EP2143989A1 - Lighting unit, LED module and method - Google Patents

Abstract

The unit has an LED module (4) arranged at an outer side of a housing. A printed circuit board (1) with a printed circuit board carrier is provided for supplying current to the LED module. A head element (12) e.g. casing element, and another head element are connected with contact elements (15) by an opening (11) of the housing, where the head elements manufacture connections for the LED module at a front side of the housing. The head element exhibits a head with a lower side that lies at a front side of the carrier of the LED module.

Description

The invention relates to a lighting unit, an LED module and a method for mounting an LED module.

Lighting units with LEDs as light sources are known. Such lighting units serve, for example, as room lighting or for lighting artworks or billboards.

In a known LED module, a flexible circuit board is mounted on a support, which has a plurality of LED areas. These LEDs are mounted on the flexible printed circuit board where they are electrically interconnected ( DE 103 50 913 ).

Another lighting unit with LED is off DE 10 2005 018175 known.

From the DE 35 24 138 A1 Furthermore, a device for contacting optoelectronic components, in particular light emitting diodes, on busbars is known. It consists of a pot-like holding element, which has on its underside latching elements for latching the retaining element on the busbar and at its top one or more through holes for the terminals of the device to be contacted.

The invention is based on the object to provide an improved lighting unit for at least one LED module, a corresponding LED module and a method for mounting an LED module to a lighting unit.

To solve this problem, the invention proposes a lighting unit with the features mentioned in claim 1. Further developments of the invention are the subject of dependent claims.

The lighting unit thus contains at least one LED module, which is for example mounted on the outside of a housing. To power a arranged in the housing busbar, which is connectable to another power supply. With the busbar a contact element is mechanically and electrically connected for each pole of the LED module. Through an opening of the housing wall engages a head element for each pole of the LED module, which produces the electrical connection with the LED module outside the housing wall and within the housing, the electrical and mechanical connection with the contact element.

In this case, a "head element" is understood in particular to be any fastening element for fastening the LED module to the outside of the housing, wherein the fastening element is designed to form an electrically conductive connection between the LED module and the busbar via a contact element that can be mounted on the fastening element ,

The bus bar can be made by methods known per se for the manufacture of printed circuit boards. For example, the bus bar has a carrier material, such as e.g. made of plastic, which carries a conductor track on one or both sides. The busbar can be a length of z. B. 0, 25 to 1 m, in particular 0.5 m, and a width of e.g. 5 mm to 20mm, in particular 12mm.

In a further development of the invention can be provided that the head element rests with the underside of its protruding over its shaft head on the housing facing away from the front of the LED module. This concern to one connected to one terminal of the LED module metallization can lead to a large-scale system and thus to low contact resistance.

Another proposed by the invention mounting option is that the head element is pressed with at least one contact pin in a plated-through hole of the LED module.

The head element, like the contact element, is a metallic or at least partially metallic element. It can therefore also be used to position the LED module and, if necessary, fix it mechanically. When formed as a partial metallic element, it preferably has a sheath or coating of insulating material to isolate it from the edge of an opening of a metal housing.

The connection between the head element and the contact element can be done in one of the usual way for the connection of metallic elements. For example It can be a connector that can make both a mechanical and an electrically secure connection.

However, it is also possible and within the scope of the invention that the connection is a screw connection. It can be provided in particular that the head element is designed as a sleeve element, for example with a blind hole.

Such a bore or blind hole can be used to compress the head element with the contact element.

It is also possible that the opening of the formed as a sleeve member head member has an internal thread. With this internal thread, the head element can be screwed onto an external thread of the contact element. This external thread can be advantageously formed on a threaded projection of the contact element. It is possible in this way that the head element connected to the contact element merges with its outer surface flush into the outer surface of the contact element.

To connect the contact element with the conductive regions of the busbar, one of the usual attachment methods can be used, as they are known in so-called power elements and printed circuit boards. In particular, the invention proposes that the contact element is pressed with a plurality of contact pins in plated-through holes of the busbar. This pressing leads both to a mechanically secure and to an electrically good connection between the contact element and the busbar.

However, it is also possible and is proposed by the invention that the contact element is connected to terminal pads in SMT.

In a development of the invention, it can be provided that the mechanical connection between the head element and the contact element is a spacer element forms, which defines a distance between the housing wall and the busbar defined.

In a further development of the invention it can be provided that between the head element and the edge of the opening of the housing through which the head element engages, a radial distance is present.

According to the invention may be provided in a development that the LED module is thermally conductively connected to the housing wall. In the operation of the LED module occurring heat can therefore be transferred to the housing wall and thus derived.

So that the head element can engage with the underside of its head on the LED module, this can according to the invention have an opening with a closed edge for at least one head element. The head element is thus guided from the front through this opening and then pushed through the opening of the wall of the housing inwardly, where it is then connected to the contact element.

However, it is also possible and is proposed by the invention that the LED module for at least one head element has an outgoing from an edge of the LED module recess, which allows for appropriate dimensioning, the LED module laterally under the head of the head element to push.

Depending on the desired application, the LED module can have several individual LEDs, which are also optically separated from one another.

But it is also possible that the LED module has a large-area LED.

According to one embodiment of the invention, there is a gap between the head element and the edge of the opening of the housing.

According to one embodiment of the invention, the LED module has a plurality of individual LEDs.

According to one embodiment of the invention, the LED module has a single large-area LED.

According to one embodiment of the invention, at least one contact element is connected to a connection pad of the busbar in SMT technology.

According to one embodiment of the invention, the bus bar can be inserted into the housing. For example, a groove is formed for this purpose in the housing, via which the busbar can be inserted into the housing until the busbar reaches an end position. The end position can be given for example by an end stop or a latching connection to be formed in the end position. When the busbar is in its end position, the already mounted on the busbar contact elements are positioned below the openings of the housing, so that an LED module can be conveniently mounted from the outside of the lighting unit using the head elements. For example, the lighting unit with the preassembled busbar and mounted on the busbar contact elements is delivered to a customer. The customer can then even mount the LED modules requested by the customer on the lighting unit or dismantle an LED module to replace it with a new one.

The easy interchangeability of an LED module of the lighting unit has the particular advantage that an existing LED module can be replaced by a new, advanced LED module. In particular, the invention makes it possible that the LED module is replaced by an organic LED module, ie an LED module with a so-called organic light emitting diode (OLED). For future developments in LED technology, the customer can continue to use the lighting unit and only has to replace the LED modules with new ones.

According to one embodiment of the invention, the lighting unit is modular, with a busbar defining a module. A busbar, for example, be designed to power eight to ten LED modules. In this case, the bus bar must be dimensioned accordingly to supply the supply current for the multiple LED modules, the supply current may be in the range of a few amps.

According to one embodiment of the invention, the housing has at least a portion of a metallic material, which is thermally conductively connected to the LED module when the LED module is mounted on the illumination unit. This makes it possible to use the housing as a heat sink to dissipate power loss of the LED module. In particular, the housing can be made entirely of a metallic material such. B. aluminum.

In another aspect, the invention relates to an LED module for mounting to an embodiment of a lighting unit according to the invention. The one or more LEDs, which carries the carrier of the LED module, can be electrically connected to the carrier via per se known construction and connection technologies, in particular so-called. Bonding technologies, such. B. by SMD, flip-chip or chip-on-board techniques.

According to one embodiment of the invention, the LED module has an exemption, in particular a defined depth exemption, which is also referred to here as a cavity in which an LED of the LED module is implanted. By implanting the LED in the clearance, the distance between the LED and the housing and thus the heat transfer resistance between the LED and the housing is reduced, so that the power dissipation can be correspondingly efficiently dissipated.

In a further aspect, the invention relates to a method for mounting an LED module to an embodiment of a lighting unit according to the invention. Embodiments of the method according to the invention are particularly advantageous since the customer can make the assembly itself as well as the disassembly, especially for the purpose of initial installation, the replacement of a defective LED module or to replace the LED module by an advanced LED module greater efficiency, especially an OLED module.

Figur 1

eine Draufsicht auf eine Stromschiene mit zwei getrennte Leiterbahnen;

Figur 2

eine Draufsicht auf ein erstes LED-Modul;

Figur 3

eine Draufsicht auf ein zweites LED-Modul;

Figur 4

eine Draufsicht auf ein drittes LED-Modul;

Figur 5

einen schematischen Schnitt durch eine Gehäusewandung mit den zur Befestigung des LED-Moduls dienenden Einzelteilen in auseinander ge zogenem Zustand;

Figur 6

das Ergebnis der Zusammensetzung der Einzelteile der Figur 5;

Figur 7

eine der Figur zwei entsprechende Darstellung eines weiteren LED-Moduls;

Figur 8

die Anbringung eines Kopfelements an einem LED-Modul;

Figur 9

eine der Figur 5 entsprechende Darstellung;

Figur 10

eine der Figur 6 entsprechende Darstellung;

Figur 11

eine der Figur 1 entsprechende Darstellung einer Stromschiene;

Figur 12

schematisch die Anbringung eines LED-Moduls aus einer Richtung quer zur Darstellung der Figuren 9 und 10;

Figur 13

stark vereinfacht eine Art der Ausbildung von Kontaktelementen;

Figur 14

eine perspektische Ansicht eines Abschnitts einer erfindungsgemäßen Beleuchtungseinheit;

Figur 15

einen Abschnitt einer Ausführungsform einer erfindungsgemäßen Strom schiene mit montierten Kontaktelementen.

Further features, details and advantages of the invention will become apparent from the claims, the wording of which is incorporated by reference into the content of the description, the following description of preferred embodiments of the invention and from the drawing. Hereby show:

FIG. 1

a plan view of a busbar with two separate tracks;

FIG. 2

a plan view of a first LED module;

FIG. 3

a plan view of a second LED module;

FIG. 4

a plan view of a third LED module;

FIG. 5

a schematic section through a housing with the serving for mounting the LED module items in auseinanderge pulled state;

FIG. 6

the result of the composition of the items FIG. 5 ;

FIG. 7

one of the figure two corresponding representation of another LED module;

FIG. 8

the attachment of a header to an LED module;

FIG. 9

one of the FIG. 5 corresponding representation;

FIG. 10

one of the FIG. 6 corresponding representation;

FIG. 11

one of the FIG. 1 corresponding representation of a busbar;

FIG. 12

schematically the attachment of an LED module from a direction transverse to the representation of FIGS. 9 and 10 ;

FIG. 13

greatly simplifies a type of training of contact elements;

FIG. 14

a perspective view of a portion of a lighting unit according to the invention;

FIG. 15

a section of an embodiment of a power rail according to the invention with mounted contact elements.

FIG. 1 shows a plan view of a busbar. The busbar includes a busbar support 1, which is responsible for the mechanical stability of the busbar; For the realization of the busbar support 1, a conventional printed circuit board substrate can be used. On the carrier 1 of the busbar are two printed conductors 2, which are insulated from each other. These interconnects 2 are connected to different potential. In several places, the tracks are widened, with the left in FIG. 1 to be seen broadened sites with plated through holes 3 are provided. For example, each of the widened locations has a number of 4, 5 or 3 * 3 holes 3. As will be shown below, these widened locations of the conductor tracks 2 serve to connect contact elements, so-called power elements.

The FIG. 2 shows a plan view of an LED module 4. The LED module 4 includes a flat support 5, on which in FIG. 2 three LEDs 6 are mounted. The carrier 5 has the shape of an elongated rectangle, at both ends of which a hole 7 is formed in each case. In the in FIG. 2 It can not be seen that the carrier 5 is designed as a plate with parallel upper sides and lower sides.

In the embodiment of the FIG. 3 the support 5 is again formed as an elongated rectangle with holes 7 in the region of its two ends. The LED 6 has here but the shape of an elongated rectangle whose length is about the arrangement of the three LEDs 6 of the FIG. 2 equivalent.

While in the embodiments according to FIG. 2 and FIG. 3 at the ends of the carrier 5 holes 7 are arranged with a closed edge shows FIG. 4 an LED module 4, at the two ends recesses 8 are present, which are open to the edge.

The FIG. 5 shows how the individual parts are arranged to form a lighting unit. There is a housing with a housing wall 9. At the in FIG. 5 shown outside 10 of the housing, an LED module 4 is to be attached. This LED module 4 runs in FIG. 5 with its longitudinal direction perpendicular to the plane of the drawing. In the housing wall 9, a through opening 11 is present. The LED module 4 is arranged in the region of this opening 11. From the outside, a head element 12 with its shaft 13 is inserted through the hole 7 of the LED module 4 and through the opening 11 in the housing wall 9. The head element 12 has a flat with respect to its shaft 13 radially projecting head 14. The diameter of the shaft 13 of the head element 12 is smaller than the diameter of the hole 11 in the housing wall 9, so that there can be a clearance between the outside of the shaft 13 and the edge of the hole 11 on all sides. The shaft 13 of the head element 12 is provided by the head 14 facing away from the front side with a blind hole having an internal thread.

The head element 12 is designed to cooperate with a contact element 15, which is also referred to as a power element. This contact element 15, which consists of solid metal, points to his in FIG. 5 lower side a plurality of pins 16 on. For example, 4, 5 or 3 * 3 contact pins 16 may be present on the contact element 15, depending on how the holes 3 in the conductor track 2 are arranged. These usually have a rectangular or square cross-section. The arrangement of the contact pins 16 corresponds to the arrangement of the plated-through holes 3 in the conductor 2 on the carrier 1 of the busbar. This is so in FIG. 5 shown. The contact element 15 is pressed with its contact pins 16 in the plated-through holes 3. The offset is determined by the concern of the body of the contact element 15 at the top of the conductor 2.

At the side facing away from the contact pins 16, the contact element 15 has a projection 17 with an external thread. On this external thread, the head member 14 is screwed. In this case, the underside of the head 14 of the head element 12 comes to rest on the upper side of the carrier 5 of the LED module 4 and establishes an electrical connection there. The result of this process is in FIG. 6 shown.

In the embodiment discussed so far, the head member 12 engages with a widened head 14 at the top of the LED module 4. But it is also possible that a head element is pressed with an LED module. This shows FIG. 7 one of the FIG. 2 corresponding representation of a further LED module 4, in which for connection to a head element 12 'at both ends of the carrier 5 through holes 20 are provided, for example four such openings 20. The associated head element 12' has at its the LED module 4 facing Side of the number of holes 20 corresponding number of pins 21, see FIG. 8 , For example, 4, 5 or 3 * 3 pins 21. With these pins 21, the head member 12 'is pressed into the holes 20. This is schematically in FIG. 8 shown.

Subsequently, the LED module 4, which now has at both ends in each case such a head piece 12 ', reversed and inserted with the head element 12' ahead through the opening 11 of the housing, see FIG. 9 , Then there is a compression between the head element 12 'and the contact element 15. Subsequently, the combination of head element 12' and contact element 15 with the Busbar 1 pressed, this step is not from the intersection of the FIG. 6 different. It is of course also possible that the process of compression between the head piece 12 'and the contact element 15 on the one hand and the contact element 15 and the busbar 1 on the other hand, a different order.

While at the busbar 1, the in FIG. 1 is shown, both tracks 2 are arranged on the top, shows FIG. 11 a busbar, in which there is a conductor track 2 with recesses on the upper side. With this existing on the top of conductor 2 groups of plated holes are connected. On the opposite side of the busbar 1, a conductor path is also present, which is connected to the other through-plated holes 3. As a result, more total space is available for each of the two tracks 2.

It was mentioned in the beginning that the head elements 12 can be connected to the contact elements 15 in various ways. Such an application example, where this is particularly useful, shows the FIG. 12 , The FIG. 12 schematically shows the arrangement of an LED module with a carrier 5 and an LED 6. For one end of the carrier 5, a head element 12 'is used, which has on its underside a blind hole, the left in FIG. 12 indicated by dashed lines. The associated contact element 15 has on its upper side a projection 17, which is adapted to the blind hole. The connection between the two parts is done by a compression.

The head element 12 "assigned to the other end of the carrier 5 of the LED module has a projection on its underside facing the contact element, while the upwardly directed end face of the contact element 15 has a blind hole which fits for this purpose. By this at both ends of the carrier 5 of the LED module different types of the head member 12 may be a wrong connection be avoided with the contact elements 15. As a result, a twist protection is thus possible.

A further safeguard against incorrect connection could also be achieved in that the contact elements 15 have contact pins 16 with different arrangement patterns on their undersides, which are intended for connection to the through-holes 3 of the busbar 1. This is in FIG. 12 represented by the fact that the two contact elements have a different number of contact pins.

Of course, this type of torsion protection can not only be done with the head elements 12, which are pressed into the carrier 5 of the LED module, but also with the head elements 12 of the embodiment according to FIGS. 5 and 6 , This is in FIG. 13 shown.

The FIG. 14 shows a perspective embodiment of a lighting unit according to the invention, wherein in this embodiment, both conductor tracks two are arranged on the same side of the carrier 1 of the busbar.

The FIG. 15 shows a further embodiment, wherein at one end of the carrier 1 of the busbar, a connector 22 is located, via which the busbar can be connected to a power supply.

Claims (15)

Lighting unit, with a housing,
at least one LED module (4) arranged on the outside of the housing,
a bus bar (1) arranged in the housing for supplying power to the LED module (4),
two with the busbar (1) electrically and mechanically connected contact elements (15), as well as with
two head elements (12, 12 ') which engage with the contact elements (15) and each engage through an opening (11) of the housing, which make the connections for the LED module (4) on the front side of the housing. Lighting unit according to claim 1, wherein the head element (12) has a head (14) with a bottom and rests with this underside on the front side of a support (5) of the LED module (4). Lighting unit according to claim 1, wherein the head element (12 ') with contact pins (21) in through-contacted holes (20) of the LED module (4) is pressed. Lighting unit according to one of the preceding claims, in which the head element (12, 12 ') mechanically positions and / or fixes the LED module (4). Lighting unit according to one of the preceding claims, in which the head element (12) is screwed or pressed to the contact element (15). Lighting unit according to one of the preceding claims, wherein the head element (12, 12 ') is formed as a sleeve member, wherein the sleeve member has a thread on its inner side, which is in engagement with a threaded projection (17) of the contact element (15). Lighting unit according to one of the preceding claims, wherein the contact element (15) in through-contacted holes (3) of the busbar (1) is pressed. Lighting unit according to one of the preceding claims,
in which the contact element (15) together with the head element (12, 12 ') constitutes a spacer element between the housing and the busbar. Lighting unit according to one of the preceding claims, wherein the LED module (4) is thermally conductively connected to the housing wall (9). Lighting unit according to one of the preceding claims, wherein the LED module (4) for at least one head element (12) has an opening (7) with a closed edge and / or in which the LED module (4) for at least one head element ( 12) has one of an edge of the LED module (4) outgoing the shaft (13) of the head element (12) receiving recess (8). Lighting unit according to one of the preceding claims, in which the head elements (12) arranged at the two ends of the support (5) of an LED module (4) have a different type of connection with the associated contact elements (15) and / or in which they are connected to the Both ends of the carrier (5) of an LED module (4) by means of the head elements (12) attached contact elements (15) have a different connection with the tracks (2) of the busbar (1). Lighting unit according to one of the preceding claims, wherein the bus bar is inserted into the housing to an end position, wherein the contact elements (15) are positioned below the openings (11) of the housing when the end position is reached, so that the at least one LED module (4) can be mounted on the contact elements with the aid of the head elements, or can be removed from the contact elements. Lighting unit according to one of the preceding claims, wherein at least a portion of the housing consists of a metallic material, wherein the portion of the housing is thermally conductively connected via the head elements with the LED module, so that the portion of the housing a heat sink to dissipate power loss of the LED Module forms. LED module for a lighting unit according to one of the preceding claims, wherein the LED module has fastening means for receiving the head elements (12, 12;), via which the LED module is mechanically fastened to the lighting unit, and via which an electrically conductive Connection to the power supply of the LED modules and a thermally conductive connection to dissipate power loss on the housing of the lighting unit can be formed. Method for mounting an LED module (4) on a lighting unit according to one of the preceding claims 1 to 13, with the following steps: Positioning of the LED module over the openings (11) of the housing, - Connection of the LED module with the contact elements by means of the head elements.

Images