Laser processing device and laser processing method

Abstract

Laser processing device (1), comprising: a laser oscillator (2) for generating laser light; a processing table (5) for placing a workpiece (10) on it, wherein the workpiece (10) has a protective film (11) on one of its surfaces, the protective film (11) comprising a laser light absorption layer (11a); a laser head (4) for processing the workpiece (10) with the laser light; and a control unit (6) for adjusting the position of the laser head (4) such that the focus of the laser light is moved away from the surface of the workpiece (10a) towards the laser head (4), and for controlling the power of the laser light so that a marking is provided by causing the laser light absorption layer (11a) to absorb the laser light and thus change the interior of the protective film (11) in order to form a gap (H) between the laser light absorption layer (11a) and the top of the workpiece (10) by separating the laser light absorption layer (11a) and the top of the workpiece (10).

Description

[Technical field]

[0001] This disclosure relates to a laser processing device and a laser processing method. [Technological background]

[0002] The laser processing device is known as a device that performs a cutting operation on a workpiece. The laser processing device performs this operation by moving its laser head relative to the workpiece while emitting laser light from the laser head onto the workpiece. In conventional laser processing, a method is known in which the laser processing is carried out with a protective film applied to the surface of the workpiece to protect it from damage. In some cases where laser processing is performed on a workpiece with a protective film, markings are applied to the protective film to convey information about the workpiece. For example, a laser processing device is known that applies a marking to the protective film of a workpiece (see, for example, patent document JP 2018 - 167 294 A).

[0003] The relevant state of the art also includes the documents JP 2015-23094A, US 6075223A, US 4847181A, US 2018 / 0355187A1 and WO 2012 / 026305A1. [Brief description of the invention][Problem to be solved by the invention]

[0004] However, conventional technology has the following problems. With regard to the laser processing device described in the aforementioned JP 2018-167294A, it is disclosed how a mark can be produced solely on the protective film. This laser processing device adjusts the power of the laser light and limits the processing area to a predetermined depth so that the protective film is not penetrated. However, controlling a laser processing device in such a way that the protective film is not penetrated is generally difficult, and strict processing conditions must be defined. Furthermore, even if only a very small amount of laser light penetrates the protective film, it reaches the workpiece and causes damage.

[0005] The present invention was made in view of the problems described above and is aimed at providing a laser processing device which, when processing a workpiece to which a protective film is attached, can apply a marking to the protective film without damaging the workpiece. [Means of solving the problems]

[0006] To solve the problem and achieve the objective described above, a laser processing device according to this disclosure comprises the combination of features of the independent device claims. Preferred embodiments are found in the dependent claims. Furthermore, the problem described above is solved by a method comprising the combination of features of the independent method claims. [Effects of the invention]

[0007] The effect of the laser processing device according to this disclosure is that marking can be carried out on a protective film without damaging a workpiece. [Brief descriptions of the drawings] Fig. Figure 1 shows a configuration diagram of a laser processing device according to embodiment 1. Fig. Figure 2 shows an enlarged view near a machining point of a workpiece. Fig. 1. Fig. 3A is a schematic layout when processing is carried out using the laser processing device according to embodiment 1. Fig. Figure 3B is a schematic representation after processing by the laser processing device according to embodiment 1. Fig. Figure 4A is a diagram showing a protective film after processing by the laser processing device according to embodiment 1. Fig. Figure 4B is a diagram showing a workpiece after processing by the laser processing device according to embodiment 1. Fig. Figure 5 is a flowchart showing a sequence of laser processing by the laser processing device according to embodiment 1. Fig. Figure 6 shows a configuration diagram of a laser processing device according to embodiment 2. Fig. Figure 7 shows an enlarged view near a processing point of a workpiece in a general example of a laser processing device using an auxiliary gas. Fig. Figure 8 shows an enlarged view near a processing point of a workpiece of the laser processing device according to embodiment 2. Fig. 9A is a cross-sectional view of a laser head along the XX line. Fig. 8. Fig. Figure 9B is a cross-sectional view of a laser head according to a variant of embodiment 2. Fig. Figure 10 shows a configuration diagram of a laser processing device according to embodiment 3. Fig. Figure 11 shows a top view of a machining table according to embodiment 3. [Embodiments of the invention]

[0008] Laser processing devices according to the embodiments of this disclosure are described below with reference to the drawings. In the drawings, the same symbols are assigned to the same or corresponding parts. Repetitive explanations are simplified or omitted where appropriate. It should be noted that the present invention is not limited by the embodiments described below. In the drawings described below, the scale of the individual components may differ from the actual scale. Design 1

[0009] The following describes a laser processing device according to embodiment 1.

[0010] Fig. Figure 1 shows a configuration diagram of the laser processing device 1 according to embodiment 1. The laser processing device 1 comprises a laser oscillator 2, a transmission unit 3, a laser head 4, a processing table 5, a control unit 6, a drive unit 7, and a memory 8. The laser processing device 1 performs laser processing operations such as cutting, grooving, and drilling on a workpiece, for example, a plate-shaped workpiece made of metal.

[0011] The laser oscillator 2 is, for example, a fiber laser oscillator that generates laser light. The laser light generated by the laser oscillator 2 is guided to the laser head 4 via the transmission unit 3, for example, an optical fiber. The laser oscillator 2 can also be a different type of oscillator than the fiber laser oscillator, such as a carbon dioxide laser oscillator, a YAG laser oscillator, or a YVO laser oscillator. The laser oscillator 2 is connected to a control unit that regulates the power and other parameters of the laser light.

[0012] The laser head 4 emits the laser light introduced via the transmission unit 3 and processes a workpiece 10. The laser head 4, which is connected to the drive unit 7, moves relative to the workpiece 10 in horizontal and vertical directions. By irradiating the workpiece 10 with the laser light from the laser head 4, it can be brought into a desired shape.

[0013] The laser processing device 1 comprises the processing table 5. The laser processing device 1 processes the workpiece 10 by emitting laser light from the laser head 4 while the workpiece 10 is placed on the processing table 5. In the following description, it is assumed that the top (upper surface) of the workpiece 10 is the surface facing the laser head 4 and the back of the workpiece is the surface that contacts the processing table 5 when the workpiece is positioned.

[0014] The worktable 5 is connected to the drive unit 7. Thus, the worktable 5 is driven by the drive unit 7. The movement of the worktable 5 sets the workpiece 10, which lies on the worktable 5, in motion. The workpiece 10 can be moved along with the worktable 5 by the movement of the worktable itself. The workpiece 10 can be moved on the worktable 5 by using a mechanism such as rollers.

[0015] The control unit 6 controls other units and components of the laser processing device 1. In addition, the control unit 6 also functions as a processing unit for processing data related to the operation of the laser processing device 1. The control unit 6 includes, for example, a CPU, main memory, a wired or wireless communication device, an input / output interface for communication with various external devices, an input device such as a keyboard or mouse, a display device such as a monitor, and a computer device that executes various programs required for the operation and data processing of the laser processing device 1.

[0016] Within the laser processing device 1, the control unit 6 is connected to the laser oscillator 2, the drive unit 7, and the memory 8, and controls their operation. The control unit 6 controls the laser light radiation by controlling the laser oscillator 2. The control unit 6 controls the power, frequency, duty cycle, energy density, and other parameters of the laser light generated by the laser oscillator 2.

[0017] Furthermore, the control unit 6, by controlling the drive unit 7, controls the movement of the laser head 4 and the processing table 5. In other words, by controlling the drive unit 7, the control unit 6 can control the relative movement between the laser head 4 and the workpiece 10 placed on the processing table 5. By controlling the horizontal movement of the laser head 4 via the drive unit 7, the control unit 6 can control the direction of movement, the extent of the movement, the processing speed, and the like. By controlling the vertical movement of the laser head 4, the control unit 6 can also adjust the focus position of the laser light. It should be noted that the control unit 6 can also control a vertical movement of the processing table 5.

[0018] Memory 8 is a storage device, such as a hard drive, and is provided in the computer device. Memory 8 stores processing programs used by the laser processing device 1 and various data, such as setpoints for the processing performed by the laser processing device 1. It should be noted that memory 8 may be located in the control unit 6.

[0019] The workpiece 10, with a protective film 11 attached to its upper surface, is the object to be processed. The workpiece 10 is placed on the processing table 5 and processed by the laser light emitted from the laser head 4. The protective film 11 protects the upper surface of the workpiece 10. This protects the workpiece 10 from damage caused by external influences.

[0020] The protective film 11 is also made of a material suitable for the wavelength of the laser light used by the laser processing device 1, so that the laser light can perform marking operations. The protective film 11 is attached to the top of the workpiece 10 with adhesive and can be removed if necessary. The laser processing device 1 can perform laser processing of the workpiece 10 while the protective film 11 is attached to the workpiece 10.

[0021] The following refers to Fig. 2. Laser processing is described. Fig. Figure 2 shows an enlarged view near a machining point of workpiece 10. Fig. 1. The processing point is an area where processing takes place using the laser light emitted by the laser processing device 1. Fig. Figure 2 shows, for the sake of simplicity, only the tip of the laser head 4, which is located near the processing point. The arrow indicates the direction in which the laser light is emitted. The circled point at the arrowhead designates a processing point P. This figure shows that the laser processing device 1 emits the laser light in the direction of the processing point P, where the processing takes place.

[0022] As in Fig. As shown in Figure 2, a protective film 11, having a two-layer structure, is attached to the workpiece 10. This protective film 11 comprises a laser light absorption layer 11a with high absorption capacity for the laser light and a laser light transmission layer 11b with low absorption capacity for the laser light. The protective film 11 has the laser light absorption layer 11a on the side facing the top of the workpiece 10 and the laser light transmission layer 11b on the side facing the laser head 4. This means that the protective film 11 has a structure in which the laser light transmission layer 11b is stacked above the laser light absorption layer 11a. It should be noted that the protective film 11 does not necessarily have to include the laser light transmission layer 11b.Alternatively, there can be another layer between the laser light transmission layer 11b and the laser light absorption layer 11a, and there can be another layer between the workpiece 10 and the laser light absorption layer 11a.

[0023] The layers of the protective film 11 are described below. The laser light absorption layer 11a, which exhibits high absorption capacity for laser light, consists of a black or gray colored rubber / natural rubber or a thermoplastic polymer / resin. For the black-colored rubber and thermoplastic polymer, materials containing a powder of carbon black or carbonized graphite as the black pigment can be used, as these generally absorb laser light strongly. The laser light absorption layer 11a comprises a material that develops adhesive properties to be attached to the workpiece 10. The black pigment is not limited to the aforementioned materials, as long as the absorption rate for laser light is high. The laser light absorption layer 11a achieves its high absorption rate for laser light by comprising a black pigment with a high absorption rate for laser light.If the absorption rate for laser light is high, this means, for example, that the absorption rate for laser light exceeds 30%. A pigment with a laser light absorption rate of more than 30% absorbs the laser light, thus facilitating the conversion of the laser light absorption layer.

[0024] The laser light transmission layer 11b, which exhibits low absorption of laser light, consists of an uncolored thermoplastic or a white-colored thermoplastic. For example, the white-colored thermoplastic can be one containing zinc oxide or titanium oxide, which are white pigments that generally have low absorption of laser light. The white pigment is not limited to those mentioned above, as long as the absorption rate for laser light is low. The laser light transmission layer 11b achieves its low absorption rate for laser light by incorporating a white pigment with a low absorption rate for laser light. In this context, a low absorption rate for laser light means, for example, that the absorption rate for laser light is 30% or less.

[0025] It should be noted that the absorption rate for the laser light is not solely determined by the color of the laser light absorption layer 11a. As long as a protective film has an absorption rate suitable for the laser light used by the laser processing device 1, the protective film can be used as protective film 11.

[0026] Regarding the materials forming the individual layers, the main component of each layer is rubber, polyethylene, or similar. If the main component of the layer constitutes 50% by weight or more, another plastic component or similar material may be added.

[0027] For example, the protective film 11 FIBERGUARD (registered trademark) SPV-310GH series, manufactured by Nitto Denko Corporation, can be used. It should be noted that the thickness of the protective film 11 is not particularly limited, but a protective film 11 with a thickness of 0.050 mm to 0.200 mm is preferable, as it exhibits good processability when applied to the workpiece 10. The numerical range specified above includes both the upper and lower limits that define the numerical range. This is also the case in the following description, unless otherwise stated.

[0028] The operation of the laser processing device 1 is described below using the following examples: Fig. 3 to Fig. 5 described. Fig. Figure 3A shows a schematic layout during laser processing with the laser processing device 1, and Fig. Figure 3B shows a schematic diagram of a workpiece after laser processing by the laser processing device 1. Fig. Figure 4A is an image showing an example of the protective film 11 after laser processing by the laser processing device 1, and Fig. 4B is an image showing an example of workpiece 10 after laser processing by the laser processing device 1. Fig. 4B shows an image in which part of the protective film 11 of the one in Fig. 4A shows workpiece 10 being subtracted. Fig. Figure 5 shows a flowchart illustrating the laser processing process using the laser processing device 1.

[0029] Fig. Figure 3A schematically shows how laser light L is directed onto the laser light absorption layer 11a of the protective film 11. The focus position F of the laser light L is set to a position located on the side of the laser head 4 away from the top surface of the workpiece 10. In practice, the focus position F of the laser light L is set to a position located on the side of the laser head 4 away from the surface of the protective film 11. The focus position F is set to a state in which the processing area is in a so-called defocused position. The energy density of the laser light L is highest at the focus position where the laser light is concentrated. Therefore, in the present embodiment, the focus position F is set to a position that defocuses the processing area, so that the energy density of the laser light L illuminating the workpiece 10 is lower than the energy density of the laser light L at the focus position.This also applies to the other embodiments.

[0030] By adjusting the focus position F as described above to the position that defocuses the processing area, the laser light can irradiate the interior of the protective film 11 with a lower energy density than the energy density at the focus position F. In other words, adjusting to the defocused position prevents the laser light absorption layer 11a from being locally irradiated with high-energy-density laser light. Therefore, the laser light can be prevented from cutting the protective film 11 and damaging the workpiece 10.

[0031] If the top surface of workpiece 10 is defined as the reference plane, the position that defocuses the machining area can be represented by the distance between the reference plane and the focus position F. The position of the top surface of workpiece 10 is set to 0 as the reference plane. If the focus position F is on the side of the laser head 4, the focus position is represented by a positive value (+) in mm.

[0032] If, however, the focus position F is located on the side opposite the laser head 4, the focus position is represented by a negative value (-) in mm. For example, if the focus position F is on the side of the laser head 4 10 mm away from the top of the workpiece 10, the focus position is +10 mm.

[0033] The position that defocuses the processing area is set, for example, to a position 0.5 mm to 10 mm away from the top surface of the workpiece 10 on the side of the laser head 4, i.e., a position in the range of +0.5 mm to +10 mm. Furthermore, the position that defocuses the processing area should, with regard to the energy density of the laser light illuminating the protective film 11, preferably be in the range of +2 mm to +8 mm and even more preferably in the range of +4 mm to +6 mm. If the defocusing of the processing area is set at a distance from the protective film 11, the processing is not affected by vibrations emanating from the installation environment of the device during processing, nor by the roughness of the surface of the protective film or the workpiece itself, so that the protective film 11 is not cut by the laser light, which has a high energy density at the focus position.In this way, adjusting to the defocused position has a beneficial effect on ensuring stable quality of the marking process on the protective film.

[0034] Next, Fig. 3B described. Fig. Figure 3B shows the condition after irradiation of the protective film 11 attached to the workpiece 10 with laser light. As in Fig. As shown in Figure 3B, the laser light absorption layer 11a, irradiated with laser light, and the top surface of the workpiece 10 are separated from each other and form a gap H. This means that the protective film 11 is internally transformed. This means that the laser light has transformed the protective film 11 by transforming the laser light absorption layer 11a, without damaging the workpiece 10 or destroying the protective film 11.

[0035] Viewed from the side of the top of the workpiece 10, on which the protective film 11 is attached, the transformed part of the protective film 11 can be visually perceived. This transformation of the protective film 11 can be perceived as a marking. In addition to the Fig. The transformation of the protective film 11 shown in 3B includes the transformation occurring inside the protective film 11, as well as the transformation that creates a cavity inside the protective film 11 itself and causes a change in the relief on the surface of the protective film 11.

[0036] In the laser processing device 1, the laser light power is controlled to perform the marking. This marking is achieved by causing the laser light absorption layer 11a to absorb the laser light and by altering the interior of the protective film 11. The laser light power is varied according to the focus position, which defocuses the processing area. For example, the laser light power is controlled between 50 W and 100 W to alter the interior of the protective film 11. Preferably, the laser light power is set to 70 W to 90 W to reliably alter the interior of the protective film 11. It should be noted that when cutting sheet metal with a fiber laser, the laser light power is typically set to, for example, 1 kW or more.In other words, one of the features of the laser processing device of the present embodiment is that the power of the laser light used in carrying out the marking is set significantly lower than the power of the laser light used in normal laser processing.

[0037] As described above, the laser light power is controlled to modify the interior of the protective film 11 by adjusting the focus position to defocus the processing area and causing the laser light absorption layer 11a to absorb the laser light. As a result, the marking is applied to the protective film 11. Because the focus position is moved to a position that defocuses the processing area, the marking is performed with laser light of lower energy density. This simplifies the control of the laser light compared to the control method used in conventional techniques, where the laser light radiation is strictly controlled with respect to the surface of the protective film.

[0038] The laser light absorption layer 11a absorbs the laser light and is heated by the thermal energy, thereby undergoing a transformation. Due to the transformation of the laser light absorption layer 11a, the laser light transmission layer 11b is also transformed. The transformation of these two layers transforms the protective film 11. The term "marking" used in the description of the present embodiment does not include marking caused by damage to the surface of the protective film 11, such as indentations, cuts, and the like, caused by the laser light. This also applies to the other embodiments.

[0039] When the laser light is applied to the protective film 11 in accordance with the conditions for providing a mark on the protective film 11, with the laser head 4 moving along a predetermined path, the predetermined path on the film is marked. By performing the laser processing in this way, the mark can be applied to the protective film 11 in a desired shape without damaging the film.

[0040] Since the marking is achieved by converting the interior of the protective film 11, the laser light does not damage the workpiece 10. Because the protective film 11 is not cut, no foreign matter is produced from it. Since a black layer with a high absorption rate for laser light is used as the laser light absorption layer 11a, the conversion of the laser light absorption layer 11a is promoted by the energy of the laser light, reliably preventing the processing from reaching the top surface of the workpiece 10. Since a white layer with a low absorption rate for laser light is used as the laser light transmission layer 11b, the visibility of the marking is improved.

[0041] The following is a description of a workpiece on which laser processing was actually carried out, with reference to Fig. 4 described. Fig. 4A is an image of the surface of the protective film 11 of the workpiece 10 on which the laser processing was actually carried out. Fig. 4B is an image of a condition in which part of the protective film 11 is removed from the one in Fig. 4A shows workpiece 10 being peeled back to expose the top of workpiece 10.

[0042] As in Fig. As shown in Figure 4A, the surface 11c of the protective film has a marking in which letters and numbers are arranged as "ABC45". This indicates that the irradiation of the protective film 11 with the laser light caused a transformation within the protective film 11, resulting in the marking. The top surface of the workpiece 10 is not exposed in the marked area. Although not shown, a cross-sectional view of the workpiece 10 and the protective film 11 after laser processing confirms that gaps have formed between the top surface 10a of the workpiece 10 and the protective film 11.

[0043] Furthermore, it is from Fig. Figure 4B shows that the top surface 10a of the workpiece 10 is not damaged in any way. This means that the laser processing by the laser processing device 1 is only carried out on the protective film 11 and not on the workpiece 10. Thus, the laser processing device 1 can make the mark on the protective film 11 without damaging the workpiece 10.

[0044] Returning to Fig. Section 3 describes the mechanism that enables the laser processing device 1 to perform the marking. When the laser light is set with focus F to the position that defocuses the processing area on the side of the laser head 4, as shown in Fig. As shown in Figure 3A, the laser light penetrates the laser light transmission layer 11b and is absorbed by the laser light absorption layer 11a. When the laser light is absorbed by the laser light absorption layer 11a, the material of which the laser light absorption layer 11a is made, such as rubber, plastic, or the like, generates heat and then melts.

[0045] Even after the material of the laser light absorption layer 11a melts, the laser light continues to be absorbed and the energy stored. This causes the molten material to evaporate. The gas produced by the evaporation of the material forms a space between the protective film 11 and the workpiece 10. As the gas increases due to the evaporation of the material, the protective film 11 is altered in such a way that it is pushed upwards from the inside. This separates the laser light absorption layer 11a from the workpiece 10, creating the space H. These processes change the state of Fig. 3B reached.

[0046] It should be noted that in the present embodiment, the power of the laser light is controlled, with the focus being moved to a position that defocuses the processing area in order to achieve marking by converting the interior of the protective film 11 without destroying it. Therefore, it is important to control the energy of the laser light applied to the laser light absorption layer. However, the control of the laser light to be performed by the control unit 6 is not limited to controlling the position that defocuses the processing area and the power of the laser light, but also includes controlling other various conditions affecting the laser light. This also applies to the other embodiments.

[0047] Setting the various laser light parameters during marking includes, for example, adjusting the laser light frequency to 50 Hz to 100 Hz, the duty cycle to 5% to 10%, and the processing speed to 500 mm / min to 1000 mm / min. The laser light frequency can be set to 70 Hz to 90 Hz. The laser light frequency, duty cycle, and processing speed parameters are not limited to those mentioned above but can be modified as needed, depending on the materials used for the protective film 11 and the film's thickness.

[0048] Next, a laser processing method used by the laser processing device 1 will be described with reference to the one described in Fig. The flowchart shown in section 5 is described.

[0049] Before the laser processing begins by the laser processing device 1, the workpiece 10 with the protective film 11 attached to it, which protective film 11 includes the laser light absorption layer 11a, is prepared and placed on the processing table 5 of the laser processing device 1 (S1).

[0050] Next, the control unit 6 of the laser processing device 1 controls the laser head 4 to adjust the focus position of the laser light to a position away from the surface of the protective film 11 on the side of the laser head 4, i.e., the position that defocuses the processing area (S2: Focus position adjustment step). Meanwhile, the control unit 6 also controls the drive unit 7 to move the laser head 4 to a position corresponding to the processing area of ​​the workpiece 10.

[0051] Next, the control unit 6 of the laser processing device 1 controls the laser light power to perform the processing such that the marking is achieved by causing the laser light absorption layer 11a to absorb the laser light, thus altering the interior of the protective film 11 (S3: Laser light power control step). It should be noted that the control unit 6 also controls the various other conditions and parameters of the laser light by adjusting the laser light power to perform the processing. These various conditions and parameters can be preset.

[0052] By performing laser processing using the laser processing device 1 according to the steps described above, the marking is applied to the protective film 11 without damaging the workpiece 10. Regarding the sequence of the preceding steps, steps S2 and S1 can be interchanged if the position of the surface of the protective film 11 is known from the information about the thickness of the workpiece 10 before laser processing. Design 2

[0053] The following describes a laser processing device 1 according to embodiment 2.

[0054] The laser processing device 1 according to embodiment 2 is based on Fig. 6 to Fig. 9 described. Fig. Figure 6 shows a configuration diagram of the laser processing device 1 according to embodiment 2. As in Fig. As shown in Figure 6, the laser processing device 1 comprises, in addition to the configuration of the laser processing device 1 according to embodiment 1, a gas supply unit 9. The following description mainly describes the configuration that differs from embodiment 1.

[0055] The gas supply unit 9, which is connected to the control unit 6, supplies and stops an auxiliary gas by being controlled by the control unit 6. The gas supply unit 9 delivers the auxiliary gas to the laser head 4 via a gas supply line designed for this purpose. Fig. Figure 7 shows an enlarged view near the processing point of the in Fig. 6 shown workpiece. Fig. Figure 7 is an example of the laser processing device 1, which uses the auxiliary gas. As in Fig. As shown in Figure 7, the auxiliary gas supplied to the laser head 4 flows through a distribution unit, which is a supply opening 4a provided in the center of the laser head 4, and is expelled from the tip of the laser head 4. With this configuration, the laser head 4 can emit the laser light and simultaneously expel the auxiliary gas.

[0056] During laser processing, molten material is produced from the workpiece 10. In general laser processing, the laser head 4 emits laser light while processing the workpiece 10, simultaneously expelling an auxiliary gas that blows off the molten material produced by the workpiece 10. Nitrogen or oxygen gas is used as the auxiliary gas.

[0057] By controlling the gas supply unit 9, the control unit 6 can adjust the pressure and flow rate of the auxiliary gas. The control unit 6 can change the type of auxiliary gas by switching a gas supply valve of the gas supply unit 9. For example, the pressure of the auxiliary gas supplied by the gas supply unit 9 is set to between 0.1 MPa and 0.5 MPa.

[0058] Fig. Figure 8 is a diagram showing the area around the tip of the laser head 4 of the laser processing device 1 according to embodiment 2. As shown in Fig. As shown in Figure 8, the laser head 4 includes supply openings 4a within its main body as a distribution unit and the laser head 4 is configured such that the auxiliary gas flows through the interior of the main body of the laser head 4. Fig. Figure 9 shows a cross-section along line XX of Fig. 8. As in Fig. As shown in Figure 9A, the laser head 4 has a circular cross-section. The laser head 4 has four auxiliary gas supply openings 4a inside its main body. The four supply openings 4a are evenly spaced from each other and along the circumference of the laser head 4.

[0059] The control unit 6 controls the gas supply unit 9 to supply the auxiliary gas via the distribution unit. The control unit 6 can control the gas supply unit 9 to select at least one of the four supply openings 4a for the supply of the auxiliary gas. With this configuration, the laser processing device 1 can expel the auxiliary gas to a predetermined position around the processing point P during laser processing.

[0060] The laser processing device 1 supplies the auxiliary gas for the marking process described in embodiment 1 by controlling the gas supply unit 9 with the aid of the control unit 6. The control unit 6 can supply the auxiliary gas from the gas supply unit 9 in a manner suitable for carrying out the marking. In this configuration, the laser processing device 1 can cool the marking section heated by the laser light during the marking process by expelling the auxiliary gas around it. Cooling the marking section suppresses further conversion due to the heat remaining in the protective film 11 and thus prevents the protective film 11 from detaching.

[0061] Furthermore, the control unit 6 can select the supply openings 4a for the auxiliary gas by controlling the gas supply unit 9. This allows the auxiliary gas to be expelled depending on the shape of the marking. This configuration prevents the marking from becoming indistinct due to excessive cooling by the auxiliary gas.

[0062] Notwithstanding the foregoing example, the number of supply openings 4a to be arranged along the circumferences can be five or more, or three or fewer. The cross-sectional shape of the supply openings 4a is not limited to a circular shape, but can also be triangular, quadrilateral, or polygonal. Alternatively, as in Fig. 9B is shown as a variant, with a feed opening 4a with an annular cross-section provided along the circumferences.

[0063] Furthermore, in a variant of embodiment 2, the auxiliary gas can be supplied in accordance with the direction of the marking process. To give a specific description of the direction of the marking process, if marking is carried out by controlling the movement of the laser head 4 along the shape of the marking, the direction in which the laser head 4 moves is the direction of the marking process. The distribution unit can, for example, be provided such that the auxiliary gas can be expelled from behind the marking process carried out by the laser processing device 1.

[0064] The control unit 6 controls the gas supply unit 9 so that the auxiliary gas is expelled as the marking process progresses. In this configuration, the auxiliary gas is only sprayed onto the advancing marking from behind. Therefore, only the area where the marking is complete is cooled, and the area where the marking is incomplete is not cooled. As a result, the marking becomes clearer.

[0065] As a further option, the auxiliary gas can be supplied depending on the shape of the marking. The term "shape of the marking" refers here to a form, for example, a line, that is drawn during a specific processing time during the marking process. If the laser processing device 1, for example, draws a straight line during the marking process, the auxiliary gas can be blown through the distribution unit by controlling the gas supply unit 9 in such a way that the drawn straight line is enclosed by bursts of the auxiliary gas.

[0066] With this configuration, the laser processing device 1 can reliably prevent the detachment of the protective film 11, which could be caused by the marking, because the auxiliary gas, which is expelled in such a way as to surround the shape of the marking, compacts the protective film 11 along the shape of the marking. embodiment 3

[0067] The following describes a laser processing device 1 according to embodiment 3.

[0068] The laser processing device 1 according to embodiment 3 is described with reference to Fig. 10 described. Fig. Figure 10 shows a configuration diagram of the laser processing device 1 according to embodiment 3. As shown in Fig. As shown in Figure 10, the laser processing device 1 comprises, in addition to the configuration of the laser processing device 1 of embodiment 2, a foil information receiving unit 12. The following description mainly describes a configuration different from that in embodiments 1 and 2.

[0069] The foil information receiver 12, which is connected to the control unit 6, sends information about the protective foil 11 to the control unit 6. It should be noted that the foil information receiver 12 may be contained within the control unit 6.

[0070] The foil information receiver 12 receives foil information via the protective film, with the foil information being input externally into the laser processing device 1. For example, it receives foil information entered by an operator via an input interface or the like. It should be noted that the foil information can be read from a barcode or two-dimensional barcode representing information associated with the foil information using a reader connected to the laser processing device 1. The reader connected to the laser processing device 1 can automatically read the foil information from the workpiece 10 placed on the processing table 5.

[0071] The term "film information" here refers to information about the protective film 11, which is applied to the workpiece 10 that is the target of laser processing. The film information includes, for example, information about the material, layer composition, thickness, product number, and laser light absorption rate of the protective film 11.

[0072] The slide information receiver 12 transmits the received slide information to the control unit 6. The control unit 6 reads from the memory 8 the marking conditions that correspond to the slide information received from the slide information receiver.

[0073] The marking conditions include, for example, the position of the laser head 4, which corresponds to the position that defocuses the processing area, and the power conditions of the laser light, with the position and conditions for each foil being specified as foil information. The marking conditions may further include conditions for the laser light such as frequency and duty cycle, processing speed, type of auxiliary gas, auxiliary gas pressure, auxiliary gas flow rate, and the like. It is assumed here that the marking conditions corresponding to the foil information are stored in memory 8 before the marking is performed.

[0074] The control unit 6 reads the marking conditions corresponding to the film information from memory 8 and then adjusts the position of the laser head 4 and the laser light power based on these conditions. If the marking conditions include other different conditions, the control unit 6 makes adjustments for these additional conditions. The control unit 6 then performs the marking process based on these adjusted conditions. As described above, the laser processing device 1 can adjust the marking conditions based on the input film information, enabling efficient and easy-to-use marking.

[0075] In a variant of embodiment 3, a test processing operation can be carried out according to the marking conditions that correspond to the foil information set by the laser processing device 1. The test processing operation is a process to check whether the marking on the workpiece 10 can be carried out correctly according to the set marking conditions before the marking is actually carried out.

[0076] This variant is based on Fig. 11 described. Fig.Figure 11 is a top view showing the workpiece 10 placed on the machining table 5. The machining table 5 comprises a workpiece machining area 5a for machining the workpiece 10 and a test machining area 5b, located outside the workpiece machining area, for test machining the test workpiece 13. The workpiece 10 is placed on the workpiece machining area 5a, and the test workpiece 13 is placed on the test machining area 5b. This figure schematically shows how the laser light, indicated by an arrow, is directed from the laser head 4 onto the test workpiece 13. It should be noted that the sizes of the workpiece machining area 5a and the test machining area 5b are not limited to these dimensions.

[0077] The laser processing device 1 adjusts the position of the laser head 4 and the laser light power according to the marking conditions specified in the foil information. The laser processing device 1 then performs the marking on the test workpiece 13, which is placed on the test processing area, according to these conditions. This configuration allows the laser processing device 1 to verify the accuracy of the marking on the workpiece 13 before the actual marking process begins, thus preventing marking errors on the workpiece 13.

[0078] For test workpiece 13, it is advantageous for machinability to use a workpiece that has the same configuration as workpiece 10, on which the marking is actually applied, but is smaller. If the marking is performed as a test operation, a test workpiece 13 can be placed on the test machining area 5b, or a suitable test workpiece 13 can be selected and automatically placed on the test machining area 5b based on the received slide information.

[0079] The foregoing is a description of the embodiments of this disclosure. However, the laser processing device and the laser processing method of the present invention are not limited to the forms described in embodiments 1 to 3 and their variations, which all represent only a part of the present invention. The laser processing device and the laser processing method of the present disclosure can be combined with other known techniques. Furthermore, it is possible to combine, omit, and partially modify the configurations in a suitable manner without departing from the core of the disclosure. [List of reference symbols] 1 laser processing device 2 Laser oscillator 3 transmission unit 4 Laser head 4a Inlet 5 processing table 5a Workpiece machining area 5b Test editing area 6 Control unit 7 Drive unit 8 memory 9 Gas supply unit 10 workpieces 10a Surface of the workpiece 11 Protective film 11a Laser light absorption layer 11b Laser light transmission layer 11c Surface of the protective film 12 slide information receiving unit 13 Test workpiece

Claims

[1] Laser processing device (1), comprising: a laser oscillator (2) for generating laser light; a machining table (5) for placing a workpiece (10) thereon, the workpiece (10) having a protective film (11) on one of its surfaces, the protective film (11) comprising a laser light absorption layer (11a); a laser head (4) for processing the workpiece (10) with the laser light; and a control unit (6) for adjusting a position of the laser head (4) so ​​that a focus position of the laser light is brought to a position away from the surface of the workpiece (10a) toward the laser head (4), and for controlling the power of the laser light so that a mark is provided by causing the laser light absorption layer (11a) to absorb the laser light and thus changing the interior of the protective film (11) to form a gap (H) between the laser light absorption layer (11a) and the top surface of the workpiece (10) by separating the laser light absorption layer (11a) and the top surface of the workpiece (10) from each other. [2] The laser processing apparatus (1) according to claim 1, wherein the protective film (11) further comprises a laser light transmission layer (11b) applied to the laser light absorption layer (11a), and the control unit (6) changes the laser light absorption layer (11a) by causing the laser light absorption layer (11a) to absorb the laser light and changes the laser light transmission layer (11b) according to the change in the laser light absorption layer (11a). [3] The laser processing apparatus (1) according to claim 2, wherein the laser light absorption layer (11a) of the protective film (11) is a layer colored with a black pigment that absorbs the laser light, and the laser light transmission layer (11b) of the protective film (11) is a layer colored with a white pigment that transmits the laser light. [4] Laser processing device (1) according to one of claims 1 to 3, further comprising: a gas supply unit (9) controlled by the control unit (6) for supplying the laser head (4) with an auxiliary gas which is blown onto the workpiece (10); and a distribution unit provided in the laser head (4) for discharging the auxiliary gas supplied from the gas supply unit, wherein the control unit (6) controls the supply of the auxiliary gas depending on the processing of the mark. [5] Laser processing device (1) according to one of claims 1 to 4, further comprising: a film information receiving unit (12) for receiving film information about the protective film (11), the film information being input from the outside; and a memory (8) for storing marking conditions based on the film information, wherein the film information receiving unit (12) transmits the received film information to the control unit (6), and the control unit (6) reads out the marking conditions corresponding to the film information from the memory (8) on the basis of the film information received from the film information receiving unit (12) and adjusts the position of the laser head (4) and the power of the laser light on the basis of the marking conditions. [6] Laser processing device (1) according to one of claims 1 to 5, wherein the processing table (5) comprises a workpiece processing area (5a) in which the workpiece (10) is processed, and a test processing area (5b) outside the workpiece processing area (5a), and the control unit (6) makes settings for the position of the laser head (4) and the power of the laser light in accordance with the settings and carries out a test processing in the test processing area (5b). [7] Laser processing method, comprising: a focus position adjustment step of adjusting a focus position of a laser light to a position away from a surface of a workpiece (10) toward a laser head (4) by controlling the laser head (4) to machine the workpiece (10) with the laser light generated by a laser oscillator (2), wherein the workpiece (10) has a protective film (11) on one of its surfaces, wherein the protective film (11) comprises a laser light absorption layer (11a); and a laser light power control step of controlling the power of the laser light to create a mark by causing the laser light absorption layer (11a) to absorb the laser light and thus changing the interior of the protective film (11) to form a gap (H) between the laser light absorption layer (11a) and the top surface of the workpiece (10) by separating the laser light absorption layer (11a) and the top surface of the workpiece (10) from each other.

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