Light module, lighting device and motor vehicle

Abstract

A light module (100) comprising a printed circuit board (102) for a lighting device (4000) of a motor vehicle, wherein the printed circuit board (102) comprises a first section (200) with a first layer structure comprising a metal carrier (202), and wherein the printed circuit board (102) comprises at least one second section (300) laterally enclosed by the first section (200) and having a second layer structure different from the first layer structure with a plurality of inner conductor layers (306, 310) arranged one above the other, wherein a dielectric layer (400) arranged between the first and the second section (200, 300) extends perpendicular to the inner conductor layers (306, 310), wherein the light module (100) comprises a number of light source components (104a-c) arranged on the first section (200), and wherein the light module (100) has at least one electronic component arranged on the second section (300). (106) of a control electronics.

Description

The invention relates to a light module comprising a printed circuit board. The invention further relates to a lighting device and a motor vehicle.DE 10 2005 047 025 A1 discloses a printed circuit board having a thermally conductive inlay which extends within the plane of the printed circuit board with the thickness of the printed circuit board and which has very good thermal conductivity, for conducting heat through the printed circuit board from a single SMD component which is arranged on one side of the printed circuit board and heats up in operation, with associated connection legs and a heating region arranged therebetween, to a heat sink arranged on the other side of the printed circuit board. The printed circuit board is provided with an additional layer which is arranged above the inlay and at the same time below the SMD component arranged above the inlay. The SMD component is electrically insulated on the additional layer from the inlay arranged underneath.DE 10 2008 016 458 A1 relates to a printed circuit board having at least one through hole in which a heat dissipation element is arranged. These so-called inlays are made of a single solid material, which can be disadvantageous in several respects.US 2014 / 0 144 677 A1 discloses a carrier comprising a substrate, a first and a second insulation layer, first and second patterned circuit layers, a first and a second conductive via, a heat dissipation channel, an adhesive layer and a heat conducting element.The object is thus to improve the thermal properties and also the integration of a plurality of functionally different components on a printed circuit board which is part of a light module.The object underlying the invention is achieved by a light module according to claim 1, a lighting device according to one independent claim and by a motor vehicle according to another independent claim. Advantageous refinements are specified in the dependent claims and are found in the following description of exemplary embodiments and in the drawing.A first aspect of the description relates to light modules comprising a printed circuit board for a lighting device of a motor vehicle, wherein the printed circuit board comprises a first section having a first layer structure comprising a metal carrier, and wherein the printed circuit board comprises at least one second section laterally enclosed by the first section and having a second layer structure different from the first layer structure and having a plurality of inner conductor layers arranged one above the other.Advantageously, the integration of the second section into the first section allows the advantages of both printed circuit board techniques to be combined with one another.Thus, firstly, a de interlacement of electrical conductors in the region of the second section is advantageously better possible than in the first section. Consequently, complex circuits on the printed circuit board can also be realized in a space-saving manner.Furthermore, the first printed circuit board section can advantageously be used for the targeted dissipation of thermal energy. Thus, the heat transfer is improved. In particular, active cooling can be dispensed with-with with or without an additional cooling body-depending on the application in the case of free convection, which reduces the costs and the complexity.Consequently, the integration of complex control electronics and comparatively easily connectable components, but generating thermal energy, such as semiconductor light sources or control electronics, on a single printed circuit board is possible. This integration eliminates printed circuit boards that have been previously separately designed. This has the consequence that plug connectors are omitted, which leads to simplified production, reduction of parts and an increase in the service life of the lighting device.The degrees of freedom in the design of the light module and the lighting device likewise increase, since installation space is free due to the omission of further printed circuit boards and corresponding connections.The invention is distinguished in that a dielectric layer arranged between the first and the second section extends perpendicularly to the inner conductor layers.The dielectric layer implements an electrical decoupling of the two printed circuit board sections. This electrical insulation mechanically securely connects the two printed circuit board sections to one another.An advantageous embodiment is characterized in that the first and the second section of the printed circuit board have a common outer conductor structure.The common outer conductor structure enables the arrangement and electrical connection of electronic components on the entire respective surface of the printed circuit board.An advantageous embodiment is characterized in that an electrically conductive layer of the outer conductor structure extends in sections over the first section and the second section, and in particular a or the dielectric layer.The electrically conductive layer advantageously enables an electrically conductive connection between the two sections to be possible in the region of the surface of the printed circuit board. Thus, inner conductor structures connecting the two sections are dispensed with. This has the advantage that the electrically conductive layer of the outer conductor structure can be produced reliably.The light module according to the invention is characterized in that it comprises a number of light source components arranged on the first section.Advantageously, the thermal energy generated by the light source components arranged on a primary side of the printed circuit board is conducted via the first section to a secondary side of the printed circuit board.The light module according to the invention is further characterized in that it comprises at least one electronic component of control electronics, in particular an integrated circuit, in particular for controlling the light source components, arranged on the second section.The second section is advantageously used to de interlace the connections of the control electronics, for example, in such a way that the light source components arranged on the comparatively easily structured first section can be controlled.An advantageous embodiment is characterized in that a heat sink is connected to the first section of the printed circuit board.Advantageously, the first section more suitable for heat transfer is used by means of the heat sink to better carry away thermal energy from the first section.A second aspect of the description relates to an illumination device of a motor vehicle, wherein the illumination device comprises the light module according to the second aspect.A third aspect of this description relates to a motor vehicle which comprises the lighting device according to the third aspect.In the drawing, the following are shown: FIG. 1 shows a light module comprising a printed circuit board in schematic form; FIG. 2 shows a schematic plan view of the printed circuit board; FIG. 3 shows a schematic section of the printed circuit board; and FIG. 4 shows a lighting device of a motor vehicle.FIG. 1 shows a schematic form of a light module 100 for a lighting device of a motor vehicle, wherein the light module 100 comprises a printed circuit board 102.The printed circuit board 102 comprises a first section 200 which has a first layer structure comprising a metal carrier. The printed circuit board 100 comprises a second section 300 having a second layer structure different from the first layer structure, which second section comprises a plurality of inner conductor layers arranged one above the other. The second section 300 is laterally surrounded by the first section 200. The second section 300 is surrounded circumferentially by the first section 200. In contrast, the second section 300 can also be enclosed in a form not shown at the edge of the first section 200 and form an outer edge of the printed circuit board 102. For example, the second section 300 is surrounded by the first section 200 from only three sides, wherein the second section 300 then forms a common edge with the first section 200, for example. To produce the printed circuit board 102, the first and the second section 200, 300 are first produced separately. An opening is then introduced into the first section 200. The second section 300 is introduced into the opening and mechanically fixed, wherein at least on one side a substantially flush termination takes place. Subsequently, a common outer conductor structure or a common outer layer pattern is applied to the surface.The light module 100 comprises a number of light source components 104 a- carranged on the respective first section 200 a- c, which emit a respective light distribution, which is collectively provided with the reference sign 110.The light module 100 comprises an electronic component 106 of control electronics in the form of an integrated circuit, which electronic component is arranged on the second section 300.The electronic component is designed to control the light source components 104 a- c,for which purpose a common outer conductor structure 500 covers the first and the second section 200, 300.A connector 112 is mechanically and electrically connected to the circuit board 102. The contacts of the connector 112 are electrically connected to the electronic component 106.A heat sink 108 is connected to the first portion 200 of the circuit board 102. The heat sink is located on a secondary side of the printed circuit board 102 and serves for cooling the light source components 104 a- carranged on a primary side of the printed circuit board 102.FIG. 2 shows a schematic plan view of the printed circuit board 102. On the second section 300 an outer conductor pattern with converging conductor tracks and proximal solder joints is shown in shaded form. The outer conductor pattern is designed for the electrical contacting of the electronic component 106, for example of an IC component (IC: Integrated Circuit) of the control electronics for the light source components. The outer conductor pattern covers the first and second portions 200, 300.FIG. 3 shows a schematic section A-A of the printed circuit board 102 from FIG. 1 or FIG. 2 The first and the second section 200, 300 of the printed circuit board 102 have a common outer conductor structure 500, 504 at least on one side, whereas the inner layer structures 506, 508 of the two sections differ.The first section 200 comprises the inner layer structure 506 in the sense of a layer structure with the metal carrier 202, a dielectric, thermally conductive layer 204 and a conductor layer 206 applied on the layer 204. The metal carrier 202 is manufactured, for example, from a metal alloy comprising aluminum and / or copper and / or molybdenum. The layer 204 comprises, for example, a ceramic or an epoxy resin with introduced ceramic additive. The conductor layer 206 includes, for example, a copper foil. A metal-filled via 208 electrically conductively connects the conductor layer 206 to the metal carrier 202. The first portion 200 is, for example, an IMS (Insulated Metal Substrate) circuit board.The second section 300 comprises the inner layer structure 508 in the sense of a layer structure having at least two inner conductor layers 306, 310. The stacked inner conductor layers 306 and 310 are separated by a reinforced dielectric layer 308. Inner conductor layers 306 and 310 are surrounded by reinforced dielectric layers 304 and 312. Furthermore, outer conductor layers 302 and 314 on both sides are applied to the respective dielectric layer 304, 312, for example in the form of copper foils. A via 316 connects the conductor layers 302 and 314 to one another in an electrically conductive manner. A via 318 connects the inner conductor layers 306 and 310 to one another in an electrically conductive manner. Via 320 connects layer 314 to layer 310. Consequently, the inner layer structure 508 of the second portion 300 is more complex than the inner layer structure 506 of the first portion 200. The relatively thick, electrically conductive metal carrier 202 of the first section 200 is separated from the inner conductor layers 306 and 310 of the second section 300 by means of the dielectric layer 400. The dielectric layer 400 arranged between the first and the second section 200, 300 extends perpendicularly to the inner conductor layers 306, 310 of the second section 300. The second section 300 is thus a multilayer printed circuit board, for example comprising a reinforced synthetic resin such as FR4.Of course, the sections 200 and 300 can have more than the layers shown and in particular further intermediate layers. The sections 200 and 300 comprise mutually different inner bearing patterns, but a common outer bearing pattern.An electrically conductive layer 502 of the outer conductor structure 500 extends in sections over the first section 200 and the second section 300 and in the present case in particular over the dielectric layer 400. Depending on the manufacturing method, a gap 510 or not is present between the layers 206 and 314. If the gap 510 exists, this is filled in the production process by means of the electrically conductive layer 502. In the case, not shown, that either the layer 314 or the layer 206 are arranged on the dielectric layer 400, the electrically conductive layer 502 is guided over the two sections 200 and 300 without a gap being filled by the layer 502.A solder stop layer 600, 602 is applied wherever no electrical contacting of the circuit board 102 is to take place.In the section shown, the electronic component 106 is electrically conductively connected to portions of the electrically conductive layer 502 of the common outer conductor structure 500 which are electrically separated from one another in section by two contact pads 106- 1 and 106- 2 and soldering material 107- 1 and 107- 2.In the section shown, the light source component 104 bis electrically conductively connected to portions of the electrically conductive layer 502 of the common outer conductor structure 500 which are electrically separated from one another in section by two contact pads 104- 1 and 104- 2 and solder material 105- 1 and 105- 2. The contact pad 104- 2 is designed, for example, for floating arrangement on the printed circuit board 102 and serves for thermally coupling the light source component 104 b. Via 208, layer 206 is electrically conductively connected to metal carrier 202. The metal carrier 202 is connected to a zero potential or ground, for example. On the other hand, potential-carrying contact pads such as the contact pad 104- 1 are also thermally conductively connected to the metal carrier 202 by means of the layer 204.An exposed surface 210 of the first section 200 is provided for producing a thermal contact with the heat sink 108 from FIG. 1. The aforementioned thermal contacting can be implemented, for example, by means of a heat-conducting paste.FIG. 4 shows a lighting device 4000 for the motor vehicle. The illumination device 4000 comprises the light module 100, which is arranged in a housing 4002. The light module 100 is operated to emit light. The light emitted by the light module 100 impinges on a transparent cover plate 4006, which closes a light passage opening of the housing 402. An emission light distribution 408 is emitted by the cover plate 4006 in the direction of travel x. In the example shown, the lighting device 4000 is a motor vehicle headlight. Of course, the light module 100 and the circuit board 102 from the preceding figures can also be used for tail lamps, flashing lamps or other lighting devices of the motor vehicle.

Claims

A light module (100) comprising a printed circuit board (102) for a lighting device (4000) of a motor vehicle, wherein the printed circuit board (102) comprises a first section (200) having a first layer structure comprising a metal carrier (202), and wherein the printed circuit board (102) comprises at least one second section (300) laterally enclosed by the first section (200), having a second layer structure different from the first layer structure, having a plurality of inner conductor layers (306, 310) arranged one above the other, wherein a dielectric layer (400) arranged between the first and the second section (200, 300) extends perpendicularly to the inner conductor layers (306, 310), wherein the light module (100) comprises a number of light source components (104a-c) arranged on the first section (200), and wherein the light module (100) comprises at least one electronic component (106) of control electronics arranged on the second section (300).The light module (100) according to claim 1, wherein the electronic component (106) of the control electronics is an integrated circuit, in particular for controlling the light source components (104a-c).The light module (100) of claim 1 or 2, wherein the first and second portions (200, 300) of the circuit board (102) have a common outer conductor structure (500).The light module (100) according to claim 3, wherein an electrically conductive layer (502) of the outer conductor structure (500) extends in sections over the first section (200) and the second section (300), and in particular over the dielectric layer (400).The light module (100) of any one of claims 1 to 4, wherein a heat sink (108) is connected to the first portion (200) of the circuit board (102).A lighting device (4000) of a motor vehicle comprising a light module (100) according to one of claims 1 to 5.A motor vehicle comprising a lighting device (4000) according to claim 6.

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