JP2011210476A - Vacuum sealing heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum sealing heater with the number of components reduced and cost reduced.SOLUTION: The vacuum sealing heater is provided with a case with an opening at an end, a heating plate blocking the opening of the case, a heater element arranged in opposition to the heating plate inside the case of a vacuum state, a reflector reflecting radiation heat from the heater element inside the case, and a heater terminal connected to the heater element and drawn outside from the inside of the case.

Description

  The present invention relates to a vacuum sealed heater.

  For example, Patent Document 1 discloses a vacuum deposition apparatus in which a filament for evaporating a metal material such as aluminum and performing deposition on an object is provided in a chamber. In the vacuum deposition apparatus disclosed herein, the inside of the chamber is evacuated, and the filament is heated while the linear metal material is hooked on the filament to evaporate the metal material to form a deposited film. ing.

JP 9-31632 A

  However, in the vacuum vapor deposition apparatus configured as described above, the filament is easily deteriorated because the filament is exposed to the evaporation material. For this reason, it is necessary to frequently replace the filament, resulting in an increase in cost.

  An object of the present invention is to provide a low-cost vacuum sealed heater.

According to an aspect of the invention,
A case having an opening at one end; a heating plate that closes the opening of the case; a heater element disposed opposite to the heating plate in the case in a vacuum state; and from the heater element in the case There is provided a vacuum-sealed heater comprising: a reflector that reflects the radiant heat; and a heater terminal connected to the heater element and drawn out from the inside of the case.

  According to this invention, a low-cost vacuum-sealed heater can be provided.

FIG. 1 is an exploded perspective view schematically showing the main part of the vacuum-sealed heater of the present embodiment. FIG. 2 is a cross-sectional view schematically showing a configuration example of the vacuum sealing heater of the present embodiment. FIG. 3 is a cross-sectional view schematically showing another configuration example of the vacuum sealing heater of the present embodiment.

  Hereinafter, an embodiment will be described in detail with reference to the drawings. In each figure, the same reference numerals are given to components that exhibit the same or similar functions, and duplicate descriptions are omitted.

  FIG. 1 is an exploded perspective view schematically showing a main part of the vacuum sealed heater 1 of the present embodiment. In this figure, for convenience, two directions orthogonal to each other in the plane are defined as an X direction and a Y direction, and a normal direction of the XY plane is defined as a Z direction. The Z direction corresponds to the axial direction of the vacuum sealed heater 1.

  That is, the vacuum sealed heater 1 includes a case 10, a heating plate 20, a heater element (sometimes referred to as a filament) 30, a reflector 40, and a heater terminal 50.

  The case 10 has a hollow inside, and is formed in a cylindrical shape extending in the Z direction, for example. In the illustrated example, the case 10 is formed in a cylindrical shape having a circular cross section in the XY plane. Note that the shape of the case 10 is not limited to the illustrated example, and can be changed as appropriate in accordance with usage conditions and the like.

  The case 10 has an opening 11 at the tip in the Z direction. In the illustrated example, the opening 11 is circular in the XY plane.

  Further, the case 10 has a recess 12 that functions as a thermal insulation zone on its outer surface 10A. That is, the case 10 sandwiches the tip end 13 in the Z direction from the recess 12, that is, the tip end 13 closer to the opening 11 than the recess 12, and the rear end in the Z direction from the recess 12, that is, the recess 12. And has a rear end portion 14 opposite to the front end portion 13. The plate thickness of the recess 12 is thinner than the plate thickness of the front end portion 13 and thinner than the plate thickness of the rear end portion 14. Such a recess 12 is formed in a continuous loop around the outer surface 10A.

  Such a case 10 is made of various metal materials such as molybdenum (Mo), iron-chromium alloy (stainless steel), and iron-nickel-cobalt alloy (Kovar).

  The heating plate 20 is formed in a shape that fits the opening 11 of the case 10. In the illustrated example, the heating plate 20 is formed in a flat pan shape having a circular bottom portion 21 and a ring-shaped flange portion 22 in the XY plane. The shape of the heating plate 20 is not limited to the illustrated example, and can be appropriately changed according to the sample to be heated (mainly solid, but may be liquid), for example, flat type, deep drawing You may form in various shapes, such as a type | mold and a convex type.

  The heating plate 20 is disposed so as to close the opening 11. At this time, the flange portion 22 is in contact with the case 10 over the entire periphery, and is joined to the case 10 by welding over the entire periphery. Thereby, the heating plate 20 is supported and fixed to the case 10. Note that various methods such as TIG (tungsten-inert gas) welding, electron beam welding, laser welding, and resistance welding can be applied as welding methods.

  Such a heating plate 20 includes, for example, tungsten (W), molybdenum (Mo), tantalum (Ta), rhenium (Re), platinum (Pt), iron-chromium alloy (stainless steel), nickel-chromium, and the like. -It is formed of a metal material having heat resistance such as an iron-based alloy (Inconel (registered trademark)).

  The heater element 30 is disposed opposite to the heating plate 20 inside the case 10. Such a heater element 30 is formed of various metal materials such as titanium (Ti), tungsten (W), tantalum (Ta), and molybdenum (Mo). The heater element 30 is formed by processing a metal wire made of these metal materials.

  In the example shown here, the heater element 30 has a first straight part 31, a second straight part 32, and a spiral part 33. The first straight portion 31 extends linearly from the one end portion 31A toward the distal end side in the Z direction. The second straight portion 32 is a straight shape substantially parallel to the first straight portion 31 and extends linearly from the other end portion 32A toward the distal end side in the Z direction. The spiral portion 33 is connected to the first straight portion 31 and the second straight portion 32 and is bent from the first straight portion 31 and the second straight portion 32, and spirals outward from the first straight portion 31. It is formed in a shape. In the illustrated example, the spiral portion 33 is formed in a plane substantially parallel to the XY plane, the position of the approximate center thereof corresponds to a position connected to the first linear portion 31, and the position of the outermost periphery is the second position. This corresponds to the position connected to the straight line portion 32.

  Such a heater element 30 is not in contact with the heating plate 20 but is disposed in the vicinity of the back surface 23 of the heating plate 20. In particular, the spiral portion 33 of the heater element 30 faces the back surface 23 of the heating plate 20. That is, in such a heater element 30, the spiral portion 33 mainly corresponds to a heating source for heating the heating plate 20.

  The reflector 40 reflects the radiant heat from the heater element 30. The reflector 40 is disposed inside the case 10 on the rear end side in the Z direction with respect to the spiral portion 33 of the heater element 30. That is, the heater element 30 is located between the heating plate 20 and the reflector 40.

  In the example shown here, the reflector 40 is formed in a substantially disk shape and faces the spiral portion 33. In addition, the reflector 40 includes a first opening 41 and a second opening 42. The first opening 41 is formed at a substantially central portion of the reflector 40. The first opening 41 is a hole through which the first straight portion 31 of the heater element 30 passes. The second opening 42 is formed in the peripheral part of the reflector 40. The second opening 42 is a hole through which the second straight portion 32 of the heater element 30 passes. The first opening 41 has a circular shape with an inner diameter larger than the outer diameter of the first straight portion 31, and the second opening 42 has a circular shape with an inner diameter larger than the outer diameter of the second straight portion 32. However, it is not limited to this example. For example, as will be described later, the inner diameter of the second opening 42 may be substantially equal to the outer diameter of the second linear portion 32, and the inner diameter of the first opening 41 is the outer diameter of the first linear portion 31. May be substantially equivalent.

  Such a reflector 40 is made of, for example, a metal material such as titanium (Ti) or molybdenum (Mo).

  The heater terminal 50 includes a first heater terminal 51 and a second heater terminal 52. The first heater terminal 51 is connected to one end 31 </ b> A of the heater element 30 inside the case 10. The second heater terminal 52 is connected to the other end 32 </ b> A of the heater element 30 inside the case 10.

  The first heater terminal 51 and the second heater terminal 52 are formed in a bar shape. The first heater terminal 51 has an insertion hole 51A into which the first straight part 31 including the one end 31A of the heater element 30 can be inserted. Further, the second heater terminal 52 has an insertion hole 52A into which the second straight portion 32 including the other end portion 32A of the heater element 30 can be inserted. The heater element 30 is supported and fixed to the first heater terminal 51 by a method such as caulking or welding while the first straight portion 31 is inserted into the insertion hole 51A, and the second straight portion 32 is inserted into the insertion hole 52A. In this state, the second heater terminal 52 is supported and fixed by a method such as caulking or welding.

  The first heater terminal 51 and the second heater terminal 52 are formed of various metal materials such as iron-chromium alloy (stainless steel) and iron-nickel-cobalt alloy (kovar).

  FIG. 2 is a cross-sectional view schematically showing a configuration example of the vacuum sealing heater 1 of the present embodiment. In addition, about the same structure as having demonstrated with reference to FIG. 1, the same referential mark is attached | subjected and detailed description is abbreviate | omitted.

  The case 10 has a front end portion 13 and a rear end portion 14 with the concave portion 12 interposed therebetween. The opening 11 formed in the distal end portion 13 is blocked by the heating plate 20. The tip portion 13 corresponds to a portion surrounding the heating plate 20, the main spiral portion 33 of the heater element 30, and the reflector 40. The rear end portion 14 corresponds to a portion from which the heater terminal 50 is drawn.

  In the illustrated example, the case 10 includes a cylindrical portion 15 and a base portion 16. The cylindrical portion 15 includes a front end portion 13 and a concave portion 12, and further includes a part of the rear end portion 14. The base portion 16 corresponds to a portion of the rear end portion 14 that is not included in the cylindrical portion 15. The cylindrical portion 15 is joined to the base portion 16 by welding over the entire circumference in a state where the cylindrical portion 15 is fitted into the base portion 16.

  The heater terminal 50 is connected to the heater element 30 inside the case 10 and is drawn out of the case 10 from the base portion 16. In the illustrated example, both the first heater terminal 51 and the second heater terminal 52 are drawn from the base portion 16 to the outside. Insulators 60 are interposed between the base portion 16 and the first heater terminal 51 and between the base portion 16 and the second heater terminal 52, respectively. That is, the insulator 60 covers the periphery of each of the first heater terminal 51 and the second heater terminal 52 and is brazed (for example, copper brazed) to the base portion 16. Thereby, the first heater terminal 51 and the second heater terminal 52 are supported and fixed to the case 10.

Such an insulator 60 is made of, for example, aluminum oxide (Al ₂ O ₃ ). The insulator 60 and the base portion 16 are preferably formed by selecting materials having the same thermal expansion coefficient. On the other hand, it is desirable that the cylindrical portion 15 is formed by selecting a material having relatively high heat resistance (for example, higher heat resistance than the material forming the base portion 16). Accordingly, the cylindrical portion 15 and the base portion 16 constituting the case 10 have different required characteristics, and may be formed of different metal materials. When a material having a relatively high heat resistance and a thermal expansion coefficient equivalent to that of the insulator 60 is applied, the cylindrical portion 15 and the base portion 16 are formed of the same material. In addition, the cylindrical portion 15 and the base portion 16 may not be separately formed but may be integrally formed. When the case 10 in which the cylindrical portion 15 and the base portion 16 are integrally formed is applied, the number of parts can be reduced compared to the case where the cylindrical portion 15 and the base portion 16 are separately formed. It can be reduced and the joining process such as welding becomes unnecessary.

In the present embodiment, the inside of the case 10 is in a vacuum state. The vacuum state here means a state in which the degree of vacuum is 10 ⁻¹ Pa or less, more desirably 10 ^-5 Pa or less, such as argon (Ar), xenon (Xe), krypton (Kr), etc. A state where the inert gas is slightly contained also corresponds to the vacuum state of the present embodiment.

  The heater element 30 and the reflector 40 are sealed inside the case 10 in a vacuum state. The reflector 40 is disposed between the spiral portion 33 of the heater element 30 and the heater terminal 50. In the heater element 30, the first straight portion 31 passes through the first opening 41 of the reflector 40 and is supported and fixed to the first heater terminal 51, and the second straight portion 32 passes through the second opening 42 of the reflector 40. The two heater terminals 52 are supported and fixed, and the spiral portion 33 faces the heating plate 20. In the example shown here, the inner diameter of the second opening 42 is substantially the same as the outer diameter of the second straight portion 32, and the reflector 40 is in a state where the second opening 42 is inserted into the second straight portion 32. The heater element 30 is supported and fixed by a method such as caulking or welding. That is, the heater element 30 and the reflector 40 can be integrated.

  While the case 10 is grounded, a heater power source 70 is connected to the first heater terminal 51 and the second heater terminal 52.

  In the vacuum sealed heater 1 having such a configuration, when a current is supplied from the heater power supply 70 to the heater element 30 and the heater element 30 is heated, the heating plate 20 is heated by the radiant heat. The radiant heat from the heater element 30 toward the heater terminal 50 is reflected by the reflector 40 and contributes to the heating of the heating plate 20. Thereby, the sample placed on the heating plate 20 is heated. By such a method, the sample can be heated at a temperature of about 500 ° C. to 1000 ° C.

  According to the vacuum-sealed heater 1 of the present embodiment described above, the heater element 30 itself is vacuum-sealed, and is not exposed to the sample evaporation material placed on the heating plate 20. For this reason, when the vacuum-sealed heater 1 of this embodiment is applied as a heating source of the vapor deposition apparatus, the heater element 30 is deteriorated as compared with the apparatus configuration in which the filament as the heating source is exposed to the evaporation material in the chamber. Can be suppressed, and the replacement frequency of the heat source can be reduced. As a result, cost reduction can be realized.

  Further, the vacuum sealed heater 1 of the present embodiment is not limited to being used as a heating source in a vacuum atmosphere, but can be used as a heating source for heating a sample at a temperature of about 1000 ° C. even in the air. The versatility is extremely high. When the vacuum sealed heater 1 according to the present embodiment is used in the atmosphere, the portion such as the outer surface of the case 10 that comes into contact with oxygen is a SiC (silicon carbide) coat or a PBN (pyrolytic nitrogen boron) coat. It is desirable to apply an oxygen resistant coating.

  Furthermore, according to the vacuum sealed heater 1 of the present embodiment, in the case 10, the loop-shaped recess 12 is formed on the outer surface between the front end portion 13 surrounding the reflector 40 and the rear end portion 14 from which the heater terminal 50 is drawn. Is formed. The thickness of the recess 12 is thinner than the thickness of the tip portion 13. Therefore, it is possible to suppress heat conduction from the front end portion 13, which has become relatively high temperature due to radiant heat from the heater element 30, to the rear end portion 14 through the thin plate-shaped recess 12. In addition, since the reflector 40 is disposed between the spiral portion 33 of the heater element 30 and the heater terminal 50, it also functions as a shielding plate that shields the radiant heat of the spiral portion 33. Accordingly, the temperature rise of the heater terminal 50 itself is suppressed, and the temperature rise of the rear end portion 14 from which the heater terminal 50 is pulled out is suppressed, so that it is possible to prevent elution of the brazed portion. An internal vacuum of 10 can be maintained. When the case 10 needs to be more actively cooled, for example, it is desirable to attach a cooling mechanism such as an air cooling mechanism, a water cooling mechanism, or a heat pump mechanism to the case 10.

  In the example described above, the recess 12 is formed on the outer surface of the case 10, but may be formed on the inner surface of the case 10. It goes without saying that the same effect as the above-described example can be obtained even in the configuration in which the loop-shaped recess 12 is formed on the inner surface of the case 10.

  Further, according to the vacuum sealed heater 1 of the present embodiment, the reflector 40 is supported and fixed to the heater element 30. For this reason, a special mechanism for supporting the reflector 40 is unnecessary, the number of parts can be reduced, and the cost can be reduced.

  In this embodiment, joining of the cylindrical part 15 and the base part 16 which comprise the case 10, and joining of the cylindrical part 15 and the heating plate 20 are TIG (tungsten-inert gas) welding, electron beam welding, The method is performed by laser welding, resistance welding, or the like. Since the insulator 60 and the case 10 are joined by brazing, the inside of the case 10 can be maintained at a high degree of vacuum.

  In the present embodiment, the heater element 30 is preferably formed of a material that functions as a getter pump. In particular, titanium (Ti) functions as a getter pump and is relatively inexpensive, and is suitable as a material for forming the heater element 30. A portion of the titanium heater element 30 evaporates with heating. The evaporated titanium adheres to the inner surface of the case 10 to form a thin film, and adsorbs gas (for example, residual gas inside the case 10) on the surface of the thin film. Thereby, the degree of vacuum inside the case 10 can be maintained.

  The reflector 40 may be formed of a material that functions as a getter pump such as titanium (Ti). In this case, a part of the reflector 40 is evaporated by the radiant heat from the heater element 30 and functions as a getter pump in the same manner as described above. For this reason, even if the heater element 30 is formed of a material that does not function as a getter pump such as tungsten (W), the reflector 40 is formed of a material that functions as a getter pump. The internal vacuum can be maintained. That is, it is desirable that at least one of the heater element 30 and the reflector 40 is formed of a material that functions as a getter pump.

  As an option of the present embodiment, an acceleration power source (electron bombard power source) 80 can be further connected to the heater power source 70. By applying a voltage of about −1000 V, for example, by such an acceleration power source 80, the thermoelectrons from the heater element 30 collide with the heating plate 20, and further in a high temperature region, for example, a high temperature of about 1000 ° C. to 1500 ° C. The sample can be heated.

  FIG. 3 is a cross-sectional view schematically showing another configuration example of the vacuum sealed heater 1 of the present embodiment. In addition, about the same structure as having demonstrated with reference to FIG. 2, the same referential mark is attached | subjected and detailed description is abbreviate | omitted.

  The configuration shown in FIG. 3 is different from the example shown in FIG. 2 in that one of the heater terminals 50 is joined to the case 10 without an insulator. In the illustrated example, the second heater terminal 52 is directly joined to the base portion 16 of the case 10. The second heater terminal 52 and the base portion 16 are joined by, for example, TIG welding. Thereby, the second heater terminal 52 is electrically connected to the base portion 16 and supported and fixed to the base portion 16. Note that the first heater terminal 51 is brazed to the base portion 16 via an insulator 60, as in the example shown in FIG. A heater power source 70 is connected to the case 10 electrically connected to the second heater terminal 52 and the first heater terminal 51. That is, it is not necessary that both the first heater terminal 51 and the second heater terminal 52 are drawn from the inside of the case 10 to the outside, and at least one heater terminal is required to be electrically connected to the heater power source 70. The other heater terminal may be pulled out to the outside as in the example shown in FIG. 2, or may be joined to the case 10 as in the example shown in FIG. good.

  According to such a configuration, the same effect as the configuration shown in FIG. 2 can be obtained, and the number of parts can be reduced as compared with the configuration shown in FIG. 3, and the cost can be further reduced. Become. Similar to the example shown in FIG. 2, an acceleration power supply 80 can be connected as an option.

  Further, the configuration shown in FIG. 3 is different from the example shown in FIG. 2 in that the reflector 40 is supported and fixed by the heater terminal 50. In the illustrated example, the reflector 40 is supported and fixed by the second heater terminal 52. The reflector 40 has a first opening 41 through which the first straight portion 31 of the heater element 30 passes and a second opening 42 through which the second straight portion 32 passes. The inner diameter of the second opening 42 is larger than the outer diameter of the second straight part 32. A second heater terminal 52 is fitted in the second opening 42. Thereby, the reflector 40 is supported and fixed to the second heater terminal 52.

  According to such a configuration, a special mechanism for supporting the reflector 40 is unnecessary, the number of parts can be reduced, and the cost can be reduced.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

DESCRIPTION OF SYMBOLS 1 ... Vacuum sealing heater 10 ... Case 11 ... Opening 12 ... Recess 13 ... Tip part 14 ... Rear end part 15 ... Cylindrical part 16 ... Base part 20 ... Heating plate 21 ... Bottom part 22 ... Flange part 23 ... Back surface 30 ... Heater Element 31... First straight line portion 32... Second straight line portion 33... Spiral portion 40 .. Reflector 41 .. First opening portion 42 ... Second opening portion 50 ... Heater terminal 51. First heater terminal 52. Second heater terminal 60. Insulator 70 ... Heater power supply 80 ... Acceleration power supply

Claims (3)

A case having an opening at one end;
A heating plate that closes the opening of the case;
Inside the case in a vacuum state, a heater element disposed opposite to the heating plate;
A reflector that reflects radiant heat from the heater element in the case;
A heater terminal connected to the heater element and drawn out from the inside of the case;
A vacuum-sealed heater comprising:   2. The vacuum sealed heater according to claim 1, wherein a loop-shaped recess is formed in an inner surface or an outer surface between a portion surrounding the reflector and a portion from which the heater terminal is drawn out in the case. . The heater element includes a first linear portion extending linearly, a second linear portion extending linearly substantially parallel to the first linear portion, and the first linear portion and the second linear portion. A spiral portion that is bent and formed in a spiral shape around the first straight portion,
The reflector has a first opening through which the first straight portion passes and a second opening through which the second straight portion passes, and is supported by the heater terminal or the heater element. The vacuum sealed heater according to claim 1.

Images