Radiation-emitting component and method for manufacturing a radiation-emitting component

Abstract

To provide a radiation-emitting component with improved properties. [Solution] The present invention relates to a radiation-emitting component having a semiconductor chip that emits electromagnetic radiation in a first wavelength range from a radiation outlet surface during operation, and a conversion element on the semiconductor chip cover surface including the radiation outlet surface, wherein the conversion element includes a matrix material and phosphor particles integrated therein that convert electromagnetic radiation in the first wavelength range to electromagnetic radiation in a second wavelength range. The conversion element has a support surface with an area equal to or smaller than the area of ​​the semiconductor chip cover surface, and the entire support surface is in direct contact with the semiconductor chip cover surface. The present invention also relates to a method for manufacturing a radiation-emitting component.

Description

[Technical Field]

[0001] A radiation-emitting component and a method for manufacturing the radiation-emitting component are disclosed.

[0002] The problem of at least one embodiment is to provide a radiation-emitting component with improved properties. The problem of at least one further embodiment is to provide a method for manufacturing a radiation-emitting component with improved properties. These problems are solved by the component described in claim 1 and the method described in claim 16. Further structures and further developments of the component and method are the subject of the dependent claims.

[0003] A radiation-emitting component is disclosed. The radiation-emitting component has a semiconductor chip that emits electromagnetic radiation in a first wavelength range from a radiation exit surface during operation. Thus, the electromagnetic radiation in the first wavelength range forms the emission spectrum of the semiconductor chip and is also called primary radiation. The radiation exit surface is also called the radiation-emitting surface.

[0004] For example, the semiconductor chip is a light-emitting diode chip or a laser diode chip. Therefore, the component can be a light-emitting diode (LED) or a laser. Preferably, the semiconductor chip has an epitaxially grown semiconductor layer sequence with an active region suitable for generating electromagnetic radiation. For example, the active region therefor may be a pn junction, a double heterostructure, a single quantum well, or a multiple quantum well structure.

[0005] During operation, the semiconductor chip may emit electromagnetic radiation from, for example, the ultraviolet spectral range and / or the visible spectral range, particularly the blue spectral range. Therefore, the wavelength of the primary radiation is, for example, in the range of 400 nm to 500 nm.

[0006] According to at least one embodiment, the radiation-emitting component further comprises a conversion element on the cover surface of the semiconductor chip, including a radiation exit surface, the conversion element comprising a matrix material and phosphor particles embedded therein, which convert electromagnetic radiation in a first wavelength range to electromagnetic radiation in a second wavelength range. The cover surface of the semiconductor chip is understood as the side facing outward from the bottom surface of the semiconductor chip, extending parallel to the main extension direction of the semiconductor chip. In addition to the radiation exit surface, the cover surface may include areas of electrical connections, saw marks, and / or dark, i.e., non-radiative edge areas.

[0007] The term "phosphor particles" here and below is understood to mean particulate wavelength-converting materials, i.e., materials designed to absorb and emit electromagnetic radiation. In particular, phosphor particles absorb electromagnetic radiation having a maximum wavelength different from the electromagnetic radiation emitted by the phosphor particles.

[0008] For example, phosphorescent particles absorb radiation at wavelengths shorter than their maximum emission wavelength, and therefore emit radiation with a maximum emission shifted to red. In this case, pure scattering or pure absorption is not considered wavelength conversion.

[0009] According to at least one embodiment, the conversion element has a support surface equal to or smaller than the cover surface of the semiconductor chip. Thus, the conversion element either completely covers the cover surface of the semiconductor chip or only partially covers it. In the case of partial covering only, i.e., partially coating the cover surface of the semiconductor chip with the conversion element, certain areas that come into contact with the semiconductor chip, such as bond pads, edge areas, and / or saw marks, can be left without the conversion element.

[0010] According to at least one embodiment, the support surface is in complete direct contact with the cover surface of the semiconductor chip. In other words, the support surface of the conversion element adheres tightly to the cover surface of the semiconductor chip without any gaps, regardless of the surface properties of the semiconductor chip's cover surface. This means that the conversion element is fixed to the cover surface of the semiconductor chip without adhesive and therefore has a common interface with the semiconductor chip.

[0011] According to at least one embodiment, a radiation emission component is disclosed which includes a semiconductor chip that emits electromagnetic radiation in a first wavelength range from a radiation exit surface when in operation, and a conversion element for the cover surface of the semiconductor chip including the radiation exit surface, wherein the conversion element includes a matrix material and phosphor particles embedded therein, which converts electromagnetic radiation in the first wavelength range to electromagnetic radiation in a second wavelength range, and the conversion element has a support surface equal to or smaller than the cover surface of the semiconductor chip, the support surface being in full direct contact with the cover surface of the semiconductor chip.

[0012] The inventors recognized that by directly placing the conversion element on the cover surface of the semiconductor chip, i.e., without adhesive, good thermal conductivity of the conversion element can be achieved. Conventionally, conversion plates that need to be bonded to the semiconductor chip are used, and silicon is usually used for this purpose. However, because silicon has low thermal conductivity, a thermal barrier is formed between the conversion plate and the semiconductor chip, and this thermal barrier increases as the thickness of the layer increases. In the component described here, since the conversion element is directly placed on the semiconductor chip, such a thermal barrier can be eliminated. This means that the component can be operated at high currents in applications requiring high brightness levels, such as headlights or stage lighting. Current density of 1 A / mm 2 Even with applications involving high currents exceeding a certain level, the heat generated by the conversion element can be easily dissipated to the semiconductor chip.

[0013] The absence of an adhesive layer also has advantages in component manufacturing. For example, if a conventional prefabricated conversion platelet is placed on a previously applied adhesive layer, the adhesive material is extruded, and / or reflective material, such as silicon filled with titanium dioxide, penetrates into the adhesive-free cavities beneath the edges of the platelet. This phenomenon leads to a decrease in brightness, meaning that the adhesive layer represents an optical barrier. This can be avoided by using the conversion element described here. Finally, omitting the adhesive layer simplifies the component manufacturing process and reduces costs because the bonding process is unnecessary, as is the required binning process, i.e., the process of classifying components according to chromaticity coordinates.

[0014] Furthermore, the conversion element can be applied to only a portion of the semiconductor chip; that is, only a defined area of ​​the semiconductor chip's cover surface can be coated with the conversion element. As a result, the conversion element is provided with only a radiation-emitting surface and a radiation-reflecting surface, and no (dark) light traps are provided, thus improving the efficiency of the component. Such partial coating eliminates the need to provide a conversion element in, for example, the edge region (mesa edge) of the semiconductor chip's cover surface, which is approximately 10 μm to 12 μm wide. Areas for electrical contact can be left without a conversion element, and / or the radiation exit surface can be partially coated with a conversion element.

[0015] The components described here are equally suitable for applications such as cool white (5700K or 6500K), warm white (3200K), and applications where a color rendering index (CRI) of 80 or higher, especially 90 or higher, is desired. Because of this high CRI, the emission spectrum has a relatively high red portion, and typical red-emitting materials are particularly sensitive to high operating currents and temperatures due to their large Stokes shift and strong thermal quenching. The conversion elements described here, especially because they are in direct contact with the semiconductor chip, can effectively dissipate the generated heat, enabling the realization of such high current densities and / or high operating temperatures. This represents a significant improvement compared to conventional conversion chips using silicon as the matrix material, because silicon has low thermal stability and thermal conductivity, which means that such conversion plates can achieve a current density of 1 A / mm² up to 150°C. 2 This means it is only suitable for less than [specific] uses.

[0016] According to at least one embodiment, the support surface of the conversion element is equal to or smaller than the radiation outlet surface.

[0017] According to at least one embodiment, the semiconductor chip has sides, and no conversion elements are provided on the sides. Hereinafter, and thereafter, the sides of the semiconductor chip are understood as regions that extend substantially perpendicular to the main extension direction of the semiconductor chip and connect the cover surface to the bottom surface of the semiconductor chip. In particular, the sides do not include the radiation outlet surface. Thus, a decrease in efficiency through the sides of the chip can be avoided.

[0018] According to at least one embodiment, the conversion element has sides with an average roughness of less than 2 μm, particularly less than 1 μm, and / or no saw marks. In particular, the sides of the conversion element extend substantially perpendicular to the support surface of the conversion element. Thus, the sides of the conversion element have particularly smooth surfaces. The smooth surfaces of the sides of the conversion element may reduce radiation from the sides. Furthermore, the smooth surfaces of the conversion element ensure that particles embedded in the matrix material of the conversion element, particularly phosphor particles, do not damage elements adjacent to the conversion element. This is advantageous compared to conventionally used conversion platelets, which are individualized by cutting or sawing, resulting in considerably rougher side surfaces.

[0019] According to at least one embodiment, the transformation element has sides with rounded corners. Thus, the two intersecting sides form a rounded corner with a radius, rather than a clearly defined corner without, for example, a 90° angle. Such radii are in the range of 0.04 mm to 0.1 mm, particularly in the range of 0.05 mm to 0.06 mm.

[0020] According to at least one embodiment, the conversion element has a cross-sectional region that tapers from the support surface toward the side of the conversion element facing outward from the semiconductor chip. Such a conical shape can result in specific optical guidance, in particular a reduction in the radiation emission area and an increase in brightness, i.e., focusing of emitted radiation.

[0021] According to at least one embodiment, the conversion element has a cross-sectional region that tapers from the side of the conversion element facing outward from the semiconductor chip toward the support surface. Such a conical shape can result in a specific optical guide, in particular, the expansion of emitted radiation.

[0022] According to at least one embodiment, the thickness of the conversion element is 150 μm or less, particularly 100 μm or less. In particular, the thickness can be 35 μm or less, for example, 25 μm or less. The exact thickness can be adjusted according to the size of the phosphor particles and the desired degree of conversion. For example, a thickness of less than 25 μm can be used for cold white emission, and a thickness of about 80 μm to 90 μm can be selected for orange tones. This makes the conversion element particularly thin, which reduces emission from the sides, for example, and ensures good thermal coupling between the conversion element and the semiconductor chip. The thickness of the conversion element described herein is particularly thin compared to conventionally used conversion platelets, which are produced on a glass plate or film and attached only to the semiconductor chip by an adhesive layer after completion.

[0023] According to at least one embodiment, the thickness of the conversion element is 10 μm or more.

[0024] According to at least one embodiment, the conversion element has a solid content of 45% by volume or more, particularly 50% by volume or more. According to one embodiment, the solid content is formed by solid particles, which are up to 100% phosphor particles. This means a high solid content in the matrix material, which has a positive effect on the temperature, radiation, and chemical resistance of the conversion element. In addition to phosphor particles, the solid content can consist of microparticles / fillers and / or nanoparticles / fillers. In other words, the phosphor particles can be partially replaced by non-converting microparticles or nanoparticles so that, for example, the chromaticity coordinates can be adjusted and / or controlled while maintaining the same thickness of the conversion layer. For example, the conversion element can withstand up to 220°C and up to 6 W / mm 2 It has remained stable in the long term.

[0025] According to at least one embodiment, the matrix material has an organic content of less than 40% by weight, and more particularly less than 20% by weight. The low organic content contributes to the long-term stability of the conversion elements and, consequently, the components.

[0026] According to at least one embodiment, the matrix material has a Shore D hardness greater than 50. This means that the side of the transformer element facing outward from the semiconductor chip can be easily reworked, such as by grinding (ground or polish). Modifications to the transformer element, such as modifications on the side facing outward from the semiconductor chip, are also conceivable. For example, this transformer element can be appropriately given additional layers, small platelets, or structuring. Furthermore, the high hardness of the transformer element provides high mechanical stability, which is advantageous, for example, when it is necessary to separate already applied transformers from each other by sawing.

[0027] In a further embodiment, the matrix material comprises a three-dimensional crosslinked polyorganosiloxane. Such a polyorganosiloxane is obtained from a precursor material having a curing temperature that does not damage the semiconductor chip and bonds or adheres well to it. Such a curing temperature is, for example, 220°C or less. Therefore, to manufacture the conversion element, the precursor material of the matrix material can be directly applied to the semiconductor chip and cured therein. In particular, this improves the thermal bonding between the conversion element and the semiconductor chip and increases efficiency compared to conventional components. Furthermore, the three-dimensional crosslinked polyorganosiloxane can be formed without cracks or pores after curing, especially when the solids content is 45% by volume or more. The three-dimensional crosslinked polyorganosiloxane also has excellent thermal conductivity, especially when the organic content is low, for example, less than 40% by weight.

[0028] Furthermore, the three-dimensional crosslinked polyorganosiloxane can be filled with a high proportion of phosphor particles, particularly exceeding 45% by volume, thereby achieving high temperature, radiation, and chemical resistance of the conversion element. After curing, the three-dimensional crosslinked polyorganosiloxane has sufficient hardness to allow for further mechanical processing and / or modification of the conversion element. The thickness of the conversion element can also be precisely adjusted, for example, by polishing, thereby enabling the setting of precise chromaticity coordinates of the radiation being converted.

[0029] According to at least one embodiment, the three-dimensional crosslinked polyorganosiloxane has the following repeating units. [Number]

[0030] In this general formula, a + b + c = 1, 0.65 ≤ a ≤ 1, 0 ≤ b + c ≤ 0.35, 0 ≤ b < 0.35, 0 ≤ c < 0.35. Further, R is independently selected from methyl, phenyl, and combinations thereof. T 1 and T 2 are independently selected from methyl, methoxy, and combinations thereof.... represents a linking point to a further repeating unit.

[0031] The three-dimensional crosslinked polyorganosiloxane also enables the embedding of various phosphor particles. According to at least one embodiment, the phosphor particles are selected from the following group. 0 < x ≤ 0.1 and 0 ≤ y ≤ 1, (RE 1-x Ce X )3(Al 1-Y A’ Y )5O 12 , 0 < x ≤ 0.1 and 0 ≤ y ≤ 2, (RE 1-x Ce X )3(Al 5-2y Mg Y Si y )O 12 , 0 < x ≤ 0.1 and 0 ≤ y ≤ 0.5, (RE 1-x Ce x )3Al 5-y Si y O 12-y N y , 0 < x ≤ 0.1, (RE 1-x Ce x )2CaMg2Si3O 12 :Ce 3+ , 0 < x ≤ 0.1, (AE 1-x Eu X )2Si5N8, When 0 < x ≤ 0.1, (AE 1-x Eu X )AlSiN3, When 0 < x ≤ 0.1, (AE 1-x Eu x )2Al2Si2N6, When 0 < x ≤ 0.1, (Sr 1-x Eu x )LiAl3N4, When 0 < x ≤ 0.1, (AE 1-x Eu x )3Ga3N5, When 0 < x ≤ 0.1, (AE 1-x Eu x )Si2O2N2, When 0 < 0.2 ≤ x ≤ 2.2 and 0 < y ≤ 0.1, (AE x Eu y )Si 12-2x-3y Al 2x+3y O y N 16-y , When 0 < x ≤ 0.1, (AE 1-x Eu x )2SiO4, When 0 < x ≤ 0.1, (AE 1-x Eu x )3Si2O5, When x ≤ 0.2 and 0 < y ≤ 1 - X, K2(Si 1-x-y Ti y Mn x )F6, When 0 < x ≤ 0.2, (AE 1-x Eu x )5(PO4)3Cl, When 0 < x ≤ 0.2, (AE 1-x Eu x )Al 10 O 17 , and any combination thereof. RE is at least one of Y, Lu, Tb, Gd, AE is at least one of Mg, Ca, Sr, Ba, A' is at least one of Sc and Ga, whereby the phosphor particles can optionally contain one or more halogens.

[0032] Therefore, three-dimensional cross-linked polyorganosiloxanes offer the same flexibility in chromaticity coordinate selection as conventional silicone matrices, and superior flexibility in chromaticity coordinate selection compared to conversion ceramics and converters in which phosphor particles are embedded in glass, while providing improved optical and thermal performance and heat resistance compared to conventional silicone matrices.

[0033] According to at least one embodiment, a three-dimensional crosslinked polyorganosiloxane is produced from a precursor material comprising an alkoxy-functionalized, particularly methoxy-functionalized, polyorganosiloxane resin. The three-dimensional crosslinked polyorganosiloxane thus produced has a low organic content, less than 40% by weight, and particularly less than 20% by weight.

[0034] According to at least one embodiment, the precursor material has the following repeating units.

number

[0035] In this general formula, a+b+c=1, 0.65≦a≦1, 0≦b+c≦0.35, 0≦b<0.35, and 0≦c<0.35. Furthermore, R can be independently selected from methyl, phenyl, and combinations thereof. 1 and T 2 The element is selected independently from methyl, methoxy, and combinations thereof. ... represents a linkage point to a further repeating unit.

[0036] According to at least one embodiment, the conversion element further comprises a filler material. The filler material can be selected from the following group: - Oxides, such as SiO2, especially nanoSiO2 and microSiO2, ZrO2, TiO2, Al2O3 and ZnO, nitrides, such as AlN, Si3N4, BN and GaN, - Carbon-based fillers, such as carbon nanotubes, graphene and its derivatives, heteropoly acids, such as 12-tungstric acid (H3P 12 WO 40) and 12-tungstosiric acid (H4SiW 12 O 40 ), - Organometallic components, such as silicon, titanium, zirconium, aluminum and / or hafnium alkoxides, - Organic molecules such as adhesion promoters, defoamers, thickeners, diluents, and plasticizers. - Organic and inorganic polymers, such as poly(dimethylsiloxane), poly(methylphenylsiloxane), poly(diphenylsiloxane), and polysilsesquioxane (PSQ), And combinations thereof can be selected. The inorganic nanoparticles described above may be provided with a coating material on their surface to achieve good miscibility with precursor materials for producing matrix materials of conversion elements.

[0037] According to at least one embodiment, the component has a connector for electrical contact, the connector located on the side of the semiconductor chip facing outward from the radiation outlet surface. This means that the connector is located on the non-emitting side of the semiconductor chip, where it can be soldered or bonded in a conductive manner. Such a semiconductor chip is also called a flip chip and can be readily combined with the conversion element described herein.

[0038] According to at least one embodiment, the component has a connection for electrical contact, the connection being located on the side of the semiconductor chip facing the radiation emission surface. Such a semiconductor chip is in particular insulatedly bonded or soldered to a base such as a substrate and can be easily combined with the conversion element described herein.

[0039] According to at least one embodiment, the component includes a connector for electrical contact, the connector located on the side of the semiconductor chip facing outward from the radiation exit surface and the side facing the radiation exit surface. Thus, the connectors are located on different sides of the semiconductor chip. For example, a bond pad is located on the side of the semiconductor chip facing the radiation exit surface, and conductive soldering or bonding is located on the side of the semiconductor chip facing outward from the radiation exit surface. Such a semiconductor chip can also be successfully combined with the conversion element described herein.

[0040] The possibility of combining the conversion elements described here with different types of semiconductor chips is based, in particular, on the fact that the conversion elements can be applied as partial coatings, and thus dark areas, especially edge areas, and / or areas in contact with the semiconductor chip, can be left without conversion elements.

[0041] A method for manufacturing the component is further disclosed. The method is particularly suited for manufacturing the component described herein. Thus, all features mentioned in relation to the component also apply to the method, and vice versa.

[0042] According to at least one embodiment, this method provides at least one semiconductor chip that emits electromagnetic radiation in a first wavelength range from a radiation exit surface during operation. It should be understood that, with at least one semiconductor chip, the method can be used to provide not only a single semiconductor chip with a conversion element, but also multiple semiconductor chips simultaneously. When multiple semiconductor chips are simultaneously provided with a conversion element, the semiconductor chips can also be interconnected and individualized after the conversion element has been added. Thus, this method enables multi-chip coating.

[0043] According to at least one embodiment, the method further includes depositing a precursor material in which phosphor particles that convert electromagnetic radiation in a first wavelength range to electromagnetic radiation in a second wavelength range are embedded. The deposition is carried out directly in at least one region of the cover surface of a semiconductor chip, including the radiation exit surface.

[0044] A precursor material is a material that reacts through a chemical reaction initiated by an external influence to form the desired material present in the finished component. External influences may include, for example, an increase in temperature or irradiation. The precursor material may be, for example, an alkoxy-functionalized, particularly methoxy-functionalized, polyorganosiloxane resin. Such a precursor material can react to form a three-dimensional crosslinked polyorganosiloxane.

[0045] Direct deposition means that the precursor material is brought into direct contact with the cover surface of the semiconductor chip, sharing a common interface with the semiconductor chip and conforming seamlessly to the cover surface. Therefore, an adhesive layer can be eliminated. This is made possible, in particular, by ensuring that the precursor material has a certain degree of tackiness and that it is fixed to the desired area of ​​the semiconductor chip.

[0046] "At least a portion of the cover surface" means that the entire cover surface of the semiconductor chip is coated with the precursor material, or that only a partial coating is performed and no precursor material remains in any particular area of ​​the cover surface of the semiconductor chip.

[0047] According to at least one embodiment, the precursor material is deposited by a method selected from the doctor blade method, the spray method, and the printing method. According to at least one embodiment, the precursor material embedded with phosphor particles is deposited in the form of a homogeneous mixture, the mixture may contain further fillers. Possible fillers and phosphor particles have already been mentioned in relation to the components and also apply to the method.

[0048] According to at least one embodiment, the method further includes curing a precursor material to form a conversion element comprising a matrix material (5) and phosphor particles (1) embedded therein, wherein the conversion element has a support surface equal to or smaller than the cover surface of the semiconductor chip, and the support surface is in complete direct contact with the cover surface of the semiconductor chip. Thus, during the curing process, a matrix material is formed from the precursor material in which the phosphor particles are embedded and which is generally or completely free of pores and cracks. The conversion element is then fixed to a region of the cover surface of the semiconductor chip on which the precursor material has been pre-deposited.

[0049] According to at least one embodiment, a method for manufacturing a radioactive component is disclosed, the method comprising the following method steps: - A step of providing at least one semiconductor chip that emits electromagnetic radiation in a first wavelength range from a radiation outlet surface during operation, - A step of directly depositing a precursor material, in which phosphor particles are embedded and which converts electromagnetic radiation in a first wavelength range to electromagnetic radiation in a second wavelength range, onto at least one area of ​​the cover surface of the semiconductor chip, including the radiation exit surface, and - A step of curing a precursor material to form a conversion element comprising a matrix material and phosphor particles embedded therein, wherein the conversion element has a support surface equal to or smaller than the cover surface of the semiconductor chip, and the support surface is in complete direct contact with the cover surface of the semiconductor chip.

[0050] The method is particularly easy to implement and cost-effective because it does not require an adhesive layer between the semiconductor chip and the conversion element. Therefore, no bonding process is necessary. Furthermore, the manufactured component does not have an adhesive layer that would act as a thermal and / or optical barrier between the conversion element and the semiconductor chip. In addition, the precursor material can be specifically deposited on the emission and / or reflection regions of the semiconductor chip, thereby mapping the shape of the active region, and for example, dark edge regions can be left without a conversion element. This reduces efficiency losses. Further advantages of components manufactured using the method described here have already been shown with respect to the components and apply similarly to components manufactured using the method.

[0051] According to at least one embodiment, curing is performed at a temperature of 220°C or less. This means that the curing is performed at a temperature that does not damage temperature-sensitive photo-emitting materials such as semiconductor chips or nitride phosphors. According to one embodiment, curing is performed over a period of 5 hours or less, particularly 2 hours or less.

[0052] According to at least one embodiment, multiple semiconductor chips are provided, which are individualized after the deposition and curing of the precursor material. Thus, this method enables multi-chip coating. Furthermore, individualization yields a semiconductor chip on which a conversion element is positioned, which has smooth surfaces. After individualization, the surface roughness of the conversion element becomes less than 2 μm, particularly less than 1 μm. Due to the hardness of the matrix material, the conversion element can be easily separated mechanically by sawing or the like. Alternatively, if the precursor material is deposited such that the support surface of the conversion element is smaller than the cover surface of the semiconductor chip, separation or individualization of the conversion element is not necessary at all. In this case, only the semiconductor chip is individualized. This variation also presents a conversion element that already has smooth surfaces as a result of the manufacturing process. If only the semiconductor chip needs to be individualized, this also leads to cost advantages as sawing and the associated wear of the conversion element are avoided. Furthermore, because the surface of the conversion element is very smooth, it is possible to provide a component with particularly excellent optical performance.

[0053] According to at least one embodiment, the thickness and shape of the conversion element are adjusted during the deposition and / or curing of the precursor material. For example, the precursor material may be applied to at least a portion of the surface of a semiconductor chip, where it is pre-cured at a first temperature and then mechanically, for example by polishing, to a desired thickness. The material can then be fully cured at a second temperature, particularly a temperature higher than the first temperature, to form a matrix material.

[0054] Alternatively or additionally, the precursor material can be structured during deposition. This can be done, for example, using a lithography process. For instance, a photoresist layer can be applied to the cover surface of the semiconductor chip before depositing the precursor material and structured by exposure. Then, the precursor material can be filled into the resulting structure, i.e., the areas of the semiconductor chip's cover surface that lack the photoresist layer, and pre-cured. Complete curing can then be achieved through further steps, such as chemically removing the structured photoresist layer. Such methods can be used, in particular, to generate conical and / or rounded corners of the conversion element, as already described above. For example, the structured photoresist layer can form a mask, and the resulting conversion element may have a cross-sectional region that extends away from the semiconductor chip. In another example, a conversion element can be generated by a so-called LDI (laser direct imaging) process, which has a cross-sectional region that tapers away from the semiconductor chip.

[0055] According to at least one embodiment, the precursor material crosslinks three-dimensionally during curing. In particular, when an alkoxy-functionalized polyorganosiloxane resin is used as the precursor material, a low three-dimensional SiO2 network is formed during curing with a weight ratio of less than 40%, particularly less than 20%, of organic residues. This network is embedded with solid particles, up to 100% of which are phosphor particles. The solid content of the conversion element is, for example, at least 45% by volume, particularly at least 50% by volume.

[0056] Further advantageous embodiments and further embodiments of the components and methods can be obtained from the exemplary embodiments described below in conjunction with the drawings. [Brief explanation of the drawing]

[0057] [Figure 1] A schematic cross-sectional view of a transformation element according to an exemplary embodiment is shown. [Figure 2] A schematic cross-sectional view of a component according to an exemplary embodiment is shown. [Figure 3]Figures a-c show schematic cross-sectional views of the component according to an exemplary embodiment. Figure d shows a top view of the component according to an exemplary embodiment. [Figure 4] Figures a-c show schematic cross-sectional views of the component according to an exemplary embodiment. Figure d shows a top view of the component according to an exemplary embodiment. [Figure 5] A schematic cross-sectional view of a component according to an exemplary embodiment is shown. [Figure 6] A schematic cross-sectional view of a component according to an exemplary embodiment is shown. [Figure 7] An optical microscope image of a transformation element according to an exemplary embodiment is shown. [Figure 8] An optical microscope image of a transformation element according to an exemplary embodiment is shown. [Figure 9] Figures a-c show schematic cross-sectional views of components according to various exemplary embodiments. [Modes for carrying out the invention]

[0058] In exemplary embodiments and drawings, identical, similar, or similarly functioning elements may be given the same reference numeral. The elements shown and their relative sizes are not proportional to their actual size. Rather, individual elements such as layers, elements, components, and regions may be shown in exaggerated sizes for better representation and / or better understanding.

[0059] To manufacture a component according to an exemplary embodiment, a plurality of semiconductor chips 10, particularly in the form of LED chips or chip wafers, are provided. A precursor material embedded with phosphor particles 1, or a homogeneous mixture containing the precursor material embedded with phosphor particles 1, is deposited directly onto the cover surface 12 of one or more semiconductor chips 10.

[0060] The precursor material is a methoxy-functionalized polyorganosiloxane resin having the following repeating units.

number

[0061] The mixture is deposited directly by doctor blade, printing, or spraying onto the area (partial coating) or the entire cover surface 12 of one or more semiconductor chips 10. For example, in the case of a partial coating, the area of the semiconductor chip 10 where the conversion element 20 is not provided is protected by a photoresist, which is removed again after the precursor material has been deposited and pre-cured.

[0062] After depositing a precursor material or a mixture containing a precursor material, the precursor material is cured to form a three-dimensional crosslinked polyorganosiloxane as the matrix material 5. Curing is carried out at a temperature of 220°C or lower. The three-dimensional crosslinked polyorganosiloxane has the following repeating units.

number

[0063] In this general formula, a+b+c=1, 0.65≦a≦1, 0≦b+c≦0.35, 0≦b<0.35, and 0≦c<0.35. Furthermore, R can be independently selected from methyl, phenyl, and combinations thereof. 1 and T 2 The element is selected independently from methyl, methoxy, and combinations thereof. ... represents a linkage point to a further repeating unit.

[0064] The thickness of the conversion element 20 manufactured in this way ranges from 10 μm to 150 μm, depending on the desired chromaticity coordinates.

[0065] Figure 1 shows a cross-section of an exemplary embodiment of the conversion element 20 manufactured as described above. For better detail, the conversion element 20 is shown here without the semiconductor chip 10 to which it is directly applied.

[0066] The conversion element 20 includes a matrix material 5 in which phosphor particles 1 are embedded. Figure 1a also shows a support surface 21 that is in direct contact with the cover surface 12 (not shown) of the semiconductor chip 10. The conversion element 20 in Figure 1a has a side surface 25 that is perpendicular and parallel to the support surface 21.

[0067] Figures 1b and 1c show two alternative shapes of the conversion element 20. In contrast to Figure 1a, the cross-sectional area 26 of the conversion element is also shown here, and in Figure 1b, it tapers from the support surface 21 to the opposite side of the support surface 21 (the side facing outward from the semiconductor chip 10). Such a conical shape makes it possible to concentrate the radiation, for example, during the operation of component 100. In Figure 1c, the conversion element 20 is also conical, but the cross-sectional area 26 of the conversion element 20 increases as the distance from the support surface 21 increases. Such a shape makes it possible to spread the radiation, for example, during the operation of component 100.

[0068] Figure 2 shows schematic cross-sectional areas of exemplary embodiments of component 100 including the conversion element 20 shown in Figure 1. In each case, a semiconductor chip 10 is shown, and the support surface 21 of the conversion element 20 is applied in direct contact with its cover surface 12, fitting snugly without adhesive. This ensures good thermal conduction between the conversion element 20 and the semiconductor chip 10. The cover surface 12 also includes, but may be larger than, the radiation outlet surface 11 of the semiconductor chip 10. Figure 2a shows component 100 with the conversion element 20 according to Figure 1a, Figure 2b shows component 100 with the conversion element 20 according to Figure 1b, and Figure 2c shows component 100 with the conversion element 20 according to Figure 1c. A side surface 15 of the semiconductor chip 10 without the conversion element 20 is also shown.

[0069] Figures 3a-c and 4a-c are schematic cross-sectional views of component 100 in which the conversion element 20 is applied as a partial coating to the semiconductor chip 10 in each case. For clarity, not all reference numerals shown in Figures 1 and 2 are shown here, but they are also applicable to Figures 3 and 4. Figures 3d and 4d show component 100 in a top view, respectively.

[0070] Figures 3a and 4a show the conversion element 20 of Figure 1a, Figures 3b and 4b show the conversion element 20 of Figure 1b, and Figures 3c and 4c show the conversion element 20 of Figure 1c on the semiconductor chip 10. In all cases, the conversion element 20 is applied to the semiconductor chip 10 as a partial coating. According to the top view of Figure 3d, the conversion element 20 is not provided in the areas of electrical connections 40 (bond pads or bond bars) and saw marks 41. The conversion element 20 covers the radiation exit surface 11 and dark edge region (mesa edge) 42 of the cover surface of the semiconductor chip 10 and is indicated by hatching for clarity.

[0071] In Figure 4, the conversion element 20 extends only to the radiation outlet surface 11, and is shown as a hatched layer in Figures 4a-4c for illustrative purposes. Figure 4d again shows this arrangement of the conversion element 20 in a top view of component 100, where the conversion element 20 is indicated by hatching.

[0072] Figure 5 shows further variations of component 100. Here, the conversion element 20 extends only to a portion of the radiation exit surface 11, which is again shown as an additional layer in Figures 5a to 5c for illustrative purposes. The conversion element in Figure 1a is placed on the semiconductor chip 10 in Figure 5a, the conversion element in Figure 1b is placed on the semiconductor chip 10 in Figure 5b, and the conversion element in Figure 1c is placed on the semiconductor chip 10 in Figure 5c.

[0073] Another difference from component 100 in the previous figure is that Figure 5 shows a potting 30 that laterally surrounds both the semiconductor chip 10 and the conversion element 20. The potting 30 can have various shapes and filler heights. The potting 30 can be flush with the conversion element 20, as shown in Figure 5a, or it can protrude beyond the conversion element 20 (Figures 5b and 5c). Furthermore, the potting 30 can have sidewalls with parallel surfaces (Figure 5a) or sidewalls that are inclined toward the conversion element 20 (Figures 5b and 5c). The potting can be formed from, for example, silicon or epoxy resin, and optionally filled with, for example, TiO2. Further configurations may include, for example, other filler materials in addition to TiO2.

[0074] Figure 6 shows a schematic cross-section of a semiconductor chip wafer as multiple consecutive semiconductor chips 10 to which the conversion element 20 has already been applied. After individualization, multiple components 100 are obtained in this way by multi-chip coating.

[0075] Figure 7 shows a top view of the conversion element 20 under an optical microscope. It can be seen that the conversion element 20 is not provided in the areas of the electrical connection part 40 (bond bar) and the saw cuts 41. Therefore, the conversion element 20 covers only the radiation outlet surface 11. The size of the conversion element 20 is approximately 1 mm. 2 In this image, the underlying semiconductor chip 10 has not yet been individualized, so the conversion element 20 was manufactured by multi-chip coating. The corners of the conversion element 20 are rounded, and the sides 25 of the conversion element 20 appear straight and flawless, i.e., no chips are visible.

[0076] Figure 8 shows the conversion elements 20 corresponding to Figure 7, still viewed obliquely, before the individualization of the semiconductor chip 10, i.e., after multi-chip coating. These have the shape described in relation to Figure 1b and are approximately 1 mm in diameter. 2This is a transformation element 20 having the following dimensions. In addition to the rounded corners, the smooth, clearly structured, and intact sides 25 of the transformation element can also be seen here. In this case, the thickness of the transformation element is 25-30 μm. Garnet phosphor particles 1 are embedded to apply a cool white color.

[0077] Figure 9 shows schematic cross-sectional views of a component 100 with different types of semiconductor chips 10 that can be combined with the conversion element 20 described herein. In each of Figures 9a to 9c, the conversion element 20 according to Figure 1a is applied to the semiconductor chip 10. However, any combination of the conversion element 20 described herein with various semiconductor chip types is also possible. In Figures 9a to 9c, each semiconductor chip 10 is provided with electrical connection parts 40, both of which can be located on the side of the semiconductor chip 10 facing outward from the cover surface 12 (flip-chip design, Figure 9a). In this case, the cover surface 12 can be completely covered by the conversion element 20, but partial coating is also intended. The electrical connection parts 40 can also be located on the cover surface 12 and on the side of the semiconductor chip 10 facing outward from the cover surface 12 (Figure 9b), or both can be located on the cover surface 12 of the semiconductor chip (Figure 9c).

[0078] Exemplary Embodiment 1: Component 100 comprising an LED flip chip 10 having a conversion element 20 for cool white application. Using an alkoxy-functionalized polyorganosiloxane resin as a precursor material, a homogeneous mixture containing nanoSiO2, optionally microSiO2, and phosphor particles 1 comprising one or more yellow-emitting garnet phosphors for generating cold-white light emission is sprayed over the entire cover surface 12 of a flip-chip designed LED semiconductor chip 10 (i.e., all electrical connections 40 for electrical contact are located on the side of the semiconductor chip 10 facing outward from the conversion element 20) or a flip-chip designed LED semiconductor chip wafer, and cured at a maximum of 150°C for several hours. The thickness of the resulting conversion element 20 layer with respect to this chromaticity coordinate is 10 to 100 μm, depending on the exact composition and particle size of the phosphor particles 1. The deposition of the homogeneous mixture can also be done by doctor blade or printing.

[0079] If the conversion element 20 is not provided in the area of ​​the cover surface 12, it can also be partially removed in that area. Alternatively, these areas can be protected with a photoresist, which is also removed after a homogeneous mixture has been deposited and the conversion element 20 has been formed. The conversion element 20 can be surface-coated afterwards with, for example, an optical coating (such as an anti-reflective coating (AR) or a coating to improve color over angle (COA)). Depending on the desired properties, the surface of the conversion element 20 facing outwards from the semiconductor chip 10 can be roughened or smoothed, and the thickness of the conversion element 20 can be readjusted.

[0080] Exemplary Embodiment 2: Component 100 having an LED semiconductor chip 10 having an electrical connection portion 40 on the cover surface 12 and on the side of the semiconductor chip 10 facing outward from the cover surface 12, and a conversion element 20 of the cover surface 12 for applying cool white light. All areas of the cover surface 12 of the semiconductor chip 10 that are maintained without leaving any conversion elements 20, such as bond pads / bars as electrical connection parts 40 for electrical connections on the cover surface 12 of the semiconductor chip 10, and optionally saw marks 41 on the cover surface 12 of the semiconductor chip 10, and optionally dark non-luminescent areas, are protected by photoresist. Next, a homogeneous mixture containing an alkoxy-functionalized polyorganosiloxane resin as a precursor material, nanoSiO2, optionally microSiO2, and phosphor particles 1 containing one or more yellow luminescent garnet phosphors for producing cold white light emission, is deposited on the cover surface 12 of the LED semiconductor chip 10 or LED semiconductor chip wafer by doctor blade method or printing and cured at a maximum of 120°C for 1 hour. After removing the photoresist, the resulting conversion elements 20 can be post-cured again at a high temperature, for example, 220°C. The thickness of the layer of this chromaticity coordinate conversion element is 10 to 100 μm, depending on the exact composition and particle size of the phosphor particles 1. Homogeneous mixtures can also be sprayed.

[0081] Alternatively, the cover surface 12 could be completely coated with a homogeneous mixture, which could then be combined with the partial removal of the conversion element 20.

[0082] The conversion element 20 can be surface-coated afterwards with, for example, an optical coating (such as an anti-reflective coating (AR) or a coating to improve color over angle (COA)). Depending on the desired characteristics, the surface of the conversion element 20 facing outwards from the semiconductor chip 10 can be rough or smooth, and the thickness of the conversion element 20 can be readjusted.

[0083] Exemplary Embodiment 3: Component 100 having an LED semiconductor chip 10 having an electrical connection portion 40 on the cover surface 12 and on the side of the semiconductor chip 10 facing outward from the cover surface 12, and a conversion element 20 on the cover surface 12 for the application of orange (amber). This component is manufactured in the same manner as in Exemplary Embodiment 2, but using an amber-colored phosphor mixture (phosphor particles 1 that emit green and red light). The thickness of this color coordinate conversion layer is 30 to 150 μm, depending on the exact composition and particle size of the phosphor particles.

[0084] The conversion element 20 can be surface-coated later with, for example, an optical coating (such as an anti-reflective coating (AR)). Depending on the desired characteristics, the surface of the conversion element 20 facing outward from the semiconductor chip 10 can be rough or smooth, and the thickness of the conversion element 20 can be readjusted.

[0085] Exemplary Embodiment 4: Component 100 comprising an LED semiconductor chip 10 having an electrical connection part 40 only on the cover surface 12 having a conversion element 20 for warm white application. The component is manufactured in the same manner as in Exemplary Embodiment 3, but comprises a different type of chip with respect to the electrical connection portion 40 and a warm white phosphor mixture containing one or more different green and red emitting phosphor particles 1. The thickness of the layer of the conversion element 20 for this chromaticity coordinate is 20 to 120 μm, depending on the exact composition and particle size of the phosphor particles 1.

[0086] The conversion element 20 can be surface-coated afterwards with, for example, an optical coating (such as an anti-reflective coating (AR) or a coating to improve color over angle (COA)). Depending on the desired characteristics, the surface of the conversion element 20 facing outwards from the semiconductor chip 10 can be rough or smooth, and the thickness of the conversion element 20 can be readjusted.

[0087] The subsequent surface coating may also be a multi-coating, meaning that multiple identical or different coatings can be applied to the conversion element 20.

[0088] The features and exemplary embodiments described in relation to 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 relation to the figures may have additional features, such as those described in the summary section, either alternatively or additionally.

[0089] The present invention is not limited by the description based on exemplary embodiments. Rather, any new features and any combination of features, including any combination of features of the claims, are included in the present invention even if the feature or combination itself is not expressly described in the claims or exemplary embodiments.

[0090] This patent application claims priority to German Patent Application No. 102021131112.8, the disclosures of which are incorporated herein by reference. [Explanation of symbols]

[0091] 1. Phosphorescent particles 5 Matrix Materials 10 Semiconductor Chips 11 Radiation exit plane 12 Cover surface 15 Side view of a semiconductor chip 20 transformation elements 21 Support surface 25 Aspects of the Transformation Elements 26 Cross-sectional area of ​​the transformation element 30 potting 40 Connection part 41 Saw marks 42 Boundary Region 100 components

Claims

1. A radiation-emitting component (100), A semiconductor chip (10) that emits electromagnetic radiation in a first wavelength range from a radiation outlet surface (11) during operation, A conversion element (20) on the cover surface (12) of the semiconductor chip (10) including the radiation exit surface (11), wherein the conversion element (20) comprises a matrix material (5) and phosphor particles (1) embedded in the matrix material (5), and the phosphor particles (1) convert electromagnetic radiation in the first wavelength range into electromagnetic radiation in the second wavelength range, The conversion element (20) has a support surface (21) that is equal to or smaller than the cover surface (12) of the semiconductor chip (10), and the support surface (21) is in direct contact with the cover surface (12) of the semiconductor chip (10) without any gaps. The conversion element (20) has a tapered cross-sectional region (26) whose width continuously decreases from the support surface (21) toward the side of the conversion element (20) opposite to the semiconductor chip (10), or the conversion element (20) has a tapered cross-sectional region (26) whose width continuously decreases from the side of the conversion element (20) opposite to the semiconductor chip (10) toward the support surface (21), The conversion element (20) has a side surface (25) with rounded corners when viewed from above, and the solid content of the conversion element (20) is 45% by volume or more, and is a radiation-emitting component (100).

2. The radiation-emitting component (100) according to claim 1, wherein the solid content of the conversion element (20) is 50% by volume or more.

3. The radiation-emitting component (100) according to claim 1 or 2, wherein the solid content is formed by solid particles that are up to 100% phosphor particles.

4. The radiation-emitting component (100) according to claim 3, wherein the phosphorescent particles are partially replaced by unconverted microparticles and / or unconverted nanoparticles.

5. The radiation-emitting component (100) according to claim 4, wherein the support surface (21) is equal to or smaller than the radiation outlet surface (11).

6. The radiation-emitting component (100) according to claim 1 or 2, wherein the semiconductor chip (10) has a side surface (15), and the conversion element (20) is not provided on the side surface (15).

7. The radiation-emitting component (100) according to claim 1 or 2, wherein the conversion element (20) has a side surface (25) having an average roughness of less than 2 μm and / or is free from cutting marks.

8. The radiation-emitting component (100) according to claim 1 or 2, wherein the conversion element (20) is deposited only in a portion of the semiconductor chip (10).

9. The radiation-emitting component (100) according to claim 1 or 2, wherein the conversion element (20) is not provided in the edge region of the cover surface (12) of the semiconductor chip (10), and the width of the edge region is selected from a range of 10 μm to 12 μm.

10. The radiation-emitting component (100) according to claim 1 or 2, wherein the thickness of the conversion element (20) is 150 μm or less and / or 10 μm or more.

11. The radiation-emitting component (100) according to claim 1 or 2, wherein the organic content of the matrix material (5) is less than 40% by weight.

12. The matrix material (5) has a Shore D hardness greater than 50, the radiation-emitting component (100) according to claim 1 or 2.

13. The radiation-emitting component (100) according to claim 1 or 2, wherein the matrix material (5) is a three-dimensional crosslinked polyorganosiloxane.

14. The radiation-emitting component (100) according to claim 13, wherein the three-dimensional crosslinked polyorganosiloxane is prepared from a precursor material containing an alkoxy-functionalized polyorganosiloxane resin.

15. The radiation-emitting component (100) according to claim 1 or 2, further comprising a connection portion (40) for electrical contact, wherein the connection portion (40) is located on the side of the semiconductor chip (10) opposite to the radiation outlet surface (11), or the connection portion (40) is located on the side of the semiconductor chip (10) facing the radiation outlet surface (11), or the connection portion (40) is located on the side of the semiconductor chip (10) opposite to the radiation outlet surface (11) and on the side of the semiconductor chip (10) facing the radiation outlet surface (11).

16. A method for manufacturing a radiation-emitting component (100), - A step of providing at least one semiconductor chip (10) that emits electromagnetic radiation in a first wavelength range from a radiation outlet surface (11) when in operation, - A step of directly depositing a precursor material in which phosphor particles (1) that convert electromagnetic radiation in the first wavelength range to electromagnetic radiation in the second wavelength range are embedded, onto at least one region of the cover surface (12) of the semiconductor chip (10), including the radiation exit surface (11). - A step of curing the precursor material to form a conversion element (20) comprising a matrix material (5) and phosphor particles (1) embedded in the matrix material (5), wherein the conversion element (20) has a support surface (21) that is equal to or smaller than the cover surface (12) of the semiconductor chip (10), and the support surface (21) is in direct, gapless contact with the cover surface (12) of the semiconductor chip (10), the forming step, The precursor material is structured during deposition, and the conversion element (20) has a tapered cross-sectional region (26) whose width continuously decreases from the support surface (21) in the direction opposite to the semiconductor chip (10) of the conversion element (20), or the conversion element (20) has a tapered cross-sectional region (26) whose width continuously decreases from the side opposite to the semiconductor chip (10) of the conversion element (20) in the direction toward the support surface (21), The method wherein the conversion element (20) has a side surface (25) with rounded corners when viewed from above, and the solid content of the conversion element (20) is 45% by volume or more.

17. The method according to claim 16, wherein the curing is performed at a temperature of 220°C or lower.

18. The method according to claim 16 or 17, wherein a plurality of semiconductor chips (10) are provided, and the precursor material is individualized after deposition and curing.

19. The method according to claim 16 or 17, wherein the thickness and shape of the conversion element (20) are adjusted during the deposition and / or curing of the precursor material.

20. The method according to claim 16 or 17, wherein the precursor material is crosslinked three-dimensionally during curing.

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