JPH05312271A - Seal surface structure for pressure reducing device - Google Patents

Abstract

PURPOSE:To secure clean vacuum by providing a pair of seal surfaces for a pressure reducing device, a recess formed in both seal surfaces, a mirror surface formed in the recesses, and a packing material made in contact with the mirror surfaces. CONSTITUTION:The form of a seal part 1 is constructed with a cover part 3 surrounding a packing material 2 and a dovetail groove 5 formed in a material 4 to be cut, each forming a specular recessed part 6 and being made in contact with the packing material 2. To form a mirror surface on the recessed part 6 a blade form of metallic blade tool is used. According to the quality of a material 4 to be cut, a blade form not hardened is used for soft material and the blade form of carbide tool hardened is used for hard material. Also metal, ceramics, plastics, etc., are used as materials to be cut. Thus, because manual work can be eliminated and the work can be conducted with common tools, a seal surface consistent in quality can be constructed to increase productivity and reliability and to reduce man-hour.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is suitable for forming a seal structure used for maintaining a constant partial pressure of a vacuum device, that is, a vacuum device.

[0002]

2. Description of the Related Art It is a well-known fact that a sputtering technique is frequently used instead of a vacuum vapor deposition method in manufacturing a semiconductor device, particularly in forming a film of various metals. This sputtering technique has a high energy which is 20 to 40 times higher than the energy required for vacuum deposition, that is, sublimation, and is a characteristic feature when applied to film formation.

The frequent use of sputtering technology in semiconductor technology lies in a technical problem called step coverage.

In a highly integrated device such as a VLSI, wiring layers are formed in multiple layers vertically and horizontally with an interlayer insulating film interposed therebetween. This wiring must be connected not only on a flat place but also on a stepped part without a break. This step is a step, and a metal film having a width of a micron order and a thickness of its tenths must be seamlessly connected to overcome the step. This is superior to vacuum deposition in sputter deposition.

This is because sputtering has a good step coverage because it can form a film without breaks.
This is because the surface movement (migration) is active and the sputtering is performed at a pressure higher than that of the vacuum deposition.

In such a sputtering technique,
A flat-plate magnetron sputtering film forming apparatus creates a large-area sputtering source, which broadens the range of applications at once and is widely used in the film forming process of semiconductor VLSI.

The film formed by such a sputtering technique has a problem in that the gas used for plasma discharge is contained in the film. Therefore, the flat plate magnetron sputtering film forming apparatus uses an ultrahigh vacuum technique. It is necessary to create a clean vacuum as the basis.

The flat panel magnetron sputtering film forming apparatus is provided with a so-called seal portion which is indispensable for connecting regions having different pressure differences.

The seal portion used to ensure a clean vacuum has a normal structure as shown in FIG. That is, a dovetail groove 2 is formed on a flat metal surface 1, a metal plate 5 is placed on a backing material 4 to be placed on a flat surface 3 at the bottom of the dovetail groove 2, and then the metal plate 5 and the flat metal plate 5 are flattened with a bolt or the like not shown. A method is adopted in which the surfaces 1 are firmly joined and integrated.

[0010]

The seal portion required as a part for securing a vacuum is a packing material disposed between the metal surfaces and the metal plate, which are arranged to face each other as described above, and is packed by the suction force by the vacuum. The material is in close contact with the metal surface portion and the metal plate portion, and blocks between areas where the pressure is different. However, it is general that the metal surface and the metal plate corresponding to the packing material are processed by ordinary cutting means and then manually finished.

Since manual work is involved in this way, there are problems in appearance and variation after completion, and in ensuring quality in the cutting process.

The present invention is made from the above points, and an object thereof is to provide a novel sealing surface structure for a pressure reducing device.

[0013]

[Means for Solving the Problems] A pair of sealing surfaces for a decompression device arranged with a packing material sandwiched between them, recesses formed in the sealing surfaces, mirror surfaces formed in the recesses, and packing material in contact with the mirror surfaces. In addition, there is a feature of the sealing surface structure for the pressure reducing device according to the present invention.

[0014]

In the sealing surface structure for a decompression device according to the present invention, a concave surface is formed as a mirror surface on a symmetrical sealing surface that comes into contact with the packing material, and the contact area between the two is increased to secure a clean vacuum.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIGS. That is, FIG. 1 is a sectional view of the seal portion before the packing material is installed, FIG. 2 is a sectional view of a completed state, and FIG. 3 is a top view after forming a dovetail groove for the seal portion. FIG. 4 shows the outline of the test apparatus.

Further, a cross-sectional view of the end mill blade tip shape used to form the seal portion, that is, the blade shape of the metal cutting tool is shown in FIG.
FIG. 6 is a sectional view of the blade shape and finish surface shape of the metal cutting tool, that is, a shape of a concave portion formed of a mirror surface portion, and FIG. 7 is a sectional view of the blade contact surface of the metal cutting tool. ing.

To form the seal portion 1, a lid portion 3 surrounding the packing material 2 shown in FIG. 2 and a dovetail groove 5 formed in the material to be cut 4 are formed, and a concave portion 6 having a mirror surface is formed in each of them. So as to come into contact with the packing material 2. That is, the mirror surface is formed symmetrically. The diameter of the upper part A of the dovetail groove 5 is 2 mm and that of the bottom part B is about 1.3 times 2.6 mm.

As shown in the completed sectional view of FIG. 2, the concave portion 6 is formed in the bottom portion B of the lid portion 3 and the dovetail groove 5 by the curved portion 21 of the blade shape 20 of the metal cutting tool which will be made clear from FIG. A packing material 2 such as an O-ring is filled between the two to complete the process, and a top view thereof is shown in FIG.

A leak test was conducted on such a seal portion 1 by the test device 7 shown in FIG. An auxiliary pump 9 is installed in a test device 7 which is a leak detector having an instrument display surface 8 on its upper surface, and an auxiliary pump 9 is attached to a tubular body 10 connected to the auxiliary pump 9. This is described above the arrow in the figure and, although not clear, there is a sealing part 1 with a recess 6. The exhaust pipe 11 formed in the seal portion 1 is connected to the tubular body 10 of the test apparatus 7.

The seal portion 1 was attached by sandwiching an O-ring 14 of Viton V380 between an upper plate 12 and a lower plate 13, and then a helium gas was blown from a helium cylinder 15 to perform a leak test. For normal measurement, Viton V
The O-ring 14 of the 380 is coated with silicone grease and then the upper plate 12 and the lower plate 13 are tightened with bolts before the test is performed. On the other hand, in the test of the seal portion 7 according to the present invention, the O-ring 14 of the Viton V380 is used. Silicone grease was not applied to, and the test was performed with the upper plate 12 still on.

However, since there was no abnormality, there was no defect in the above-mentioned cutting work, and the mirror surface formed in the concave portion 6 and the packing material 2 were better than the finished product of the cutting process including the conventional manual work.
This is proof that the contact area with the seal is large and a more complete seal part 1 can be formed.

Next, formation of the concave portion 6 having such a mirror surface will be described with reference to FIGS. 6 to 8.

In order to form the mirror surface in the concave portion 6, a blade shape 20 of a metal cutting tool may be used, and the surface thereof may be hardened or may not be hardened. This is selected according to the material of the material to be cut 4, and the blade shape 20 that is not hardened is used for soft ones, and the blade shape 20 of a so-called cemented carbide tool that is hardened is used for hard ones. . The material to be cut may be metal, ceramic, plastic, or the like. As shown in FIG. 5, the blade shape 20
Is composed of a flat portion 21 that comes into contact with the material to be cut 4, a rising portion 22 that rises from the end thereof, and a curved portion 23 that is located between the both portions. R of the curved portion 23 is 1 as shown in FIG.
± 0.5.

The concave portion 2 having a mirror surface portion shown in FIG. 2 is used as, for example, a sealing surface formed in a flat plate type magnetron sputtering film forming apparatus, and the depth of the concave portion 2 is 0.
It is about 1 mm to 0.12 mm, and the cut amount is extremely small. Moreover, R1 ± 0.5 of the curvature portion 6 of the blade shape 1, that is, the obtuse angle shape is utilized to form the concave portion 2 having a mirror surface of 2S, and it is possible to prevent the occurrence of burrs near the portion A of the workpiece 3. ..

In the conventional cutting process using an acute-angled blade shape,
It is possible to prevent an accident in which a burr having an acute-angled tip is generated and the packing material installed here is damaged to cause a decrease in vacuum degree.

[0026]

As described above, the blade-shaped structure of the cutting tool and the processing method thereof according to the present invention require less manual work than the conventional processing methods and can perform work with a common tool, so that a concave portion having a constant quality is obtained. That is, since the sealing surface can be configured by a mirror surface, a product with high productivity and reliability can be obtained.
Moreover, since the number of steps is smaller than that of manual work, the cost is reduced, and the mirror-like sealing surface has the advantages that the appearance of the product is good and the product value is further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a seal part according to the present invention.

FIG. 2 is a completed sectional view of a seal portion according to the present invention.

FIG. 3 is a top view of the vicinity of a recess formed for the seal portion according to the present invention.

FIG. 4 is a schematic view showing a state in which a leak test of a seal portion of the present invention is performed.

FIG. 5 is a cross-sectional view showing a blade shape used to form a seal portion according to the present invention.

FIG. 6 is a cross-sectional view showing the shape of the concave surface formed by the blade shape of FIG.

7 is a cross-sectional view of the blade contact surface of the blade shape of FIG.

[Explanation of symbols]

 1: Sealing part, 2: Packing material, 3: Lid part, 4: Cutting material, 5: Dovetail groove, 6: Recessed part, 7: Testing device, 8: Display surface, 9: Auxiliary pump, 10: Cylindrical body, 11: exhaust pipe, 12: upper plate, 13: lower plate, 14: O-ring, 15: cylinder, 20: blade shape, 21: flat part, 22: rising part, 23: curved part.

Claims (1)

[Claims] 1. A pair of sealing surfaces for a decompression device arranged with a packing material sandwiched between them, recesses formed in the sealing surfaces, mirror surfaces formed in the recesses, and packing material in contact with the mirror surfaces. Seal surface structure for decompression equipment characterized by