JP3407356B2 - High voltage box for ion implanter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage box for accommodating an ion beam generator of an ion implantation apparatus, and more specifically, to increasing its plane size. And a means for improving the insulation strength. FIG. 4 is a side view partially showing an ion implantation apparatus using a conventional high voltage box. A top plate 21, a bottom plate 22, and four side plates 23
The ion beam generator 4 including, for example, an ion source, a mass analysis electromagnet, and a power supply for them is accommodated in a square box-shaped high voltage box 2 having A part of the side plate 23 also serves as a door that opens left and right in this example. [0004] The ion beam extracted from the ion beam generator 4 is accelerated by an acceleration tube 12 provided between the high voltage box 2 and the ground potential portion. Therefore, a high voltage (for example, about several tens to several hundreds of KV) is applied to the high voltage box 2 by the acceleration power supply 8.
Is applied. This high voltage box 2 is
Are supported by a plurality of support insulators 6. The high-voltage box 2 and the accelerating tube 12
Around the electrical shield and the high-voltage box 2
It is surrounded by a shield cabinet 14 which also serves as a shield for X-rays emitted from inside. [0007] The above high voltage box 2
Since a high voltage is applied, a predetermined insulation strength is required for the ground potential, but the shape of the corner has a great influence on the insulation strength. This is because the electric field is concentrated at the corners, and the insulation strength at the corners is the weakest. [0008] Figure 5 shows a cross-sectional shape of the corner portion of the bottom portion of the high voltage box 2, who curvature radius R ₁ of the corner portion is large, the electric field intensity is mitigated. However, the radius of curvature R _{1 of the} corner portion is
As shown by the two-dot chain line in FIG. 5, the plane area of the bottom plate 22 is reduced and the effective use area is reduced, and necessary equipment for forming the ion beam generator 4 is installed on the bottom plate 22. You can't do that. In order to avoid this, the plane dimensions of the high-voltage box 2 must be increased. In such a case, the distance between the high-voltage box 2 and the shield cabinet 14 is shortened.
Therefore, another problem that the entire ion implantation apparatus becomes large occurs. SUMMARY OF THE INVENTION Accordingly, it is a main object of the present invention to provide a high-voltage box capable of improving the insulation strength by increasing the radius of curvature of the corner without reducing the effective use area on the bottom plate. And In order to achieve the above object, a high-voltage box according to the present invention comprises a trough-shaped side corner curved plate between each side plate and a bottom plate as described above. most of which, it along four sides of the bottom plate in the vicinity of each side
The present invention is characterized in that each of the corner corner curved plates is provided so as to cover the existing side vicinity region, and each corner corner curved plate is connected so as to connect the side corner curved plates. According to the above construction, each side corner curved plate and each corner corner curved plate have a shape that wraps around each side area and each corner of the bottom plate, respectively. The radius of curvature of each side corner curved plate and each corner corner curved plate can be increased without reducing the effective use area of. As a result, the electric field intensity at the corners is reduced, so that the insulation strength can be improved. FIG. 1 is a side view partially showing an ion implantation apparatus using a high voltage box according to an embodiment of the present invention. FIG. 2 is a diagram of the high voltage box in FIG. 1 as viewed from below. FIG. 3 is a line B- of the high voltage box in FIG.
It is an expanded sectional view which follows B. Parts that are the same as or correspond to those in the conventional example of FIG. 4 are denoted by the same reference numerals, and differences from the conventional example will be mainly described below. In the high-voltage box 2a of this embodiment, four gutter-shaped side corner curved plates 24 are provided between the four side plates 23 and the bottom plate 22, as shown in FIG. Most of the side corner curved plate 24 is formed on each of the four sides of the bottom plate 22.
Side neighborhood area 2 which is present near each side along the side
Each is provided so that each may be covered by 2a . Further, as shown in FIG. 2, four corner corner curved plates 25 are provided so as to connect the side corner curved plates 24, respectively. In this embodiment, the height from the ground stand 10 to the bottom plate 22 and the height from the bottom plate 22 to the top plate 21 are the same as in the case of the conventional example shown in FIG. By providing the side corner curved plate 24 and the corner corner curved plate 25 as described above, their lower ends are slightly lowered from the bottom plate 22. Since the insulation distance in the height direction originally has a margin, even if the lower ends of the corner curved plates 24 and 25 are slightly lowered from the bottom plate 22, the decrease in insulation strength due to the lower end does not pose a problem. In this high voltage box 2a, FIG.
As shown in FIG.
The shape is such that the side vicinity regions 22a are respectively wrapped.
Similarly, each corner corner curved plate 25 is connected to each corner 2 of the bottom plate 22.
2b (see FIG. 2).
Therefore, the bottom plate 22 may be a flat plate, and there is no need to round the sides (see FIG. 5) as in the conventional case. Therefore, the bottom plate 22
The effective use area above does not decrease. Moreover, the radius of curvature R ₂ of each side corner curved plate 24 and each corner corner curved plate 25 can be made large. For example, in the conventional high-voltage box 2, but the radius of curvature R ₁ of the corner portion of the bottom plate 22 is not confirmed only about 50 mm, in the high voltage box 2a, and the same planar dimensions as the high voltage box 2 in the conventional example If it is possible to the radius of curvature R ₂ of the corner Kyokuban 24,25 to about 100 mm. As a result, the electric field intensity at the corner of the high voltage box 2a is reduced, so that the insulation strength can be improved. Of course, there is no need to increase the planar size of the high voltage box 2a, so there is no need to increase the size of the shield cabinet 14, and therefore, the size of the entire ion implantation apparatus does not increase. Further, as shown in FIG. 3, a tunnel-like space 26 is formed between each side corner curved plate 24 and each corner corner curved plate 25 and the bottom plate 22. It can be used effectively. For example, by arranging the power line 30 in the space 26 and arranging the signal line 32 on the bottom plate 22 or vice versa, the bottom plate 22 and the curved curved plates 24 and 25 act as shield boxes. In addition, it is possible to prevent noise from the power line 30 from being mixed into the signal line 32. In the conventional example, the power line and the signal line are mixed on the same bottom plate 22, so that it is difficult to take measures against noise.
Noise countermeasures can be easily implemented. As described in the conventional example, in this embodiment, a part of the side plate 23 also serves as a door that opens to the left and right, but this is not always necessary. As described above, according to the present invention, each side corner curved plate and each corner corner curved plate are close to each side of the bottom plate.
Since the shape wraps the side area and each corner, the radius of curvature of each side corner curved plate and each corner corner curved plate can be increased without reducing the effective use area on the bottom plate. . As a result, the electric field intensity at the corner portion is reduced, so that the insulation strength can be improved. In addition, since it is not necessary to increase the plane size of the high-voltage box, the size of the entire ion implantation apparatus does not increase. Also, a tunnel-shaped space is formed between each side corner curved plate and each corner corner curved plate and the bottom plate. By using this space for wiring of electric wires, a special space is formed. Noise countermeasures can be easily implemented without using a simple shield member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view partially showing an ion implantation apparatus using a high-voltage box according to one embodiment of the present invention. FIG. 2 is a view of the high voltage box in FIG. 1 as viewed from below. FIG. 3 is an enlarged sectional view taken along line BB of the high-voltage box in FIG. 1; FIG. 4 is a side view partially showing an ion implantation apparatus using a conventional high voltage box. FIG. 5 is an enlarged sectional view of the high-voltage box in FIG. 4 taken along line AA. [Description of Signs] 2a High voltage box 4 Ion beam generator 21 Top plate 22 Bottom plate 23 Side plate 24 Side corner curved plate 25 Corner corner curved plate

Claims (1)

(57) [Claim 1] A box-shaped housing for accommodating an ion beam generator, having a top plate, a bottom plate, and four side plates, and insulated from a ground potential portion. in the high-voltage box to which a high voltage state is applied with the between the side plates and the bottom plate, a trough-shaped sides corner curved plate for the most part, each along four sides of the bottom plate side Edges near each of
A high-voltage box for an ion implantation apparatus, characterized in that a corner corner curved plate is provided so as to cover each of the adjacent corner curved plates and to connect between the side corner curved plates.