Light-emitting device, laser processing system, method for manufacturing a light-emitting device, and method for manufacturing a laser processing system

Abstract

This light-emitting device comprises: a first laser diode that has a plurality of emitters for emitting first laser beams; a second laser diode that has a plurality of emitters for emitting second laser beams and that is different from the first laser diode; a first beam twister unit provided to correspond to the first laser diode; and a second beam twister unit that is provided to correspond to the second laser diode and that is different from the first beam twister unit.

Description

[Technical Field]

[0001] The present disclosure relates to a light-emitting device, a laser processing system, a method for manufacturing a light-emitting device, and a method for manufacturing a laser processing system. [Background Art]

[0002] As a technology related to laser processing systems, Wavelength Beam Combining (WBC) technology, which condenses laser beams from a plurality of laser emission sources, is known (Patent Document 1 and Patent Document 2). A high-power laser processing system can be realized by applying the WBC technology.

[0003] Laser processing systems are used for applications such as welding, cutting, perforating, and material processing.

[0004] A WBC-type laser processing system typically includes a laser diode in which a plurality of emitters emitting laser light are arranged one-dimensionally, an optical fiber that guides the laser light from the emitters, and an optical system that irradiates a workpiece with the laser light guided by the optical fiber. For example, Patent Document 3 discloses a laser diode bar suitable for such a laser processing system.

[0005] In a laser processing system, a plurality of laser beams emitted from a plurality of emitters are condensed on a diffraction grating, then guided into an optical fiber, and irradiated onto a workpiece by an optical system. In this way, the workpiece is processed by the laser beam. [Prior Art Documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent Publication No. 20180198257 Specification [Patent Document 2] Japanese Unexamined Patent Publication No. 2015-106707 [Patent Document 3] Japanese Patent Publication No. 2002-335047 [Overview of the project]

[0007] A light-emitting device according to one aspect of this disclosure is: A first laser diode having multiple emitters that emit a first laser beam, It has multiple emitters that emit a second laser beam, and the second laser diode is different from the first laser diode, A first beam twister unit provided in correspondence with the first laser diode, A second beam twister unit is provided in correspondence with the second laser diode and is different from the first beam twister unit. ,of Preparation 、 The first beam twister unit has a first FAC lens for adjusting the divergence angle in the fast direction of a plurality of the first laser beams, The second beam twister unit has a second FAC lens for adjusting the fast-direction divergence angle of a plurality of the second laser beams, The curvature of the first laser diode and the curvature of the second laser diode are both 3.0 μm or less. The focal lengths of the first FAC lens and the second FAC lens are both between 30 μm and 50 μm. .

[0008] A method for manufacturing a light-emitting device according to one aspect of this disclosure is: A step of arranging a first laser diode having multiple emitters that emit a first laser beam, The process involves having multiple emitters that emit a second laser beam, and arranging a second laser diode that is different from the first laser diode, It has a first FAC lens for adjusting the divergence angle in the fast direction of multiple first laser beams. A step of arranging the first beam twister unit in correspondence with the first laser diode, It has a second FAC lens for adjusting the divergence angle in the fast direction of multiple second laser beams, The steps include: arranging a second beam twister unit, which is different from the first beam twister unit, in correspondence with the second laser diode; ,of Preparation 、 The curvature of the first laser diode and the curvature of the second laser diode are both 3.0 μm or less. The focal lengths of the first FAC lens and the second FAC lens are both between 30 μm and 50 μm. . [Brief explanation of the drawing]

[0009] [Figure 1] FIG. 1 is a conceptual diagram of a conventional WBC laser processing system. [Figure 2] FIG. 2 is a schematic diagram showing a conventional light-emitting device. [Figure 3] FIG. 3 is a schematic diagram showing the conventional light-emitting device with an upper electrode and a beam twister unit removed therefrom. [Figure 4] FIG. 4 is a schematic diagram showing a conventional laser diode. [Figure 5] FIG. 5 is a schematic diagram showing a beam twister unit provided in a conventional light-emitting device. [Figure 6] FIG. 6 is a diagram showing the relationship between the shift of laser light on a diffraction grating and the amount of warpage of a laser diode. [Figure 7] FIG. 7 is a diagram for explaining the shift of laser light on a diffraction grating. [Figure 8] FIG. 8 is a conceptual diagram of the WBC laser processing system according to the first embodiment. [Figure 9] FIG. 9 is a schematic diagram showing the light-emitting device according to the first embodiment. [Figure 10] FIG. 10 is a schematic diagram showing the light-emitting device with an upper electrode and a beam twister unit removed therefrom. [Figure 11] FIG. 11 is a schematic diagram showing a laser diode provided in the light-emitting device according to the first embodiment. [Figure 12] FIG. 12 is a schematic front view of the light-emitting device according to the first embodiment. [Figure 13] FIG. 13 is a schematic side view of the light-emitting device according to the first embodiment. [Figure 14] FIG. 14 is a diagram for explaining the orientation of a beam twister unit provided in the light-emitting device according to the first embodiment. [Figure 15] FIG. 15 is a flowchart showing a manufacturing process of the light-emitting device according to the first embodiment. [Figure 16]Figure 16 shows the state of the light-emitting device while the beam twister unit's position is being adjusted. [Figure 17] Figure 17 shows the state of the light-emitting device during the fixing operation of the beam twister unit. [Figure 18] Figure 18 shows the state of the light-emitting device while the positional adjustment of the other beam twister unit is being performed. [Figure 19] Figure 19 shows the state of the light-emitting device during the fixing operation of the other beam twister unit. [Figure 20] Figure 20 is a graph showing the intensity distribution of laser light on the diffraction grating of a laser processing system. [Figure 21] Figure 21 is a schematic diagram showing the light-emitting device included in the laser processing system according to the second embodiment. [Figure 22] Figure 22 is a schematic diagram showing the light-emitting device with the upper electrode and beam twister unit removed. [Figure 23] Figure 23 is a schematic diagram of the light-emitting device as viewed from the front, excluding the upper electrode and beam twister unit. [Figure 24] Figure 24 is a schematic diagram of the light-emitting device as viewed from the front. [Figure 25] Figure 25 shows the vicinity of the light-emitting device of the laser processing system according to Modified Example 1. [Figure 26] Figure 26 is a diagram illustrating the positional relationship of each optical component in the laser processing system according to Modification Example 1. [Figure 27] Figure 27 is a schematic diagram showing a light-emitting device according to Modification 2, and is a diagram showing the light-emitting device with the upper electrode and beam twister unit removed. [Modes for carrying out the invention]

[0010] [background] First, we will explain the background leading to the present disclosure of the light-emitting device, laser processing system, method for manufacturing the light-emitting device, and method for manufacturing the laser processing system.

[0011] Figure 1 is a conceptual diagram of a conventional WBC-type laser processing system 10. Figure 2 is a schematic diagram showing a conventional light-emitting device 20. Figure 3 is a schematic diagram showing a conventional light-emitting device 20 with the upper electrode 25 (described later) and beam twister unit 26 (described later) removed. Figure 4 is a schematic diagram showing a laser diode 24. Figure 5 is a schematic diagram showing a beam twister unit 26.

[0012] The WBC (Whole Body Combination) laser processing system 10 is a system that combines laser beams 1 of different wavelengths and emits the combined light as output light 3.

[0013] The laser processing system 10 includes a light-emitting device 20, a SAC (Slow Axis Collimation) lens 30, a diffraction grating 40, and an external resonance half mirror 70.

[0014] In the laser processing system 10, multiple laser beams 1 emitted from the light-emitting device 20 are adjusted by an SAC lens 30 or the like, and then focused onto a diffraction grating 40. The laser processing system 10 then causes the laser beams 1 to resonate between the external resonant half mirror 70 and the light-emitting device 20, thereby causing laser oscillation and irradiating the workpiece (not shown) with output light 3.

[0015] The light-emitting device 20 includes a laser diode module (hereinafter referred to as "LD module") 90, which is the source of the laser light 1, and a beam twister unit 26 (see Figure 2).

[0016] The LD module 90 comprises a lower electrode 21, an insulating sheet 22, a submount 23, a laser diode 24, and an upper electrode 25, as shown in Figures 2 and 3.

[0017] The insulating sheet 22 is placed between the lower electrode 21 and the upper electrode 25 to electrically insulate the lower electrode 21 from the upper electrode 25.

[0018] The submount 23 is positioned on the lower electrode 21 to control the temperature of the laser diode 24. This temperature control includes cooling the laser diode 24, which becomes hot due to heat generation when the laser light 1 is emitted. The laser diode 24 is cooled via the lower electrode 21 and the submount 23 by a cooling system (not shown).

[0019] The laser diode 24 is a semiconductor element that emits multiple laser beams 1 and is located on a submount 23. As shown in Figure 4, the laser diode 24 also includes a laser emission layer 81, a p-side electrode 82, and an n-side electrode 83.

[0020] In order to achieve high output in the laser processing system 10, multiple emitters 80 that emit laser light 1 are formed in the laser emission layer 81. For example, 48 emitters 80 are formed in the laser emission layer 81 at a pitch of several hundred micrometers.

[0021] The p-side electrode 82 and the n-side electrode 83 are electrodes within the element that are electrically connected to the lower electrode 21 and the upper electrode 25, respectively. Multiple p-side electrodes 82 are provided, corresponding to each emitter 80. The laser diode 24 is positioned on the submount 23 such that the n-side electrode 83 faces the lower electrode 21. In this specification, the side of the laser diode 24 where the p-side electrode is located is referred to as the "p-side," and the side where the n-side electrode is located is referred to as the "n-side."

[0022] The lower electrode 21 and the upper electrode 25 are block-shaped electrodes that electrically connect the p-side and n-side of the laser diode 24 to an external power supply, respectively. By passing current between the lower electrode 21 and the upper electrode 25, multiple emitters 80 emit light, and laser light 1 is emitted from each emitter 80.

[0023] The beam twister unit 26 is positioned on the laser emission side of the laser diode 24 (see Figure 2). The beam twister unit 26 collimates multiple laser beams 1 emitted from the laser diode 24 in the fast direction and further rotates the multiple laser beams 1 before emission. Rotating the laser beams 1 means rotating the cross-sectional shape in a plane perpendicular to the propagation direction of the laser beams 1.

[0024] As shown in Figure 5, the beam twister unit 26 includes a FAC (Fact Axis Collimation) lens 27, a beam twister lens 28, and a holding block 29.

[0025] The FAC lens 27 is a lens that collimates the laser beam 1 emitted from the emitter 80 in the fast direction, adjusting the divergence angle in the fast direction. Multiple FAC lenses 27 are arranged to correspond to each of the multiple emitters 80. Each laser beam 1 is collimated in the fast direction by passing through the FAC lens 27, and the beam shape changes.

[0026] The beam twister lens 28 has multiple cylindrical lenses. More specifically, on the incident side of the laser light 1 in the beam twister lens 28, multiple cylindrical lenses are arranged to correspond to each of the multiple emitters 80, and furthermore, multiple cylindrical lenses are arranged on the exit side of the laser light 1 to correspond to each of the multiple emitters 80. These cylindrical lenses are positioned at a 45-degree angle with respect to the fast axis.

[0027] The beam twister lens 28 is aligned so that the optical axes of the multiple cylindrical lenses coincide with the emission axes of the multiple emitters 80 of the laser diode 24. The multiple laser beams 1 that have passed through the FAC lens 27 rotate as they pass through the beam twister lens 28. As a result, the fast axis and slow axis of the laser beams 1 emitted from the beam twister lens 28 are swapped with those of the laser beams 1 before they enter the beam twister lens 28.

[0028] The holding block 29 is a component that holds the FAC lens 27 and the beam twister lens 28, and is adhesively fixed to the upper electrode 25. This fixes the positional relationship between the FAC lens 27 and the beam twister lens 28 and the emitter 80 of the laser diode 24.

[0029] The SAC lens 30 is a lens that focuses the laser light 1 that has passed through the beam twister unit 26 in the slow direction and adjusts the beam divergence angle in the slow direction. The laser light 1 is collimated in the slow direction by passing through the SAC lens 30, and the beam shape changes.

[0030] Multiple laser beams 1 emitted from the SAC lens 30 are focused onto the diffraction grating 40.

[0031] The diffraction grating 40 and the light-emitting device 20 are arranged such that the emission angle from the diffraction grating 40 is constant and corresponds to the lock wavelength of the light-emitting device 20. Therefore, the diffraction grating 40 diffracts multiple laser beams 1 at different angles according to their wavelengths and emits them as combined light 2.

[0032] The combined light 2 emitted from the diffraction grating 40 passes through the convex lens 50 and the concave lens 60 before entering the external resonant half mirror 70. A portion of the combined light 2 is vertically reflected by the external resonant half mirror 70 and returns to each emitter 80 of the laser diode 24, causing laser oscillation. As a result, output light 3, which is a combination of laser light 1 of different wavelengths, is emitted from the external resonant half mirror 70. In this way, the beam intensity of the laser processing system 10 can be increased by combining laser light 1 of different wavelengths.

[0033] In a laser diode 24, the points where laser light is emitted from the emitter 80 (hereinafter referred to as "laser emission points") are ideally aligned at the same height. However, if the laser diode 24 is warped, there will be a difference in the heights of the multiple laser emission points. The magnitude of the warp of the laser diode 24 can be expressed, for example, as the difference between the height of the emission point located furthest to the p-side and the height of the emission point located furthest to the n-side among the laser emission points of the laser diode 24.

[0034] If multiple laser emission points are at different heights, the positions of some of the laser emission points will deviate from their ideal position (i.e., height) relative to the FAC lens 27. The greater the deviation of the optical axis of the laser beam 1 from the optical axis of the FAC lens 27 (hereinafter referred to as "deviation on the FAC lens"), the greater the deviation of the optical axis of the laser beam 1 from the focal point of the diffraction grating 40 (hereinafter referred to as "deviation on the diffraction grating"), in proportion to the distance from the laser diode 24 to the diffraction grating 40.

[0035] Figure 6 shows the relationship between the displacement on the diffraction grating and the magnitude of the warp of the laser diode 24 under predetermined conditions. The predetermined conditions are that the distance from the emitter 80 to the FAC lens 27 is approximately 30 μm, and the distance from the FAC lens 27 to the diffraction grating 40 is 1000 mm.

[0036] For example, if the curvature of the laser diode 24 is 2 μm, even if the relative positions of the laser diode 24 and the FAC lens 27 are determined to minimize the displacement on the FAC lens, the displacement on the FAC lens will be 1 μm. In this case, as shown in Figure 6, the displacement on the diffraction grating will be approximately 8 mm.

[0037] The FAC lens 27 is extremely small, measuring only a few hundred micrometers. Therefore, its focal length is small. Consequently, even a slight misalignment on the FAC lens can result in a large misalignment on the diffraction grating.

[0038] If the curvature of the laser diode 24 is adjusted to be between 0 and 2 μm, then the laser diode 24 will have a maximum curvature of approximately 2 μm. The heights of the multiple laser emission points will vary according to the curvature. As a result, the optical axis of the laser beam 1 emitted from each emitter 80 projected onto the diffraction grating 40 will be shifted in the fast direction.

[0039] Figure 7 illustrates the shift of the laser beam 1 on the diffraction grating 40. The solid line shows the beam spot BS1 of the laser beam 1 when the optical axis of the FAC lens 27 coincides with the optical axis of the laser beam 1 for each emitter 80. The dashed line shows the beam spot BS2 of the laser beam 1 when the curvature of the laser diode 24 is relatively large and the distance between the optical axis of the laser beam 1 and the optical axis of the FAC lens 27 is large. Figure 7 shows that the beam spot BS2 is shifted in the fast direction relative to the beam spot BS1.

[0040] Thus, if the optical axis of laser beam 1 is shifted in the fast direction, the overlap of the laser beams 1 on the external resonant half mirror 70 deteriorates, and the beam quality of output light 3 worsens.

[0041] Furthermore, the laser diode 24 is cut out in chip form from a semiconductor wafer. Depending on the relationship between the dimensions of the semiconductor wafer and the dimensions of the laser diode 24, the number of laser diodes 24 that can be cut out from one semiconductor wafer (hereinafter referred to as "cut-out quantity") may become extremely small. For example, if the number of emitters 80 arranged on one laser diode 24 is increased in order to increase the laser output of the laser processing system 10, the dimensions of the laser diode 24 in the direction in which the emitters 80 are arranged will increase. In this case, there is a risk that the cut-out quantity will decrease.

[0042] Furthermore, increasing the number of emitters 80 placed on the laser diode 24 increases the likelihood of the laser diode 24 containing faulty emitters, causing the yield rate of the laser diode 24 to deteriorate exponentially in proportion to the number of emitters 80.

[0043] Thus, increasing the number of emitters incorporated into a laser diode to achieve higher power output in a laser processing system increases the length of the laser diode, making it more susceptible to warping. When warping occurs in the laser diode, the multiple emitters are no longer aligned in a one-dimensional manner and are no longer positioned at the same height. In this case, the laser beam is not focused to the desired position, and the beam quality of the laser processing system deteriorates.

[0044] Therefore, in view of the above-mentioned problems, the present inventors have invented the light-emitting device, laser processing system, method for manufacturing the light-emitting device, and method for manufacturing the laser processing system according to the present disclosure. According to the light-emitting device, laser processing system, method for manufacturing the light-emitting device, and method for manufacturing the laser processing system according to the present disclosure, beam quality can be improved.

[0045] Furthermore, the yield rate of the laser diode 24 can be improved. Moreover, according to one embodiment of the light-emitting device, laser processing system, method for manufacturing the light-emitting device, and method for manufacturing the laser processing system of this disclosure, semiconductor wafers can be effectively utilized.

[0046] This disclosure aims to provide a light-emitting device, a laser processing system, a method for manufacturing a light-emitting device, and a method for manufacturing a laser processing system that can improve beam quality.

[0047] The light-emitting device, laser processing system, method for manufacturing the light-emitting device, and method for manufacturing the laser processing system described herein will be explained in detail below with reference to the drawings. The embodiments described below are examples only, and the numerical values, shapes, materials, components, arrangement positions of components, connection configurations, processes, and order of processes are not intended to limit the disclosure. Therefore, among the components in the embodiments below, those not described in the independent claims representing the highest-level concepts of the disclosure will be described as optional components.

[0048] Furthermore, each figure is a schematic diagram and not a strictly accurate representation. Therefore, the scale and other details in each figure may not necessarily be consistent. In each figure, the same reference numerals are used for substantially identical components, and redundant explanations are omitted or simplified.

[0049] [First Embodiment] Figure 8 is a conceptual diagram of the WBC type laser processing system 100 according to this embodiment. Figure 9 is a schematic diagram showing the light-emitting device 120. Figure 10 is a schematic diagram showing the light-emitting device 120 excluding the upper electrode 125 (described later) and the beam twister units 126A and 126B (described later). Figure 11 is a schematic diagram showing the laser diodes 124A and 124B. Figure 12 is a schematic diagram of the light-emitting device 120 viewed from the front. Figure 13 is a schematic diagram of the light-emitting device 120 viewed from the side. Figure 14 is a diagram to explain the orientation of the beam twister units 126A and 126B.

[0050] The laser processing system 100 comprises a light-emitting device 120, a SAC lens 130, a diffraction grating 140, and an external resonance half mirror 170. These are arranged in the following order from the upstream side in the direction of laser beam propagation: light-emitting device 120, SAC lens 130, diffraction grating 140, and external resonance half mirror 170.

[0051] Furthermore, a convex lens 150 and a concave lens 160 may be placed between the diffraction grating 140 and the external resonance half mirror 170.

[0052] The emission principle of the output light 104 of the laser processing system 100 is the same as that of the output light 3 of the conventional laser processing system 10 described above. The difference between the laser processing system 100 according to this embodiment and the conventional laser processing system 10 lies in the structure of the light-emitting device.

[0053] (Light-emitting device) As shown in Figure 9, the light-emitting device 120 includes an LD module 190 that emits laser beams 101 and 102, a first beam twister unit 126A, and a second beam twister unit 126B.

[0054] The LD module 190 comprises a lower electrode 121, an insulating sheet 122, a first submount 123A, a second submount 123B, a first laser diode 124A, a second laser diode 124B, and an upper electrode 125, as shown in Figures 9 and 10.

[0055] The insulating sheet 122 is placed between the lower electrode 121 and the upper electrode 125 to electrically insulate the lower electrode 121 from the upper electrode 125.

[0056] The first submount 123A and the second submount 123B are made of different materials and are provided corresponding to the first laser diode 124A and the second laser diode 124B, respectively. Similar to the submount 23 described above, the submounts 123A and 123B are positioned on the lower electrode 121 to control the temperatures of the laser diodes 124A and 124B, respectively. The second submount 123B is independent of and separate from the first submount 123A.

[0057] The first laser diode 124A and the second laser diode 124B are semiconductor devices. The second laser diode 124B is a different device from the first laser diode 124A, having the same structure as the first laser diode 124A. The first laser diode 124A and the second laser diode 124B are arranged on the first submount 123A and the second submount 123B, respectively.

[0058] The configuration of the first laser diode 124A will be described below. The configuration of the second laser diode 124B is the same as that of the first laser diode 124A, so its description will be omitted.

[0059] The first laser diode 124A, as shown in Figure 11, comprises a laser emission layer 181, a p-side electrode 182, and an n-side electrode 183. The laser emission layer 181 is the layer that emits the first laser beam 101. Multiple emitters 180 that emit the first laser beam 101 are formed on the laser emission layer 181, for example, at a pitch of several hundred μm.

[0060] The number of emitters 180 formed on the laser emission layer 181 is less than the number of emitters 80 formed on a conventional laser diode 24 used in a laser processing system 10 having the same laser output as the laser processing system 100, for example, 35 emitters. Therefore, in the direction of the emitter arrangement, the dimensions of the first laser diode 124A are shorter than those of the conventional laser diode 24. Note that the number of emitters 180 formed on the laser emission layer 181 only needs to be two or more; for example, it is sufficient if two or more emitters 180 are formed at a pitch of several hundred μm.

[0061] The p-side electrode 182 and the n-side electrode 183 are electrodes within the element that are electrically connected to the lower electrode 121 and the upper electrode 125, respectively, and are the same as the p-side electrode 82 and the n-side electrode 83 described above.

[0062] The first laser diode 124A and the second laser diode 124B are arranged on the first submount 123A and the second submount 123B, respectively, such that their laser emission surfaces are flush with each other and the n-side electrode 183 faces the lower electrode 121.

[0063] The first laser diode 124A and the second laser diode 124B may be arranged such that the p-side electrode 182 faces the lower electrode 121. In the following explanation, the first laser diode 124A and the second laser diode 124B will be explained using the example where the n-side electrode 183 faces the lower electrode 121.

[0064] The lower electrode 121 and the upper electrode 125 are block-shaped electrodes that electrically connect the p-side and n-side of the laser diodes 124A and 125B, respectively, to an external power supply.

[0065] In the light-emitting device 120, the first laser diode 124A, the first submount 123A, and the lower electrode 121 are capable of conducting without current loss. Similarly, the second laser diode 124B, the second submount 123B, and the lower electrode 121 are capable of conducting without current loss. Furthermore, when the first laser diode 124A and the second laser diode 124B are electrically connected, their polarities face the same direction. Therefore, when current flows between the lower electrode 121 and the upper electrode 125, the current flows in parallel with the laser diodes 124A and 125B.

[0066] In other words, by passing a current between the lower electrode 121 and the upper electrode 125, current flows in parallel to all emitters 180 of the laser diodes 124A and 124B. When a current exceeding a certain value flows through the emitters 180, the laser beams 101 and 102 emit light and are emitted from the emitters 180.

[0067] The warpage of the first laser diode 124A and the second laser diode 124B is within 3.0 μm, preferably within 2.0 μm. This warpage will be explained in detail later.

[0068] The first beam twister unit 126A and the second beam twister unit 126B are different components and are provided corresponding to the first laser diode 124A and the second laser diode 124B, respectively. The second beam twister unit 126B is independent of and separate from the first beam twister unit 126A.

[0069] As shown in Figures 12 and 13, the first beam twister unit 126A comprises an FAC lens 127, a beam twister lens 128, and a holding block 129. The FAC lens 127, like the FAC lens 27 described above, is a lens that collimates the laser beam 101 in the fast direction to adjust the divergence angle in the fast direction, and multiple FAC lenses 127 are arranged to correspond to each of the multiple emitters 180.

[0070] In this embodiment, a lens with a focal length of 30 μm or more and 50 μm or less is used as the FAC lens 127. This focal length will be explained in detail later.

[0071] The beam twister lens 128, like the beam twister lens 28 described above, has multiple cylindrical lenses 128R. Multiple cylindrical lenses 128R are arranged on the incident side of the laser beams 101 and 102 in the beam twister lens 128, corresponding to each of the multiple emitters 180. Furthermore, multiple cylindrical lenses 128R are also arranged on the exit side of the laser beams 101 and 102, corresponding to each of the multiple emitters 180 (see Figure 12). These cylindrical lenses 128R are positioned at a 45-degree angle with respect to the fast axis.

[0072] The retaining block 129 is a component that holds the FAC lens 127 and the beam twister lens 128, and is fixed to the upper electrode 125 with adhesive 110. This fixes the positional relationship between the FAC lens 127 and the beam twister lens 128 and the emitter 180 of the laser diode 124A.

[0073] The first beam twister unit 126A is positioned such that one cylindrical lens 128R is located for each emitter 180. Specifically, it is aligned so that the optical axis CL1 of each emitter 180 of the first laser diode 124A coincides with the optical axis CL2 of each cylindrical lens 128R.

[0074] The configuration of the second beam twister unit 126B is the same as that of the first beam twister unit 126A. Furthermore, the positional relationship between the second beam twister unit 126B and the second laser diode 124B is the same as that between the first beam twister unit 126A and the first laser diode 124A. Therefore, a detailed explanation of these is omitted.

[0075] The beam twister units 126A and 126B are arranged such that multiple first laser beams 101 emitted from beam twister unit 126A and multiple second laser beams 102 emitted from beam twister unit 126B are directed toward the same position on the diffraction grating 140. For example, as shown in Figure 14, the beam twister units 126A and 126B are arranged such that their laser emission surfaces are non-parallel to each other. In Figure 14, α is the angle between the laser emission surface of the second beam twister unit 126B and the laser emission surface of the first beam twister unit 126A.

[0076] As described above, the laser diodes 124A and 124B are arranged so that their laser emission surfaces are flush with each other. By adjusting the orientation of the beam twister units 126A and 126B, the emission direction of the first laser beam 101 and the second laser beam 102 from the beam twister units 126A and 126B can be adjusted.

[0077] (Dimensions of laser diode warpage and alignment direction) The warping of the first laser diode 124A and the second laser diode 124B is caused, for example, by stress resulting from the layer structure of the quantum well structure within the laser emission layer 181.

[0078] Assuming that the dimension of the emitter 180 of laser diodes 124A and 124B in the direction of arrangement is 10 mm, and that a 2 μm U-shaped warp (so-called smile) occurs in laser diodes 124A and 124B, the radius of curvature of that warp is approximately 6253 mm.

[0079] Furthermore, even if the positional relationship between the FAC lenses 127 of the beam twister units 126A and 126B and the laser diodes 124A and 124B is adjusted, the misalignment between the optical axes of the first laser beam 101 and the second laser beam 102 and the optical axis (central axis) of the FAC lens 127 can be as large as 1 μm.

[0080] If the dimension of the emitter 180 of laser diodes 124A and 124B in the alignment direction is 7.5 mm, and the laser diodes 124A and 124B are warped to a radius of curvature of 6253 mm, then the warp is 1.1 μm. Therefore, the maximum misalignment between the optical axes of the first laser beam 101 and the second laser beam 102 and the optical axis (central axis) of the FAC lens 127 is 0.55 μm.

[0081] Thus, when warping occurs with the same radius of curvature, the shorter the dimension of the laser diodes 124A and 124B in the direction of arrangement, the smaller the warping. Consequently, when the positional relationship between the beam twister units 126A and 126B and the laser diodes 124A and 124B is adjusted, the misalignment between the optical axes of the first laser beam 101 and the second laser beam 102 and the optical axis (central axis) of the FAC lens 127 becomes smaller.

[0082] In addition to the U-shaped curvature, other types of curvature include the S-shape with one peak and one valley, the M-shape with two peaks and one valley, and the W-shape with one peak and two valleys. Regardless of the shape of the curvature, the shorter the dimension in the direction of the arrangement of the laser diodes 124A and 124B, the smaller the resulting curvature and the smaller the height difference between the multiple laser emission points within the same laser diode. Consequently, the misalignment between the optical axes of the first laser beam 101 and the second laser beam 102 and the optical axis (central axis) of the FAC lens 127 becomes smaller.

[0083] Therefore, in this embodiment, the laser diodes in the light-emitting device are made into a segmented structure, and by shortening the dimensions in the arrangement direction compared to conventional laser diodes with an integrated structure, the warping that occurs in each laser diode is suppressed, thereby improving beam quality.

[0084] (Relationship between curvature and focal length of FAC lens) The following explanation will use laser diode 124A, which is a blue direct laser diode, as an example.

[0085] The laser light 101 emitted from the laser diode 124A is coherent light, but the beam shape of the laser light 101 expands between the time it is emitted from the emitter 180 and the time it reaches the diffraction grating 140. When the diffraction grating 140 is positioned 1000 mm away from the laser diode 124A, the beam diameter of the laser light 101 on the diffraction grating 140 becomes approximately 30 mm.

[0086] Here, we will explain beam diameter. When a laser diode contains only one emitter (a so-called single-mode laser diode), the light intensity distribution of the laser light emitted from the laser diode is a Gaussian distribution. Beam diameter refers to the diameter of the beam in the range where the intensity ratio from the peak of the intensity distribution is 13.5% or more (that is, the range of ±σ from the peak position, where σ is the standard deviation of the intensity distribution).

[0087] On a diffraction grating, the M2 parameter of laser light emitted from a single-mode laser diode is 1. On the other hand, the M2 parameter of the combined light of multiple laser beams emitted from a laser diode containing multiple emitters is greater than 1. For example, if the laser diode has a warp of 2 μm, the M2 parameter will be 2 or greater.

[0088] In the laser processing system 100, the curvature of the FAC lens 127 is selected according to the distance between the emitters 180 of the laser diodes 124A and 124B.

[0089] The laser beams 101 and 102 emitted from the emitter 180 expand in diameter before entering each FAC lens 127. If the divergence angle in the fast direction is 50°, in order to direct the laser beams 101 and 102 into the beam twister lens 128, it is necessary to use an FAC lens 127 with a focal length of 30 μm or more and 50 μm or less.

[0090] When using an FAC lens 127 with a focal length of 30 μm or more and 50 μm or less, in order to make the M2 parameter on the diffraction grating 140 located 1000 mm away from the laser diodes 124A and 124B 4 or less, the curvature of the laser diodes 124A and 124B must be 3.0 μm or less, preferably 2.0 μm or less.

[0091] In this embodiment, the dimensions of the laser diodes 124A and 124B in the alignment direction are shorter than those of the conventional laser diode 24, making it easier to suppress warping to 3.0 μm or less.

[0092] (Manufacturing method) Referring to Figure 15, the manufacturing method of the light-emitting device 120 will be explained using the example of manufacturing using a semiconductor wafer produced through an exposure process by stepper exposure. Figure 15 is a flowchart of the manufacturing process of the light-emitting device 120 according to this embodiment.

[0093] The manufacturing method for the light-emitting device 120 includes (1) a cutting step S100 of laser diodes 124A and 124B from a semiconductor wafer, (2) an assembly step S200 of the LD module 190, and (3) a placement step S300 of beam twister units 126A and 126B.

[0094] (1) Laser diode cutting process S100 In process S100, laser diodes 124A and 124B are cut from the semiconductor wafer. Here, the dimensions of the emitters 180 of the laser diodes 124A and 124B in the alignment direction (hereinafter sometimes simply referred to as "dimensions in the alignment direction") are set to a predetermined dimension X0.

[0095] The predetermined dimension X0 satisfies the relationship Y≧X0≧0.8Y, where Y is the quotient obtained by dividing the dimension of the part of the semiconductor wafer to be cut (hereinafter referred to as the "part to be cut") by an integer N of 4 or greater.

[0096] The portion of the semiconductor wafer that can be cut is the portion that remains after removing any parts that are held by arms or other equipment during the processing of the semiconductor wafer and can no longer be cut. For example, the portion that can no longer be cut is the area from the periphery of the semiconductor wafer to about 2 mm inward.

[0097] For example, if the laser diodes 124A and 124B are blue direct diodes, a semiconductor wafer with a diameter of 2 inches (50 mm) is generally used. In this case, the dimensions of the area to be cut out will be 46 mm (50 mm - 2 mm x 2).

[0098] For example, if N is set to 4, the given dimension X0 becomes 11.5 mm (46 mm ÷ 4) ≥ X0 ≥ 9.2 mm (46 mm ÷ 4 × 0.8), and if N is set to 5, the given dimension X0 becomes 9.2 mm (46 mm ÷ 5) ≥ X0 ≥ 7.3 mm (46 mm ÷ 5 × 0.8) (rounded down to the second decimal place).

[0099] The reason for setting the lower limit of the predetermined dimension X0 to 80% of Y is that it is assumed that there will be some gaps between the exposure ranges of the stepper exposure.

[0100] (2) Assembly process of LD module S200 The assembly process S200 of the LD module 190 includes steps S201 in which laser diodes 124A and 124B are bonded onto submounts 123A and 123B, respectively; step S202 in which laser diodes 124A and 124B are placed onto the lower electrode 121, respectively; and step S203 in which the upper electrode 125 is bonded.

[0101] First, the laser diodes 124A and 124B are placed on submounts 123A and 123B so that their n-sides face each other, and then bonded together with solder (step S201). Next, the laser diodes 124A and 124B are placed on the lower electrode 121 so that the submounts 123A and 123B are in contact with the lower electrode 121, and then bonded together (step S202).

[0102] Next, the insulating sheet 122 is bonded onto the lower electrode 121, electrical connection parts such as bumps are formed on the laser diodes 124A and 124B, and then the upper electrode 125 is bonded onto the electrical connection parts (step S203).

[0103] (3) Arrangement process S300 of beam twister units 126A and 126B In addition to Figure 15, the placement process S300 of the beam twister units 126A and 126B will be explained in detail with reference to Figures 16 to 19. Figure 16 shows the state of the light-emitting device 120 during the position adjustment of the first beam twister unit 126A. Figure 17 shows the state of the light-emitting device 120 during the fixing operation of the first beam twister unit 126A. Figure 18 shows the state of the light-emitting device 120 during the position adjustment of the second beam twister unit 126B. Figure 19 shows the state of the light-emitting device 120 during the fixing operation of the second beam twister unit 126B.

[0104] As shown in Figure 15, process S300 comprises processes S1 to S3.

[0105] First, the LD module 190 is placed (step S1).

[0106] Next, the first beam twister unit 126A is positioned (step S2). Step S2 comprises steps S21 to S25.

[0107] First, the first beam twister unit 126A is held in a holder (not shown) and positioned in a predetermined location (step S21). The predetermined location is the laser emission end side of the first laser diode 124A.

[0108] Next, as shown in Figure 16, current is passed between the upper electrode 125 and the lower electrode 121 to cause the emitter 180 of the first laser diode 124A to emit light and emit the first laser beam 101 (step S22). At this point, the second laser beam 102 is also emitted from the second laser diode 124B, but the second laser beam 102 is blocked by a shutter or the like so as not to interfere with the measurement of the first laser beam 101.

[0109] Next, the position of the first beam twister unit 126A is adjusted (step S23).

[0110] The following describes step S23 in detail. First, a measuring camera (not shown) having a beam quality confirmation lens is placed at the irradiation site of the first laser beam 101. Then, the first beam twister unit 126A is moved in the direction of the optical axis of the first laser beam 101 and in a direction perpendicular to the optical axis to adjust the position of the first beam twister unit 126A to a position that satisfies (A) to (C) below. (A) The distance from the emitter 180 to the incident plane of the FAC lens 127 is equal to the focal length of the FAC lens 127. (B) When the combined light based on multiple first laser beams 101 is viewed through the beam quality confirmation lens of the measurement camera, the beam shape of the combined light is smallest. (C) Multiple first laser beams 101 are focused at predetermined positions.

[0111] Subsequently, the LD module 190 and the first beam twister unit 126A are placed in a simulated external resonant optical system. The simulated external resonant optical system is a pre-measurement system that mimics the laser processing system 100 and has optical components corresponding to the SAC lens 130, diffraction grating 140, convex lens 150, concave lens 160, and external resonant half mirror 170.

[0112] Furthermore, the aforementioned measuring camera is positioned where the output light 104 emitted from the optical component corresponding to the external resonant half-mirror 170 will illuminate. The position of the first beam twister unit 126A is then adjusted so that the intensity of the output light 104 is maximized and the beam shape of the output light 104 is minimized on the measuring camera.

[0113] Next, the current between the upper electrode 125 and the lower electrode 121 is interrupted to stop the emission of light from the first laser diode 124A (step S24).

[0114] Then, the first laser diode 124A is fixed in place (step S25). In step S25, adhesive 110 is applied to the holding block 129, and ultraviolet light 106 is irradiated onto the adhesive 110 to cure it (see Figure 17).

[0115] Furthermore, after applying the adhesive 110, the position of the first beam twister unit 126A may be readjusted by repeating steps S22 to S23.

[0116] After the position of the first beam twister unit 126A is adjusted and fixed, the positioning operation of the second beam twister unit 126B is performed (step S3).

[0117] The second beam twister unit 126B is positioned (step S3). Step S3 comprises steps S31 to S35, which correspond to steps S21 to S25, and is the same as step S2 except that the object to be positioned, the object to be adjusted, and the object to be fixed are the "second beam twister unit 126B" (see Figures 18 and 19).

[0118] The light-emitting device 120 is completed after going through processes S100 to S300.

[0119] Next, the manufacturing method of the laser processing system 100 will be described. The manufacturing method of the laser processing system 100 includes a placement step S400 of the light-emitting device 120 and a placement step S500 of the optical components.

[0120] First, the light-emitting device 120 is positioned (step S400). Next, optical components such as the SAC lens 130, diffraction grating 140, convex lens 150, concave lens 160, and external resonance half mirror 170 are positioned in appropriate locations (step S500).

[0121] After going through the above steps S400 and S500, the laser processing system 100 is completed.

[0122] In this embodiment, since the laser processing system 100 is equipped with one SAC lens 130, it is not necessary to adjust the position of the SAC lens 130 separately for the first beam twister unit 126A and the second beam twister unit 126B.

[0123] The light-emitting device 120 according to this embodiment includes a first laser diode 124A having a plurality of emitters 180 that emit a first laser beam 101, a second laser diode 124B having a plurality of emitters 180 that emit a second laser beam 102 and being different from the first laser diode 124A, a first beam twister unit 126A provided in correspondence with the first laser diode 124A, and a second beam twister unit 126B provided in correspondence with the second laser diode 124B and being different from the first beam twister unit 126A.

[0124] The manufacturing method for the light-emitting device 120 according to this embodiment comprises the steps of: arranging a first laser diode 124A having a plurality of emitters 180 that emit a first laser beam 101 (step S202); arranging a second laser diode 124B having a plurality of emitters 180 that emit a second laser beam 102 and being different from the first laser diode 124A (step S202); arranging a first beam twister unit 126A corresponding to the first laser diode 124A (step S2); and arranging a second beam twister unit 126B, different from the first beam twister unit 126A, corresponding to the second laser diode 124B (step S3).

[0125] Therefore, as the light-emitting device 120, instead of using a laser diode with a relatively long dimension in the direction of the emitter 180, a structure can be adopted in which multiple laser diodes with a relatively short dimension in the direction of the array can be arranged. As a result, the curvature of the laser diodes 124A and 124B of the light-emitting device 120 can be reduced, making it easier to focus the multiple laser beams 101 and 102 when the light-emitting device 120 is used in the laser processing system 100. In turn, the beam quality of the output light 3 of the laser processing system 100 can be improved.

[0126] Furthermore, since beam twister units 126A and 126B are positioned corresponding to laser diodes 124A and 124B respectively, the position and orientation of the beam twister unit can be adjusted for each laser diode. Therefore, the focusing ability of the laser beams 101 and 102 can be further improved, and the beam quality can be enhanced.

[0127] Furthermore, since the light-emitting device 120 can employ a structure in which multiple laser diodes with relatively short dimensions in the array direction are arranged, more emitters 180 can be placed within the light-emitting device 120 than in the conventional light-emitting device 20 without compromising beam quality. Therefore, the optical output of the light-emitting device 120 can be increased.

[0128] To explain in more detail, in order to suppress the degree of warping of the laser diode 24, there was an upper limit to the dimensions of the laser diode 24 placed in the conventional light-emitting device 20. In other words, there was a limit to how long the dimensions of the laser diode 24 could be made in order to fit more emitters 80.

[0129] According to this embodiment, since the dimensions of the laser diodes 124A and 124B in the alignment direction are relatively short, the number of emitters 180 placed in the light-emitting device 120 can be increased simply by increasing the number of laser diodes placed in the light-emitting device 20, without increasing the curvature of the laser diodes. Consequently, the laser output value of the light-emitting device 120 can be increased.

[0130] Furthermore, since the dimensions of the laser diodes 124A and 124B in the arrangement direction can be made relatively short, the number of emitters contained in one laser diode is less than the number of emitters 80 contained in a conventional laser diode 24. Therefore, the yield rate in the manufacturing of laser diodes can be increased.

[0131] The following will explain the effects of (1) improved beam quality, (2) improved light output of the light-emitting device, and (3) improved yield rate with specific examples.

[0132] (1) Beam quality improvement Let's explain beam quality improvement with a specific example. Figure 20 is a graph showing the intensity distribution of laser light on the diffraction grating of a laser processing system.

[0133] P1 is the intensity distribution when the laser processing system is equipped with a light-emitting device having a single-mode laser diode. P2 is the intensity distribution of the combined light of multiple laser beams 1 when the laser processing system is equipped with a light-emitting device 20 having a conventional laser diode 24. P3 is the intensity distribution of the combined light of multiple laser beams 101 and 102 when the laser processing system is equipped with a light-emitting device 120 having the laser diodes 124A and 124B of this embodiment.

[0134] In measuring the intensity distribution shown in Figure 20, the curvature of the single-mode laser diode, the conventional laser diode 24, and the laser diodes 124A and 124B was set to 6253 mm. Furthermore, the average height of the laser emission point of each laser diode was matched to the height of the central axis of the FAC lens.

[0135] Figure 20 shows that the intensity distribution P3 has a shape closer to the intensity distribution P1 than the intensity distribution P2. In other words, using the light-emitting device 120 of this embodiment results in higher focusing of the laser light from the emitter and higher beam quality of the laser processing system compared to the conventional light-emitting device 20.

[0136] (2) Improvement of the light output of the light-emitting device As mentioned above, when the dimension in the array direction is increased in order to arrange many emitters 80 on the laser diode 24, the warping of the laser diode 24 tends to increase. Therefore, in order to suppress the amount of warping, there was an upper limit to the dimension in the array direction of the laser diode 24. For example, in the case of the laser diode 24 of a conventional light-emitting device 20, if the upper limit to the dimension in the array direction of the laser diode 24 is 10 mm, then when the emitters 80 are arranged at a pitch of 200 μm, 48 emitters 80 can be arranged on the laser diode 24.

[0137] If the light output value of laser beam 1 from each emitter 80 is 1.5W, the light output value of laser diode 24 will be 72W (1.5W x 48 diodes).

[0138] In this embodiment, if the dimension of the laser diodes 124A and 124B in the light-emitting device 120 is 7.5 mm in the arrangement direction, and the emitters 180 are arranged at a pitch of 200 μm, then 35 emitters 180 can be arranged on each of the laser diodes 124A and 124B.

[0139] If the light output value of the laser beams 101 and 102 from each emitter 180 is 1.5W, the light output value of the light-emitting device 120 will be 105.0W (1.5W x 35 beams x 2).

[0140] Therefore, by using a segmented structure for the laser diode, it is possible to reduce the amount of warping while increasing the number of emitters that can be placed in one light-emitting device 120, compared to the conventional integrated structure. This improves beam quality while increasing the optical output of the light-emitting device.

[0141] (3) Improvement of yield rate The following explanation assumes a yield rate of 99.0% for one emitter. If a laser diode has 48 emitters, the yield rate of that laser diode will be 61% (0.99%). 48 ) On the other hand, if a laser diode has 35 emitters, the yield rate of the laser diode is 70% (0.99). 35 )

[0142] Therefore, according to this embodiment, a laser diode with a relatively short dimension in the arrangement direction can be used as the laser diode, which improves the yield rate of the laser diode.

[0143] To describe the manufacturing method of the light-emitting device 120 in more detail, the step of arranging the first beam twister unit 126A (step S2) includes steps of adjusting and fixing the position of the first beam twister unit 126A (steps S23 and S25), and the step of arranging the second beam twister unit 126B (step S3) includes steps of adjusting and fixing the position of the second beam twister unit 126B after the first beam twister unit 126A has been fixed (steps S33 and S35).

[0144] In this way, by adjusting and fixing the position of each of the multiple beam twister units 126A and 126B, it is easy to focus the laser beams 101 and 102 from the laser diodes 124A and 124B.

[0145] In fact, the first beam twister unit 126A and the second beam twister unit 126B are arranged such that multiple first laser beams 101 emitted from the first beam twister unit 126A and multiple second laser beams 102 emitted from the second beam twister unit 126B are directed toward the same position.

[0146] Therefore, the focusing ability of the multiple laser beams 101 and 102 from the multiple laser diodes 124A and 124B can be improved, thereby improving beam quality.

[0147] In this embodiment, the first beam twister unit 126A has an FAC lens 127 for adjusting the divergence angle in the fast direction of a plurality of first laser beams 101, and the second beam twister unit 126B has an FAC lens 127 for adjusting the divergence angle in the fast direction of a plurality of second laser beams 102. Furthermore, the curvature of the first laser diode 124A and the curvature of the second laser diode 124B are both 3.0 μm or less, and the focal length of the FAC lens 127 of the beam twister units 126A and 126B is 30 μm or more and 50 μm or less.

[0148] Since the dimensions of the laser diodes 124A and 124B in the alignment direction can be made relatively short, their curvature can be easily kept below 3.0 μm. In addition, the focal length of the FAC lens 127 of the beam twister units 126A and 126B is between 30 μm and 50 μm. Therefore, the laser beams 101 and 102 can be appropriately incident onto the beam twister lenses 128 of the beam twister units 126A and 126B, respectively.

[0149] The manufacturing method of the light-emitting device 120 according to this embodiment further includes a step (step S100) of cutting out the first laser diode 124A and the second laser diode 124B from a semiconductor wafer such that the dimensions of the multiple emitters 180 of the first laser diode 124A and the second laser diode 124B in the arrangement direction are a predetermined dimension X0. This predetermined dimension X0 satisfies the relationship Y≧X0≧0.8Y, where Y is the quotient obtained by dividing the dimensions of the part of the semiconductor wafer to be cut out by an integer N of 4 or more.

[0150] The number of laser diodes 124A and 124B obtained depends on the dimensions of the arrangement direction of the laser diodes 124A and 124B relative to the dimensions of the semiconductor wafer. Furthermore, the number of obtained diodes also changes depending on the gaps between the exposure areas in the stepper exposure used in the semiconductor wafer manufacturing process.

[0151] In this embodiment, since the predetermined dimension X0 is set to Y≧X0≧0.8Y, the number of semiconductor wafers obtained can be increased while taking into account the gaps between exposure ranges in stepper exposure. In other words, the excess portion of the semiconductor wafer can be reduced as much as possible, and the semiconductor wafer can be used effectively.

[0152] The laser processing system 100 according to this embodiment includes a light-emitting device 120. Therefore, as described above, it is possible to improve the beam quality of the output light 104 of the laser processing system 100 and improve the optical output of the output light 104.

[0153] [Second Embodiment] The following describes the second embodiment, focusing primarily on the differences from the first embodiment.

[0154] Figure 21 is a schematic diagram showing the light-emitting device 220 included in the laser processing system 200 according to the second embodiment. Figure 22 is a schematic diagram showing the light-emitting device 220 with the upper electrode 125 and beam twister units 126A and 126B removed. Figure 23 is a schematic diagram of the light-emitting device 220 with the upper electrode 125 and beam twister units 126A and 126B removed, viewed from the front. Figure 24 is a schematic diagram of the light-emitting device 220 viewed from the front.

[0155] The laser processing system 200 according to the second embodiment includes a light-emitting device 220 in place of the light-emitting device 120. As shown in Figure 21, the light-emitting device 220 includes an LD module 290, a first beam twister unit 126A, and a second beam twister unit 126B.

[0156] The LD module 290 comprises a lower electrode 121, an insulating sheet 122, a first laser diode 124A, and a second laser diode 124B.

[0157] Furthermore, the LD module 290 is equipped with a first submount 223A and a second submount 223B in place of the first submount 123A and the second submount 123B.

[0158] The first submount 223A and the second submount 223B are different components and are positioned on the lower electrode 121. The thickness of the first submount 223A is different from that of the second submount 223B, as shown in Figures 23 and 24, where the first submount 223A is thicker than the second submount 223B.

[0159] The first laser diode 124A is positioned on the first submount 223A with its p-side facing the lower electrode 121. On the other hand, the second laser diode 124B is positioned on the second submount 223B with its n-side facing the lower electrode 121. Therefore, the lower electrode 121 is electrically connected to the p-side of the first laser diode 124A and to the n-side of the second laser diode 124B.

[0160] As described above, the first submount 223A is thicker than the second submount 223B, and their respective thicknesses are set so that the laser emission layer 181 of the first laser diode 124A and the laser emission layer 181 of the second laser diode 124B are at the same height. In other words, when the first laser diode 124A and the second laser diode 124B are placed on the first submount 223A and the second submount 223B, respectively, the multiple laser emission points of the first laser diode 124A and the multiple laser emission points of the second laser diode 124B are at the same height.

[0161] The LD module 290 is equipped with a first upper electrode 225A and a second upper electrode 225B in place of the upper electrode 125.

[0162] The first upper electrode 225A is electrically connected to the n side of the first laser diode 124A. The second upper electrode 225B is electrically connected to the p side of the second laser diode 124B and is spaced apart from the first upper electrode 225A. Therefore, the first upper electrode 225A and the second upper electrode 225B are electrically insulated from each other.

[0163] In the LD module 290, when current flows between the first upper electrode 225A and the second upper electrode 225B, the current flows in the following order: second upper electrode 225B, second laser diode 124B, lower electrode 121, first laser diode 124A, and upper electrode 225A. In other words, the first laser diode 124A and the second laser diode 124B are connected in series.

[0164] The following describes the manufacturing method of the light-emitting device 220 according to the second embodiment. The manufacturing method of the light-emitting device 120 according to the second embodiment includes the above-described step S100. Furthermore, the manufacturing method of the light-emitting device 220 includes step S600 (steps S601 to S603) instead of step S200 (steps S201 to S203), and step S700 instead of step S300.

[0165] First, step S600 will be explained. The p-side of the first laser diode 124A is bonded to the first submount 223A, and the n-side of the second laser diode 124B is bonded to the second submount 223B (step S601).

[0166] Next, the laser diodes 124A and 124B are placed on the lower electrode 121 and bonded together, such that the submounts 223A and 223B are in contact with the lower electrode 121 (step S602).

[0167] Then, the insulating sheet 122 is bonded onto the lower electrode 121, electrical connection parts such as bumps are formed on the laser diodes 124A and 124B, and the upper electrode 225A and the second upper electrode 225B are bonded onto the first laser diode 124A and the second laser diode 124B, respectively (step S603).

[0168] Step S700 is the same as step S300 described above, except that a current is passed between the first upper electrode 225A and the second upper electrode 225B when the laser diodes 124A and 124B emit light.

[0169] The light-emitting device 220 according to the second embodiment includes an upper electrode 225A, an upper electrode 225B positioned spaced apart from the upper electrode 225A, and a lower electrode 121 positioned spaced apart from the upper electrodes 225A and 225B. The upper electrode 225A is electrically connected to the n side of the first laser diode 124A, the lower electrode 121 is electrically connected to the p side of the first laser diode 124A and the n side of the second laser diode 124B, and the upper electrode 225B is electrically connected to the p side of the second laser diode 124B.

[0170] In other words, in the light-emitting device 220, the first laser diode 124A and the second laser diode 124B are connected in series.

[0171] The effects of connecting the first laser diode 124A and the second laser diode 124B in series will be explained below using a laser processing system equipped with 10 light-emitting devices as an example.

[0172] In the first embodiment, if 35 emitters 180 are arranged on each of the laser diodes 124A and 124B of the light-emitting device 120, the current and voltage values ​​required to output laser light from the light-emitting device 120 are, for example, 88A and 4.5V. In this case, in order to emit the output light 104 from the laser processing system 100, a power supply capable of outputting a current of 88A and a voltage of 45V (4.5V x 10) is required.

[0173] On the other hand, in the light-emitting device 220 according to the second embodiment, since the laser diodes 124A and 124B are connected in series with each other, the voltage value required to output laser light from the light-emitting device 220 is high (9.0V), but the required current value is relatively small. For example, if the laser diodes 124A and 124B have 35 emitters 180, the required current value is 44A.

[0174] Therefore, if the laser processing system is equipped with the light-emitting device 220 according to the second embodiment, a power supply capable of outputting a current of 44A and a voltage of 90V (9.0V x 10) is required to emit output light from the laser processing system.

[0175] In other words, according to the second embodiment, compared to the first embodiment, although the power value required from the power supply to output the laser beams 101 and 102 is the same, the current value required from the power supply is smaller, making it easier to assemble the power supply circuit in the laser processing system.

[0176] Furthermore, in the second embodiment, the first laser diode 124A is positioned so that its p-side faces the lower electrode 121, and the second laser diode 124B is positioned so that its n-side faces the lower electrode 121, and the laser emission layer 181 of the second laser diode 124B is positioned to be the same height as the laser emission layer 181 of the first laser diode 124A.

[0177] Specifically, the light-emitting device 220 includes a first submount 223A positioned on the lower electrode 121 and a second submount 223B positioned on the lower electrode 121 and different from the first submount 223A. The first laser diode 124A is positioned on the first submount 223A, and the second laser diode 124B is positioned on the second submount 223B. The thickness of the first submount 223A is different from the thickness of the second submount 223B.

[0178] This makes it possible to align the heights of the laser emission layers 181 of the laser diodes 124A and 124B, which are arranged in opposite directions. Therefore, the heights of the optical axes of the laser beams 101 and 102 emitted from the laser diodes 124A and 124B can be aligned, thereby improving the focusing ability of the laser beams 101 and 102 and enhancing beam quality.

[0179] [Example 1] The following describes the differences between the first embodiment and the laser processing system 300 according to Modification 1, primarily.

[0180] Figure 25 shows the vicinity of the light-emitting device 320 of the laser processing system 300 according to Modification 1. Figure 26 is a diagram illustrating the positional relationships of each component in the laser processing system 300. Note that the light-emitting device 320 according to Modification 1 is the same as the light-emitting device 120 according to the first embodiment in terms of function and configuration.

[0181] The laser processing system 100 according to the first embodiment was equipped with one SAC lens 130. However, the laser processing system 300 according to this modified example is equipped with a first SAC lens 330A and a second SAC lens 330B. In the laser processing system 300, optical components such as a diffraction grating 140 and an external resonance half mirror 170 are arranged downstream of the first laser beam 101 and the second laser beam 102 in the direction of travel of the first SAC lens 330A and the second SAC lens 330B.

[0182] The first SAC lens 330A and the second SAC lens 330B are arranged to correspond to the first laser diode 124A and the second laser diode 124B, respectively.

[0183] Multiple first laser beams 101 emitted from the first beam twister unit 126A pass through the first SAC lens 330A. At this time, the multiple first laser beams 101 are focused in the slow direction. Similarly, multiple second laser beams 102 emitted from the second beam twister unit 126B pass through the second SAC lens 330B. At this time, the multiple second laser beams 102 are focused in the slow direction.

[0184] In the laser processing system 300 according to this modified example, the distance X1 from the center position between the light-emitting points at both ends of the first laser diode 124A to the center position between the light-emitting points at both ends of the second laser diode 124B satisfies relation (1).

[0185] X1 ≥ X4 × X3 / (X3 - X2) (1) Here, X2 is the focal length of the SAC lenses 330A and 330B, X3 is the distance from the first laser diode 124A to the diffraction grating 140, and X4 is the distance between the light-emitting points at both ends of the first laser diode 124A and the distance between the light-emitting points at both ends of the second laser diode 124B.

[0186] In other words, the first laser diode 124A, the second laser diode 124B, the first SAC lens 330A, the second SAC lens 330B, and the diffraction grating 140 are arranged such that relation (1) is satisfied.

[0187] Furthermore, the manufacturing method of the light-emitting device 320 according to this modified example 1 includes steps S100 to S300, similar to the first embodiment.

[0188] The following describes the manufacturing method of the laser processing system 300 according to this modified example.

[0189] The manufacturing method for the laser processing system 300 according to this modified example includes a step S800 for arranging the light-emitting device 320 and a step S900 for arranging optical components. Step S800 corresponds to step S400 described above.

[0190] Process S900 comprises processes S901 to S903. First, in process S901, the first SAC lens 330A and the second SAC lens 330B are positioned. Process S901 will be described in detail below.

[0191] First, the first SAC lens 330A and the second SAC lens 330B are positioned on the laser emission side of the first beam twister unit 126A and the second beam twister unit 126B, respectively. Next, a measurement camera (not shown) is positioned where the external resonance half mirror 170 should be placed. Furthermore, the combined light of the first laser beam 101 emitted from the first SAC lens 330A and the second laser beam 102 emitted from the second SAC lens 330B is measured with the measurement camera (not shown). Then, the positions of the first SAC lens 330A and the second SAC lens 330B are adjusted so that the beam shape of the combined light is minimized in the slow direction.

[0192] Next, in step S902, a diffraction grating 140 is placed downstream of the first SAC lens 330A and the second SAC lens 330B in the direction of propagation of the laser beams 101 and 102.

[0193] Next, in step S903, the remaining optical components, such as the external resonance half mirror 170, are placed.

[0194] Through the above process, the laser processing system 300 according to this modified example is manufactured.

[0195] In this modified example, in steps S100, S200, and S300 of the manufacturing method for the light-emitting device 320, and in steps S800 and S900 of the manufacturing method for the laser processing system 300, the first laser diode 124A, the second laser diode 124B, the first SAC lens 330A, the second SAC lens 330B, and the diffraction grating 140 are arranged such that the above-mentioned relation (1) is satisfied.

[0196] For example, in process S202, which is a part of process S200, laser diodes 124A and 124B are arranged spaced apart from each other such that the distance X1 satisfies the above-mentioned relation (1). This is because the focal lengths X2 of the SAC lenses 330A and 330B, the distance X3 from the first laser diode 124A to the diffraction grating 140 are predetermined, and the dimensions X4 between the light-emitting points at both ends of the first laser diode 124A and the dimensions X4 between the light-emitting points at both ends of the second laser diode 124B are also predetermined.

[0197] The laser processing system 300 according to this modified example includes a first SAC lens 330A that adjusts the divergence angle in the slow direction of a plurality of first laser beams 101 emitted from a first beam twister unit 126A, and a second SAC lens 330B which is a different lens from the first SAC lens 330A and adjusts the divergence angle in the slow direction of a plurality of second laser beams 102 emitted from a second beam twister unit 126B.

[0198] The manufacturing method for the laser processing system 300 according to this modified example includes the steps of: arranging the light-emitting device 320 (step S800); and arranging a first SAC lens 330A that focuses a plurality of first laser beams 101 emitted from the first beam twister unit 126A in the slow direction, and a second SAC lens 330B which is a different lens from the second SAC lens 330B and focuses a plurality of second laser beams 102 emitted from the second beam twister unit 126B in the slow direction (step S901).

[0199] If there is an error in the positioning of the laser diodes 124A and 124B in the light-emitting device 320, a single SAC lens may not be able to sufficiently focus the laser beams 101 and 102 from the laser diodes 124A and 124B onto the diffraction grating 140.

[0200] However, in this modified configuration, since SAC lenses 330A and 330B are provided corresponding to laser diodes 124 and 124B respectively, even if there is some error in the positioning of the laser diodes 124A and 124B, the SAC lenses 330A and 330B can adjust the laser beams 101 and 102 respectively, thereby improving the focusing ability on the diffraction grating 140. Consequently, the beam quality of the output light from the laser processing system 300 can be improved.

[0201] Furthermore, the laser processing system 300 further includes a diffraction grating 140 positioned downstream of the first SAC lens 330A and the second SAC lens 330B in the direction of propagation of the first laser beam 101 and the second laser beam 102.

[0202] The first laser diode 124A and the second laser diode 124B are arranged such that the distance X1 from the center position between the light-emitting points at both ends of the first laser diode 124A to the center position between the light-emitting points at both ends of the second laser diode 124B satisfies the above-mentioned relation (1), where X2 is the focal length of the first SAC lens 330A, X3 is the distance from the first laser diode 124A to the diffraction grating 140, and X4 is the dimension between the light-emitting points at both ends of the first laser diode 124A.

[0203] Accordingly, the manufacturing method of the laser processing system 300 includes a step (step S902) of arranging the diffraction grating 140 downstream of the first SAC lens 330A and the second SAC lens 330B in the direction of propagation of the first laser beam 101 and the second laser beam 102. Then, when X1 is the distance from the center position between the light-emitting points at both ends of the first laser diode 124A to the center position between the light-emitting points at both ends of the second laser diode 124B, X2 is the focal length of the first SAC lens 330A, X3 is the distance from the first laser diode 124A to the diffraction grating 140, and X4 is the dimension between the light-emitting points at both ends of the first laser diode 124A, the first laser diode 124A, the second laser diode 124B, the first SAC lens 330A, and the diffraction grating 140 are arranged to satisfy the above-mentioned relation (1).

[0204] This allows multiple first laser beams 101 emitted from the first laser diode 124A to be incident on the second SAC lens 330B without being incident on the second SAC lens 330B. Furthermore, multiple second laser beams 102 emitted from the second laser diode 124B can be incident on the second SAC lens 330B without being incident on the first SAC lens 330A.

[0205] In the above-described modified example 1, the light-emitting device 320 was described as being the same in function and configuration as the light-emitting device 120 according to the first embodiment, but it may also be the same in function and configuration as the light-emitting device 220 according to the second embodiment.

[0206] [Differentiation 2] The following describes the differences between the laser processing system and light-emitting device 420 according to Modification 2 and the first embodiment described above. Figure 27 is a schematic diagram showing the light-emitting device 420 according to Modification 2, and shows the light-emitting device 420 with the upper electrode and beam twister unit removed.

[0207] The laser processing system (not shown) according to the second modified example includes a light-emitting device 420 having an LD module 490, and the LD module 490 has a single submount 423. That is, laser diodes 124A and 124B are bonded to the single submount 423.

[0208] The manufacturing method of the light-emitting device 420 according to this modified example is the same as the manufacturing method of the light-emitting device 120 of the first embodiment, except that the laser diodes 124A and 124B are bonded to a single submount 423.

[0209] According to Modification 2, the same effects and advantages as those of the first embodiment described above can be obtained.

[0210] In addition, the light-emitting device 420 may be arranged similarly to the light-emitting device 220 according to the second embodiment, such that the p-side of the first laser diode 124A faces the lower electrode 121, and the n-side of the second laser diode 124B faces the lower electrode 121.

[0211] In this case, the submount 423 has a step, and the first laser diode 124A is positioned higher than the second laser diode 124B on the submount 423. As a result, the laser emission layer 181 of the first laser diode 124A and the laser emission layer 181 of the second laser diode 124B are positioned at the same height, so that the multiple laser emission points of the first laser diode 124A and the multiple laser emission points of the second laser diode 124B are at the same height.

[0212] Furthermore, the light-emitting device 420 includes a first upper electrode connected to the n side of the first laser diode 124A, and a second upper electrode positioned spaced apart from the first upper electrode so as to be electrically insulated from it, and connected to the p side of the second laser diode 124B.

[0213] Thus, in the light-emitting device 420, the p-side of the first laser diode 124A faces the lower electrode 121, the n-side of the second laser diode 124B faces the lower electrode 121, and the laser light-emitting points of the laser diodes 124A and 124B are arranged to be at the same height, thereby obtaining the same effects as in the second embodiment.

[0214] [Other variations] In the embodiments and modifications described above, two laser diodes are mounted on one light-emitting device, but three or more laser diodes may be mounted on one light-emitting device.

[0215] Furthermore, in the second embodiment and each of its modifications, it was described that the p-side of the first laser diode 124A faces the lower electrode 121, and the n-side of the second laser diode 124B faces the lower electrode 121. However, the first laser diode 124A may be arranged so that the n-side faces the lower electrode 121, and the p-side of the second laser diode 124B faces the lower electrode 121.

[0216] Furthermore, in the laser processing systems according to each of the embodiments and modified examples described above, multiple light-emitting devices may be installed.

[0217] According to this disclosure, it is possible to provide a light-emitting device, a laser processing system, a method for manufacturing a light-emitting device, and a method for manufacturing a laser processing system that can improve beam quality. [Industrial applicability]

[0218] The light-emitting device, laser processing system, method for manufacturing the light-emitting device, and method for manufacturing the laser processing system described herein are suitable for semiconductor laser processing devices using a wavelength beam coupling method. [Explanation of symbols]

[0219] 1. Laser light 2. Synthetic light 3. Output light 10 Laser Processing Systems 20 Light-emitting device 21 Lower electrode 22 Insulating Sheet 23 Submount 24A First laser diode 24B Second laser diode 25 Upper electrode 26 Beam Twister Unit 27 FAC lens 28 Beam Twister Lens 29 Holding block 30 SAC lens 40 Diffraction Gratings 50 convex lens 60 concave lenses 70. Half mirror for external resonance 80 emitters 81 Laser Emitting Layer 82 p side electrode 83 n-side electrode 90 Laser Diode Modules 100 Laser Processing Systems 101 First laser beam 102 Second laser beam 104 Output light 106 Ultraviolet rays 110 Adhesive 120 Light-emitting devices 121 Lower electrode 122 Insulating Sheet 123A First submount 123B Second submount 124A First laser diode 124B Second laser diode 125 Upper electrode 126A First Beam Twister Unit 126B Second Beam Twister Unit 127 FAC lens 128 Beam Twister Lens 129 Holding block 130 SAC lens 140 Diffraction Gratings 150 convex lens 160 concave lens 170 External resonance half mirror 180 emitters 181 Laser Emitting Layer 182 p side electrode 183 n-side electrode 190 Laser Diode Modules 200 Laser Processing Systems 220 Light-emitting devices 223A First submount 223B Second submount 225A First upper electrode 225B Second upper electrode 290 Laser Diode Modules 300 Laser Processing Systems 320 Light-emitting devices 330A First SAC lens 330B Second SAC lens 400 Laser Processing System 420 Light-emitting device 423 Submount BS1 Beam Spot BS2 Beam Spot CL1 Optical axis CL2 optical axis P1 intensity distribution P2 intensity distribution P3 intensity distribution

Claims

1. A first laser diode having multiple emitters that emit a first laser beam, It has multiple emitters that emit a second laser beam, and the second laser diode is different from the first laser diode, A first beam twister unit provided in correspondence with the first laser diode, The system comprises a second beam twister unit, which is provided in correspondence with the second laser diode and is different from the first beam twister unit, The first beam twister unit has a first FAC lens for adjusting the divergence angle in the fast direction of a plurality of the first laser beams, The second beam twister unit has a second FAC lens for adjusting the fast-direction divergence angle of a plurality of the second laser beams. The curvature of the first laser diode and the curvature of the second laser diode are both 3.0 μm or less. The focal lengths of the first FAC lens and the second FAC lens are both between 30 μm and 50 μm. Light-emitting device.

2. The first electrode and A second electrode is positioned spaced apart from the first electrode, A third electrode is positioned spaced apart from the first electrode and the second electrode, Furthermore, The first electrode is electrically connected to the n side of the first laser diode. The third electrode is electrically connected to the p-side of the first laser diode and the n-side of the second laser diode. The second electrode is electrically connected to the p-side of the second laser diode. The light-emitting device according to claim 1.

3. The first laser diode has a first laser light-emitting layer including the plurality of emitters, The second laser diode has a second laser light-emitting layer including the plurality of emitters, The first laser diode is positioned such that its p-side faces the third electrode. The second laser diode is arranged such that its n-side faces the third electrode, and the second laser emission layer is at the same height as the first laser emission layer. The light-emitting device according to claim 2.

4. A first submount is disposed on the third electrode, A second submount, which is positioned on the third electrode and is different from the first submount, Furthermore, The first laser diode is positioned on the first submount, The second laser diode is positioned on the second submount, The thickness of the first submount is different from the thickness of the second submount. The light-emitting device according to claim 3.

5. The first beam twister unit and the second beam twister unit are arranged such that the multiple first laser beams emitted from the first beam twister unit and the multiple second laser beams emitted from the second beam twister unit are directed toward the same position. A light-emitting device according to any one of claims 1 to 4.

6. A first laser diode having a plurality of emitters that emit a first laser beam, It has multiple emitters that emit a second laser beam, and the second laser diode is different from the first laser diode, A first beam twister unit provided in correspondence with the first laser diode, A light-emitting device comprising: a second beam twister unit provided in correspondence with the second laser diode and different from the first beam twister unit; A first SAC lens that adjusts the divergence angle in the slow direction of a plurality of first laser beams emitted from the first beam twister unit, Unlike the first SAC lens, the second SAC lens adjusts the divergence angle in the slow direction of the multiple second laser beams emitted from the second beam twister unit, The system comprises a diffraction grating positioned downstream of the first SAC lens and the second SAC lens in the direction of propagation of the first laser beam and the second laser beam, The first laser diode and the second laser diode are, The distance X1 from the center position between the light-emitting points at both ends of the first laser diode to the center position between the light-emitting points at both ends of the second laser diode is such that, when X2 is the focal length of the first SAC lens, X3 is the distance from the first laser diode to the diffraction grating, and X4 is the distance between the light-emitting points at both ends of the first laser diode, X1≧X4×X3 / (X3-X2) They are arranged such that they satisfy the relationship shown by Laser processing system.

7. A step of arranging a first laser diode having multiple emitters that emit a first laser beam, The process involves having multiple emitters that emit a second laser beam, and arranging a second laser diode that is different from the first laser diode, A step of arranging a first beam twister unit having a first FAC lens for adjusting the divergence angle in the fast direction of a plurality of the first laser beams in correspondence with the first laser diode, The process includes arranging a second beam twister unit, which has a second FAC lens for adjusting the divergence angle in the fast direction of a plurality of the second laser beams, and which is different from the first beam twister unit, in correspondence with the second laser diode, The curvature of the first laser diode and the curvature of the second laser diode are both 3.0 μm or less. The focal lengths of the first FAC lens and the second FAC lens are both between 30 μm and 50 μm. A method for manufacturing a light-emitting device.

8. The step of arranging the first beam twister unit is: The process includes adjusting and fixing the position of the first beam twister unit, The step of arranging the second beam twister unit is as follows: The process includes adjusting and fixing the position of the second beam twister unit after the first beam twister unit has been fixed. A method for manufacturing a light-emitting device according to claim 7.

9. The process further includes cutting the first laser diode and the second laser diode from a semiconductor wafer such that the dimensions of the plurality of emitters of the first laser diode and the second laser diode in the arrangement direction are a predetermined dimension X0. The predetermined dimension X0 is determined when the dimension of the part of the semiconductor wafer to be cut is divided by an integer N of 4 or more, and the quotient Y is obtained from that division, Y ≥ X ≥ 0.8Y Satisfying the relationship, A method for manufacturing a light-emitting device according to claim 7 or 8, comprising:

10. A step of arranging the light-emitting device described in claim 1, The process involves arranging a first SAC lens for adjusting the divergence angle in the slow direction of a plurality of first laser beams emitted from the first beam twister unit, and a second SAC lens, unlike the first SAC lens, for adjusting the divergence angle in the slow direction of a plurality of second laser beams emitted from the second beam twister unit. A method for manufacturing a laser processing system equipped with the following features.

11. The process further includes the step of arranging a diffraction grating downstream of the first SAC lens and the second SAC lens in the direction of propagation of the first laser beam and the second laser beam, When X1 is the distance from the center position between the light-emitting points at both ends of the first laser diode to the center position between the light-emitting points at both ends of the second laser diode, X2 is the focal length of the first SAC lens, X3 is the distance from the first laser diode to the diffraction grating, and X4 is the distance between the light-emitting points at both ends of the first laser diode, X1≧X4×X3 / (X3-X2) A method for manufacturing a laser processing system according to claim 10, wherein the first laser diode, the second laser diode, the first SAC lens, and the diffraction grating are arranged to satisfy the relation shown by .

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