(19)
(11)EP 3 586 412 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
09.09.2020 Bulletin 2020/37

(21)Application number: 18710764.4

(22)Date of filing:  14.02.2018
(51)International Patent Classification (IPC): 
H01S 5/042(2006.01)
H01S 5/183(2006.01)
H01S 5/42(2006.01)
H01S 5/022(2006.01)
(86)International application number:
PCT/EP2018/053660
(87)International publication number:
WO 2018/153744 (30.08.2018 Gazette  2018/35)

(54)

ARRAY OF LIGHT SOURCES COMPRISING MULTIPLE VCSELS

LICHTQUELLEN MATRIX MIT EINER MEHRZAHL VON VCSELS

RESEAU DE SOURCES LUMINEUSES COMPRENANT UNE PLURALITE DE VCSELS


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 21.02.2017 EP 17157130

(43)Date of publication of application:
01.01.2020 Bulletin 2020/01

(73)Proprietor: Lumileds Holding B.V.
1118 CL Schiphol (NL)

(72)Inventors:
  • ENGELEN, Rob
    52068 Aachen (DE)
  • PFEFFER, Nicola, Bettina
    52068 Aachen (DE)
  • VAN DER SIJDE, Arjen
    52068 Aachen (DE)

(74)Representative: ter Heegde, Paul Gerard Michel 
Lumileds Germany GmbH Philipsstraße 8
52068 Aachen
52068 Aachen (DE)


(56)References cited: : 
EP-A2- 2 366 549
US-A1- 2006 098 706
  
  • MATSUO S ET AL: "Use of polyimide bonding for hybrid integration of a vertical cavity surface emitting laser on a silicon substrate", ELECTRONICS LET, IEE STEVENAGE, GB, vol. 33, no. 13, 19 June 1997 (1997-06-19) , pages 1148-1149, XP006007611, ISSN: 0013-5194, DOI: 10.1049/EL:19970752
  • UEKI N ET AL: "COMPLETE POLARIZATION CONTROL OF 12 X 8-BIT MATRIX-ADDRESSED OXIDE-CONFINED VERTICAL-CAVITY SURFACE-EMITTING LASER ARRAY", JAPANESE JOURNAL OF APPLIED PHYSICS, JAPAN SOCIETY OF APPLIED PHYSICS, JP, vol. 40, no. 1 A/B, PART 02, 15 January 2001 (2001-01-15), pages L33-L35, XP001001707, ISSN: 0021-4922, DOI: 10.1143/JJAP.40.L33
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

FIELD OF THE INVENTION:



[0001] The invention relates to an array of light sources, a device comprising such an array and a method for manufacturing an array of light sources.

BACKGROUND OF THE INVENTION:



[0002] Separately packaged infrared (IR) and visible light emitters have been used in a variety of applications, including photography, spectral or hyperspectral analysis, 3D sensing, and communication. The layout, material, or design of the IR emitters, optics, or package can affect overall appearance of a carrying device when being installed in this device.

[0003] It would be desirable to obtain device components, especially IR emitter modules, being visible from the environment not disturbing the overall optical appearance of devices carrying these components which might be of particular interest in consumer applications.

[0004] EP2366549A2 and US2006/098706A1 disclose vertical cavity surface emitting lasers comprising an upper electrode covered with a dielectric film.

SUMMARY OF THE INVENTION:



[0005] It is an object of the present invention to provide a device component, especially an IR emitter module, with an optical appearance match to the overall optical appearance of a device carrying this component. An array of light sources comprising multiple vertical cavity surface emitting lasers, so-called VCSELs, is an IR emitter module. A simple design for a VCSEL array can be improved if the VCSEL appearance allows for color changes to provide a more uniform appearance of the carrying device.

[0006] The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

[0007] According to a first aspect an array of light sources is provided. The array of light sources comprises multiple VCSELs arranged laterally to each other on top of a substrate, wherein each VCSEL comprises a light emitting area surrounded by an electrode structure which does not emit light, wherein a shielding layer is applied on top of at least the electrode structure covering at least a surface of the electrode structure facing towards an average light emitting direction of the VCSELs, the shielding layer being adapted to optically match the array in a switched-off state, where no light is emitted, to a demanded appearance. Here the term "applied on top of' denotes the direct coating of a layer on top of another layer or component as well as a coating applied above another layer or component, where additional material layers might be arranged in between. In an embodiment the shielding layer being adapted to optically match the array in a switched-off state to an outer surface of a housing of a device, where the array of light sources is to be installed.

[0008] The vertical-cavity surface-emitting laser or VCSEL is a type of semiconductor laser diode with laser beam emission perpendicular from the top surface, contrary to conventional edge-emitting semiconductor lasers (also in-plane lasers) which emit from surfaces formed by cleaving the individual chip out of a wafer. The laser resonator of a VCSEL consists of two distributed Bragg reflector (DBR) mirrors parallel to the wafer surface with an active region consisting of one or more quantum wells for the laser light generation in between. VCSELs for wavelengths from 650 nm to 1400 nm are typically based on gallium arsenide wafers with DBRs formed from GaAs and aluminum gallium arsenide. Longer wavelength devices, from 1400 nm to 2000 nm, have been demonstrated with at least the active region made of indium phosphide. The light emitting area is typically arranged in the center of the emitting surface of the DBR mirrors, where the top electrode is arranged as a metal layer on top of the DBR mirror, typically made of gold. The VCSEL emits light with an average light emitting direction perpendicular to the DBR mirrors, where the light emitting area is small in comparison to the surface of the surrounding electrode structure leading to an optical appearance dominated by the appearance of the electrode material. The ratio between light-emitting area and electrode structure is far below 50%, e.g. 20 - 30%. Therefore VCSEL arrays typically have a golden appearance which does not match to the common appearance of device housings. In contrast to the electrode structures the light emitting areas of VCSELs have a dark color appearance when being switched of.

[0009] The applied shielding layer covers at least the electrode structure in order to prevent light from being reflected from the electrode structure or at least modifies the light being reflected from the electrode structure to provide a desired optical appearance. Eventually the shielding layer covers all non-light-emitting areas of the array of light sources. Therefore the shielding layer is a non-transparent layer being either opaque or semi-transparent at least with the visible range of the wavelength spectrum of light. The shielding layer may be of any material having e.g. a white, black or colored appearance. As an example, the shielding layer might be a silver layer, a chrome layer, a layer comprising phosphor particles or an ink layer, where the particular phosphor particles or inks are selected depending on the desired appearance. The electrode structure does not actively emit light. The electrode structure only absorbs or reflects light from the environment.

[0010] The laterally arranged VCSELs provide a lateral array of VCSELs, where the VCSELs are arranged side-by-side of each other. The term "lateral" denotes the extension of the arrangement of VCSELs parallel to the light emitting areas of the VCSELs.

[0011] The array of light sources may be arranged in such a way that all visible surfaces of the electrode structure are coated by the shielding layer. In this case the overall appearance of the array can be adapted without influence of any non covered part of the array. The term "visible" denotes all surfaces contributing to the overall optical appearance of the array of light sources to the environment.

[0012] The array of light sources may be arranged in such a way that the array of light sources comprise non-active areas between neighbored VCSELs, where the shielding layer also covers the non-active areas. The non-active areas might be parts of the substrate not covered by the VCSELs arranged on top of the substrate. The shielding layer covering the non-active areas prevents any influence of the substrate on the overall optical appearance of the array.

[0013] The array of light sources may be arranged in such a way that the non-active areas define volumes between neighbored VCSELs, where at least the volumes are suitably filled by a filler material to provide a smooth surface between neighbored VCSELs to be coated with the shielding layer. The arrangement of VCSELs provide a structured non-flat surface, which is difficult to be coated with a homogeneous coating in order to influence the optical properties of the outer surface of the array of light sources for matching the overall appearance of the array. When filling the volumes (gaps) a smooth and flat surface can be provided in between the light-emitting areas which can be coated with the shielding layer more easily with an improved homogeneity of this layer. The flat (smooth) surface denotes a surface with a significantly lower height difference between highest and lowest point of the surface compared to a corresponding surface without filled volumes. Significantly lower means at least a factor of ten lower.

[0014] The array of light sources may be arranged in such a way that the filler material fills out at least one volume to a highest distance of the electrode structures of the neighbored VCSELs above the substrate. This especially provides a flat surface outside the light emitting area of the VCSELs which can be easily coated with the shielding layer providing homogeneous optical properties and a good adhesion to the coated surface.

[0015] The array of light sources may be arranged in such a way that the filler material is a photoresist material. The photoresist material can be applied and structured easily in order to cover the light emitting areas of the VCSELs. The use of photoresist material enables a coating process for the filler material without required masks to shield the light emitting areas of the VCSELs. After coating the filled material can be stabilized in non-light-emitting areas by suitable laser treatment. The photoresist material not being laser treated can be simply removed, e.g. by a suitable washing process.

[0016] The array of light sources may be arranged in such a way that the shielding layer has an absorption or reflection spectrum within the visible wavelength range being different from the corresponding absorption or reflection spectrum of a material of the electrode structure. In order to modify the overall appearance of the non-coated electrode structures, these structures have to be coated with a material modifying the optical properties of the resulting layer stack. Therefore the optical properties of the shielding layer must be different compared to the optical properties electrode structure where the material of the electrode structure might be gold. As an example, not being part of the invention, the shielding layer might be non transparent, so the color of the electrode structure is not visible. If the shielding layer is semi-transparent the electrode structure is partially visible. In this case the optical appearance of the shielding layer is adapted to counteract the spectral absorption of the electrode. For electrode structures made of gold (absorbing blue light), a shielding layer with green and red absorption will result in an overall optical appearance of electrode structure and shielding layer being white or grey. Layer materials providing such appearances are known.

[0017] As an example, not being part of the invention, the array of light sources may be arranged in such a way that the thickness of the shielding layer is adapted to be semitransparent for at least visible light and to provide an optical appearance in combination with the electrode structure underneath the shielding layer matching to the outer surface of the housing of the device. Depending on the material of the electrode structure and the material of the shielding layer, the thickness can be adapted to shift the optical appearance of the resulting array from an appearance close to the appearance of non-coated electrode structured to an appearance to the shielding layer itself regardless of the electrode material underneath.

[0018] According to a second aspect a device comprising at least one array of light sources in accordance with any embodiment described above is provided. The device further comprises a housing with an outer surface where the shielding layer optically matches the array in a switched-off state to the outer surface. Such a device provides an overall homogeneous optical appearance. The term "device" may denote tablet PCs, laptop, cameras or mobile communication devices such as smartphone, cell phones or PDAs where a certain appearance (e.g. black, white, specifically colored or mirror-like) to the environment is desired.

[0019] According to a third aspect a method to manufacture an array of light sources in accordance with any embodiment described above is provided. The method comprises the steps of
  • Arranging multiple VCSELs on top of a substrate in an lateral array, where each VCSEL comprises a light emitting area surrounded by an electrode structure which does not emit light;
  • Applying a shielding layer at least on top of the electrode structure to cover at least a surface of the electrode structure facing towards an average light emitting direction of the VECSELs in order to optically match the array in a switched-off state to a demanded appearance.


[0020] The process for applying the shielding layer on top of the electrode structure can be any suitable process, e.g. a masking process shielding the light-emitting area of the VCSELs during deposition. Alternatively to the masking process or in support of the masking process a photoresist deposition process followed by laser hardening of the photoresist material and washing off the non-hardened areas may be used to shield or fill up different areas depending on the embodiment of the used process to apply the shielding layer. There are positive and negative photoresist available. Depending on which material is used, the light-exposed area stays or is removed when developing the photoresist layer. In an embodiment the shielding layer being adapted to optically match the array in a switched-off state to an outer surface of a housing of a device, where the array of light sources is to be installed.

[0021] The method may be arranged in such a way that wherein prior to the step of applying the shielding layer the method further comprises the steps of
  • covering the light-emitting areas with a photoresist material before applying the shielding layer; and
  • washing away the photoresist layer covering the light-emitting areas after having applied the shielding layer in order to remove any material on top of the light-emitting areas.


[0022] The method may be arranged in such a way that the step of applying the shielding layer will also coat non-active areas within the array located between neighbored VCSELs.

[0023] The method may be arranged in such a way that prior to the step of applying the shielding layer the method further comprises the step of suitably filling volumes between neighbored VCSELs defined by the non-active areas by a filler material to provide a smooth surface between neighbored VCSELs to be coated with the shielding layer.

[0024] The method may be arranged in such a way that suitable filling denotes the filling of at least one volume to a highest distance of the electrode structures of the neighbored VCSELs above the substrate.

[0025] The method may be arranged in such a way that the step of applying the shielding layer is performed via a mask-less electrophoretic deposition process in order to locally deposit the shielding layer on top of the electrode structure. During this process the array of VCSELs is arranged in a wet solution comprising the material of the shielding layer to be deposited on top of the electrode structure and electrical field is applied between solution and VCSEL electrodes. The electrical field directs the to-be-deposited material to the areas with a high electrical field density, which is located above the electrode structures. The electrode structures especially are the to-be-coated areas in order to be able to match the optical appearance of the array of light sources to a required appearance. Therefore the material of the shielding layer is mainly or exclusively deposited on top of the electrode structure leaving the light-emitting areas of the VCSELs uncoated. With this electrophoretic process the VCSELS can be locally coated without applying a mask process or a layer hardening process. Therefore the electrophoretic deposition process requires less effort compared to alternative deposition processes.

[0026] Further advantageous embodiments are defined below.

BRIEF DESCRIPTION OF THE DRAWINGS:



[0027] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0028] The invention will now be described, by way of example, based on embodiments with reference to the accompanying drawings.

[0029] In the drawings:
Fig. 1
shows a principal sketch of an array of VCSELs in a top view without applied shielding layer.
Fig. 2
shows a principal sketch of a VCSEL of the array of VCSELs in a side view with applied shielding layer on top of the electrode structure.
Fig. 3
shows a principal sketch of an array of VCSELs in a side view with filled volumes between neighbored VCSELs (a) before applying the shielding layer and (b) with applied shielding layer on top of a flat surface provided by the filler material.
Fig. 4
shows a principal sketch of a device comprising the array of light sources according to the present invention.
Fig. 5
shows a principal sketch of an embodiment of the method according to the present invention.


[0030] In the Figures, like numbers refer to like objects throughout. Objects in the Figs. are not necessarily drawn to scale.

DETAILED DESCRIPTION OF EMBODIMENTS:



[0031] Various embodiments of the invention will now be described by means of the Figures.

[0032] Fig. 1 shows a principal sketch of an array 1 of VCSELs 2 in a top view without applied shielding layer 4. The array of light sources 1 comprising multiple donut shaped VCSELs 2 arranged laterally to each other on top of a substrate 3, wherein each VCSEL 2 comprises a light emitting area 21 surrounded by an electrode structure 22 which does not emit light. The array of light sources 1 comprises non-active areas 6 (approximately between neighbored VCSELs 2 defining volumes 61 between neighbored VCSELs 2. In other embodiments covered by the present invention, the arrangement might by different to the arrangement shown in fig.1. The VCSELs 2 in the shown array 1 are arranged side-by-side of each other resulting in a lateral arrangement of the VCSELs 2, where the lateral extensions of the array 1 denote the extensions parallel to the light emitting areas 21 of the VCSELs 2. In this example the VCSELs 2 have a lateral extension of 0.5mm x 0.5mm and a height above the substrate 3 of 0.2mm.

[0033] Fig. 2 shows a principal sketch of a VCSEL 2 of the array 1 of VCSELs 2 in a side view with applied shielding layer 4 on top of the electrode structure 22 covering all visible surfaces 22s, 221 of the electrode structure 22 are coated by the shielding layer 4. The side view is along the plane P1 as indicated in fig.1. In other embodiment only a surface 22s of the electrode structure 22 facing towards an average light emitting direction 5 of the VECSELs 2 might be coated. The shielding layer 4 is adapted to optically match the array 1 in a switched-off state, where no light is emitted, to an outer surface 11s of a housing 11 of a device 10, where the array 1 of light sources is to be installed (see also fig.4). The shielding layer 4 has an absorption or reflection spectrum within the visible wavelength range being different from the corresponding absorption or reflection spectrum of a material of the electrode structure 22. In an embodiment the material of the electrode structure 22 is gold. The thickness of the shielding layer 4 can be adapted to be semitransparent for at least visible light and to provide an optical appearance in combination with the electrode structure 22 underneath the shielding layer 4 matching to the outer surface 11s of the housing 11 of the device 10.

[0034] Fig. 3 shows a principal sketch of an array 1 of VCSELs 2 in a side view with filled volumes 61 between neighbored VCSELs 2 (a) before applying the shielding layer 4 and (b) with applied shielding layer 4 on top of a flat surface 71 provided by the filler material 7. The side view is along the plane P2 as indicated in fig.1. The non-active areas 6 define volumes 61 between neighbored VCSELs 2, which are filled by a filler material 7 to provide a flat (smooth) surface 71 between neighbored VCSELs 2 to be coated with the shielding layer 4. The flat surface 71 denotes a surface with a significantly lower height difference between highest and lowest point of the surface 71 compared to a corresponding surface without filled volumes 61. Significantly lower means at least a factor of ten lower. Here the filler material 7 fills up the entire volume 61 to a highest distance D1 of the electrode structures 22 of the neighbored VCSELs 2 above the substrate 3. In this embodiment the filler material 7 is a photoresist material. In fig. 3b the flat surface 71 is coated directly with the shielding layer 4 on top of the flat surface 71. The viewing direction VD indicated from which side a viewer (not shown here) may look onto the array 1 provided a corresponding appearance to the viewer.

[0035] Fig. 4 shows a principal sketch of a device 10 comprising the array of light sources 1 according to the present invention. The device 10 comprises one array of light sources 1 and a housing 11 with an outer surface 11s, where the shielding layer 4 optically matches the array 1 in a switched-off state to the optical appearance of the outer surface 11s.

[0036] Fig. 5 shows a principal sketch of an embodiment of the method 100 according to the present invention to manufacture an array of light sources 1 comprising the steps of arranging 110 multiple VCSELs 2 on top of a substrate 3 in an lateral array 1, where each VCSEL 2 comprises a light emitting area 21 surrounded by an electrode structure 22 which does not emit light and applying 140 a shielding layer 4 at least on top of the electrode structure 22 to cover at least a surface 22s of the electrode structure 22 facing towards an average light emitting direction 5 of the VECSELs 2 in order to optically match the array 1 in a switched-off state to an outer surface 11s of a housing 11 of a device 10, where the array of light sources 1 is to be installed. The process for applying 140 the shielding layer on top of the electrode structure 22 can be any suitable process, e.g. a masking process shielding the light-emitting area 21 of the VCSELs 2 during deposition. Alternatively the method may comprise the step of covering 120 the light-emitting areas 21 with a photoresist material before applying 140 the shielding layer. The step of applying 140 the shielding layer 4 may also coat non-active areas 6 within the array 1 located between neighbored VCSELs 2. In an embodiment the method further comprises the step of suitably filling 130 volumes 61 between neighbored VCSELs 2 defined by the non-active areas 6 by a filler material 7 to provide a smooth surface 71 between neighbored VCSELs 2 to be coated with the shielding layer 4 in the applying step 140. The term suitable filling 130 may denote the filling of at least one volume 61 to a highest distance D1 of the electrode structures 22 of the neighbored VCSELs 2 above the substrate 3. In case of the light-emitting areas 21 being covered with a photoresist material before applying 140 the shielding layer, the photoresist layer covering the light-emitting areas 21 will be washed away 160 after having applied 140 the shielding layer 4 in order to remove any material on top of the light-emitting areas 21. In another embodiment with non-covered light emitting areas 21 the step of applying 140 the shielding layer 4 might be performed via a mask-less electrophoretic deposition process 150 in order to locally deposit the shielding layer 4 on top of the electrode structure 22. During this process 150 the array 1 of VCSELs 2 is arranged in a wet solution comprising the material of the shielding layer 4 to be deposited on top of the electrode structure 22 and electrical field is applied between solution and VCSEL electrode structures 22. The electrical field directs the to-be-deposited material to the areas with a high electrical field density, which is located close to the electrode structures 22. Especially the electrode structure 22 are the to-be-coated areas in order to be able to match the optical appearance of the array of light sources 1 to a required appearance, because these areas contribute to far more than 50% to the visible areas of the array 1. Therefore the material of the shielding layer 4 is mainly or exclusively deposited on top of the electrode structure 22 leaving the light-emitting areas 21 of the VCSELs 2 uncoated. With this electrophoretic process 150 the VCSELs 2 can be locally coated without applying a mask process or a layer hardening process. Therefore the electrophoretic deposition process 140 requires less effort compared to alternative deposition processes.

[0037] While the invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive.

[0038] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality of elements or steps.

[0039] Any reference signs in the claims should not be construed as limiting the scope thereof.

LIST OF REFERENCE NUMERALS:



[0040] 
1
array of light sources according to the present invention
2
vertical cavity surface emitting layer (VCSEL)
21
light emitting area of the VCSEL
22
electrode structure of the VCSEL surrounding the light emitting area of the VCSEL
22s
surface of the non-emitting structure facing towards an average light emitting direction
221
surface of the non-emitting structure facing towards neighbored VCSELs
3
substrate of the array
4
shielding layer
5
average light emitting direction of the VCSEL
6
non-active areas between neighbored VCSELs
61
volume between neighbored VCSELs defined by the non-active areas
7
filler material
71
smooth surface of the filler material
10
device comprising the array of light sources according to the present invention
11
housing of the device
11s
outer surface of the housing
100
method to manufacture the array of light sources according to the present invention
110
Arranging multiple VCSELs on top of a substrate in an lateral array
120
covering the light-emitting areas with a photoresist material before applying the shielding layer
130
suitably filling volumes between neighbored VCSELs defined by the non-active areas
140
Applying a shielding layer at least on top of the electrode structure
150
performing a mask-less electrophoretic deposition process
160
washing away the photoresist layer after having applied the shielding layer
D1
highest distance of the non-light-emitting structures of the neighbored VCSELs above the substrate
P2, P3
cross section planes 2 and 3 for fig.2 and 3, respectively
VD
viewing direction



Claims

1. An array of light sources (1) comprising multiple VCSELs (2) arranged laterally to each other on top of a substrate (3), wherein each VCSEL (2) comprises a light emitting area (21) surrounded by an electrode structure (22) which does not emit light, wherein a shielding layer (4) is applied on top of at least the electrode structure (22) only covering a surface (22s) of the electrode structure (22) facing towards an average light emitting direction (5) of the VCSELs (2), the shielding layer (4) is an opaque layer and being adapted to optically match the array (1) in a switched-off state, where no light is emitted, to a demanded appearance, preferably to an outer surface (11s) of a housing (11) of a device (10) where the array (1) of light sources is to be installed.
 
2. The array of light sources (1) in accordance with claim 1, wherein all visible surfaces (22s, 221) of the electrode structure (22) are coated by the shielding layer (4).
 
3. The array of light sources (1) in accordance with claim 1 or 2, wherein the array of light sources (1) comprise non-active areas (6) between neighbored VCSELs (2), where the shielding layer (4) also covers the non-active areas (6).
 
4. The array of light sources (1) in accordance with claim 3, wherein the non-active areas (6) define volumes (61) between neighbored VCSELs (2), where at least the volumes (61) are suitably filled by a filler material (7) to provide a flat surface (71) between neighbored VCSELs (2) to be coated with the shielding layer (4), preferably the filler material (7) is a photoresist material.
 
5. The array of light sources (1) in accordance with claim 4, wherein the filler material (7) fills out at least one volume (61) to a highest distance (D1) of the electrode structures (22) of the neighbored VCSELs (2) above the substrate (3).
 
6. The array of light sources (1) in accordance with one of the preceding claims, wherein the shielding layer (4) has an absorption or reflection spectrum within the visible wavelength range being different from the corresponding absorption or reflection spectrum of a material of the electrode structure (22).
 
7. The array of light sources (1) in accordance with claim 6, wherein the material of the electrode structure (22) is gold.
 
8. A device (10) comprising at least one array of light sources (1) in accordance with claim 1 and a housing (11) with an outer surface (11s), where the shielding layer (4) optically matches the array (1) in a switched-off state to the outer surface (11s).
 
9. A method (100) to manufacture an array of light sources in accordance with claim 1 comprising the steps of

- Arranging (110) multiple VCSELs (2) on top of a substrate (3) in an lateral array (1), where each VCSEL (2) comprises a light emitting area (21) surrounded by an electrode structure (22) which does not emit light;

- Applying (140) a shielding layer (4) as an opaque layer at least on top of the electrode structure (22) only covering a surface (22s) of the electrode structure (22) facing towards an average light emitting direction (5) of the VECSELs (2) in order to optically match the array (1) in a switched-off state to a demanded appearance, preferably to an outer surface (11s) of a housing (11) of a device (10) where the array of light sources (1) is to be installed


 
10. The method (100) in accordance to claim 9, wherein prior to the step of applying (140) the shielding layer (4) the method further comprises the steps of

- covering (120) the light-emitting areas (21) with a photoresist material before applying (140) the shielding layer; and

- washing away (160) the photoresist layer covering the light-emitting areas (21) after having applied the shielding layer in order to remove any material on top of the light-emitting areas (21).


 
11. The method (100) in accordance to claim 9 or 10, wherein the step of applying (140) the shielding layer (4) will also coat non-active areas (6) within the array (1) located between neighbored VCSELs (2).
 
12. The method (100) in accordance to claim 11, wherein prior to the step of applying (140) the shielding layer (4) the method further comprises the step of suitably filling (130) volumes (61) between neighbored VCSELs (2) defined by the non-active areas (6) by a filler material (7) to provide a flat surface (71) between neighbored VCSELs (2) to be coated with the shielding layer (4).
 
13. The method (100) in accordance to claim 12, wherein suitable filling (130) denotes the filling of at least one volume (61) to a highest distance (D1) of the electrode structures (22) of the neighbored VCSELs (2) above the substrate (3).
 
14. The method (100) in accordance to claim 9, wherein the step of applying (140) the shielding layer (4) is performed via a mask-less electrophoretic deposition process (150) in order to locally deposit the shielding layer (4) on top of the electrode structure (22).
 


Ansprüche

1. Anordnung von Lichtquellen (1), umfassend mehrere VCSELs (2), die auf einem Substrat (3) lateral zueinander angeordnet sind, wobei jeder VCSEL (2) einen Licht emittierenden Bereich (21) umfasst, der von einer Elektrodenstruktur (22) umgeben ist, die kein Licht emittiert, wobei eine Abschirmungsschicht (4) wenigstens auf die Elektrodenstruktur (22) aufgebracht ist, die nur eine Oberfläche (22s) der Elektrodenstruktur (22) bedeckt, die einer Richtung (5) mittlerer Lichtemission der VCSELs (2) zugewandt ist, wobei die Abschirmungsschicht (4) eine lichtundurchlässige Schicht und so ausgelegt ist, dass sie die Anordnung (1) in einem ausgeschalteten Zustand, in welchem kein Licht emittiert wird, optisch an ein verlangtes Erscheinungsbild, vorzugsweise an eine Außenfläche (11s) eines Gehäuses (11) einer Vorrichtung (10) anpasst, auf der die Anordnung (1) von Lichtquellen installiert werden soll.
 
2. Anordnung von Lichtquellen (1) nach Anspruch 1, wobei alle sichtbaren Oberflächen (22s, 221) der Elektrodenstruktur (22) mit der Abschirmungsschicht (4) beschichtet sind.
 
3. Anordnung von Lichtquellen (1) nach Anspruch 1 oder 2, wobei die Anordnung von Lichtquellen (1) nicht aktive Bereiche (6) zwischen benachbarten VCSELs (2) umfasst, wobei die Abschirmungsschicht (4) auch die nicht aktiven Bereiche (6) bedeckt.
 
4. Anordnung von Lichtquellen (1) nach Anspruch 3, wobei die nicht aktiven Bereiche (6) Volumina (61) zwischen benachbarten VCSELs (2) definieren, wobei wenigstens die Volumina (61) in geeigneter Weise mit einem Füllmaterial (7) gefüllt sind, um eine flache Oberfläche (71) zwischen benachbarten VCSELs (2) bereitzustellen, die mit der Abschirmungsschicht (4) beschichtet werden soll, wobei das Füllmaterial (7) vorzugsweise ein Fotolackmaterial ist.
 
5. Anordnung von Lichtquellen (1) nach Anspruch 4, wobei das Füllmaterial (7) mindestens ein Volumen (61) bis zu einer höchsten Distanz (D1) der Elektrodenstrukturen (22) der benachbarten VCSELs (2) über dem Substrat (3) ausfüllt.
 
6. Anordnung von Lichtquellen (1) nach einem der vorhergehenden Ansprüche, wobei die Abschirmungsschicht (4) ein Absorptions- oder Reflexionsspektrum innerhalb des sichtbaren Wellenlängenbereichs aufweist, das vom entsprechenden Absorptions- oder Reflexionsspektrum eines Materials der Elektrodenstruktur (22) verschieden ist.
 
7. Anordnung von Lichtquellen (1) nach Anspruch 6, wobei das Material der Elektrodenstruktur (22) Gold ist.
 
8. Vorrichtung (10), umfassend mindestens eine Anordnung von Lichtquellen (1) nach Anspruch 1 und ein Gehäuse (11) mit einer Außenfläche (11s), wobei die Abschirmungsschicht (4) die Anordnung (1) in einem ausgeschalteten Zustand optisch an die Außenfläche (11s) anpasst.
 
9. Verfahren (100) zur Herstellung einer Anordnung von Lichtquellen nach Anspruch 1, umfassend die folgenden Schritte:

- Anordnen (110) mehrerer VCSELs (2) auf einem Substrat (3) in einer lateralen Anordnung (1), wobei jeder VCSEL (2) einen Licht emittierenden Bereich (21) umfasst, der von einer Elektrodenstruktur (22) umgeben ist, die kein Licht emittiert;

- Aufbringen (140) einer Abschirmungsschicht (4) als eine lichtundurchlässige Schicht wenigstens auf die Elektrodenstruktur (22), die nur eine Oberfläche (22s) der Elektrodenstruktur (22) bedeckt, die einer Richtung (5) mittlerer Lichtemission der VECSELs (2) zugewandt ist, um die Anordnung (1) in einem ausgeschalteten Zustand optisch an ein verlangtes Erscheinungsbild, vorzugsweise an eine Außenfläche (11s) eines Gehäuses (11) einer Vorrichtung (10) anzupassen, auf der die Anordnung von Lichtquellen (1) installiert werden soll.


 
10. Verfahren (100) nach Anspruch 9, wobei das Verfahren vor dem Schritt des Aufbringens (140) der Abschirmungsschicht (4) ferner die folgenden Schritte umfasst:

- Bedecken (120) der Licht emittierenden Bereiche (21) mit einem Fotolackmaterial vor dem Aufbringen (140) der Abschirmungsschicht; und

- Wegspülen (160) der Fotolackschicht, welche die Licht emittierenden Bereiche (21) bedeckt, nach dem Aufbringen der Abschirmungsschicht, um jegliches Material auf den Licht emittierenden Bereichen (21) zu entfernen.


 
11. Verfahren (100) nach Anspruch 9 oder 10, wobei der Schritt des Aufbringens (140) der Abschirmungsschicht (4) auch nicht aktive Bereiche (6) innerhalb der Anordnung (1) beschichtet, die sich zwischen benachbarten VCSELs (2) befinden.
 
12. Verfahren (100) nach Anspruch 11, wobei das Verfahren vor dem Schritt des Aufbringens (140) der Abschirmungsschicht (4) ferner den Schritt des geeigneten Füllens (130) von Volumina (61) zwischen benachbarten VCSELs (2), die durch die nicht aktiven Bereiche (6) definiert werden, mit einem Füllmaterial (7) umfasst, um eine flache Oberfläche (71) zwischen benachbarten VCSELs (2) bereitzustellen, die mit der Abschirmungsschicht (4) beschichtet werden soll.
 
13. Verfahren (100) nach Anspruch 12, wobei das geeignete Füllen (130) das Füllen mindestens eines Volumens (61) bis zu einer höchsten Distanz (D1) der Elektrodenstrukturen (22) der benachbarten VCSELs (2) über dem Substrat (3) bedeutet.
 
14. Verfahren (100) nach Anspruch 9, wobei der Schritt des Aufbringens (140) der Abschirmungsschicht (4) durch einen Prozess maskenloser elektrophoretischer Abscheidung (150) durchgeführt wird, um die Abschirmungsschicht (4) lokal auf die Elektrodenstruktur (22) abzuscheiden.
 


Revendications

1. Réseau de sources lumineuses (1) comprenant de multiples VCSEL (2) agencées latéralement les unes par rapport aux autres sur un substrat (3), dans lequel chaque VCSEL (2) comprend une zone d'émission de lumière (21) entourée par une structure d'électrode (22) qui n'émet pas de lumière, dans lequel une couche de blindage (4) est appliquée au-dessus d'au moins la structure d'électrode (22) de façon à ne recouvrir qu'une surface (22s) de la structure d'électrode (22) faisant face à une direction d'émission de lumière moyenne (5) des VCSEL (2), la couche de blindage (4) est une couche opaque et étant conçue pour adapter optiquement le réseau (1) dans un état éteint, où aucune lumière n'est émise, à un aspect exigé, de préférence à une surface externe (11s) d'un boîtier (11) d'un dispositif (10) dans lequel le réseau (1) de sources lumineuses doit être installé.
 
2. Réseau de sources lumineuses (1) selon la revendication 1, dans lequel toutes les surfaces visibles (22s, 22l) de la structure d'électrode (22) sont revêtues par la couche de blindage (4).
 
3. Réseau de sources lumineuses (1) selon la revendication 1 ou 2, dans lequel le réseau de sources lumineuses (1) comprend des zones non actives (6) entre des VCSEL (2) voisines, où la couche de blindage (4) recouvre également les zones non actives (6).
 
4. Réseau de sources lumineuses (1) selon la revendication 3, dans lequel les zones non actives (6) définissent des volumes (61) entre des VCSEL (2) voisines, où au moins les volumes (61) sont remplis de manière appropriée par un matériau de remplissage (7) pour fournir une surface plane (71) entre des VCSEL (2) voisines devant être revêtue avec la couche de blindage (4), de préférence le matériau de remplissage (7) est un matériau photorésistant.
 
5. Réseau de sources lumineuses (1) selon la revendication 4, dans lequel le matériau de remplissage (7) remplit au moins un volume (61) jusqu'à une distance la plus élevée (D1) des structures d'électrode (22) des VCSEL (2) voisines au-dessus du substrat (3).
 
6. Réseau de sources lumineuses (1) selon l'une des revendications précédentes, dans lequel la couche de blindage (4) a un spectre d'absorption ou de réflexion au sein de la plage de longueurs d'ondes visibles différent du spectre d'absorption ou de réflexion correspondant d'un matériau de la structure d'électrode (22).
 
7. Réseau de sources lumineuses (1) selon la revendication 6, dans lequel le matériau de la structure d'électrode (22) est de l'or.
 
8. Dispositif (10) comprenant au moins un réseau de sources lumineuses (1) selon la revendication 1 et un boîtier (11) avec une surface externe (Ils), où la couche de blindage (4) adapte optiquement le réseau (1) dans un état éteint à la surface externe (Ils).
 
9. Procédé (100) pour fabriquer un réseau de sources lumineuses selon la revendication 1, comprenant les étapes suivantes :

- agencement (110) de multiples VCSEL (2) au-dessus d'un substrat (3) dans un réseau latéral (1), où chaque VCSEL (2) comprend une zone d'émission de lumière (21) entourée par une structure d'électrode (22) qui n'émet pas de lumière ;

- application (140) d'une couche de blindage (4) sous forme de couche opaque au moins sur la structure d'électrode (22) de façon à ne recouvrir qu'une surface (22s) de la structure d'électrode (22) faisant face à une direction d'émission de lumière moyenne (5) des VCSEL (2) afin d'adapter optiquement le réseau (1) dans un état éteint à un aspect exigé, de préférence à une surface externe (11s) d'un boîtier (11) d'un dispositif (10) dans lequel le réseau de sources lumineuses (1) doit être installé.


 
10. Procédé (100) selon la revendication 9, dans lequel avant l'étape d'application (140) de la couche de blindage (4), le procédé comprend en outre les étapes suivantes :

- recouvrement (120) des zones d'émission de lumière (21) avec un matériau photorésistant avant application (140) de la couche de blindage ; et

- lavage (160) de la couche photorésistante recouvrant les zones d'émission de lumière (21) après avoir appliqué la couche de blindage afin d'éliminer tout matériau au-dessus des zones d'émission de lumière (21).


 
11. Procédé (100) selon la revendication 9 ou 10, dans lequel l'étape d'application (140) de la couche de blindage (4) revêtira également les zones non actives (6) au sein du réseau (1) situées entre des VCSEL (2) voisines.
 
12. Procédé (100) selon la revendication 11, dans lequel avant l'étape d'application (140) de la couche de blindage (4), le procédé comprend en outre l'étape de remplissage approprié (130) de volumes (61) entre des VCSEL (2) voisines définis par les zones non actives (6) au moyen d'un matériau de remplissage (7) pour fournir une surface plane (71) entre les VCSEL (2) voisines devant être revêtue avec la couche de blindage (4).
 
13. Procédé (100) selon la revendication 12, dans lequel le remplissage approprié (130) désigne le remplissage d'au moins un volume (61) jusqu'à une distance la plus élevée (D1) des structures d'électrode (22) des VCSEL (2) voisines au-dessus du substrat (3).
 
14. Procédé (100) selon la revendication 9, dans lequel l'étape d'application (140) de la couche de blindage (4) est réalisée via un procédé de dépôt électrophorétique sans masque (150) afin de déposer localement la couche de blindage (4) au-dessus de la structure d'électrode (22).
 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



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Patent documents cited in the description