JP2005282864A - Sealing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing structure where oxidized dust during formation of a semiconductor film is not collected on the clean space side K and workability of mounting on a dovetail groove is excellent, and an elastic seal keeping an always stable and clean posture in the dovetail groove is provided. <P>SOLUTION: The sealing structure comprises the elastic seal 1, a member 2 to be mounted having the dovetail groove 3, and a mating member 21. The elastic seal 1 is formed in a bilaterally asymmetrical shape in regard to a central line L, a high shoulder 12H is present on the clean space side K, and a middle shoulder 12L is present on the atmosphere side M. A space G is formed between the elastic seal 1 and an opening end 4b of the dovetail groove 3 from the middle shoulder 12L to a protrusion 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a sealing structure used for sealing a fluid (vacuum), and more particularly to a sealing structure used for a chamber gate portion of a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus.

Conventionally, as a sealing structure used in a semiconductor (liquid crystal) manufacturing apparatus or the like, an O shown in FIG.
A ring (seal 41a) is widely used, and one composed of an elastic seal having a tridental cross section and a dovetail groove is known (for example, see Patent Document 1). Furthermore, FIG.
(B) Elastic seals 41b, 41c having various cross-sectional shapes as shown in (C), (D) and (E), respectively.
A sealing structure including 41d and 41e and a dovetail groove 42 is known.
Regardless of the elastic seals 41b, 41c, 41d, and 41e, the plan view has an overall annular shape as illustrated in FIG. In addition, since the above-described O-ring (seal 41a) is a circular ring as a whole in a free state, a rectangular shape as shown in FIG. In some cases, there was a problem with the sealing surface due to the tension.
JP 2000-356267 A

The three-pronged elastic seal described in Patent Document 1 and the elastic seals 41b and 41e having the cross-sectional shapes shown in FIGS. 6B, 6D and 6E have postures in the dovetail 42. It may become unstable and the sealing performance may not be stable, and the seating (stability) with respect to the bottom surface of the groove is poor. This dust should be strictly prohibited in the production of liquid crystals and semiconductors.

Further, the elastic seal (O-ring) 41a shown in FIG. 6 (A) may be twisted in the dovetail groove 42 and may be cut off. Also, the elastic seal (O-ring) 41a is fixed to the lid body by pressure contact with the lid body. There is a problem that the groove 42 falls off (drops out), and further, there is a problem that abrasion powder (particles) is generated by friction with the opening edge portions 43 and 43 of the dovetail groove 42. In addition, a metal touch may occur.

Next, the elastic seal 41c of FIG. 6C may be reversely assembled into the dovetail groove. Also, rubber wear particles (particles) are generated (similar to FIG. 6A).
Next, the elastic seal 41d shown in FIG. 6D may be reversely assembled into the dovetail groove 42, and there is a problem that rubber wear powder (particles) is generated.
6 (C) and 6 (D), in particular, the arrow K indicates the clean space side (inner diameter side), which indicates the side on which liquid crystal and semiconductor are stored and processed and required cleanliness. The elastic seals 41c and 41d were rubbed against the opening edge 43 on the clean space side (inner diameter side) K to generate wear powder (particles).

The sealing structure according to the present invention solves the above-described problems of the conventional elastic seal,
No wear particles (particles) are generated between the elastic seal and the edge of the dovetail opening on the inner diameter side, and it is easy to insert into the dovetail. It is an object of the present invention to provide an elastic seal (sealing structure) free from any problem.

The present invention relates to a mounting member having a dovetail groove having an opening, a first side wall surface and a second side wall surface that approach each other as they approach the opening side, and a bottom wall surface; A sealing structure that seals the clean space side and the atmosphere side with each other, and includes an elastic seal that is attached to the mating member and a mating member that presses the protruding portion protruding from the dovetail. The elastic seal has a bottom straight portion corresponding to the bottom wall surface of the dovetail in an uncompressed mounting state where the elastic seal is installed in the dovetail and the flat surface of the mating member is not pressed, and A high shoulder portion that is close to or abuts in the vicinity of the opening with respect to the first side wall surface corresponding to the clean space side, and a dovetail depth with respect to the second side wall surface corresponding to the atmosphere side A middle shoulder that abuts at a medium height, and the protrusion protrudes from the middle shoulder. Over the section being configured to form a gap between the opening edge portion of the opening.

  The elastic seal has a cross-sectional shape that extends from the high shoulder to the bottom straight portion with a side straight portion in a direction substantially perpendicular to the bottom wall surface of the dovetail groove and a rounded portion or a gradient portion. Yes.

Rubber wear powder (particles) is hardly generated on the clean space side (inner diameter side), which is suitable for semiconductor and liquid crystal manufacturing apparatuses. Furthermore, it is possible to mount the dovetail groove relatively easily. Further, since there is almost no gap between the opening edge of the dovetail (on the clean space side) and the elastic seal, oxidized dust (depot) does not accumulate during semiconductor film formation. Further, it is possible to prevent the elastic seal from being pulled out from the dovetail by being pulled out together with the opening of the manufacturing apparatus lid (counter member). Furthermore, the elastic seal always maintains a stable posture in the dovetail.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
1 to 4, an embodiment of a sealing structure according to the present invention is shown.
A to-be-attached member 2 having a dovetail groove 3, an elastic seal 1 made of rubber or the like mounted in the dovetail groove 3, and
And a mating member 21 that has a flat surface 20 and presses the elastic seal in the dovetail 3.
The elastic seal 1 as a whole has an annular shape such as a substantially rectangular shape (see FIG. 7) or a competition track shape (oval shape).

This sealing structure is suitable for sealing (mainly vacuum) the gate portion of the chamber entrance of a semiconductor manufacturing apparatus or (large) liquid crystal manufacturing apparatus. At this time, the mounted member 2 corresponds to a valve seat (or gate), and the mating member 21 having the flat surface 20 corresponding to the approachable and separable portion corresponds to a gate (or valve seat).

The dovetail 3 has an opening 4 and a first side wall surface 5 that approaches the opening 4 toward each other.
It has a substantially trapezoidal cross section having a second side wall surface 6 and a bottom wall surface 7. The corner portion 28 between the bottom wall surface 7 and the first side wall surface 5 and the corner portion 28 between the bottom wall surface 7 and the second side wall surface 6 are connected in a round shape (curved shape). In this way, the dovetail 3 has a substantially trapezoidal shape in cross section (slightly rounded), and is recessed in the flat surface 2a and has an enlarged back side.

K indicates the clean space (inner diameter side), and M indicates the atmosphere side (outer diameter side). What is clean space K?
It is the side where the chamber space where semiconductors, liquid crystals, etc. are housed and various types of processing are present, and particularly a space that is required to be clean (no dust). 1 and 2, the dovetail 3
The first side wall surface 5 corresponds to the clean space side (inner diameter side) K, and the second side wall surface 6 corresponds to the atmosphere side (outer diameter side) M. The sealing structure according to the present invention seals the clean space side K and the atmosphere side M by blocking them.

The cross-sectional shape of the elastic seal 1 will be described. This elastic sheath 1 is installed in the dovetail 3 and is not compressed (contacted) with the flat surface 20 of the mating member 21. Refer to FIGS. 1 and 2.
──, the abutment groove 3 has an asymmetric shape with respect to the center line L on the left and right sides. For example, the protruding portion 9 protruding from the dovetail groove 3 has an asymmetric shape with respect to the center line L, and Side) biased to K. The flat surface 20 of the mating member 21 directly presses the top surface 10 of the protruding portion 9. The elastic seal 1 has a bottom straight portion 11 corresponding to the bottom wall surface 7 of the dovetail 3.

In the uncompressed state, the upper shoulder portion 12H that is in close contact with (lightly) the first side wall surface 5 corresponding to the clean space side K in the vicinity of the opening portion 4 (the opening edge portion 4a thereof). and has a has a contact with middle shoulder 12L at the height of the dovetail groove depth dimensions H ₃ middle with respect to the second side wall surface 6 corresponding to the air side M (middle). A gap G is formed between the middle shoulder 12L and the protrusion 9 and the opening edge 4b (corner) on the atmosphere side M of the opening 4. Specifically, (cross section)
A slope portion 14 having a predetermined inclination angle θ reaching the arcuate top surface 10 is provided, and this inclination angle θ is the second angle of the dovetail 3.
As the inclination angle of the side wall surface 6 is substantially the same, the gradient portion 14 and the second side wall surface 6 form a gap portion G having a constant width substantially in parallel.

The height dimension H ₁₃ from the bottom wall surface 7 where the high shoulder 12H comes close to or lightly contacts the first side wall surface 5 is set to 80% to 95% of the depth dimension H ₃ of the dovetail groove 3. That is, 0.80 × H ₃ ≦ H ₁₃ ≦ 0.95 × H ₃
And On the other hand, the height dimension H ₁₂ from the bottom wall surface 7 where the middle shoulder 12L abuts against the second side wall surface 6 is set to 30% to 70% of the depth dimension H ₃ of the dovetail groove 3. That is, 0.30 × H ₃ ≦ H ₁₂ ≦ 0.70 × H ₃
And In addition, the relational expression H ₁₂ <H ₁₃ is also established. In the case of H ₁₃ <0.80 × H ₃ , there is a high possibility that a space is generated between the opening edge portion 4a and the large rounded portion 16 and deposits are accumulated. On the contrary, when H ₁₃ > 0.95 × H ₃ , the possibility that the elastic seal 1 comes out of the dovetail groove 3 increases. When H ₁₂ <0.30 × H ₃ , the gap G becomes too large. Conversely, when H ₁₂ > 0.70 × H ₃ , the gap becomes small.

FIG. 3 is a view for explaining the cross-sectional shape of the elastic seal 1 according to the present invention in more detail. If it is described in combination with FIG. 1 and FIG. 2, the elastic seal 1 has its clean space portion K side. (Fig. 3
In the right half), a large rounded portion 16 having a quarter radius 15 with a central angle of about 90 ° at a large radius R ₁ is provided. The lower end (right end) of the large rounded portion 16 corresponds to the high shoulder 12H, and the vertical portion (in the direction of the vertical line) is substantially perpendicular to the bottom wall surface 7 of the dovetail 3 from the high shoulder 12H.
Side straight portion) 17. From the lower end of the substantially vertical portion (side straight portion) 17, the bottom portion straight portion 11 is smoothly connected (connected) with a rounded portion (arc portion) 18 having a slightly smaller radius R ₂ . With respect to the left and right center line L, the right half of the figure --- the clean space side K can be said to have a half side shape obtained by dividing the mussels in the vertical direction.
In addition, the side straight part 17 and the bottom straight part 11 may be communicated with each other with an inclined linear slope part instead of the round part 18 (not shown).

On the other hand, on the atmosphere side (outer diameter side) M of the elastic seal 1 ──the left half of FIG. 3 ─, the curved portion 19 having a radius R ₃ smaller than the radius R ₁ is The slope portion 14 is in communication. In FIG. 3, a short top surface straight portion 22 may be interposed between the large rounded portion 16 and the curved portion 19, and if desired, the top surface straight portion 22 may be formed larger than FIG. ,
The top surface of the protruding portion 9 may be a flat surface, and may be brought into contact with the flat surface 20 of the mating member 21 in FIG. 1 in a stable posture (not shown).

Middle shoulder 12L is formed with a rounded portion of small radius R _4, this small corner slope portion 14 intersects the circle of radius R ₄ is via a small recess 23 of smaller radius R _5, interconnected (linked ). The small recess 23 plays an important role (action) when the elastic seal 1 is twisted and installed in the dovetail groove 3 in FIG. 4 described later.
The left end of FIG. 3 of the bottom straight portion 11 (the end on the atmosphere side M) is a rounded portion 24 having a small radius R ₆ ,
And, it is connected to the middle shoulder portion 12L via a straight reverse slope portion 25 (inclined in the direction in which the width dimension decreases toward the bottom straight portion 11 side).

In FIG. 2, a dotted line 26 indicates a virtual cutting line that is flush with the flat surface 2 a of the mounted member 2, and in an uncompressed state, the virtual cutting line (left ) The (thickness) dimensions Tm and Tk up to the intersection where the slope portion 14 and (right) large round portion 16 intersect are set such that the latter is larger than the former, as Tm <Tk. As described above, by setting R ₁ > R ₃ , if the mating member 21 (in FIG. 1) is pressed, the protruding portion 9 made of an elastic material such as rubber is
It is elastically deformed to fit within the gap G (see FIG. 5A). As shown in FIGS.
The gradient portion 14 connected from the middle shoulder portion 12L via the small recess 23 is inclined to the clean space side (inner diameter side) K from the vertical direction (direction parallel to the center line L). With the elastic deformation, the gap G can be reliably stored (the elastically deformed portion). Therefore, the upper shoulder portion 12H formed with a part of the large radius portion 16 having a large radius R ₁ does not (strongly) contact the opening edge 4a,
Prevents generation of particles (rubber wear powder). Also, the bottom straight part
Since 11 is formed large, the posture in the dovetail 3 is always stable, the sealing performance can be exhibited stably, and twisting does not occur.

The middle shoulder portion 12L and the high shoulder portion 12H are in contact (pressure contact) with the second and first side wall surfaces 6 and 5, respectively, thereby preventing the elastic seal 1 from being pulled out from the dovetail groove 3. For example, when the mating member 21 is separated from the top surface 10 as shown in FIG. 5 and the mating member 21 moves away (for example, when the lid is opened), the elastic seal 1 is flat. Sticking to the surface 20 and pulling out of the dovetail 3
It can be effectively prevented.

As shown in FIG. 4, the elastic seal 1 is rotated (inclined) so that the protruding middle shoulder 12 is formed.
As shown by the arrow N, the small concave portion 23 between the projecting middle shoulder portion 12L and the slope portion 14 corresponds (contacts) with the opening edge (corner) portion 4b. If the rounded portion 18 is pushed into the dovetail groove 3, the state shown in FIGS. 1 and 2 is obtained. When pushing around the small recess 23 while rotating in the direction of the arrow N in the cross section, the presence of the rounded portion 18 can smoothly get over the opening edge (corner) portion 4a and be installed in the dovetail 3 . And the thickness dimension T from the corner of the small recess 23 to the rounded portion 18
₁₈ is set to be the same as or slightly larger than the width dimension W ₄ of the opening 4 of the dovetail 3. In addition, Earl part 18
It is also possible to make a part or the whole of a straight inclined surface (the width dimension decreases in the direction of the bottom surface) freely (not shown).

Next, FIG. 5 (A) shows a compression use state in which the elastic seal 1 according to the present invention is installed in the dovetail groove 3 and the flat surface 20 of the mating member 21 is pressed, and the contact surface pressure P in that state is shown. It is a FEM analysis figure (by a finite element method) which shows. FIG. 5B is an FEM analysis diagram showing the contact surface pressure in the same compression usage state for the O-ring 41a.

As can be seen by comparing FIGS. 5A and 5B, in the O-ring 41a, the contact surface pressure on the upper and lower surfaces is substantially the same, and the contact surface pressure P distribution with the mating member 21 is a Maruyama type. Thus, a peak pressure is generated at the center, and it is easy to adhere to the mating member 21. When the mating member 21 is opened, there is a risk that it will fall off the dovetail groove 42 together with the mating member. Further, since the O-ring 41a is compressed while rubbing against the left and right opening edge portions 4a and 4b, rubber wear powder (particles) is likely to be generated, and the clean space K is adversely affected.

On the other hand, in the present invention, as shown in FIG. 5A, the contact surface pressure P distribution with the mating member 21 becomes a comparatively gentle plateau type, and there is a difference in the vertical surface width (the lower surface width than the upper surface width). Therefore, it is difficult to adhere to the counterpart member 21. Furthermore, in the case of FIG. 5 (A), since the contact surface pressure P distribution is gentle, its integrated value (withstand load value) is larger than in the case of the round mountain shape in FIG. It is possible to resist the contact between the mating member 21 and the mounted member 2, and so-called metal touch.

The present invention includes a dovetail groove 3 having the opening 4 as described above, the first side wall surface 5 and the second side wall surface 6 that approach each other toward the opening 4 side, and the bottom wall surface 7. And a mating member 2, an elastic seal 1 mounted in the dovetail groove 3, and a mating member 21 that presses the protruding portion 9 protruding from the dovetail groove 3. A sealing structure that seals the space side K and the atmosphere side M by blocking, and the elastic seal 1 is mounted in the dovetail 3 and the flat surface 20 of the mating member 21 is not pressed. In the state, it has a bottom straight portion 11 corresponding to the bottom wall surface 7 of the dovetail 3 and is close to the opening 4 with respect to the first side wall surface 5 corresponding to the clean space K. And a dovetail groove with respect to the second side wall surface 6 corresponding to the atmosphere side M. It has a middle shoulder 12L that abuts at a middle height of the depth dimension H ₃ , and extends from the middle shoulder 12L to the protrusion 9 and between the opening edge 4b of the opening 4 Since the gap portion G is formed at the bottom, the bottom straight portion 11 can always maintain a stable posture and can withstand high loads. Further, in the clean space K, the opening edge of the dovetail 3 Since there is no space (gap) between the portion 4a, oxide dust (depot) during film formation does not accumulate, which is preferable. On the opposite atmosphere side M, since the gap G is formed, moderate compression and elastic deformation occurs, and even if dust accumulates on the atmosphere side M, there is no influence on the semiconductor manufacturing chamber and no problem arises. Further, when the mating member 21 presses the protruding portion 9, the protruding portion 9 is elastically deformed into the gap portion G and the rubber escapes, and the high-side shoulder 12 H on the opposite side is strongly against the first side wall surface 5. Prevents friction and prevents the generation of particles. In addition, it is possible to effectively prevent the middle shoulder portion 12L from coming into pressure contact with the second side wall surface 6 and the elastic seal 1 from coming out together with the gate lid (counter member 21) from the dovetail groove 3. Further, since the gap G is formed from the middle shoulder 12L to the protrusion 9, it is rotated and inserted into the dovetail 3 through the opening 4 as shown in FIG. Is possible.

Further, the elastic seal 1 reaches the bottom straight portion 11 from the high shoulder 12H with a side straight portion 17 and a rounded portion 18 or a gradient portion in a direction substantially perpendicular to the bottom wall surface 7 of the dovetail groove 3. Since it has a transverse cross-sectional shape, as shown in FIG.
Further, the height dimension H ₁₃ from the bottom wall surface 7 in which the high shoulder 12H comes close to or abuts against the first side wall surface 5 is set to 80% to 95% of the dovetail groove depth dimension H _3. In addition, the middle shoulder 12 above
Since the height dimension H ₁₂ from the bottom wall surface 7 where L abuts against the second side wall surface 6 is set to 30% to 70% of the dovetail groove depth dimension H ₃ , Elastic seal 1 fixed to flat surface 20
Can be prevented, and deposits (oxidized dust at the time of film formation) can be prevented from accumulating in the clean space K, and a space for dust to escape during compression elastic deformation can be secured on the opposite atmosphere side M. .

It is sectional drawing of the uncompressed mounting state which shows one Embodiment of this invention. It is a simplified diagram explaining a shape and a dimensional relationship. It is sectional shape explanatory drawing. It is explanatory drawing of mounting work. It is comparison explanatory drawing of the compression use state which compared and demonstrated this invention and O-ring. It is principal part explanatory drawing of a prior art example. It is the whole top view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic seal 2 To-be-attached member 3 Dovetail groove 4 Opening part 4b Opening edge part 5 1st side wall surface 6 2nd side wall surface 7 Bottom wall surface 9 Protrusion part
11 Bottom straight section
12H High shoulder
12L Middle shoulder
17 Side straight section
18 Earl Club
20 Flat surface
21 Mating member G Gap H ₃ , H ₁₂ , H ₁₃ Height K Clean space side (inner diameter side)
M Atmosphere side (outer diameter side)
θ Inclination angle

Claims (1)

A dovetail groove having an opening (4), a first side wall surface (5) and a second side wall surface (6) approaching each other toward the opening (4) side, and a bottom wall surface (7) ( 3) a to-be-attached member (2) provided with, an elastic seal (1) to be mounted in the dovetail groove (3), and a protruding portion in which the elastic seal (1) protrudes from the dovetail groove (3) And (9) an opposing member (21) for pressing, and a sealing structure that seals the clean space side (K) and the atmosphere side (M) by sealing the elastic seal (1). Corresponding to the bottom wall surface (7) of the dovetail groove (3) in the uncompressed attachment state in which the flat surface (20) of the mating member (21) is mounted without being pressed into the dovetail groove (3). It has a bottom straight portion (11) and is close to the first side wall surface (5) corresponding to the clean space side (K) in the vicinity of the opening (4). Contacting the high shoulder has a (12H), abuts at the height of the middle of the second side wall surface corresponding to the atmosphere side (M) (6) relative to the dovetail groove depth (H ₃₎ It has a middle shoulder (12L), and extends from the middle shoulder (12L) to the protrusion (9) between the opening edge (4b) of the opening (4) and a gap ( G), and the elastic seal (1) is a side straight portion (in the direction substantially perpendicular to the bottom wall surface (7) of the dovetail groove (3) from the high shoulder (12H) ( 17) A sealing structure characterized by having a cross-sectional shape that reaches the bottom straight portion (11) with a rounded portion (18) or a gradient portion.

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