JP2019071288A - Lamp heating device - Google Patents

Abstract

To provide a lamp heating device capable of making a temperature of a product to be processed quickly follow a target value without requiring a work, such as fine adjustment of a control parameter.SOLUTION: A lamp heating device comprises a light source, a temperature sensor, a light quantity sensor, a temperature controller, and a light quantity controller. The light source irradiates a product to be processed with light to heat it. The temperature sensor detects a temperature of the product to be processed. The light quantity sensor detects a quantity of light of the light source. The temperature controller outputs the quantity of light to be emitted from the light source for the purpose of making a detection temperature of the temperature sensor accord with a temperature target value, as a light quantity target value. The light quantity controller drives the light source so as to make the quantity of light detected by the light quantity sensor accord with the light quantity target value outputted from the temperature controller.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a heating device used for heat treatment such as baking treatment of an electrode of a solar cell, and more particularly to a lamp heating device provided with a visible light to near-infrared region light source such as a halogen lamp.

  A lamp heating device using a visible light to near-infrared region light source such as a halogen lamp as a heat source is used for heat treatment such as baking treatment of an electrode of a solar cell. The lamp heating device measures the temperature of the object by means of a radiation thermometer, and drives the light source by single-loop feedback control so that the temperature of the object becomes an appropriate processing temperature (see, for example, Patent Document 1) ).

JP, 2006-147943, A

  However, although the response of the light amount of the light source by feedback control is sufficiently fast, the response of the temperature of the object to the light amount is slow, the feedback control by single loop causes the temperature of the object to quickly follow the target value. Is difficult. For this reason, when using a conventional lamp heating apparatus to rapidly change the temperature of an object at a speed exceeding 100 ° C./sec, such as spike annealing in the firing treatment of an electrode of a solar cell, for example, It requires complicated operations such as fine adjustment.

  Such a problem generally occurs not only in the firing process of the electrodes of the solar cell but also in the heat process in the lamp heating apparatus.

  Therefore, an object of the present invention is to provide a lamp heating apparatus capable of quickly making the temperature of an object to be processed follow a target value without requiring an operation such as fine adjustment of control parameters.

  A lamp heating device according to the present invention includes a light source, a temperature sensor, a light amount sensor, a temperature control unit, and a light amount control unit. The light source irradiates and heats an object to be processed. The temperature sensor detects the temperature of the object to be treated. The light amount sensor detects the light amount of the light source. The temperature control unit outputs the amount of light to be emitted by the light source as the light amount target value in order to make the detected temperature of the temperature sensor coincide with the temperature target value. The light amount control unit drives the light source such that the light amount detected by the light amount sensor matches the light amount target value output from the temperature control unit.

  In the lamp heating apparatus, the temperature control unit executes feedback control of a first loop (temperature control loop) to make the object to be processed match the target temperature based on the temperature detected by the temperature sensor, and the light amount control unit The feedback control of the second loop (light amount control loop) for controlling the light amount of the light source based on the detected light amount of is executed. Thereby, the lamp heating device carries out feedback control of the dual control loop comprising the first loop and the second loop. Then, the light amount of the light source for heating the object to be processed is directly controlled by the feedback control of the second loop, whereby the temperature of the object to be processed quickly matches the target temperature.

  In the lamp heating apparatus, it is preferable that in the light amount sensor, the detection sensitivity wavelength range overlaps with the wavelength range of the irradiation light of the light source, and the absorption range of the light wavelength substantially coincides with the absorption range of the object to be treated. The wavelength range in which the detection sensitivity of the light amount sensor is high coincides with the wavelength range of the light that heats the object to be processed, and the light amount in the wavelength range to heat the object to be processed can be accurately detected.

  Further, it is preferable that the light amount sensor be disposed on the opposite side of the processing object with the light source interposed therebetween. While being able to reliably receive the light of the light source, it becomes difficult to receive the reflected light from the object to be processed, and the light quantity of the light source can be accurately detected.

  According to the present invention, the temperature of the object to be processed can be made to quickly follow the target value without requiring an operation such as fine adjustment of control parameters.

1 is a schematic cross-sectional view of a lamp heating device according to an embodiment of the present invention. It is sectional drawing of the principal part of a lamp heating apparatus. It is a figure which shows an example of the emissivity characteristic of the light quantity sensor of a lamp heating apparatus. It is a block diagram of a control part of a lamp heating device. It is a figure which shows the temperature change of the to-be-processed object in a lamp | ramp control apparatus.

  Hereinafter, a lamp heating device according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the lamp heating device 10 according to the embodiment includes a furnace body 1, a halogen lamp 2, a temperature sensor 3, a light amount sensor 4, a control unit 5 and a lamp driving unit 6. Heat to the temperature of The object to be treated W is, for example, an electrode material of a solar cell which is made of silicon and exhibits a plate shape.

  The furnace body 1 is a casing having heat insulation, and the workpiece W is carried in and out. The halogen lamps 2 are light sources according to the present invention, and five halogen lamps 2 are arranged at the top and bottom, as an example, inside the furnace body 1. The workpiece W is carried between the upper and lower halogen lamps 2. The light source of the present invention is not limited to the halogen lamp, and the number, the arrangement position, and the shape are not limited to the state shown in FIG.

  The temperature sensor 3 is a radiation thermometer as an example, and measures the temperature of the object W to be processed. The temperature sensor 3 is disposed outside the furnace body 1 and is opposed to the bottom surface of the object to be treated W via the through hole 11 formed in the furnace body 1. The temperature sensor 3 is not limited to the radiation thermometer, and may directly measure the temperature of the object W, for example.

  The light amount sensor 4 is, for example, a silicon photodiode, which is disposed outside the furnace 1 and measures the light amount of the halogen lamp 2 via the through hole 12 formed in the furnace 1. The control unit 5 outputs drive data of the halogen lamp 2 created based on the detection temperature of the temperature sensor 3 and the detection light amount of the light amount sensor 4 to the lamp driving unit 6. The lamp driver 6 drives the halogen lamp 2 based on the drive data. The control unit 5 and the lamp drive unit 6 correspond to a drive control unit of the present invention.

  The temperature sensor 3 and the light quantity sensor 4 will be described in more detail with reference to FIGS. 2 and 3. As shown in FIG. 2, the temperature sensor 3 is located between two halogen lamps 2 disposed in the furnace body 1 in the horizontal direction, and the bottom surface of the processing object W via the through hole 11 It is directly opposed to. Thus, the temperature sensor 3 can measure the temperature of the object W accurately.

  Among the plurality of halogen lamps 2 disposed in the furnace body 1, the light quantity sensor 4 has a large influence on the overall temperature of the object to be treated W. It is arrange | positioned in the position which does not receive to the influence of the reflected light from the thing W and the inner wall of the furnace 1 easily.

  The light amount sensor 4 receives the light of the halogen lamp 2 through the light reduction filter 41 provided in the through hole 12. In addition, the light amount sensor 4 is attached to the heat dissipation member 42. The light amount sensor 4 can minimize the temperature rise due to the light of the halogen lamp 2 by the light reduction filter 41 and the heat radiating member 42, and can accurately measure the light amount of the halogen lamp 2.

  In addition, the arrangement | positioning position of the temperature sensor 3 and the light quantity sensor 4 is not restricted to the downward direction of the furnace body 1, One or both can also be arrange | positioned above the furnace body 1 or side. However, in order to measure the temperature of the flat object W to be processed by the temperature sensor 3 which is a radiation thermometer, it is preferable to dispose the temperature sensor 3 opposite to the main surface of the object W. In addition, the light amount sensor 4 needs to directly face the halogen lamp 2 at a position that is not easily affected by the reflected light from the workpiece W or the inner wall of the furnace body 1. Furthermore, since both the temperature sensor 3 and the light amount sensor 4 are connected to the control unit 5, they are preferably arranged close to each other. For example, both can be integrally fixed via the heat dissipation member 42.

  FIG. 3 shows the emissivity characteristic of the light amount sensor 4 constituted by a silicon photodiode as an example of the emissivity characteristic of the light amount sensor 4. As shown in the figure, the emissivity characteristic of the light amount sensor 4 substantially matches the emissivity characteristic of silicon which is the material of the object W to be treated. Further, the detection sensitivity wavelength range of the silicon photodiode overlaps with the emission wavelength of the halogen lamp 2. Emissivity characteristics are considered to be equivalent to light absorption characteristics. Therefore, the light amount sensor 4 can accurately detect the heating state of the object to be processed W by the light of the halogen lamp 2 based on the light amount of the light of the halogen lamp 2.

  The light source of the present invention is not limited to the halogen lamp 2. Even if it is other than the halogen lamp 2, it has a detection sensitivity wavelength range which overlaps with the light emission wavelength of the light source to be used, and is processed by using the light quantity sensor 4 made of a material whose emissivity characteristics substantially match. The heating state by the light of the light source of the object W can be accurately detected by the light amount of the light of the light source.

The drive control of the halogen lamp 2 based on the detection values of the temperature sensor 3 and the light amount sensor 4 will be described in more detail with reference to FIG. As shown in FIG. 4, the control unit 5 includes a temperature controller 51, a light amount controller 52, and a power converter 53. Control unit 5 over time to set the target temperature T _O of the workpiece W in accordance with the sequence stored in advance in a storage unit not shown. Temperature controller 51, based on the difference between the current temperature T _R and the temperature target value T _O of the workpiece W which is a temperature sensor 3 detects a halogen lamp 2 outputs a light amount target value L _O to be irradiated . Light amount control unit 52 determines the power control value to be supplied to the halogen lamp 2 on the basis of the difference between the current light amount L _R and the light amount target value L _O of the halogen lamp 2 to the light amount sensor 4 has detected, the power converter Enter in 53

  That is, in addition to the feedback control of the first loop that causes the object W to match the target temperature based on the temperature detected by the temperature sensor 3, the controller 5 determines the light intensity of the halogen lamp 2 based on the light intensity detected by the light intensity sensor 4. Perform feedback control of the second loop that controls The control unit 5 can directly control the light amount of the halogen lamp 2 for heating the object W, can quickly make the temperature of the object W coincide with the target temperature, and can control the temperature locus of the object W It can be controlled at a high speed of 1/10 seconds.

  As shown in the control theory, when performing constant value control in which the control target value is a constant value that does not change in time series, if the control system has one integration pole, no control delay occurs (control deviation is 0) . On the other hand, when performing ramping control to follow a control target value that changes in time series, it is desirable for the control system to have two integrating poles.

The transfer function C (s) of the control system in general PID control is K _P , the integral gain is K _I , and the derivative gain is K _D
C (s) = K _P + K _I · 1 / s + K _D · s
Is represented by When the control target has an integration pole, even a control system of a single control loop having only one integration pole 1 / s can suppress the control deviation in ramping control, but in general, the control target is an integration pole. There is little to have. Therefore, by providing two control loops in the control system and providing two controllers each having an integrating pole, it is possible to make the control deviation in the ramping control zero.

  For example, when a spike annealing process for holding the temperature of the object W at a desired peak temperature is performed using a control system having only one control loop, the desired peak temperature is reached as shown in FIG. It is necessary to hold the target value for a fixed time p later, and an adjustment operation of the target value is required. In addition, a control delay occurs and the control target can not follow the target value.

  On the other hand, in a control system having two control loops and two integrating poles, the control amount can be set to 0 when the target value reaches a desired peak value, and spike annealing processing, etc. The control object can be made to follow the target value which changes in time series of

  Therefore, the response of the temperature of the object to be processed W to the light amount is improved by the feedback control of the light amount of the halogen lamp 2, and the temperature of the object to be processed W is set to the target temperature locus without requiring work such as fine adjustment of control parameters. Can be made to follow quickly.

  The above description of the embodiments should be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated not by the embodiments described above but by the claims. Further, the scope of the present invention is intended to include all modifications within the scope and meaning equivalent to the claims.

DESCRIPTION OF SYMBOLS 1 furnace body 2 halogen lamp, light source 3 temperature sensor 4 light quantity sensor 5 control part 6 lamp drive part W processed object 10 lamp heating device 11, 12 through hole 41 light reduction filter 42 heat dissipation member 51 temperature controller 52 light quantity controller 53 Power converter

Claims (5)

A light source for irradiating the object to be treated with light and heating;
A temperature sensor for detecting the temperature of the object to be treated;
A light amount sensor for detecting the light amount of the light source;
A temperature control unit which outputs, as a light amount target value, a light amount to be irradiated by the light source in order to make the detected temperature of the temperature sensor coincide with a temperature target value;
A light amount control unit for driving the light source such that the light amount detected by the light amount sensor matches the light amount target value output from the temperature control unit;
, A lamp heating device. The temperature control unit executes feedback control of a temperature control loop that causes the detected temperature to match the temperature target value based on the temperature detected by the temperature sensor.
The light amount control unit executes feedback control of a light amount control loop that controls the light amount of the light source based on the light amount detected by the light amount sensor.
The lamp heating apparatus according to claim 1, wherein feedback control of a dual control loop comprising the temperature control loop and the light amount control loop is performed.   The lamp heating device according to claim 1, wherein the light amount sensor has an absorption area of light wavelength substantially coincident with an absorption area of the object to be processed.   The lamp heating device according to claim 3, wherein the light amount sensor has a detection sensitivity wavelength range overlapping a wavelength range of irradiation light of the light source.   The lamp light device according to any one of claims 1 to 4, wherein the light amount sensor is disposed on the opposite side of the object with the light source interposed therebetween.

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