KR101443842B1 - Temperature control system using synchronization control - Google Patents

Abstract

An embodiment of the present invention relates to a temperature control system using a synchronization control. An objective of the present invention is to enable a synchronization control between plural heaters when a plurality of divided areas of a heating target object is heated by using the heaters. To this end, a temperature control system according to an embodiment of the present invention, which utilizes a synchronization control between plural heaters when a plurality of divided areas of a heating target object is heated by using the heaters, includes: a detecting unit for detecting temperature of each area of the heating target object; and a process unit for calculating temperature gradients based on the detected temperature of the each area, setting the lowest temperature gradient among the temperature gradients of each area as a reference gradient, and reducing outputs of the other heaters except for a heater having the lowest temperature gradient until the temperature gradients of the other heaters are within a temperature rising rate preset to the reference temperature gradient.

Description

[0001] TEMPERATURE CONTROL SYSTEM USING SYNCHRONIZATION CONTROL [0002]

An embodiment of the present invention relates to a temperature control system using synchronous control.

In general, when an object to be heated such as a wafer or glass used in a semiconductor manufacturing process is divided into a plurality of regions and temperature is controlled, each region is controlled independently.

However, this independent control method does not consider the influence on each region, and it takes a long time until stabilization in which the temperature of the object to be heated becomes uniform.

1 is a view showing a heating system using a plurality of heaters according to the prior art.

As shown in FIG. 1, in the heating system using a plurality of heaters according to the related art, even if one region A reaches a desired temperature, if the temperature of the peripheral region B or C is not equal to the desired temperature, The power supply will be continuously supplied.

At this time, due to the heat transfer from the region B or C, the region A rises above a desired temperature, which may cause defective products.

Therefore, in the case of the heating systems interconnected as described above, there is a need for an efficient control system capable of correcting the influence of temperature on each other.

Korean Patent Registration No. 10-1314001 'Temperature control method, temperature controller and heat treatment apparatus' Korean Patent Registration No. 10-0777558 'Temperature control method, temperature controller, recording medium and heat treatment apparatus'

An embodiment of the present invention provides a temperature control system using synchronous control between respective heaters when heating a plurality of divided regions of an object to be heated by using a plurality of heaters.

A temperature control system using synchronous control according to an embodiment of the present invention is a temperature control system that uses synchronous control between respective heaters when heating a plurality of divided regions of an object to be heated using a plurality of heaters, A detector for detecting the temperature of each region of the object; And calculating a temperature slope for each region based on the detected temperature for each region, setting a lowest temperature slope among the temperature slopes for each region as a reference temperature slope, and outputting a heater having a remaining temperature slope as a preset temperature slope And decreasing the temperature until the temperature reaches a temperature increase rate.

The processor unit controls the temperature of the first heater 31 so that the temperature increase rate of the first heater 31 having the remaining temperature gradient is maintained within the set value of the temperature increase rate of the second heater 32 having the reference temperature slope You can limit the output.

Wherein the processor unit comprises: an arithmetic unit operable to calculate a temperature gradient for each region based on the detected temperature for each region; A main controller for independently controlling a temperature of each of the regions of the object to be heated; And an auxiliary control unit for controlling the temperature of the object to be heated equally under the control of the main control unit.

The main controller controls the output of the heater by setting the lowest temperature region as the reference region and divides the temperature gradient in the reference region by the temperature gradient of each region to the current output of the heater in the remaining regions other than the reference region And the auxiliary controller can control the output of the heater by multiplying a value obtained by subtracting the temperature of each region from the temperature of the reference region by a preset reference value.

The operation unit may set a time for reaching the target temperature from the current temperature based on the calculated temperature gradient.

The temperature control system using the synchronous control according to an embodiment of the present invention is different from the conventional general control system for each zone in which the object to be heated is divided into a plurality of zones and controlled, The temperature of the entire region of the object to be heated can be raised uniformly, and the stabilization time to the desired temperature can be minimized.

1 is a view showing a heating system using a plurality of heaters according to the prior art.
2 is a schematic view of a temperature control system using synchronous control according to an embodiment of the present invention.
3A and 3B are graphs for explaining the operation of a temperature control system using synchronous control according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating an operation of a temperature control system using synchronous control according to an embodiment of the present invention.
5 is a view schematically showing a temperature control system using synchronous control according to another embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which those skilled in the art can readily implement the present invention.

FIG. 2 is a schematic view of a temperature control system using synchronous control according to an embodiment of the present invention. FIGS. 3A and 3B illustrate operations of a temperature control system using synchronous control according to an embodiment of the present invention. FIG. 4 is a flowchart illustrating the operation of a temperature control system using synchronous control according to an embodiment of the present invention. FIG. 5 schematically illustrates a temperature control system using synchronous control according to another embodiment of the present invention. Fig.

Referring to FIG. 2, a temperature control system using synchronous control according to an embodiment of the present invention includes a plurality of heaters 30 for heating a plurality of divided regions of a heated object 1, 30, and includes a detection unit 10 and a processor unit 20. The detection unit 10 and the processor unit 20 are connected to each other.

The plurality of heaters and the object to be heated 1 may be provided in a chamber (not shown) in which a heating process is performed. A heating plate (not shown) for uniformly heating the object 1 (for example, a substrate, a wafer, or the like) may be provided in the chamber. On the heating plate, the object 1 to be heated may be placed in a horizontal direction. A support pin (not shown) may be provided on the upper surface of the heating plate to support the object 1 in a horizontal direction. Further, a base for stably supporting the heating plate is provided below the heating plate. A Teflon coating may be formed on the surface of the base to prevent convection from occurring in the chamber due to a temperature difference with the outside of the chamber, and a heat insulating layer may be formed to prevent heat held inside the chamber from being discharged to the outside . A plurality of heaters 30 (a first heater 31, a second heater 32, and a third heater 33) for individually heating the upper surface of the heating plate are provided in the heating plate.

The detection unit 10 is a device for detecting the temperature of each region of the object 1 to be heated and includes a plurality of temperature sensors for detecting the respective temperatures of the regions of the heating plate. The temperature sensor is disposed inside the heating plate so as to be evenly distributed over the entire area of the heating plate. 2, the temperature sensor includes a first detecting portion 11 for detecting the temperature of the first heater 31 region, a second detecting portion for detecting the temperature of the second heater 32 region 12), and a third detector (13) for detecting the temperature of the third heater (33) region. It is preferable that the temperature sensor has about 5 to 20 temperature sensors. If the number of the temperature sensors is less than 5, it is difficult to accurately measure the dispersion of the temperature with respect to the entire surface of the object to be heated 1. If the number of temperature sensors is 20 or more, it becomes difficult to manage the temperature sensor. That is, when the temperature sensors are mounted, it is necessary to periodically inspect and manage whether the temperature sensors are normally operating. However, when the temperature sensors are too many, such management is difficult.

The processor unit 20 calculates a temperature gradient for each region based on the temperature detected by the detection unit 10, sets the lowest temperature gradient among the temperature gradients for each region as a reference temperature gradient, Is decreased within a predetermined temperature increase rate with respect to the reference temperature slope. That is, the processor unit 20 sets the temperature increase rate of the first heater (the second and third heaters 32 and 33 in FIG. 2) having the remaining temperature gradients to the second heater The output of the first heater 31 can be limited so as to be kept within the set value of the temperature increase rate of the first heater 31. In other words, the processor unit 20 calculates the temperature gradient using the temperature detected by the temperature sensors, compares the calculated temperature gradient with the reference temperature gradient having the lowest gradient, and outputs the output of the heater having the remaining temperature gradient To be close to the temperature increase rate of the reference temperature slope.

The processor unit 20 includes an operation unit 23, a main control unit 22, and an auxiliary control unit 21 as shown in FIG.

The arithmetic unit 23 is a device for calculating a temperature gradient for each region based on the temperature of each region detected by the detection unit 10. 2, based on the temperatures detected by the first detecting unit 11, the second detecting unit 12, and the third detecting unit 13, the calculating unit 23 calculates, based on the temperatures detected by the first calculating unit 23a, The second heater 32 and the third heater 33 through the second calculation unit 23b and the third calculation unit 23c. Further, the calculating unit 23 can set a time for reaching the target temperature from the current temperature based on the calculated temperature gradient. The calculating unit 23 can calculate a temperature increase rate and set a slope for determining a time to reach the target temperature.

The main control unit 22 is an apparatus for controlling the temperature of the object 1 to be heated independently. The main control unit 22 sets the lowest temperature region as a reference region and controls the output of the heater 30, The output of the heater 30 can be controlled by multiplying the current output of the heater 30 by a value obtained by dividing the temperature gradient in the reference region by the temperature gradient in each region.

More specifically, the main controller 22 controls the first heater 31, the second heater 32 and the third heater 33 so as to equalize the temperature-rising slopes of the first heater 31, the second heater 32, The output of the remaining two heaters is limited based on the inclination of the heater 30 having the lowest temperature increase rate of the heater 32 and the third heater 33 to match the inclination of the heater 30 having the lowest temperature increase rate do. The main control unit 22 limits the outputs of the remaining two heaters based on the inclination of the heater 30 having the lowest temperature rise rate so that the temperature rise rate width is adjusted to match the slope of the heater 30 having the lowest temperature rise rate Can be set. The main control unit 22 may control only the first heater 31 among the plurality of heaters 30 and may control the n heaters including the first heater 31.

The auxiliary control unit 21 is an apparatus for individually controlling the temperature of the object 1 to be heated. The auxiliary control unit 21 multiplies the value obtained by subtracting the temperature of each region from the temperature of the reference region by a preset reference value, That is, power supply). For this purpose, the auxiliary controller 21 may include a plurality of auxiliary controllers (i.e., a first auxiliary controller 21a, a second auxiliary controller 21b, and a third auxiliary controller 21c) have. The auxiliary control unit 21 can control the temperature of the area of the object 1 to be heated under the control of the main control unit 22 in the same manner. At this time, the output of the heater through the auxiliary controller 21 is calculated in consideration of the current temperature and the temperature gradient of each region.

The processor unit 20 configured as described above controls the output of the main control unit 22 that performs independent control for each area and the output of the auxiliary control unit 21 that considers mutual interference for each area, And the output of the branches is summed to apply the combined control output.

3A to 4, when the MV of the first heater 31, the second heater 32, and the third heater 33 is 100%, the operation of the processor unit 20 will be described in more detail with reference to FIGS. 3A, the processor unit 20 reduces the MVs of the second heater 32 and the third heater 33 by a predetermined amount and outputs the reduced MV as shown in FIG. 3B. The temperature of the second heater 32 and the temperature of the third heater 32 are increased until the rate of temperature rise is within the set amount (within a certain range of PV of the first heater 31) 33) gradually decreases. The processor unit 20 controls the temperature of the second heater 32 and the temperature of the third heater 33 to be lower than the set temperature of the first heater 31, 32 and the third heater 33 are limited and output. Thus, mutual interference between the heaters 30 can be minimized, and the temperature stabilization time can be minimized.

The present invention is characterized in that the main control unit 22 and the auxiliary control unit 21 considering interconnectivity with respect to each region in the control of a plurality of regions of the heated object 1 are provided and the main control unit 22, By controlling the outputs of the respective heaters with the combined control output of the sum of the temperatures of the respective heaters 21, the temperature of each region can be made to rise in the same time.

5, a temperature control system using synchronous control according to another embodiment of the present invention includes a heater or an electric furnace (not shown) which requires a constant temperature uniformity by installing a multi-channel heater in the same equipment or space 1000). In order to realize this operation, in the present embodiment, as in the embodiment of Figs. 2 to 4, the object to be heated 1 provided inside the electric furnace 1000, The first detection unit 110, the second detection unit 120 and the third detection unit 130) connected to the detection unit 100 and the processor unit 200 (i.e., the first auxiliary control unit The main control unit 220 and the auxiliary control unit 210 including the first auxiliary control unit 211, the second auxiliary control unit 212 and the third auxiliary control unit 213. [

According to the present invention, unlike conventional single-loop control, temperature control is performed in consideration of temperature, temperature gradient, etc. of different channels of a plurality of heaters, thereby minimizing overshooting and hunting. And the temperature difference between the heaters can be minimized at the time of heating the heating block provided with the heaters having different capacities, so that the temperature can be raised.

Meanwhile, the processor units 20 and 200 in the present invention are provided inside a main body case (not shown) for protecting the respective components. In this case, the body case may comprise a polyolefin resin composition comprising 25 to 39% by weight of an olefin resin and 61 to 75% by weight of an inorganic filler which is glass fiber, barium sulfate or a mixture thereof.

The olefin-based resin preferably contains 25 to 39% by weight of the ultrafine crystalline resin and improves the flowability of the inorganic filler and improves the heat resistance, rigidity and thermal deformation of the polyolefin resin composition. When the amount of the inorganic filler is less than 25% by weight, the inorganic filler is excessively used to lower the flowability and moldability of the resin. If the amount is more than 39% by weight, the injection molded product is not effective in improving the strength, impact resistance and dimensional stability I have a problem. Specifically, the ultra-crystalline olefin-based resin may be an isotactic polypropylene, a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer and a propylene- Polymer, and a copolymer or random copolymer of propylene or a mixture thereof.

The olefin resin preferably has a melt index of 1 to 70 g / 10 min (230 ° C), more preferably 3 to 30 g / 10 min.

It is preferable that the isotactic peptad fraction of the homo part in the olefin resin is 96 to 99% by C13-NMR. If it is less than 96%, the heat resistance, rigidity and heat change of the polyolefin resin composition are deteriorated .

The inorganic filler is preferably glass fiber, barium sulfate, or a mixture thereof. The inorganic filler includes 61 to 75% by weight of the inorganic filler and improves strength and impact resistance during injection molding. If the amount of the inorganic filler is less than 61% by weight, the strength and impact resistance are lowered and the problem is caused by the low weight. When the inorganic filler is more than 75% by weight, the production process is not smooth due to high weight and high rigidity.

The glass fiber preferably has a chopped strand shape having an average particle diameter of 5 to 15 탆 and a length of 1 to 16 mm. When the average particle diameter is less than 5 탆, the glass fiber tends to be broken during mixing The stiffness effect is insufficient. When the thickness exceeds 15 탆, the deformation of the molded article may be deteriorated and the appearance of the molded article may be deteriorated. If the length is less than 1 mm, the strength, impact resistance and weight are lowered. If the length is more than 16 mm, it is difficult to input the material in the processing step. Specifically, it is preferable that the glass fiber is a glass fiber whose surface has been treated with a modified polypropylene obtained by grafting an unsaturated carboxylic acid or its anhydride. In the case of injection molded articles, the strength, impact resistance and heat resistance of the molded article are improved . The unsaturated carboxylic acid is preferably one selected from the group consisting of acrylic acid, tricrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, ditralic acid, sorbic acid and phosphoric acid, and the anhydride is preferably an acid anhydride, an ester, And metal salts, and specific examples thereof include maleic anhydride, itaconic anhydride, anhydrodithioconic acid, sodium acrylate, and sodium methacrylate. In order to treat the surface of the glass fiber, it is preferable to use a modified polypropylene prepared by charging an unsaturated carboxylic acid or its anhydride and a catalyst to a crystalline polypropylene into a twin-screw extruder and melting by heating at 180 to 220 ° C , The modified polypropylene and the glass fiber are preferably treated at a ratio of 1: 9.

The barium sulfate preferably has an average particle diameter of 0.5 to 1 μm by laser diffraction scattering. When used in combination with glass fibers, the barium sulfate plays an effective role in exhibiting high weight characteristics. If less than 0.5 μm, high weight and high rigidity properties And it is difficult to inject in the processing step. When the thickness exceeds 1 탆, there is a problem that the gloss of the surface appearance of the molded article is lowered during the production of an injection molded article.

When the glass fiber and barium sulfate are mixed and used as an inorganic filler, the mixing ratio of glass fiber and barium sulfate is preferably 2: 8 to 8: 2, more preferably 4: 6 to 5: 5.

In addition, the polyolefin resin composition can be applied based on the production method and processing conditions of the resin composition known in the art. For example, polypropylene may be blended at the melting point or higher and used. That is, the polyolefin resin composition may be used for producing a body case through a conventional molding method such as injection molding and extrusion molding.

Hereinafter, the polyolefin resin composition will be described by way of examples.

≪ Examples 1 to 4 and Comparative Examples 1 to 4 >

An olefin resin and an inorganic filler were charged into a hopper of a kneading extruder after being dry blended in a ribbon mixer for 0.5 to 4 hours and then melt kneaded at 180 to 220 ° C to prepare a polyolefin resin composition. The contents are shown in Table 1 below.

Category (% by weight) Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Olefin resin 39 30 25 39 100 70 46 70 weapon
Filler Fiberglass-1 31 30 30 - - 30 - - Fiberglass-2 - - - 21 - - - - Fiberglass-3 - - - - - - - 30 Barium sulfate 30 40 45 40 - - 54 -

(1 to 70 g / 10 min, ethylene unit content: 10.5 mol%, isotactic peptad fraction: 96 to 99%) was used as the olefinic resin, and the glass fiber-1 The glass fiber-2 has an average particle diameter of 9 to 13 탆 and a length of 10.0 to 15.0 mm, and the glass fiber-3 has an average particle diameter of 28 to 32 탆 , And a length of 3.0 to 4.5 mm is used.)

<Test Example>

In order to measure the mechanical properties of the polyolefin resin compositions prepared through Examples 1 to 4 and Comparative Examples 1 to 4, specimens were produced by injection molding at a mold temperature of 70 ° C. and an injection pressure of 60 to 100 bar. The results are shown in Table 2 below.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Flexural modulus 90,000 100,000 100,000 70,000 14,000 62,000 31,000 89,000 Impact strength at room temperature 15 15 15 21 10 15 4 22 Low temperature impact strength 12 12 12 18 5 9 3 13 importance 1.53 1.87 1.91 1.67 0.91 1.12 1.56 1.12 MD Shrinkage 3.1 3.1 3.1 2.8 15.8 9.0 9.0 8.8 TD shrinkage 2.6 2.6 2.6 2.4 15.8 2.0 8.8 1.9 Surface gloss 35 30 28 40 75 20 60 10

The flexural modulus (kg / cm 2) was measured at room temperature by the method of ASTM D 790 and the impact strength at room temperature (kg · cm / cm) was measured at room temperature by the method of ASTM D 256, (kg · cm / cm) was measured at -10 ° C. according to the method of ASTM D 256, and specific gravity was measured at room temperature according to the method of ASTM D 1238. The surface gloss (%, 60 ') was measured by ASTM D 523 And the MD shrinkage (%) was measured by the method of ASTM D 955 in the machine direction at room temperature. The TD shrinkage (%) was measured by the method of ASTM D 955 at room temperature in the transverse direction Respectively.

As shown in Table 2, the polyolefin resin compositions prepared in Examples 1 to 4 have higher flexural modulus, impact strength and specific gravity than the comparative examples 1 to 4, and have a low shrinkage ratio, have.

Accordingly, the polyolefin resin composition can improve strength, impact resistance and dimensional stability when it is produced into a body case through injection molding.

As described above, the present invention is not limited to the above-described embodiment, but may be applied to a temperature control system using synchronous control according to the present invention It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

1: object to be heated 10, 100:
11, 110: first detection unit 12, 120: second detection unit
13, 130: third detecting unit 20, 200:
21, 210: auxiliary control unit 21a, 211: first auxiliary control unit
21b, 212: second sub control unit 21c, 213: third sub control unit
22, 220: main control unit 23:
23a: first calculation unit 23b: second calculation unit
23c: a third calculating unit 30, 300: a heater
31, 310: first heater 32, 320: second heater
33, 330: third heater 1000: electric furnace

Claims (5)

A temperature control system using synchronous control between respective heaters when heating a plurality of divided regions of a heated object (1) by using a plurality of heaters,
A detection unit (10) for detecting the temperature of each region of the object (1) to be heated; And
Wherein the temperature gradient of each region is calculated based on the detected temperature of each region, and the output of the heater having the lowest temperature slope as the reference temperature slope and the lowest temperature slope as the reference temperature slope, (20) until it is within a predetermined rate,
The processor unit 20
An operation unit (23) for calculating a temperature slope for each region based on the detected temperature for each region;
A main control unit (22) for controlling the temperature of the object to be heated (1) independently; And
And an auxiliary control unit (21) for controlling the temperature of the area of the object (1) to be heated under the control of the main control unit (22)
The main controller 22 sets the lowest temperature region as a reference region and controls the output of the heater. In the remaining regions other than the reference region, the temperature gradient in the reference region is added to the current output of the heater, The output of the heater is controlled by multiplying the value divided by the slope,
Wherein the auxiliary controller (21) multiplies a value obtained by subtracting the temperature of each region from the temperature of the reference region by a predetermined reference value to control the output of the heater. The method according to claim 1,
The processor unit 20 controls the temperature of the first heater 31 having the remaining temperature gradient so that the heating rate of the first heater 31 having the remaining temperature gradient is maintained within the set value of the heating rate of the second heater 32 having the reference temperature slope, And the output of the temperature control unit (31) is limited. delete delete The method according to claim 1,
Wherein the operation unit (23) can set a time at which the temperature reaches the target temperature from the current temperature based on the calculated temperature gradient.

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