Cover for laser device, laser processing device, and laser processing method

Abstract

A cover (30) for a laser processing device (1) is provided with: a cylindrical section (31) extending in the axial direction; a cover glass (31a) that is provided at one end of the cylindrical section (31) in the axial direction and that transmits the laser light; an opening (31b) provided at the other end of the cylindrical section (31) in the axial direction; and a nozzle (34) that is disposed in the cylindrical section (31) and that supplies gas to the inside thereof. The nozzle (34) is disposed in the central portion in the axial direction and in a portion in the circumferential direction of the cylindrical portion (31).

Description

Technical Field

[0001] The present invention relates to a cover for a laser device, a laser processing device and a laser processing method. Background Art

[0002] Conventionally, there is known a laser processing apparatus that irradiates a workpiece (object to be processed) with laser light to perform laser processing such as annealing (for example, see Patent Document 1).

[0003] In such laser processing equipment, laser processing is sometimes performed while the workpiece is exposed to an inert gas or other gas. In such cases, for example, a cover having a gas supply nozzle at its top is placed over the workpiece, and the gas supplied from the nozzle is used to purge the interior of the cover. Laser processing is then performed by irradiating the cover with laser light through a protective glass on the top surface of the cover.

[0004] Previous technical literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-1372 Summary of the Invention

[0007] Technical issues to be solved by the invention

[0008] However, in the conventional structure described above, the nozzle is located at the uppermost portion of the housing (the end in the direction of laser irradiation), resulting in a single airflow within the housing in the direction of laser irradiation. This airflow sometimes stirs and lifts dust, such as particles, generated from the workpiece during laser processing, causing it to adhere to the protective glass on the upper surface of the housing. Dust adhering to the protective glass attenuates the laser light transmitted through it.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress the attenuation of laser light.

[0010] Means for solving technical problems

[0011] The present invention is a cover for a laser device, comprising:

[0012] a cylindrical portion extending in the axial direction;

[0013] a transmission portion, disposed at one axial end of the cylindrical portion and allowing the laser to pass through;

[0014] an opening portion, provided at the other axial end of the cylindrical portion; and

[0015] The nozzle supplies gas to the interior of the cylindrical portion.

[0016] The nozzle is arranged at the axial center portion of the cylindrical portion and at a portion in the circumferential direction.

[0017] Effects of the Invention

[0018] According to the present invention, attenuation of laser light can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of a laser processing device according to an embodiment.

[0020] Figure 2 It is a cross-sectional view of a cover according to a modification of the embodiment.

[0021] Figure 3A It is a perspective view of a cover according to a modified example of the embodiment.

[0022] Figure 3B It is a perspective view of a cover according to a modified example of the embodiment.

[0023] Figure 4A It is a diagram showing the airflow in the hood according to the embodiment.

[0024] Figure 4B This is a diagram showing the airflow in a conventional hood.

[0025] Figure 5A It is a diagram showing the airflow in the hood according to the embodiment.

[0026] Figure 5B It is a diagram showing the airflow in the hood according to a modification.

[0027] Figure 6A It is a diagram showing the airflow in the hood according to a modification of the embodiment.

[0028] Figure 6B It is a diagram showing the airflow in the hood according to a modification of the embodiment.

[0029] Figure 7A is a graph showing the analysis results.

[0030] Figure 7B is a graph showing the analysis results.

[0031] Figure 7C is a graph showing the analysis results.

[0032] Figure 8A is a graph showing the analysis results.

[0033] Figure 8B is a graph showing the analysis results.

[0034] Figure 8C is a graph showing the analysis results.

[0035] Figure 9A is a graph showing the analysis results.

[0036] Figure 9B is a graph showing the analysis results.

[0037] Figure 9C is a graph showing the analysis results.

[0038] Figure 10A is a graph showing the analysis results.

[0039] Figure 10B is a graph showing the analysis results.

[0040] Figure 10C is a graph showing the analysis results.

[0041] Figure 11A It is a cross-sectional view of a cover according to a modification of the embodiment.

[0042] Figure 11B It is a cross-sectional view of a cover according to a modification of the embodiment.

[0043] Figure 12 It is a diagram showing a laser processing apparatus according to a modified example of the embodiment. DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0045] [Overall structure of laser processing equipment]

[0046] Figure 1 It is a schematic diagram of the laser processing apparatus 1 according to this embodiment.

[0047] like Figure 1 As shown, the laser processing apparatus 1 according to the present embodiment irradiates a workpiece WP with laser light to perform annealing, welding, etc. The material of the workpiece WP is not particularly limited, and is, for example, silicon, silicon carbide, etc.

[0048] Specifically, the laser processing apparatus 1 includes a laser irradiation unit 10 , a support table (stage) 20 , a cover 30 , a gas supply unit 40 , and a control unit 50 .

[0049] The laser irradiation unit 10 includes a laser oscillator and an optical system (not shown). The laser irradiation unit 10 irradiates a predetermined laser beam according to the type of processing downward.

[0050] The support table 20 is disposed below the laser irradiation unit 10 and supports the workpiece WP with its upper surface.

[0051] In addition, at least one of the laser irradiation unit 10 and the support table 20 may include a movable portion so that the laser irradiation position on the workpiece WP can be adjusted.

[0052] The cover 30 is disposed below the laser irradiation unit 10 and above the support table 20 to cover the workpiece WP placed on the support table 20. A predetermined gas is supplied into the cover 30 from the gas supply unit 40. The cover 30 exposes the workpiece WP to a predetermined gas atmosphere and transmits the laser beam from the laser irradiation unit 10 above.

[0053] The specific structure of the cover 30 will be described later.

[0054] The gas supply unit 40 supplies (applies) a predetermined gas into the cover 30. The supplied gas is, for example, an inert gas such as nitrogen or oxygen. The gas supply unit 40 includes a gas source 41 such as an air pump or a gas tank, a valve 42, and a pipe 43 connecting the gas source 41 to the cover 30 (each nozzle 34) via the valve 42.

[0055] The control unit 50 is composed of, for example, a CPU (Central Processing Unit), and controls various components of the laser processing apparatus 1. Specifically, the control unit 50 controls the operation of the laser irradiation unit 10 to irradiate the laser beam, and controls the operation of the valve 42 and gas source 41 of the gas supply unit 40 to supply a predetermined gas to the cover 30. Furthermore, various components of the gas supply unit 40 can be manually controlled.

[0056] [Specific structure of the cover]

[0057] like Figure 1 As shown, the cover 30 includes a cylindrical portion 31 and a nozzle 34 .

[0058] The cylindrical portion 31 is formed in a cylindrical shape having a central axis Ax extending in the vertical direction. However, the shape of the cylindrical portion 31 is not limited to a cylindrical shape as long as it is cylindrical.

[0059] Hereinafter, the direction along the central axis Ax is sometimes referred to as the "axial direction", and the direction perpendicular to the axial direction is sometimes referred to as the "radial direction". Figure 1 The left and right directions on the paper (such as the left and right directions) are called "left and right (direction)".

[0060] The upper end (one end) of the cylindrical portion 31 is closed and has a protective glass 31 a (transmitting portion) that transmits laser light.

[0061] The protective glass 31a is provided over substantially the entire upper end surface of the cylindrical portion 31. The protective glass 31a transmits most of the laser light irradiated from the laser irradiation unit 10 above into the cover 30 (cylindrical portion 31). Furthermore, the protective glass 31a prevents dust PA (see FIG. 1 ) such as particles generated from the workpiece WP by laser processing. Figure 4A 、 Figure 4Betc.) is attached to the optical system of the laser irradiation unit 10.

[0062] The lower end (the other end) of the cylindrical portion 31 is formed as an opening portion 31 b that is open over the entire surface.

[0063] The opening 31 b faces the upper surface of the support base 20 in the vertical direction with a predetermined gap therebetween.

[0064] The nozzle 34 is provided upright on the outer peripheral surface of the cylindrical portion 31 , and blows gas into the interior of the cylindrical portion 31 .

[0065] The nozzles 34 of this embodiment are arranged in pairs, two on the left and right, facing each other in the radial direction of the cylindrical portion 31. Two nozzles (two groups) are arranged in the axial direction, for a total of four nozzles. Specifically, one group (two) of upper nozzles 34a and one group (two) of lower nozzles 34b are provided. The nozzles 34 are arranged in parallel along the radial direction.

[0066] However, as long as the nozzles 34 include the nozzles disposed in the central portion in the axial direction as described later, their number and basic configuration are not particularly limited. For example, the nozzles 34 may be provided only as single-sided nozzles that are not paired in the radial direction (i.e., an odd number), or one group or more than three groups may be provided, and the two nozzles on opposite sides in the radial direction may not be opposite to each other (the positions in the axial direction may be different). The two nozzles 34 that are opposed to each other on the left and right may not be symmetrical or axially symmetrical to each other. In addition, as described later, each nozzle 34 may be divided into multiple nozzles in the width direction (refer to Figure 3B Furthermore, when the two nozzles 34 are opposed to each other on the left and right, the two nozzles 34 only need to be opposed to each other in a plane perpendicular to the axial direction of the cylindrical portion 31 and do not need to be opposed to each other in the radial direction.

[0067] like Figure 2 As shown, each nozzle 34 is located axially at the center of the cylindrical portion 31. The "center" in the axial direction refers to the portion excluding the upper and lower ends of the cylindrical portion 31. In other words, each nozzle 34 only needs to be separated from the upper and lower ends of the cylindrical portion 31.

[0068] In other words, each nozzle 34 is arranged at an axial position defined by the following first length L1 and second length L2. The first length L1 is the axial length from the upper end (one end) of the cylindrical portion 31 to the nozzle 34, and the second length L2 is the axial length from the lower end (the other end) of the cylindrical portion 31 to the nozzle 34. The first length L1 and the second length L2 do not need to be zero.

[0069] In addition, Figure 2 , for ease of understanding, the cover 30 is illustrated as being provided with only one set of nozzles 34 in the axial direction.

[0070] Here, the "axial position of the nozzle 34" refers to the center position of the portion of the nozzle 34 that opens to the inner diameter of the cylindrical portion 31. However, the first length L1 may be set as the distance from the upper end of the inner diameter (hole portion) of the nozzle 34, and the second length L2 may be set as the distance from the lower end of the inner diameter of the nozzle 34.

[0071] The first length L1 in the axial direction from the upper end of the cylindrical portion 31 to each nozzle 34 preferably satisfies the following formula (3):

[0072] L1≥0.3D……(3)

[0073] More preferably, the first length L1 satisfies the following formula (6):

[0074] L1≥0.5D……(6)

[0075] Here, D is the inner diameter of the cylindrical portion 31. When the cylindrical portion 31 is a square cylinder, D may be, for example, the equivalent diameter (the diameter of the cylindrical portion 31 with the same cross-sectional area), or the minimum width or maximum width of the cross section perpendicular to the axial direction.

[0076] Alternatively, the first length L1 is preferably 50 mm or more.

[0077] The second length L2 in the axial direction from the lower end of the cylindrical portion 31 to each nozzle 34 preferably satisfies the following formula (4):

[0078] L2≥0.3D……(4)

[0079] Alternatively, the second length L2 is preferably 50 mm or more.

[0080] More preferably, the second length L2 satisfies the following formula (7):

[0081] L2≥0.5D……(7)

[0082] like Figure 3A As shown, the width W of each nozzle 34 preferably satisfies the following formula (5) relative to the inner diameter D of the cylindrical portion 31:

[0083] W≥0.3D……(5)

[0084] In addition, Figure 3A and Figure 3B , for ease of understanding, the cover 30 is illustrated as being provided with only one set of nozzles 34 in the axial direction.

[0085] Here, "width W of nozzle 34" refers to the length of the portion of nozzle 34 that opens into the inner diameter (hole) of cylindrical portion 31, along a direction perpendicular to the axial direction. Furthermore, the center of nozzle 34 in the width direction (the direction along width W) does not necessarily coincide with the center of cylindrical portion 31 in that direction (i.e., central axis Ax).

[0086] In addition, if Figure 3B As shown, the nozzle 34 may be composed of a plurality of partial nozzles 34c arranged in a row along the width direction. In addition, the nozzle 34 may include a structure that is not arranged radially with respect to the central axis Ax of the cylindrical portion 31 when viewed from the axial direction.

[0087] And, as Figure 11A and Figure 11B As shown, the nozzle 34 can be tilted relative to the axial direction. At this time, the left and right nozzles 34 in a group can face different tilt directions (for example, one faces obliquely upwards and the other faces obliquely downwards).

[0088] Furthermore, the length (thickness) of the inner diameter (hole portion) of the nozzle 34 in the axial direction is not particularly limited, but is preferably sufficiently smaller than the axial height of the cylindrical portion 31 .

[0089] Furthermore, the length of the airflow along the inner diameter (hole portion) of the nozzle 34 that is perpendicular to the width direction (in this embodiment, the length along the radial direction) is not particularly limited, but preferably has a specified run-up length so that a certain degree of uniform airflow is formed in the width direction within the nozzle 34.

[0090] [Laser processing method]

[0091] like Figure 1 As shown, when laser processing is performed on the workpiece WP in the laser processing apparatus 1 , the workpiece WP is first placed on the upper surface of the support table 20 so that the processed portion of the workpiece WP is located inside the cover 30 (opening 31 b ) in a plan view.

[0092] Then, a predetermined gas such as an inert gas is supplied to the cover 30 by the gas supply unit 40 to purge the interior of the cover 30. This gas is supplied from each nozzle 34 into the cylindrical portion 31 of the cover 30 at a predetermined flow rate (e.g., approximately 10 L / min), forming an airflow in the cylindrical portion 31 of the cover 30.

[0093] At this time, each nozzle 34 of the cover 30 is arranged at the central portion in the axial direction of the cylindrical portion 31. Figure 4A As shown, a multi-layer vortex airflow is formed in the cylindrical portion 31 along the axial direction.

[0094] In this state, the control unit 50 drives the laser irradiation unit 10 to irradiate the laser downward. The laser light passes through the protective glass 31a of the cover 30 and irradiates the cylindrical portion 31, performing predetermined laser processing on the workpiece WP disposed in the opening 31b.

[0095] At least the cover 30 and the support table 20 are housed in a chamber (not shown), and gas leaking from the opening 31b of the cover 30 is trapped in the chamber. The gas in the chamber is exhausted to the outside through an exhaust line connected to the chamber.

[0096] In this manner, in the laser processing apparatus 1, the workpiece WP is processed by laser light while a multi-layer airflow is formed in the axial direction within the cover 30 (cylindrical portion 31). This prevents dust PA generated from the workpiece WP by laser irradiation from being swept up, thereby preventing the dust PA from adhering to the protective glass 31a.

[0097] That is, Figure 4B As shown, in a conventional cover 80, the nozzle 84 is positioned substantially at the uppermost portion of the cylindrical portion 81, thereby forming a single airflow in the axial direction within the cylindrical portion 81. Consequently, dust PA generated from the workpiece WP may be swept up by the airflow and adhere to the protective glass 81a at the upper end of the cover 80. The dust PA adhered to the protective glass 81a attenuates the laser light transmitted through the protective glass 81a.

[0098] In this embodiment, multiple layers of airflow are formed in the axial direction within the cover 30. Even if dust PA is swept up by the lower airflow, the airflow above the lower airflow can prevent the dust PA from approaching the protective glass 31a. This prevents the dust PA from adhering to the protective glass 31a, thereby suppressing the attenuation of the laser light.

[0099] The airflow in the cylindrical portion 31 only needs to form at least two layers in the axial direction. Here, a single airflow refers to an airflow in substantially the same direction, and a two-layer airflow refers to an airflow in different directions (including vortices in different rotation directions).

[0100] So, for example, Figure 5A As shown, the gas supply amounts of the left and right nozzles 34 facing each other can be made different. Even in this case, the balance of the left and right airflows is destroyed, but at least two layers of airflow can be formed in the axial direction.

[0101] Or, as Figure 5B As shown, only one set of nozzles 34 may be provided. In this case, Figure 6A As shown, the airflow to the lower side may not be vortex-shaped. Figure 6B As shown, even when the nozzles 34 are provided in one set, the gas supply amounts of the left and right nozzles 34 can be made different.

[0102] [Technical Effects of Implementation Methods]

[0103] As described above, according to the present embodiment, the nozzle 34 of the cover 30 is arranged at the axial center portion of the cylindrical portion 31. That is, the nozzle 34 is arranged at an axial position spaced apart from the upper and lower ends of the cylindrical portion 31.

[0104] Therefore, the gas supplied from the nozzle 34 forms at least two layers of airflow in the axial direction within the cylindrical portion 31. This can suppress the dust PA from adhering to the protective glass 31a, and further suppress the attenuation of the laser light.

[0105] Furthermore, the nozzles 34 are located in a portion of the circumference of the cylindrical portion 31. That is, the nozzles 34 are not formed along the entire circumference of the cylindrical portion 31. Therefore, gas is likely to leak vertically from the inner portion of the circumferential surface of the cylindrical portion 31 where the nozzles 34 are not formed. This allows for the appropriate formation of a vertically rotating vortex.

[0106] Furthermore, according to this embodiment, since the first axial length L1 from the upper end of the cylindrical portion 31 to the nozzle 34 satisfies the above-mentioned formula (3), it is possible to more reliably form an airflow above the nozzle 34. Therefore, it is possible to more reliably suppress the dust PA from adhering to the protective glass 31a.

[0107] Furthermore, according to this embodiment, since the second length L2 in the axial direction from the lower end of the cylindrical portion 31 to the nozzle 34 satisfies the above-mentioned formula (4), it is possible to more reliably form an airflow below the nozzle 34. Therefore, it is possible to more reliably suppress the dust PA from adhering to the protective glass 31a.

[0108] Furthermore, according to this embodiment, the width W of the nozzle in a direction perpendicular to the axial direction satisfies the above-mentioned formula (5), so that at least two layers of airflow in the axial direction can be appropriately formed in the width direction within the cylindrical portion 31. Therefore, it is possible to more reliably suppress the adhesion of dust PA to the protective glass 31a.

[0109] Furthermore, according to this embodiment, the nozzle 34 includes a pair of nozzles facing each other in a plane perpendicular to the axial direction. This allows the airflow to collide in the plane perpendicular to the axial direction, thereby appropriately forming a vertical vortex that swirls in the vertical direction.

[0110] Furthermore, according to this embodiment, the nozzles 34 are not arranged radially relative to the central axis Ax of the cylindrical portion 31 when viewed from the axial direction. Even if the nozzles 34 are not arranged radially, a vertical vortex can be formed that swirls in the vertical direction.

[0111] [Analysis Example 1]

[0112] Next, the effect of preventing the dust PA from adhering to the airflow formed in the cover 30 will be described using an analytical example.

[0113] In this analysis example 1, the flow of air in the cylindrical portion 31 when the shape of the cover 30 and the gas flow conditions are changed is calculated through fluid analysis.

[0114] Specifically, based on the shape of the cover 30 of the above embodiment, the following models were analyzed: omitting the lower nozzle group (model 1), making the left and right gas amounts evenly balanced (model 2), and making the left and right gas amounts unevenly balanced (model 3). Figure 4B ) was also analyzed as a comparative example.

[0115] The dimensions of each part of the analysis model are as follows:

[0116] ●Shape of the cover

[0117] Total height: 258mm

[0118] Inner diameter D: 160mm

[0119] 1st length L1: 103mm

[0120] Axial distance between upper and lower nozzles: 54mm

[0121] Axial height of each nozzle's blowing port: 2mm

[0122] Width of each nozzle W: 136mm

[0123] The left-right distance L3 between the ends of the left and right nozzles (reference Figure 2 ): 300mm

[0124] ●Axial clearance between the cover and the support platform: 5mm

[0125] ●Axial range under atmospheric pressure: within 100mm from the top surface of the support platform

[0126] ●Radial range under atmospheric pressure conditions: diameter within

[0127] However, the first length L1 and the axial distance between the upper and lower nozzles are defined as the length to the blowing port (hole portion) of each nozzle.

[0128] The gas flow rate conditions of Models 1 to 3 are shown in the upper column of the following Table 1. In this column, the left and right gas flow rates are indicated as "(left flow rate), (right flow rate)".

[0129] [Table 1]

[0130]

[0131] exist Figures 7A to 10C The contour plot of the analytical results is shown in FIG. Figures 7A to 7C For model 1, Figures 8A to 8C For model 2, Figures 9A to 9C For model 3, Figures 10A to 10CThese are the analysis results for a conventional cover 80. In each figure, (a) shows the streamline trajectory at the lower portion of the cover (e.g., at a height of 50 mm), (b) shows the gas (e.g., nitrogen) concentration distribution, and (c) shows the velocity vector diagram. In each of Figures (a) through (c), the top and bottom and left and right sides of the paper correspond to the top and bottom and left and right sides of the cover.

[0132] according to Figures 7A to 7C , regarding model 1 (without the cover 30 of the lower nozzle group), the following conclusions can be drawn:

[0133] The airflow forms a vortex below the nozzle 34, making it difficult for the dust PA below the cover 30 to reach the protective glass 31a.

[0134] The gas concentration in the cover 30 is generally high.

[0135] ●Two layers of vortex airflow are formed above and below the nozzle 34.

[0136] according to Figures 8A to 8C , regarding model 2 (the gas amount balance on the left and right is balanced), we can say that the following conclusions are drawn:

[0137] The airflow forms a vortex below the lower nozzle 34b, and the dust PA at the lower portion of the cover 30 becomes less likely to reach the protective glass 31a or the upper nozzle 34a.

[0138] The gas concentration in the cover 30 is generally high.

[0139] Three layers of vortex airflow are formed above the upper nozzle 34a, below the lower nozzle 34b, and between the upper and lower nozzle groups 34.

[0140] according to Figures 9A to 9C , Regarding Model 3 (the gas amount balance on the left and right is unbalanced), the following conclusions can be drawn:

[0141] The airflow forms a vortex below the lower nozzle 34b, and the dust PA at the lower portion of the cover 30 becomes less likely to reach the protective glass 31a or the upper nozzle 34a.

[0142] The gas in the cover 30 is discharged from the side of the lower nozzle 34b where the blowing intensity is greater.

[0143] ●A vortex airflow with three layers, upper and lower, is formed.

[0144] according to Figures 10A to 10C , about the previous cover 80, we can draw the following conclusions:

[0145] The airflow is a single-layer vortex flow in the upper and lower parts, and there is a risk that the dust PA at the lower part of the cover 30 will be swept up to the protective glass 31a.

[0146] The gas concentration in the cover 30 is generally high.

[0147] The results of the comparison of the above results in Models 1 to 3 (excluding the conventional cover) are shown in the lower column of Table 1. The comparison results are listed below:

[0148] In any of Models 1 to 3, an effect of preventing the dust PA from adhering to the cover glass 31 a can be expected.

[0149] Compared to Model 1, which forms two layers of airflow, Models 2 and 3, which form three layers of airflow, are expected to achieve a higher effect in preventing the adhesion of dust particles PA.

[0150] ● In Model 1, unlike Models 2 and 3, there may be a problem in that the discharge of dust PA is not smooth.

[0151] The gas purge in the cover 30 can be appropriately performed in any of the models 1 to 3.

[0152] [Analysis Example 2]

[0153] In Analysis Example 2, the effect of preventing the adhesion of the dust PA when the gas applied by each nozzle 34 was changed was evaluated by fluid analysis for the cover 30 of the embodiment.

[0154] Gas application refers to the relative gas flow rate relative to the size of the cover 30 (the volume of the cylindrical portion 31), and is evaluated in three levels: strong, weak, and none. The dust PA adhesion prevention effect is evaluated in the same manner as in Analysis Example 1 above.

[0155] The main gas application combinations that can achieve the desired effect of preventing dust PA adhesion are shown in Table 2 below.

[0156] As shown in Table 2, the gas application of at least one of the upper nozzles 34a is preferably "strong".

[0157] In addition, among the combinations shown in Table 2, No. 1 and No. 2 achieved the best results. Furthermore, it is believed that the same effect can be achieved even when the difference in gas application between the left and right sides of each nozzle group is reversed. Furthermore, when three or more nozzle groups are used, the pattern of the third and subsequent groups may affect the magnitude of the effect of preventing the adhesion of dust particles PA, but it does not affect the presence or absence of this effect.

[0158] [Table 2]

[0159]

[0160] [other]

[0161] As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment.

[0162] For example, in the above-described embodiment, the laser beam is irradiated along the axial direction of the cover 30 , but the laser beam may be irradiated obliquely with respect to the axial direction.

[0163] Furthermore, the structure of the laser processing device is not limited to Figure 1 The structure shown.

[0164] For example, in Figure 12 The laser processing apparatus 1A shown in the figure is equipped with a regulator 44, an on-off valve 45, and a flow control valve 46 as devices for adjusting the blowing conditions of the gas blown from the nozzle 34. The regulator 44 adjusts the pressure of the gas blown from a gas source 41, such as a gas cylinder. The on-off valve 45 switches the blowing on and off. The flow control valve 46 is arranged in the upper and lower sections to adjust the flow rate of the blowing gas in each section.

[0165] In the laser processing apparatus 1A, laser light emitted from a laser oscillator 11 is shaped and output adjusted by an optical system 12 , and then the irradiation position of the laser light is controlled by a galvanometer scanner 13 .

[0166] The cover 30 is fixed to the chamber 21 within the cover 22. The support table (workbench) 20, on which the workpiece WP is placed, is position-controlled and positioned relative to the cover 30 during processing. The axial clearance between the lower end of the cover 30 and the upper surface of the support table 20 is set to an extremely short distance (approximately 2 mm in the actual equipment). This allows the interior of the cover 30 to be properly purged with an inert gas such as nitrogen, maintaining a low oxygen concentration (e.g., tens of ppm) near the workpiece WP. This enables optimal laser processing of the workpiece WP.

[0167] Furthermore, the above-mentioned structures are controlled by the control unit 50 (refer to Figure 1 )control.

[0168] Furthermore, the laser processing device of the present invention can be widely used in situations where laser processing is performed on a workpiece in a gas environment, and is not limited by the type of processing, the material of the workpiece, etc.

[0169] Furthermore, the detailed configurations described in the above embodiments can be appropriately modified without departing from the spirit of the invention.

[0170] Industrial applicability

[0171] As described above, the present invention is useful for suppressing the attenuation of laser light.

[0172] Explanation of symbols

[0173] 1-Laser processing device, 10-Laser irradiation part (Laser irradiation mechanism), 20-Support platform, 30-Hood (Hood for laser device), 31-Cylinder, 31a-Protective glass (Transmitting part), 31b-Opening part, 34-Nozzle, 34a-Upper nozzle, 34b-Lower nozzle, 34c-Partial nozzle, 40-Gas supply part (Gas supply mechanism), 41-Gas source, 42-Valve, 43-Piping, 50-Control part, 80-Conventional hood, 81-Conventional cylindrical part, 81a-Conventional protective glass, 84-Conventional nozzle, Ax-Center axis, D-Inner diameter, PA-Particles, W-Width, WP-Workpiece

Claims

1. A cover for a laser device, comprising: a cylindrical portion extending in the axial direction; a transmissive portion disposed at one end of the cylindrical portion in the axial direction and transmitting the laser light; an opening portion provided at the other end of the cylindrical portion in the axial direction; and The nozzle supplies gas to the interior of the cylindrical portion. The nozzle is arranged at the axial center portion of the cylindrical portion and at a portion in the circumferential direction.

2. The cover for a laser device according to claim 1, wherein: When the inner diameter of the cylindrical portion is set to D, a first length (L1) from the one end of the cylindrical portion to the nozzle in the axial direction satisfies the following formula (3): L1≥0.3D……(3).

3. The cover for a laser device according to claim 1, wherein: When the inner diameter of the cylindrical portion is set to D, the second length (L2) from the other end of the cylindrical portion to the nozzle in the axial direction satisfies the following formula (4): L2≥0.3D……(4).

4. The cover for a laser device according to claim 1, wherein: When the inner diameter of the cylindrical portion is set to D, the width (W) of the nozzle along the direction perpendicular to the axial direction satisfies the following formula (5): W≥0.3D……(5).

5. The cover for a laser device according to claim 1, wherein The nozzles include a group of nozzles facing each other in a plane perpendicular to the axial direction.

6. The cover for a laser device according to claim 5, wherein: The nozzles include a plurality of nozzle groups arranged along the axial direction.

7. The cover for a laser device according to claim 1, wherein: The nozzle is inclined relative to the axial direction.

8. The cover for a laser device according to claim 1, wherein: The nozzles are not arranged radially with respect to the central axis of the cylindrical portion when viewed in the axial direction.

9. A laser processing device comprising: The cover for a laser device according to any one of claims 1 to 8; a support table disposed on the opening side of the cylindrical portion and supporting the workpiece; a laser irradiation mechanism for irradiating laser light into the cylindrical portion through the transmission portion; and The gas supply mechanism supplies gas into the cylindrical portion through the nozzle.

10. A laser processing method for processing a workpiece covered by a cover by irradiating the workpiece with laser light, wherein: The cover is a cover having the following components: a cylindrical portion extending in the axial direction, a transmissive portion provided at one axial end of the cylindrical portion and transmitting the laser light, an opening provided at the other axial end of the cylindrical portion, and a nozzle provided at the axial center of the cylindrical portion and at a portion of the circumference thereof and supplying gas to the interior. While gas is supplied from the nozzle into the cylindrical portion to form at least two gas flows in the axial direction, laser light is irradiated into the cylindrical portion through the transmission portion to process a workpiece disposed in the opening.

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