WO2013056916A2

WO2013056916A2 - Pad for a lighting device

Info

Publication number: WO2013056916A2
Application number: PCT/EP2012/068044
Authority: WO
Inventors: Gertrud KRÄUTER; Bernd Barchmann; Krister Bergenek; Dirk Becker; Andreas Biebersdorf; Ralph Wirth
Original assignee: Osram Gmbh
Priority date: 2011-10-20
Filing date: 2012-09-14
Publication date: 2013-04-25
Also published as: WO2013056916A3; DE102011084885A1

Abstract

The invention relates to a pad (17) that is provided for a substrate (12) of a lighting device (11) and has at least one opening (18) for at least one semiconductor light source (14) of the lighting device (11), wherein the pad (17) has at least one peripheral wall (19a-g), which surrounds at least one opening (18). The lighting device (11) has a substrate (12) on which at least one semiconductor light source (14) is mounted, wherein the substrate (12) is provided with a pad (17) according to one of the preceding claims, such that the at least one semiconductor light source (14) is located within an opening (18) of the pad (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 mass (23, 24a-c, 25).

Description

description

Support for a lighting device 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 are a substrate

have, 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 characteristics of the independent

Claims solved. 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 at least one

has circumferential wall, which at least one recess surrounds. By the circumferential wall (significant, so not negligible height), a box is created, which as a laterally limiting Verfüllform, in particular

Casting mold, can serve. 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, so a much lower volume of

Filling material needed, which can counteract even a high creep of the filling compound. In addition, one can

Adjustment level at the semiconductor light sources more accurate, and thickness variations can be locally reduced.

The support may further comprise at least one recess for at least one contact surface (e.g.

Contact field, e.g. for fixing a bonding wire) of

Substrate have a simple electrical

To enable contacting. 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, a filling of the filling compound in large

Distance from the at least one semiconductor light source allows this recess and thereby the

Likelihood reduces that when filling

Can spray filling compound on the semiconductor light source.

It is further an embodiment that the at least one circumferential wall one of a basis of the edition high wall is. As a result, the basis of the pad can be kept relatively thin, and it can

high walls at the same time with low material costs

to be provided.

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 encircling wall may have several superimposed

Have 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 pad

at least on its top, possibly also on her

Side surfaces, reflective designed. 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 sufficient

Yellowing stability of plastic, in particular of 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

Platelets have a white color. In particular, a white pigment may be added to the above-mentioned materials, e.g. TiO 2, ZrO 2, ZnO or BaSO 4. However, alternatively or additionally, other additives are usable, e.g.

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 can inside at least one stop edge

exhibit .

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 through the

at least one circumferential wall formed box with

at least one filling compound is filled. These

Lighting device has the same advantages as the support and can be configured in an analogous manner.

For example, such an area next to a

Semiconductor light source are cast 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. TiO 2, ZrO 2, ZnO or BaSO 4. 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

Covering share and thus a lighting device with a particularly high light yield before. Additionally or alternatively, the at least one

Semiconductor light source with at least one (further, material technically different or the same) filling material to be covered. Such a filling compound can be transparent or be diffusely translucent. The filling compound may have at least one phosphor. Different boxes may have different filling compositions, for example with or without a phosphor and / or with different

Phosphors.

Preferably, the at least one

Semiconductor light source at least one light emitting diode. at

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). This can also be done by the at least one

LED emitted light is 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 training that at least one

Semiconductor light source is not surrounded by a filling material or covered with it.

It is an embodiment that the at least one

Semiconductor light source comprises at least one LED chip.

These LED chips are typically flat (eg, type "Thin GaN ") and a precise casting therefore especially

difficult, so that the support for this purpose is particularly advantageous. 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 a plurality of semiconductor light sources (same or

different type), which are surrounded by different circumferential walls (or are present in different boxes) and with a different

Filling compound, in particular potting compound, filled, in particular potted, are. This will in a simple way an individual covering, especially an individual

Potting, the semiconductor light sources allows.

It is also an embodiment that the peripheral wall is lower than the surrounding at least one

Semiconductor light source. Thus, in particular, a reflective bottom plate, which is the

Semiconductor light source (s) not covered, easy and safe to manufacture. Specifically, the filling compound can thus pass over the wall in the event of local overfilling of the box, thereby preventing a 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 possible to fill the at least one

Box also by the pad is separated by a defined gap from the substrate, for example via spacers, so that there is a gap under the support. You fill Liquid filling material at one edge or by at least one dedicated filling passage in the gap, so it runs in the gap under the support and finally swells out of the recesses, wherein the areas around the

Semiconductor light sources and possibly contact surfaces completely wetted. This type of filling is particularly time-saving and can, for example, a spraying of the filling on one

Avoid semiconductor light source. An associated gap height is preferably between about 30 microns and 100

Micrometers.

For example, a lighting device may be manufactured such that a substrate having at least one

Semiconductor light source is fitted 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 material

Base plate next to the at least one semiconductor light source and optionally at least one contact surface overlapping. 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 are achieved will become clearer and more clearly understood

In connection with the following schematic description of exemplary embodiments that are associated with the

Drawings are explained in more detail. It can to Clarity identical or equivalent elements must be provided with the same reference numerals.

Fig.l shows in plan view a lighting device with

a support according to a first embodiment;

2 shows a sectional side view of a

Section of the lighting device according to the first embodiment;

3 shows a plan view of a lighting device

a support according to a second embodiment; and

4 shows a sectional side view of a

Detail of the lighting device with the

Pad according to the second embodiment.

Fig.l shows a plan view of a lighting device 11 with a plate-shaped, circular substrate 12, on the

shown top surface 13 ten semiconductor light sources in the form of LED chips 14 are arranged. The top 13 of

Substrate 12 is further provided with a support 17 of a reflective, e.g. white, plastic material used. The overlay 17 is in the form of a foil or platelet as a base, e.g. on the substrate 12

is glued on.

The support 17 has seven recesses 18a-g, so that each of the LED chips 14 is located within one of the recesses 18a-g. The recesses 18a-c and 18e-g are each of a circumferential, of the support 17 vertically

surrounded high wall 19a-g. The walls 19a-g form separate boxes 20a-g to form different ones

Potting areas and are higher than the / of it

While the boxes 20a-c and 20e-g each have a recess 18a-c or 18e-g for each one LED chip 14 (or the walls 19a-c and 19e-g are each surrounded by a recess 18a-c or eg for a respective single LED chip 14), The box 20d has a recess 18d for four LED chips 14. FIG. 2 shows an exemplary section through the box 20b along a section line AA shown in FIG. For the electrical contacting of the LED chips 14, a recess 21 for a contact pad 22 provided on the substrate 12 is additionally provided in the boxes 20a-c and 20e-g, while the recess 18d is also present as a

Recess for at least one contact pad 22 is used.

Each of the boxes 20a-g is filled with two filling compounds in the form of potting compounds 23 and 24a-c (see FIG. 2 for box 20b with potting compound 24c). Namely, first, the recesses 18a-g and 21a-c and 21e-g with a first

Potting compound 23 are cast, e.g. Silicone with a white pigment as an additive, and only so high that a top-side emitter surface of the LED chips 14 is not covered. After curing of the first potting compound 23, it forms together with the support 17 a white, diffuse

reflective base plate with a large area coverage to achieve a high light output.

Since the walls 19a-g are higher than the LED chips 14, can each have a via the (cured) first potting compound 24

further, second potting compound 24a-c are applied, which covers the emitter surface of the LED chips 14 and is locally limited to the respective box 20a-g. 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 shown in FIG. 2, can be implemented: the LED chips 14 are

identical, for example, 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 into visible light different color converts. So the second likes

Casting compound 24a convert UV light into red light, the second potting compound 24b convert UV light into green light and the third potting compound 24c convert UV light into blue light. For example, can emerge from the boxes 20a, 20c, 20e and 20g with the second potting compound 24a red light, emerge from the box 20d with the second potting compound 24b green light and emerge from the boxes 20b and 20f with the second potting compound 24b blue light. The mixed light thus obtained in the far field (for example, from a distance of about 20 cm) may, for example, be a white one

Be mixed light.

On the second potting compound 24a-c, a third

Potting compound 25 may be applied, which is transparent to visible light, but blocks UV light (UV filter).

In order to be able to comply with a precise fill level of the first potting compound 23, of the second potting compound 24a-c and of the third potting compound 25, the inside of the walls 19a-g has a respective stop edge 26k-m which inter alia creep up the respective potting compound 23, 24a and 25 effectively prevented beyond them. However, in principle, the stop edges 26k-m can be omitted.

Alternatively, for example, the following configuration

convertible: the LED chips 14 emit blue light and are covered in the boxes 20b and 20f with a second potting compound 24a, which is transparent and has no phosphor, covered in the boxes 20a, 20c, 20e and 20g with a second potting compound 24b which converts blue to red light and in box 20d to a second one

Potting compound 24c covered, which converts blue into green light. The resulting mixed light can also be a white mixed light.

However, any other configurations can be used, for example, with blue-yellow phosphor, etc. Also can Different LED chips are used, especially LED chips, which light a different one

Radiate spectral range. To prevent potting compound laterally over the

Luminous device 11 runs out, the support can integrally have a raised outer ring 27, which may also have at least one stop edge. 3 shows a plan view of a lighting device 31 with a support 37 according to a second embodiment. 4 shows a sectional side view of a detail of the lighting device 31 in the region of the section line B-B of Figure 3.

The support 37 has no specially pronounced walls, but is so thick that a free side surface 39 of its recesses 38 (see Figure 4) forms a respective peripheral wall. In particular, the first potting compound 23 can be filled into the boxes 40 thus formed and together with the support 37 form a reflective bottom plate. If the free side surfaces 39 are high enough (in particular higher than the LED chips 14), a suitable second potting compound 24a, 24b and / or 24c can also be filled there. The third potting compound 25 can over the entire surface above the

Recesses 38 are applied. In particular, however, if the free side surfaces 39 are lower than the LED chips 14 surrounded by them, for example, the second potting compounds 24a-c can be dispensed with.

To improve a filling in particular the

Potting compound 23 has the recess 38 and its peripheral wall or free side surface 39 a recessed

Bulge 41, in which, for example, the potting compound 23 can be introduced, with a reduced risk of splashing the potting compound 23 on the one or more surrounding LED chips 14th Alternatively, the support 37 may be separated from a substrate 32 by a gap, and the first potting compound 23 may be introduced laterally into the gap, until the recesses 38 are sufficiently filled with it.

Although the invention is shown in detail by the

Embodiments have been further illustrated and described, the invention is not limited thereto and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Such is the number and composition of the potting compounds

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 with the same or different potting compounds, in particular with different

Phosphors, (partly) can be potted.

Moreover, a shape and location of the upstanding walls is not limited and may be e.g. also a vertical one

upstanding wall.

In general, characteristics of the various

Embodiments exchanged or combined. Thus, the thick support 37 of the lighting device 31, which is brought close to an upper side of the LED chips 14, can be used instead of the thin base of the support 17. This makes it possible in particular for the (optional)

Stop edge 26k be waived. Reference sign list

11 lighting device

12 substrate

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 substrate

37 edition

38 recess for LED chip

39 side surface of the recess

40 box

41 bulge

A-A cutting line

B-B cutting line

Claims

claims

1st edition (17, 37) for a substrate (12, 32) of a

Lighting device (11; 31), comprising at least one recess (18; 38) for at least one

Semiconductor light source (14) of the lighting device (11; 31), wherein the support (17; 37) at least one

circumferential wall (19a-g; 39) surrounding at least one recess (18; 38).

Second edition (37) according to claim 1, wherein the at least one circumferential wall (39) by a free side surface (39) of the recess (38) is formed.

3. edition (37) according to claim 2, wherein the peripheral wall (39) at least one recess (38) a

having recessed bulge (41).

A support (17) according to any preceding claim, wherein the at least one peripheral wall (19a-g) is a wall upstanding from a base of the support (17).

5. support (17) according to any one of the preceding claims, wherein the circumferential wall (19a-g) on its inner side at least one stop edge (26k-m).

6th edition (17, 37) according to one of the preceding

Claims, wherein the support (17, 37) is designed to be reflective at least on its upper side.

7th edition (17, 37) according to one of the preceding

Claims, wherein the support (17, 37) has a

having upstanding edge (27).

8. lighting device (11, 31), comprising a with

at least one semiconductor light source (14) equipped substrate (12; 32), wherein the substrate (12; 32) with a Support (17, 37) according to one of the preceding claims is occupied, so that the at least one

Semiconductor light source (14) within a

Recess (18; 38) of the support (17; 37) is located, 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.

The lighting device (11; 31) of 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 at least one semiconductor light source (14) surrounded by it.

Lighting device (11) according to claim 10, comprising a plurality of semiconductor light sources (14), which of

surrounded by different circumferential walls (19a-g) and with a different filling compound (24a-c) are shed.

Lighting device (31) according to one of claims 8 or 9, wherein the peripheral wall (39) is lower than the at least one semiconductor light source (14) surrounded by it.

A lighting device (31) according to any one of claims 8 to 12, wherein the support (37) is separated from the substrate (32) by a gap.