Method for producing a conversion element and optoelectronic assembly

Abstract

A Method for producing a conversion element (1) is specified. The method comprises providing a substrate (2) comprising chip regions (24), arranging a source wafer (3) above the substrate (2), wherein a source layer (4) comprising a conversion material (5) is arranged on a side of the source wafer (3) facing the substrate (2), depositing a part (51) of the conversion material (5) on the substrate (2) by irradiating the source wafer (3) with a laser radiation (6), wherein the part (51) of the conversion material (5) at least partially forms the conversion element (1), and wherein the depositing is configured to arrange different amounts of the conversion material (5) on different chip regions (24). Furthermore, an optoelectronic assembly (8) is disclosed. The optoelectronic assembly (8) may comprise a micro-LED.

Description

[0001] 2023PF01337 January 22, 2025P2023,1349 WO N -1 –Description METHOD FOR PRODUCING A CONVERSION ELEMENT AND OPTOELECTRONIC ASSEMBLY A method for producing a conversion element and an optoelectronic assembly are specified. It is an object to provide a simple and efficient method for producing a conversion element. In particular, the conversion element shall further have improved properties. Additionally, an optoelectronic assembly with improved properties shall be provided. According to at least one embodiment, the method serves to produce a conversion element. Here and in the following a conversion element is an element which converts electromagnetic radiation of a first wavelength range into electromagnetic radiation of a second wavelength range. In particular, the conversion element is a continuous layer in an optoelectronic device. For example, the conversion element comprises a matrix material and a conversion material embedded therein. The wavelength converting properties of theconversion element for instance arise from the conversionmaterial. The conversion element can be a conversion elementproduced separately from an optoelectronic semiconductor chip. However, it is also possible that the conversionelement is produced directly on the optoelectronicsemiconductor chip. According to at least one embodiment, the method comprises providing a substrate. In particular, the substrate comprises chip regions. Here and in the following, chip regions are2023PF01337 January 22, 2025P2023,1349 WO N -2 –regions of the substrate which correspond to an optoelectronic semiconductor chip or a part of an optoelectronic semiconductor chip. In particular, in a fully assembled optoelectronic device, the chip regions are associated with the optoelectronic semiconductor chip or the part of the optoelectronic semiconductor chip. The term chip region does not necessarily imply that the substrate comprises an optoelectronic semiconductor chip. For example, the substrate comprises a plurality of optoelectronic semiconductor chips. An optoelectronic semiconductor chip then corresponds to a chip region.For example, the substrate comprises a transparent carrierwhich can be singulated into individual platelets. Inparticular, the substrate does not comprise light-generating regions in this case. A platelet then corresponds to a chip region. For example, the substrate is a pixelated light emitting diode. A pixel then corresponds to a chip region. According to at least one embodiment of the method, a source wafer is arranged above the substrate. In particular, the source wafer is arranged in a distance to the substrate. In other words, the source wafer and the substrate are not indirect contact. The source wafer can be a wafer having arectangular, square, or round shape when seen in plan view. In particular, a shape of the source wafer in plan view corresponds to a shape of the substrate in plan view. It isalso possible that the source wafer is provided in the formof a band conveyor. This advantageously offers a continuousprocess.2023PF01337 January 22, 2025P2023,1349 WO N -3 –According to at least one embodiment of the method, a source layer is arranged on a side of the source wafer facing the substrate. In particular, the source wafer is arranged in such a way above the substrate that a gap is between furthersource layer and the substrate. The source layer is, forexample, a layer which forms a precursor for the conversion element. According to at least one embodiment of the method, thesource layer comprises the conversion material. In otherwords, the source layer is the source for the conversionmaterial. In particular, the conversion material converts theelectromagnetic radiation of the first wavelength range into the electromagnetic radiation of the second wavelength range. In particular, the conversion material is selected from the group consisting of ceramic phosphors, semiconductor nanocrystals, and combinations thereof. The semiconductornanocrystals can also be referred to as quantum dots. Forexample, the conversion material comprises or consists of particles of the ceramic phosphor and / or the semiconductornanocrystals. The quantum dots may have a size of between andincluding 1 to 100 nanometers. The ceramic phosphor is, for example, a garnet-type phosphor or a nitride-type phosphor. For example, the ceramic phosphor is selected from the following group:Ce3+ doped garnets like YAG and LuAG, for example (Y,Lu,Gd,Tb)3(Al1-x,Gax)5O12:Ce3+; Eu2+ doped nitrides, for example(Ca,Sr)AlSiN3:Eu2+, Sr(Ca,Sr)Si2Al2N6:Eu2+(SCASN), (Sr,Ca)AlSiN3*Si2N2O:Eu2+, (Ca,Ba,Sr)2Si5N8:Eu2+, SrLiAl3N4:Eu2+,SrLi Al O N : 2+ 3+2 2 2 2 Eu ; Ce doped nitrides, for example (Ca,Sr)Al(1-2023PF01337 January 22, 2025P2023,1349 WO N -4 –Si N :C 2+4x / 3) (1+x) 3 e; (x = 0,2 – 0,5); Eu doped sulfides,(Ba,Sr,Ca)Si 2+2O2N2:Eu , SiAlONs, nitride orthosilicates (e.g.AE -x-aRExEuaSi1-yO4-x-2yNx), orthosil 2+2 icates (Ba,Sr,Ca)2SiO4:Eu ;chlorosilicates (e.g. Ca Mg(S 2+ 4+8 iO4)4Cl2:Eu ); Mn dopedfluorides, for example (K,Na) 4+ 2+ 3+2(Si,Ti)F6:Mn ; Eu or Cedoped litho-silicates, such as (Li,Na,K,Rb,Cs)(Li3SiO4):Ewith E = Eu2+, Ce3+, or (Sr,Li)Li 2+ 2+3AlO4:Eu or SrLi3AlO4:Eu .Additionally or alternatively, the ceramic phosphor is selected from the following group:(Ba1-x-ySrxCay)SiO4:Eu2+ (0 ^ x ^ 1, 0 ^ y ^ 1), (Ba1-x-Sr Ca ) SiO :Eu2+ (0 ^ x ^ 1, 0 ^ y ^ 1), Li Sr 2+y x y 3 5 2 SiO4:Eu , oxo-nitrides such as (Ba Sr Ca )Si O N :E 2+1-x-y x y 2 2 2 u (0 ^ x ^ 1; 0 ^ y ^1), SrSiAl O N :Eu2+, Ba Ca Si O 2+2 3 2 4-x x 6 N10:Eu (0 ^ x ^ 1), (Ba1-Sr )Y Si Al O N :Eu2+ (0 ^ x 2+x x 2 2 2 2 5 ^ 1), SrxSi(6-y)AlyOyN(8-y):Eu (0,05^ x ^ 0,5; 0,001 ^ y ^ 0,5), Si 2+6-zAlzOzN8-z:Eu (0 ^ z ^ 0,42),MxSi12-m-nAlm+nOnN16-n:Eu2+(M = Li, Mg, Ca, Y; x = m / v; v =valency of M, x ^ 2), M 3+xSi12-m-nAlm+nOnN16-n:Ce , AE2-x-aRExEuaSi1-yO4-x-2yNx(AE = Sr, Ba, Ca, Mg; RE = rare earth element), AE2-x-aRExEuaSi1-yO4-x-2yNx(AE = Sr, Ba, Ca, Mg; RE = rare earthelement), Ba Si O N :Eu2+ or nitrides suc 3+3 6 12 2 h as La3Si6N11:Ce ,(La1-xYx)3Si6N11:Ce3+, (Ba1-x-ySrxCay)2Si5N8:Eu2+, (Ca1-x-ySrxBay)AlSiN3:Eu2+ (0 ^ x ^ 1; 0 ^ y ^ 1), Sr(Sr1-Ca )Al Si N :Eu2+ (0 ^ x ^ 0,2), Sr 3+x x 2 2 6 (Sr1-xCax)Al2Si2N6:Ce (0 ^ x^ 0,2) SrAlSi N :E 2+ 2+4 7 u , (Ba1-x-ySrxCay)SiN2:Eu (0 ^ x ^ 1; 0 ^ y^ 1), (Ba Sr C 3+1-x-y x ay)SiN2:Ce (0 ^ x ^ 1; 0 ^ y ^ 1), (Sr1-Ca )LiAl N : 2+ 2+x x 3 4 Eu (0 ^ x ^ 1), (Ba1-x-ySrxCay)Mg2Al2N4:Eu (0 ^ x^ 1; 0 ^ y ^ 1), (Ba 2+1-x-ySrxCay)Mg3SiN4:Eu (0 ^ x ^ 1; 0 ^ y ^1). According to at least one embodiment of the method, a part of the conversion material is deposited on the substrate by2023PF01337 January 22, 2025P2023,1349 WO N -5 –irradiating the source wafer with a laser radiation. In otherwords, the part of the conversion material is transferred from the source layer to the substrate. The part of the conversion material deposited on the substrate forms at leastpartially the conversion element. For example, the conversionmaterial is deposited on a main surface of the substrate. In particular, the conversion material is locally applied to thesubstrate. For example, during the depositing only a part ofthe conversion element is formed. The depositing can berepeated as necessary to form the conversion element. Inparticular, the part of the conversion material deposited corresponds to a part of the conversion material in the source layer which is arranged in the region of the source layer which is irradiated with the laser radiation. Here and in the following, laser radiation is electromagnetic radiation which is produced by a laser. Laser radiation is for example characterized by a high intensity and / or a small frequency region of the electromagnetic radiation.Furthermore, the laser radiation is for instance highlyfocused. In particular, the laser radiation is positioned on the source wafer by a galvanometer scanner. The galvanometer scanner comprises for example mirrors for reflecting the laser radiation. In this way, the laser radiation can be aligned as desired on the source wafer. In particular, due to the irradiation of the source wafer with the laser radiation, the conversion material is released from the source layer. For instance, the laser radiationheats the source wafer such that the conversion material isreleased from the source layer. For example, the deposition2023PF01337 January 22, 2025P2023,1349 WO N -6 –of the conversion material on the substrate is induced by asudden temperature change which results from the irradiationwith the laser radiation. The sudden temperature change inparticular modifies an adherence of the conversion material in the source layer. According to at least one embodiment of the method, the depositing is configured to arrange different amounts of theconversion material on different chip regions. In otherwords, after the deposition of the conversion material, the substrate can comprise chip regions having different amounts of the conversion material. According to at least one embodiment, the method comprises:- providing the substrate comprising the chip regions,- arranging the source wafer above the substrate, wherein thesource layer comprising the conversion material is arranged on the side of the source wafer facing the substrate, and- depositing the part of the conversion material on thesubstrate by irradiating the source wafer with the laser radiation, wherein the part of the conversion material at least partially forms the conversion element, wherein the depositing is configured to arrange different amounts of the conversion material on different chip regions. In particular, the steps of the method are performed in the order indicated. It is an idea of the present application to use laser radiation to transfer conversion material from the source layer on the source wafer to the substrate. This process can be called laser induced forward transfer. Due to the laser radiation used, a fast and selective transfer of the part ofthe conversion material can be achieved. For example, up to2023PF01337 January 22, 2025P2023,1349 WO N -7 –0.1 m2of the substrate can be covered with the conversion material per second. During the depositing, the amount of the conversion materialis in particular determined by the concentration of theconversion material in the source layer and / or the size of a region of the source wafer irradiated with the laser radiation. For example, the laser induced forward transfer ofthe conversion material offers a high spatial resolution ofthe conversion material on the substrate. Furthermore, as thesource wafer is arranged above the substrate, inhomogeneities in a height of the substrate are negligible. By scanning the source wafer with the laser radiation it is possible to transfer large portions of the conversion material. However, it is also possible to individually apply the conversion material on selected regions of the substrate. According to at least one embodiment of the method, the source wafer comprises a transparent layer and a light absorbing layer. It is also possible that the source wafer does not comprise the light absorbing layer. The transparent layer is in particular transparent for the laser radiation. For example, the transparent layer comprises or consists of a material selected from the group consisting of fused silica, sapphire, and combinations thereof. The light absorbing layer in particular absorbs the laser radiation and transfers the absorbed energy to the source layer. For example, the light absorbing layer comprises or consists of black chromium. For instance, the light absorbing layer is arranged between thesource layer and the transparent layer. That is, the laserradiation has to first pass the transparent layer before it is absorbed by the light absorbing layer. Advantageously, the light absorbing layer enables an efficient energy transfer to2023PF01337 January 22, 2025P2023,1349 WO N -8 –the source layer. The transferred energy then enables arelease of the part of the conversion material from the source layer. Additionally or alternatively, the source layer absorbs the energy of the laser radiation. The conversion material is then, for example, transferred by evaporation of the solvent. According to at least one embodiment of the method, thesource wafer comprises a grid structure. In particular, thegrid structure is arranged on a side of the source wafer facing away from the source layer. For instance, the grid structure is used to target the correct position for transferring the part of the conversion material from the source layer to the substrate. For example, the grid structure corresponds to a pattern in which the conversion material shall be applied to the substrate. For instance, the grid structure is aligned with the substrate before the source wafer is irradiated with the laser radiation. Advantageously, the grid structure allows for a more defined deposition of the part of the conversion material on the substrate in terms of position and amount of the conversion material. In particular, the grid structure comprises or consist of a material which is impermeable for the laser radiation and / or offers a contrast for the laser radiation. For example, the grid structure comprises or consists of a metal such as aluminum or a colored photoresist. The grid structure can beformed by photostructuring or photolithographic patterning.According to at least one embodiment of the method, the source layer comprises a solvent. In particular, the source2023PF01337 January 22, 2025P2023,1349 WO N -9 –layer substantially consists of or consists of the conversion material and the solvent. For example, the solvent is compatible with the conversion material and does not evaporate fast at room temperature, that is 25 °C. Here and in the following compatible means that the solvent does not react with and / or dissolve the conversion material. For instance, the solvent has a boiling point above 25 °C and below 500 °C. In particular, the boiling point of the solvent is between and including 100 °C and 300 °C. For example, glycerin is used as solvent. During the depositing of the part of the conversion material on the substrate, the solvent is in particular evaporated due to a heat transfer of the source wafer, in particular thelight absorbing layer of the source wafer, to the solvent inthe regions of the source wafer which are irradiated with the laser radiation. For example, the solvent is suddenlyevaporated. As the solvent is removed, the part of theconversion material arranged in the region of the source wafer which is irradiated with the laser radiation no longer adheres to the source wafer. Thus it drops down from the source wafer and is deposited on the substrate. According to at least one embodiment of the method, the source layer comprises a binder and / or a matrix material. A part of the binder and / or the matrix material of the source layer can be deposited together with the conversion material. The binder advantageously changes, in particular increases, the viscosity of the source layer. For example, the binder in the source layer makes it possible to handle the source layer in a liquid form. For instance, the binder is a polymer such as a polysiloxane. The binder can be contained in the source2023PF01337 January 22, 2025P2023,1349 WO N -10 –layer in an amount of between and including 1 wt.% and 10 wt.%. The matrix material is in particular a compound in which the conversion material is embedded. The matrix material canprotect and / or mechanically connect the conversion materialin the conversion element. The matrix material is, for example, a material selected from the group consisting of a polysiloxane, an epoxy resin, and combinations thereof. Thepolysiloxane is for instance a silicone.According to at least one embodiment of the method, the source layer is applied on the source wafer by spray coating, spin coating, slit coating, or dispensing. All these methods allow for an even application of the source layer in a simple and efficient manner. In particular, all components of the source layer are applied at the same time on the sourcewafer. In other words, the source layer is provided assuspension of the conversion material in the solvent, the binder and / or the matrix material and the suspension is applied by the previously mentioned methods on the source wafer. According to at least one embodiment of the method, the source layer is applied on the source wafer by first applying carrier material such as the solvent, the binder, and / or the matrix material and then applying the conversion material. In particular, the conversion material is applied by a mechanical process. According to at least one embodiment of the method, the laser radiation comprises wavelengths in the infrared region. Such a laser radiation ensures for an efficient heating of the2023PF01337 January 22, 2025P2023,1349 WO N -11 –source wafer and thus an efficient deposition of the part of the conversion material. According to at least one embodiment of the method, a single particle of the conversion material is deposited on the substrate during the depositing of the part of the conversion material on the substrate. The single particle is, for example, a single semiconductor nanocrystal, a single particle comprising the semiconductor nanocrystal, or a single particle of the ceramic phosphor. In particular, a transfer of the single particle of the conversion material is achieved by the presence of the grid structure in the source wafer and / or a low concentration of the particles of the conversion material in the source layer. According to at least one embodiment of the method, the substrate comprises a layer with a matrix material. In particular, the layer with the matrix material is configured to capture the part of the conversion material and / or fix thepart of the conversion material to the substrate. The matrixmaterial is, for example, a material selected from the group consisting of a polysiloxane, an epoxy resin, and combinations thereof. The matrix material in the layer with the matrix material can be the same or different to thematrix material in the source layer. In particular, the layerwith the matrix material is present when the source layersubstantially consists of or consists of the solvent and the conversion material. According to at least one embodiment of the method, the substrate comprises at least one optoelectronic semiconductor chip. In particular, the substrate comprises a plurality of optoelectronic semiconductor chips. The plurality of2023PF01337 January 22, 2025P2023,1349 WO N -12 –optoelectronic semiconductor chips can be arranged in a wafer composite. If the substrate comprises the plurality of optoelectronic semiconductor chips, one chip region corresponds to one optoelectronic semiconductor chip. According to at least one embodiment of the method, theoptoelectronic semiconductor chip is a mini-LED, a micro-LEDand / or a pixelated LED. Here and in the following, LED is theabbreviation for light emitting diode. As a broad definition, a micro-LED could be seen as any light emitting diode with a particularly small size. Micro-LEDs may comprise 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, inparticular in plan view of layers of a semiconductor layersequence, of the radiation exit surface smaller than or equalto 70 micrometers, for example smaller than or equal to 50 micrometers. For example, a micro-LED is a light emittingdiode with a growth substrate removed, such that a thicknessof the micro-LED is in the range between and including, forexample, 1.5 micrometers and 10 micrometers. For example, themicro-LED is provided on a wafer having releasable retaining structures. The micro-LED can be detached from the wafer in anon-destructive manner. In contrast, the growth substrate maystill adhere to the mini-LEDs, resulting in a thickness of approximately between and including 50 micrometers and 100 micrometers. In particular, micro-LEDs are mainly used in displays. The micro-LEDs form pixels or subpixels and emit light of a2023PF01337 January 22, 2025P2023,1349 WO N -13 –defined color. Small pixel size and a high density with close distances make micro-LEDs suitable, among others, for small monolithic displays for augmented reality applications, especially data glasses. In addition, other applications are being developed, in particular regarding the use in data communication or pixelated lighting applications. A pixelated LED, for example, comprises different emission regions which are individually operable. Advantageously, with the method described herein it is possible to selectively deposit the part of the conversion material only on one of the emission regions. According to at least one embodiment of the method, the substrate is free of radiation-generating regions. In other words, the substrate is free of optoelectronic semiconductor chips. In particular, the substrate comprises a material selected from the group consisting of a glass or a plastic. For example, the substrate is transparent for theelectromagnetic radiation of the first and / or the secondwavelength range. After the depositing the part of the conversion material, the substrate with the conversionelement is for instance singulated. In this way individualconversion platelets can be formed. A platelet in particularcorresponds to a chip region of the substrate.According to at least one embodiment of the method, the substrate comprises a conversion layer. In particular, thepart of the conversion material is deposited on theconversion layer. The conversion layer is, in particular, formed on a carrier, for example formed with a glass or aplastic. The carrier is for instance free of radiation-generating regions. Alternatively, the conversion layer is2023PF01337 January 22, 2025P2023,1349 WO N -14 –arranged on an optoelectronic semiconductor chip. In this case, the conversion layer is, for example, in direct contact with a radiation exit surface of the optoelectronic semiconductor chip. The conversion layer comprises, for instance, a conversion material and a matrix material. In particular, the conversion material deposited and theconversion material in the conversion layer are the same.Additionally or alternatively, the matrix material of the source layer and the matrix material of the conversion layer are the same. The source layer and the conversion layer may have the same or a similar thickness. In particular, a further layer may be arranged on the conversion layer. The further layer is, for example, a thin layer stack, which for instances increases an outcoupling efficiency. According to at least one embodiment, the method further comprises determining a color point of an electromagnetic radiation emitted by the substrate. In particular, this step is performed before the part of the conversion material is deposited on the substrate. The color point is for example expressed in chromaticity coordinates CIE-x and CIE-y in the CIE 1931 color space. For the determination of the color point, the substrate does not necessarily comprise radiation- generating regions. According to at least one embodiment of the method, the part of the conversion material is deposited on the substrate depending on the color point of the electromagnetic radiation emitted by the substrate. Advantageously, in this way it is possible to correct the color point in regions of the substrate. Thus, a conversion element can be produced which2023PF01337 January 22, 2025P2023,1349 WO N -15 –emits electromagnetic radiation with a homogenous color point over all its chip regions. According to an embodiment of the method, the depositing of a part of the conversion material is repeated at least once. In particular, the determining of the color point of the electromagnetic radiation emitted by the substrate is performed again between two deposition steps. The part of theconversion material is, for example, deposited on the samechip region of the substrate or on different chip regionsduring two different deposition steps.According to at least one embodiment of the method, layer with the matrix material or the matrix material deposited together with the part of the conversion material is cured. Furthermore, an assembly is specified. In particular, the assembly comprises a conversion element or a plurality of conversion elements produced by the method described herein. Thus, all embodiments, features, and advantages described in combination with the method also apply to the assembly and vice versa. According to at least one embodiment, the assembly comprises a plurality of optoelectronic semiconductor chips. The optoelectronic semiconductor chips can be arranged in a wafer composite, in particular an artificial wafer composite. The optoelectronic semiconductor chips are in particular configured as described in combination with the optoelectronic semiconductor chips of the substrate in the method. The optoelectronic semiconductor chips are for example configured to generate and emit electromagnetic radiation of a first wavelength range.2023PF01337 January 22, 2025P2023,1349 WO N -16 –According to at least one embodiment, the assembly further comprises conversion elements. The conversion elements can convert the electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelengthrange. In particular, a conversion element is arranged on amain emission surface of each optoelectronic semiconductor chip of the plurality of optoelectronic semiconductor chips.In other words, one conversion element is associated with oneoptoelectronic semiconductor chip. For example, theconversion element associated with an optoelectronic semiconductor chip is in direct contact with the optoelectronic semiconductor chip.In particular, no adhesive is arranged between the conversionelement and the optoelectronic semiconductor chip. In other words, the conversion element is formed directly on the optoelectronic semiconductor chip. This reduces production costs and increases the thermal contact between the conversion element and the optoelectronic semiconductor chip. In this way, the resulting assembly shows improvedreliability. However, it is also possible that an adhesive isarranged between the conversion element and the optoelectronic semiconductor chip.According to at least one embodiment of the assembly, theconversion elements comprise a conversion material embedded in a matrix material. In particular, the matrix material is selected from the group consisting of a polysiloxane, an epoxy resin, and combinations thereof. According to at least one embodiment of the assembly, each of the plurality of optoelectronic semiconductor chips with the2023PF01337 January 22, 2025P2023,1349 WO N -17 –conversion element emits a mixed light with chromaticity coordinates. The mixed light in particular comprises the electromagnetic radiation of the first wavelength range and the electromagnetic radiation of the second wavelength range. The chromaticity coordinates are determined in the CIE 1931 color space. The mixed light can be white light. According to an embodiment of the assembly, the chromaticity coordinates are located within a square having a side length of 0.002. In particular, the chromaticity coordinates are the coordinates CIE-x and CIE-y. CIE-x and CIE-y, in particular, range from 0 to 1 in the CIE 1931 color space. For example, the chromaticity coordinates CIE-x and CIE-y of the mixed light emitted by each of the plurality of optoelectronic semiconductor chips with the conversion element deviate less than 0.002 from each other. According to at least one embodiment, the assembly comprises a plurality of optoelectronic semiconductor chips, wherein a conversion element is arranged on a main emission surface of each optoelectronic semiconductor chip, wherein the conversion elements comprises a conversion material embedded in a matrix material, each of the plurality of optoelectronic semiconductor chips with the conversion element emits a mixed light with chromaticity coordinates, and the chromaticity coordinates are located within a square having a side length of 0.002. Advantageously, an assembly is provided which produces mixed light having a homogenous color point. After singulation the individual optoelectronic semiconductor chips can be applied in automotive applications, sensor applications, and / or display applications.2023PF01337 January 22, 2025P2023,1349 WO N -18 –According to at least one embodiment of the assembly, atleast 80%, in particular at least 90%, of all optoelectronicsemiconductor chips with conversion elements in the assembly emit the mixed light with chromaticity coordinates within the square having the side length of 0.002. According to at least one embodiment of the assembly, the chromaticity coordinate CIE-x of the mixed light of each of the optoelectronic semiconductor chips with the conversion element deviate at most 0.0006 from each other. According to at least one embodiment of the assembly, thechromaticity coordinate CIE-xy of the mixed light of each ofthe optoelectronic semiconductor chips with the conversion element deviate at most 0.001 from each other. Advantageous embodiments and developments of the structure, the method for producing the structure, and the light emitting component will become apparent from the exemplary embodiments described below in conjunction with the figures. In the figures:Figures 1 to 4 show schematic sectional views of steps of amethod for producing a conversion element according to an exemplary embodiment. Figures 5 shows a schematic sectional view of a step of a method for producing a conversion element according to an exemplary embodiment.2023PF01337 January 22, 2025P2023,1349 WO N -19 –Figures 6 to 9 show schematic sectional views of substratesuseable in a method for producing a conversion elementaccording to an exemplary embodiment. Figures 10A, 10B, and 11 show different view of a sourcewafer useable in a method for producing a conversion elementaccording to an exemplary embodiment.Figures 12 to 15 shows schematic top views of steps of amethod for producing a conversion element according to an exemplary embodiment.Figure 16 shows a schematic sectional view of an assemblyaccording 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.To produce a conversion element 1 according to a method of anexemplary embodiment, a source wafer 3 is provided as shown in figure 1. The source wafer 3 presently comprises a transparent layer 31 and a light absorbing layer 32. The transparent layer 31 comprises or consists of fused silica or sapphire. The light absorbing layer 32 comprises or consists of black chromium. A source layer 4 is arranged on the light absorbing layer 32. As shown in figure 2, the light absorbing layer 32 is2023PF01337 January 22, 2025P2023,1349 WO N -20 –arranged between the source layer 4 and the transparent layer 31. The source layer 4 can be applied to the light absorbing layer 32 by spray coating or spin coating. The source layer 4 comprises a conversion material 5. The conversion material 5comprises a ceramic phosphor and / or semiconductornanocrystals. The source layer 4 also comprises a binder, a solvent, and / or a matrix material. The source wafer 3 with the source layer 4 is arranged above a substrate 2 with chip regions 24 as shown in figure 3. The source wafer 3 is thereby arranged in a distance to the substrate 2. Furthermore, the source wafer 3 is arranged in such a way that the source layer 4 faces the substrate 2. The source wafer 3 is irradiated by laser radiation 6. The laser radiation 6 can comprise wavelengths in the infrared region.As a result of the irradiation with the laser radiation 6,the light absorbing layer 32 is heated. The thermal energy is then transferred from the light absorbing layer 32 to the source layer 4. In this way a part of the source layer 4 and thus also a part 51 of the conversion material 5 of the source layer 4 loses its adherence to the source wafer 3.Thus, the part 51 of the conversion material 5 is depositedon the substrate 2 as shown in figure 4. Presently, theconversion material 5 is only deposited on a region of the chip region 24. The part 51 of the conversion material 5 is deposited together with a part of the binder and / or the matrix material in the source layer 4. The part 51 of the conversion material 5 forms at least a part of the conversionlayer 1. The deposition process can be repeated as desireduntil the conversion element 1 is formed.2023PF01337 January 22, 2025P2023,1349 WO N -21 –The part 51 of the conversion material 5 is determined by the region which is irradiated with the laser radiation 6. In particular, only the part 51 of the conversion material 5 is transferred from the source wafer 3 to the substrate 2 whichcorresponds to a region of the source wafer 3 irradiated withthe laser radiation 6. Properties of the laser radiation 6 such as a wavelength, a beam diameter, and an intensity can be set as desired. An area of the source wafer 3 irradiatedwith the laser radiation 6 can also be set. For example, thearea of the source wafer 3 irradiated with the laser radiation 6 can be increased by scanning the source wafer 3 with the laser radiation 6. As a result it is possible to arrange different amounts of the conversion material 5 ondifferent chip regions 24 during depositing the part 51 ofthe conversion material 5. Figure 5 schematically shows another exemplary embodiment of a method for producing a conversion element 1. As already described in combination with figures 1 to 3, a source wafer 3 with a source layer 4 is prepared and arranged above a substrate 2. In contrast to the previous exemplary embodiment, the source layer 4 is free of a matrix material.That is the source layer 4 substantially consists of orconsists of the conversion material 5 and the solvent. Thesolvent is, for example, glycerin. Another difference to theexemplary embodiment of figures 1 to 4 is that the substrate2 comprises a layer with a matrix material 21. The layer withthe matrix material 21 is arranged on the chip regions 24 andfaces the source wafer 3. To deposit a part 51 of the conversion material 5, the source wafer 3 is irradiated with laser radiation 6. As before, thereby, the light absorbing layer 32 is heated. The heat is2023PF01337 January 22, 2025P2023,1349 WO N -22 –transferred from the light absorbing layer 32 to the source layer 4. As a result the solvent suddenly evaporates and the part 51 of the conversion material 5 is no longer adhered to the source wafer 3. Thus, it drops down on the layer with thematrix material 21. The matrix material 21 then fixes thepart 51 of the conversion material 5 to the substrate 2. Presently only one particle of the conversion material 5 forms the part 51 of the conversion material 5. In other words, only one particle of the conversion material 5 is deposited on the substrate 2 by irradiating the source wafer 3 with the laser radiation 6. Different configurations of the substrate 2 on which the part51 of the conversion material 5 is deposited to form theconversion element 1 are shown in figure 6 to 9. The substrate 2 of figure 6 comprises a carrier 25 which isdividable into chip regions 24. The carrier 25 is transparentfor visible light. A conversion layer 23 is arranged on the carrier 25. The conversion layer 23 comprises a matrix material 231 and the conversion material 5. The matrix material 231 and the matrix material which can be deposited together with the part 51 of the conversion material 5 are, for example, the same. The conversion layer 23 together with the part 51 of the conversion material 5 forms the finished conversion element 1.The substrate 2 of figure 7 comprises a plurality ofoptoelectronic semiconductor chip 22. Each of the optoelectronic semiconductor chips 22 corresponds to a chip region 24. The optoelectronic semiconductor chips 22 presently are arranged in a wafer composite.2023PF01337 January 22, 2025P2023,1349 WO N -23 –As shown in figure 8, the conversion layer 23 can also be arranged on the plurality of optoelectronic semiconductor chips 22. Figure 9 shows a configuration of the substrate 2 comprising a layer with a matrix material 21. This layer can be used to capture the part 51 of the conversion material 5 during depositing on the substrate 2. Furthermore, the matrix material 21 can serve in the finished conversion element 1 to mechanically stabilize and protect the conversion material 5.Figure 10A shows a schematic top view of a source wafer 3which can be used in a method for producing a conversionelement 1 according to an exemplary embodiment. The sourcewafer 3 comprises a grid structure 33. The grid structure 33 comprises or consists of a metal or a photoresist, which are both impermeable for the laser radiation 6. The grid structure 33 is, for example, formed by photostructuring or a photolithographic process. Seen in top view, the source wafer 3 has a round shape. However it is also possible that the source wafer has a rectangular shape. A schematic cross section of the source wafer 3 is shown in figure 10B. The source wafer 3 comprises the grid structure 33, a transparent layer 31, and a light absorbing layer 32. The transparent layer 31 is arranged between the grid structure 33 and the light absorbing layer 32. The transparent layer 31 and the light absorbing layer 32 can comprise the materials described in combination with the source wafer 3 of figure 1.2023PF01337 January 22, 2025P2023,1349 WO N -24 –Figure 11 shows the source wafer 3 of figures 10A and 10B with a source layer 4 applied on the side of the lightabsorbing layer 32. The source layer 4 comprises at leastconversion material 5 and a solvent. Additionally, the source layer 4 comprises a binder and / or a matrix material.Figures 12 to 15 shows another exemplary embodiment of amethod for producing a conversion element 1 by means ofschematic top views.In a first step, a substrate 2 comprising a plurality ofoptoelectronic semiconductor chips 22 is provided. Each optoelectronic semiconductor chip 22 corresponds to a chip region 24. The optoelectronic semiconductor chips 22 are arranged in a wafer composite. The wafer composite can arise from the epitaxial growth of the optoelectronic semiconductor chips 22. Alternatively, the wafer composite is an artificial wafer composite, wherein already singulated optoelectronicsemiconductor chips 22 are arranged. The optoelectronicsemiconductor chips 22 of the substrate 2 emit electromagnetic radiation in the ultraviolet to blue spectral range. As can be seen from figure 12, individual optoelectronic semiconductor chips 22 differ in the electromagnetic radiation emitted. This is indicated by the different shades of the individual optoelectronic semiconductor chips 22. A conversion layer 23 is arranged on the plurality of semiconductor chips 22. The conversion layer 23 is shown infigure 13. The conversion layer 23 comprises a conversionmaterial 5 embedded in a matrix material 231.2023PF01337 January 22, 2025P2023,1349 WO N -25 –A color point of an electromagnetic radiation emitted by the substrate 2 is determined depending on the position on the substrate 2. The electromagnetic radiation of the substrate corresponds to an electromagnetic radiation emitted by the optoelectronic semiconductor chips 22 and an electromagnetic radiation emitted by the conversion layer 23. The determined color points are converted into a map 7 shownin figure 14. The map 7 indicates where an addition ofconversion material 5 is needed on the conversion layer 23such that a more homogeneous color point can be reached for the substrate 2. According to the map 7, that is depending on the color point of the electromagnetic radiation emitted by the substrate 2, additional conversion material 5 is locally deposited on thesubstrate 2 with the method steps shown in figures 1 to 4. Inthis way, the color point of the electromagnetic radiation emitted by the substrate 2 can be harmonized.The method results in an assembly 8 according to an exemplaryembodiment having a conversion element 1 which emits electromagnetic radiation in a predetermined color point range. In figure 15, the assembly 8 is shown schematically in top view, whereas in figure 16, the assembly 8 is shown in aschematic cross-sectional view.The assembly 8 comprises a plurality of optoelectronic semiconductor chips 22. The optoelectronic semiconductor chips 22 are arranged in a wafer composite. A conversion element 1 is arranged on a main emission surface of each optoelectronic semiconductor chip 22. In other words, the assembly 8 comprises also a plurality of conversion elements2023PF01337 January 22, 2025P2023,1349 WO N -26 –1 each of which is assigned to a single optoelectronic semiconductor chip. The conversion elements 1 can be formed continuous or can be individual conversion elements 1. The conversion elements 1 comprise a conversion material 5 and a matrix material 21. The conversion material 5 is embedded in the matrix material 21. The conversion elements 1have a varying thickness resulting from the production methodof the conversion elements 1. The thickness is an extension of the conversion element perpendicular to a main extension plane of the assembly 8.The optoelectronic semiconductor chip 22 together with itsassociated conversion element 1 emits a mixed light. The mixed light comprises electromagnetic radiation emitted by the optoelectronic semiconductor chip 22 and electromagnetic radiation emitted by the conversion element 1. The mixed light has chromaticity coordinates CIE-x and CIE-y. The chromaticity coordinates of the mixed light emitted by each optoelectronic semiconductor chip 22 with its conversion element 1 is within a square having a side length of 0.002. Presently, all optoelectronic semiconductor chips 22 with their conversion elements 1 of the assembly 8 emit mixed light having color coordinates within the square having the side length of 0.002. 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.2023PF01337 January 22, 2025P2023,1349 WO N -27 –This patent application claims the priority of German patent application 102024 102 618.9, the disclosure content of which is hereby incorporated by reference. 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.

[0002] 2023PF01337 January 22, 2025P2023,1349 WO N -28 –References1 conversion element2 substrate21 matrix material22 optoelectronic semiconductor chip23 conversion layer231 matrix material24 chip region25 carrier3 source wafer31 transparent layer32 absorbing layer33 grid structure4 source layer5 conversion material51 part of the conversion material6 laser radiation7 map8 assembly

Claims

2023PF01337 January 22, 2025P2023,1349 WO N -29 –Claims 1. Method for producing a conversion element (1) comprising:- providing a substrate (2) comprising chip regions (24),- arranging a source wafer (3) above the substrate (2),wherein a source layer (4) comprising a conversion material(5) is arranged on a side of the source wafer (3) facing thesubstrate (2), wherein the source wafer (3) comprises a gridstructure (33), wherein the grid structure (33) is arranged on a side of the source wafer (3) facing away from the sourcelayer (4), and- depositing a part (51) of the conversion material (5) onthe substrate (2) by irradiating the source wafer (3) with alaser radiation (6), wherein the part (51) of the conversionmaterial (5) at least partially forms the conversion element(1), wherein the depositing is configured to arrangedifferent amounts of the conversion material (5) on different chip regions (24).

2. Method according to claim 1, wherein the source wafer (3)comprises a transparent layer (31) and a light absorbing layer (32).

3. Method according to any of the previous claims, whereinthe source layer (4) comprises a solvent.

4. Method according to any of the previous claims, whereinthe source layer (4) comprises a binder and / or a matrixmaterial.

5. Method according to any of the previous claims, whereinthe source layer (4) is applied on the source wafer (3) byspray coating, spin coating, slit coating, or dispensing.2023PF01337 January 22, 2025P2023,1349 WO N -30 –6. Method according to any of the previous claims, whereinthe laser radiation (6) comprises wavelengths in the infraredregion.

7. Method according to any of the previous claims, wherein asingle particle of the conversion material (5) is depositedon the substrate (2) during the depositing the part of theconversion material (5) on the substrate (2).

8. Method according to any of the previous claims, wherein the substrate (2) comprises a layer with a matrix material (21).

9. Method according to any of the previous claims, whereinthe substrate (2) comprises at least one optoelectronicsemiconductor chip (22).

10. Method according to the previous claim, wherein theoptoelectronic semiconductor chip (22) is a mini-LED, a micro-LED and / or a pixelated LED.

11. Method according to any of the previous claims, wherein the substrate (2) is free of radiation-generating regions.

12. Method according to any of the previous claims, whereinthe substrate (2) comprises a conversion layer (23).

13. Method according to any of the previous claims,- the method further comprising determining a color point ofan electromagnetic radiation emitted by the substrate (2),- wherein the part of the conversion material (5) isdeposited on the substrate (2) depending on the color point2023PF01337 January 22, 2025P2023,1349 WO N -31 –of the electromagnetic radiation emitted by the substrate (2).

14. Method according to any of the previous claims, wherein the depositing of a part of the conversion material (5) on the substrate (2) is repeated at least once.

15. Assembly (8) comprising:- a plurality of optoelectronic semiconductor chips (22),wherein- a conversion element (1) is arranged on a main emissionsurface of each optoelectronic semiconductor chip (22),wherein- the conversion elements (1) comprises a conversion material(5) embedded in a matrix material (21),- each of the plurality of optoelectronic semiconductor chips(22) with the conversion element (1) emits a mixed light withchromaticity coordinates, and- the chromaticity coordinates are located within a squarehaving a side length of 0.002.

16. Assembly according to the previous claim, wherein atleast 80% of all optoelectronic semiconductor chips (22) withconversion elements (1) in the assembly (8) emit the mixed light with chromaticity coordinates within the square having the side length of 0.002.

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