Optoelectronic component and method for producing an optoelectronic component

Abstract

The invention relates to an optoelectronic component, comprising: - a semiconductor chip (2) which, during operation, emits electromagnetic primary radiation in a first wavelength range, - a connection layer (3) which comprises a matrix material (4) and a plurality of particles (5), and - a cover layer (6), wherein the connection layer (3) is arranged between the semiconductor chip (2) and the cover layer (6) and at least some of the particles (5) have an outer surface (7) with at least one edge (8) and at least one corner (9). The invention further relates to a method for producing an optoelectronic component.

Description

[0001] 2023PF00957 14. November 2024 P2023,1283 WO N - 1 - A method for producing an optoelectronic component is specified. One problem to be solved is to specify an optoelectronic component that has improved properties. In addition, a method for producing an optoelectronic component with improved properties is to be specified. Optoelectronic components can have at least one semiconductor chip that emits and / or receives electromagnetic radiation in a specific wavelength range. For example, the optoelectronic component is a semiconductor laser component, a photodiode, or a light-emitting diode. According to at least one embodiment, the optoelectronic component comprises at least one semiconductor chip that, during operation, emits electromagnetic primary radiation of a first wavelength range.The semiconductor chip, such as a light-emitting diode chip and / or a laser diode chip, has an epitaxially grown semiconductor layer sequence with an active zone configured to generate electromagnetic radiation. During operation, the semiconductor chip can, for example, emit electromagnetic radiation from a wavelength range 2023PF00957 November 14, 2024 P2023,1283 WO N - 2 - of UV radiation, visible radiation, and / or in the infrared range. According to at least one embodiment, the optoelectronic component has a connecting layer. The connecting layer comprises a matrix material and a multiplicity of particles. A silicone, an epoxy, a polysiloxane, or a hybrid material, for example, is used as the matrix material. The matrix material preferably comprises a transparent material. The multiplicity of particles is preferably homogeneously distributed in the matrix material.Alternatively, the plurality of particles can sediment in the matrix material. This means that a larger quantity of particles is present in the part of the connecting layer that is arranged closer to the semiconductor chip than in the part of the connecting layer that is further away from the semiconductor chip. The plurality of particles can be the same particles; preferably, the plurality of particles differ in their material and / or shape. In particular, the connecting layer is an adhesive layer that holds the semiconductor chip and another layer, for example a cover layer, together and / or connects them to one another. The connecting layer preferably has no scattering properties. According to at least one embodiment, the optoelectronic component has a cover layer. The connecting layer is arranged between the semiconductor chip and the cover layer. The cover layer is preferably described in 2023PF00957 14.November 2024 P2023,1283 WO N - 3 - arranged in direct contact with the. The connecting layer is in particular arranged in direct contact with the semiconductor chip. The semiconductor chip, the connecting layer and the cover layer are preferably flush laterally. According to at least one embodiment, at least some of the particles have an outer surface with at least one edge and at least one corner. Preferably, a large proportion of the particles have an outer surface with at least one edge and at least one corner. Particularly preferably, all of the particles have an outer surface with at least one edge and at least one corner. In the case of a polyhedron, for example, an edge is the connecting line between two adjacent corners or the intersection of two side surfaces. In the case of a corner, two edges form an angle or two surfaces form an angle. The edges and / or the corners are preferably sharp edges / corners.In particular, the outer surface has a long edge. A long edge is, for example, an edge that has a longer extension than the other edges in the particle. The plurality of particles preferably differs in their outer surface. This means that the particles can have different outer surfaces. Furthermore, the particles preferably have different sizes and / or shapes. According to at least one embodiment, the optoelectronic component comprises a semiconductor chip that emits electromagnetic primary radiation of a first wavelength range during operation, a connecting layer comprising a matrix material and a plurality of particles, and a cover layer, wherein the connecting layer is arranged between the semiconductor chip and the cover layer, and at least some of the particles have an outer surface with at least one edge and at least one corner.The corners and edges of the outer surface of the particles serve to create microcracks in the matrix material. The microcracks serve, among other things, to relieve stress in the bonding layer. This advantageously prevents the semiconductor chip from detaching from the cover layer. Components with a bonding layer that only contains silicone age due to semiconductor chip emission and heat, resulting in material hardening and shrinkage. This can lead to the formation of long cracks (hereinafter referred to as cracks), which lead to delamination of the bonding layer at an interface. Mechanical instability and local differences in brightness and color location / conversion are the consequences. According to at least one embodiment, the bonding layer is free of phosphor particles. The primary radiation emitted by the semiconductor chip is therefore not converted in the bonding layer.The connecting layer is not a conversion layer. According to at least one embodiment, the outer surface of the particles has at least two edges and / or at least two corners. In particular, the outer surface of the particles has a plurality of edges and / or a plurality of corners. Advantageously, the outer surface of the particles leads to microcracks in the connecting layer, which then compensate for browning of the optoelectronic component and suppress the detachment of the cover layer from the semiconductor chip. 2023PF00957 November 14, 2024 P2023,1283 WO N - 5 - According to at least one embodiment, the outer surface of the particles has an irregular shape. Irregular means a shape that is not even or arranged at unequal intervals. For example, the outer surface of the particles is tapered. This means that at least two edges of the particles are longer than other edges and these enclose an acute angle.Furthermore, the particles can, for example, have depressions or cavities. The particles can also be tetrahedral in shape or the particles can be flat platelets. In addition, the particles can be conical. A variety of configurations are possible here. According to at least one embodiment, the particles do not have a round shape and / or do not have a spherical shape. A round shape is, for example, a spherical shape, which means that this shape does not have to be completely round or spherical, but can, for example, be egg-shaped. A round shape and a spherical shape both have no corners and no edges. The spherical shape consists of a spherical surface whose points are all the same distance from the center of the sphere. According to at least one further embodiment, the connecting layer has further particles and the further particles have a spherical shape or round shape.This means that, in addition to the particles having at least one outer surface with at least one edge and at least one corner, the connecting layer also contains particles having a round and / or spherical shape. 2023PF00957 November 14, 2024 P2023,1283 WO N - 6 - According to at least one embodiment, the matrix material is selected from the following group: silicone, polysiloxane, and combinations thereof. These matrix materials are particularly suitable because, during operation of the component, they exhibit little cracking and thus little detachment of the semiconductor chip from the cover layer. Polysiloxanes are compounds having T units and / or D units. The polysiloxane is formed into a three-dimensional network. In particular, the polysiloxane has a basic framework composed of alternating oxygen atoms and silicon atoms. For example, the polysiloxane has no carbon-carbon bonds in the basic framework.In a T unit (-OSiRO2-) of the polysiloxane, one silicon atom is bonded in particular to three oxygen atoms and one carbon atom. In a D unit (-OSiR2O-) of the polysiloxane, however, one silicon atom is bonded in particular to two oxygen atoms and two carbon atoms. In particular, the T units and / or the D units have a methyl group as an organic radical. In other words, R in -OSiRO2- and / or -OSiR2O- is Me. For example, the polysiloxane comprises T units and D units, with the D units having a proportion between 10 wt% and 20 wt% inclusive. Alternatively, the polysiloxane comprises T units and no D units, or the polysiloxane comprises D units and no T units. In particular, the polysiloxane comprises 100 wt% T units. A polysiloxane comprising D units and no T units, and R is Me, is also called silicone.For example, the 2023PF00957 November 14, 2024 P2023,1283 WO N - 7 - polysiloxane is not a This means that the building blocks of the polysiloxane are randomly connected in the polysiloxane. In particular, a polysiloxane with T units has a viscosity between 1 mPa∙s and 50 mPa∙s inclusive. This advantageously eliminates the need to dilute the polysiloxane with a solvent for use as a precursor. Furthermore, a bonding layer with a polysiloxane comprising T units is particularly hard and thermally stable, and a bonding layer with a small thickness can be produced. This can be explained, for example, by the fact that the T units create a denser three-dimensional polymer network. Bonding layers with a silicone as the matrix material are characterized in particular by greater elasticity than polysiloxanes with T units.Therefore, thicker bonding layers can be produced with silicones than with polysiloxanes with T units. For example, polysiloxanes containing T units provide bonding layers with a thickness of at most 50 µm. Silicones can also produce bonding layers with a thickness of at least 100 µm. According to at least one embodiment, the particles have a refractive index that differs by a maximum of ±10% from the refractive index of the matrix material. In other words, the refractive index of the particles differs by a maximum of 10% from the refractive index of the matrix material. The 2023PF00957 November 14, 2024 P2023,1283 WO N - 8 - particles have, in particular, optical properties, are transparent, and have non-scattering and non-absorbing properties. Advantageously, the particles serve only to minimize long cracks in the bonding layer.According to at least one embodiment, the particles comprise an oxide. The oxide is preferably a binary oxide, a metal oxide, or a mixed oxide. The particles comprise, for example, different oxides. A particle may be coated with a different oxide. In other words, a particle may have a coating, wherein the coating comprises a different oxide than the particle. For example, a particle may comprise TiO2 and the coating of the particle may comprise aluminosilicate. This leads, among other things, to improved adhesion promotion, passivation, or adjustment of the zeta potential or dispersibility and rheological properties. Various particles consisting of different oxides may also be embedded in the bonding layer. According to at least one embodiment, the particles comprise an oxide selected from the following group: SiO2, TiO2, Al2O3, ZrO. 2,Glass and combinations thereof. In particular, the particles have no absorbing properties and no scattering properties and are transparent. SiO2 has a refractive index similar to the matrix material silicone and is thus particularly well suited as particles. Glass is very well suited for use as particles because it is inexpensive and various angular shapes can be easily achieved upon milling. Glass mixtures are also used as particles. It is also conceivable to use phosphors as phosphors. The phosphors can be doped or undoped. According to at least one embodiment, a carrier is arranged on the side of the cover layer facing away from the semiconductor chip. The carrier is in particular a ceramic substrate. The carrier serves in particular to ensure the stability of the optoelectronic component.For example, the carrier has a greater extent than the semiconductor chip, the cover layer and the connecting layer. According to at least one embodiment, the particles have an average diameter of 0.35 µm up to and including 5 µm. Preferably, the particles have an average diameter of 0.5 µm up to and including 5 µm. Particularly preferably, the particles have an average diameter of 0.35 µm up to and including 2 µm. The average diameter is the d50 value. Smaller particles are particularly advantageous over larger particles because they allow better use of microcracking to relieve stress. Furthermore, the size of the particles is limited by the thickness of the connecting layer and the processability of the matrix material.According to at least one embodiment, the bonding layer comprises between 5 wt% and 30 wt% particles inclusive. Preferably, the bonding layer comprises between 15 wt% and 25 wt% particles inclusive. The amount of particles in the matrix material advantageously leads to a reduction in crack formation and thus to a reduction in the detachment of the cover layer and of the material at the interface to the bonding layer. According to at least one embodiment, the particles are homogeneously distributed in the matrix material. As a result, the microcracks can advantageously be distributed over the entire bonding layer and are not bound locally to one location. This leads to little detachment of the cover layer from the bonding layer. According to at least one embodiment, the bonding layer comprises nm-sized SiO2 particles. The nm-sized SiO2 particles are also referred to as aerosils.Aerosil, or nm-sized SiO2 particles, is a very lightweight material often used in adhesives. Aerosil is fumed silicon dioxide, a synthetically produced colloidal material with defined properties and particle size, used as a filler in plastics. It consists entirely of amorphous silicon dioxide particles that aggregate into larger units. Aerosil in its non-agglomerated state has small, spherical SiO2 particles, which then agglomerate to form long, thin shapes. Aerosil, in particular, has no edges or corners. The particle size of Aerosils is preferably 30 nanometers. Advantageously, the bonding layer contains nm-sized SiO2 particles, as these prevent sedimentation of the particles. According to at least one embodiment, the bonding layer is free of nm-sized SiO2 particles.In the bonding layer, which is free of nm-sized SiO2 particles, microcracks that start at the particles can be formed. This prevents long cracks in the bonding layer, which would promote the detachment of the cover layer from the semiconductor chip. According to at least one embodiment, the cover layer is selected from the following group: conversion layer, reflection layer, or transparent layer. It is also possible for the cover layer to have multiple layers. The conversion layer is configured to convert the electromagnetic primary radiation of the first wavelength range into electromagnetic secondary radiation of a second wavelength range and to emit this radiation. The conversion layer comprises, for example, phosphors and a matrix.The matrix is ​​preferably permeable or transparent to electromagnetic radiation, for example, visible light. The conversion layer preferably converts the primary radiation of the semiconductor chips into secondary radiation. The conversion layer is preferably applied as a continuous layer to the connecting layer. The phosphors are incorporated into the matrix in the form of phosphor particles. The matrix preferably completely envelops the phosphor particles, i.e., the phosphor particles are preferably embedded in the matrix. During operation, the phosphor particles convert the primary radiation of the first wavelength range into secondary radiation of the second wavelength range. The primary radiation is preferably different from the secondary radiation. The phosphor particles embedded in the matrix preferably impart wavelength-converting properties to the conversion element. For example, 2023PF00957 14.November 2024 P2023,1283 WO N - 12 - The phosphor particles only partially convert the primary radiation of the semiconductor chip into secondary radiation, while another part of the primary radiation of the semiconductor chip is transmitted by the conversion element. The phosphor is, for example, a ceramic phosphor and / or a quantum dot phosphor. The ceramic phosphors preferably comprise a garnet phosphor. The garnet phosphor is particularly preferably a YAG phosphor with the chemical formula Y3Al5O. 12 :Ce 3+ or a LuAG phosphor of the chemical formula Lu3Al5O 12 :Ce 3+. Furthermore, the ceramic phosphors can also comprise a nitride phosphor or an oxynitride phosphor. The nitride phosphors or oxynitride phosphors preferably convert blue primary radiation into red secondary radiation. The nitride or oxynitride phosphor can be, for example, an alkaline earth silicon (oxy)nitride, an oxynitride, an aluminum oxynitride, a silicon nitride, or a SiAlON. The ceramic phosphors are preferably selected from the following group: Ce 3+ -doped garnets such as YAG and LuAG, for example (Y,Lu,Gd,Tb)3(Al 1-x ,Ga x )5O 12 :Ce 3+ ; Eu 2+ and / or Ce 3+ -doped nitrides, such as (Ca,Sr)AlSiN3:Eu 2+ / Ce 3+ , Sr(Ca,Sr)Si2Al2N6:Eu 2+ / Ce 3+ (SCASN), (Sr,Ca)AlSiN3*Si2N2O:Eu 2+ / Ce 3+ , (Ca,Ba,Sr)2Si5N8:Eu 2+ / Ce 3+ , SrLiAl3N4:Eu 2+ / Ce 3+ , SrLi2Al2O2N2:Eu2+ / Ce 3+ , (Ca,Sr)Al (1- 4x / 3) Si (1+x) N3:Eu / Ce (x = 0.2 – 0.5), (La,Y)3Si6N 11 :Ce 3+ ; Eu 2+ / Ce 3+ - doped sulfides, (Ba,Sr,Ca)Si2O2N2:Eu 2+ / Ce 3+ , SiAlONs, nitrido-orthosilicates (e.g. AE 2-x-a RE x Eu a Si 1-y O 4-x- 2y N x ), orthosilicates (Ba,Sr,Ca)2SiO4:Eu 2+ ; Chlorosilicates (for 2023PF00957 14 November 2024 P2023,1283 WO N - 13 - Particularly preferably, the ceramic phosphors are selected from the following group: Ce 3+ -doped garnets such as YAG and LuAG, for example (Y,Lu,Gd,Tb)3(Al 1-x ,Ga x )5O 12 :Ce 3+ ; Ce 3+ -doped nitrides, such as (Ca,Sr)AlSiN3:Ce 3+ , Sr(Ca,Sr)Si2Al2N6:Ce 3+ (SCASN), (Sr,Ca)AlSiN3*Si2N2O:Ce 3+ , (Ca,Ba,Sr)2Si5N8:Ce 3+ , SrLiAl3N4:Ce 3+ , SrLi2Al2O2N2:Ce3+ ; Ce 3+ -doped nitrides, for example (Ca,Sr)Al (1-4x / 3) Si (1+x) N3:Ce; (x = 0.2 – 0.5), (La,Y)3Si6N 11 :Ce 3+ ; (Ba,Sr,Ca)Si2O2N2:Eu 2+ , SiAlONs, nitrido-orthosilicates (for example AE 2-x-a RE x Eu a Si 1-y O 4-x-2y N x ), orthosilicates (Ba,Sr,Ca)2SiO4:Eu 2+ ; Chlorosilicates (for example Ca8Mg(SiO4)4Cl2:Eu 2+ ); or Ce 3+ -doped lithosilicates, such as (Li,Na,K,Rb,Cs)(Li3SiO4):E with E as Eu 2+ , Ce 3+ , or (Sr,Li)Li3AlO4:Eu 2+ / Ce 3+ or SrLi3AlO4:Eu 2+ / Ce 3+ . Other possible materials for the phosphors are in particular the following aluminum-containing and / or silicon-containing phosphor particles: (Ba 1-x-y Sr x Ca y )SiO4:Eu 2+ (0 ^ x ^ 1, 0 ^ y ^ 1), (Ba 1-x- y Sr x Ca y )3SiO5:Eu 2+(0^x^1, 0^y^1), Li2SrSiO4:I 2+ , Oxo-Nitride wie (Ba 1-x-y Mr. x Here y )Si2O2N2:Eu 2+ (0^x^1; 0^y^1), SrSiAl2O3N2:I 2+ , Ba 4-x Here x Si6ON 10 :I 2+ (0^x^1), (Ba 1- x Mr. x )Y2Si2Al2O2N5:Eu 2+ (0^x^1), Mr x Yes (6-y) Al y THE y N (8-y) :I 2+ (0.05^x^0.5; 0.001^y^0.5), Ba3Si6O 12 N2: Me 2+ , Yes 6-z Al z THE z N 8-z :I 2+ (0^z^0.42), M x Yes 12-m-n Al m+n THE n N 16-n :I 2+ (M = Li, Mg, Ca, Y; x 2023PF00957 14. November 2024 P2023,1283 WO N - 14 - = m / v; v = Wertigkeit von M, ^ 2), M x Yes 12-m-n Al m+n THE n N 16-n :Ce 3+ , AE 2-x-a RE x I a Yes 1-y THE 4-x-2y N x(AE = Sr, Ba, Ca, Mg; RE = Seltenerdelemente), AE 2-x-a RE x I a Yes 1-y THE 4-x-2y N x (AE = Sr, Ba, Ca, Mg; RE = Seltenerdelemente),oder Nitride wie (La,Y)3Si6N 11 :Ce 3+ , (Ba 1-x-y Mr. x Here y )2Si5N8:Eu 2+ , (Ca 1-x- y Mr. x Ba y )AlSiN3:Eu 2+ (0^x^1; 0^y^1), Sr(Sr 1- x Here x )Al2Si2N6:Eu 2+ (0^x^0.2), Sr(Sr 1-x Here x )Al2Si2N6:Ce 3+ (0^x^0.2) SrAlSi4N7:Eu 2+ , (Ba 1-x-y Mr. x Here y )SiN2:Eu 2+ (0^x^1; 0^y^1), (Ba1-x-ySrxCay)SiN2:Ce 3+ (0^x^1; 0^y^1), (Sr1- x Here x )LiAl3N4:Eu 2+ (0^x^1), (Ba 1-x-y Mr. x Here y )Mg2Al2N4:Eu 2+ (0^x^1; 0^y^1), (Ba 1-x-y Mr. x Here y )Mg3SiN4:Eu 2+(0 ^ x ^ 1; 0 ^ y ^ 1). For example, the combination of several different phosphor particles is possible. The reflection layer is a layer that reflects the primary radiation emitted by the semiconductor chip. A transparent layer is understood to mean, for example, a lens or a layer that transmits the electromagnetic radiation of the primary radiation of a first wavelength range. According to at least one embodiment, the cover layer is selected from the following group: conversion layer or transparent layer. According to at least one embodiment, a thickness of the connecting layer is between 0.5 µm and 100 µm inclusive. Preferably, the thickness of the connecting layer is between 0.5 µm and 10 µm inclusive. Particularly preferably, the thickness of the connecting layer is between 0.5 µm and 6 µm inclusive.Although a very thin bonding layer, less than or equal to 2 μm, has the advantage of reducing the leakage of the matrix material beyond the semiconductor chip edge, the disadvantage of this very thin bonding layer is that the adhesion tends to decrease over the product's lifetime, thereby further exacerbating the aforementioned delamination problem. According to at least one embodiment, the particles are configured to generate microcracks in the bonding layer, wherein the microcracks have a preferred direction running transversely to a main extension plane of the semiconductor chip. Preferably, the microcracks do not run completely parallel to the main extension plane, thus minimizing detachment of the cover layer from the semiconductor layer. In particular, the microcracks run transversely or perpendicularly to the main extension plane of the semiconductor chip.The preferred direction is the direction in which the microcracks have their maximum extent. This means that microcracks, for example, initially run transversely and then bend and continue vertically. The microcracks preferably arise at an operating time of 0 hours. This means that the microcracks ideally form immediately after the bonding layer has been produced. This advantageously allows the color location to be kept almost constant. According to at least one embodiment, the particles are configured to generate microcracks in the bonding layer, which are formed at the edges and / or corners of the particles. This means that the particles, in particular, are the starting point of the microcracks. This means that the microcracks originate at the edges and / or corners of the particles.This advantageously creates microcracks that do not, or only rarely, run horizontally to the main extension plane of the semiconductor chip, thus minimizing detachment of the cover layer from the semiconductor chip. One idea of ​​the present invention of the present optoelectronic component is to minimize stresses in the bonding layer. The matrix material, for example, silicone, ages due to semiconductor chip emission and heat, leading to material hardening and shrinkage. This leads, among other things, to large and long cracks in the matrix material and / or to delamination of the matrix material at an interface, which weakens the mechanical stability of the bonding layer and leads to local differences in brightness and color point / conversion.By adding particles to the bonding layer that have edges and / or corners, these cracks, which lead to delamination of the silicone, can be minimized, and microcracks are formed on the particles. The mechanical stability of the bonding layer is advantageously enhanced, and brightness is maintained. The optoelectronic component finds application in the automotive industry, for example, in brake lights and headlights. Furthermore, a method for producing an optoelectronic component is specified. In particular, the method for producing an optoelectronic component described here can be used to produce an optoelectronic component as described here. This means that all features disclosed for the method for producing optoelectronic components are also disclosed for the optoelectronic component, and vice versa.According to at least one embodiment of the method for producing an optoelectronic component, a semiconductor chip is provided which is configured to emit primary radiation of a first wavelength range during operation. In a further method step, a connecting layer described here is applied to the semiconductor chip, wherein the connecting layer comprises a matrix material and a multiplicity of particles. In a further step, a cover layer is applied to the connecting layer, wherein at least some of the particles have an outer surface with at least one edge and at least one corner. According to at least one embodiment, the semiconductor chip is applied to a carrier. According to at least one embodiment, the connecting layer is applied directly to the semiconductor chip. According to at least one further embodiment, the cover layer is applied directly to the connecting layer.According to at least one embodiment, the method is carried out in the specified order. One idea of ​​the present optoelectronic component is to introduce a large number of particles having edges and / or corners in order to initiate microcracks at these. This leads to a reduction in the detachment of the 2023PF00957 November 14, 2024 P2023,1283 WO N - 18 - connecting layer at the semiconductor chip and the cover layer. This, in turn, leads to an increase in mechanical stability, and the brightness of the optoelectronic component, as well as the color points and conversion, are maintained. Furthermore, the sharp edges / corners of the particles lead to a high stress concentration at the interface between the particle edges / corners and the matrix material, which can lead to the formation of microcracks in the matrix material.The particles thus create a multitude of such microcracks, which reduce the mechanical stresses within the matrix material and thus also at the surfaces between the semiconductor chip and the bonding layer, and between the cap layer and the bonding layer. Since the mechanical stresses in the bonding layer due to aging-related shrinkage of the matrix material are relieved via the numerous microcracks around the particles, large, long cracks or even extensive delamination are prevented. Since there is no long crack or air gap, less light is scattered back from the semiconductor chip, thus lessening the optical performance. Furthermore, the adhesion force is better maintained.Further advantageous embodiments and developments of the optoelectronic component and of the method for producing an optoelectronic component will become apparent from the following exemplary embodiments described in conjunction with the figures. They show: 2023PF00957 14.November 2024 P2023,1283 WO N - 19 - Figures 1 to 3 each show a schematic sectional view of an optoelectronic component according to a respective exemplary embodiment, Figures 4 and 5 each show a sectional view of a multiplicity of particles according to a respective exemplary embodiment, Figure 6 shows a sectional view of a connecting layer according to a comparative example, Figure 7 shows a sectional view of a connecting layer according to an exemplary embodiment, Figure 8 shows a schematic sectional view of an optoelectronic component according to an exemplary embodiment, and Figure 9 shows a schematic sectional view of a method for producing an optoelectronic component according to an exemplary embodiment. Identical, similar, or equivalent elements are provided with the same reference numerals in the figures. The figures and the size relationships of the elements shown in the figures to one another are not to scale.Rather, individual elements, in particular layer thicknesses, may be exaggerated for clarity and / or clarity. The optoelectronic component 1 according to the exemplary embodiment of Figure 1 comprises a semiconductor chip 2, 2023PF00957 November 14, 2024 P2023,1283 WO N - 20 - which, during operation, emits primary radiation of a first wavelength range, a connecting layer 3 comprising a matrix material 4 and a multiplicity of particles 5, and a cover layer 6, wherein the connecting layer 3 is arranged between the semiconductor chip 2 and the cover layer 6 and at least some of the particles 5 have an outer surface 7 with at least one edge 8 and at least one corner 9. All particles 5 have an outer surface with at least one edge 8 and at least one corner 9. The outer surface 7 of the particles 5 can have an irregular shape.In the exemplary embodiment, the particles 5 do not have a round shape and / or a spherical shape. The matrix material 4 is selected from the following group: silicone, polysiloxane, and combinations thereof. The matrix material 4 is preferably a silicone. The particles 5 have a refractive index that differs by a maximum of + / - 10% from a refractive index of the matrix material 4. The particles 5 are an oxide. The oxide is, for example, a mixed oxide, a metal oxide, or a binary oxide. The particles 5 can be selected from an oxide selected from the following group: SiO2, TiO2, Al2O3, ZrO2, glass, phosphors, and combinations thereof. Preferably, different particles 5, which are formed from different oxides, are embedded in the connecting layer 3. The shape and size of the particles 5 can also vary greatly from particle 5 to particle 5.The particles 5 have an average diameter, d50, of 0.35 µm up to and including 5 µm. Preferably, the particles 5 have an average diameter, d50, of 0.5 µm up to and including 2 µm. The particles 5 are homogeneously distributed in the matrix material 4. Preferably, the connecting layer 3 has no particles or only a small amount. The covering layer 6 is selected from the following group: conversion layer, reflection layer, or transparent layer. Preferably, the covering layer 6 is a conversion layer and is designed to convert the primary radiation emitted by the semiconductor chip 2 into electromagnetic secondary radiation of a second wavelength range. The connecting layer 3 has between 5% by weight and 30% by weight of particles 5. Figure 2 also shows an optoelectronic component 1 according to an embodiment.The optoelectronic component 1 of Figure 2 differs from the optoelectronic component 1 of Figure 1 in that, in addition to the plurality of particles 5 having at least one edge 8 and at least one corner 9, round and / or spherical particles 5 are also embedded in the connecting layer 3. The exemplary embodiment of Figure 3 shows an optoelectronic component 1 that differs from the optoelectronic component 1 of Figure 1 in that the semiconductor chip 2 is arranged on a carrier 10. The carrier 10 is a ceramic substrate and serves to provide mechanical stability. The exemplary embodiment of Figure 4 shows two differently shaped particles 5, each according to an exemplary embodiment. The particle 5 on the left shows a triangular shape with at least three corners 9 and at least three surfaces 8. The right 2023PF00957 14.November 2024 P2023,1283 WO N - 22 - The sectional view of Figure 5 shows at least four surfaces 8 and at least four corners 9. Figure 5 also shows sectional views of particles 5 according to one exemplary embodiment. The particles 5 have an average diameter of 0.5 µm up to and including 2 µm. Figures a), b) and c) each show depressions or cavities and / or hollow spaces in the particle 5. Figures a), b) and c) are designed as flat platelets. The outer surfaces of the particles 5 d) and e) are shaped similarly to a tetrahedron and have a pointed corner. The particles 5 can also have cavities, hollow spaces and elevations for forming edges 8 and corners 9. For the sake of clarity, only a certain portion of the corners 9 and edges 8 are provided with reference numerals in Figures 4 and 5. Figure 6 shows a sectional view of a comparative example of a connecting layer 3.In this case, a matrix material 4 and a multiplicity of particles 5 are arranged in the connecting layer 3, wherein the particles 5 mostly have a round or spherical shape. This leads to long cracks 12 in the connecting layer 3, as a result of which the connecting layer 3 detaches from the semiconductor chip 2 at the interface, since the cracks 12 run horizontally to the main extension plane. Furthermore, cracks 12 are formed which run vertically to the main extension plane and thus also cause losses in the brightness and lifetime of the optoelectronic component 1. 2023PF00957 November 14, 2024 P2023,1283 WO N - 23 - Figure 7 shows a connecting layer 3 according to an exemplary embodiment. In this case, the connecting layer 3 comprises a matrix material 4 and a multiplicity of particles 5, wherein at least some of the particles 5 have an edge 8 and a corner 9. The connecting layer 3 comprises 20 wt% particles 5.During operation, microcracks 11 form in the connecting layer 3, which are formed at the edges 8 and / or corners 9 of the particles 5. The microcracks 11 in the connecting layer 3 have a preferred direction that runs transversely to a main extension plane of the semiconductor chip 2. This means that the microcracks 11 do not run horizontally at the interface between the semiconductor chip 2 and the connecting layer 3 or between the connecting layer 3 and the cover layer 6. This minimizes detachment of the cover layer 6 from the semiconductor chip 2. The microcracks 11 preferably run transversely in the connecting layer 3 and have a significantly shorter length than the cracks 12 of the comparative example. In the optoelectronic component 1 according to the embodiment of Figure 8, microcracks 11 are shown in the connecting layer 3. The microcracks 11 have a preferred direction that runs transversely to the main extension plane of the semiconductor chip 2.The microcracks form at the edges 8 and / or corners 9 of the particles 5 after a certain operating period and the associated mechanical stresses due to material aging, or they may even be present after production, for example due to stresses after curing. The formation of the microcracks 11 reduces the stresses in the connecting layer 3, and large-area delamination can thus be prevented. 2023PF00957 November 14, 2024 P2023,1283 WO N - 24 - Figure 9 describes the method for producing an optoelectronic component 1 according to an exemplary embodiment. First, a semiconductor chip 2 is provided. This is configured to emit primary radiation of a first wavelength range during operation. In a further step, a connecting layer 3 comprising a matrix material 4 and a multiplicity of particles 5 is applied to the semiconductor chip 2.The connecting layer 3 and the semiconductor chip 2 are thus in direct contact. In a further step, a cover layer 6 is applied to the connecting layer 3. At least some of the particles 5 of the connecting layer 3 have an outer surface 7 with at least one edge 8 and at least one corner 9. The semiconductor chip 2 can also be applied to a carrier 10. The carrier is, for example, a ceramic substrate. The features and exemplary embodiments described in connection with the figures can be combined with one another according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures can alternatively or additionally have further features according to the description in the general part. The invention is not limited to these by the description based on the exemplary embodiments.Rather, the invention encompasses any novel feature and any combination of features, including, in particular, any combination of features in the patent claims, even if this feature or combination is explicitly stated in the patent claims or exemplary embodiments. This patent application claims priority from German patent application 102023133805.6, the disclosure of which is hereby incorporated by reference.

[0002] 2023PF00957 14 November 2024 P2023,1283 WO N - 26 - List of reference symbols 1 optoelectronic component 2 semiconductor chip 3 connection layer 4 matrix material 5 particles 6 cover layer 7 outer surface 8 edge 9 corner 10 carrier 11 microcracks 12 cracks

Claims

2023PF00957 November 14, 2024 P2023,1283 WO N - 27 - Claims 1. Optoelectronic component (1) with - a semiconductor chip (2) which emits electromagnetic primary radiation of a first wavelength range during operation, - a connecting layer (3) which comprises a matrix material (4) and a multiplicity of particles (5), and - a cover layer (6), wherein the connecting layer (3) is arranged between the semiconductor chip (2) and the cover layer (6) and at least some of the particles (5) have an outer surface (7) with at least one edge (8) and at least one corner (9), in which a thickness (D) of the connecting layer (3) is between 0.5 µm and 10 µm inclusive.

2. Optoelectronic component (1) according to the preceding claim, wherein the outer surface (7) of the particles (5) has at least two edges (8) and / or at least two corners (9).Optoelectronic component (1) according to one of the preceding claims, in which the outer surface (7) of the particles (5) has an irregular shape.

4. Optoelectronic component (1) according to one of the preceding claims, in which the particles (5) do not have a round shape and / or a spherical shape.

5. Optoelectronic component (1) according to one of the preceding claims. 2023PF00957 November 14, 2024 P2023,1283 WO N - 28 - wherein the matrix material is selected from the following group: silicone, polysiloxane, and combinations thereof.

6. Optoelectronic component (1) according to one of the preceding claims, wherein the particles (5) have a refractive index that differs by a maximum of ±10% from a refractive index of the matrix material (4).

7. Optoelectronic component (1) according to one of the preceding claims, wherein the particles (5) comprise an oxide.

8. Optoelectronic component (1) according to one of the preceding claims, wherein the particles (5) comprise an oxide selected from the following group: SiO 2 , TiO 2 , Al 2 O 3 , ZrO 2,Glass and combinations thereof.

9. Optoelectronic component (1) according to one of the preceding claims, in which a carrier (10) is arranged on the side of the cover layer facing away from the semiconductor chip (2).

10. Optoelectronic component (1) according to one of the preceding claims, in which the particles (5) have an average diameter of 0.35 µm to 5 µm inclusive.

11. Optoelectronic component (1) according to one of the preceding claims, 2023PF00957 November 14, 2024 P2023,1283 WO N - 29 - in which the (3) comprises between 5 wt% and 30 wt% inclusive of particles (5).

12. Optoelectronic component (1) according to one of the preceding claims, in which the particles (5) are homogeneously distributed in the matrix material (4).

13. Optoelectronic component (1) according to one of the preceding claims, in which the cover layer (6) is selected from the following group: conversion layer or transparent layer.

14. Optoelectronic component (1) according to one of the preceding claims, wherein the connecting layer (3) is free of phosphor particles.

15. Optoelectronic component (1) according to one of the preceding claims, wherein the particles (5) are configured to generate microcracks (11) in the connecting layer (3), wherein the microcracks (11) have a preferred direction extending transversely to a main extension plane of the semiconductor chip (2).Optoelectronic component (1) according to one of the preceding claims, in which the particles (5) are designed to produce microcracks (11) in the connecting layer (3), which are formed at the edges (8) and / or corners (9) of the particles (5). 2023PF00957 November 14, 2024 P2023,1283 WO N - 30 - 17. A method for optoelectronic component (1) comprising the steps of: - providing a semiconductor chip (2) which is configured to emit primary radiation of a first wavelength range during operation, - applying a connecting layer (3) to the semiconductor chip (2), wherein the connecting layer (3) comprises a matrix material (4) and a multiplicity of particles (5), and - applying a cover layer (6) to the connecting layer (3), wherein at least some of the particles (5) have an outer surface (7) with at least one edge (8) and at least one corner (9), wherein a thickness (D) of the connecting layer (3) is between 0.5 µm and 10 µm inclusive.

Images