Optoelectronic arrangement for improved thermal management and method of manufacturing the same

Abstract

The invention concerns an optoelectronic arrangement comprising edge emitting lasers for improved thermal management while minimizing overall package size. A method of manufacturing the proposed optoelectronic arrangement is also presented.

Description

[0001] OPTOELECTRONIC ARRANGEMENT FOR IMPROVED THERMAL MANAGEMENT AND METHOD

[0002] OF MANUFACTURING THE SAME

[0003] The present application claims priority from German patent application DE 10 2024 110 526 . 7 filed on April 15 , 2024 , the disclosure of which is incorporated by way for reference in its entirety .

[0004] The present invention concerns an optoelectronic arrangement and a method for manufacturing an optoelectronic arrangement .

[0005] BACKGROUND

[0006] High power laser devices are characterized by high thermal output , necessitating proper cooling for reliable performance . Heat generation density is particularly high in micro- and nanoscale semiconductor devices comprising active regions with nanometre-scale thickness . Inefficient thermal management results in adverse effects on the spectral characteristics and lifetime of a high-power laser device . Dissipation of thermal energy is therefore a significant consideration in design of laser packages .

[0007] It is an obj ect of the present application to present an approach for efficient thermal management applicable to multichannel high power optoelectronic device packages , in particular, high power laser device packages .

[0008] SUMMARY OF THE INVENTION

[0009] This and other obj ects are addressed by the subj ect matter of the independent claims . Features and further aspects of the proposed principles are outlined in the dependent claims .

[0010] The inventors propose an optoelectronic arrangement comprising multiple optoelectronic devices , in particular , edge-emitting laser devices , each mounted on a thermally conductive submount . Proper cooling is an essential consideration in design of high-power laser devices . Laser packages therefore comprise thermally conductive heat sinks , which may be mounted in various configurations . For high power applications , an additional heat spreading layer is arranged between the chip and the thermally conductive , usually metallic carrier surface , resulting in chip on submount assemblies ( COSA) . Such submounts comprise materials with high thermal conductivity, including but not limited to alumina, Beryllium Oxide , Silicon carbide and Aluminium Nitride . The submount may additionally include a metallization layer comprising, for example , Au / Sn, Ti / Pt / Au, Cu or Ti / Ni / Au .

[0011] The effectiveness and efficiency of thermal dissipation in laser packages is commonly expressed as thermal resistance , which is a function of the thermal power output of the laser device . The thermal resistance Rthis determined from the laser thermal power dissipated by a laser device Pthand the temperature difference AT between the hottest point of the laser device and a reference point at a bottom side of the heat sink furthest from the laser device as :

[0012] Lower thermal resistance values correspond to more efficient thermal management , allowing operation at higher heatsink temperature without exceeding the maximum j unction temperature of the semiconductor stack of the laser device , or operation of the chip at lower temperatures without a corresponding loss of efficiency .

[0013] Laser packages comprising multiple edge-emitting lasers , in particular, high power laser devices , are commonly implemented as chip on submount assemblies ( COSAs ) , wherein each laser device is mounted on a thermally conductive submount . Multiple COSAs are arranged adj acent to each other on a common thermally conductive baseplate , with the laser devices oriented such that the main direction of light emission from the lasers comprising the package follows substantially parallel paths . Optical elements comprising prisms and / or mirrors may be arranged in front of each laser device to deflect the light to the exterior of the laser package . The baseplate may then be mounted on a PCB, whereby thermal grease and / or a heat sink may additionally be provided during mounting for further heat dissipation .

[0014] Thermal energy generated in the laser device is transferred to the individual submounts , and subsequently transferred therefrom to the underlying common baseplate . Lateral dissipation of heat through and from the submounts results in formation of an effective heat transmission area laterally surrounding the laser device and the connected submount . The size of the effective heat transmission area is dependent on the thermal output of the laser device , the dimensions of the laser device , submount and baseplate , the distance of directly adj acent laser devices , and the thermal conductivity of the submount and baseplate material .

[0015] An arrangement comprising multiple emitters pointing in the same direction results in multiple effective heat transmission areas corresponding to the laser emitters arranged adj acent to each other on the common baseplate . As a result , the useful cross section available for heat transfer is limited, with laser emitters at the peripheral ends of the arrangement are characterized by a larger available effective heat transmission area in comparison with laser emitters arranged between adj acent laser emitters . In particular the lateral dimensions of the effective heat transmission area of laser emitters arranged between adj acent laser emitters is limited to substantially the lateral dimensions of the laser emitters . An increase in the number of COSAs in a single laser package is therefore associated with increased thermal resistance , which can be mitigated either by operating the laser emitters at lower power output levels or by increasing the pitch between adj acent laser devices , thereby increasing the surface area of the common baseplate . A trade-off thereby ensues between the overall package size , achievable power output and thermal efficiency of the laser arrangement .

[0016] In this regard, the inventors propose a laser arrangement wherein the available heat transmission area of the common baseplate is more efficiently utilized, allowing for reduced thermal resistance in laser packages without a corresponding increase in device pitch .

[0017] According to the proposed principle , the proposed laser arrangement comprises a plurality of optoelectronic modules , each comprising a light emitting device , in particular, an edge-emitting laser device in particular implemented as a chip on submount assembly . Literature related to aspects to be considered in material selection, dimensioning, and attachment of the laser chip to a submount is available to the person s killed in the art .

[0018] In some aspects , at least one first optoelectronic module comprises a light emitting device configured to emit light at a first wavelength, and at least one second optoelectronic module comprises a light emitting device configured to emit light at a second wavelength, wherein the second wavelength is different from the first wavelength . An optoelectronic arrangement according to the proposed principle may thus be advantageously employed to produce white light through the combination of light emitting devices configured to emit red, green and blue wavelengths . The emission wavelengths of the light emitting devices are not confined to the visible spectrum, therefore , in some aspects , at least one light emitting device may be configured to emit infrared or ultraviolet light .

[0019] Each optoelectronic module additionally comprises an optical element , in particular comprising a prism and / or a mirror, configured to deflect the light . The optical element is positioned along the main direction of light emission of the corresponding light emitting device .

[0020] According to the proposed principle , multiple optoelectronic modules are mounted onto a common heat conductive baseplate such that alternate emitters are rotated with respect to each other . In particular, the proposed arrangement comprises a first and at least one second optoelectronic module . The first optoelectronic module comprises a first light emitting device characterized by a first main direction of light emission, wherein the emitted light beam may take the form of a cone originating from a surface of the light emitting device . The emitted light beam is deflected by an optical element located along the main direction of light emission . In some aspects , the deflected beam is substantially parallel to the growth direction the light emitting device , or substantially perpendicular to the direction of main direction of light emission of the light emitting device . The second optoelectronic module is arranged adj acent to the first optoelectronic module on the baseplate such that the second light emitting device corresponding to the second optoelectronic module emits light characterized by a second main direction of light emission, wherein the second main direction of light emission is substantially opposite to the first direction of light emission . A plan view of the baseplate in such an arrangement thus shows an emitter corresponding to the first optoelectronic module laterally adj acent to an optical element corresponding to the second optoelectronic module , and vice versa .

[0021] In the proposed arrangement , adj acent optoelectronic modules are characterized by a rotation substantially equal to 180 ° around a vertical axis . By this better thermal management can be achieved by increasing the useful cross-section available for heat transfer , as each emitter on the common baseplate is no longer laterally adj acent to another emitter but to optical elements , which typically generate no heat energy . The effective heat transmission area of adj acent optoelectronic modules in this case extends laterally to sections of the baseplate vertically below the optical elements of adj acent optoelectronic modules , allowing for lower thermal resistance using the same materials for the same package size , with the same number of optoelectronic modules . In an exemplary embodiment comprising 5 optoelectronic modules comprising the same materials , in packages of the same size , and with the same pitch between emitters a reduction in thermal resistance was observed, with a measured thermal resistance of 7 . 6 K / W obtained when all emitters were arranged such that the main direction of light emission from all the light emitting devices was substantially the same , and a measured thermal resistance of 7 . 1 K / W obtained when the optoelectronic modules were arranged according to the proposed principle . By means of the proposed arrangement the thermal resistance can thus for example be reduced by almost 7% . In some aspects , the arrangement comprises more than two optoelectronic modules . In particular the optoelectronic arrangement comprises a first group of optoelectronic modules characterized by a first main direction of light emission and a second group of optoelectronic modules characterized by a second main direction of light emission . Each optoelectronic module from the first group of optoelectronic modules is arranged adj acent to at least one optoelectronic module from the second group of optoelectronic modules , and similarly, each optoelectronic module from the second group of optoelectronic modules is arranged adj acent to at least one optoelectronic module from the first group of optoelectronic modules .

[0022] In some aspects , the optoelectronic modules are arranged such that the deflected light beams exiting the optical elements corresponding to adj acent optoelectronic modules are substantially collinear . In particular, in such aspects wherein the deflected light beams are characterized by a substantially conical shape originating from a surface of the optical element facing away from the baseplate , with the point of origin corresponding to a central axis through the apex of the light cone , the optoelectronic arrangement comprises at least three optoelectronic modules mounted on the common baseplate such that the centre of the light cones exiting the at least three optical elements are substantially collinear . In such aspects , it may be necessary to laterally offset alternate optoelectronic modules , such that surfaces of the optical elements of a first group of optoelectronic modules comprising light emitting devices characterized by a first main direction of light emission, said surfaces being positioned farthest from the light emitting devices on the corresponding optoelectronic modules , are oriented along a common first plane . Further, surfaces of the light emitting devices of a second group of optoelectronic modules comprising light emitting devices characterized by a second main direction of light emission substantially opposite to the first main direction of light emission, said surfaces corresponding to the light emitting surfaces of the light emitting device , are oriented along a common second plane , wherein the common first plane is laterally offset and, in particular, substantially parallel to the common second plane . Such an arrangement allows for emission of substantially parallel light beams from the optical elements of the optoelectronic arrangement . This is in particular beneficial in optoelectronic systems wherein the emitted light beams are coupled to optical elements , such as lenses , optical gratings , prisms , diffusers , optical filters and / or reflective elements , configured to sequentially proj ect the light emitted from the optoelectronic modules , usually at a specified frequency . The need for alignment of the required optical elements to correspond to the relative offset between light beams emitted from the optoelectronic modules is thereby reduced or substantially eliminated .

[0023] In some aspects , the optoelectronic modules are arranged such that end surfaces of the optoelectronic modules viewed from a lateral direction substantially perpendicular to the main direction of light emission are aligned along at least one common plane . In such aspects , the end surfaces comprise alternating end surfaces of optical elements and light emitting devices respectively . In some aspects comprising optoelectronic modules having substantially equal lengths , the end surfaces of the optoelectronic modules are preferably arranged with the end surfaces aligned along two parallel planes , with the distance of separation between the two parallel planes corresponding to the length of an optoelectronic module . These aspects have an inherent advantage of compactness , as one lateral dimension of the arrangement corresponds to a length of the longest optoelectronic module within the arrangement .

[0024] Some aspects of the proposed optoelectronic arrangement further comprise a housing . The housing is arranged such that it at least laterally surrounds the baseplate . In some aspects , the housing extends vertically such that a top surface of the housing substantially parallel to and furthest away from the baseplate protrudes above top surfaces of the optoelectronic modules furthest away from the baseplate . In some aspects , parts of the housing may be arranged in contact with an upper surface of the baseplate . The housing may comprise a dielectric material . In some aspects , the housing material is opaque to the wavelength of light emitted by the light-emitting devices . The housing may comprise a cover , wherein the cover is arranged on the top surface of the housing facing away from the baseplate . The cover is optically transparent to the light emitted by the optoelectronic modules comprising the optoelectronic arrangement . In some aspects , the cover may comprise optical elements , such as lenses , optical gratings , prisms , diffusers and / or optical filters . In some aspects , the baseplate , the housing and the cover are bonded to form a hermetically sealed space within which the optoelectronic modules are arranged .

[0025] In some aspects , the housing further comprises electrically conductive contact surfaces , thereby allowing electrical supply to the optoelectronic modules . The contact surfaces may be located along lateral surfaces of the housing . In some aspects , at least four contact surfaces are provided, with at least two contact surfaces associated with a first group of optoelectronic modules comprising light emitting devices characterized by a first main direction of light emission, and a further two contact surfaces associated with a second group of optoelectronic modules comprising light emitting devices characterized by a second main direction of light emission, said second main direction oriented substantially opposite the first main direction of light emission . In some aspects , at least two electrical contact surfaces are arranged along a common lateral surface of the housing , with a dielectric material arranged between the at least two electrical contact surfaces . In some aspects , the optoelectronic modules are electrically connected to each other and the contact surfaces provided on the housing to form a series circuit .

[0026] Some aspects of the proposed invention relate to a method for manufacturing an optoelectronic arrangement for improved thermal management . In the proposed method, a first step comprises providing a thermally conductive baseplate . Any suitable material characterized by high heat conductivity may be employed for the baseplate . Common commercially available baseplate materials include metals and metallic alloys such as Cu or W / Cu . Ceramic baseplates comprising , for example , AIN, SiC or AI2O3 are also commonly available . The baseplate may comprise a substantially uniform material or may comprise layers of different materials . A metallization layer may be deposited on the surface of a ceramic baseplate to allow electrical conductivity and / or improve adhesive properties .

[0027] In a subsequent step, multiple optoelectronic modules are arranged on an upper surface of the baseplate . Each optoelectronic module comprises a light emitting device and at least one optical element . The light emitting device is , in particular , an edge emitting laser device . The optoelectronic modules are arranged on the baseplate such that a first main direction of light emission of a light emitting device corresponding to a first optoelectronic module is oriented along a substantially opposite direction to a second main direction of light emission of a light emitting device corresponding to a second optoelectronic module , wherein the second optoelectronic module is laterally adj acent to the first optoelectronic module .

[0028] According to the proposed method, the step of providing the optoelectronic modules comprises an initial step of providing a heat conductive submount . A light emitting device is arranged on an upper surface of the heat-conductive submount . In some aspects , the submount extends laterally beyond the sides of the light emitting device , surrounding the light emitting device . In some aspects , the light emitting device and the submount are characterized by substantially equal lateral dimensions . In a subsequent step , an optical element is positioned along the main direction of light emission of the light emitting device . The optical element is mounted on an upper surface of the heat conductive baseplate , and is configured to deflect the light emitted by the light emitting device . In some aspects the optical element is configured such that the deflected beam from the optical element is substantially perpendicular to the main direction of light emission of the corresponding light emitting device .

[0029] In some aspects , the optical elements of at least three optoelectronic modules are arranged such the centre of a light cone from the surface of the optical element deflected outwards is substantially collinear . In some aspects , a subsequent step involves providing a housing , wherein the housing is arranged to laterally surround the baseplate . In some aspects , portions of internal sidewalls of the housing are arranged to extend laterally onto an upper surface of the baseplate . In some aspects the housing comprises a dielectric material . The housing may be bonded to the baseplate using any suitable method, including using adhesives , form-fitting methods , soldering materials or metallic bonding .

[0030] Some aspects of the proposed method further comprise a step of providing electrical contact surfaces , wherein such electrical contact surfaces may be provided on a surface of the housing . Such a surface may, in particular, be vertically displaced from the baseplate , and is , in particular, substantially parallel to the upper surface of the baseplate . In some aspects , the housing comprises at least two contact surfaces , with the contact surfaces arranged on different sidewalls of the housing, in particular the contact surfaces are arranged on sidewalls of the housing facing each other . In alternative aspects , the housing comprises at least two contact surfaces along a common sidewall , wherein the at least two contact surfaces are laterally separated from each other by dielectric material . The electrical contact surfaces comprise any suitable electrically conductive material , and may be deposited by any suitable method, including but not limited to atomic layer deposition, sputtering or photolithography . Where the housing comprises a multilayer ceramic package , the electrical contact surfaces may be dispensed or printed onto a surface of the housing .

[0031] Further aspects of the proposed method relate to providing of a cover , wherein the cover is arranged on an upper surface of the housing facing away from the baseplate . The cover is in particular transparent to the light emissions from the optoelectronic modules arranged on the baseplate . Such a cover may comprise , for example , a lens , a diffuser, an optical filter, or an optical grating . The cover may comprise multiple layers and / or multiple elements , depending on desired optical characteristics of the light beam exiting the optoelectronic package . In some aspects , the baseplate , housing and cover are bonded to each other to form a hermetically sealed enclosure .

[0032] SHORT DESCRIPTION OF THE DRAWINGS

[0033] Further aspects and embodiments in accordance with the proposed principle will become apparent in relation to the various embodiments and examples described in detail in connection with the accompanying drawings in which

[0034] Figures 1 and 2 show an optoelectronic arrangement ;

[0035] Figures 3A and 3B illustrate a plan view of an optoelectronic arrangement in accordance with some aspects of the proposed principle ;

[0036] Figure 4 illustrates an isometric view of an optoelectronic arrangement in accordance with some aspects of the proposed principle ; and

[0037] Figure 5 illustrates a side view of an optoelectronic arrangement in accordance with some aspects of the proposed principle .

[0038] DETAILED DESCRIPTION

[0039] The following embodiments and examples disclose various aspects and their combinations according to the proposed principle . The embodiments and examples are not always to scale . Likewise , different elements can be displayed enlarged or reduced in size to emphasize individual aspects . It goes without saying that the individual aspects of the embodiments and examples shown in the figures can be combined with each other without further ado , without this contradicting the principle according to the invention . Some aspects show a regular structure or form. It should be noted that in practice slight differences and deviations from the ideal form may occur without , however, contradicting the inventive idea .

[0040] In addition, the individual figures and aspects are not necessarily shown in the correct size , nor do the proportions between individual elements have to be essentially correct. Some aspects are highlighted by showing them enlarged. However, terms such as "above", "over", "below", "under" "larger", "smaller" and the like are correctly represented with regard to the elements in the figures. So it is possible to deduce such relations between the elements based on the figures .

[0041] Figures 1 and 2 show an optoelectronic arrangement comprising multiple light emitting devices (11) , in particular edge emitting laser devices and optical elements (13) . Each light emitting device (11) is arranged on a heat-conductive submount (12) for dissipation of heat energy generated during operation of the light emitting device. A light emitting device (11) , optionally arranged on a submount (12) , and a corresponding optical element (13) are hereafter referred to collectively as an optoelectronic module. The optical element deflects light from the corresponding light emitting device characterized by a main direction u of light emission outwards from the optoelectronic package along the direction v. The optical elements may be aligned such that the exit surfaces (132) are aligned along a common plane and configured to emit substantially colinear light beams. For optimal compactness, the optoelectronic modules are arranged such that the end surfaces (131) of the optical elements and the end surfaces (111) of the light emitting devices are respectively flush.

[0042] Multiple optoelectronic modules are arranged adjacent to each other on a common heat-conductive baseplate (10) , which serves to dissipate heat away from the light emitting devices . The optoelectronic modules are surrounded by a housing (14) , which is arranged to surround the baseplate. The housing comprises electrical contact surfaces (142) , which are arranged along the sidewalls (141) of the housing in the illustrated embodiment.

[0043] Each light emitting device (11) generates heat during operation, which is dissipated away from the light emitting device through the submount (12) into the baseplate (10) . As shown in Figure 2, each light emitting device (11A, 11B) is associated with an effective heat transmission area (21A, 21B) , wherein the effective heat transmission area surrounds the respective light emitting device . In a conventional optoelectronic arrangement , adj acent light emitting devices on their respective submounts ( 12A, 12B ) are arranged on the baseplate ( 10 ) such that the lateral distance between adj acent submounts is minimized for reduction of overall package size . Such an arrangement is however characterized by variation in the size of available heat transmission areas for devices at the periphery of the arrangement in comparison with devices arranged between other laser devices . For instance , the device 11A is characterized by a larger available heat transmission area 21A in comparison to the device 11B, whose corresponding available heat transmission area 21B is comparatively smaller . In such a conventional arrangement , efficiency losses or a wavelength shift of the light emitted has to be accepted when driving the optoelectronic arrangement .

[0044] Figures 3A and 3B illustrate aspects of an optoelectronic arrangement according to the proposed principle . Each optoelectronic arrangement comprises multiple optoelectronic modules . An exemplary embodiment comprising 5 optoelectronic modules is shown herein . Each optoelectronic module comprises a light emitting device ( 11A, 11B ) arranged on a submount ( 12 ) and an associated optical element ( 13A, 13B ) . A first optoelectronic module comprising a light emitting device ( 11A) characterized by a first main direction ui of light emission and a corresponding optical element ( 13A) is arranged on a baseplate ( 10 ) . The light emitting device ( 11A) is associated with an effective heat transmission area ( 21A) surrounding the light emitting device and its corresponding submount . The effective heat transmission area is when viewed in growth direction of the semiconductor devices at least 1 . 5 times larger than the area of the respective light emitting device , in particular, at least 2 times larger . In particular the effective heat transmission area surrounds the area of a respective light emitting device in circumferential direction with its outer edges being distant from the area of the light emitting device , in particular distant from the area of the light emitting device at least by 10% of the lateral extend of the area of the light emitting device . A second optoelectronic module comprising a light emitting device ( 11B ) and a corresponding optical element ( 13B ) is arranged on the baseplate ( 10 ) such that the light emitting device ( 11B ) is characterized by a second main direction u2of light emission, wherein the second main direction u2is substantially opposite the first main direction u2of light emission .

[0045] As illustrated in Figure 3A, the optical elements ( 13A, 13B ) associated with the optoelectronic modules are arranged such that at least three central points ( 134 ) corresponding to the centre of a cone of light emanating from the optical elements after emission from the associated light emitting devices ( 11A, 11B ) and subsequent deflection by the optical elements ( 13A, 13B ) are substantially collinear . The resultant emitted light beams from the optical elements in the optoelectronic arrangement are therefore substantially collinear . To achieve collinear beams , however, it is necessary to laterally offset alternate optoelectronic modules . In aspects comprising optoelectronic modules characterized by substantially equal dimensions , for example , a first group of optoelectronic modules comprising light emitting devices characterized by the first main direction of emission u2is arranged such that the end surfaces ( 131A) of the associated optical elements are aligned along a common first plane . The common first plane is preferably substantially parallel to a common second plane , along which end surfaces ( 111A) of light emitting devices corresponding to a second group of optoelectronic modules are aligned, wherein the light emitting devices are characterized by the second main direction of emission u2.

[0046] The proposed arrangement comprising alternate optoelectronic modules rotated by an angle substantially equal to 180 ° results in an improved thermal management without necessitating increase in package size . A trade-off for the collinearity of the emitted light beams is an increase in the lateral dimension w of the space occupied by the optoelectronic modules , wherein the lateral dimension w is larger than the length of an optoelectronic module . The space requirements can however be mitigated by further reducing the lateral pitch between adj acent optoelectronic modules .

[0047] A further aspect illustrated in Figure 3B shows an exemplary embodiment wherein the optoelectronic modules are arranged for optimized package sizing . The optoelectronic modules are arranged such that alternate end surfaces ( 111A) of light emitting devices ( 11A) corresponding to a first group of optoelectronic modules comprising light emitting devices (11A) characterized by a first main direction ui of light emission are arranged such that they are substantially flush with adjacent end surfaces (131B) of optical elements corresponding to a second group of optoelectronic modules comprising light emitting devices (11B) characterized by a second main direction U2 of light emission. The resultant lateral dimension w of the space occupied by the optoelectronic modules corresponds to the length of an optoelectronic module. In some aspects, space requirements are further reduced by arranging adjacent optoelectronic modules such that at least portions of the corresponding submounts (12) are almost in contact with each other, as seen in the circled region. The associated effective heat transmission areas (21A, 21B) in this case are characterized by a substantially diagonal boundary portion between adjacent optoelectronic modules. The effective heat transmission area extends laterally to portions of the common baseplate vertically below the optical elements of adjacent optoelectronic modules, such that the width of the available effective heat transmission area (21A, 21B) for each optoelectronic module is at least in some portions larger than the width of the corresponding submount (12) .

[0048] The optoelectronic arrangement further comprises a housing (14) , which is arranged to laterally surround the baseplate (10) , as seen in Figure 4. The housing may comprise any suitable dielectric material, and in some aspects, comprises a material that is opaque to the light emitted by the optoelectronic modules .

[0049] In some aspects, the sidewalls (141) of the housing (14) are structured to provide electric contact surfaces (142) for provision of electrical supply to the optoelectronic modules. In some aspects, a pair of electrical contact surfaces (142) are positioned on opposite sidewalls (141) of the housing, such that they are electrically isolated by the housing material. In some aspects, the electrical contact surfaces are arranged on a surface of the housing that is vertically separated from the baseplate (10) . Some aspects comprise electrical contact surfaces that are substantially parallel to an upper surface of the baseplate (10) . In some aspects the housing is dimensioned such that an upper surface

[0050] (143) of the housing (14) extends beyond the upper surfaces (133) of the optoelectronic modules farthest away from the baseplate, which in some aspects corresponds to an upper surface of the optical elements. The housing therefore protrudes vertically beyond the optoelectronic modules, surrounding and enclosing them in a lateral direction. In some further aspects, a cover is arranged on the upper surface (143) of the housing, such that an enclosure comprising the baseplate (10) , the housing (14) and the cover is formed, within which the optoelectronic modules are arranged. In some aspects the covered enclosure is hermetically sealed from the environment.

[0051] Further aspects of the proposed optoelectronic arrangement, illustrated in Figure 5, comprise a housing wherein a portion (144) of the housing sidewalls protrudes into the enclosure formed by the housing (14) and the baseplate (10) , laterally extending over part of an upper surface (101) of the baseplate (10) . The inclusion of such a protruding portion

[0052] (144) may serve to improve the mechanical stability of the optoelectronic arrangement. A portion of the upper surface of the protruding portion is used in some aspects for provision of electrical contact surfaces (142) .

[0053] In some aspects, an interface layer (15) is arranged between the light emitting device (11) and the submount (12) and / or between the submount (12) and the baseplate (10) . The material comprising the interface layer is dependent on the required functionality, and on the material comprising the surfaces adjacent to the interface layer. In some aspects, the interface layer (15) comprises an adhesive material. In some aspects, the interface layer (15) additionally or alternatively comprises a metallization layer, which may serve a variety of purposes, such as improved adhesion between the light emitting device and the submount, and between the submount and the baseplate, in particular, wherein the submount comprises a ceramic material. The metallization layer between the light emitting device and the submount may alternatively or additionally be used for electrical connection between the optoelectronic modules. In some aspects, the interface layer comprises a continuous layer. In some other aspects, the interface layer comprises a structured or patterned layer.

[0054] LIST OF REFERENCES

[0055] 10 baseplate

[0056] 11 , 11A, 11B light emitting device 111 , 111A, 111B end surface of light emitting device

[0057] 12 , 12A, 12B submount

[0058] 13 , 13A, 13B optical element

[0059] 131 , 131A, 131B end surface of optical element

[0060] 132 light exit surface of optical element 133 upper surface of optical element

[0061] 134 centre of light beam / cone from optical element

[0062] 14 housing

[0063] 141 sidewalls of housing

[0064] 142 electrical contact surfaces 143 top surface of housing

[0065] 144 lateral protrusion of housing sidewalls

[0066] 15 interface layer

[0067] 21A, 21B effective heat transmission area

Claims

CLAIMS1 . Optoelectronic arrangement comprising a plurality of optoelectronic modules , each optoelectronic module comprising : a light emitting device , comprising a semiconductor stack with a first semiconductor layer of a first doping type , a second semiconductor layer of a second doping type , and an active region arranged between the first and the second semiconductor layer , wherein a main direction of emission of light of the light emitting device is in a direction perpendicular to a growth direction of the semiconductor layers of the semiconductor stack; and at least one optical element arranged in front of the light emitting device along the main direction of emission of light , wherein the at least one optical element is configured to deflect the light emitted from the light emitting device in a direction different from the main direction of emission of light of the light emitting device ; wherein the plurality of optoelectronic modules is arranged such that the main direction of emission of light of a light emitting device of a first optoelectronic module is oriented in substantially opposite direction to the main direction of emission of light of a light emitting device of a second optoelectronic module , and that in plan view of the optoelectronic arrangement the light emitting device of the first optoelectronic module is laterally adj acent to the at least one optical element of the second optoelectronic module and the light emitting device of the second optoelectronic module is laterally adj acent to the at least one optical element of the first optoelectronic module .2 . Optoelectronic arrangement according to claim 1 , wherein the optical element comprises or consists of a mirror or prism .3 . Optoelectronic arrangement according to any of the preceding claims , wherein the at least one optical element is configured to deflect the light emitted from the light emitting device in a directionsubstantially parallel to the growth direction of the semiconductor layers of the semiconductor stack .4 . Optoelectronic arrangement according to any of the preceding claims , wherein the centre of a light cone emitted by the light emitting device of at least three optoelectronic modules and subsequently deflected by the optical elements is substantially collinear .5 . Optoelectronic arrangement according to any of the preceding claims , wherein the first optoelectronic module is configured to emit light of a different wavelength than the second optoelectronic module .6 . Optoelectronic arrangement according to any of the preceding claims , wherein the optoelectronic modules are arranged on at least one common heat conductive baseplate , such that a surface of the first semiconductor layer of the light emitting devices facing away from the active region faces the at least one common heat conductive baseplate .7 . Optoelectronic arrangement according to claim 6 , wherein a heat conductive submount is arranged between each optoelectronic module and the at least one common heat-conductive baseplate .8 . Optoelectronic arrangement according to any of the preceding claims , further comprising a housing , wherein the housing laterally surrounds and encloses the optoelectronic modules and the at least one common heat conductive baseplate , and wherein the housing protrudes beyond the plurality of optoelectronic modules in growth direction of the semiconductor layers of the optoelectronic devices .9 . Optoelectronic arrangement according to claim 8 , further comprising a cover arranged on the housing, wherein in particular the cover comprises at least one optical structure , in particular, an optical lens for shaping the light emitted from the optoelectronic modules .10 . Optoelectronic arrangement according to claim 9 , wherein the housing together with the heat conductive baseplate and the cover hermetically seals the optoelectronic arrangement .11 . Optoelectronic arrangement according to any of claims 6 or 7 , wherein each optoelectronic module is associated with an effective heat transmission area of the heat-conductive baseplate , each effective heat transmission area surrounding one of the light emitting devices , and wherein the effective heat transmission areas of adj acent optoelectronic modules do not overlap .12 . Optoelectronic arrangement according to claim 11 , wherein the effective heat transmission areas are , when seen in growth direction of the optoelectronic devices , each at least 1 . 5 times , in particular 2 times larger than a proj ection of the associated optoelectronic device .13 . Optoelectronic arrangement according to either of claims 11 or 12 , wherein the effective heat transmission areas , when seen in growth direction of the light emitting devices , each extend at least partially laterally beyond a proj ection of the associated light emitting device .14 . Optoelectronic arrangement , wherein at least one first optoelectronic module is arranged between two second optoelectronic modules , and wherein the light emitting device of the at least one first optoelectronic module emits light in a first direction, and the light emitting devices of the two second optoelectronic modules emit light in a second direction, wherein the second direction is substantially opposite to the first direction .15 . Method for manufacturing an optoelectronic arrangement , comprising the steps :Providing a heat-conductive baseplate ;Arranging a plurality of optoelectronic modules on an upper surface of the heat-conductive baseplate , wherein each of the plurality of optoelectronic modules comprises a light emitting device and at least one optical element , and wherein the plurality of optoelectronic modules is arranged such that the main direction of emission of light of a light emitting device of a first optoelectronic module is oriented in a substantially opposite direction to the main direction of emission of light of a light emitting device of a secondoptoelectronic module , and that in plan view of the optoelectronic arrangement the light emitting device of the first optoelectronic module is laterally adj acent to the at least one optical element of the second optoelectronic module and the light emitting device of the second optoelectronic module is laterally adj acent to the at least one optical element of the first optoelectronic module .16 . Method according to claim 15 , wherein the step of providing each of the plurality of optoelectronic modules comprises the steps : Providing a heat-conductive submount ;Arranging a light-emitting device on an upper surface of the heat- conductive submount ;Arranging an optical element on the upper surface of the heat- conductive baseplate , wherein the optical element is positioned along the main direction of light emission of the light-emitting device , and wherein the optical device is configured to transmit the emitted light along a direction different from the light emission path of the light-emitting device .17 . Method according to any of claims 15 or 16 , wherein the optical elements of at least three optoelectronic modules are arranged such that the centre of a light cone comprising light emitted by the light emitting device and deflected by the optical elements is substantially collinear .18 . Method according to any of claims 15 to 17 further comprising a step of arranging a housing , wherein the housing laterally surrounds the baseplate .19 . Method according to claim 18 , further comprising a step of arranging a cover on an upper surface of the housing facing away from the baseplate , wherein the cover is transparent to the light emitted by the optoelectronic module .20 . Method according to claim 19 , wherein the cover comprises at least one of a lens , an optical grating, a diffuser and / or an optical filter .

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