DE102018113607A1 - Optoelectronic semiconductor device - Google Patents

Abstract

In one embodiment, the optoelectronic semiconductor component (1) comprises at least one semiconductor chip (2) for generating radiation, a low-refractive layer (6) and an optical attachment (4), which is optically arranged downstream of a main side (20) of the semiconductor chip (2). A reflector (5) surrounds the optical attachment (4) laterally all around and is set up to reflect the radiation and visible light. The optical attachment (4) has a base surface (A) facing the semiconductor chip (2) and an exit surface (B) facing away from the semiconductor chip (2). In the direction away from the semiconductor chip (2), the optical attachment (4) tapers. The low refractive layer (6) lies between the main side (20) and the exit surface (B).

Description

An optoelectronic semiconductor component is specified.

An object to be solved is to specify an optoelectronic semiconductor component which has a high luminance.

This object is achieved inter alia by an optoelectronic semiconductor component having the features of claim 1. Preferred developments are the subject of the other claims.

In accordance with at least one embodiment, the semiconductor component comprises one or more semiconductor chips. The at least one semiconductor chip is set up to generate a radiation, in particular a primary radiation. The radiation is preferably visible light, especially blue light. Alternatively, the radiation can also be ultraviolet radiation, for example with a maximum intensity wavelength of at least 360 nm or 385 nm and / or at most 420 nm or 405 nm. The semiconductor chip is preferably a light-emitting diode chip, or LED chip for short. Furthermore, it is possible for the at least one semiconductor chip to be set up for generating infrared radiation, in particular for near-infrared radiation, for example with an intensity maximum at at least 680 nm and / or at most 1060 nm.

According to at least one embodiment, the semiconductor chip or each of the semiconductor chips each have a main side. The main side is preferably a radiation exit surface, in particular the single radiation exit surface of the relevant semiconductor chip. If a plurality of semiconductor chips and thus a plurality of radiation exit surfaces are present, then the radiation exit surfaces can lie in a common plane.

To generate the radiation, the semiconductor chip comprises a semiconductor layer sequence. The semiconductor layer sequence has an active zone, which may preferably have a pn junction and / or a quantum well structure. The semiconductor layer sequence is based, for example, on a III-V compound semiconductor material. The semiconductor material is, for example, a nitride compound semiconductor material such as Al _n In _{1 nm} Ga _m N or a phosphide compound semiconductor material such as Al _n In _{1 nm} Ga _m P or an arsenide compound semiconductor material such as Al _n In _{1 nm} Ga _m As or as Al _n Ga _m In _{1 nm} As _k P _1-k , where 0 ≦ n ≦ 1, 0 ≦ m ≦ 1 and n + m ≦ 1 and 0 ≦ k <1. For at least one layer or for all layers of the semiconductor layer sequence, 0 <n ≦ 0.8, 0.4 ≦ m <1 and n + m ≦ 0.95 and 0 <k ≦ 0.5 preferably apply here. In this case, the semiconductor layer sequence may have dopants and additional constituents. For the sake of simplicity, however, only the essential constituents of the crystal lattice of the semiconductor layer sequence, that is to say Al, As, Ga, In, N or P, are indicated, even if these may be partially replaced and / or supplemented by small amounts of further substances.

In accordance with at least one embodiment, the semiconductor component includes an optical attachment or a plurality of optical attachments. The at least one light-transmissive, preferably transparent, optical attachment which is transparent to the radiation and / or visible light is optically arranged downstream of the at least one main side of the at least one semiconductor chip. The optical attachment can be constructed in one piece or in several pieces. In the case of a multi-piece optical attachment, the individual parts may be attached directly to one another or may be present separately from one another in the semiconductor component.

In accordance with at least one embodiment, the optical attachment is integrally molded and monolithic. In particular, the optical attachment is free of internal cavities. The optical attachment is then formed, for example, of a single piece and / or of a single material.

In accordance with at least one embodiment, the optical attachment is made of a high refractive index material, such as a plastic such as polycarbonate, silicone or epoxy or a hybrid material thereof. Furthermore, the optical attachment can be made of a glass or a mineral. In particular, the optics cap is made of a material, for example sapphire, with a refractive index of at least 1.55 or 1.7 or 1.8 or 2.0, based on the wavelength of maximum intensity of the radiation of the semiconductor chip and at a temperature of 300 K. If the optical attachment is designed in several parts, the individual parts can be made of materials with different refractive indices, and less preferably all parts can be made of the same material.

In accordance with at least one embodiment, a refractive index of the parts of the optical attachment decreases in the direction away from the semiconductor chip. That is, parts further from the semiconductor chip have a lower refractive index. Within the individual parts, the refractive index can be constant. The respectively associated low-refractive-index layers can accordingly be adapted, so that a refractive index of the low-refractive-index layers in the direction away from the semiconductor chip can also decrease, but alternatively can also remain the same.

In accordance with at least one embodiment, the optical attachment is not an imaging element. That is, the optics attachment has no focal point and no focal plane. In particular, the optical attachment is not designed as a converging lens.

In accordance with at least one embodiment, the semiconductor device comprises one or more low-refraction layers. A refractive index of the at least one low-index layer for the radiation is preferably at most 1.5 or 1.4 or 1.3 or 1.1. For example, the low refractive index layer is of a plastic such as an acrylate, especially a fluorinated acrylate, a low refractive index glass or a mineral such as fluorides, especially magnesium fluoride. The low-refractive-index layer is preferably a gas layer, for example of air or of an inert gas such as nitrogen or argon. Less preferred is the low refractive index layer of a low refractive liquid. If several low-index layers are present, they can be made of materials with different refractive indices or else each of the same material.

In accordance with at least one embodiment, the semiconductor component comprises one or more reflectors. The at least one reflector is attached laterally to the optical attachment and to the low refractive layer. The reflector preferably surrounds the optical attachment and the low-refractive layer all around in a form-fitting manner. It is possible that side surfaces of the optical attachment and / or the low-refraction layer are partially or completely covered by the reflector. The reflector can be located directly on the side surfaces.

In accordance with at least one embodiment, the reflector is designed for reflection of the radiation generated in the semiconductor chip and / or of visible light. This means, for example, that the reflector in the spectral range from 380 nm to 700 nm has an average reflectivity or continuously a reflectivity of at least 80% or 90% or 95%. Alternatively or additionally, the reflector may be configured to reflect a secondary radiation generated by an optional converter.

In accordance with at least one embodiment, the optical attachment has a base surface facing the at least one semiconductor chip. The base can be designed plan. In particular, the base area is aligned parallel to the main side of the at least one semiconductor chip.

In accordance with at least one embodiment, the optical attachment has an exit surface facing away from the at least one semiconductor chip. The exit surface lies opposite the base surface. It is possible for the base area and the exit area to be flat in the middle, that is to say they do not have a curvature extending overall over the base area or the exit area, as is the case, for example, with converging lenses or with Fresnel lenses. In particular, the base surface and the exit surface can be oriented parallel or on average parallel to one another. "Middle plan" does not exclude that in particular the exit surface can be provided with a roughening for better radiation decoupling.

In accordance with at least one embodiment, the optical attachment tapers in the direction away from the at least one semiconductor chip, preferably monotonically or strictly monotonically. 'Strictly monotone' means that the optical attachment tapers continuously and steadily away from the semiconductor chip. 'Monotone' means that the optical attachment in the direction away from the semiconductor chip can also taper in steps, so that the optical attachment sections can have a constant width. However, the optics attachment preferably does not widen at any point in the direction away from the semiconductor chip, apart from roughening, damage, or manufacturing tolerances. The fact that the optical attachment tapers refers to at least one or more cross sections, preferably to all cross sections through the optical attachment, especially in the direction perpendicular to the emission surface and / or to the base.

In accordance with at least one embodiment, the at least one low-refraction layer is located between the main side and the exit surface. The low-refractive-index layer or one of the low-refractive-index layers is preferably located directly on the main side and / or directly on a phosphor body attached to the main side.

In at least one embodiment, the optoelectronic semiconductor component comprises at least one semiconductor chip for generating radiation, at least one low-refraction layer and an optical attachment, which is optically arranged downstream of a main side of the semiconductor chip. A reflector surrounds the optical attachment laterally all around and is adapted to reflect the radiation and visible light. The optical attachment has a base area facing the semiconductor chip and an exit area facing away from the semiconductor chip. In the direction away from the semiconductor chip, the optical attachment tapers. The low refractive layer lies between the main side and the exit surface.

The current density in LED chips can not be arbitrarily increased, so that a luminance of LED chips and thus also of semiconductor components based on LED chips is limited. However, the emitted luminance plays an important role in many applications in which the light generated is in an optical system is further processed. Only if an etendue of a design is less than or equal to the etendue of the optical system, the emitted light becomes usable in the application. Since a surface of the emitter, in particular of the LED chip, enters the etendue linearly, the usable luminous flux is often limited by the luminance of the design and the etendue of the optical system.

In the semiconductor device described here, on the one hand, the luminance of the design can be increased over that of the individual LED chips, and, on the other hand, the etendue can be optimized for the target application so that more light is available for the application.

In this case, radiation from the semiconductor chip outside a given etendue is to receive another opportunity to leave the semiconductor component within the target etendue.

This is also known under the keyword light-recycling. For this purpose, usually the semiconductor chip itself is used as a reflector. In contrast, in the case of the semiconductor component described here, at least one plane lying in the light path is used as the reflector, that is, the at least one low-refractive layer is used. As a result, incident light can be reflected to this level almost completely lossless by internal total reflection within a certain angular range, contrary to the usual emission direction.

The advantage of this procedure is in particular that the concept is not limited by the reflectivity of the semiconductor chip itself. For example, the reflectivity for red emitting LEDs is around the emission wavelength in the range of only 30%. In this case, however, a refractive index jump on the low-refractive-index layer should also not be too large in order not to excessively reduce light coupling into the optical attachment.

Instead of semiconductor chips or LED chips, other planar emitters can also be provided with a corresponding optical attachment, a low-refraction layer and a reflector, for example organic light-emitting diodes or planar arrangements of other light sources such as fluorescent tubes.

The exit surface of the optical attachment can be adapted by a coating or by structuring in terms of transmission and emission characteristics. The optical attachment and / or the reflector can have light-scattering properties that optimize the light flux through the exit surface.

According to at least one embodiment, one or more phosphor bodies are located between the optical attachment and the semiconductor chip. The at least one phosphor body is set up for the partial or complete conversion of the radiation of the at least one semiconductor chip into a longer-wavelength secondary radiation. If a plurality of semiconductor chips are present, then each semiconductor chip can be assigned a separate phosphor body, or a single phosphor body can extend over all the semiconductor chips together. Likewise, a plurality of phosphor bodies can be assigned to one of the semiconductor chips. Furthermore, different phosphor bodies may be present, which are assigned to different semiconductor chips.

In accordance with at least one embodiment, the base area completely covers the phosphor body or bodies. That is, the at least one phosphor body is covered over the entire surface of the optical attachment.

In accordance with at least one embodiment, the low-refractive-index layer has a thickness of at least 5 L or 10 L, where L is the maximum-intensity vacuum wavelength of the radiation emitted by the semiconductor chip during operation. Alternatively or additionally, the thickness is at least 5 μm or 10 μm and / or at most 0.3 mm or 0.1 mm or 50 μm or 20 μm. If several low-index layers are present, this is preferably true for each individual low-index layer.

In accordance with at least one embodiment, the phosphor body is located directly on the main side of the relevant semiconductor chip or directly on the base surface of the optical attachment. 'Direct' does not exclude the presence of a bonding agent, such as an adhesive layer, which secures the respective components together.

In accordance with at least one embodiment, the semiconductor chip has a structuring on the main side. Due to the structuring, a coupling-out efficiency of the radiation out of the semiconductor chip is increased, and / or a directional radiation towards the optical attachment takes place, in comparison to a semiconductor chip without such structuring. The structuring may be formed by an irregular roughening or by a regular surface texture.

In accordance with at least one embodiment, a refractive index difference between the optics cap and the low refractive index layer is at least 0.15 or 0.25 or 0.3. Alternatively or additionally, the refractive index difference is at most 1.0 or 0.5 or 0.47. Preferably, the refractive index difference is between 0.3 and 0.5 inclusive, a high total reflectance contribution to the low refractive index layer for radiation from the reflector, and high coupling of Radiation in the optical attachment into the semiconductor chip ago to get.

According to at least one embodiment, the optical attachment is designed in several parts and thus has several parts. The parts of the optical attachment follow each other in the direction away from the main side of the semiconductor chip. Between adjacent parts, a low-refractive layer is arranged in each case. Furthermore, a low-refractive-index layer is preferably located on the base surface, that is to say on a side of the part of the optical attachment facing the semiconductor chip which is closest to the semiconductor chip. A number of the low-refractive layers are in particular equal to the number of parts of the optical attachment.

In accordance with at least one embodiment, the reflector is narrower in the region of the low-refractive-index layer than in the region of the semiconductor chip. Thus, the reflector can form a receptacle for the semiconductor chip. Thus, the semiconductor chip is defined to be storable in the reflector, optionally together with the phosphor body, even if the low-refractive layer is of a gas.

In accordance with at least one embodiment, the optical attachment has one or more spacers. The at least one spacer preferably defines a thickness of the low refractive index layer. The spacer can completely penetrate the low refractive index layer. In particular, the spacer extends to the main side of the semiconductor chip and / or to the top of the phosphor body. The spacer can be designed as a ring that surrounds the optical attachment on the outside of the base all around.

In accordance with at least one embodiment, the semiconductor component comprises one or more spacers. The at least one spacer is located between the optical attachment and the semiconductor chip. By means of the spacer body, the low-refractive layer can be defined. The low-refractive-index layer and the spacer body preferably have the same thickness. It is possible that the spacer body is designed as a sealing ring against a material of the reflector.

In accordance with at least one embodiment, a quotient of the base area and a height of the optical attachment is at least 1 mm or 2 mm or 3 mm or 4 mm. Alternatively or additionally, this quotient is at most 30 mm or 20 mm or 15 mm or 12 mm or 10 mm or 8 mm. The base area denotes the surface area of the surface facing the at least one semiconductor chip, measured approximately in mm ² . The height is the extent of the optical attachment, in particular from the base surface to the exit surface, determined in particular in the direction perpendicular to the base surface and measured approximately in mm. This results in a unit of length such as mm for the quotient of the base area and the height.

In accordance with at least one embodiment, a quotient of the base area and the emission area is at least 1 or 1.05 or 1.5 or 2. Alternatively or additionally, this quotient is at most 8 or 5 or 3.5. In other words, the footprint is about twice or three times the size of the radiating surface. For example, with a quotient of 1, a preferably area-preserving transformation of the emission surface is possible, for example from a rectangle to a square of the same size.

In accordance with at least one embodiment, the base area has a size of at least 1 mm ² or 4 mm ² or 6 mm ² and / or of at most 50 mm ² or 30 mm ² or 15 mm ² . Alternatively or additionally, the height of the optical attachment is at least 0.2 mm or 1 mm or 1.5 mm and / or at most 7 mm or 5 mm or 3 mm. Accordingly, the above-mentioned values for the quotient of the base area and the height result.

In accordance with at least one embodiment, the optical attachment is seen in cross-section and shaped along a direction away from the semiconductor chip in regions or completely like a symmetrical trapezoid. A mirror symmetry axis is preferably aligned perpendicular to the base surface and / or perpendicular to the main side of the semiconductor chip. Thus, the optics essay on some areas or in whole constant obliquely to the base surface extending side surfaces. In particular, the optical attachment is designed as a regular truncated pyramid with a square or rectangular base.

In accordance with at least one embodiment, the optical attachment is seen in cross section and shaped away from the at least one semiconductor chip from the following three basic forms: rectangle, symmetrical trapezoid, rectangle. Thus, the trapeze between two rectangles can be introduced. The side surfaces of the optical attachment thus run perpendicular to the base surface on the semiconductor chip, then at a constant angle and then again vertically. The optical attachment has, seen in cross-section, preferably a single mirror symmetry axis perpendicular to the base surface.

According to at least one embodiment, the optical attachment is seen in cross-section and in the direction away from the at least one semiconductor chip partially or completely shaped like a step pyramid, preferably like a symmetrical step pyramid. The step pyramid can be regular be shaped and seen in plan view in particular have two or four axes of symmetry, depending on whether the base is square or rectangular, which is preferably the case. The step pyramid has, for example, two or three stages, but may also be formed by four or more stages. The individual stages of the stepped pyramid are preferably formed by rectangles when viewed in cross-section.

As an alternative to a symmetrical construction, the optical attachment can, viewed in cross-section, also be asymmetrically shaped. In this case, it is possible for the optical attachment to have no axis of symmetry in at least one or in all cross sections.

According to at least one embodiment, the optical attachment is seen in cross-section partially or completely concave curved. In this case, a mirror symmetry axis is aligned, for example, perpendicular to the base surface. Concave in this context means, in particular, that the optical attachment near the semiconductor chip tapers more strongly than in regions that are farther from the semiconductor chip. Due to the concave curvature, therefore, a rate of the taper in the direction away from the semiconductor chip can decrease continuously and / or steadily. For example, seen in cross section, a concave curved portion is combined with a rectangular base.

Alternatively, seen in cross section, the optics attachment may be curved in regions or completely convexly, so that the optics attachment then tapers more strongly at least in areas further away from the semiconductor chip than in areas that lie closer to the semiconductor chip.

The aforementioned explanations on the shape of the optical attachment can apply to the optical attachment as a whole or only for individual parts of a multipart optics attachment.

According to at least one embodiment, the base surface is square or rectangular or regularly hexagonal. In contrast, the radiating surface in plan view on a different geometric shape. In particular, the radiating surface is then round or circular or elliptical.

In accordance with at least one embodiment, the base area merges into the emission surface in the direction away from the at least one semiconductor chip with a continuously differentiable side surface. This means, for example, that in the cross section perpendicular to the base surface, any side line of the side surface can run without kinking.

Alternatively, the side surface may also have a kink and / or a step, or also several kinks and / or several steps. In this case, the side surface is not continuously differentiable.

According to at least one embodiment, the reflector is partially or completely formed by a potting. Preferably, the potting is diffusely reflective for visible light and the radiation from the semiconductor chip. The casting can appear white to a viewer. For example, the potting is made of a transparent and radiation-transparent matrix material such as a silicone or an epoxide, which is filled with metal oxide particles, such as titanium dioxide.

In accordance with at least one embodiment, the encapsulation is plan-shaped on a reflector top facing away from the at least one semiconductor chip. Alternatively or additionally, the reflector upper side can run parallel to the main side of the at least one semiconductor chip. This makes it possible for the semiconductor component to appear cuboid in cross section.

In accordance with at least one embodiment, the encapsulation, which forms the reflector, has a minimum thickness of 0.1 mm or 0.2 mm or, preferably, 0.3 mm, on the reflector top remote from the at least one semiconductor chip, in particular directly on the optical attachment. It can thereby be ensured that the reflector is also impermeable to the radiation and / or to visible light on the reflector top near the optical attachment.

In accordance with at least one embodiment, the reflector top side terminates flush with the emission surface. That is, the reflector top and the radiating surface may lie in a common plane and / or smoothly merge.

In accordance with at least one embodiment, the reflector is formed in places or completely by a specularly reflective coating on the optical attachment. The coating can be applied directly to the side surfaces of the reflector. For example, the reflective coating covers at least 30% or 50% or 70% or 95% of the side surfaces of the optical attachment and / or at most 90% or 60%.

In particular, it is possible that the reflector is composed of the reflective coating and the reflective potting and thus has specular as well as diffuse reflecting subregions.

In accordance with at least one embodiment, the reflective one is Coating around a metal coating, alternatively a dielectric coating in the form of a Bragg mirror. A thickness of the coating is preferably at most 10 μm or 2 μm or 0.5 μm. Alternatively or additionally, this thickness is at most 1% of the height of the optical attachment. The coating is thus thin compared to the optical attachment.

In accordance with at least one embodiment, the semiconductor component comprises a plurality of the semiconductor chips. The semiconductor chips are preferably arranged in a regular pattern. Preferably, at least four or six and / or at most 32 or 16 of the semiconductor chips are present, which are preferably arranged in a square grid.

In accordance with at least one embodiment, the semiconductor chips are covered continuously and uninterruptedly by the base area. In this case, the optical attachment is preferably free of a beam guiding device for individual or groups of the semiconductor chips. That is, after entering the optical attachment, a difference blurs between radiation components coming from the different semiconductor chips. In other words, there is a single, common and internally unstructured optical attachment for all semiconductor chips together.

In accordance with at least one embodiment, gaps are formed between adjacent semiconductor chips. The gaps have, for example, a width of at least 1 .mu.m and / or at most 150 .mu.m or 50 .mu.m or 10 .mu.m. The interstices may be partially or completely filled with a potting. The potting body is preferably reflective, designed at least for the primary radiation, preferably also for the secondary radiation and / or for visible light.

Hereinafter, an optoelectronic semiconductor device described here will be explained in more detail with reference to the drawings based on embodiments. The same reference numerals indicate the same elements in the individual figures. However, there are no scale relationships shown, but individual elements can be shown exaggerated for better understanding.

• 1 bis 8 schematische Schnittdarstellungen von Ausführungsbeispielen von hier beschriebenen optoelektronischen Halbleiterbauteilen,
• 9A eine schematische Schnittdarstellung eines Ausführungsbeispiels eines hier beschriebenen optoelektronischen Halbleiterbauteils,
• 9B eine schematische perspektivische Darstellung des Halbleiterbauteils der 9A,
• 10 bis 12 schematische Schnittdarstellungen von Ausführungsbeispielen von hier beschriebenen optoelektronischen Halbleiterbauteilen, und
• 13A und 13B schematische Draufsichten auf Ausführungsbeispiele von hier beschriebenen optoelektronischen Halbleiterbauteilen.

Show it:

• 1 to 8th schematic sectional views of embodiments of optoelectronic semiconductor devices described herein,
• 9A FIG. 2 a schematic sectional view of an embodiment of an optoelectronic semiconductor component described here, FIG.
• 9B a schematic perspective view of the semiconductor device of 9A .
• 10 to 12 schematic sectional views of embodiments of optoelectronic semiconductor devices described herein, and
• 13A and 13B schematic plan views of embodiments of optoelectronic semiconductor devices described herein.

In 1 is an embodiment of an optoelectronic semiconductor device 1 shown. On a carrier 9 For example, a ceramic circuit board or a metal core board is a semiconductor chip 2 arranged. A light-emitting main page 20 of the semiconductor chip 2 is the carrier 9 away. The carrier 9 preferably comprises conductor tracks and connection points for electrical contacting of the semiconductor chip 2 , not drawn. Accordingly, electrical insulation layers may be present, not drawn.

The semiconductor chip 2 is an optical attachment 4 , for example made of sapphire, downstream. This is the optics attachment 4 made of a transparent, transparent material for visible light and has a comparatively high refractive index for from the semiconductor chip 2 generated during operation radiation.

Between the semiconductor chip 2 and the optics attachment 4 there is a low refractive layer 6 which has a relatively low refractive index for the radiation generated during operation. For example, it is the low-refractive layer 6 around a thin layer of low-refractive silicon. Since sapphire has a refractive index of about 1.8 and the silicone has a refractive index of about 1.4, it lies between the low refractive index layer 6 and the optics attachment 4 a refractive index jump of about 0.4. As an alternative to a solid, the low-refraction layer 6 also be from a gas such as air or nitrogen or be formed by an evacuated area.

The optics attachment 4 tapers away from the semiconductor chip 2 , This affects the optical attachment 4 as a light concentrator and the semiconductor device 1 has a smaller light emission surface, so that higher luminance can be realized.

The optics attachment 4 is for example composed of two areas. Directly at the low refractive layer 6 and thus directly on a base area A of the optics tower 4 is a rectangular in cross-section area. Directly on a semiconductor chip 2 remote exit surface B of the optics tower 4 there is a trapezoidal area. The areas go in one kink 43 into each other. faces 42 of the optics tower 4 are each planar shaped. A thickness of the rectangular area at the base A is preferably at least 0.1 mm and / or at most 0.5 mm. A height of the optics attachment 4 total is preferably at least 0.5 mm and / or at most 3 mm.

Furthermore, the semiconductor device comprises 1 a reflector 5 with a carrier 9 opposite reflector top 51 , The reflector top 51 goes planar into the exit surface B about. Due to the reflector 5 the semiconductor device appears 1 Seen in cross section rectangular and is a total of cuboid.

The reflector 5 is preferably formed by a potting, for example, by a silica filled with titanium dioxide particles, so that the reflector appears diffusely reflected and white.

Due to the refractive index jump between the optical attachment 4 and the low-refractive layer 6 forms the low-refractive layer 6 a totally reflective interface for radiation from the reflector 5 around the optics attachment 4 around to the low-refractive layer 6 arrives. Thus, an effective light recycling can be achieved because absorption of this radiation component in the semiconductor chip 2 can be avoided. The refractive index jump here is preferably not too large, so that a Lichteinkoppeleffizienz from the semiconductor chip 2 into the optics attachment 4 is high enough.

In the embodiment of 2 is shown that the optics attachment 4 at the exit surface B with a structuring 45 and / or may be provided with an antireflection coating to exit the high refractive optical attachment 4 to achieve a high light extraction efficiency.

Furthermore, in 2 the semiconductor chip 2 shown in more detail. The semiconductor chip 2 comprises a semiconductor layer sequence 21 , The semiconductor layer sequence 21 is optionally located on a chip substrate 25 , The chip substrate 25 is preferably a replacement carrier for a growth substrate, but may also be a growth substrate for the semiconductor layer sequence 21 his. Is the chip substrate 25 a replacement carrier, so is located between the replacement carrier and the semiconductor layer sequence 21 preferably a chip mirror 24 , For example, a metal mirror or a metal-dielectric combination mirror.

At the main page 20 is the semiconductor chip 2 preferably with a structuring 22 provided to a high Lichtauskoppeleffizienz and a directed radiation towards the optical attachment 4 to achieve. Furthermore, on the main page 20 a passivation 23 to be appropriate.

Such structuring 45 and / or antireflection layer and such a semiconductor chip 2 , as in connection with 2 illustrated, are preferably present in all other embodiments.

According to 3 is the optics attachment 4 from several parts 4a . 4b composed. The parts 4a . 4b are moving away from the semiconductor chip 2 ever smaller, relative to a lateral extent. Next take the refractive indices of the parts 4a . 4b in the direction away from the semiconductor chip 2 preferably off, so the part 4b a smaller refractive index than the part 4a that is closer to the semiconductor chip 2 located. Deviating from the illustration in 3 can the parts 4a . 4b Seen in cross-section also have different basic shapes.

Between adjacent parts 4a . 4b is one of the low-refractive layers 6 , This low-refractive layer 6 covers the adjacent surfaces of the parts 4a . 4b preferably completely or at least predominantly, in particular at least 90%. The layers 6 are preferably all made of the same material, but may also have a refractive index of the individual layers 6 in the direction away from the semiconductor chip 2 lose weight.

It can also have more than two parts 4a . 4b and more than two of the low refractive layers 6 to be available.

Such multi-part optics essays 4 can be used in all other embodiments, other than shown.

As in all other embodiments, a respect to the outer contour in cross-section seen stepped shaped reflector 5 be used. Alternatively, unlike in 3 represented, also a cuboid reflector 5 be used.

In the embodiment of 4 has the semiconductor device 1 additionally a phosphor body 3 on. The phosphor body 3 is right on the main page 20 appropriate. It is located between the phosphor body 3 and the main page 20 only a thin layer of glue 8th , preferably with a thickness of at most 5 microns or 2 microns.

The low-refractive layer 6 is located on one of the main page 20 opposite top 30 of the phosphor body 3 , The phosphor body 3 , the layer 6 as well as the semiconductor chip 2 and optionally the adhesive layer 8th can be arranged congruently one above the other, as well as the optical attachment 4 ,

The optics attachment 4 is seen in cross-section of two rectangular areas on the exit surface B and at the base A and a trapezoidal intermediate region. Due to the rectangular cross section of the optics attachment 4 at the exit surface B is the reflector 5 also on the entire reflector top 51 light-tight, so from the semiconductor device 1 only at the exit surface B the generated light escapes.

The carrier 9 can be omitted. This is also possible in the other embodiments.

In 5 is illustrated that the phosphor body 3 not on the semiconductor chip 2 but on the optics attachment 4 is appropriate. Optionally, the not shown adhesive layer is present.

The optics attachment 4 of the 5 points at the exit surface B seen in cross-section a concave shape. This area with the concave shape is on a cuboid base directly on the base A appropriate. The cuboid and the concave area go with a kink 43 into each other.

In 6 is illustrated that the reflector 5 in the area of the semiconductor chip 2 has a broadening. Thus, a recess for receiving the semiconductor chip 2 educated. This allows the low-refractive layer 6 be from a gas, as a thickness of the layer 6 through the reflector 5 is defined. In this case, the reflector 5 preferably prefabricated, and the optical attachment 4 as well as the semiconductor chip 2 can in the finished reflector 5 placed and glued, for example. The recess for the semiconductor chip 2 can be wider than the semiconductor chip 2 self.

According to 7 has the optics attachment 4 a spacer 48 on, for example, a ring on the outside around the base A around. Through the spacer 48 is the low refractive layer 6 defined, which is for example from a gas.

The semiconductor device 1 of the 8th additionally comprises an annular spacer, for example 7 , The spacer 7 can be made of a transparent material. Through the spacer body 7 is the low refractive layer 6 , for example from a gas defined.

In the case of a gas layer for the low-refractive layer 6 can the optics tower 4 of a material having a comparatively low refractive index, for example of a silicone, to realize a refractive index difference of 0.4.

The spacer 7 and / or the spacer 48 can create a cavity for the low-refractive layer 6 caulk. So can the optics attachment 4 first on the semiconductor chip 2 put on and the reflector 5 then be formed subsequently. Is a phosphor body on the optics attachment 4 or on the semiconductor chip 2 present, so can the spacer body 7 and / or the spacer 48 on the optics attachment 4 and / or on the semiconductor chip 2 seated.

In 8th is also shown that the side surfaces 42 Seen in cross-section, each formed by two straight sections, by the kink 43 separated. The two sections of the optical attachment 4 are thus each designed truncated pyramid, the section further from the semiconductor chip 2 way points to the side surfaces 42 a bigger slope.

In the embodiment of 9A and 9B are several of the semiconductor chips 2 present, for example, are six semiconductor chips 2 mounted in a 2 x 3 arrangement. The semiconductor chips 2 For example, have a footprint of 2 mm ² , so that a size of the base area A total is about 12 mm ² . The side surfaces 42 of the optics tower 4 run continuously concave curved from the base A up to the exit area B ,

In 10 is illustrated that the optics attachment 4 can be realized by a step pyramid with two or more, in this case four stages. Furthermore, in 10 shown that the reflector 5 may be formed by a coating covering the side surfaces 42 completely cover. The base area A as well as the exit surface B are preferably free of this coating 5 , The coating 5 is for example a specularly reflecting metallic layer or else a dielectric layer stack, for example a Bragg mirror. The coating 5 may be laterally adjacent to the low refractive layer 6 extend or, unlike drawn, flush with the base A to lock.

Optionally, a potting body 5c available in which the optics tower 4 , the coating 5 and optionally the carrier 9 can be embedded. The potting body 5c may be reflective and in particular white designed or transparent or absorbent, such as black, depending on the particular requirements of the semiconductor device 1 ,

Such a coating for the reflector 5 , as in 10 can also be shown in the embodiments of the 1 to 9 be present, in addition to the potting for the reflector 5 , This makes it possible that the reflective effect not by the potting, but by the Coating is created. As a result, less light output and thus less heat is introduced into the potting.

In 11 is shown that the side surfaces 42 partly through the reflector 5a in the form of a specularly reflecting coating and partly through the reflector 5b are formed in the form of a diffusely reflecting potting. The side surfaces 42 optionally have a kink 43 on. Below the bend 43 , closer to the semiconductor chips 2 , are the side surfaces 42 continuous concave curve, above the bend 43 are the side surfaces 42 perpendicular to the base A oriented and straight. An area between the semiconductor chips 2 can through the reflector 5b filled out.

An appropriate combination of a coating and a casting on the side surfaces 42 is also possible in all other embodiments.

Optionally, the optics attachment 4 the semiconductor chips 2 significantly higher in the lateral direction, unlike in the embodiments of the 1 to 10 , Furthermore, in 11 illustrated the possibility that in the optics essay 4 a scattering agent 49 is introduced. The scattering agent 49 is formed, for example, by light-scattering particles. It is possible that the scattering agent 49 sedimented in the optics attachment 4 near the semiconductor chips 2 is concentrated. Alternatively to the representation of 11 can the scattering agent 49 also homogeneous in the optics attachment 4 distributed. Corresponding configurations can also be applied in all other embodiments in a corresponding manner.

In 12 is illustrated that the exit surface B with the structuring 45 is provided. The structuring 45 is formed for example by regularly arranged domes. About structuring 45 is a Lichtauskoppeleffizienz increasable. The structuring 45 can the reflector top 51 overshoot or, deviating from 12 , also from the reflector 5 be surpassed. Alternatively or in addition to such structuring 45 An optically active coating such as the antireflective coating can also be present. The same applies to all other embodiments.

The optics attachment 4 is formed by two truncated pyramids and by a cuboid. The truncated pyramid, which is closer to, for example, only a semiconductor chip 2 located, has steeper running side surfaces 42 on as the centrally arranged truncated pyramid.

The reflector 5 is designed as a potting, but the potting forms a contour of the optical attachment 4 after. This is the semiconductor device 1 seen in cross section not necessarily rectangular shaped.

In 13A is shown that the footprint A and the main side of the semiconductor chip or the arrangement of the semiconductor chips 2 are designed rectangular. In contrast, the exit surface B round, preferably shaped as an ellipse. A transition from the larger, angular base A towards the round, smaller exit area B preferably runs continuously and without cracks or edges.

In 13B is illustrated that the footprint A is square and the associated exit surface B is shaped as a circle.

The forms shown in the various embodiments for the optical attachment 4 can each with a reflector 5 be combined in the form of a coating and / or a potting. Likewise, the different configurations are for the low refractive index layer and the carrier as well as for the optional potting body 5c and also the scattering agent 49 combinable with each other.

Unless otherwise indicated, the components shown in the figures preferably each directly follow one another in the order indicated. Layers not in contact with the figures are preferably spaced apart from one another. As far as lines are drawn parallel to each other, the corresponding surfaces are preferably also aligned parallel to each other. Also, unless otherwise indicated, the relative positions of the drawn components relative to one another are correctly represented in the figures.

The invention described here is not limited by the description based on the embodiments. Rather, the invention encompasses any novel feature as well as any combination of features, including in particular any combination of features in the claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments.

LIST OF REFERENCE NUMBERS

1

optoelectronic semiconductor device

2

Semiconductor chip

20

Home

21

Semiconductor layer sequence

22

structuring

23

passivation

24

chip mirror

25

chip substrate

3

Luminescent body

30

Top of the phosphor body

4

optic attachment

4a, 4b

Parts of the optics attachment

42

Side surface of the optics attachment

43

Kink in the side surface of the optics attachment

45

structuring

48

spacer

49

spreading material

5

reflector

51

Reflector top

6

low refractive layer

7

spacers

8th

adhesive layer

9

carrier

A

Base of the optics attachment

B

Exit surface of the optics attachment

Claims (19)

Optoelectronic semiconductor device (1) with at least one semiconductor chip (2) for generating a radiation having a main side (20), a non-imaging optical attachment (4) which is optically subordinate to the main side (20) of the at least one semiconductor chip (2), - At least one low-refractive layer (6), and a reflector (5) which surrounds the optical attachment (4) and the at least one low-refraction layer (6) laterally all around and which is set up to reflect the radiation and / or visible light, in which the optics attachment (4) has a base area (A) facing the at least one semiconductor chip (2) and an exit area (B) facing away from the at least one semiconductor chip (2), the optics attachment (4) tapers in the direction away from the at least one semiconductor chip (2), and - The at least one low-refractive layer (6) between the main side (20) and the exit surface (B) is located. Optoelectronic semiconductor component (1) according to the preceding claim, in which at least one phosphor body (3) is located between the at least one semiconductor chip (2) and the optical attachment (4), which is set up for the partial or complete conversion of the radiation of the semiconductor chip (2) into a longer-wave secondary radiation, wherein the base (A) completely covers the phosphor body (3). Optoelectronic semiconductor component (1) according to the preceding claim, in which the phosphor body (3) is located either directly on the main side (20) or directly on the base surface (A). Optoelectronic semiconductor component (1) according to one of the preceding claims, in which the low-refractive layer (6) is located directly on the main side (20) of the semiconductor chip (2) or directly on one of the main side (20) facing away from the upper side (30) of the phosphor body (3 ) is located. Optoelectronic semiconductor component (1) according to one of the preceding claims, wherein the low refractive index layer (6) has a thickness of at least 5 L, where L is the maximum wavelength vacuum wavelength of the radiation emitted by the semiconductor chip (2) during operation, and wherein the thickness of the low-refractive layer (6) is at most 0.1 mm. Optoelectronic semiconductor component (1) according to one of the preceding claims, wherein the semiconductor chip (2) on the main side (20) has a structuring (22), so that a coupling-out efficiency of the radiation from the semiconductor chip (2) is increased and a directional radiation toward the Optics attachment (4) takes place. An optoelectronic semiconductor device (1) according to any one of the preceding claims, wherein a refractive index difference between the optical device (4) and the low refractive layer (6) is at least 0.25 and at most 1.0. Optoelectronic semiconductor component (1) according to one of the preceding claims, in which the optical attachment (4) is designed in several parts and comprises a plurality of parts (4a, 4b), wherein the parts (4a, 4b) follow one another in the direction away from the main side (20) of the semiconductor chip (2) and a respective low-refractive layer (6) is arranged between adjacent parts (4a, 4b). Optoelectronic semiconductor component (1) according to one of the preceding claims, wherein the reflector (5) in the region of the low-refractive layer (6) is narrower than in the region of the semiconductor chip (2), so that the reflector (5) has a receptacle for the semiconductor chip (2 ). Optoelectronic semiconductor device (1) according to one of the preceding claims, wherein the optical attachment (4) has at least one spacer (48), wherein by means of the spacer (48) a thickness of the low-refractive layer (6) is defined and the Spacer (48) to the main side (20) or to the top (30) of the phosphor body (3) extends. Optoelectronic semiconductor component (1) according to one of the preceding claims, further comprising at least one spacer (7), wherein the spacer body (7) between the optical attachment (4) and the semiconductor chip (2) and has the same thickness as the low-refractive layer (6). Optoelectronic semiconductor component (1) according to one of the preceding claims, in which - a quotient of the base area (A) and a height of the optical attachment (4) lies between 1 mm and 30 mm, - a quotient of the base area (A) and Radiating area (B) is between 1.05 and 5 inclusive, - the base area (A) is between 1 mm ^{2 and} 30 mm ² , and - the height is between 0.2 mm and 5 mm. Optoelectronic semiconductor component (1) according to one of the preceding claims, wherein the optical attachment (4) seen in cross-section along a direction away from the at least one semiconductor chip (2) is formed in regions or in whole as a symmetrical trapezoid. Optoelectronic semiconductor device (1) according to the preceding claim, wherein the optical attachment (4) in cross-section in the direction away from the at least one semiconductor chip (2) of the following three basic shapes is formed: rectangle, symmetrical trapezoid, rectangle. Optoelectronic semiconductor component (1) according to one of Claims 1 to 12 in which the optical attachment (4) is formed, as seen in cross-section, along a direction away from the at least one semiconductor chip (2), in regions or as a whole, like a symmetrical step pyramid. Optoelectronic semiconductor component (1) according to one of Claims 1 to 12 in which the optical attachment (4) has a symmetrically concave curve when viewed in cross-section. Optoelectronic semiconductor component (1) according to one of the preceding claims, wherein the base area (A) is square or rectangular, whereas the radiating surface (B) is circular or elliptical in plan view, wherein the base area (A) in the direction away from the at least one semiconductor chip (2) merges with a continuously differentiable side surface (42) in the emitting surface (B). Optoelectronic semiconductor component (1) according to one of the preceding claims, in which the reflector (5) is formed by a potting which diffusely reflects and which appears white to a viewer, wherein the potting on a the at least one semiconductor chip (2) facing away from the reflector top (51) is flat and parallel to a main side (20) of the at least one semiconductor chip (2). Optoelectronic semiconductor component (1) according to the preceding claim, in which the potting on the reflector top (51) remote from the at least one semiconductor chip (2) has a minimum thickness of 0.2 mm, wherein the reflector top (51) is flush with the radiating surface (B).

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