EP2396590B1 - Lighting device - Google Patents

Description

The invention relates to a lighting device, in particular an LED retrofit lamp or an LED module for a retrofit lamp.

LED retrofit lamps or their light sources are typically operated with a safety extra low voltage (SELV). For this purpose, the LED retrofit lamp has a driver for operating the LED (s), which comprises a voltage regulator for converting a mains voltage, for example 230 V, to a voltage of approximately 10 V to 25 V, typically a transformer. The efficiency of a SELV driver is typically between 70% and 80%. For SELV devices, to protect a consumer, insulation distances between a primary side and a secondary side with respect to the voltage regulator of at least 5 mm must be maintained in order to avoid electric shock caused by leakage currents. In particular, originating from a voltage network overvoltage pulses of up to 4 KV should be kept away from the secondary side, so that even then there is no danger to the user if he electrically conductive touchable parts such. B. touches the heat sink during the occurrence of the pulse.

For example, LED retrofit lamps may be constructed so that the LED (s) are mounted on a carrier which is bolted to the heat sink and is electrically isolated therefrom. A necessary length of the creepage distance or insulation between electrically conductive or electrically conductive surface areas (contact fields, conductor traces, etc., eg on copper and / or conductive paste with, for example, silver) and the heat sink is achieved in that, firstly, the potential-carrying surface areas keep a distance of at least 5 mm to an edge of the carrier and secondly an electrical insulating area of at least 5 mm around the screwing points is maintained. However, such a design has a large space requirement.

The US 2006 / 227558A1 shows in the figures 14 and 15, a lighting device according to the preamble of claim 1. A disadvantage is the complex positioning of the support for the semiconductor light source, which takes place via a screw which takes up much space on the support.

It is the object of the present invention to provide a particularly compact lighting device, in particular LED retrofit lamp.

This object is achieved by means of a lighting device according to the independent claim. Preferred embodiments are in particular the dependent claims.

The lighting device comprises: a heat sink with at least one carrier applied to its outside for at least one semiconductor light source; a recess for receiving a driver; and at least one electrically insulating supply which connects the recess to the outside of the heat sink; wherein the supply has a flush on the outside of the heat sink adjacent support surface, which is at least partially covered by the carrier. Furthermore, the feed has a protrusion projecting outward on the outside of the heat sink, wherein a surface of the projection and the support surface form a step. The carrier may, for example, be configured as a substrate, a printed circuit board or the like.

The heat sink may advantageously consist of a good heat-conducting material with λ> 10 W / (m · K), particularly preferably λ> 100 W / (m · K), in particular of a metal such as aluminum, copper or an alloy thereof. The heat sink can also be completely or partially made of an art consist of material; Particularly advantageous for the electrical insulation and extension of the creepage distances is a good heat-conducting and electrically insulating plastic, but it is also the use of a highly thermally conductive and electrically conductive plastic possible. The heat sink may preferably be symmetrical, in particular rotationally symmetric, z. B. about a longitudinal axis. The heat sink may advantageously comprise cooling elements, for. B. cooling fins or cooling pins.

The type of semiconductor light source is not limited in principle, but an LED is preferred as the emitter. The semiconductor light source may include one or more emitters. The semiconductor emitter or semiconductors may be mounted on the carrier on which other electronic components such as resistors, capacitors, logic devices, etc. may be mounted. The semiconductor emitters may, for example, be applied to the carrier by means of conventional soldering methods. However, the semiconductor emitters may also be connected to a substrate by chip-level connection types, such as bonding (wire bonding, flip-chip bonding), etc. ("submount"), e.g. B. by equipping a substrate made of AlN with LED chips. Also, one or more submounts may be mounted on a circuit board. In the presence of multiple semiconductor emitter they can radiate in the same color, z. For example, you know what enables easy scalability of brightness. However, the semiconductor emitters can at least partially also have a different jet color, z. Red (R), green (G), blue (B), amber (A) and / or white (W). As a result, if necessary, a beam color of the light source can be tuned, and it can be set any color point. In particular, it may be preferred if semiconductor emitters of different jet color can produce a white mixed light. Instead of or in addition to inorganic light emitting diodes, z. B. based on InGaN or AlInGaP, organic LEDs (OLEDs) are generally used. Also z. B. diode lasers are used.

The carrier may be implemented as a circuit board or other substrate, e.g. B. as a compact ceramic body. The carrier may include one or more wiring layers.

The recess has an insertion opening for insertion of a driver, for. B. a driver board. The insertion opening of the recess may advantageously be located on a rear side of the heat sink. The Einführöffnüng and the feeder are advantageously located on opposite sides of the recess. The recess may for example be designed cylindrical. The recess may advantageously be electrically insulated from the heat sink to avoid direct creepage distances, z. B. by means of an electrically insulating lining (also housing the driver cavity, GTK, called), z. B. in the form of an inserted through the insertion opening into the recess plastic pipe. The liner may include one or more fasteners for securing the driver. the supply serves to supply or carry out at least one electrical line between the driver located in the recess and the at least one semiconductor light source or the carrier equipped therewith. The feeder and liner may be integrally formed as a single element. With the insertion of the lining into the recess, the supply is then simultaneously pushed through a passage opening of the cooling body.

The at least one electrical lead, which may be configured, for example, as a wire, cable or connector of any type, may be contacted by any suitable method, e.g. B. by soldering, resistance welding, laser welding, etc.

The driver may be a general drive circuit for driving the at least one semiconductor light source. Preferably, the driver is designed as a non-SELV driver, in particular as a transformerless non-SELV driver. A non-SELV driver has over a SELV driver higher efficiency of typically more than 90% and can also be built more cost-effectively. There is no need for safety margins in the driver from the primary side to the secondary side, as prescribed for a SELV driver using a transformer. A separation between the primary side and the secondary side rather takes place primarily between the carrier and the heat sink. at a transformerless non-SELV driver, the transformer can advantageously be replaced by a coil or a buck configuration / a step-down converter.

The part of the outside of the heat sink on which the carrier is mounted, and the flush-fitting contact surface of the feed can advantageously form a common planar surface. In particular, the carrier can partially rest on a flat front side or front side of the heat sink and partially on the flush and coplanar adjoining support surface or cover it. The carrier does not need to lie flat over the entire surface covered by it, but may for example also be partially spaced over a gap from the surface covered by it.

By providing the electrically insulating support surface (i.e., the support surface of electrically insulating material), the creepage distance can be shortened laterally and thus a laterally more compact lighting device can be achieved. For example, in the event that an inner edge of an electrically insulating support rests on the support surface, the creepage distance may be extended by the lateral distance of the inner edge of the electrically conductive heat sink. Consequently, potential-carrying surfaces of the carrier can be positioned closer to the edge by the same distance, which in turn enables the carrier to have a smaller lateral (lateral) extent. In general, a creepage distance in the region of the support surface of the feed can be extended by its electrically insulating design, since the leakage currents then have to travel a long distance to the heat sink. Electrically conductive, in particular potential, surfaces can advantageously copper and / or conductive pastes with z. B. have silver.

Advantageously, the carrier may be secured to the heat sink by means of an electrically insulating transition layer. The electrically insulating transition layer can advantageously be adhesive on both sides for reliable connection between the carrier and the heat sink. The transition layer may advantageously be a thermal interface material (TIM) such as a thermal grease (eg, silicone oil with additions of alumina, zinc oxide, boron nitride, or silver powder), a film, or an adhesive. The film may for example be provided on both sides with an adhesive in the manner of a double-sided adhesive tape.
The adhesive can be applied, for example, by means of a dispersion process and a subsequent doctoring. The transitional layer may also have the advantages of high dielectric strength and elongation of the creepage path. Also, by the transitional position, a screwless structure can be achieved by which an otherwise required isolation area on the carrier can be omitted around the screw passages to the heat sink around. This also supports a compact construction of the lighting device.

However, the carrier may in principle be attached to the heat sink in other ways. Thus, the carrier can also be screwed by means of one or more plastic screws with the heat sink or through the heat sink with the lining of the driver cavity. Another way of securing the carrier is to use a plastic pin integrated in the lining of the driver cavity which projects through the heat sink and through the carrier. The pin can be hot-staked for fastening the carrier, for example. Also, a fastening by means of riveting, in particular Taumelnietens possible, especially using plastic rivets. Also, an attachment, for example by means of a centrally guided by the carrier screw, in particular plastic screw possible; Among other things, in this case, the supply may be arranged off-center. Another possibility of attachment consists in a magnetic attachment, for example, with a magnetic pole in the Liner integrated or attached and attached to a magnetic opposite pole to the carrier, for. B. by gluing etc.

In general, the feed may also be arranged off-center, for. B. offset laterally from the longitudinal axis of the heat sink or the substrate. In this case, the feed can also be arranged outside a lateral extent of the carrier. Then, the at least one electrical line can be guided from the outside to the outside of the carrier.

Advantageously, the thermal interface material may laterally extend beyond an inner edge and / or an outer edge beyond the carrier. As a result, the creepage distance at the respective edge can be lengthened by the length by which the thermal transfer material projects laterally beyond the respective edge.

The support may advantageously have at least one electrically insulating insulation layer. Particularly advantageously, an insulating layer may consist of a material or composite material which is thermally well and electrically poorly conductive, at least in the thickness direction. Particularly advantageous is an insulating layer of ceramic, such. With Al ₂ O ₃ , AlN, BN or SiC. The insulating layer may be configured as a multilayer ceramic carrier, z. In LTCC technology. In this case, for example, layers can be used with different materials, eg. B. with different ceramics. These may, for example, be alternately highly dielectric and low dielectric. Also, the at least one insulating layer may consist of a typical circuit board base material, such as FR4, which is less thermally advantageous but very inexpensive. The insulation layer can be applied on one side or on both sides. In particular, the use of an insulated metal substrate (IMS) or a metal core board (MCPCB) as a carrier is conceivable.

The carrier may advantageously have a dielectric strength of at least 4 KV, so that overvoltage pulses of at least this magnitude do not strike through the carrier.

Advantageously, the carrier may comprise at least one insulating layer and a metal layer arranged on the underside thereof, wherein the underside metal layer is retracted laterally at an inner edge of the carrier. Thereby, a creepage distance at an edge of the carrier can be further extended, since a leakage current then has to travel an additional distance from the edge of the base material layer to the metal layer and further from the base material layer to the edge of the thermal transfer material. It may be particularly advantageous if the underside metal layer is retracted by more than 1 mm from the inner or inner edge of the carrier. Together with the thermal transition material thus results in a particularly compact in the lateral plane creepage distance or isolation distance, which is S-shaped in depth. For ease of attachment and shaping, the underside metal layer may advantageously be a DCB (Direct Copper Bonding) layer of copper. However, the carrier can also have a DCB layer on the upper side.

Alternatively or additionally, it may be advantageous in an analogous manner if the carrier has at least one insulating layer and a metal layer arranged thereon on the underside, wherein the underside metal layer is retracted laterally at an outer edge of the carrier.

In order to achieve a particularly advantageous compromise between, on the one hand, maximizing the isolation distance and, on the other hand, minimizing the thermal path between the light source (s) and heat sink, a thickness of the carrier can advantageously be in the range between 0.16 mm and 1 mm.

In general, it may be preferred if a creepage path is at least 1 mm long, particularly preferably at least 5 mm.

An at least local thermal conductivity or heat spread of the carrier may advantageously be between 20 (W / m * K) and 400 (W / m * K), e.g. B. about 400 (W / m · K) for a copper layer.

It may be advantageous if the feed has a protrusion projecting outwards on the outside of the heat sink, wherein a surface of the projection and the support surface form a rectangular step. The projection may advantageously be perpendicular to a flat surface of the heat sink, for. B. a flat face, projecting. As a result, in particular a substantially uniform component geometry in the direction of rotation can be achieved. Also, the carrier can be placed with close clearance (a small distance around the outward-facing projection of the feeder around, which also supports a compact design.) The projection can serve as a centering aid during assembly of the carrier on the heat sink to have a central opening.

For uniform distribution of multiple LEDs with a simple design of the creepage distances while maintaining predetermined isolation distances, it may be advantageous if the carrier is arranged circumferentially and concentrically or coaxially to the feed. Also, a small lateral extent of the carrier is achieved relative to a longitudinal axis of the heat sink. It may be advantageous for compliance with predetermined isolation distances, when the LEDs are arranged uniformly in the circumferential direction.

To ensure a reliable attachment of the carrier on the heat sink, it may be advantageous if the lighting device further comprises at least one pressing element for pressing the carrier on the heat sink.

For uniform pressure application and the resulting avoidance of bending stresses in the carrier and its local lifting, the pressure element can advantageously have a circumferential or partially rotating, in particular sectored, ring of a - in particular electrically insulating - material.

For ease of assembly, the lighting device can advantageously have a (at least partially translucent) piston (eg, clamped on the heat sink), which has a Anpresshilfe pressing on the carrier and / or the pressure element to an additional contact pressure on the heat sink enable. For example, the piston can be equipped with a contact pressure in the form of a circumferential hold-down for the carrier.

In order to maintain a required creepage distance, the carrier can advantageously have on the upper side at least one electrically conductive surface region which maintains a minimum distance from an inner edge of the carrier and / or an outer edge of the carrier, in particular a minimum distance of 3.5 mm or more.

The semiconductor light source may advantageously be powered by means of a non-SELV voltage, but use with a safety extra-low voltage (SELV) is also possible.

The lighting device can be configured particularly advantageously as retrofit lamp, in particular LED retrofit lamp, or as a module for this purpose.

FIG 1

zeigt in Aufsicht eine LED-Retrofitlampe mit einem bestückten Träger gemäß einer ersten Ausführungsform;

FIG 2

zeigt in Aufsicht den Träger aus FIG 1 in einer detaillierteren Darstellung;

FIG 3

zeigt die LED-Retrofitlampe gemäß der ersten Ausführungsform als Schnittdarstellung entlang der Schnittlinie A-A aus FIG 1 in Seitenansicht;

FIG 4

zeigt einen Ausschnitt aus FIG 3 der LED-Retrofitlampe gemäß der ersten Ausführungsform im Bereich eines Kabelkanals;

FIG 5

zeigt in einer zu FIG 4 analogen Darstellung einen Ausschnitt im Bereich eines Kabelkanals aus einer LED-Retrofitlampe gemäß einer zweiten Ausführungsform;

In the following figures, the invention will be described schematically with reference to exemplary embodiments. It can be provided with the same reference numerals for better clarity identical or equivalent elements.

FIG. 1

shows in plan an LED retrofit lamp with a populated carrier according to a first embodiment;

FIG. 2

shows in supervision the carrier FIG. 1 in a more detailed presentation;

FIG. 3

shows the LED retrofit lamp according to the first embodiment as a sectional view along the section line AA FIG. 1 in side view;

FIG. 4

shows a section FIG. 3 the LED retrofit lamp according to the first embodiment in the region of a cable duct;

FIG. 5

shows in one too FIG. 4 analogous representation of a section in the region of a cable channel of a LED retrofit lamp according to a second embodiment;

FIG. 1 shows in plan an LED retrofit lamp 1 according to a first embodiment. The LED retrofit lamp 1 serves to replace a conventional light bulb with Edison base and therefore has an outer contour, which roughly reproduces the contour of the conventional light bulb in its basic form (see also FIG. 3 ). The LED retrofit lamp 1 has an outer shell 2, into which an LED module 3 is inserted. The LED module 3 has an aluminum heat sink 4, on the upper side or front surface 5 shown here, an Al ₂ O ₃ carrier 6 is fixed with an octagonal outer contour. The carrier 6 is equipped with semiconductor light sources in the form of light-emitting diodes 7. The light-emitting diodes 7 shine in the upper half-space, ie in this illustration with a main emission direction out of the image plane. The carrier 6 has a central hole, with which the carrier 6 can be inserted tightly over a feed formed here as a cable channel 8. The cable channel 8 serves as an element for the passage of electrical lines (o. Fig.) Of a in the heat sink The carrier 6 and the cable channel 8 are thus positioned coaxially with respect to a vertically projecting from the image axis longitudinal axis L of the lighting device 1, wherein the longitudinal axis L extends centrally through the cable channel 8.

FIG. 2 shows in supervision the carrier 6 FIG. 1 in a more detailed presentation. A front surface 5 of the carrier 6 is equipped with three white LEDs 7, which are arranged approximately angularly symmetrical about a longitudinal axis L, wherein the longitudinal axis L extends centrally through the hole 9 of the carrier 6. The LEDs 7 are electrically contacted to their power supply by means of contact surfaces 10 a with the carrier 6. For power supply electrical lines (o. Fig.) From the driver through the cable channel to cable connection surfaces 10b out. The electrical conductor tracks used for current conduction are formed by a correspondingly structured (here greatly simplified) outer-side copper layer 11. Both the contact surfaces 10 a and the cable connection surfaces 10 b and the copper layer 11 represent potential-carrying surface areas, which are electrically insulated against the heat sink 4 over sufficiently long isolation distances, at least by means of the carrier 6. The copper layer 11 is not executed completely circumferential, but has a radially with respect to the longitudinal axis L extending gap 12 in order to avoid a short circuit.

FIG. 3 shows the LED retrofit lamp 1 according to the first embodiment as a sectional view along the section line AA FIG. 1 , The LED retrofit lamp 1 does not surmount the outer contour of a conventional incandescent lamp and can be used with its Edison base 13 as a substitute for a corresponding incandescent lamp. In the heat sink 4, a cylindrical recess in the form of a driver cavity 14 is present, which on its lateral lateral surface 15 and upper end surface 16 with an electrically insulating lining 17 (hereinafter also "housing the driver cavity", GTK, called) is made of a plastic. A lower insertion opening 18 is electrically sealed against the heat sink 4 by an attachment 19, which also includes the Edison base 13. In the driver cavity 14 and the lining 17, a driver board 20 is accommodated, which has all or at least some of the required for operating the light emitting diodes 7 elements. The driver board 20 is electrically connected to the Edisonsockel 13 for power supply and outputs the required for operating the light emitting diodes 7 voltage and / or current via electrical cable 21 to the light emitting diodes 7 on. For this purpose, the driver board 20 is connected via the electrical cable 21 with suitable cable connection surfaces 10b. The driver implemented on the driver board 20 is here a transformerless non-SELV driver. A separation between the primary side and the secondary side takes place primarily between the carrier 6 and the heat sink 4. The transformerless non-SELV driver may have a coil or buck configuration / step-down converter for voltage conversion.

For passing the cables 21 through the upper end surface 16, the upper end surface 16 has a passage opening 22. For electrical insulation of the driver board 20 with respect to the heat sink 4, the liner 17 is configured so that the cable channel 8 is integrally integrated into the liner 17 connecting the recess 14 and the interior of the liner 17 to the front surface 5 of the heat sink 4. The front surface 5 is covered with an opaque or light-scattering piston 27 for its protection and for the homogenization of the light emitted by the lighting device 1. For example, the piston 27 may be clamped to the heat sink 4 and e.g. be equipped with a circumferential Anpresshilfe in the form of a hold-down for the carrier.

FIG. 4 shows a section B from the LED retrofit lamp 1 FIG. 3 , as indicated by the circle B there. In addition is a section C of the LED retrofit lamp 1 in the region of the support surface 24 is shown. The cable channel 8 has a radially widened region 23, the upper surface of which serves as a bearing surface 24 for the support 6 when the lining is inserted and rests flush on the front surface 5 of the cooling body 4. As a result, a plane 5, 24 which is planar on the front side and perpendicular to the longitudinal axis L is created for supporting the carrier 6. In order to easily guide the cables 21 to the support 6, the lining 17 or the cable duct 8 integrated into it has a projection 25 directed perpendicularly from the heat sink 4 to the outside (here: in the longitudinal direction L). The projection 25 and the bearing surface 24 of the lining form a right-angled step 26. The carrier 6 closely surrounds the projection 25 (with little play or tolerance), so that the projection 25 can serve as a centering aid in an assembly of the carrier 6. The carrier 6 completely covers the support surface 24, and the flat front surface 5 of the heat sink 4 partially. The carrier 6 is connected on the underside with the support surface 24 and the flat front surface 5 via an electrically insulating and adhesive transition layer 28 of a thermal transfer material (TIM). The transition layer 28 provides additional puncture protection and is thermally well conductive. The transitional layer 28 also extends on the inside to the projection 25 and protrudes on the outside (in a lateral direction perpendicular to the longitudinal axis L) beyond the carrier 6. To ensure a firm seat of the carrier 6 on the heat sink 4, the carrier 6 is pressed by means of a pressure element 35, which is present here in the form of an electrically insulating, circumferential plastic ring, on the heat sink 4. For example, the pressing element 35 itself can be pressed onto the carrier 6 by means of a pressing aid ('hold-down'), not shown here, wherein the pressing aid is located on the piston for easy mounting. The Anpresshilfe can be performed, for example, rotating. As can be seen in particular in section C, by the electrically insulating support surface 24, a (crawl drawn) inner creepage distance K over the inner edge 29th the carrier 6 extended. Thus, a beginning M of the shortest inner creepage distance K on the copper layer 11 can begin and radially to the inner edge 29 of the carrier (to the right in FIG. 4 ), from there over the inner edge 29 of the carrier 6 and the transition layer 28 down (neglecting the thickness of the transitional layer 28), and again outwards (to the left in FIG. 4 ) over the support surface 24 to a next point N on the heat sink 4. The total length of the creepage distance K results from an addition of the distance d1 of the copper layer 11 to the inner edge 29 of the carrier, the thickness d2 of the carrier 6 and possibly the transition layer 28th and from the subsequent distance d3 of the inner edge 29 to the heat sink (which corresponds to the radial or lateral extent of the support surface 24). In the exemplary embodiment shown, this results in a length of the creepage distance K to d1 = 3.5 mm + d2 = 0.4 mm + d3 = 2 mm of a total of 5.9 mm at a lateral distance of the copper layer 11 from the projection 25 of only d1 = 3.5 mm. Thus, a sufficiently long inner creepage distance K or isolation distance can be provided in a laterally particularly compact manner.
In general, the creepage distance should be selected so that requirements for the safety of the device are met. Regulations for this are made in various standards. In general, a creepage distance of more than 6.4 mm has proven to be sufficiently safe for the common applications.

A creepage distance extending over an outer edge 30 of the carrier 6, as shown in section B, is calculated in this embodiment from a lateral distance d4 = 2.2 mm between an outer point O of the copper layer 11 and the outer edge 30, plus Thickness or depth of the outer edge 30 of d2 = 0.4 mm and the radial extent d5 = 3.3 mm of the outwardly over the carrier protruding portion of the transition layer 28 to a point P on the heat sink 4. This results in an entire outer Creepage distance of also 5.9 mm, in which case the lateral space gain corresponds to the thickness of the carrier 6 of d2 = 0.4 mm.

FIG. 5 shows in one too FIG. 4 analogous representation of a section in the region of a cable channel 8 from a LED retrofit lamp 31 according to a second embodiment, in which now compared to the first embodiment of the carrier 32 is designed differently. Namely, the carrier 32 is now multi-layered in that it has an identical to the support 6 of the first embodiment Al ₂ O ₃ insulation layer 33, on the upper side, the copper layer 11 is attached, but now at the bottom of the insulating layer 33 a Metal layer in the form of a lower copper layer 34 is attached. The carrier 32 can then be embodied particularly simply as a double-sided DCB ("Direct Copper Bonding") -bonded carrier 32. The lower copper layer 34 is thus located between two electrically insulating layers, namely the transition layer 28 and the insulating layer 33. Compared to the insulating layer 33, the lower copper layer 34 at each edge to a respective recess or withdrawal d6 or d7, so that neglected a thickness of the copper layer 34 each results in a creepage distance extended by twice the radial or lateral length d6 or d7 of the retraction compared to the first embodiment. More precisely, as shown in more detail in detail D, at the inner edge 29 at the same lateral extent the inner creepage distance of 5.9 mm to 5.9 mm + 2 · d6 = 5.9 mm + 2 · 1.1 mm = 8.1 mm lengthened. Similarly, the outer creepage distance can be extended from 5.9 mm to 5.9 mm + 2 × d7 = 5.9 mm + 2 × 0.6 mm = 7.1 mm.

Fig. 6 shows an example of the attachment of the carrier 6 by means of a pressing element 35. The carrier 6 with the LEDs 7 surrounds the cable channel 8 and is fixed on the heat sink 4 and the transitional layer 28 of 4 retaining tabs 36. The retaining tabs 36 together with a retaining ring 37 substantially the pressure element 35. To Positonierung and fixing serve retaining pins 38. In addition, a circumferential Anpresshilfe 39 is provided. The retaining pins may be designed according to the knowledge of the skilled person, for example as press-fit pins, snap connectors, screws or as Heißverstemmstift.

Of course, the present invention is not limited to the embodiments shown. Thus, it may be generally advantageous if at least one of the distances d1 to d7 is at least 1 mm long, preferably between 1 mm and 5 mm. In general, it may also be preferred if the length of the creepage paths or creepage distances is at least 1 mm, particularly preferably at least 5 mm. Also, the material of the cooling body except pure aluminum and an aluminum alloy or another metal or its alloy or even have a good heat conducting plastic. Furthermore, the cable channel can also be arranged eccentrically (laterally offset with respect to the longitudinal axis). The supply can generally be a separate component or, for example, integrated into the lining of the recess and / or in the heat sink, for example in one piece.

LIST OF REFERENCE NUMBERS

1

LED retrofit

2

shell

3

LED module

4

heatsink

5

front surface

6

carrier

7

led

8th

Cabel Canal

9

Hole of the carrier

10

contact area

11

copper sheet

12

gap

13

Edison socket

14

Treiberkavität

15

lateral surface

16

upper end surface

17

lining

18

insertion

19

essay

20

driver board

21

electric wire

22

Through opening

23

radially expanded area

24

bearing surface

25

head Start

26

step

27

piston

28

Transition layer

29

inner edge of the vehicle

30

outer edge of the carrier

31

LED retrofit

32

carrier

33

insulation layer

34

lower copper layer

35

pressing element

36

retaining tab

37

retaining ring

38

retaining pin

39

Anpresshilfe

d

distance

K

inner creepage distance

L

longitudinal axis

M

Beginning of the inner creepage distance

N

End of the inner creepage

O

Beginning of the outer creepage distance

P

End of the outer creepage distance

Claims (14)

1. Lighting device (1; 31), having

   - a cooling element (4) having at least one carrier (6; 32) attached to its outer side (5) for at least one semiconductor light source (7), in particular a light-emitting diode;

   - a recess (14) for holding a driver (20);

   - at least one electrically insulating feed (8), which connects the recess (14) to the outer side (5) of the cooling element (4);

   - the feed (8) having a contact surface (24) adjoining the outer side (5) of the cooling element (4) in a flush manner, which contact surface (24) is at least partly covered by the carrier (6; 32),

   characterized in that
   the feed (8) has a projection (25) projecting outwards with respect to the outer side (5) of the cooling element (4), wherein a surface of the projection (25) and the contact surface (24) form a step (26).
2. Lighting device (1; 31) according to Claim 1, in which the carrier (6; 32) is fixed to the cooling element (4) by means of an electrically insulating transition layer (28).
3. Lighting device (1; 31) according to Claim 2, in which the transition layer (28) extends laterally over an inner edge (29) and/or an outer edge (30) of the carrier (6; 32).
4. Lighting device (31) according to either of Claims 2 and 3, in which the carrier (32) has an insulating layer (33) and a metal layer (34) arranged on the underside thereof, wherein the metal layer (34) on the underside is set back laterally on an inner edge (29) and/or an outer edge (30) of the carrier (32).
5. Lighting device (31) according to Claim 4, in which the metal layer (34) on the underside is a DCB layer.
6. Lighting device (1; 31) according to one of the preceding claims, wherein a surface of the projection (25) and the contact surface (24) form a rectangular step (26).
7. Lighting device (1; 31) according to one of the preceding claims, in which the carrier (6; 32) is arranged circumferentially and concentrically with respect to the feed (8).
8. Lighting device (1) according to one of the preceding claims, further having at least one pressure element (35) for pressing the carrier (6) onto the cooling element (4).
9. Lighting device (1) according to Claim 8, in which the pressure element (35) has a circumferential or partially circumferential ring made of an electrically insulating material.
10. Lighting device according to Claim 8 or 9, which has a piston (27) which has a pressing aid which presses on the carrier (6) and/or the pressure element (35).
11. Lighting device (1; 31) according to one of the preceding claims, in which the carrier (6; 32) has on the upper side at least one electrically conductive surface region (10, 11) which maintains a minimum spacing (d1, d4) from an inner edge (29) of the carrier (6; 32) and/or an outer edge (30) of the carrier (6; 32), in particular a minimum spacing (d1) of 3.5 mm or more.
12. Lighting device (1; 31) according to one of the preceding claims, in which the semiconductor light source (7) is fed with a non-SELV voltage.
13. Lighting device (1; 31) according to Claim 12, in which the driver is a transformerless non-SELV driver.
14. Lighting device (1; 31) according to one of the preceding claims, which is configured as an LED retrofit lamp or as LED module for an LED retrofit lamp.

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