Optoelectronic component and method for manufacturing an optoelectronic component

Abstract

Optoelectronic device (100) comprising a light-emitting semiconductor chip (110), a conversion element (120) and a body (130), wherein the conversion element (120) is arranged above a light-emitting side (113) of the light-emitting semiconductor chip (110), wherein the conversion element (120) is embedded in the body (130), wherein a layer (131) of the body (130) covers the conversion element (120) on a side (121) of the conversion element (120) facing away from the light-emitting semiconductor chip (110), wherein the layer (131) of the body (130) covering the conversion element (120) is between 15 and 55 micrometers thick, wherein the body (130) is an injection-molded body, wherein the injection-molded body comprises a silicone (132), an epoxy and / or a hybrid material, wherein a filler (133) is embedded in the injection molded body,wherein the weight of the filler (133) is 10 percent to 90 percent of the weight of the injection-molded part and wherein a proportion of the filler (133) is selected based on the thickness of the layer (131), wherein the thicker the layer (131) is, the lower the proportion of the filler (133) to the weight of the injection-molded part.

Description

[0001] The invention relates to an optoelectronic component and a method for producing an optoelectronic component.

[0002] For optoelectronic components that emit white light and are based on light-emitting semiconductor chips, it is desirable to create a white color impression of the component. This can be achieved by embedding it in a white housing. The white light is generated by converting blue light in a conversion phosphor. This conversion phosphor cannot be made white, but rather has a slightly yellowish color. Such a component can be used, for example, as a flash for a cell phone camera.

[0003] The document DE 10 2012 102 420 A1 shows an optoelectronic semiconductor component and a manufacturing method in which a semiconductor chip is embedded in a housing and a sacrificial layer is arranged above a conversion element arranged on the semiconductor chip, wherein the conversion element and sacrificial layer are also embedded in the housing.

[0004] The document DE 10 2014 114 372 A1 shows an optoelectronic semiconductor component and a manufacturing method in which a semiconductor chip is also arranged with a conversion element arranged on the semiconductor chip.

[0005] A light-emitting diode with a reflective molded body is known from the document US 2011 / 0 018 017 A1.

[0006] An object of the invention is to provide an optoelectronic component which has better optical properties or a better appearance.

[0007] A further object of the invention is to provide a manufacturing method for such an optoelectronic component.

[0008] This object is achieved with the optoelectronic component and the method for producing an optoelectronic component of the independent patent claims. Further advantageous embodiments are specified in the dependent patent claims.

[0009] An optoelectronic component comprises a light-emitting semiconductor chip, a conversion element, and a body. The conversion element is arranged above a light-emitting side of the light-emitting semiconductor chip. Light emitted by the light-emitting semiconductor chip can be absorbed by the conversion element and converted into light with a longer wavelength. The conversion element is embedded in the body. A layer of the body is provided on a side of the conversion element facing away from the light-emitting semiconductor chip, with the layer of the body covering the conversion element. The layer has a maximum thickness of 55 micrometers.

[0010] Because the conversion element has the body layer on the side facing away from the light-emitting semiconductor chip, the optical appearance of the entire optoelectronic component is uniform, and an observer cannot detect any color difference between the areas of the optoelectronic component where the conversion element is installed and the remaining areas of the optoelectronic component. Due to the maximum layer thickness of 55 micrometers, only a small portion of the light emitted by the light-emitting semiconductor chip is absorbed by the layer, allowing the majority of the light to leave the optoelectronic component. The overall appearance of the optoelectronic component is thus improved.

[0011] According to the invention, the body is an injection-molded body. This also simplifies the production of the optoelectronic component.

[0012] According to the invention, the injection-molded body comprises a silicone, an epoxy, or a hybrid, with a filler embedded in the injection-molded body. In particular, the body consists of the silicone, the epoxy, or the hybrid with the embedded filler. The filler can consist of particles that can scatter light incident on the optoelectronic component and thus create a white color impression. This advantageously results in a white-looking optoelectronic component.

[0013] According to the invention, the weight of the filler is between 10 percent and 90 percent of the weight of the injection-molded body. The lower the proportion of filler, the lower the scattering of the light emitted by the optoelectronic component within the injection-molded body. On the other hand, a certain minimum degree of scattering is necessary so that the light incident from outside onto the optoelectronic component is sufficiently scattered to create the white color impression. A weight proportion of filler in the injection-molded body between 10 percent and 90 percent is suitable for achieving both boundary conditions: sufficient scattering of the light incident from outside and reducing the scattering of the light emitted by the optoelectronic component. The greater the proportion of filler in the injection-molded body, the thinner the layer covering the conversion element can be.

[0014] According to the invention, the layer covering the conversion element on the side facing away from the light-emitting semiconductor chip is between 15 and 55 micrometers thick. Such a layer thickness is suitable for achieving both sufficient scattering of the externally incident light and the smallest possible scattering of the light emitted by the optoelectronic component. If the body is designed as an injection-molded silicone body with a filler, a filler content of 90 percent is advantageous for a 15 to 25 micrometer thick layer, while a filler content of 15 percent is advantageous for a 45 to 55 micrometer thick layer. Therefore, the thicker the layer, the lower the proportion of filler should be in relation to the weight of the injection-molded body.

[0015] According to the invention, a proportion of the filler is selected based on the thickness of the layer.

[0016] In one embodiment, the body forms a housing. This enables particularly simple production of the optoelectronic component.

[0017] In one embodiment, the silicone is a potting silicone or an injection-molding silicone. These two types of silicone are particularly well suited for the production of an optoelectronic component.

[0018] In one embodiment, the filler comprises titanium dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler comprises aluminum oxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler comprises silicon dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. Likewise, a combination of titanium dioxide particles, aluminum oxide particles, and silicon dioxide particles, consisting of two or three of the aforementioned particle types, can be provided as the filler.

[0019] In a method for manufacturing an optoelectronic component, the following steps are performed sequentially. First, a light-emitting semiconductor chip, which has a conversion element on a light-emitting side, is introduced into an injection mold with the applied conversion element. The injection mold comprises a film for carrying out a film-assisted injection molding process. Furthermore, in addition to the light-emitting semiconductor chip, other components, such as leadframe sections, vias, bond wires, and / or other electronic components, can be introduced. The injection mold is then closed such that a gap remains between the film and the conversion element.Subsequently, the light-emitting semiconductor chip is overmolded with an injection molding material to form an injection-molded body in such a way that the gap between the conversion element and the film is filled with the injection molding material. Finally, the injection molding tool is opened, and the component with the injection-molded body and the overmolded light-emitting semiconductor chip is removed. This method enables simple process control and consequently cost-effective production of the optoelectronic component, since only one injection molding process is performed during the production of the optoelectronic component.

[0020] According to the invention, the gap between the film and the conversion element is at least 15 micrometers and at most 55 micrometers.

[0021] In one embodiment, the injection molding material comprises a silicone, an epoxy and / or a hybrid, wherein a filler is embedded in the injection molded body, wherein the weight of the filler is 10 percent to 90 percent of the weight of the injection molding material and wherein a proportion of the filler is selected based on the width of the gap.

[0022] In one embodiment of the method, the injection-molding material comprises a silicone, with a filler embedded in the silicone. This results in an optoelectronic component with an optimized appearance. In particular, a white-looking optoelectronic component can be produced.

[0023] In one embodiment of the process, the silicone is a potting silicone or an injection-molding silicone. Potting silicone is initially liquid, then injected into the injection mold at the desired locations around the light-emitting semiconductor chip and the conversion element, and then cured. Injection-molding silicone consists of two solid components. By mixing the components, they liquefy and can then be injected into the desired locations around the light-emitting semiconductor chip and the conversion element using an injection molding process. There, the silicone cures quickly due to its two-component structure.

[0024] In one embodiment of the method, the filler comprises titanium dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler comprises aluminum oxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler comprises silicon dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. Likewise, a combination of titanium dioxide particles, aluminum oxide particles, and silicon dioxide particles, consisting of two or three of the aforementioned particle types, can be provided as the filler.

[0025] In one embodiment of the method, the weight of the filler is between 10 percent and 35 percent of the weight of the injection-molded material. The lower the proportion of filler, the lower the scattering of the light emitted by the optoelectronic component within the injection-molded body. On the other hand, a certain minimum degree of scattering is necessary so that the light incident from outside onto the optoelectronic component is sufficiently scattered to create the white color impression. A weight proportion of filler in the injection-molded body between 10 percent and 35 percent is suitable for achieving both boundary conditions—that is, sufficient scattering of the light incident from outside and reducing the scattering of the light emitted by the optoelectronic component.

[0026] The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understandable in connection with the following description of the embodiments, which are explained in more detail in connection with the drawings. In each case, in a schematic representation Fig. 1 a cross-section through an optoelectronic component; Fig. 2 a cross-section through another optoelectronic component; Fig. 3 a cross-section through a layer consisting of a silicone with a filler; and Fig. 4 a cross-section through an injection mold during the production of an optoelectronic component.

[0027] Fig. 1 shows a cross-section through an optoelectronic component 100. The optoelectronic component 100 has a light-emitting semiconductor chip 110. A first contact point 111 is arranged on an underside of the light-emitting semiconductor chip 110. A side of the semiconductor chip 110 opposite the underside has a second contact point 112 and simultaneously represents a light-emitting side 113 of the light-emitting semiconductor chip 110. A conversion element 120 is arranged on the light-emitting side 113 of the light-emitting semiconductor chip 110, which can convert light emitted by the light-emitting semiconductor chip 110 into light with a longer wavelength.

[0028] The light-emitting semiconductor chip 110 is arranged on a first leadframe section 141 such that the first contact point 111 is in electrical contact with the first leadframe section 141. A second leadframe section 142 is arranged next to the first leadframe section 141 such that the leadframe sections 141, 142 do not touch each other. A bonding wire 143 connects the second contact point 112 of the light-emitting semiconductor chip 110 to the second leadframe section 142. The light-emitting semiconductor chip 110, the conversion element 120, the leadframe sections 141, 142, and the bonding wire 143 are embedded in a body 130. The body 130 has a layer 131 that covers a side 121 of the conversion element 120 facing away from the light-emitting semiconductor chip 110.

[0029] Since the conversion element 120 has the layer 131 of the body 130 on the side 121 facing away from the light-emitting semiconductor chip 110, the optical impression of the entire optoelectronic component 100 is uniform and an observer does not perceive any color difference between areas of the optoelectronic component 100 where the conversion element 120 is installed compared to the remaining areas of the optoelectronic component 100. The layer 131 is a maximum of 55 micrometers thick.

[0030] The body may have a white color. Layer 131 completely embeds the conversion element 120 into the body 130, so that a non-white conversion element 120 does not impair the white color impression of the optoelectronic component 100.

[0031] Fig. Figure 2 shows a cross-section through another embodiment of an optoelectronic component 100, in which the light-emitting semiconductor chip 110 is embodied as a flip chip. The light-emitting semiconductor chip 110 has a first contact point 111 and a second contact point 112, which are opposite a light-emitting side 113 of the light-emitting semiconductor chip 110. The first contact point 111 is in direct contact with a first leadframe section 141, while the second contact point 142 is in direct contact with a second leadframe section 142.

[0032] A conversion element 130 is arranged on the light-emitting side 113 of the light-emitting semiconductor chip 110. The light-emitting semiconductor chip 110, the conversion element 120, and the leadframe sections 141, 142 are embedded in a body 130. The body 130 has a layer 131 that covers a side 121 of the conversion element 120 facing away from the light-emitting semiconductor chip 110. The layer 131 is also a maximum of 55 micrometers thick.

[0033] The layer 131 in turn creates a uniform color impression of the optoelectronic component 100.

[0034] The examples of the Fig. 1 and Fig. 2 therefore differ only in the type of light-emitting semiconductor chip 110 installed, whereby the appearance of the two optoelectronic components 100 is similar, and in particular both embodiments have a uniform color impression.

[0035] In one embodiment, the body 130 forms a housing. In one embodiment, the body 130 is an injection-molded body.

[0036] Fig. 3 shows a cross-section through an enlarged view of layer 131 of body 130, wherein body 130 is an injection-molded body and comprises a silicone 132 with a filler 133. Filler 133 is embedded in silicone 132. The mechanical properties of body 130 are determined by silicone 132, while the optical properties of body 130 are determined by filler 133. In particular, filler 133 can be white in color, so that optoelectronic component 100 has a white color appearance.

[0037] In one embodiment, the silicone 132 is a potting silicone or an injection-molding silicone. In one embodiment, the filler 133 comprises titanium dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler 133 comprises aluminum oxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler 133 comprises silicon dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. Likewise, a combination of titanium dioxide particles, aluminum oxide particles, and silicon dioxide particles, consisting of two or three of the aforementioned particle types, can be provided as filler 133.

[0038] Instead of silicone 132, an epoxy or a hybrid can also be used as the material for the injection-molded body. The filler 133, consisting of titanium oxide, aluminum oxide, and / or silicon dioxide particles, is then also embedded in the injection-molded body.

[0039] In one embodiment, the proportional weight of the filler 133 on the body 130 is between 10 and 90 percent.

[0040] In one embodiment, layer 131 is between 15 and 55 micrometers thick. In particular, a filler content of 90 percent by weight can be provided for a layer thickness of 15 micrometers or a filler content of 10 percent by weight for a layer thickness of 55 micrometers.

[0041] Fig. Figure 4 shows a cross section through an injection mold 151, 152 during a method for producing an optoelectronic component. A light-emitting semiconductor chip 110, which corresponds to the light-emitting semiconductor chip 110 of the Fig. 2, is on a first lead frame section 141 and a second lead frame section 142 analogous to Fig. 2. A conversion element 120 is arranged on a light-emitting side 113, which is opposite the leadframe sections 141, 142. The light-emitting semiconductor chip 110 with the conversion element 120 and the leadframe sections 141, 142 is arranged on a lower injection mold 151. An upper injection mold 152 has a film 153, which enables a film-assisted injection molding process. This allows an injection molding material to be more easily released from the upper injection mold 152. In addition, the film 153 has a certain flexibility, which also simplifies the injection molding process.

[0042] Another light-emitting semiconductor chip 110 with conversion element 120 and lead frame sections 141, 142 is also arranged in the injection mold 151, 152.

[0043] The upper injection mold 152 is moved toward the lower injection mold 151 when the injection mold 151, 152 is closed such that a gap 154 ​​remains between the film 153 and the conversion element 120.

[0044] Now, free spaces 155 and gaps 154 within the injection mold 151, 152, i.e., all locations not occupied by the light-emitting semiconductor chips 110 with conversion elements 120 and lead frame sections 141, 142, can be filled with an injection molding material to form an injection molded body. Subsequently, the injection mold 151, 152 can be opened again, and the injection molded body removed. If only one light-emitting semiconductor chip 110 was arranged in the injection mold 151, 152, the optoelectronic component of the Fig. 2, with several light-emitting semiconductor chips 110 in the injection mold 151, 152, the optoelectronic components 100 can be obtained by singulation.

[0045] Analogously, the optoelectronic component of the Fig. 1 can be generated.

[0046] In one embodiment, the gap 154 ​​is between 15 and 55 micrometers wide. As a result, the layer 131 of the optoelectronic components 100 of the Fig. 1 and Fig. 2 15 to 55 micrometers thick.

[0047] In one embodiment, the injection-molding material comprises a silicone 132 in which a filler 133 is embedded. In particular, the injection-molding material consists of the silicone 132 in which the filler 133 is embedded.

[0048] In one embodiment, the silicone 132 is a potting silicone or an injection-molding silicone. A potting silicone is initially liquid, then injected within the injection mold 151, 152 into the free spaces 155 and gaps 154 around the light-emitting semiconductor chip 110 and the conversion element 120, and subsequently cured. An injection-molding silicone can consist of two components, each of which is solid. By mixing the components, the components liquefy and can then be used for the injection-molding process. Alternatively, the components can be liquid. The injection-molding silicone is introduced into the free spaces 155 and gaps 154 around the light-emitting semiconductor chip 110 and the conversion element 120 by means of an injection-molding process. There, the silicone 132 cures quickly due to its two-component structure.

[0049] In one embodiment, the filler 133 comprises titanium dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler 133 comprises aluminum oxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. In one embodiment, the filler 133 comprises silicon dioxide particles with a diameter between 0.5 and 10 micrometers and consists in particular of these particles. Likewise, a combination of titanium dioxide particles, aluminum oxide particles, and silicon dioxide particles, consisting of two or three of the aforementioned particle types, can be provided as filler 133. LIST OF REFERENCE SYMBOLS 100 Optoelectronic component 110 light-emitting semiconductor chip 111 first contact point 112 second contact point 113 light-emitting side 120 Conversion element 121 side facing away from the light-emitting semiconductor chip 130 bodies 131 shift 132 Silicone 133 Filler 141 first ladder frame section 142 second ladder frame section 143 Bonding wire 151 lower injection mold 152 upper injection mold 153 Slide 154 gap 155 open space

Claims

[1] Optoelectronic component (100), comprising a light-emitting semiconductor chip (110), a conversion element (120) and a body (130), wherein the conversion element (120) is arranged above a light-emitting side (113) of the light-emitting semiconductor chip (110), wherein the conversion element (120) is embedded in the body (130), wherein on a side (121) of the conversion element (120) facing away from the light-emitting semiconductor chip (110), a layer (131) of the body (130) covers the conversion element (120), wherein the layer (131) of the body (130) covering the conversion element (120) is between 15 and 55 micrometers thick, wherein the body (130) is an injection-molded body, wherein the injection-molded body is a silicone (132), an epoxy and / or a hybrid, wherein a filler (133) is embedded in the injection-molded body,wherein the weight of the filler (133) is 10 percent to 90 percent of the weight of the injection-molded body, and wherein a proportion of the filler (133) is selected based on the thickness of the layer (131), wherein the thicker the layer (131), the lower the proportion of the filler (133) in the weight of the injection-molded body. [2] Optoelectronic component (100) according to claim 1, wherein the body (130) forms a housing. [3] Optoelectronic component (100) according to claim 1 or 2, wherein the injection-molded body comprises silicone (132), wherein the silicone (132) is a potting silicone or an injection-molding silicone. [4] Optoelectronic component (100) according to one of claims 1 to 3, wherein the filler (133) comprises titanium dioxide particles with a diameter of 0.5 to 10 micrometers. [5] Optoelectronic component (100) according to one of claims 1 to 3, wherein the filler (133) comprises aluminum oxide particles with a diameter of 0.5 to 10 micrometers. [6] Optoelectronic component (100) according to one of claims 1 to 3, wherein the filler (133) comprises silicon dioxide particles with a diameter of 0.5 to 10 micrometers. [7] Method for producing an optoelectronic component (100) comprising the steps: - introducing a light-emitting semiconductor chip (110) having a conversion element (120) on a light-emitting side (113), with the applied conversion element (120) into an injection mold (151, 152), wherein the injection mold (151, 152) has a film (153) for carrying out a film-assisted injection molding process; - closing the injection mold (151, 152) such that a gap (154) remains between the film (153) and the conversion element (120), the gap (154) being between 15 and 55 micrometers wide; - overmolding the light-emitting semiconductor chip (110) with an injection-molding material to form an injection-molded body such that the gap (154) between the conversion element (120) and the film (153) is filled with the injection-molding material; - Opening the injection molding tool (151, 152) and removing the optoelectronic component (100) with the injection molded body and the overmolded light-emitting semiconductor chip (110). [8] The method of claim 7, wherein the injection molding material comprises a silicone (132), an epoxy and / or a hybrid, wherein a filler (133) is embedded in the injection molded body, wherein the weight of the filler (133) is 10 percent to 90 percent of the weight of the injection molding material and wherein a proportion of the filler (133) is selected based on the width of the gap (154), wherein the wider the gap (154), the smaller the proportion of the filler (133) in the weight of the injection molded body. [9] The method of claim 8, wherein the silicone (132) is a potting silicone or an injection molding silicone. [10] Method according to one of claims 8 or 9, wherein the filler (133) comprises titanium dioxide particles with a diameter of 0.5 to 10 micrometers and / or aluminum oxide particles with a diameter of 0.5 to 10 micrometers and / or silicon dioxide particles with a diameter of 0.5 to 10 micrometers.

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