SPUTTERING APPARATUS

Abstract: A sputtering apparatus having a casing (3), a cylindrical target (15) disposed in the casing (3), and a plurality of guide rollers (21) for guiding a length of material (20) such as cloth or a film, the guide rollers (21) being disposed on a circum­ ferential surface concentric with the cylindrial target (15) such as to make a moving path of the length of material (20) cenform to a circumferential surface encircling the cylindri­ cal target (15).

Description: TITLE OF THE INVENTION SPUTTERING APPARATUS BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a sputtering apparatus for applying a sputtering treatment to a string or length of a material such as cloth or a film. Description of the Related Art Winding types of sputtering apparatuses have been known as apparatuses for forming a metal coating on a length of a metal material such as a film. As shown in Fig. 23, an apparatus of this type has a tank 201 in which a target 202 in the form of a flat plate is horizontally disposed, and a length of material 204 which is supplied from a supplying roller 203 extends around a guide roller 205 disposed opposite and parallel to the target 202 and is then wound around a winding roller 206. Since, in this arrangement, the area on which the sputtering metal which has flown off the target 202 attaches is small, it is difficult to increase the winding speed. Since the arrangement uses a flat plate target, it necessitates a high sputtering pressure of about 10 3 Torr, so that the color of a metal coating formed on the length of material 204 tends to be blackish. In addition, the length of material 204 may become loose On the side of theguide roller 205, owing to its weight and slippage, and it may become wrinkled. In such a case, the metal may not stick to the material surface. Thus is a possibility of unevenness in the metal coated over the length of material. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sputtering apparatus which has a high sputtering speed and which is designed to prevent the metal coating formed by the sputtering process from becoming blackish. It is another object of the present invention to provide a sputtering apparatus which enables a sputtering metal to be attached over a wide area of a length of material, and to be securely formed to a prescribed thickness on the surface thereof, even when the length of material is wound at a higher speed. It is still another object of the present invention to provide a sputtering apparatus which securely prevents the length of material from being contaminated by sputtering metal sticking to the guide roller, or being affected by the heat applied to the guide roller. It is a further object of the present invention to provide a sputtering apparatus whose sputtering treatment chamber can be evacuated to a given degree within a short treatment chamber having a cylindrical target and guide rollers for guiding a length of material such as cloth or a film, a plurality of the guide rollers being disposed on a circumference concentric with the cylindrical target so as to form a moving path of the length of material around a circumferential surface encircling the cylindrical target; and a work accommodating chamber adjacent to the sputtering treatment chamber, the work accommodating chamber having a supplying roller for supplying the length of material and a winding roller for winding up the length of material which has undergone the sputtering treatment. The present invention provides in still another of its aspects a sputtering apparatus comprising: a casing; a cylindrical target disposed in the casing; a supplying roller for supplying a length of material such as cloth or a film; a winding roller for winding the length of material which has undergone a sputtering treatment; and a suspension means which suspends the length of material at the upper end thereof and transferring and circulating the length of material over its transferring passage from the supply side to the winding side. Other objects of the present invention will be apparent when the same is read in conjunction with the preferred embodiment described below, and various advantages of the present invention will be thereafter apparent to those who skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional plan view of the body of a sputtering apparatus which is the first embodiment of the present invention; Fig. 2 is a partially cut away front view of the sputtering apparatus shown in Fig. 1; Fig. 3 is a sectional view taken along a line III - III of Fig. 1; Fig. 4 is a partial perspective view illustrating a portion around a rack of the first embodiment; Fig. 5 is a sectional plan view of a sputtering apparatus which represents an altered example of the first embodiment. Fig. 6 is a sectional plan view of the body of a sputtering apparatus which is the second embodiment of the present invention; Fig. 7 is a partially cut away front view of the sputtering apparatus shown in Fig. 6; Fig. 8 is a sectional view taken along a line VIII - VIII of Fig. 6; Figs. 9 and 10 are sectional plan views of sputtering apparatuses representing altered examples of the second embodiment; Fig. 11 is a sectional plan view of the body of a sputtering apparatus which is the third embodiment of the present invention; Fig. 12 is a sectional view taken along a line XII XII of Fig. ll; Fig. 13 is a sectional view taken along a line XIII XIII of Fig. 11; Figs. 14 and 15 are a longitudinal sectional view and a sectional plan view of the body of an altered example of the third embodiment; ; Fig. 16 is a sectional view taken along a line XVI XVI of Fig. 15; Figs. 17 and 18 are perspective view illustrating guide rollers which are other examples of guide rollers incorporated in the first and second embodiments; Figs. 19 to 22 are a sectional plan views of other examples of guard members incorporated in the first and second embodiments; Fig. 23 is a longitudinal sectional view of a sputtering apparatus according to a related conventional method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described hereunder with reference to Figs. 1 to 4. The body l of a sputtering apparatus is formed by a base support 2 and a casing 3 mounted on the base support 2 with a packing (not shown) interposed therebetween such as to make this portion air-tight. Two pairs of stationary blocks 4 which are rotatably supported by a frame (not shown) are disposed above the casing 3. Two wires 5 for suspending the casing 3 each of which is connected at its one end to a hooking ring 6 fixed to and protruding from the upper portion of the casing 3 and is connected at the other end to a balancing weight 7 are wound around the stationary blocks 4. The total weight of the two balancing weights 7 is set to be slightly lighter than the weight of the casing 3 so that the casing 3 can be moved up and down by small force. A roller 9 which engages with a guide rails 8 vertically disposed in the vicinity of the casing 3 is rotatably attached to the front of the casing 3 (shown in the lower part of Fig. 1). As shown in Figs. 1 and 4, a rack 12 adapted for engaging with a pinion 11 which is attached to the rotating shaft of a motor 10 is provided on the rear portion of the casing 3 where an engaging portion 14 adapted for engaging with the top of a pushing-up member 13 which is moved up and down in accordance with the normal and reverse rotation of the motor 10 is protrusively formed. The casing 3 is thereby raised and failed by the vertical movement of the pushing-up member 13. A target 15 in the form of a cylinder having a bottom is detachably suspended at the center of the cylindrical portion of the casing 3. At least the outermost stratum of the target 15 is formed of sputtering metal, and a supporting cylinder 17 to which permanent magnets in the form of rings 16 are fitted in given spaced apart relationship with each other is inserted into the interior space of the target 15. A bellows 18 into which a quantity of compressed air is supplied from the outside is disposed under the supporting cylinder 17 so as to moving this up and down in accordance with the state of the compressed air being supplied or discharged. An anode 19 in the form of a cage having eight vertically extending thin rods is disposed around a cathode or the target 15 such that the thin rod portions are located on a circumferential surface concentric with the target 15. A direct current voltage of 50 to 1000 is applied between the cathode or the target 15 and the anode 19. At the circumference of the cylindrical target 15, six guide rollers 21 for guiding a length of material 20 such as cloth and a film are disposed at equal intervals on a circumference which is concentric with the target 15. The guide rollers 21 are mounted on the base support 2 and are rotatably supported between an upper supporting frame 22 substantially in the form of a hexagon and a lower supporting frame 23. Pillars 24 for supporting the upper supporting frame 22 function as guard member for preventing sputtering metal from sticking to each guide roller 21, and so they are disposed on the inner side of the guide roller 21 and each of them are formed such as to be wider than the diameter of the guide roller 21. A water cooling piping 25 is disposed on one side of each pillar 24 opposite to the surface which faces the target 15. A supplying roller 27 for supplying a length of material and a winding roller 28 for winding up the length of material 20 which has undergone a sputtering treatment are rotatably disposed vertically on the outside of the outer circumferential surface formed by the guide rollers 21. Both rollers 27 and 28 are respectively disposed on the base support 2 and detachably supported between driving shafts 29a and 29b driven by external driving mechanism (not shown) and driven shafts 31a and 31b rotatably attached to a supporting bracket 30 protrusively mounted on the upper supporting frame 22. A pair of auxiliary guide rollers 32a and 32b are disposed between one pair of the guide rollers 21 which are adjacent to the rollers 27 and 28. The length of material is supplied from the supplying roller 27 through the auxiliary guide roller 32a and is guided to the guide roller 21, and the length of material which has undergone a sputtering treatment is guided through the other auxiliary guide roller 32b and wound around the winding roller 28. A guard plate 33 stands in a position corresponding to a gap formed between both auxiliary guide rollers 32a and 32b, and the water cooling piping 25 is disposed, in the same manner as those of the pillars 24, on one side of the guard plate 33 which does not face the target 15. A pipe 34 connected to a pump for evacuating the interior of the sputtering apparatus body 1 is connected to the base support 2. The pipe 34 branches into: a line connected to a diffusion pump 36 through a final-evacuation valve 35; and a line connected to a mechanical booster pump 38 and a rotary pump 39 through a pre-evacuation valve 37, and the diffusion pump 36 and the mechanical booster pump 38 are connected with each other through an auxiliary valve 40. A leak valve 41 is connected to the pipe 34. A pipe 45 which is connected to an Ar gas bomb 43 and an oxygen gas bomb 44 through valves 42a and 42b is joined to the casing 3. The operation of the apparatus thus constituted will now be described. The motor 10 is rotated in the normal direction while the inner pressure of the casing 3 is maintained in equilibrium with the atmospheric pressure after the leak valve 41 has been released. The pushing-up member 13 is pushed up, so that the casing 3 is rifted and suspended, as shown by the chain line in Fig. 2. In this state, the supplying roller 27 is detached from the driving shaft 29a and the driven shaft 31a, and the length of material 20 is wound around the supplying roller 27. Then, the supplying roller 27 around which the length of material 10 has been wound is set between the driving shaft 29a and the driven shaft 31a. The length of material 10 is led by its one end over the auxiliary guide roller 32a, the guide rollers 21 and the auxiliary guide roller 32b to the winding roller 28, and it is attached at its end to the surface of the widing roller 28. Next, the motor 10 is driven to rotate in the reverse direction, and the pushing-up member 13 is moved down by the action of the pinion 11 and the rack 12, thus mounting the casing 3 on the base support 2. The casing 3 is mounted on the base support 3 while maintaining the air-tight property therebetween effected by its weight and the packing. Next, the interior of the sputtering apparatus body 1 is evacuated. As the diffusion pump 36 and the rotary pump 39 are constantly working, the leak valve 41 is first closed and the pre-evacuation valve 31 is opened. After the internal pressure of the sputtering apparatus body 1 is reduced to equal or less than 20 Torr by the effect of the rotary pump 39, the mechanical booster pump 38 is actuated. Then, after the internal pressure of the apparatus body 1 is reduced equal to or less than 5 x 10 2 Torr, the pre-evacuation valve 37 is closed, and the auxiliary valve 40 and the final-evacuation valve 35 are opened so as to evacuate the interior of the apparatus body 1 to the higher degree of vacuum of 10## 5 Torr. If the exhaust speed is reduced by gas discharged from the length of material 20, it is possible to drive the winding roller 28 and the supplying roller 27 such as to wind up and rewind the length of material 20 in order to raise the exhaust speed. In this case, the winding up and rewinding operation is carried out after the final-evacuation valve 35 is opened. If the amount of discharged gas is large, it is to be done after the mechanical booster pump 38 is actuated. The winding up and rewinding operation is carried out at a speed of about 10 m/min. Next, while being supplied with argon gas from a argon gas bomb 43, the interior of the apparatus body 1 is gradually evacuated by the diffusion pump 36, thus maintaining a low-pressure argon gas atmosphere therein. Next, the water cooling piping 25 is supplied with a quantity of water, and the supplying roller 27 and the winding roller 28 are driven while a high direct current voltage is applied between the target 15 and the anode 19. A glow discharge is caused by appling a high direct current voltage between the target 15 and the anode 19, and a quantity of argon gas in the sputtering apparatus body 1 is ionized by the discharge energy. Argon ions caused by this ionization are accelerated toward the target (cathode) 15 and they collide against the target 15 such as to drive metal out of the surface of the target 15. The metal driven out from the surface of the target 15 radially scatters out of the target 15. The length of material 20 passes over the auxiliary guide roller 32a, the guide rollers 21 and the auxiliary guide roller 32b, that is, a generally circular transferring passage encircling the substantially entire circumference of the target 15, and it is wound around the winding roller 28. Accordingly, the area on the length of material 20 to which the sputtering metal radially scattering from the target 15 is attached is so wide that a metal coat having prescribed thickness is securely formed on the surface of the length of material 20, even when the winding speed of the winding roller 28 is increased. According to the above-described related art, the winding speed is at most 2 to 3 m/min in order to form a coat having thickness of 500 angstrom, but this embodiment is capable of forming a metal coat having thickness of 500 angstrom on the surface of the length of metal 20 at a winding speed of 6 m/min, thus performing the sputtering treatment at a speed two or three times higher than that of the apparatus according to the related art. Sputtering metal scattered out of the target 15 sticks to portions other than the surface of the length of material 20, but, in this embodiment, pillars 24 disposed on the inner side of the guide rollers 21 (on the side of the target 15) function as covers for the guide rollers 21, namely, as guard plates, and the guide rollers 21 are constantly cooled by the water cooling piping 25, so that the sputtering metal is prevented from sticking to and heating the guide rollers 21. It is thus possible to securely reduce contaminations of the length of material 20 due to the sputtering metal sticking to the guide rollers 21 or reduce the influence of the heat applied thereto upon the length of material 20. When a metal oxide coat is formed on the length of material in place of the metal coat from the metal which constitutes the target 15, the valve 42b communicated to the oxygen gas bomb 44 is opened such as to supply oxygen gas together with argon gas to the interior of the sputtering apparatus body 1, a high direct current voltage is applied between the target 15 and the anode 19 while a low-pressure argon-oxygen mixture atmosphere is maintained in the apparatus body 1. When the argon and oxygen gas exists, metal which has been driven out of the target 15 in a manner similar to that described above is immediately oxidized by oxygen ions and changed into an oxide, it is attached in the form of the oxide to the length of material 20, thus forming a coat of the metal oxide on the surface of the length of material 20. As shown in Fig. 5, the supplying roller 27 and the winding roller 28 may be disposed on the circumferential surface on which the guide rollers 21 are disposed. In such a case, it is necessary to provide a guard member 46 for preventing sputtering metal from sticking to the length of material 20 wound around the supplying roller 27 and the winding roller 28. The second embodiment of the present invention will now be described with reference to Figs. 6 to 10. The sputtering apparatus body 1 is partitioned such that the casing 3 is separated by a partition wall 47 to form a sputtering treatment chamber 48 and a work accommodating chamber 49. The sputtering treatment chamber 48 is closed and sealed at its top opening by a lid 50. An air-tight door is disposed on the front of the work accommodating chamber 49 (lower side of Fig. 6). A target 15 in the form of a cylinder with a bottom is inserted from the outside of the lid 50 while maintaining air-tight property thereof and is detachably fixed to the center of the sputtering treatment chamber 48. The supplying roller for supplying the length of material 20 and the winding roller 28 for winding up the length of material which has undergone a sputtering treatment are vertically disposed in the work accommodating chamber 49. Both rollers are disposed on a bottom wall and detachably attached between the driving shafts 29a and 29b driven by external driving mechanisms 52a and 52b, and the driven shafts 31a and 31b rotatably attached to the upper portion of the chamber. The driving mechanisms 52a and 52b control the driving shafts 29a and 29b such that, when the length of material 20 supplied from the supplying roller 27 is wound around the winding roller 28, the peripheral speed of the winding roller 28 is higher than that of the supplying roller 27 by a constant degree. That is, looseness, wrinkles, etc. of the length of material 20 are prevented by providing a difference between peripheral speeds of these rollers 27 and 28 such as to apply a constant tension to the length of material in the winding direction thereof. Accordingly, the length of material 20 is guided between the guide rollers 21 while being tensioned at a constant degree by both the rollers 27 and 26. fl#e tension is set to be-at a degree such as to evade deformation of the length of material 20. In this embodiment, it is preferably 2 to 20 kg/cm. An openings for communicating the sputtering treatment chamber 48 and the work accommodating chamber 49 with each other is formed in the central portion of partition wall 47 which separates both chambers 48 and 49. The opening is closed by three auxiliary rollers 54a, 54b and 54c vertically disposed such as to form gaps 53 which allow the length of material 20 to pass therethrough. The length of material 20 passes between the auxiliary guide rollers 54a and 54b and introduced into the sputtering treatment chamber 48, and a part of the length of material which has undergone a sputtering treatment is wound up by the winding roller 28 after passing between the auxiliary guide rollers 54b and 54c. The guard plate 33 for preventing sputtering metal from sticking to the auxiliary guide rollers 54a, 54b and 54c is disposed in the sputtering treatment chamber 48, and the water cooling piping 25 is disposed on one side of the guard plate 33 which does not face the target 15 in the same manner as the pillars 24. A pipe 55 connected to a pump for evacuating the interior of the sputtering treatment chamber 48 is joined to this chamber. On the other hand, a pipe 56 connected to another pump independent of the exhaust system for the sputtering treatment chamber 48 is joined to the work accommodating chamber 49 in order to evacuate the interior thereof. The operation of the apparatus thus arranged as the second embodiment of the present invention will now be described. The door 51 of the work accommodating chamber 49 is opened while the internal pressure of the sputtering treatment chamber 48 and the work accommodating chamber 49 is being in equiliblium with the atmospheric pressure after the leak valves 41 and 41a have been opened. The supplying roller 27 is detached from the driving shaft 29a and the driven shaft 31a, and the length of material 20 is wound around the supplying roller 27. Next, the supplying roller around which the length of material 20 is wound is set between the driving shaft 29a and the driven shaft 31a. The length of material 20 is led by its one end through the gap formed between the auxiliary guide roller 54a and 54b to the interior of the sputtering treatment chamber 48 and is set around the six guide rollers 21. It is then introduced again into the work accommodating chamber 49 through the gap between the guide rollers 54b and 54c, and the end of the length of material 20 is attached to the surface of the winding roller 28. Then, the lid 50 and the door 51 are closed in an air-tight manner. Next, the interior of the sputtering apparatus body 1 is evacuated. At this time, it is not necessary to evacuate the work accommodating chamber 49 to a degree as high as the sputtering treatment chamber 48. The vacuum in the work accommodating chamber 49 may be maintained at 10 2 to 10 Torr. Next, while the sputtering treatment is being performed, the length of material 20 passes between the auxiliary guide rollers 54a and 54b and the guide rollers 21 then between the auxiliary guide rollers 54b and 54c, finally being wound around the winding roller 28. At this time, the winding roller 28 is controlled such that the peripheral speed of the winding roller 28 is higher than that of the supplying roller 27 by a constant degree. That is, the length of material 20 is guided on the guide rollers 21 while tensioned by a constant degree in the winding direction thereof. It is thereby prevented from loosening while being guided on the guide rollers 21. Even when it is loosed and wrinkled, it is stretched by the tension. Thus, it is possible to uniformly apply a sputtering treatment to the length of material 20 over the entire area thereof. When a sheet of cloth is used as the length of material 20, even the interior of the mesh can be coated with metal oxide, since the mesh of the cloth is opened by the above-described tensile force. A means for preventing the length of material from loosening between the supplying roller 27 and the winding roller 28 may be constituted as follows. As shown in Fig. 10, driving capstans 57a and 57b and pinch rollers 58a and 58b may be disposed on the sides of the supplying roller 27 and the winding roller 28 in order to set the winding speed to be consistently higher than the supplying speed by providing the driving force through the capstans 57a and 57b. In this case, the capstan 57a and the pinch roller 58a on the supplying side may be removed and the driving mechanism itself may be designed such as to tension the length of material in the reverse direction. That is, any method is applicable if only it can apply tensile force between both rollers 27 and 28, and it is not limited to the above constitution and combination. A tensile force applying means for tensioning the length of material 20 in the direction perpendicular to the supplying direction may be provided. The length of material 20 can thereby be prevented from expanding considerably in one direction, and, when a material in the form of a mesh is used, it is possible for metal to attach to the interior of the mesh, because the mesh is uniformly expanded in both longitudinal and transverse directions. As shown in Fig. 9, only a gap which allows the length of material to pass therethrough may be formed in the partition wall 47 located between the sputtering treatment chamber 48 and the work accommodating chamber 49, instead of disposing the auxiliary guide rollers 54a to 54c in the partition wall 47. In that case, a contacting surface facing the length of material 20 may preferably formed smoothly in order to reduce the friction thereof. Instead of forming the upper and lower supporting frames 22 and 23, the upper wall of the sputtering treatment chamber 48 may be extended to the position in which the guide rollers 21 are disposed, such as to rotatably support the guide rollers 21 between the upper and bottom walls, and a cover for the guide rollers 21 may be formed otherwise. This cover is not necessarily provided. The third embodiment of the present invention will now be described with reference to Figs. 11 to 16. A plurality of supporting shafts 59a (five shafts, in this embodiment) and a supporting and driving shaft 59b stand at the corner portions of the lower supporting frame 23 in the form of a hexagonal ring, and the upper supporting frame which has the same size and shape as those of the lower supporting frame 23 is supported on the tops of the supporting shafts 59a and the supporting and driving shaft 59b. The supporting shafts 59a are fixed to the lower supporting frame 23 and they fixingly support the upper supporting frame 22. A pulley 60a is rotatably attached to the top of each supporting shaft 59a, The supporting and driving shaft 59b is rotatably supported by a driving unit 61 mounted on the reverse side of the base support 2. A pulley 60b is fixingly attached to the top of this shaft 59b A belt 62 is wound around the pulleys 60a and 60b, and a plurality of needles 63 project at given intervals from the outer peripheral surface of the belt 62. A pair of left and right guide rollers 64 and 65 are vertically and rotatably supported between the upper and lower supporting frames 22 and 23 in the vicinity and on the outside of the driving and supporting shaft 59b. A roller 66 is vertically and rotatably supported in the vicinity of the guide rollers 65. As shown in Fig. 13, grooves 67 and 68 are respectively formed on the peripheral surfaces of the upper portions of the guide rollers 64 and 65 such as to correspond to the position of the belt 62. The belt 62 is tensioned and pressed against the peripheral surfaces of these guide rollers 64 and 65. The needles 63 are introduced into the grooves 67 and 68. The length of material 20 which is supplied from the supplying roller 27 is guided between the guide roller 64 and the driving and supporting shaft 59b and is led along the outside of the supporting rollers 59a, and it is introduced into a gap formed between the guide roller 65 and the driving and the supporting shaft 59b and into a gap between the guide roller 65 and the roller 66, finally being wound around the winding roller 28. The length of material 20 supplied from the supplying roller 27 is introduced into a gap between the guide roller 64 and the belt being turned on a passage forming a hexagonal ring around the pulleys 60a and 60b by the rotational driving force of the driving and supporting shaft 59b, and it is stabbed at its upper end with the needles 63 projecting on the outer surface of the belt 62 by the effect of the belt 62 and the guide roller 64 which press the needles on the length of material. The length of material 20 stabbed with the needles 63 is guided with the belt 62 while being vertically suspended from the belt 62 which is turning on the passage in the form of a hexagonal ring, and sputtering metal scattering from the target 15 is attached to the inner surface of the length of material 20. That is, the length of material 20 undergoes the sputtering treatment while being vertically suspended from the belt 62 which is turning on the prescribed circling passage, thus eliminating looseness which causes the length of material to be wrinkled while it is wound up. Accordingly, even when the length of material 20 is not tensioned, it can wound up without being wrinkled. It is thus possible to apply a sputtering treatment to elastic weaves such as knitted goods and to extremely thin cloth or a film which can not be tensioned. Since, according to the arrangement of this embodiment, the guide rollers 64 and 65 for the length material 20 are not disposed on the area where sputtering metal may stick to these rollers, it is possible to eliminate the risk of guide rollers being heated by sputtering metal sticking thereto, thus reducing the influence on the length of material 20. The length of material 20 which has undergone a sputtering treatment on one side thereof while being suspended and guided around the supporting shafts 59a is introduced into a gap formed between the driving and supporting shaft 59b and the guide roller 65, and it is released from the needles 63 by the roller 66 and passes between this roller 66 and the guide roller 65, finally wound around the winding roller 28. It is possible for the position of the belt 62 to be adjusted in the vertical direction by designing the positions of the pulleys 60a and 60b to be adjustable along the supporting shafts 59a and 59b. Accordingly, the length of material can be set to be suspended in the most suitable position for the sputtering treatment in accordance with the width of the material. The third embodiment is thus constituted and it may be altered as described below. Fig. 14 shows one altered embodiment in which, in a manner similar to that in the third embodiment, the length of material 20 is suspended and supported at its upper end by the needle 63 disposed on the belt 62 and, besides, it is supported at its lower end by a suspension means composed of a pulley 70, belt 71 and needles 72 disposed on the outer peripheral surface of this belt 71 similar to the above suspension means of the third embodiment, thus being transferred more smoothly while vertically suspended. Figs 15 and 16 show another altered embodiment in which supporting shafts 74 are vertically disposed at three corners of a lower supporting frame 73 in the form of a rectangular frame. An upper supporting frame 75 similar to the supporting frame 73 is supported on and fixed to the top ends of these supporting shafts 74. Guide rollers 76 and 77 which are driven and rotated by a driving means (not shown) are vertically supported between both supporting frames 73 and 75 at another angle thereof, and a roller 78 is disposed in the vicinity of the guide roller 77. A bevel gear 79 is rotatably attached to the top portion of each supporting shaft 74, and similar bevel gears (not shown) are fixedly attached to the top portions of both guide rollers 76 and 77. A ring 80 is engaged with and rotatably supported by each bevel gear. A plurality of needles 81 are disposed at given intervals on the outer peripheral surface of the ring 80, and they are movable in grooves 82 formed on the peripheral surfaces of the upper portions of the guide rollers 76 and 77. The ring 80 is rotated around the target 15 by the rotational driving movement of the guide rollers 76 and 77, and the length of material 20 supplied from the supplying roller 27 is stabbed at its upper end by the needles 81 at the area between the guide roller 76 and the ring 80. It is thereby suspended and guided with the rotating ring 80 around the target 15, thus undergoing a sputtering treatment. The length of material 20 which has substantially completed a revolution around the target 15 is detached from the ring 80 by the roller 78 and wound around the winding roller 28. Is is a matter of course, according to this arrangement, that a sputtering treatment can be applied to a length of material which can not be tensioned. In addition, it is possible to for the sputtering treatment to be carried out more effectively, since, inside the length of material 20, there is few members which prevent sputtering metal from being attached to the material, In the altered embodiment shown in Figs 15 and 16, a plurality of clips may be attached, instead of the needles 81, to the outer peripheral surface of the ring 80 such as to clip the upper end of the length of material, and the clip may be opened by a cam mechanism at the area between the guide rollers 76 and-77 and may be closed at the other area, thus enabling the length of material to be vertically suspended and supported. Otherwise, an endless belt may be pressed against the outer peripheral surface of the ring 80 at the area other than that between the guide rollers 76 and 77, for the purpose of suspending the length of material. The present invention is not limited to the above-described embodiments, and it is possible to carry out the present invention as follows. In the first and second embodiments, guide pins 111 may be protrusively disposed at both ends of the outer peripheral surface of the guide roller 21; a fastener 112 may be attached to the surface of the guide roller 21; or the surface of the guide roller 21 may be formed to be a roughened surface. These arrangements enable the length of material to be tensioned at a lower level, thus being specifically advantageous when applying a sputtering treatment to materials such as cloth which can not be highly tensioned. When the guide rollers 21 are positively driven, it is possible to further reduce the tension which is applied to the length of material 20. The number of the guide rollers 21 and the interval at which this rollers are disposed vary in accordance with the kind of cloth used as the length of material and with the intensity of the tension applied thereto. The interval may preferably be 20 to 80 cm, and, preferably, more than five guide rollers 21 may be disposed in order that the length of material 20 is moved around the target 15 while assuming a substantially circular form. As shown in Figs 19 to 22, a pillar 24 having a function of a guard member may be provided in the form of an angle, an arc and a channel and a plate in section. It is not always necessary to dispose the pillars 24 as-guard' members for guide rollers 21 on the'inside thereof. The pillars 24 may be disposed on the outside of the transferring passage of the length of material 20, and guard members may be provided such as to be separate from the pillars 24. In that case, the material for the guard member is not limited to metal and may be ceramics, etc. having heat-resisting property. If a time for continuously operating the sputtering apparatus is short, the water cooling piping 25 is not necessarily disposed while the guard members are disposed in spaced relationship with the guide rollers 21. The apparatus may be arranged such that the guide rollers 21 may be positively driven. In the first to third embodiments, matal for forming the target 15 is not specifically defined, any metal including all matal (alloys) available for sputtering process may be applicable. That is, gold, silver, aliminium, tin, zinc, titanium, nickel, copper, cobalt, chromium, etc. as simple substance metal, and hastelloy, permalloy and stainless steel as alloys are suitable in terms of corrosion resistance and color. These kinds of metals or alloys may be selected in accordance with purpose, color and cost. In these embodiments, a nitrogen gas bomb may be substituted for the oxigen gas bomb. It is thereby possible to form a metal nitride coat instead of metal oxide coat on the surface of the length of material 20. An inert gas such as xenon may be used instead of argon gas. In the first and third embodiments, instead of forming the sputtering apparatus body 1 by the base support 2 and the casing 3 mounted on the upper surface of the support 2, the sputtering apparatus body 1 may be constituted by a casing having a bottom and a lid for covering the upper opening of the casing in a air-tight manner. It is apparent that these embodiments can be largely altered or modified without departing from the spirit and scope of the present invention, and the present invention is not limited to those particular embodiments while it is specified in the appended claims

Claims: Patent Claims: 1. A sputtering apparatus for applying, in a casing (3), a sputtering treatment to a length of material(20) such as cloth or a film with sputtering metal which has flown off a target, while transferring said length of material(201 said sputtering apparatus comprising: a cylindrical target(15)disposed as said target in said casing (3); a plurality of guide rollers (21 )for guiding said length of material (20), said guide rollers (21)being disposed on a circumferential surface concentric with said cylindrical target (15) such as to make a moving path of said length of material(20)conforll to a circumferential surface encircling said cylindrical target(15). 2. A sputtering apparatus according to Claim 1, further comprising a supplying roller for supplying said length of material, and a winding roller ! for winding up said length of material which has undergone a sputtering treatment. 3. A sputtering apparatus according to Claim 2, wherein said supplying roller ahd said winding roller are disposed on the outside of said circumferential surface defined by said guide rollers. 4. A sputtering apparatus according to Claim 1, wherein said cylindrical target includes inside a vertically movable supporting cylinder and a plurality of permanent magnet attached to said supporting cylinder at given intervals. 5. A sputtering apparatus according to Claim 4, further colllprislrlg: a bellows disposed under the lower end of said supporting cylinder, said bellows vertically expanding when supplied with compressed air from the outside; and an anode in the form of a cage having thin rods extending vertically, said anode being located on a circumferential surface concentric with said cylindrical target. 6. A sputtering apparatus according to Claim 2, further comprising a plurality of pillars having width wider than the diameter of each of said guide rollers, said pillars being disposed between said guide rollers and said cylindrical target such as to face each guide rollers. 7. A sputtering apparatus according to Claim 6, wherein each of said pillars has at least one water-cooling piping for cooling said pillar, which is disposed on one side of each pillar which does not face said target, and said pillar is disposed in the vicinity of each of said guide rollers. 8. A sputtering apparatus according to Claim 2, further comprising upper and lower supporting frames rotatably supporting said plurality of guide rollers disposed at equal intervals. 9.. A sputtering apparatus according to Claim 8, further comprising: a pair of auxiliary guide rollers disposed between a pair of said guide rollers located in the vicinity of said supplying roller and said winding roller; and a guard plate vertically disposed between said auxiliary guide rollers and said cylindrical target, said guard plate has a water-cooling piping disposed one side of said guard plate which does not face said target. 10. A sputtering apparatus according to Claim 3, wherein said supplying roller and said winding roller are disposed on a said circumferential surface defined by said guide rollers, and guard members for preventing sputtering metal from sticking to said supplying roller and said winding roller are provided. 11. A sputtering apparatus for applying, in a casing (3), a sputtering treatment to a length of material(20)such as cloth or a film with sputtering metal which has flown off a target, while transferring said length of material(200 said sputtering apparatus comprising: : a sputtering treatment chamber (48) and a work accommodating chamber (49) adjacent to said sputtering treatment chamber, said sputtering treatment chamber having a cylindrical target (15)and plurality of guide rollers(21) for guiding a length of material (20) such as cloth or a film, said plurality of guide rollers(21)being disposed on a circumferential surface concentric with said cylindrical target such as to make a moving path of said length of material (20) conform to a circumferential surface encircling said cylindrical targetc15), and said work accomodating chamber(49)incorporating a supplying roller(27) for supplying said length of material (20) and a winding roller (28) for minding up said length of material (20) which has undergone a sputtering treatment. 12. A sputtering apparatus according to Claim 11, further comprising: a partition wall for separating said sputtering treatment chamber and said work accommodating chamber, said partition wall having two gaps which allow said length of material to pass therethrough; and exhaust systems for evacuating said sputtering treatment chamber and said work accommodating chamber, said exhaust systems being independently adapted to each of said chambers. 13. A sputtering apparatus according to Claim 12, wherein said gaps are formed between three auxiliary guide rollers. 14. A sputtering apparatus according to Claim 12, wherein at least one of said supplying roller and said winding roller has a tensioning means for applying a constant tensile force to said length of material. 15. A sputtering apparatus according to Claim 14, wherein said tensioning means includes an external driving mechanism which rotates said winding roller at a constant peripheral speed'higher than that of said supplying roller by a given degree. 16. A sputtering apparatus according to Claim 14, wherein said tensioning means includes driving capstans and pinch roller attached to said supplying roller and said winding roller. 17. A sputtering apparatus for applying, in a casing(31 a sputtering treatment to a length of material(20)such as cloth or a film with sputtering metal which has flown off a target, while transferring said length of material(20} said sputtering apparatus comprising: a cylindrical target(l5)disposed as said target in said casing(}); a supplying roller (27 )for supplying said length of material(20; a winding roller 28)for winding up said length of material(20)which has undergone a sputtering treatment; and a suspension means for suspending said length of material (20 )at the upper end thereof and circularly moving said length of material (20)on its moving path from the supply side to the winding side. 18 A sputtering apparatus according to Claim 17, wherein said suspension means includes: a plurality of supporting shafts encircling said cylindrical target; a supporting and driving shaft; a plurality of pulleys rotatably attached to the top portions of said supporting shafts and said supporting and driving shaft; a belt wound around said pulleys; and an attaching means disposed# on the outer peripheral surface of said belt, the upper portion of said length of material being engagingly attached to said attaching means. 19. A sputtering apparatus according to Claim 18, further comprising: a pair of guide rollers rotatably disposed on the outside and in the vicinity of said supporting and driving shaft, said belt being pressed against the outer peripheral surface of said guide rollers by the tensile force applied to said belt; and a roller rotatably and vertically disposed in the vicinity of said guide rollers. 20. A sputtering apparatus according to Claim 19, wherein each of said guide rollers has a groove formed on the outer peripheral surface thereof such as to correspond to the position of said belt, said attaching means being introduced into said groove. 21. A sputtering apparatus according to Claim 20, further comprising a supporting means disposed in a position correspondijiy to the lower end of said length of material, said supporting means having: a plurality of pulleys rotatably attached to said supporting shafts and said supporting and driving shaft; a belt wound around said pulleys; and an attaching means formed of the outer peripheral surface of said belt, the lower portion of said length of material being engagingly attached to said attaching means. 22. A sputtering apparatus according to Claim 18, wherein said attaching means includes a plurality of needles with which said length of material is stabbed. 23. A sputtering apparatus according to Claim 18, wherein said attaching means includes a plurality of guide pins engaging with said length of material. 24. A sputtering apparatus according to Claim 18, wherein said attachiny means includes at least one fastener surface enyaginy with said length of material. 25. A sputtering apparatus according to Claim 17, wherein said suspension means includes: a plurality of supporting shatts encircling said cylindrical target; a plurality of bevel gears rotatably attached to the upper portions of said supporting shafts; a ring engagingly rotated by said bevel gears; and an attaching means disposed on the outer circumferential surface, the upper portion of said length of material being engagingly attached to said attaching means. 26. A sputtering apparatus according to Claim 25, wherein said attaching means includes a plurality of needles with which said length of material is stabbed.

Inventors: MANABE, KATSUHIDE C/O TOYODA GOSEI CO., LTD., TSUTSUI, MASATOSHI C/O TOYODA GOSEI CO., LTD.
Applicants: TOYODA GOSEI CO., LTD.
Application year: 1986
Main classification: H01J37
IPC codes: C23C14, H01L21, H01J37