EP2753863A1

EP2753863A1 - Lighting device

Info

Publication number: EP2753863A1
Application number: EP12755960.7A
Authority: EP
Inventors: Raimund Oberschmid; Martin Moeck
Original assignee: Osram GmbH
Current assignee: Osram GmbH
Priority date: 2011-09-07
Filing date: 2012-08-10
Publication date: 2014-07-16
Anticipated expiration: 2032-08-10
Also published as: CN103917819A; EP2753863B1; WO2013034395A1; US20150241004A1; DE102011112710A1

Abstract

The invention relates to a lighting device for room lighting which has a carrier plate (8) having a reflective assembly surface (89) on which a plurality of light emitting semiconductor chips (1) spaced apart from each other is arranged, and furthermore a translucent or transparent emission plate (20) arranged downstream of the light emitting semiconductor chips (1) in the emission direction and having a light decoupling surface (29) facing away from the light emitting semiconductor chips (1), wherein the emission plate (20) has a plurality of recesses (22) which are each arranged after at least one semiconductor chip (1), and wherein each of the recesses (22) has a diffusor material and/or a wavelength conversion material (21) on the inner surface (28) facing the semiconductor chips (1), and spaced apart from the light emitting semiconductor chips (1).

Description

description

Beieuchtungs orrichtung It is a lighting device, for example, for room lighting, specified.

This patent application claims the priority of German Patent Application 10 2011 112 710.4, the disclosure of which is hereby incorporated by reference.

For room lighting is a high light intensity

required, whereby even when using light

emitting diodes (LED) as light sources, a high waste heat can occur. Known LED-based light sources are therefore usually with particular regard to the

Constructed chip materials and the heat dissipation materials and often have an active cooling, which cools a heat sink using a fan air flow.

In order to produce mixed-colored and in particular white light, LED-based light sources usually have

Light-emitting diode chips, which are individually provided with a phosphor. So that a uniform color impression in a light source with a plurality of such LED-based

Light sources with individual phosphors can arise from the outset by a precise selection of the

LED chips and the phosphor layers are each set very precisely the radiated color. This results in high demands on an exact

Color measurement and accurate production control of LED chips. In addition, typical ballasts for LED-based light sources are usually considered potential-free compact

Switched-mode power supplies are not normally used

may have negligible power losses of up to 20%.

At least one object of certain embodiments is to provide a lighting device having a plurality of light-emitting semiconductor chips.

This object is achieved by an article according to the

independent claim solved. advantageous

Embodiments and further developments of the subject matter are characterized in the dependent claims and will become apparent from the following description and the drawings.

According to at least one embodiment, a

Lighting device, a support plate on which a plurality of mutually spaced apart light-emitting semiconductor chips is arranged. In particular, the

Lighting device to be suitable for room lighting.

According to a further embodiment, the carrier plate to a plastic material and can, for example

in particular have a plastic plate or plastic layer. Furthermore, the carrier plate conductor tracks or electrical contact tracks on a surface or in the

Have inside, by means of which the light-emitting

Semiconductor chips can be contacted electrically. In addition, the carrier plate, for example, a

Have metal layer and / or a metal plate.

For example, the carrier plate can be a plastic layer have, which is glued to a metal plate or a metal foil. The metal plate or metal foil can

for example, facing away from the semiconductor chips

Rear side of the support plate may be arranged.

According to a further embodiment, the carrier plate has a reflective mounting surface, on which the plurality of light-emitting semiconductor chips is arranged. The reflective mounting surface can be formed in particular by a metallically conductive layer, ie

for example, by an applied layer with a reflective metal. The metallically conductive layer can also provide, for example, an electrical connection for the semiconductor chips and at least partially in the form of conductor tracks, contact paths and / or connection surfaces

be educated. The metallically conductive layer can, for example, be vapor-deposited or patterned by phototechnical means and subsequently electrolytically reinforced. It is also possible for the metallically conductive layer by others

Process print and then thermally and / or chemically produce the desired structure. Alternatively, it is also possible to apply a punched-out metal foil surface by gluing. In particular, the

metallic conductive layer to be applied to a plastic film or plastic plate.

According to a further embodiment, the semiconductor chips are applied by gluing, for example by means of a conductive adhesive, or by soldering to the metallically conductive layer. It is also possible to electrically connect light-emitting semiconductor chips with contact terminals facing away from the carrier by bonding, that is to say by so-called bonding wires, to the metallically conductive layer. According to another embodiment, the

light-emitting semiconductor chips in the emission direction a translucent or transparent, that is a diffuse

translucent or transparent, radiating plate facing away from the light-emitting semiconductor chips

Subordinated light output surface. The radiating plate may comprise or be made of a transparent or translucent material, for example a plastic material or a glass.

The radiating plate may be formed, for example, as a diffuser, which in particular in conjunction with the reflective mounting surface of the support plate a

has glare-free light output surface.

According to a further embodiment, the radiation plate has over each of the plurality of light-emitting

Semiconductor chips on a recess, wherein each of the

Recesses on a semiconductor chips facing

Inner surface of a diffuser material and / or a

Has wavelength conversion substance. The recesses have such dimensions that the

Diffuser material or the wavelength conversion substance is spaced from the semiconductor chips.

According to a further embodiment, the recesses are dome-shaped. In particular, the

Recesses in the form of spherical sections or

Ellipse sections be formed, so that the respective inner surface is in the form of a spherical shell or a

Ellipse shell has. The recesses can be in the

Radiation plate, for example, incorporated by embossing be. It is also possible to make the recesses in the manufacture of the radiating plate simultaneously. Rejects that

Radiator plate is a plastic or a glass or is made of it, the recesses in the molding of the

Radiation plate, for example, by casting, incorporated. It is also possible to have the recesses in one

To incorporate rolling processes.

According to a further embodiment, the recesses are formed the same, ie in particular with the same shape and the same size. It is alternatively also possible that the recesses are formed differently.

According to a further embodiment, exactly one light-emitting semiconductor chip is in each case one

Recess arranged. Furthermore, each of the

Semiconductor chips exactly one recess downstream.

According to a further embodiment, the recesses have a diameter which is at least twice greater than side lengths of the light-emitting semiconductor chips. Furthermore, the recesses diameter

which are less than or equal to twenty times the side lengths of the light-emitting semiconductor chips. In this case, adjacent recesses may preferably

be spaced apart. Alternatively, it is also possible that adjacent recesses merge into each other.

According to a further embodiment, the radiating plate is fixed to the carrier plate. For example, the

Radiation plate by means of a fixed but detachable connection possibility to be attached to the support plate. For example, the radiating plate by means of clamping nails be connected to the carrier plate. The clamping nails, which may be formed, for example, as plastic nails or plastic rivets, can by the light emitting surface of the radiating plate through the radiating plate and the

Carrier plate through to a back of the support plate, where they are connected with Klemmnagelkappen in a clamping connection. The radiating plate and the carrier plate may have holes through which the clamping nails protrude. As an alternative to the clamping nails can also others

Connecting pins are used, such as screws. Furthermore, the radiating plate can also be mounted laterally displaceable on the support plate, for example with

Connecting pins such as clamping nails or

Eccentric screws and holes or holes in the

Support plate and / or the radiating plate, which have a larger diameter than the connecting pins or which are designed for example as slots. In addition, other known fastening and

Justiermöglichkeiten and Justiereinstellhilfen be provided by means of which two larger plates laterally displaceable precisely adjusted to each other and can be fixed.

According to another embodiment, the light

emissive semiconductor chips suitable light in one

Wavelength range from ultraviolet radiation to

infrared radiation, more preferably visible light. In this case, one or more or all of the semiconductor chips may be monochromatic light or else

emit mixed-colored light, for example white light. A semiconductor chip can be a light-emitting

Have semiconductor layer sequence that emits directly monochromatic light or on the additional one

Wavelength conversion element in the form of a Phosphor layer, a phosphor plate or a phosphor-containing potting is applied, the

At least a portion of the radiation generated by the semiconductor layer sequence can convert into light with a different wavelength. The semiconductor chips may in particular be formed as epitaxially grown semiconductor layer sequences or in each case an epitaxially grown one

Have semiconductor layer sequence. The

Semiconductor layer sequence may comprise an arsenide, phosphide and / or nitride compound semiconductor material, which is formed in accordance with the desired light in terms of its composition and in terms of its layer structure. In particular, one or more or all

Semiconductor chips directly on the carrier body, ie

in particular on the reflective mounting surface, be mounted without a respective housing body.

According to a further embodiment, the semiconductor chips are equal to one another and emit at least substantially the same light. "Essentially the same light" and "same semiconductor chips" means here and in the

Below, that the light emitted by the individual semiconductor chips and also the compositions of the

Semiconductor chips as in the usual

Can distinguish manufacturing fluctuations. In particular, the semiconductor chips may preferably emit blue light. The light of the semiconductor chips can continue as below

is executed, are converted by means of the wavelength conversion substance partially in different colored light, so that the illumination device can emit mixed-colored light. According to a further embodiment, semiconductor chips emitting different colors are used, which do not start until the

illuminated place a desired mixed-color, in particular white lighting allow. This allows the

Lichtabstrahlplatte have different colored points of light, while the lighting effect by the superposition and the mixture of each different colors of the

Semiconductor chips is generated. This may also make it possible, for example, for information, for example traffic information, notes or logos, such as company logos, to be clearly color readable on the light emitting surface, while white light is perceived by the arrangement of differently colored semiconductor chips at a location to be illuminated. Such an unusual experience has hitherto been known, for example, only from polished glass prisms of chandeliers, in which colored areas of the lamp are artificially caused by white light. According to a further embodiment, the semiconductor chips on the carrier plate are spaced apart from one another in such a way

arranged that the distance of two each directly

mutually adjacent semiconductor chips is a multiple of the side lengths of the semiconductor chips. typical

Side lengths for semiconductor chips may for example be less than or equal to a few millimeters, in particular less than or equal to 1 millimeter.

According to a further embodiment, the semiconductor chips having a density of about 1 semiconductor chip per

Square centimeters distributed on the support plate. The spaced arrangement of the semiconductor chips on the

Carrier plate allows for a large jet area

simultaneous low power dissipation, that is, the heat loss power generated during operation of the light-emitting semiconductor chips is evenly distributed in the carrier body and thus no so-called "emergency spots" arise.

In particular, the lighting device can be a large light emitting surface associated with a small

Have power dissipation through the spaced-apart light-emitting semiconductor chips, thereby easily on the support plate and on the

Lichtauskoppelfläche the radiating plate an effective

Heat transfer from the semiconductor chips to the surrounding air is possible. In particular, it may be advantageous if the metallically conductive layer has a significantly larger area than the area occupied by the semiconductor chips, whereby an effective heat distribution on the carrier plate is achieved. At the same time, as described above, the semiconductor chips can be adhesively bonded or soldered onto the metallically conductive layer in an electrically conductive manner, so that the metallically conductive layer simultaneously

Having contact terminals and can serve for power supply. If the carrier plate has an insulating layer, for example a plastic layer on which the metallically conductive layer is applied, and if the insulating layer has sufficiently high electrical insulation of contact possibilities, the entire interconnection of the light-emitting semiconductor chips can, for example, also be based on the power grid potential. It can be simple low-loss power supplies with voltages of several times the respective individual voltage of a semiconductor chip used become. Below, an embodiment of a suitable electrical circuit is described.

The widened by the metallic conductive layer

Although heat flow from the individual semiconductor chips must flow through the insulating layer as far as the rear side of the carrier plate, the thermal resistance thereof is usually much lower in relation to the transition between the carrier plate and the air. The maximum density of

Semiconductor chips on the support plate, in particular on the metallically conductive layer, is essentially determined by the physically limited air-heat transfer rate with natural convection of a maximum of about 10 W / (Km ² ), wherein the natural convection still by a

Heat radiation can be supplemented in the best of the same order of magnitude.

According to a further embodiment, the carrier plate has a plurality of webs on the mounting surface and / or on the rear side opposite the mounting surface.

The webs may be formed, for example, in the form of profile knobs or web-shaped elevations. By the webs, for example, an increase in the stability of the

Carrier plate can be achieved. For example, the

Carrier plate between the webs have a thickness of about 0.5 mm to about 2 mm, while the webs may have a web height in the order of 0.3 mm to 2 mm, the boundaries are respectively included, whereby the material of the support plate mechanical Strength and thus security against bending and twisting can be given.

Bends or warps of the support plate are to be avoided, since these solder or adhesive cracks the

Could cause semiconductor chips on the mounting surface. The radiating plate may have grooves on the side facing the carrier plate in which on the mounting side of the

Support plate existing webs are arranged. As a result, an increase in the stability of the connection between the carrier plate and the radiating plate can be achieved.

Furthermore, in particular webs on the of the

Mounting surface opposite back are arranged, for example, also serve for cooling. For cooling, it is particularly advantageous if the on the back

arranged webs run so that they are parallel to the

Main cooling air flow are, in natural convection so perpendicular to the later operating orientation of the

Lighting device. In other words, the back webs can be particularly preferably along the

Direction of gravity at one arranged for operation

Lighting device run. By the webs, especially back webs,

for example in the form of profile knobs in vertical

Air flow direction to achieve a chimney effect, thus can be a mechanical stiffening and at the same time

Surface enlargement to improve the heat transfer to passing air, ie convection, as well as to improve the heat dissipation can be achieved.

According to a further embodiment, the radiating plate has a web-shaped structure on the light outcoupling surface. With this, a similar effect can be achieved as through the webs of the carrier plate. Furthermore, by the web-shaped structure on the light output surface and the Abstrahlcharakteristik the lighting device can be influenced.

In accordance with a further embodiment, the carrier plate or at least the rear side of the carrier plate facing away from the mounting surface has a material or a coating which has good heat radiation. In particular, under a good heat radiation, a heat emissivity

understood, which is in a temperature range of about 50 ° C to about 100 ° C as close to 1. Such a

Heat emission can, for example, using glass as

Material of the carrier plate can be achieved. In the case of a back coating of the carrier plate, the

Coating in particular be rough, for example, formed by a radiator paint or a suitable paint or a glaze.

According to a further embodiment, the

Mounting surface opposite back of the support plate formed by a metal plate or metal foil. The

Metal plate or metal foil may have, for example, webs described above and / or a heat-radiating surface coating described above. In the case of a metal plate or metal foil forming the rear side of the carrier plate, the heat radiating

Surface coating, for example, be designed as Eloxalschicht. Furthermore, it is also possible to

to provide back metal plate or metal foil for connection of a protective conductor for the lighting device.

According to another embodiment, the

each light-emitting semiconductor chip

Subordinated wavelength conversion substance. It can, how described above, the wavelength conversion substance can be arranged in the form of a phosphor directly on the semiconductor chips. Particularly preferred is the

Wavelength conversion material but arranged in the recesses of the radiating plate. It is also possible that both directly on a semiconductor chip and on the

Inner surface of the semiconductor chip downstream

Recess each a wavelength conversion material

is formed, wherein the wavelength conversion substances may be the same or different, to a desired

To achieve radiation characteristic.

According to a further embodiment, the respective one

Wavelength conversion substance in the recesses suitable by the respectively associated light-emitting

Semiconductor chips radiated primary light into one of them

to convert different secondary light. The primary light and the secondary light may be one or more wavelengths and / or wavelength ranges in an infrared to

Ultraviolet wavelength range, in particular in a visible wavelength range. For example, the primary light may be a wavelength range of one

have ultraviolet to green wavelength range, while the secondary light may have a wavelength range from a blue to infrared wavelength range. Particularly preferably, the primary light and the

Secondary light superimposed to create a white-colored luminous impression. For this purpose, the primary light preferably give a blue-colored luminous impression and the secondary light a yellow-colored luminous impression caused by spectral

Components of secondary radiation in yellow

Wavelength range and / or spectral components in the green and red wavelength range can arise. The wavelength conversion substance may comprise one or more of the following materials: rare earth and alkaline earth metal garnets, for example YAG: Ce ³⁺ , nitrides, nitridosilicates, sions, sialones, aluminates, oxides,

Halophosphates, orthosilicates, sulfides, vanadates and

Chlorosilicates. Furthermore, the

Wavelength conversion material additionally or alternatively comprise an organic material selected from a group

which comprises perylenes, benzopyrene, coumarins, rhodamines and azo dyes. Of the

Wavelength conversion substance in the recesses may in each case comprise suitable mixtures and / or combinations of the stated materials.

The material or materials for the wavelength conversion substance may be in the form of particles which may have a size of 2 to 10 μm. According to a further embodiment is to the

Inner surfaces of the recess a diffuser material

arranged, in particular, the scattering particles have or may be formed by, for example, a

Metal oxide, such as titanium oxide or aluminum oxide such as corundum, and / or have glass particles or may be therefrom. The scattering particles can be diameter or

Have grain sizes of less than one micron up to an order of 10 microns or even up to 100 microns.

Furthermore, the diffuser material and / or the

Wavelength conversion substance in a transparent

Embedded matrix material and / or chemically be bound. The transparent matrix material can

For example, siloxanes, epoxies, acrylates,

Methyl methacrylates, imides, carbonates, olefins, styrenes, urethanes or derivatives thereof in the form of monomers,

Oligomers or polymers and also mixtures,

Have copolymers or compounds therewith. For example, the matrix material may comprise or be an epoxy resin, polymethylmethacrylate (PMMA), polystyrene, polycarbonate, polyacrylate, polyurethane or a silicone resin such as polysiloxane or mixtures thereof.

The respective diffuser material and / or the respective

Wavelength conversion material in the recesses may be distributed homogeneously in the matrix material. Furthermore, in one or more or all recesses, a combination of a plurality of said materials for the

Diffuser material and / or the wavelength conversion substance may be arranged, which mixed or in different

Layers can be present.

According to another embodiment, the

Diffuser material and / or the wavelength conversion substance formed on the inner surface layered. As a result, the diffuser material and / or the

Wavelength conversion material in particular spaced from the respective associated light-emitting semiconductor chips in the recess to be arranged. The diffuser material and / or the wavelength conversion substance may be evenly distributed over the inner surface of a recess. Alternatively, it is also possible that one

Wavelength conversion substance, for example by a

Sedimentation method or other suitable method uneven in terms of its composition and / or is applied with respect to its thickness in a recess, for example, a desired

Color luminance and color effect. According to a further embodiment, the radiation plate in at least some or all recesses on the inner surface facing the semiconductor chips one

Wavelength conversion substance on the the

Semiconductor chips each side facing a

Reflector layer having for the of

Wavelength conversion material has reflected secondary light reflecting and for that of the semiconductor chips

radiated primary light is permeable. The

Reflector layer, for example, in the form of such

said Bragg reflector in the multi-layer process

be upset.

In the case of one spaced from a semiconductor chip

arranged wavelength conversion substance at the

Inner surface of a recess can the

Wavelength conversion substance thermally separated from

Be semiconductor chips. This avoids that the so-called

Stokes conversion loss heat resulting from the conversion of the primary light of the semiconductor chip into the secondary light

arises, the semiconductor chip warms up. The

Conversion loss heat can rather be delivered via the radiating plate to the ambient air at the light output surface, whereby the wavelength conversion material and also the semiconductor chip can be kept cooler than in the case of a directly arranged on a semiconductor chip

Wavelength conversion substance. Furthermore, the offers

Wavelength conversion substance on the inner surface of the Recess over the semiconductor chip with respect to a direct chip coating larger converter layer surface, whereby the power density of the primary light in

Wavelength conversion substance is lower. This is a significantly lower aging of the

Wavelength conversion material to be expected.

Furthermore, by the diffuser material and / or the

Wavelength conversion substance on the inner surface of the recesses with a direct view of the

Lichtauskoppelfläche without additional scattering measures, the glare by the light-emitting semiconductor chips be so low that in a viewer no

unpleasant consequences.

According to a further embodiment, the carrier plate is equipped with the light-emitting semiconductor chips.

For example, during operation, the semiconductor chips can all emit the same light, in particular blue light.

Manufacturing tolerances with respect to the individual

Semiconductor chips, which result in slightly different color locations and / or wavelength ranges of the respectively emitted light, can be detected by means of a short operation of the semiconductor chips and a preferably fast,

Spectral measurement can be determined. From this, the respective compositions and thicknesses of the

Wavelength conversion materials and their respective

Distributions can be calculated on the inner surfaces of the recesses of the radiating plate, which are required that over the entire radiating plate as uniformly bright and the same color, such as white, light can be emitted. For example, at by the

Semiconductor chips radiated slightly different blue Wavelengths corresponding different materials and / or compositions of the wavelength conversion materials and / or different thicknesses of the wavelength conversion materials

be calculated. In particular, by the data of the spectral measurements, for example, automatically running, individually controlled coating processes for the

Wavelength conversion materials in the recesses of

Radiating plate are controlled so that the

Color variations of the semiconductor chips by adapted

Wavelength conversion materials can be compensated.

This makes it possible to select semiconductor chips from a larger color and brightness tolerance range and obstruct, since no complex individual color compensation must be performed chip by chip. Rather, a spectral measurement of all, for example, over one hundred, light-emitting semiconductor chips on the support, which ranges from an individual coating of the recesses of

Radiation plate can be followed in an automatic process, after which the radiation plate with the carrier

is joined together.

According to a further embodiment, the radiation plate distributed for diffuse scattering in the radiation plate

Scattering particles on. The scattering particles, which can be melted in, for example, in the production of the radiating plate, for example, a previously described

Have diffuser material. Furthermore, it is also possible that the radiating plate has a translucent, light-scattering coating on the light output surface. With particular advantage, the scattering body and / or the

Coating the highest possible degree of absorption or spreading in the temperature range from 30 ° C to 80 ° C on.

Furthermore, it is also possible that the radiation plate on the light output surface scattering structures, for example in the form of depressions or elevations, which

may be evenly or randomly distributed on the light output surface. Additionally or alternatively, it is also possible that the radiating plate on the

Lichtauskoppelfläche opposite and the carrier plate side facing a scattering coating or

Has scattering structures.

According to a particularly preferred embodiment, the lighting device is particularly preferably spatially

spaced apart, so spaced light emitting semiconductor chips on the mounting surface on which the

Radiating plate is arranged downstream of the recesses, wherein in the recesses a wavelength conversion substance

is arranged. In comparison with conventionally used expensive aluminum or copper carriers or corresponding metal core boards, good heat dissipation can preferably be achieved by a metallically conductive layer on one

Plastic layer or plate are formed, on which the semiconductor chips are electrically and simultaneously thermally connected. By the arrangement of the semiconductor chips on the carrier plate and the semiconductor chips

downstream radiating plate, the individual

Semiconductor chips in terms of their size and power as well as in terms of their radiated color grades limited requirements meet. In addition to the wavelength conversion substance in the recesses, the radiation plate preferably has scattering structures on the light emission surface and / or the light emitting surface opposite

Surface and / or in the form of embedded in the volume of scattering particles. In addition, the combination with the webs described above, in particular on the back of the support plate is particularly advantageous to a simple yet sufficient cooling effect at the same time

to achieve mechanical strength and stiffening.

According to a further embodiment, the radiation plate has a lenticular shape over at least some recesses

Surface structure on. The surface structure can

especially as a bulge, ie convex, on the

Be light emitting surface formed. It is also possible that the lenticular surface structure in the form of a recess, ie concave, as a depression in the

Lichtauskoppelfläche protrudes. Due to the lenticular surface structures, it may be possible that

Radiation behavior especially for the far field of the

To optimize lighting device as desired. It does not have to be a lenticular over all recesses and thus over all light-emitting semiconductor chips

Surface structure be present. But it may also be possible that a lenticular surface structure is arranged over each of the recesses, so that there is exactly one recess or indentation per recess. The

Lenticular surface structures can be incorporated simultaneously as described above for the recesses in producing the radiating plate, for example by a stamping or rolling process or by a casting process by which the radiating plate, for example from a

Plastic material or glass is produced. It is also possible to use the lenticular surface structures

in particular in the case of convex bulges of a transparent or translucent material in one

Rolling subsequently applied to the light output surface of the radiating plate. The material of the lenticular surface structures may be the same as for the radiating plate or another.

According to a further embodiment, the

Lighting device an electrical circuit for

Operation of the semiconductor chips of the lighting device. The electrical circuit, which may allow, for example, the operation of the lighting device with mains voltage, for example, a non netzpotentialfreies

Ballast with bridge rectifier, current limiting series capacitor and the inrush current limiting small series resistance in an electrical supply line

Have lighting device. This allows the

Support plate with the semiconductor chips and the radiating plate are made particularly filigree. Alternatively, it is also possible to use parts of the electrical circuit,

for example, the ballast in the

To integrate lighting device.

The lighting device described here can

be glare-free according to the listed features and embodiments, for example. Furthermore, the heat, for example, directly to the environment, so the room air, are delivered without additional fans and the associated noise development must be taken into account. Furthermore, the mechanical assembly can be done easily, at the same time the electrical contact and the heat dissipation and the high voltage insulation, for example, up to 4 kV, can be made possible. Further advantages, advantageous embodiments and

Further developments emerge from the following in

Compound described with the figures

Exemplary embodiments.

Show it:

Figure 1 is a schematic representation of a

Lighting device according to one embodiment, Figures 2A to 7C are schematic representations of

Lighting devices according to others

Embodiments,

Figure 8 shows schematic representations of arrangements of

Lighting devices in a room according to further embodiments and

Figure 9 is a schematic representation of an electrical

Circuit for operating a lighting device according to another embodiment. In the exemplary embodiments and figures, identical, identical or identically acting elements can each be provided with the same reference numerals. The illustrated elements and their proportions with each other are not to be regarded as true to scale, but individual elements, such as layers, components, components and areas, for better presentation and / or better understanding may be exaggerated.

FIG. 1 shows a section of a lighting device 100 according to a first exemplary embodiment. The

Lighting device 100 has a plurality of

light-emitting semiconductor chips 1, which on a

Support plate 8 are arranged. The support plate has in the embodiment shown, a plastic plate or plastic layer on which as a reflective

Mounting surface 89 is disposed a metallically conductive layer, in addition to the reflection of the of

Light emitting semiconductor chips 1 emitted primary light can also serve to electrically connect the semiconductor chips 1.

The light-emitting semiconductor chip 1 is in

Emission direction a translucent or transparent

Downstream of the radiation plate 20, which has a light output surface 29, which faces away from the semiconductor chip 1 and over which the light emitted from the semiconductor chip 1 light from the illumination device 100 can be emitted. The radiation plate 20 has the light emitting

Semiconductor chips 1 recesses 22, wherein each of the

Recesses 22 has an inner surface 28 on which a wavelength conversion substance 21 is arranged. Alternatively or additionally, the wavelength conversion substance 21 may also have a diffuser material on the inner surfaces 28 of FIG

Recesses 22 may be arranged.

The semiconductor chips 1 can, for example, emit blue light, which is partially converted by the wavelength conversion substance 22 into yellow and / or green and red secondary light, so that the illumination device 100 emits white light during operation.

The light-emitting semiconductor chips 1 radiate in

all shown an identical light from. This may mean, in particular, that the semiconductor chips 1 emit blue light, which is not exactly the same in the context of manufacturing variations, but rather of semiconductor chip too Semiconductor chip may be different. To be a homogeneous

To achieve color distribution over the light output surface 29, the semiconductor chips 1 after assembly of the

reflective mounting surface 89 of the support plate. 8

measured spectrally one after the other. According to the respective color locus of the semiconductor chips 1, the

Wavelength conversion substance 21 in each associated

Recess 22 according to its

Composition and / or its thickness are fitted in order to achieve the highest possible homogeneity over the Lichtabstrahlfläche 29 both in terms of radiated brightness and the radiated color locus.

In the exemplary embodiment shown, exactly one semiconductor chip 1 is followed by a recess 22 in each case. Alternatively, it is also possible that a plurality of semiconductor chips 1 are arranged within a recess 22. The

Semiconductor chips 1 are considered relatively small units

a large area a on the mounting surface 89 of the carrier. 8

distributed. Particularly preferably, the carrier 8 has approximately one

Semiconductor chip 1 per square centimeter on. This allows a large radiator surface and a small

Power dissipation can be achieved. The radiating plate 20 is made of a plastic material or a glass that is transparent, ie transparent, or

translucent, that is diffuse translucent. A translucent effect, for example, by scattering body within the radiating plate 20 or by scattering

Surface structures or coatings on the

Lichtabstrahlfläche 29 or the light emitting surface 29 opposite side of the radiating plate 20 can be achieved. The illumination device 100 can be designed in any desired size and can have, for example, more than 100 light-emitting semiconductor chips 1. A suitable electrical circuit for operating the lighting device 100 is shown in conjunction with FIG.

The embodiments of lighting devices shown in the following figures represent modifications and developments of those shown in FIG

Lighting device 100 is.

The illumination device 101 according to the exemplary embodiment in FIGS. 2A and 2B, which respectively show a schematic sectional view and a plan view of the light outcoupling surface 29 of the illumination device 101, has, in addition to the illumination device 100 of the exemplary embodiment in FIG. 1, the rear side 88 facing away from the semiconductor chips 1 Support plate 8 a plurality of webs 33. These serve on the one hand the stiffening of the

Support plate 8 and thus the entire lighting device 101, but are also suitable to increase the surface of the back 88 of the support plate 8 to a better

To achieve heat transfer between the support plate 8 and the surrounding air. For example, the webs 33 may be in the form of profile nubs, based on the

Arrangement of the lighting device 101 during the

Operation are preferably arranged along the air flow direction to achieve a chimney effect. Due to the convection achieved in this way, an improvement of the heat release to the passing air can be achieved. In the illustrated embodiment, the support plate 8 and the radiating plate 20 are connected to each other by means of clamping nails 31. These are formed as plastic nails, protrude through the radiating plate 20 and the support plate 8 and are clamped with arranged on the back 88 of the support plate 8 Klemmnagelkappen 32. By the

Clamping nails 31, which may also be designed as plastic rivets, and the Klemmnagelkappen 32, also known as

Counter-clamping caps can be called, the

Radiating plate 20 and the support plate 8 fixed but also releasably stapled together.

FIG. 3 shows a further exemplary embodiment of a lighting device 102. This has as so-called flip-chip semiconductor chips 1, which are arranged on a metallically conductive layer 4 of the carrier 8 and connected to this electrically conductive. This is between the back

Chip metal contact layers 2 of the semiconductor chips 1 and

Terminal regions of the metallically conductive layer 4, a connecting layer 6, for example in the form of a

Conductive adhesive or a solder layer, arranged. The

Semiconductor chips 1 are furthermore by means of a transparent potting 18 on the metallically conductive layer 4th

encapsulated, so that a touch protection against the metallically conductive layer 4 can be achieved by the potting 18.

The carrier 8 further comprises a plastic plate on which the metallically conductive layer 4 is applied, and whose rear side 88 has webs 33. The plastic plate of the support plate 8 has in the illustrated embodiment, a thickness dL of about 0.5 mm to about 2 mm, while the above arranged radiating plate 20 has a thickness d2 of about 1 mm to about 2 mm, wherein the boundaries are each included. The webs 33 on the back 88 of the support plate 8 have a height of about 0.3 mm to about 2 mm, so that by the webs 33, the lighting device 102 can be significantly stiffened and so mechanical resistance to bending and twisting can be achieved that otherwise cracks in the

Connection layer 6 could lead semiconductor chip 1 and the metallically conductive layer 4.

In addition to the power supply is the metallically conductive

Layer 4 as described in the general part of the

Heat distribution of the heat generated in the semiconductor chips 1 during operation loss, which can be transmitted over the metallically conductive layer 4 effectively and over a large area on the support plate 8. For improved radiation of the heat over the back 88 of the support plate 8 to the

Environment is applied to this a surface coating 34, for example in the form of a heart body color, which has a high heat emissivity of as close to 1 in a temperature range of 50 ° C to 100 ° C, for example, preferably at about 80 ° C. Such

Temperature can be the typical operating temperature of the

Lighting device 102 correspond.

The radiating plate 20 has, as clearly shown in Figure 3, dome-shaped recesses 22 which are spherical or elliptical and which are preferably embossed or cast. The recesses 22 continue to have one

Diameter, which is at least twice the side length of each arranged in a recess 22

Semiconductor chips 1 corresponds. The on the inner surface 28 the recess 22 arranged layer of the

Wavelength conversion substance 21 can thereby be arranged thermally separated from the respective semiconductor chip 1, whereby the advantages described above in the general part can be achieved.

Alternatively to the embodiment shown with the

Wavelength conversion substance 21 on the inner surface 28 of the recesses 22 it may also be possible, a

Wavelength conversion material applied directly to the semiconductor chip 1 and to provide the inner surfaces 28 of the recesses 22 with a further wavelength conversion material 21 and / or a diffuser material. Furthermore, the radiation plate 20 scattering particles 25 and on the Lichtabstrahlfläche 29 and the

Light emitting surface 29 remote surface scattering structures

23 and 24, by means of which the radiation plate 20 diffusely translucent and thus translucent. Furthermore, the radiation plate 20 has embedded scattering particles. By the scattering structures 23, 24 and the scattering particles 25, an improvement in the homogeneity of the radiated brightness and the emitted color impression can be achieved. Furthermore, the illumination device 102 may be obstructive to a viewer from the side of the light emitting surface 29

Glare effects are perceived. The scattering structures 23 and

24 can be formed by embossing or by casting. As an alternative to the exemplary embodiment shown, only scattering particles 25 or only scattering structures 23 and / or 24 can also be present.

FIG. 4 shows a further exemplary embodiment of a lighting device 103, which differs from the one shown in FIG Lighting device 102 of the previous

Embodiment, a support plate 8 with a

insulating plastic layer 41, on which the metallic conductive layer 4 as a reflective

Mounting surface 89 and this facing away from a metal plate or metal foil 22 are arranged. The metal plate or

Metal foil 42 and the insulating plastic layer 41 may be glued together, for example. The

Metal plate or metal foil 42 is, for example

in accordance with the applicable electrical installation regulations, connected to a protective conductor 43. This can also be achieved in addition to a shield against any existing alternating electric fields of the power grid. The metal plate or metal layer 42 further comprises on the rear side 88 of the support plate 8 forming side of a paint or anodized or other coating 34, which has a particularly high Wärmeleistungsabstrahlkoeffizienten in a wavelength range of about 10 ym, especially at slightly elevated room temperature. This can be achieved by glazing or anodization or by a radiator color, which can be designed, for example, also colored and not black. If the semiconductor chips 1 are fixed by soldering on the metallic conductive layer 4 and connected thereto, for example by means of a tin-indium solder, the insulating plastic layer 41 is designed to be resistant for a short time during the soldering for a few seconds. Alternatively is also one

Bonding by means of a heat and current conductive adhesive possible, which can also be bonded with heat support. In Figure 5, a further embodiment of a lighting device 104 is shown, in which compared to the previous embodiment, the metal plate 42, which forms the back of the support plate 8, webs 33 for

Improvement of the mechanical strength and rigidity and also to improve the heat dissipation has.

The radiating plate 20 of the lighting device 104 furthermore has lens-shaped openings 20 over the cutouts 20

Surface structures 26 on. Im shown

Embodiment, the lenticular surface structure 26 is formed as a convex elevation. Alternatively, with a corresponding thickness of the radiation plate 20, the lenticular surface structure 26, for example, as a concave

Be formed indentation. Preferably, the

Bulges 22 and each arranged above

Lenticular surface structure 26 arranged centered to each other. Furthermore, preferably also the

Semiconductor chips 1 centered in the recesses 22 arranged to these.

The lenticular surface structures 26 may

For example, in the production of the radiation plate 20 are formed by appropriate casting or embossing. Furthermore, it is also possible, the lenticular

Surface structure 26 subsequently by a corresponding method, such as a rolling process, with a comparison with the radiating plate 20 or the like

Material to form. Even if the recesses 22 and the lens-shaped surface structures 26 in the shown

Embodiment shown spherical, these can also be aspherically shaped, for example, to optimize a same color radiation in all emission directions. FIG. 6 shows a further exemplary embodiment of a lighting device 105 which is located on the

Light emitting surface 29 lens-shaped surface structures 26 has. By means of the dashed lines, the beam paths of the semiconductor chip 1 are shown in FIG

radiated primary light and of the

Wavelength conversion material 21 in the recess 22nd

produced secondary light shown.

The primary light is through the lenticular

Surface structure, while the secondary light from the wavelength conversion substance 21 almost with a

Lambert's radiation distribution is radiated, although bundled, but with a different one

Radiation characteristic than the directly emitted

Primary light. By a suitable arrangement of

Semiconductor chips on the support plate 8 and by

For example, additional scattering measures such as scattering particles, a scattering coating or scattering structures, it can be achieved that the light emitting surface 29 can detect individual points of light with the primary light, while at a location to be illuminated, a homogeneous superposition of the primary light and the secondary light is perceived.

To improve the radiation of the

Wavelength conversion substance 21 emitted secondary light is on the semiconductor chip 1 side facing the

Wavelength conversion substance 21, a reflector layer 27 which is generated for the semiconductor chip 1

Primary light is permeable and that of the

Wavelength conversion substance 21 generated secondary light is reflective. The reflector layer 27 can

be formed for example in the form of a Bragg filter.

FIGS. 7A to 7C show a further exemplary embodiment of a lighting device 106. The

schematic sectional views of Figures 7A and 7B extend along the webs 36 and 33 according to the plan view in Figure 7C. By means of the dashed lines in each case the elements not shown in the respective image plane are indicated in FIGS. 7A and 7B.

The lighting device 106 shown has both on the reflective mounting surface 89 and on the opposite rear side 88 webs 33 and 36 which are perpendicular to each other. This can be a further improvement and an increase in stiffness or

mechanical strength of the lighting device 106 can be achieved in comparison to the previous embodiments. The radiation plate 20 has grooves 30 in which the webs 36 formed on the reflective mounting surface 89 are arranged.

FIG. 8 shows exemplary embodiments of the arrangement of lighting devices in a room. The lighting devices 107 to 112 illustrated in FIG. 8 may be designed, for example, according to one or more of the aforementioned exemplary embodiments.

The illumination devices 107 and 108 are horizontal and perpendicular to or in the wall of the example shown

Room arranged. In an arrangement on the wall, the lighting devices are preferably mounted in front of the wall, that a rear ventilation is possible while at an arrangement in the wall heat dissipation can take place through the wall.

The lighting devices 109 and 110 are arranged horizontally and vertically in room surface corners, while the

Lighting devices 111 is arranged symmetrically tilted against each other on the ceiling. The

Lighting device 112 is, for example, horizontal or tilted to the horizontal, arranged hanging from the ceiling and can, for example, in a

Flow wing shape be formed.

According to the horizontal or vertical arrangement of the lighting devices 107 to 112, the webs 33 shown in the previous embodiments may be the

Carrier body 8 aligned along the direction of gravity to achieve a convection flow for cooling.

In Figure 9, an electronic circuit 200 is shown, which is suitable to the lighting devices of

to operate previous embodiments. By the electronic circuit 200, the described

Lighting devices are easily operated and controlled on a 230V AC power network with a phase conductor L, a neutral conductor N and a protective conductor SL, wherein parts of the electronic circuit 200 as

Ballast cost-effective, reliable and easy

be constructed and can have a good active power factor and high efficiency.

The electronic circuit 200 has circuit parts 91, 92 and 93, wherein the circuit part 93 by one of the vorab shown lighting devices 100 to 112 can be formed.

The circuit part 91, which is designed as a so-called switch-on, serves to adjust the electrical

Power, with the designated as ballast circuit part 92, the designated as the circuit part 93

Lighting device to be operated. The switches Sl and S2 of the circuit part 91, which is also part of a room installation or in the circuit part 92nd

can be integrated, each serve to adjust half the power of the lighting device by each half of the light-emitting semiconductor chips of the lighting device labeled with D in Figure 9 can be switched by the switches Sl and S2.

By dividing the maximum power in the two switchable by means of the switches Sl and S2 circuits can provide protection against a total failure in a

Defect can be achieved in one of the circuits. The switch S3 is used to set a small power,

for example, for a night light function.

For controlling the lighting device in the circuit part 93 by means of the switches Sl and S2 of the circuit part 1, the lighting device also has two separate circuits with a plurality of semiconductor chips connected in series. For a high power factor (cos φ) should the

Cumulative current voltage of the semiconductor chip rows in the

Magnitude of the AC effective voltage or slightly below it. For example, as shown in the embodiment of Figure 4, the lighting device is in Circuit part 93 to the protective conductor SL by means of

Protective contact Sch connected.

The executed as a ballast circuit part 92 can be separated from the circuit part 93, so the

Lighting device, in the supply of the

Lighting device or alternatively also be implemented integrated in the lighting device. Of the

Circuit part 92 has in the illustrated embodiment current limiting series capacitors Cl and C2, which have a high voltage and current pulse strength in the order C = Im / (π-f (Us-Uc)), where Im is the average current, the the semiconductor chips are applied, f the mains frequency, Us the mains peak voltage and Uc the summation flux voltage of a semiconductor chip series circuit. For example

are calculated for a 50 Hz 230 V AC mains and one lighting device with one

electrical power of 20 W with a semiconductor chip series voltage of about 200 V, the current Im to 20 W / 200 V = 0.1 A and the series capacity to about 5 yF.

The capacitor C3 in the small power circuit has to limit the operating current of the semiconductor chips to a desired fraction of the current in the over

Switches Sl and S2 switchable current branches one

corresponding fraction of the capacitance of the capacitors Cl and C2. For limiting the operating current Im in the small power circuit to 1/100 of the operating current Im, the capacitance of the capacitor C3 is as shown

Embodiment then about 50 nF.

The circuit part 92 continues to have

Switch-on limiting resistors R on, which in the Order of magnitude of about 0.03-Ueff / P with the effective voltage Ueff and the power loss P are, which in the shown

Embodiment corresponds to a resistance of about 80 ohms with a power loss of less than 1.5 W. The

Kondenstoren C4 and C5 are shown in the

Embodiment on the order of about 2 nF, while the capacitors C6 and C7 as

Electrolytic capacitors are designed with a capacity of about 1 yF to about 5 yF. Furthermore, the circuit part 92 rectifier units Bl and B2, which as

Bridge rectifier for a current of up to 2 A

are designed to be load resistant to turn-on pulses. Alternatively to the embodiment shown, the

electrical circuit 200 also only one branch of current,

For example, the switchable via the switch Sl

Current branch, exhibit. The embodiments shown in the individual

contained features and modifications can also be used individually or in other combinations

Lighting devices may be present, even if they are not explicitly shown. Furthermore, features according to the embodiments described in the general part in the embodiments may alternatively or additionally

be provided.

The invention is not limited by the description based on the embodiments of these. Rather, the invention encompasses any novel feature as well as any combination of features, including in particular any combination of features in the claims, even if this feature or that combination itself is not explicit in the

Claims or embodiments is given.

Claims

claims

1. Lighting device for room lighting, comprising

- A support plate (8) with a reflective

Mounting surface (89) on which a plurality of spaced-apart light-emitting semiconductor chips (1) is arranged,

a semiconductor chip (1) emitting the light in

Radiation direction downstream translucent or

transparent radiation plate (20) facing away from the light emitting semiconductor chip (1)

Light output surface (29),

- wherein the radiating plate (20) has a plurality of

Recesses (22), which are each arranged downstream of at least one semiconductor chip (1),

- Wherein each of the recesses (22) on a the

Semiconductor chips (1) facing the inner surface (28) of the light-emitting semiconductor chips (1) spaced from a diffuser material and / or a

Wavelength conversion substance (21).

2. Lighting device according to claim 1, wherein the

Recesses (20) are dome-shaped.

3. Lighting device according to claim 1 or 2, wherein the recesses (20) each have a diameter

having a factor greater than or equal to 2 and less than or equal to 20 greater than side lengths of

Semiconductor chips (1) is.

4. Lighting device according to one of the previous

Claims, wherein the radiating plate (20) on the

Lichtauskoppelfläche (29) over at least some Recesses (22) has a lenticular surface structure (26).

5. Lighting device according to one of the previous

Claims, wherein each one emitting light

Semiconductor chip (1) in each case a recess (22) is arranged.

6. Lighting device according to one of the previous

Claims, wherein the reflective mounting surface (89) is formed by a metallically conductive layer (4).

7. Lighting device according to claim 6, wherein the light-emitting semiconductor chips (1) through the metallically conductive layer (4) are electrically connected.

8. Lighting device according to one of the previous

Claims, wherein the carrier plate (8) has a plurality of webs (33, 36) on the mounting surface (89) and / or one of the mounting surface (89) opposite

Rear side (88).

9. Lighting device according to claim 8, wherein the

Radiating plate (20) has grooves (30) in which on the mounting side (89) existing webs (36) of the support plate (8) are arranged.

10. Lighting device according to one of the previous

Claims, wherein one of the mounting surface (89)

opposite rear side (88) of the carrier plate (8) by a metal plate or metal foil (42) is formed.

11. Lighting device according to one of the previous

Claims, wherein one of the mounting surface (89)

opposite rear side (88) of the carrier plate (8) has a heat-radiating coating (34).

12. Lighting device according to one of the previous

Claims, wherein the radiation plate (20) distributed for diffuse scattering in the radiation plate (20)

Scattering particles (25) and / or on one of

Lichtauskoppelfläche (29) opposite back scattering structures (23) and / or on the

Light output surface (29) has a translucent coating and / or scattering structures (24).

13. Lighting device according to one of the previous

Claims, wherein the radiation plate (20) in each of the recesses (22) on the inner surface (28) facing the semiconductor chips (1) has a

Wavelength conversion substance (21), which converts the light emitted by the semiconductor chips (1) emitted light into converted light, and wherein on the semiconductor chips (1) respectively facing side of the

Wellenlängenkonversionsstoffs (21) one each

Reflector layer (27) is arranged, which is reflective for the converted light and transparent to the light emitted by the semiconductor chips (1) light.

14. Lighting device according to one of the preceding

Claims, wherein the radiating plate (20) by means of

Clamping nails (31) with the support plate (8) is connected.