LED module and headlight for vehicle

Abstract

An LED module and a headlight for a vehicle, in particular an LED module for a headlight for a vehicle, comprising: a heat sink; an electronic component disposed on the heat sink; and at least one LED directly connected to the heat sink, the at least one LED being connected to the electronic component via at least one contact bridge, where an insulating element is disposed on the heat sink below the contact bridge, where the contact bridge is formed by one or more spaced apart bare conductors or bare strips, wherein the contact bridge extends from the surface contact of the electronic component to the surface contact of the at least one LED, which LED module can be reliably and safely handled and protected from improper handling damage.

Description

TECHNICAL FIELD

[0001] The present invention relates to an LED module, in particular for a headlight of a vehicle. The present invention further relates to a headlight comprising such an LED module. BACKGROUND

[0002] In known LED modules, one or more light emitting diodes (LEDs) and an electronic assembly comprising, for example, a driver for the LEDs, are arranged on a common heat sink. Here, both the electronic assembly and the LEDs necessarily come into direct contact with the heat sink, so that heat can be effectively dissipated from both the electronic assembly and the LEDs. This leads to problems with the electrical contacting between the electronic assembly and the LEDs. For this purpose, in known LED modules, a contact bridge is provided between the electronic assembly and the respective LED. In this case, the contact bridge is connected at a first end to a contact point of the electronic assembly and at a second end to a contact point of the LED and otherwise extends freely in space. On the one hand, this can have the advantage that installation is particularly simple in an automated production process. However, at the same time, there is the risk that the contact bridge is damaged, for example, pressed down, when being handled, and thus comes into contact with the surface of the heat sink. As a result, the electrical contacting is short-circuited and correct functioning of the LED and thus of the entire LED module is no longer possible. SUMMARY

[0003] It is an object of the present invention to provide an LED module which can be handled reliably and safely and is protected from damage through mishandling.

[0004] This object is achieved by an LED module and by a headlight for a vehicle. The LED module comprises a heat sink, an electronic assembly arranged on the heat sink, and at least one LED directly connected to the heat sink, the at least one LED being connected to the electronic assembly via at least one contact bridge, wherein an insulating element is provided on the heat sink below the contact bridge, wherein the contact bridge is formed by one or more spaced-apart bare wires or bare strips, wherein the contact bridge extends from a surface contact of the electronic assembly to a surface contact of the at least one LED. The headlight for a vehicle comprises the LED module.

[0005] The LED module according to the application, in particular for a headlight of a vehicle, comprises a heat sink, wherein the electronic assembly is directly connected to the heat sink and arranged on the heat sink. Furthermore, at least one LED is directly connected to the heat sink. Thus, the heat generated by the electronic assembly and / or the LED can be effectively dissipated by the heat sink. Here, the at least one LED is connected to the electronic assembly via at least one contact bridge. Via the at least one contact bridge, an electrical current is supplied to the at least one LED, so that the LED can be illuminated. In this case, the contact bridge is connected at a first end to a contact point of the electronic module and at a second end to a contact point of the LED and is otherwise free to extend in space. In particular, the contact bridge can extend in an arc from the contact point of the electronic module to the contact point of the LED. This makes the contacting of the LED with the electronic module particularly simple and, in particular, automated. An insulating element is arranged below the at least one contact bridge on the heat sink. In particular, the insulating element is made of a non-conductive material. This ensures electrical insulation between the contact bridge and the heat sink. Without the insulating element, if the contact bridge is inadvertently pressed down, it will come into contact with the surface of the heat sink, resulting in a short circuit. The insulating element ensures the correct functioning of the LED, even if the LED module is handled carelessly, since when the contact bridge is pressed down, the contact bridge does not come into contact with the surface of the heat sink, but remains electrically isolated from the heat sink by the insulating element.

[0006] Preferably, the LED module has more than one LED, wherein each LED is connected to a contact bridge or all LEDs are connected to a common contact bridge. The individual LEDs can be designed as independent components or formed on a common substrate or carrier, such as a PCB.

[0007] Preferably, more than one contact bridge is provided. In particular, the plurality of contact bridges is arranged at a distance from one another and preferably extends substantially parallel to one another. In particular, each LED is provided with exactly one contact bridge. Here, a second contact of the LED can be formed by the electrical contact between the respective LED and the heat sink. As an alternative, exactly two contact bridges are provided for each LED.

[0008] Preferably, exactly one insulating element is provided, which extends below all contact bridges. As an alternative, more than one insulating element can be provided. For example, exactly one insulating element can be provided below each contact bridge.

[0009] Preferably, the at least one contact bridge is formed from bare metal wires or bare metal strips. In particular, the advantage of the strips is that they have an increased cross-section to improve current conduction, whereby the flexibility and, in particular, the adaptability of the shape of the contact bridge is still ensured due to the flat cross-section.

[0010] Preferably, when a plurality of contact bridges is provided, all contact bridges are designed identically. Alternatively, at least two contact bridges can differ in design, such as in length, width, material, radius of curvature, shape, etc.

[0011] Preferably, the wire or strip is made of aluminum or copper, or comprises an aluminum and / or copper alloy.

[0012] Preferably, the at least one contact bridge extends from a surface contact of the electronic component to a surface contact of the at least one LED. This allows for a simple and in particular automated contacting of the LEDs of the LED module with the electronic component. In particular, the surface contacts of the electronic component and the LEDs are accessible from above, thereby allowing for a particularly simple processing.

[0013] Preferably, the at least one contact bridge is not in contact with the insulating element when in an undamaged state. Thus, the heat generated via the contact bridge due to the current conduction has no effect on the insulating element. In particular, it is possible for the contact bridge to be cooled by convection of air flowing around it.

[0014] Preferably, the at least one contact bridge is only in contact with the insulating element when it is pressed down, in particular in the case of incorrect handling of the LED module. Thus, the contact bridge is still separated from the heat sink by the insulating element. A short circuit and thus a malfunction of the LED module can be prevented.

[0015] Preferably, the insulating element comprises silicone. In particular, the insulating element is made of silicone.

[0016] The insulating element is preferably transparent, white or gray. This means that the insulating element does not create an absorption surface within the LED module which would impair the radiation properties of the LED module.

[0017] Preferably, the LED is connected to the heat sink with an adhesive, and in particular an electrically conductive adhesive, the curing temperature of which is the same or similar to the curing temperature of the insulating element. This allows the adhesive and the insulating element to be cured simultaneously. In the manufacturing process, the adhesive for bonding the LED is first applied to the heat sink, and then the LED is connected to the adhesive. The material of the insulating element is then applied. Subsequently, both the adhesive and the material of the insulating element are cured, such that the insulating element is formed and the LED is permanently connected to the heat sink, in particular in an electrically conductive manner.

[0018] Preferably, the electronic component is designed as a printed circuit. Here, the electronic component can in particular be designed as a PCBA (printed circuit board assembly). In this case, the electronic component can provide, for example, a driver for the LEDs, an ESD (electrostatic discharge) protection, an overheat protection, a voltage former, a voltage limiter, etc.

[0019] Preferably, the surface of the electronic component facing away from the heat sink is electrically insulating.

[0020] Preferably, the electronic component is arranged in a recess of the heat sink. In particular, the electronic component is riveted, adhered, screwed, or otherwise permanently connected to the heat sink. This ensures good thermal conductivity from the electronic component to the heat sink.

[0021] Furthermore, the invention relates to a headlight for a vehicle having an LED module as described above. BRIEF DESCRIPTION OF DRAWINGS

[0022] In the following, the invention is described in more detail by means of preferred embodiments, with reference to the accompanying drawings.

[0023] These drawings show:

[0024] Figure 1 is a perspective view of an LED module according to the invention,

[0025] Figure 2 is a cross-sectional view of the LED module of Figure 1 and

[0026] Figure 3 is a detail in a top view. DETAILED DESCRIPTION

[0027] Figures 1 to 3 An LED module according to the invention, in particular for a headlight of a vehicle, is shown. Here, the LED module 10 has a heat sink 12, in particular made of aluminum. Light emitting elements 14 are arranged on the heat sink 12. In the example of the shown embodiment, the light emitting elements 14 comprise two LEDs 14A and 14B, which are arranged on a common substrate of the light emitting elements 14. The light emitting elements 14 are arranged directly on the surface of the heat sink 12, so that the heat generated by the LEDs 14A, 14B can be directly dissipated to the heat sink 12. In particular, for this purpose, the light emitting elements 14 are bonded to the heat sink 12. Even though an LED module with two LEDs is shown in the figures, an LED module according to the invention can have more than two LEDs or only one LED.

[0028] Furthermore, the PCBA 16 is arranged on the heat sink 12 and in particular in the recess 22 of the heat sink. The PCBA 16 has a surface facing away from the heat sink 12. This surface is also coated with a non-conductive coating. The PCBA 16 has electrical components required for operating the LEDs 14. This includes, for example, ESD protection, voltage limiting, temperature detection, etc. The plug 18 is also arranged on the PCBA 16 for connecting to a power supply, in particular to the on-board electronics of the vehicle. Furthermore, the cooling element 12 has a reference element 20 which can be used to uniquely position the LED within the headlight of the vehicle.

[0029] For operating the LEDs 14A, 14B, the PCBA 16 is in electrically conductive connection with the respective LED 14A, 14B via two contact bridges 24A, 24B. The contact bridges 24A, 24B are connected to the contact surfaces of the PCBA 16 and the light emitting element 14. The contact bridges 24A, 24B are formed by one or more spaced apart bare wires or bare strips. In the example of the drawing, the contact bridges 24A and 24B are formed by two strips arranged next to each other, which extend in an arc shape from the respective contact points 28A, 28B of the electronic assembly to the corresponding contact points 30A, 30B of the light emitting element 14. In particular, the width of the strips is greater than (and in particular significantly greater than) the thickness of the strips. For example, the width can be 10 times the thickness and in particular 20 times the thickness. On the one hand, this creates a sufficiently large cross section for the LED power supply. At the same time, the flexibility of the contact bridges is maintained, in particular for the automated production of the LED module 10.

[0030] In the embodiment shown, exactly one contact bridge is provided for each LED 14A, 14B. In this case, the second contact of the LEDs 14A, 14B can be provided by contacting the heat sink 12 itself. This can be achieved, for example, by attaching the light emitting element 14 carrying the two LEDs 14A, 14B using a conductive adhesive. As an alternative, the second contact of the respective LED 14A, 14B can be provided via a further contact bridge (and in particular a common contact bridge).

[0031] Due to the flexibility of contact bridges 24A and 24B, they may be pressed down if the LED module 10 is handled improperly. To prevent the strips of contact bridges 24A and 24B from contacting the surface of the heat sink 12, an insulating element 26 is arranged below the contact bridges 24A and 24B. This insulating element 26 comprises or is composed of silicone resin. The insulating element 26 is applied to the surface of the cooling element 12 and then cured. In the undamaged state, contact bridges 24A and 24B do not contact the insulating element 26. Contact bridges 24A and 24B are guided above the insulating element 26 in a non-contact manner. However, if one or both contact bridges 24A and 24B are pressed down, the corresponding contact bridges 24A and 24B will only contact the insulating element 26, and not the surface of the heat sink 12. Therefore, short circuits are avoided due to the electrical insulation of the insulating element 26.

[0032] The insulating element 26 is transparent, white, or gray, so that it has no effect on the radiation characteristics of the LED module 10. Specifically, the material has a curing temperature for the insulating element 26 that is substantially the same as the curing temperature of the adhesive used to attach the light-emitting element 14 to the heat sink 12. Therefore, the insulating element 26 and the connection between the light-emitting element 14 and the heat sink 12 can be cured in the same curing process. Thus, a method for manufacturing an LED module may include the following steps:

[0033] a) Provide radiator 12;

[0034] b) Apply adhesive to bond LED 14 to heat sink 12;

[0035] c) Apply material for insulating element 26;

[0036] d) Position LED 14 in the adhesive;

[0037] e) Co-curing of insulating element 26 and adhesive;

[0038] f) Provide and secure PCBA 16 on heatsink 12; and

[0039] g) Establish an electrical connection between PCBA 16 and the LED via one or more contact bridges 24A, 24B.

[0040] Of course, the order of steps c) and d) can be interchanged. Furthermore, this method is designed based on the aforementioned characteristics of the LED module.

[0041] Therefore, an LED module is provided in a simple way that ensures the safe operation of the LED even if it is mishandled, and thus reduces the possibility of failure.

Claims

1. An LED module, particularly an LED module for vehicle headlights, characterized in that, The LED module includes: heat sink; Electronic components arranged on the heat sink; and At least one LED is directly connected to the heat sink, and the at least one LED is connected to the electronic component via at least one contact bridge. The insulating element is located on the heat sink, below the contact bridge. The contact bridge is formed by one or more spaced-apart bare wires or strips. The contact bridge extends from the surface contact of the electronic component to the surface contact of the at least one LED.

2. The LED module according to claim 1, characterized in that, When undamaged, the contact bridge does not contact the insulating element.

3. The LED module according to claim 1, characterized in that, When pressed down, the contact bridge only contacts the insulating element.

4. The LED module according to any one of claims 1 to 3, characterized in that, The insulating element includes silicone resin.

5. The LED module according to any one of claims 1 to 3, characterized in that, The insulating element is transparent, white, or gray.

6. The LED module according to any one of claims 1 to 3, characterized in that, The LED is connected to the heat sink by an adhesive, the curing temperature of which is the same as or similar to the curing temperature of the insulating element.

7. The LED module according to any one of claims 1 to 3, characterized in that, The electronic components are designed as printed circuits.

8. The LED module according to any one of claims 1 to 3, characterized in that, The electronic components are arranged in the recesses of the heat sink.

9. A headlight for a vehicle, characterized in that, The headlights for vehicles include an LED module according to any one of claims 1 to 8.

Images