electrically by the electrical tracks extending continuously from the sources to the connection portion.
According to an advantageous embodiment of the invention, the substrate comprises at least one front wall protruding from at least one of the lateral walls, at least one of the electrical tracks extending over the at least one of the front walls and being intended to be linked to the ground in order to form an electromagnetic shielding.
According to an advantageous embodiment of the invention, the support further comprises: a part added onto the substrate, the part comprising an opening intended to receive at least one of the connection portions of the substrate.
According to an advantageous embodiment of the invention, the added part comprises at least one protruding portion supporting a light source of the organic light-emitting diode type.
Also a subject of the invention is a light module, notably for a motor vehicle, comprising: a support for light source(s); at least one optical device suitable for deflecting light rays produced by the light source or sources in order to form at least one light beam; noteworthy in that the support conforms to the invention.
According to an advantageous embodiment of the invention, the optical device or devices is/are supported directly by the substrate.
According to an advantageous embodiment of the invention, at least one of the optical devices comprises a translucent or transparent element forming at least one, preferably two, diopters, the element being a collimator of optical rays in order to form one of the light beams.
According to an advantageous embodiment of the invention, one of the collimators is housed in the cavity of the support.
The provisions of the invention are advantageous in that they make it possible to produce a support with a high level of integration. In effect, the support comprises at least one connection portion of a piece with the rest of the substrate. The electrical tracks can then be deposited directly on the substrate, from the light sources to the portion or portions or vice versa. The substrate can then be molded in a complex form and serve not only as support for light sources but also as support for optical parts and moreover be a visible, and therefore aesthetic, element of a light module.
Other features and advantages of the present invention will be better understood from the description and the drawings in which:
These and other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
The module 2 comprises a substrate 4 and a part 6 added onto the substrate 4. The added part 6 can be fixed to the substrate 4 by means of the screws 15. The substrate 4 comprises, essentially, a central part 41, two lateral walls 42, two front walls 43 protruding from the lateral walls 42. The two lateral walls 42 form a cavity housing light sources (not visible in
The added part 6 comprises two supports 61 and a rear part 62. The supports 61 are arranged in such a way as to protrude from the central part 41 of the substrate 4 essentially opposite one another. Each of these supports 61 supports a diode of the OLED type 8. An OLED is a light-emitting diode comprising a superposition of a number of organic semiconductor layers between two electrodes, of which (at least) one is transparent. In this case, these OLED diodes 8 ensure a side marker light function. The rear part 62 of the added part 6 is configured to house an electrical power supply connector 14.
The substrate 4 of the module 2 also supports one or more light sources (not visible) between the lateral walls 42 and the OLED diodes 8, this or these light source(s) being covered by a collimator 12 in order to ensure a stop light function. More specifically, the rays emitted by these light sources and deflected by the collimator 12 to meet the front face of the corresponding OLED diode 8 and be reflected there toward the front of the module 2.
The longitudinal axis of the module 2 represented in
The collimators 10 and 12 are parts made of transparent or translucent material, such as glass or polycarbonate (PC) or polymethyl methacrylate (PMMA). They comprise input and/or output surfaces oriented in such a way as to deflect the rays in a main direction, in application of the Snell-Descartes refraction principle. The input and output faces in effect each form a diopter, namely a surface separating two homogeneous and isotropic transparent media, of different refractive indices. The refractive index of air is in effect of the order of 1 whereas that of glass and of polycarbonate lies between approximately 1.4 and 1.6. The principle of operation of a collimator is well known per se to those skilled in the art; there is consequently no need to provide more detail thereof.
The light sources 16, preferentially of the LED type, arranged directly on the substrate 4, are thus powered electrically by the electrical tracks 18 extending continuously from the light sources 16 to the connection portion 20.
The substrate 4, including the connection portion 20, is made of plastic material produced by molding and supports the light sources 16 and the electrical tracks 18, in accordance with the MID (Molded Interconnect Device) technology.
The plastic material of the substrate 4 can be doped with metal particles suitable for ensuring the bonding of the electrical tracks 18 made of metal material on its outer surface.
The electrical tracks 18 can be produced by the technology denoted LDS, standing for Laser Direct Structuring. This involves passing a laser ray over the corresponding surface of the substrate 4, according to the configuration of the electrical tracks 18 to be produced. The laser ray has the effect of forming a roughness suitable for favoring the bonding. This step is followed by a metallization by dipping of the substrate 4 in one or more successive metal baths.
Alternatively, or complementarily, the electrical tracks 18 can be produced by printing of the inkjet type with ink that includes metal particles.
The electrical tracks 18 can also be produced by a two-step molding of the substrate 4, also called “two-shot molding”. This is an injection molding process using two different resins in which just one of the two resins can be metallized. Typically, the metallizable resin is ABS and the non-metallizable resin is polycarbonate. The substrate 4 is then subjected to an autocatalytic deposition process in which butadiene is used to chemically roughen the surface and allow the adhesion of a primary layer of copper.
Because of the thermoplastic nature of the substrate 4, the use of conventional soldering methods for the electrical contacts is not suitable. The LEDs or light sources 16 are thus fixed mechanically and electrically by application of a glue based on polymer and filled with metal elements. It is thus a so-called “cold” application method that does not damage the substrate 4. After polymerization of the glue, the latter ensures the mechanical and electrical fixing of the LED or light source 16.
The connection portion 20 of the substrate 4 is in the form of a generally rectangular tongue. It can have a variable thickness as can be seen in
Still referring to
Again referring to
The connection portion 20 can comprise a notch or any other means serving as poka-yoke relative to the direction of the connector 14. The latter can in effect in principle be oriented in two 180° opposing directions, one corresponding to the correct orientation and the other to an orientation 180° from the correct orientation. The notch can be provided on just one of the two sides of the connection portion 20, the notch allowing a corresponding edge of the connector 14 to advance until the connector 14 is in the position of engagement on the connection portion 20. In the case of the opposite orientation, the edge concerned will then abut on a part of the connection portion 20 without any notch, not allowing for the engagement of the connector 14.
While the system, apparatus, process and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus, process and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
1458669 | Sep 2014 | FR | national |