DE102015101573A1 - Conversion element and optoelectronic component - Google Patents

Abstract

The invention relates to a conversion element which can be arranged on a pixelated radiation-emitting semiconductor chip. The conversion element has a carrier layer, a conversion layer and an intermediate layer arranged between the carrier layer and the conversion layer. The carrier layer has a radiation-transmissive carrier material. The conversion layer has a conversion material for radiation conversion. The intermediate layer comprises an intermediate layer material having a refractive index which is smaller than a refractive index of the carrier material and a refractive index of the conversion material. The invention further relates to an optoelectronic component having a pixelated radiation-emitting semiconductor chip and a conversion element, and to a method for producing a conversion element.

Description

The invention relates to a conversion element which can be arranged on a pixelated radiation-emitting semiconductor chip. The invention further relates to an optoelectronic component having a pixelated radiation-emitting semiconductor chip and a conversion element, and to a method for producing a conversion element.

Conventional headlights in the automotive sector are rigid units of lighting, optics and body, with which only a central area in front of a vehicle can be illuminated. The focus of recent developments is the targeted control of the light distribution. Examples include the so-called cornering light or camera-based systems, with which an adjustment of the light distribution is made possible to the driving situation. This includes, for example, dimming the left side of the high beam for oncoming traffic, whereas the right side is not changed for optimal illumination. Such systems are also referred to as Adaptive Frontlighting Systems (AFS).

An adaptive lighting system can be realized with the aid of individually controllable light-emitting diodes or LED light sources (Light Emitting Diode). Another, currently developed approach is the use of a radiation-emitting LED chip with a large number of individually controllable radiation-emitting regions (pixels). Such a pixelated semiconductor chip may have a semiconductor surface for emitting radiation, which is structured in smaller controllable units. A system with such a semiconductor chip is also referred to as a μAFS system.

In order to generate white light, a conversion layer for radiation conversion on the pixelated semiconductor chip is additionally used. In such an optoelectronic component, for example, the semiconductor chip for generating a blue light radiation and the conversion layer for partially converting the blue into a yellow light radiation may be formed. A conversion material of the conversion layer may comprise a matrix material and phosphor particles.

A requirement in the operation of a pixelized semiconductor chip provided with a conversion layer is to avoid as far as possible an optical crosstalk to the region of non-luminous pixels, that is to say luminization in the region of non-driven pixels caused by luminous pixels. This serves to achieve a legally prescribed high contrast between light and shadow areas. Fulfilling this requirement is hampered by effects such as undirected light output from a conversion layer and scattering of phosphor particles.

One measure for reducing crosstalk is to form a conversion layer with a small thickness. The flatter the layer, the lower the possibility that a light radiation generated in a pixel area reaches an adjacent pixel area. This can be realized by applying the conversion layer directly to a semiconductor chip. The coating can take place at wafer level, ie in a manufacturing state in which semiconductor chips are still present in a composite, or in the mounted state of a semiconductor chip in a housing. This can cause problems such as yield losses and contamination of the housing.

The object of the present invention is to provide an improved solution for the conversion of radiation of a pixelated radiation-emitting semiconductor chip.

This object is solved by the features of the independent claims. Further advantageous embodiments of the invention are specified in the dependent claims.

According to one aspect of the invention, a conversion element is proposed, which can be arranged on a pixelated radiation-emitting semiconductor chip. The conversion element has a carrier layer, a conversion layer and an intermediate layer arranged between the carrier layer and the conversion layer. The carrier layer has a radiation-transmissive carrier material. The conversion layer has a conversion material for radiation conversion. The intermediate layer comprises an intermediate layer material having a refractive index which is smaller than a refractive index of the carrier material and a refractive index of the conversion material.

The conversion element can be used on a pixelated radiation-emitting semiconductor chip. Such a semiconductor chip, which may be, for example, a light-emitting diode chip, may have a plurality of individually controllable radiation-emitting regions (pixels). The pixels of the semiconductor chip may be arranged in a regular grid.

The conversion element is a component that can be manufactured separately from a semiconductor chip. In the context of the production of an optoelectronic component, the separately manufactured conversion element can be arranged on the semiconductor chip. at the optoelectronic component produced in this way, the conversion layer may be opposite to the semiconductor chip and facing it. The carrier layer may be present in the region of a side of the conversion element facing away from the semiconductor chip.

The separate production makes it possible to avoid contamination, for example, a housing provided for receiving the semiconductor chip or optoelectronic component. Also yield losses can be avoided. For this purpose, the conversion properties of the separately manufactured conversion element can be determined with the aid of a measurement, and based on this, a likewise measured and suitable semiconductor chip can be selected. If necessary, (only) the conversion element can be sorted out, which is more cost-effective than sorting out a semiconductor chip which is incorrectly coated in a direct manner with a conversion layer.

The separate production also offers the possibility to provide configurations for the conversion element, which can not or hardly implement in a direct coating of a semiconductor chip. For example, during the production of the conversion element, processing may also be carried out at a high temperature, which may result in impairment of semiconductor material of the chip in the case of a direct coating of a semiconductor chip.

The carrier layer of the conversion element can provide a high mechanical stability, so that the conversion element is cantilevered. This allows easy handling of the conversion element, for example when arranging the conversion element on a semiconductor chip. Even during production of the conversion element, the carrier layer can provide sufficient mechanical stability. Furthermore, the carrier layer can serve as a protective layer for the other layers of the conversion element, as well as in the associated optoelectronic component for the semiconductor chip.

In operation of the optoelectronic component, which has the conversion element and the pixelated radiation-emitting semiconductor chip on which the conversion element is arranged such that the conversion layer faces the semiconductor chip, the semiconductor chip or at least one pixel of the semiconductor chip can generate radiation (primary radiation). This can be at least partially converted into a conversion radiation (secondary radiation) with the aid of conversion material of the conversion layer of the conversion element present in this area. After passing through the intermediate layer and the carrier layer of the conversion element, radiation which may comprise converted and non-converted radiation fractions can be emitted by the conversion element.

Since the refractive index of the radiation-transmissive interlayer material of the intermediate layer is smaller than the refractive indices of the carrier material of the carrier layer and the conversion material of the conversion layer, it can be achieved that total reflection of radiation predominantly occurs in the region of a side of the conversion layer facing away from the semiconductor chip. As a result, a total reflection of radiation in the region of a side of the carrier layer facing away from the semiconductor chip can be substantially smaller or negligibly small. The intermediate layer can serve here as an optical isolation layer.

This results in that a lateral propagation of radiation in the carrier layer and thus a radiation conductor function of the carrier layer can be kept small. As a result, it is possible to achieve that radiation emission during operation of the optoelectronic component is essentially limited to the region of the at least one driven pixel, and optical crosstalk to regions of unselected pixels is suppressed with high reliability. The optoelectronic component equipped with the conversion element can therefore be characterized by a low crosstalk and a high contrast between radiation-emitting and non-radiation-emitting regions.

In the following, further possible details and embodiments are described in more detail.

The refractive index property of the interlayer material, as well as the following values for refractive indices, can refer to the spectral range of visible light, ie the range with wavelengths of about 380 nm to 780 nm.

It is possible that lateral radiation propagation occurs in the intermediate layer and in the conversion layer of the conversion element. The configuration of the conversion element with the mechanically stabilizing carrier layer in this context offers the possibility of forming the intermediate layer and the conversion layer with small layer thicknesses. In this way, the lateral radiation propagation in these layers can be reliably attenuated with sufficient scattering, thereby further promoting the suppression of crosstalk. As will be explained in more detail below, can for the intermediate layer and the conversion layer can be layer thicknesses in the single-digit or low two-digit micrometer range.

The carrier layer material of the carrier layer may have a refractive index greater than 1.4. Also, the conversion material of the conversion layer may have a refractive index greater than 1.4. Examples of possible materials for the support and conversion layers which may have such refractive indices are given below.

Cross-talk can be better achieved the smaller the refractive index of the interlayer interlayer radiation-transmitting material is to the refractive indices of the substrate and the conversion material, or in other words, the closer the refractive index of the interlayer material is to the refractive index of air (approximately 1.0) , In this sense, according to another embodiment, it is provided that the refractive index of the interlayer material is less than 1.2. The refractive index may in particular be less than 1.1.

In another embodiment, the radiation-transmissive interlayer material is an airgel material. Such a material can have a refractive index close to the refractive index of air or close to 1.0, so that the suppression of crosstalk can reliably be realized. This property results from the high porosity of the airgel material, which have a lattice or pore structure with a small solids content and therefore can consist essentially of air or vacuum. The solids content may be based on, for example, a metal oxide such as silicon, titanium, zirconium or alumina.

An airgel material also has a low specific gravity and a low thermal conductivity. Also, the latter property may prove to be favorable for the equipped with the conversion element optoelectronic device. In this case, the intermediate layer having an airgel material can bring about thermal insulation, as a result of which a thermal influence between pixel areas in the radiation mode can be suppressed.

With a radiation conversion not only a conversion radiation, but also a heat energy (conversion heat) is generated by means of a conversion material. The conversion properties of a conversion material, and thus the color location of a radiation comprising converted and non-converted radiation components, can be dependent on the respective prevailing temperature. The configuration of the intermediate layer of an airgel material makes it possible that in the radiation mode, an amount of heat generated in the region of a pixel is substantially not distributed to adjacent pixel regions, but instead can be dissipated via the semiconductor chip of the associated optoelectronic component. As a result, inhomogeneities due to temperature differences can be avoided.

In order to achieve that a radiation coming from the conversion layer does not tunnel through the intermediate layer in the radiation mode of the optoelectronic component, and as a result the total reflection can essentially occur in the region of the side of the conversion layer facing away from the semiconductor chip of the component, the intermediate layer can have a layer thickness of at least 1 μm , This thickness may correspond to at least two wavelengths of the radiation.

In order to avoid through-tunneling with a high degree of reliability, it is provided according to a further embodiment that the intermediate layer has a thickness in a range from 2 μm to 5 μm. Such a thickness also offers the possibility of reliably suppressing lateral radiation propagation in the intermediate layer. This is for example advantageous in view of the above-mentioned embodiment of the intermediate layer of an airgel material. Here, the high porosity of the airgel material can be associated with a high inherent scattering.

In a further embodiment, the radiation-permeable carrier material of the carrier layer is a glass material. For example, the use of quartz glass is possible. Such a material may have a relatively small refractive index in the range of just above 1.4, which makes it possible to suppress surface reflections (Fresnel reflections) on the carrier layer. This can further promote the prevention of crosstalk. Also, the conversion element can be produced inexpensively.

The carrier layer may, for example, have a thickness in a range of 100 μm to 200 μm. As a result, the carrier layer can have a high stability. However, it is also possible to have a smaller layer thickness below 100 μm, for example in the range of 50 μm.

With a thickness of the carrier layer below 100 μm, an embodiment of the carrier layer made of a carrier material, such as, for example, sapphire, may optionally be considered.

The optoelectronic component equipped with the conversion element can, as indicated above, be distinguished by a high contrast between radiation-emitting and non-radiation-emitting regions. Due to this property, the optoelectronic component can be used, for example, in a headlight of an adaptive headlight system. In this case, for example, the pixelated semiconductor chip for generating a primary blue light radiation and the conversion element or its conversion layer for partially converting the blue into a secondary yellow light radiation can be formed. It is also possible that the conversion layer in the radiation mode several secondary light radiation of different spectral ranges, for example, a yellow or yellow-green and a red light radiation, provides. This may possibly be accompanied by improved color rendering. The different colored (primary and secondary) radiation parts can be superimposed to a white light radiation.

The conversion material may comprise phosphor particles and a base or matrix material for fixing the phosphor particles. The phosphor particles may, for example, have a size in the range of 10 μm to 15 μm. This makes it possible to achieve high efficiency. However, smaller particle sizes are also possible, for example in the range of 5 μm. Depending on the size of the phosphor particles, the conversion layer may, for example, have a layer thickness in the range from 30 μm to 50 μm or else a smaller layer thickness. As a result, lateral radiation propagation in the conversion layer can be reliably damped.

Phosphor particles for producing a yellow or green light radiation can be realized, for example, from a material from the garnet family. These include, for example, with cerium-doped yttrium-aluminum garnet or with gallium or lutetium modified variants. For phosphor particles for generating a red light radiation, for example, materials from the family of nitrides or silicon oxynitrides may be considered.

Optionally, the conversion material may additionally comprise scattering particles. This makes it possible to further promote the suppression of crosstalk.

The matrix material may be, for example, a silicone material. Such a material may be characterized by a high radiation stability with respect to a primary blue light radiation.

The separate production of the conversion element alternatively offers the possibility of providing for the conversion material processed at a high temperature matrix material. For example, a glass material or a ceramic binder are possible. Such materials may have higher temperature resistance compared to silicone.

Moreover, it is possible due to the separate production of the conversion element that the conversion material has only one or more phosphors, and no matrix material. In this embodiment, the conversion material may be a ceramic-compacted phosphor. In this way, the conversion layer can be realized with a small layer thickness which is smaller than the above-mentioned thickness (30 .mu.m to 50 .mu.m).

In addition to the carrier layer, the intermediate layer and the conversion layer, the conversion element can have further layers. An example is a protective layer disposed between the intermediate layer and the conversion layer. This can be considered, for example, in an embodiment of the intermediate layer of an airgel material, in order to prevent penetration of matrix material of the conversion material into the pore structure of the airgel material in the context of production of the conversion element.

In a further embodiment, the conversion element has at least one antireflection coating. Such an antireflection layer may be realized in the form of a dielectric layer stack. One or more antireflection layers may be arranged, for example, on a side of the carrier layer facing away from the intermediate layer, between the carrier layer and the intermediate layer and / or between the intermediate layer and the conversion layer. With the aid of an antireflection coating, a radiation reflection (Fresnel reflection) at a surface or boundary surface can be suppressed, which can also prove to be advantageous for suppressing crosstalk.

In a further embodiment, the intermediate layer additionally has a limiting structure for limiting a lateral radiation propagation. In this way, the suppression of crosstalk can be further promoted. The confinement structure may comprise a radiation absorbing or reflecting material which differs from the intermediate layer material of the intermediate layer which is explained above and which has the refractive index property. When using a reflective material, high efficiency can be provided. An example of an absorbent material is a Metal with a low reflectance, such as chromium. With respect to a reflective material, for example, a metal such as aluminum or a matrix or silicone material filled with reflective particles or white pigments may be considered.

The boundary structure of the intermediate layer may have a thickness corresponding to the intermediate layer, or may also have a smaller thickness. In the first variant, the boundary structure may be formed of a reflective material. In the second variant, the limiting structure may be formed of an absorbent material, and relatively flat. Furthermore, the delimiting structure can have at least one structural element, for example an elongated or web-shaped structural element.

In a further embodiment, the boundary structure of the intermediate layer has a plurality of separate recesses. For this purpose, the boundary structure in the form of a grid having a plurality of web-shaped and partially crossing structural elements can be realized. In the recesses may be included the refractive index property sufficient intermediate layer material. This structure can be matched to the pixelated configuration of the semiconductor chip of the optoelectronic component, that is, to the arrangement of the pixels of the semiconductor chip. By way of example, one or more pixels of the semiconductor chip can each be assigned to the recesses of the delimiting structure.

The conversion layer may also be configured to allow optical confinement. In this sense, according to a further embodiment, the conversion layer has a delimiting structure for limiting a lateral radiation propagation. Also in this way the suppression of crosstalk can be further promoted. The limiting structure can have a radiation-absorbing or reflective material which differs from the conversion material of the conversion layer used for the radiation conversion. By using a reflective material, high efficiency can be achieved.

The boundary structure of the conversion layer may be formed of the same materials as mentioned above for the boundary structure of the intermediate layer. Furthermore, the delimiting structure may have a thickness corresponding to the conversion layer or a smaller thickness. In the first variant, the boundary structure may be formed of a reflective material. In the second variant, the limiting structure may be formed of an absorbent material, and relatively flat. Furthermore, the delimiting structure can have at least one structural element, for example an elongated or web-shaped structural element.

In a corresponding manner, the limiting structure of the conversion layer can be formed with a plurality of separate recesses. For this purpose, the boundary structure in the form of a grid having a plurality of web-shaped and partially crossing structural elements can be realized. The recesses may contain conversion material for radiation conversion. This structure can be matched to the pixelated configuration of the semiconductor chip of the optoelectronic component, that is, to the arrangement of the pixels of the semiconductor chip. By way of example, one or more pixels of the semiconductor chip can each be assigned to the recesses of the delimiting structure.

The conversion element or the associated optoelectronic component are not limited to use in a headlight. A possible example of an alternative application is a display device with the aid of which, for example, information or even advertising messages can be displayed.

For such or other applications, the optoelectronic component may optionally be designed such that a different light radiation from white can be generated. This can be made possible by a suitable embodiment of the conversion element or of the conversion material. In this case, it may also be considered that with the aid of the conversion material, the primary light radiation of the semiconductor chip is substantially completely converted into at least one secondary light radiation.

In this context, an embodiment is also conceivable in which the optoelectronic component has pixel regions for emitting light radiation in different colors. For this purpose, the conversion material of the conversion layer of the conversion element may be formed in different areas for generating different conversion radiations. In these areas, the conversion material may comprise the same matrix material, for example silicone, and different phosphor particles. The refractive index of the conversion material which is varied in some regions in this embodiment may be essentially uniform and, if appropriate, essentially predetermined by the matrix material. The conversion layer may further comprise additional regions of non-converting material in which no radiation conversion occurs, and in which the primary, for example, blue, Light radiation of the semiconductor chip can pass through the conversion layer. Such areas may comprise the matrix material without phosphor particles and possibly additionally scattering particles.

With respect to the above-described configuration, it is possible that the conversion layer of the conversion element further has a limiting structure for limiting lateral radiation propagation. Here, the limiting structure may have a plurality of separate recesses for receiving conversion material and non-converting material. As indicated above, this can be achieved, for example, by a lattice-shaped configuration of the delimiting structure with partially crossing structural elements. The limiting structure may also have a thickness corresponding to the conversion layer in order to spatially separate these materials. It is also conceivable to form the delimiting structure in such a way that the delimiting structure only partially ensures a limitation of the lateral radiation propagation and is otherwise radiation-permeable. For this purpose, the limiting structure may comprise both a radiation-absorbing or reflective material and a transparent material. In this way, for example, pixel regions can be provided which are subdivided into subpixels for producing differently colored light radiation, wherein with respect to the conversion layer only the pixel regions are optically separated and within the pixel regions a radiation propagation is possible.

For the aforementioned embodiments, which may be considered, for example, with regard to an application in a display device, it is also possible to use a conversion material which comprises a matrix material and phosphor particles with a size in the nanometer range, so-called quantum dots.

According to a further aspect of the invention, an optoelectronic component is proposed. The optoelectronic component has a pixelated radiation-emitting semiconductor chip and a conversion element. The conversion element has the structure described above or a construction according to one or more of the embodiments described above. The conversion element is arranged on the semiconductor chip. In this case, the conversion layer of the conversion element faces the semiconductor chip.

The configuration of the conversion element with the intermediate layer offers the possibility that in the radiation mode of the optoelectronic component a total reflection of radiation predominantly occurs in the region of a side of the conversion layer facing away from the semiconductor chip. In this way, optical crosstalk in the radiation mode to areas of non-driven pixels can be prevented.

In the case of the radiation-emitting semiconductor chip, the pixels can have lateral dimensions in the range of, for example, 100 μm. The semiconductor chip as well as the conversion element and the component may have lateral dimensions, for example in the millimeter or centimeter range.

The conversion element can be fastened to the semiconductor chip via a layer of a radiation-permeable connection means. The bonding agent may be, for example, a silicone adhesive or a glass solder.

For further possible embodiments, features and details, reference is made to the above description. In addition to details of the conversion element, this also applies to details already mentioned above regarding the semiconductor chip and the optoelectronic component. For example, one possible application of the component is in a headlight of an adaptive headlight system. The semiconductor chip can be designed, for example, in the form of a light-emitting diode chip for generating a primary blue light radiation. For example, in the conversion element, the intermediate layer may comprise an airgel material, and for example the intermediate layer and / or the conversion layer may additionally have a delimiting structure for limiting a lateral radiation propagation, wherein such a structure may be matched to the pixelated configuration of the semiconductor chip , The above-mentioned details can also be used for the procedure explained below.

According to a further aspect of the invention, a method for producing a conversion element is proposed. The conversion element having the structure described above or a structure according to one or more of the embodiments described above can be arranged on a pixelated radiation-emitting semiconductor chip. The method comprises providing a carrier layer, wherein the carrier layer comprises a radiation-transmissive carrier material. It is further provided to form an intermediate layer on the carrier layer, wherein the intermediate layer comprises an intermediate layer material. The method further comprises forming a conversion layer on the intermediate layer, wherein the conversion layer comprises a conversion material for radiation conversion. The interlayer material has a refractive index that is less than one Refractive index of the carrier material and a refractive index of the conversion material.

The construction of the conversion element with the intermediate layer offers the possibility of realizing an optoelectronic component which can be operated such that an optical crosstalk is largely suppressed.

The formulation used above, that a layer is formed on another layer, comprises both an embodiment in which these layers are formed directly adjacent to one another, as well as an embodiment in which a layer is formed on a layer which has been previously coated with (at least) another layer was provided. The further layer can thus be located between these layers, ie between the carrier layer and the intermediate layer or between the intermediate layer and the conversion layer. In this context, the following embodiments may also be considered.

In one possible embodiment, a protective layer and / or an antireflection layer are formed on the intermediate layer before the conversion layer is formed on the thus coated intermediate layer. A further embodiment comprises forming an antireflection layer on the carrier layer before the intermediate layer is formed on the carrier layer coated in this way.

As stated above, an airgel material may be considered for the intermediate layer material of the intermediate layer. Therefore, a common airgel manufacturing process can be performed to form the intermediate layer. Here, a gelatinous starting material can be formed on the carrier layer from a liquid, and this can be converted into the airgel material by drying. A process that can be used in this sense is a sol-gel process. Optionally, the intermediate layer comprising the airgel material may subsequently be polished and / or provided with a protective layer.

Due to the separate production of the conversion element, a number of different embodiments may be considered for the formation of the conversion layer on the intermediate layer. Forming the conversion layer may include applying conversion material, for example, by means of a printing process. Possible, for example, screen printing or stencil printing, or else an application followed by stripping by means of a doctor blade. In these processes, a conversion material comprising a matrix material, for example silicone, phosphor particles and optionally scattering particles, including a solvent, can be applied and subsequently dried.

Such a conversion material mixed with a solvent can also be applied by means of a spraying process and then dried.

Another variant of the method is an electrophoretic deposition of phosphor particles and possibly scattering particles, followed by a subsequent application of a matrix material such as silicone for fixing the particles.

Furthermore, it can be considered to use a glass material or a ceramic binder as the matrix material. The first method variant may comprise applying a molten glass material mixed with phosphor particles and possibly scattering particles, which material may subsequently harden by cooling. In the second variant, a mixture of phosphor particles, the binder and optionally further additives can be applied and subsequently converted into a ceramic conversion material in a process carried out at a high temperature (sintering process).

A further embodiment for forming the conversion layer comprises depositing at least one phosphor by means of a sputtering method and subsequent ceramic compacting of the phosphor in a sintering process carried out at a high temperature. The ceramic conversion material formed thereby can have only the compacted phosphor and no matrix material.

The separate production of the conversion element also makes it possible to produce the conversion element in a simple manner and without yield losses with a delimiting structure for limiting a lateral radiation propagation. As explained above, the intermediate layer and / or the conversion layer may be formed with such a limiting structure. In this connection, the following embodiments of the method for the formation of the intermediate layer or conversion layer may be considered.

One possible embodiment includes forming the confinement structure, then applying interlayer material (in the fabrication of the interlayer) or conversion material (in the fabrication of the conversion layer), and optionally subsequent removal of excess interlayer or conversion material for planarization. The Forming the boundary structure previously may include forming a continuous layer of material of the boundary structure and lithographically patterning that layer. The Zwischenschichtbzw. Conversion material can be applied with a thickness corresponding to the boundary structure or with a greater thickness. In the first variant, the interlayer or conversion material can adjoin the limiting structure only laterally. In the second variant, the interlayer or conversion material can additionally cover the boundary structure on one side.

Another possible embodiment comprises forming a (first) continuous layer of the interlayer. Conversion material, forming openings in the form of the limiting structure to be generated in this layer, and introducing a material of the limiting structure in the openings.

It is possible to produce a plurality of conversion elements in the layer composite with the aid of the method. In this case, the carrier layer is provided with lateral dimensions which are matched to the conversion elements to be manufactured. The subsequent layers are also formed with corresponding lateral dimensions. At the end of the process, the layer composite can be separated into separate conversion elements, for example by sawing.

To produce an optoelectronic component, a conversion element can be produced separately as described above and then arranged on a pixelated radiation-emitting semiconductor chip. For fixing the conversion element on the semiconductor chip, a connecting material such as a silicone adhesive or a low-melting glass solder can be used.

A precise placement of the conversion element on the semiconductor chip can be realized by means of image recognition. Furthermore, it may possibly be considered to form the conversion element and / or the semiconductor chip with alignment marks for precise adjustment.

It may be considered, based on measurements, to select a pair of conversion element and a semiconductor chip suitable for given properties, for example a given color location of the producible radiation, before these components are connected to one another as indicated above.

The advantageous embodiments and further developments of the invention explained above and / or reproduced in the subclaims can be used individually or else in any desired combination with one another-except, for example, in cases of clear dependencies or incompatible alternatives.

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 description of exemplary embodiments, which are explained in more detail in connection with the schematic drawings. Show it:

1 an optoelectronic component having a pixelated radiation-emitting semiconductor chip and a conversion element arranged thereon, the conversion element having a carrier layer, a conversion layer and an intermediate layer arranged therebetween;

2 a further representation of the conversion element, wherein additionally by means of beam paths, a radiation propagation is illustrated in the conversion element;

3 a representation of a layer stack comprising only the carrier layer and the conversion layer, wherein radiation propagation is likewise additionally illustrated by means of ray paths;

4 to 6 a process flow for the production of conversion elements;

7 a further conversion element, which additionally has a protective layer;

8th another conversion element, which additionally has antireflection layers;

9 a further conversion element, wherein the intermediate layer additionally has a limiting structure;

10 and 11 Further conversion elements, in which the conversion layer additionally has a limiting structure.

On the basis of the following figures, possible embodiments of an optoelectronic component with a pixelated radiation-emitting semiconductor chip and a conversion element and an associated production method will be described. In this case, known processes can be carried out from semiconductor technology and from the production of optoelectronic components, and conventional materials can be used in these areas, so that this is only partially discussed. In the same way, in addition to processes shown and described, further processes can be carried out, and a design can be provided for a component in which, in addition to components shown and described, further components and structures are present. It is further noted that the figures are merely schematic in nature and are not to scale. In this sense, components and structures shown in the figures may be exaggerated or oversized for clarity.

1 shows an optoelectronic device 100 in a schematic side sectional view. The optoelectronic component 100 has a pixelated radiation-emitting semiconductor chip 120 and one on the semiconductor chip 120 arranged conversion element 110 for radiation conversion. The component 100 can be used, for example, in a headlight, not shown, an adaptive headlight system or μAFS system.

The radiation-emitting semiconductor chip 120 is for example an LED chip. The semiconductor chip 120 has a plurality of individually controllable pixels on a front side 121 on, with the help of a primary light radiation can be generated. As in 1 is indicated, the semiconductor chip 120 For this purpose, for example, have a planar semiconductor body, which in the pixels 121 is divided. The pixels 121 may have lateral dimensions in the range of 100μm. The with the help of pixels 121 producible and from the pixels 121 emissive primary radiation can be, for example, a blue light radiation. The pixels 121 can be arranged in the form of a regular grid. The semiconductor chip 120 and thus the conversion element 110 and the whole component 100 may have lateral dimensions, for example in the millimeter or centimeter range.

It should be noted that the semiconductor chip 120 in cross-section a much larger number of pixels 121 as the in 1 shown three pixels 121 can have. 1 can in this sense as a detail of the semiconductor chip 120 and the optoelectronic device 100 be understood. This can apply in a corresponding manner for subsequent figures.

The conversion element 110 has a carrier layer 111 , a conversion layer 113 for radiation conversion and an interposed intermediate layer 112 on. It is possible that these layers 111 . 112 . 113 , as in 1 is indicated, immediately adjacent. In the optoelectronic component 100 is the conversion element 110 such on the semiconductor chip 120 arranged that the conversion layer 113 the front of the semiconductor chip 120 opposite. In this state, the carrier layer is located 111 in the region of the semiconductor chip 120 opposite side of the conversion element 110 , An attachment of the conversion element 110 on the semiconductor chip 120 is about one between these components 110 . 120 arranged radiation-transparent compound layer 130 realized. The connection layer 130 For example, it may include a silicone adhesive or a low melting glass solder.

As will be explained in more detail below, the semiconductor chip 120 and the conversion element 110 made separately from each other, and then joined together. This makes it possible to manufacture the conversion element 110 without affecting the semiconductor chip 120 make.

The carrier layer 111 of the externally produced conversion element 110 is formed of a radiation-transparent carrier material, for example a cost-effective glass material or quartz glass. The transparent carrier layer 111 , which may have a thickness in a range of 100μm to 200μm, confers the conversion element 110 a high mechanical stability. This facilitates easy handling both in the production of the conversion element 110 as well as when arranging the conversion element 110 on the semiconductor chip 120 , Due to the carrier layer 111 can the conversion element 110 be self-supporting. In addition, the carrier layer 111 serve as a protective layer, eliminating the other layers 112 . 113 the conversion element 110 and the semiconductor chip 120 can be protected from external influences.

The conversion layer 113 the conversion element 110 has a conversion material for radiation conversion. The conversion material includes, as in 1 is indicated, a radiation-permeable base or matrix material 115 in which a powdered and the radiation conversion causing phosphor in the form of phosphor particles 116 is embedded. The matrix material 115 For example, it may be a silicone material. The production of the conversion element 110 separately from the semiconductor chip 120 offers the possibility of another matrix material 115 such as using a glass material.

The phosphor particles 116 can have a particle size or a diameter in a range of 10 .mu.m to 15 .mu.m, whereby a high efficiency can be achieved. Alternatively, other particle sizes, for example in the range of 5 microns, may be present. The conversion or phosphor layer 113 may have a layer thickness in the range of 30μm to 50μm or a smaller layer thickness. The layer thickness may vary according to the size of the phosphor particles 116 judge.

With regard to an application in a headlight is the optoelectronic device 100 designed to produce a white light radiation. This can be realized by using the phosphor layer 113 or the phosphor particles 116 that of the semiconductor chip 120 generated blue primary radiation is partially converted into a yellow conversion radiation (secondary radiation). Here, all the phosphor particles 116 be made of the same phosphor material. Also possible is an embodiment of the phosphor layer 113 with phosphor particles 116 of different phosphor materials for producing differently colored conversion radiations, for example a yellow-green and a red light radiation. In this way, an improved color reproduction can be achieved. By superimposing the primary and secondary radiation parts, the white light radiation can be generated.

For a headlight, a color temperature of white radiation in the range of 5000K to 6000k is typically sought. This can be done with the help of phosphor particles 116 made of a material from the garnet family. These include, for example, with cerium-doped yttrium-aluminum garnet or with gallium or lutetium modified variants. Phosphor particles 116 such materials can produce a yellow or yellow-green conversion radiation. As stated above, not only phosphor particles 116 for generating a yellow or yellow-green conversion radiation, but in addition also phosphor particles 116 For example, the latter can be formed from materials of the family of nitrides or silicon oxynitrides.

The intermediate layer 112 the conversion element 110 has a radiation-transmissive interlayer material whose refractive index is smaller or substantially smaller than the refractive indices of the carrier material of the carrier layer 111 and the conversion material of the conversion layer 113 , In this way, an optical crosstalk during operation of the optoelectronic device 100 be suppressed. With regard to the above-mentioned embodiments, both the carrier layer material of the carrier layer 110 as well as the conversion material of the conversion layer 113 have a refractive index greater than 1.4. In contrast, the interlayer material has a smaller refractive index which is less than 1.2, in particular less than 1.1.

For this purpose, an embodiment is provided, in which the intermediate layer material of the intermediate layer 112 an airgel material. This material may have a refractive index which approximates the refractive index of air. The low refractive index results from the high porosity of the airgel material, which has a pore structure (not shown) with a relatively small solids content, and thus can consist essentially of air or vacuum. For the solids content of the airgel material of the intermediate layer 112 For example, an embodiment based on a metal oxide such as silica may be considered. Alternatively, titanium, zirconium or aluminum oxide can be used.

In the following, reference is made to an operating mode of the optoelectronic component 100 and on that with the help of the interlayer 112 the conversion element 110 achieved the prevention of crosstalk. During operation of the optoelectronic component 100 can the semiconductor chip 120 or at least one driven pixel 121 of the semiconductor chip 120 generate the primary blue light radiation and in the direction of the conversion element 110 submit. The primary radiation can be in the conversion layer 113 the conversion element 110 partially converted, so as indicated above in a yellow or yellow-green light radiation and optionally in addition to a red light radiation. These light radiations or parts thereof can be the intermediate layer 112 and the carrier layer 111 go through and overlap to a white light radiation. This light radiation can via the semiconductor chip 120 opposite side of the conversion element 110 be delivered.

The low refractive index of the airgel material compared to the refractive indices of the conversion material and of the carrier material leads to a total reflection of radiation, ie of converted and unconverted radiation components, predominantly already at the semiconductor chip 120 opposite side of the conversion layer 113 or at the interface between the conversion layer 113 and the intermediate layer 112 occurs. In contrast occurs at the semiconductor chip 120 opposite side of the carrier layer 110 or at the interface between the carrier layer 110 and air substantially no total reflection of radiation, so that the radiation is the carrier layer 111 can go through as unhindered as possible.

To illustrate this condition is in 2 the conversion element 110 including selected radiation paths in the conversion element 110 spreading radiation 200 shown. This illustration refers to the case that the in 1 left-sided pixels 121 of the semiconductor chip 120 is controlled. The radiation 200 includes converted and non-converted radiation parts as indicated above. The radiation 200 can, as in 2 is shown at different angles to the interface between the conversion layer 113 and the intermediate layer 112 incident. This is because the phosphor particles 116 the conversion radiation isotropic emit, and that the primary radiation and the conversion radiation of a scattering in the conversion layer 113 may be subject.

Provided that on the interface between the conversion layer 113 and the intermediate layer 112 incident radiation 200 has an angle of incidence which exceeds the critical angle (total reflection angle) applicable for this range, the radiation becomes 200 , as in 1 is indicated by the right of the three radiation paths, totally reflected. Upon impact at a smaller angle of incidence, the radiation can 200 into the interlayer 112 enter, and after passing through the interlayer 112 and then the carrier layer 111 from the conversion element 110 be delivered. In this way, to the semiconductor chip 120 opposite side of the carrier layer 111 no or substantially no radiation 200 reach which has an angle of incidence greater than the applicable critical angle for this point. In other words, using the interlayer 112 the total reflection causing interface to the conversion layer 113 relocated. A consequence of this is that a radiation emission in the optoelectronic component 100 essentially to the area of the driven pixel 121 of the semiconductor chip 120 - or with several activated pixels 121 essentially to the area (s) of the plurality of driven pixels 121 - remains limited. The airgel intermediate layer 112 can form an optical isolation layer in this sense.

To clarify the effect of the intermediate layer 112 is in 3 For comparison, by means of selected radiation paths, a propagation of the radiation 200 shown in a layer stack, in which the intermediate layer 112 is omitted and which consequently only the carrier layer 111 and then arranged the conversion layer 113 having. The representation of the radiation paths refers in a similar way to the case that the layer stack of 3 on the semiconductor chip 120 from 1 is arranged, and here too the conversion layer 113 the semiconductor chip 120 facing, and the left pixel 121 of the semiconductor chip 120 is controlled. Furthermore, a condition is used, in which the carrier material of the carrier layer 111 and the conversion material of the conversion layer 113 have approximately the same refractive index.

As in 3 shown is the radiation 200 without change of direction from the conversion layer 113 in the carrier layer 111 transgressed. In this way, part of the radiation 200 at an angle of incidence exceeding the critical angle to the semiconductor chip 120 remote surface of the carrier layer 111 incident. This proportion of radiation 200 can go back to the conversion layer 113 be reflected back, in a range of several pixels 121 away from the driven pixel 121 , which leads to a crosstalk. According to 3 For example, back reflection can be in a range of pixels 121 occur in which it is with respect to the driven pixel 121 at the next but one pixel 121 is. This case may be, for example, at a thickness of the carrier layer 111 of 150μm occur. The totally reflected radiation 200 can be a backscatter at the conversion layer 113 subject. In the case of a primary, totally reflected radiation part, conversion radiation may be generated.

Because the radiation 200 in the area of the driven pixel 121 isotropic from the conversion layer 113 can be discharged when using the layer stack of 3 on the semiconductor chip 120 a relatively large part of the radiation 200 at an angle of incidence exceeding the critical angle on the front surface of the carrier layer 111 to be hit and totally reflected. For example, the critical angle may be 42 ° with a refractive index of 1.5 of the carrier layer 111 be. This causes the backing layer 111 can act as a light guide, with the result that a radiation emission from the layer stack is not limited to the area of the driven pixel 121 remains limited, but a radiation output to a large extent in the range of non-driven pixels 121 can be done. Thus, crosstalk when using the layer stack of 3 clearly pronounced.

At the conversion element 110 of the optoelectronic component 100 from 1 allows the design with the intermediate layer 112 on the other hand, the occurrence of total reflection at the conversion layer 113 lead and consequently a light guide function of the carrier layer 111 and thus largely suppress crosstalk. In this context, it is further provided that the intermediate layer 112 the conversion element 110 has a thickness in a range of 2μm to 5μm. This can be with A high reliability can be ensured, that of the conversion layer 113 emitted radiation, the intermediate layer 112 not tunneled, and consequently the total reflection at the semiconductor chip 110 opposite side of the conversion layer 113 can occur.

In 2 is not shown for reasons of clarity, that is not subject to total reflection radiation 200 when going through the conversion element 110 at the interfaces between the different layers 111 . 112 . 113 as well as on the front of the carrier layer 111 to a small extent a back reflection (Fresnel reflection) can be subject. Furthermore, it may be in the interlayer 112 and in the conversion layer 112 come to a lateral radiation propagation. These effects may possibly be negligible. In this sense, for example, provide the above-mentioned layer thicknesses for the intermediate layer 112 (2μm to 5μm) and the conversion layer 113 (30μm to 50μm) the possibility of one in these layers 112 . 113 radiation propagation to be largely attenuated with appropriate scattering.

If crosstalk should still occur due to these effects, this only applies to adjacent and not to the layer stack of 3 further away pixel areas. In addition, it is possible for the conversion element 110 provide appropriate training, by means of which the prevention of cross-talk can be further promoted. For example, it may be considered that the conversion material of the conversion layer 113 smaller phosphor particles 116 and / or additional scattering particles not shown, in order to reduce (possibly occurring) crosstalk at the expense of efficiency. Further possible approaches will be discussed in more detail below.

The airgel material of the intermediate layer 112 is characterized not only by a small refractive index, but also by a low thermal conductivity. In this way, the intermediate layer 112 as a thermal insulator during operation of the optoelectronic component 100 serve.

In the radiation mode, part of the primary radiation is in the conversion material or in the phosphor particles 116 the conversion layer 113 converted into heat energy. The intermediate layer made of the airgel material 112 can make sure that in the area of a pixel 121 in the conversion layer 113 generated amount of heat substantially not distributed to adjacent pixel areas. Instead, the heat energy can be transferred via the semiconductor chip 120 of the optoelectronic component 100 be derived. As a result, temperature-induced inhomogeneities can be avoided.

As stated above, the conversion element becomes 110 separately from the semiconductor chip 120 produced. It can be considered a variety of conversion elements 110 to produce in a layer composite and then to separate this. This procedure is described below on the basis of 4 to 6 explained in more detail in which a possible procedure for the production of conversion elements 110 is shown. In this context, in part to further possible embodiments of a conversion element 110 received.

In the process, a carrier layer 111 provided, which has a radiation-transparent support material (see. 4 ). The provided carrier layer 111 has comparatively large lateral dimensions, which depend on the number of conversion elements to be manufactured 110 are coordinated. As stated above, the carrier layer 111 have a thickness in a range of 100μm to 200μm, and the substrate may be a glass material such as quartz glass.

Alternatively, the carrier layer 111 be formed of a more stable transparent material such as sapphire. This makes it possible, the carrier layer 111 with a smaller thickness below 100μm, for example in the range of 50μm. Although sapphire has a higher refractive index than quartz glass, a larger part of the radiation can undergo a surface or back reflection during radiation operation. This effect can be compensated with the aid of antireflection or antireflection layers, as will be explained in more detail below.

Subsequently, as also in 4 shown is an intermediate layer 112 on the carrier layer 111 educated. The intermediate layer 112 has an airgel material which may be based on a metal oxide such as silicon, titanium, zirconium or alumina. The intermediate layer 112 is formed with a thickness in a range of 2μm to 5μm.

For producing the airgel intermediate layer 112 For example, a liquid can form a gel-like starting layer on the carrier layer 111 can be formed, and this subsequently by a drying process in the airgel intermediate layer 112 being transformed. One possible process sequence that includes these steps is a sol-gel process.

Optionally, the airgel layer 112 subsequently polished. This may be considered when the airgel layer produced 112 has a high surface roughness. By polishing, scattering effects associated with roughness can be avoided.

The following will, as in 5 shown is a conversion layer 113 on the interlayer 112 educated. At the in 5 indicated processing of phosphor in powder form, the conversion layer 113 a conversion material comprising a matrix material 115 , For example, silicone, and embedded therein phosphor particles 116 , The phosphor particles 116 can be designed as described above to produce a yellow or yellow-green conversion radiation, and be made for this purpose of a phosphor material of the garnet family. Optionally, the conversion material may additionally phosphor particles 116 for generating a red light radiation, which can be realized with materials from the family of nitrides or Siliziumoxynitride. Furthermore, the conversion material may optionally additionally comprise scattering particles (not shown). The conversion layer 113 can be formed with a thickness in the range of 30μm to 50μm or even smaller.

To form the conversion layer 113 on the interlayer 112 For example, a printing process such as a screen printing or stencil printing process or doctoring may be performed. Here, a printing paste of the conversion material and a solvent on the intermediate layer 112 applied, which is subsequently dried. In order for the printing paste to flow, a minimum amount of matrix material is required.

A solvent-added conversion material can also be applied by means of a spray process (spray coating) and then dried. Compared to printing, the conversion layer 113 thus with a higher packing density of phosphor particles 116 be made.

This also applies to a further variant in which initially phosphor particles 116 and optionally scattering particles by means of electrophoretic deposition (EPD), and then a matrix material 115 as silicone are applied to fix the particles.

The production separately from a semiconductor chip 120 also allows other embodiments in which, for example, processes with temperatures of more than 400 ° C are performed. In this regard, the following variants may be considered.

It is possible, for example, as a matrix material 115 instead of silicone, use another material, for example a glass material or a ceramic binding material. Such materials can be characterized by a high temperature resistance. In contrast, a silicone material can be subject to embrittlement at a continuous load at a temperature of well above 150 ° C.

In this sense, it is conceivable, for example, as a conversion material with a phosphor particles 116 and, optionally, scattered particles to apply added molten glass material, which can subsequently cool and thereby harden. Also a precipitation of glasses from the liquid phase ("water glass") is possible. Another approach is to use a mixture of phosphor particles 115 , Apply a ceramic binder and optionally other additives and then convert this mixture in a sintering process in a ceramic conversion material.

Alternatively, it may be considered to form the conversion layer 113 depositing one or also different phosphors with the aid of a sputtering method and subsequently densifying them in a sintering process in a ceramic manner. In this way, the conversion layer 113 a deviating from the figures structure, ie only one or more compacted phosphors and no matrix material include.

The after forming the conversion layer 113 present layer composite is then, as in 6 is shown in separate conversion elements 110 sporadically. Here are the conversion elements 110 with lateral dimensions corresponding to the size of a semiconductor chip 120 educated. The cutting through of the layer composite, which can be carried out for example by sawing, takes place along corresponding dividing lines 210 ,

A conversion element produced according to the above method 110 can then be on a semiconductor chip 120 be arranged to an optoelectronic device 100 with the in 1 realize realized construction. Here comes a connecting material 130 , For example, a silicone adhesive or a glass solder, used. A precise positioning of the conversion element 110 on the semiconductor chip 120 can be achieved with the help of an image recognition. Furthermore, it is conceivable, the conversion element 110 and / or the semiconductor chip 120 with adjustment marks form (not shown) to favor an accurate adjustment. This may be considered, for example, if the conversion element 110 additionally with a below explained and on the pixels 121 of the semiconductor chip 120 coordinated absorptive or reflective separation structure is made.

In terms of the production of optoelectronic components 100 It may also be considered, conversion elements 110 before mounting on semiconductor chips 120 subjected to a measurement to detect their conversion properties. Also semiconductor chips 120 can be subjected to a measurement. Based on this, suitable pairs of a conversion element can each be used 110 and a semiconductor chip 120 be selected and connected with each other. This can be achieved that of the components 100 generated radiation can correspond to predetermined properties such as a given color location.

In the following, further modifications or developments of a conversion element 110 an optoelectronic component 100 described. In this regard, it should be understood that consistent features and aspects will not be described again in detail below. For details, reference is made to the above description instead. Furthermore, it is possible that a feature described in relation to one embodiment may also apply to another embodiment or that features of several embodiments can be combined with one another.

7 shows a detail of another conversion element 110 , which in addition one between the intermediate layer 112 and the conversion layer 113 arranged protective layer 140 having. The protective layer 140 For example, it may be silicon oxide. In a manufacturing process, the protective layer 140 after forming the intermediate layer 112 and before forming the conversion layer 113 on the interlayer 112 be formed. With the help of the protective layer 140 can the pore structure of the airgel material of the intermediate layer 112 closed, and thus a penetration of matrix material 115 the subsequently formed conversion layer 113 be prevented in the pores.

With the help of the following embodiments of a conversion element 110 Suppression of crosstalk can be further promoted. One possible measure is an embodiment with one or more antireflection layers.

In this sense shows 8th partially another conversion element 110 which additionally has several antireflection layers 141 . 142 . 143 having. The antireflection coating 141 is on one of the interlayer 112 opposite side of the carrier layer 111 educated. The antireflection coating 142 is located between the carrier layer 111 and the intermediate layer 112 , and the antireflection coating 143 is located between the intermediate layer 112 and the conversion layer 113 , The antireflection layers 141 . 142 . 143 make it possible reflections of a the conversion element 110 passing radiation at the surfaces or interfaces of the respective layers 141 . 142 . 143 to prevent. In this way, the crosstalk can be additionally suppressed. Furthermore, the antireflection coating 143 as a protective layer for closing the pores of the airgel material of the intermediate layer 112 serve.

The antireflection layers 141 . 142 . 143 can be realized in the form of dielectric layer pairs. In a manufacturing process, the carrier layer 111 with the antireflection layers 141 . 142 be provided before on the thus coated carrier layer 111 or on the antireflection coating 142 the intermediate layer 112 is trained. The following may be the antireflection coating 143 on the interlayer 112 can be formed, and then the conversion layer 113 on the thus coated intermediate layer 112 or on the antireflection coating 143 be formed.

It is possible to have a conversion element 110 deviating from 8th with a smaller number of antireflection layers or even with only one antireflection layer.

The production of a conversion element 110 separately from a semiconductor chip 120 In addition, it offers the option of the conversion element 110 in a simple manner and without loss of yield additionally with a limiting structure for limiting a lateral radiation propagation form. Such a light barrier may also prove beneficial for suppressing crosstalk. Possible embodiments of a conversion element 110 will be explained in more detail with reference to the following figures.

9 shows another conversion element 110 in which the intermediate layer 112 additionally a boundary structure of structural elements 151 having. The structural elements 151 may comprise a radiation-absorbing or reflective material. This material differs from the airgel material of the intermediate layer 112 which is like in 9 indicated in layer areas 161 is available. For an embodiment of the structural elements 151 For example, a metal having a low reflectivity, such as chromium, may be considered as a radiation absorbing material. For a reflective design of the structural elements 151 , what with a high efficiency in the radiation mode is connected, for example, a metal such as aluminum is conceivable.

The structural elements 151 have the same thickness as the remaining intermediate layer 112 , In the 9 shown in cross section structural elements 151 For example, they may be in the form of elongated webs. Furthermore, it is possible for the delimiting structure to be realized in the form of a grid, so that the delimiting structure has a plurality of structural elements which partly cross each other 151 has (not shown). In such an embodiment, the structural elements 151 the boundary structure separate recesses, within which the airgel material of the intermediate layer 112 is arranged. Here, the intermediate layer 112 separate layer areas 161 from the airgel material. This structure can be based on the pixelated design of a semiconductor chip 120 be coordinated. For example, the layer areas 161 each a corresponding pixel 121 of the semiconductor chip 120 be assigned.

In a manufacturing process for realizing the construction of 9 can be the boundary structure with the structural elements 151 on the provided carrier substrate 111 be formed. Forming the confinement structure may include forming a continuous layer of material of the confinement structure and lithographically patterning that layer. Subsequently, an application of the airgel material can take place. Optionally, subsequently or before the formation of the conversion layer 113 on the structural elements 151 airgel material for planarizing the intermediate layer 112 be removed.

10 shows another conversion element 110 in which the conversion layer 113 In addition, a boundary structure with structural elements 152 for limiting lateral radiation propagation. The structural elements 152 are made of a material of the conversion material (in the embodiment shown, a matrix material 115 with phosphor particles 116 ) of the conversion layer 113 formed distinctive material. The structural elements 152 may have a radiation absorbing material such as chromium. In this way, the structural elements 152 be held relatively flat and as in 10 shown a smaller thickness than the conversion layer 113 have. The structural elements 152 can be assigned to one (in 10 downward) side of the conversion material 113 . 115 be covered.

Also the structural elements 152 For example, they may be in the form of elongated webs. Furthermore, the delimiting structure can be realized in the form of a grid, so that the delimiting structure has a plurality of structural elements that partially cross each other 152 has (not shown). This structure can be based on the pixelated design of a semiconductor chip 120 be coordinated. For example, of the structural elements 152 laterally enclosed areas in each case a corresponding pixel 121 of the semiconductor chip 120 be assigned.

In a manufacturing process for realizing the embodiment of 10 can be the boundary structure with the structural elements 152 on the interlayer 112 be formed. Forming the confinement structure may include forming a continuous layer of material of the confinement structure and lithographically patterning that layer. Subsequently, an application of conversion material 115 . 116 respectively. Optionally, below may be a part of the conversion material 115 . 116 be removed to the conversion layer 113 at the interlayer 112 planarize on the opposite side.

11 shows another conversion element 110 in which the conversion layer 113 also in addition a boundary structure with structural elements 153 having. The structural elements 153 For example, they may include a reflective material. This may be, for example, a silicone material filled with reflective particles.

The structural elements 153 have the same thickness as the rest of the conversion layer 113 , Again, the structural elements 153 be elongated webs or the boundary structure in the form of a grid with partially crossing structural elements 153 be realized (not shown). Here, the structural elements 153 the boundary structure separate separate recesses within which the conversion material 115 . 116 is arranged so that the conversion layer 113 separate layer areas 163 from the conversion material 115 . 116 having. This structure can be based on the pixelated design of a semiconductor chip 120 be coordinated. For example, the layer areas 163 each a corresponding pixel 121 of the semiconductor chip 120 be assigned.

To realize the construction of 11 can be a continuous layer of the conversion material 115 . 116 on the interlayer 112 be formed. Below is the conversion material 115 . 116 be removed locally, so that openings in the form of to be produced Limiting structure are formed. The openings can then be filled with the material of the boundary structure.

The conversion elements described above 110 with boundary structures can be modified in different ways. It is also possible to combine features. For example, it is conceivable to use a silicone material filled with reflective particles, as described with reference to FIGS 11 has been described embodiment, also in the in 9 shown embodiment for the boundary structure of the intermediate layer 112 provided. In this case, it can be considered in an analogous manner to first manufacture a continuous layer of an airgel material, to open it locally and then to fill the openings with material of the boundary structure. Furthermore, it is possible to use the intermediate layer 112 with an absorptive boundary structure, in which the structural elements analogous to those in 10 shown construction a smaller thickness than the intermediate layer 112 exhibit.

A further modification consists in that recesses or regions enclosed in a grid-shaped limiting structure are not assigned to one but to a plurality of pixels of the semiconductor chip. It is also possible to provide a different shape for a delimiting structure instead of a grid. For example, a delimiting structure may comprise only one or more separate structural elements. In addition, embodiments are conceivable in which both the intermediate layer 112 as well as the conversion layer 113 have a delimiting structure.

The embodiments explained with reference to the figures represent preferred or exemplary embodiments of the invention. In addition to the described and illustrated embodiments, further embodiments are conceivable which may include further modifications and / or combinations of features. For example, it is possible to use other materials instead of the above materials. Also, the above figures are to be regarded as examples, which can be replaced by other information.

With respect to a production of optoelectronic components 100 is a common singulation of conversion elements 110 and semiconductor chips 120 possible. For this purpose, a layer composite comprising (at least) a carrier layer 111 , an intermediate layer 112 and a conversion layer 113 manufactured and then on a multiple semiconductor chips 120 comprehensive component composite or wafer can be arranged. Subsequently, this composite can be used in separate optoelectronic components 100 to be isolated.

Apart from a headlight, other fields of application for a conversion element 110 or one with a conversion element 110 equipped optoelectronic component 100 be considered. For example, an application in a display device for displaying information and / or advertising messages is possible.

In this case, the optoelectronic component 100 optionally be designed to produce a light radiation other than white. This can be achieved by a corresponding embodiment of the conversion material of the conversion layer 113 achieve. It is also conceivable that the primary radiation of the associated semiconductor chip 120 essentially completely converted into one or more conversion radiations.

Another possible embodiment is a conversion element with pixel areas for emitting light radiation in different colors. For this purpose, the conversion material of the conversion layer 113 be formed in different areas for generating different conversion radiations. This can be realized by the conversion material having a matrix material such as silicone and different phosphor particles in different areas. In addition, nonconverting regions of a non-converting material may be formed in the conversion layer, which may be formed by the primary radiation of the semiconductor chip 120 can be passed. Such areas may include the matrix material and scattering particles.

In a conversion element for emitting light radiation in different colors, moreover, the associated conversion layer may be formed with a delimiting structure. Here, the restriction structure may be realized in the form of a grid with separate recesses for receiving conversion material and non-converting material. The delimiting structure can furthermore be designed in such a way that the delimiting structure only partially ensures a limitation of the lateral radiation propagation and is otherwise radiation-transmissive. For this purpose, the limiting structure may comprise both a radiation-absorbing or reflective material and a transparent material. In this way, for example, pixel regions can be formed which are subdivided into subpixels for emitting differently colored light radiation, wherein with respect to the conversion layer only the different pixel regions are optically separated and within the pixel regions a radiation propagation between the subpixels is possible.

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

LIST OF REFERENCE NUMBERS

100

 module

110

 conversion element

111

 backing

112

 interlayer

113

 conversion layer

115

 matrix material

116

 Phosphor particles

120

 Semiconductor chip

121

 pixel

130

 link layer

140

 protective layer

141, 142

 Antireflection coating

143

 Antireflection coating

151, 152

 structural element

153

 structural element

161, 163

 layer region

200

 radiation

210

 parting line

Claims (10)

Conversion element ( 110 ), which is mounted on a pixelated radiation-emitting semiconductor chip ( 120 ), comprising: a carrier layer ( 111 ) comprising a radiation-transparent support material; a conversion layer ( 113 ) comprising a conversion material ( 115 . 116 ) for radiation conversion; and one between the carrier layer ( 111 ) and the conversion layer ( 113 ) arranged intermediate layer ( 112 ) comprising an intermediate layer material having a refractive index which is smaller than a refractive index of the carrier material and a refractive index of the conversion material. Conversion element according to claim 1, wherein the refractive index of the interlayer material of the intermediate layer ( 112 ) is less than 1.2, in particular less than 1.1. Conversion element according to one of the preceding claims, wherein the interlayer material of the intermediate layer ( 112 ) is an airgel material. Conversion element according to one of the preceding claims, wherein the intermediate layer ( 112 ) has a thickness in a range of 2μm to 5μm. Conversion element according to one of the preceding claims, wherein the carrier material of the carrier layer ( 111 ) is a glass material. Conversion element according to one of the preceding claims, further comprising at least one antireflection coating ( 141 . 142 . 143 ). Conversion element according to one of the preceding claims, wherein the intermediate layer ( 112 ) additionally a boundary structure ( 151 ) for limiting lateral radiation propagation. Conversion element according to one of the preceding claims, wherein the conversion layer ( 113 ) additionally a boundary structure ( 152 . 153 ) for limiting lateral radiation propagation. Optoelectronic component ( 100 ), comprising a pixelated radiation-emitting semiconductor chip ( 120 ) and a conversion element ( 110 ) according to one of the preceding claims, wherein the conversion element ( 110 ) on the semiconductor chip ( 120 ) and the conversion layer ( 113 ) of the conversion element ( 110 ) the semiconductor chip ( 120 ) is facing. Method for producing a conversion element ( 110 ) according to one of claims 1 to 8, wherein the conversion element ( 110 ) on a pixelated radiation-emitting semiconductor chip ( 120 ), comprising: providing a carrier layer ( 111 ), wherein the carrier layer ( 111 ) has a radiation-transparent carrier material; Forming an intermediate layer ( 112 ) on the carrier layer ( 111 ), the intermediate layer ( 112 ) has an interlayer material; and forming a conversion layer ( 113 ) on the intermediate layer ( 112 ), where the conversion layer ( 113 ) a conversion material ( 115 . 116 ), wherein the interlayer material has a refractive index which is less than a refractive index of the carrier material and a refractive index of the conversion material.

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