Laser power control device, laser processing device, and laser power control method

Abstract

To provide a laser power control device, a laser working device and a laser power control method capable of shortening a time required for measuring power of a laser beam.SOLUTION: A laser working device (1) and a laser power control device (10) include a storage part (12) which stores relation data with which a measurement value of a heat radiation sensor (27) for measuring heat radiation of an irradiation object (42) irradiated with laser beams from the laser processing device and a power value of laser beams on a working surface of the laser working device are allowed to correspond.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laser power control device, a laser processing device, and a laser power control method. [Background technology]

[0002] There is a laser annealing apparatus that irradiates a semiconductor wafer as a workpiece with a laser beam to perform an annealing process. The laser annealing apparatus is generally equipped with a power meter that measures the power of the laser beam at the workpiece surface. The power meter measures the power of the laser beam before the apparatus starts operating or each time one or more workpieces are processed, and the power of the laser beam irradiated on the workpiece surface during the subsequent annealing process is adjusted.

[0003] Patent Document 1 discloses a technique for monitoring leakage light of a laser beam during annealing processing in a laser annealing apparatus, and quickly detecting abnormalities such as a decrease in the energy density of the laser beam. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-059458 Summary of the Invention [Problem to be solved by the invention]

[0005] A power meter that measures the power of a laser beam has a light-receiving surface that converts the irradiated laser beam into heat, and obtains the laser beam power value by converting the temperature of the light-receiving surface into a voltage. In such a power meter, the measured value stabilizes when the heat input to the light-receiving surface due to the laser beam irradiation and the heat dissipation from the light-receiving surface reach an equilibrium state. This poses a problem: it takes a long time to obtain a stable measured value. For example, a measurement time of about one minute is required to meet the measurement accuracy required for a laser annealing device. Such a long measurement time significantly reduces the throughput of the laser annealing device.

[0006] An object of the present invention is to provide a laser power control device, a laser processing device, and a laser power control method that can shorten the time required to adjust the power of a laser beam. [Means for solving the problem]

[0007] The laser control device according to the present invention comprises: a storage unit that stores relationship data that associates a measurement value of a thermal radiation sensor that detects the intensity of thermal radiation of an irradiation object irradiated with laser light from a laser processing device with a power value of the laser light on a processing surface of the irradiation object; The relationship data 、 The configuration is such that it is created when the irradiation object is replaced.

[0008] The laser processing device according to the present invention comprises: an optical system that irradiates a workpiece with laser light; a thermal radiation sensor that measures thermal radiation from an irradiation object irradiated with laser light by the optical system; a storage unit that stores relationship data that associates the measurement value of the thermal radiation sensor with the power value of the laser light on the processing surface; Equipped with The relationship data 、 The configuration is such that it is created when the irradiation object is replaced.

[0009] The laser power control method according to the present invention comprises: Measure the thermal radiation of an irradiation object irradiated with laser light from a laser processing device; estimating a power value of the laser light on the processing surface of the irradiation object from the measured thermal radiation value; A laser power control method for adjusting the power of the laser light on the processing surface based on an estimated power value, The laser beam power value is associated with the thermal radiation value, and the relationship data is 、 It is now created when the irradiation target is replaced. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a laser power control device, a laser processing device, and a laser power control method that can reduce the time required to adjust the power of a laser beam. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a configuration diagram showing a laser processing apparatus according to an embodiment of the present invention; [Figure 2] 10 is a flowchart showing a relational data creation process executed by a creation processing unit. [Figure 3] 10 is a flowchart showing a laser beam power adjustment process executed by the control device. [Figure 4] 10 is a flowchart showing a process of determining whether or not power adjustment is necessary, which is executed by a necessity determining unit; [Figure 5] 2 is a diagram showing a display example of the display unit in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

[0013] 1 is a configuration diagram showing a laser processing apparatus according to an embodiment of the present invention, in which the optical path of the laser beam is indicated by a dashed line and a two-dot dashed line, heat radiation is indicated by a broken line, and signal lines are indicated by a solid line.

[0014] A laser processing apparatus 1 according to an embodiment of the present invention is a laser annealing apparatus that irradiates a workpiece 41, which is a wafer of semiconductor device material, with laser light to perform an annealing process. The laser processing apparatus 1 includes a control device 10, a laser light source 21, an attenuation optical system 22, a dichroic mirror 24, lenses 25 and 26, a thermal radiation sensor 27, a power meter 29, a stage 31, a total reflection mirror 33, and an irradiation object 42. Of these, the configuration of the control device 10 that controls the power of the laser light corresponds to an example of a laser power control device according to the present invention.

[0015] The laser light source 21 is, for example, a solid-state laser such as a YAG laser, a gas laser such as a CO2 laser, or a semiconductor laser such as an LD (Laser Diode), and outputs laser light that is irradiated onto the workpiece 41 and heats the workpiece 41 to a high temperature. The laser light source 21 is controlled by the control device 10 to output and stop the laser light. The laser light source 21 may also be called a laser oscillator.

[0016] The attenuation optical system 22 attenuates and passes the laser light emitted from the laser light source 21. The attenuation optical system 22 is capable of changing the attenuation ratio of the laser light, and the attenuation ratio is controlled by the control device 10.

[0017] The dichroic mirror 24 reflects light of the output wavelength of the laser light source 21 and transmits light in the infrared region, including thermal radiation.

[0018] The lens 25 converges the laser light onto a predetermined irradiation position P0, and also collects thermal radiation emitted from the periphery of the irradiation position P0 of the laser light.

[0019] The lens 26 converges the thermal radiation that has been condensed by the lens 25 and passed through the dichroic mirror 24 onto the thermal radiation sensor 27 .

[0020] The thermal radiation sensor 27 is, for example, an infrared sensor, and measures the intensity of thermal radiation input to the light receiving portion.

[0021] Stage 31 is a platform that holds workpiece 41 and is configured to be movable in two directions intersecting the optical axis of the laser beam. Stage 31 has area W1 for holding workpiece 41, area W2 for holding irradiation object 42 used to estimate laser power, and area W3 for mounting total reflection mirror 33. By driving stage 31, areas W1, W2, and W3 can each be aligned with laser beam irradiation position P0. When area W1 is located at irradiation position P0, the top surface of workpiece 41 placed in area W1 becomes the processing surface. Areas W1 and W2 are located at the same height. In FIG. 1, the two-dot chain line indicates the optical path of the laser beam when total reflection mirror 33 is moved to laser beam irradiation position P0.

[0022] When the stage 31 is driven to move to an extension of the irradiation position P 0 of the laser light, the total reflection mirror 33 reflects the laser light irradiated via the lens 25 toward the power meter 29 .

[0023] The power meter 29 receives the laser beam and measures its power. Power refers to the energy of the laser beam per unit time, and units of power are, for example, J (joule) / second or W (watt). Alternatively, energy may be converted to heat, and power may be expressed in units of heat. The power meter 29 has a light-receiving surface that converts the incident laser beam into heat, and a sensor unit that converts the temperature of the light-receiving surface into voltage. The light-receiving surface receives heat due to the incidence of the laser beam, increasing its temperature. However, heat dissipation occurs due to the temperature increase. When the heat input and heat dissipation reach an equilibrium state, the output of the sensor unit stabilizes. Due to this configuration, the power meter 29 requires approximately 60 seconds to measure the power of the laser beam with the accuracy required for annealing.

[0024] The irradiation object 42 is a material that generates thermal radiation when irradiated with laser light when estimating the power of the laser light from the measurement results of the thermal radiation sensor 27. The irradiation object 42 may be made of the same material as the workpiece 41, or may be made of a material that dissipates heat easily, such as a metal material. The irradiation object 42 may also be called a reference workpiece.

[0025] The control device 10 is a computer equipped with a CPU (Central Processing Unit), a storage device storing control programs and control data executed by the CPU, and an interface for inputting and outputting signals from each unit. The control device 10 includes a relationship data creation processing unit 11 that creates relationship data correlating thermal radiation with laser beam power, a relationship data storage unit 12 that stores the relationship data, and an estimation unit 13 that estimates the laser beam power. The control device 10 further includes an adjustment unit 14 that adjusts the laser beam power, a necessity determination unit 15 that determines whether power adjustment is necessary, and a display unit 16 that can output images or text. The relationship data creation processing unit 11, the estimation unit 13, the adjustment unit 14, and the necessity determination unit 15 are functional modules that function when the CPU executes the control program. The relationship data storage unit 12 is an area within the storage area that is set up to store relationship data in advance, and corresponds to an example of a storage unit according to the present invention.

[0026] The relational data used to estimate the power of the laser beam is data such as a data table or a relational expression that shows the correspondence between the measurement values ​​of the thermal radiation sensor 27 and the measurement values ​​of the power meter 29. The measurement values ​​of the thermal radiation sensor 27 shown in the relational data are the measurement values ​​of the thermal radiation sensor 27 obtained when the irradiation target 42 is placed at the irradiation position P0 and is irradiated with laser beam. The measurement values ​​of the power meter 29 associated with these are the measurement values ​​of the power meter 29 obtained when the total reflection mirror 33 is placed on an extension of the irradiation position P0 in a state where the power of the laser beam is not changed from when the thermal radiation was measured.

[0027] When the irradiation object 42 is irradiated with high-frequency pulsed laser light, the thermal radiation sensor 27 produces measurement results showing repeated peaks at a frequency corresponding to the pulses of the laser light, demonstrating extremely high responsiveness from the time the laser light is irradiated to the time the corresponding thermal radiation is generated. Furthermore, unless the laser light is continuously irradiated onto the same point for a long period of time, the power of the laser light and the peak value of the thermal radiation of the irradiation object 42 have a nearly constant relationship. For example, the peak value of the thermal radiation immediately after irradiating a room-temperature portion of the irradiation object 42 with a predetermined number of pulses (e.g., 10 pulses) of laser light accurately reflects the power of the laser light. The value thus obtained is used as the measurement value of the thermal radiation sensor 27 for the relationship data.

[0028] As mentioned above, it takes a long time, such as 60 seconds, for the power meter 29 to stabilize its measurement value, and the power measurement value shown in the relationship data corresponds to the stable measurement value obtained from the power meter 29 over such a long period of time.

[0029] The relational data creation processing unit 11 executes a relational data creation process, which will be described later, to create the above-mentioned relational data.

[0030] The relational data storage unit 12 stores the relational data created by the creation processing unit 11. Alternatively, the relational data storage unit 12 may store in advance relational data created by another device or the like.

[0031] The estimation unit 13 estimates the power of the laser light at the irradiation position P0 from the intensity of thermal radiation from the irradiation object 42 irradiated with the laser light and the relational data stored in the relational data storage unit 12.

[0032] In the adjustment process that is carried out before the laser processing device starts operating or when a fluctuation of a certain level or more occurs in the power of the laser light, the adjustment unit 14 controls the attenuation optical system 22 based on the power of the laser light estimated by the estimation unit 13 to adjust the power of the laser light at the irradiation position P0.

[0033] The necessity determination unit 15 executes a necessity determination process (described later) to determine when readjustment of the laser beam power is required during operation of the laser processing apparatus 1. The power of the laser beam at the irradiation position P0 fluctuates slightly during operation of the laser processing apparatus 1 due to factors such as temperature drift. Conventional laser processing apparatuses have performed readjustment of the laser beam power every time a predetermined number of annealing processes have been performed to address such power fluctuations. However, this method determines the interval between readjustments so that the power is readjusted when the power fluctuations are sufficiently small to avoid a decrease in yield. This can result in frequent readjustments and a decrease in the efficiency of the annealing process. The necessity determination unit 15 determines whether power readjustment is required while suppressing fluctuations in the laser beam power within a range that does not result in a decrease in yield, thereby preventing frequent power readjustments.

[0034] The display unit 16 displays the power value of the laser light estimated by the estimation unit 13, the power value of the laser light adjusted during the adjustment process, and the like (see FIG. 5).

[0035] <Relational data creation process> Next, a process for creating relational data used for estimating the power of a laser beam will be described with reference to a flowchart of FIG.

[0036] The process of creating the relational data is executed by the creating unit processing section 11 automatically or in response to an instruction from an operator when the laser processing device 1 is initially set up or when the irradiation object 42 is replaced due to deterioration or the like.

[0037] When the process of creating the relationship data is started, the creation processing unit 11 drives the stage 31 to move the irradiation target 42 to the laser beam irradiation position P0 (step S1). Next, the creation processing unit 11 irradiates the irradiation position P0 with a predetermined number of shots of laser beam (step S2) and inputs the measurement value of the thermal radiation sensor 27 (step S3). Here, the creation processing unit 11 may use the average value of the peak values ​​of the thermal radiation measurement values ​​corresponding to the irradiation of the predetermined number of shots of laser beam as the measurement value of the thermal radiation. The irradiation of the laser beam may be performed by switching the operation of the laser light source 21 on and off, or by switching between transmitting and blocking the laser beam emitted from the laser light source 21 using an optical element.

[0038] Next, the production processing unit 11 drives the stage 31 to move the total reflection mirror 33 to an extension of the laser light irradiation position P0 (step S4). Then, the production processing unit 11 irradiates the laser light to the irradiation position P0 (step S5), inputs the measurement value of the power meter 29 (step S6), and stops the irradiation of the laser light when a stable measurement value is obtained (step S7). Then, the production processing unit 11 stores the measurement value of step S3 and the measurement value of step S6 in association with each other (step S8).

[0039] Next, the creation processing unit 11 determines whether the power setting of the laser beam has been changed to a predetermined number of steps (step S9), and if not, controls the attenuation optical system 22 to change the power setting by one step (step S10). Then, the process returns to step S1, and the processes of steps S1 to S8 are repeated. By repeating the loop process from step S1 to step S10, data is obtained for each of the multiple power settings, which is a combination of the measured value of thermal radiation and the corresponding measured value of the laser beam power.

[0040] Then, if it is determined in step S9 that the process is complete, the relationship data that associates the measured values ​​of thermal radiation with the power values ​​of the laser beam is updated using the data stored in step S8, and stored in the relationship data storage unit 12 (step S11).Then, the relationship data creation process ends.

[0041] By the above-described relationship data creation process, it is possible to automatically create relationship data that associates the measured values ​​of thermal radiation with the measured values ​​of the power meter 29. Note that the relationship data may also be created by a human operation that performs the same process as in FIG.

[0042] <Adjustment processing> Next, an adjustment process for adjusting the power of a laser beam will be described. Fig. 3 is a flowchart showing the adjustment process for adjusting the power of a laser beam executed by the control device. This adjustment process corresponds to an example of a laser power control method according to the present invention.

[0043] The adjustment process of the laser light power is executed before the laser processing apparatus 1 starts operating, when the laser light power fluctuates by a predetermined amount during operation, or when an operator gives an instruction, in a subsequent adjustment step.

[0044] When the adjustment process is started, the control device 10 drives the stage 31 to move the irradiation target 42 to the irradiation position P0 (step S21). Next, the control device 10 irradiates the irradiation position P0 with a predetermined number of shots of laser light (step S22) and inputs the measurement value of the thermal radiation sensor 27 (step S23). Here, the control device 10 may use the average value of the peak values ​​of the thermal radiation measurement values ​​corresponding to the irradiation of the predetermined number of shots of laser light as the measurement value of thermal radiation.

[0045] Next, the estimation unit 13 of the control device 10 estimates the power of the laser beam at the irradiation position P0 based on the relationship data stored in the relationship data storage unit 12 and the measured value of the thermal radiation acquired in step S23 (step S24). Here, the relationship data associates the measured value of the thermal radiation with the corresponding measured value of the power of the laser beam, so the estimation unit 13 estimates the power of the laser beam in accordance with this correspondence.

[0046] Once the power of the laser beam is estimated, the control device 10 displays the estimated power value on the display unit 16 (step S25, see FIG. 5). The estimated power value displayed during the repeatedly executed steps S22 to S26 corresponds to an adjusted value representing the power of the laser beam after adjustment. Next, the adjustment unit 14 of the control device 10 determines whether the power is within a specified range (step S26). If it is outside the range, the adjustment unit 14 controls the attenuation optical system 22 to adjust the power so that it falls within the range (step S27). The control device 10 then returns the process to step S22 and executes the processes of steps S22 to S26 again. Here, the specified power range corresponds to the power of the laser beam to be irradiated onto the workpiece 41 in the laser annealing process.

[0047] On the other hand, if it is determined in step S26 that the power is within the specified range, the control device 10 ends the adjustment process. By performing such adjustment process, the power of the laser beam can be adjusted to within the specified range quickly and with high accuracy.

[0048] In this embodiment, an example has been shown in which a functional module within the device executes processes from estimating the power of the laser beam (step S24) to controlling the attenuation optical system 22 to adjust the power of the laser beam (step S27). However, some or all of these processes may be performed manually by a person. For example, the measured value of thermal radiation may be output to the display unit 16, and a person may estimate the power by referring to that value and related data, and then the person may operate a knob to adjust the attenuation amount of the attenuation optical system 22 so that the power falls within a specified range.

[0049] Furthermore, in this embodiment, the process of adjusting the power of the laser beam is shown based on the measured value of thermal radiation when the laser beam is irradiated onto the irradiation object 42. However, when the irradiation object 42 and the workpiece 41 are made of the same material, the workpiece 41 may be used as the irradiation object 42, and a part of the workpiece 41 may be irradiated with the laser beam, and the measured value of thermal radiation at this time may be used to estimate and adjust the power of the laser beam.

[0050] <Processing> The processing step is a step in which processing (annealing) is performed on the workpiece 41, and is carried out with the power of the laser light irradiated at the irradiation position P0 adjusted. In the processing step, the control device 10 drives the stage or the optical system to change the relative position between the irradiation position P0 and the workpiece 41 so that the irradiation position P0 traces each location in the area to be processed on the workpiece 41. Furthermore, the control device 10 irradiates the irradiation position P0 with laser light while moving the irradiation position P0, thereby applying heat treatment to the workpiece 41. When heat treatment has been completed on all of the areas to be processed on one workpiece 41, the processing for that one workpiece 41 is complete.

[0051] <Process for determining whether power adjustment is necessary> Next, a process for determining whether or not the power of the laser beam needs to be adjusted will be described with reference to a flowchart of FIG.

[0052] The necessity determination process is executed by the necessity determination unit 15 while the laser processing apparatus 1 is operating and multiple workpieces 41 are being annealed sequentially. When the necessity determination process is started, the necessity determination unit 15 determines whether annealing has started for one workpiece 41 (step S31), and proceeds to the next step if started. The necessity determination unit 15 then inputs and records the measurement value of the thermal radiation sensor 27 while the workpiece 41 is being irradiated with laser light (step S32), and determines whether annealing for one workpiece 41 has been completed (step S33). The input and recording of the measurement value are then repeated until the annealing process is completed. This accumulates the measured values ​​of thermal radiation when each location in the region to be processed of the workpiece 41 is irradiated with laser light.

[0053] When the annealing process for one workpiece 41 is completed, the necessity determination unit 15 calculates a statistical value indicating the average thermal radiation from the multiple measured values ​​of thermal radiation recorded during the annealing process (step S34). The statistical value may simply be the average of the multiple measured values, or may be the average value of a range excluding the measured values ​​of thermal radiation at the periphery of the annealing region. Alternatively, the necessity determination unit 15 may calculate the variance of thermal radiation as the statistical value.

[0054] Next, the necessity determination unit 15 estimates the amount of fluctuation in the power of the laser beam from the statistical value calculated in step S34 and the relationship data stored in the relationship data storage unit 12 (step S35). Because the measurement conditions for obtaining the thermal radiation measurements in the relationship data are different from those during annealing of the workpiece 41, the laser beam power cannot be accurately obtained from the thermal radiation value during annealing using the relationship data. However, the relationship data can be used to determine the ratio of the amount of change in thermal radiation to the amount of change in laser beam power, and there is a correlation between this ratio and the ratio of the amount of change in thermal radiation to the amount of change in power during annealing. This correlation is provided in advance to the necessity determination unit 15, and the necessity determination unit 15 can calculate the ratio of the amount of change in laser beam power to the amount of change in thermal radiation value per annealing process from this correlation and the ratio obtained from the relationship data. In step S35, the necessity determination unit 15 calculates the amount of change in thermal radiation for each annealing process from the statistical values ​​calculated in the previous step S34, and estimates the amount of fluctuation in the power of the laser light by multiplying the amount of change by the ratio calculated from the correlation and the relational data.

[0055] After estimating the amount of fluctuation in the power of the laser beam, the necessity determination unit 15 determines whether the amount of fluctuation exceeds a threshold (step S36). If not, the process returns to step S31 to continue the necessity determination process. On the other hand, if the threshold is exceeded, the process proceeds to adjustment processing to readjust the power of the laser beam before the next annealing process. The threshold is set to a value that does not reduce the yield of the annealing process and that can keep the frequency of power readjustment low.

[0056] By such a necessity determination process, readjustment of the laser light power is carried out only when adjustment is necessary, thereby realizing more efficient annealing of the work-piece 41.

[0057] In the above-described necessity determination process, an example has been shown in which the relationship data and the measured value of thermal radiation are used to estimate the amount of fluctuation in the power of the laser beam and determine whether or not power readjustment is necessary. However, there is a correlation between the value of thermal radiation of the work-piece 41 during processing and the power value of the laser beam. Therefore, the necessity determination unit 15 may determine whether or not power readjustment is necessary by comparing the statistical value of the measured value of thermal radiation during processing with a threshold value without using the relationship data. Alternatively, the necessity determination unit may determine whether or not power readjustment is necessary during processing of multiple work-pieces 41 based on the amount of fluctuation in the statistical value from the previous or the time before last.

[0058] As described above, the laser processing apparatus 1 and power control device of this embodiment store relationship data correlating the measured value of thermal radiation when the laser beam is irradiated onto the irradiation target 42 with the power of the laser beam at the irradiation position P0 measured by the power meter 29. Therefore, the power of the laser beam at the irradiation position P0 can be estimated from the relationship data and the measured value of thermal radiation. By utilizing the results of this laser beam power estimation, the power of the laser beam can be accurately estimated and adjusted quickly based on the measurement of thermal radiation, without having to spend a long time measuring the power using the power meter 29 every time. This improves the throughput of the processing. Note that in this embodiment, the estimation of the power of the laser beam and the adjustment of the power may be performed manually by a person.

[0059] Furthermore, the laser processing apparatus 1 and power control device of this embodiment are provided with an estimation unit 13 that estimates the power of the laser beam from the measured value of thermal radiation and related data. Therefore, the estimation of the power of the laser beam can be performed within the apparatus by the estimation unit 13, which can eliminate tedious manual work compared to when it is done manually by a person, and can obtain estimation results with fewer errors.

[0060] Furthermore, the laser processing apparatus 1 and power control device of this embodiment are provided with an adjustment unit 14 that adjusts the power of the laser beam at the irradiation position P0 based on the power estimation result. Therefore, the power adjustment of the laser beam can be performed within the apparatus by the adjustment unit 14, which eliminates the need for complicated manual work compared to when it is performed manually by a person, and enables accurate and rapid power adjustment.

[0061] Furthermore, the laser processing apparatus 1 and power control device of this embodiment are provided with a necessity determination unit 15 that determines whether or not power adjustment of the laser beam at the irradiation position P0 is necessary based on the relationship data and the measurement results of thermal radiation during processing. Therefore, while processing of multiple workpieces 41 continues, the determination by the necessity determination unit 15 can appropriately determine the timing for the next power readjustment. For example, it is possible to determine an appropriate timing for power readjustment so as to prevent the frequency of power readjustment from increasing while suppressing fluctuations in the power of the laser beam to a range that does not reduce the yield of the laser processing apparatus 1. This improves the processing throughput of the laser processing apparatus.

[0062] The above describes embodiments of the present invention. However, the present invention is not limited to the above embodiments. For example, while the above embodiments illustrate examples in which a power meter is provided in the laser processing apparatus, the laser processing apparatus may be configured without a power meter, in which relationship data correlating measured values ​​of thermal radiation with laser beam power values ​​is provided from outside the apparatus. Furthermore, while the above embodiments illustrate the case in which the laser processing apparatus is a laser annealing apparatus, the laser processing apparatus may also be a laser drilling apparatus that drills through holes or blind holes in a wiring board using laser beams, a laser welding apparatus that performs welding using laser beams, or the like. Furthermore, various optical systems that perform various functions may be added to the optical path from the laser light source to the workpiece, and the details illustrated in the embodiments may be modified as appropriate without departing from the spirit of the invention. [Industrial Applicability]

[0063] The present invention can be used in a laser power control device, a laser processing device, and a laser power control method. [Explanation of symbols]

[0064] 1. Laser processing equipment 10 Control device 11 Creation processing section 12 Relational data storage unit 13 Estimation part 14 Adjustment part 15 Necessity determination section 16 Display section 21 Laser light source 22 Attenuation optical system 24 Dichroic mirror 25, 26 lenses 27 Thermal radiation sensor 29 Power Meter 31 Stages 33 Total reflection mirror P0 Irradiation position (processed surface)

Claims

1. a storage unit that stores relationship data that associates a measurement value of a thermal radiation sensor that detects the intensity of thermal radiation of an irradiation object irradiated with laser light from a laser processing device with a power value of the laser light on a processing surface of the irradiation object; A laser power control device in which the relationship data is created when the irradiation object is replaced.

2. an estimation unit that estimates the power of the laser light on the processing surface based on the measurement value of the thermal radiation sensor and the relationship data stored in the storage unit; 2. The laser power control device according to claim 1.

3. further comprising an adjustment unit that adjusts the power of the laser light on the processing surface based on the estimation result of the estimation unit.

3. The laser power control device according to claim 2.

4. further comprising a display unit that displays the power of the laser beam estimated by the estimation unit or the power of the laser beam adjusted by the adjustment unit.

4. The laser power control device according to claim 3.

5. a necessity determination unit that determines whether or not adjustment of the power of the laser beam is necessary based on the measurement value of the thermal radiation sensor obtained during irradiation of the laser beam to the workpiece and the relationship data; 5. The laser power control device according to claim 1.

6. an optical system that irradiates a workpiece with laser light; a thermal radiation sensor that measures thermal radiation from an irradiation object irradiated with laser light by the optical system; a storage unit that stores relationship data that associates the measurement value of the thermal radiation sensor with the power value of the laser light on the processing surface; Equipped with The relationship data is created when the irradiation object is replaced.

7. Measure the thermal radiation of an irradiation object irradiated with laser light from a laser processing device; estimating a power value of the laser light on the processing surface of the irradiation object from the measured thermal radiation value; A laser power control method for adjusting the power of the laser light on the processing surface based on an estimated power value, a relational data correlating the thermal radiation value with the power value of the laser beam, the relational data being created when the irradiation object is replaced; Laser power control method.

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