METHOD FOR PRODUCING OPTOELECTRONIC SEMICONDUCTOR COMPONENTS
The method integrates miniaturized optical elements into optoelectronic semiconductor components by forming a reflector beyond the light exit surface, addressing the challenge of space-saving design and enabling efficient production for applications like backlighting and time-of-flight sensing.
Patent Information
- Application Number
- DE112019006996
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2019-03-08
- Publication Date
- 2025-07-31
- Estimated Expiration
- 2039-03-08
AI Technical Summary
Existing methods for producing optoelectronic semiconductor components face challenges in achieving efficient and space-saving optical elements, particularly in integrating miniaturized lenses and reflectors, which are crucial for applications like backlighting and time-of-flight sensing.
A method involving the application of a temporary spacer to protect the light exit surface, followed by forming a reflector around the semiconductor chip and spacer, removing the spacer to extend the reflector beyond the exit surface, and integrating an optical element to create a gap, allowing for the incorporation of meta- or microlenses in a compact design.
Enables miniaturized chip-scale packaging with integrated optical elements, facilitating cost-effective and efficient production of optoelectronic components suitable for applications such as backlighting and time-of-flight sensing.
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Abstract
Description
[0001] A method for producing optoelectronic semiconductor components is specified.
[0002] The document DE 10 2015 107 590 A1 relates to a method for mirroring the lateral surfaces of optical components for use in optoelectronic semiconductor bodies and comprises a step A) in which a plurality of optical components are arranged on a carrier, each component having a front side, a back side, and side surfaces running transversely to the front side. In a step B), a sacrificial layer is applied to each component such that the front side of each component is at least partially covered by the sacrificial layer. In a step C), a mirror layer is applied to the components such that the mirror layer at least partially covers the sacrificial layer and all sides of each component not covered by the carrier.In a step D), the sacrificial layer and the mirror layer located thereon are removed from the front side of each component, whereby the mirror layer remains on the remaining sides of the components previously covered by the mirror layer.
[0003] Publication WO 2016 / 066476 A1 is directed to a light-emitting arrangement for generating directed light projections with a sharply defined beam profile. The light from a top-emitting solid-state light source with a reflective side coating is pre-collimated via beam-shaping optics before being passed through a secondary collimation funnel, which collects all light rays with an exit angle that is still too large. By using a thin-film side coating and undersized phosphor layers, chip-scale package dimensions can be achieved. The substrate-level process flow also enables the parallel processing of a large number of components.
[0004] One problem to be solved is to provide a method for producing optoelectronic semiconductor components which comprise an efficient and space-saving optical element.
[0005] This object is achieved, inter alia, by a method for producing optoelectronic semiconductor components according to claim 1. Preferred developments form the subject matter of the dependent claims.
[0006] The method is used to produce an optoelectronic semiconductor component. The optoelectronic semiconductor component is, in particular, a light-emitting diode configured to emit visible light during operation. Alternatively or additionally, the optoelectronic semiconductor component can emit near-ultraviolet radiation and / or near-infrared radiation. Furthermore, the optoelectronic semiconductor component can be a laser component. Furthermore, it is possible for the optoelectronic semiconductor component to be a photodetector or a combined light-emitting and light-receiving element, such as a photosensor.
[0007] The method comprises providing at least one optoelectronic semiconductor chip as a method step. The semiconductor chip or chips is / are a light-emitting diode chip, a laser diode chip, or a photodetector chip. With a plurality of semiconductor chips, all semiconductor chips can be constructed identically, or different types of semiconductor chips can be combined.
[0008] The method comprises applying at least one temporary spacer as a method step. The spacer is designed to temporarily protect a light exit surface of the associated optoelectronic semiconductor chip. For example, the spacer consists of a photoresist. The spacer is no longer present in the finished optoelectronic semiconductor component.
[0009] The method comprises forming a reflector as a method step. The reflector directly borders the optoelectronic semiconductor chip and the temporary spacer in a lateral direction. In particular, the reflector is formed directly on side surfaces of the optoelectronic semiconductor chip and the temporary spacer. Preferably, the reflector completely and / or directly surrounds the optoelectronic semiconductor chip and the temporary spacer in plan view, in particular onto the light exit surface.
[0010] The method includes the removal of the temporary spacer as a process step. This process step is performed after the formation of the reflector. After the spacer is removed, the reflector protrudes beyond the light exit surface. Therefore, the height of the reflector can exceed the height of the optoelectronic semiconductor chip.
[0011] The method comprises applying an optical element to the reflector as a process step. This creates a gap between the light exit surface of the optoelectronic semiconductor chip and a light entry surface of the optical element. Preferably, the optical element completely covers the light exit surface of the optoelectronic semiconductor chip.
[0012] Thus, the process is used to manufacture optoelectronic semiconductor components and comprises the following steps: A) Providing an optoelectronic semiconductor chip, B) Applying a temporary spacer to protect a light exit surface of the optoelectronic semiconductor chip, C) forming a reflector in a lateral direction directly around the optoelectronic semiconductor chip and around the temporary spacer, D) subsequent removal of the temporary spacer so that the reflector extends beyond the light-emitting surface, and E) Applying an optical element to the reflector, so that a gap exists between the light exit surface of the optoelectronic semiconductor chip and a light entry surface of the optical element. Typically, a phosphor layer is applied to a light exit surface of an LED chip, and a reflector frame is formed around the LED chip, with the phosphor covering the reflector frame. To achieve the desired optical properties, a comparatively large external lens must be mounted over such an LED component.
[0013] Using the method described here, for example, a space-saving meta- or microlens can be formed near the light exit surface above the reflector. This allows an optical element to be integrated into the optoelectronic semiconductor component in a space-saving manner.
[0014] This enables miniaturization of CSP with meta- and / or microlenses. CSP stands for "chip-scale package." Furthermore, optical elements such as meta-lenses, micro-lenses, or Fresnel lenses can be used to enable applications for the optoelectronic semiconductor component, such as floor lighting or time-of-flight (ToF) applications. The height of the gap can be adjusted by using different thicknesses of the temporary spacer to achieve the distance required for the advantageous optics. Furthermore, a simplified manufacturing process is enabled; in particular, the optoelectronic semiconductor component can be manufactured in a single assembly. This makes production more cost-effective and faster. Flip chips can be used as optoelectronic semiconductor chips.
[0015] According to at least one embodiment, the optical element is a meta-lens. A meta-lens is a lens made of a meta-material. A meta-material comprises structures such as antennas, capacitors, and / or coils or similar elements that have geometric dimensions smaller than a wavelength for which the optical element is configured. For example, negative refractive indices can be realized with such meta-materials. For example, the meta-material, and thus the meta-lens, comprises split-ring resonators and wires mounted on interlocking foils.
[0016] According to at least one embodiment, the optical element is a microlens or a microlens array. This means that the optical element can be composed of a plurality of microlenses. For example, the individual microlenses can be designed as convex lenses or else as concave lenses. The microlenses can be designed as freeform lenses. The shape of the microlenses is preferably dome-shaped, but cylindrical microlenses can also be used. An average diameter of the microlenses is, for example, at least 10 µm or at least 50 µm and / or at most 500 µm or at most 200 µm or at most 100 µm in a plan view of a top surface of the semiconductor component. For example, the number of microlenses in the optical element is at least 9 or 16 or 25 and / or at most 100,000 or at most 10,000 or at most 1,000 or at most 100.
[0017] According to at least one embodiment, the optical element, viewed in cross-section, is constructed from microprisms. Thus, the optical element can be a Fresnel lens or a lens similar to a Fresnel lens. An average width and / or height of the prisms, viewed in cross-section, is, for example, at least 10 µm or at least 50 µm and / or at most 500 µm or at most 200 µm or at most 100 µm.
[0018] According to at least one embodiment, the optical element is flat. This means that the optical element can be approximated by a plane-parallel plate. Compared to the lateral dimensions, the optical element can be comparatively thin. For example, a quotient of the mean diameter of the optical element and a thickness of the optical element is at least 3, or at least 5, or at least 10. Alternatively or additionally, this quotient is at most 1000, or at most 100, or at most 20.
[0019] According to at least one embodiment, the reflector is manufactured by molding. The reflector preferably comprises a transparent matrix material such as silicone and additionally comprises reflective particles, for example, made of a metal oxide such as titanium dioxide. It is possible for the reflector to be diffusely reflective and / or white in color. Alternatively, the reflector can be based on at least one metal or Bragg reflector and be spectrally reflective. Combinations of spectrally and diffusely reflective components are also possible.
[0020] According to at least one embodiment, the gap is filled with a gas. For example, the gap is filled with a protective gas such as nitrogen or argon. However, the gap is preferably filled with air. Alternatively, the gap can be an evacuated area.
[0021] Process step B) is performed before process step A). This means that the temporary spacer is manufactured before the optoelectronic semiconductor chips are provided. This allows the optoelectronic semiconductor chips to be placed on the respective temporary spacer.
[0022] In process step B), a first carrier is provided. A raw material for the spacer is applied to the first carrier. The raw material is, for example, a photoresist. The first carrier can comprise a first release tape.
[0023] Step B) involves developing the photoresist in spots to define the shape of the temporary spacer. Excess spacer material can then be removed.
[0024] In process step A), the optoelectronic semiconductor chip is mounted on a side of the temporary spacer facing away from the first carrier. The optoelectronic semiconductor chip can be mounted by adhesively bonding the semiconductor chip to the respective spacer. Thus, an adhesive can be located between the spacer and the optoelectronic semiconductor chip. Alternatively, the spacer itself can be adhesive, allowing the optoelectronic semiconductor chip to be placed and temporarily secured on the spacer without the aid of a separate adhesive material.
[0025] According to at least one embodiment, prior to method step C), a second carrier is applied to a lower side of the optoelectronic semiconductor chip. The second carrier may comprise a second release tape. The lower side is opposite the light exit side. Electrical contact surfaces may be present on the lower side. The electrical contact surfaces may consist of one or more metals. The contact surfaces may be pressed into the second carrier, in particular into the second release tape.
[0026] According to at least one embodiment, the first carrier is removed after the second carrier has been applied. This step is preferably performed before process step C).
[0027] According to at least one embodiment, the gap, at least in a region above the light exit surface, is truncated pyramid-shaped or truncated conical, or intermediate between a truncated pyramid and a truncated cone. Otherwise, the gap can be shaped as a cuboid or as a combination of two or more cuboids.
[0028] According to at least one embodiment, a plurality of optoelectronic semiconductor chips are provided in method step A). In method step C), preferably exactly one molded body is formed for all reflectors, so that all optoelectronic semiconductor chips are mechanically integrated in this molded body and connected by it.
[0029] According to one embodiment, in a further process step F), which follows process step E), the molded body is separated into the individual reflectors. Thus, the reflectors and the optoelectronic semiconductor components are produced by separation. The separation is carried out, for example, by sawing or laser cutting.
[0030] According to at least one embodiment, in process step E), the optical elements are applied as an optical film. The optical film is preferably a continuous and coherent layer that covers all optoelectronic semiconductor chips prior to process step F). Furthermore, the molded body can also be partially or completely covered with the optical film.
[0031] According to at least one embodiment, in process step F), the optical film is separated into the optical elements. The separation of the optical film and the molded body can take place in a simultaneous process step or, alternatively, in two consecutive process steps.
[0032] According to at least one embodiment, the gap extends completely through the reflector in a lateral direction. This creates at least one ventilation opening. A gas such as air can pass into and out of the gap through the ventilation opening.
[0033] According to at least one embodiment, a shape of the at least one ventilation opening is defined by a shape of the temporary spacer. This means that the reflector is formed around the temporary spacer, and the temporary spacer can have webs that correspond to a negative shape of the ventilation openings. Thus, after removal of the temporary spacer, both the gaps and the ventilation openings are created.
[0034] According to at least one embodiment, at least two ventilation openings are formed per gap and per semiconductor chip. The two ventilation openings, or at least two of the ventilation openings, can be arranged symmetrically in a plan view of the light exit surface. Axial symmetry or point symmetry can be present with respect to the ventilation openings.
[0035] According to at least one embodiment, the reflector and the optical element are flush with one another around the finished semiconductor components, particularly in the lateral direction. Thus, the optoelectronic semiconductor component can have planar side surfaces consisting of the reflector and the optical element, and optionally additionally of an adhesive between the reflector and the optical element. Thus, the cover surface of the optical semiconductor component can be formed exclusively with the optical element.
[0036] According to at least one embodiment, the thickness of the gap is greater than the thickness of the optoelectronic semiconductor chip. In the present case, the thickness of the gap is preferably at least 0.2 mm or 0.4 mm and / or at most 2 mm or at most 0.7 mm. The thickness of the gap is thus comparatively large.
[0037] According to at least one embodiment, the thickness of the gap is comparatively small. In particular, the thickness of the optoelectronic semiconductor chip is then greater than the thickness of the gap. In this case, the thickness of the gap can be at most 30 µm, at most 50 µm, or at most 100 µm. Alternatively or additionally, the thickness of the gap is at least 2 µm, at least 5 µm, or at least 10 µm.
[0038] According to at least one embodiment, the optoelectronic semiconductor chip is provided with or comprises at least one phosphor. The at least one phosphor is configured to convert the radiation emitted by the light-emitting semiconductor chip into radiation with a different wavelength, in particular with a longer wavelength. Partial or complete wavelength conversion can occur through the at least one phosphor. For example, mixed white light is generated by blue light from the optoelectronic semiconductor chip and yellow light from the phosphor.
[0039] According to at least one embodiment, the reflector completely and directly surrounds the phosphor in the lateral direction, preferably all around the phosphor, as seen in a plan view of the light exit surface. The reflector preferably protrudes beyond the phosphor in a direction away from the lower side of the optoelectronic semiconductor chip. Thus, the gap is preferably located between the phosphor and the optical element.
[0040] A method and an optoelectronic semiconductor component produced thereby are explained in more detail below using examples with reference to the drawings. Elements that are the same in the individual figures are identified by the same reference numerals. However, the relative sizes of the elements are not shown to scale; rather, individual elements may be exaggerated for clarity.
[0041] They show: Fig. 1 to 13 show sectional views of method steps of an embodiment of a method described here; Fig. 14 to 18 are sectional views of method steps of an embodiment of a method described here; Fig. 19 to 31 are sectional views of process steps of a modification of a process not according to the invention; Fig. 32 to 44 Method steps of an embodiment of a method described herein, wherein the Fig. 36 and Fig. 42 top views are and the remaining Fig. 32 to 35, 37 to 41, 43 and 44 are sectional views; Fig. 45 and Fig. 46 schematic plan views of embodiments of optical elements for optoelectronic semiconductor components described here; Fig. 47 a sectional view of an optoelectronic semiconductor chip for optoelectronic semiconductor components described here; and Fig. 48 a modification of an optoelectronic semiconductor component.
[0042] In Fig. 1 to 13, an embodiment of a method for producing optoelectronic semiconductor components 1 is illustrated. According to Fig. 1, a first carrier 61 is provided. The first carrier 61 can be a rigid body or a flexible film.
[0043] According to Fig. 2, a first release tape 71 is applied to the carrier 61. The release tape 71 is, for example, a thermal release tape. Alternatively, the release tape 71 can be a radiation-sensitive release tape. This means that the adhesive properties of the release tape 71 can be reduced by heat and / or radiation.
[0044] In the process step of Fig. 3, a photoresist 33 is applied directly to the first release tape 71. The photoresist 33 may be limited to the first release tape 71. The photoresist 33 may be a negative photoresist or a positive photoresist.
[0045] According to Fig. 4, the photoresist 33 is structured, for example, using a masking technique and an illumination technique not shown. This creates temporary spacers 3. The spacers 3 consist, in particular, of hardened portions of the photoresist 33.
[0046] In Fig. 5 shows that uncured parts of the photoresist 33 are removed so that only the temporary spacers 3 remain on the first release tape 71.
[0047] In the process step of Fig. 6, the optoelectronic semiconductor chips 2 are applied to the sides of the spacers 3 facing away from the first release tape 71. The semiconductor chips 3 are, for example, light-emitting diode chips. A light exit side 20 of the semiconductor chips faces the first release tape 71. A lower side 21 faces away from the first release tape 71.
[0048] On the lower side 21, the semiconductor chips 2 can comprise electrical contact surfaces 26. This means that the semiconductor chips 2 can be flip chips, each of which has electrical contact surfaces 26 on the respective lower side 21.
[0049] In the process step of Fig. 7, a second carrier 62 with a second release tape 72 is provided on the lower sides 21 of the semiconductor chips 2. The second carrier 62 can be a rigid body or a flexible film. The second release tape 72 can have the same adhesive properties as the first release tape 71. Thus, the second release tape can be a thermal release tape or a radiation-sensitive release tape, so that the adhesive properties of the second release tape 72 can be deactivated by heat and / or radiation, in particular by ultraviolet radiation.
[0050] As in all other embodiments, the electrical contact surfaces 26 can touch the second release tape 72. Alternatively, the contact surfaces 26 can be fully or partially pressed into the second release tape 72. Thus, the lower sides 21 of the semiconductor chips 2 can be flush with the second release tape 72 when the electrical contact surfaces 26 are fully pressed into the second release tape 72. Alternatively, the semiconductor chips 2 themselves can be partially pressed into the second release tape 72.
[0051] In Fig. Figure 8 shows that the first carrier 61 and the second carrier 62 have been removed. Thus, the semiconductor chips 2 with the spacers 3 are located on the second carrier 62 with the second release tape 62.
[0052] In the process step of Fig. 9, a molded body 40 is formed. The molded body 40 rests directly against the semiconductor chips 2 and also against the spacers 3 on the side surfaces 22. The molded body 40 is applied directly to the second release tape 72. Depending on how far the semiconductor chips are pressed into the second release tape 72, the molded body 40 can touch the electrical contact surfaces 26 or end at a distance from the contact surfaces 26.
[0053] For example, the molded body 40 is formed by casting. Alternatively, the molded body 40 can also be produced by molding, such as film-assisted molding (FAM).
[0054] The molded body 40 preferably appears white. For example, the molded body 40 consists of a silicone in which reflective titanium dioxide particles are embedded. In a direction away from the second release tape 72 and / or in a direction away from the second carrier 62, the molded body 40 can be flush with the spacers 3.
[0055] In the process step of Fig. 10, the spacers 3 have been removed. This creates gaps 42 above the light exit surfaces 20. In the lateral direction, the gaps 42 can be flush with the side surfaces 22 of the respective associated semiconductor chips 2.
[0056] According to Fig. 11, a continuous optical film 55 is provided above the molded body 40. The optical film 55 comprises a plurality of optical elements 5. As a result, the gaps 42 are completely covered by the optical elements 5. A light entry surface 50 of the optical elements 5 faces the respective semiconductor chip 2, and an emission surface 51 faces away from the semiconductor chips 2.
[0057] The optical film 55 can be applied directly to the molded body 40. Alternatively, an adhesive layer (not shown) can be present between the optical film 55 and the molded body 40.
[0058] In Fig. 12 shows that the molded body 40 and the optical film 55 are separated, for example, by sawing. It is possible for the second carrier 62 and optionally the second release tape 72 to remain unaffected by the separation. Thus, the separation produces individual reflectors 4 and individual optical elements 5 from the molded body 40 and the optical film 55.
[0059] In Fig. 12 also illustrates that the gaps 42 have a comparatively small thickness T. For example, the thickness T is approximately 50 µm. In comparison, a thickness C of the semiconductor chips 2 is comparatively large and can be approximately 0.2 mm.
[0060] In Fig. Figure 13 shows the finished optoelectronic semiconductor components 1. The second release tape 72 and the second carrier 62 have been removed.
[0061] In the Fig. 14 to 18, a further embodiment of the method is shown. The method of Fig. 14 to 18 essentially corresponds to the procedure of Fig. 1 to 13.
[0062] According to Fig. 14, several photoresist layers 33 are applied, for example three photoresist layers 33.
[0063] As a result, see Fig. 15, comparatively thick temporary spacers 3 are achieved.
[0064] According to Fig. 16, the molded body 40 is formed analogously to the process step of Fig. 9 manufactured.
[0065] Below, see Fig. 17, the optical film 55 comprising the optical elements 5 is applied to the molded body 40. As a result of the thick temporary spacers 3, comparatively thick gaps 42 result. For example, the thickness T of the gaps exceeds a thickness C of the semiconductor chips 2. For example, the thickness T is approximately 1 mm.
[0066] In Fig. 18 shows the resulting optoelectronic semiconductor components 1 with the comparatively thick gaps 42.
[0067] A variation of the procedure is described in the Fig. 19 to 31. The process steps of the Fig. 19 to 23 essentially correspond to the procedural steps of the Fig. 1 to 6. In Fig. 23, however, only the first parts 31 of the spacers are present. These first parts 31 of the Fig. 23 essentially correspond to the distance keeping 3 of the Fig. 6.
[0068] In the following process step, as in Fig. As shown in Figure 24, second parts 33 of the spacers are created by applying another photoresist 34 around the first parts 31 onto the first release tape 71. The another photoresist 34 can partially wet the side surfaces 22 of the semiconductor chips 2.
[0069] The resulting spacer 3 is in Fig. 25. This means that the spacer 3 has approximately the shape of a truncated pyramid with rounded corners.
[0070] After removing the first carrier 61 and the first release tape 71, see Fig. 26, the spacers 3 point away from the second support 62. In a direction away from the second support 62, the spacers 3 become wider.
[0071] As in Fig. As shown in Figure 27, the molded body 40 is formed. Thus, negatives of the spacers 3 are formed in the molded body 40.
[0072] According to Fig. 28, the spacers 3 are removed. As a result, the light exit surfaces 20 are completely exposed and the side surfaces 22 are partially exposed from the molded body 40. As a result, the resulting gaps 42 are shaped like reflectors, and the gaps 42 widen in the direction away from the respective associated semiconductor chip 2.
[0073] In the procedural steps of the Fig. 29 to 31, the optical film 55 is provided, separated and the second carrier 62 is removed. The method of Fig. 29 to 31 is thus analogous to the procedure of Fig. 11 to 13.
[0074] A further embodiment of the method is described in the Fig. 32 to 44. The general concept of the procedure of Fig. 32 to 44 is the same as the procedure of Fig. 1 to 13. Therefore, the differences to the aforementioned procedures are essentially explained below.
[0075] In Fig. Figure 36 illustrates a plan view of a single spacer 3. The spacer 3 comprises a rectangular base body. Two webs 35 protrude from the base body on opposite sides. The webs 35 have, for example, a rectangular shape. As can be seen from Fig. 37, the webs 35 project laterally beyond the semiconductor chips 2. The Fig. 37 and the following sectional views are sectional views through a line along the webs 35.
[0076] In the Fig. 31 and Fig. 42 shows that ventilation openings 44 are created at the location where the webs 35 were previously arranged. This is how they run, see Fig. 44, the ventilation openings 44 in the lateral direction completely through the associated reflector 4. This allows air to flow into and out of the gap 42, depending, for example, on a temperature and thus on a density of the air in the gap 42.
[0077] Of course, the different thicknesses of the gap 42, the ventilation openings 44 and the gaps 42 having a different width can be combined within one embodiment of the method. For example, the ventilation openings 44 of the components of the Fig. 44 with the widening gap 42 of the embodiment of the Fig. 31 can be combined.
[0078] In the Fig. 45 and Fig. 46 shows plan views of the emission surface 51 of the optical elements 5. According to Fig. 45, the optical element 5 comprises a plurality of structural elements 52. A metamaterial is formed by means of the structural elements 52. Typical lateral dimensions of the structural elements 52 are smaller than a wavelength to be processed by the optical element 5. Thus, typical dimensions of the structural elements 52 can be approximately 100 nm to 500 nm.
[0079] According to Fig. 46, the optical element 5 is a microlens array. Thus, a plurality of microlenses 52 form the emission surface 51.
[0080] As in all other embodiments, the light entry surface 50 of the optical element 5 can be planar. Alternatively, the light entry surface 50 can also be provided with structural elements, microlenses, and / or Fresnel elements.
[0081] In Fig. 47 shows an embodiment of the semiconductor chip 2. The semiconductor chip 2 comprises a semiconductor layer sequence 27 configured to emit light. A substrate 28 is optionally present. The substrate 28 can be a growth substrate for the semiconductor layer sequence 27. Depending on the electrical properties of the substrate 28, the positions of the semiconductor layer sequence 27 and the substrate 28 can be interchanged, so that the electrical contact pads 26 can be located directly on the semiconductor layer sequence 27. As already mentioned, the substrate 28 can also be omitted in order to produce a thin-film semiconductor chip without a substrate.
[0082] The semiconductor layer sequence 27 is preferably based on a III-V compound semiconductor material. The semiconductor material is, for example, a nitride compound semiconductor material such as Al n In 1-n-m Ga m N or a phosphide compound semiconductor material such as Al n In 1-n-m Ga m P or an arsenide compound semiconductor material such as Al n In 1-n-m Ga m As, where 0 ≤ n ≤ 1, 0 ≤ m ≤ 1, and n + m ≤ 1 apply. The semiconductor layer sequence can comprise dopants and additional components. For the sake of simplicity, however, only the essential components of the crystal lattice of the semiconductor layer sequence are specified, i.e., Al, As, Ga, In, N, or P, even if these can be partially replaced and / or supplemented by small amounts of other substances. The semiconductor layer sequence is particularly preferably based on the AlInGaN material system.
[0083] As in all other embodiments, a phosphor layer 25 can be applied to the semiconductor layer sequence 27 and / or to the substrate 28. Thus, the phosphor 25 can be an integral component of the semiconductor chip 2. Alternatively, such a phosphor 25 can be a separate component within the optoelectronic semiconductor device 1, which is not shown.
[0084] The phosphor 25 is preferably a phosphor material or a phosphor mixture comprising at least one of the following materials: Eu 2+ -doped nitrides such as (Ca,Sr)AlSiN3:Eu 2+ , Sr(Ca,Sr)Si2Al2N6:Eu 2+ , (Sr,Ca)AlSiN3*Si2N2O:E u 2+ , (C a ,Ba,Sr)2Si5N8:Eu 2+ , (Sr,Ca) [LiAl3N4]:Eu 2+ Garnets from the general system (Gd,Lu,Tb,Y)3(Al,Ga,D)5(O,X) 12 :RE with X = halide, N or divalent element, D = tri- or tetravalent element and RE = rare earth metals such as Lu3(Al1-x Ga x )5O 12 :Ce 3+ , Y3(Al 1-x Ga x )5O 12 :Ce 3+ ; Eu 2+ -doped sulfides such as (Ca,Sr,Ba)S:Eu 2+ ; Eu 2+ -doped SiONs such as (Ba,Sr,Ca)Si2O2N2:Eu 2+ ; SiAlONs, for example, from the Li system x M y Ln z Si 12-(m+n) Al (m+n) O n N 16-n ; beta-SiAlONs from the Si system 6-x Al z O y N 8-y :RE z ; Nitrido orthosilicates such as AE 2-x-a RE x Eu a SiO 4-x N x , AE 2-x-a RE X Eu a Si 1- y O 4-x-2y N x with RE = rare earth metal and AE = alkaline earth metal; orthosilicates such as ((Ba,Sr,Ca,Mg)2SiO4:Eu 2+ ; Chlorosilicates such as Ca8Mg(SiO4)4Cl2:Eu 2+ ; Chlorophosphates such as (Sr,Ba,Ca,Mg) 10 (PO4)6Cl2:Eu 2+; BAM phosphors from the BaO-MgO-Al2O3 system such as BaMgAl 10 O 17 :Eu 2+ ; halophosphates such as M5(PO4)3(Cl,F): (Eu 2+ ,Sb 3+ ,Mn 2+ ); SCAP phosphors such as (Sr,Ba,Ca)5(PO4)3Cl:Eu 2+ ; KSF phosphors such as K2SiF6:Mn 4+ . Quantum dots can also be introduced as luminescent materials. Quantum dots in the form of nanocrystalline materials containing a group II-VI compound and / or a group III-V compound and / or a group IV-VI compound and / or metal nanocrystals are preferred in this case.
[0085] Fig. 48 shows a modification 8 of an optoelectronic semiconductor component. In this modification 8, the semiconductor chip 2 is laterally surrounded by the reflector 4. The reflector 4 and the semiconductor chip 2 are completely covered with the phosphor 25, which forms the cover surface 10 of the modification 8.
[0086] When using such a modification 8, comparatively large optical elements (not shown) are required to achieve the desired optical properties. In contrast, the optoelectronic semiconductor components 1 described here allow a space-saving arrangement with respect to the optical element. List of reference symbols 1 optoelectronic semiconductor component 10 Cover area 2 optoelectronic semiconductor chip 20 light exit surface 21 bottom page 22 side surface 25 fluorescent 26 electrical contact surfaces 27 Semiconductor layer sequence 28 Substrat 3 temporary spacers 31 first part of the spacer 32 second part of the spacer 33 / 34 Photoresist / additional photoresist 35 jetty 4 Reflector 40 molded bodies 42 gap 44 Ventilation opening 5 optical element 50 light entry area 51 Emission surface of the optical element 52 structural element 55 optical film 61 first carrier 62 second carrier 71 first release tape 72 second release tape 8 Modification of an optoelectronic semiconductor component C Thickness of the semiconductor chip T Thickness of the gap
Claims
[1] A method for producing optoelectronic semiconductor components (1) comprises: A) Providing an optoelectronic semiconductor chip (2), B) applying a temporary spacer (3) to protect a light exit surface (20) of the optoelectronic semiconductor chip (2), C) forming a reflector (4) in the lateral direction directly around the optoelectronic semiconductor chip (2) and around the temporary spacer (3), D) Subsequent removal of the temporary spacer (3) so that the reflector (4) projects beyond the light exit surface (20), and E) applying an optical element (5) to the reflector (4) so that a gap (42) exists between the light exit surface (20) and a light entry surface (50) of the optical element (5), wherein - process step B) is carried out before process step A), - in process step B) a first carrier (61) is provided, onto which a photoresist (31) is applied, - subsequently, the photoresist (31) is developed in places so that the temporary spacer (3) is formed, and - subsequently, in method step A), the optoelectronic semiconductor chip (2) is mounted on a side of the temporary spacer (3) facing away from the first carrier (61). [2] Method according to the preceding claim, wherein the optical element (5) is a meta-lens or a microlens array, wherein the reflector (4) is produced by molding and is diffusely reflective and has a white color, and wherein the gap (42) is filled with a gas. [3] Method according to claim 1, where - before method step C), a second carrier (62) is applied to a lower side (21) of the optoelectronic semiconductor chip (2), the lower side (21) being opposite the light exit side (20), and - subsequently, but before process step C), the first carrier (61) is removed. [4] Method according to one of the preceding claims, wherein at least in a region above the light exit surface (20) the gap (42) is formed as a truncated pyramid or as a truncated cone or as an intermediate shape between a truncated pyramid and a truncated cone. [5] The method according to any one of the preceding claims, wherein - in method step A) a plurality of optoelectronic semiconductor chips (2) are provided, - in process step C) exactly one molded body (40) is formed for all reflectors (4), so that all optoelectronic semiconductor chips (2) are mechanically integrated in this molded body (40) and connected by it, and - the method further comprises a method step F) following method step E), wherein in step F) the shaped body (40) is separated into the individual reflectors (4). [6] Method according to claim 5, wherein - in process step E), the optical elements (5) are applied as an optical film (55), wherein the optical film (55) is a continuous layer covering all optoelectronic semiconductor chips (2) before step F), and - in step F) the optical film (55) is separated into the optical elements (5). [7] Method according to one of the preceding claims, wherein the gap (42) passes completely through the reflector (4) in the lateral direction, so that at least one ventilation opening (45) is formed, wherein a shape of the at least one ventilation opening (45) is defined by a shape of the temporary spacer (3). [8] Method according to claim 7, wherein at least two ventilation openings (45) are formed, wherein the two ventilation openings (45) or two of the ventilation openings (45) are arranged symmetrically in the plan view of the light exit surface (20). [9] Method according to one of the preceding claims, wherein the reflector (4) and the optical element (5) are flush with one another around the finished optoelectronic semiconductor component (1), so that a cover surface (10) of the optoelectronic semiconductor component (1) is formed exclusively by the optical element (5). [10] Method according to one of the preceding claims, wherein a thickness (T) of the gap (42) exceeds a thickness (C) of the optoelectronic semiconductor chip (2), wherein the thickness (T) of the gap (42) is at least 0.2 mm. [11] Method according to one of claims 1 to 9, wherein a thickness (C) of the optoelectronic semiconductor chip (2) exceeds a thickness (T) of the gap (42), wherein the thickness (T) of the gap (42) is at most 50 µm. [12] Method according to one of the preceding claims, wherein the optoelectronic semiconductor chip (2) is a light-emitting diode chip, wherein the optoelectronic semiconductor chip (2) is provided with at least one phosphor (25) to convert radiation emitted by the light-emitting diode chip into radiation with a longer wavelength, and wherein the reflector (4) completely and directly surrounds the phosphor (25) in a lateral direction.
Citation Information
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