WO2017055401A1

WO2017055401A1 - Component comprising a light emitting semiconductor chip

Info

Publication number: WO2017055401A1
Application number: PCT/EP2016/073189
Authority: WO
Inventors: Gunnar Petersen; Konrad Wagner; Peter Brick; Daniel Wiener
Original assignee: Osram Opto Semiconductors Gmbh
Priority date: 2015-09-30
Filing date: 2016-09-29
Publication date: 2017-04-06
Also published as: DE102015116595A1

Abstract

The invention relates to a component (1) comprising a light emitting semiconductor chip (1), and a cover (4) for the semiconductor chip (2); the cover (4) is placed over the emitting side of the semiconductor chip (2) and has an emitting side (6) which has a structured surface (9, 23).

Description

CONSTRUCTION ELEMENT WITH A LIGHT-EMITTING SEMICONDUCTOR CHIP

DESCRIPTION The invention relates to a device with a light emit ^¬ animal semiconductor chip according to claim. 1

This patent application claims the priority of German Patent Application 10 2015 116 595.3, the disclosure of which is hereby incorporated by reference.

In the prior art, it is known to provide components with light-emitting semiconductor chips, wherein the semiconductor chip is provided with a cover for protection against environmental influences.

The object of the invention is to provide a device with improved luminance. The object of the invention is achieved by the device according to Pa ^¬ tentanspruch 1. Further embodiments are given in the dependent claims.

The proposed device has the advantage that the luminance is increased in a radiation region of the component. The increased luminance is achieved in that the cover has a structured surface on a radiation side. Due to the structured surface, more light can be coupled out and / or improved radiation in the desired direction can be achieved.

In one embodiment, the structured surface is in the form of planar surfaces, which are arranged in an angular range between 40 ° and 80 ° relative to a surface normal of the Ab- beam side. By the arrangement of the plan

Surfaces in this angular range, an improved beam steering is achieved in the desired emission range. An increase of the luminance is achieved by an improved radiating when the planar surfaces are arranged with respect to an angular range between 50 ° and 75 ° to the surface of the emission side Norma ^¬ le.

In one embodiment, the structured surface of a roughened surface, the roughened surface was prepared for example with ^¬ means of grinding and / or by means of particle beams. The roughened surface may have an average roughness in the range of 0.1 ym to 10 ym. Furthermore, the average roughness can be in the range of 0.1 to 1 μm, in particular in the range of 0.4 μm. As a result, a better coupling of the light and an increase in the luminance he ^¬ reaches.

An increase in the luminance is achieved by better off ^¬ coupling when at least 30% of the emission side have a structured surface.

The flat surfaces can be statistically distributed on the emission side. In a further embodiment, the planar surfaces are designed to be planar at least in one direction, wherein the surfaces are designed to be plane in particular in two directions or, in particular, are designed to be rotationally symmetrical with respect to an axis. The structured surfaces may be in the form of conical surfaces, in the form of pyramidal surfaces or in the form of prismatic surfaces. The structured surfaces can be evenly distributed on the emission side. Also in this manner a raised stabili ^¬ hung luminance is achieved in the emission direction.

In one embodiment, the cover is arranged at a distance from the semiconductor chip. In this case, an air gap between the semiconductor chip and the cover may be provided. In addition, in a further embodiment, a material layer, in particular an adhesive layer, may be provided between the cover and the semiconductor chip. In a further embodiment, the cover has at least a first and a second layer, wherein the first layer has the emission side, and wherein the first

Layer and the second layer are formed in particular of different materials. The two-part embodiment of the Ab ^¬ cover provides increased flexibility in the manufacture of the cover. Thus, the first layer may for example be formed in the form of a thin film, wherein the second layer may be formed in the form of a glass plate.

In one embodiment, the first layer is formed from a substrate. In addition, the cover, that is to say the first and / or the second layer, may at least partially comprise glass, sapphire, plastic, silicone, epoxy material or semiconductor material.

In a further embodiment, the semiconductor chip and / or the cover are laterally surrounded by a frame, wherein the frame is at least partially light-reflecting and / or light-scattering. For example, the frame may include a material that reflects white light. In this way, a further increase in light ^¬ density is achieved as a side emitting light ER is more difficult.

In one embodiment, the structured surface of the Ab ^¬ cover is provided with a cover layer, wherein the Bre ^¬ deviation index of the material of the structured surface is not equal to the refractive index of the cover layer. In particular, the refractive index of the material of the structured surface is greater than the refractive index of the covering layer. As a result, an improved radiation can be achieved. The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments. Games, which are explained in more detail in connection with the drawings. 1 shows a component with a semiconductor chip and a cover, the emission side being in the form of a separate layer,

FIG. 2 shows a schematic view from above of a component with a roughened surface,

3 shows a second embodiment of a component, wherein the cover is formed integrally with the structured emission side,

FIG. 4 shows a further embodiment of a component in which the component and the cover are surrounded by a reflecting frame,

Figure 5 shows another embodiment of a device in which the cover is mounted on the semiconductor chip, Figure 6 is a schematic top view of the device of Figure 5, and

Figure 7 is a schematic diagram of a luminance in response to a flank angle of the structured FLAE ^¬ chen.

1 shows a schematic representation of a first embodiment of the device 1, which has a light emittie ^¬ in power semiconductor chip. 2 The semiconductor chip 2 is arranged on a carrier 3. In addition, a cover 4 is provided, which protects the semiconductor chip 2, for example against environmental influences. The cover 4 is fastened on the carrier 3 and covers an upper side 6 and four side surfaces 7 of the semiconductor chip 2. The semiconductor chip 2 is ^{ausgebil ¬} det to emit light, that is electromagnetic radiation on the top 6. By way of example, the semiconductor chip 2 is designed in the form of a light-emitting diode. The semiconductor chip 2 can be designed as a surface emitter of the volume emitter. The cover 4 has a layer 8 which is arranged gegenüberlie ^¬ ing to the upper side 6 of the semiconductor chip 2 on a Obersei ^¬ te the cover 4. The layer 8 has an emission side 5 with a structured surface 9 on an upper side. The structured surface may be formed in the form of pla ^¬ nen surfaces 9, which are arranged in an angular range 21 between 40 ° and 80 ° relative to a surface normal 10 of the emission side 5 of the cover 4. The angle ^{¬ range} 21 relative to the surface normal 10 between 40 ° and 80 ° corresponds to a flank angle 22 of the flat surfaces 9 between 10 ° and 50 °. In the ^illustrated embodiment, the surface normal 10 is also perpendicular to a plane of the upper side 6 of the semiconductor chip 2. The layer 8 is ^{likewise arranged} parallel to the plane of the upper side 6 of the semiconductor chip 2. The light emitted by the semiconductor chip 2 is emitted in a rotationally symmetrically arranged emitting region 11. The emitting region 11 may be provided in an emission cone with an opening width of 120 °, which is Rotati ^¬ onssymmetrisch and arranged centrally relative to the emission side. 5

The angular arrangement of the flat surfaces 9 can be identical for all surfaces 9. In addition, the flat surfaces 9 in the angular range between 40 ° and 80 °, in particular between 50 ° and 75 ° relative to the emission direction 10 may be arranged at different angles.

Depending on the selected embodiment, the structured surface may also be formed as a roughened surface. The roughened surface may have an average roughness (in a tactile measurement) in the range of 0.1 ym to 10 ym. In particular, the roughness can be in the range of 0.1 to 1 μm, in particular in the range of 0.4 μm. The roughened surface can be produced using a grinding process or a par ^¬ tikelstrahlverfahrens.

In addition, depending on the selected embodiment, not the entire emission side 5 of the cover 4, but only a predetermined portion of the emission side 5, a structured Have surface. For example, already produce a ge ^¬ desired increase in the luminance in the emitting area 11 on the emission side 5 for 30% of constructive ^¬ structure surface.

For example, the flat surfaces 9 may be formed at least in plan ei ^¬ ner direction. For example, the structured surfaces 9 may be formed in the form of conical surfaces, which are rotationally symmetrical to the emission direction 10. In addition, the structured surfaces can also be designed in the form of pyramidal surfaces or in the form of prismatic surfaces. The structured surfaces 9 may be arranged in a periodic pattern or randomly distributed on the emission side 5. In addition, 5 different types of structured surfaces may be provided on the emission side, which are arranged in the angular range between 40 ° and 80 ° relative to the emission direction 10, in particular in a Winkelbe ^¬ rich between 50 ° and 75 ° relative to the emission direction 10.

In addition, the emission side 6 aufwei ^¬ sen structured surfaces, which are formed in the form of flat surfaces, wherein the flat surfaces are arranged in the angular range between 40 ° and 80 ° to the emission direction 10, and wherein the flat surfaces are also roughened. The planar surfaces may have an average roughness in the range of 0.1 to 10 ym ym aufwei ^¬ sen.

In addition, the emission side 6 can have partial surfaces with flat surfaces and partial surfaces with roughened surfaces. The flat surfaces are arranged in the angular range between 40 ° and 80 ° to the emission direction 10. The roughened surfaces have an average roughness in the range of 0.1 ym to 10 ym.

The layer 8 may be formed for example in the form of a film or a substrate. The cover 4 may be in the form of silicone, plastic, plastic, sapphire, glass or Semiconductor material may be formed. In the illustrated embodiment, an air gap 13 is vorgese ^¬ hen between the cover 4 and the top 6 of the semiconductor chip 2. Depending on the selected embodiment, instead of the air gap 13, a material layer may also be provided in order, for example, to achieve better matching of the refractive indices.

In another embodiment, the radiation face 5 of the layer 8 is covered with a covering layer 24, as shown in Fi gur ^¬. 1 The refractive index of the layer 8 is not equal to the refractive index of the cover layer 24 Insbesonde ^¬ re the refractive index of the layer 8 is larger than the Bre ^¬ deviation index of the covering layer 24. However, it may also be dispensed with the cover 24th

Figure 2 shows a schematic representation of a device 1, which is constructed substantially in accordance with Figure 1, but where the radiation face 5 of the cover 4 with an up roughened surface 23 is provided at ^¬. Depending on the selected

Embodiment, only a part of the emission side 5 may be provided with a roughened surface 23. In addition, only a part of the emission side 5 of the cover 4 can be provided with flat surfaces. Furthermore, a part of the emission side 5 of the cover 4 may be provided with flat surfaces and with a roughened surface. Furthermore, at least a part of the emission side 5 of the cover 4 can be provided with planar surfaces, wherein the planar surfaces also have a roughness. The roughness can be in the range between 0.1 .mu.m and 10 .mu.m.

Also in this embodiment, the emission side 5 of the

Layer 8 may be covered with a cover layer 24. The Bre ^¬ deviation index of the layer 8 is equal to 24. In particular, the refractive index of the cover layer is the refractive index of the

Layer 8 is larger than the refractive index of the covering layer 24. However, it can dispense with the covering layer 24 ^¬ the. Figure 3 shows a further embodiment of the device 1, in this embodiment, the cover 4 is not in two parts, but formed integrally and the structured surfaces 9 are located on the emission side 5 of the Abde ^¬ ckung. 4 The structured surfaces 9 may be formed according to the embodiment of FIG. Also in this embodiment, the structured surfaces 9 of the cover 4 may be covered with a cover layer 24, as shown in FIG. The structured surfaces 9 are formed, for example, of the same material as the cover 4. The refractive index of the cover 4 is not equal to 24, the refractive index of the cover layer specifically, the Bre ^¬ deviation index of the cover 4 is larger than the refractive index of the cladding layer 24. However, it may also be dispensed with the cover 24th

Figure 4 shows a further embodiment in which the Abde ^¬ ckung 4 is laterally surrounded by a frame 15th In addition, between the cover 4 and the semiconductor chip 2, an air gap 13 or a material layer with a low Bre ^¬ index of index, for example 1 is arranged. The frame 15 is formed of a light-reflecting and / or light-scattering material and serves to reflect laterally emitted light back toward the cover 4 or in the emission area 11 or to scatter. The frame 15 may be formed, for example, to scatter white light. For example, the frame 15 may have Ti ^¬ tanoxid, which is embedded in plastic or silicone. In the illustrated embodiment, the frame 15 is guided with an upper side 16 up to a height in which the emission side 5 of the cover 4 is arranged.

Furthermore, the cover 4 may be formed in the form of a cover frame 17, which is arranged on the carrier 3 and surrounds the semiconductor chip 2 on all four sides. On the frame 17, the cover 4, which is designed as a plate, are glued ^¬ on, as shown schematically in Figure 4. Of the Cover frame 17 may be made of plastic, silicone or plastic.

Also in this embodiment, the structured surfaces 9 of the cover 4 may be covered with a cover layer 24, as shown. The structured surfaces 9 are formed, for example, of the same material as the cover 4. The Bre ^¬ deviation index of the cover 4 is not equal to 24, the refractive index of the cover layer In particular, the refractive index of the cover 4 is larger than the refractive index of the cladding layer 24. However, it may also be dispensed with the cover 24th

FIG. 5 shows a further embodiment of the component 1, wherein in this embodiment the cover 4 is not fixed on the carrier 3 but on the semiconductor chip 2. For example, the cover 4 with a lower side 18 can rest directly on the semiconductor chip 2 or be connected by means of an adhesive layer 14. In addition, in this embodiment, the semiconductor chip 2 and the cover 4 are surrounded by a frame 15. The cover 4 is formed in the illustrated embodiment in the form of a film having a radiation side 5 with structured surfaces 9. The structured surfaces 9 may have the shapes and materials shown in FIG. Likewise, the cover 4 may also have the different structures and embodiments based on FIGS. 1, 2 and 3.

Also in this embodiment, the structured surfaces 9 may be covered with a cover layer 24, as shown in the figure. The structured surfaces 9 are formed, for example, of the same material as the cover 4. The Bre ^¬ deviation index of the cover 4 is not equal to 24, the refractive index of the cover layer In particular, the refractive index of the cover 4 is larger than the refractive index of the cladding layer 24. However, it may also be dispensed with the cover 24th When the cover layer 24 is provided, the frame is guided to the top of the cover layer 24. Is no cover Layer 24 provided, then the frame 15 ends at the level of the top of the cover 4, as shown in dashed lines. FIG. 6 shows a schematic representation of the arrangement of FIG. 5 from above, wherein the representation of the covering layer has been dispensed with.

FIG. 7 shows a schematic diagram of a diagram showing a luminance L as a function of an angle α of the plane surface to the surface normal of the emission side 5 for the use of surfaces that are at least planar, such as prism surfaces, pyramid surfaces or conical surfaces , The prism faces are triangular, the pyramid faces are spheres, and the conical faces are squares. It can be clearly seen that in an arrangement of the surfaces at an angle α between 80 ° and 50 ° relative to the surface normal 10, ie at a flank angle of the flat surface between 10 ° and 40 ° relative to a plane of the emission side Ma ^¬ Maximum of the light flux is achieved.

For the increase of the light flux, it is not necessary that the arrangement of the flat surfaces is periodic. It is important to cover as much as possible the radiation side with the flat surfaces. The emission side 5 may also include part ^¬ surfaces with the roughened surfaces. Thus, roughened surfaces for improved light extraction and plane surfaces with the aforementioned angular arrangements can provide an improvement in the luminous efficacy. Thus, a brightness ^¬ increase of the device can be achieved in particular in LEDs. A basic idea is to use a structured, transparent material as a cover for the semiconductor chips. The cover may be at least partially or entirely made of glass, sapphire, plastic, silicone, epoxy or semiconductor material and so on. In addition, a side frame may be provided, which acts as a white diffuser and reduces lateral radiation losses. Farther the emission side and / or underside 18 of the Cover B ^¬ ckung 4, which is assigned to the semiconductor chip using egg ^¬ ner anti-reflection layer may be coated. For example, sapphire having a refractive index of 1.7 may be used to form the cover. In addition, Zvi ^¬ rule of the cover is made of sapphire and the semiconductor chip may be an adhesive layer having a refractive index of 1.6 is provided. Furthermore, the semiconductor chip may have a refractive index n of 3.2. By providing the adhesive layer, improved index matching can be achieved.

Depending on the selected embodiment, only a part of the emission side 5 can be provided with a roughened surface 23 in all described embodiments of the components. In addition, only a part of the emission side 5 of the cover 4 can be provided with flat surfaces. Furthermore, a part of the emission side 5 of the cover 4 may be provided with flat surfaces and with a roughened surface. Furthermore, at least a part of the emission side 5 of the cover 4 can be provided with planar surfaces, wherein the planar surfaces also have a roughness. The average roughness of the roughened surface and the plano-roughened surfaces may be in the range between 0.1 ym and 10ym.

Although the invention in detail by the preferred embodiment has been illustrated and described in detail, the invention is not limited ^¬ by the disclosed examples and other variations can be derived therefrom by the skilled artisan without departing from the scope of the invention. LIST OF REFERENCE NUMBERS

1 component

2 semiconductor chip

3 carriers

4 cover

5 radiation side

6 top

7 side surface

8 layer

9 area

10 emission direction

11 radiation area

13 air gap

14 adhesive layer

15 frames

16 top

17 cover frame

18 bottom

21 angle range

22 flank angle

23 roughened surface

24 cover layer

Claims

PATENTA S PRUCHE

Component (1) having a light-emitting semiconductor chip (2), with a cover (4) for the semiconductor chip (2), wherein the cover (4) is arranged above a radiation side of the semiconductor chip (2), wherein the cover (4) has a ^Radiating side (5), wherein the Abstrahl ^¬ side (5) of the cover (4) has a structured surface (9,23).

2. The component according to claim 1, wherein the structured surface has plane surfaces (9), wherein the plane surfaces (9) are planar in at least one direction, and wherein the plane surfaces are in an angular range between 80 ° and 40 ° relative to a Surface normal (10) of Ab ^¬ beam side (6) are arranged.

3. The component according to claim 2, wherein the flat surfaces (9) in an angular range between 75 ° and 50 ° relative to the surface normal (10) of the emission side (5) are arranged.

4. The component according to one of the preceding claims, wherein the structured surface in the form of a roughened surface (23) is formed.

5. The device of claim 4, wherein an average roughness is in the range of 0.1 ym and 10ym.

6. The component according to one of the preceding claims, wherein at least 30% of the emission side (6) as a structured surface (9,23) are formed.

7. The component according to one of claims 2 or 3, wherein the flat surfaces are formed flat in two directions or are formed rotationally symmetrical to an axis. Component according to claim 7, wherein the structured surfaces (9) are in the form of conical surfaces and / or pyramidal surfaces and / or prismatic surfaces.

Component according to one of the preceding claims, wherein the cover (4) is arranged at a distance to a light emitting side (6) of the semiconductor chip (2), and wherein between the semiconductor chip (2) and the cover (4) an air gap (13 ) is provided. Component according to one of claims 1 to 8, wherein the cover (4) is arranged at a distance to a light-emitting side (6) of the semiconductor chip (2), and where ^¬ between the semiconductor chip (2) and the cover (4). a material layer (14), in particular an adhesive layer is provided.

A device according to any one of the preceding claims, wherein the cover (4) comprises at least first and second layers (4, 8), the first layer (8) having the emission side, and wherein the first layer (8) and the second layer (4) are formed of different materials.

Component according to claim 10, wherein the first layer is formed as a film.

Component according to one of the preceding claims, wherein the semiconductor chip (2) and / or the cover (4) is laterally surrounded by a frame (15), wherein the frame (15) is at least partially light-reflecting and / or light-scattering formed, and is formed in particular from ei ^¬ nem white reflective material.

Component according to one of the preceding claims, wherein the cover (4) at least partially glass, sapphire, plastic, silicone, epoxy material or semiconductor material. Component according to one of the preceding claims, wherein the cover (4) on a cover frame (17) is fixed, wherein the cover (4) is formed as a plate, and wherein the cover frame (17) framing the semiconductor chip (2).

Component according to one of the preceding claims, wherein the structured surface (9, 23) of the cover (4) is provided with a covering layer (24), and wherein the refractive index of the material of the structured surface (9, 23) is unequal and, in particular, greater than that is Bre ^¬ deviation index of the covering layer (24).