Conversion element, method for producing a conversion element, and optoelectronic device

Abstract

A conversion element is specified. According to one embodiment, the conversion element (1) comprises a substrate (2) and a first layer (3) comprising a phosphor (31) in a matrix material (32) on the substrate (2), wherein the first layer (3) is configured to convert primary radiation into secondary radiation, and wherein a lateral extension of the substrate (2) is larger than a lateral extension of the first layer (3) in at least one extension direction parallel to a main extension plane of the conversion element (1). Furthermore, a method for producing a conversion element and an optoelectronic device, in particular comprising a micro- LED, are specified.

Description

[0001] 2023PF01591 February 21, 2025P2023,1569 WO N -1 -Description CONVERSION ELEMENT, METHOD FOR PRODUCING A CONVERSION ELEMENT, AND OPTOELECTRONIC DEVICE A conversion element, a method for producing a conversion element, and an optoelectronic device are specified. It is an object to provide a conversion element with improvedefficiency and improved quality. Additionally, it is anobject to provide a simple method for producing a conversionelement with improved efficiency and improved quality.Furthermore, it is an object to provide an optoelectronic device with improved efficiency. A conversion element is specified. According to at least one embodiment, the conversion elementcomprises a substrate. In particular, the substrate isconfigured for providing a support and / or improving the mechanical stability of the conversion element. For example, the substrate is a plate. According to at least one embodiment, the conversion elementcomprises a first layer comprising a phosphor in a matrixmaterial on the substrate. In particular, the matrix materialis transparent. The phosphor is present, for example, in the form of particles. In particular, the phosphor is homogeneously distributed in the matrix material. Alternatively, the phosphor can comprise a gradient in the matrix material. That is, on a first side of the first layer, the phosphor has a greater concentration than on a second side of the first layer.2023PF01591 February 21, 2025P2023,1569 WO N -2 -According to at least one embodiment, the first layer is configured to convert primary radiation into secondary radiation. In other words, the first layer is configured to convert electromagnetic radiation of a first wavelength range into electromagnetic radiation of a second wavelength range. In particular, the second wavelength range comprises longerwavelengths than the first wavelength range. For example, anability of the first layer to convert electromagneticradiation is attributed to the phosphor converting primaryradiation into secondary radiation. In particular, thephosphor is configured for absorbing primary radiation in the blue to green wavelength range, for example, in the wavelength range of 360 nm to 500 nm. In particular, thephosphor is configured for emitting secondary radiation inthe visible and / or IR spectral range. According to at least one embodiment, a lateral extension of the substrate is larger than a lateral extension of the first layer in at least one extension direction parallel to a mainextension plane of the conversion element. In particular, themain extension plane extends along two lateral extension directions, such as along a length and a width, of the conversion element. The main extension plane extends, within the bounds of manufacturing tolerances, parallel to or alonga top face and / or a bottom face of the conversion element.Perpendicular to the main extension plane, in a verticaldirection, the conversion element has a thickness. Thethickness of the conversion element is small compared withthe extent of the conversion element in the lateraldirections. For example, when the conversion element isplaced in a radiation beam of a semiconductor chip having acertain emitting area, the main extension plane of the2023PF01591 February 21, 2025P2023,1569 WO N -3 -conversion element is parallel to that emitting area and thethickness of the conversion element is perpendicular to thatemitting area. Here and in the following, the terms length and width of any components or elements refer to extensionsparallel to the main extension plane, and the term thicknessof any components or elements refers to an extension perpendicular to the main extension plane. In particular, the lateral extension of the substrate is larger than the lateral extension in more than one extensiondirection parallel to a main extension plane of theconversion element. For example, the lateral extension of the substrate is larger on all lateral sides of the first layer. In other words, a length of the substrate is larger than alength of the first layer and / or a width of the substrate islarger than a width of the first layer. According to at least one embodiment, the conversion elementcomprises a substrate and a first layer comprising a phosphorin a matrix material on the substrate, wherein the first layer is configured to convert primary radiation into secondary radiation, and wherein a lateral extension of the substrate is larger than a lateral extension of the first layer in at least one extension direction parallel to a main extension plane of the conversion element. It is an idea of the present application to provide aconversion element having an improved strength and animproved yield. The conversion element comprises a first layer that is free of defects, in particular free of chipped and / or spalled side surfaces perpendicular to the main extension plane of the conversion element. Further, the sidesurfaces of the first layer are protected during handling of2023PF01591 February 21, 2025P2023,1569 WO N -4 -the conversion element due to the larger lateral extension ofthe substrate. Thus, the conversion element can be picked upby the substrate and moved without interfering with the first layer.According to at least one embodiment, the substrate is indirect mechanical contact to the first layer. In particular, the conversion element is free of a bonding agent between the substrate and the first layer, for example an adhesive layer. With the substrate in direct mechanical contact to the first layer, the thermal stability and the thermal conductivity of the conversion element can advantageously be increased.According to at least one embodiment, a side surface of thefirst layer has a distance from a side surface of thesubstrate of less than 25 µm, in particular of less than12.5 µm. Here and in the following, side surfaces of thefirst layer and side surfaces of the substrate are surfacesperpendicular to the main extension plane of the conversionelement. In particular, the distance of a side surface of thefirst layer from a side surface of the substrate is definedhere and in the following as the shortest distance of a sidesurface of the first layer from any side surface of thesubstrate. For example, each side surface of the first layerhas a distance from a corresponding side surface of thesubstrate of less than 25 µm. In other words, the substrate protrudes less than 50 µm, in particular less than 25 µm,beyond the first layer in any extension direction parallel tothe main extension plane of the conversion element. With sucha configuration, a conversion element in which only the edgeregions of the substrate are free of the first layer canadvantageously be realized.2023PF01591 February 21, 2025P2023,1569 WO N -5 -According to at least one embodiment, a length and a width ofthe substrate are greater than or equal to 1.00 mm and anarea of defects on a surface of the substrate is less than1 % of a total area of the surface of the substrate. Here andin the following, the surface of a component or element is composed of main surfaces and side surfaces of the componentor element. A main surface of a component or element is asurface parallel to the main extension plane of theconversion element and a side surface of a component elementis a surface perpendicular to the main extension plane of the conversion element. The main surface can be a top face or abottom face of the component or element. In particular, anextension of the main surface is defined by the length andthe width of the component or element. Here and in thefollowing, an area of defects is an area that is chipped and / or spalled. In other words, an area of defects has protrusions and / or indentations. A large conversion element having an area of defects of less than 1 % can advantageously have an optimized edge quality and thus an improved mechanical strength. Furthermore, such a conversion element can advantageously have an improved yield since one of the main losses for the conversion element, made with alternativemeans such as saw dicing, can be defects in the substrate.According to at least one embodiment, a length and a width ofthe substrate are greater than 0.50 mm and less than 1.00 mm,and an area of defects on a surface of the substrate is lessthan 2 % of a total area of the surface of the substrate. Amedium conversion element having an area of defects of less than 2 % can advantageously have an optimized edge qualityand thus an improved mechanical strength. Furthermore, such aconversion element can advantageously have an improved yield since one of the main losses for the conversion element, made2023PF01591 February 21, 2025P2023,1569 WO N -6 -with alternative means such as saw dicing, can be defects inthe substrate.According to at least one embodiment, a length and a width ofthe substrate are greater than 0.25 mm and less than 0.50 mm,and an area of defects on a surface of the substrate is lessthan 3 % of a total area of the surface of the substrate. Asmall conversion element having an area of defects of less than 3 % can advantageously have an optimized edge qualityand thus an improved mechanical strength. Furthermore, such aconversion element can advantageously have an improved yield since one of the main losses for the conversion element, madewith alternative means such as saw dicing, can be defects inthe substrate.According to at least one embodiment, a mean flexural stressof the conversion element is at least 200 MPa, in particularat least 250 MPa. In particular, the mean flexural stress ofa conversion element during a three-point bend test is at least 200 MPa, in particular at least 250 MPa. For example,the conversion element is bent substrate-side up. Aconversion element having a mean flexural stress of at least 200 MPa advantageously has an improved quality. In this case,improved quality means improved mechanical properties such asan improved mechanical strength. In other words, theconversion element can be more resistant to breakage.According to at least one embodiment, a thickness of thesubstrate is between and including 50 µm and 200 µm.According to at least one embodiment, the substrate comprisesat least one of a glass, a transparent polycrystallinematerial, or a transparent single crystal material. In2023PF01591 February 21, 2025P2023,1569 WO N -7 -particular, the glass is at least one of borosilicate, aluminosilicate, or fused silica. In particular, the transparent polycrystalline material is at least one of yttrium aluminum garnet, aluminum oxide, aluminum oxynitride, or magnesium aluminate (spinel). In particular, thetransparent single crystal material is at least one ofsapphire or quartz. For example, the substrate is aborosilicate substrate.According to at least one embodiment, the phosphor is atleast one of a garnet, an oxynitride, a nitride, an oxide, asilicate, a halogenide, a phosphate, or a semiconductornanocrystal. In particular, the phosphor is at least one of (RE1-xCex)3(Al1-yA´y)5O12with 0 < x ≤ 0.1 and 0 ≤ y ≤ 1, (RE1-xCex)3(Al5-2yMgySiy)O12with 0 < x ≤ 0.1 and 0 ≤ y ≤ 2, (RE1-xCex)3Al5-ySiyO12-yNywith 0 < x ≤ 0.1 and 0 ≤ y ≤ 0.5,(RE1-xCex)2CaMg2Si3O12 with 0 < x ≤ 0.1, (AE1-xEux)2Si5N8 with 0 <x ≤ 0.1, (AE1-xEux)AlSiN3 with 0 < x ≤ 0.1, (AE1-xEux)2Al2Si2N6with 0 < x ≤ 0.1, (Sr1-xEux)LiAl3N4with 0 < x ≤ 0.1,(AE1-xEux)3Ga3N5 with 0 < x ≤ 0.1, (AE1-xEux)Si2O2N2 with 0 < x ≤0.1, (AExEuy)Si12-2x-3yAl2x+3yOyN16-y with 0.2 ≤ x ≤ 2.2 and 0 < y≤ 0.1, (AE1-xEux)2SiO4 with 0 < x ≤ 0.1, (AE1-xEux)3Si2O5 with0 < x ≤ 0.1, K2(Si1-x-yTiyMnx)F6 with 0 < x ≤ 0.2 and 0 < y ≤1-x, (AE1-xEux)5(PO4)3Cl with 0 < x ≤ 0.2, (AE1-xEux)Al10O17with 0 < x ≤ 0.2, wherein RE is one or more of Y, Lu, Tb and Gd,AE is one or more of Mg, Ca, Sr, Ba, A´ is one or more of Scand Ga. Alternatively or additionally, the phosphor can be anEuropium(II)-doped β-SiAlON or a luminescent material dopedwith Cr3+, Ni2+, Co2+, Cu2+, or any other optically activedopant. For example, the phosphor is a Ce3+-activated garnetsuch as (RE1-xCex)3(Al1-yA’y)5O12, where 0 < x ≤ 0.1 and 0 ≤ y ≤2023PF01591 February 21, 2025P2023,1569 WO N -8 -1, RE is at least one of Y, Lu, Tb, and Gd, and A’ is at least one of Sc and Ga.In particular, a semiconductor nanocrystal is a particlehaving a diameter between and including 1 nm and 50 nm, forexample between and including 2 nm and 20 nm, for examplebetween and including 2 nm and 10 nm. Due to their small size, semiconductor nanocrystals have different properties than a bulk material formed from the same material. It is possible for the semiconductor nanocrystal to be spherical, rod-shaped or cuboid. In particular, the semiconductor nanocrystal is a nanoparticle with a predominantly crystalline structure, for example a semiconductor nanoparticle or a quantum dot. In particular, the semiconductor nanocrystal is made up of atoms in a monocrystalline or polycrystalline arrangement. The semiconductor nanocrystal is formed, for example, from at least one semiconductor material. The semiconductor nanocrystal may comprise or be formed from at least one of the semiconductor materials CdSe, CdS, InP, GaP or GaAs.According to at least one embodiment, the matrix materialcomprises at least one of polysiloxane, silicone, or glass. In particular, the polysiloxane comprises the formula [RSiO3 / 2]x[R2SiO]y[R3SiO1 / 2]z, where R is any combination of methyl and / or phenyl, and x, y, and z indicate the relative proportion of the three types of siloxane groups, T-units, D-units, and M-units, respectively. For example, the above formula is the formula of the polysiloxane in cured form. In particular, x + y + z = 1, 0.5 ≤ x ≤ 1.0, 0 ≤ y ≤ 0.5, and0 ≤ z < 0.1. For example, 0 < x ≤ 1, 0 ≤ y < 0.3, and z = 0.2023PF01591 February 21, 2025P2023,1569 WO N -9 -For instance, the polysiloxane is a methyl polysiloxane having exclusively T-unit bonding. In particular, the polysiloxane is free of carbon-carbon bonds in its main polymer chain. In other words, crosslinking throughout the matrix material is made from silicon-oxygenbonds. In the case where R = phenyl, there are carbon-carbonbonds in the phenyl groups, but those groups are not part ofthe crosslinked network. Instead, the phenyl groups aremerely side groups. In particular, the polysiloxane is cured via condensation reactions. For example, the polysiloxane is not cured via addition reactions. In other words, the polysiloxane is not based on systems that crosslink via aSi-H group on a first precursor material and a vinyl group ona second precursor material.A polysiloxane matrix material can advantageously be used for applications requiring a high flux in the blue spectral range and / or high temperature. In particular, the silicone is a silicone having primarily D-unit bonding. For example, the d-unit silicone is of the addition-cure type or of the moisture-cure type. For the D-unit silicone of the addition-cure type, carbon-carbon bonds are involved in the crosslinking. For the D-unit silicone of the moisture-cure type, no carbon-carbon bonds are involved in the crosslinking.According to at least one embodiment, the first layer furthercomprises filler particles. In particular, the fillerparticles are mixed in the matrix material. For example, the filler particles are at least one of silica particles, fumed silica particles, fused silica particles, polysilsesquioxane2023PF01591 February 21, 2025P2023,1569 WO N -10 -particles, oxide particles, or particles transparent in the UV and / or the visible and / or the IR spectral range. In particular, the silica particles are present in the firstlayer in a concentration of more than 0 vol% and at most45 vol%. In particular, the silica particles comprise a sizeof at most 10 µm. For example, the size of the silicaparticles is a mixture of sub-micron to 10 µm particles inany proportion. In particular, the fumed silica particles are present in thefirst layer in a concentration of more than 0 vol% and atmost 15 vol%. For example, the fumed silica particles have asurface area greater than 175 m2 / g. For instance, the fumed silica particles are hydrophobic fumed silica particles. In particular, the fused silica particles are present in thefirst layer in a concentration of more than 0 vol% and atmost 45 vol%. For example, the fused silica particles have adiameter between and including 0.5 µm and 50 µm. For instance, the fused silica particles have a spherical shape. The fused silica particles can be porous or non-porous.In particular, the polysilsesquioxane particles are presentin the first layer and a concentration of more than 0 vol%and at most 45 vol%. For example, the polysilsesquioxaneparticles have a diameter between and including 0.1 µm to10 µm. For instance, the polysilsesquioxane particles have aspherical shape. In particular, the oxide particles comprise or consist ofsapphire spheres, ZnO particles, or TiO2 particles.2023PF01591 February 21, 2025P2023,1569 WO N -11 -The filler particles can advantageously help tune the coefficient of thermal expansion (CTE). For example, the CTE of a matrix material of a polysiloxane matrix material in the first layer can be above 100 ppm / deg, whereas the CTE of a glass substrate can be below 10 ppm / deg. Adding filler particles, in particular silica particles, to the matrix can decrease the thermal expansion of the first layer, bringing it closer to the thermal expansion of the glass substrate.Having the CTEs of the first layer and the substrate closerto each other can reduce the likelihood of delaminationbetween the first layer and the substrate or crack formationin the first layer.Further, adding filler particles, in particular silicaparticles, to the matrix material can advantageously increasethe rigidity of the first layer, which makes it less prone todamage during handling.Furthermore, the filler particles can advantageously modifythe refractive index of the first layer, which changes thescattering behavior or light extraction properties of theconversion element.In addition, adding filler particles, in particular verysmall, fumed silica particles, can advantageously aid in themanufacturing process, where the filler particles can be usedto tune the viscosity of a precursor of the first layer.According to at least one embodiment, a main surface of thesubstrate opposite the first layer is modified. Inparticular, the main surface of the substrate opposite the first layer is modified to change the way electromagnetic radiation propagates through the conversion element.2023PF01591 February 21, 2025P2023,1569 WO N -12 -For example, an anti-reflective coating or a dielectric stack is applied to the main surface of the substrate opposite thefirst layer. The dielectric stack can modify thetransmittance of electromagnetic radiation as a function of wavelength and / or angle. Alternatively, the main surface of the substrate opposite thefirst layer can be roughened. A roughened surface can changethe light extraction behavior of electromagnetic radiation.For example, a micro-lens array, a meta-lens, or a photoniccrystal are formed on the main surface of the substrateopposite the first layer. A micro-lens array, a meta-lens, ora photonic crystal can alter the propagation ofelectromagnetic radiation according to the needs of a given application.Furthermore, a method for producing a plurality of conversionelement is specified. In particular, the conversion element described herein is produced by the method for producing a plurality of conversion elements. Thus, embodiments, features, and advantages described in combination with the conversion element also apply to the method for producing aplurality of conversion element and vice versa.According to at least one embodiment, the method comprisesproviding a substrate. In particular, the substrate is acommon substrate for a plurality of conversion elements. For example, the substrate is provided in the form of a plate such as a glass plate. According to at least one embodiment, the method comprises applying a precursor of a first layer comprising a phosphor2023PF01591 February 21, 2025P2023,1569 WO N -13 -and a precursor of a matrix material on the substrate in a patterned manner, wherein first regions comprising theprecursor of the first layer and second regions free of theprecursor of the first layer are formed. In particular, theprecursor of the first layer is a slurry formed by mixing the phosphor with the precursor of the matrix material. The slurry can then be applied to the substrate. The precursor ofthe first layer can further comprise filler particles and / orhardeners.In particular, the second regions form a continuous andmultiply connected structure. For example, each first region is completely surrounded by second regions. In other words,the second regions form gaps around the precursor of thefirst layer in the first regions. The second regions candefine a boundary of each of the conversion elements produced with this method.In particular, each second region is linear. For example,each linear second region has a width that is perpendicularto a main extension direction of the second region andparallel to the main extension plane of the conversionelement. For instance, the width of the second region is lessthan 50 µm, in particular less than 25 µm. In particular, the second regions comprise or consist of aplurality of parallel, linear second regions. The parallel,linear second regions can further be equidistant. Forexample, a first group of parallel, linear second regionsintersects a second group of parallel, linear second regions.For instance, the first group intersects the second group at an angle of 90°.2023PF01591 February 21, 2025P2023,1569 WO N -14 -According to at least one embodiment, the method comprises curing the precursor of the first layer to form the firstlayer. In particular, the first layer is formed in the firstregions. For example, the second regions are free of thefirst layer. In particular, curing the matrix precursorincludes forming a matrix material from the matrix precursor. For example, curing the matrix precursor forms a solid body of the slurry. According to at least one embodiment, the method comprisesstealth dicing the substrate in the second regions. Inparticular, the substrate is stealth diced in the second regions to form a plurality of conversion elements. Forexample, the second regions are used as fiducials for stealthdicing. In particular, a laser is used to form a disruption zone ineach second region. For example, electromagnetic radiationemitted by the laser is internally absorbed in the substrateto create the disruption zone. The pattern of the first andsecond regions can be used to align the laser. Subsequently,the substrate can be expanded to singulate the individualconversion elements. For example, stealth dicing does notremove material of the substrate. As a result, there can be a step in length and width dimensions at the interface betweenthe substrate and the first layer.According to at least one embodiment, the method comprises providing a substrate, applying a precursor of a first layer comprising a phosphor and a precursor of a matrix material on the substrate in a patterned manner, wherein first regions comprising the precursor of a first layer and second regions free of the precursor of the first layer are formed, curing2023PF01591 February 21, 2025P2023,1569 WO N -15 -the precursor of the first layer to form the first layer, and stealth dicing the substrate in the second regions.With such a method, a conversion element having an improvedstrength and an improved yield can advantageously be producedsimply and cost-efficiently. By applying the first layer onthe substrate in a patterned manner, the substrate can besingulated without having to singulate the first layer, forexample by dicing, sawing, or ablating through the firstlayer. Thus, the substrate and the first layer are both separated with good quality. Furthermore, applying and patterning the first layer on the substrate avoids the handling of the first layer by itself without the support of the substrate thereby improving the quality of the first layer. A further method step of dispensing an adhesive and picking-and-placing of the substrate on the first layer and, thus, additional cost and complexity can be avoided. In addition, the alignment between the substrate and the firstlayer can be assured. Also, an overflow or coating of theside surfaces of the substrate by material of the first layer can be prevented.Furthermore, by using stealth dicing for singulating thesubstrate, the substrate has a lower number of areas ofdefects, in particular in edge regions of the substrate,compared to substrates singulated by, for example saw dicing,resulting in a higher mechanical stability and a betterquality of the conversion element. In addition, no material is ejected or scattered during stealth dicing and, thus, surface contamination during singulation can be prevented. Furthermore, the method described herein has a fasterprocessing speed and a lower consumable cost as stealth2023PF01591 February 21, 2025P2023,1569 WO N -16 -dicing is both faster and cheaper compared to, for example,saw dicing.According to at least one embodiment, applying the precursorof the first layer on the substrate in a patterned manner comprises applying the precursor of the first layer to the substrate, applying a stamp to the precursor of the first layer in the second regions, and removing the stamp together with the precursor of the first layer in the second regions. The method steps of applying the stamp and removing the stamp can be referred to as reverse stamping. In particular, the precursor of the first layer is applied in such a way that the precursor of the first layer covers a main surface of the substrate parallel to the main extension plane of the substrate as completely as possible. In otherwords, the precursor of the first layer covers at least 90 %,in particular at least 95 %, for example 100 % of the mainsurface of the substrate. For example, the precursor of thefirst layer is applied by tape-casting or spraying. In particular, the stamp comprises a pattern of elevations and recesses. For example, the pattern of the stampcorresponds to the pattern of first regions and secondregions in such a way that the recesses of the stampcorrespond to the first regions and the elevations of thestamp correspond to the second regions. In particular, thematerial of the stamp, in particular of the elevations of thestamp, has an affinity to the precursor of the first layer.The precursor of the first layer can then adhere to theelevations of the stamp. For example, the material of the stamp is a silicone, in particular a silicone with a tacky surface.2023PF01591 February 21, 2025P2023,1569 WO N -17 -In particular, removing the stamp removes the precursor ofthe first layer, for example completely, in all regions inwhich the stamp, in particular the elevations of the stamp, has a direct mechanical contact to the precursor of the firstlayer. For example, the precursor of the first layer in thesecond regions has a higher affinity to the stamp than to the substrate and is thus removed together with the stamp from the substrate. The precursor of the first layer can remain on the substrate in the first regions. For instance, removing the stamp leaves behind the inverse pattern of the stamp inthe form of the precursor of the first layer on thesubstrate. By using a stamp, the precursor of the first layer can advantageously be applied to the substrate in a patterned manner simply and efficiently.According to at least one embodiment, applying the precursorof the first layer on the substrate in a patterned manner comprises printing the precursor of the first layer on thesubstrate in the first regions. In particular, the precursorof the first layer is only printed in the first regions. In other words, the precursor of the first layer is not printed in the second regions. For example, the precursor of the first layer is directly printed in the first regions with thedesired spacing between the first regions that form thesecond regions. In particular, the precursor of the firstlayer is printed using laser printing, flexographic printing,or screen printing. By printing the precursor of the firstlayer in the first regions, the precursor of the first layer can advantageously be applied to the substrate in a patterned manner simply and efficiently.2023PF01591 February 21, 2025P2023,1569 WO N -18 -According to at least one embodiment, applying the precursorof the first layer on the substrate in a patterned manner comprises applying a photoresist to the substrate, patterning the photoresist by removing the photoresist in the first regions, applying the precursor of the first layer to thepatterned photoresist, and removing the photoresist and theprecursor of the first layer in the second regions. In particular, the photoresist is applied in such a way that the photoresist covers a main surface of the substrate parallel to the main extension plane of the substrate as completely as possible. In other words, the photoresistcovers at least 90 %, in particular at least 95 %, forexample 100 % of the main surface of the substrate. Forexample, the photoresist is applied by spin-coating, slot-diecoating, tape-casting, or spraying.In particular, the photoresist is patterned by exposing the photoresist to electromagnetic radiation in either the first regions or the second regions through a mask. For example, the photoresist is exposed to electromagnetic radiation insuch a way that, after the exposure, the photoresist is solidin the second regions and liquid in the first regions.Alternatively, the photoresist is exposed to electromagneticradiation in such a way that, after the exposure, the photoresist is solid, and insoluble to certain solvents, in the second regions and solid, but soluble in certain solvents, in the first regions. In both instances, the photoresist can be removed in the first regions, inparticular completely, and remains on the substrate in thesecond regions. In particular, patterning the photoresistforms a patterned photoresist on the substrate. For example,2023PF01591 February 21, 2025P2023,1569 WO N -19 -the patterned photoresist forms pockets of first regions freeof the photoresist surrounded by second regions of thephotoresist. In particular, the precursor of the first layer is applied to the patterned photoresist in such a way that the precursor ofthe first layer covers the patterned photoresist ascompletely as possible. In other words, the precursor of thefirst layer covers at least 90 %, in particular at least95 %, for example 100 % of patterned photoresist. Forexample, the precursor of the first layer fills, in particular completely, the pockets in the first regions. Inaddition, the precursor of the first layer can be applied ontop of the photoresist in the second regions. For instance,the precursor of the first layer is applied by tape-casting or spraying. In particular, removing the photoresist and the precursor ofthe first layer in the second region comprises stripping thephotoresist from the substrate. By protecting the second regions of the substrate with a photoresist, the precursor of the first layer can advantageously be applied to the substrate in a patterned manner simply and efficiently. According to at least one embodiment, removing the photoresist and the precursor of the first layer in the second regions comprises removing the photoresist together with the precursor of the first layer in the second regions.In particular, the precursor of the first layer in the secondregions is removed by removing the photoresist in the second regions. For example, stripping the photoresist in the second2023PF01591 February 21, 2025P2023,1569 WO N -20 -regions removes the precursor of the first layer that wasapplied on top of the photoresist in the second regions. Byremoving the photoresist together with the precursor of thefirst layer in the second regions, the precursor of the firstlayer can advantageously be removed simply and efficiently inthe second regions in a single method step.According to at least one embodiment, removing thephotoresist and the precursor of the first layer in the second regions comprises removing the precursor of the firstlayer in the second regions, in particular completely, andsubsequently removing the photoresist in the second regions.In other words, the precursor of the first layer is removedprior to removing the photoresist in the second regions. Forexample, the precursor of the first layer is removed bygrinding or lapping. For instance, the precursor of the firstlayer on top of the photoresist in the second regions isremoved prior to stripping the photoresist. By removing theprecursor of the first layer prior to removing the photoresist in the second regions, the photoresist canadvantageously be removed simply and efficiently as there isno precursor of the first layer blocking the photoresist thatis to be stripped away. Furthermore, an optoelectronic device is specified. In particular, the optoelectronic device comprises the conversion element described herein. Thus, embodiments, features, and advantages described in combination with the conversion element and the method for producing a conversion element also apply to the optoelectronic device and vice versa.2023PF01591 February 21, 2025P2023,1569 WO N -21 -According to an embodiment, the optoelectronic device comprises a semiconductor chip configured to emit a primary radiation. In other words, the semiconductor chip isconfigured to emit electromagnetic radiation of a firstwavelength range. In particular, the primary radiation comprises wavelengths in the ultraviolet to blue spectralrange, for example between and including 360 nm and 500 nmsuch as of 450 nm. According to at least one embodiment, the optoelectronic device comprises a conversion element described herein configured to convert at least a part of the primary radiation into a secondary radiation. In other words, the conversion element converts the electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelength range. For example, the first wavelength range is at least partially different from the secondwavelength range. In particular, an ability of the conversionelement to convert electromagnetic radiation is attributed tothe phosphor converting primary radiation into secondaryradiation. According to at least one embodiment, the optoelectronic device comprises a semiconductor chip configured to emit electromagnetic radiation of a first wavelength range, and aconversion element described herein configured to convert atleast a part of a primary radiation into a secondaryradiation. Advantageously, the optoelectronic device described hereinhas an improved efficiency due to the configuration of theconversion element having a substrate that is slightly largerthan the first layer. The better quality of the first layer2023PF01591 February 21, 2025P2023,1569 WO N -22 -of the conversion element, in particular the reduced number of areas of defects, reduces the amount of chipped areas of the first layer being filled with packaging materials that can block some of the electromagnetic radiation emitted bythe optoelectronic device or influence color-over-spaceproperties of the optoelectronic device. Thus, a reduced amount of chipped areas of the first layer increases the efficiency and the yield of the optoelectronic device. According to at least one embodiment, the semiconductor chip is a micro-LED. Here and in the following, LED is anabbreviation for the term “light-emitting diode”. Micro-LEDsmay have a width, a length, a thickness and / or a diameter smaller than or equal to 100 micrometers, in particular smaller than or equal to 70 micrometers, for example smaller than or equal to 50 micrometers. In particular, micro-LEDs, for example rectangular micro-LEDs, have an edge length, for instance in plan view of layers of a layer stack, of a luminous surface smaller than or equal to 70 micrometers, for example smaller than or equal to 50 micrometers. For example,the micro-LED is a light-emitting diode, wherein a growthsubstrate is removed, such that a thickness of the micro-LED is, for instance, between and including 1.5 micrometers and 10 micrometers. For example, the micro-LED is provided on a wafer having releasable retaining structures. The micro-LED can be detached from the wafer in a non-destructive manner. According to at least one embodiment, the optoelectronic device is used in lighting applications, in particular in automotive applications, for example in headlamps or in turn signals.2023PF01591 February 21, 2025P2023,1569 WO N -23 -Advantageous embodiments and developments of the conversion element, the method for producing a conversion element, and the optoelectronic device will become apparent from the exemplary embodiments described below in conjunction with the figures. In the figures:Figures 1A to 1D, 2, and 3A to 3D each show a schematicillustration of a conversion element according to different exemplary embodiments, Figures 4A to 4E, 6A to 6H, 7A to 7H, and 8A to 8I show schematic illustrations of methods for producing a conversion element according to different exemplary embodiments, and Figures 5A and 5B each show a confidence interval plot for a mean flexural stress of a substrate and of a conversionelement according to an exemplary embodiment and acomparative example, respectively, andFigure 9 shows a schematic illustration of an optoelectronicdevice according to an exemplary embodiment. In the exemplary embodiments and figures, similar or similarly acting constituent parts are provided with the same reference signs. The elements illustrated in the figures and their size relationships among one another should not be regarded as true to scale. Rather, individual elements may be represented with an exaggerated size for the sake of better representability and / or for the sake of better understanding.2023PF01591 February 21, 2025P2023,1569 WO N -24 -Figure 1A shows an exemplary embodiment of a conversion element 1 in a top view, figure 1B shows the exemplary embodiment of the conversion element 1 in a bottom view, figure 1C shows the exemplary embodiment of the conversion element 1 in a cross-sectional side view, and figure 1D shows the exemplary embodiment of the conversion element 1 in a perspective view. The conversion element 1 of the exemplary embodiment offigures 1A to 1D comprises a substrate 2, for example a glasssubstrate such as borosilicate glass. The substrate has twomain surfaces 22, 23 both perpendicular to a main extensionplane of the conversion element 1 as well as side surfaces 21 perpendicular to the main extension plane of the conversionelement 1. The substrate 2 has a length x1 and a width y1.Further, the substrate 2 has a thickness z1, for example between and including 50 µm and 200 µm.On the main surface 22 of the substrate 2, a first layer 3 isarranged, in particular with a direct mechanical contact. In other words, no bonding agent such as a glue layer, is arranged between the substrate 2 and the first layer 3. The first layer 3 comprises a phosphor 31 in a matrixmaterial 32. In particular, the phosphor 31 is a Ce3+-activated garnet. For example, the phosphor 31 comprises the formula (RE1-xCex)3(Al1-yA’y)5O12, where 0 < x ≤ 0.1 and 0 ≤ y ≤ 1, RE is at least one of Y, Lu, Tb, and Gd, and A’ is at least one of Sc and Ga. In particular, the matrix material 32 comprises a polysiloxane comprising the formula [RSiO3 / 2]x[R2SiO]y[R3SiO1 / 2]z, where R is any combination of methyl and / or phenyl, x + y + z = 1, and x, y, and z indicate the relative proportion of the three types of siloxane2023PF01591 February 21, 2025P2023,1569 WO N -25 -groups, T-units, D-units, and M-units respectively. For instance, 0 < x ≤ 1, 0 ≤ y < 0.3, and z = 0.The first layer 3 has a length x2 and a width y2 parallel tothe main extension plane of the conversion element 1. In the exemplary embodiment of figures 1A to 1D, the length x2 andthe width y2 of the first layer 3 are shorter than the lengthx1 and the width y2 of the substrate 2. In other words, there is a step in length and width dimensions at the interfacebetween the substrate and the first layer. This step can bedefined in terms of a distance d between a side surface 33 ofthe first layer and a side surface 21 of the substrate 2. Thedistance d can be less than 25 µm, in particular less than 12.5 µm.The conversion element 1 of the exemplary embodiment offigure 2 corresponds essentially to the conversion element 1of the exemplary embodiment shown in figure 1B. Figure 2 shows exemplarily an area of a defect 4 on the main surface23 of the substrate 2 opposite the first layer 3. Such areasof defects 4 can also be present on the main surface 22 facing the first layer 3 and on side surfaces 21 of thesubstrate 2. For a conversion element 1 having a length x1and width y1 of the substrate 2 greater than or equal to1.00 mm, the area of defects 4 is less than 1 % of the totalarea of the substrate surface 21, 22, 23. For a conversion element 1 having a length x1 and width y1 of the substrate 2greater than 0.50 mm and less than 1.00 mm, the area ofdefects 4 is less than 2 % of the total area of the substratesurface 21, 22, 23. For a conversion element 1 having alength x1 and width y1 of the substrate 2 greater than0.25 mm and less than 0.5 mm, the area of defects 4 is less2023PF01591 February 21, 2025P2023,1569 WO N -26 -than 3 % of the total area of the substrate surface 21, 22,23.The conversion element 1 of the exemplary embodiment offigure 3A corresponds essentially to the conversion element 1of the exemplary embodiment shown in figure 1C. Figure 3Ashows the substrate 2 and the first layer 3 with phosphorparticles 31 dispersed in the matrix material 32.The conversion element 1 of the exemplary embodiment offigure 3B corresponds essentially to the conversion element 1of the exemplary embodiment shown in figure 3A. In addition,the first layer comprises filler particles 34 dispersed inthe matrix material 32. For example, the filler particles are silica particles having a concentration of more than 0 vol% and at most 45 vol%. The size of the silica particles can be a mixture of submicron to 10 µm particles in any proportion. Alternatively or additionally, the filler particles 34 can comprise fumed silica particles, fused silica particles,polysilsesquioxane particles, oxide particles and / ortransparent particles.The conversion element 1 of the exemplary embodiment offigure 3C corresponds essentially to the conversion element 1of the exemplary embodiment shown in figure 3A. In addition,the second main surface 23 of the substrate 2 is modified insuch a way that a layer 24 is arranged on the main surface 23 of the substrate 2 opposite the first layer 3. The layer 24 can be an antireflective coating or a dielectric stack for modifying the transmittance of electromagnetic radiation as a function of wavelength and / or angle.2023PF01591 February 21, 2025P2023,1569 WO N -27 -The conversion element 1 of the exemplary embodiment offigure 3D corresponds essentially to the conversion element 1of the exemplary embodiment shown in figure 3A. In addition,the main surface 23 of the substrate 2 opposite the firstlayer 3 is modified in such a way that a surface structure 25is formed on the main surface 23. To form the surfacestructure 25, the main surface 23 can be roughened to change the electromagnetic radiation extraction behavior. Forexample, the surface structure 25 is a micro-lens array, ameta-lens, or a photonic crystal. The conversion element 1 according to the exemplaryembodiments of figures 1A to 1D, 2, and 3A to 3D can beproduced by the method for producing a plurality ofconversion elements 1 as described in conjunction withfigures 4A to 4E.A substrate 2, in particular a common substrate 2, isprovided (figure 4A).A precursor 5 of the first layer 3 comprising a phosphor 31,a precursor of the matrix material 32, and optionally fillerparticles 35 and a hardener is applied, in particular in the form of a slurry, on the substrate 2 in a patterned manner such that the precursor 5 of the fist layer 4 is present in first regions 6 and second regions 7 are free of the precursor 5 of the first layer 3 (figure 4B). The second regions 7 can be linear regions that are multiply connected to one another. As can be seen in figure 4B, the secondregions 7 surround the first regions 6, in particularcompletely. The precursor 5 of the first layer 3 can beapplied in a patterned manner by printing the precursor 5 of the first layer 3 directly in the first regions 6 leaving the2023PF01591 February 21, 2025P2023,1569 WO N -28 -second regions 7 free of the precursor 5 of the first layer 3. For example, the precursor 5 of the first layer can be printed by laser printing, flexographic printing, or screen printing. Alternatively, the precursor 5 of the first layer 3 can be applied on the substrate in a patterned manner as discussed below in conjunction with figures 6A to 6H, 7A to 7H, and 8A to 8H. Subsequently, the precursor 5 of the first layer 3, in particular the precursor of the matrix material 32, is cured to form the first layer 3 in the first regions 6 on the substrate 2 (figure 4C). Subsequently, the individual conversion elements are singulated by stealth dicing. First, laser disruption zones71 are established in the second regions 7(figure 4D). Thepattern of first regions 6 and second regions 7 can be used to align the laser. Afterwards, the substrate 2 is expanded to make the individual conversion element 1 (figure 4E). Figure 5A shows a confidence interval plot for the mean flexural stress measured during a three-point bend test of a substrate 2 of borosilicate glass singulated by saw dicing (5-1) or stealth dicing (5-2). Figure 5A shows that it takes more force to break a substrate of glass singulated by stealth dicing compared to saw dicing. Figure 5B shows a confidence interval plot for the mean flexural stress measured during a three-point bend test of a conversion element 1 described herein singulated by sawdicing (5-1) or stealth dicing (5-2). In both cases, thesamples were broken substrate-side up. Like the results shown in figure 5A, the conversion element 1 singulated by stealth2023PF01591 February 21, 2025P2023,1569 WO N -29 -dicing has a higher strength compared to the conversion element 1 singulated by saw dicing. Figures 5A and 5B show that a singulation by stealth dicingis advantageous for the substrate 2 and the mechanicalstrength of the conversion element 1. The advantage of themethod described herein is that the need of singulating thefirst layer 3 by either a mechanical or a laser process is negated. Instead, individual first layers 3 are defined in regions of the substrate 2 that are not subjected to singulation. Thus, the benefits of stealth dicing the substrate 2 can be maintained, without the disadvantages ofbreaking or sawing the first layer 3.The conversion element 1 according to the exemplaryembodiments of figures 1A to 1D, 2, and 3A to 3D can beproduced by the method for producing a plurality ofconversion elements 1 as described in conjunction withfigures 6A to 6H. Figures 6A, 6B, and 6F to 6H show topviews, whereas figures 6C to 6E show side views. Method stepsalready discussed in conjunction with figures 4A to 4E are not discussed in detail below. A substrate 2, in particular a common substrate 2, is provided (figure 6A). The precursor 5 of the first layer 3 is applied on thesubstrate 2, in particular in such a way that the precursor 5of the first layer 3 covers the first main surface 22 of thesubstrate 2 completely (figure 6B). For example, theprecursor 5 of the first layer 3 is applied by tape-casting or spraying.2023PF01591 February 21, 2025P2023,1569 WO N -30 -Subsequently, a stamp 8 is applied to the precursor 5 of thefirst layer 3 (figure 6C). The stamp 8 comprises a pluralityof elevations 81. The elevations 81 are brought into contactwith the precursor 5 of the first layer 3 in second regions 7(figure 6D). The elevations 81 comprise a silicone such as a silicone with a tacky surface. The precursor 5 of the first layer 3 adheres to the elevations 81. Subsequently, the stamp 8 is removed (figure 6E). Theprecursor 5 of the first layer 3 that are in contact with thestamp 8 are selectively removed together with the stamp 8.Thus, an inverse pattern of the stamp 8 is left behind on thesubstrate 2 comprising the precursor 5 of the first layer 3in the first regions 6 whereas the second regions 7 are freeof the precursor 5 of the first layer 3.Subsequently, the precursor 5 of the first layer 3 is cured to form the first layer 3 in the first regions 6 on the substrate 2 (figure 6F). Subsequently, the individual conversion elements are singulated by stealth dicing. Laser disruption zones 71 areestablished in the second regions 7 (figure 6G) and thesubstrate 2 is expanded to make the individual conversionelement 1 (figure 6H). The conversion element 1 according to the exemplaryembodiments of figures 1A to 1D, 2, and 3A to 3D can beproduced by the method for producing a plurality ofconversion elements 1 as described in conjunction withfigures 7A to 7H. Method steps already discussed inconjunction with figures 4A to 4E or figures 6A to 6H are not discussed in detail below.2023PF01591 February 21, 2025P2023,1569 WO N -31 -A substrate 2, in particular a common substrate 2, is provided (figure 7A). A photoresist 9 is applied on the substrate 2, in particular in such a way that the photoresist 9 covers the first main surface 22 of the substrate 2 completely (figure 7B). The photoresist 9 is patterned by removing the photoresist 9in the first regions 6 (figure 7C). The photoresist 9 ispatterned by exposing the photoresist to electromagneticradiation through a mask either in the first regions 6 or inthe second regions 7 depending on the type of photoresist. Inparticular, the photoresist 9 is exposed to electromagneticradiation in such a way that, after the exposition, thephotoresist 9 is solid in the second regions 7 and liquid inthe first regions 6. Alternatively, the photoresist 9 isexposed to electromagnetic radiation in such a way that, after the exposition, the photoresist 9 is solid, andinsoluble to certain solvents, in the second regions 7 andsolid, but soluble in certain solvents, in the first regions6. The liquid, or soluble, part of the photoresist 9 in thefirst regions 6 can then be removed. The photoresist 9 in thesecond regions 7 surrounds the first regions 6 and formspockets in the first regions 6.Subsequently, the precursor 5 of the first layer 3 is appliedto the patterned photoresist 9, in particular completely(figure 7D). The precursor 5 of the first layer 3 is appliedin such a way that the precursor 5 of the first layer 3 fillsthe pockets in the first regions 6. Additionally, theprecursor 5 of the first layer 3 can cover the photoresist 9in the second regions 7.2023PF01591 February 21, 2025P2023,1569 WO N -32 -Subsequently, the photoresist 9 in the second regions 7 isremoved together with the precursor 5 of the first layer 3 inthe second regions (figure 7E). The photoresist 9 can bestripped away along with any precursor 5 of the first layer 3that is on top of the photoresist 9. Subsequently, the precursor 5 of the first layer 3 is cured to form the first layer 3 in the first regions 6 on the substrate 2 (figure 7F). Subsequently, the individual conversion elements are singulated by stealth dicing. Laser disruption zones 71 are established in the second regions 7 (figure 7G) and thesubstrate 2 is expanded to make the individual conversionelement 1 (figure 7H). The conversion element 1 according to the exemplaryembodiments of figures 1A to 1D, 2, and 3A to 3D can beproduced by the method for producing a plurality of conversion elements 1 as described in conjunction withfigures 8A to 8I. Method steps already discussed inconjunction with figures 4A to 4E, figures 6A to 6H, or figures 7A to 7H are not discussed in detail below. A substrate 2, in particular a common substrate 2, is provided (figure 8A). A photoresist 9 is applied on the substrate 2, in particular in such a way that the photoresist 9 covers the first main surface 22 of the substrate 2 completely (figure 8B).2023PF01591 February 21, 2025P2023,1569 WO N -33 -The photoresist 9 is patterned by removing the photoresist 9in the first regions 6 (figure 8C).Subsequently, the precursor 5 of the first layer 3 is appliedto the patterned photoresist 9, in particular completely (figure 8D).Subsequently, the precursor 5 of the first layer 3 is removedin the second regions 7, in particular completely (figure8E). For example, the precursor 5 of the first layer 3 isremoved by grinding or lapping. After this method step, thephotoresist 9 in the second regions 7 is free of theprecursor 5 of the first layer 3.Subsequently, the photoresist 9 is removed in the second region 7, for example by stripping away the photoresist 9 (figure 8F). In this method step, there is no precursor 5 ofthe first layer 3 blocking the photoresist 9 that needs to bestripped away. Subsequently, the precursor 5 of the first layer 3 is cured to form the first layer 3 in the first regions 6 on the substrate 2 (figure 8G). Subsequently, the individual conversion elements are singulated by stealth dicing. Laser disruption zones 71 are established in the second regions 7 (figure 8H) and thesubstrate 2 is expanded to make the individual conversionelement 1 (figure 8I). The optoelectronic device 10 of the exemplary embodiment offigure 9 comprises a semiconductor chip 20 configured to emita primary radiation. The semiconductor chip 20 can be a2023PF01591 February 21, 2025P2023,1569 WO N -34 -micro-LED. For example, primary radiation is in the blue spectral range, for instance 450 nm. A conversion element 1 as described herein is arranged on a radiation exit surface of the semiconductor chip 20. The conversion element 1 can be arranged directly on the radiation exit surface or in a distance to the radiation exit surface. The conversion element 1 can be in the form of a platelet. In particular, the platelet is glued directly to the semiconductor chip 20, for example via a silicone glue. In particular, the platelet is glued to the semiconductorchip 20 with the first layer 3 towards the semiconductor chip20, and the substrate 2 facing away from the semiconductorchip 20. The conversion element 1 converts at least a part ofthe primary radiation into a secondary radiation. The features and exemplary embodiments described in connection with the figures can be combined with each other according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures may have alternative or additional features as described in the general part. The invention is not restricted to the exemplary embodiments by the description on the basis of said exemplary embodiments. Rather, the invention encompasses any new feature and also any combination of features, which in particular comprises any combination of features in the patent claims and any combination of features in the exemplary embodiments, even if this feature or this combination itself is not explicitly specified in the patent claims or exemplary embodiments.2023PF01591 February 21, 2025P2023,1569 WO N -35 -This patent application claims the priority of US provisionalpatent application 63 / 568,751, the disclosure content of which is hereby incorporated by reference.

[0002] 2023PF01591 February 21, 2025P2023,1569 WO N -36 -References1 conversion element2 substrate21 side surface22 main surface23 main surface24 layer25 surface structure3 first layer31 phosphor32 matrix material33 side surface34 filler particles4 defect5 precursor6 first region7 second region71 disruption zone8 stamp81 elevations9 photoresist10 optoelectronic device20 semiconductor chipd distancex1 lengthy1 widthz1 thicknessσfflexural stress5-1 saw dicing5-2 stealth dicing

Claims

2023PF01591 February 21, 2025P2023,1569 WO N -37 -Claims 1. A conversion element (1) comprising- a substrate (2), and- a first layer (3) comprising a phosphor (31) in a matrixmaterial (32) on the substrate (2), wherein the first layer (3) is configured to convert primary radiation into secondary radiation, and wherein a lateral extension of the substrate (2) is larger than a lateral extension of the first layer (3) in at least one extension direction parallel to a main extension plane of the conversion element (1).

2. The conversion element (1) according to the preceding claim, wherein the substrate (2) is in direct mechanical contact to the first layer (3).

3. The conversion element (1) according to at least one of the preceding claims, wherein a side surface (33) of the first layer (3) has a distance (d) from a side surface (21) of the substrate (2) of less than 25 µm.

4. The conversion element (1) according to at least one of the preceding claims, wherein a length (x1) and a width (y1) of the substrate (2) are greater than or equal to 1.00 mm, andwherein an area of defects (4) on a surface (21, 22, 23) ofthe substrate (2) is less than 1 % of a total area of the surface (21, 22, 23) of the substrate (2).2023PF01591 February 21, 2025P2023,1569 WO N -38 -5. The conversion element (1) according to at least one of the claims 1 to 3, wherein a length (x1) and a width (y1) of the substrate (2) are greater than 0.50 mm and less than 1.00 mm, andwherein an area of defects (4) on a surface (21, 22, 23) ofthe substrate (2) is less than 2 % of a total area of the surface (21, 22, 23) of the substrate (2).

6. The conversion element (1) according to at least one of the claims 1 to 3, wherein a length (x1) and a width (y1) of the substrate (2) are greater than 0.25 mm and less than 0.50 mm, andwherein an area of defects (4) on a surface (21, 22, 23) ofthe substrate (2) is less than 3 % of a total area of the surface (21, 22, 23) of the substrate (2).

7. The conversion element (1) according to at least one of the preceding claims, wherein a mean flexural stress of the conversion element (1) is at least 200 MPa.

8. The conversion element (1) according to at least one of the preceding claims, wherein a thickness (z1) of the substrate (2) is between and including 50 µm and 200 µm.

9. The conversion element (1) according to at least one of the preceding claims, wherein the substrate (2) comprises at least one of a glass,a transparent polycrystalline material, or a transparentsingle crystal material.2023PF01591 February 21, 2025P2023,1569 WO N -<sub>39 -10. The conversion element (1) according to at least one of the preceding claims, wherein the phosphor (31) is at least one of a garnet, an oxynitride, a nitride, an oxide, a silicate, a halogenide, a phosphate, or a semiconductor nanocrystal.

11. The conversion element (1) according to at least one of the preceding claims, wherein the matrix material (32) comprises at least one of polysiloxane, silicone, or glass.

12. The conversion element (1) according to at least one of the preceding claims, wherein the first layer (3) further comprises filler particles (34).

13. The conversion element (1) according to at least one of the preceding claims, wherein a main surface (23) of the substrate (2) opposite the first layer (3) is modified.

14. A method for producing a plurality of conversion elements (1) comprising- providing a substrate (2),- applying a precursor (5) of a first layer (3) comprising aphosphor (31) and a precursor of a matrix material (32) on the substrate (2) in a patterned manner, wherein firstregions (6) comprising the precursor (5) of the first layer(3) and second regions (7) free of the precursor (5) of thefirst layer (3) are formed,- curing the precursor (5) of the first layer (3) to form thefirst layer (3), and- stealth dicing the substrate (2) in the second regions (7).2023PF01591 February 21, 2025P2023,1569 WO N -40 -15. The method according to the preceding claim, wherein applying the precursor (5) of the first layer (3) on the substrate (2) in a patterned manner comprises- applying the precursor (5) of the first layer (3) to thesubstrate (2),- applying a stamp (8) to the precursor (5) of the firstlayer (3) in the second regions (7), and- removing the stamp (8) together with the precursor (5) ofthe first layer (3) in the second regions (7).

16. The method according to claim 14, wherein applying the precursor (5) of the first layer (3) on the substrate (2) in a patterned manner comprises- printing the precursor (5) of the first layer (3) on thesubstrate (2) in the first regions (6).

17. The method according to claim 14, wherein applying the precursor (5) of the first layer (3) on the substrate (2) in a patterned manner comprises- applying a photoresist (9) to the substrate (2),- patterning the photoresist (9) by removing the photoresist(9) in the first regions (6),- applying the precursor (5) of the first layer (3) to thepatterned photoresist (9), and- removing the photoresist (9) and the precursor (5) of thefirst layer (3) in the second regions (7).

18. An optoelectronic device (10) comprising- a semiconductor chip (20) configured to emit a primaryradiation, and2023PF01591 February 21, 2025P2023,1569 WO N -41 -- a conversion element (1) according to at least one of theclaims 1 to 13 configured to convert the primary radiation into a secondary radiation.

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