ES2875777T3 - LED layout - Google Patents

Abstract

LED arrangement, comprising - an insulating material holding device for an LED, a short LED support (1), an LED (2), - conductors (4) for an external power supply connection, and - a heat sink of heat (3), the LED support (1) comprising a flat and plate-shaped construction unit, with two superimposed plates (6, 7), which are made of an insulating material, the LED (2) being placed on a support (10), which in turn is attached to the heat sink (3) through the plates (6, 7), - the lower plate (7) being oriented towards the heat sink, - presenting the plates (6, 7) each with a cutout for the mask, abbreviated mask (16, 17), for a reliable positioning of the carrier (10), - the mask (17) of the lower plate (7) being adapted to the shape of the support (10), - the mask (16) of the upper plate (6) being shaped in such a way that the upper plate (6) only partially covers the carrier (10 ), so that the luminous surface of the LED (2) is not covered, pressing the upper plate (6) to the carrier (10), with the LED (2), against the heat sink (3), characterized in that the plates (6, 7) are composed of a thermally stable insulating material, that is, a mica-based insulating material, and to supply the LED (2) with current, current-conducting contacts (8) are placed between the two plates (6, 7), which are connected to the conductors (4), - pressing the plates (6, 7) to the current conducting contacts (8) on the provided contact surfaces (11) of the carrier ( 10).

Description

DESCRIPTION

LED layout

The invention relates to an LED arrangement, comprising a light emitting diode (LED) holder, abbreviated LED holder, with LEDs, conductors, and a heat sink, according to the preamble of claim 1.

Light-emitting diodes transform more than half of their absorbed energy into heat, but at the same time the high temperature reduces their useful life. Hence, they need very good cooling. From here, the LED bracket must supply both power to an LED, as well as ensure a constant high pressure of the LED against the heat sink. For supplying power to the LED, it is known, from document Wo 2011/043441 A1, to use printed circuit boards, equipped with contacts, to contact the LED. The printed circuit boards, as carriers of the contacts, are made of electrically insulating material, but nevertheless this material is thermally stable only to a limited extent. Printed circuit boards of an electrically insulating material are already known from US 4,921,748 A. In order to avoid the formation of stress cracks, when the contacts arranged on the printed circuit board are soldered to other electrical conductors, the Printed circuit board, made of a glass or epoxy, is laminated with a mixture of polyamide resin and potassium fluorohectorite. For supplying power to an LED, it is further known, from patent application US 2011/0211351 A1, to use printed circuit boards equipped with contacts. Here too, an electrical conductor is additionally provided, which establishes electrical connections to other circuit components. For the electrical insulation of such a conductor, components made of epoxy resins, graphite foils, mica, silicon carbide or other materials are indicated.

Due to the large number of applications, and consideration of costs, the LED supports are made of the most varied thermoplastic synthetic materials. Since these materials typically lose their mechanical stability with increasing temperature, the practical application of the LED holder shows on several occasions the disadvantage that the reduced mechanical stability of the LED holder, during LED operation, can no longer guarantee a Sufficient pressure of the LED against the heat sink, and the cooling effect decreases, with the result that the projected life of the LED is not reached.

For the power connection, these LED holders generally contain cut-off or plug-in terminals for a cable connection. However, these terminals require a housing. The required dimensions of such housings are often so large that, in the case of a very flat LED, shadows are cast in the surroundings, not since they protrude too much on the flat LED.

Furthermore, from DE 102008000582 A1, it is known to use spring elements for contacting the LED, which are housed in an insulating housing, their arrangement and the spring force influencing a secure contact.

Hence, the aim of the invention is to configure an LED support of the type mentioned at the beginning, in such a way that, from a construction point of view, it is configured to be flat, and its mechanical properties are not lost, even under high loads. thermals. Finally, reliable pressure of the LED against the heat sink must be ensured, and the power supply to the LED must be done safely. In a further configuration, the LED holder has to ensure enhanced cooling of the LED.

This objective is achieved through an arrangement of the LED with the characteristics of claim 1.

The LED support is a flat constructive unit, and configured in the form of a plate, each plate consisting of a thermally stable insulating material, based on mica. This insulating material contains mainly mineral ingredients, namely a weight ratio of> 85% of minerals in the insulating material. As for minerals, it is mica, or artificial mica. Artificial mica, such as micanite, is pressed from mica fragments and heat-resistant binders, such as silicone binders, into sheets or shaped pieces. In this, the proportion of binder is <15%, preferably <10%.

The LED to be held and cooled is provided on a support that, in turn, can be attached to the heat sink through the support of the l Ed. The plate-shaped LED holder is provided with a first mask, which conforms to the shape of the holder for reliable positioning. Furthermore, a second additional mask is provided, which is smaller than the first mask, and is adapted to the shape of the LED so that the light from the LED passes through.

As previously described, the insulating material is constructed of mica. However, since this material cannot be processed in the conventional injection molding process, the body of the LED holder is made up of two or more plates. The thickness of the bottom plate is chosen for each LED used, so that it is slightly thinner than the bracket itself.

In an example of execution with two plates for the LED support, the lower plate is provided with a first mask, which adapts to the shape of the LED support, in order to position it. Furthermore, a second mask is provided on the top plate, which is smaller than the first mask, but enables the light from the LED to pass through.

In another embodiment of a plate-shaped LED holder, several masks are provided in order to simultaneously connect several LEDs to the LED holder. In this case, the LEDS can be respectively mounted on a holder or on a common holder, and after connection to the LED holder, the latter forms a housing for the LEDS.

Further details of the invention appear from the dependent claims, as well as from the special description.

In the drawing, the object of the invention is shown in several execution examples:

Figure 1 shows in a perspective view the LED support, with heat sink,

Figure 2 shows the LED support in an exploded view, with its construction components, Figure 3a the view from below on the LED support, without the LED insert,

Figure 3b is the top plan view on the LED support with LED,

Figure 4 a perspective representation of a current conducting contact,

Figure 5 is a top plan view of the lower plate of the LED support.

Figure 6 is a perspective representation of an LED holder, with an LED and a heat sink. In the first exemplary embodiment, according to Figures 1 and 2, the LED support 1 is fixed to a heat sink 3 by means of screws 5, pressing the LED 2, with its support 10, onto the heat sink 3. Conductors 4 are routed to bracket 1 of the LED. The screw fixing 5 serves for a firm and secure support and to press the LED holder 1 onto the heat sink 3.

The LED holder 1 is, as can be seen in figure 2, constructed from individual plates, namely an upper plate 6 and a lower plate 7, both of which are composed of a mica material. The plate 6 and the plate 7 respectively have a mask 16, 17. The LED 2 is output through these masks 16, 17.

The plate 6 and the plate 7 are connected to each other through adhesive sections 18. Between the adhesive sections 18, the bottom plate 7 supports current-conducting contacts 8, which, as shown in Figure 4, are provided with bevels 13 and of a tab 21 leading to the support 10. In front of these contacts 8, on the opposite side of the plate 7, pressure aids 9, similarly configured, are shown. Plates 6 and 7 can then be precisely aligned with each other. The current conducting contacts 8 are provided with conductors 4, which can be fixed through soldering, gluing or the like. The tabs 21 of the current-conducting contacts 8 grip the contact surfaces 11 of the holder 10.

This carrier 10 presents the LED 2. The mask 17 of the lower plate 7 is adapted to the shape of the various supports 10 for an LED 2 available on the market. The holder 10 of the LED 2 is placed on the mask 17 from the bottom of the plate 7, the plate 6 then making contact with the holder 10 through the mask 17. In this, the holder 10 grips the contacts 8 current conductors from below, with their contact surfaces 11. The thickness of the plate 7 is less than the thickness of the bracket 10, so that, after mounting, the bracket 10 protrudes slightly over the bottom of the LED bracket 1 .

The LED holder 1 is further provided with screws 5, which are guided through the openings of the plates 6, 7 and the adhesive sections 18 of the LED holder 1, and with which the holder 10 can be fastened with the LED 2 on the heat sink 3. In the exemplary embodiment according to figures 3a and 3b, the two plates 6, 7 are joined by rivets 12, and then they are fixed to the heat sink 3 by means of the screws 5, which penetrate through rivets 12.

Conductors 4 are directed to current conducting contacts 8. As shown in figure 3b, the conductors 4 on the plate 6 are located in their guide recesses 15, in order to avoid that projecting parts of the conductors 4 may meet in the upper part of the holder 1 of the LED. Furthermore, the LED 2 protrudes, through the mask 16, onto the surface of the plate 6.

In assembly, the bracket 10 is guided from the bottom against the LED bracket 1, so that the bottom of the bracket 10 protrudes slightly from the bottom of the LED bracket 1. By means of the screws 5, which are guided through the rivets 12, a secure fixing on the heat sink 3 is then possible, in such a way that the bracket 10 simultaneously presses against the heat sink 3.

In the embodiment of FIG. 5, the insert recesses 14 of the lower plate 7 for the current-conducting contact 8 or for the bezels 13 are specified particularly clearly.

Finally, the exemplary embodiment according to FIG. 6 shows an LED holder 1 with a heat sink 3, the LED holder 1 being shown with clamping recesses 20. These clamping recesses 20 are fitted with extensions, in the form of plug, of an optical element 19, not designated in more detail, in order to thus be able to fasten the optical element 19 to the support 1 of the LED, and to the heat sink 3.

Here it is further indicated that the mask 17 of the plate 7 is adapted to the shape of the carrier 10. The thickness of this plate 7 is selected for each LED 2 used, in such a way that it is slightly thinner than the carrier 10 of the LED 2 The second plate 6, as already explained, also has a mask 16, which, however, covers only the carrier 10 of the LED 2, but not so much that the luminous surface of the LED 2 is covered. If the superimposed plates 6 and 7, with the LED 2 and its carrier 10, are now pressed onto the heat sink 3, with the help of the screws 5, due to the small thickness of the lower plate 7 with respect to the carrier 10, it is generated the pressure of the carrier 10 against the heat sink. The thermal stability of the mica material of the plates 6, 7 guarantees that this pressure does not decrease during the entire useful life of the LED 2, at the temperatures generated by it.

It is also emphasized that if at the same time the connection of the LED 2 to its power supply has to be made, between the two plates 6 and 7 the conductive contacts 8 are placed, and they are positioned in such a way that the same pressures on the provided contact surfaces 11 of the carrier 10, and thereby connect the LED 2. The current is brought to the contacts 8 with the help of the conductors 4. The conductors 44 are connected to the contacts 8, either through soldering, tinned, tightened, or crimped. The fixing is advantageously carried out by welding, because the smallest dimensions can be achieved thereby.

In order to be able to position reliably the contacts 8 during production, they are provided with bezels 13, which engage in specially provided snap-in recesses 14 in the bottom plate 7, thus providing a practical alignment of the contacts 8. As already mentioned, it should be emphasized again here that, when fixing the LED bracket 1 to the heat sink 3 with the help of the screws 5, and where appropriate the rivets 12, the contacts 8 are clamped between the upper plate 6 and the lower plate 7. As a result, the pressure of the carrier 10 against the heat sink 3 is generated on the contacts 8. 6 is close to both the luminous surface of the LED 2, which covers the contacts 8, and thus a direct transmission path of the pressure force of the screws 5 is achieved, through the upper plate 6, on the contacts 8 , and with it I know reach carrier 10.

Since the electrical contacts of the holder 10 are often arranged on one side, the pressure of the holder 10 against the heat sink 3 will only take place on one side, in the manner described above. It is advantageous if similar pressure is also applied to the side of the carrier 10 that is offset by approximately 180 degrees. Pressure aids 9 are used for this. This can only happen, as already mentioned, if pressure aids 9, similar or similar, are placed for the contacts 8, which only take care of the symmetry of the pressure. These pressure aids 9 can physically have the same shape and configuration as the contacts 8. But they can also differ from them. It is only important that they generate a pressure similar to that of the contacts 8. To facilitate the assembly of such an arrangement, of heat sink 3, carrier 10 with LED 2, and LED holder 1, it is advantageous to carry out a preliminary assembly , so that the two plates 6 and 7, in their case with the contacts 8, in their case with conductors 4 and the additional pressure aids 9, are joined to form a constructive unit, which is easy to handle. This can be achieved when the two plates 6 and 7, with the contacts 8 inserted and pressure aids 9, are joined by rivets 12. The number of rivets 12 can be selected as required, and depends on the respective construction or application. . The use of rivets of this type generally allows the use of higher torques for the fixing screws 5, and thus higher pressures of the bracket 10 on the heat sink 3.

It should also be noted that the use of rivets 12 nevertheless leads to the heads of the rivets protruding above the plates 6, 7. Hence, the heat sinks 3 must have corresponding recesses, which are difficult to produce. For this reason, it is advantageous to bond the two plates 6, 7 to one another with adhesive forces, preferably via adhesive sections 18 on both sides. The thickness of these adhesive sections 18 has to be considered in such a way that it is guaranteed that the screws 5 through the upper plate 6 and, where appropriate, the contacts 8 and additional pressure aids 9, can exert a sufficient pressure on carrier 10.

It is also to be mentioned here that the pressure aids 9 can also be configured in such a way as to take care of an additional cooling effect. These pressure aids 9 serve to achieve a uniform load of the LED holder 1 on the heat sink 3.

It should be added here that the bezels 13 can also be designed in such a way that they have two directions, so that either the lower plate 7, and / or the upper plate 6 come into contact with the pleats 13.

In an example useful for understanding the invention, the two plates 6, 7 could also be configured as a one-piece housing. Such a configuration would be reasonable if only the properties are required mechanical LED mount 1. If the electrical connection took place simultaneously, the contacts 8 would then be inserted into the housing. Direct incorporation into the one-piece housing would also be conceivable. The measures provided for fastening the light-conducting optics could also be designed as plug-like continuations, which engage in recesses in the LED holder 1, and are held there with a positive friction connection.

List of reference signs:

1 LED bracket

2 LEDs

3 heat sinks

4 conductors

5 bolts

6 top plate

7 bottom plate

8 current conducting contacts

9 contacts as pressure aids

10 carrier for 2

11 contact surfaces in 10

12 rivets

13 bezels in 8

14 insert cut-outs for 13

15 guide recesses at 6

16 mask in 6

17 mask in 7

18 adhesive sections between 6, 7

19 optical element

20 mounting recesses for 19

21 reed

Claims (12)

1. LED arrangement, comprising - an insulating material holding device for an LED, a short LED holder (1), an LED (2), - conductors (4) for an external power supply connection, and - a heat sink (3), the LED support (1) comprising a flat and plate-shaped constructive unit, with two superimposed plates (6, 7), which are composed of an insulating material, the LED (2) being placed on a support (10) , which in turn is attached to the heat sink (3) through the plates (6, 7), - the bottom plate (7) being oriented towards the heat sink, - the plates (6, 7) each presenting a notch for the mask, abbreviating mask (16, 17), for a reliable positioning of the wearer (10), - the mask (17) of the lower plate (7) being adapted to the shape of the support (10), - the mask (16) of the upper plate (6) being shaped so that the upper plate (6) only partially covers the wearer (10), so that the luminous surface of the LED (2) is not covered, pressing the upper plate (6) to the holder (10), with the LED (2), against the heat sink (3), characterized by that the plates (6, 7) are composed of a thermally stable insulating material, that is, an insulating material based on mica, and that to supply the LED (2) with current, current conducting contacts (8) are placed between the two plates (6, 7), which are connected to the conductors (4), - pressing the plates (6, 7) to the contacts (8), conductors of the current, on provided contact surfaces (11) of the carrier (10). LED arrangement according to claim 1, characterized in that the plate (7), facing the heat sink (3) has a thickness less than the thickness of the carrier (10). LED arrangement according to one of claims 1 or 2, characterized in that the top plate (6) covers the support (10), except for the LED (2). LED arrangement according to one of claims 1 to 3, characterized in that the two plates (6, 7) are fixed to the heat sink (3) by means of screws (5). LED arrangement according to claim 1, characterized in that tabs (21) are arranged on the contacts (8), with which the contacts (8) press against the contact surfaces (11) of the holder (10). 6. LED arrangement according to claim 5, characterized in that , for better alignment, these contacts (8) have bevels (13) in one or two directions, so that the bevels (13) can optionally engage in snap-in housings (14) from the upper plate and / or from the lower plate (6 or 7). LED arrangement according to one of Claims 5 or 6, characterized in that the contacts (8) are provided on one side of the holder (10), and pressure aids (9) are arranged on the other side for a similar pressure carrier (10). LED arrangement according to one of Claims 1-7, characterized in that the two plates (6, 7) are connected to one another by means of adhesive sections (18), the adhesive sections (18) preferably being formed as shaped parts , adhesive on both sides. LED arrangement according to one of Claims 1-8, characterized in that the upper plate (6) is provided with guide recesses (15), from which the conductors (4) for the contacts (8) protrude, being the guide recesses (15) are configured in such a way that the conductors (4) can be accommodated therein. 10 . LED arrangement according to one of Claims 1 to 9, characterized in that , for fixing an optical element (19), the upper plate (6) has retaining recesses (20) for extensions of this optical element (19), like pegs. LED arrangement according to one of Claims 1 to 10, characterized in that, for mounting several LEDs, several masks (16) are provided on the plate (6), and possibly several masks (17) on the plate ( 7). LED arrangement according to one of Claims 1 to 11, characterized in that the material of the plates (6, 7) is mica or synthetic mica, with up to 15% heat-resistant binders.