JPH0538051Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention can be applied to film (10 to 100 μm thick)
The present invention relates to a film holding mechanism that can be used in a film forming apparatus that forms a thin film on a film.

[Prior Art] In this type of film holding mechanism, it is important to maintain tension so that the film does not wrinkle. For this reason, attempts have been made to maintain the tension of the film by variously improving the cross-sectional shape of the retaining ring that holds the outer periphery of the film. For example, the one shown in FIG. 5 is one in which the holding surfaces of the rings Ra ₁ and Ra ₂ are formed into tapered surfaces forming an angle with the tension surface of the film F, and the one shown in FIG. The clamping surfaces of the rings Rb ₁ and Rb ₂ are made to mesh with the chevron-shaped unevenness.

[Problems to be solved by the invention] However, although such a holding mechanism is effective in applying and maintaining tension to the film during installation, once the film is loosened due to factors after installation, the original tension is lost. It may not be possible to restore the state.
That is, if the film is deformed or stretched by applying external force or heating, it is no longer possible to maintain a uniform tension in the inner circumferential direction.

The present invention solves these problems and provides an improved film holding mechanism that is capable of holding the film surface in a flat tensioned state even if an external force is applied to the film or it is heated after being set in a holding ring. It is something to do.

[Means for Solving the Problems] The film holding mechanism according to the present invention includes a holding ring that holds the outer periphery of the film, an inner ring that annularly presses the film held by the holding ring from one side, and the inner ring. An outer ring is provided between the ring and the retaining ring to annularly press the film from the surface opposite to the inner ring.

[Operation] With this structure, the opposite forces of the inner ring and outer ring, which annularly press both sides of the film from the inside and outside in the vicinity of the retaining ring, apply equal radial force to the film from the entire circumference. tension is applied. If at least one of the inner and outer rings is arranged so that it can be pushed against the film with a constant stroke, even if the film is deformed or stretched by external force or heating, the outer ring will remain stable relative to the inner ring. This is absorbed by the displacement, and the film does not loosen around the inner periphery of the inner ring.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 show an example of the structure of a film holding mechanism according to the present invention. In the figure, reference numeral 1 denotes a holding ring constructed by tightening a pair of upper and lower holding rings 1a, 1a, which holds the outer periphery of the film F between them and holds it flat under appropriate tension. ing. The retaining ring 1 is set in a predetermined position by passing set screws 2 through its front and back surfaces at a suitable number of locations in the circumferential direction and engaging with a fixing part (not shown) such as a bracket. Furthermore, by inserting and removing the set screw 2, the film F can be reversed together with the retaining ring 1, and the manner in which the upper and lower surfaces are attached can be easily reversed. For example, it is also possible to create a thin film on both sides of the film F. It is designed to be easy to perform.

An inner ring 3 for pressing the lower surface of the film F held between the retaining ring 1 and the inner ring 3 is concentrically disposed below the retaining ring 1. The inner ring 3 has a slightly smaller diameter than the retaining ring 1, and as shown in FIG. At the fixed position, the tip 3a presses the lower surface of the film F in an annular manner.

On the other hand, above the retaining ring 1, an outer ring 4 for pressing the upper surface of the film F held by the retaining ring 1 is disposed concentrically. The outer ring 4 has a slightly larger diameter than the inner ring 3, but has a slightly smaller diameter than the retaining ring 1. That is, as shown in FIG.
and the inner ring 3, and at this position, its tip 4a presses the upper surface of the film F in an annular shape.
The outer ring 4 is supported so that it can move downward by a distance of an appropriate stroke L while pushing the film F from its plane, and its own weight is used to apply an appropriate pressing force f to the film F. is mounted on the film F (if necessary, a presser spring for biasing the outer ring 4 against the film surface may also be used).

With the above film holding mechanism, the film F
The pressing force f of the outer ring 4 applied near the outer periphery of
However, since tension is constantly and evenly applied to the film F in the radial direction using the tip 3a of the inner ring 3 on the inner periphery as a fulcrum, the film F can be held in a tensioned state on a flat surface. . For example, when the film F is subjected to thin film formation in a vacuum atmosphere, when a heater is brought into contact with one surface of the film F or when the film surface is directly or indirectly heated, the film F may be damaged due to external force or thermal expansion applied to the film F. Even if deformation or elongation occurs (see Figure 3), this is immediately restored and no loosening occurs (see Figure 4). That is, in this case, the outer ring 4 is connected to the inner ring 3.
A radial tension T is applied to the film F with the fulcrum at
The film F, whose tension has been reduced, is pushed down within a predetermined stroke L range while applying a This is because the film F can recover its tension state.

Although the above description has mainly been made regarding the case where the present invention is used in a film holder of a film forming apparatus, the present invention can be similarly used in film holding mechanisms for other uses. In the above embodiment, the outer ring 4 is arranged so as to be able to be pushed with a predetermined stroke L in order to obtain the holding force f for the film F, but depending on the conditions of use, the inner ring 3 may be moved in one direction. In other words, it is sufficient to make the inner and outer rings relatively movable so as to press the film F.

Note that the dimensions and tip shapes of both rings 3 and 4 with respect to the retaining ring 1, as well as their mounting structure, etc., can be arbitrarily changed in design, regardless of the illustrated example.

[Effects of the invention] As explained above, the film holding mechanism of the invention reliably prevents the film from becoming loose even if external force or heat is applied to the film after it is set in the holding ring, and its structure is also improved. It can be made very simple.

[Brief explanation of the drawing]

1 and 2 are schematic sectional views showing the film holding mechanism according to the present invention, with FIG. 1 showing the film holding mechanism in its separated state and FIG. 2 showing its usage state.
3 and 4 are schematic cross-sectional views of the main parts showing the operation of the film holding mechanism according to the present invention. Fifth
FIG. 6 and FIG. 6 are sectional views showing improved examples of the conventional retaining ring. F...Film, 1...Retaining ring, 3...Inner ring, 4...Outer ring.

Claims (1)

[Scope of utility model registration request] A holding ring that holds the outer circumference of the film; an inner ring that presses the film held by the holding ring in an annular shape from one side; and an outer ring that holds the film in an annular shape.