Light heating device

Abstract

To provide an optical heating device capable of automatically adjusting the temperature distribution of an object to be heated with high accuracy.SOLUTION: An optical heating device includes: a heating light source unit having a plurality of planar light source areas in each of which a light source body is arranged; and a control unit configured to control, per light source area, light output of the light source body located in each of the light source areas. The control unit includes: a storage section configured to store temperature distribution characteristic information describing a relation between a relative ratio of the light output of each light source body among the plurality of light source areas and temperature distribution on a main surface of a tabular test piece, when light from the heating light source unit is irradiated toward the test piece; and an output control part configured to change a ratio of the light output among the plurality of light source areas based on the temperature distribution characteristic information, in order to bring the temperature distribution of a main surface of an object to be heated obtained when the light from the heating light source unit is irradiated under a predetermined light output for distribution measurement closer to a desired temperature distribution.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a light heating device. [Background technology]

[0002] In the semiconductor manufacturing process, various heat treatments such as film formation, oxidation and diffusion, modification, and annealing are performed on substrates to be processed, such as semiconductor wafers. Light heating, which allows non-contact processing, is generally used as a method for performing these heat treatments. For example, the following Patent Document 1 describes a heat treatment apparatus for heat-treating silicon wafers by irradiating the surface of the semiconductor wafer to be processed with heating light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-58722 A Summary of the Invention [Problem to be solved by the invention]

[0004] The characteristics and appearance of a manufactured semiconductor device may depend on the temperature during heating. In particular, from the viewpoint of suppressing variation in characteristics between devices, it is required to heat a semiconductor wafer uniformly across its surface during heat treatment.

[0005] The heating light source is composed of multiple light source bodies made of halogen lamps or LED elements arranged at positions facing each other at a distance from each other on the main surface of the object to be heated (a wafer in the above example). However, simply turning on each light source body with the same light output does not result in a uniform temperature distribution on the main surface of the object to be heated. This is because, while the heating light tends to concentrate near the center of the main surface of the object to be heated, the illuminance tends to be lower near the periphery compared to near the center.

[0006] In view of this tendency, a method of controlling the output of a light source body located at a position facing the center of the main surface of the object to be heated to be lower than the output of a light source body facing an area outside the center can be considered. However, a uniform temperature distribution cannot be obtained by simply lowering the output of the light source body closest to the center among the multiple light source bodies that make up the heating light source. This is because the light from each light source body reaches the irradiated surface of the object to be heated with a certain divergence angle.

[0007] The main surface of the object to be heated is heated by overlapping the light from multiple light source bodies. That is, each region on the main surface of the object to be heated is heated under heating conditions realized by mutual influence of the light and heat from the multiple light source bodies, and the temperature is determined. That is, when it is desired to lower the temperature of a specific region R1 on the main surface of the object to be heated to approach the temperature of another region Rj, it is not enough to simply lower the output of the light source body (group) Q1 located at a position corresponding to this region R1 below the output of the light source body (group) Qj located at a position corresponding to the region Rj. This is because, when the output of the light source body (group) Q1 is lowered, the temperature of the region R2 adjacent to the region R1 on the main surface of the object to be heated is also lowered.

[0008] If the output of the light source Q2 adjacent to the light source Q1 is increased in order to raise the temperature of the region R2, the temperature of the region R1 also rises in accordance with this increase in output.

[0009] The temperature distribution also tends to be affected by the individual characteristics of the object to be heated. For example, even if the object to be heated is a semiconductor silicon wafer, the surface condition of each silicon wafer may differ slightly.

[0010] Due to these circumstances, in practice, the process of making the temperature distribution of the object to be heated uniform was carried out by having the operator (user) measure the temperature distribution of the object to be heated and then adjusting the light output of each light source based on his or her own experience and intuition.

[0011] In view of the above problems, an object of the present invention is to provide a light heating device that makes it possible to automatically adjust the temperature distribution of an object to be heated with high precision. [Means for solving the problem]

[0012] The optical heating device according to the present invention is an optical heating device for heating a flat plate-shaped heating object, A heating light source unit having a plurality of planar light source regions in which one or a plurality of light source bodies are arranged, in a direction along a light source surface formed by the light source regions; a control unit capable of controlling the light output of the light source body present in each of the light source regions on a light source region basis; The control unit a storage unit that stores temperature distribution characteristic information that describes a relationship between a relative ratio of the light output of each of the light source bodies among a plurality of light source regions and a temperature distribution in a plane direction of a main surface of the test body when light from the heating light source unit is irradiated toward the flat test body arranged at a predetermined distance from the light source region in a direction perpendicular to the light source surface, and desired temperature distribution information that describes a desired temperature distribution in the plane direction of the main surface of the heating object; an input receiving unit that receives input of measured temperature distribution information describing a temperature distribution in a surface direction of a main surface of the object to be heated, the temperature distribution being obtained when the object to be heated is irradiated with light from the heating light source unit in a state in which the light output of the light source body is set to a predetermined light output for distribution measurement for each of the light source regions; and an output control unit that changes the ratio of the light output of each of the light source bodies among the plurality of light source regions based on the temperature distribution characteristic information so as to bring the temperature distribution described in the measured temperature distribution information closer to the temperature distribution described in the desired temperature distribution information.

[0013] According to the above-described optical heating device, it is possible to automatically adjust the temperature distribution of an object to be heated to a desired temperature distribution, for example, by the following procedure.

[0014] First, the light output of the light source body is set to a predetermined light output for distribution measurement, and the heating light source unit irradiates the object to be heated with light. Information (actual temperature distribution information) obtained at this time regarding the temperature distribution on the main surface of the object to be heated is input to the control unit from the input receiving section. The light output for distribution measurement is set, for example, so that the output of the light source body in all light source regions is the same value. As a more specific example, the output of the light source body in all light source regions is set to 10% of the maximum output.

[0015] The optical heating device itself may be equipped with a function for measuring the temperature distribution of the main surface of the object to be heated, i.e., a first thermometer. As an example, a thermocouple, a radiation thermometer, or a thermo camera is preferably used as such a first thermometer. From the viewpoint of measuring the temperature distribution with high accuracy, a thermocouple is preferably used. Also, from the viewpoint of measuring the temperature distribution simply, a thermo camera is preferably used.

[0016] The control unit includes a storage unit having temperature distribution characteristic information recorded therein. The temperature distribution characteristic information is information measured in advance using a flat plate-shaped test piece. The temperature distribution characteristic information may be acquired and recorded in the storage unit in advance before the light heating device is shipped.

[0017] The temperature distribution characteristic information is information describing the relationship between the relative ratio of the light output of the light source body between each light source region and the temperature distribution in the surface direction of the test piece when light is irradiated from the heating light source unit (each light source region) in a state where a flat test piece is placed at a predetermined distance from the light source region so as to face the light source region. More specifically, it is as follows.

[0018] The heating light source unit has n light source areas X i (i=1,...,n). As described above, each light source area X i Each of the light source regions X i Each light source area in units of X i This configuration allows control of the light output of the light source body included in the light source.

[0019] A flat test specimen is placed in a predetermined position, and each light source area X i The light output P of the light source belonging to (i=1,…,n) i (i=1,...,n) are changed to change the irradiation conditions, and the heating light is irradiated under these different irradiation conditions. Then, the temperature distribution on the main surface of the specimen when the light is irradiated under each of the conditions is measured. The temperature distribution is information that associates multiple positions on the main surface of the specimen, specified in polar coordinate format or Cartesian coordinate format, with the temperatures at those positions. Note that, in addition to being specified in the coordinate format, this temperature distribution may also be information in which the main surface of the specimen is divided into multiple regions and a temperature is associated with each region.

[0020] For example, each light source area X i The light output P of the light source included in i While changing the output from the minimum output (output 0%) to the maximum output (output 100%) in 10% increments, that is, the optical output P i The temperature distribution can be measured while changing the light source area X to 11 different values. i If the number of items is 7 (n=7), this measurement will 11 Data on the temperature distribution characteristics of the X i The number of light sources is n, and each light source area X i The light output P of the light source included in i When m types of changes are made between the minimum and maximum output, m n Such temperature distribution characteristic information is recorded in the storage unit of the control unit.

[0021] The control unit includes a storage unit that stores information (desired temperature distribution information) related to the temperature distribution (desired temperature distribution) of the main surface of the object to be heated that is desired by the user. As described above, when the object to be heated by the optical heating device is a semiconductor wafer, uniformity of the temperature distribution in the surface direction is usually required, and therefore the storage unit may store the desired temperature distribution information to that effect in advance.

[0022] In other words, the desired temperature distribution information may be information indicating that the main surface of the object to be heated exhibits a substantially uniform temperature distribution in the surface direction. The term "substantially uniform temperature distribution" as used herein means that it is acceptable that there is almost no variation in temperature at each position on the main surface of the object to be heated, and typically means that, when the average value of the temperature at each position on the main surface of the object to be heated is used as a reference, the temperature at each position is suppressed to a fluctuation range of ±10% of the average value.

[0023] As another example, depending on the circumstances of the user, it may be possible that a completely uniform temperature is not required over the entire main surface of the heated object, but that the temperature of a certain spot is relatively higher than the surrounding area of ​​that spot. In such a case, the desired temperature distribution information input by the user may be taken into the control unit via the input receiving unit and recorded in the memory unit.

[0024] The output control section of the control unit compares information on the temperature distribution of the main surface of the object to be heated (actual temperature distribution information) obtained when the object to be heated is irradiated with light from the heating light source unit in a state set to the light output for distribution measurement, with the desired temperature distribution information recorded in the storage section. Then, in order to bring the temperature distribution indicated by the actual temperature distribution information closer to the temperature distribution indicated by the desired temperature distribution information, each light source region X i The light output P of the light source included in i When determining this relative ratio, the temperature distribution characteristic information recorded in the storage unit is used.

[0025] As described above, the temperature distribution characteristic information includes the temperature distribution characteristic information for each light source area X i It describes how the temperature distribution on the main surface of the test specimen changes when the light output of the light source body included in (i=1, ..., n) is changed in various ways. Therefore, in order to reduce the discrepancy between the temperature distribution obtained under the light output for distribution measurement (actual temperature distribution information) and the temperature distribution described in the desired temperature distribution information, it is necessary to adjust each light source area X i(i=1, . . . , n) can recognize how to change the ratio of the light output between the light source areas X i By adjusting the relative ratio of the light outputs (i=1, ..., n), the temperature distribution on the main surface of the object to be heated can be changed to a temperature distribution desired by the user (e.g., a highly uniform temperature distribution) without relying on the user's experience or intuition.

[0026] After the temperature distribution on the main surface of the heating object is adjusted to the desired temperature distribution, each light source area X i While maintaining the relative ratio of the light output of each light source area X (i=1,…,n), i By increasing the light output of (i=1, . . . , n) or adjusting the heating time, the temperature of the object to be heated can be raised to a target temperature.

[0027] In other words, the output control unit may adjust the ratio of the light output of each of the light source bodies among the multiple light source regions so that the deviation between the temperature distribution described in the measured temperature distribution information and the temperature distribution described in the desired temperature distribution information is below a threshold, and then control the light output of the multiple light source regions to be increased from the light output for distribution measurement while maintaining the ratio.

[0028] For example, the temperature of a specific point on the object to be heated is measured, and each light source area X i While maintaining the relative ratio of the light output of the light sources included in (i=1,…,n), each light source area X i (i=1, . . . , n) may be used to increase the light output.

[0029] The light source region may have at least a first region including a central position of the light source surface, and a second region located outside the first region.

[0030] In this case, the second region may be further divided into a plurality of light source regions along the circumferential direction of the light source surface.

[0031] In particular, since the peripheral portion of the object to be heated is more likely to become colder than the central portion, and the peripheral portion is larger in area than the central portion, the above-mentioned configuration enables more precise control of the temperature of the portion close to the peripheral portion.

[0032] The control unit a first processing step in which, when the object to be heated is placed, the output control unit turns on the light source body in a state in which the light output of the light source body is set to the light output for distribution measurement; a second processing step in which the first thermometer measures a temperature distribution in a planar direction of a main surface of the heating object during execution of the first processing step, thereby acquiring the measured temperature distribution information; After executing the second processing step, the output control unit may sequentially execute a third processing step in which the ratio of the light output of each of the light source bodies among the multiple light source regions is changed based on the temperature distribution characteristic information read from the memory unit so as to bring the temperature distribution described in the measured temperature distribution information closer to the temperature distribution described in the desired temperature distribution information.

[0033] The optical heating device further includes a second thermometer for measuring the temperature of a specific point on the main surface of the object to be heated, The input receiving unit is configured to receive an input of information regarding a target temperature of a main surface of the object to be heated, the third processing step is a processing step in which the output control unit adjusts a ratio of light output of each of the light source bodies among the plurality of light source regions so that a deviation between a temperature distribution described in the measured temperature distribution information and a temperature distribution described in the desired temperature distribution information becomes equal to or smaller than a threshold value; The output control unit may be configured to execute a fourth processing step in which, after execution of the third processing step, the light output of the plurality of light source regions is increased from the light output for distribution measurement while maintaining the ratio adjusted in the third processing step so that the temperature information indicated by the second thermometer reaches the target temperature. Effect of the Invention

[0034] According to the optical heating device of the present invention, it is possible to automatically adjust the temperature distribution of an object to be heated with high accuracy without relying on the experience or intuition of a user. [Brief description of the drawings]

[0035] [Figure 1] 1 is a diagram showing a schematic configuration of an embodiment of a light heating device of the present invention. [Diagram 2] 2 is a plan view of the heating object 3 in FIG. 1 as viewed from the +Z side. [Diagram 3] FIG. 2 is a plan view showing a schematic configuration of a heating light source unit 10 in FIG. [Figure 4] FIG. 4 is a diagram in which the drawing in FIG. 3 has been simplified for the purpose of explanation and reference numerals have been added. [Diagram 5] 2 is a block diagram showing a schematic configuration of a control unit 20 in FIG. 1. [Figure 6A] FIG. 4 is a conceptual diagram of a simulation model of a heating light source unit. [Figure 6B] FIG. 6B is a conceptual diagram of a simulation model of a heating light source unit, in which the hatched portions in FIG. 6A are assigned reference numerals. [Figure 7] 13 shows simulation results illustrating temperature distribution on the irradiated surface when each light source model is turned on in lighting modes #1 to #12. [Figure 8] 1 is an example of a flowchart showing a procedure for heating an object to be heated 3 using a light heating device 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The light heating device of the present invention will be described below with reference to the drawings. Note that the following drawings related to the light heating device are all schematic illustrations, and the dimensional ratios and the number of elements in the drawings do not necessarily match the actual dimensional ratios and the number of elements.

[0037] Fig. 1 is a diagram showing a schematic configuration of a light heating device. The light heating device 1 shown in Fig. 1 includes a heating light source unit 10 having a plurality of light source bodies, and a control unit 20 that controls the light output of the light source bodies provided in the heating light source unit 10.

[0038] The optical heating device 1 of this embodiment includes a chamber 30 that houses an object to be heated 3. When the optical heating device 1 is used, heating light L1 is radiated from the heating light source unit 10 with the object to be heated 3 placed at a predetermined position in the chamber 30. As a result, the heating light L1 is irradiated onto the main surface 3a of the object to be heated 3, and the object to be heated 3 is heated.

[0039] In the following description, as shown in FIG. 1, the direction in which the heating light source unit 10 and the object to be heated 3 are separated from each other is defined as the Z direction, and the plane perpendicular to the Z direction is defined as the XY plane. When expressing a direction, a positive or negative sign is added, such as "+Z direction" and "-Z direction", and when expressing a direction without distinguishing between positive and negative directions, it is simply described as "Z direction". Using this expression, the heating light L1 from the heating light source unit 10 travels in the -Z direction and is irradiated onto the main surface 3a of the object to be heated 3, thereby heating the object to be heated 3. The main surface 3a of the object to be heated 3 is a surface parallel to the XY plane.

[0040] The heating object 3 is typically a silicon wafer. However, the light heating device 1 of this embodiment can also be applied to heat treatment of heating objects 3 other than silicon wafers, examples of which include glass substrates, ceramic substrates, ALTIC (alumina titanium carbide) substrates, and SiC (silicon carbide) substrates.

[0041] Heating light source unit 10 includes a plurality of light source bodies. More specifically, heating light source unit 10 is configured by arranging a plurality of light source bodies along a surface parallel to the XY plane. These plurality of light source bodies are configured such that the light output can be controlled in a predetermined unit (hereinafter referred to as a "light source region"). This will be described later with reference to Figs. 3 and 4.

[0042] In this embodiment, the light source body mounted on the heating light source unit 10 is composed of a halogen lamp. However, the light source body may be a solid-state light source such as an LED element, or a lamp other than a halogen lamp. In the former case, more specifically, the light source body may be an LED element having a peak wavelength of 365 nm to 480 nm. The peak wavelength of this LED element is typically 395 nm.

[0043] 1, chamber 30 includes a support member 31 for supporting object 3 to be heated. Support member 31 may have any structure as long as it can support main surface 3a of object 3 to be heated in a state substantially parallel to the arrangement surface of multiple light source bodies mounted in heating light source unit 10.

[0044] In the example shown in Fig. 1, the chamber 30 has a window 32 and a window 33. The window 32 is a light-transmitting window that allows the heating light L1 radiated from the heating light source unit 10 located outside the chamber 30 to travel inside the chamber 30. The window 33 is an observation window for measuring the temperature distribution of the object 3 to be heated by a thermo camera 41. More specifically, the thermo camera 41 measures the temperature distribution of the main surface 3a of the object 3 to be heated by receiving infrared light L2 radiated from the object 3 to be heated. In this example, the thermo camera 41 corresponds to the "first thermometer."

[0045] As described later, the first thermometer represented by the thermo camera 41 only needs to be able to measure the temperature distribution in the direction along the XY plane of the main surface 3a of the object to be heated 3 when each light source of the heating light source unit 10 is turned on under a predetermined light output condition. From this viewpoint, a thermocouple or a radiation thermometer can also be used as the first thermometer in addition to the thermo camera 41. In these cases, the temperature at a plurality of positions distributed on the main surface 3a of the object to be heated 3 is measured, thereby obtaining the temperature distribution of the main surface 3a of the object to be heated 3.

[0046] Information regarding the temperature distribution on the main surface 3a of the heating target 3 obtained by the thermo camera 41 is input to the control unit 20. Based on this temperature distribution information, the control unit 20 controls the output of each light source element of the heating light source unit 10. The configuration and processing content of the control unit 20 will be described later with reference to Figs. 5 and 8.

[0047] As described later, the light heating device 1 of this embodiment is not configured to feedback control the output of each light source of the heating light source unit 10 based on information on the temperature distribution of the main surface 3a of the object to be heated 3. For this reason, since fast response is not required, a thermo camera 41 can be used as a means for measuring the temperature distribution of the main surface 3a of the object to be heated 3.

[0048] Fig. 2 is a plan view of the heating object 3 as viewed from the +Z side. In the example shown in Fig. 2, the main surface 3a of the heating object 3 has a circular shape. However, the shape of the main surface 3a is not limited to a circle, and may be an ellipse or a polygon.

[0049] 3 and 4 are plan views showing a schematic configuration of the heating light source unit 10, both of which are plan views of the heating light source unit 10 as viewed in the +Z direction from the side of the object to be heated 3. In the example shown in FIG. 3, 37 light source bodies 12 are arranged along the XY plane. Then, as shown in FIG. 4, these light source bodies 12 provided in the heating light source unit 10 are divided into seven light source regions 11 (11a, 11b, 11c, 11d, 11e, 11f, 11g). The number of light source bodies 12 and the number of light source regions 11 are arbitrary.

[0050] The light source region 11a is located approximately at the center of the light source surface (a surface along the XY plane) of the heating light source unit 10, and includes one light source body 12 here. The light source region 11b is located in a region surrounding the light source region 11a, and includes six light source bodies 12 here. The light source region 11c is located in a region surrounding the light source region 11b, and includes twelve light source elements 12 here.

[0051] The groups of light source regions 11d, 11e, 11f, and 11g are located in an area surrounding the light source region 11c. These groups are separated into four light source regions (11d, 11e, 11f, and 11g) in the circumferential direction. The light source region 11d and the light source region 11f each include five light source bodies 12, and the light source region 11e and the light source region 11g each include four light source bodies 12.

[0052] As described above, the control unit 20 is configured to be able to control the light output for each light source region 11 with respect to each light source body 12 mounted on the heating light source unit 10. The configuration and control content of the control unit 20 will be described below.

[0053] 5 is a block diagram showing a schematic configuration of the control unit 20. The control unit 20 includes an output control unit 21, a storage unit 22, and an input receiving unit .

[0054] The input receiving unit 23 is an interface that receives information input from outside the control unit 20. More specifically, the input receiving unit 23 receives input of information related to the temperature distribution on the main surface of the heating target 3 measured by the thermo camera 41 (hereinafter referred to as "actually measured temperature distribution information dT1").

[0055] The storage unit 22 is a storage medium for recording various types of information, and is typically a hard disk, a flash memory, etc. The storage unit 22 records temperature distribution characteristic information d1 and desired temperature distribution information d2.

[0056] The desired temperature distribution information d2 is information about the temperature distribution of the main surface 3a of the object to be heated 3 that the user of the optical heating device 1 wishes to realize. When the object to be heated 3 is a silicon wafer, it is typically required that the main surface 3a of the object to be heated 3 be heated uniformly. In this case, the desired temperature distribution information d2 contains information indicating that a uniform temperature distribution is to be shown regardless of the coordinate position on the XY plane. In this case, the desired temperature distribution information d2 may be recorded in advance in the storage unit 22 at a stage before the user uses the device.

[0057] As another example, depending on the circumstances of the user, it may be possible that a completely uniform temperature is not required over the entire main surface of the heated object, but that the temperature of a certain spot is desired to be relatively higher than the surrounding area of ​​that spot. In such a case, the user inputs the desired temperature distribution information d2 into the control unit 20 using a terminal or the like, and this desired temperature distribution information d2 is taken into the control unit 20 via the input receiving unit 23 and recorded in the memory unit 22.

[0058] The temperature distribution characteristic information d1 is information acquired in advance using a flat test object before the light heating device 1 is delivered to the user, typically before shipment. This temperature distribution characteristic information d1 describes the manner of change in temperature distribution on the main surface of the test object when a flat test object is placed at a predetermined distance in the Z direction from the heating light source unit 10 and the output of the light source body 12 mounted on the heating light source unit 10 is changed. At this time, the output of the light source body 12 is changed in light source region 11 units.

[0059] 4, the temperature distribution characteristic information d1 corresponds to information on the temperature distribution of the principal surface of the test object measured while gradually changing the light output of the light source bodies included in all the light source regions 11 (11a, 11b, ..., 11g). In other words, the temperature distribution characteristic information d1 makes it possible to read how the change in which light source region 11 affects the temperature distribution of the principal surface of the test object.

[0060] 6A and 6B are conceptual diagrams of a light source model 10S of the heating light source unit 10 used in the simulation. In Fig. 6A, the position of a simulated light source body 12S that simulates the light source body 12 is hatched. In Fig. 6B, the simulated light source bodies 12S are denoted by reference characters A1 to A19 for explanatory purposes.

[0061] The simulated light source bodies A1 to A19 shown in Fig. 6B were lit in the lighting modes #1 to #12 shown in Table 1 below, and the temperature distribution in the planar direction at a location 45 mm away from the light source model 10S was calculated by simulation. The results are shown in Fig. 7.

[0062] [Table 1]

[0063] 7, it is confirmed that the temperature distribution of the irradiated surface is affected by varying the relative values ​​of the light output between the simulated light source bodies (A1 to A19). In other words, when the simulated light source bodies A1 to A19 correspond to the light source regions 11 in the light heating device 1 of this embodiment, it is found that changing the relative values ​​of the light output between the light source regions 11 affects the temperature distribution of the main surface 3a of the object to be heated 3 (as well as the main surface of the test specimen).

[0064] In other words, in the light heating device 1 of this embodiment, the degree of effect on the temperature distribution of the main surface of a test specimen when the relative value of the light output of the light source body 12 is changed for each light source region 11 is measured in advance using a test specimen, and temperature distribution characteristic information d1 reflecting the measurement results is recorded in the memory unit 22.

[0065] The output control unit 21 controls the light output of each light source body 12 mounted on the heating light source unit 10 for each light source region 11. This output control unit 21 is a calculation processing means that calculates the amount of current or voltage supplied to each light source region 11, and is composed of, for example, a CPU or MPU. Although not shown, the light heating device 1 includes a power supply circuit, and this power supply circuit supplies each light source region 11 with a current or voltage for realizing the light output dP1 for each light source region 11 calculated by the output control unit 21. As a result, each light source region 11 is turned on under the output ratio determined by the output control unit 21.

[0066] Hereinafter, a flow of using the light heating device 1 will be described with reference to Fig. 8. Fig. 8 is an example of a flow chart showing a procedure when the light heating device 1 is used to heat the heating target 3.

[0067] (Step S1) When the object to be heated 3 is placed in the chamber 30, the control unit 20 first sets the optical output of each light source 12 mounted on the heating light source unit 10 to a predetermined output (hereinafter referred to as "optical output for distribution measurement"). The heating light source unit 10 irradiates the object to be heated 3 with heating light L1 under the optical output for distribution measurement. As a result, the object to be heated 3 is slightly heated by the heating light L1 under the optical output for distribution measurement. Note that this step S1 is executed for the purpose of measuring the temperature distribution of the main surface 3a of the object to be heated 3 in the next step S2, so the optical output for distribution measurement is set so that the object to be heated to a temperature much lower than the actual target heating temperature.

[0068] The optical output for distribution measurement may be set, for example, so that the relative outputs of the light source bodies 12 included in all the light source regions 11 are the same. As a specific example, the outputs of the light source bodies in all the light source regions 11 are set to 10% of the maximum output.

[0069] This step S1 corresponds to the "first processing step."

[0070] (Step S2) The thermo camera 41 measures the temperature distribution on the main surface 3a of the heating target 3. Measured temperature distribution information dT1 obtained by this measurement is input to the control unit 20. This step S2 corresponds to the "second processing step."

[0071] (Step S3) The output control unit 21 reads out the desired temperature distribution information d2 from the storage unit 22, and compares it with the actually measured temperature distribution information dT1 obtained in step S2. Normally, it is extremely rare for the two to match.

[0072] (Step S4) Based on the comparison result in step S3 and the temperature distribution characteristic information d1 read out from the memory unit 22, the output control unit 21 calculates how the relative output ratio of each light source area 11 (more specifically, the relative output ratio of the light source bodies 12 included in each light source area 11) should be set in order to bring the measured temperature distribution information dT1 closer to the desired temperature distribution information d2.

[0073] As described above, the temperature distribution characteristic information d1 describes what effect the temperature distribution on the main surface of the test piece has when the relative output ratio between each light source region 11 is changed by a certain amount. Therefore, it is possible to calculate how the relative output ratio of each light source region 11 should be set by the comparison result in step S3 and the temperature distribution characteristic information d1.

[0074] Then, the light source bodies 12 in each light source area 11 are turned on based on the calculated relative output ratio of each light source area 11.

[0075] Steps S3 to S4 correspond to a "third processing step."

[0076] (Step S5) The output control unit 21 increases the output of each light source body 12 while maintaining the relative ratio set in step S4. Then, the heating process ends when the temperature of the main surface 3a of the heating object 3 reaches the target temperature. Note that information regarding the target temperature may be input in advance by the user to the control unit 20 using a terminal or the like before the start of step S5. This information regarding the target temperature is taken into the control unit 20 via the input receiving unit 23 and recorded in the memory unit 22.

[0077] At this time, a second thermometer (not shown) may be used in addition to the thermo camera 41 to measure the temperature of a specific location on the main surface 3a of the heating target 3. A thermocouple or a radiation thermometer is preferably used as this second thermometer. When a thermocouple or a radiation thermometer is used as the first thermometer, the first thermometer and the second thermometer may be the same thermometer.

[0078] This step S5 corresponds to the "fourth processing step."

[0079] As described above, according to the optical heating device 1 of this embodiment, the control unit 20 automatically performs calculations and then adjusts the output of each light source body 12 so that the temperature distribution on the main surface 3a of the object to be heated 3 becomes the temperature distribution desired by the user. This makes it possible to automatically adjust the temperature distribution on the main surface 3a of the object to be heated 3 with high accuracy without relying on the experience or intuition of the user.

[0080] When multiple objects to be heated 3 are sequentially placed in the chamber 30 and heated using the optical heating device 1, the output ratio of each light source region 11 may be set based on already measured actual temperature distribution information dT1. That is, steps S1 and S2 do not need to be performed every time an object to be heated 3 is placed in the chamber 30. In this case, after the object to be heated 3 is placed in the chamber 30, steps S3 to S5 are performed sequentially.

[0081] [Another embodiment] Another embodiment will now be described.

[0082] <1> The temperature distribution characteristic information d1 recorded in the storage unit 22 may be described as information for each separation distance in the Z direction between the heating light source unit 10 and the test object. In this case, assuming that the number of light source regions 11 is n and the number of types of light output of the light source body included in each light source region 11 is m, the temperature distribution characteristic information d1 for each separation distance is m. n The type of temperature distribution characteristic information d1 is recorded in the storage unit 22.

[0083] In this case, the distance in the Z direction between the object to be heated 3 and the heating light source unit 10 is measured in step S1. Then, in step S3, the output control unit 21 reads out desired temperature distribution information d2 corresponding to the measured distance from the storage unit and compares it with the actually measured temperature distribution information dT1. According to this method, although the amount of information recorded in the storage unit 22 increases, the temperature distribution of the main surface 3a of the object to be heated 3 can be made to approach the temperature distribution desired by the user with greater accuracy.

[0084] <2> The number of light source bodies 12 included in each light source region 11 may be the same or different. In the former case, the relative ratio of the light output of the light source bodies 12 between each light source region matches the relative ratio between each light source region 11. [Explanation of symbols]

[0085] 1:Light heating device 3: Object to be heated 3a: Main surface 10: Heating light source unit 11:Light source area 12:Light source 20: Control unit 21: Output control section 22: Storage section 23: Input reception section 30: Chamber 31: Support member 32: Window 33: Window 41: Thermal camera d1: Temperature distribution characteristic information d2: Desired temperature distribution information dP1: Optical output dT1: Measured temperature distribution information

Claims

1. A light heating device for heating a flat heating object, a heating light source unit having a plurality of planar light source regions in a direction along a light source surface formed by the light source regions, the planar light source regions being formed by one or a plurality of light source bodies; a control unit capable of controlling the light output of the light source body present in each of the light source regions on a light source region basis; The control unit a storage unit that stores temperature distribution characteristic information that describes a relationship between a relative ratio of the light output of each of the light source bodies among a plurality of light source regions and a temperature distribution in a plane direction of a main surface of the test body when light from the heating light source unit is irradiated toward the flat test body arranged at a predetermined distance from the light source region in a direction perpendicular to the light source surface, and desired temperature distribution information that describes a desired temperature distribution in the plane direction of the main surface of the heating object; an input receiving unit that receives input of measured temperature distribution information describing a temperature distribution in a surface direction of a main surface of the object to be heated, the temperature distribution being obtained when the object to be heated is irradiated with light from the heating light source unit in a state in which the light output of the light source body is set to a predetermined light output for distribution measurement for each of the light source regions; and an output control unit that changes the ratio of the light output of each of the light source bodies among the plurality of light source regions based on the temperature distribution characteristic information so as to bring the temperature distribution described in the measured temperature distribution information closer to the temperature distribution described in the desired temperature distribution information.

2. The storage unit stores m values ​​obtained when the light output is changed between a minimum output and a maximum output for each of the n light source regions formed in the heating light source unit. n The optical heating device according to claim 1 , wherein the type of the temperature distribution characteristic information is recorded. (where m and n are both natural numbers greater than or equal to 2.)

3. The light heating device according to claim 1 or 2, characterized in that the light source region has at least a first region including a central position of the light source surface, and a second region located outside the first region.

4. The light heating device according to claim 3 , wherein the second region is further divided into a plurality of the light source regions along a circumferential direction of the light source surface.

5. The light heating device according to claim 1 or 2, characterized in that the output control unit adjusts the ratio of the light output of each of the light source bodies among the multiple light source regions so that the deviation between the temperature distribution described in the measured temperature distribution information and the temperature distribution described in the desired temperature distribution information is below a threshold, and then controls the light output of the multiple light source regions to be increased from the light output for distribution measurement while maintaining the ratio.

6. 3. The optical heating device according to claim 1, wherein the desired temperature distribution information is information indicating that a main surface of the object to be heated exhibits a substantially uniform temperature distribution in a planar direction.

7. A first thermometer is provided to measure a temperature distribution in a planar direction of a main surface of the object to be heated, The control unit a first processing step in which, when the object to be heated is placed, the output control unit turns on the light source body in a state in which the light output of the light source body is set to the light output for distribution measurement; a second processing step in which the first thermometer measures a temperature distribution in a planar direction of a main surface of the heating object during execution of the first processing step, thereby acquiring the measured temperature distribution information; The light heating device according to claim 1 or 2, characterized in that after executing the second processing step, the output control unit sequentially executes a third processing step in which the ratio of the light output of each of the light source bodies between the multiple light source regions is changed based on the temperature distribution characteristic information read from the memory unit so as to bring the temperature distribution described in the measured temperature distribution information closer to the temperature distribution described in the desired temperature distribution information.

8. A second thermometer is provided to measure the temperature of a specific point on the main surface of the object to be heated, The input receiving unit is configured to receive an input of information regarding a target temperature of a main surface of the object to be heated, the third processing step is a processing step in which the output control unit adjusts a ratio of light output of each of the light source bodies among the plurality of light source regions so that a deviation between a temperature distribution described in the measured temperature distribution information and a temperature distribution described in the desired temperature distribution information becomes equal to or smaller than a threshold value; The light heating device described in claim 7, characterized in that after executing the third processing step, the output control unit executes a fourth processing step in which the light output of the multiple light source regions is increased from the light output for distribution measurement while maintaining the ratio adjusted in the third processing step so that the temperature information indicated by the second thermometer reaches the target temperature.

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