WO2012041925A1

WO2012041925A1 - Optoelectronic component and method for producing an optoelectronic component

Info

Publication number: WO2012041925A1
Application number: PCT/EP2011/066917
Authority: WO
Inventors: Magnus Ahlstedt; Johann Ramchen; David Racz; Gertrud KRÄUTER
Original assignee: Osram Opto Semiconductors Gmbh
Priority date: 2010-09-30
Filing date: 2011-09-28
Publication date: 2012-04-05
Also published as: TW201240160A; DE102010047156A1

Abstract

An optoelectronic component having a light-emitting chip and a housing laterally surrounding the light-emitting chip are stated. A method for producing an optoelectronic component is also stated, in which a liquid housing material is applied to a substrate.

Description

description

Optoelectronic component and method for producing an optoelectronic component

It is an optoelectronic component and a method for producing an optoelectronic component

indicated.

This patent application claims the priority of German Patent Application 10 2010 047 156.9, the disclosure of which is hereby incorporated by reference.

Optoelectronic components, such as LEDs, have housings. These are in accordance with previously known methods in separate shaping method, for example by

Injection molding or by means of a thin film / thick film based process.

Object of at least one embodiment of the invention is the provision of an optoelectronic component having an improved housing. This object is achieved by an optoelectronic component according to claim 1.

Object of at least one further embodiment of the

The invention is the provision of a method for

Production of an optoelectronic component with a housing that is easy to carry out. This object is achieved by a method according to claim 7.

Further embodiments of the optoelectronic component and of the method for producing an optoelectronic component are the subject of dependent claims. An optoelectronic component is specified which has a substrate, a light-emitting chip on the substrate and a housing laterally surrounding the light-emitting chip on the substrate. Between side walls of the light-emitting chip and the housing, a distance of less than 2 μπι be present. This will be one

Optoelectronic device provided, the housing has a reduced distance from the side walls of the light-emitting chip. The distance between chip and

Housing may also be selected from a range that includes 10 nm to less than 2 μπι.

The housing may comprise a material comprising a matrix and a filler. The matrix may be selected from a group comprising silicone, unsaturated polyesters and epoxy resin. The filler may be selected from a group comprising ZrC> 2, ZnO, BaSC> 4 and 10O2. The degree of filling of the filler in the matrix may be greater than 20% by weight, for example 25 to 30% by weight. Thus, the housing comprises a material that can be applied in a liquid state and is curable. As a result, the formation of the housing during its manufacture can be simplified. The filler may be evenly distributed throughout the matrix.

According to an embodiment, the housing may reflect light emitted from the chip. Thus, a housing of an optoelectronic component is provided, which also serves as a reflector. The reflective properties are given by the filler, for example 10 2 particles. The filler, for example 1O2 particles, may have diffuse reflective properties. In addition, if the housing is shaped to have a rounded surface facing away from the substrate, it may cooperate with produce good color homogeneity over the entire viewing angle of the filler. Furthermore, by the

Material of the housing, for example, 1O2 filled silicone, the coupling efficiency of an optoelectronic device can be increased, since this housing material a

Reflectivity of up to 95%. Thus, losses of emitted light are kept low. In particular, when the light-emitting chip emits light laterally, it can be reflected by the housing and thus the

Outcoupling efficiency can be increased.

The light-emitting chip may be an LED chip.

In particular, a sapphire chip can also be used.

Thus, the combination of sapphire chip and T1O2-containing reflector can be provided.

By sapphire chip is meant in this context an LED chip comprising a substrate comprising Al ₂ O ₃ . On this substrate then further functional layers are arranged.

According to a further embodiment, a method for producing an optoelectronic component is specified, which has a housing which has the following

Process steps include:

A) coating at least a first subregion of a substrate with a non-wettable layer, B) coating at least one light-emitting chip with a non-wettable layer, C) applying the light-emitting chip on a second portion of the substrate, free of the wettable

Layer is,

D) applying a liquid housing material on the

substrate

E) hardening of the housing material, wherein in the method step D) the housing material between the at least one first portion and

Forms sidewalls of the light emitting chip on the substrate to a housing, which is formed in step E).

Thus, a simple method for producing an optoelectronic component is specified, the housing of which is formed by self-assembly of a liquid housing material which is applied between a light-emitting chip and a non-wettable layer. In the method steps A) and B) can thus first

Subregions of the substrate, such as saw marks and edge areas, as well as a light-emitting chip are coated with the non-wettable layer. The non-wettable layer can be applied with a thickness of less than 2 μπι. For example, it may be applied with a thickness selected from a range including 10 nm to less than 2 μπι.

Overflow of the liquid housing material over the chip is avoided by the non-wettable coating of the chip. Thus, a housing forms on the substrate only where no non-wettable layer is present. The term "saw marks" refers to the areas of the substrate in which the substrate can be divided in order to obtain a plurality of substrates each having a chip and a housing.

Edge regions are to be understood as meaning the regions which surround the second subregion on which a chip is applied, so that the chip is applied to an uncoated region and is surrounded by a non-wettable layer on the substrate.

The light-emitting chip is coated, in particular on the side walls and on its upper side, which faces away from the substrate after application of the chip, with the non-wettable layer, while the underside, the side facing the substrate after application of the chip, free from the is not wettable layer. For this purpose, the underside, which should remain free of the non-wettable layer, during the coating of the chip

For example, be protected with a foil.

With this method, a plurality of optoelectronic components can be produced simultaneously. For this purpose, a plurality of first subregions are coated with the non-wettable layer and in process step D) several light

emitting chips are deposited on second portions of the substrate that are free of the wettable layer. In particular, the first partial regions may have a symmetrical arrangement on the substrate, for example forming a grid on the substrate. In the second

Subareas, thus squares within first

Represent partial areas, light-emitting chips can be applied. The chips have a smaller one Diameter, as the predetermined by the first partial areas square second portions. Between the chips and the first sections is then each

applied liquid housing material, so that in the finished device each chip has a housing on the substrate.

The at least one light-emitting chip can be based on a metallization which is located in second subregions of the

Substrate is applied. In the

Metallization may be a metal layer whose diameter is at least as large as the diameter of the chip, and smaller than the diameter of the second portion bounded by the non-wettable layer of the first portion.

According to one embodiment, the at least one light-emitting chip is glued or soldered onto the substrate or to the metallization in method step C), for example.

An inexpensive method for producing an optoelectronic component is provided, since the

Housing material in this process in a batch process

can be applied.

With the method, a device according to the above

Versions are manufactured.

According to a further disclosed embodiment can form in a

Process step F) following process step E), the non-wettable layer is removed. The removal of the non-wettable layer can be done with an agent that is selected from a group that includes 02 ^_ plasma, CF4 plasma, Ar plasma, and isopropanol. So that can

Surfaces of the light-emitting chip with others

Layers or components are provided.

Furthermore, this results in a distance between the housing and the light-emitting chip, which is determined by the thickness of the removed non-wettable layer. Thus, a very small distance between the housing and

Sidewalls of the chip are generated.

For example, a Lichtauskoppelkörper be applied over a light-emitting chip, which rests for example on the housing surrounding the chip. The housing wall forms in the production of Lichtauskoppelkörpers a suitable stopper edge for example dispensable or screenprintbare materials, with which, for example

Auskoppellinsen be generated from transparent or phosphor-filled material.

Thus, in a further process step, a liquid material for forming a light extraction body, which may be either transparent or phosphor-filled,

getting produced. This is also favored by the shape of the surface facing away from the substrate surface of the housing, which due to the self-organization of the liquid

Housing material is round.

The non-wettable layer in process steps A) and B) may comprise a material that is hydrophobic. The material may be selected from a group which

fluorinated silicone, polytetrafluoroethylene or derivatives thereof. These materials may be treated with agents according to the above versions are well removed after curing of the housing material. Thus, a temporary,

provided structurable, non-wettable layer, which is used for the manufacture of the housing.

According to another disclosed embodiment form can in a the

Process step F) following process step G) the

Substrate are shared in the region of at least a first portion. The division thus takes place after the removal of the non-wettable layer so that only one material, that of the substrate, has to be severed. This will be the

Separation process, when multiple components are to be produced, optimized. The first subarea can therefore represent a saw track.

The substrate may be a printed circuit board (PCB), a

Be ceramic, a circuit board or an aluminum layer.

The housing material in process step D) can be applied by a method selected from the group consisting of screen printing, spin coating, spraying, jetting,

Dispensing or pouring covers. With these methods, the housing material can be applied by means of a batch process.

The non-wettable layer can be applied in process steps A) and B) by means of photolithography. Depending on which form the liquid housing material should take, the wetting angle can be adjusted with this method. For example, a ball-like shape of the surface facing away from the substrate surface of the housing can be formed. Here are not wettable areas, ie first portions on the substrate, and the coated chip, as a stopper edges for the liquid

Housing material. The wetting angle can be determined by the polarity of the surface groups of the non-wettable

Layer as well as the roughness of the non-wettable

Depend on the layer.

In method step D), a housing material may be applied which comprises a matrix and a filler.

For example, the matrix may comprise a material selected from a group consisting of silicone, unsaturated

Polyester and epoxy resin. As a filler can

ZnO, ZrO 2, BaSO 4 or 10 O 2, for example. The filler may be present in the matrix at a level greater than 20% by weight. This provides a reflective filler which imparts reflective properties to the package of the device. Thus, the housing of the device is also a reflector. The housing

or the reflector are produced by Selbstausformung with the method described above. By suitable selection of the material of the housing, the housing can also be used as insulation for a surface contact,

For example, a CPHF contact (CPHF: compact planar high flux) serve. In method step B), an LED chip can be coated. This is a method for the production of LEDs with

Housings provided. This method is suitable for LED chips with two back contacts, for LED chips with top contacts and for sapphire chips, which can be contacted, for example, by means of CPHF contacts.

For example, an LED chip with two bottom contacts can be produced by the method in which both the housing or the reflector and a Auskoppelkörper can be produced by Selbstausformung.

With reference to the figures and the embodiments, the invention will be explained in more detail.

Figure 1 a) to d) schematic side view of

Production of an Optoelectronic Component, Figure 2 a) to e) schematic three-dimensional

Side view of making a

optoelectronic component.

FIG. 1 shows the schematic side view of the production of an optoelectronic component using the example of an LED.

In Figure la), the substrate 10 is shown, which may be, for example, a PCB, a ceramic substrate, a printed circuit board or an aluminum plate. On the substrate 10 11 non-wettable layers 30 are arranged in first sub-areas. These are in this example in Sägespurbereich for later division of the substrate 10. Furthermore, metallizations 15 are present on the substrate, on each of which a light-emitting LED chip 20 is applied. These are located on second regions 12 of the substrate 10.

The production of two LEDs is shown using the example of FIG. 1, but with the method only one LED chip 20 or a plurality of LED chips 20 can also be applied to a substrate 10. The LED chip 20 is also coated with a non-wettable layer 30, to the

Side edges and on the side facing away from the substrate 10 top of the chip. The non-wettable layer 30 may comprise a fluorinated silicone, polytetrafluoroethylene or derivatives thereof. The

Coating of the LED chip 20 and the substrate 10 with the non-wettable layer 30 may, for example, by

Photolithography done. The coating of the LED chips 20 takes place prior to their application to the substrate 10 and after their separation from the wafer bundle. The LED chips 20 are glued or soldered to the substrate or to the metallization 15.

In Figure lb), the housing 40 is further shown. This is applied as a liquid housing material and forms due to the non-wetting properties of the non-wettable layer 30 between side walls of the LED chip 20 and the non-wettable layer 30 coated second portions 12 on the substrate. By adjusting the wetting angle, housing with one of the

Substrate remote round surface formed. Due to the symmetrical structure of the non-wettable areas (not visible in FIGS. 1 a to 1 d), the housing forms in wettable areas, the second partial areas 12 on the substrate 10.

The application of the liquid housing material can

For example, by screen printing, spin coating, spraying, jetting, dispensing or pouring done. The housing material may comprise a matrix and a filler. The matrix is for example silicone or epoxy resin, the filler for example T1O2 ·

Thus, the housing material has also reflective

Characteristics, with which the housing 40 also acts as a reflector for light emitted by the LED chip 20. After this Applying the liquid housing material, the housing material is cured, for example at a temperature of 150 ° C. Figure lc) shows the cured housing 40 surrounding the LED chips 20 after the non-wettable layer 30 has been removed. Thus, there is no non-wettable

Layer more on the LED chips 20 and in the first one

Partial regions of the substrate 10. The removal of the non-wettable layer 30, for example, by 02 ^_ plasma, CF4 plasma, Ar plasma and / or isopropanol effected.

The distance between the housing 40 and the LED chip 20 is only as great as the thickness of the removed non-wettable layer 30.

By removing the non-wettable layer 30, it is possible to apply further components or layers. This is shown in Figure ld), where an example

Auskoppellinse 50 above the LED chip 20 and between two

Housing walls 40 is applied. The coupling-out lens 50 can also be applied as a liquid material, form itself between housing walls, which serve as stopper edges, and then hardened. A coupling-out lens can be transparent and thus only decouple the emitted radiation or the emitted light, or it can be filled with phosphor materials, so that the

emitted light can be converted to another wavelength. The presence of the reflective housing 40 increases the coupling-out efficiency of the device in any case. This method can also be used to process a sapphire chip for producing an optoelectronic component.

Figure 2 shows the manufacturing process in a schematic side view in three-dimensional form. Same

Reference numerals denote the same elements as in FIG. 1.

In FIG. 2, by way of example, four light-emitting LED chips 20 are applied to a substrate 10, see FIG. 2b).

In FIG. 2a), the substrate 10 is shown, on which a non-wettable layer 30 is applied in first partial regions 11, and metallizations 15 are applied in second partial regions 12 which are free of the non-wettable layer. The metallizations have a smaller diameter than the second portion, which is present between the first provided with a non-wettable layer portion. Thus, the second portion is partially free of metallization 15. Due to the symmetrical arrangement of the first portion 11, the second portion is 12th

square shaped.

On the metallizations 15 LED chips 20 are applied with two contacts 25 (Figure 2b). Subsequently, liquid casing material is applied to the second portions, between the non-wettable layer 30 and the LED chips 20, as shown in Figure 2c). By Selbstausformung forms a housing 40, which is completed by curing. Subsequently, the non-wettable layer 30 is removed from the substrate 10 and the LED chips 20. FIG. 2d) shows how a coupling-out lens 50 for coupling out the emitted light is applied between the housing 40 via the LED chips 20. This can also be created by self-forming, in which the housing 40 serves as a stopper edge and is helpful for self-formation of the liquid applied material of the coupling-out lens.

Finally, an exemplary contact 60 is shown in FIG. 2e) which contacts the individual LED chips 20. It may be like CPHF contacting here. The substrate 10 may be in the areas in which a non-wettable layer 30 was present, ie the first

Subareas to be separated and thus several components, each with an LED chip 20 are provided.

Thus, a simplified manufacturing method is given, the Selbstausformung a housing 40, and the

Separating only a single material, namely that of the substrate 10 allows.

The invention is not limited to the above

Embodiments limited. Rather, they are too

Combinations thereof and embodiments includes, even if they are not explicitly stated in the embodiments or the claims.

Claims

claims

1. Optoelectronic component having

a substrate (10),

a light emitting chip (20) on the substrate (10), and

- A laterally surrounding the light emitting chip (20) housing (40) on the substrate (10), wherein between

Side walls of the light-emitting chip (20) and the

Housing (40) a distance of less than 2 μπι is present.

2. The component according to the preceding claim, wherein the housing (40) comprises a material comprising a matrix and a filler.

A device according to the preceding claim, wherein the matrix is selected from a group consisting of silicone,

unsaturated polyester and epoxy resin.

4. The device according to any one of claims 2 to 3, wherein the filler is selected from a group comprising ZrC> 2, ZnO, BaSC> 4 and 1O2.

5. The component according to one of the preceding claims, wherein the housing (40) of the chip (20) emitted light

reflected.

6. The component according to one of the preceding claims, wherein the light-emitting chip (20) is an LED chip.

7. Method for producing an optoelectronic

Component having a housing (40), comprising the method steps:

A) coating at least a first portion (11) of a substrate (10) with a non-wettable layer

(30),

B) coating at least one light-emitting chip (20) with a non-wettable layer (30),

C) applying the light-emitting chip (20) on a second subregion (12) of the substrate (10), which is free of the wettable layer (30),

D) applying a liquid housing material on the

Substrate (10),

E) hardening of the housing material,

wherein in the method step D) the housing material between the at least one first portion (11) and side walls of the light-emitting chip (20) on the

Substrate (10) to a housing (40) forms, which in

Process step E) is formed.

8. The method according to the preceding claim, wherein in a process step E) following process step F), the non-wettable layer (30) is removed.

9. The method according to any one of claims 7 or 8, wherein in a method step F) following step G), the substrate (10) in the region of at least a first

Division (11) is shared.

10. The method according to any one of claims 7 to 9, wherein in the method steps A) and B) as a non-wettable layer (30), a material is applied, which consists of a group is selected, the fluorinated silicone,

Polytetrafluoroethylene or derivatives thereof.

A method according to any one of claims 7 to 10, wherein the housing material in step D) is applied by a method selected from the group consisting of screen printing, spin coating, spraying, jetting, dispensing or pouring.

12. The method according to any one of claims 7 to 11, wherein the non-wettable layer (30) in the process steps A) and B) is applied by means of photolithography.

13. The method of claim 8, wherein the non-wettable layer (30) is removed in the process of claim F) with an agent selected from a group that Q> 2 ^~ comprises plasma, CF4 plasma, Ar plasma and isopropanol ,

14. The method according to any one of claims 7 to 13, wherein in step D) a housing material is applied, which comprises a matrix and a filler.

15. The method according to any one of claims 7 to 14, wherein in step B) an LED chip (20) is coated.