JP2002158081A - Heater unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat conduction efficiency of a heating element between metal plates and suppress cost hike. SOLUTION: A heating element pinched by sheet insulating materials from top and bottom faces is interposed between a convex and a concave faces arranged opposite to each other up and down and formed with their circumference edges sealed. A heating element with its top and bottom faces pinched by sheet insulating materials is interposed between the two metal plates arranged opposite to each other up and down, and all of them are integrally compression molded. A plurality of concave grooves are formed on either of the two metal plates arranged opposite to each other with their circumference sealed, and a heating element wound round sheet insulating materials are interposed in each groove. The two metal plates are screwed down to each other at any desired place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heater unit,
In particular, it is an object to obtain a heater unit having improved thermal efficiency.

[0002]

2. Description of the Related Art 1) Conventionally, a heater structure in which a heating plate is built in a metal plate used in a semiconductor processing device or the like, that is, a so-called heater unit is generally formed by casting a stainless steel sheath heater in an aluminum plate,
A stainless steel sheath heater is sandwiched between two aluminum or stainless steel plates, tightened with bolts, and the outer periphery of the sandwiched plate is welded to form a heater unit.

[0003] In particular, in a bolt-tightened heater unit, a metal plate is divided into upper and lower plates, and a stainless sheath heater is installed in a groove formed in a lower plate made of aluminum, stainless steel, or the like. Then, the upper plate is brought into close contact with the upper plate, and appropriate portions of the upper plate are tightened with bolts, or the periphery of the plate is sealed by welding or the like, and integrated as a unit.

[0004] 2) Further, instead of using a sheath heater, a groove is filled with magnesia powder, and a nichrome wire is embedded in the magnesia powder.

[0005]

1) In the above-mentioned conventional apparatus, for example, in a cast-type heater unit,
Since aluminum is used as the metal plate, its melting point is relatively low at about 540 ° C., and it is difficult to use it in an environment of 500 ° C. or more.

Further, since stainless steel and aluminum used as protective pipes for sheath heaters have different thermal expansion coefficients, the heater is deformed by the thermal stress at a high temperature, so that the heater is frequently used and used repeatedly. When the number of heaters increases, the heater unit is disconnected or the entire heater unit is deformed.

2) In addition, these sheath heaters are configured such that a sheath tube having a heating wire therein is bent and disposed in a groove provided in a plate, and the sheath tube is at an acute angle or near this angle. Since the heater is crushed when bent, the shape and density of the heater are limited, and it is difficult to design the heater wiring or layout so that the entire plate can be heated uniformly and at an early temperature.

[0008] 3) The plate heater by bolting has poor heat conductivity due to low adhesion between the upper and lower plates and the sheath heater or between the plates, and in some cases, the temperature is locally increased and the heater is heated. Could be damaged.

4) On the other hand, when embedding the nichrome wire in the magnesium powder, the nichrome wire is formed in a desired density and shape within a deformable range of the nichrome wire so that the nichrome wire does not contact the wall surface or the bottom surface of the groove of the plate. Subtle adjustments were required for the work to place them.

The present invention has been made to eliminate the above disadvantages.

[0011]

SUMMARY OF THE INVENTION A heater unit according to the present invention is formed on two metal plates which are vertically opposed to each other and whose peripheral edges are sealed, and formed on one of the two metal plates. It is characterized by comprising a concave surface, a convex surface fitted on the concave surface formed on the other side, and a heating element interposed between the convex surface and the concave surface and having upper and lower surfaces sandwiched by a sheet-like insulating material.

Further, the heater unit of the present invention has two metal plates disposed vertically opposed to each other, and the upper and lower surfaces interposed between the two metal plates are sandwiched by sheet-like insulating materials. It is characterized by comprising a heating element, and these are integrally compression molded.

[0013] The heater unit of the present invention comprises two metal plates which are disposed vertically facing each other and whose peripheral edges are sealed, and a plurality of grooves formed in one of the two metal plates. And a heating element inserted in each of the grooves and wound by a sheet-shaped insulating material.

Further, in the heater unit of the present invention, desired portions of the two metal plates are screwed to each other.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIG. 1, a concave surface 4 is formed by leaving an edge 3 on one of the metal plates 1 and 2, which are vertically opposed to each other, for example, the upper surface of the lower metal plate 2. And
On the other hand, for example, a convex surface 5 which fits into the concave surface 4 is formed on the lower surface of the upper metal plate 1, and a nichrome wire or the like is formed on the bottom surface of the concave surface 4 via a sheet-like insulating material 6 such as a ceramic fiber sheet as shown in FIG. The heating element 7 is arranged in an arbitrary shape, the heating element 7 is covered with another sheet-like insulating material 8, and the upper metal plate 1 is placed on the sheet-like insulating material 8 via the convex surface 5. With the two metal plates 1 and 2 pressed, the periphery of the two metal plates 1 and 2 is hermetically bonded by brazing 9 or the like.

Since the heater unit of the present invention has the above-described configuration, the layout of the heating element 7 can be arbitrarily set without causing disconnection due to a difference in thermal expansion coefficient when a sheath heater is used. , 2 can be improved in heat conduction.

In another embodiment of the present invention, as shown in FIG. 3, through holes 10 and screw holes 11 are provided at desired positions of the upper and lower two metal plates 1 and 2, respectively, and inserted from the through hole 10 side. The screw 12 is screwed into the screw hole 11 to fix the two together.

In this way, the metal plates 1 and 2 and the heating element 7
The uniform thermal contact between them can be further improved.

In still another embodiment of the present invention, as shown in FIG. 4, the upper and lower metal plates 1 and 2 are not formed with a convex surface 5 and a concave surface 4, respectively, and a sheet-like shape is formed between the two metal plates 1 and 2. An insulating material 8, a heating element 7, and a sheet-like insulating material 6 stacked in this order are inserted, and these are integrally compression-molded by a press molding machine.

In still another embodiment of the present invention, as shown in FIG. 5, the convex surface 5 and the concave surface 4 are not formed on the upper and lower metal plates 1 and 2, respectively. Are formed on the lower metal plate 2, for example,
A heating element 7 wound with a sheet-like insulating material 14 such as a ceramic fiber tape is inserted into each groove 13.

According to this embodiment, the same effects as those of the above embodiments can be obtained.

[0023]

As described above, according to the heater unit of the present invention, since the sheath heater is not used, there is no disconnection or deformation due to a difference in thermal expansion coefficient between the sheath heater and the metal plate. It is possible to improve the thermal conductivity by making good contact with the metal plate and prevent the heating element from being damaged by local heating.

Further, the layout of the heating element can be set arbitrarily, and there is a great advantage that the setting operation is easy and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a heater unit of the present invention.

FIG. 2 is a perspective view of a part of the heater unit of the present invention.

FIG. 3 is a longitudinal sectional front view showing another embodiment of the heater unit of the present invention.

FIG. 4 is a longitudinal sectional front view showing still another embodiment of the present invention.

FIG. 5 is a longitudinal sectional front view showing still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate 2 Metal plate 3 Edge 4 Concave surface 5 Convex surface 6 Sheet-shaped insulating material 7 Heating element 8 Sheet-shaped insulating material 9 Brazing 10 Through-hole 11 Screw hole 12 Screw 13 Groove 14 Sheet-shaped insulating material

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Claims (4)

[Claims] 1. Two metal plates, which are vertically opposed to each other and whose peripheral edges are sealed, a concave surface formed on one of the two metal plates, and a concave surface formed on the other. A heater unit comprising: a convex surface to be fitted; and a heating element interposed between the convex surface and the concave surface and having upper and lower surfaces sandwiched by a sheet-like insulating material. 2. A heating element comprising two metal plates arranged vertically opposed to each other, and a heating element interposed between the two metal plates and having upper and lower surfaces sandwiched by a sheet-like insulating material. Is a compression molding unit. 3. Two metal plates which are vertically opposed to each other and whose peripheral edges are sealed, a plurality of grooves formed in one of the two metal plates, and a plurality of grooves are provided in each of the grooves. A heater unit comprising a heating element inserted and wound by a sheet-like insulating material. 4. The metal plate according to claim 1, wherein desired portions of the two metal plates are screwed to each other.
The heater unit as described.