JP2003031341A - Plate heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate heater capable of controlling precise temperature distribution including uniform heating while avoiding size increase of heating elements or considerable increase in cost. SOLUTION: The plate heater consists of a plurality of plate-shaped heating elements 3 interposed between a pair of heat conducting plates 1 and 2. Heating control of each heating element 3 can be performed separately. The subdivide means A for reducing the thickness of one conducting plate 1 is arranged between the corresponding area to the element 3 and the other area in at least one of the pair of heat conducting plates 1 and 2. The subdivide means A consists of cutting lines s along which each plate meets each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate heater such as an IR heater used in a heat treatment process in various manufacturing processes, and more particularly to a technique for improving the degree of freedom in temperature control.

[0002]

2. Description of the Related Art A conventional plate heater is disclosed in Japanese Patent Laid-Open No. 11-
As disclosed in Japanese Patent No. 54248, the heating element is sandwiched between a pair of metal plate bodies such as aluminum. That is, a double-sided plate heater is configured by interposing a thin heater having a mica plate plate as an insulating material on both sides between a pair of copper plates.

For example, when a planar sample such as a glass substrate is heated by a plate heater using far infrared rays as a heating element, the amount of far infrared rays irradiated is smaller in the outer portion than in the central portion. Due to this, the temperature outside the sample tends to be low.

Therefore, in order to improve it, the following measures (1) to (3) have been conventionally adopted. A means for heating the heater by making the temperature distribution of the heater extremely accurate and shortening the distance between the sample and the heater. A means to make the size of the heater large enough for the sample. Means of simply arranging and heating small plate heaters.

[0005]

In the above means, there is a contradictory relationship between making the temperature distribution of the heater extremely accurate and increasing the size of the heater, and increasing the cost. With the above-mentioned means, the heater and the entire device become very large, and the power consumption also increases and the running cost increases. this is,
For example, when used in a clean room or the like, there are problems of installation space and weight. The above-mentioned means is difficult in that the heater is complicated to handle and the irradiation is likely to be non-uniform due to the influence of the frame or the like. That is, each of the above-mentioned means has merits and demerits, and there is room for further improvement.

An object of the present invention is to provide a plate heater which can control the temperature distribution with high accuracy such as uniform heating while avoiding an increase in size of the heating element and a large increase in cost.

[0007]

According to a first aspect of the present invention, there is provided a plate heater having a plate-shaped heating element interposed between a pair of heat transfer plate members, and a plurality of heating elements are provided. The heat generating element of each of the heat generating elements is configured to be freely controllable, and at least one of the pair of heat transmitting plate materials is provided between the area corresponding to the heat generating element and the other area. It is characterized in that a dividing means for reducing the thickness of one heat transfer plate is provided so as to divide the two regions.

According to the structure of the first aspect, since a plurality of heating elements whose heat generation can be controlled individually are provided, the temperature of each heating element can be individually controlled as needed. For example, it is possible to control so that the heat generation amount of the heating element located in the outer peripheral portion is larger than that of the heating element located in the central portion as the plate heater, or to make the temperature of the right half and the left half different. You will be able to do it freely.

According to a second aspect of the present invention, in the first aspect of the invention, the dividing means are cutting lines which are in contact with each other.

According to the second aspect of the present invention, the splitting means are cutting lines which are in contact with each other, that is, the heat transfer plates which are independent of each other are arranged in contact with each other. Since the continuity as a line is interrupted at the cutting line and it is in a partial contact state, the heat conduction action becomes extremely slow at that cutting line, and the heat generation control in each heating element is performed by other heating elements. It becomes difficult to reach other areas such as areas. And since adjacent heat transfer plates are in contact with each other at the cutting line, when viewed as a heat transfer plate,
Although the cutting line is visible on the appearance, the shape as a single plate is maintained and the original heating action is not adversely affected. Also, the strength required for the plate heater can be secured by the other heat transfer plate material.

According to a third aspect of the present invention, in the first aspect, the dividing means is a groove that does not cut.

According to the third aspect of the present invention, since the slitting means is a groove that does not lead to cutting, the thickness of the heat transfer plate material, that is, the cross-sectional area is sharply reduced at the groove portion, and the heat conduction effect is achieved. The heat becomes slow, and it becomes difficult for the heat generated by the heating element to be transferred to a region of the heat transfer plate other than the portion corresponding to the heating element. Since the slitting means is a groove,
The plate for heat transfer on the side where the groove is formed is also one continuous plate, which is advantageous in terms of strength as compared with the case where the cutting line is formed. If the groove appears on the outer surface side,
It can be seen from the outside that the heat transfer plate is separated by the groove, but when it appears on the inner surface side, the outer surface has the same appearance as a single plate without grooves, and both sides have heat A state that is easy to use as an irradiation surface can be obtained.

According to a fourth aspect of the present invention, the cutting line according to the second aspect or the groove according to the third aspect is formed in the entire area between the both areas.

According to the structure of claim 4, the portion surrounded by the cutting line or the groove corresponds to a single heating element,
Since the heat transfer plate material part whose heat generation is controlled by a single heating element is more clearly separated from other areas, the heat transfer plate material partly This makes it possible to perform temperature control more finely in a state where the heat influence on other parts is reduced.

According to a fifth aspect of the present invention, in the first to fourth aspects, the heat transfer plate is made of an aluminum alloy.

According to the fifth aspect of the invention, since the heat transfer plate is made of an aluminum alloy having excellent heat conduction performance and relatively high mechanical strength, a cutting line or a groove that does not lead to cutting is formed. Alternatively, even if the slitting means is formed by a long hole or the like, it is possible to satisfy both of the original heat conduction effect and the heat transmission regulation effect by the slitting means in a high dimension.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the plate heater P includes a pair of heat equalizing plates (an example of a heat transfer plate material) 1.
A plate-shaped space heater between the two (an example of a heating element)
IR (Far Infrared) of sandwich structure consisting of 3
It is composed of a heater. Both the front-side soaking plate 1 and the back-side soaking plate 2 are made of aluminum alloy, and the space heater 3 is
Insulating layers 5 and 5 are provided above and below the heat generating portion 4 formed by a heater wire or the like.

As shown in FIG. 2, in this example, six space heaters 3 are provided, and the heat generation of each of the six space heaters 3 can be controlled independently. Between the area corresponding to the space heater 3 in the front side heat equalizing plate 1 of 2 and the other area,
A dividing means A for reducing the thickness of the front side heat equalizing plate 1 is provided so as to divide these two regions.

That is, the front side heat equalizing plate 1 is composed of six rectangular unit heat transfer plates 1a arranged side by side in front and rear, right and left without contact so as to be in contact with each other. A space heater 3 is provided corresponding to each heat transfer plate 1a. That is, the dividing means A is constituted by the vertical and horizontal cutting lines s formed by bringing adjacent unit heat transfer plates 1a, 1a into contact with each other. The six space heaters 3 and the unit heat transfer plates 1a are strongly supported by the one back side heat equalizing plate 2, and are integrated with each other to form the form as the rate heater P. There is.

The space heater 3 is formed so that its outer shape is slightly smaller than the unit heat transfer plate 1a, and a space is provided between the space heaters 3 and 3 which are adjacent to each other so as not to contact each other. The pair of terminals 6, 6 of the cathode is set to exist outside the unit heat transfer plate 1a. Further, the terminals 6 and 6 are connected to a control device 9 through an anode wire 7 and a cathode wire 8 which are lead wires, and a controller 10 corresponding to each space heater 3 is also connected to the control device 9. It is connected.

In other words, each space heater 3 can be controlled in heat generation by a controller (temperature controller) 10 dedicated to the space heater 3, and the temperature can be freely set. Thereby, for example, all the regulators 10 are set to the same operation amount and all the unit heat transfer plates 1a are set to the same temperature, or only the two center unit heat transfer plates 1a and 1a are changed in temperature. You are free to do anything. As shown in FIG. 2, if the cutting line s is formed in the entire area between the adjacent unit heat transfer plates 1a, 1a, heat generation control can be performed more efficiently and with less thermal influence on others.

However, the back side heat equalizing plate 2 is turned to the upper side, and this back side heat equalizing plate 2 is used to heat an object to be heated (a glass substrate for liquid crystal, a planar sample such as a semiconductor wafer). It is also possible. Even in this case, by controlling the heat generation of each space heater 3 individually, it is possible to partially make the temperature difference of the back side heat equalizing plate 2, but the cutting line s
The front-side heat equalizing plate 1 whose heat conduction has been cut off is more remarkably able to hold a temperature difference for each unit heat transfer plate 1a during heating.

The following is described for reference. The small space heater 3 as the heating element 3 has independent wiring so that individual control can be performed, and by operating the controller 10, the space heater 3 at a position where a high temperature is desired to have a large output and a high temperature. The output is made small for the space heater 3 at a portion which is not desired to be raised. However, in the conventional structure, heat is transferred by the heat conduction of the pair of heat transfer plates sandwiching the space heater 3, and the temperature gradient cannot be applied to the surface of the plate heater 3. Therefore, the pair of heat transfer plates 1 and 2 sandwiching the space heater 3 is divided only on the irradiation surface to suppress the movement of heat due to heat conduction, and a temperature gradient is given to the surface of the plate heater 3. At this time, even if the cut and independent plates (unit heat transfer plates 1a, 1a) are in contact with each other at the cutting line s, the heat conduction is significantly worse than that in the single plate state. The independence of heat generation control is improved.

By providing a temperature gradient, the amount of far infrared rays irradiated from the space heater 3 to the heating target becomes equal, and the heating target can be heated uniformly. Since the plate heater 3 and the heating target have a certain distance, the temperature distribution of the heating target can be made more uniform than the temperature distribution of the plate heater 3. That is, since it is not necessary to make the temperature distribution of the plate heater 3 so accurate, the cost can be reduced and the plate heater 3 can be manufactured. As a result, it is possible to increase the size of the plate heater P in response to an increase in the size of the heating target without significantly increasing the cost.

The appearance of the plate heater P is a single heater having a sandwich structure, and it is easy to handle.
Even when it is attached to any device, it can be fixed simply by supporting the end and does not require a frame or the like. Therefore, the far infrared irradiation of the heating target by the space heater 3 does not become uneven due to the influence of the frame or the like.

If the heat equalizing plate members 1 and 2 for sandwiching the space heater (heat generating member) 3 are made of a material having good heat conduction such as aluminum (aluminum alloy), the temperature distribution of the heat generating member 3 due to the heater wire or the like is used. Even if the temperature is bad, the temperature distribution on the surface of the plate heater 3 can be made uniform by heat conduction. That is, it is possible to improve the temperature distribution in each heat generation region (the unit heat transfer plate 1a or the unit heat transfer range 1b shown in FIG. 3). At this time, the thicker the soaking plate materials 1 and 2, the greater the effect. Each heating area 1
The temperature distribution in a and 1b can be made more uniform.

For example, space heaters 3 and 3 having different capacities
Even if they are arranged in advance and the same output is given, the same effect as above can be expected. In this case, since it is not necessary to make the wiring independent, the number of terminals 6 of the space heater 3 can be significantly reduced. As a result, the terminal 6 portion is set to the heating area 1a or 1b.
It is possible to take it out from the outside, and the structure of the terminal 6 can be simplified. This makes it possible to solve problems such as the heat resistant temperature of the heater end 6 and the cleanliness. As described above, the plate heater P can be used to uniformly heat an object to be heated (a glass substrate for liquid crystal, a planar sample such as a semiconductor wafer), and the cost thereof can be suppressed.

[Other Embodiments] << 1 >> As shown in FIG. 3, the front-side heat equalizing plate 1 is provided with a groove m on its inner side (space heater 3 side) that does not reach the upper surface, that is, does not lead to cutting. By forming the space heater 3, the area 1b (unit heat transfer range) corresponding to the space heater 3 and the area 1b (unit heat transfer range) other than the area 1b can be divided into the area 1b and 1b. good. The groove m is
The cross section may be triangular or U-shaped, and these grooves m
The above-mentioned cutting line s functions as a dividing means A for reducing the thickness of the front side heat equalizing plate 1.

<< 2 >> As the heating element 3, an IR heater,
Various modifications such as nichrome wire are possible. Further, the front side heat transfer plate material 1 is laminated with an upper surface plate made of a thin plate and a lower surface plate made of a plurality of independent unit heat transfer plates 1a having a large thickness for each heating element 3. As a matter of fact, the plate heater P provided with the dividing means A by the groove s which does not result in cutting
Also good.

<< 3 >> In FIG. 1, the cutting line s is not limited to being provided only on the heat transfer plate member 1, and the cutting line s may be provided on the heat transfer plate member 2. At this time, the cutting line s of one or both of the heat transfer plate members 1 and 2 is filled with heat-resistant cement or the like so that the whole is not disassembled. Further, in FIG. 2, the groove m is not limited to being provided only in the heat transfer plate material 1, and the groove m can be provided in the heat transfer plate material 2 as well. In this case, the grooves m of the heat transfer plate materials 1 and 2 are preferably inward with respect to each other, but the grooves m of the heat transfer plate material 2 may be open outward. Further, the cutting line s may be provided on one heat transfer plate and the groove m may be provided on the other heat transfer plate. In this way, when the cutting line m and / or the cutting line s is provided on both of the heat transfer plate members 1 and 2, the temperature of the surface of one heat transfer plate member used for heating is different from that of the other heat transfer plate member. It is less susceptible to heat transfer through and allows for more precise temperature control as a whole.

[0031]

As described above, in the plate heater according to the present invention, a plurality of heat generating elements whose heat generation can be controlled are provided for each of the pair of heat transmitting plate materials and the heat generating element in one of the heat transfer plate materials is used. Between the corresponding area and the other area,
Since the subdivision means for reducing the thickness of one of the heat transfer plate members is provided so as to divide these two regions, the heat generation amount of the heat generating element located in the outer peripheral portion is smaller than that of the heat generating element located in the central portion as the plate heater. It becomes possible to control the temperature of each heating element individually, such as by controlling it so that it becomes larger, and it is possible to uniformly heat it while avoiding enlargement of the heating element and significant cost increase. As a result, the temperature distribution can be accurately controlled.

By providing the dividing means by the cutting lines which are in contact with each other, the heat generation can be efficiently controlled while reducing the thermal influence on other areas, and in the case of providing the dividing means by the groove which does not lead to the cutting, It is possible to achieve the above-mentioned effect while making no change in appearance. Further, if a cutting line or a groove that does not lead to cutting is formed in the entire area between the area corresponding to the heating element in one heat transfer plate and the other area, it is more efficient and heat to the other. Heat generation can be controlled with little influence, and if the heat transfer plate is made of an aluminum alloy, there is an advantage that the above effect can be satisfactorily exhibited while the strength is sufficient.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure.

FIG. 2 is a plan view showing a plate heater and a heat generation control system.

FIG. 3 is a partial cross-sectional view of the splitting means showing another structure of the splitting means.

[Explanation of symbols]

1, 2 Heat transfer plate 3 heating element A small break means s cutting line m Not cut

Claims (5)

[Claims] 1. A plate heater having a plate-shaped heating element interposed between a pair of heat transfer plate members, wherein a plurality of the heating elements are provided, and the plurality of heating elements are separately provided. While being configured to control heat generation, between a region corresponding to the heating element in at least one heat transfer plate member of the pair of heat transfer plate members and a region other than the heat transfer plate member, these two regions are divided so as to be separated from each other. A plate heater provided with slicing means for reducing the thickness of one heat transfer plate. 2. The plate heater according to claim 1, wherein the dividing means are cutting lines that are in contact with each other. 3. The plate heater according to claim 1, wherein the dividing means is a groove that does not lead to cutting. 4. The cutting line according to claim 2, or claim 3.
A plate heater in which the groove described in 1) is formed in the entire area between the both areas. 5. The plate heater according to claim 1, wherein the heat transfer plate is made of an aluminum alloy.