WO2019042559A1

WO2019042559A1 - Optoelectronic component

Info

Publication number: WO2019042559A1
Application number: PCT/EP2017/071922
Authority: WO
Inventors: Ee Lian LEE; Chun Siang LAU; Rajah Prakash; Manfred Scheubeck
Original assignee: Osram Opto Semiconductors Gmbh
Priority date: 2017-08-31
Filing date: 2017-08-31
Publication date: 2019-03-07

Abstract

The invention refers to an optoelectronic component comprising a carrier, an optoelectronic chip and an optically active layer. The optoelectronic chip is mounted on a top of the carrier. A barrier layer is arranged on top of the optically active layer, which comprises silicon dioxide.

Description

OPTOELECTRONIC COMPONENT

DESCRIPTION The invention refers to an optoelectronic component and a production method thereof.

Optoelectronic components may comprise a carrier with a semi^¬ conductor chip placed on top of that carrier. The semiconduc- tor chip may be an optoelectronic semiconductor chip, for example a light emitting diode or a diode laser. An optically active layer may be arranged on top of the optoelectronic semiconductor chip or adjacent to the optoelectronic semicon^¬ ductor chip. The optically active layer may be a converter layer or a reflecting layer. The converter layer may be placed on top of the optoelectronic semiconductor chip and may be used to convert light emitted by the semiconductor chip to another wavelength. A transparent cover layer may be used to cover the semiconductor chip and the converter layer. The transparent cover layer may work as an optical element. The reflecting layer may be arranged adjacent to the optoe^¬ lectronic semiconductor chip.

One disadvantage of such an optoelectronic component is that the optically active layer may not be mechanically stable.

Therefore, cracks may occur within the optically active layer leading to an impairment of the optical properties of the op^¬ toelectronic component. An assignment of the invention is to provide an improved op^¬ toelectronic component, in which the optically active layer comprises improved mechanical stability leading to a more stable optoelectronic component. Another assignment of the invention is to provide a production method of such an optoe- lectronic component. The solution of these assignments is disclosed in the inde^¬ pendent claims of this invention. Preferred embodiments are disclosed in the dependent claims. An optoelectronic component comprises a carrier, an optoelec^¬ tronic chip mounted on a top of said carrier and an optically active layer. A barrier layer comprising silicon dioxide is arranged on top of the optically active layer. The barrier layer may be made of silicon dioxide.

The barrier layer comprising silicon dioxide is mechanically stable and therefore increasing the mechanical stability of the optoelectronic component. In one embodiment, a thickness of the barrier layer is be^¬ tween 0.5 and 100 microns, particularly between 0.5 and 20 microns. Within this thickness range, the mechanical proper^¬ ties of the optoelectronic component are increased. One occurring disadvantage of an optoelectronic component may be that cracks may occur within the converter layer, which subsequently propagate to the transparent cover layer. There^¬ fore, the lifetime of the optoelectronic component is reduced as the cracks impair the optical properties of the optoelec- tronic component.

In one embodiment, the optoelectronic component comprises a converter layer as optically active layer and a transparent cover layer. The optoelectronic chip is mounted on top of the carrier. The converter layer is arranged above the optoelec^¬ tronic chip. The converter layer may convert light emitted from the optoelectronic chip to another wavelength. The transparent cover layer is arranged on top of the converter layer and thusly also on top of the optoelectronic semicon- ductor chip. The barrier layer is arranged between the converter layer and the transparent cover layer. This barrier layer comprises silicon dioxide. Due to the barrier layer between the converter layer and the transparent cover layer, cracks occurring within the convert^¬ er layer cannot propagate to the transparent cover layer. Therefore, the optical properties of the optoelectronic com- ponent are enhanced. The silicon dioxide within the barrier layer may be amorphous silicon dioxide or glass. Another al^¬ ternative is monocrystalline silicon dioxide. These silicon dioxide layers are mechanically stabile and thusly able to hinder cracks from the converter layer to propagate to the transparent cover layer.

In one embodiment, the converter layer comprises a silicone based first matrix material with converter particles. Con^¬ verter layers formed by these materials are easily accessible and easily producible.

In one embodiment, the barrier layer is made of oxidized sil^¬ icone. Therefore, the silicone based first matrix material of the converter layer may be oxidized to silicon dioxide to form a barrier layer. Therefore, the forming of the barrier layer is easily achievable.

In one embodiment, the thickness of the barrier layer is within the range between 0.5 and 100 microns, particularly between 0.5 and 20 microns. Within this thickness range, the barrier layer stops cracks from the converter layer to propagate to the transparent cover layer.

In one embodiment, the thickness of the converter layer is within the range between 2 and 80 microns. Within this thick^¬ ness range, the converter layer may be able to convert all the light emitted from the optoelectronic semiconductor chip to another wavelength. Therefore, the barrier layer may comprise a thickness of up to 25 % of the thickness of the con- verter layer. In one embodiment, the thickness of the barrier layer is be^¬ tween 20 and 100 microns. The converter layer comprises a thickness within the range of 50 to 300 microns. In one embodiment, the transparent cover layer comprises a silicone. Transparent cover layers comprising a silicone are easily producible and therefore suitable for optoelectronic components . In one embodiment, the transparent cover layer is formed as an optical element. This optical element may be a lens or a diffusion element.

In one embodiment, the carrier is part of a housing. This housing comprises a cavity. The optoelectronic semiconductor chip, the converter layer and the barrier layer are arranged within the cavity. Subsequently, the cavity is filled by a material forming the transparent cover layer within the cavity.

In one embodiment, the carrier is partly covered with a re^¬ flecting layer. A converter layer is arranged above the reflecting layer. This can be used to reflect light emitted from the optoelectronic semiconductor chip, leading to an increased light output of the optoelectronic component.

In one embodiment, the reflecting layer comprises a second matrix material comprising reflecting particles. These re^¬ flecting particles may be titanium dioxide particles. Titani- urn dioxide is suitable to form reflecting particles, as it has a white appearance and therefore leads to diffused re^¬ flection of light emitted from the optoelectronic semiconduc^¬ tor chip. Therefore, features of the carrier, like lead frames or other contact elements may be concealed by the re- fleeting layer.

One occurring disadvantage of an optoelectronic component may be that cracks occur within a reflecting layer adjacent to the optoelectronic chip. Therefore, oxygen from an area sur^¬ rounding the optoelectronic device may propagate through the reflecting layer, leading to oxidation of inner parts of the optoelectronic component.

In one embodiment, a reflecting layer as optically active layer covers the carrier at least partly. The barrier layer comprising silicon dioxide on top of the reflecting layer prevents oxygen from reaching inner parts of the optoelec- tronic component.

In one embodiment, the optoelectronic chip is attached to the carrier, particularly to a conductive region of the carrier, by a conductive adhesive. The conductive adhesive may be sil- ver conductive paint or silver glue. As most conductive adhe- sives are vulnerable to oxygen due to oxidation processes, it is beneficial to prevent oxygen from reaching the conductive adhesive, utilizing the barrier layer on top of the reflect^¬ ing layer.

In one embodiment, the reflecting layer comprises a silicone based second matrix material with reflecting particles. Such reflecting layers are easily achievable. In one embodiment, the barrier layer is made of oxidized sil^¬ icone. Particularly the silicone based second matrix material may be oxidized to form the silicon dioxide of the barrier layer . In one embodiment, the reflecting particles comprise titanium dioxide particles. Titanium dioxide powder immersed within the second matrix material leads to a white reflecting layer, reflecting light of the visible spectrum. In one embodiment, the optoelectronic component comprises the barrier layer on top of the reflecting layer, a converter layer and a transparent cover layer. The converter layer is arranged on top of the optoelectronic chip. The transparent cover layer is arranged on top of the converter layer. Between the converter layer and the transparent cover layer another barrier layer is arranged. This other barrier also comprises silicon dioxide.

Therefore, both the converter layer and the reflecting layer comprise a barrier layer with the advantages of the layers explained above. In one embodiment, the converter layer comprises a silicon based first matrix material with converter particles. In one embodiment, the other barrier layer is made of oxidized sili^¬ cone . In one embodiment, the optoelectronic chip comprises a light emitting diode or a diode laser.

To produce an optoelectronic component, initially a carrier is provided. Subsequently, an optoelectronic chip is mounted on top of the carrier. Thereafter, a converter layer is deposited on top of the optoelectronic chip. Subsequently, a barrier layer is formed. The barrier layer comprises silicon dioxide. As a final step, a transparent cover layer is ar^¬ ranged on top of the barrier layer.

In one embodiment of the method, the barrier layer is formed using an oxygen plasma. A silicone based first matrix material comprising silicone is oxidized within the oxygen plasma, forming the silicon dioxide of the barrier layer. The silicon dioxide thereby may be amorphous silicon dioxide, for in^¬ stance glass. Alternatively, the silicon dioxide may be mono- or polycrystalline silicon dioxide.

The production of an optoelectronic component may also com- prise the initial step of providing a carrier. Subsequently, an optoelectronic chip is mounted on top of the carrier. A reflecting layer is deposited, partially covering the carri- er. A barrier layer is formed on top of the reflecting layer. Thereby, the barrier layer comprises silicon dioxide.

In one embodiment, the optoelectronic chip is mounted to the carrier using a conductive adhesive, particularly silver conductive paint or silver glue.

In one embodiment, the reflecting layer comprises a silicon based second matrix material comprising reflecting particles, particularly titanium oxide particles. The barrier layer is formed by an oxidation process of the second matrix material, forming the silicon dioxide of the barrier layer. The silicon dioxide thereby may be amorphous silicon dioxide, for in^¬ stance glass. Alternatively, the silicon dioxide may be mono- or polycrystalline silicon dioxide

The oxidation process may be executed using a low-pressure oxygen plasma. Low-pressure in this context means that the pressure of oxygen during the plasma application is well be- low atmospheric pressure, typically below 100 or even below 10 Pascal.

In one embodiment, the low-pressure oxygen plasma comprises an oxygen flow in the range between 40 and 80 standard cubic centimeters per minute. Standard cubic centimeter per minute in this context means that the amount of oxygen induced to a plasma chamber is similar to the amount of oxygen within a volume of one cubic centimeter at standard conditions (273.15 Kelvin and 1.0325 bar) per minute. Therefore one standard cu- bic centimeter of oxygen per minute corresponds to 1.429 mil^¬ ligram of oxygen per minute. Within the plasma chamber, a voltage is applied to two electrodes, typically above 100 volt up to several kilovolt. Due to the voltage, the oxygen is ionized forming positively charged oxygen ions and elec- trons . Therefore, a current flows between the electrodes. A power of this current is within the range of 300 to 700 watt, and therefore such a power is applied to the oxygen plasma. The oxygen plasma is applied for a time within the range of 150 to 450 seconds. With these parameters, the silicon diox^¬ ide is formed, leading to the improvement of the optoelec^¬ tronic component as described above. In one embodiment, the oxygen flow is in the range between 45 and 55 standard cubic centimeters per minute, the power is within the range of 450 to 550 watt, and the oxygen plasma is applied for a time within the range of 270 to 330 seconds. These parameters may be typically applied to form silicon di- oxide.

In one embodiment, the converter layer comprises a silicone based first matrix material with converter particles. The barrier layer is formed by an oxidation process of the first matrix material due to the oxygen plasma. The converter par^¬ ticles may comprise a higher density than the first matrix material. In this case, after the deposition of the converter layer, the converter particles sink within the first matrix material, leading to a higher concentration of converter par- tides adjacent to the optoelectronic chip within the con^¬ verter layer. A concentration of converter particles on the opposite site of the converter layer, opposite of the optoe^¬ lectronic semiconductor chip, may be smaller or even zero. Subsequently, the first matrix material comprising silicone opposite of the optoelectronic semiconductor chip is oxidized forming silicon dioxide during the oxygen plasma step. Using this process, the barrier layer may easily be achieved.

The oxygen plasma may also be used to oxidize both the sili- con based first matrix material of the converter layer and the silicon based second matrix material of the reflecting layer in one oxidation step. Therefore, both reflecting layer and converter layer are deposited previous to the oxidation process due to the oxygen plasma.

In one embodiment of the method, the converter layer is de^¬ posited using a spray coating process. In one embodiment, the transparent cover material is arranged by a mold process. Thereby, the case mold may be in the form of an optical element, leading to a transparent cover layer forming an optical element.

In one embodiment of the method, the carrier is part of a housing. The housing comprises a cavity wherein the optoelec^¬ tronic chip and the converter layer are arranged. The barrier layer is formed within the cavity, for example by the oxygen plasma step. Subsequently, the material of the transparent cover layer is inserted to the cavity to at least partially fill the cavity. The material forming the transparent cover layer may also completely fill the cavity. The above described properties, features and advantages of this invention as well as the method of obtaining them, will be more clearly and obviously understandable in the context of the following description of the embodiments, which are explained in more detail in the context of the Figures.

In schematic illustration show

Fig. 1 a cross section through an optoelectronic

component ;

Fig. 2 a cross section of another optoelectronic

component ;

Fig. 3 a cross section of another optoelectronic

component;

Fig. 4 a cross section of another optoelectronic

component ; Figs. 5 to 7 intermediate steps during the production of an optoelectronic component; Fig. 8 a cross section of another optoelectronic

component ;

Fig. 9 a cross section of another optoelectronic

component ;

Fig. 10 a cross section of another optoelectronic

component ;

Fig. 11 a cross section of another optoelectronic

component ;

Figs. 12 to 14 intermediate steps during the production of an optoelectronic component.

Fig. 1 shows a cross section of an optoelectronic component 1, comprising a carrier 2, an optoelectronic chip 3, a converter layer 4 and a transparent cover layer 5. The optoelec^¬ tronic chip 3 is mounted on top of the carrier 2. Above the optoelectronic chip 3, the converter layer 4 is arranged. On top of the converter layer 4, a barrier layer 6 is arranged. The transparent cover layer 5 is arranged on top of the con^¬ verter layer 4. Therefore, the barrier layer 6 is arranged between the converter layer 4 and the transparent cover layer 5. The barrier layer 6 comprises silicon dioxide.

Cracks occurring in the converter layer 4 therefore cannot propagate to the transparent cover layer 5, as the propaga^¬ tion of the cracks is stopped by the barrier layer 6 between the converter layer 4 and the transparent cover layer 5. Sil^¬ icon dioxide is a material well suited to stop cracks from propagating and thusly a suitable material for the barrier layer 6. The converter layer 4 acts as an optically active layer, as light emitted from the optoelectronic chip 3 may be converted to another wavelength within the converter layer 4. In one embodiment, the converter layer 4 comprises a silicone based first matrix material with converter particles. In one embodiment, the barrier layer 6 is made of oxidized silicone. Therefore, the barrier layer 6 may be made of oxidized sili- cone from the converter layer 4, especially from an oxidation process of the first matrix material of the converter layer 4.

In one embodiment, the thickness of the barrier layer 6 is within the range between 0.5 and 100 microns, particularly between 0.5 and 20 microns. In one embodiment, the thickness of the converter layer 4 is within the range between 2 and 80 microns. In one embodiment, the transparent cover layer 5 comprises a silicone.

Fig. 2 shows a cross section of another embodiment of an op^¬ toelectronic component 1, comprising a carrier 2, an optoe^¬ lectronic chip 3, a converter layer 4, a transparent cover layer 5 and a barrier layer 6. The transparent cover layer 5 is formed as an optical element 7, in the embodiment of Fig. 2 as a lens. The transparent cover layer 5 forming the opti^¬ cal element 7 still covers the carrier 2, the optoelectronic chip 3, the converter layer 4 and the barrier layer 6. The optical element 7 is formed as a convex lens. It is also possible that the optical element 7 forms a concave lens. Al^¬ ternatively, the optical element 7 may be a diffusion ele^¬ ment. In one embodiment, the transparent cover layer 5 com^¬ prises diffusing particles to diffuse light emitted from the optoelectronic semiconductor chip 3.

Fig. 3 shows a cross section of an optoelectronic component 1, wherein the carrier 2 is part of a housing 8. The housing 8 comprises a cavity 9, in which the optoelectronic chip 3, the converter layer 4 and the barrier layer 6 are arranged. The transparent cover layer 5 is arranged within the cavity 9, fully filling the cavity 9. The transparent cover layer 5 may also only fill the cavity 9 partially. Furthermore, the transparent cover layer 6 may be forming an optical element comparable to the optical element 7 of Fig. 2 within the cav^¬ ity 9 of Fig. 3. In the embodiments of Figs. 1 to 3, the optoelectronic chip 3, the converter layer 4 and the barrier layer 6 are stacked on top of each other. It is also possible that the barrier layer 6 covers side portions of the converter layer 4. Fig. 4 shows a cross section through another embodiment of an optoelectronic component 1. Adjacent to an optoelectronic chip 3 on top of a carrier 2, a reflecting layer 10 is arranged, partially covering the carrier 2. The reflecting layer 10 may comprise the same height as the optoelectronic chip 3 adjacent to the optoelectronic chip, as shown in Fig. 4. On the other hand, the reflecting layer 10 may comprise a lower height than the optoelectronic chip 3. A converter layer 4 is arranged on top of the optoelectronic chip 3 and parts of the reflecting layer 10. A barrier layer 6 is arranged on top of the converter layer 4 and therefore also above parts of the reflecting layer 10. A transparent cover layer 5, which is formed similar to the transparent cover layer of Fig. 1, is arranged on top of the barrier layer 6. Therefore, the converter layer 4 extends to areas above the carrier 2, but not above the optoelectronic chip 3. The con^¬ verter layers 4 of Figs. 1 to 3 may also extend to areas above the carrier 2, but not above the optoelectronic chip 3, although no reflecting layer 10 is present in the embodiments of Figs. 1 to 4.

The reflecting layer 10 and the shape of the converter layer 4 and the barrier layer 6 may also be applied to the optoe^¬ lectronic components 1 of Fig. 1 to 3.

In one embodiment, the reflecting layer 10 comprises a second matrix material comprising reflecting particles. The reflect^¬ ing particles may be titanium dioxide particles. Fig. 5 shows an intermediate step during a production of an optoelectronic component. An optoelectronic chip 3 is mounted on top of a carrier 2. Subsequently, a converter layer 4 has been deposited on top of the optoelectronic chip 3. In the embodiment of Fig. 5, the converter layer 4 comprises a first matrix material 11 with converter particles 12. Alternative^¬ ly, other forms of converter layers 4 may be applicable. In a next production step, a barrier layer 6 is formed on top of the converter layer 4. This formation of the barrier layer 6 may be performed using an oxygen plasma. Another cross sec^¬ tion of an intermediate product of this step is shown in Fig. 6. In the example of Fig. 6, the converter particles 12 com^¬ prise a higher density than the first matrix material 11. Therefore, the converter particles 12 sink within the con^¬ verter layer 4, leading to an increased concentration of converter particles 12 adjacent to the optoelectronic chip 3, wherein an upper region 13 of the converter layer 4 is free from converter particles 12. Applying the intermediate prod- uct of Fig. 6 to an oxygen plasma leads to an oxidation of the upper region 13 of the converter layer 4, thereby forming a barrier layer on top of the converter layer 4.

Fig. 7 shows a cross section of the intermediate product of Fig. 6 after the oxygen plasma has been applied. On top of the converter layer 4, the upper region 13 of the converter layer 4 has been oxidized to form a barrier layer 6. Subsequently, the optoelectronic chip 3, the converter layer 4 and the barrier layer 6 have been covered by a transparent cover layer 5, thereby forming an optoelectronic component 1 simi^¬ lar to the optoelectronic component 1 of Fig. 1.

The oxidation process may be executed using a low-pressure oxygen plasma. Low-pressure in this context means that the pressure of oxygen during the plasma application is well be^¬ low atmospheric pressure, typically below 100 or even below 10 Pascal. In one embodiment, the low-pressure oxygen plasma comprises an oxygen flow to a plasma chamber in the range between 40 and 80 standard cubic centimeters per minute. Within the plasma chamber, a voltage is applied to two electrodes, typi- cally above 100 volt up to several kilovolt. Due to the volt^¬ age, the oxygen is ionized forming positively charged oxygen ions and electrons. Therefore, a current flows between the electrodes. A power of this current is within the range of 300 to 700 watt, and therefore such a power is applied to the oxygen plasma. The oxygen plasma is applied for a time within the range of 150 to 450 seconds.

In one embodiment, the oxygen flow is in the range between 45 and 55 standard cubic centimeters per minute, the power is within the range of 450 to 550 watt, and the oxygen plasma is applied for a time within the range of 270 to 330 seconds. In one embodiment, the first matrix material 11 is silicone based. Therefore, during the oxygen plasma step, the silicone based first matrix material 11 is oxidized to silicon dioxide forming the barrier layer 6.

Fig. 8 shows a cross section of an optoelectronic component 1 comprising a carrier 2 and an optoelectronic chip 3 mounted on top of the carrier 2. A reflecting layer 10 is arranged adjacent to the optoelectronic chip 3, partially covering the carrier 2. A barrier layer 6 comprising silicon dioxide is arranged on top of the reflecting layer 10, sealing the re^¬ flecting layer 10 from the surroundings. Therefore, the inner parts of the optoelectronic component 1 are less prone to ox- idation.

The reflecting layer 10 thereby acts as an optically active layer, as light is reflected by the reflecting layer 10. Fig. 9 shows a cross section of another embodiment of an op^¬ toelectronic component 1, largely similar to the optoelec^¬ tronic component of Fig. 8. The reflecting layer 10 in this embodiment fully covers the carrier 2. The optoelectronic chip 3 is attached to the carrier 2, particularly to a conductive area of the carrier 2, by a conductive adhesive 14. The conductive adhesive 14 may be silver conductive paint or silver glue. The conductive adhesive 14 may be prone to oxi- dation, which may be prevented by the barrier layer 6, as ox^¬ ygen from the surroundings is hindered from penetrating the reflecting layer 10 due to the barrier layer 6.

Fig. 10 shows a cross section of another embodiment of an op- toelectronic component 1, largely similar to the optoelec^¬ tronic component of Figs. 8 and 9. The reflecting layer 10 comprises a silicone based second matrix material 15 compris^¬ ing reflecting particles 16. The reflecting particles 16 may comprise titanium dioxide, particularly titanium dioxide pow- der. The barrier layer 6 may be formed by an oxidation of the second matrix material. The barrier layer 6 may comprise or be made of oxidized silicone.

The embodiments of Figs. 8 to 10 may comprise a transparent cover layer 5 similar to the transparent cover layers of Figs. 1 to 4.

Fig. 11 shows a cross section of an optoelectronic component 1 comprising a carrier 2 and an optoelectronic chip 3 mounted on top of the carrier 2. Adjacent to the optoelectronic chip 3, the carrier 2 is covered by a reflecting layer 10 with a barrier layer 6 as explained with regard to Figs. 8 to 10. Above the optoelectronic chip 3, a converter layer 4 is ar^¬ ranged. On top of the converter layer 4, another barrier lay- er 17 is arranged. A transparent cover layer 5 is arranged on top of the converter layer 4. Therefore, the other barrier layer 17 is arranged between the converter layer 4 and the transparent cover layer 5. The barrier layer 6 and the other barrier layer 17 comprise silicon dioxide.

Therefore, the advantages of both barrier layers 6, 17 may be utilized within one optoelectronic component 1. The converter layer 4, the transparent cover layer 5 and the other barrier layer 17 may be realized similar to any of Figs. 1 to 4.

In one embodiment, the optoelectronic chip 3 comprises a light emitting diode or a diode laser.

Fig. 12 shows an intermediate step during a production of an optoelectronic component. An optoelectronic chip 3 is mounted on top of a carrier 2. Subsequently, a reflecting layer 10 has been deposited on top of the carrier 2, covering the carrier 2. Alternatively, the reflecting layer 10 may only partially cover the carrier 2. In the embodiment of Fig. 12, the reflecting layer 10 comprises a second matrix material 15 with reflecting particles 16. Alternatively, other forms of reflecting layers 10 may be applicable. In a next production step, a barrier layer 6 is formed on top of the reflecting layer 10. This formation of the barrier layer 6 may be performed using an oxygen plasma. Another cross section of an intermediate product of this step is shown in Fig. 13. In the example of Fig. 13, the reflecting particles 16 comprise a higher density than the second matrix material 15. Therefore, the reflecting particles 16 sink within the reflecting layer 10, leading to an increased concentration of reflecting particles 16 adjacent to the carrier 2, wherein an upper region 18 of the reflecting layer 10 is free from reflecting particles 16. Applying the intermediate product of Fig. 13 to an oxygen plasma leads to an oxidation of the upper region 18 of the reflecting layer 10, thereby forming a barrier layer on top of the reflecting layer 10.

Fig. 14 shows a cross section of the intermediate product of Fig. 13 after the oxygen plasma has been applied. On top of the reflecting layer 10, the upper region 18 of the reflecting layer 10 has been oxidized to form a barrier layer 6, thereby forming an optoelectronic component 1 similar to the optoelectronic component 1 of Fig. 8. In one embodiment, the optoelectronic chip 3 is mounted to the carrier 2 using a conductive adhesive 14, particularly silver conductive paint or silver glue. The oxidation process may be executed using a low-pressure oxygen plasma. Low-pressure in this context means that the pressure of oxygen during the plasma application is well be^¬ low atmospheric pressure, typically below 100 or even below 10 Pascal.

In one embodiment, the low-pressure oxygen plasma comprises an oxygen flow to a plasma chamber in the range between 40 and 80 standard cubic centimeters per minute. Within the plasma chamber, a voltage is applied to two electrodes, typi- cally above 100 volt up to several kilovolt. Due to the volt^¬ age, the oxygen is ionized forming positively charged oxygen ions and electrons. Therefore, a current flows between the electrodes. A power of this current is within the range of 300 to 700 watt, and therefore such a power is applied to the oxygen plasma. The oxygen plasma is applied for a time within the range of 150 to 450 seconds.

In one embodiment, both a reflecting layer 10 and a converter layer 4 are deposited. The converter layer 4 comprises a sil^¬ icone based first matrix material 11 with converter particles 12 as described above. The reflecting layer 10 comprises a silicone based second matrix material 15 with reflecting par^¬ ticles 16 as described above. Subsequently, both matrix mate^¬ rials are oxidized within an oxygen plasma as described above, leading to the barrier layer 6 and the other barrier layer 17 of Fig. 11.

In one embodiment, the converter layer 4 is deposited using a spray coating process.

In one embodiment, the transparent cover layer is arranged by a mold process. Depending on the case mold, the shape of the transparent cover layer 5 can be similar to Figs. 1 or 2.

In one embodiment, the carrier 2 is part of a housing 8, wherein the housing 8 comprises a cavity 9. The optoelectronic chip 3, the converter layer 4 and the barrier layer 6 are arranged or formed within the cavity 9. Subsequently, the cavity 9 is filled with a material forming the transparent cover layer. Thereby, the cavity 9 may be fully or partially filled. During the filling, the cavity 9 may also be covered by a forming part of a mold case, and the material forming the transparent cover layer 5 may be molded into the cavity 9.

Although the invention was described and illustrated in more detail using preferred embodiments, the invention is not lim^¬ ited to these. Variants of the invention may be derived by a person skilled in the art from the described embodiments without leaving the scope of the invention.

REFERENCE NUMERALS

1 optoelectronic component

2 carrier

3 optoelectronic chip

4 converter layer

5 transparent cover layer

6 barrier layer

7 element

8 housing

9 cavity

10 reflecting layer

11 first matrix material

12 converter particles

13 upper region of the converter layer

14 conductive adhesive

15 second matrix material

16 reflecting particles

17 other barrier layer

18 upper region of the reflecting layer

Claims

An optoelectronic component (1) comprising a carrier (2), an optoelectronic chip (3), an optically active layer (4, 10), wherein the optoelectronic chip (3) is mounted on a top of the carrier (2), wherein a barrier layer (6) is arranged at a top of the optically active layer (4, 10), and wherein the barrier layer (6) comprises silicon dioxide .

The optoelectronic component (1) of claim 1, wherein the thickness of the barrier layer (6) is within the range between 0.5 and 100 microns, particularly between 0.5 and 20 microns.

The optoelectronic component (1) of claims 1 or 2, where^¬ in the optically active layer is a converter layer (4) arranged on top of the optoelectronic chip (3) , wherein the optoelectronic component (1) further comprises a transparent cover layer (5) , wherein the converter layer (4) is arranged above the optoelectronic chip (3), where^¬ in the transparent cover layer (5) is arranged on top of the converter layer (4), wherein the barrier layer (6) is arranged between the converter layer (4) and the transparent cover layer (5) .

The optoelectronic component (1) of claim 3, wherein the converter layer (4) comprises a silicone based first ma^¬ trix material (11) with converter particles (12) .

The optoelectronic component (1) of claim 4, wherein the barrier layer (6) is made of oxidized silicone.

The optoelectronic component (1) of any of the claims 3 to 5, wherein the carrier (2) is partly covered with a reflecting layer (10), wherein the converter layer (4) is arranged above the reflecting layer (10) . The optoelectronic component (1) of claims 1 or 2, where^¬ in the optically active layer is a reflecting layer (10), wherein the carrier (2) is at least partly covered by the reflecting layer (10) .

The optoelectronic component (1) of claim 7, wherein the optoelectronic chip (3) is attached to the carrier (2) by a conductive adhesive (14), wherein the reflecting layer

(10) comprises a silicon based second matrix material

(15) comprising reflective particles (16).

The optoelectronic component (1) of claim 8, wherein the barrier layer (6) is made of oxidized silicone.

The optoelectronic component (1) of claims 8 or 9, where^¬ in the reflecting particles (16) comprise titanium diox^¬ ide .

The optoelectronic component (1) of claims 8 to 10, fur^¬ ther comprising a converter layer (4) and a transparent cover layer (5), wherein the converter layer (4) is arranged above the optoelectronic chip (3) , wherein the transparent cover layer (5) is arranged on top of the converter layer (4), wherein another barrier layer (17) is arranged between the converter layer (4) and the transparent cover layer (5) , and wherein the other barrier layer (17) comprises silicon dioxide.

The optoelectronic component (1) of claim 11, wherein the converter layer (4) comprises a silicone based first ma^¬ trix material (11) with converter particles (12) .

13. The optoelectronic component (1) of claim 12, wherein the other barrier layer (17) is made of oxidized silicone. A method of producing an optoelectronic component (1) comprising the steps:

- Providing a carrier (2);

- Mounting an optoelectronic chip (3) on a top of the carrier (2 ) ;

- Depositing of a converter layer (4) on top of the optoelectronic chip (3) ;

- Forming of a barrier layer (6), wherein the barrier layer (6) comprises silicon dioxide;

- Arranging a transparent cover layer (5) on top of the barrier layer (6) .

The method of claim 14, wherein the converter layer (4) comprises a silicone based first matrix material (11) with converter particles (12), and wherein the barrier layer (6) is formed by an oxidation process of the first matrix material (11) due to an oxygen plasma.

A method of producing an optoelectronic component (1) comprising the steps:

- Providing a carrier (2);

- Mounting an optoelectronic chip (3) on a top of the carrier (2 ) ;

- Depositing of a reflecting layer (10), partly covering the carrier (2);

- Forming of a barrier layer (6), wherein the barrier layer (6) comprises silicon dioxide.

The method of claim 16, wherein the optoelectronic chip (3) is mounted to the carrier (2) using a conductive ad^¬ hesive ( 14 ) .

The method of claims 16 or 17, wherein the reflecting layer (10) comprises a silicon based second matrix mate^¬ rial (15) comprising reflecting particles (16), particu^¬ larly titanium oxide particles, and wherein the barrier layer (6) is formed by an oxidation process of the sec^¬ ond matrix material (15) due to an oxygen plasma. The method of claim 15 or 18, wherein the oxygen plasma is a low-pressure plasma with an oxygen flow in the range between 40 and 80 standard cubic centimeters per minute, wherein a power within the range of 300 to 700 watt is applied to the oxygen plasma, and wherein the oxygen plasma is applied for a time within the range of 150 to 450 seconds.

The method of claim 19, wherein the oxygen flow is in the range between 45 and 55 standard cubic centimeters per minute, wherein the power is within the range of 450 to 550 watt, and wherein the oxygen plasma is applied for a time within the range of 270 to 330 seconds.