Optoelectronic component and method for producing an optoelectronic component

Abstract

The invention relates to an optoelectronic component comprising an optoelectronic semiconductor chip having an emission surface, and comprising an optical element. The optical element has a first portion made of a first material, a second portion made of a second material, and a third portion made of a third material. The first portion is adjacent to the emission surface. The second portion is adjacent to the first portion. The third portion is adjacent to the second portion. The third portion is larger than the first portion in a direction parallel to the emission surface. A refractive index of the first material is greater than a refractive index of the second material. A refractive index of the third material is greater than the refractive index of the second material.

Description

[0001] 2024PF00802 1

[0002] OPTOELECTRONIC COMPONENT AND METHOD FOR MANUFACTURING AN OPTOELECTRONIC COMPONENT

[0003] DESCRIPTION

[0004] The present invention relates to an optoelectronic component and a method for manufacturing an optoelectronic component.

[0005] This patent application claims priority over German patent application DE 10 2024 128 604 . 0, the disclosure content of which is hereby incorporated by reference.

[0006] Optoelectronic components with optoelectronic semiconductor chips are known from the prior art. It is known to form optical elements of such optoelectronic components by forming processes.

[0007] One object of the present invention is to provide an optoelectronic component. Another object of the present invention is to provide a method for manufacturing an optoelectronic component. These objects are achieved by an optoelectronic component and by a method for manufacturing an optoelectronic component with the features of the independent claims. Various embodiments are specified in the dependent claims.

[0008] An optoelectronic device comprises an optoelectronic semiconductor chip with an emission surface and an optical element. The optical element has a first section made of a first material, a second section made of a second material, and a third section made of a third material. The first section is adjacent to the emission surface. The second section is adjacent to the first section. The third section is adjacent to the second section. The refractive index of the first material is greater than the refractive index of the second material. A 2024PF00802 2

[0009] The refractive index of the third material is greater than the refractive index of the second material.

[0010] Because the optical element of this optoelectronic component has several sections with different refractive indices, it can advantageously achieve particularly strong light shaping. Furthermore, because the sections of the optical element are directly adjacent to one another, it can be manufactured particularly simply and cost-effectively.

[0011] In one variant of the optoelectronic component, the first interface formed between the first and second sections is spherical. This allows light emitted from the optoelectronic semiconductor chip to pass advantageously from the first section into the second section of the optical element with no or only minimal reflection.

[0012] In one variant of the optoelectronic component, the center of the sphere of the first interface lies within the emission surface. This advantageously ensures that light emitted from the emission surface of the optoelectronic component strikes the spherical first interface essentially perpendicularly and is therefore not reflected, or only to a minimal extent, at the first interface. Furthermore, refraction of light at the first interface is then advantageously either absent or minimal.

[0013] In one variant of the optoelectronic component, the first section is larger than the emission surface in a direction parallel to it. This advantageously allows light emitted from all areas of the emission surface to strike the first interface between the first and second sections of the optical element at a small angle. 2024PF00802 3

[0014] The third section is larger than the first section in a direction parallel to the emission surface. Advantageously, this allows light traveling at an oblique angle through the first section of the optical element to reach the third section of the optical element.

[0015] In one variant of the optoelectronic component, a second interface formed between the second and third sections is concave, planar, or convex. This design flexibility advantageously allows the imaging properties of the optical element to be optimized for a specific application.

[0016] In one variant of the optoelectronic component, a third interface formed between the third section and the surroundings of the optical element is spherical. Advantageously, this allows the light exiting the optical element to be focused at the third interface.

[0017] In one variant of the optoelectronic component, the first and third sections do not touch each other. This ensures that light emitted by the optoelectronic semiconductor chip passes from the first section first into the second section and only then into the third section, undergoing a change in refractive index at each stage. This advantageously enables effective light shaping by the optical element.

[0018] In one variant of the optoelectronic component, the refractive index of the first material and / or the refractive index of the third material is greater than 1.5. A high refractive index of the first material advantageously results in effective extraction of light emitted by the optoelectronic semiconductor chip at the emission surface of the optoelectronic semiconductor chip. A high refractive index of the third material advantageously results in effective refraction of light at the interfaces between the second and third sections and between the third section and the surroundings of the optical element.

[0019] In one variant of the optoelectronic component, the refractive index of the second material is below 1.45, and in particular even below 1.4. Advantageously, this results in a distinct jump in the refractive index at the boundaries between the first section, the second section, and the third section of the optical element.

[0020] In one variant of the optoelectronic component, the first and third materials are identical. This advantageously allows for simple and cost-effective fabrication of the optical element of this optoelectronic component. Furthermore, the first and third materials also have the same coefficients of thermal expansion, which minimizes thermal stresses in the optical element.

[0021] In one variant of the optoelectronic component, the optoelectronic semiconductor chip is arranged on the top side of a substrate. The substrate can, for example, be used for electrical contact with the optoelectronic semiconductor chip. The substrate can also simultaneously serve as a support for the optical element.

[0022] In one variant of the optoelectronic component, the optical element has a base section that adjoins the top of the substrate. This advantageously allows for simple and cost-effective manufacturing of the optical element.

[0023] A method for fabricating an optoelectronic device comprises steps for providing an optoelectronic semiconductor chip with an emission surface, for forming a first 2024PF00802 5 adjacent to the emission surface

[0024] section of an optical element made of a first material in a first forming process, to form a second section of the optical element adjacent to the first section made of a second material in a second forming process, wherein a refractive index of the first material is greater than a refractive index of the second material, and to form a third section of the optical element adjacent to the second section made of a third material in a third forming process, wherein a refractive index of the third material is greater than the refractive index of the second material.

[0025] Advantageously, this method enables the simple and cost-effective production of an optoelectronic component of the aforementioned type.

[0026] In one variant of the process, the first, second, and / or third forming processes are compression molding processes. Compression molding advantageously allows for the simple and cost-effective production of the optical element sections of the optoelectronic component.

[0027] In one variant of the process, the first, second, and third forming processes are each carried out using separate forming tools. A hardening process can be performed between each of the individual forming processes. Advantageously, this method enables the simple and cost-effective production of the optical element of the optoelectronic component.

[0028] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the drawings. These drawings show, in each case, a schematic representation. 2024PF00802 6

[0029] Fig. 1 shows a first variant of an optoelectronic component;

[0030] Fig. 2 shows a second variant of an optoelectronic component; and

[0031] Fig. 3 shows a third variant of an optoelectronic component.

[0032] Fig. 1 shows a schematic cutaway side view of a first variant of an optoelectronic component 10. The optoelectronic component 10 is configured to emit light, for example visible light or light from the infrared or ultraviolet spectral range. The optoelectronic component 10 can be used, for example, for illumination, and in particular, for example, for illumination in combination with a sensor application.

[0033] The optoelectronic component 10 has a substrate 100 with a top surface 101. In the example shown, the top surface 101 of the substrate 100 is flat. Alternatively, the top surface 101 could also have a textured surface. The substrate 100 could, for example, be a ceramic substrate or a printed circuit board. Metallizations forming electrical conductors and electrical contact surfaces can be arranged on the top surface 101 of the substrate 100. The substrate 100 can also have electrical through-holes.

[0034] The optoelectronic component 10 further comprises an optoelectronic semiconductor chip 200 with an emission surface 201. The optoelectronic semiconductor chip 200 is configured to emit light from its emission surface 201. The light emitted by the optoelectronic semiconductor chip 200 can, for example, have a wavelength from the visible spectral range, the infrared spectral range, or the ultraviolet spectral range. The 2024PF00802 7 optoelectronic semiconductor chip 200 can, for example, be a light-emitting diode chip (LED chip).

[0035] The optoelectronic semiconductor chip 200 is arranged on the top surface 101 of the carrier 100 such that the emission surface 201 of the optoelectronic semiconductor chip 200 faces away from the top surface 101 of the carrier 100. The optoelectronic semiconductor chip 200 can be electrically contacted via conductor tracks and contact surfaces arranged on the top surface 101 of the carrier 100 such that the optoelectronic semiconductor chip 200 can be subjected to electrical voltage and electrical current.

[0036] The optoelectronic component 10 further comprises an optical element 300. The optical element 300 is designed to shape the light emitted by the optoelectronic semiconductor chip 200 such that a desired light distribution results in a target area illuminated by the optoelectronic component 10. In particular, the optical element 300 can be configured such that a large proportion of the light emitted by the optoelectronic semiconductor chip 200 is emitted into a narrow solid angle region around a direction 211 perpendicular to the emission surface 201 of the optoelectronic semiconductor chip 200. The optical element 300 can, for example, be configured such that a top-hat light distribution results in the illuminated target area.

[0037] The optical element 300 comprises a first section 310, a second section 320, and a third section 330. The first section 310 contains a first material 315. The second section 320 contains a second material 325. The third section 330 contains a third material 335. The first material 315, the second material 325, and the third material 335 can, for example, be silicones. The first material 315 and the third material 335 can be the same. However, the first material 315 and the third material 335 can also be different materials.

[0038] It is advantageous if the coefficients of thermal expansion of the first material 315, the second material 325, and the third material 335 differ as little as possible from one another. In this case, the first section 310, the second section 320, and the third section 330 of the optical element 300 exhibit similar changes in size under temperature changes, resulting in only small thermo-mechanical stresses in the optical element 300.

[0039] The first material 315 of the first section 310, the second material 325 of the second section 320, and the third material 335 of the third section 330 each have optical refractive indices. The refractive index of the first material 315 is greater than the refractive index of the second material 325. The refractive index of the third material 335 is also greater than the refractive index of the second material 325. Thus, the refractive index of the second material 325 is less than the refractive index of the first material 315 and less than the refractive index of the third material 335. The refractive index of the first material 315 and the refractive index of the third material 335 can, for example, be greater than 1.5. The refractive index of the second material 325 can, for example, be less than 1.45 or even less than 1.4.

[0040] The first section 310 of the optical element 300 borders the emission surface 201 of the optoelectronic semiconductor chip 200. In a lateral direction 210 oriented parallel to the emission surface 201, the first section 310 is larger than the emission surface 201, such that the first section 310 extends beyond and projects beyond the emission surface 201 in the lateral direction 210. Thus, the emission surface 201 is completely covered by the first section 310 of the optical element 300. 2024PF00802 9

[0041] Light emitted from the optoelectronic semiconductor chip 200 can pass through the emission surface 201 into the first section 310 of the optical element 300. The comparatively high refractive index of the first material 315 of the first section 310 supports the extraction of light from the optoelectronic semiconductor chip 200.

[0042] In the example shown in Fig. 1, the optical element 300 additionally comprises a bottom section 340, which has the same material 315 as the first section 310. The bottom section 340 borders the top surface 101 of the carrier 100 in the vicinity of the optoelectronic semiconductor chip 200 and is formed contiguously with the first section 310.

[0043] The second section 320 of the optical element 300 is arranged in a perpendicular direction 211 above the first section 310 and borders the first section 310. In Fig.

[0044] In the example shown, the second section 320 also borders the floor section 340.

[0045] A first interface 350 is formed in the contact area between the first section 310 and the second section 320 of the optical element 300. Light emitted from the optoelectronic semiconductor chip 200 can pass from the first section 310 into the second section 320 of the optical element 300 at the first interface 350. In doing so, the light passes from the first material 315 into the second material 325, which has a lower refractive index.

[0046] In the example shown in Fig. 1, the first interface 350 is convex from the perspective of the first section 310. This allows for converging refraction of light at the first interface 350. Furthermore, this can reduce or prevent total internal reflection at the first interface 350. 2024PF00802 10

[0047] The first interface 350 can, for example, be spherical. In this case, it is advantageous if a center point 355 of the spherically shaped first interface 350 lies in or near the emission surface 201. A radius 356 of the spherically shaped first interface 350 can be such that the first section 310 of the optical element 300 is larger in the lateral direction 210 than the emission surface 201 of the optoelectronic semiconductor chip 200.

[0048] The third section 330 of the optical element 300 is arranged in a perpendicular direction 211 above the second section 320 and borders the second section 320. A second interface 360 ​​is formed in the contact area between the second section 320 and the third section 330. In the example of the optoelectronic component 10 shown in Fig. 1, the second interface 360 ​​is planar and oriented parallel to the emission surface 201 of the optoelectronic semiconductor chip 200.

[0049] Light emitted from the optoelectronic semiconductor chip 200 can pass from the second section 320 into the third section 330 of the optical element 300 at the second interface. In doing so, the light passes from the second material 325 of the second section 320 into the third material 335 of the third section 330, which has a higher refractive index. Thus, converging refraction can occur when the light passes through the second interface 360.

[0050] A third interface 370 is formed between the third section 330 of the optical element 300 and an environment of the optical element 300, i.e., on an outer surface of the optical element 300. At the third interface 370, light emitted from the third section 330 of the optical element 300 by the optoelectronic semiconductor chip 200 can escape into the environment of the optical element 300. In doing so, the light from the third material 335 of the third 2024PF00802 11

[0051] Section 330 of the optical element 300 opens into the surrounding medium, for example air, which may have a lower refractive index than the third material 335. Thus, light refraction can also occur when passing through the third interface 370. In the example shown in Fig. 1, the third interface 370 is convex from the perspective of the third section 330, so that converging light refraction can occur.

[0052] The third boundary surface 370 can, for example, be spherical. The center of the sphere 375 of the spherically shaped third boundary surface 370 can, for example, be located in or near the second boundary surface 360.

[0053] In the example shown in Fig. 1, the radius 376 of the spherically formed third boundary surface 370 is so large that the third section of the optical element 300 completely covers the second section 320 of the optical element 300, and the third section 330 is larger than the first section 310 in the lateral direction 210 parallel to the emission surface 201.

[0054] The first section 310 and the third section 330 of the optical element 30 do not touch each other, so that light emitted by the optical element 300 always passes from the first section 310 first into the second section 320 and only then into the third section 330.

[0055] To manufacture the optoelectronic component 10, the optoelectronic semiconductor chip 200 is first provided and positioned on the top surface 101 of the carrier 100. Subsequently, the first section 310 of the optical element 300, adjacent to the emission surface 201, is formed from the first material 315 in a first forming process. Then, the second section 320 of the optical element 300, adjacent to the first section 310, is formed from the second material 325 in a second forming process. Finally, the third section 320, adjacent to the second section 320, is formed from the second material 325.

[0056] Section 330 of the optical element 300 is formed in a third forming process from the third material 335.

[0057] Thus, the optical element 300 of the optoelectronic component 10 is manufactured in three separate, sequential forming processes. The first, second, and third forming processes can each be, for example, compression molding. The first, second, and third forming processes each take place in separate molds.

[0058] After each forming process, a further step can be carried out to harden the respective formed section 310, 320, 330 of the optical element 300.

[0059] The bottom section 340 is formed together with the first section 310 of the optical element 300 in the first forming process. This can facilitate the simultaneous production of multiple identical optoelectronic components 10. Alternatively, the bottom section 340 can be omitted. In this case, the second section 320 borders directly on the top surface 101 of the carrier 100 in the vicinity of the first section 310.

[0060] The optical element 300 produced in this way can be described as monolithic, since the first section 310, the second section 320, and the third section 330 of the optical element 300 are directly adjacent to one another. It is advantageous if the optical element 300 has no air gaps whatsoever.

[0061] Fig. 2 shows a schematic sectional side view of a second variant of the optoelectronic component 10. Fig. 3 shows a schematic sectional side view of a third variant of the optoelectronic component 10. The variants of the optoelectronic component 10 shown in Figs. 2 and 3 correspond to the first variant shown in Fig. 1, except for the differences described below.

[0062] Variant of the optoelectronic component 10. Thus, the above description of the first variant of the optoelectronic component 10 and the method for its manufacture also applies to the variants of the optoelectronic component 10 shown in Figs. 2 and 3, except for the deviations described below.

[0063] In the variant of the optoelectronic component 10 shown in Fig. 2, a section of the second interface 360 ​​between the second section 320 and the third section 330 of the optical element 300 is convex from the perspective of the second section 320. The convex section of the second interface 360 ​​is arranged centrally above the emission surface 201 of the optoelectronic semiconductor chip 200 and the first interface 350.

[0064] The convex section of the second interface 360 ​​can, for example, be spherical. It is advantageous if the radius 366 of the spherically shaped section of the second interface 360 ​​is larger than the radius 356 of the spherically shaped first interface 350. A center point 365 of the spherically shaped second section 360 is advantageously located on or near a central axis of the optoelectronic component 10.

[0065] In the variant of the optoelectronic component 10 shown in Fig. 3, a section of the second interface 360 ​​between the second section 320 and the third section 330 of the optical element 300 is concave from the perspective of the second section 320. In the example shown in Fig. 3, the entire second interface 360 ​​is concave. The concave section of the second interface 360 ​​can, for example, be spherically shaped. In the example shown, the radius 366 of the spherically shaped section of the second interface 360 ​​is larger than the radius 356 of the spherically shaped first interface 350. The center point 365 of the spherically shaped 2024PF00802 14

[0066] The section of the second boundary surface 360 ​​lies on or near the central axis of the optoelectronic component 10.

[0067] The different designs of the second interface 360 ​​in the variants of the optoelectronic component 10 shown in Figures 1, 2, and 3 result in different light shapes due to varying degrees of refraction at the second interface 360. By appropriately selecting the shape of the second interface 360, the light distribution of the light emitted by the optoelectronic component 10 can be adapted to a specific application.

[0068] The invention has been illustrated and described in more detail with reference to preferred embodiments. However, the invention is not limited to the disclosed examples. Other variations can be derived by a person skilled in the art.

[0069] 2024PF00802 15

[0070] REFERENCE MARK LIST

[0071] 10 optoelectronic component

[0072] 100 carriers

[0073] 101 Top

[0074] 200 optoelectronic semiconductor chips

[0075] 201 emission area

[0076] 210 lateral direction

[0077] 211 vertical direction

[0078] 300 optical elements

[0079] 310 first section

[0080] 315 first material

[0081] 320 second section

[0082] 325 second material

[0083] 330 third section

[0084] 335 third material

[0085] 340 floor section

[0086] 350 first boundary surface

[0087] 355 Center point

[0088] 356 radius

[0089] 360 second boundary surface

[0090] 365 Center

[0091] 366 radius

[0092] 370 third boundary surface

[0093] 375 Center point

[0094] 376 radius

Claims

2024PF00802 16 PATENT CLAIMS 1. Optoelectronic device (10) comprising an optoelectronic semiconductor chip (200) with an emission surface (201) and an optical element (300), wherein the optical element (300) comprises a first section (310) made of a first material (315), a second section (320) made of a second material (325) and a third section (330) made of a third material (335), wherein the first section (310) is connected to the emission surface (201) adjoins, the second section (320) adjoins the first section (310) and the third section (330) adjoins the second section (320), wherein the third section (330) is larger than the first section (310) in a direction (210) parallel to the emission surface (201), wherein a refractive index of the first material (315) is larger than a refractive index of the second material (325) and a refractive index of the third material (335) is larger than the refractive index of the second material (325).

2. Optoelectronic component (10) according to claim 1, wherein a first interface (350) formed between the first section (310) and the second section (320) is spherically shaped.

3. Optoelectronic component (10) according to claim 2, wherein a sphere center (355) of the first interface (350) is located in the emission surface (201).

4. Optoelectronic component (10) according to one of the preceding claims, wherein the first section (310) is larger than the emission area (201) in a direction (210) parallel to the emission area (201). 2024PF00802 17 5. Optoelectronic component (10) according to one of the preceding claims, wherein a second interface (360) formed between the second section (320) and the third section (330) is concave, planar or convex.

6. Optoelectronic component (10) according to one of the preceding claims, wherein a third interface (370) formed between the third section (330) and a surrounding area of ​​the optical element (300) is spherically shaped.

7. Optoelectronic component (10) according to one of the preceding claims, wherein the first section (310) and the third section (330) do not touch each other.

8. Optoelectronic component (10) according to one of the preceding claims, wherein the refractive index of the first material (315) and / or the refractive index of the third material (335) is greater than 1, 5.

9. Optoelectronic component (10) according to one of the preceding claims, wherein the refractive index of the second material (325) is below 1.45, in particular below 1.

4.

10. Optoelectronic component (10) according to one of the preceding claims, wherein the first material (315) and the third material (335) are the same.

11. Optoelectronic component (10) according to one of the preceding claims, wherein the optoelectronic semiconductor chip (200) is arranged on a top surface (101) of a carrier (100). 2024PF00802 18 12. Optoelectronic component (10) according to one of the preceding claims, wherein the optical element (300) has a bottom section (340) adjacent to the top (101) of the carrier (100).

13. Method for manufacturing an optoelectronic device (10) comprising the following steps: - Providing an optoelectronic semiconductor chip (200) with an emission area (201) ; - Forming a first section (310) of an optical element (300) adjacent to the emission surface (201) from a first material (315) in a first forming process; - Forming a second section (320) of the optical element (300) adjacent to the first section (310) from a second material (325) in a second forming process, wherein a refractive index of the first material (315) is greater than a refractive index of the second material (325) ; - Forming a third section (330) of the optical element (300) adjacent to the second section (320) from a third material (335) in a third forming process, wherein a refractive index of the third material (335) is greater than the refractive index of the second material (325).

14. Method according to claim 13, wherein the first forming process, the second forming process and / or the third forming process are compression molding processes.

15. Method according to one of claims 13 and 14, wherein the first forming process, the second forming process and the third forming process are each carried out using separate forming tools.

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