Optoelectronic device and method for producing optoelectronic device

Abstract

The invention relates to an optoelectronic device, comprising: a carrier substrate having a first contact region and a second contact region which is electrically insulated therefrom; and a light emitting device arranged on the carrier substrate and electrically coupled to the first contact region and the second contact region. Furthermore, the optoelectronic device comprises a reflective encapsulation arranged on the carrier substrate, the reflective encapsulation surrounding the light emitting device in a lateral direction, the reflective encapsulation exceeding the light emitting device in a vertical direction, and the reflective encapsulation forming a cavity above a light emitting surface of the light emitting device. In the cavity, a light conversion layer is arranged on the light-emitting device, which light conversion layer is formed substantially coincident with the light-emitting surface in a top view of the light-emitting surface. The light conversion layer comprises a light emitting surface and a reflective packaging part, the reflective packaging part comprises a light emitting surface and a light conversion layer, a formed cavity is provided with a bottom, the bottom and the light emitting surface are located in the same plane, the formed cavity is provided with a side face, and the side face and the light conversion layer are at least partially arranged in a spaced mode, so that a gap is formed between the light conversion layer and the reflective packaging part.

Description

[0001] This application claims the priority of German patent application 102022112418.5 filed on May 18, 2022, the disclosure of which is incorporated by reference into this application. Technical Field

[0002] The invention relates to an optoelectronic device and a method for producing an optoelectronic device. Background Art

[0003] When producing optoelectronic devices, in particular LED packages including a conversion layer for converting, for example, blue light into white light, the following problems currently exist:

[0004] - the known possibilities for applying the conversion layer to the LED chip do not provide the desired efficiency in terms of light conversion;

[0005] - the optoelectronic device is not sufficiently robust against external mechanical and chemical influences; and / or

[0006] The thermal and electrical connection of the LED chip, for example on a printed circuit board, is not optimal, since for optimal connection usually high temperatures are required at the point in time when the conversion layer is already applied to the LED chip, which can however damage the conversion layer.

[0007] Furthermore, current possible solutions that attempt to improve at least one of the above-mentioned problems require complex manufacturing concepts and process flows, resulting in high process costs (eg, through complex sequential processes or auxiliary processes) and, thus, high product costs. Summary of the invention

[0008] Therefore, there is a need to provide an optoelectronic device and a method for manufacturing an optoelectronic device that eliminate at least one of the above-mentioned problems.

[0009] This need is met by an optoelectronic device as claimed in claim 1 and by a method for producing an optoelectronic device as claimed in claim 9. Further embodiments are subject matter of the dependent claims.

[0010] The core of the present invention is to arrange the conversion layer very close, accurately and without bonding seams above the light-emitting epitaxial layer of the light-emitting chip, and to arrange the conversion layer on the chip only at a certain moment after the chip is applied to the carrier substrate (such as a lead frame or a circuit board). This can improve the efficiency of light conversion, because the conversion material of the conversion layer is limited to the region of the light-emitting epitaxial layer or the light-emitting surface of the chip on the one hand, thereby reducing the loss at the edge of the light-emitting surface, and on the other hand, the light coupling-out loss is reduced due to the elimination of the adhesive layer. Therefore, the light conversion layer is arranged directly on the light-emitting surface of the chip without adhesive. In addition, the thermal and electrical connection of the chip on the carrier substrate can be improved, because this connection is performed at the moment when the conversion layer is not yet arranged on the chip and therefore a higher temperature can be used.

[0011] To this end, according to a first embodiment, the chip is arranged on a carrier substrate, such as a lead frame or a circuit board, electrically connected, and then encapsulated with a reflective encapsulation material. The carrier substrate has in particular already formed the final substrate, on which the chip is also arranged in the final device. Through the encapsulation step, the chip is surrounded by the encapsulation material in the lateral direction, and is thus protected by the encapsulation. In addition, the tool for encapsulating the chip is configured so that the encapsulation material exceeds the chip in the vertical direction and forms a cavity above the light-emitting epitaxial layer or the light-emitting surface of the chip, which at least exposes the light-emitting surface. For example, the light-emitting surface of the semiconductor chip may be smaller than the upper side of the semiconductor chip, and therefore only extends within the range of a partial area of ​​the upper side of the semiconductor chip, but it is also possible that the light-emitting surface of the semiconductor chip extends within the range of the entire upper side of the semiconductor chip.

[0012] Since the encapsulation step is a relatively imprecise process for producing a cavity that is constructed or arranged to essentially coincide with the light emission surface not only in size but also in position, the cavity can be intentionally selected to be larger than the light emission surface so that, despite manufacturing tolerances, the light emission surface is completely located within the cavity and is not covered by the encapsulation material.

[0013] However, due to manufacturing tolerances and, in particular, larger cavities, the exact position of the light emission surface relative to the cavity is not precisely known but can vary from device to device. Therefore, in a further step, the position of the light emission surface relative to the cavity is determined. This can be done with the aid of very precise optical methods, both in a state in which the chip emits light through the light emission surface and in a state in which the chip does not emit light. The known position of the light emission surface relative to the cavity can then be used to structure the photosensitive material introduced into the cavity, i.e., such that the photosensitive material has an opening that substantially coincides with the light emission surface.

[0014] Compared to the encapsulation step, the step of structuring the photosensitive material is a relatively precise process for producing an opening or cavity. Thus, with the aid of the photosensitive material and its structuring, an opening that is relatively precisely positioned and precisely dimensioned relative to the light emission surface can be produced in a relatively imprecisely positioned and "oversized" cavity in the encapsulation material in a subsequent step. Here, the step of structuring the photosensitive material or in particular exposing the photosensitive material to open the photosensitive material in the desired area can be carried out on the one hand with an external / separate light source, but it is also conceivable to open the photosensitive material above the light emission surface with the aid of a light-emitting device of the optoelectronic device itself.

[0015] In addition, the opening formed in the photosensitive material is then used as a template or mask to produce the light conversion layer directly on the chip very close, precisely and seamlessly above the light emitting surface. For this purpose, the opening can be filled with a light conversion material (for example a matrix material comprising light conversion particles) and the material is cured.

[0016] The remaining photosensitive material can then be removed, and the gap formed thereby between the reflective encapsulation material and the light conversion layer can be filled with a reflective potting material to further improve the light outcoupling efficiency and the efficiency of light conversion.

[0017] According to another embodiment, the chip is arranged and electrically connected on a carrier substrate (e.g., a lead frame or a circuit board), and the position of the light emitting surface of the chip relative to or in relation to the carrier substrate is determined. This can be done with the aid of very precise optical methods, both in a state where the chip emits light through the light emitting surface and in a state where the chip does not emit light. The determination of the position may be necessary because the arrangement of the chip on the carrier substrate may be relatively imprecise due to positioning tolerances, so that the position of the light emitting surface relative to the carrier substrate can only be relatively imprecisely known.

[0018] The position of the light emission surface relative to the carrier substrate known by this determination can then be used to structure the photosensitive material applied to the chip and optionally to the carrier substrate, i.e., the photosensitive material remains on the light emission surface substantially in coincidence with the light emission surface, and the regions of the photosensitive material that do not coincide with the light emission surface are removed. Thus, by determining the position of the light emission surface in combination with the step of structuring the photosensitive material, the photosensitive material can be structured by means of a simple but relatively precise process, so that the photosensitive material remains on the light emission surface substantially in coincidence with a relatively precise positioning and precise dimensioning.

[0019] The step of structuring the photosensitive material or in particular exposing the photosensitive material in desired areas can here on the one hand be carried out using an external / separate light source, but it is also conceivable to expose the photosensitive material above the light emission surface by means of the light-emitting device itself.

[0020] Alternatively, the photosensitive material can be applied or structured onto the light emitting surface with high position accuracy while the chip is still in the chip complex, i.e., on the growth wafer or manufacturing substrate of the chip. In this case, it is possible to dispense with the determination of the position of the light emitting surface of the chip by means of a separate optical method, since the exact position of the light emitting surface of the chip relative to the growth substrate is already known due to the production on the same substrate, or can be easily determined without a separate optical method. Correspondingly, the photosensitive material can already be arranged on the light emitting surface of the chip with high position accuracy in advance, without the need for another optical method to determine the position of the light emitting surface at a later time.

[0021] In addition, the photosensitive material arranged on the light emitting surface and substantially coincident with the light emitting surface can be used as a position holder for a light conversion layer, which is formed on the light emitting surface at a later time instead of the photosensitive material. To this end, the chip on the carrier substrate is encapsulated with a reflective encapsulation material together with the photosensitive material arranged on the chip. Through the encapsulation step, the chip and the photosensitive material are surrounded by the encapsulation material in the lateral direction and are thus protected by the encapsulation. The encapsulation material can be substantially flush with the photosensitive material at the surface relative to the carrier substrate, or a cavity can be formed above the photosensitive material with the help of a corresponding tool for encapsulating the chip, so that the encapsulation material exceeds the chip and the photosensitive material in the vertical direction, and forms a cavity above the photosensitive material that at least exposes the photosensitive material.

[0022] The photosensitive material can be used as a position-accurate position holder for the subsequent light conversion layer in relatively imprecise processes (e.g. encapsulation of a chip on a carrier substrate with a reflective encapsulation material) to form a position-accurate cavity in the reflective encapsulation part, which cavity can then be filled with the light conversion material to form the light conversion layer. For this purpose, after encapsulation of the chip on the carrier substrate and curing of the reflective encapsulation material, the photosensitive material on the light emission surface is removed and the cavity thus formed in the reflective encapsulation part is used as a template or mask to produce the light conversion layer directly on the chip very close, accurately and without bonding seams above the light emission surface. For this purpose, the cavity is filled with light conversion material (e.g. a matrix material comprising light conversion particles) and the material is cured.

[0023] The package produced by the steps of the various embodiments described protects all sensitive components of the device and is therefore very robust mechanically. It can also be manufactured at low cost due to a large proportion of parallelizable processes and can achieve an increase in brightness of the optoelectronic device relative to conventional similar devices.

[0024] The optoelectronic device according to the invention combines the following features:

[0025] - Achieve a precisely defined orientation and a small thickness of the conversion layer and dispense with adhesive seams (compared to so-called layer bonding processes or other alternatives);

[0026] - implementation of the conversion layer at a later point in the production process (compared to a process in which the light conversion layer is applied to the chip while the chip is still in the wafer assemblage) and the advantages resulting therefrom;

[0027] The conversion layer and the advantages brought about by this are realized without the use of a temporary carrier, since the step of applying the conversion layer is carried out when the chip is already arranged on the final carrier substrate.

[0028] According to at least one embodiment, an optoelectronic device includes a carrier substrate having a first contact region and a second contact region electrically insulated therefrom, and a light-emitting device arranged on the carrier substrate and electrically coupled to the first contact region and the second contact region. In addition, a reflective encapsulation portion is arranged on the carrier substrate, the reflective encapsulation portion surrounds the light-emitting device in a lateral direction, exceeds the light-emitting device in a vertical direction, and forms a cavity above a light-emitting surface of the light-emitting device. In the cavity, a light conversion layer is arranged on the light-emitting device, and the light conversion layer is formed to substantially coincide with the light-emitting surface in a top view of the light-emitting surface. The formed cavity has a bottom, which is located in the same plane as the light-emitting surface, and the formed cavity has side surfaces, which are at least partially arranged at a distance from the light conversion layer, so that a gap is generated between the light conversion layer and the reflective encapsulation portion.

[0029] The light conversion layer can be, for example, a layer comprising a matrix material having light conversion particles therein, which are configured to convert light of a first wavelength emitted by the light emitting device and incident on the light conversion particles into light of a second wavelength different from the first wavelength. The light conversion particles can be, for example, so-called luminescent materials or phosphors. The matrix material can be, for example, silicone.

[0030] The reflective encapsulation part or the reflective encapsulation material may be, for example, a white encapsulation part or a white encapsulation material.

[0031] According to at least one embodiment, the bottom of the formed cavity is larger than the light emitting surface in a top view of the light emitting surface. In particular, the bottom surface of the cavity is larger than the light emitting surface and is arranged relative to the light emitting surface so that the light emitting surface remains free from being covered by the reflective encapsulation.

[0032] According to at least one embodiment, a distance from a first side of the cavity to a first edge of the light emitting surface closest to the first side is greater than a distance from a second side of the cavity to a second edge of the light emitting surface closest to the second side. The bottom or bottom surface of the cavity may be correspondingly off-center or asymmetrically arranged relative to the center of gravity of the light emitting surface.

[0033] According to at least one embodiment, the distance between the opposite side faces of the cavity decreases gradually from the side of the reflective encapsulation opposite the carrier substrate to the bottom of the cavity. The side faces of the cavity are correspondingly inclined relative to the light emission surface or the side of the reflective encapsulation opposite the carrier substrate, in particular at an angle between 0° and 90°, so that the cavity tapers toward the light emission surface. This may be caused in particular by the fact that the tool / mold for forming the cavity may have a mold inclination for demolding the cavity. However, the desired radiation characteristics of the optoelectronic device can also be achieved by inclination of the side faces.

[0034] According to at least one embodiment, the optoelectronic device further comprises a potting material, which is arranged in a gap between the reflective encapsulation portion and the light conversion layer in the cavity, in particular fills the gap. The potting material may be, for example, a TiO2 silicone resin, which is introduced into the gap and is configured to reflect light emitted by the light-emitting device and light converted by the conversion layer toward a main emission direction of the optoelectronic device.

[0035] According to at least one embodiment, the upper side of the light conversion layer is substantially flush with the side of the reflective encapsulation portion opposite the carrier substrate. The light conversion layer can accordingly have a thickness such that it is flush with the reflective encapsulation portion in the vertical direction. Such a flatness can be achieved, for example, by precisely selecting the amount of light conversion material introduced into the opening to produce the light conversion layer so that the light conversion material accurately fills the opening, or the flatness can be achieved by grinding the light conversion layer and / or the reflective encapsulation portion.

[0036] According to at least one embodiment, the light conversion layer has light conversion particles arranged in the light conversion layer with a concentration gradient gradually increasing from the upper side of the light conversion layer to the light emitting device. Most of the light conversion particles in the light conversion layer can be correspondingly located in the area close to the light emitting surface of the light conversion layer, while the area of ​​the light conversion layer away from the light emitting surface can have a lower concentration of light conversion particles. On the one hand, this can achieve an improved light conversion efficiency, and the optoelectronic device can be polished without the risk of changing the chromaticity, because there are no or almost no light conversion particles on the upper side of the light conversion layer, which may be removed when polishing the upper side.

[0037] The light emitting device may be an LED chip configured to emit light of a specific wavelength. In particular, the light emitting device may be an LED chip pre-classified corresponding to the emitted wavelength, such an LED chip being configured to emit blue light, for example.

[0038] The light emitting device may have a size of, for example, 0.5 mm 2 Up to 2mm 2 The light emission area within the range of 1mm 2The light emitting device may have a light emitting area of ​​100 μm and a height of between 80 μm and 200 μm, in particular up to 120 μm. The side length of such a light emitting device may be in the range of between 10 μm and 50 μm, for example.

[0039] According to at least one embodiment, the light emitting device is formed by a flip chip. The flip chip can have electrical connection surfaces on the same side, that is, on the underside of the chip. The electrical connection surfaces on the underside can be arranged on the first contact area or the second contact area and electrically connected thereto. The reflective encapsulation can be designed in particular to be only slightly higher than the chip on the carrier substrate, so that a depth is generated for the cavity that is related to the desired thickness of the conversion layer.

[0040] According to at least one embodiment, the light emitting device is electrically coupled to the second contact area by means of a bonding wire, and the bonding wire is completely surrounded by the reflective encapsulation portion. The light emitting device can be formed, for example, by a top contact chip having an electrical connection surface on its lower side and an electrical connection surface on the upper side of the chip opposite to the lower side. The electrical connection surface on the lower side can be arranged on the first contact area and electrically connected thereto, while the electrical connection surface on the upper side can be electrically coupled to the second contact area by means of a bonding wire. The reflective encapsulation portion can be formed on the carrier substrate, in particular, at least as high as to make the bonding wire completely covered by the encapsulation material. Due to the height of the reflective encapsulation portion thus formed, the cavity can correspondingly have a greater height than when using a flip chip. Therefore, due to the height of the cavity, it may be desirable that the light conversion layer has light conversion particles arranged in the light conversion layer with a concentration gradient gradually increasing toward the light emitting device, so that a near-Epi, dense luminescent material package of light conversion particles is produced in the light conversion layer.

[0041] In addition, a method for manufacturing an optoelectronic device is proposed. The method comprises the following steps:

[0042] - providing a carrier substrate having at least one light-emitting device arranged thereon, the light-emitting device having a light-emitting surface;

[0043] - determining the position of the light emitting surface;

[0044] - arranging and structuring the photosensitive material so that the openings in the photosensitive material are substantially coincident with the light emission surface in a plan view of the light emission surface, or so that the photosensitive material is substantially coincident with the light emission surface in a plan view of the light emission surface on the light emission surface;

[0045] - encapsulating at least one light emitting device on the carrier substrate with a reflective encapsulation material, such that the at least one light emitting device is surrounded by the reflective encapsulation material in a lateral direction,

[0046] The reflective encapsulation material extends beyond at least one light emitting device in a vertical direction, and

[0047] The reflective encapsulation material forms a cavity above the light emitting surface of at least one light emitting device, the cavity having a bottom, the bottom being in the same plane as the light emitting surface;

[0048] as well as

[0049] A light conversion layer is produced in the cavity on the light emission surface, such that the light conversion layer is formed on the light emission surface substantially coinciding with the light emission surface in a plan view onto the light emission surface.

[0050] The steps of arranging and structuring the photosensitive material can include, in particular, conventional photolithography processes as well as nanoimprinting processes, laser and etching processes for producing the respectively desired structuring in the photosensitive material.

[0051] According to at least one embodiment, the method further comprises: after encapsulating at least one light emitting device on the carrier substrate with the reflective encapsulation material, removing the photosensitive material so that a precisely positioned cavity is formed in the encapsulation material above the light emitting surface. The step of producing the light conversion layer can then be performed in the precisely positioned cavity after the step of removing the photosensitive material.

[0052] According to at least one embodiment, the step of arranging and structuring the photosensitive material is performed after the step of encapsulating at least one light-emitting device in a cavity in the first reflective encapsulation material. The formed cavity here in particular has side surfaces, which are arranged at least partially at a distance from the light emission surface and thus from the light conversion layer, and the arrangement and structuring of the photosensitive material is in particular performed so that the opening in the photosensitive material is substantially formed to coincide with the light emission surface in a top view of the light emission surface. Then, the light conversion layer is produced in the opening so that the gap between the light conversion layer and the reflective encapsulation material is filled with the photosensitive material.

[0053] According to at least one embodiment, the step of arranging and structuring the photosensitive material is performed before the step of encapsulating at least one light-emitting device. In particular, the step of arranging and structuring the photosensitive material is performed here so that in a top view of the light-emitting surface, the photosensitive material is formed on the light-emitting surface substantially coinciding with the light-emitting surface. Subsequently, the light-emitting device on the carrier substrate is encapsulated with a reflective encapsulation material so that at least one light-emitting device and the photosensitive material on the light-emitting surface are surrounded by the reflective encapsulation material in a lateral direction, the reflective encapsulation material exceeds at least one light-emitting device in a vertical direction, and the reflective encapsulation material forms a cavity filled with the photosensitive material above the light-emitting surface of the at least one light-emitting device. Subsequently, the photosensitive material in the cavity is removed, and a light conversion layer formed substantially coinciding with the light-emitting surface can be formed in the cavity.

[0054] The step of producing the light conversion layer in the cavity of the reflective encapsulation material or the opening of the photosensitive material may include: filling the opening with the light conversion material. The filling with the light conversion material may be performed by means of doctor blade coating, pressing, spraying, dispensing or spraying.

[0055] According to at least one embodiment, the step of producing the light conversion layer further comprises: curing or heating the light conversion material so that the light conversion material is stable inside itself on the one hand, and forms a strong connection with at least one light emitting device on the other hand. The conversion layer thus formed can correspondingly have a strong connection with at least one light emitting device.

[0056] According to at least one embodiment, the step of encapsulating at least one light-emitting device includes a film-assisted molding step. Film-Assisted Molding (FAM) is a variant of transfer molding. In film-assisted molding, a plastic film is used in the mold before the product to be encapsulated is placed in the mold, and the plastic film is sucked into the inner surface (gate, cavity and cutout) of the mold under vacuum. Next is the overmolding or encapsulation process. The molding material is first liquefied by heat and pressure, and then pressed into the closed mold cavity, where it continues to be kept under heat and pressure until all the materials solidify (ie, solidify). After opening the mold, the encapsulated product is taken out. Film-assisted molding provides a series of advantages over traditional transfer molding. These advantages include simple demoulding of the encapsulated product, and the metal surface of the mold can be kept from being covered by the sticky molding material. Another advantage is that the film is used as a protective part, which causes less wear on the mold parts, that is, a longer service life. In addition, more delicate and more closely arranged structures can be manufactured with the help of FAM, or the structures can be cleanly demoulded.

[0057] According to at least one embodiment, the method further comprises: removing the photosensitive material in the gap between the reflective encapsulation material and the light conversion layer. The gap between the reflective encapsulation material and the light conversion layer and in particular the final optoelectronic device may be free of photosensitive material accordingly.

[0058] According to at least one embodiment, the method further comprises: introducing an encapsulation material, in particular a reflective encapsulation material, into the gap between the reflective encapsulation material and the light conversion layer. The encapsulation material can be used as a reflector, which further increases the efficiency of the optoelectronic device.

[0059] According to at least one embodiment, the method further comprises planarizing at least the light conversion layer and optionally also the reflective encapsulation material and the reflective potting material.

[0060] According to at least one embodiment, the step of producing the light conversion layer includes depositing light conversion particles in the light conversion layer so that the light conversion layer has a concentration gradient of light conversion particles arranged in the light conversion layer gradually increasing from the upper side of the light conversion layer to the light emitting device.

[0061] Furthermore, a method for producing an optoelectronic device is proposed. The method comprises the following steps:

[0062] - providing a carrier substrate having at least one light emitting device arranged on the carrier substrate;

[0063] - encapsulating at least one light emitting device on the carrier substrate with a reflective encapsulation material, such that the at least one light emitting device is surrounded by the reflective encapsulation material in a lateral direction,

[0064] The reflective encapsulation material extends beyond at least one light emitting device in a vertical direction, and

[0065] The reflective encapsulation material forms a cavity above the light emitting surface of at least one light emitting device, the cavity having a bottom, the bottom and the light emitting surface being located in the same plane;

[0066] - determining the position of the light emitting surface of at least one light emitting device relative to the formed cavity;

[0067] - arranging and structuring the photosensitive material in the cavity so that, in a plan view of the light emitting surface, the openings of the photosensitive material are formed to substantially coincide with the light emitting surface; and

[0068] - producing a light conversion layer on the light emitting surface in the openings in the photosensitive material;

[0069] The cavity is formed with a side surface which is at least partially arranged at a distance from the light conversion layer; and

[0070] During the production of the light conversion layer, the gap between the light conversion layer and the reflective encapsulation material is filled with a photosensitive material.

[0071] Possible advantages that can be achieved by the optoelectronic arrangement according to the invention are:

[0072] -The process can be implemented on leadframes, circuit boards, ceramic substrates or other substrates;

[0073] -The conversion efficiency of the conversion layer is independent of the height of the light-emitting chip;

[0074] - The carrier substrate backside is accessible during the entire process chain so that each chip can be electrically contacted, e.g. for color adjustment;

[0075] Different chips and therefore different optoelectronic devices can be individually adapted with regard to the number of light-converting particles in the light-converting layer, ie adapted to a (known) wavelength;

[0076] The individually adjustable number of light-converting particles combined with the continuous operability of the chip results in the chromaticity of the converted light being individually determinable and adjustable during production;

[0077] - The conversion layer is not loaded by high temperature processes (such as wire bonding or thermocompression bonding processes);

[0078] - Near-Epi, dense phosphor packaging, for example by means of deposition of light-converting particles in a light-converting layer;

[0079] - Exact orientation of the conversion layer relative to the light emitting surface;

[0080] - There is no adhesive between the light conversion layer and the chip or light emitting surface;

[0081] - the conversion layer is not subjected to mechanical stress during the production of the optoelectronic device;

[0082] - Rigid packaging due to encapsulation with reflective encapsulation material (molding compound);

[0083] - possible bonding wires are completely embedded in the hard encapsulation material and are thus protected;

[0084] The optoelectronic device can be ground without the risk of a change in chromaticity and without having to grind the luminescent material particles (risk of cracking);

[0085] - the contrast of the light emission of the optoelectronic device can be optimized by the reflective encapsulation material (for example TiO2 silicone) in the gap between the conversion layer and the reflective encapsulation material;

[0086] - the optoelectronic device may comprise a chip type with a top contact or a backside contact (eg a flip chip);

[0087] - Can be realized in different structural forms and substrate types. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] The embodiments of the present invention will be explained in more detail below with reference to the accompanying drawings. The accompanying drawings schematically show:

[0089] Figures 1A to 1K Method steps of a method for manufacturing an optoelectronic device according to some aspects of the proposed principles are shown;

[0090] FIG. 2A to FIG. 2N Method steps of another method for producing an optoelectronic device are shown; and

[0091] FIG. 3A to FIG. 3M Method steps of a further method for producing an optoelectronic arrangement are shown. DETAILED DESCRIPTION

[0092] The following embodiments and examples illustrate different aspects and combinations thereof according to the proposed principles. The embodiments and examples are not always to scale. Similarly, in order to highlight various aspects, different elements may be shown in an enlarged or reduced manner. It is of course understood that the various aspects and features of the embodiments and examples shown in these figures can be easily combined with each other without affecting the principles of the present invention. Some aspects have regular structures or shapes. It should be noted that slight deviations from the ideal shape may occur in practice, but this does not violate the concept of the invention.

[0093] In addition, each figure, feature and aspect are not necessarily shown in the correct size, and the ratio between each element is not necessarily correct in principle. Some aspects and features are highlighted by showing them enlarged. However, terms such as "upper", "above", "lower", "below", "larger", "smaller" are correctly shown relative to the elements in these figures. Therefore, this relationship between the elements can be derived from the diagram.

[0094] Figures 1A to 1K Method steps of a method for manufacturing an optoelectronic device according to some aspects of the proposed principles are shown.

[0095] In the first step, as in Figure 1A For this purpose, a carrier substrate 2, such as a circuit board or a lead frame, is provided, which has a first contact area 3a and a second contact area 3b electrically insulated from the first contact area 3a. Contact pads are respectively arranged on the first contact area 3a and the second contact area 3b. In a subsequent step, for example, Figure 1B As shown in FIG. 1 , the light-emitting component 4 is applied to the contact pad in the form of a flip chip. The light-emitting component 4 has a light-emitting surface 4a on the side opposite to the electrical contact surface of the component and is configured to emit light in a main emission direction L.

[0096] In a further step, as in Figure 1C As shown in , the light emitting component 4 is then encapsulated with the help of a reflective encapsulation material 5. The encapsulation step can especially be a film-assisted molding, by which the light emitting component 4 is encapsulated, so that the light emitting component 4 is surrounded by the reflective encapsulation material 5 in the lateral direction, the reflective encapsulation material 5 exceeds the light emitting component 4 in the vertical direction, and a cavity 6 is formed above the light emitting surface 4a, so that at least the light emitting surface 4a is not covered by the reflective encapsulation material 5.

[0097] The cavity has a bottom 6a, which coincides with the light emission surface or is located in the same plane as the light emission surface. In addition, the cavity has side surfaces 6b, 6c, which are arranged at a distance from the respective nearest edge of the light emission surface 4a. In the case shown, the light emission surface is arranged centrally in the cavity, so that the center of gravity of the light emission surface coincides with the center of gravity of the cavity bottom. However, it is also possible to arrange the cavity or the bottom offset relative to the light emission surface 4a.

[0098] In particular, due to manufacturing tolerances and relatively imprecise manufacturing steps to create the cavity, the position of the cavity relative to the light emitting surface may vary from device to device, so it is desirable to construct the cavity to be "oversized" in a first step to ensure that the light emitting surface is not covered by the reflective encapsulation material.

[0099] In a further step, as in Figure 1D As shown in FIG, the exact position of the light emitting surface 4a relative to the cavity 6 is then determined by optical methods (indicated by two arrows). The information thus obtained is then used to Figures 1E to 1G The structured photosensitive material 11 embedded in the cavity 6 is shown in FIG. Figure 1E )(See Figure 1F ), so that the photosensitive material has an opening 12 (see Figure 1G ), the opening is formed to substantially coincide with the light emitting surface 4a in a top view of the light emitting surface 4a. The precise position of the light emitting surface 4a relative to the carrier substrate 2 can also be performed at an earlier time, for example, after the light emitting component 4 is positioned on the carrier substrate 2.

[0100] By introducing and structuring the photosensitive material 11 in the cavity 6 and by producing the opening 12 in the photosensitive material 11, the cavity 6, which is produced relatively imprecisely, can be reduced by means of a relatively precisely adjustable method. As a result, the following opening 12 can be produced, which is formed substantially coincident with the light emission surface 4a and can be produced individually at a corresponding position for different positions of the light emission surface 4a.

[0101] In a further step, as in Figure 1H As shown in FIG, the light conversion material is introduced into the now very precisely positioned openings 12 to produce the light conversion layer 7. The very precisely positioned openings 12 make it possible to simply dimension and form the light conversion layer 7 so that it is arranged very close, precisely, and without adhesive seams above the light emission surface 4a and does not protrude beyond it.

[0102] After the light conversion layer 7 is cured, the remaining photosensitive material 11 in the gap 8 between the light conversion layer 7 and the reflective encapsulation material 5 can be removed, such as in Fig. 1IThe gap 8 can now remain free of any material or can be filled with a potting material 9, in particular a reflective potting material, as in Figure 1J as shown in .

[0103] Subsequently, the carrier substrate 2 and the encapsulation material 5 are separated (for example by sawing), as in Figure 1K ), the optoelectronic device 1 is peeled off from the composite. In steps 1A to 1K, only one optoelectronic device 1 is shown as an example of production, but it should be understood that the method described can also be used to simultaneously produce multiple optoelectronic devices 1 on the same carrier substrate 2, and finally as in Figure 1K The optoelectronic devices are separated out in the separation steps shown in FIG.

[0104] FIG. 2A to FIG. 2N Method steps of another method for manufacturing an optoelectronic device according to some aspects of the presented principles are shown.

[0105] However, with Figures 1A to 1K Compared to the steps shown in Figure 2A and Figure 2B As shown in FIG. 1 , a light-emitting component 4 in the form of a top-contact chip is arranged on a carrier substrate 2 on a first contact region 3 a and is electrically connected to a second contact region 3 b by means of a bonding wire 10 .

[0106] In addition, the bonding wire also causes the reflective encapsulation material 5 to have a greater height, such as in Figure 2D As shown in FIG. , the bonding wire 10 is also encapsulated by means of the reflective encapsulation material 5 to protect the bonding wire 10 from external influences. Figure 1C This also results in a greater depth of the cavity 6 compared to the step shown in FIG. In addition, the bonding wire 10 or the position of the bonding wire 10 is as shown in FIG. Figure 2D The illustration in FIG. 4 may result in an eccentric arrangement of the cavity 6 relative to the light emission surface 4 a , so that the side surfaces 6 a , 6 c of the cavity 6 are at different distances from the respectively nearest edge of the light emission surface 4 a .

[0107] Then, Figures 2E to 2H The steps can correspond to Figure 1D to Figure 1G Follow the steps described in .

[0108] However, due to the greater depth of the cavity, Figure 1H As described above, generating the light conversion layer 7 may also include: depositing light conversion particles in the light conversion layer 7, so that the light conversion layer 7 has a concentration gradient of light conversion particles arranged in the light conversion layer that gradually increases from the upper side of the light conversion layer to the light emitting device 4. This embodiment should be Figure 2JThe two regions of the light conversion layer in FIG. 4 are marked, wherein the region of the conversion layer 7 adjacent to the light emitting surface 4 a has a higher concentration of light conversion particles than the region located above. Fig.2I The light conversion layer 7 shown in FIG. 1 , by contrast, has only one region in which the light conversion particles are distributed uniformly.

[0109] By producing the light conversion layer 7 or when producing the light conversion layer 7, it may also occur that the light conversion layer 7 extends beyond the reflective encapsulation material 5 (by Figure 2K ). This may be desirable, but it may also be desirable to remove the protruding areas by grinding. In the case where it is desired to grind off the protruding areas of the light conversion layer, it may be preferred to deposit the light conversion particles in the light conversion layer 7 so that the light conversion particles are arranged more in the area adjacent to the light emitting surface 4a of the conversion layer 7, so that the light conversion layer is not damaged or its characteristics are changed by grinding it.

[0110] Then, Figure 2L to Figure 2N The steps can correspond to Figures 1I to 1K Follow the steps described in .

[0111] FIG. 3A to FIG. 3M Method steps of another method for manufacturing an optoelectronic device according to some aspects of the presented principles are shown.

[0112] with Figures 1A to 1K and Figures 2A to 2K The precisely positioned cavities or openings are produced in a slightly different form compared to the steps shown in , in order to produce a precisely positioned light conversion layer that substantially coincides with the light emitting surface of the light emitting device.

[0113] In other words, the photosensitive material is used in the form of an inversion process, not as a positive mold for precisely positioned cavities or openings, but as a negative mold for producing precisely positioned cavities or openings in the reflective encapsulation material.

[0114] In the first step, as in Figure 3A As shown in , a carrier substrate 2, such as a circuit board or a lead frame, is provided, which has a first contact area 3a and a second contact area 3b electrically insulated from the first contact area 3a. Figure 3B As shown in FIG. 1 , a light emitting component 4 in the form of a top contact chip on the first contact area 3 a is arranged on the carrier substrate 2 and as shown in FIG. Figure 3C As shown in FIG. 1 , the light emitting component 4 is electrically connected to the second contact region 3 b by means of a bonding wire 10 .

[0115] Then in a further step, such as Figure 3D As shown in FIG. 1 , the exact position of the light emitting surface 4 a relative to the carrier substrate 2 is determined by optical methods (indicated by two arrows). The information thus obtained is then used to Figures 3E to 3GThe photosensitive material 11 (see FIG. 1 ) to be applied to the light emitting component 4 and the carrier substrate 2 is shown in FIG. Figure 3E ) Structural (see Figure 3F ), so that the photosensitive material 11 remains only on the area of ​​the light-emitting component 4 that is substantially coincident with the light-emitting surface 4a in a plan view of the light-emitting surface 4a (see Figure 3G ).

[0116] Then in a further step, as in Figure 3H As shown in the figure, the light-emitting component 4 and the photosensitive material 11 are encapsulated by means of a reflective encapsulation material 5. The encapsulation step may be, for example, film-assisted molding, by means of which the light-emitting component 4 is encapsulated. The light-emitting component 4 and the photosensitive material 11 are encapsulated so that the light-emitting component 4 and the photosensitive material 11 are surrounded by the reflective encapsulation material 5 in the lateral direction, and the reflective encapsulation material 5 exceeds the light-emitting component 4 in the vertical direction and is at least flush with the photosensitive material 11.

[0117] Then, as in Fig. 3I As shown in , the photosensitive material 11 is removed so that a precisely positioned cavity 6 is formed in the reflective encapsulation material 5 above the light emitting surface 4a. In a further step, as in Figure 3J As shown in , the cavity is filled with a conversion material, so that a conversion layer 7 is formed. By means of the very precisely positioned cavity 6, the light conversion layer 7 can be easily dimensioned and formed so that the light conversion layer 7 is arranged very close, precisely and without adhesive seams above the light emission surface 4a and does not extend beyond the light emission surface.

[0118] Subsequently, the carrier substrate 2 and the encapsulation material 5 are separated (for example by sawing), as in Figure 3K ) is peeled off the optoelectronic device 1 from the composite. In steps 3A to 3K, only one optoelectronic device 1 is shown as an example, but it should be understood that multiple optoelectronic devices 1 can be manufactured simultaneously on the same carrier substrate 2 by means of the described method, and finally by Figure 3K The optoelectronic devices are separated out in the separation steps shown in FIG.

[0119] Figure 3L and Figure 3M Further embodiments of optoelectronic devices 1 produced in this way are shown.

[0120] As in Figure 3L As shown in , the manufacturing of the optoelectronic device 1 or the light conversion layer 7 may also include: depositing light conversion particles in the light conversion layer 7 so that the light conversion layer 7 has a concentration gradient gradually increasing from the upper side of the light conversion layer to the light emitting device 4. This should be done by Figure 3LThe two regions of the light conversion layer in FIG. 4 are indicated, wherein the region of the conversion layer 7 adjacent to the light emission surface 4 a has a higher concentration of light conversion particles than the region located above.

[0121] According to Figure 3M In the embodiment shown in , the step of encapsulating the light-emitting component 4 and the photosensitive material 11 is performed with the help of the reflective encapsulation material 5, so that the reflective encapsulation material 5 exceeds the light-emitting component 4 in the vertical direction and forms a cavity above the photosensitive material. With the help of a correspondingly structured tool for encapsulating the chip, a cavity can be formed above the photosensitive material, so that the encapsulation material exceeds the chip and the photosensitive material in the vertical direction, and forms a cavity above the photosensitive material that at least exposes the photosensitive material.

[0122] Reference numerals list

[0123] 1 Optoelectronic devices

[0124] 2 Carrier substrate

[0125] 3a, 3b contact area

[0126] 4 Light-emitting devices

[0127] 4a Light emitting surface

[0128] 5. Reflective packaging materials

[0129] 6 Cavity

[0130] 6a Bottom

[0131] 6b, 6c side

[0132] 7Light conversion layer

[0133] 8 Gap

[0134] 9Potting materials

[0135] 10 Bonding wire

[0136] 11 Photosensitive materials

[0137] 12 Opening

[0138] L Main emission direction

Claims

1. An optoelectronic device (1), comprising: A carrier substrate (2) having a first contact region and a second contact region (3a, 3b) electrically insulated from the first contact region; a light emitting device (4) arranged on the carrier substrate (2) and electrically coupled to the first contact region and the second contact region (3a, 3b); a reflective encapsulation portion (5), the reflective encapsulation portion being arranged on the carrier substrate (2), the reflective encapsulation portion surrounding the light-emitting device (4) in a lateral direction, the reflective encapsulation portion extending beyond the light-emitting device (4) in a vertical direction, and the reflective encapsulation portion forming a cavity (6) above a light-emitting surface (4a) of the light-emitting device (4); as well as A light conversion layer (7) is arranged directly on the light-emitting device (4) in the cavity (6); wherein the light conversion layer (7) is formed so as to substantially coincide with the light emission surface (4a) in a plan view of the light emission surface (4a), The cavity (6) is provided with a bottom (6a), the bottom and the light emitting surface (4a) are located in the same plane, and The cavity (6) formed therein has side surfaces (6b, 6c) which are arranged at least partially spaced apart from the light conversion layer (7) so that a gap (8) is formed between the light conversion layer (7) and the reflective encapsulation (5).

2. The optoelectronic device according to claim 1, wherein a bottom (6a) of the formed cavity (6) is larger than the light emitting surface (4a) in a plan view of the light emitting surface (4a).

3. An optoelectronic device according to claim 1 or 2, wherein a distance from a first side surface (6b) of the cavity (6) to a first edge of the light emitting surface (4a) closest to the first side surface (6b) is greater than a distance from a second side surface (6c) of the cavity (6) to a second edge of the light emitting surface (4a) closest to the second side surface (6c).

4. An optoelectronic device according to any of the preceding claims, wherein the distance between opposite side surfaces (6b, 6c) of the cavity (6) gradually decreases from the side of the reflective encapsulation portion (5) opposite the carrier substrate (2) to the bottom (6a) of the cavity (6).

5. The optoelectronic device according to claim 1, Also included is a potting material (9), which is arranged in the cavity (6) in the gap (8) between the reflective encapsulation part (5) and the light conversion layer (7) and in particular fills the gap (8).

6. The optoelectronic device according to any one of the preceding claims 1 to 5, The upper side of the light conversion layer (7) is essentially flush with the side of the reflective encapsulation (5) which is opposite the carrier substrate (2).

7. The optoelectronic device according to any one of the preceding claims 1 to 6, The light conversion layer (7) has light conversion particles arranged in the light conversion layer (7) with a concentration gradient gradually increasing from the upper side of the light conversion layer (7) to the light emitting device (4).

8. The optoelectronic device according to claim 1, wherein the luminous means (4) is electrically coupled to the second contact region (3b) by means of a bonding wire (10), and the bonding wire (10) is completely surrounded by the reflective encapsulation (5).

9. A method for manufacturing an optoelectronic device (1), comprising the following steps: Providing a carrier substrate (2) having at least one light-emitting device (4) arranged thereon, the light-emitting device having a light-emitting surface (4a); Determining the position of the light emitting surface (4a); Arranging and structuring a photosensitive material (11) so that an opening (12) in the photosensitive material (11) is substantially coincident with the light emitting surface (4a) in a plan view of the light emitting surface (4a), or so that the photosensitive material (11) is substantially coincident with the light emitting surface (4a) in a plan view of the light emitting surface (4a) on the light emitting surface (4a); At least one light emitting device (4) on the carrier substrate (2) is encapsulated with a reflective encapsulation material (5) so that The at least one light emitting device (4) is surrounded by the reflective encapsulation material (5) in a lateral direction, The reflective encapsulation material (5) extends beyond the at least one light emitting device (4) in a vertical direction, and The reflective encapsulation material (5) forms a cavity (6) having a bottom (6a) above the light emitting surface (4a) of the at least one light emitting device (4), wherein the bottom and the light emitting surface (4a) are located in the same plane; A light conversion layer (7) is generated on the light emitting surface (4a) in the cavity (6), so that the light conversion layer (7) is formed on the light emitting surface (4a) in a plan view of the light emitting surface (4a) so as to substantially coincide with the light emitting surface (4a).

10. The method according to claim 9, further comprising: After encapsulating the at least one light-emitting device (4) on the carrier substrate (2) with the reflective encapsulation material (5), the photosensitive material (11) is removed, wherein the step of producing the light conversion layer (7) is performed after the step of removing the photosensitive material (11).

11. The method according to claim 9, wherein the step of arranging and structuring the photosensitive material (11) is performed after the step of encapsulating the at least one light-emitting device (4) in the formed cavity (6), and wherein the light conversion layer (7) is produced in the opening (12).

12. A method according to claim 11, wherein the formed cavity (6) has side surfaces (6b, 6c), which are arranged at least partially spaced apart from the light conversion layer (7), and the gap (8) between the light conversion layer (7) and the reflective packaging material (5) is filled with the photosensitive material (11).

13. The method according to claim 12, further comprising: The photosensitive material (11) in the gap (8) is removed.

14. The method according to claim 13, further comprising: A potting material (9), in particular a reflective potting material, is introduced into the gap (8).

15. The method according to any one of claims 9 to 14, further comprising: At least the light conversion layer (7) is planarized.

16. The method according to any one of claims 9 to 15, wherein the step of producing the light conversion layer (7) comprises: Light conversion particles are deposited in the light conversion layer (7), so that the light conversion layer (7) has light conversion particles arranged in the light conversion layer with a concentration gradient gradually increasing from the upper side of the light conversion layer to the light emitting device (4).

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