LASER PACKAGE, LASER DEVICE AND METHOD FOR MANUFACTURING

Abstract

The invention relates to a laser package comprising: a base element having a mounting surface on which at least one semiconductor laser element is arranged; a cover element, at least partially transparent to the laser light emitted by the at least one semiconductor laser element, which is connected to the base element and forms a frame that surrounds the at least one semiconductor laser element in a lateral direction and encapsulates the at least one semiconductor laser element with the base element; an optical element arranged on the cover element; and at least one deflecting element arranged in the beam path of the at least one semiconductor laser element and configured to deflect laser light emitted by the at least one semiconductor laser element in the direction of the at least one optical element.The optical element is attached to the lid element by means of an adhesive material comprising: at least 10 percent of a silicone mixture; and a light-curing component. Furthermore, the adhesive material is light-activated and at least partially curable by light curing.

Description

[0001] The present invention relates to a laser package and a laser device comprising at least two laser packages, as well as a method for producing a laser package. BACKGROUND

[0002] An encapsulated laser package with a deflection mirror is an advanced technology widely used in the laser industry. This type of laser module is characterized by its compact design, in which a laser beam is deflected toward an optical element using a deflection mirror to enable precise light extraction from the laser package. The encapsulated design offers many advantages, such as protecting the laser elements from external influences and allowing easy integration into various applications.

[0003] Despite the numerous advantages, however, there are some potential disadvantages, particularly in the manufacture of the laser packages and in particular in the alignment of the optical element with respect to the optical axis of a semiconductor laser arranged in the laser package.

[0004] In known laser packages, two different, separately applied adhesives are used to fasten the optical element to a cover element of the laser package in an aligned position. One of the two adhesives is light-activated or light-curable in order to achieve rapid curing of the adhesive and thus keep cycle times during assembly of the aligned optical element short. This adhesive is used accordingly in the active alignment process for the rapid attachment of the optical element. This first adhesive is usually carbon-based, e.g., acrylate or epoxy-based. However, acrylates and epoxies exhibit aging problems, particularly when exposed to light in the shorter wavelength range (this includes both the wavelength range of blue light and the wavelength range of UV light), and are therefore not light-aging stable.For this reason, a second adhesive is used to ensure a long-term, stable bond. The second adhesive is silicone-based, but only thermally curable. After being briefly fixed in the correct position, the adhesive cures in a downstream batch process under thermal influence. Such silicone-based adhesives are resistant to aging, but due to their long curing time (thermal curing), they are not suitable for processes in which the optical element must be placed and fixed in place until the adhesive has at least partially cured.

[0005] There is therefore a need to provide a laser package and a laser device comprising at least two laser packages, by means of which at least some of the aforementioned disadvantages can be overcome. Furthermore, there is a need to provide an improved method for producing such a laser package. SUMMARY OF THE INVENTION

[0006] This need is addressed by the subject matter of the independent patent claims. Further developments and embodiments of the proposed principle are specified in the subclaims.

[0007] The inventors propose a laser package in which a silicone-based adhesive is used to assemble an optical element. Furthermore, the adhesive is light-activated and cures at least partially upon exposure to light. The at least partial curing results in a dimensionally stable adhesive bond that at least temporarily holds the optical element in a desired target position before the bond can be further cured by thermal curing, if necessary. The adhesive bond is cured either exclusively by light activation or by light activation with parallel or staggered thermal treatment. The initial, at least partial curing of the adhesive, however, is achieved in short or very short process times, in particular a few seconds or less.Once the adhesive has completely cured, a permanently dimensionally stable, strong, and radiation-stable bond is created between the base package of the laser package and the optical element. The major advantage of the adhesive used is that only one adhesive is required for the bond between the base package of the laser package and the optical element, and that processing steps can be eliminated compared to conventional methods.

[0008] According to one aspect of the invention, a laser package comprises a base element having an arrangement surface on which at least one semiconductor laser element is arranged. Furthermore, the laser package comprises a cover element that is at least partially transparent to the laser light emitted by the at least one semiconductor laser element, is connected to the base element, and forms a frame that surrounds the at least one semiconductor laser element in a lateral direction and encapsulates the at least one semiconductor laser element with the base element. Furthermore, the laser package comprises a cover element that is substantially transparent to the laser light emitted by the at least one semiconductor laser element, is arranged on the cover surface, and at least one optical element that is arranged on the cover element.In addition, the laser package comprises at least one deflection element arranged in the beam path of the at least one semiconductor laser element and configured to deflect laser light emitted by the at least one semiconductor laser element toward the at least one optical element. The optical element is secured to the cover element by means of a bonding material, wherein the bonding material comprises at least 10 percent, at least 20 percent, at least 50 percent, or at least 80 percent of a silicone mixture and a light-curing component, and wherein the bonding material is light-activated and at least partially curable by light curing.In particular, the optical element is fastened to the cover element by means of a connecting material, wherein the connecting element is an adhesive which consists partly but at least 30% of a silicone or silicone mixture, and wherein a subsequent polymerization of the connecting material is light-activated or at least partially triggered by light curing.

[0009] The "light-curing component" acts as a type of "catalyst" whose mechanism of action is activated by light to partially or completely cure the bonding material. The concentration of the light-curing component can, for example, be in the low single-digit percentage range, such as in the range of 5, 3, or 2 percent, often even well below 1 percent. However, the term "catalyst" should not be understood to mean that the light-curing component is consumed after its activation by light; rather, it is present in the cured bonding material even after activation. For example, the silicone component can be directly stimulated to polymerize using high-energy light, or polymerization can occur indirectly via organic end groups attached to the silicone, which are, for example, acrylate-based.

[0010] In one aspect, the optical element is attached to the cover element solely by means of the connecting material. In particular, no additional connecting material, adhesive, or other fastening component is required to connect the optical element to the cover element. This allows for savings in process steps and thus costs compared to known methods, which require more than one connecting material or adhesive to connect the optical element to the cover element.

[0011] In one aspect, the bonding material has a bond energy of greater than 350 kJ / mol, greater than 400 kJ / mol, or greater than 450 kJ / mol. In particular, the bond energy of a -Si-O-Si- bond is approximately 450 kJ / mol, which is why silicone-based bonding materials are particularly suitable for age-stable bonds. In contrast, a -C-C- bond (e.g., epoxy) only has a bond energy of approximately 350 kJ / mol, so such bonding materials are unsuitable, or less suitable, for age-stable bonds.

[0012] In one aspect, the connecting material is light-activated by light having a wavelength between 315 nm and 470 nm, or between 250 nm and 450 nm, and at least partially curable by light curing by light having a wavelength between 315 nm and 470 nm, or between 250 nm and 450 nm. In particular, the connecting material is designed to at least begin to harden or cure after irradiation with light having a wavelength between 315 nm and 470 nm, or between 250 nm and 450 nm. This can be understood, in particular, that the connecting material can be hardened by irradiation with light having a wavelength between 315 nm and 470 nm, or between 250 nm and 450 nm, such that it is at least dimensionally stable and holds the optical element in a desired position relative to the cover element, at least temporarily.The bonding material can then be fully cured by a further thermal step or may already have been fully cured by irradiation with light.

[0013] In one aspect, the bonding material, in its cured state, exhibits high stability against light with a wavelength between 315 nm and 700 nm inclusive. In particular, the bonding material, in its cured state, can exhibit high blue light stability. This can be understood, in particular, to mean that the aging behavior of the bonding material is only insignificantly affected by the influence or long-term influence of light with a wavelength between 315 nm and 700 nm inclusive. Likewise, the bonding material, in its cured state, can exhibit high stability against other external influences, such as the effects of moisture, high temperatures, or oxygen, and can therefore be highly resistant to aging.

[0014] In one aspect, the connecting material is arranged in the form of a plurality of adhesive dots or individual adhesive beads between the optical element and the cover element. For example, adhesive dots or individual adhesive beads can be arranged in each corner of the cover element or corners of the optical element, respectively, which connect the optical element and the cover element to one another. Furthermore, further adhesive dots can also be arranged between adhesive dots or individual adhesive beads in the corners of the optical element or cover element. However, it may be desirable for the connecting material to be arranged not in the beam path of the laser light emitted by the semiconductor laser element, but in regions that are not directly in the beam path of the laser light emitted by the semiconductor laser element. The arrangement and number of adhesive dots can be freely selected.

[0015] In one aspect, the connecting material is arranged in the form of an adhesive bead or an adhesive surface in linear form, in particular a circumferential adhesive bead or adhesive surface in linear form, between the optical element and the cover element. For example, one or more adhesive beads can each be arranged along one or more edges of the cover element or of the optical element, which connect the optical element and the cover element to one another. The adhesive bead(s) can in particular be circumferential in such a way that an area within the adhesive bead(s) between the optical element and the cover element is sealed. However, the adhesive bead can also have interruptions such that an area within the adhesive bead between the optical element and the cover element is not sealed.However, it may be desirable for the bonding material to be positioned away from the beam path of the laser light emitted by the semiconductor laser element, but rather in areas that are not directly in the beam path of the laser light emitted by the semiconductor laser element. The arrangement and number of the adhesive bead(s) can be freely selected.

[0016] In one aspect, the connecting material is designed such that it at least partially cures by light curing within less than 100 seconds, less than 80 seconds, less than 40 seconds, less than 10 seconds, less than 5 seconds, or less than 2 seconds, in particular such that it is at least dimensionally stable. Dimensionally stable can be understood in particular to mean that the connecting material holds the optical element relative to the cover element at least temporarily in a desired position. The connecting material can then be fully cured by means of a further thermal step or may already have been fully cured by irradiation with light.

[0017] In one aspect, the bonding material is designed such that light irradiation initiates polymerization of the bonding material. Depending on the curing mechanism, this can generally lead to the bonding material solidifying either very quickly through so-called radical crosslinking within the bonding material, for example within one minute, or more slowly through addition crosslinking, for example over five minutes, such that the bonding material solidifies to such an extent that a stable positioning of the optical element relative to the cover element is achieved. The polymerization of the bonding material is essentially based on activating the light-curing component in the form of, for example, photoinitiators using light. Such photoinitiators can typically be radical or cationic systems. Various systems and combinations are possible.Such photoinitiator-initiated polymerization can also be combined with platinum-catalyst-based, addition-curing silicones or components. These can also be further accelerated in their curing rate through heat treatment or can contribute to the solidification and adhesion development of the bonding material, especially in shadow areas with poor accessibility for light curing.

[0018] In one aspect, the bonding material comprises at least one inorganic, inert filler, and in particular one of the following fillers: Al2O3; SiO2; ZrO2, CaF, and AlN. In particular, the filler can be a glassy, ​​ceramic, or metallic-based filler. The fillers can serve, in particular, to specifically adjust the rheological properties of the bonding material. This can make it possible, in particular, to adjust adhesive gaps between the optical element and the cover element in a range from 5 µm to 300 µm or even up to 500 µm, which is necessary for the active adjustment of the optical element in order to correctly adjust the optical axis of the optical element relative to the beam path of the laser light emitted by the semiconductor laser element. However, it is also possible for the bonding material to comprise at least one organic filler.In such a case, however, it should be ensured that no additional aging effects are triggered in the connecting material.

[0019] In one aspect, the cover element comprises a frame element having a ceramic as the main material, which is arranged adjacent to the base element on the base element and forms a frame that surrounds the at least one semiconductor laser element in a lateral direction. Furthermore, the cover element has a substantially transparent element or a substantially transparent cover arranged on the frame element or a cover surface of the frame element.

[0020] In one aspect, the frame element has a circumferential first step extending laterally from a base surface with a connecting surface that is at least partially connected to a part of the arrangement surface, and the frame element has a circumferential second step extending laterally from a cover surface opposite the base surface.

[0021] In one aspect, an optical axis of the at least one optical element is tilted relative to a direction perpendicular to the lateral direction and / or the at least one deflection element is configured to deflect the laser light by less than 90° such that at least a portion of the deflected laser light intersects a region between the rotating second stage and the cover element.

[0022] Thanks to the circumferential second step, the deflection element for deflecting the light emitted by the semiconductor laser element can deflect the main axis of the laser beam by an angle of less than 90° to the horizontal in order to direct the laser beam further in the direction of the at least one optical element in the region of an outer edge of the laser package without being shadowed by the frame element, as would be the case with a frame element without such a step. The optical element placed on the cover element can thus be pushed onto this outer edge of the laser package into the deflected beam path, and its optical axis can be tilted in such a way that a vertical light exit from the laser package is nevertheless ensured. This type of arrangement allows the emission point of the laser package to be pushed as close as possible to one of the outer edges of the laser package without being shadowed by the frame element.

[0023] In one aspect, the optical axis of the at least one optical element is tilted toward a first side surface of the frame element connecting the base surface and the cover surface. In particular, the at least one optical element also borders a first plane extending through the first side surface and is spaced apart from a second plane extending through a second side surface of the frame element opposite the first side surface. The optical element can in particular be arranged eccentrically above the at least one semiconductor laser element and in particular very close to one of the outer edges of the laser package. In addition, the optical axis of the at least one optical element is tilted toward this outer edge in order to ensure perpendicular light exit from the laser package despite the deflection of the laser beam by less than 90° by the deflection element.

[0024] In one aspect, the laser package is configured to emit laser light in a direction substantially perpendicular to the lateral direction. Furthermore, the laser package has, in particular, a laser light emission region arranged off-center of the laser package. This laser light emission region is, in particular, arranged adjacent to the first plane or is arranged along or adjacent to an outer edge of the laser package.

[0025] In one aspect, the base element essentially does not protrude beyond the base surface, but rather is essentially flush with the base surface. The frame element has a surrounding frame, particularly in the area of ​​the surrounding first step, into which the base element is inserted with the aim of creating a substantially flush component underside of the laser package.

[0026] In one aspect, the base element is arranged at a laterally spaced distance from a third side surface of the frame element, which connects the base surface and the connecting surface to one another. In particular, the base element is not pressed into the frame element, but is arranged at a distance from the frame element on at least opposite side surfaces of the base element. However, the base element is in particular designed and arranged such that the arrangement surface and the connecting surface have a continuous contact area with one another, viewed in the circumferential direction. The frame element can be closed accordingly on one side by means of the base element.

[0027] In addition to the at least one deflection element, the laser package can also comprise further optical elements for beam shaping or beam deflection, which are arranged in the beam path between the at least one semiconductor laser element and the at least one optical element. Such a further optical element for beam shaping or beam deflection can be arranged, for example, on the base plate.

[0028] In one aspect, the laser package comprises a plurality of semiconductor laser elements arranged at a distance from one another on the base element and laterally surrounded by the cover element. In particular, one or more semiconductor laser elements can be provided in the laser package to emit light of the same or different wavelengths. For example, the laser package can be provided to emit only short-wave laser light in the range of, for example, 450 nm, which is subsequently converted into a desired color. Alternatively, the laser package can be provided to emit light of different wavelengths, for example, red, green, and blue light, thus forming an RGB laser package. However, any other combination of wavelengths / colors that can be emitted by the laser package using multiple semiconductor laser elements is also conceivable.

[0029] In one aspect, the semiconductor laser elements of the plurality of semiconductor laser elements can be arranged next to one another in a row. In particular, the semiconductor laser elements can be arranged equidistantly or at different distances from one another on the base plate.

[0030] In one aspect, the laser package comprises a plurality of optical elements, each of which, for example, has an optical axis that is tilted relative to a direction perpendicular to the lateral direction. In particular, the laser package comprises an optical element that is assigned to a semiconductor laser element. In the case of a plurality of semiconductor laser elements, the laser package can have the same number of optical elements as the number of semiconductor laser elements. However, it is also conceivable for the optical element to be formed by a lens array that has a plurality of optical axes, wherein each semiconductor laser element is assigned an optical axis.

[0031] In one aspect, the laser package comprises a plurality of deflection elements, each of which is arranged in the beam path of one of the plurality of semiconductor laser elements and is designed to deflect laser light emitted by the corresponding semiconductor laser element in the direction of the at least one first optical element. In particular, the laser package comprises a respective deflection element assigned to a semiconductor laser element. In the case of a plurality of semiconductor laser elements, the laser package can have the same number of deflection elements as the number of semiconductor laser elements. However, it is also conceivable for the deflection element to be formed by a continuous mirror, which deflects the light emitted by the semiconductor laser elements in the direction of the at least one optical element by substantially 90° or by less than 90°.

[0032] In one aspect, contact surfaces are arranged on the circumferential second stage, which are electrically coupled to at least one of the plurality of semiconductor laser elements. In particular, the circumferential second stage has contact surfaces on its upper side, which are electrically connected, for example, to the bottom surface of the frame element via internal conductor tracks and vias. The conductor tracks or vias can in particular be formed by contact planes integrated into the frame element, which are electrically connected to the contact surfaces. For this purpose, the frame element can be designed, for example, as a multilayer ceramic (e.g.: Al2O3, AlN). In particular, the contact surfaces on the circumferential second stage can be formed at different heights in order to facilitate contacting of the contact surfaces or arrangement of the contact planes.The contact surfaces at different heights in the circumferential second stage are connected, for example, to different connection levels in the frame element.

[0033] In one aspect, the plurality of semiconductor laser elements are coupled in series. In particular, the two outer series-coupled semiconductor laser elements can be contacted by means of bonding wires to contact surfaces on the circumferential second stage.

[0034] In one aspect, however, at least two of the plurality of semiconductor laser elements are each electrically coupled to at least two contact surfaces on the rotating second stage such that each of the at least two of the plurality of semiconductor laser elements can be operated individually. In particular, using the contact surfaces in or on the rotating second stage in conjunction with appropriate internal wiring in the frame element, it is possible to control several semiconductor laser elements mounted in the laser package independently of one another. In the case of an RGB laser package, for example, this can be particularly advantageous, since it allows a desired color mixing of the light emitted by the laser package to be achieved.The circumferential second stage offers the advantage of providing a corresponding surface for the contact surfaces adjacent to the respective semiconductor laser elements, enabling wiring between the semiconductor laser element and the contact surfaces over a short distance and without contact with other components of the laser package. Contacting the semiconductor laser elements with the contact surfaces can be achieved, for example, using bonding wires to the contact surfaces on the circumferential second stage.

[0035] In one aspect, the base element comprises a ceramic as the main material and, in particular, has a metallic coating and / or electrical vias, at least in some regions. The ceramic base element can comprise AlN or SiC, for example, and have a metallic coating and / or electrical vias, at least in some regions. Alternatively, the base element can be formed substantially entirely from a metallic material such as Cu or a Cu-based alloy.

[0036] In one aspect, a submount is arranged between the at least one semiconductor laser element and the base plate. In particular, the at least one semiconductor laser element and the submount can form a subassembly that is arranged on the arrangement surface. The submount can, on the one hand, enable better heat dissipation from the at least one semiconductor laser element and, on the other hand, can represent a raised area in order to prevent so-called beam clipping of the laser light emitted from a laser facet of the at least one semiconductor laser element. The submount can, for example, be metallic or have a ceramic as the main material and, in particular, have a metallic coating at least in some regions and / or electrical vias. In particular, the laser package comprises a submount that is assigned to a semiconductor laser element.In the case of a plurality of semiconductor laser elements, the laser package can have the same number of submounts as the number of semiconductor laser elements. However, it is also conceivable for only one contiguous submount to be provided on which the semiconductor laser elements are arranged. Furthermore, it is also conceivable for multiple submounts to have different heights, such that the semiconductor laser elements are also arranged at different heights and emit laser light at different heights. This can be particularly advantageous since multiple deflection elements and optical elements can also be arranged at different heights and thus can be laterally offset from one another to enable an even more compact arrangement of the elements, thus further increasing the luminance of the LES.

[0037] In one aspect, the laser package further comprises at least one electrical component that is arranged on the second stage or integrated into the frame element in the region of the second stage and is electrically coupled to contact surfaces on the circumferential second stage. The circumferential second stage can be configured accordingly for the integration of additional functions. For example, at least one of the following components can be arranged on the second stage or integrated into the frame element in the region of the second stage: an ESD protection diode, a photodiode with a monitoring function, an NTC as a temperature sensor, a capacitor as a voltage source, or other passive electrical components.

[0038] In one aspect, the at least one semiconductor laser element is hermetically encapsulated in the interior space between the base element and the cover element. In particular, the cover element and the base element can be hermetically joined together. For this purpose, connecting elements between the components can be formed, for example, by a metallic solder (Cu / Sn; Cu / Sn / Ag) or by a glass. This results in a hermetically encapsulated laser package that prevents rapid aging of the semiconductor laser elements.

[0039] A further aspect relates to a laser device comprising a plurality of laser packages according to at least one of the aspects described above. In this case, two laser packages are arranged adjacent to one another in such a way that the optical axes of the optical elements of the two laser packages are arranged adjacent to one another or run in a mirrored manner. The laser packages are arranged in particular in a so-called vis-à-vis arrangement such that the individual light spots of the laser packages arranged next to one another are arranged as close to one another as possible. In particular, the laser device comprises an even number of laser packages, with two of the laser packages always being arranged in a vis-à-vis arrangement and pairs of laser packages being arranged in rows and / or columns.

[0040] Such a laser device can also be referred to as a cluster of laser packages and can be used as a light source for laser projection applications.

[0041] In one aspect, the plurality of laser packages are arranged on a common carrier substrate, in particular a printed circuit board. For example, the carrier substrate can be formed by a so-called "exposed copper board" on which the laser packages are arranged.

[0042] A further aspect relates to a method for producing a laser package comprising the steps: Providing a: Base element having an arrangement surface on which at least one semiconductor laser element is arranged, Deflecting element arranged in the beam path of the at least one semiconductor laser element, and a cover element which is at least partially transparent for the laser light emitted by the at least one semiconductor laser element, which cover element is connected to the base element and which forms a frame which surrounds the at least one semiconductor laser element in a lateral direction and encapsulates the at least one semiconductor laser element on the base element; Providing a light-activatable and at least partially light-curable bonding material on the cover element, wherein the bonding material comprises at least 10 percent, at least 20 percent, at least 50 percent, or at least 80 percent of a silicone mixture and comprises a light-curing component; Arranging an optical element on the connecting material; Aligning the optical element such that a laser light emitted by the at least one semiconductor laser element and deflected by the deflection element passes through the optical element; and Light curing of the bonding material in particular in such a way that it is at least dimensionally stable, in particular by means of light with a wavelength between 315nm and 470nm.

[0043] In one aspect, the light-curing step takes place for less than 100 seconds, in particular less than 80 seconds, in particular less than 40 seconds, in particular less than 20 seconds, in particular less than 20 seconds, in particular less than 5 seconds, and in particular less than 2 seconds. As a result of the light-curing step of less than 100 seconds, less than 80 seconds, less than 40 seconds, less than 10 seconds, less than 5 seconds, or less than 2 seconds, the connecting material is at least partially cured, in particular such that it is at least dimensionally stable. Dimensionally stable can be understood in particular to mean that the connecting material holds the optical element in a desired position relative to the cover element, at least temporarily.The bonding material can then be fully cured by a further thermal step or may already have been fully cured by irradiation with light.

[0044] In one aspect, the method further comprises thermally curing the bonding material after the light-curing step. Through the thermal curing step, the already partially cured and, in particular, dimensionally stable bonding material can be fully cured with further exposure to light or simply heat.

[0045] In one aspect, the light-curing step takes place substantially at room temperature. In particular, the light-curing step can take place substantially at room temperature, i.e., around 22°C. However, it can also be advantageous for the light-curing step to take place at a temperature greater than room temperature, i.e., greater than 22°C. For example, depending on the composition of the bonding material, an appropriate ambient temperature for the light-curing step can be selected to ensure optimal curing of the bonding material during the light-curing step.

[0046] In one aspect, the bonding material exhibits high blue light stability in the cured state. In particular, the bonding material exhibits high stability against light with a wavelength between 315 nm and 700 nm in the cured state. This can be understood, in particular, to mean that the aging behavior of the bonding material is only insignificantly affected by light with a wavelength between 315 nm and 700 nm in the cured state. Likewise, the bonding material can exhibit high stability against other external influences in the cured state, such as the effects of moisture, high temperatures, or oxygen, and can therefore be very stable against aging.

[0047] In one aspect, the step of providing the base element, deflection element, and at least one semi-elliptical laser element comprises inserting the base element into a frame element. This may, for example, comprise gluing or bonding the base element into the frame element. In particular, the step of inserting the base element into the frame element may comprise hermetically joining the base element into the frame element.

[0048] In one aspect, the step of providing the base, deflection, and at least one semiconductor laser element comprises arranging the at least one semiconductor laser element on the arrangement surface. This may, in particular, comprise gluing or bonding the at least one semiconductor laser element to the arrangement surface. Furthermore, the step may comprise arranging a submount on the arrangement surface and subsequently arranging the at least one semiconductor laser element on the submount. Furthermore, the step may comprise arranging a subassembly comprising a submount and the at least one semiconductor laser element on the arrangement surface.

[0049] In one aspect, the step of providing the ground, deflection, and at least one half-elite laser element comprises arranging the at least one deflection element. This may include arranging and aligning the deflection element on the arrangement surface.

[0050] In one aspect, the step of providing the base, deflection, and at least one semiconductor laser element comprises providing the cover element, which is at least partially transparent to the laser light emitted by the at least one semiconductor laser element, in the form of providing a substantially transparent cover on a cover surface of a frame element. In particular, the step can comprise gluing or bonding the substantially transparent cover to the frame element, and in particular, hermetically joining the substantially transparent cover to the frame element.

[0051] The method for producing a laser package can in particular be a method for producing a laser package according to at least one of the aspects described above, so that the aspects described for the laser package are also applicable to the laser package produced by means of the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Further aspects and embodiments according to the proposed principle will become apparent with reference to the various embodiments and examples which will be described in detail in conjunction with the accompanying drawings. Fig. 1A to 1C show a cross-sectional view and two plan views of a laser device; Fig. 2A to 2C show a cross-sectional view and two plan views of a laser device comprising two laser packages according to some aspects of the proposed principle; Fig. 3A and Fig. 3B shows a cross-sectional view and a plan view of another embodiment of a laser device comprising laser packages according to some aspects of the proposed principle; Fig. 4 shows a cross-sectional view of another embodiment of a laser device comprising laser packages according to some aspects of the proposed principle; and Fig. 5 shows a cross-sectional view of another embodiment of a laser device comprising laser packages according to some aspects of the proposed principle. DETAILED DESCRIPTION

[0053] The following embodiments and examples illustrate various aspects and their combinations according to the proposed principle. The embodiments and examples are not always to scale. Likewise, various elements may be enlarged or reduced in size to emphasize individual aspects. It goes without saying that the individual aspects and features of the embodiments and examples shown in the figures can be readily combined with one another without compromising the inventive principle. Some aspects have a regular structure or shape. It should be noted that minor deviations from the ideal shape may occur in practice without, however, contradicting the inventive idea.

[0054] Furthermore, the individual figures, features, and aspects are not necessarily depicted in the correct size, nor are the proportions between the individual elements necessarily accurate. Some aspects and features are emphasized by being enlarged. However, terms such as "top," "above," "below," "below," "larger," "smaller," and the like are correctly depicted in relation to the elements in the figures. This makes it possible to infer such relationships between the elements from the illustrations.

[0055] The Fig. 1A, Fig. 1B and Fig. 1C show a cross-sectional view and two plan views of a laser device comprising two laser packages, each with a base element 2 having an arrangement surface 3 on which semiconductor laser elements 4 are arranged. The laser packages also each comprise a cover element 11 comprising a frame element 5 that is connected to the base element 2 and forms a frame that surrounds the semiconductor laser elements 4 in a lateral direction x.

[0056] The frame element 5 has a circumferential step 7 extending laterally from a base surface 6 with a connecting surface 8 that is connected to the arrangement surface 3. Furthermore, the cover elements 11 each comprise a substantially transparent cover 19 that is arranged on a cover surface 9 of the frame element 5 opposite the base surface. Furthermore, a deflection element 14 is arranged on the arrangement surface 3 in the beam path of the semiconductor laser elements 4, which deflects a laser light L emitted by the semiconductor laser elements 4 by 90° in the direction of optical elements 12. The optical elements 12 are arranged such that their optical axis 13 runs perpendicularly and along the main axis of the deflected laser light L in order to ensure laser light emission in a direction y of the laser packages that is perpendicular to the lateral direction x.

[0057] The optical elements 12 are attached to the cover element 11 or the substantially transparent cover 19 by means of two different adhesives 26a and 26b, which are applied in the form of adhesive dots in the corners of the cover element 11. Fig. Figure 1B shows a top view of a state in which the optical elements 12 have not yet been applied to the adhesive dots, and Figure 1C shows a state in which the optical elements 12 have been applied to the adhesive dots. A first adhesive 26a of the two adhesives is light-activated or curable in order to achieve rapid curing of the adhesive and thus keep cycle times during assembly of the aligned optical element 12 short. This adhesive is used accordingly in the active alignment process for the rapid attachment of the optical element 12. This first adhesive 26a is usually carbon-based, e.g., acrylate- or epoxy-based. However, acrylates and epoxies exhibit aging problems, particularly in the shorter wavelength range (this includes both the wavelength range of blue light and the wavelength range of UV light), and are therefore not stable to light aging.For this reason, the second adhesive 26b is used to ensure a long-term, stable bond. The second adhesive 26b is silicone-based but only thermally curable. After the optical element 12 has been briefly fixed in the correct position, the second adhesive 26b cures in a subsequent batch process under thermal influence. Such silicone-based adhesives are resistant to aging, but due to their long curing time (thermal curing), they are not suitable for processes in which the optical element 12 must be set and fixed in position until the adhesive has at least partially cured.

[0058] The inventors therefore propose a laser package 1 in which only a silicone-based connecting material 26 is required for assembling an optical element 12. The connecting material is light-activatable and cures at least partially upon exposure to light. The at least partial curing results in a dimensionally stable adhesive bond that at least temporarily holds the optical element 12 in a desired target position before the bond can be further cured, if necessary, by thermal curing. The bond is accordingly cured either exclusively by light activation or by light activation with parallel or staggered thermal treatment. The first, at least partial curing of the connecting material 26 is achieved in short or very short process times, in particular a few seconds or less.After the connecting material 26 has completely hardened, a permanently dimensionally stable, solid and radiation-stable connection is created between the base package of the laser package 1 and the optical element 12. The great advantage of the connecting material 26 used is that only one connecting material 26 is required for the connection between the base package of the laser package 1 and the optical element 12 and that process steps are reduced compared to the method described in the . Fig. 1A to 1C can be saved.

[0059] The method proposed by the inventors and described in the Fig. The laser device 100 shown in Figures 2A to 2C comprises two laser packages 1 each with a cover element 11 comprising a frame element 5, in which the frame element 5 together with a base element 2 forms a cavity for at least one semiconductor laser element 4.

[0060] Subassemblies comprising a submount 22 and a semiconductor laser element 4 are arranged on an arrangement surface 3 of the base element 2. The laser packages 1 can each have one or more such subassemblies, i.e., one or more semiconductor laser elements 4, arranged on the base element.

[0061] The frame elements 5 comprise a ceramic as their main material and are each connected to the base element 2. Furthermore, the frame elements 5 form a frame that surrounds the semiconductor laser elements 4 in a lateral direction x. The frame element 5 has a circumferential first step 7 extending laterally from a base surface 6 and having a connecting surface 8 that is connected to the arrangement surface 3.

[0062] Furthermore, the cover elements 11 each comprise a substantially transparent cover 19, which is arranged on the cover surface 9 of the frame element 5 and, together with the frame element 5 and the base element 2, forms a closed interior space 24 of the laser package 1. An optical element 12 is attached to the cover element 11 or the substantially transparent cover 19 by means of the connecting material 26. The connecting material 26 is applied in the form of adhesive dots in the corners of the cover element 11. Fig. 2B shows a top view of a state in which the optical elements 12 are not yet applied to the adhesive dots and Fig. 2C shows a state in which the optical elements 12 have been applied to the adhesive dots. However, the arrangement of the connecting material 26 is merely exemplary and can also be in the form of adhesive beads or multiple adhesive dots.

[0063] The bonding material 26 is, in particular, a silicone-based and light-activatable adhesive that cures at least partially upon exposure to light. The at least partial curing results in a dimensionally stable adhesive bond that at least temporarily holds the optical element 12 in a desired target position before the bond can be further cured, if necessary, by thermal curing. Accordingly, the adhesive bond is cured either exclusively by light activation or by light activation with parallel or staggered thermal treatment.

[0064] In addition, a deflection element 14 is arranged on the arrangement surface 3 in the beam path of the semiconductor laser elements 4, which deflects a laser light L emitted by the semiconductor laser elements 4 in the direction of the optical elements 12. The deflection element 14 is designed such that it deflects the laser light L emitted by the semiconductor laser elements 4 by an angle of substantially 90° in the direction of the optical element 12.

[0065] In the illustrated embodiments, the base element 2 essentially does not protrude beyond the base surface 6 and is essentially flush with the base surface 6. This has the advantage of enabling a flat application to the carrier substrate 25, thus increasing the mechanical stability of the laser device 100. Furthermore, electrical contacts can be provided over the entire contact area between the laser packages and the carrier substrate 25 for operating the laser packages 1.

[0066] In addition to the Fig. 2A to 2C has the features described in the Fig. 3A and Fig. The embodiment shown in Figure 3B comprises a frame element 5 in which an inner side wall of the frame element 5 has a circumferential step 10 extending from a top side of the laser package 1 or from a cover surface 9 of the frame element 5, which has several functions. Firstly, the circumferential step 10 causes the inner side wall of the frame element 5 to be set back in the region of the circumferential step 10, thereby preventing shadowing of a laser light L emitted by the at least one semiconductor laser element 4. Secondly, the circumferential step 10 can be used according to further developments of the invention to provide further functionalities of the laser package 1 in or on it.Thanks to the circumferential step 10, a deflection mirror 14 for deflecting a laser light L emitted by the semiconductor laser element 4 can deflect the main axis of the laser light L by an angle of less than 90° to the horizontal in order to direct the laser light L further toward an outer edge of the laser package 1 without being shaded by the frame element 5, as would be the case with a frame element according to the embodiments described above. A lens 12 mounted on the cover element 11 can then be pushed onto this outer edge of the laser package 1 into the deflected beam path of the laser light L, and its optical axis 13 can be tilted such that a vertical light exit from the laser package 1 is ensured. By means of this type of arrangement, the emission point of the laser package 1 can be moved as close as possible to one of the outer edges of the laser package 1, so that in the case of a laser device 100 which is similar to that in the . Fig. 2A and Fig. 2C, the main axes of the laser light L emitted by the laser packages 1 have a comparatively smaller distance d from each other. In the case of such a laser device 100, in which the laser packages 1 are arranged in such a way that the emission points of the laser packages 1 are arranged directly next to each other and only at a distance d from each other, the luminance within a jointly emitting light emission surface (LES) of the laser device 100 can be reduced compared to a Fig. 2A and Fig. 2C shown laser device, can be significantly increased.

[0067] The Fig. 3A and Fig. 3B show a cross-sectional view and a plan view of such a laser device 100 comprising two laser packages 1. The laser device 100 has two laser packages 1, each with a base element 2, which has an arrangement surface 3 on which subassemblies consisting of a submount 22 and a semiconductor laser element 4 are arranged. The laser packages 1 can each have one or more such subassemblies, i.e., one or more semiconductor laser elements 4, which are arranged on the base element.

[0068] The cover elements 11 also each comprise a frame element 5, which has a ceramic as its main material, which is connected to the base element 2 and forms a frame that surrounds the semiconductor laser elements 4 in a lateral direction x. The frame element 5 has a circumferential first step 7 extending laterally from a base surface 6 with a connecting surface 8 that is connected to the arrangement surface 3, as well as a circumferential second step 10 extending in the lateral direction x from a cover surface 9 opposite the base surface 6.

[0069] Furthermore, the cover elements 11 each comprise a substantially transparent cover 19, which is arranged on the cover surface 9 of the frame element 5 and, together with the frame element 5 and the base element 2, forms a closed interior space 24 of the laser package 1. An optical element 12 is fastened to the cover element 11 or to the substantially transparent cover 19 by means of the connecting material 26. Furthermore, a deflection element 14 is arranged on the arrangement surface 3 in the beam path of the semiconductor laser elements 4, which deflects a laser light L emitted by the semiconductor laser elements 4 in the direction of the optical elements 12. The optical elements can, in particular, be a glass plate with integrated micro-optics.Such a design can be particularly advantageous because the joints between the cover element 11 and the optical element 12 are located outside the area through which the laser light radiates. Accordingly, the efficiency of the laser packages 1 can be increased.

[0070] The deflection element 14 is designed such that it deflects the laser light L emitted by the semiconductor laser elements 4 by an angle α of less than 90° such that at least a portion of the deflected laser light L intersects a region 15 between the rotating second stage 10 and the substantially transparent cover 19. Furthermore, the optical elements 12 are arranged and aligned such that their optical axis 13 is tilted relative to a direction y perpendicular to the lateral direction x in order to ensure laser light emission in a direction y of the laser packages 1 perpendicular to the lateral direction x. Accordingly, the optical elements 12 can realign the laser light L passing "obliquely" through the region 15 so that it exits the laser packages 1 in a direction y perpendicular to the lateral direction x.

[0071] By deflecting the laser light by less than 90°, it is possible to guide a light emission closer to an edge region of the laser package 1 and by means of the optical elements 12, the laser light L passing "obliquely" through the region 15 can then be realigned again. In the illustrated case of two laser packages 1 arranged opposite one another on a carrier substrate 25, the main axes of the laser light L emitted by the laser packages 1 can be pushed together accordingly up to a distance d in the lateral direction x, so that compared to the embodiment of the Fig. 2A and Fig. 2C the luminance can be increased within a smaller LES due to the same light power emitted by the laser packages 1.

[0072] In particular, the optical axes 13 of the optical elements 12 are tilted toward a first side surface 16a of the frame element 5, connecting the base surface 6 and the cover surface 9, in order to align the laser light L passing "obliquely" through the region 15. In the laser device, the side surfaces 16a of the laser packages 1 are arranged opposite one another in such a way as to result in the desired face-to-face arrangement. In addition, the optical elements 12 border a first plane 17a passing through the first side surface 16a and are spaced apart from a second plane 17b passing through a second side surface 16b of the frame element 5 opposite the first side surface 16a in order to enable light emission from the laser packages at their edge. A laser light emission region 18 of the laser packages is thus arranged off-center above the region 15 and in particular adjacent to the first plane 17a.

[0073] In the illustrated embodiments, the base element 2 essentially does not protrude beyond the base surface 6 and is essentially flush with the base surface 6. This has the advantage of enabling a flat application to the carrier substrate 25, thus increasing the mechanical stability of the laser device 100. Furthermore, electrical contacts can be provided over the entire contact area between the laser packages and the carrier substrate 25 for operating the laser packages 1.

[0074] In addition, the base element 2 is arranged at a lateral distance from a third side surface 16c of the frame element 5, which connects the base surface 6 and the connecting surface 8. In particular, the base element 2 is glued or bonded to the connecting surface 8 and not pressed into the frame element 5, which determines the distance shown. For example, the base element 2 and the frame element 5 can be hermetically joined.

[0075] From the top view 2B, it can be seen how the optical element 12 of a laser package 1 and the respective associated underlying semiconductor laser elements 4 are arranged in series along an outer edge of the laser package 1. Laser light emitted from the optical elements 12 of the two laser packages 1 can together form a jointly emitting light emission surface (LES) of the laser device 100.

[0076] The Fig. 4 differs from the version shown in Fig. 2A, the cover element 11 or the frame element 5 is arranged on the base element 2, in particular such that the base element 2 forms a support for the frame element and is not arranged in a step of the frame element. In addition, the base element is formed from a ceramic as the main material and has through-hole(s) and contact surfaces via which the semiconductor laser element 4 is electrically connected. In addition, the frame element 5 and the base element 5 have bonding surfaces by means of which a connection is created between the base element 2, the frame element 5 and the essentially transparent cover 19. However, this is to be understood merely as an example, and the described features of the base element 2 and the bonding surfaces can also be transferred to the further embodiments of the proposed principle.

[0077] The Fig. The version shown in Figure 5 differs from the one shown in Fig. 4, the cover element 11 is formed by a one-piece or one-piece, substantially transparent cover that is connected to the base element 2 and forms a frame that surrounds the semiconductor laser element 4 in the lateral direction x and encapsulates the semiconductor laser element 4 with the base element 2. For example, the cover element 11 can be formed from glass in such a case. LIST OF REFERENCE SYMBOLS 1 laser package 2 floor elements 3 Arrangement area 4 semiconductor laser element 5 frame element 6 Floor area 7 circumferential steps 8 Connecting surface 9 Lid area 10 circumferential steps 11 Cover element 12 optical element 13 optical axis 14 Deflection element 15 Area 16a, 16b, 16c side surface 17a, 17b Level 18 Laser light emission area 19 Cover 22 Submount 24 Interior 25 Carrier substrate 26 Connecting material 26a, 26b Adhesive x direction y direction L Laser light d distance

Claims

[1] Laser package (1) comprising: a base element (2) having an arrangement surface (3) on which at least one semiconductor laser element (4) is arranged; a cover element (11) which is at least partially transparent to the laser light (L) emitted by the at least one semiconductor laser element (4), which cover element is connected to the base element (2), which forms a frame which surrounds the at least one semiconductor laser element (4) in a lateral direction (x), and which encapsulates the at least one semiconductor laser element (4) with the base element (2); an optical element (12) arranged on the cover element (11); and at least one deflection element (14) which is arranged in the beam path of the at least one semiconductor laser element (4) and is designed to deflect a laser light (L) emitted by the at least one semiconductor laser element (4) in the direction of the at least one optical element (12); wherein the optical element (12) is fixed to the cover element (11) by means of a connecting material (26), wherein the connecting material (26) comprises: at least 30 percent of a silicone mixture; a light-curing component; and wherein the connecting material (26) is light-activated and at least partially curable by light curing. [2] Laser package according to claim 1, wherein the optical element (12) is fixed to the cover element (11) only by means of the connecting material (26). [3] Laser package according to claim 1 or 2, wherein the bonding material (26) has a bonding energy of greater than 400 kJ / mol. [4] Laser package according to one of claims 1 to 3, wherein the connecting material (26) is light-activated by light having a wavelength between 315nm and 470nm and at least partially curable by means of light curing by light having a wavelength between 315nm and 470nm. [5] Laser package according to one of claims 1 to 4, wherein the connecting material (26) in the cured state has a high stability against light with a wavelength between 315nm and 700nm inclusive. [6] Laser package according to one of claims 1 to 5, wherein the connecting material (26) is arranged in the form of several adhesive points or several non-contiguous adhesive beads between the optical element (12) and the cover element (11). [7] Laser package according to one of claims 1 to 5, wherein the connecting material (26) is arranged in the form of a circumferential adhesive bead between the optical element (12) and the cover element (11), wherein in particular the circumferential adhesive bead has interruptions. [8] Laser package according to one of claims 1 to 7, wherein the connecting material (26) is designed such that it cures at least partially by light curing within less than 20 seconds, in particular such that it is at least dimensionally stable. [9] Laser package according to one of claims 1 to 8, wherein the connecting material (26) comprises at least one of the following fillers: Al2O3; SiO2; ... [10] Laser package according to one of the preceding claims, comprising a plurality of semiconductor laser elements (4) which are arranged at a distance from one another on the base element (2) and are surrounded and encapsulated by the cover element (11) in the lateral direction (x). [11] Laser package according to one of the preceding claims, wherein the cover element (11) comprises a frame element (5) having a ceramic as the main material, wherein the frame element (5) is arranged adjacent to the base element (2) and surrounds the at least one semiconductor laser element (4) in a lateral direction (x). [12] Laser package according to claim 11, wherein the frame element (5) has a circumferential first step (7) extending in the lateral direction from a bottom surface (6) with a connecting surface (8) which is at least partially connected to a part of the arrangement surface (3), and wherein the frame element (5) has a circumferential second step (10) extending in the lateral direction (x) from a cover surface (9) opposite the bottom surface (6). [13] Laser package according to claim 12, wherein an optical axis (13) of the at least one optical element (12) is tilted relative to a direction (y) perpendicular to the lateral direction (x), and wherein the at least one deflection element (14) is designed to deflect the laser light (L) by an angle (α) of less than 90° such that at least a portion of the deflected laser light (L) intersects a region (15) between the circumferential second step (10) and a substantially transparent region of the cover element (11). [14] Laser package according to one of claims 11 to 13, comprising a plurality of optical elements (12), each having an optical axis (13) which is tilted with respect to a direction (y) perpendicular to the lateral direction (x). [15] Laser package according to one of claims 11 to 14, comprising a plurality of deflection elements (14) which are each arranged in the beam path of one of the plurality of semiconductor laser elements (4) and are designed to deflect a laser light (L) emitted by the corresponding semiconductor laser element (4) in the direction of the at least one optical element (12). [16] Laser package according to one of the preceding claims, wherein a submount (22) is arranged between the at least one semiconductor laser element (4) and the base plate (2). [17] Laser package according to one of the preceding claims, wherein the at least one semiconductor laser element (4) is hermetically encapsulated in the interior space (24) between the base element (2) and the cover element (11). [18] Laser device (100) comprising a plurality of laser packages (1) according to one of the preceding claims, wherein two laser packages (1) are arranged adjacent to one another in such a way that the optical axes (13) of the optical elements (12) of the two laser packages (1) are arranged adjacent to one another. [19] Laser device according to claim 17, wherein the plurality of laser packages (1) are arranged on a common carrier substrate (25), in particular a printed circuit board. [20] Method for producing a laser package (1) comprising the steps: Providing a: Base element (2) having an arrangement surface (3) on which at least one semiconductor laser element (4) is arranged, Deflecting element (14) arranged in the beam path of the at least one semiconductor laser element (4), and a cover element (11) which is at least partially transparent for the laser light (L) emitted by the at least one semiconductor laser element (4), which cover element is connected to the base element (2) and forms a frame which surrounds the at least one semiconductor laser element (4) in a lateral direction (x) and encapsulates the at least one semiconductor laser element (4) on the base element (2); Providing a light-activatable and at least partially light-curable bonding material (26) on the cover element (11), wherein the bonding material (26) comprises at least 30 percent of a silicone mixture and comprises a light-curing component; Arranging an optical element (12) on the connecting material (26); Aligning the optical element (12) such that a laser light (L) emitted by the at least one semiconductor laser element (4) and deflected by the deflection element radiates through the optical element (12); and Light-curing the connecting material (9) such that it is at least dimensionally stable, in particular by means of light with a wavelength between 315nm and 470nm. [21] The method of claim 20, wherein the light-curing step is performed for less than 20 seconds. [22] A method according to claim 20 or 21, wherein the step of light curing occurs substantially at room temperature. [23] The method of any one of claims 20 to 22, further comprising thermally curing the bonding material (26) after the light curing step. [24] Method according to one of claims 20 to 23, wherein the bonding material (26) has a high blue light stability in the cured state.

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