Laser irradiation device and laser processing device

Abstract

This invention provides a laser irradiation apparatus and a laser processing apparatus capable of suppressing temperature deviations between multiple laser elements. The laser irradiation apparatus of this invention comprises: a laser array having multiple laser elements including a first laser element and a second laser element; and a cooling substrate for cooling the laser array, the cooling substrate comprising: a substrate having a mounting surface for mounting the laser array; a supply flow path extending in a direction intersecting the mounting surface to supply coolant to the interior of the substrate; a first flow path extending along the mounting surface to cool the first laser element of the laser array via the substrate; and a second flow path extending along the mounting surface to cool the second laser element of the laser array via the substrate. When viewed from above the mounting surface, the first flow path and the second flow path branch off from the supply flow path between the first laser element and the second laser element, thereby allowing coolant to flow separately.

Description

Technical Field

[0001] This invention relates to laser irradiation devices and laser processing devices. Background Technology

[0002] Patent Document 1 disclosed a semiconductor laser device in which a passage for coolant flow is provided inside a heat sink that houses a semiconductor laser array element having multiple laser elements.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2015-153963

[0004] In the aforementioned semiconductor laser device, considering the cooling characteristics of multiple laser elements and preventing the coolant from flowing inside the heat sink, it is possible for temperature deviations to occur between the multiple laser elements. Summary of the Invention

[0005] To address the aforementioned issues, according to one aspect of the present invention, a laser irradiation apparatus is provided, comprising: a laser array consisting of a plurality of laser elements including a first laser element and a second laser element; and a cooling substrate for cooling the laser array, the cooling substrate having: a substrate including a mounting surface for mounting the laser array; a supply flow path extending in a direction intersecting the mounting surface for supplying coolant into the interior of the substrate; a first flow path extending along the mounting surface for cooling the first laser element via the substrate; and a second flow path extending along the mounting surface for cooling the second laser element via the substrate, wherein, when viewed from above the mounting surface, the first flow path and the second flow path branch off from the supply flow path between the first laser element and the second laser element, respectively, and the coolant flows via the supply flow path to the first flow path and the second flow path.

[0006] In addition, according to another aspect of the present invention, a laser processing apparatus is provided, comprising: a laser irradiation head that uses a laser irradiation device of the above-described manner; and a worktable on which a workpiece to be processed is placed by the laser irradiated from the laser irradiation head. Attached Figure Description

[0007] Figure 1 This is a perspective view showing the schematic structure of a laser processing apparatus according to one embodiment.

[0008] Figure 2 It is a three-dimensional diagram showing the structure of a laser irradiation device.

[0009] Figure 3 This is a diagram showing the main structural components of a laser irradiation device.

[0010] Figure 4This is a diagram showing the main structural components of the laser irradiation device in the first modified example.

[0011] Figure 5 This is a diagram showing the main structural components of the laser irradiation device in the second modified example.

[0012] Figure 6 This is a diagram showing the main structural components of the laser irradiation device in the third modified example.

[0013] Figure 7 This is a diagram showing the main structural components of the laser irradiation device in the fourth modified example.

[0014] Label Explanation

[0015] 1: Laser processing equipment; 2, 2A, 2B, 2C, 2D: Laser irradiation equipment; 4: Worktable; 21, 21C, 21D: Cooling substrate; 22: Laser array; 210, 310, 410: Substrate; 210a, 310a, 410a: Mounting surface; 221, 221a: Laser element; 221a: First laser element; 221b: Second laser element; 221c: Third laser element; 221d: Fourth laser element Laser element; 232, 332, 432: Second flow path; 230, 330, 430: Supply flow path; 231, 331, 431: First flow path; 233, 335, 435: Discharge flow path; 234, 336, 436: First connection flow path; 235, 337, 437: Second connection flow path; 333, 433: Third flow path; 334: Fourth flow path; E: Coolant; L: Laser; W: Object to be processed. Detailed Implementation

[0016] Hereinafter, embodiments of the present invention will be described using the accompanying drawings.

[0017] In the following figures, the scales of the dimensions are sometimes different depending on the constituent elements so as to facilitate observation of each constituent element.

[0018] Implementation

[0019] Figure 1 This is a perspective view showing the schematic structure of the laser processing apparatus of this embodiment.

[0020] like Figure 1 As shown, the laser processing apparatus 1 of this embodiment includes a laser irradiation device 2, a moving mechanism 3, a worktable 4, and a control unit 5. The laser processing apparatus 1 is, for example, a metal 3D printer that utilizes SLM (Selective Laser Melting).

[0021] In the following description, the XYZ orthogonal coordinate system will be used as needed.

[0022] In the accompanying drawings, the X-axis is the axis along the direction of movement of the laser irradiation device 2 relative to the worktable 4. The Y-axis is an axis orthogonal to the X-axis, and the XY plane is a plane parallel to the mounting surface 4a of the worktable 4. The Z-axis is an axis orthogonal to both the X-axis and the Y-axis, and is an axis along the vertical direction.

[0023] In this embodiment, the direction along the Z-axis is referred to as the "vertical direction Z", +Z as the "upper side" and -Z as the "lower side", the direction along the X-axis is referred to as the "left-right direction X", +X as the "right side" and -X as the "left side", and the direction along the Y-axis is referred to as the "front-back direction Y", +Y as the "front side" and -Y as the "rear side". Furthermore, the vertical direction Z, left-right direction X, and front-back direction Y are merely names used to describe the arrangement of the structural components of the laser processing apparatus 1 and do not specify the actual orientation and direction of the components within the laser processing apparatus 1.

[0024] The laser irradiation device 2 is a laser irradiation head that irradiates the workpiece W placed on the worktable 4 with laser L.

[0025] Figure 2 This is a three-dimensional diagram showing the structure of the laser irradiation device 2. (For example...) Figure 2 As shown, the laser irradiation device 2 includes a cooling substrate 21, a laser array 22 mounted on the cooling substrate 21, a focusing lens 23, and a material supply unit 24.

[0026] The cooling substrate 21 cools the laser array 22. The laser array 22 consists of multiple laser elements 221. These laser elements 221 are arranged in a matrix on the cooling substrate 21. Each laser element 221 emits a laser beam LB. Figure 2 In the example, the planar shape of the laser element 221 is a circle.

[0027] Laser element 221 is, for example, a photonic crystal surface-emitting laser (PCSEL) element utilizing the photonic crystal effect. The laser beam LB emitted from laser element 221, which is composed of a PCSEL element, has a narrow emission angle and high light output.

[0028] The laser beams LB from the multiple laser elements 221 are emitted in parallel directions. The emission direction of the laser beams LB from the laser elements 221 is perpendicular to the imaginary plane in which the multiple laser elements 221 are arranged and along the Z-axis, which is consistent with the optical axis AX of the laser irradiation device 2.

[0029] The focusing lens 23 is a convex lens that generates a high-output laser L by converging the laser beams LB from multiple laser elements 221 toward the convergence point SP. The surface of the workpiece W is positioned at the convergence point SP of the laser L. Thus, the laser irradiation device 2 irradiates the surface of the workpiece W with the laser L that has converged the multiple laser beams LB.

[0030] The material supply section 24 is, for example, composed of a tubular component capable of supplying material powder, and discharges material powder 25 toward the workpiece W. The material powder can be, for example, metal powders such as stainless steel, nickel-based alloys, cobalt-based alloys, or titanium. Furthermore, the material supplied from the material supply section 24 to the workpiece W can be any metal, for example, it can be a wire-shaped metal rod.

[0031] According to this structure, the laser irradiation device 2 can perform additive processing, in which a laser L composed of multiple laser beams LB is irradiated onto the surface of the workpiece W, and metal powder is supplied to the workpiece W, thereby melting the metal and forming a metal layer on the surface of the workpiece W.

[0032] like Figure 1 As shown, the moving mechanism 3 can move the laser irradiation device 2 in one direction. The moving mechanism 3 changes the relative position of the laser irradiation device 2 and the worktable 4. In this embodiment, the driving of the moving mechanism 3 is controlled by the control unit 5.

[0033] The moving mechanism 3, for example, moves the laser irradiation device 2 so that it faces the workpiece W. With the laser irradiation device 2 facing the workpiece W, the laser processing apparatus 1 irradiates the workpiece W from the laser irradiation device 2 toward the workpiece W on the worktable 4, thereby performing the aforementioned processing.

[0034] The worktable 4 has a mounting surface 4a for placing the workpiece W.

[0035] The worktable 4 is a dual-axis worktable that allows the mounting surface 4a of the workpiece W to move along two axes: the left-right direction (X) and the front-back direction (Y). The worktable 4 can also adjust the position of the workpiece W relative to the laser irradiation device 2 by moving the mounting surface 4a. This enables high-precision irradiation of the workpiece W with the laser L.

[0036] In this embodiment, the drive of the worktable 4 is controlled by the control unit 5.

[0037] The control unit 5 may be configured as a computer, for example, having a processor, main memory, and an input / output interface for signal input and output to the outside. The control unit 5 performs various functions, for example, by executing programs loaded into the main memory via the processor. Thus, the control unit 5 controls the driving of the laser irradiation device 2, the moving mechanism 3, and the worktable 4. Alternatively, the control unit 5 may not be a computer, but rather a combination of multiple circuits.

[0038] In this embodiment, the laser irradiation apparatus 2 uses PCSEL elements as laser elements 221, resulting in a large amount of heat generation per laser element 221. Consequently, it is sometimes impossible to efficiently cool each laser element 221, leading to temperature deviations between the laser elements 221 and changes in the output of the laser L. If the output of the laser L changes in this way, the irradiation amount of the laser L becomes unstable, and the processing accuracy of the workpiece W may decrease.

[0039] In contrast, in the laser irradiation apparatus 2 of this embodiment, the laser array 22 is cooled by the cooling substrate 21, thereby suppressing temperature deviations between the individual laser elements 221. As a result, by stabilizing the irradiation amount of the laser L on the workpiece W, the processing accuracy of the workpiece W can be improved.

[0040] The structure of the laser irradiation device 2 of this embodiment will be described in detail below.

[0041] Figure 3 This is a diagram showing the main structural components of the laser irradiation device 2. Figure 3 The middle section is a top view showing the main structure of the laser irradiation device 2 as viewed from the +Z side to the -Z side. Figure 3 The upper section is a sectional view of the middle section along line AA. Figure 3 The lower section is a sectional view of the middle section from line BB. Figure 3 This is a diagram showing the peripheral structure of any two adjacent laser elements 221 in the laser irradiation device 2, namely the first laser element 221a and the second laser element 221b.

[0042] like Figure 3 As shown, the cooling substrate 21 has a substrate 210, a supply flow path 230, a first flow path 231, a second flow path 232, a discharge flow path 233, a first connecting flow path 234, and a second connecting flow path 235.

[0043] The substrate 210 includes a mounting surface 210a for mounting the laser array 22. In this embodiment, the substrate 210 is constructed with a laminated structure, for example, having a first layer 211, a second layer 212, and a third layer 213. The first layer 211, the second layer 212, and the third layer 213 are stacked sequentially from the upper side to the lower side in the vertical direction Z. Therefore, the surface of the third layer 213 corresponds to the mounting surface 210a.

[0044] The first layer 211, the second layer 212, and the third layer 213 are made of, for example, a metallic material with excellent thermal conductivity, such as copper. The first layer 211, the second layer 212, and the third layer 213 are bonded together by an adhesive or the like (not shown). In addition, the number of layers constituting the substrate 210 is not limited to three.

[0045] The supply flow path 230 extends in the vertical direction Z, intersecting the mounting surface 210a, and is a flow path for supplying coolant E from the outside to the inside of the substrate 210. The supply flow path 230 is formed to penetrate the first layer 211 and the second layer 212 in the vertical direction Z.

[0046] The first flow path 231 is a flow path through which the coolant E supplied by the supply flow path 230 flows. The first flow path 231 extends along the mounting surface 210a and cools the first laser element 221a via the third layer 213. That is, the first flow path 231 is disposed above the first laser element 221a in the third layer 213. Therefore, the heat from the first laser element 221a is transferred to the coolant E disposed above the first flow path 231 in the third layer 213, and the coolant E, heated by the heat from the first laser element 221a, flows downstream of the first flow path 231. Therefore, heat dissipation from the first laser element 221a is efficient.

[0047] The first flow path 231 is formed by cutting off a portion of the boundary surface between the third layer 213 and the second layer 212. That is, the first flow path 231 is formed by the space divided by the surface 212a of the second layer 212 and the recess 213H formed in the third layer 213.

[0048] The second flow path 232 is a flow path through which the coolant E supplied by the supply flow path 230 flows. The second flow path 232 extends along the mounting surface 210a and cools the second laser element 221b via the third layer 213. That is, the second flow path 232 is the upper layer of the second laser element 221b in the third layer 213, and is formed in the substrate 210 in the same layer as the first flow path 231. Therefore, the heat from the second laser element 221b is transferred to the coolant E in the second flow path 232, which is located on the upper layer of the third layer 213, and the coolant E, heated by the heat from the second laser element 221b, flows downstream of the second flow path 232. Therefore, heat dissipation from the second laser element 221b is efficient.

[0049] The second flow path 232 is formed by cutting off a portion of the boundary surface between the third layer 213 and the second layer 212. That is, the second flow path 232 is formed by the space divided by the surface 212a of the second layer 212 and the recess 213H formed in the third layer 213.

[0050] Hereinafter, the view of the mounting surface 210a from the normal direction will be referred to as "top view".

[0051] When viewed from above, the first flow path 231 and the second flow path 232 branch off from the supply flow path 230 between the first laser element 221a and the second laser element 221b, respectively. Therefore, coolant E flows through the supply flow path 230 to the first flow path 231 and the second flow path 232. In this embodiment, the flow rates of coolant E supplied to the first flow path 231 and the second flow path 232 from the branch of the supply flow path 230 are the same. This reduces the temperature difference of the coolant E flowing in each flow path 231, 232.

[0052] In a top-view configuration, the supply flow path 230 is located at the center of the front side (+Y) of the substrate 210. In a top-view configuration, the first flow path 231 extends from the supply flow path 230 to the left end of the substrate 210, then bends and extends towards the rear side (-Y side). In a top-view configuration, the second flow path 232 extends to the right end of the substrate 210, then bends and extends towards the rear side (-Y side).

[0053] The lateral width of the first flow path 231 is preferably equal to or greater than the outer diameter of the first laser element 221a. The lateral width of the second flow path 232 is preferably equal to or greater than the outer diameter of the second laser element 221b. According to this structure, since the first flow path 231 and the second flow path 232 completely overlap with the first laser element 221a and the second laser element 221b, the first laser element 221a and the second laser element 221b can be cooled efficiently.

[0054] The discharge path 233 extends in the vertical direction Z, intersecting the mounting surface 210a, and discharges the coolant E from the substrate 210 after cooling the first laser element 221a and the second laser element 221b. In top view, the discharge path 233 is positioned differently from the supply path 230, the first path 231, and the second path 232. In top view, the discharge path 233 is located behind (-Y) the supply path 230. Therefore, since the discharge path 233 does not affect the layout of the supply path 230, the first path 231, and the second path 232, the design freedom of the supply path 230, the first path 231, and the second path 232 can be increased.

[0055] The first connecting flow path 234 is a flow path that extends along the mounting surface 210a and connects the first flow path 231 and the discharge flow path 233. One end of the first connecting flow path 234 is connected to the first flow path 231, and the other end of the first connecting flow path 234 is connected to the discharge flow path 233.

[0056] In this embodiment, the first connecting flow path 234 is disposed within the substrate 210 in a layer different from the first flow path 231. Specifically, the first connecting flow path 234 is formed by removing a portion of the boundary surface between the second layer 212 and the first layer 211. That is, the first connecting flow path 234 is formed by a space divided by the surface 211a of the first layer 211 and the recess 212H formed in the second layer 212. Therefore, one end 234a of the first connecting flow path 234 is connected to the end end 231a of the first flow path 231 via a through hole 212K that penetrates the second layer 212 in the vertical direction Z.

[0057] The second connecting flow path 235 extends along the mounting surface 210a and connects the second flow path 232 and the discharge flow path 233. One end of the second connecting flow path 235 is connected to the second flow path 232, and the other end of the second connecting flow path 235 is connected to the discharge flow path 233.

[0058] The second connecting flow path 235 is disposed within the substrate 210 in a different layer than the second flow path 232. Specifically, the second connecting flow path 235 is formed by removing a portion of the boundary surface between the second layer 212 and the first layer 211. That is, the second connecting flow path 235 is formed by a space divided by the surface 211a of the first layer 211 and the recess 212H formed in the second layer 212. Therefore, one end 235a of the second connecting flow path 235 is connected to the end end 232a of the second flow path 232 via a through hole 212K that penetrates the second layer 212 in the vertical direction Z.

[0059] In a top-down view, the first connecting flow path 234, after flowing from the front (+Y) to the rear (-Y) at the left end of the substrate 210, bends to the right (+X) and extends towards the center. The second connecting flow path 235, after flowing from the front (+Y) to the rear (-Y) at the right end of the substrate 210, bends to the left (-X) and extends towards the center. Furthermore, the first connecting flow path 234 and the second connecting flow path 235 merge and connect to the discharge flow path 233.

[0060] Alternatively, the first connecting flow path 234 and the second connecting flow path 235 may also be disposed in the substrate 210 in the same layer as the first flow path 231 and the second flow path 232. In this case, the discharge flow path 233 is formed to penetrate the second layer 212 and the first layer 211 in the vertical direction Z.

[0061] Thus, the laser irradiation apparatus 2 of this embodiment includes: a laser array 22 composed of a plurality of laser elements 221, including a first laser element 221a and a second laser element 221b; and a cooling substrate 21 for cooling the laser array 22. The cooling substrate 21 includes: a substrate 210 including a mounting surface 210a for mounting the laser array 22; a supply flow path 230 extending in a direction intersecting the mounting surface 210a to supply coolant E into the interior of the substrate 210; a first flow path 231 extending along the mounting surface 210a to cool the first laser element 221a via the substrate 210; and a second flow path 232 extending along the mounting surface 210a to cool the second laser element 221b via the substrate 210. When viewed from above the mounting surface 210a, the first flow path 231 and the second flow path 232 branch off from the supply flow path 230 between the first laser element 221a and the second laser element 221b, respectively. Coolant E flows through supply path 230 to first flow path 231 and second flow path 232.

[0062] According to the laser irradiation apparatus 2 of this embodiment, by reducing the difference between the cooling performance of the first flow path 231 on the first laser element 221a and the cooling performance of the second flow path 232 on the second laser element 221b, the temperature deviation between the first laser element 221a and the second laser element 221b can be reduced.

[0063] In this embodiment, the first laser element 221a and the second laser element 221b are any two adjacent laser elements among the plurality of laser elements 221. Therefore, the laser irradiation apparatus 2 according to this embodiment can reduce the temperature difference between two adjacent laser elements among the plurality of laser elements 221.

[0064] Therefore, according to the laser irradiation apparatus 2 of this embodiment, by suppressing the temperature deviation between adjacent first laser element 221a and second laser element 221b among the plurality of laser elements 221, the irradiation amount of laser L can be stabilized.

[0065] The laser processing apparatus 1 of this embodiment includes: the laser irradiation device 2 described above; and a worktable 4, which holds the work object W to be processed by the laser L irradiated by the laser irradiation device 2.

[0066] According to the laser processing apparatus 1 of this embodiment, by stabilizing the irradiation amount of the laser L on the workpiece W, the workpiece W can be processed with high precision through laser L-based processing.

[0067] In addition, in the laser irradiation device 2 of the above embodiment, a plurality of laser elements 221 are arranged in a matrix on the cooling substrate 21, but the plurality of laser elements 221 may also be arranged in a concentric circle on the cooling substrate 21.

[0068] The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0069] Example 1

[0070] Figure 4 This is a diagram showing the main structural components of the laser irradiation device in the first modified example. Figure 4 The middle section is a top view showing the main structural components of the laser irradiation device as viewed from the +Z side to the -Z side. Figure 4 The upper section is a sectional view of the middle section along line AA. Figure 4 The lower section is a sectional view of the middle section from line BB. Figure 4 This diagram shows the peripheral structure of any three adjacent laser elements in the laser irradiation device 2A, namely the first laser element 221a, the second laser element 221b, and the third laser element 221c. Furthermore, in this modified example, structures and components identical to those in the above embodiment are labeled with the same reference numerals, and detailed descriptions are omitted.

[0071] like Figure 4 As shown, when viewed from above the mounting surface 210a, the third laser element 221c is positioned between the first laser element 221a and the second laser element 221b. Specifically, the third laser element 221c is positioned at a location overlapping with the supply flow path 230.

[0072] According to the laser irradiation apparatus 2A of this modification, the third laser element 221c, which is positioned directly below the supply flow path 230, can be cooled by the coolant E flowing in the supply flow path 230. The coolant E used to cool the third laser element 221c is separated into two parts and supplied to the first flow path 231 and the second flow path 232. The flow rate of the coolant E cooling the third laser element 221c is approximately twice the flow rate of the coolant E cooling the laser elements 221a and 221b in the first flow path 231 and the second flow path 232. Therefore, the temperature of the coolant E after cooling the third laser element 221c is less prone to change. Therefore, by reducing the difference in cooling performance between the supply flow path 230 and the third laser element 221c, the first flow path 231 and the first laser element 221a, and the second flow path 232 and the second laser element 221b, the temperature deviation of the first laser element 221a, the second laser element 221b, and the third laser element 221c can be reduced.

[0073] In this modified example, the first laser element 221a, the third laser element 221c, and the second laser element 221b are any three adjacent laser elements among the plurality of laser elements 221. Therefore, the laser irradiation apparatus 2A according to this modified example can reduce the temperature difference between three adjacent laser elements among the plurality of laser elements 221.

[0074] Therefore, according to the laser irradiation apparatus 2A of this modified example, by suppressing the temperature deviation between adjacent first laser element 221a, third laser element 221c and second laser element 221b among the plurality of laser elements 221, the irradiation amount of laser L can be stabilized.

[0075] (Second variation)

[0076] Figure 5 This is a diagram showing the main structural components of the laser irradiation device in the second modified example. Figure 5 The middle section is a top view showing the main structural components of the laser irradiation device as viewed from the +Z side to the -Z side. Figure 5 The upper section is a sectional view of the middle section along line AA. Figure 5 The lower section is a sectional view of the middle section from line BB. Figure 5 This diagram shows the peripheral structure of any three adjacent laser elements—namely, the first laser element 221a, the second laser element 221b, and the third laser element 221c—among a plurality of laser elements in the laser irradiation device 2B. Furthermore, in this modified example, structures and components identical to those in the above embodiment are labeled with the same reference numerals, and detailed descriptions are omitted.

[0077] like Figure 5 As shown, when viewed from above the mounting surface 210a, the third laser element 221c is positioned to the right (+X) of the second laser element 221b. That is, the third laser element 221c is positioned downstream of the second laser element 221b in the second flow path 232.

[0078] In this modified example, the discharge path 233 is positioned, when viewed from above, in the longitudinal direction Y, corresponding to the position between the second laser element 221b and the third laser element 221c. Alternatively, the discharge path 233 may be positioned, when viewed from above, on the rear side (-Y) of the supply path 230.

[0079] Here, as a comparative example, consider the case where the first laser element 221a, the second laser element 221b, and the third laser element 221c are arranged sequentially in the flow direction of the coolant E. In this case, the temperature difference between the first laser element 221a, located at the upstream end of the flow of the coolant E, and the third laser element 221c, located at the downstream end of the flow of the coolant E, becomes larger.

[0080] In contrast, according to the modified laser irradiation apparatus 2B, similar to the above embodiment, by reducing the difference between the cooling performance of the first flow path 231 on the first laser element 221a and the cooling performance of the second flow path 232 on the second laser element 221b, the temperature deviation between the first laser element 221a and the second laser element 221b can be reduced.

[0081] Furthermore, in this modified example, the temperature of the third laser element 221c, located downstream of the second laser element 221b in the second flow path 232, is higher than the temperatures of the first laser element 221a and the second laser element 221b. However, according to the structure of this modified example, the temperature deviation generated between the laser elements is smaller than the temperature deviation generated in the structure of the comparative example.

[0082] Therefore, according to the laser irradiation apparatus 2B of this modified example, by suppressing the temperature deviation between adjacent first laser element 221a, second laser element 221b and third laser element 221c among the plurality of laser elements 221, the irradiation amount of laser L can be stabilized.

[0083] Furthermore, in this modified example, the third laser element 221c is disposed downstream of the second laser element 221b in the second flow path 232, but the third laser element 221c may also be disposed downstream of the first laser element 221a in the first flow path 231.

[0084] (3rd variation)

[0085] Figure 6 This is a diagram showing the main structural components of the laser irradiation device in the third modified example. Figure 6 This is a top view showing the main structural components of the laser irradiation device 2C as viewed from the -Z side to the +Z side. Figure 6 This is a diagram showing the peripheral structure of any four adjacent laser elements 221 in the laser irradiation device 2C, namely the first laser element 221a, the second laser element 221b, the third laser element 221c, and the fourth laser element 221d.

[0086] like Figure 6 As shown, the cooling substrate 21C of this modified example has a substrate 310, a supply flow path 330, a first flow path 331, a second flow path 332, a third flow path 333, a fourth flow path 334, a discharge flow path 335, a first connecting flow path 336, a second connecting flow path 337, a third connecting flow path 338, and a fourth connecting flow path 339.

[0087] The first flow path 331 extends along the mounting surface 310a of the substrate 310 and cools the first laser element 221a via the third layer 313 of the substrate 310.

[0088] The second flow path 332 extends along the mounting surface 310a of the substrate 310 and cools the second laser element 221b via the third layer 313 of the substrate 310.

[0089] The third flow path 333 extends along the mounting surface 310a of the substrate 310 and cools the third laser element 221c via the third layer 313 of the substrate 310.

[0090] The fourth flow path 334 extends along the mounting surface 310a of the substrate 310 and cools the fourth laser element 221d via the third layer 313 of the substrate 310.

[0091] When viewed from above the mounting surface 310a, the first flow path 331, the second flow path 332, the third flow path 333, and the fourth flow path 334 branch off from the supply flow path 330 in four different directions. The first flow path 331 and the fourth flow path 334 extend in opposite directions, as do the second flow path 332 and the third flow path 333. The directions in which the first flow path 331 and the fourth flow path 334 extend are orthogonal to the directions in which the second flow path 332 and the third flow path 333 extend.

[0092] When viewed from above the mounting surface 310a, the first laser element 221a, the second laser element 221b, the third laser element 221c, and the fourth laser element 221d are arranged in a square grid pattern. The supply flow path 330 is located in the center of the square grid.

[0093] In this modified example, the discharge path 335 is composed of a first discharge path 335a, a second discharge path 335b, a third discharge path 335c, and a fourth discharge path 335d. Each discharge path 335a to 335d is a flow path extending in the vertical direction Z within the substrate 310.

[0094] The first connecting flow path 336 is an L-shaped flow path extending along the mounting surface 310a and connecting the first flow path 331 and the discharge flow path 335. Specifically, the central portion of the first connecting flow path 336 is connected to the first flow path 331, one end of the first connecting flow path 336 is connected to the first discharge path 335a of the discharge flow path 335, and the other end of the first connecting flow path 336 is connected to the second discharge path 335b of the discharge flow path 335.

[0095] The second connecting flow path 337 is an L-shaped flow path extending along the mounting surface 310a and connecting the second flow path 332 and the discharge flow path 335. Specifically, the central portion of the second connecting flow path 337 is connected to the second flow path 332, one end of the second connecting flow path 337 is connected to the second discharge path 335b of the discharge flow path 335, and the other end of the second connecting flow path 337 is connected to the fourth discharge path 335d of the discharge flow path 335.

[0096] The third connecting flow path 338 is an L-shaped flow path extending along the mounting surface 310a and connecting the third flow path 333 and the discharge flow path 335. Specifically, the central portion of the third connecting flow path 338 is connected to the third flow path 333, one end of the third connecting flow path 338 is connected to the first discharge path 335a of the discharge flow path 335, and the other end of the third connecting flow path 338 is connected to the third discharge path 335c of the discharge flow path 335.

[0097] The fourth connecting flow path 339 is an L-shaped flow path extending along the mounting surface 310a and connecting the fourth flow path 334 and the discharge flow path 335. Specifically, the central portion of the fourth connecting flow path 339 is connected to the fourth flow path 334, one end of the fourth connecting flow path 339 is connected to the third discharge path 335c of the discharge flow path 335, and the other end of the fourth connecting flow path 339 is connected to the fourth discharge path 335d of the discharge flow path 335.

[0098] The first connecting flow path 336 and the third connecting flow path 338 converge in the first discharge path 335a, the first connecting flow path 336 and the second connecting flow path 337 converge in the second discharge path 335b, the third connecting flow path 338 and the fourth connecting flow path 339 converge in the third discharge path 335c, and the second connecting flow path 337 and the fourth connecting flow path 339 converge in the fourth discharge path 335d.

[0099] The first connecting flow path 336, the second connecting flow path 337, the third connecting flow path 338, and the fourth connecting flow path 339 together have a four-sided frame structure.

[0100] In this modified example, the first connecting flow path 336, the second connecting flow path 337, the third connecting flow path 338, and the fourth connecting flow path 339 are formed in the substrate 310 at a position higher than the first flow path 331, the second flow path 332, the third flow path 333, and the fourth flow path 334 (the second layer of the substrate 310). Alternatively, the first connecting flow path 336, the second connecting flow path 337, the third connecting flow path 338, and the fourth connecting flow path 339 may also be formed in the same layer as the first flow path 331, the second flow path 332, the third flow path 333, and the fourth flow path 334 (the third layer 313 of the substrate 310).

[0101] In the laser irradiation apparatus 2C of this modified example, the flow rate of coolant E supplied to the first flow path 331 to the fourth flow path 334, which branch out from the supply flow path 330 in four directions, is the same, so the temperature difference of the coolant E flowing in each flow path 331 to 334 can be reduced.

[0102] Therefore, according to the laser irradiation apparatus 2C of this modified example, by reducing the difference in cooling performance of each flow path 331 to 334 to the laser elements 221a to 221d, the temperature deviation of each laser element 221a to 221d can be reduced.

[0103] In this modified example, the first laser element 221a, the second laser element 221b, the third laser element 221c, and the fourth laser element 221d are any four adjacent laser elements among the plurality of laser elements 221. Therefore, the laser irradiation apparatus 2C according to this modified example can reduce the temperature deviation between four adjacent laser elements among the plurality of laser elements 221.

[0104] Therefore, the laser irradiation device 2C of this modified example can make the irradiation amount of laser L more stable by suppressing the temperature deviation between four adjacent laser elements among the multiple laser elements 221.

[0105] Alternatively, in this modified example, the following structure can also be adopted: the first connecting flow path 336, the second connecting flow path 337, the third connecting flow path 338 and the fourth connecting flow path 339 are all arcs, and they are connected to each other to form a circular frame as a whole.

[0106] (4th variation)

[0107] Figure 7 This is a diagram showing the main structural components of the laser irradiation device in the fourth modified example. Figure 7 This is a top view showing the main structural components of a 2D laser irradiation device as viewed from the -Z side towards the +Z side. Figure 7 This is a diagram showing the peripheral structure of any three adjacent laser elements 221 in the laser irradiation device 2D, namely the first laser element 221a, the second laser element 221b, and the third laser element 221c.

[0108] like Figure 7 As shown, the cooling substrate 21D of this modified example has a substrate 410, a supply flow path 430, a first flow path 431, a second flow path 432, a third flow path 433, a discharge flow path 435, a first connecting flow path 436, a second connecting flow path 437, and a third connecting flow path 438.

[0109] The first flow path 431 extends along the mounting surface 410a of the substrate 410 and cools the first laser element 221a via the third layer 413 of the substrate 410.

[0110] The second flow path 432 extends along the mounting surface 410a of the substrate 410 and cools the second laser element 221b via the third layer 413 of the substrate 410.

[0111] The third flow path 433 extends along the mounting surface 410a of the substrate 410 and cools the third laser element 221c via the third layer 413 of the substrate 410.

[0112] When viewed from above the mounting surface 410a, the first flow path 431, the second flow path 432, and the third flow path 433 branch off from the supply flow path 430 in three different directions. In this modified example, the first flow path 431, the second flow path 432, and the third flow path 433 extend in directions that differ by 120 degrees in the circumferential direction of the supply flow path 430.

[0113] When viewed from above on the mounting surface 410a, the first laser element 221a, the second laser element 221b, and the third laser element 221c are arranged in a triangular grid pattern. The supply flow path 430 is located in the center of the triangular grid.

[0114] In this modified example, the discharge path 435 is composed of a first discharge path 435a, a second discharge path 435b, and a third discharge path 435c. Each discharge path 435a to 435c is a flow path extending in the vertical direction Z within the substrate 410.

[0115] The first connecting flow path 436 extends along the mounting surface 410a and connects the first flow path 431 and the discharge flow path 435. The first connecting flow path 436 has a shape formed by connecting a pair of L-shaped lines that are linearly symmetrical. Specifically, the central portion of the first connecting flow path 436 is connected to the first flow path 431, one end of the first connecting flow path 436 is connected to the first discharge path 435a of the discharge flow path 435, and the other end of the first connecting flow path 436 is connected to the third discharge path 435c of the discharge flow path 435.

[0116] The second connecting flow path 437 is an L-shaped flow path extending along the mounting surface 410a and connecting the second flow path 432 and the discharge flow path 435. Specifically, the central portion of the second connecting flow path 437 is connected to the second flow path 432, one end of the second connecting flow path 437 is connected to the first discharge path 435a of the discharge flow path 435, and the other end of the second connecting flow path 437 is connected to the second discharge path 435b of the discharge flow path 435.

[0117] The third connecting flow path 438 is an L-shaped flow path extending along the mounting surface 410a and connecting the third flow path 433 and the discharge flow path 435. Specifically, the central portion of the third connecting flow path 438 is connected to the third flow path 433, one end of the third connecting flow path 438 is connected to the second discharge path 435b of the discharge flow path 435, and the other end of the third connecting flow path 438 is connected to the third discharge path 435c of the discharge flow path 435.

[0118] The first connecting flow path 436 and the second connecting flow path 437 converge in the first discharge path 435a, the second connecting flow path 437 and the third connecting flow path 438 converge in the second discharge path 435b, and the first connecting flow path 436 and the third connecting flow path 438 converge in the third discharge path 435c.

[0119] The first connecting flow path 436, the second connecting flow path 437, and the third connecting flow path 438 together form a four-sided frame structure.

[0120] In this modified example, the first connecting flow path 436, the second connecting flow path 437, and the third connecting flow path 438 are formed in the substrate 410 on a layer higher than the first flow path 431, the second flow path 432, and the third flow path 433 (the second layer of the substrate 410). Alternatively, the first connecting flow path 436, the second connecting flow path 437, and the third connecting flow path 438 may also be formed on the same layer as the first flow path 431, the second flow path 432, and the third flow path 433 (the third layer 413 of the substrate 410).

[0121] In the laser irradiation apparatus 2D of this modified example, the flow rate of coolant E supplied to the first flow path 431 to the third flow path 433, which branch from the supply flow path 430 in three directions, is the same, so the temperature difference of the coolant E flowing in each flow path 431 to 433 can be reduced.

[0122] Therefore, according to the laser irradiation apparatus 2D of this modified example, by reducing the difference in cooling performance of each flow path 431 to 433 on the laser elements 221a to 221c, the temperature deviation of each laser element 221a to 221c can be reduced.

[0123] In this modified example, the first laser element 221a, the second laser element 221b, and the third laser element 221c are any three adjacent laser elements among the plurality of laser elements 221. Therefore, according to the laser irradiation apparatus 2D of this modified example, the temperature difference between three adjacent laser elements among the plurality of laser elements 221 can be reduced.

[0124] Therefore, the laser irradiation device 2D of this modified example can make the irradiation amount of laser L more stable by suppressing the temperature deviation between three adjacent laser elements among the multiple laser elements 221.

[0125] Alternatively, in this modified example, the following structure can also be adopted: the first connecting flow path 436, the second connecting flow path 437 and the third connecting flow path 438 are all arcs, which are connected to each other to form a circular frame structure.

[0126] The following is a summary published in this note.

[0127] (Postscript 1)

[0128] A laser irradiation apparatus includes: a laser array comprising a plurality of laser elements including a first laser element and a second laser element; and a cooling substrate for cooling the laser array, the cooling substrate having: a substrate including a mounting surface for mounting the laser array; a supply flow path extending in a direction intersecting the mounting surface for supplying coolant into the interior of the substrate; a first flow path extending along the mounting surface for cooling the first laser element via the substrate; and a second flow path extending along the mounting surface for cooling the second laser element via the substrate, wherein, when viewed from above the mounting surface, the first flow path and the second flow path branch off from the supply flow path between the first laser element and the second laser element, respectively, and the coolant flows via the supply flow path to the first flow path and the second flow path.

[0129] According to this laser irradiation device, since the flow rate of coolant supplied from the supply flow path branch to the first flow path and the second flow path is the same, the temperature difference of the coolant flowing in each flow path can be reduced. Therefore, by reducing the difference in cooling performance between the first flow path and the second flow path for the first laser element, the temperature deviation between the first and second laser elements can be reduced.

[0130] In this structure, for example, when the first laser element and the second laser element are any two adjacent laser elements among a plurality of laser elements, the temperature deviation between two adjacent laser elements among the plurality of laser elements can be reduced.

[0131] Therefore, according to this structure, by suppressing the temperature deviation between adjacent first and second laser elements among multiple laser elements, the laser irradiation amount can be stabilized.

[0132] (Postscript 2)

[0133] According to the laser irradiation apparatus described in Appendix 1, the cooling substrate further has a discharge path extending in a direction intersecting the mounting surface, through which the coolant after cooling the first laser element and the second laser element is discharged from the substrate.

[0134] According to this structure, the coolant after cooling the laser element can be discharged to the outside of the cooling substrate.

[0135] (Note 3)

[0136] According to the laser irradiation device described in Appendix 2, when viewed from above the mounting surface, the discharge path is located at a different position from the supply path, the first path, and the second path.

[0137] According to this structure, since the discharge flow path does not affect the layout of the supply flow path, the first flow path, and the second flow path, the design freedom of the supply flow path, the first flow path, and the second flow path can be improved.

[0138] (Postscript 4)

[0139] According to the laser irradiation apparatus described in Appendix 2 or 3, the cooling substrate further comprises: a first connecting flow path extending along the mounting surface to connect the first flow path and the discharge flow path; and a second connecting flow path extending along the mounting surface to connect the second flow path and the discharge flow path.

[0140] According to this structure, the coolant heated by cooling the laser element can be discharged from the first flow path and the second flow path to the discharge flow path.

[0141] (Note 5)

[0142] The laser irradiation apparatus according to any one of Appendices 1 to 4, wherein the plurality of laser elements further includes a third laser element, which, when viewed from above the mounting surface, is positioned to overlap with the supply flow path.

[0143] This structure can reduce the temperature deviation between three adjacent laser elements in a plurality of laser elements.

[0144] (Note 6)

[0145] The laser irradiation apparatus according to any one of Appendices 1 to 4, wherein the plurality of laser elements further includes a third laser element, which, when viewed from above the mounting surface, is disposed on either the downstream side of the first laser element in the first flow path and the downstream side of the second laser element in the second flow path.

[0146] This structure can reduce the temperature deviation between three adjacent laser elements in a plurality of laser elements.

[0147] (Note 7)

[0148] The laser irradiation apparatus according to any one of Appendices 1 to 4, wherein the plurality of laser elements further includes a third laser element, the cooling substrate further has a third flow path extending along the mounting surface and cooling the third laser element via the substrate, wherein, when viewed from above the mounting surface, the first flow path, the second flow path, and the third flow path branch from the supply flow path in three different directions.

[0149] This structure can reduce the temperature deviation between three adjacent laser elements in a plurality of laser elements.

[0150] (Note 8)

[0151] According to any one of Appendices 1 to 4, the laser irradiation apparatus further includes a third laser element and a fourth laser element, and the cooling substrate further has: a third flow path extending along the mounting surface to cool the third laser element via the substrate; and a fourth flow path extending along the mounting surface to cool the fourth laser element via the substrate, wherein, when viewed from above the mounting surface, the first flow path, the second flow path, the third flow path, and the fourth flow path branch from the supply flow path in four different directions.

[0152] This structure can reduce the temperature deviation between four adjacent laser elements in a plurality of laser elements.

[0153] (Note 9)

[0154] The laser irradiation apparatus according to any one of Appendices 1 to 8, wherein the plurality of laser elements are photonic crystal surface emitting laser elements.

[0155] This structure allows for a narrowing of the emission angle of lasers from each laser element.

[0156] (Postscript 10)

[0157] A laser processing apparatus comprising: a laser irradiation device as described in any one of Appendices 1 to 9; and a worktable on which a workpiece to be processed is placed, which is irradiated by the laser irradiation device.

[0158] According to this laser processing device, by stabilizing the amount of laser irradiation on the object being processed, the object can be processed with high precision through laser-based processing.

Claims

1. A laser irradiation device comprising: a laser array consisting of a plurality of laser elements including a first laser element and a second laser element; and a cooling substrate for cooling the laser array. The cooling substrate has: A substrate having a mounting surface on which the laser array is mounted; A supply flow path extends in a direction intersecting the mounting surface to supply coolant into the interior of the substrate; A first flow path extends along the mounting surface and cools the first laser element via the substrate; as well as A second flow path extends along the mounting surface and cools the second laser element via the substrate. When viewed from above the mounting surface, the first flow path and the second flow path branch off from the supply flow path between the first laser element and the second laser element, respectively. The coolant flows through the supply path to the first flow path and the second flow path.

2. The laser irradiation device according to claim 1, wherein, The cooling substrate also has a discharge path that extends in a direction intersecting the mounting surface to discharge the coolant after cooling the first laser element and the second laser element from the substrate.

3. The laser irradiation device according to claim 2, wherein, When viewed from above, the discharge path is located at a different position than the supply path, the first path, and the second path.

4. The laser irradiation device according to claim 2, wherein, The cooling substrate further comprises: A first connecting flow path extends along the mounting surface, connecting the first flow path and the discharge flow path; and A second connecting flow path extends along the mounting surface and connects the second flow path and the discharge flow path.

5. The laser irradiation device according to claim 1, wherein, The plurality of laser elements also includes a third laser element. When viewed from above, the third laser element is positioned to overlap with the supply flow path.

6. The laser irradiation device according to claim 1, wherein, The plurality of laser elements also includes a third laser element. When viewed from above the mounting surface, the third laser element is disposed on either the downstream side of the first laser element in the first flow path or the downstream side of the second laser element in the second flow path.

7. The laser irradiation device according to claim 1, wherein, The plurality of laser elements also includes a third laser element. The cooling substrate also has a third flow path that extends along the mounting surface and cools the third laser element via the substrate. When viewed from above, the first flow path, the second flow path, and the third flow path branch out from the supply flow path in three different directions.

8. The laser irradiation device according to claim 1, wherein, The plurality of laser elements further includes a third laser element and a fourth laser element. The cooling substrate further comprises: A third flow path, extending along the mounting surface, cools the third laser element via the substrate; and A fourth flow path extends along the mounting surface and cools the fourth laser element via the substrate. When viewed from above, the first flow path, the second flow path, the third flow path, and the fourth flow path branch out from the supply flow path in four different directions.

9. The laser irradiation device according to claim 1, wherein, The plurality of laser elements are photonic crystal surface-emitting laser elements.

10. A laser processing apparatus, comprising: The laser irradiation apparatus according to any one of claims 1 to 9; and A worktable on which a workpiece is placed to be processed by laser light irradiated by the laser irradiation device.

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