DE102011084885A1 - Support for a lighting device - Google Patents

Abstract

A support (17) is provided for a substrate (12) of a lighting device (11) and has at least one recess (18) for at least one semiconductor light source (14) of the lighting device (11), the support (17) having at least one peripheral wall (19a-g) which surrounds at least one recess (18). The lighting device (11) has a substrate (12) equipped with at least one semiconductor light source (14), the substrate (12) being covered with a support (17) according to one of the preceding claims, so that the at least one semiconductor light source (14) is located within a recess (18) of the support (17), and wherein at least one box (20a-g) formed by at least one peripheral wall (19a-g) is filled with at least one filling compound (23, 24a-c, 25). .

Description

The invention relates to a support for a lighting device with at least one semiconductor light source. The invention further relates to a lighting device with such a support. The support is preferably applicable as a filling aid and / or bottom plate.

There are known LED lighting modules, which have a substrate which is equipped with a plurality of light emitting diode (LED) chips. In order to obtain a high light outcoupling, the surface of the substrate is encapsulated next to the LED chips with a white potting compound, which forms a diffusely reflecting bottom plate after curing. In this case, however, the problems occur that it can come to a covering of an emitter surface of the LED chips with the silicone by a crawling of the silicone on the LED chips. By creeping up the silicone on outer boundary walls, it can also lead to an uneven thickness of the bottom plate. In addition, an inhomogeneous wetting of the substrate may occur.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide an improved possibility for filling a lighting device, in particular at least for providing a base plate.

This object is achieved according to the features of the independent claims. Preferred embodiments are in particular the dependent claims.

The object is achieved by a support for a substrate of a lighting device, comprising at least one recess for at least one semiconductor light source of the lighting device, wherein the support has at least one peripheral wall which surrounds at least one recess. By the circumferential wall (significant, so not negligible height), a box is created, which can serve as a laterally limiting Verfüllform, in particular casting mold. By means of this box, the advantage is achieved that different, matched to one or more semiconductor light sources and spatially separate filling compounds, in particular potting compounds, can be filled. In addition, a much lower volume of the filling compound is needed, which can also counteract a high creep of the filling compound. In addition, a filling height at the semiconductor light sources can be more accurately adjusted, and thickness variations can be locally reduced.

The support may further include at least one recess for at least one contact surface (e.g., a planar contact pad, e.g., for attaching a bonding wire) of the substrate to facilitate easy electrical contact.

It is an embodiment that the at least one circumferential wall is formed by one or the free side surface of the recess. The pad is so thick that it can already form the box itself. This allows a particularly easy to produce and stable support. The filling compound can thus be filled into the recess, in which there are also one or more semiconductor light sources.

It is still an embodiment that the circumferential wall of at least one recess has a recessed bulge. Thus, filling of the filling compound is made possible at a great distance from the at least one semiconductor light source of this recess, thereby reducing the likelihood that during filling filling compound can be injected onto the semiconductor light source.

It is furthermore an embodiment that the at least one circumferential wall is a wall which projects from a base of the support. Thereby, the basis of the pad can be kept comparatively thin, and it can be provided at the same time with low material costs high walls.

It is also an embodiment that the circumferential wall has at least one stop edge on its inside. The stop edge prevents the filling compound from creeping up. The circumferential wall may have a plurality of stacked stop edges, e.g. to be able to reach different filling levels exactly or to be able to fill different filling materials with high accuracy one above the other.

It is also an embodiment that the support is at least on its upper side, possibly also on their side surfaces, designed to be reflective. Thus, a particularly high light output can be realized. For this purpose, the support may for example consist of a diffusely or specularly reflective material or may have a reflective layer on its upper side, e.g. of silver and / or aluminum, e.g. "MIRO" or "MIRO SILVER" by Alanod.

It is generally preferred that the overlay to achieve high temperature stability and adequate yellowing stability be made of plastic, in particular PTFE or other F-plastics, polyamide, polybutylene terephthalate (PBT), polyethylene terephthalate (PET) or copolymers or blends thereof, as well as thermosets such as unsaturated Polyesters, diallyl phthalates or silicones or silicone / epoxy hybrid plastics.

To achieve a diffuse reflectivity, the plate may have a white color. In particular, the above-mentioned materials may be added with a white pigment, eg TiO 2, ZrO 2, ZnO or BaSO 4. However, alternatively or additionally other additives can be used, eg mineral additives and / or glass fibers.

It is also an embodiment that the support integrally has an upstanding (edge) edge or outer ring. Thereby, leakage or trespassing of the filling material can be avoided laterally of the support. Also, the possibility of a large-scale backfilling, in particular potting, over the entire edition is possible. Also, the outer ring may have on the inside at least one stop edge.

The object is also achieved by a lighting device comprising a substrate equipped with at least one semiconductor light source, wherein the substrate is covered with a support as discussed above, so that the at least one semiconductor light source is located within a recess of the support, and wherein at least one at least one circumferential wall formed box is filled with at least one filling material. This lighting device has the same advantages as the support and can be configured in an analogous manner.

For example, such a region may be potted next to a semiconductor light source to provide a reflective bottom plate together with the support. Also, the covering, in particular the potting, an electrical contact surface, if available, easily possible.

The filler preferably also comprises a white pigment, e.g. TiO2, ZrO2, ZnO or BaSO4. The base material may be a polymer, for example silicone. After curing of the filling compound, in particular of the silicone / pigment mixture, there is a, in particular white, bottom plate with a high coverage proportion and thus a lighting device with a particularly high luminous efficacy.

Additionally or alternatively, the at least one semiconductor light source may be covered with at least one (further, material technically different or the same) filling compound. Such a filling compound may be transparent or diffusely transparent. The filling compound may have at least one phosphor. Different boxes may have different filling masses, e.g. with or without a phosphor and / or with different phosphors.

Preferably, the at least one semiconductor light source comprises at least one light-emitting diode. If several LEDs are present, they can be lit in the same color or in different colors. A color may be monochrome (e.g., red, green, blue, etc.) or multichrome (e.g., white). The light emitted by the at least one light-emitting diode can also be an infrared light (IR LED) or an ultraviolet light (UV LED). Several light emitting diodes can produce a mixed light; e.g. a white mixed light. The at least one light-emitting diode may contain at least one wavelength-converting phosphor (conversion LED). The at least one light-emitting diode can be in the form of at least one individually housed light-emitting diode or in the form of at least one LED chip. Several LED chips can be mounted on a common substrate ("submount"). The at least one light emitting diode may be equipped with at least one own and / or common optics for beam guidance, e.g. at least one Fresnel lens, collimator, and so on. Instead of or in addition to inorganic light emitting diodes, e.g. based on InGaN or AlInGaP, organic LEDs (OLEDs, for example polymer OLEDs) can generally also be used. Alternatively, the at least one semiconductor light source may be e.g. have at least one diode laser.

It is a development that at least one semiconductor light source is not surrounded by or covered by a filling compound.

It is an embodiment that the at least one semiconductor light source comprises at least one LED chip. These LED chips are typically flat (e.g., of the "thin GaN" type), and precise potting is therefore particularly difficult, so that the overlay can be used to particular advantage.

It is still an embodiment that the peripheral wall is higher than the surrounding at least one semiconductor light source. Thus, a semiconductor light source locally filled to above its top, in particular shed, be, especially with a phosphor containing filler.

It is also an embodiment that the lighting device has a plurality of semiconductor light sources (same or different type), which are surrounded by different peripheral walls (or are present in different boxes) and filled with a different filling material, in particular potting compound, in particular potted, are , As a result, individual coverage, in particular individual encapsulation, of the semiconductor light sources is made possible in a simple manner.

It is also an embodiment that the peripheral wall is lower than the at least one semiconductor light source surrounded by it. That's how it works In particular, a reflective bottom plate, which does not cover the semiconductor light source (s), easily and safely produce. Specifically, the filling compound can thus pass over the wall in the event of local overfilling of the box, thereby preventing the surface of the semiconductor light source (s) from being covered.

For example, the filling material may be filled locally in a box, e.g. from a top.

Alternatively, it is also possible to fill the at least one box by separating the support from the substrate by a defined gap, e.g. over spacers, so that there is a gap under the support. If liquid filling material is filled into the gap at one edge or through at least one dedicated filling passage, it runs into the gap under the support and finally swells out of the recesses, completely wetting the regions around the semiconductor light sources and possibly contact surfaces. This type of filling is particularly time-saving and can, for example, avoid spraying the filling compound onto a semiconductor light source. An associated gap height is preferably between about 30 microns and 100 microns.

A lighting device can be produced, for example, so that a substrate is equipped with at least one semiconductor light source and then the support is applied to the substrate, namely surface contacting or spaced (with a preferably small distance). Subsequently, the at least one semiconductor light source can be electrically contacted, e.g. by bonding wires, e.g. with at least one contact surface. In particular, a filling compound can be introduced as a subsequent step, in particular for producing a reflective base plate in addition to covering the at least one semiconductor light source and optionally at least one contact surface. Furthermore, at least one filling compound may be filled, which covers at least one semiconductor light source, in particular at least two semiconductor light sources with different filling compound, especially with different phosphors, covered. Also, a filling compound may be filled in which covers all the semiconductor light sources in common, e.g. as a protective layer.

The above-described characteristics, features, and advantages of this invention, as well as the manner in which they will be achieved, will become clearer and more clearly understood in connection with the following schematic description of exemplary embodiments which will be described in detail in conjunction with the drawings. In this case, the same or equivalent elements may be provided with the same reference numerals for clarity.

1 shows in plan view a lighting device with a support according to a first embodiment;

2 shows a sectional view in side view of a section of the lighting device according to the first embodiment;

3 shows in plan view a lighting device with a support according to a second embodiment; and

4 shows a sectional view in side view of a section of the lighting device with the support according to the second embodiment.

1 shows in plan view a lighting device 11 with a plate-shaped, circular substrate 12 , on whose top side shown 13 ten semiconductor light sources in the form of LED chips 14 are arranged. The top 13 of the substrate 12 is also available with an edition 17 made of a reflective, eg white, plastic material. The edition 17 is in the form of a foil or a platelet as a base, for example on the substrate 12 is glued on.

The edition 17 has seven recesses 18a -G on, so that each of the LED chips 14 inside one of the recesses 18a -G is located. The recesses 18a -C and 18e -G are each of a circulating, of the edition 17 vertically upstanding wall 19a -G surrounded. The walls 19a -G form separate boxes 20a -G to form different potting areas and are higher than the LED chip (s) surrounded by it 14 ,

While the boxes 20a -C and 20e -G one recess each 18a -C or 18e -G for each one LED chip 14 have (or the walls 19a -C and 19e -G one recess each 18a -C or e-g for a single LED chip 14 surrounded), the box points 20d a recess 18d for four LED chips 14 on. 2 shows an exemplary section through the box 20b along an in 1 shown section line AA.

For electrical contacting of the LED chips 14 is in the boxes 20a -C and 20e -G additionally each a recess 21 for one on the substrate 12 existing contact field 22 present while the recess 18d also as a recess for at least one contact field 22 serves.

Each of the boxes 20a -G is with two fillers in the form of potting compounds 23 and 24a -C (see 2 for box 20b with the potting compound 24c ) filled. Namely, first the recesses 18a -G and 21a -C and 21e -G with a first potting compound 23 To be cast, for example, silicone with a white pigment as an additive, and only so high that a top side emitter surface of the LED chips 14 not covered. After curing of the first potting compound 23 make them together with the pad 17 a white, diffusely reflecting base plate with a large area coverage to achieve a high light output.

Because the walls 19a -G are higher than the LED chips 14 , can over the (hardened) first potting compound 24 in each case a further, second potting compound 24a C are applied, which are the emitter surface of the LED chips 14 covered and locally on the respective box 20a -G is restricted. The second potting compounds 24a C can be designed differently, for example, as in this case have a same base material in the form of silicone, but (possibly different) additives.

For example, the following configuration, which is also in 2 shown is feasible: the LED chips 14 are identical, eg ultraviolet emitting (UV) LED chips 14 , The second potting compounds 24a . 24b and 24c each have a different wavelength converting phosphor, which converts the ultraviolet light to visible light of different colors. So likes the second potting compound 24a Convert UV light to red light, the second potting compound 24b Convert UV light to green light and the third potting compound 24c Convert UV light to blue light. For example, this way out of the boxes 20a . 20c . 20e and 20g with the second potting compound 24a red light come out of the box 20d with the second potting compound 24b go out green light and out of the boxes 20b and 20f with the second potting compound 24b blue light emerge. The resulting in the far field (eg, from a distance of about 20 cm) mixed light can be, for example, a white mixed light.

On the second potting compound 24a -C may be a third potting compound 25 which is transparent to visible light but blocks UV light (UV filter).

To a precise filling level of the first potting compound 23 , the second potting compound 24a -C and the third potting compound 25 To be able to keep up, indicates the inside of the walls 19a -G a respective stop edge 26k On, among other things, a crawling of the respective potting compound 23 . 24a respectively. 25 effectively prevented beyond them. However, in principle also on the stop edges 26k -M be waived.

Alternatively, for example, the following configuration can be implemented: the LED chips 14 emit blue light and are in the boxes 20b and 20f with a second potting compound 24a covered, which is transparent and has no phosphor, in the boxes 20a . 20c . 20e and 20g with a second potting compound 24b covered, which turns blue into red light and in the box 20d with a second potting compound 24c covered, which transforms blue into green light. The resulting mixed light can also be a white mixed light.

However, any other configurations are usable, e.g. with blue-yellow phosphor, etc. Also, different LED chips can be used, in particular LED chips, which emit light of a different spectral range.

To prevent potting compound sideways over the lighting device 11 runs out, the support can integrally a raised outer ring 27 have, which may also have at least one stop edge.

3 shows in plan view a lighting device 31 with an edition 37 according to a second embodiment. 4 shows a sectional view in side view of a section of the lighting device 31 in the area of the section line BB 3 ,

The edition 37 has no distinctive walls, but is so thick that a free side surface 39 their recesses 38 (please refer 4 ) forms a respective peripheral wall. In particular, the first potting compound 23 can into the boxes thus formed 40 be filled and together with the pad 37 form a reflective bottom plate. If the free side surfaces 39 high enough (especially higher than the LED chips 14 ), there can also be a matching second potting compound 24a . 24b and or 24c be filled. The third potting compound 25 can be over the entire area above the recesses 38 be applied. In particular, however, if the free side surfaces 39 lower than the surrounding LED chips 14 can, for example, on the second potting compounds 24a -C be waived.

To improve a filling in particular the potting compound 23 has the recess 38 or the circumferential wall or free side surface 39 a recessed bulge 41 on, in which, for example, the potting compound 23 can be introduced, with a reduced risk of splashing the potting compound 23 on the surrounded or the LED chips 14 ,

Alternatively, the edition 37 through a gap from a substrate 32 be separated and the first potting compound 23 in particular be introduced laterally into the gap until the recesses 38 sufficiently filled with it.

Although the invention has been further illustrated and described in detail by the illustrated embodiments, the invention is not so limited and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Thus, the number and composition of the potting compounds is flexible and may include only one potting compound or any number of multiple potting compounds (two, three, four potting compounds, etc.).

Also, mutually different light-emitting diodes or other semiconductor light sources may be arranged on a common substrate, which may be cast (partially) with the same or different casting compounds, in particular with different phosphors.

Moreover, a shape and location of the upstanding walls is not limited and may be e.g. also include a vertically upstanding wall.

In general, features of the various embodiments may be interchanged or combined. So can the thick edition 37 the lighting device 31 which is close to a top of the LED chips 14 instead of the thin base of the edition 17 be used. As a result, in particular, the (optional) stop edge 26k be waived.

LIST OF REFERENCE NUMBERS

11

 lighting device

12

 substratum

13

 Top of the substrate

14

 LED chip

17

 edition

18a-g

 Recess for LED chip

19a-g

 wall

20a-g

 box

21a-g

 Recess for contact field

22

 Contact field

23

 potting compound

24a-c

 potting compound

25

 potting compound

26k-m

 stop edge

27

 outer ring

31

 lighting device

32

 substratum

37

 edition

38

 Recess for LED chip

39

 Side surface of the recess

40

 box

41

 bulge

A-A

 intersection

B-B

 intersection

Claims (13)

Edition ( 17 ; 37 ) for a substrate ( 12 ; 32 ) a lighting device ( 11 ; 31 ), having at least one recess ( 18 ; 38 ) for at least one semiconductor light source ( 14 ) of the lighting device ( 11 ; 31 ), whereby the edition ( 17 ; 37 ) at least one circumferential wall ( 19a -G; 39 ), which at least one recess ( 18 ; 38 ) surrounds. Edition ( 37 ) according to claim 1, wherein the at least one peripheral wall ( 39 ) by a free side surface ( 39 ) of the recess ( 38 ) is formed. Edition ( 37 ) according to claim 2, wherein the peripheral wall ( 39 ) at least one recess ( 38 ) a recessed bulge ( 41 ) having. Edition ( 17 ) according to one of the preceding claims, wherein the at least one circumferential wall ( 19a -G) one from a basis of the edition ( 17 ) high wall is. Edition ( 17 ) according to one of the preceding claims, wherein the peripheral wall ( 19a -G) at least one stop edge on its inside ( 26k -M). Edition ( 17 ; 37 ) according to any one of the preceding claims, wherein the support ( 17 ; 37 ) is designed to be reflective at least on its upper side. Edition ( 17 ; 37 ) according to any one of the preceding claims, wherein the support ( 17 ; 37 ) an upright border ( 27 ) having. Lighting device ( 11 ; 31 ) comprising having at least one semiconductor light source ( 14 ) equipped substrate ( 12 ; 32 ), the substrate ( 12 ; 32 ) with a condition ( 17 ; 37 ) according to one of the preceding claims, so that the at least one semiconductor light source ( 14 ) within a recess ( 18 ; 38 ) of the edition ( 17 ; 37 ), and wherein at least one by at least one circumferential wall ( 19a -G; 39 ) formed box ( 20a -G; 40 ) with at least one filling material ( 23 . 24a c, 25 ) is filled. Lighting device ( 11 ; 31 ) according to claim 8, wherein the at least one semiconductor light source ( 14 ) comprises at least one LED chip. Lighting device ( 11 ) according to one of claims 8 or 9, wherein the peripheral wall ( 19a -G) is higher than the surrounding at least one semiconductor light source ( 14 ). Lighting device ( 11 ) according to claim 10, comprising a plurality of semiconductor light sources ( 14 ), which by different circumferential walls ( 19a -G) are surrounded and with a different filling material ( 24a -C) are shed. Lighting device ( 31 ) according to one of claims 8 or 9, wherein the peripheral wall ( 39 ) is lower than the surrounding at least one semiconductor light source ( 14 ). Lighting device ( 31 ) according to one of claims 8 to 12, wherein the support ( 37 ) through a gap from the substrate ( 32 ) is disconnected.

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