Process for Manufacturing Optoelectronic Components and Optoelectronic Component

Abstract

In an embodiment a method includes providing a plurality of radiation-emitting semiconductor chips configured to emit primary radiation of a first wavelength range, applying a converter on the plurality of radiation-emitting semiconductor chips, the converter configured to emit secondary radiation of a second wavelength range, applying a mirror layer sequence arranged downstream of the converter, the mirror layer sequence configured to reflect the primary radiation and transmit the secondary radiation and singulating the plurality of radiation-emitting semiconductor chips in order to produce optoelectronic components, wherein the converter is applied on the plurality of radiation-emitting semiconductor chips by spray coating, and wherein the mirror layer sequence is applied on the converter by sputtering, atomic layer deposition and/or plasma-enhanced chemical vapor deposition (PECVD).

Claims

1-17. (canceled)

18. A method comprising: providing a plurality of radiation-emitting semiconductor chips configured to emit primary radiation of a first wavelength range; applying a converter on the plurality of radiation-emitting semiconductor chips, the converter configured to emit secondary radiation of a second wavelength range; applying a mirror layer sequence arranged downstream of the converter, the mirror layer sequence configured to reflect the primary radiation and transmit the secondary radiation; and singulating the plurality of radiation-emitting semiconductor chips in order to produce optoelectronic components, wherein the converter is applied on the plurality of radiation-emitting semiconductor chips by spray coating, and wherein the mirror layer sequence is applied on the converter by sputtering, atomic layer deposition and/or plasma-enhanced chemical vapor deposition (PECVD).

19. The method of claim 18, wherein the plurality of radiation-emitting semiconductor chips is provided in a wafer assembly.

20. The method of claim 18, wherein the mirror layer sequence is applied directly on the converter.

21. The method of claim 18, wherein the mirror layer sequence is applied on a carrier, wherein the carrier is arranged downstream of the converter so that the mirror layer sequence is arranged between the converter and the carrier.

22. The method of claim 18, wherein the converter is cured after applying the mirror layer sequence.

23. The method of claim 18, wherein the secondary radiation of the converter is red light.

24. The method of claim 18, wherein the converter is configured as a layer and has a thickness of between at least 50 micrometers and at most 100 micrometers, inclusive.

25. The method of claim 18, wherein the mirror layer sequence has a thickness of at most 10 micrometers.

26. The method of claim 18, wherein the mirror layer sequence comprises a plurality of layers with respectively different refractive indices.

27. An optoelectronic component comprising: a radiation-emitting semiconductor chip configured to emit primary radiation of a first wavelength range; a conversion element configured to emit secondary radiation of a second wavelength range; and a dielectric mirror, wherein the dielectric mirror is configured to reflect the primary radiation and transmit the secondary radiation, wherein the dielectric mirror is arranged downstream of the semiconductor chip, wherein side faces of the dielectric mirror and of the conversion element comprise tracks of a singulation process, and wherein a color locus of the emitted radiation of the optoelectronic component lies in the range of red light with a color purity greater than or equal to 80%.

28. The optoelectronic component of claim 27, wherein the conversion element comprises a matrix material and a phosphor.

29. The optoelectronic component of claim 27, wherein the secondary radiation of the conversion element is red light.

30. The optoelectronic component of claim 27, wherein the optoelectronic component is configured to emit predominantly the secondary radiation.

31. The optoelectronic component of claim 27, wherein the color locus of the emitted radiation of the optoelectronic component lies in a color rectangle having corners at coordinates (0.655, 0.337), (0.658, 0.337), (0.655, 0.339) and (0.658, 0.339) in a xy CIE standard color system.

32. The optoelectronic component of claim 27, wherein the conversion element is arranged downstream of the semiconductor chip and between the semiconductor chip and the dielectric mirror.

33. The optoelectronic component of claim 27, wherein the conversion element is configured as a layer and has a thickness of between at least 50 micrometers and at most 100 micrometers, inclusive.

34. The optoelectronic component of claim 27, wherein the dielectric mirror has a thickness of at most 10 micrometers.

35. The optoelectronic component of claim 27, wherein the dielectric mirror comprises a plurality of layers with respectively different refractive indices.

36. The optoelectronic component of claim 27, further comprising a carrier element arranged on the dielectric mirror.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Further advantageous embodiments and refinements of the method for producing optoelectronic components and of the optoelectronic component may be found in the exemplary embodiments described below in connection with the figures, in which:

[0057] FIGS. 1 and 2 show schematic sectional representations of various method stages of a method for producing optoelectronic components, respectively according to an exemplary embodiment;

[0058] FIG. 3 shows a cross section of a light-microscopy image of a comparative example of an optoelectronic component;

[0059] FIG. 4 shows a cross section of a light-microscopy image of an optoelectronic component according to one exemplary embodiment;

[0060] FIG. 5 shows a schematic sectional representation of a comparative example of an optoelectronic component and a schematic sectional representation of an optoelectronic component according to one exemplary embodiment;

[0061] FIG. 6 shows a detail of an xy CIE standard color system;

[0062] FIG. 7 shows a luminous flux comparison at 350 mA and 1A of a comparative example of an optoelectronic component and of an optoelectronic component according to one exemplary embodiment; and

[0063] FIG. 8 shows a schematic dependency of the brightness on the color purity of a comparative example of an optoelectronic component and a schematic dependency of the brightness on the color purity of an optoelectronic component according to one exemplary embodiment.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0064] Elements which are the same or similar, or which have the same effect, are provided with the same references in the figures. The figures and the size proportions of the elements represented in figures with respect to one another are not to be considered as being true to scale. Rather, individual elements, and in particular layer thicknesses, may be represented exaggeratedly large for improved representability and/or improved understanding.

[0065] In the method for producing optoelectronic components 1 according to the exemplary embodiment of FIG. 1, in a first step a multiplicity of radiation-emitting semiconductor chips .sub.2, which are designed to emit primary radiation of a first wavelength range during operation, are provided. The provision of the multiplicity of radiation-emitting semiconductor chips 2 is carried out in a wafer assembly 12. The wafer assembly 12 is a 6" wafer assembly fully occupied with radiation-emitting semiconductor chips 2 having a size of 1 mm.sup.2.

[0066] In a next step, a converter .sub.3, which is designed for emitting secondary radiation of a second wavelength range, is applied onto the multiplicity of radiation-emitting semiconductor chips .sub.2. The converter 3 is applied surface-wide onto the multiplicity of radiation-emitting semiconductor chips .sub.2. This is carried out still in the wafer assembly 12. That surface of the converter 3 which faces away from the multiplicity of semiconductor chips 2 is configured nonuniformly. The converter 3 is sprayed onto the multiplicity of radiation-emitting semiconductor chips 2 in from one to three sprayed layers.

[0067] The converter 3 comprises a matrix and a phosphor. The phosphor is preferably present in the form of phosphor particles. The converter 3 preferably comprises red phosphor particles. The matrix is for example a silicone, a hybrid material or an epoxide, and is uncured in this step.

[0068] In a further step, a mirror layer sequence 4, which is designed to reflect the primary radiation and transmit the secondary radiation, is applied. The mirror layer sequence 4 is arranged downstream of the converter .sub.3. The mirror layer sequence 4 is arranged surface-wide on the converter .sub.3. The mirror layer sequence 4 is applied on the converter 3 by means of sputtering, atomic layer deposition and/or plasma-enhanced chemical vapor deposition. The mirror layer sequence 4 is in this case applied directly on the converter .sub.3. The mirror layer sequence 4 likewise has an uneven top face.

[0069] The converter 3 is cured after the application of the mirror layer sequence 4.

[0070] Subsequently, the multiplicity of radiation-emitting semiconductor chips .sub.2, the converter 3 and the mirror layer sequence 4 are singulated in order to produce optoelectronic components .sub.1. In this case, sawing is preferably carried out along the edge of the semiconductor chips 2 without thereby damaging the semiconductor chips 2.

[0071] In the exemplary embodiment of FIG. 2, likewise in a first step, a multiplicity of radiation-emitting semiconductor chips .sub.2, which are designed to emit primary radiation of a first wavelength range during operation, are provided. The multiplicity of radiation-emitting semiconductor chips 2 are applied in a wafer assembly 12. The wafer assembly 12 is fully occupied with radiation-emitting semiconductor chips 2 having a size of 1 mm.sup.2.

[0072] Subsequently, a converter .sub.3, which is designed for emitting secondary radiation of a second wavelength range, is applied onto the multiplicity of radiation-emitting semiconductor chips .sub.2. This is likewise carried out here by means of spray coating. The converter 3 comprises a matrix and a phosphor, the phosphors preferably being introduced into the matrix as phosphor particles. The matrix is for example a silicone, a hybrid material or an epoxide, and is uncured in this step.

[0073] In a next step, the mirror layer sequence 4 is vapor-deposited onto a carrier 5 and the carrier 5 is arranged downstream of the converter 3, so that the mirror layer sequence 4 is arranged between the converter 3 and the carrier 5. The carrier 5 comprises, for example, a glass. The mirror layer sequence 4 is for example vapor-deposited onto the carrier 5 at room temperature, and the carrier 5 and the mirror layer sequence 4 are then thinned to a thickness of at most 200 micrometers. After the application of the mirror layer sequence 4 and the carrier 5 onto the converter .sub.3, the converter 3 is cured so that a smooth surface is formed and the mirror layer sequence 4 is connected firmly to the converter .sub.3. The smooth surface of the converter 3 is located on the side facing away from the semiconductor chip .sub.2. Subsequently, the multiplicity of semiconductor chips .sub.2, converter .sub.3, mirror layer sequence 4 and carrier 5 are singulated in order to produce optoelectronic components 1.

[0074] In the light-microscopy image of FIG. 3 of the comparative example 11 of an optoelectronic component, a conversion element 6 applied by means of spray coating is shown on a radiation-emitting semiconductor chip .sub.2. The comparative example 11 is arranged on a surface 13 which comprises electrical contacts. The comparative example 11 does not have a dielectric mirror 7. The spray coating is carried out in at least six sprayed layers. Furthermore, the conversion element 6 is arranged directly on the semiconductor chip .sub.2. The conversion element 6 has a thickness of about 150 micrometers. The phosphor of the conversion element 6 is a red-emitting phosphor.

[0075] In FIG. 4, an optoelectronic component 1 is likewise represented in a cross section of a light-microscopy image according to one exemplary embodiment. The optoelectronic component 1 is arranged on a surface 13, which comprises electrical contacts. In this case, a conversion element 6 is applied on the radiation-emitting semiconductor chip .sub.2. On the conversion element 6, there are a dielectric mirror 7 and a carrier element 10. The phosphor is in this case a phosphor in which the secondary radiation is red light. The conversion element 6 has a thickness of between at least 50 micrometers and 65 micrometers. In particular, the conversion element 6 has a thickness of approximately 56 micrometers. The dielectric mirror 7 has a thickness of at most 10 micrometers. The carrier element 10 has a thickness of at most 200 micrometers.

[0076] FIG. 5 shows a comparison between two schematic sectional representations of an optoelectronic component 1, 11. The left schematic sectional representation shows a comparative example of an optoelectronic component 11, in which a dielectric mirror 7 is not arranged on the conversion element 6.

[0077] The right schematic sectional representation according to an exemplary embodiment shows a radiation-emitting semiconductor chip 2 which emits primary radiation of a first wavelength range during operation, a conversion element 6 which is designed to emit secondary radiation of a second wavelength range, and a dielectric mirror 7, the dielectric mirror 7 being designed to reflect the primary radiation and transmit the secondary radiation. On the dielectric mirror 7, there is furthermore a carrier element 10. The carrier element 10 for example comprises a glass, and may optionally also be omitted. The conversion element 6 comprises a phosphor 9, preferably phosphor particles and a matrix material 8. The difference between the two figures is the thickness of the conversion element 6. The thickness of the conversion element 6 may be configured to be particularly thin in the optoelectronic component 1 described here. The thickness of the conversion element 6 may be reduced by up to more than 60% in comparison with the comparative example 11. This leads to a cost reduction.

[0078] FIG. 6 shows by way of example an xy CIE standard color system. In this case, CIE y is plotted against CIE x. When using the same phosphor in the conversion element 6 of the optoelectronic component 1, 11, the comparative example of the optoelectronic component 11 exhibits a different color locus than the optoelectronic component 1 described here. The color locus of the emitted radiation of the optoelectronic component 1 described here lies in a color rectangle having corners at the coordinates (0.655, 0.337), (0.658, 0.337), (0.655, 0.339) and (0.658, 0.339). The color locus of the comparative example 11 is shifted toward larger CIE x values and smaller CIE y values.

[0079] FIG. 7 represents a comparison between an optoelectronic component 1a and 1b as described here and a comparative example 11a and 11b. Here, a luminous flux comparison is shown at 350 mA and 1A. 1a and 11a are the results of the measurements at 1 A, and 1b and 11b are results of the measurements at 350 mA. The optoelectronic component 1 described here has an approximately 36% higher luminous flux because of the thinner conversion element 6 and the dielectric mirror 7.

[0080] FIG. 8 shows the brightness Φ.sub.v as a function of the color purity p of a comparative example of an optoelectronic component 11 and an optoelectronic component 1 as described here. The comparative example of the optoelectronic component 11 has an enlarged conversion element or an increased concentration of phosphor particles or scattering particles in comparison with the optoelectronic component 1 as described here. For the comparative example of the optoelectronic component 11, this leads to not inconsiderable losses due to reabsorption. The optoelectronic component 1 described here shows scarcely any losses in the brightness Φ.sub.v in comparison with the comparative example 11 for a color purity p of more than 90%. The color purity p is preferably greater than or equal to 92% in the case of full conversion.

[0081] The features and exemplary embodiments described in connection with the figures may be combined with one another according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures may alternatively or additionally comprise further features according to the description in the general part.