JP2014159809A - Getter member storage tool, getter device, and getter pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a getter pump capable of efficiently utilizing radiation heat from a heater to uniformly activate a getter member.SOLUTION: A getter pump includes a container 11, a getter device 13 accommodated in the container 11 and in which a plurality of disk-like getter members 14 are accommodated vertically in a form of one or more stages, and heating means 12 for heating the getter members 14, accommodated in the container 11 and arranged to face the getter members 14 accommodated in the getter device 13.

Description

  The present invention relates to a getter pump using a disk-shaped (pill-shaped) non-evaporable getter (referred to as NEG), a getter member storage device used in the getter pump, and a getter device.

  Getter pumps using non-evaporable getters have been known for a long time in the field of vacuum technology. The getter pump is a stationary vacuum pump and is highly evaluated in that it is a simple vacuum pump that does not require any energy during operation because it has no moving parts.

  In the getter pump, an alloy with high gas absorption and gas absorption (non-evaporable getter material) is once pulverized to increase the surface area, and the powder is collected and compressed or sintered to be porous. A getter member formed into a disk shape (pill shape) is used. Exhaust by the non-evaporable getter is performed by chemically adsorbing reactive gas species such as oxygen, hydrogen, water, and carbon oxide on the constituent elements of the non-evaporable getter and diffusing them inside the non-evaporable getter.

  One form of the getter member is one in which a large number of donut-like getter members are stacked so as to increase the exhaust speed and the gas sorption amount.

  For example, as shown in FIG. 17A, a rod heater 53 is arranged at the center of the bottom of the vacuum vessel 51, and a plurality of getter members 52 are stacked on the rod heater 53 in a skewered manner with a certain gap therebetween. There is what I did.

  Further, as shown in FIG. 17B, the getter member 62a is stacked in a skewered manner on a rod-shaped fixing bracket 62b to form a getter member assembly 62, and around the heater 63 disposed at the center of the bottom in the vacuum vessel 61. There are also a plurality of getter member assemblies 62 arranged (Patent Document 1). A vacuum pump using this type of getter member is known as a vacuum pump having a large displacement.

JP-A-11-190274

  By the way, the getter member formed by solidifying the alloy powder conducts heat through the joint portion between the powders, and thus it is difficult to conduct the heat originally.

  In addition, in the arrangement method of the getter member 52 shown in FIG. 17A, heat is transmitted over a relatively long distance from the center (the heater 53 side) of the getter member 52 toward the outside (the wall side of the vacuum vessel 51). For this reason, a large temperature difference occurs between the central portion and the outer peripheral portion of the getter member 52 close to the heater 53, and it is difficult to uniformly heat the entire getter member 52.

  For example, in a circular disk made of a non-evaporable getter alloy called St707 (trade name of SAES) with an outer diameter of about 20 mm and a thickness of 2 mm, even if the temperature of the heater 53 is raised to about 500 ° C., On the outer peripheral surface of the getter member 52, the temperature is about 400 ° C., which is far from the optimum activation temperature 450 ° C. of the getter member 52.

  Further, this temperature difference is further promoted because the material of the vacuum vessel 51 is stainless steel. That is, stainless steel is a metal with a very high emissivity of 0.35 (having a very low thermal conductivity of about 16 W / m / ° C), so there is little reflection and the radiant heat radiated from the periphery of the getter member is The temperature will not rise easily because it is continuously absorbed by the vacuum vessel wall. For this reason, the temperature difference is further increased between the central portion and the peripheral portion of the getter member 52. That is, heat loss increases and uniform activation of the getter member assembly becomes difficult.

  Further, as shown in FIG. 17B, when the getter member assembly 62 is arranged closer to the container wall around the heater 63 in the stainless steel vacuum container 61, the heat loss is further increased and the getter is further increased. It becomes difficult to uniformly activate the member assembly 62. That is, in the disk-like getter member 62a, the getter member 62a is heated from the circumferential portion near the heater 63, and the heat moves toward the container wall side and is transmitted to the opposite circumferential portion near the container wall. As a result, the distance that heat is conducted through the getter member 62a is further increased. Moreover, since the getter member 62a is close to the container wall, heat is continuously absorbed by the container wall from the circumferential portion of the getter member 62a on the container wall side, and the temperature does not rise easily. As described above, heat loss is further increased, and a larger temperature difference is generated between the heater 63 side and the container wall side of the getter member assembly 62.

  The present invention was created in view of the above-described problems of the conventional example, and can efficiently use the radiant heat from the heater and uniformly activate the getter member, and the getter pump. A getter member storage tool and a getter device for use in a pump are provided.

  In order to solve the above-described problem, according to one aspect, a getter member storage device is provided that stores a disk-like getter member between concentrically spaced members.

  According to another aspect, there is provided a getter device characterized in that a disk-like getter member is accommodated between members arranged concentrically at intervals.

  According to still another aspect, a getter device in which a disk-like getter member is stored between members arranged concentrically at intervals, and the getter member stored in the getter device so as to face each other. There is provided a getter pump which is disposed and has heating means for heating the getter member.

  According to the present invention, since the disk-like getter member is accommodated between the members arranged concentrically at intervals, the getter member is arranged so that a wide surface faces the heating means.

  Thereby, since the radiant heat from a heating means injects into the wide surface of a getter member substantially perpendicularly, the radiant heat from a heating means can be efficiently transmitted to a getter member.

  Further, since the radiant heat incident on the getter member from the heating means is conducted in the thickness direction of the getter member, the distance that the radiant heat should be conducted to heat the getter member is significantly shortened. As a result, the loss of heat conducted in the getter member is reduced, and even if there is a heat loss, the heat is supplied immediately, so that the temperature difference between the portion near the heating means of the getter member and the portion far from it is reduced. Therefore, the getter member can be activated uniformly.

It is a top view of the getter pump according to the first embodiment of the present invention. It is a sectional side view which follows the II line | wire of FIG. It is a perspective view which decomposes | disassembles and shows the getter member storage tool of FIG. It is a side view which shows the state which accommodated the getter member of FIG. 1 in the getter member storage tool. (A) thru | or (c) is a side view which shows the modification of the getter member used for the getter pump of 1st Embodiment, and the arrangement | positioning method of the getter member in the getter member storage tool of FIG. It is a top view of the getter pump of the second embodiment of the present invention. It is a sectional side view which follows the II-II line of FIG. (A) is a perspective view of the getter member storage tool used for the getter pump of the third embodiment of the present invention, and (b) is a perspective view of a getter device using the getter member storage tool of (a). is there. It is a side view of the NEG cartridge (getter apparatus) used for the getter pump of 4th Embodiment of this invention. (A) is a perspective view of the heater attachment member attached to the NEG cartridge in 4th Embodiment of this invention, (b) is a side view which shows the state which attached the linear heater to the heater attachment member. It is a sectional side view of the getter pump of 5th Embodiment of this invention. It is a sectional side view of the getter apparatus used for the getter pump of 6th Embodiment of this invention. It is a top view of a getter pump according to a seventh embodiment of the present invention. It is the side view seen from the cross section which follows the III-III line of FIG. (A) thru | or (c) is a side view which shows the method of attaching the NEG cartridge in 7th Embodiment of this invention to a vacuum device. (A) And (b) is sectional drawing to which the connection flange part of FIG. 15 (a) and (c) was expanded, respectively. It is a sectional side view of the getter pump of a prior art example.

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

(First embodiment)
A getter pump 101 according to a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a top view of the getter pump 101 according to the first embodiment of the present invention, and FIG. 2 is a side sectional view taken along the line I-I. However, in FIG. 2, only the heater 12 is shown as viewed from the side.

  In the getter pump 101 according to the first embodiment, a spiral heater 12 and a plurality of circular disk-like non-evaporable getter members (NEG members) 14 are provided in a vacuum vessel (also referred to as a housing) 11. And a NEG cartridge (getter device) 13 provided so as to surround the heater 12.

  The NEG cartridge 13 is placed on the bottom surface of the container 11 via the support member 16. The NEG cartridge 13 may be fixed to the upper portion of the vacuum vessel 11 directly or via a fixing bracket (not shown). For example, a groove that can accommodate the fixing metal fitting connected to the NEG cartridge 13 may be formed on the surface of the flange 11c, and the fixing metal fitting may be fixed by screwing or the like in the groove so as not to protrude from the surface of the flange 11c. The getter member 14 performs exhaustion by chemically adsorbing reactive gas species such as oxygen, hydrogen, water, and carbon oxide in a reduced-pressure atmosphere and diffusing the reaction gas species inside the getter member 14.

  The vacuum vessel 11 has a cylindrical shape and is closed at the lower end surface corresponding to the bottom. The upper end of the vacuum vessel 11 is an open end 11f, and has a flange 11c around the open end 11f. Using this flange 11c, another vacuum chamber (not shown) to be exhausted is connected via a vacuum seal material (not shown). Reference numeral 11d denotes a bolt hole provided in the flange 11c, which is used when the vacuum vessel 11 is attached to another vacuum chamber. Then, the other vacuum chamber is decompressed by the getter pump 101 through the open end 11f. As a material of the vacuum vessel 11 of the getter pump 101, a copper alloy that is a low radiation high heat conductor, for example, a beryllium copper alloy having a radiation rate of 0.1 or less and a heat conductivity of 100 W / m / ° C. or aluminum copper It is preferable to use an alloy.

  A spiral heater 12 that is long in the direction of the central axis of the cylinder of the vacuum vessel 11 is provided at the center of the bottom 11b of the vacuum vessel 11. At the center of the bottom 11b of the vacuum vessel 11, a hole is made in the copper alloy, and an electric insulator 11e is embedded therein, and the current introduction terminals 12b and 12c of the heater 12 pass through the insulator 11e to the outside. Has been pulled out.

  Further, the NEG cartridge 13 disposed so as to surround the heater 12 has a structure in which a plurality of getter members 14 are stored vertically in a getter member storage tool 15 in which a mesh bag-shaped storage portion is formed into a cylindrical shape. Have. The getter member storage tool 15 is lower in height (shorter in length) than the heater 12. A heater 12 is placed at the center of the cylinder of the getter member housing 15. Thus, the wide plate surfaces of all the getter members 14 stored in the getter member storage tool 15 face the heater 12.

  As shown in FIG. 3, the getter member storage tool 15 is made of two mesh members 15a and 15b obtained by forming a plain weave metal mesh into cylindrical shapes having different diameters, and a mesh member 15a having a large diameter and a mesh member 15a having a small diameter. Are inserted so that the central axes of the two cylindrical shapes coincide with each other, and the lower portion 16b of the mesh member 15b is bent into a bag shape. The diameters of the two mesh members 15a and 15b are set such that there is an interval between the two mesh members 15a and 15b so that the getter member 14 can be stored vertically.

  That is, the getter member storage tool 15 is formed by concentrating two cylindrical mesh members 15a and 15b concentrically in a plan view with a gap wider than the thickness of the getter member 14.

  A support member 16a is formed at the lower part of the mesh member 15a using the mesh member 15a. The getter member storage tool 15 is attached to the bottom surface of the vacuum vessel 11 via the support member 16a as shown in FIG. Supported.

  As the material of the mesh members 15a and 15b of the getter member storage tool 15, a metal or ceramic having excellent heat resistance, low thermal conductivity, and low outgassing can be used. Examples of such a metal material include titanium, a titanium alloy, stainless steel, and Inconel.

  The net members 15a and 15b of the getter member storage tool 15 are not limited to plain weave metal nets. An etching wire mesh, a punching metal wire mesh, or the like may be used in which a metal plate is processed to provide a large number of holes in a size that does not allow a disk-like getter member to pass through.

  As shown in FIG. 4, a plurality of getter members 14 are packed between the two mesh members 15 a and 15 b of the getter member storage tool 15. The getter member storage tool 15 has an interval that allows the getter member 14 to be stored vertically between the two mesh members 15a and 15b, so that the getter members 14 can be packed so as not to overlap each other. . At this time, if the getter members 14 are packed in the vertical rows and the horizontal rows so that the pitch between adjacent rows is shifted by 1/2, the gap between the getter members 14 is minimized and maximized. A number of getter members 14 can be accommodated.

  Instead of the circular disk-shaped getter member 14, as shown in FIGS. 5 (a) to 5 (c), square or rhombic or regular hexagonal disk-shaped getter members 14a, 14b such as a square or a rectangle having the same shape are used. 14c can be used. 5A to 5C, the gap between the getter members 14 is minimized, and the maximum number of getter members 14a, 14b, 14c is stored in the getter member storage tool 15. be able to.

  Next, the operation of the getter pump 101 according to the first embodiment will be described with reference to FIGS. 1 and 2.

It is assumed that the getter pump 101 is connected to another vacuum chamber that is an exhaust target. The other vacuum chamber is connected to an auxiliary exhaust pump (not shown) such as a turbo molecular pump, and is exhausted to 10 ^-3 Pa, and the exhaust is continuously performed by the auxiliary exhaust pump. To do.

  In this state, in order to activate the getter member 14, the heater 12 of the getter pump 101 is energized to cause the heater 12 to generate heat, and the getter member 14 is heated.

When the temperature of the getter member 14 rises and reaches 100 to 200 ° C., the gas adsorbed on the oxide film (ZeO ₂ ) on the surface of the getter member 14 is separated from the surface, and the vacuum vessel is passed through another vacuum chamber by an auxiliary exhaust pump. 11 is discharged from the inside. Further, when the temperature of the getter member 14 rises and exceeds 300 ° C., an oxide film (ZeO ₂ ) covering the surface of the getter member 14 is deposited inside the getter member 14, and the oxide film is further cracked. A new metal surface appears on the surface of the member 14. This metal surface has a getter function, and a large exhaust speed can be obtained, and the activation of the getter member 14 is completed.

As a result, the other vacuum chambers are exhausted by the getter pump 101. Therefore, after that, even if the auxiliary exhaust pump is stopped, the exhaust is continued only by the getter pump 101, and an ultrahigh vacuum or an extremely high vacuum of 10 ⁻⁸ Pa or less can be maintained.

  As described above, in the getter pump 101 according to the first embodiment, the disk-like getter member 14 is placed vertically so that the plate surface of the getter member 14 faces the heater 12. The radiant heat is incident on the wide plate surface of the getter member 14 substantially perpendicularly.

  Further, since the vacuum container 11 is made of a copper alloy having a low emissivity (and therefore high thermal conductivity), most of the radiant heat from the getter member 14 whose temperature has been raised is the side wall (container wall) of the vacuum container 11. It will be reflected and return and heat loss can be reduced. For example, if the emissivity is 5%, 95% of the radiant heat from the getter member 14 whose temperature has been raised is reflected by the container wall and returned.

  Furthermore, in order to fix the NEG cartridge 13 in the vacuum vessel 11, it is necessary to contact them directly or via a metal fitting. According to the first embodiment, the net member 15a of the getter member storage tool 15 is used. , 15b can be made of a metal or ceramic having a low thermal conductivity, so that the heat from the getter member 14 whose temperature has been raised can be made difficult to escape to the vacuum vessel 11 by conduction.

  As described above, each of the above configurations contributes to heating the getter member 14 with a small amount of electric power by efficiently using the radiant heat from the heater 12.

  Further, since the disk-like getter member 14 is placed vertically and the plate surface of the getter member 14 faces the heater 12, the heat is obtained from the incident surface of the radiant heat from the heater in the getter member 14. Flow in the direction. This shortens the distance that radiant heat should be conducted to heat the getter member 14. Therefore, the loss of heat conducted inside the getter member 14 is reduced, and even if there is a heat loss, heat is supplied immediately, so the temperature difference between the portion of the getter member 14 close to the heater and the portion far from the heater is reduced. it can.

  Furthermore, since the vacuum vessel 11 of the getter pump 101 is made of a low emissivity copper alloy, heat absorption from the getter member 14 to the vessel wall is reduced. The temperature difference between the distant parts is further improved.

  Further, by forming the height (length) of the heater 12 to be sufficiently higher (longer) than the height (length) of the NEG cartridge 13, any getter member 14 in the NEG cartridge 13 can be made uniform. It is possible to raise the temperature.

  As described above, each of the above configurations contributes to the uniform activation of the NEG cartridge 14.

(Example)
Next, an investigation experiment conducted by the present inventor will be described.

(Production of getter pump)
A method for manufacturing the getter pump 101 used in the investigation experiment will be specifically described with reference to FIGS.

  First, as shown in FIG. 3, two 12 mesh plain woven wire meshes of pure titanium wire having a wire diameter of 0.6 mm are prepared and rolled to produce two cylindrical shapes. One sheet is formed to have a diameter of 37 mm for use as the outer cylinder 15a, and the joint is spot welded. The other sheet is formed to have a diameter of 28 mm for use as the inner cylinder 15b, and the joint is spot welded. In both cases, the height is 58 mm.

  Next, the inner cylinder 15b is inserted inside the outer cylinder 15a so that the cylindrical central axes coincide. Remove the horizontal wire at the lower end of the inner cylinder 15b and bend the vertical wire 90 degrees toward the outer cylinder 15a to close the lower end of the gap between the inner cylinder 15b and the outer cylinder 15a. And As a result, the getter member 14 to be inserted is prevented from falling.

  The getter member 14 has a diameter of 10 mm and a height of 3 mm by compressing or sintering an alloy powder containing 70% zirconium (Zr), 24.6% vanadium (V), and 5.4% iron (Fe) called St707. It is a porous disk hardened in a disk shape (also called a pill shape or a tablet shape). This is put into a gap between the outer cylinder 15a and the inner cylinder 15b of the getter member storage tool 15, and eight pieces are arranged per one turn and stacked in five stages. Thus, the NEG cartridge 13 having a total of 40 getter members 14 is manufactured. The height of the NEG cartridge 13 is 37 mm.

  The heater 12 is a tantalum wire having a wire diameter of 1 mm and a length of 500 mm, wound 12 turns in a spiral shape having a diameter of about 12 mm. The current introduction terminals 12b and 12c are composed of two terminals made of nickel rods so that the resistance when the heater is abnormal can be confirmed, and a current of 16.5A can flow. Note that one of the current introduction terminals can be a rod terminal and the other can be a ground terminal.

  The material of the vacuum vessel 11 is, for example, a copper alloy (beryllium copper alloy) containing 0.2% beryllium. This vacuum material was invented by the present applicant and has already obtained a patent right (Patent No. 4829485). The inner diameter of the vacuum vessel 11 is 39mmφ, the height is 60mm, and the upper end flange with the open end 11f is formed in accordance with the ICF70 Conflat Flange standard, and the connection surface of other vacuum chambers adheres to the copper gasket Nickel phosphorus plating is applied to prevent it.

(Investigation experiment and results)
Next, a description will be given of an investigation experiment performed using the above-described getter pump 101 and its result.

  First, a heating experiment was conducted in which the temperature of the getter member assembly housed in the NEG cartridge 13 was raised to 500 ° C. For comparison, a stainless steel vacuum container was also used for the experiment as a container for accommodating the NEG cartridge 13.

  According to the experiment, the electric power required to raise the temperature of the getter member assembly to 500 ° C. was 200 W in the case of stainless steel, but about 70 W in the case of beryllium copper alloy and about 1 in the case of stainless steel. / 3. This is thought to be because the surface heat emissivity of the beryllium copper alloy is as small as about 1/5 that of stainless steel, making it difficult to absorb heat. In the beryllium copper alloy, the thermal conductivity is 13 times as large as that of stainless steel, corresponding to a small heat radiation rate.

  Further, the temperature on the atmosphere side surface of the vacuum vessel 11 measured at the same time rose to about 250 ° C. in the case of stainless steel, but was about 80 ° C. or less in the case of beryllium copper alloy. This indicates that in the beryllium copper alloy of the present application, the radiant heat from the heater 12 is almost efficiently absorbed by the getter member 14.

  Further, when the temperature of the front and back surfaces of each getter member 14 was measured at a predetermined position including the lowermost stage and the uppermost stage of the getter member assembly using a thermocouple while the temperature was raised to 500 ° C., beryllium copper In the case of alloys, the maximum temperature difference was within 20 ° C.

  Next, the activation experiment of the getter member assembly was performed.

  In the experiment, the getter member assembly was activated by leaving it for about 30 minutes in a state where the temperature was raised to 500 ° C. After further natural cooling, the exhaust speed of the NEG cartridge 13 was measured by a well-known throughput method. As an experimental result, the exhaust speed of the NEG cartridge 13 was 70 L / s for hydrogen and 40 L / s for nitrogen.

  As described above, according to the first embodiment of the present invention, the getter member assembly can be heated with low power by efficiently using thermal energy and the getter member assembly can be uniformly activated. It became possible to provide a getter pump that can be used.

(Second Embodiment)
A getter pump 102 according to a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 6 is a top view of the getter pump 102 according to the second embodiment of the present invention, and FIG. 7 is a side sectional view taken along the line II-II. However, in FIG. 7, only the heater 12 is shown as viewed from the side.

  In the getter pump 102 according to the second embodiment, as a member for supporting the getter member 14, a plain-woven wire mesh is formed in a cylindrical shape, like the net members 15a and 15b of the getter member storage tool 15 according to the first embodiment. A molded mesh member 18 is used. Further, the lower end of the mesh member 18 is bent outward so that the lower end of the getter member 14 can be supported.

  A plurality of getter members 14 are placed vertically in the net member 18. Then, while supporting the lower end of the getter member 14 by the mesh member 18, the other plate surface of the getter member 14 is pressed and supported so that one plate surface of the getter member 14 contacts the side wall of the vacuum vessel 11. . As described above, the getter member storage tool is constituted by the mesh member 18.

  The net-like member 18 formed into one cylindrical shape and the plurality of getter members 14 constitute a getter device 17. In addition, the other code | symbol same as 1st Embodiment shows the same thing as 1st Embodiment.

  In such a second embodiment, the getter member 14 is brought into contact with the inner wall of the vacuum vessel 11, but the contact is point contact. As a material for the vacuum vessel 11, a copper alloy that is a low radiation high heat conductor is used as in the first embodiment, and a material having a low thermal conductivity is used as the mesh member 18. Therefore, heat conduction from the getter member 14 to the inner wall of the vacuum vessel 11 is suppressed, and heat absorption into the vacuum vessel 11 is suppressed.

  Therefore, it has become possible to provide a getter pump capable of heating the getter member assembly with low power by efficiently using heat energy and uniformly activating the getter member assembly.

(Third embodiment)
FIG. 8A is a perspective view showing a getter member storage tool 19 used in a getter pump according to the third embodiment of the present invention. FIG. 8B is a perspective view showing a state in which the getter member 14 is stored in the getter member storage tool 19.

  The getter member storage device 19 bridges the first and second linear members 19a and 19b, which are concentrically spaced in parallel, and the first linear member 19a and the second linear member 19b. And a plurality of third linear members 19c provided at intervals along the circumference. The getter member storage portion 19e is formed between the adjacent third linear members 19c, and the distance between the first linear member 19a and the second linear member 19b is wider than the thickness of the disk-like getter member. The interval between the linear members 19c is formed narrower than the diameter of the disk-like getter member.

  A plurality of such structures are stacked in a hierarchical manner via the support member 19d, and the getter member storage device 19 is formed. If the adjacent layers are formed so that the getter members 14 stored in the getter member storage portion 19e are shifted by 1/2 pitch as shown in FIG. 8B, the gap between the getter members 14 is reduced. Many getter members 14 can be accommodated.

  The getter member housing 19 is composed of two plain weave mesh members (one is a first linear member 19a in the horizontal direction and a support member 19d in the vertical direction, and the other is The second linear member 19b and the longitudinal support member 19d) are formed into two cylindrical shapes having different diameters, arranged in concentric cylinders, and further arranged in the lateral direction. This corresponds to a structure in which a third linear member 19c that bridges the linear member 19a and the second linear member 19b is provided.

  When the circular disk-shaped getter member 14 is placed vertically in the getter member storage portion 19e, the interval between the adjacent third linear members 19c is smaller than the diameter of the getter member 14, and thus is supported vertically without falling off. . As the material of the first to third linear members 19a to 19c, the same material as that of the mesh member of the first embodiment is used.

  The getter device 20 is configured by storing the getter member 14 in the getter member storage portion 19e of the getter member storage tool 19.

  Also according to the third embodiment of the present invention, as in the first embodiment, the getter member assembly is heated with a small amount of electric power by efficiently using the heat energy and the getter member assembly is activated. It is possible to provide a getter pump that can uniformly perform the process.

(Fourth embodiment)
A getter pump according to a fourth embodiment of the present invention will be described with reference to FIGS.

  FIG. 9 is a side view showing, in particular, the NEG cartridge 21 and the heater 23 in the getter pump according to the fourth embodiment of the present invention, and FIG. 10A shows the heater attachment member 22 attached to the NEG cartridge 21. It is a perspective view, (b) is a side view showing a state in which a linear heater 23 is attached to the heater attachment member 22. However, the NEG cartridge 21 shown in FIG. 9 is actually formed in a cylindrical shape, but in FIG.

  The NEG cartridge 21 includes a getter member storage tool 15 and a getter member 14 that have mesh bag-like storage portions arranged in a cylindrical shape, similar to the getter member storage tool of the first embodiment. In this case, as the heater 23 for heating the getter member 14, a linear heater is used. As shown in FIG. 9, the getter member 14 is attached to the heater attachment member 22 and around the outer cylinder 15a of the getter member storage tool 15. It is stretched near the storage device 15. Note that the getter member storage tool 15 may be stretched around the inner cylinder 15b (shown in FIG. 3). The heater 23 may be a belt-like one in addition to a linear one.

  The heater mounting member 22 is composed of a thin plate 22 having a thin plate 22b whose diameter is substantially the same as the diameter of the getter member 14, and a column 22a fixed upright at the center of one side of the disc 22b. The support post 22a is provided with a hole through which the linear heater 23 passes near the end opposite to the attachment end of the disc 22b.

  When the getter member 14 is stored in the getter member storage tool 15, the heater mounting member 22 is also stored together. The struts 22a of the heater mounting member 22 are made to come out from the mesh of the getter member storage tool 15. At this time, since the diameter of the disk 22b of the heater mounting member 22 is substantially the same as the diameter of the getter member 14, the heater mounting member 22 can be placed between the getter members 14 without disturbing the arrangement of the getter members 14. Various arrangements of the heater mounting members 22 around the NEG cartridge 21 are possible, but it is preferable that the heater mounting members 22 are alternately placed on the upper and lower portions of the NEG cartridge 21.

  The heaters 23 are sequentially attached to the columns 22a of the heater attachment members 22 arranged alternately on the upper and lower sides of the NEG cartridge 21. Accordingly, the heater 23 is stretched around the outer cylinder 15a of the getter member storage tool 15 and near the outer cylinder 15a.

  Such a configuration is particularly effective when the diameter of the vacuum container 11 of the getter pump is increased. That is, when the diameter of the vacuum vessel 11 is increased, in the arrangement of the getter member 14 as in the first embodiment, the distance from the heater 23 placed at the center of the vacuum vessel 11 to the getter member 14 is increased, and heat is obtained by the getter member. It becomes difficult to reach 14. In this case, the heater 23 can always be placed near the getter member 14 by stretching the heater 23 around the outer cylinder 15a of the getter member housing 15 and near the outer cylinder 15a. Thereby, the heat energy of the heater 23 can be used effectively.

  In addition, the getter member 14 is placed vertically so that the plate surface faces the heater 23 and heat enters from a wide surface of the getter member 14, so that in each getter member 14 a portion close to and far from the heater 23 The temperature difference becomes smaller.

  As described above, according to the fourth embodiment of the present invention, as in the first embodiment, the heat energy is efficiently used to heat the getter member assembly with less power, and the getter member assembly is heated. It becomes possible to provide a getter pump capable of performing activation uniformly.

(Fifth embodiment)
FIG. 11 is a side sectional view showing a getter device used for a getter pump 103 according to a fifth embodiment of the present invention.

  In this structure, the assembly of getter members 14 is placed horizontally so as not to overlap the bottom of the vacuum vessel 11, and a metal mesh (mesh member) 24 is provided thereon. Also in this case, the linear heater 26 is stretched around the mesh member 24 by a heater mounting member 25 similar to the heater mounting member 22 of the fourth embodiment. As the material of the wire mesh 24, the same material as that of the first embodiment can be used. The getter device includes a wire mesh 24 and an assembly of getter members 14.

  In the heater mounting member 25 of the fifth embodiment, the washer 25b is passed through the column 25a and fixed at a position slightly below the tip of the column 25a. Then, the support column 25 a is fixed to the bottom of the vacuum vessel 11 through the wire mesh 24. Further, the washer 25b is fixed to the wire mesh 24 by welding or the like. Then, the heater 26 is passed through a hole formed in the tip end portion of the support column 25a and is stretched near the mesh member 24.

  Also according to the fifth embodiment of the present invention, as in the first embodiment, the getter member assembly is heated with less power by efficiently using the heat energy and the getter member assembly is activated. It is possible to provide the getter pump 103 that can uniformly perform the above.

(Sixth embodiment)
FIG. 12 is a side sectional view showing a NEG cartridge 27 used for a getter pump according to a sixth embodiment of the present invention.

  The NEG cartridge 27 includes a getter member storage tool 28 and a plurality of getter members 14 that are the same as those in the first embodiment.

  In the same manner as in the first embodiment, the getter member storage tool 28 is made of two mesh members 28a and 28b obtained by forming a plain weave metal mesh into a cylindrical shape having a different diameter, and a mesh member 28b having a small diameter is made a mesh member having a large diameter. It is inserted into the inner side of 28a so that two cylindrical central axes coincide with each other, and the lower part of the net-like member 28b is bent into a bag shape. The difference from the first embodiment is that the diameters of the two mesh members 28a and 28b are set such that there is an interval between the two mesh members 28a and 28b so that the getter member 14 can be stored horizontally. It is a point.

  The plurality of getter members 14 are stacked and supported in a mesh bag-like storage portion of the getter member storage tool 28 via a spherical or cylindrical interposition member 29.

  In the getter pump according to the sixth embodiment, the NEG cartridge 27 is placed at the bottom of the same container as in the first embodiment. According to such a getter pump, the getter member 14 is held horizontally, but the temperature is raised particularly by using a copper alloy that is a low radiation high heat conductor as the material of the vacuum vessel. Much of the radiant heat from the getter member 14 is reflected back by the container wall, and heat loss can be reduced. As a result, the getter member assembly can be activated uniformly as a result.

(Seventh embodiment)
FIG. 13 is a top view of the getter pump 104 according to the seventh embodiment of the present invention.

  FIG. 14 is a side view as seen in the direction of the arrow from a cross section taken along line III-III in FIG.

  In the getter pump 104 of the seventh embodiment of the present invention, a plurality of circular disc-shaped non-evaporable getter members (NEG members) 14 are housed, and NEG cartridges (getter devices) provided along the inner wall of the vacuum vessel 30. ) 21a and a ring flange 30.

  The NEG cartridge 21a is composed of a getter member storage tool 15 and a getter member 14 that have a mesh bag-shaped storage portion arranged in a cylindrical shape, similar to the getter member storage tool according to the fourth embodiment. In this case, the heater 23 for heating the getter member 14 is attached to the heater attachment member 22 and stretched around the inner cylinder 15b of the getter member storage tool 15, as shown in FIG.

  The heater mounting member 22 is the same as that shown in FIG. 10 and is alternately arranged at the upper and lower portions of the inner cylinder 15b around the inner cylinder 15b of the getter member storage tool 15, and is welded to the inner cylinder 15b. It is fixed. The heater mounting member 22 may be mounted on the inner cylinder 15b by storing it in the getter member storage tool 15 together with the getter member 14 and fixing it between the getter members 14 as in FIG. . In FIG. 13, the heater mounting member 22 is omitted.

  The linear heaters 23 are sequentially attached to the pillars 22a of the heater attachment members 22 that are alternately arranged at the upper part and the lower part around the inner cylinder 15b of the getter member storage tool 15. Thus, the heater 23 is stretched around the inner cylinder 15b of the getter member storage tool 15 and in the vicinity of the inner cylinder 15b so as to face the getter member 14.

  The ring flange 30 has a cylindrical shape having a predetermined thickness, and the periphery thereof is a flange 31a. Further, an edge E for performing vacuum sealing is provided on the cylindrical inner surface of the flange 31a, and a flange 31c protruding inward is provided on the inner side thereof. The NEG cartridge 21a is detachably mounted on the flange 31c so that the center axis of the cylinder of the getter member housing 15 is aligned with the center axis of the cylinder of the ring flange 30. Further, a part of the flange 31a is provided with electric current introduction terminals 32a and 32b that are passed through the flange 31a in the radial direction from the central axis and insulated from the flange 31a, and heat the heater 23 from the outside to the inside. Can be led. The terminals inside the current introduction terminals 32 a and 32 b are connected to the heater 23. Also, the flange 31a is provided with a bolt hole 31b so that it can be attached to another vacuum vessel.

  Note that the shape of the vacuum seal portion (edge E) of the ring flange 30 is not limited to the knife edge type conflat flange. Alternatively, helicoflex, viton, or the like may be used for the vacuum seal portion.

  Next, a method for attaching the getter pump 104 to a vacuum apparatus will be described.

  FIGS. 15A to 15C are side views showing a method of attaching the getter pump 104 to a vacuum apparatus.

  In FIG. 15A, two vacuum vessels A and B are connected to each other with their flanges 33 and 34 butted together to constitute one vacuum device. The mutual flanges 33 and 34 are tightened with bolts and nuts to achieve a vacuum seal of the vacuum device. FIG. 16A is an enlarged cross-sectional view of the connection portion between the vacuum vessels A and B. FIG. In FIG. 16A, reference numeral 40 denotes a bolt and 41 denotes a nut. Reference numeral G denotes a gasket that is sandwiched between the edges E of the mutual chambers 33 and 34 to reliably perform vacuum sealing.

  Note that the upper end of the vacuum vessel A and the lower end of the vacuum vessel B may be closed or open ends. If it is an open end, another vacuum vessel is connected to it.

  When the getter pump 104 is attached to this vacuum apparatus, first, as shown in FIG. 15B, the bolts 40 of the flanges 33 and 34 are loosened and removed, and the vacuum containers A and B are separated. Next, the NEG cartridge 21a is inserted into the vacuum container A. Then, the ring flange 30 of the NEG cartridge 21a is sandwiched between the flange 33 of the vacuum vessel A and the flange 34 of the vacuum vessel B, and the three flanges 30, 33, 34 are overlapped. After that, tighten the three flanges 30, 33, 34 with bolts and nuts. FIG. 16B is an enlarged cross-sectional view of the connecting portion between the flanges. In FIG. 16B, reference numeral G denotes between the edge E of the flange 33 of the vacuum vessel A and the upper edge E of the ring flange 30, the edge E of the flange 34 of the vacuum vessel B and the lower edge of the ring flange 30. Each gasket is sandwiched between E.

  In this way, as shown in FIG. 15C, the vacuum apparatus provided with the NEG cartridge 21a is completed.

  As described above, according to the getter pump 104 of the seventh embodiment, the NEG cartridge 21a has a cylindrical shape, and the heater 23 is disposed around the inner cylinder 15b of the getter member housing 15 and the inner cylinder 15b. It is stretched nearby. For this reason, the NEG cartridge 21a can be arranged along the inner wall of the vacuum vessel A with the central portion thereof spaced by arranging the NEG cartridge 21a in the cylindrical vacuum vessel A with the central axis of the cylinder aligned. .

  For this reason, an electron beam or the like can be guided from the vacuum container A to the vacuum container B or in the opposite direction through the central portion of the vacuum container A. In addition, the substrate to be processed can be transported between the vacuum containers A and B through the center of the vacuum container A. Therefore, the usability of the vacuum device is improved and the use of the vacuum device is expanded.

  Further, since the NEG cartridge 21a and the ring flange 30 are integrated, the NEG cartridge 21a can be easily attached to the vacuum apparatus.

(Example)
Next, an investigation experiment of the getter pump 104 conducted by the present inventor will be described.

(Production of getter pump)
With reference to FIG. 14, a method for manufacturing the getter pump 104 used in the investigation experiment will be described in detail.

  First, as shown in FIG. 14, two 10 mesh plain woven wire meshes of a stainless steel wire mesh having a wire diameter of 0.6 mm are prepared and rolled to produce two cylindrical shapes. One sheet is formed to a diameter of 150 mm for use as the outer cylinder 15a, and the joint is spot welded. The other sheet is formed to have a diameter of 140 mm for use as the inner cylinder 15b, and the joint is spot welded. In both cases, the height is 200 mm.

  Next, the inner cylinder 15b is inserted inside the outer cylinder 15a so that the cylindrical central axes coincide with each other, the lower end portion of the gap between the inner cylinder 15b and the outer cylinder 15a is closed, and the gap is formed into a bag shape. .

  A disc of 10 mm in diameter and 3 mm in height with alloy powder containing 70% zirconium (Zr), 24.6% vanadium (V) and 5.4% iron (Fe), called St707, between the bag-shaped double metal meshes About 820 NEG (getter member) 14 hardened in a shape were packed to produce a NEG cartridge 21a.

  Further, the NEG cartridge 21a is attached to the ring flange 30 so that the center axis of the cylinder is aligned, and then a heater 23 made of a tantalum wire having a wire diameter of 0.6 mm is disposed around the inner cylinder 15b as shown in FIG. A getter pump 104 was produced.

(Investigation experiment and results)
Next, a description will be given of an investigation experiment conducted using the above-described getter pump 104 and its result.

After the getter pump 104 was attached to the vacuum vessel, 50 V × 7 A electric power was supplied to the heater 23 to increase the temperature of the NEG to 450 ° C. to activate it. After activation, the temperature was returned to room temperature, and the exhaust rate for hydrogen was measured by the throughput method. As a result, a large pumping speed of 2.0 m ³ / s was obtained. In addition, an exhaust speed of 0.8 m ³ / s was obtained for nitrogen.

  Although the present invention has been described in detail with the embodiments, the scope of the present invention is not limited to the examples specifically shown in the above embodiments, and the scope of the above embodiments within the scope of the present invention is not limited. Modifications are within the scope of this invention.

  For example, as a getter member 14, a non-evaporable getter alloy powder containing 70% zirconium (Zr), vanadium (V) 24.6%, and iron (Fe) 5.4%, called St707, is 10 mm in diameter and 3 mm in height. Although a porous disk hardened in a shape is used, the dimensions of the disk can be appropriately changed according to the size of the vacuum vessel.

  Also, instead of the non-evaporable getter alloy called St707, a vanadium-titanium non-evaporable getter alloy called St185 (trade name of SAES) or other non-evaporable getter alloy may be used. Good.

  In the embodiment, the NEG cartridges (getter devices) 13, 17, 20, 21, 21 a, 27 and the getter device 20 are placed in the vacuum vessel 11. 17, 17, 21, 21 a, 27 are arranged so that the central axis of the cylinder is parallel, but considering the direction of the connection of the vacuum pump to another vacuum chamber to be exhausted, etc. It can be changed.

  Further, in the getter devices 13, 17, 20, 21, and 21a, a plurality of disc-shaped getter members having a fixed shape and size are arranged vertically and stored so as not to overlap each other. However, it is not limited to this.

  The disc-shaped getter members are not of a fixed shape and size, but may be random shape and size getter members, and the getter members may partially overlap each other. Also in this case, since the interval between the storage portions is narrow, the distance that heat from the heater conducts heat through the getter member is the same as when a disc-like getter member having a fixed shape and size is used. Therefore, the loss of heat transmitted through the getter member is reduced, and heat is supplied immediately even if there is a heat loss, so that the temperature difference between the portion near the heating means of the getter member and the portion far from it is reduced. Therefore, the getter member can be activated uniformly.

  Further, although a plain weave wire mesh is used as the mesh member, a plain weave mesh member of an electrical insulator such as a heat-resistant resin or ceramic may be used.

  The above-mentioned present invention is summarized as an appendix.

  (Additional remark 1) The getter member storage tool which stores a disk-like getter member between the members arranged concentrically at intervals.

  (Additional remark 2) The said getter member storage tool makes two cylindrical mesh members concentrically face in plan view with a gap wider than the thickness of the getter member, and the getter member is placed between the mesh members. The getter member storage device according to appendix 1, wherein the getter member storage device is stored.

  (Additional remark 3) The said getter member storage tool is a 1st and 2nd linear member which is parallel and spaced apart from the thickness of the said getter member concentrically, and this 1st linear member and this 2nd linear member And a plurality of third linear members provided at intervals smaller than the diameter of the getter member along the circumference of the concentric circle, and a plurality of structures are stacked by the support member The getter member storage device according to appendix 1, wherein the getter member is stored so as to form one or more layers between the first linear member and the second linear member.

  (Additional remark 4) The material of the said net-like member or the 1st thru | or 3rd linear member is titanium, a titanium alloy, stainless steel, an Inconel, or a ceramic, The getter member storage tool of Additional remark 2 or 3 characterized by the above-mentioned .

  (Appendix 5) A getter device characterized in that a disk-like getter member is accommodated between members arranged concentrically at intervals.

  (Supplementary note 6) The getter device according to supplementary note 5, wherein the plurality of getter members are stored vertically so as not to overlap each other.

  (Appendix 7) The getter device according to appendix 5, wherein the getter member is a non-evaporable getter material.

  (Supplementary note 8) The getter device according to supplementary note 7, wherein the non-evaporable getter material is an alloy containing 70% zirconium, 24.6% vanadium, and 5.4% iron, or a powder obtained by hardening the powder.

  (Supplementary Note 9) A getter device in which a disk-like getter member is housed between concentrically spaced members, and a getter device housed in the getter device. A getter pump comprising a heating means for heating the getter member.

  (Supplementary note 10) The getter pump according to supplementary note 9, wherein the getter member is a solidified powder of a non-evaporable getter alloy.

  (Appendix 11) The getter pump according to appendix 10, wherein the non-evaporable getter alloy is an alloy containing 70% zirconium, 24.6% vanadium, and 5.4% iron.

  (Additional remark 12) The getter device has two cylindrical mesh members concentrically opposed to each other in plan view with a gap wider than the thickness of the getter member, and stores the getter member between the mesh members The getter pump according to appendix 9, which has a member storage tool.

  (Supplementary note 13) The getter device includes a first linear member and a second linear member that are concentrically arranged in parallel with a gap larger than the thickness of the getter member, the first linear member, and the second linear member, And a plurality of structures including a plurality of third linear members provided at intervals smaller than the diameter of the getter member along the circumference of the concentric circles. The getter pump according to appendix 9, further comprising a getter member storage device for storing a getter member having one or more layers between the first linear member and the second linear member.

  (Appendix 14) The getter pump according to appendix 12 or 13, wherein the getter device is accommodated in a container.

  (Supplementary Note 15) The getter device is housed in a container and the other plate surface of the getter member is pressed by a mesh member so that one plate surface of the getter member is in contact with the inner wall of the container. The getter pump according to appendix 9, wherein the getter member has a configuration in which the lower end of the getter member is supported.

  (Additional remark 16) The said heating means is a heater long in the central-axis direction of the said container, The getter pump of Additional remark 14 or 15 characterized by arrange | positioning this heater in the center part of the said container.

  (Supplementary note 17) The supplementary note 14 or 15, wherein the heating means is a linear or belt-like heater, and the heater is attached to at least one of an outer peripheral surface and an inner peripheral surface of the mesh member. Getter pump.

  (Supplementary Note 18) Any one of Supplementary Notes 12, 13, and 15, wherein the material of the mesh member or the first to third linear members is titanium, titanium alloy, stainless steel, inconel, or ceramic. Getter pump as described in.

  (Supplementary note 19) The getter pump according to supplementary note 14 or 15, wherein the material of the container is a metal or an alloy having an emissivity of 0.1 or less and a thermal conductivity of 100 W / m / ° C or more.

  (Supplementary note 20) The getter pump according to supplementary note 19, wherein the material of the container is a beryllium copper alloy or an aluminum copper alloy.

  (Additional remark 21) It further has a cylindrical flange, The said getter apparatus was attached to the said flange so that the center axis | shaft of the said getter member storage tool might be matched with the central axis of the cylinder of the said flange. 12. A getter pump according to 12.

  (Supplementary note 22) The getter pump according to supplementary note 21, wherein the heating means is a linear or belt-like heater, and the heater is attached to at least one of an outer peripheral surface and an inner peripheral surface of the mesh member. .

11 Vacuum container (housing)
11a Side wall of vacuum vessel
11b Bottom of vacuum vessel
11c, 31a flange
11d, 31b bolt hole
11e electrical insulation
11f Open end
12 Heater (heating means)
12a Spiral heater member
12b, 12c Current introduction terminal
13, 21, 21a, 27 NEG cartridge (getter device)
14, 14a, 14b, 14c Getter member
15, 18, 19, 28 Getter member storage
15a, 28a Mesh member (outer cylinder)
15b, 28b Mesh member (inner cylinder)
16 Support member
17, 20 Getter device
19a to 19c first to third linear members
22 Heater mounting member
22a, 25a support
22b disc
23, 26 Linear heater
24 Wire mesh
29 Interposition material
32a, 32b Current introduction terminal
40, 40a bolt
41, 41a Nut
101, 102, 103, 104 Getter pump

Claims (12)

  A getter member storage tool for storing a disk-like getter member between concentrically spaced members.   The getter member storage device has two cylindrical mesh members concentrically opposed to each other in a plan view with a gap wider than the thickness of the getter member, and stores the getter member between the mesh members. The getter member storage tool according to claim 1.   The getter member storage tool is concentrically arranged between a first linear member and a second linear member that are parallel to each other with a gap wider than the thickness of the getter member, and between the first linear member and the second linear member. A plurality of structures including a plurality of third linear members that are bridged and provided at intervals smaller than the diameter of the getter member along the circumference of the concentric circles are stacked by a support member, The getter member storage device according to claim 1, wherein the getter member is stored so as to form one or more layers between one linear member and the second linear member.   A getter device characterized in that a disk-like getter member is accommodated between members arranged concentrically at intervals.   The getter device according to claim 4, wherein the plurality of getter members are stored vertically so as not to overlap each other.   The getter device according to claim 4, wherein the getter member is a solidified powder of a non-evaporable getter alloy. A getter device in which a disk-like getter member is housed between members arranged concentrically at intervals;
A getter pump, comprising: a heating unit arranged to face the getter member housed in the getter device, and heating the getter member.   The getter device has two cylindrical mesh members concentrically in plan view with a gap wider than the thickness of the getter member, and stores the getter member between the mesh members. The getter pump according to claim 7, comprising:   The getter device bridges the first and second linear members that are concentrically arranged in parallel with an interval wider than the thickness of the getter member, and the first linear member and the second linear member. And a plurality of structures including a plurality of third linear members provided at intervals narrower than the diameter of the getter member along the circumference of the concentric circles, and a plurality of structures are stacked by a support member, 8. The getter pump according to claim 7, further comprising a getter member storage device that stores the getter member so as to form one or more layers between the linear member and the second linear member. The getter pump according to claim 8 or 9, wherein the getter device is accommodated in a container.   The getter device is accommodated in a container, and the other plate surface of the getter member is pressed by the mesh member so that one plate surface of the getter member is in contact with the inner wall of the container, and 8. The getter pump according to claim 7, wherein the getter pump has a configuration in which a lower end of the getter member is supported.   The getter pump according to claim 10 or 11, wherein the material of the container is beryllium copper alloy or aluminum copper alloy.

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