Vacuum relay

Abstract

The diameter of the ceramic tube in the vacuum relay is reduced to miniaturize the vacuum relay. [Solution] The vacuum relay 1 has a ceramic tube 2, a common terminal 3, a-contact terminal 4, a-contact terminal 5, and a movable terminal 7. The movable terminal 7 is housed in the ceramic tube 2 and enables conductivity between the common terminal 3 and the a-contact terminal 4 or between the common terminal 3 and the b-contact terminal 4. One of the terminals, the common terminal 3, the a-contact terminal 4, or the b-contact terminal 5, is located at one end of the ceramic tube 2.

Description

Technical Field

[0001] The present invention relates to a miniaturized vacuum relay suitable for switching of a power supply circuit such as a semiconductor manufacturing apparatus.

Background Art

[0002] As a vacuum relay used in a power supply circuit, for example, there is a relay device of a c-contact relay system disclosed in Patent Document 1. This relay device is composed of a ceramic tube provided with an a-contact terminal, a b-contact terminal, and a c-contact terminal which is a common terminal thereof. In a vacuum chamber inside this ceramic tube, a movable terminal is disposed between the a-contact terminal and the b-contact terminal, and through this movable terminal, the a-contact terminal and the c-contact terminal are electrically connected or the b-contact terminal and the c-contact terminal are electrically connected. The movable terminal is supported by an insulating rod, and the power supply circuit is switched by the operation of the insulating rod by a driving unit.

[0003] The a-contact terminal, the b-contact terminal, and the c-contact terminal ensure an atmospheric surface insulation distance corresponding to the withstand voltage on the atmospheric side of the ceramic tube. The diameter of the ceramic tube is set on the condition of ensuring the diameters of the respective terminals arranged in the radial direction thereof and the atmospheric surface insulation distance between the terminals. In particular, the diameter of the ceramic tube of Patent Document 1 is set such that the atmospheric surface insulation distance between the a-contact terminal and the b-contact terminal is larger than the atmospheric surface insulation distance between the a-contact terminal and the c-contact terminal and the atmospheric surface insulation distance between the b-contact terminal and the c-contact terminal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, there has been a growing demand for further miniaturization of semiconductor manufacturing equipment and other devices, and consequently, for miniaturized vacuum relays, which are components of these devices. However, the diameter of the ceramic tube, which greatly affects the dimensions of the vacuum relay, must be set large enough to ensure sufficient creepage distance in the atmosphere between terminals arranged radially along the ceramic tube, thus limiting the miniaturization of vacuum relays.

[0006] In view of the above circumstances, the present invention aims to miniaturize a vacuum relay by reducing the diameter of the ceramic tube of the vacuum relay. [Means for solving the problem]

[0007] One aspect of the present invention is a vacuum relay having a common terminal, an a-contact terminal, a b-contact terminal, a movable terminal that enables conductivity between the common terminal and the a-contact terminal or between the common terminal and the b-contact terminal, and a ceramic tube housing the movable terminal. One of the common terminal, the a-contact terminal, or the b-contact terminal is located at one end of the ceramic tube.

[0008] In one aspect of the present invention, in the vacuum relay, two terminals other than the one terminal are arranged on the side wall of the ceramic tube.

[0009] In one aspect of the present invention, in the vacuum relay, one end of the two terminals faces the other inside the ceramic tube.

[0010] In one aspect of the present invention, the vacuum relay is configured such that an uneven surface is formed on the side wall.

[0011] In one aspect of the present invention, in the vacuum relay, one terminal is arranged at one end coaxially with the ceramic tube via a flange portion made of ceramic. [Effects of the Invention]

[0012] According to the present invention described above, the diameter of the ceramic tube of the vacuum relay can be reduced, making it possible to miniaturize the vacuum relay. [Brief explanation of the drawing]

[0013] [Figure 1] A schematic cross-sectional view of a vacuum relay according to Embodiment 1 of the present invention. [Figure 2] A schematic cross-sectional view of a vacuum relay according to Embodiment 2 of the present invention. [Figure 3] A schematic cross-sectional view of a vacuum relay according to Embodiment 3 of the present invention. [Figure 4] A schematic cross-sectional view showing an example of a terminal arranged at one end of a ceramic tube of a vacuum relay, which is one aspect of the present invention. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings.

[0015] The vacuum relay 1 of Embodiment 1, one aspect of the present invention shown in Figure 1, is based on a c-contact relay system, and one of the following terminals—a common terminal 3, an a-contact terminal 4, or a b-contact terminal 5—is arranged at one end of the ceramic tube 2. This embodiment aims to reduce the size of the ceramic tube 2 in the radial direction while ensuring the creepage insulation distance in the atmosphere between the common terminal 3, the a-contact terminal 4, and the b-contact terminal 5.

[0016] The vacuum relay 1 comprises a ceramic tube 2, a common terminal 3, a contact terminal 4, a contact terminal 5, a drive unit 6, a movable terminal 7, and an insulating rod 8.

[0017] The ceramic tube 2 is cylindrical in shape, housing the movable terminal 7, insulating rod 8, and base portion 9 of the drive unit 6, and is vacuum-sealed by the a-contact terminal 4, b-contact terminal 5, common terminal 3, and drive unit 6. One of the a-contact terminal 4, b-contact terminal 5, or common terminal 3 is located at one end of the ceramic tube 2. In the illustrated configuration, the common terminal 3 is located at the upper end 23 of the ceramic tube 2, while the a-contact terminal 4 and b-contact terminal 5 are located on the side wall 21 of the ceramic tube 2. The outer surface of the side wall 21 has a pleated, uneven surface 22.

[0018] The common terminal 3 is disposed at the upper end 23 which is one end of the ceramic tube 2, and can be electrically connected to the a contact terminal 4 or the b contact terminal 5 via the movable terminal 7 inside the ceramic tube 2. The common terminal 3 includes a flange portion 31 that is brazed to the upper end 23 of the ceramic tube 2 to seal the opening of the upper end 23, and a terminal body portion 32 that is coaxially disposed with the ceramic tube 2 at the central portion of the flange portion 31 and whose outer surface near one end contacts the movable terminal 7.

[0019] The a contact terminal 4 is disposed to penetrate the side wall 21 in the radial direction of the ceramic tube 2 at a substantially middle position of the side wall 21 of the ceramic tube 2, one end of which faces one end of the b contact terminal 5 inside the ceramic tube 2, and can be electrically connected to the b contact terminal 5 via the movable terminal 7.

[0020] The b contact terminal 5 is disposed to penetrate the side wall 21 in the radial direction of the ceramic tube 2 at a substantially middle position of the side wall 21 of the ceramic tube 2, one end of which faces one end of the a contact terminal 4 inside the ceramic tube 2, and can be electrically connected to the a contact terminal 4 via the movable terminal 7.

[0021] The drive unit 6 is brazed and disposed at the lower end 24 which is the other end of the ceramic tube 2, and enables the pedestal portion 9 with the insulating rod 8 erected inside the ceramic tube 2 to be disposed obliquely or horizontally. The pedestal portion 9 is made of a metal member that receives the magnetic force of the coil 61 of the drive unit 6, and is disposed obliquely by the repulsive force of the spring 62 of the drive unit 6 inside the ceramic tube 2 in advance, while it can be disposed substantially horizontally by the excitation of the coil 61 due to the energization of the drive unit 6.

[0022] The movable terminal 7 is housed in the vacuum chamber inside the ceramic tube 2, and enables the electrical connection between the common terminal 3 and the a contact terminal 4 or the electrical connection between the common terminal 3 and the b contact terminal 5 by the operation of the insulating rod 8. The movable terminal 7 is made of a conductive plate material (for example, molybdenum plate, etc.) with a U-shaped cross-section formed by bending, and contacts the outer surface near one end of the terminal body portion 32 of the common terminal 3 and can contact the a contact terminal 4 or the b contact terminal 5. And a hole 71 into which the insulating rod 8 is inserted is formed at the lower part of the movable terminal 7.

[0023] The insulating rod 8 is erected on the base portion 9 and inserted into the hole 71 of the movable terminal 7. By operating the movable terminal 7 in conjunction with the horizontal or inclined positioning of the base portion 9, the insulating rod 8 connects the common terminal 3 and the normally open (a) contact terminal 4 or the common terminal 3 and the normally closed (b) contact terminal 5. The upper end of the insulating rod 8 has an insertion portion 81 that is inserted into the hole 71 of the movable terminal 7, and a support surface 82 that supports the movable terminal 7 around this insertion portion 81.

[0024] An example of the operation of the vacuum relay 1 will be explained with reference to Figure 1.

[0025] When the coil 61 of the drive unit 6 is not energized, the base portion 9 tilts due to the repulsive force of the spring 62, causing the insulating rod 8 to tilt and the movable terminal 7 to contact the b-contact terminal 5, thus creating electrical contact between the common terminal 3 (terminal body portion 32) and the b-contact terminal 5.

[0026] When the coil 61 of the drive unit 6 is energized, the magnetic force of the coil 61 causes the base 9 to become horizontal and the insulating rod 8 to be positioned vertically, causing the movable terminal 7 to contact the normally open contact terminal 4, thus creating electrical conductivity between the common terminal 3 (terminal body 32) and the normally open contact terminal 4.

[0027] In the vacuum relay 1 described above, one terminal (common terminal 3) of the c-contact relay is located at the upper end 23 of the ceramic tube 2, and the other two terminals (a-contact terminal 4, b-contact terminal 5) of the c-contact relay are arranged facing each other radially in the ceramic tube 2 at the midpoint of the side wall 21. In this configuration, the creepage insulation distance in the atmosphere between the one terminal and the other two terminals is secured along the height direction of the ceramic tube 2, and two creepage insulation distances in the atmosphere via the other two terminals are secured along the outer circumference of the ceramic tube 2. Therefore, the outer circumference of the ceramic tube 2 can be utilized efficiently, and the outer diameter of the ceramic tube 2 can be reduced.

[0028] In particular, the outer diameter of the ceramic tube 2 of the vacuum relay 1 is the value obtained by dividing the sum of the outer diameters of the two contact terminals + the sum of the creepage insulation distance in air between the two contact terminals by pi.

[0029] On the other hand, the outer diameter of a ceramic tube in a conventional vacuum relay, in which three contact terminals are arranged on the outer circumference of the ceramic tube, is the value obtained by dividing the sum of the outer diameters of the three contact terminals (a-contact terminal, b-contact terminal, and c-contact terminal) + (the sum of the creepage insulation distance in air between the three contact terminals) by pi.

[0030] Furthermore, the outer diameter of the ceramic tube of the vacuum relay disclosed in Patent Document 1 is the value obtained by dividing the sum of the outer diameters of the three contact terminals (a-contact terminal, b-contact terminal, and c-contact terminal) + (creepage insulation distance in air between two contact terminals (a-contact terminal and b-contact terminal)) + (creepage insulation distance in air between the other contact terminal (c-contact terminal) and the two contact terminals) × 2 by pi.

[0031] Therefore, according to the vacuum relay of the present invention, the outer diameter of the ceramic tube 2 can be reduced to about two-thirds of that of a conventional vacuum relay, and to about half of that of the vacuum relay described in Patent Document 1.

[0032] In Embodiment 1, the a-contact terminal 4 and the b-contact terminal 5 are arranged on the side wall 21 facing each other in the radial direction of the ceramic tube 2. However, depending on the internal structure of the ceramic tube 2, the same effect as in Embodiment 1 can be obtained even if they are arranged in close proximity to each other on the side wall 21.

[0033] The vacuum relay of the present invention is not limited to the vacuum relay 1 of Embodiment 1 in Figure 1. Alternatively, as in the vacuum relay 1 of Embodiment 2 in Figure 2, a b-contact terminal 5 may be placed on the upper end 23 of the ceramic tube 2, and a common terminal 3 and an a-contact terminal 4 may be placed on the side wall 21 of the ceramic tube 2.

[0034] In the vacuum relay 1 of Embodiment 2, when the coil 61 of the drive unit 6 is not energized, the insulating rod 8 tilts as the base portion 9 tilts due to the repulsive force of the spring 62, and electrical conductivity is established between the common terminal 3 on the side wall 21 side and the b-contact terminal 5 on the upper end 23 side via the movable terminal 7. When the coil 61 of the drive unit 6 is energized, the base portion 9 becomes horizontal due to the magnetic force of the coil 61, and the insulating rod 8 is positioned vertically, so that electrical conductivity is established between the common terminal 3 on the side wall 21 side and the a-contact terminal 4 of the ceramic tube 2 via the movable terminal 7. The movable terminal 7 and its hole 71 are formed by processing the plate material in such a way.

[0035] Alternatively, as shown in the vacuum relay 1 of Embodiment 3 in Figure 3, the normally open (a) contact terminal 4 may be placed on the upper end 23 of the ceramic tube 2, and the common terminal 3 and normally closed (b) contact terminal 5 may be placed on the side wall 21 of the ceramic tube 2.

[0036] In the vacuum relay 1 of Embodiment 3, when the coil 61 of the drive unit 6 is not energized, the insulating rod 8 tilts as the base portion 9 tilts due to the repulsive force of the spring 62, and electrical conductivity is established between the common terminal 3 on the side wall 21 side and the b-contact terminal 5 via the movable terminal 7. When the coil 61 of the drive unit 6 is energized, the base portion 9 becomes horizontal due to the magnetic force of the coil 61, and the insulating rod 8 is positioned vertically, so electrical conductivity is established between the common terminal 3 on the side wall 21 side and the a-contact terminal 4 on the upper end 23 side via the movable terminal 7. The movable terminal 7 and its hole 71 are formed by processing the plate material in such a manner.

[0037] It is clear that the vacuum relay 1 of Embodiments 2 and 3 described above can achieve the same effects as the vacuum relay 1 of Embodiment 1.

[0038] The side wall 21 of the ceramic tube 2 has a recessed area 22 formed for the vacuum relay 1. The recessed area 22 is formed when the vacuum relay 1 is used under high voltage conditions, but it is not necessary to form the recessed area 22 when it is used under low voltage conditions. Since the vacuum insulation inside the ceramic tube 2 has a high voltage resistance configuration, there is no need to change the internal structure of the ceramic tube 2, and components can be shared by changing only the structure on the atmospheric side.

[0039] In addition, in the vacuum relay 1 of embodiments 1, 2, and 3, the common terminal 3, a-contact terminal 4, and b-contact terminal 5, which are located at the upper end 23 of the ceramic tube 2, may be formed in a columnar shape coaxial with the ceramic tube 2, as illustrated in Figure 4. These columnar common terminal 3, a-contact terminal 4, and b-contact terminal 5 are brazed to the upper end 23 of the ceramic tube 2 via a flange portion 25 made of ceramic that is coaxial with the ceramic tube 2. According to the vacuum relay 1 of this embodiment, the creepage insulation distance in the atmosphere between the single contact terminal located at the upper end 23 of the ceramic tube 2 and the two contact terminals located on the side wall 21 of the ceramic tube 2 is increased, thereby improving the withstand voltage of embodiments 1, 2, and 3. [Explanation of symbols]

[0040] 1…Vacuum relay 2...Ceramic tube, 21...Side wall, 22...Rubbed section, 23...Upper end, 24...Lower end, 25...Flange section 3... Common terminal, 31... Flange part, 32... Terminal body part 4...a-contact terminal 5... normally closed contact terminal 6...Drive unit, 61...Coil, 62...Spring 7...Movable terminal, 71...hole 8...Insulating rod, 81...Insertion part, 82...Support surface 9…Base

Claims

1. Common terminal and a-contact terminal and b-contact terminal and A movable terminal that enables conductivity between the common terminal and the a-contact terminal or between the common terminal and the b-contact terminal, A ceramic tube housing this movable terminal, It has, A vacuum relay characterized in that one of the following terminals is arranged at one end of the ceramic tube: the common terminal, the a-contact terminal, or the b-contact terminal.

2. The vacuum relay according to claim 1, wherein two terminals other than the one terminal are arranged on the side wall of the ceramic tube.

3. The vacuum relay according to claim 2, characterized in that one end of the two terminals faces the other inside the ceramic tube.

4. The vacuum relay according to claim 2, characterized in that an uneven surface is formed on the side wall.

5. The vacuum relay according to claim 1, characterized in that one of the terminals is arranged at one end coaxially with the ceramic tube via a flange portion made of ceramic.

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