WO2017162736A1

WO2017162736A1 - Method for producing an optoelectronic component, and optoelectronic component

Info

Publication number: WO2017162736A1
Application number: PCT/EP2017/056819
Authority: WO
Inventors: Siegfried Herrmann; Georg DIRSCHERL
Original assignee: Osram Opto Semiconductors Gmbh
Priority date: 2016-03-24
Filing date: 2017-03-22
Publication date: 2017-09-28
Also published as: DE102016105582A1

Abstract

The invention relates to a method for producing an optoelectronic component comprising the following steps: A) providing a substrate (1), B) applying semiconductor chips (2) to the substrate (1), wherein the semiconductor chips (2) are spaced apart laterally with respect to one another and are capable of emitting radiation, C) providing a composite carrier (3), D) shaping the composite carrier (3) by means of a shaping tool (4), E) pressing the composite carrier (3) and the substrate (1), with the result that a reflection element (6) is shaped, – wherein the reflection element (6) comprises at least one fluoropolymer (7) comprising the structural unit A of the following general formula (I): – wherein the reflection element (6) is arranged laterally with respect to the semiconductor chips (2) and at least regionally on the surface (22) of the semiconductor chips (2) facing away from the substrate (1), and F) singulating the semiconductor chips (2).

Description

description

Process for producing an optoelectronic

Component and optoelectronic device

The invention relates to a method for producing an optoelectronic component. Furthermore, the invention relates to an optoelectronic component. An object of the invention is to provide a method for

Production of an optoelectronic component

to provide that is easy to carry out. It is another object of the invention to provide an optoelectronic device, which is characterized by a particularly high

Stability and a long service life.

In particular, the component is stable for radiation from the UV and / or blue-emitting region. In addition, in particular, the device has a compact construction. These objects are achieved by a method for producing an optoelectronic component according to claim 1. Advantageous embodiments and modifications of the invention are the subject of the dependent claims. Furthermore, this object is achieved by an optoelectronic component according to claim 14.

In at least one embodiment, the method for producing an optoelectronic component comprises

Steps :

A) providing a substrate, in particular a temporary substrate, B) applying semiconductor chips to the substrate, wherein the semiconductor chips laterally spaced from each other and to

Emission of radiation capable,

C) providing a composite carrier,

D) shaping the composite support by means of a molding tool,

E) pressing the composite support and the substrate so that a reflective element is formed, wherein the

Reflection element comprises at least one fluoropolymer or consists thereof, wherein the reflection element laterally to the semiconductor chips and at least partially on the

Substrate remote surface of the semiconductor chip

is arranged and in particular surrounds the semiconductor chips, and

F) singulating the semiconductor chips.

In accordance with at least one embodiment, the method comprises a step A), providing a substrate. The substrate may for example comprise one or more materials in the form of a layer, a plate, a foil or a laminate, which are selected from glass, quartz,

Plastic, metal, silicon wafers. In particular, the substrate comprises or consists of glass, a thermoplastic or a releasable adhesive. The substrate is preferably designed temporarily. In other words, the substrate will be in a later

Step removed again, so it does not

Part of the finished optoelectronic device is. According to at least one embodiment of the method, this has a step B), applying semiconductor chips to the substrate, wherein the semiconductor chips laterally

spaced apart and to the emission of radiation are set up. In particular, several

Semiconductor chips on a substrate, such as a wafer applied. That a layer, a foil or an element "on" or "over" another layer, foil or another

Here, and in the following text, the element arranged or applied may mean that one layer, film or one element is arranged directly in direct mechanical and / or electrical contact with the other layer, film or the other element. Furthermore, it can also mean that one layer, film or one element is arranged indirectly on or over the other layer, foil or the other element. In this case, further layers, films and / or elements can then be arranged between the one and the other layer or film or between the one and the other element.

The semiconductor chip has at least one

Semiconductor layer sequence on. In the

Semiconductor layer sequence is preferably a III-V compound semiconductor material. The semiconductor material may preferably be based on a nitride compound semiconductor material. "Based on a nitride compound semiconductor material" in the present context means that the semiconductor layer sequence or at least one layer thereof comprises a III-nitride compound semiconductor material, preferably In _x AlyGa _] __ _x _yN, where 0 <x <1, 0 <y <1 and x + y

<1. This material does not necessarily have a

have mathematically exact composition according to the above formula. Rather, it may have one or more dopants as well as additional components that the

characteristic physical properties of the Substantially do not change in _x AlyGa _] __ _x _yN material. Of the

For the sake of simplicity, however, the above formula contains only the essential constituents of the crystal lattice (In, Al, Ga, N), even if these may be partially replaced by small amounts of other substances.

The optoelectronic component and / or the semiconductor chip includes an active layer with at least one pn junction and / or with one or more

Quantum well structures. During operation of the optoelectronic component, a

generates electromagnetic radiation. A wavelength or a wavelength maximum of the radiation is preferably in the ultraviolet and / or visible range, in particular at wavelengths between 420 nm and 680 nm inclusive, for example between 440 nm and 480 nm inclusive.

In accordance with at least one embodiment, the optoelectronic component is a light-emitting diode, or LED for short. The device is then preferably configured to emit blue light or white light.

According to at least one embodiment, the

Semiconductor layer sequence on an active layer. The active layer is disposed between the semiconductor regions.

In particular, the active layer is in direct to both the n-doped and the p-doped semiconductor region

Contact arranged. Direct means here, direct mechanical and / or electrical contact. The active area of the

Semiconductor layer sequence is in particular for

Radiation generation, ie for the emission or absorption of radiation, set up. Preferably, the active area is everywhere along the entire lateral extent to Emission or absorption of radiation set up and forms there a light area or detection area.

By way of example, the active layer is formed coherently within the active region. The active area can also form a pixelated or segmented illuminated area.

The semiconductor chips each have one

Radiation exit surface on. The radiation exit surface is preferably perpendicular to the growth direction of

Semiconductor layer sequence arranged. The

Radiation exit surface is applied in particular on the substrate in step B). In other words, that is

Radiation exit surface of the respective semiconductor chip directly or indirectly downstream of the substrate.

Indirect means here in particular that, for example, an adhesive layer between the substrate and the

Radiation exit surface is arranged. The semiconductor chips are in particular arranged on the substrate in such a way that they are laterally spaced apart in cross section. The semiconductor chips are in particular adapted, preferably radiation from the visible

Area to emit. According to at least one embodiment, the semiconductor chip has contacts, in particular a p- and n-contact, which at least the p-doped

Semiconductor layer and the at least one n-doped

Semiconductor layer electrically contacted. The contacts are preferably both arranged on the side opposite the radiation exit surface of the respective semiconductor chip. In particular, the semiconductor layer sequence is applied to a further substrate, for example a sapphire substrate. In accordance with at least one embodiment, the method comprises a step C) providing a composite carrier. In step D), the composite carrier is subsequently formed. The molding can be done by means of a molding tool, for example a pressing tool, such as a stamp. The shaping can be carried out under temperatures, for example at temperatures> 200 °, and / or in vacuo. In accordance with at least one embodiment, the composite carrier has a radiation-transmissive fluoropolymer film containing the

Fluoropolymer has, and a reflective metal foil or a reflective plastic film on. As a result, after step E), a reflection element from the

Fluoropolymer film and the metal foil or the

Formed plastic film, wherein the fluoropolymer film

is arranged in particular in direct mechanical contact between the respective semiconductor chip and the metal foil. With "radiation-permeable" is here and below one

Element, foil or a layer that is transparent to visible light or UV light. In this case, the transparent layer can be transparent or at least partially light-scattering and / or partially light-absorbing, so that the radiation-permeable film can be translucent, for example, also diffuse or milky. Particularly preferred is an element or film referred to herein as transparent to radiation, as transparent as possible, so that

In particular, the absorption of light or radiation generated in the operation of the component in the semiconductor layer sequence is as low as possible. By "reflective" is meant here and below that the element, the layer or the film has a reflectance of> 99%. In accordance with at least one embodiment, the composite carrier has a radiation-transmissive fluoropolymer film and a reflective fluoropolymer film. Thus, after step E), the reflection element is formed from two fluoropolymer films. Preferably, the radiation-transmissive

Fluoropolymer film between the semiconductor chips and the reflective fluoropolymer film arranged laterally in cross section.

In accordance with at least one embodiment, the composite carrier has a reflective fluoropolymer film. The

Fluoropolymer film has in particular the fluoropolymer. After step E) is a reflection element of the

Fluoropolymer film is formed, which is arranged in direct lateral contact with the semiconductor chips.

According to at least one embodiment, the

Fluoropolymer film scattering particles on. Preferably, the scattering particles are titanium dioxide. The scattering particles are in the

Embedded fluoropolymer film and arranged in indirect lateral contact with the semiconductor chips. In other words, the scattering particles are embedded in the fluoropolymer film and spaced from the semiconductor chips. Thus, they do not directly adjoin the side surfaces of the semiconductor chips, but are spatially spaced apart from the side surfaces of the semiconductor chips by the fluoropolymer. The fluoropolymer film is disposed in direct mechanical contact with the side surfaces of the respective semiconductor chips.

In accordance with at least one embodiment, the composite carrier has a fluoropolymer film which is particularly suitable for the outer Viewer a white impression. These

Fluoropolymer film is formed in particular reflective.

In accordance with at least one embodiment, the composite carrier has a layer sequence, that is to say a film sandwich, made of a transparent fluoropolymer film and a metal foil or of a transparent fluoropolymer foil and a

Plastic film on. Alternatively, the layer sequence of the composite carrier may be formed from a transparent and reflective fluoropolymer film.

In accordance with at least one embodiment, the method comprises a step E), pressing the composite carrier and the substrate. By pressing a reflection element is formed. The reflective element comprises or consists of the fluoropolymer. The reflection element is lateral to the semiconductor chips and / or at least partially on the surface of the semiconductor chips facing away from the substrate

arranged. In other words, the semiconductor chips in the reflection element with their side surfaces and the

Radiation exit surface opposite side embedded in the reflection element. In particular, the

Radiation exit surface of the semiconductor chips free of the reflection element.

The pressing can be done at high temperatures. According to at least one embodiment, the pressing in step E) takes place at a temperature of at least the

Melting temperature of the fluoropolymer, wherein the fluoropolymer by injection molding, injection compression molding, transfer molding, hot stamping or welding is applied and / or fixed. By pressing creates a reflection element, which has at least the fluoropolymer. Alternatively or additionally, the Fluoropolymer a metal foil or plastic film on.

In particular, the reflection element is reflective, that is, as a mirror coating, formed. The reflection element can simultaneously serve as a housing for the semiconductor chips. The border, so the metal foil or plastic film can be formed very thin. In particular, the border has a thickness of less than 50 ym, 40 ym, 30 ym, 20 ym or 15 ym. Will not be a metal foil or plastic film

used, in particular, the reflection element only on the fluoropolymer, which is then formed reflective.

According to at least one embodiment, the metal foil is formed reflecting, so it is completely opaque. Opaque here means that there is a transmission of <1% or 0.5%.

In accordance with at least one embodiment, the method comprises step F) and preferably after step E) a further step, removal of the substrate. In other words, the semiconductor chips are detached from the substrate.

In accordance with at least one embodiment, the method has a step F) of singulating the semiconductor chips. The separation or separation can be done for example by means of plasma or a laser.

In accordance with at least one embodiment, the fluoropolymer has a structural unit A of the following general formula:

wherein the substituents Xi to X ₄ each independently

are selected from the group comprising:

- hydrogen,

- halogens, in particular F and Cl,

- R,

- OR,

wherein each R may be a hydrocarbon radical C ₁ -C ₁₀ or a fluorinated hydrocarbon radical C ₁ -C ₁₀ , and wherein at least one of the substituents Xi to X _{4 is} fluorine.

In accordance with at least one embodiment, the fluoropolymer is selected from the following group or combinations thereof: polytetrafluoroethylene (PTFE),

Perfluoromethylalkoxy copolymer (MFA),

Perfluoroalkoxy polymer (PFA),

Ethylene-chlorotrifluoroethylene copolymer (ECTFE),

Ethylene tetrafluoroethylene copolymer (ETFE),

Fluorinated ethylene-propylene copolymer (FEP)

Polyvinylidene fluoride (PVDF),

- Polychlorotrifluoroethylene (PCTFE).

In particular, the fluoropolymer is a perfluoromethylalkoxy copolymer (MFA), perfluoroalkoxy polymer (PFA) or a

Fluorinated ethylene-propylene copolymer (FEP).

In accordance with at least one embodiment, the fluoropolymer is a modified polytetrafluoroethylene (PTFE). Under fluoropolymer are in particular organic

Fluoropolymers comprising carbon, fluorine bonds and a backbone comprising carbon-carbon bonds to understand. Organic fluoropolymers have an extremely strong CF bond (460 kJ / mol). The fluoro groups also shield the polymer backbone, having CC bonds, to the outside. For this reason, fluoropolymers are suitable for

Continuous use temperatures of about 260 ° C. This is well above temperatures of about 150 ° C, as in

Radiation-emitting optoelectronic components, for example, in LEDs (light-emitting diodes) may occur. In addition, fluoropolymers are also resistant to a wide range of chemicals and have low flammability. In addition, there is a very high

Transparency and radiolucency even against short-wave UV radiation, especially against high-energy UVB and UVA radiation.

Fluoropolymers have high stability in a broad spectral range against UV radiation. They even keep a permanent irradiation with UV radiation, especially against high-energy UVB and UVA radiation,

Stand. This high long-term stability against short-wave radiation is surprisingly also given for fluoropolymers which have a high transmission with respect to UV radiation and visible light. With such high transmittance fluoropolymers for short wavelength radiation and visible light, the radiation is not already reflected or absorbed by the outer layers of the polymer material. In accordance with at least one embodiment, the substrate is formed from the fluoropolymer. The composite support then has a metal foil or plastic film, so that after step E) the reflection element of the fluoropolymer of the substrate and the metal foil of the composite carrier is formed. The

Inventors have recognized that by providing a substrate from the fluoropolymer and the subsequent

Pressing in process step E) the fluoropolymer for

Reflection element can be shaped, so a

subsequent removal of the substrate is not required.

In accordance with at least one embodiment, the composite carrier comprises a transparent fluoropolymer and a metal foil or

Plastic film on. The metal foil or plastic film is shaped in particular as a frame. The transparent ones

Properties of the fluoropolymer and the low

Refractive index are particularly important here

Material properties in addition to the high stability compared

Blue light and / or UV light and / or temperature. In addition, the composite carrier has a high total reflection due to the large difference in refractive index to the semiconductor chip. The finished component thus has a reflection element, ie a side mirroring of a

Metal plastic film laminate or plastic film laminate, which laterally or conformally transforms the semiconductor chip. The fluoropolymer in the composite carrier has in particular two

Functions. On the one hand it serves for electrical insulation and on the other hand for improving the reflectivity. In the first plane, the light is reflected by the low-refraction fluoropolymer, then the light continues to penetrate and attaches to the metal foil or plastic foil, which is called the

Reflector serves, thrown back. It is therefore a heterogeneous composite reflection element. In addition, the inventors have recognized that by using the ductile plastic material in combination with a ductile, very thin metal foil or plastic film, a compact and UV or blue light stable component

can be provided.

According to at least one embodiment, only the

Fluoropolymer be part of the composite support.

In particular, the fluoropolymer then directly surrounds the

Side surfaces of the respective semiconductor chips as a border. In particular, the fluoropolymer gives a white

Color impression for an external observer. The White

Fluoropolymer and the supporting low refractive index have a high reflectivity. Also own

in particular fully fluorinated fluoropolymers the highest

Stability to blue light and / or UV light and / or temperature.

In accordance with at least one embodiment, the semiconductor chip may also have a different design than described here.

In accordance with at least one embodiment, the reflectance of the fluoropolymer is adjusted by the degree of crystallization. Thus, a fluoropolymer type can be used, which can have both transparent and reflective properties by adjusting the degree of crystallization.

In particular, the reflection element with the so-called hot pressing, in the English hot embossing process, formed. Subsequently, the outer layer can be tempered near the melting point of the fluoropolymer, so that the

Increased degree of crystallization and thus the transparent or opaque layer is formed reflective and white. According to at least one embodiment may in the composite support and / or in the reflection element a

Be embedded phosphor or a converter material. In particular, the fluoropolymer serves as a matrix material in which the converter material is embedded. Of the

Crystallization effect of the fluoropolymer is used in some applications, such as flash applications

Generation of a white surface used (White

Appearance).

The converter material may be shaped as a particle and embedded in the fluoropolymer. When

Converter materials can be, for example, phosphors, such as YAG phosphors, garnets, calsines, orthosilicates or

Erdalkalinitride be used.

It will continue to be an optoelectronic device

specified. Preferably, the optoelectronic component is produced by the method described above. That is, all features disclosed for the method are also disclosed for the optoelectronic component and vice versa.

According to at least one embodiment, the

Optoelectronic component on a semiconductor chip with a radiation exit surface. The semiconductor chip is configured in operation to transmit radiation over the

Emit radiation exit surface. The component has a reflection element. The reflective element comprises or consists of the fluoropolymer. The reflection element is lateral to the semiconductor chip and / or at least

partially on the radiation exit surface

remote surface of the semiconductor chips arranged.

Preferably, the radiation exit surface of the Semiconductor chips free of the reflection element. In other words, the semiconductor chip is embedded in the reflective element such that it covers the side surfaces and the

Radiation exit side opposite surface in the

Surrounding fluoropolymer, wherein the radiation exit surface is free of the reflection element.

Further advantages, advantageous embodiments and

Further developments emerge from the following in

Compound described with the figures

Embodiments. Show it:

FIGS. 1A to II a method for producing an optoelectronic component according to an embodiment, FIGS. 2A to 21 a method for producing an optoelectronic component according to an embodiment, FIGS. 3A to 5B each an optoelectronic component

FIG. 6A shows a heating curve of a fluoropolymer according to one embodiment

6B shows the temperature dependence of the fluoropolymer according to an embodiment, FIG. 7A shows a transmission spectrum of a fluoropolymer according to an embodiment, FIG. 7B shows fluoropolymers according to an embodiment, FIG. 7C shows a fluoropolymer according to an embodiment, FIGS. 8A to 10 each show a reflection element according to FIG

In one embodiment, Figures IIA and IIB each have a reflection spectrum, and Figures 12A and 12B light scattering or light diffraction.

In the exemplary embodiments and in the figures, identical, identical or identically acting elements can each be provided with the same reference numerals. The illustrated elements and their proportions with each other are not to be regarded as true to scale. Rather, individual elements, such as layers, components, components and areas for exaggerated representability and / or better understanding can be displayed exaggerated. FIGS. 1A to II show a method for producing an optoelectronic component according to FIG

Embodiment.

In Figure 1A, a substrate 1, in particular a

Substrate made of glass and temporarily shaped,

provided. On this substrate 1 semiconductor chips 2 are applied. The semiconductor chips 2 are in particular each with its radiation exit surface 23 on the

Surface of the substrate 1 is arranged. The semiconductor chips 2 each have a semiconductor layer sequence which

in particular are capable of emitting radiation from the UV or blue emitting region. Of the

Radiation exit surface 23 opposite side Contacts 21 for contacting the

Semiconductor layer sequence shown.

FIG. 1B shows the provision of a composite carrier 3. The composite support 3 comprises a fluoropolymer film 32 comprising the fluoropolymer 7. The composite carrier 3 further comprises a metal foil 31, for example

Aluminum, up. Instead of a metal foil can also be a reflective

Plastic film 31 can be used.

FIG. 1C shows the molding of the composite support by means of a molding tool 4. The mold 4 can

for example, be a pressing tool.

In FIG. 1D, it is shown that the composite carrier 3 is applied to the forming tool 4 and, taking advantage of the thermoplastic and ductile properties of the

Composite support, for example, by a hot mold with negative pressure is formed. In other words, the

Composite support 3 a negative impression of the pressing tool 4. In FIG. IE it is shown that the composite carrier 3 and the

Substrate 1 are pressed together. The pressing can be done, for example, at temperatures greater than or equal to 150 °. Thereby, as shown in Figure 1F, the

respective semiconductor chip 2 embedded in the fluoropolymer 7, so is lateral to the semiconductor layer sequence and the

Semiconductor chip 2 and at least partially on the surface facing away from the substrate surface of the semiconductor chip

arranged. This surface is especially in cross section the surface between the contacts and left and right sides of the contacts.

The mold 4 can be shaping. For example, it may be a parabolic mirror CSP.

In FIG. 1G it is shown that the substrate 1 is removed again. The result is a composite of semiconductor chips 2, each having a reflection element 6, which comprises at least the fluoropolymer 7. In addition, this indicates

Reflection element on a metal foil or plastic film 61.

FIG. 1H shows that the semiconductor chips 2

are isolated or were, so that an optoelectronic device 100 is generated. In a subsequent

Method vias 8 can be produced by at least the metal foil 61. The plated-through hole 8 may already be provided in the laminate or be made subsequently with the known methods.

The generation of the through holes for the contact 8 can be generated for example by means of a laser. FIGS. 2A to 21 show a method for producing an optoelectronic component according to FIG

Embodiment. In comparison with the method of FIG. 1, the substrate 1 is formed from the fluoropolymer and is not removed completely or not at all in a subsequent process. In FIG. 2A, the provision of the substrate 1 comprising the fluoropolymer is shown. On the substrate 1, the semiconductor chips 2, as explained in Figure 1, applied. FIG. 2B shows the provision of a composite carrier 3, which here is formed only from a metal foil or plastic film 31.

FIG. 2C provides a pressing tool 4 which, as shown in FIG. 2D, forms the composite carrier 3.

FIG. 2E shows the pressing of the composite carrier, that is to say the metal foil 31, with the substrate 1, which has the fluoropolymer 7, so that a reflection element 6 is formed, which comprises at least the fluoropolymer 7. The

Pressing can be done by means of pressure and / or temperature 5. The process steps, as shown in FIGS. 2G to 21, can be carried out analogously to the process steps as explained in FIGS. IG to II.

FIG. 3A shows a plan view of an optoelectronic component 100 according to an embodiment. The component 100 has a semiconductor chip 2. The semiconductor chip 2 is surrounded by a reflection element 6 which has at least one fluoropolymer 7. The reflection element 6 also has a metal foil 61 as a border. In particular, the fluoropolymer 7 is formed in a transparent manner and the metal foil is reflective. Thus, an optoelectronic component 100 can be provided, which has a compact design and is also UV and / or blue light stable. Alternatively, the metal foil 61 may be missing. In particular, then the fluoropolymer is formed reflective. Alternatively, instead of the metal foil 61 also a plastic film can be used.

FIG. 3B shows a bottom view of an optoelectronic component 100 according to an embodiment. The component 100 has a reflection element 6, in particular here the metal foil 61 is shown as a border. The metal foil 61 in cross-section laterally surrounds both the semiconductor chip 2 and the radiation exit surface

opposite side of the semiconductor chip 2. The

Metal foil 61 has holes which serve for contacting the p and n contacts.

FIGS. 4A to 4C each show a schematic

Side view of an optoelectronic component according to one embodiment. The component 100 of FIG. 4A has a semiconductor chip 2 which is embedded in a reflection element 6. In particular, the side surfaces of the semiconductor chip 2 and the side opposite the radiation exit surface have a direct mechanical contact with the fluoropolymer 7. The reflection element 6 also has a metal foil 61 which forms a border of the

Reflection element 6 represents. In FIG. 4B, another component geometry is one

Optoelectronic device shown. The component of FIG. 4B additionally has a converter element 9, which in the

Reflection element 6 is additionally embedded. In other words, the side surfaces of the converter element 9 and the side surfaces of the semiconductor chip form and

Material fit of the fluoropolymer 7 and / or the

Reflection element 6 covered. In particular, only the Radiation exit surface of the converter element 9 free of the fluoropolymer. 7

As a converter, for example, a YAG phosphor

be embedded.

FIG. 4C shows a plated-through hole 21 which extends out of the reflection element 6 beyond the metal foil. FIGS. 5A and 5B each show a schematic

Side view of an optoelectronic component according to one embodiment. Depending on the reflectivity of the

Fluoropolymer 7, the component geometries may be different.

In FIG. 5A, the fluoropolymer is formed in a transparent manner and a reflective metal foil 61 is arranged as a border. As a result, a better light mixture can be generated because of the distance of the reflector.

FIG. 5B shows the less expensive and more compact variant. Here, no metal foil 61 is used as a metal frame, but only the fluoropolymer as

Reflection element 6. The fluoropolymer is here in particular reflective, for example white, shaped, so that the radiation emitted by the semiconductor chip 2 is reflected. Alternatively, a transparent fluoropolymer and instead of a metal foil 61, a reflective fluoropolymer or plastic film may be used as the reflection element 6 (not shown here). The reflectivity or radiation transmission of the

Fluoropolymer 7 can be adjusted by the degree of crystallization. Figure 6A shows differential calorimetric curves (DSC) of one or several fluoropolymers. The WR5775 ECA 3000 from the former DuPont was used.

It is the heat Q in W · g ^~ l as a function of au

shown. The melting temperature of the fluoropolymer increases from 315 ° C to 322 ° C. It is a long-term growth to recognize, that is, the heat resistance increased by the formation of larger lamellae. growing

crystalline areas lead to reflective behavior. The reflectivity can be increased or adjusted by the temperature pretreatment.

Figure 6B shows the confirmation and the melting temperature for different fluoropolymers. At melting temperatures below 320 ° C, fluoropolymers can be applied by injection molding, injection compression or transfer molding. With the melting temperatures above, the fluoropolymers can be made into a film that can be laminated or applied by hot stamping or welding. At a melting temperature of 305 ° C, the PFA IV can be melted. At a temperature of 320 ° C, the so-called MOLDFLON III can be melted. At a temperature of 327 ° C, the modified PTFE II, the polytetrafluoroethylene, can be melted. At 327 ° C, the polytetrafluoroethylene I can be melted. The PTFE is not by nature

moldbar. Only by side chain modification, such as Moldflon or PFA, it is, for example, injection-moldable. Figure 7A shows a transmission curve in percent of different fluoropolymers at different

Wavelengths λ in nm. The data are based on measurements of a reflection element 6 consisting of the respective

Fluoropolymer with a layer thickness of 0.5 mm each. The curve provided with the reference numeral I shows the

Transmission of Hyflon® PFA. The curve provided with the reference symbol II shows the transmission of Hyflon PFA M640, the curve provided with the reference symbol III shows the

Transmission of Hyflon MFA F1540 and the with the

Reference numeral IV curve shows the transmission of a fluoropolymer consisting of a combination of PFA-1 and MFA. It can be seen from the transmission curves that in particular the fluoropolymer IV has a high transparency even for smaller wavelengths, in particular for wavelengths of 200 to 400 nm, in comparison to the fluoropolymers I to III.

The MOLDFLON is a fluoropolymer available from ElringKlinger Kunststofftechnik.

FIG. 7B shows possible fluoropolymers according to

Embodiment. The fluoropolymers shown here, which are shown by the abbreviations in column I, are very stable and for use in optoelectronic

Components, especially LEDs, outstanding suitable.

Preferably, these are blue light and / or temperature stable. Column II shows the chemical structural formulas. The PTFE is a homopolymer, the MFA is a random copolymer, the PFA and FEP are each a random copolymer, the ECTFE is an alternating copolymer, the PVDF is a homopolymer, the ETFE is an alternating copolymer and the PCTFE is a homopolymer. The concentrations of comonomers in percent are in the Column III shown. The column T _m in ° C shows the

Melting temperatures of the corresponding fluoropolymers.

In particular, the pressing takes place at least in these

Melting temperatures, so that the composite carrier 3 and the

Substrate 1 are joined together.

Figure 7C shows the adhesive ETFE. In particular, the adhesion of the ETFE to polyamide 12 PA is shown here. The PA has a terminal amine group. At a functional

The backbone of the ETFE attaches the terminal amine group at 260 ° C to 330 ° C, which leads to the formation of an imide bond.

FIGS. 8A to 10 each show a schematic

Side view of a reflection element according to a

Embodiment.

The reflection element 6 of Figure 8A is formed as a heterogeneous film reflector. The reflection element 6 is formed as a multi-stage reflector. In the first layer, a large part of the light is reflected. The

Reflection element 6 has a metal foil 61. The

Metal foil 61 is formed of aluminum, for example. The metal foil 61 is followed by a fluoropolymer film 62, in which scattering particles 10, such as titanium dioxide, are embedded. The combination of the metal foil 61 and the scattering particles 10, such as titanium dioxide, in the plastic matrix or fluoropolymer foil 62 results in particular in an absolutely light-tight aging-stable and super-thin

Reflection element 6.

FIG. 8B shows a scanning electron microscope

Receiving the metal foil 61, on which the scattering particles 10th are arranged. The scattering particles 10 have in particular a diameter of 300 nm.

As shown in Figure 8C, the fluoropolymer film 62 has a light transmittance. In particular, the transmission is about 10% with a layer thickness of 250 ym. Preferably, the proportion of scattering particles 10, such as titanium dioxide, is 25% in the fluoropolymer film as

Matrix material.

FIG. 9A shows a reflection element 6, which in the

Essentially as the reflection element 6 of Figure 8A is constructed. By contrast, this indicates

Reflection element 6 of Figure 8A on both sides of the

Metal foil 61, the fluoropolymer film 62, which lacks in Figure 9A on the one side. The reflection element 6 of FIG. 9B shows a plated-through hole 8 as well as a

Insulation 81. Alternatively, instead of a metal foil 61, a plastic film may also be used. Alternatively, instead of an aluminum metal foil and copper, silver

or a variety of metals or coated metals such as copper-silver can be used.

FIG. 9C shows a reflection element 6 with a

Metal foil 61, another metal foil 63 and a

Fluoropolymer film 62, are embedded in the scattering particles 10. The further metal foil 63 may be the same

Have materials such as the metal foil 61. Alternatively, the metal foil 61 and the further metal foil 63 may each comprise a different material.

FIG. 10 shows a schematic side view of a reflection element 6. The reflection element 6 has a Plastic insulation with titanium dioxide 11 on, an adhesive bond 12 and on the back of a metal or a double-sided insulation on. Furthermore, the

Reflection element 6 a metal core 14.

As scattering particles a variety of scattering materials can be used. For example, litter materials of the following table may be used. The table shows plastics that can also be used in the reflection element 6.

FIGS. IIA and IIB each show reflection spectra. In each case, the reflection R in percent% as a function of the wavelength λ in nm is shown. Figure IIA shows the reflectance curve of aluminum, gold and silver, respectively, and Figure IIB shows reflectance spectra of titania as anastas and rutile. I designates in FIG. IIB

Ultraviolet spectral range, II referred to in Figure IIB the visible spectral range and III denotes the infrared spectral range in Figure IIB.

FIG. 12A shows the relative scattering force S in

Dependence of the particle size d in ym of scattering particles 10. FIG. 12B shows the difference between light diffraction (left) and light scattering (right) at scattering particles 10.

According to the invention, a thin ductile metal foil 61, in particular with a layer thickness of less than 50 μm, is used here. The metal foil 61 acts in particular as

light-tight mirror, resulting in a white appearing surface. The light is here next to the

Scattering and diffraction additionally reflected on the metal foil 61.

The inventors have found that by using a reflection element 6, side emission with a small wall thickness of the semiconductor chip can be avoided. In comparison, in standard designs, light is emitted through the thin sidewall.

The ones described in connection with the figures

Embodiments and their features can also be combined with each other according to further embodiments, even if such combinations are not explicitly shown in the figures. Furthermore, the embodiments described in connection with the figures may have additional or alternative features as described in the general part.

The invention is not limited by the description based on the embodiments of these. Rather, it includes the invention includes any novel feature as well as any combination of features, including in particular any combination of features in the claims, even if this feature or combination itself is not explicitly set forth in the claims

Claims or embodiments is given.

This patent application claims the priority of German Patent Application 10 2016 105 582.4, the disclosure of which is hereby incorporated by reference.

Reference sign list

100 optoelectronic component

1 substrate

2 semiconductor chip

21 contacting

22 the surface facing away from the substrate surface

23 radiation exit surface

3 composite beams

31 metal foil or plastic foil

32 fluoropolymer film

4 mold

5 pressure or temperature

6 reflection element

61 Metal foil or plastic foil

62 fluoropolymer film

63 more metal foil or plastic foil

7 fluoropolymer

8 via or contact

81 Insulation

9 converters

10 scattering particles

11 plastic insulation with titanium dioxide

12 adhesive bond

13 metal

14 metal core

Claims

claims

1. A method for producing an optoelectronic

Component with the steps:

A) providing a substrate (1),

B) applying semiconductor chips (2) to the substrate (1), wherein the semiconductor chips (2) are laterally spaced apart and capable of emitting radiation,

C) providing a composite carrier (3),

D) shaping the composite support (3) by means of a molding tool (4),

E) pressing the composite support (3) and the substrate (1) so that a reflection element (6) is formed,

- wherein the reflection element (6) comprises at least one fluoropolymer (7),

- Wherein the reflection element (6) lateral to the

Semiconductor chips (2) and at least partially on the substrate (1) facing away from surface (22) of the semiconductor chips (2) is arranged, and

F) singulating the semiconductor chips (2).

2. The method according to claim 1,

wherein the fluoropolymer (7) comprises a structural unit A of the following general formula:

wherein the substituents Xi to X4 are each independently selected from the group comprising:

- hydrogen,

- halogens, in particular F and Cl, - R,

- OR,

wherein each R may be a hydrocarbon radical Ci-Cio or a fluorinated hydrocarbon radical Ci-Cio, and wherein at least one of the substituents Xi to X4 is fluorine.

3. Method according to at least one of the preceding

Claims,

wherein the pressing in step E) takes place at a temperature of at least the melting temperature of the fluoropolymer (7), the fluoropolymer (7) being injection molded,

Injection-compression molding, transfer molding, hot stamping or welding is applied and / or fixed.

4. Method according to at least one of the preceding

Claims,

wherein the composite carrier (3) is a radiation-transmissive

Fluoropolymer film (32) comprising the fluoropolymer (7) and a reflective metal foil or plastic film (31) such that after step E) the reflective element (6) is made of the fluoropolymer film (32) and metal foil or film

Plastic film (31) is formed, wherein the

Fluoropolymer film (32) between the semiconductor chip (2) and the metal foil or plastic film (31) is arranged.

5. The method according to at least one of the preceding

Claims,

wherein the composite carrier (3) is a radiation-transmissive

Having fluoropolymer film and a reflective fluoropolymer film, so that after step E), the reflection element (6) is formed from the fluoropolymer films.

6. Method according to at least one of the preceding

Claims,

wherein the substrate (1) comprises the fluoropolymer (7) and the composite support (3) comprises a metal foil or plastic film (31) so that after step E) the reflective element (6) is made of the fluoropolymer (7) and the metal foil or

Plastic film (31) is formed.

7. The method according to at least one of the preceding

Claims,

wherein the composite support (3) has a reflective

Fluoropolymer film (32) comprising the fluoropolymer (7), such that after step E), the reflective element (6) is formed from the fluoropolymer film (32) and positioned in direct lateral contact with the semiconductor chips (2).

8. Method according to the preceding claim,

wherein the fluoropolymer film (32) comprises titanium dioxide scattering particles (10) embedded in the fluoropolymer film (32) and arranged in indirect lateral contact with the semiconductor chips (2).

9. Method according to at least one of the preceding

Claims,

wherein before step F) an additional step takes place:

Removing the substrate (1).

10. The method according to at least one of the preceding

Claims,

wherein the fluoropolymer (7) from the following group or

Combinations thereof is selected:

Polytetrafluoroethylene (PTFE),

Perfluoromethylalkoxy copolymer (MFA), Perfluoroalkoxy polymer (PFA),

Ethylene-chlorotrifluoroethylene copolymer (ECTFE),

Ethylene tetrafluoroethylene copolymer (ETFE),

Fluorinated ethylene-propylene copolymer (FEP)

Polyvinylidene fluoride (PVDF),

- Polychlorotrifluoroethylene (PCTFE).

11. The method according to at least one of the preceding

Claims,

wherein the fluoropolymer (7) is a perfluoromethylalkoxy copolymer (MFA), perfluoroalkoxy polymer (PFA) or fluorinated ethylene-propylene copolymer (FEP).

12. The method according to at least one of the preceding

Claims,

wherein the fluoropolymer (7) is a modified

Polytetrafluoroethylene (PTFE) is.

13. The method according to at least one of the preceding

Claims,

wherein the semiconductor chips (2) each have a

Have radiation exit surface and the respective

Radiation exit surface (23) on the substrate (1) in

Step B) is applied.

14. Optoelectronic component (100) having

a semiconductor chip (2) having a

Radiation exit surface (23), wherein the semiconductor chip (2) in operation radiation over the

Emitted radiation exit surface (23),

a reflection element (6) comprising at least one fluoropolymer (7), wherein the reflection element (6) laterally to the semiconductor chip (2) and at least partially on the radiation exit surface (23) facing away

Surface (21) of the semiconductor chips is arranged, wherein the radiation exit surface (23) of the semiconductor chip (2) is free of the reflection element (6).