JP4646592B2 - Electric heater and furnace equipped with the same - Google Patents

Description

  The present invention relates to an electric heater (except for a substrate processing apparatus) and a furnace (except for a substrate processing apparatus) provided with the same.

Conventionally, as the above-described electric heater, for example, an electric heater as shown in FIG. 19 is known. The electric heater 100 has a structure in which both end portions of a curved heating element 101 are inserted and supported in an insertion portion 102 a provided on the support body 102. However, there is a structural problem in which uniform heating by the heating element 101 is easily hindered by the support. Further, the heating element 101 is internally distorted by its own heat generation, and the distorted heating element 101a may fall off the insertion portion 102a. Moreover, as described in the following Patent Document 1, an electric heater provided with a structure for preventing dropout has been proposed.
JP 2000-113968 A

  However, the heater according to the publication still requires an assembling accuracy between the support and the insulation to reliably support the heating element, and it is insufficient in terms of uniform heating.

In view of the conventional situation, a first object of the present invention is to provide a heater capable of performing more uniform heating and a furnace including the heater.
The second object of the present invention is to provide a heater capable of reliably supporting a heating element and a furnace equipped with the heater.

In order to achieve the first and second objects, the first feature of the electric heater according to the present invention (except for the substrate processing apparatus) is that a meandering circuit is formed by forming a plurality of slits in the plate-like body. A plurality of heating elements, and the upper end of each heating element is fixed to a support made of an insulating material, and the lower end of each heating element is made movable in the vertical direction. Heat insulation for attaching the support by bringing the upper end of the heating element close to the lower end of the other heating element by overlapping the support that supports the upper end of the heating element so as to cover the lower end of the other heating element on the upper side. The intermediate portion of each heating element is separated from the body.
In order to achieve the above object, the second feature of the electric heater according to the present invention (except for the substrate processing apparatus) is to form a meandering circuit by forming a plurality of slits in the plate-like body. A plurality of heating elements, and the upper end of each heating element is fixed to a support made of an insulating material, the lower end of each heating element is movable in the vertical direction, and the upper end of the heating element is A bent portion that is bent at a substantially right angle to be hooked on the support is formed, and the hook of the support is also formed at a substantially right angle to receive the bent portion, and the upper end of the heating element and the other heating elements The lower end is brought close to each other, and the intermediate portion of each heating element is separated from the heat insulator to which the support is attached.
Furthermore, in order to achieve the above object, the third feature of the electric heater according to the present invention (except for the substrate processing apparatus) is that a meandering circuit is formed by forming a plurality of slits in the plate-like body. A plurality of heating elements, the upper end of each heating element is fixed to a support made of an insulating material, the lower end of each heating element is movable in the vertical direction, and the lower end from the upper end of the heating element is A curved part is formed on the upper side of each heating element so as to hang from the middle part to the lower end of this heating element located on the heat dissipation side, and the upper end of the heating element and the lower end of another heating element are close to each other The intermediate portion of each heating element is separated from the heat insulator to which the support is attached.
Since the upper end and the lower end are close to each other, the distance between the heating elements is not increased, and more uniform heating is possible.

  The hook portion is substantially parallel to the lower wall portion and the lower wall portion where the bent portion is hooked, and prevents the upper wall portion and the bent portion from falling off in the horizontal direction. And a horizontal wall portion that hangs down from the upper wall portion. The lower wall portion is separable from the upper wall portion and the horizontal wall portion.

A first insulating piece for preventing a short circuit of the heating element between the upper release slits may be interposed in the bent portion of the upper release slit of the heating element.
In order to fix the heating element by other means, the support for fixing the upper end of the heating element may be passed through the lower release slit of the heating element. In this case, the support passes through an insulating piece interposed between the heating element and the heat insulator.

  The lower end side of the heat generating body may be held by the heat insulator in a state where a lower fixing body (pin) is passed through the slit and is movable in the slit longitudinal direction and restricted in the movement in the slit vertical direction.

In each of the above features, the intermediate portion in the vertical direction of the heating element may be curved so as to protrude to the side opposite to the heat insulator.
The electric heater described in any of the above features can be implemented as a furnace equipped with the electric heater.

Thus, according to the characteristics of the electric heater according to the present invention and the furnace equipped with the same, the upper end and the lower end are brought close to each other, so that heating can be performed uniformly. In addition, since the intermediate portion of the heating element is separated from the heat insulating body, heat dissipation efficiency is good and uniform heating is possible. In addition, the upper end is fixed and the lower end is free, so there is no risk of dropout even if thermal expansion or deformation occurs, and it can be reliably supported and can be manufactured at low cost without requiring assembly accuracy. is there.
Other objects, configurations, and effects of the present invention will become apparent from the following embodiments of the present invention.

  Next, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the electric heater 1 according to the present invention generally includes a plurality of heating elements 10, a support 20 that supports the heating elements 10, and a ceramic board 30 that supports the support 20. It is an insulator and a heat insulating member. And the electric heater 1 is provided in the furnace body, and comprises a furnace. Since the performance of the furnace greatly depends on the performance of the heater, the present invention can be interpreted as a feature of the furnace.

  The heating element 10 is formed with a plurality of slits 11 intersecting with the longitudinal direction of a plate-like body made of, for example, Fe—Cr—Al or nickel chrome alloy, and the heating element 10 constitutes a meandering circuit. Yes. Further, as shown in FIG. 2A, at one end of the heating element 10, a bent portion 13 that is bent in a substantially L shape, that is, a substantially right angle, is provided to be hooked on the support body 20. ing. Further, the heating element 10 is continuous in a planar shape with respect to the width direction.

  As shown in FIG. 2A, the support 20 is formed by forming a substantially L-shaped hook 23 between an upper support 21 and a lower support 22. The hook portion 23 includes a lower wall portion 22a on which the bent portion 13 is hooked, an upper wall portion 21b that is substantially parallel to the lower wall portion 22a and prevents the bent portion 13 from being pulled upward, and a bent portion. 13 is provided with a horizontal wall portion 21a that hangs down from an upper wall portion 21b for preventing the horizontal displacement of 13.

  Since the heat generating body 10 is supported in the vertical direction only by the latching portion 23 and heat escape from the intermediate portion of the heat generating body 10 is suppressed, the heat efficiency is good. Since it overlaps with the support body 20 in the horizontal direction (or the direction Dh perpendicular to the heat generation surface of the entire electric heater H) and is separated from the ceramic board 30 rather than the upper end of the heat generation element 10, the heat generation element 10 is thermally expanded. There is no risk of contact between the upper and lower ends. In this case, the lower end of the heating element 10 may ride on the horizontal wall portion 21a or may have a gap with the horizontal wall portion 21a. The horizontal separation between the lower end and the upper end of the heating element 10 may be adjusted so that heating between the two is performed uniformly. In addition, the ceramic board 30 which is a heat insulator is continuous in a planar shape with respect to the width direction.

Next, a modified example of the first embodiment of the present invention will be described. In the following embodiments and modifications, members similar to those described above are denoted by the same reference numerals.
The modified example shown in FIG. 2B is different from the modified example shown in FIG. A curved portion 14 is formed in the heating element 10, and most of the heating element 10 is suspended vertically while providing an offset distance with respect to the heat radiation side between the upper end and the lower end of the heating element 10. That is, the lower end from the upper end of the heating element is located on the heat dissipation side, and a curved portion is formed on the upper side of each heating element so as to hang from the intermediate part to the lower end of the heating element, and the upper end of the heating element and the other end The lower end of the heating element is brought close to each other, and the intermediate portion of each heating element is separated from the heat insulator to which the support is attached.

In the modified example shown in FIG. 2C, the lower end of the heating element 10 does not ride on the lateral wall portion 21 a and is separated from the support 20 by the amount of thermal expansion.
In the modified example shown in FIG. 2D, the shape of the lower support portion 22 is different from that in FIG. 2A, and a protrusion 24 that is an insulator is provided at the tip of the adjacent upper support portion 21. The lower support portion 22 is shaped flat, and the protrusion 24 prevents the heating element 10 from being thermally deformed and the lower end thereof protruding to the front side.

  Next, still another embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the member similar to previous 1st embodiment.

  In the second embodiment shown in FIGS. 3 (a) and 4, as shown in FIG. 4, the heating element 10, the support 20 and the ceramic board 30 are curved, and the heating element is used by the fixture 40. The second embodiment is different from the first embodiment in that the support 20 that supports 10 is fixed to the ceramic board 30. As shown in FIG. 3, the fixture 40 includes a bolt 41, a nut 42, and a washer 43, and a support 20 having a clasp 44 attached at an appropriate interval is attached to the ceramic board 30 to which the stainless steel plate 31 is attached by the bolt 41. Then, the washer 42 is sandwiched between the bolts 41 and the nut 42 is fastened and fixed. The support body 20 is increased in strength by being fixed to the ceramic board 30 by a fixing tool 40 at an appropriate interval. As shown in FIG. 5, the heating element 10 has a notch in a part in the circumferential direction, and is connected to a power source through a pair of terminals 10x and 10y.

  FIG. 3B shows a modification of the second embodiment. In this modification, the structure of the support is different. The support body 50 includes a fixing portion 51 fixed to the ceramic board 30, an adjustment portion 52 that can be inserted into and removed from the fixing portion 51, and a latching portion 53. The fixing portion 51 is provided with a concave portion 51 a corresponding to the lower wall portion for hooking the bent portion 13 of the heating element 10, and the adjustment portion 52 is grasped for insertion into and removal from the fixing portion 51. It consists of a knob 52a that functions as a horizontal wall portion and an insertion shaft 52b that functions as an upper wall portion. By adjusting the insertion position of the adjustment portion 52, the insertion shaft 52b becomes an upper wall portion that prevents the bent portion 13 from falling off, and maintenance work such as removal of the heating element 10 is facilitated.

  Next, in the third embodiment shown in FIG. 6, as shown in FIG. 6B, the support body 60 includes an L-shaped hanger pin 61, a spacer 62, and an insulator 63. 10 is formed flat without providing the bent portion 13. 6 to 12 use the curved support body 20 and the ceramic board 30 as in the embodiment of FIG. The hanger pins 61 are fixed to the ceramic board 30 so as to have the same height at appropriate intervals, and the heating element 10 is hooked on the hanger pins 61 by the slits 11. Then, the heating element 10 is sandwiched between the spacer 62 attached to the hanger pin 61 and the insulator 63 attached to the protruding portion of the hanger pin 61. Further, the lower end of the heating element 10 is close to the adjacent insulator 63 so as to ride on or overlap with the adjacent insulator 63 and close to the upper end of the heating element 10.

  Here, a modified example of the third embodiment will be described with reference to FIGS. In the modified example shown in FIG. 7, the shape of the insulator 63 is different, and the stability of the heating element 10 is enhanced by forming the insulator 63 wider in the horizontal direction.

  In the modified example shown in FIG. 8, the lower end of the heating element 10 is separated from the ceramic board 30 rather than the upper end by the convex portion 32 provided on the ceramic board 30 without using the insulator 63. Are in close proximity.

  In the modified example shown in FIG. 9, a convex portion 33 having a height different from that of the convex portion 32 shown in FIG. Furthermore, by using a hanger pin 61 for the convex portion and penetrating the lower end of the upper release slit 11a of the heating element 11, the heating element 10 is movable in the longitudinal direction of the slit 11, but the slit is moved in the vertical direction. It is regulated by the hanger pin 61.

In the modified example shown in FIG. 10, the upper end and the lower end of the heating element 10 are brought close to each other by a plate-like insulator 64 that is an insulator fixed to the ceramic board 30.
In the modified example shown in FIG. 11, the hanger pin 61 provided with a recess 61 a having substantially the same width as the thickness of the heating element 10 is used, the slit 11 is fitted into the recess 61 a, and the heating element 10 is hooked.

  The fourth embodiment shown in FIG. 12 relates to modification of the shape of the heating element 10. The heating element 10 is deformed to the ceramic board 30 side due to thermal expansion. Therefore, the intermediate portion of the heating element 10 is curved so as to protrude in the opposite direction to the ceramic board 30 so that the vertical intermediate portion of the heating element 10 is separated from the ceramic board 30 in advance, thereby preventing the support body from falling off due to deformation. is doing.

  In the fifth embodiment shown in FIGS. 13 to 15, the insulator 30 is configured by laminating a plurality of divided bodies 30 a. A through hole 20a is formed in the support 20 and is fixed to the insulator by an L-shaped fixing nail 20b. A first insulating piece 16, which is a small soot tube (insulator), is inserted into the upper release slit 11 b of the bent portion 13 of the heat generator 10 to prevent a short circuit between the heat generators 10 sandwiching the upper release slit 11 b. The first insulating piece 16 is housed in a latching portion 23 surrounded by the upper support portion 21 and the lower support portion 22 and is prevented from falling off. The lower part of the heating element 10 has a lower fixing pin 65, which is an insulator, passed through the slit 11, and is a second insulating piece that is an insulator in a state in which movement in the longitudinal direction of the slit 11 and movement in the vertical direction of the slit 11 are restricted. It is fixed to the insulator 30 via 17. Further, the fixing by the lower fixing pin 65 may be performed at the position of the lower release slit 11a as indicated by reference numeral 65x in addition to the upper release slit 11b.

  In the sixth embodiment shown in FIG. 16, the heating element 10 is suspended and supported by an upper fixing pin 66 that is an insulator. The insulator 30 is configured by stacking second to fourth divided bodies 30b to 30d. An upper fixing pin 66 is passed through each lower release slit 11a, and 10 is fixed to the insulator 30 via a third insulating piece 18 which is an insulator.

  The embodiment shown in FIG. 17 and below is mainly for solving the second object of the present invention. Here, the reference embodiment of FIG. 17A is mainly used for the ceiling portion, and the structure of the support is different. The support body 70 fixed to the ceramic board 30 via the fixing tool 40 includes a fixing portion 70a fixed to the ceramic board 30 and an adjusting portion 70b that can be inserted into and removed from the fixing portion 70a. The fixing portion 70 a is provided with an insertion portion 71 for hooking the bent portions 13 provided at both ends of the heating element 10. The bent portion 13 is inserted into the insertion portion 71 of the support body 70, the adjustment portion 70b is inserted into the fixing portion 70a, and the heating element 10 is fixed.

  FIG. 17B shows a modification of the embodiment of FIG. In this modified example, the support 72 is fixed to the ceramic board 30 by the fixture 40 without attaching a clasp. Further, on both sides of the support 72, there are provided insertion portions 74 formed so as to make it easier to attach the heating element. The insertion part 74 has a dent formed in the opposite direction to the insertion part 71 shown in FIG. 17 (a). The bent part 13 is hooked on the insertion part 74 to fix the heating element 10. ing.

  Further, in the modified example shown in FIG. 17C, in the curved ceramic board 30, the bent portions 13 of the heating elements 10 are respectively inserted into the insertion portions 75 provided on the support body 73, and the repulsive force of the heating elements 10 The support 73 is fixed to the ceramic board 30. This modified example can be used not only on the ceiling but also on the wall as long as it is curved.

  In the reference embodiment shown in FIG. 18A, the protrusion 90 that prevents the heat generating element 10 from falling off due to distortion is provided. The protrusion 90 is provided between the ceramic boards 30 and 30 so that the tip of the protrusion 90 is positioned substantially at the center of the heating element 10, and the tip of the protrusion 90 and the center of the heating element 10 are close to each other. Yes. Therefore, even if the heating element 10 is distorted toward the ceramic board 30, the distortion is suppressed by the protrusion 90, and the heating element 10 can be removed from the insertion portion 81 in which the upper end of the heating element 10 is inserted. Can be prevented.

  18B and 18C show modified examples of (a). The modified example shown in FIG. 18B plays the same role as the protruding portion 90 by providing the convex portion 34 at the substantially central portion of the ceramic board 30. Further, in the modified example shown in FIG. 18C, a slight gap C is provided between the heating element 10 and the ceramic board 30. Due to the gap C, the heating element 10 that is distorted by heat comes into contact with the ceramic board 30, and can prevent the heating element 10 from falling off due to the distortion.

  In each of the above embodiments, in the embodiment of FIGS. 1 and 2, the heating element 10 and the heat insulator 30 are linearly continuous with respect to the longitudinal direction of the heating element 10, and in the embodiments and modifications of FIGS. The heating element 10 and the heat insulator 30 continued in a curved manner in the longitudinal direction. However, in the embodiment of FIGS. 1 and 2, the heating element 10 and the heat insulator 30 are curvedly continuous with respect to the longitudinal direction of the heating element 10, and in the embodiment of FIGS. 10 and the heat insulator 30 may be linearly continuous.

In each of the above-described embodiments and modifications, the meandering heater is not limited to a flat plate shape, and a wire rod developed in a meandering shape may be used.
In each of the above embodiments and modifications, the heating element is not only arranged vertically in the vertical direction, but the plane of the heating element may be arranged inclined in the vertical direction or arranged horizontally.

  Examples of the insulating material constituting the support, protrusions, fixing pins, insulating pieces, insulators, etc. include ceramics, silicon carbide, silicon nitride mainly composed of alumina, alumina silica, mullite, zircon, or cordierite. In addition to the above, various materials can be used as long as they are harder and have better heat conductivity than the heat-insulating refractory of the heat insulator. Further, as the heat insulating refractory constituting the heat insulating member (insulator) 30, various materials such as ceramic fibers or ceramic powder mixed with an organic / inorganic binder can be used. The kind and the mixing | blending of the material which comprise these heat insulation bodies and a support body can be suitably changed according to the operating temperature etc. of an electric heater.

  The heater according to the present invention can be used as a heater for heat treatment of glass, ceramic and metal. Further, it can be applied to a reaction furnace and a diffusion furnace, and can be used in a low temperature environment of, for example, about 700 ° C. to 900 ° C. or a high temperature environment of, for example, over 1200 ° C. Applicable up to 1400 ° C. However, the heater and furnace for a substrate processing apparatus for manufacturing a semiconductor device on a substrate such as a silicon wafer or a glass substrate are excluded from the protection target of the present invention.

It is a front view of the electric heater which concerns on this invention. (A) is AA sectional drawing of FIG. 1, (b)-(d) is sectional drawing which shows the modification of (a). (A) is a figure equivalent to Drawing 2 (a) showing a second embodiment of the present invention, and (b) is a sectional view showing a modification of (a). It is BB sectional drawing of Fig.3 (a). It is a schematic sectional drawing which shows the connection state of a heat generating body. (A) is a front view which shows 3rd embodiment of this invention, (b) is CC sectional drawing of (a). (A) is a front view which shows the modification of 3rd embodiment of this invention, (b) is DD sectional drawing of (a). (A) is a front view which shows the modification of 3rd embodiment of this invention, (b) is EE sectional drawing of (a). (A) is a front view which shows the modification of 3rd embodiment of this invention, (b) is FF sectional drawing of (a). (A) is a front view which shows the modification of 3rd embodiment of this invention, (b) is GG sectional drawing of (a). (A) is a front view which shows the modification of 3rd embodiment of this invention, (b) is HH sectional drawing of (a). (A) is the FIG. 2 equivalent view which shows 4th embodiment of this invention. (A) is a front view which shows 5th embodiment of this invention, (b) is II sectional drawing of (a). It is an enlarged view of the support body part of FIG.13 (b). It is a figure which shows the relationship between a heat generating body upper part and an insulation piece. (A) is a front view which shows 6th embodiment of this invention, (b) is JJ sectional drawing of (a). FIG. 2A is a view corresponding to FIG. 2A showing a reference embodiment, and FIGS. 2B and 2C are cross-sectional views showing modified examples of FIG. FIG. 2A is a view corresponding to FIG. 2A showing a reference embodiment, and FIGS. 2B and 2C are cross-sectional views showing modified examples of FIG. It is an equivalent figure of Drawing 2 (a) showing an embodiment of the conventional electric heater.

Explanation of symbols

  1: electric heater, 10: heating element, 10x, 10y: terminal, 11: slit, 11a: lower release slit, 11b: upper release slit, 12: edge, 13: bent portion, 14: curved portion, 16: 1st insulation piece, 17: 2nd insulation piece, 18: 3rd insulation piece, 20: Support body, 20a: Through-hole, 20b: Fixed nail, 21: Upper support part, 21a: Horizontal wall part, 21b: Upper wall part 22: lower support part, 22a: tip part, 23: latching part, 24: protrusion, 30: ceramic board (insulator), 30a to d: first to fourth divided bodies, 31: stainless steel plate, 32, 33, 34: convex part, 40: fixing tool, 41: bolt, 42: nut, 43: washer, 44, 45: clasp, 50: support, 51: fixing part, 51a: concave part (tip part), 52 : Adjustment part, 52a: knob (horizontal wall part), 52b: insertion shaft (upper wall part), 3: latching part, 60: support, 61: hanger pin, 61a: recess, 62: spacer, 63, 64: insulator, 65: lower fixing pin, 66: upper fixing pin, 70: support, 70a: fixing Part, 70b: adjustment part, 71: insertion part, 72, 73: support body, 74, 75: insertion part, 80: support body, 81: insertion part, 90: protrusion part, 100: heater, 101, 101a: heating element, 102: support, 102a: insertion part, 103: molded body

Claims (10)

  A plurality of heating elements that constitute a meandering circuit by forming a plurality of slits in the plate-like body, the upper end of each heating element is fixed to a support made of an insulator, The lower end is movable in the vertical direction, and the upper end of the heating element and other heat generation are overlapped with the support that supports the upper end of the lower heating element so as to cover the lower end of the other heating element. An electric heater (except for a substrate processing apparatus) that brings a lower end of the body close to each other and separates an intermediate portion of each heating element from a heat insulator to which the support is attached.   A plurality of heating elements that constitute a meandering circuit by forming a plurality of slits in the plate-like body, the upper end of each heating element is fixed to a support made of an insulator, The lower end is made movable in the vertical direction, and a bent portion bent at a substantially right angle is formed on the upper end of the heating element and is hooked on the support, and the hook of the support is also bent. An electric heater (substrate) that is formed at a substantially right angle to receive the portion, and that the upper end of the heating element and the lower end of the other heating element are brought close to each other, and the intermediate portion of each heating element is separated from the heat insulator to which the support is attached Except for processing equipment).   A plurality of heating elements that constitute a meandering circuit by forming a plurality of slits in the plate-like body, the upper end of each heating element is fixed to a support made of an insulator, The lower end is movable in the vertical direction, and the lower end is located on the heat dissipation side from the upper end of the heating element, and a curved portion is provided on the upper side of each heating element so that it hangs from the middle to the lower end of the heating element. An electric heater (except for a substrate processing apparatus) that is formed and moves the upper end of the heating element close to the lower end of another heating element to separate the intermediate portion of each heating element from the heat insulator to which the support is attached . The hook portion is substantially parallel to the lower wall portion and the lower wall portion where the bent portion is hooked, and prevents the upper wall portion and the bent portion from falling off in the horizontal direction. The electric heater according to claim 2, further comprising: a horizontal wall portion that hangs down from an upper wall portion, and the lower wall portion being separable from the upper wall portion and the horizontal wall portion. The electric heater according to claim 2 or 4, wherein a first insulating piece for preventing a short circuit of the heating element between the upper release slits is interposed in the bent portion of the upper release slit of the heating element. The electric heater according to any one of claims 1 to 5, wherein the support for fixing the upper end of the heating element passes through a lower release slit of the heating element. The electric heater according to claim 6, wherein the support passes through an insulating piece interposed between the heating element and the heat insulator. The lower end side of the heat generating body is held in the heat insulating body in a state where the lower fixed body is passed through the slit, is movable in the slit longitudinal direction, and is restricted from moving in the slit vertical direction. Electric heater. The electric heater according to any one of claims 1 to 8, wherein an intermediate portion in the vertical direction of the heating element is curved so as to protrude to the side opposite to the heat insulating body. A furnace (except for a substrate processing apparatus) comprising the electric heater according to any one of claims 1 to 9.

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