Method for producing an optoelectronic component, and optoelectronic component

Abstract

A method for producing an optoelectronic component (1) is described. The method comprises the steps of providing a radiation-emitting semiconductor chip (2), providing a layer (3) comprising a partially cured matrix material (4) and comprising a luminescent material (5), joining the radiation-emitting semiconductor chip (2) and the layer (3), curing the partially cured matrix material (4) to form a matrix material (6) so that a conversion layer (7) having the matrix material (6) and having the luminescent material (5) is formed in direct contact with the radiation-emitting semiconductor chip (2). An optoelectronic component (1), in particular having a micro-LED, is also described.

Description

[0001] METHOD FOR PRODUCING AN OPTOELECTRONIC COMPONENT AND OPTOELECTRONIC COMPONENT

[0002] Description

[0003] A method for producing an optoelectronic component and an optoelectronic component are specified.

[0004] This patent application claims priority from German patent application 10 2023 108 532 . 8 , the disclosure of which is hereby incorporated by reference .

[0005] One object is to provide a simple and efficient method for producing an optoelectronic component. Furthermore, an optoelectronic component with increased efficiency is to be provided.

[0006] According to at least one embodiment of the method, a radiation-emitting semiconductor chip is provided. In particular, the radiation-emitting semiconductor chip is configured to emit electromagnetic radiation in the ultraviolet and / or visible wavelength range of the electromagnetic spectrum. For example, the radiation-emitting semiconductor chip emits ultraviolet to blue electromagnetic radiation. The radiation-emitting semiconductor chip is, for example, a light-emitting diode chip.

[0007] It is possible for individual semiconductor chips or a plurality of semiconductor chips to be provided in a composite - for example in a wafer composite. According to at least one embodiment of the method, a layer is provided. The layer comprises a partially cured matrix material and a phosphor. For example, the layer is provided in the form of a plate. Alternatively, the layer has the size of a wafer. In particular, the plate has a similar or identical shape and / or size, viewed in plan view, to the radiation-emitting semiconductor chip or the composite of semiconductor chips, viewed in plan view.

[0008] In particular, the partially cured matrix material is solid at room temperature, that is to say between 20°C and 30°C inclusive. However, it is possible to at least partially liquefy or melt the partially cured matrix material by increasing the temperature and / or pressure. In other words, the partially cured matrix material is thermoresponsive. At room temperature, the partially cured matrix material displays in particular no or only very low reactivity with regard to crosslinking to form a cured matrix material. Storing the partially cured matrix material below 10°C or below 0°C reduces in particular the reactivity of the partially cured matrix material.

[0009] The phosphor is in particular homogeneously distributed in the partially cured matrix material. For example, the phosphor is embedded in the partially cured matrix material. The phosphor can convert the electromagnetic radiation emitted by the radiation-emitting semiconductor chip. For example, the phosphor converts the electromagnetic radiation emitted by the semiconductor chip into electromagnetic radiation with lower energy. This is particularly evident in the fact that electromagnetic radiation emitted by the phosphor has longer wavelengths compared to the electromagnetic radiation emitted by the radiation-emitting semiconductor chip.

[0010] It is also possible for the phosphor to be layered within the partially cured matrix material. This advantageously allows heat generated during conversion to be more effectively dissipated from the phosphor. This also makes it possible to use temperature-sensitive phosphors.

[0011] According to at least one embodiment of the method, the radiation-emitting semiconductor chip and the layer are bonded. In particular, the radiation-emitting semiconductor chip and the layer are in direct contact with one another at least partially, in particular completely, during and / or after bonding. In other words, no further layer, such as an additional adhesive layer, is arranged between the semiconductor chip and the layer. The bonding is carried out in particular using pressure and / or elevated temperature.

[0012] For example, pressure and elevated temperature are applied to bond the radiation-emitting semiconductor chip and the layer. The elevated temperature can melt the partially cured matrix material. The pressure ensures, in particular, sufficient adhesion of the layer to the radiation-emitting

[0013] Semiconductor chip achieved. According to at least one embodiment of the method, the partially cured matrix material is cured, in particular completely, to form a matrix material. It is possible for the partially cured matrix material to cure during the bonding of the layer and the radiation-emitting semiconductor chip. The partially cured matrix material is cured in particular using temperature and / or pressure. For example, the partially cured matrix material crosslinks to form the matrix material under the influence of elevated temperature. Elevated temperature is understood here and below to mean in particular a temperature above room temperature.

[0014] According to at least one embodiment of the method, curing takes place such that a conversion layer is formed in direct contact with the radiation-emitting semiconductor chip. The conversion layer comprises the matrix material and the phosphor. The layer with the partially cured matrix material and the phosphor is therefore in particular a precursor for the conversion layer. In other words, during curing, the layer with the partially cured matrix material is converted into the conversion layer. The matrix material has, for example, adhesive properties. This advantageously ensures effective adhesion of the conversion layer to the radiation-emitting semiconductor chip even without an additional adhesive layer.

[0015] According to at least one embodiment, the method for producing an optoelectronic component comprises the steps of: - providing a radiation-emitting

[0016] semiconductor chips,

[0017] - Providing a layer comprising a partially cured matrix material and a phosphor,

[0018] - Connecting the radiation-emitting semiconductor chip and the layer,

[0019] - Curing the partially cured matrix material to a matrix material such that a conversion layer comprising the matrix material and the phosphor is formed in direct contact with the radiation-emitting semiconductor chip.

[0020] In other methods for producing an optoelectronic component, an additional adhesive layer is used in particular to bond the radiation-emitting semiconductor chip to the conversion layer. The thickness of the additional adhesive layer is important in this case. If the thickness is too great, this can have a negative effect on the heat distribution in the optoelectronic component. In particular, here and in the following, heat distribution is understood to mean the dissipation of heat generated by a Stokes shift in the conversion layer via the radiation-emitting semiconductor chip. The radiation-emitting semiconductor chip serves, for example, as a heat sink.

[0021] Inadequate heat distribution, in particular insufficient heat dissipation via the radiation-emitting semiconductor chip as a heat sink, can reduce the lifetime of the optoelectronic component due to overheating of individual elements. Furthermore, it is possible that an additional adhesive layer that is too thick or a poorly controlled formation of the additional adhesive layer has a negative influence on the component brightness. This can reduce the emission efficiency of the optoelectronic component. If the additional adhesive layer is too thin, on the other hand, it is possible that the radiation-emitting semiconductor chip is damaged during the bonding of the radiation-emitting semiconductor chip and the conversion layer, or that air bubbles form between the radiation-emitting semiconductor chip and the conversion layer.The air bubbles can result in poorer heat distribution, particularly poorer heat dissipation, and / or lower emission efficiency. The low emission efficiency can be explained in particular by additional scattering centers.

[0022] In this case, the radiation-emitting semiconductor chip is in direct contact with the conversion layer, meaning no additional adhesive layer is used between the radiation-emitting semiconductor chip and the conversion layer. As a result, the manufactured optoelectronic component advantageously exhibits improved heat distribution and emission efficiency. Furthermore, the method described here is advantageous in terms of process control and process stability, since no additional adhesive layer is produced between the conversion layer and the radiation-emitting semiconductor chip, thus reducing interfaces for potential delamination damage mechanisms.

[0023] Furthermore, especially with miniaturization of the optoelectronic component, for example, by using a micro-LED as a radiation-emitting semiconductor chip, dosing the adhesive is only possible with increased effort. In the process described here, this process step is not required, since no additional adhesive layer is present.

[0024] The method described here simplifies the production of optoelectronic components and simultaneously provides a more efficient and longer-lasting optoelectronic component. This is due in particular to the fact that the radiation-emitting semiconductor chip is in direct contact with the conversion layer, with the matrix material serving in particular to adhere the conversion layer to the radiation-emitting semiconductor chip.

[0025] According to at least one embodiment of the method, the partially cured matrix material has a lower degree of crosslinking than the matrix material. The term “degree of crosslinking” is understood here and below to mean the crosslinking density in a material. In other words, the degree of crosslinking of a material describes how many groups of a material that are suitable for crosslinking are already connected to another group that is suitable for crosslinking. In particular, the degree of crosslinking in the present case is not dependent on the number of groups of a material that are suitable for crosslinking. This means that a material with many groups that are suitable for crosslinking does not automatically have a higher degree of crosslinking than a material with fewer groups that are suitable for crosslinking.

[0026] According to at least one embodiment of the method, the matrix material comprises a polysiloxane. In particular, the partially cured matrix material is also a polysiloxane, which, for example, has a lower degree of crosslinking than the

[0027] Polysiloxane of the matrix material. In other words, the polysiloxane of the partially cured matrix material is a precursor to the polysiloxane of the matrix material.

[0028] Here and in the following, polysiloxane is understood to be a polymer composed of the building units M unit, D unit, T unit, and / or Q unit and primarily has a backbone of alternating oxygen atoms and silicon atoms. For example, the polysiloxane has only a few, ideally no, carbon-carbon bonds in the backbone. In particular, the polysiloxane is not a block copolymer. This means that the building units of the polysiloxane are randomly linked to one another.

[0029] In an M unit (RaSiO-), three organic residues and one oxygen are bonded to a silicon atom. In a D unit (-OSiR2O-), two organic residues and two oxygens are bonded to a silicon atom. In a T unit (-OSiRO2-), one organic residue and three oxygens are bonded to a silicon atom. In a Q unit (-OSiO3-), four oxygens are bonded to a silicon atom. Polysiloxanes are advantageously characterized by high thermal and chemical stability.

[0030] The organic radicals on the silicon atoms are in particular selected independently of one another from a group consisting of aliphatic and aromatic hydrocarbon groups. For example, an organic radical is methyl (Me, CH3), ethyl (CH3CH2, Et), propyl (CH3CH2CH2, Pr) or phenyl (Ph, C6H5). The organic radicals on the M, D and T units can be the same or different. According to at least one embodiment of the process, the polysiloxane has a proportion of at least 25 wt. % T units. In other words, 25 wt. % of the building units of the polysiloxane are T units. In particular, the polysiloxane has a proportion of at least 50 wt. % T units, in particular at least 70 wt. %, for example at least 80 wt. %. A polysiloxane with at least 25 wt. % T units is characterized by greater hardness and higher thermal stability compared to polysiloxanes with only D units.Polysiloxanes that only contain D units are also called silicones.

[0031] According to at least one embodiment of the method, the partially cured matrix material has a molecular weight of at least 5000 g / mol, in particular of at least 10000 g / mol. Upon curing of the partially cured matrix material, the molecular weight increases, so that the matrix material has a higher molecular weight than the partially cured matrix material. Due to the high molecular weight, the partially cured matrix material is in the solid state, in particular.

[0032] According to at least one embodiment of the method, the partially cured matrix material and / or the matrix material has a refractive index in the range between 1.51 and 1.59, in particular between 1.53 and 1.55. Advantageously, the partially cured matrix material and / or the matrix material therefore has a higher refractive index than other polysiloxanes or silicones.

[0033] An additional adhesive layer between the radiation-emitting semiconductor chip and the conversion layer has, for example, a refractive index in the range between 1.41 and 1.44 inclusive. The difference in the refractive index of the radiation-emitting semiconductor chip and the additional adhesive layer, which generates an additional interface, can reduce the emission efficiency of the optoelectronic component. Since in the method described here for producing an optoelectronic component no additional adhesive layer is used to connect the radiation-emitting semiconductor chip and the conversion layer, the emission efficiency of the optoelectronic component is increased. The number of interfaces at which reflection occurs due to differences in refractive index can be reduced by the absence of an additional adhesive layer.

[0034] According to at least one embodiment of the method, the phosphor is a ceramic phosphor and / or a quantum dot phosphor. In particular, the phosphor is a mixture of at least two different phosphors.

[0035] According to at least one embodiment, the phosphor comprises at least one material from the following group:

[0036] Ce 3+ doped garnets such as YAG and LuAG, for example (Y , Lu, Gd, Tb )3(Al 1-x , Ga x )5O 12 : Ce 3+ ; Eu 2+ doped nitrides, for example (Ca, Sr) AlSiN3: Eu 2+ , Sr ( Ca, Sr ) Si2Al2N6: Eu 2+ (SCASN) , (Sr, Ca) AlSiN3 Si2N2O:Eu 2+ , (Ca, Ba, Sr )2Si5N8: Eu 2+ ,

[0037] SrLiAl3N4: Eu 2+ , SrLi2Al2O2N2: Eu 2+ ; Ce 3+ doped nitrides, for example (Ca, Sr) Al (1-4x / 3) Si (1+x) N3: Ce; (x 0.2 0.5) ;

[0038] Eu 2+ doped sulfides, (Ba,Sr,Ca) Si2O2N2: Eu 2+ , SiAlONe,

[0039] Nitrido-orthosilicates (for example AE 2-x-a RE x EU a Si 1-y O 4-x-2y N x ),

[0040] Orthosilicates such as (Ba, Sr, Ca)2SiO4: Eu 2+ ; Chlorosilicates such as

[0041] Ca8Mg (SiO4)4CI2: Eu 2+ ; Mn 4+ doped fluorides, for example

[0042] (K, Na) 2 ( Si , Ti ) F6:Mn 4+ ; Eu 2+ or Ce 3+ doped litho-silicates, such as (Li, Na, K, Rb, Cs) (Li3SiO4) :E with E Eu 2+ , Ce 3+ ,

[0043] (Sr, Li ) Li3AlO4: Eu 2+ or Sr Li3AlO4: Eu 2+ , and mixtures thereof.

[0044] Alternatively or additionally, the phosphor comprises an aluminum-containing and / or silicon-containing phosphor, in particular selected from the following group:

[0045] ( Ba1-x-y Here y ) SiO4:Eu 2+ (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) , (Bai-- ySr x Here y )3SiO5:Eu 2+ (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) , Li2SrSiO4:I 2+ , Oxo-

[0046] Nitride wie (Bai-xy. Ca y ) Si2O2N2:Eu 2+ (0 ≤ x ≤ 1; 0 ≤ y ≤ 1),

[0047] SrSiAl2O3N2:Eu 2+ , Ba 4-x Here x Si6ON 10 :I 2+ (0 ≤ x ≤ 1) , (Bai-

[0048] Mr. x ) Y2Si2Al2O2N5:Eu 2 + (0 ≤ x ≤ 1) , Mr x Yes (6-y) Al y THE y N (8-y) :I 2+ (0.05 ≤ x ≤ 0.5; 0.001 ≤ y ≤ 0.5), Ba3Si6O 12 N2: Me 2+ , Yes 6-z Al z THE z N 8-z : I 2+

[0049] (0 ≤ z ≤ 0.42) , M x Yes 12 -m-n Al m+n THE n N 16-n :I 2+ (M Li, Mg, Ca, Y; m / v; v Wertigkeit von M, x ≤ 2 ) , M x Yes 12-m-n Al m+n THE n N 16-n : Ce 3+ ,

[0050] AE 2-x-a RE x I a S i 1-y THE 4-x-2y N : (AE Sr, Ba, Ca, Mg; RE

[0051] Seltenerdmetallelemente) , AE 2-x-a RE x I a S i 1-y THE 4-x-2y N : (AE Sir,

[0052] Ba, Ca, Mg; RE Seltenerdmetallelemente), Ba3Si6O 12 N2: Me 2+ Oder

[0053] Nitride like La3Si6N 11 : Ce 3+ , (Ba 1-x-y Mr. x Here y )2Si5N8: I 2+ , (Ca 1-x- y Mr. x Ba y ) AlSiN3:Eu 2+ (0 ≤ x ≤ 1; 0 ≤ y ≤ 1) , Sr (Sr1- xCax) Al2Si2N6:I 2+ (0 ≤ x ≤ 0.2) , Mr (Mr 1-x Here x ) Al2Si2N6:Ce 3+ (0 ≤ ≤ 0.2) SrAlSi4N7:Eu 2+ , (Bai-x-ySr x Cay) SiN2:Eu 2+ (0 ≤ x ≤ 1; 0 ≤ y ≤ 1), (Ba 1-x-y Mr. x Here y) SiN2:Ce 3+ (0 ≤ x ≤ 1; 0 ≤ y ≤ 1) , (Sri-xCax) LiAl3N4:Eu 2+ (0 ≤ x ≤ 1) , (Ba 1-x-y Sr x Ca y )Mg2Al2N4:Eu 2+ (0 ≤ ≤ 1; 0 ≤ y ≤ 1) , (Bai-x- y Sr x Ca y )Mg3SiN4:Eu 2+ (0 ≤ x ≤ 1; 0 ≤ y ≤ 1) and mixtures thereof.

[0054] According to at least one embodiment of the method, the proportion of the phosphor in the conversion layer and / or the layer is between 50 wt.% and 85 wt.% inclusive, in particular between 65 wt.% and 80 wt.% inclusive, for example between 70 wt.% and 76 wt.% inclusive. For example, the remaining proportion of the conversion layer and / or the layer is formed by the matrix material or the partially cured matrix material. A phosphor proportion of at least 50 wt.% ensures, in particular, that the conversion layer is not too soft to separate. A phosphor proportion of at most 85 wt.% advantageously ensures that the conversion layer is hard but not brittle.

[0055] According to at least one embodiment of the method, the layer is provided on a carrier. In particular, the carrier comprises a material that is transparent to the phosphor and / or the radiation-emitting semiconductor chip. For example, the carrier transmits at least 90%, in particular at least 95%, for example at least 99%, of the electromagnetic radiation emitted by the phosphor and / or the radiation-emitting semiconductor chip. For example, the carrier comprises or consists of glass or sapphire.

[0056] Advantageously, the carrier provides a higher

[0057] The partially cured matrix material achieves dimensional stability of the layer. This can lead to better handling of the layer during the process for manufacturing the optoelectronic component. For example, the carrier also enables better force distribution when bonding the layer to the radiation-emitting semiconductor chip.

[0058] According to at least one embodiment of the method, the provision of the layer comprises the steps of providing the carrier, applying a mixture of the partially cured matrix material, the phosphor and a solvent to the carrier and removing the solvent so that the layer is formed on the carrier.

[0059] In particular, the mixture of the partially cured matrix material, the phosphor and the solvent is applied to the carrier by means of a coating process such as doctor blade coating or tape casting or a spraying process. The solvent is removed, for example, by elevated temperature and / or under reduced pressure.

[0060] For example, the solvent is selected from carboxylic acid esters or ethers with a boiling point of at least 100 °C. Methyl ethers or acetic acid esters are particularly used as solvents. For example, the solvent is propylene glycol monomethyl ether acetate (PGMEA), butyl acetate, or anisole.

[0061] According to at least one embodiment, the carrier, when provided, has a multiple of the size of the radiation-emitting semiconductor chip, in particular when viewed in plan view. After removing the

[0062] After the solvent has been applied to form the layer on the substrate, the substrate is then separated into layers. The separation is carried out, for example, by punching, sawing, laser dicing, or hybrid dicing. In this way, for example, small plates are formed with the layer, which are then bonded to the radiation-emitting semiconductor chip or semiconductor wafer.

[0063] When singulating the carrier with the layer, a proportion of phosphor in the layer in the range of between 50% and 85% by weight is particularly advantageous. Such a proportion of phosphor advantageously ensures that good-quality saw edges are formed during singulation.

[0064] According to at least one embodiment of the method, the layer is tested for its optical properties before being connected to the radiation-emitting semiconductor chip. In particular, the color coordinate of electromagnetic radiation emitted and / or transmitted by the layer is examined. This advantageously prevents the production of optoelectronic components with a defective color coordinate. For example, this can reduce production costs because fewer defective optoelectronic components are produced.

[0065] According to at least one embodiment of the method, the bonding of the layer and the radiation-emitting semiconductor chip takes place at a temperature in the range between 60°C and 180°C inclusive, in particular in the range between 100°C and 150°C inclusive. In particular, the curing of the partially cured matrix material to form the matrix material also takes place at this temperature. For example, the partially cured matrix material condenses, so that the matrix material is formed. Condensation increases, in particular, the molecular weight.

[0066] According to at least one embodiment of the method, the partially cured matrix material is cured in an additional step. In particular, the curing takes place at a temperature in the range between 60 °C and 200 °C inclusive, for example between 100 °C and 180 °C inclusive. The curing of the matrix material takes place in particular for a time of between 1 hour and 10 hours inclusive, in particular between 1 hour and 5 hours inclusive. For example, curing takes place for about 4 hours at a temperature of about 160 °C.

[0067] According to at least one embodiment of the method, when connecting the layer and the radiation-emitting semiconductor chip, a pressure of between 0.1 N and 5 N inclusive, in particular between 1.0 N and 2.5 N inclusive, is exerted on the layer. Advantageously, by exerting the pressure on the layer, a good connection is created between the layer and also between the conversion layer and the radiation-emitting semiconductor chip. It is also possible that by choosing the pressure appropriately, the time and / or the temperature required for the connection can be reduced. This advantageously makes it possible to produce a larger number of optoelectronic components per time interval.

[0068] According to at least one embodiment of the method, when connecting the layer and the radiation-emitting semiconductor chip, pressure is exerted on the layer for a time of at most 60 seconds, in particular of at most 30 seconds, for example of at most 1 second. For example, the pressure is exerted on the layer for a time of approximately 5 seconds. A time of at most 60 seconds enables effective connection of the layer to the radiation-emitting semiconductor chip. By means of a temperature in the range from 100 °C to 150 °C inclusive and by means of a pressure in the range from 1.0 N to 1.5 N inclusive, the time in which the pressure is exerted on the layer can advantageously be reduced to a maximum of 5 seconds.

[0069] Furthermore, an optoelectronic component is specified. The optoelectronic component is preferably produced using the method for producing an optoelectronic component described here. Features, embodiments, and advantages described in connection with the method therefore also apply to the optoelectronic component, and vice versa. In particular, statements made regarding the layer with the partially cured matrix material also apply to the conversion layer, and vice versa.

[0070] According to at least one embodiment, the optoelectronic component comprises a radiation-emitting semiconductor chip. In particular, the radiation-emitting semiconductor chip comprises a

[0071] Main emission area on .

[0072] According to at least one embodiment, the optoelectronic component has a conversion layer. The conversion layer comprises a matrix material and a phosphor. In particular, the conversion layer is arranged on the main emission surface of the radiation-emitting semiconductor chip.

[0073] According to at least one embodiment of the optoelectronic component, the conversion layer is in direct contact with the radiation-emitting semiconductor chip. In particular, the conversion layer is in direct contact with the main emission surface of the radiation-emitting semiconductor chip. In other words, the optoelectronic component has no additional adhesive layer between the radiation-emitting semiconductor chip and the conversion layer.

[0074] According to at least one embodiment of the optoelectronic component, side surfaces of the radiation-emitting semiconductor chip are free of the conversion layer. In particular, the side surfaces extend perpendicular to a main extension plane of the radiation-emitting semiconductor chip. For example, the side surfaces and the main emission surface form edges of the optoelectronic component.

[0075] According to at least one embodiment, the optoelectronic component comprises a radiation-emitting semiconductor chip and a conversion layer with a matrix material and a phosphor, wherein the conversion layer is in direct contact with the radiation-emitting semiconductor chip and side surfaces of the radiation-emitting semiconductor chip are free of the conversion layer.

[0076] Due to the direct contact between the conversion layer and the radiation-emitting semiconductor chip, the optoelectronic component advantageously exhibits improved heat distribution. Furthermore, increased reliability of the optoelectronic component can be observed due to the absence of an additional adhesive layer. The adhesive properties of the matrix material of the conversion layer serve to adhere the conversion layer to the radiation-emitting semiconductor chip.

[0077] According to at least one embodiment of the optoelectronic component, the conversion layer and the radiation-emitting semiconductor chip are flush at the side surfaces. In other words, the radiation-emitting semiconductor chip and the conversion layer each have the same or approximately the same shape and extent when viewed in plan view. This advantageously provides a compact optoelectronic component without protruding regions.

[0078] According to at least one embodiment of the optoelectronic component, a carrier is arranged on a side of the conversion layer facing away from the radiation-emitting semiconductor chip. In other words, the conversion layer is arranged between the carrier and the radiation-emitting semiconductor chip. The carrier is in particular in direct contact with the conversion layer. For example, the carrier comprises glass or sapphire or is made of glass or sapphire. In particular, the carrier is not a lens. For example, the carrier does not have any optical structures, such as scattering particles or a structured surface.

[0079] The carrier advantageously serves for the mechanical stabilization of the conversion layer, in particular during the process for producing the optoelectronic component.

[0080] According to at least one embodiment of the optoelectronic component, the carrier has a thickness of between 50 micrometers and 200 micrometers inclusive, in particular between 100 micrometers and 175 micrometers inclusive.

[0081] According to at least one embodiment of the optoelectronic component, the conversion layer has a thickness of between 10 micrometers and 250 micrometers inclusive, in particular between 30 micrometers and 150 micrometers inclusive.

[0082] According to at least one embodiment of the optoelectronic component, the conversion layer comprises fillers and / or scattering particles. Alternatively, it is possible for the conversion layer not to comprise fillers and / or scattering particles. In particular, the layer with the partially cured matrix material also comprises fillers and / or scattering particles during the method for producing an optoelectronic component. Advantageously, the hardness of the conversion layer is adjusted by the fillers. The fillers and / or scattering particles can also influence the rheological properties of the layer with the partially cured matrix material and / or the conversion layer.

[0083] The fillers and / or scattering particles, for example, are designed to be non-converting. In other words, the fillers and / or scattering particles do not convert the electromagnetic radiation emitted by the radiation-emitting semiconductor chip and / or the phosphor in the conversion layer.

[0084] For example, particles with an inorganic oxide, such as SiO2, are used as a filler. By using particles with an inorganic oxide, the hardness of the conversion layer can be increased. Alternatively or additionally, particles with a polysiloxane can be used as a filler. For example, the polysiloxane of the filler particles has a higher proportion of D units than the matrix material. In this way, the hardness of the conversion layer can be reduced.

[0085] Scattering particles, in particular, comprise an inorganic compound. For example, the scattering particles comprise or are formed from an oxide such as SiO2, TiO2, or Al2O3.

[0086] According to at least one embodiment of the optoelectronic component, the radiation-emitting semiconductor chip comprises a micro light-emitting diode (LED). In particular, the radiation-emitting

[0087] Semiconductor chip a micro-LED . Micro-LEDs can have a width, a length, a thickness and / or a diameter less than or equal to 100

[0088] Micrometers, in particular less than or equal to 70 micrometers, for example less than or equal to 50 micrometers. In particular, micro-LEDs, for example rectangular micro-LEDs, have an edge length, in particular in plan view of the layers of the layer stack, of a luminous area less than or equal to 70 micrometers, for example less than or equal to 50 micrometers. A micro-LED is, for example, a light-emitting diode in which a growth substrate has been removed, such that a thickness of the micro-LED is, for example, in the range from 1.5 micrometers inclusive to 10 micrometers inclusive.

[0089] For example, the micro-LED is provided on a wafer with detachable support structures. The micro-LED can be removed from the wafer without causing any damage.

[0090] According to at least one embodiment of the optoelectronic component, the conversion layer does not detach from the radiation-emitting semiconductor chip under a shear force of at least 0.40 kilogram-force (kg-f), in particular of at least 0.80 kg-f, for example of at least 1.10 kg-f. 1 kg-f corresponds in particular to 9.80665 N. The optoelectronic component described here thus tolerates similar shear forces as an optoelectronic component with an additional adhesive layer between the radiation-emitting semiconductor chip and the conversion layer.

[0091] Furthermore, a method for producing an optoelectronic component according to one or more of the embodiments of the method described here is described, wherein the optoelectronic component is produced according to one or more embodiments of the optoelectronic component described here.

[0092] Advantageously, the process is simplified compared to other methods and has fewer steps. This can be explained, for example, by the fact that no additional adhesive layer is applied. Advantageously, the simplification of the process results in cost savings. The optoelectronic component is characterized in particular by a longer service life and improved heat distribution.

[0093] Further advantageous embodiments, refinements and developments of the method for producing an optoelectronic component and of the optoelectronic component emerge from the following embodiments shown in conjunction with the figures.

[0094] Figures 1 to 4 show schematic sectional views of various steps of a method for producing an optoelectronic component according to an embodiment.

[0095] Figure 5 shows a diagram in which shear forces are represented for various optoelectronic components.

[0096] Identical, similar, or functionally identical elements are provided with the same reference symbols in the figures. The figures and the relative sizes of the elements shown in the figures are not to scale. Rather, individual elements, particularly layer thicknesses, may be exaggerated for clarity and / or clarity.

[0097] In a step for producing an optoelectronic component 1 according to an exemplary embodiment, a radiation-emitting semiconductor chip 2 is provided, which is illustrated in Figure 1. The radiation-emitting semiconductor chip 2 is configured to generate electromagnetic radiation in the ultraviolet to visible range of the electromagnetic spectrum. The generated electromagnetic radiation is emitted through a main emission surface. The main emission surface of the radiation-emitting semiconductor chip 2 is parallel to a main extension plane of the radiation-emitting semiconductor chip 2.

[0098] According to a further step, which is shown in Figure 2, a carrier 8 is provided. In this case, the carrier 8 has a plan view multiple of the size of the semiconductor chip 2. The carrier 8 has a material that is transparent to visible light. In this case, the carrier 8 is made of glass. The carrier 8 has a thickness in the range between 50 micrometers and 200 micrometers inclusive.

[0099] A mixture of a partially cured matrix material 4, a solvent and a phosphor 5 is applied to the carrier 8 by doctor blade coating or film casting. In the present case, the partially cured matrix material 4 comprises a polysiloxane with a proportion of at least 80 wt. % T-units. The partially cured matrix material 4 has a molecular weight of at least 5000 g / mol. The solvent is

[0100] Propylene glycol monomethyl ether acetate. The organic residues on the silicon atoms of the siloxane groups in the partially cured matrix material are methyl or phenyl.

[0101] The solvent is removed under elevated temperature and / or reduced pressure. In this way, the carrier 8 shown in Figure 3 is formed with a layer 3 comprising the partially cured matrix material 4 and the phosphor 5. The partially cured matrix material 4 is solid, but can be liquefied under the influence of elevated temperature and pressure. The layer 3 has a proportion of between 70% by weight and 72% by weight of the phosphor 5.

[0102] After the formation of layer 3, the carrier 8 with the layer 3 is separated by sawing or punching. After the separation, the carrier 8 with the layer 3 has, as seen in plan view, an approximately identical dimension to the semiconductor chip 2. Thus, the separation forms a wafer with the carrier 8 and layer 3.

[0103] The platelet is applied to the radiation-emitting semiconductor chip 2. In the process, the layer 3 is connected to the radiation-emitting semiconductor chip 2. The layer 3 is in direct contact with the main emission surface of the semiconductor chip 2. While the layer 3 is being connected to the radiation-emitting semiconductor chip 2, the layer 3 is cured. In the process, the partially cured matrix material 4 reacts to form the matrix material 6 and a conversion layer 7 is formed. The matrix material 6 has a higher degree of crosslinking than the partially cured matrix material 4. The curing of the partially cured matrix material 4 to form the matrix material 6 is induced by pressure and / or elevated temperature. Reaction parameters for the curing and bonding are shown in Table 1, which is described in conjunction with Figure 5.

[0104] The optoelectronic component 1 produced by the method is shown in Figure 4. The optoelectronic component 1 comprises the radiation-emitting semiconductor chip 2, the conversion layer 7, and the carrier 8. The conversion layer 7 is in direct contact with the carrier 8 and the radiation-emitting semiconductor chip 2. The conversion layer has a thickness in the range between 10 micrometers and 250 micrometers inclusive.

[0105] The conversion layer 7 in the present case comprises a polysiloxane with a proportion of at least 80 wt . % T units as matrix material 6 . The phosphor 5 is distributed in the conversion layer 7 . The phosphor 5 has a proportion in the range between 70 wt . % and 72 wt . % of the conversion layer inclusive. The phosphor 5 is embedded in the matrix material 6 .

[0106] The side surfaces 9 of the carrier 8, the conversion layer 7, and the radiation-emitting semiconductor chip 2 are flush with one another in the present case. The conversion layer 7 is arranged on the main emission surface of the radiation-emitting semiconductor chip 2. The radiation-emitting semiconductor chip 2 does not have its own conversion layers in the present case. In other words, the radiation-emitting semiconductor chip 2 emits only the electromagnetic radiation generated in the radiation-emitting semiconductor chip 2.

[0107] Figure 5 shows a diagram which shows the shear forces F in kg - f which are tolerated by optoelectronic components 1 which were produced according to the method described here. The dashed line R serves as a reference and represents the shear force which an optoelectronic component with an additional adhesive layer between the cured conversion layer 7 and the radiation-emitting semiconductor chip 2 tolerates. Table 1 shows the process parameters which were used in the production of the optoelectronic components 1. In particular, these process parameters were used when connecting and curing the layer 3 and the radiation-emitting semiconductor chip 2.

[0108] Table 1 : Process parameters

[0109] The measured shear forces F show that the stability of the optoelectronic component 1 can be increased by increasing the temperature and pressure during the bonding and curing of the radiation-emitting semiconductor chip 2 and the layer 3. This is demonstrated by the fact that the optoelectronic component 1 tolerates higher shear forces.

[0110] Furthermore, especially in the exemplary embodiments 5-

[0111] 4 , 5-5 and 5- 6 even achieve a higher stability of the optoelectronic component 1 compared to the reference R .

[0112] The features and exemplary embodiments described in conjunction with the figures can be combined with one another according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in conjunction with the figures can alternatively or additionally comprise further features according to the description in the general part.

[0113] The invention is not limited to the embodiments described herein. Rather, the invention encompasses any novel feature and any combination of features, including, in particular, any combination of features in the claims, even if this feature or combination itself is not explicitly stated in the claims or embodiments.

[0114] Reference symbol list

[0115] 1 optoelectronic component

[0116] 2 radiation-emitting semiconductor chip 3 layer

[0117] 4 partially cured matrix material

[0118] 5 fluorescent

[0119] 6 Matrix material

[0120] 7 Conversion layer 8 Carrier

[0121] 9 Side surface

[0122] F Shear force R Reference

Claims

Patent claims 1. A method for producing an optoelectronic component (1) comprising the steps - providing a radiation-emitting semiconductor chip (2), - Providing a layer (3) comprising a partially cured matrix material (4) and a phosphor (5), - connecting the radiation-emitting semiconductor chip (2) and the layer (3), - Curing the partially cured matrix material (4) to a matrix material (6) so that a conversion layer (7) is formed with the matrix material (6) and the phosphor (5) in direct contact with the radiation-emitting semiconductor chip (2).

2. A method for producing an optoelectronic component (1) according to the preceding claim, wherein the partially cured matrix material (4) has a lower degree of crosslinking than the matrix material (6).

3. A method for producing an optoelectronic component (1) according to one of the preceding claims, wherein the matrix material (6) comprises a polysiloxane.

4. A method for producing an optoelectronic component (1) according to the preceding claim, wherein the polysiloxane has a proportion of at least 25 wt.% T units.

5. A method for producing an optoelectronic component (1) according to one of the preceding claims, wherein the partially cured matrix material (4) has a molecular weight of at least 5000 g / mol.

6. A method for producing an optoelectronic component (1) according to one of the preceding claims, wherein a proportion of the phosphor (5) in the conversion layer (7) is between 50 wt.% and 85 wt.% inclusive.

7. A method for producing an optoelectronic component (1) according to one of the preceding claims, wherein the layer (3) is provided on a carrier (8).

8. A method for producing an optoelectronic component (1) according to the preceding claim, wherein the provision of the layer (3) comprises the following steps: - Providing the carrier (8) , - applying a mixture of the partially cured matrix material (4), the phosphor (5) and a solvent to the carrier (8), and - Removing the solvent so that the layer (3) is formed on the support (8).

9. A method for producing an optoelectronic component (1) according to one of the preceding claims, wherein the bonding of the layer (3) and the radiation-emitting semiconductor chip (2) takes place at a temperature in the range between 100 °C and 150 °C inclusive.

10. A method for producing an optoelectronic component (1) according to one of the preceding claims, wherein, during the bonding of the layer (3) and the radiation-emitting semiconductor chip (2), a pressure of between 0.1 N and 5 N inclusive is exerted on the layer (3).

11. A method for producing an optoelectronic component (1) according to one of the preceding claims, wherein, when connecting the layer (3) and the radiation-emitting semiconductor chip (2), a pressure is exerted on the layer (3) for a time of at most 60 seconds.

12. Optoelectronic component (1) with - a radiation-emitting semiconductor chip (2), and - a conversion layer (7) with a matrix material (6) and a phosphor (5), wherein - the conversion layer (7) is in direct contact with the radiation-emitting semiconductor chip (2), and - side surfaces (9) of the radiation-emitting semiconductor chip (2) are free of the conversion layer (7).

13. Optoelectronic component (1) according to the preceding claim, wherein the conversion layer (7) and the radiation-emitting semiconductor chip (2) are flush at the side surfaces (9).

14. Optoelectronic component (1) according to one of the preceding claims, wherein a carrier (8) is arranged on a side of the conversion layer (7) facing away from the radiation-emitting semiconductor chip (2).

15. Optoelectronic component (1) according to the preceding Claim, wherein the carrier (8) has a thickness between 50 and 100 mm micrometers and including 200 micrometers.

16. Optoelectronic component (1) according to one of the preceding claims, wherein the conversion layer (7) has a thickness between and including 10 micrometers and including 250 micrometers.

17. Optoelectronic component (1) according to one of the preceding claims, wherein the conversion layer (7) comprises fillers and / or scattering particles.

18. Optoelectronic component (1) according to one of the preceding claims, wherein the radiation-emitting semiconductor chip (2) comprises a micro-LED.

19. A method for producing an optoelectronic component (1) according to one of claims 1 to 11, wherein the optoelectronic component (1) is produced according to one of claims 12 to 18.

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