DE102011087614A1 - Optoelectronic arrangement for use in headlight in vehicle, has planar light conductor for mixing of electromagnetic radiation, arranged downstream to semiconductor chips in radiation pattern and covering gap between semiconductor chips - Google Patents

Abstract

The arrangement (402) has a carrier (102) on which semiconductor chips (104) are located for emission of electromagnetic radiation. A gap (106) is formed between the adjacent semiconductor chips. A planar light conductor (108) is provided for mixing of the electromagnetic radiation, arranged downstream to the semiconductor chips in radiation pattern and covers the gap. A conversion element is arranged between a radiation emission side of the semiconductor chips and the light conductor. The gap is filled with reflective silicone encapsulation in which scattered particles are introduced. The light conductor is comprised of matrix materials e.g. silicone, glass, polymethyl methacrylate and polycarbonate. The semiconductor chips are thin film chips. The conversion element is designed as a ceramic plate. The planar light conductor is designed as silicone- or glass plates. The carrier is designed as a lead frame or a ceramic carrier. The electromagnetic radiation is blue or green light. Independent claims are also included for the following: (1) an illumination device (2) a method for manufacturing an optoelectronic arrangement.

Description

The present invention relates to an optoelectronic device, a method for producing an optoelectronic device and a lighting device.

Optoelectronic devices may include a plurality of semiconductor chips. The semiconductor chips can emit electromagnetic radiation. The semiconductor chips are usually arranged on a carrier. The carrier is necessary for the mechanical and electrical contacting of the semiconductor chips. Such optoelectronic arrangements are also called multichip modules, which can be used, for example, as so-called headlamps ("headlamps") in vehicles. For procedural reasons, a minimum distance between adjacent semiconductor chips is necessary. Depending on the contacting method for the semiconductor chips, the minimum achievable distances between adjacent semiconductor chips are up to 200 μm. This results in spatially inhomogeneous luminances and radiation characteristics of the light emitted by the multichip modules.

An object of the present invention is to improve the prior art.

A further object of the invention is to specify an optoelectronic device and a method for producing an optoelectronic device, so that the luminance and the radiation characteristic of the optoelectronic device are better homogenized.

This object is achieved by an optoelectronic device according to independent device claim 1 and by a method for producing an optoelectronic device according to independent method claim 15.

A further object of the invention is to specify a lighting apparatus having an optoelectronic arrangement, so that the luminance and the radiation characteristic of the lighting apparatus are better homogenized.

This object is achieved by a lighting device according to independent device claim 14.

Further developments and advantageous embodiments of the optoelectronic device are specified in the dependent claims.

Exemplary embodiments

The present invention relates to an optoelectronic device having at least two semiconductor chips, which are arranged on a carrier. The semiconductor chips are designed for the emission of electromagnetic radiation. Between adjacent semiconductor chips, a gap is formed in each case. A planar light guide is arranged downstream of the semiconductor chips in the emission direction and covers the respective gap. In the planar light guide, the electromagnetic radiation is mixed. In particular, spatial mixing of the electromagnetic radiation takes place in the planar light guide. In other words, the luminance and the radiation characteristic of the optoelectronic device are better homogenized by the planar light guide. The luminance is increased above the respective gap. As a result of the use of the planar light guide, in particular the requirements for the maximum permissible distance between adjacent semiconductor chips are less stringent. This reduces in particular the requirements with regard to the placement tolerances when loading the carrier with semiconductor chips. The homogenization of the luminance over the extent of the optoelectronic arrangement is advantageous in particular for the use of the optoelectronic arrangement as headlights in vehicles. With the optoelectronic arrangement according to the invention, the space in front of a vehicle can be illuminated more homogeneously. Compared to the prior art, less dark areas occur. It is particularly advantageous that the optoelectronic arrangement according to the invention can be implemented simply and inexpensively. As a planar light guide, for example, a simple glass or silicone plate can be used.

• – eine Leiterplatte (PCB),
• – ein Keramiksubstrat,
• – eine Metallkernplatine,
• – einen Leadframe oder
• – ein Kunststofflaminat
• – ein Panel.

In a preferred embodiment, the support has one of the following elements:

• A printed circuit board (PCB),
• A ceramic substrate,
• A metal core board,
• - a leadframe or
• - a plastic laminate
• - a panel.

In particular, as a carrier, a metal core board is advantageous because it is simple and inexpensive to manufacture and has a high thermal conductivity.

The semiconductor chips have at least one active zone which emits electromagnetic radiation. The active zones may be pn junctions, double heterostructure, multiple quantum well structure (MQW), single quantum well structure (SQW). Quantum well structure means quantum wells (3-dim), quantum wires (2-dim) and quantum dots (1-dim).

In a preferred embodiment, the semiconductor chip is based on a III-V compound semiconductor material. III-V Compound semiconductor materials are advantageous because high internal quantum efficiencies can be achieved in radiation generation. In a preferred embodiment, the semiconductor chip may comprise aluminum indium gallium nitride (Al _x In _y Ga _1-xy N). These semiconductor chips can emit electromagnetic radiation from the ultraviolet spectral range over the blue spectral range to the green spectral range. In a further preferred embodiment, the semiconductor chip may comprise aluminum indium gallium phosphide (Al _x In _y Ga _1-xy P). These semiconductor chips can emit electromagnetic radiation from the red spectral range to the yellow spectral range. In this case, 0 ≦ x ≦ 1, 0 ≦ y ≦ 1 and x + y ≦ 1, in particular with x ≠ 1, y ≠ 1, x ≠ 0 and / or y ≠ 0.

In a preferred embodiment, the semiconductor chip may be formed as a surface emitter, in particular as a so-called thin-film chip. For thin-film chips, the radiation predominates in the forward direction. This is advantageous, for example, when used in a headlight. The thin-film chip is for example from the published patent application WO2005081319A1 known.

The semiconductor chips may be contacted by wire bonding. In the case of light-emitting semiconductor chips which have a layer with an n-polarity and a layer with a p-polarity, one of the two layers can be contacted via a bonding wire. In an alternative embodiment, both layers can be contacted with one bonding wire each. The bonding wire connects a bonding pad on the carrier and a contact pad on the light emitting semiconductor chip. The bonding wire reaches an absolute height above the semiconductor chip of at least about 70 μm with a minimum diameter of about 15 μm.

In a preferred embodiment, the contacts of the n-polarity layer and the p-polarity layer are realized on the side of the semiconductor chip facing the carrier. An example of such an embodiment is a so-called flip-chip arrangement. The lack of contact structures on the radiation emission side of the semiconductor chip is particularly advantageous since the planar light guide can be arranged directly on the radiation emission side of the semiconductor chips.

In a preferred embodiment, a conversion element is arranged in each case between the radiation emission side of the semiconductor chips and the planar light guide. This is particularly advantageous for the wavelength conversion of the light emitted by the semiconductor chip. The conversion element may have a thickness of between about 20 μm and about 200 μm. The conversion element has phosphor particles. The phosphor particles convert a portion of the short wavelength electromagnetic radiation (e.g., blue light) emitted by the semiconductor chip into longer wavelength electromagnetic radiation (e.g., yellow light). The mixed light of blue and yellow light can produce white light.

• – Lanthan dotiertes Yttriumoxid (Y₂O₃-La₂O₃),
• – Yttrium Aluminium Granat (Y₃Al₅O₁₂),
• – Dysprosiumoxid (Dy₂O₃),
• – Aluminium Oxynitrid (Al₂₃O₂₇N₅) oder
• – Aluminium Nitrid (AlN).

The phosphor particles have at least one of the following materials:

• Lanthanum-doped yttrium oxide (Y ₂ O ₃ -La ₂ O ₃ ),
• Yttrium aluminum garnet (Y ₃ Al ₅ O ₁₂ ),
• Dysprosium oxide (Dy ₂ O ₃ ),
• Aluminum oxynitride (Al ₂₃ O ₂₇ N ₅ ) or
• - Aluminum nitride (AlN).

The conversion element may be formed as a ceramic plate with a thickness between about 40 microns and about 200 microns, preferably with a thickness of about 100 microns. Alternatively, the conversion element may be formed as a silicon wafer with a thickness between about 20 microns and about 30 microns. Alternatively, the conversion element may be electrophoretically deposited to a thickness of between about 50 μm and about 100 μm. Alternatively, the conversion element can be molded onto the semiconductor chip with silicone as the molding material embedded in the phosphor particle. Particularly advantageous are the thinnest possible conversion elements. The thinner the conversion element, the lower the undesired angular expansion. The smaller the angle widening, the more light can be coupled into the planar light guide.

In a preferred embodiment, the gaps between the semiconductor chips are filled with a reflective potting. In addition, the reflective encapsulation may be arranged between the semiconductor chips and the edges of the optoelectronic device. This overcomes the disadvantage that exposed carriers of optoelectronic devices at least partially absorb incident electromagnetic radiation from the visible spectral range.

The reflective casting has a matrix material in which scattering particles are introduced. The scattering particles occur in a concentration of 5 percent by weight to 60 percent by weight. The matrix material may comprise silicone, epoxy or hybrid materials. The scattering particles may comprise titanium dioxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO) and / or barium fluoride (BaF ₂ ). The reflective potting may completely cover the carrier, the side surfaces of the semiconductor chips, and the side surfaces of the conversion elements. By means of this reflective encapsulation, it is achieved that at least part of the light emerging laterally from the conversion elements is reflected back into the conversion elements. Even the unwanted Absorption of the light by adjacent semiconductor chips or by the carrier is reduced.

In a preferred embodiment, the edge of the planar light guide on one or more side surfaces. This is advantageous because the arrangement of the at least one side surface, the light extraction from the planar light guide can be optimized. The at least one side surface is arranged at an angle of greater than 90 ° to the semiconductor chip side facing the planar light guide. This is advantageous since the proportion of the radiation totally reflected at the at least one side surface increases relative to a side surface which encloses an angle of 90 ° to the side of the planar light guide facing the semiconductor chips.

In a preferred embodiment, the edge of the planar light guide can be provided with a mirror, in particular a silver mirror. This mirroring is particularly advantageous in combination with an inclined side surface of the edge of the planar light guide, since a particularly large amount of light can be coupled out of the planar light guide. Silver is highly reflective of electromagnetic radiation from the visible spectral range. Silver is chemically inert. Silver adheres well to the aforementioned materials of the planar light guide.

In a preferred embodiment, the planar light guide has a thickness of about 50 microns to about 200 microns, preferably from about 75 microns to about 175 microns, more preferably from about 100 microns to about 150 microns. The smaller the distances between the semiconductor chips are selected, the lower the thickness of the planar light guide can be selected to achieve the desired light mixing and homogenization. This is particularly advantageous since the overall height of the optoelectronic device according to the invention is only marginally increased by a thin planar optical waveguide.

• – Silikon,
• – Glas,
• – Polymethylmethacrylat (PMMA),
• – Polycarbonat (PC) auf.

In a preferred embodiment, the planar light guide has at least one of the following matrix materials

• - silicone,
• - Glass,
• Polymethylmethacrylate (PMMA),
• - Polycarbonate (PC) on.

In particular light guides made of glass or silicone are advantageous because they are simple and inexpensive to produce.

In the case of silicone as a matrix material preferably hard silicone with a hardness greater than Shore A 60 is used. Hard silicone ensures the necessary edge fidelity of the edge of the planar light guide.

White light can be generated by a mixture of differently colored light. In an optoelectronic arrangement which emits white light, it can be achieved by the low dispersion in the planar light guide that the differently colored light travels through the planar light guide in almost the same way. This is particularly advantageous since an undesirable separation of light of different wavelengths in the planar light guide can be largely avoided.

In a preferred embodiment, particles are introduced into the planar light guide, which serve to better mix the light in the planar light guide. The particles act as diffusers. As particles scattering particles and / or totally reflecting particles can be used. The particles may be present at a level of from 0.001% to 10% by weight. Scattering particles have a greater refractive index than the refractive index of the matrix material of the planar light guide. The scattering particles may comprise titanium dioxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO) or barium fluoride (BaF ₂ ). The scattering particles may advantageously have a particle size of about 500 nm. Thus, the diameter of the scattering particles is in the range of the wavelength of the light to be scattered. Totally reflecting particles have a smaller refractive index than the refractive index of the matrix material of the planar light guide.

As an alternative or in addition to the above-mentioned scattering particles, SiO ₂ (glass) particles can be introduced into the planar light guide. The glass particles may have diameters between about 500 nm to 5 μm. Smaller glass particles act as scattering particles or diffusers. Larger glass particles act as lenses. Even by such larger glass particles, a mixture of the light in the planar light guide can be achieved. Glass particles are also advantageous because they have good thermal conductivity and good mechanical stability.

In a preferred embodiment, the planar light guide can have local refractive index differences over its volume. This is advantageous because it also allows a thorough mixing of the electromagnetic radiation in the planar light guide can be achieved. For the inner region of the planar light guide, a lower refractive index can be selected than for the outer region of the planar light guide, or vice versa. The transition from a low refractive index region to a high refractive index region may be continuous or discontinuous.

In a preferred embodiment, the use of particles and refractive index differences in the planar light guide can be combined become. This is particularly advantageous because it allows a particularly efficient spatial and / or spectral mixing of the light can be achieved. By this combination, the necessary for the light mixture thickness of the planar light guide can be reduced to a minimum of about 50 microns. This small thickness of the planar light guide is particularly advantageous since the height of the optoelectronic device is kept low and less material is necessary. The saving of material reduces the costs.

In a preferred embodiment, the refractive indices of the planar light guide and of the conversion element can fulfill the following condition:
n (optical fiber) <n (conversion element).

This is advantageous because a part of the electromagnetic radiation is totally reflected at the interface of the conversion element and the planar light guide. Part of this totally reflected light can leave the planar light guide above the conversion elements. This leads to less losses due to absorption in the conversion element. This also leads to a more homogeneous luminance distribution. The refractive index of the conversion element is dependent on the matrix material and on the concentration of the phosphor particles. It can vary between about 1.4 and about 1.8. The refractive index of the planar light guide is also dependent on the matrix material. For glass as a matrix material, the refractive index of the planar light guide can vary between about 1.4 and 1.6.

In a preferred embodiment, the planar light guide and the conversion element can be connected by an adhesive layer, in particular made of silicone. The thickness d of the adhesive layer may satisfy the following condition with respect to the wavelength λ of the electromagnetic radiation emitted from the semiconductor chips: d <λ / 2.

This is advantageous since no optically disadvantageous effect occurs due to the adhesive layer with the above thickness d.

In a preferred embodiment, the planar light guide and the conversion element can be connected by an adhesive layer that satisfies the following condition with respect to the refractive indices:
n (optical fiber) <n (adhesive) <n (conversion element).

This is advantageous since the above adaptation of the refractive indices minimizes the luminance losses at the interfaces from optical fiber to adhesive or from adhesive to conversion element.

In a preferred embodiment, the surface facing away from the carrier surface of the planar light guide is roughened. This is advantageous because the roughening of the planar light guide increases the coupling-out efficiency for the light. The roughening of the planar light guide can be generated during the production of the planar light guide or subsequently.

The roughening can have a pyramidal structure. The pyramids can be applied by a sputtering process on the planar light guide.

Alternatively or additionally, the roughening may have a moth-eye structure. The surface of the moth eyes is finely structured. It consists of conical suppositories smaller than the wavelength of visible light. From inside to outside the nub diameter is also smaller. The refractive index of the light does not change abruptly but continuously. As a result, no recognizable interface is present. As a result, the light is not reflected during the transition from the planar light guide to the ambient air.

The present invention further relates to a lighting device that combines an opto-electronic device with a secondary optics. The optoelectronic device may be configured according to one of the above embodiments. The combination of optoelectronic arrangement and secondary optics is advantageous since it allows the light emanating from the optoelectronic arrangement to be forwarded and / or imaged.

• – einen Lichtleiter,
• – eine Streuscheibe,
• – eine Linse oder
• – einen Reflektor.

In a preferred embodiment of the lighting device, the secondary optics has at least one of the following elements:

• - a light guide,
• - a diffuser,
• - a lens or
• - a reflector.

The use of a light guide is advantageous because it allows light to be passed on almost without loss over long distances. The use of a diffusing screen is advantageous because it allows the light emanating from the optoelectronic arrangement to be mixed even more. The use of a lens is advantageous because it allows the light emanating from the optoelectronic device to be focused. The use of a reflector is advantageous since the light emanating from the optoelectronic device can be focused in the forward direction. In particular, light which is radiated at angles greater than 90 ° to the solder from the optoelectronic components can be reflected to the front and is thus not lost.

The present invention further relates to a method for producing an optoelectronic device with the following steps. First, a carrier is provided. At least two semiconductor chips for emission of electromagnetic radiation are arranged on the carrier. Between each adjacent semiconductor chips, a gap is formed. A planar light guide for mixing the electromagnetic radiation is arranged downstream of the semiconductor chips in the emission direction and covers the respective gap. This method is advantageous because a better homogenization of the luminance of the optoelectronic device is achieved without significantly increasing the overall height of the optoelectronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are explained in more detail below with reference to the drawings. The same, similar or equivalent elements are provided in the figures with the same reference numerals. The figures and the proportions of the elements shown in the figures with each other are not to be considered to scale. On the contrary, individual elements can be shown exaggeratedly large or reduced in size for better representability and better understanding.

1a shows a first embodiment of an optoelectronic device according to the invention in sectional view;

1b shows a second embodiment of an optoelectronic device according to the invention in sectional view;

1c shows a third embodiment of an optoelectronic device according to the invention in sectional view;

2a . 2 B . 2c show semiconductor chips with electrical contacts in sectional view;

3 shows a fourth embodiment of an optoelectronic device according to the invention in sectional view;

4 shows a fifth embodiment of an optoelectronic device according to the invention in sectional view;

5a . 5b . 5c and 5d show planar light guide in sectional view;

6 shows a sixth embodiment of an optoelectronic device according to the invention in a sectional view;

7 shows a seventh embodiment of an optoelectronic device according to the invention in plan view;

8th shows an eighth embodiment of an optoelectronic device according to the invention in plan view;

nine shows an embodiment of a lighting device in a sectional view.

EMBODIMENTS

1a shows a first embodiment of an optoelectronic device according to the invention 402 in sectional view. There are three semiconductor chips 104 shown that emit electromagnetic radiation. However, the invention is not limited to three semiconductor chips. The semiconductor chips 104 are on a carrier 102 , in particular a leadframe or a ceramic carrier, arranged. The semiconductor chips 104 may be based on the aluminum indium gallium nitride (AlInGaN) material system and emit electromagnetic radiation, particularly light of a color, for example, blue or green light. A planar light guide 108 is the semiconductor chips 104 downstream in the emission direction. Because of placement tolerances in arranging the semiconductor chips 104 on the carrier 102 and because of the lot 107 , each side between the semiconductor chips 104 and the carrier 102 exits, the minimum achievable distance between the semiconductor chips is about 50 microns. In other words, arises between adjacent semiconductor chips 104 one gap each 106 , The planar light guide 108 covers the gaps 106 Completely. The planar light guide 108 may have a thickness of 50 microns to 200 microns. The planar light guide 108 may have silicone. The electromagnetic radiation of the semiconductor chips 104 becomes in the surface light guide 108 mixed. By mixing the electromagnetic radiation, a better homogenization of the luminance is achieved. In particular, light now also occurs at the locations of the planar light guide 108 from the planar light guide 108 out, over the gaps 106 are located. The mixing of the electromagnetic radiation in the planar light guide 108 can be increased by talking about the volume of the planar light guide 108 Introduces refractive index differences. These refractive index differences are not shown in the figures for reasons of clarity.

1b shows a second embodiment of an optoelectronic device according to the invention 404 in sectional view. Unless otherwise stated, the present embodiment corresponds to the embodiment in FIG 1a , Between the radiation emission sides 124 the semiconductor chips 104 and the planar light guide 108 Is respectively a conversion element 112 arranged for wavelength conversion. The conversion element 112 may be a silicone plate, are incorporated in the phosphor particles. The thickness of the silicone plate can be about 30 microns. The phosphor particles may comprise, for example, yttrium aluminum garnet (Y ₃ Al ₅ O ₁₂ ). The semiconductor chips 104 can be based on the AlInGaN material system and emit blue light. Part of the short-wave, in particular blue, primary radiation will be converted by the phosphor particles into longer-wave, in particular yellow, secondary radiation. The mixed light of blue and yellow light can produce white light. Due to the small thickness of the conversion element 112 ensures that the vast majority of the white mixed light on the side of the conversion element 112 emerges, the surface of the light guide 108 is facing. The proportion of light that the conversion elements 112 leaves through the side surfaces, which are substantially perpendicular to the semiconductor chips 104 can stand in the conversion elements 112 be scattered back. This will be the gaps 106 between the semiconductor chips 104 with a reflective potting 109 , in particular made of silicone in the TiO ₂ particles are completely filled. Also the areas between the semiconductor chips 104 and the edge of the optoelectronic device 404 are complete with the reflective potting 109 filled. The reflective casting 109 also prevents that from the semiconductor chips 104 emitted light from the carrier 102 is absorbed. The planar light guide 108 is in contact with the conversion elements 112 and with reflective potting 109 , The refractive indices of the planar light guide 108 and the conversion element 112 can fulfill the following condition:
n (optical fiber) <n (conversion element).

1c shows a third embodiment of an optoelectronic device according to the invention 406 in sectional view. The conversion elements 112 are through a translucent adhesive layer 140 with the planar light guide 108 connected. The adhesive layer 140 may have silicone. The thickness d of the adhesive layer 140 satisfies the following condition with respect to the wavelength λ of the semiconductor chips 104 emitted electromagnetic radiation: d <λ / 2. Regardless of the thickness d of the adhesive layer 140 , the refractive indices n of the planar light guide can 108 , the adhesive layer 140 and the conversion element 112 satisfy the following condition:
n (optical fiber) <n (adhesive) <n (conversion element).

In all embodiments, the planar light guide 108 through a translucent adhesive layer 140 with the semiconductor chips 104 and / or with the conversion elements 112 and / or with the (cured) reflective potting 109 get connected. For the sake of clarity, this adhesive layer 140 however, only in the embodiment of 1c shown.

In an embodiment not shown, the planar light guide 108 with a clamp on the semiconductor chips 104 and / or on the conversion elements 112 and / or on the cured reflective potting 109 be attached.

The following are on hand of the 2a . 2 B and 2c various types of semiconductor chips with associated electrical contacts explained that in the embodiments according to the 1a . 1b and 1c can be used.

2a shows a semiconductor chip 104a in sectional view at the radiation emission side 124 is contactless. Both electrical contacts are on the side of the semiconductor chip 104a realized that to the carrier 102 has. Losses due to shading can thus be avoided. The two chip contacts 120 of the semiconductor chip 104a are on the to the carrier 102 facing side of the semiconductor chip 104a arranged. On the carrier 102 are for the connection of the semiconductor chip 104a two bondpads 122 intended. The chip contacts 120 and the bondpads 122 can be connected by solder. A possible embodiment of such a semiconductor chip 104a is the so-called "flip chip".

2 B shows another example of a semiconductor chip 104b in sectional view, in which the radiation emission side 124 is contactless. Unlike the semiconductor chip in 2a be in 2 B the layers with different conductivity and the detailed contact structure are shown. An AlInGaN semiconductor chip 104b is designed here as a so-called thin-film semiconductor chip. The radiation emission side 124 has pyramidal structures. The epitaxial layer has an n-type layer 202 and a p-type layer 206 on. Between these two layers 202 and 206 is an active zone 204 arranged. About vias 207 that with an n-metallization 212 filled, becomes the n-type layer 202 energized. The vias are complete with passivation for electrical isolation from p-type regions 208 surrounded by SiO ₂ . Over a silver mirror 210 becomes the p-type layer 206 energized. Via electrically conductive channels 216 in a chip carrier 214 becomes an n-pad 220 with the n-metallization 212 and a p-pad 222 with the silver mirror 210 connected. The chip carrier 214 can consist of an electrically insulating ceramic. The electrically conductive channels 216 can be filled with solder. The epitaxial layers are on the side of the chip carrier 214 arranged by the carrier 102 turned away. The n-pad 220 and the p-pad 222 are on the opposite side of the chip carrier 214 arranged. With the n-pad 220 and the p-pad 222 can the semiconductor chip 104b on a carrier 102 , For example, on a printed circuit board (PCB), mechanically and electrically conductive are attached. Such a semiconductor chip 104b is suitable for use in an optoelectronic device, eg according to the embodiments in 1a . 1b or 1c ,

In all types of optoelectronic semiconductor chips, the radiation emission side 124 the semiconductor chips 104 be roughened. As a roughening pyramidal structures can serve. The pyramids can have a height between 0.5 μm and 4 μm. The roughening significantly reduces the proportion of the radiation totally reflected at the interface between the semiconductor chip and the surroundings. In other words, the roughening significantly increases the coupling-out efficiency of the semiconductor chip. For clarity, however, this roughening is only in the semiconductor chip of 2 B shown.

2c shows an example of a semiconductor chip 104c in sectional view, in which one of the two electrical contacts on the radiation emission side 124 of the semiconductor chip 104c is arranged. The semiconductor chip 104c is via a semiconductor chip contact layer 130 electrically and mechanically with the carrier 102 connected. The second electrical contact of the semiconductor chip 104c is via a bonding wire 136 realized. The bonding wire 136 has a diameter of at least 15 microns. The bonding wire 136 connects the bondpad 132 on the carrier 102 with the contact pad 134 on the radiation emission side 124 of the semiconductor chip 104c , bonding wire 136 , Bondpad 132 and contact pad 134 may have gold. The contact pad 134 and the bondpad 132 may have thicknesses between 0.5 microns and 5 microns. The bonding wire 136 has a bend, the so-called loop. The height 138 this loop over the semiconductor chip 104c is at least about 70 microns. So that the bonding wire 136 not in contact with the planar light guide 108 (not in 2c shown) comes and it is damaged, the conversion element (not in 2c represented) overhang the loop.

However, it is also possible to use any other type of semiconductor chip in the optoelectronic arrangements according to the invention.

3 shows a fourth embodiment of an optoelectronic device according to the invention 408 for producing white light in sectional view. There are three wire-bonded semiconductor chips 104c shown on each of which a conversion element 112 is arranged. The conversion elements 112 essentially cover the area of the radiation emission side 124 the semiconductor chips 104c not from the contact pad 134 are covered. For the sake of clarity, the adhesive layers and the semiconductor chip contact layers are not shown. The wire bonding requires for each semiconductor chip 104c the arrangement of a bond pad 132 on the carrier 102 , If the bondpads 132 between the semiconductor chips 104c are arranged, the minimum possible distance between the semiconductor chips 104c about 150 μm. The white light can be in the planar light guide 108 be mixed in such a way that the drop in luminance between the semiconductor chips 104c is reduced. The planar light guide 108 can be made of clear silicone. Alternatively, the planar light guide 108 have refractive index differences across its volume. These are not shown in the figure.

4 shows a fifth embodiment of an optoelectronic device according to the invention 410 for producing white light in sectional view. The present embodiment largely corresponds to the in 3 illustrated embodiment. Deviating from the embodiment in 3 are in the embodiment in 4 in the planar light guide 108 particle 114 brought in. The particles may be scattering particles and / or totally reflecting particles. By the concentration of the particles 114 can the strength of the mixing of the light in the planar light guide 108 be set. The gaps 106 between the semiconductor chips 104c are complete with a reflective potting 109 refilled.

5a shows a planar light guide 108 , as used in the embodiments, in sectional view. The edge 110 of the planar light guide 108 has a side surface 110a on. The angle α the side surface 110a with the plane of the planar light guide 108 includes, is about 90 °.

5b shows a planar light guide 108 , as used in the embodiments, in sectional view. Here's the edge 110 for optimizing the light extraction from the planar light guide 108 educated. The side surface 110a closes with the plane of the planar light guide 108 an angle greater than 90 °. This will change the proportion of the side surface 110a totally reflected light compared to an arrangement according to 5a elevated. In addition, by the inclined side surface 110a the light reflects in the forward direction.

5c shows a planar light guide 108 , as used in the embodiments, in sectional view. The side surface 110a is coated with a mirror. The mirror can be designed as a silver mirror. The mirroring makes up the proportion of the side surface 110a reflected Light opposite to an arrangement according to 5b increased again.

5d shows a planar light guide 108 , as used in the embodiments, in sectional view. This planar light guide 108 is a development of the planar light guide in 5b , The edge 110 has several side surfaces 110a on. The side surfaces 110a are each at the angle α, which is greater than 90 °, with respect to the plane of the planar light guide 108 inclined.

In a further development of the planar light guide, not shown 108 out 5d can also use the multiple side surfaces 110a of the edge 110 be mirrored.

6 shows a sixth embodiment of an optoelectronic device according to the invention 412 for producing white light in sectional view. These are two wire-bonded semiconductor chips 104c shown. One contact each of the semiconductor chips 104c is over a bonding wire 136 realized. On the semiconductor chips 104c is each a conversion element 112 arranged. The conversion element 112 surmounted the highest point of the bonding wire 136 , At a "loop height" of the bonding wire 136 of about 70 microns, the conversion element 112 have a height of more than 70 microns. The gap 106 and the area between the semiconductor chips 104c and the edge region of the optoelectronic device 412 are with a reflective potting 109 shed. The planar light guide 108 has silicone in the particle 114 introduced to the light mixture. The edge 110 of the planar light guide 108 has a side surface 110a at an angle α greater than 90 ° with the plane of the planar light guide 108 includes. The from the carrier 102 remote surface 116 of the planar light guide 108 is roughened. As a roughening a moth eye structure is shown.

7 shows a seventh embodiment of an optoelectronic device according to the invention 414 in plan view. The wire-bonded semiconductor chips 104c are arranged in a row. The contacting of the semiconductor chips 104c is in each case via a laterally arranged bonding wire 136 realized, which leads to a laterally arranged bonding pad 132 on the carrier 102 leads. By this lateral contacting, the minimum distance between the semiconductor chips 104c be reduced to about 50 microns. To the luminance, over the approximately 50 μm wide gaps 106 occurs, is a thin planar light guide 108 sufficient with a thickness of about 50 microns. The light guide 108 covers the semiconductor chips 104c , the bonding wires 136 , the bond pads 132 , the contact pads 134 and especially the gaps 106 Completely. The planar light guide 108 has a circumferential border 110 on. The edge 110 can one of the in the 5a . 5b . 5c or 5d have shown structures.

8th shows an eighth embodiment of an optoelectronic device according to the invention 416 in plan view. The semiconductor chips 104 are arranged in a hexagonal closest packing. This is the width of the gaps 106 between the semiconductor chips 104 minimized. The planar light guide 108 covers the arrangement of the plurality of semiconductor chips 104 Completely. For reasons of clarity, any wire contacts are not shown. As in the embodiment of 7 is a planar light guide 108 with a thickness of about 50 microns for better homogenization of the luminance over the gaps 106 sufficient.

nine shows a lighting device according to the invention 300 in sectional view. A secondary optic 302 in the form of a lens, the optoelectronic arrangement is arranged downstream in the emission direction. As optoelectronic arrangement, all the above-mentioned optoelectronic arrangements 402 to 416 to get voted.

In the method for producing an optoelectronic device 402 . 404 . 406 . 408 . 410 . 412 . 414 . 416 becomes a carrier first 102 provided. Subsequently, at least two semiconductor chips 104 . 104a . 104b . 104c for emission of electromagnetic radiation on the carrier 102 arranged. This is between adjacent semiconductor chips 104 . 104a . 104b . 104c one gap each 106 educated. Subsequently, a planar light guide 108 for mixing the electromagnetic radiation of the semiconductor chips 104 . 104a . 104b . 104c the semiconductor chips 104 . 104a . 104b . 104c downstream in the emission direction. This ensures that the planar light guide 108 the respective gaps 106 covered.

The optoelectronic semiconductor device and the method for producing an optoelectronic semiconductor device have been described to illustrate the underlying idea based on some embodiments. The embodiments are not limited to specific feature combinations. Although some features and configurations have been described only in connection with a particular embodiment or individual embodiments, they may each be combined with other features from other embodiments. It is also possible to omit or add in individual embodiments illustrated features or particular embodiments, as far as the general technical teaching is realized.

Although the steps of the method of manufacturing an optoelectronic semiconductor device are described in a particular order, it is to be understood that any of the methods described in this disclosure may be performed in any other meaningful order, including but not limited to, method steps. unless deviated from the basic idea of the technical teaching described.

LIST OF REFERENCE NUMBERS

102

 carrier

104

 Semiconductor chip

104a

 Flip chip with non-contact radiating surface

104b

 Semiconductor chip with contact-free radiation surface

104c

 Semiconductor chip, wire bonded

106

 Gap between semiconductor chips

107

 Lot, in particular laterally exiting

108

 planar light guide

109

 reflective casting

110

 Edge of the planar light guide

110a

 side surface

112

 conversion element

114

 Particles, scattering and / or totally reflective

116

 Surface of the planar light guide

120

 Contact chip

122

 Bondpad on carrier

124

 Radiation emission side of a semiconductor chip

130

 Semiconductor chip contact layer

132

 Bondpad on carrier

134

 Contact pad on the semiconductor chip

136

 bonding wire

138

 loop height

140

 adhesive layer

α

 angle

202

 n-type layer

204

 active zone

206

 p-type layer

207

 vias

208

 passivation

210

 silver mirror

212

 n-metallization

214

 The semiconductor die carrier

216

 conductive channel

220

 n-Pad

222

 p-Pad

300

 lighting device

302

 secondary optics

402-416

 optoelectronic arrangement

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2005081319 A1 [0014]

Claims (15)

Optoelectronic arrangement ( 402 . 404 . 406 . 408 . 410 . 412 . 414 . 416 ) with: - a carrier ( 102 ), - at least two semiconductor chips ( 104 . 104a . 104b . 104c ) for emitting electromagnetic radiation emitted on the support ( 102 ) are arranged between each adjacent semiconductor chips ( 104 . 104a . 104b . 104c ) a gap ( 106 ) is formed and - a planar light guide ( 108 ) for mixing the electromagnetic radiation that the semiconductor chips ( 104 . 104a . 104b . 104c ) is arranged downstream in the emission direction and the respective gap ( 106 ) covered. Optoelectronic assembly according to claim 1, wherein between a radiation emission side ( 124 ) of the semiconductor chips ( 104 . 104a . 104b . 104c ) and the planar light guide ( 108 ) each have a conversion element ( 112 ) is arranged. Optoelectronic device according to claim 1 or 2, wherein the gap ( 106 ) between the semiconductor chips ( 104 . 104a . 104b . 104c ) with a reflective potting ( 109 ), in particular of silicone, in which scattering particles of at least one of the following materials - titanium dioxide (TiO ₂ ), - alumina (Al ₂ O ₃ ) - zirconium oxide (ZrO) - barium fluoride (BaF ₂ ) are introduced, wherein the scattering particles in a total concentration of 5% by weight to a total of 60% by weight in the casting ( 109 ) are present. Optoelectronic arrangement according to one of the preceding claims, wherein an edge ( 110 ) of the planar light guide ( 108 ) one or more side surfaces ( 110a ) which is at an angle (α) of greater than 90 ° to the semiconductor chips ( 104 . 104a . 104b . 104c ) facing side of the planar light guide ( 108 ) are arranged. Optoelectronic assembly according to claim 4, wherein the one or more side surfaces ( 110a ) of the planar light guide ( 108 ) are provided with a mirror, in particular a silver mirror. Optoelectronic arrangement according to one of the preceding claims, wherein the planar light guide ( 108 ) has a thickness of about 50 μm to about 200 μm, preferably from about 75 μm to about 175 μm, particularly preferably from about 100 μm to about 150 μm. Optoelectronic arrangement according to one of the preceding claims, wherein the planar light guide ( 108 ) has at least one of the matrix materials - silicone, - glass, - polymethylmethacrylate (PMMA), - polycarbonate (PC). Optoelectronic arrangement according to one of the preceding claims, wherein in the planar light guide ( 108 ) Particles ( 114 ), in particular scattering particles of at least one of the materials - titanium dioxide (TiO ₂ ), - alumina (Al ₂ O ₃ ) - zirconium oxide (ZrO) - barium fluoride (BaF ₂ ) and / or totally reflecting particles, in a total concentration of 0.001 percent by weight to a total of 10 weight percent, are embedded. Optoelectronic arrangement according to one of the preceding claims, wherein the planar light guide ( 108 ) has refractive index differences across its volume. Optoelectronic arrangement according to one of claims 2 to 9, wherein the refractive indices n of the planar light guide ( 108 ) and the conversion element ( 112 ) satisfy the following condition: n (optical fiber) <n (conversion element) Optoelectronic arrangement according to one of claims 2 to 10, wherein the planar light guide ( 108 ) and the conversion element ( 112 ) by an adhesive layer ( 140 ), in particular of silicone, whose thickness d of the following condition with respect to the wavelength λ of the semiconductor chip ( 104 ) emitted electromagnetic radiation is sufficient: d <λ / 2 Optoelectronic arrangement according to one of claims 2 to 11, wherein the planar light guide ( 108 ) and the conversion element ( 112 ) by an adhesive layer ( 140 ) satisfies the following condition with respect to refractive indices n: n (optical fiber) <n (adhesive) <n (conversion element). Optoelectronic device according to one of the preceding claims, wherein the carrier ( 102 ) facing away from the surface ( 116 ) of the planar light guide ( 108 ) is roughened and has as structure in particular a pyramidal structure and / or a moth eye structure. Lighting device ( 300 ) with an optoelectronic arrangement ( 402 . 404 . 406 . 408 . 410 . 412 . 414 . 416 ) according to one of claims 1 to 13, wherein a secondary optic ( 302 ), in particular one Lens, the radiation exit surface of the planar light guide ( 108 ) is subordinate. Method for producing an optoelectronic device ( 402 . 404 . 406 . 408 . 410 . 412 . 414 . 416 ) comprising the following steps: - providing a carrier ( 102 ); Arranging at least two semiconductor chips ( 104 . 104a . 104b . 104c ) for the emission of electromagnetic radiation ( 108 ) on the support ( 102 ), wherein in each case between adjacent semiconductor chips ( 104 . 104a . 104b . 104c ) a gap ( 106 ) is formed; Arranging a planar light guide ( 108 ) for mixing the electromagnetic radiation that the semiconductor chips ( 104 . 104a . 104b . 104c ) is arranged downstream in the emission direction and the gap ( 106 ) covered.

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