JPH0336735B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for transporting workpieces into and out of a vacuum processing apparatus.

The time required to transport the workpiece into and out of the vacuum system and the time required to pump it to the appropriate pressure are often the limiting factors in the speed at which the workpiece can be processed. This is especially true in high speed deposition methods where the coating time of an individual substrate is sometimes short compared to the time required to sufficiently evacuate the coating chamber.
Coating equipment has been developed in which the workpiece or substrate passes through separate vacuum lock chambers on its way into and out of the coating or processing chamber. In this case, the volume of the lock chamber can be minimized and processing of successive substrates can be continued without bringing the chamber to atmospheric pressure, thereby increasing production rates. U.S. Pat. No. 3,945,903 (Subender et al.) discloses a vacuum coating apparatus that includes an inlet lock chamber, an outlet lock chamber, and a roller conveyor for transporting glass sheets through the apparatus. ing.

In some situations, the expense of a complete double-ended system with vacuum lock chambers at both the inlet and outlet of the coating chamber is not justified. An alternative is to provide a single lock chamber and reversible conveyor through which workpieces can enter and exit the processing chamber. Such devices are called single-ended coating devices. US Patent No.
No. 4,405,435 (Tateishi et al.) discloses a single-ended vacuum coating apparatus that includes a cassette elevator for both a multilever workpiece cassette and a lock chamber and an intermediate chamber between the lock chamber and the sputter coating chamber. It has

SUMMARY OF THE INVENTION The present invention is a method and apparatus for loading and unloading workpieces into a single-ended vacuum processing apparatus. The apparatus has a processing chamber and a second chamber, the second chamber housing a workpiece transport device that includes two conveyors supported on a common frame and a workpiece conveyor in both directions through the second chamber. and a device for selectively moving each conveyor to convey the conveyor. The second chamber may be an end lock chamber with an exit/exit to the outside, or it may be an intermediate lock or holding chamber between the processing chamber and the end lock chamber.
Preferably, the conveyor includes two sets of parallel horizontal rollers and an elevator for selectively aligning each set of rollers with the transfer line to move the workpieces along the transfer line between the end lock chamber and the holding chamber. and transport between the holding chamber and the processing chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a single-ended vacuum processing apparatus comprising a process chamber 10, a holding chamber 16 and a lock chamber 1.
It is equipped with 8. Vacuum treatment is a coating treatment,
In this process, the workpiece is conveyed from the inlet buffer 12 past multiple spatter coating sources 11 within the process chamber and into an overrun buffer 14. Workpieces may be transported back and forth through the processing chamber 10 if desired. The processing area of the device is the first internal gate valve 2
0 from the holding chamber 16, this gate valve 20 can be opened and closed as desired by an actuator 22. The holding chamber 16 and the locking chamber 18 are interconnected by a second internal gate valve 24, which is connected to the actuator 2.
6. An actuator 29 is used to enter and exit the lock chamber 18 from the work piece loading/unloading area 19.
This is done by an external gate valve 28 which can be operated by. The gate valve and actuator may be of any conventional design suitable for transporting workpieces of desired size and shape. One such gate valve is shown in US Pat. No. 4,065,097 (Teimin).

Each of the chambers of the processing apparatus can be evacuated separately by conventional equipment. Lock chamber 18 can be evacuated by a blower or other mechanical pump 32. In the case of sputtering or electron beam heating coating methods, the holding chamber 16 and the processing chamber 10
can be evacuated, preferably by means of a diffusion pump 30. Processing chamber 10 may include a source 34 of the desired sputtering gas.

Each chamber of the vacuum processing apparatus is equipped with a conveyor for supporting and transporting the workpieces. For glass sheets and similar substrates, each conveyor preferably comprises a series of parallel horizontal rollers 42, which
is provided on the frame 44 and driven by a reversible motor 46. Preferably, the separate chamber conveyors are aligned to move substrates into and out of the apparatus along transfer line 48.

In the preferred device, the holding chamber 16 is equipped with a vertically moving multilevel conveyor 50 having two horizontal conveyors 52, 54 mounted one above the other on a common frame 60. As shown in FIGS. 2, 3a and 3b, the frame 60 consists of two parallel longitudinal upper members 6 interconnected by a number of transverse members 63.
2 and two parallel lower longitudinal members 64 interconnected by the same number of transverse members 65 and aligned directly below the upper member.

When the frame 60 is in its lower position (as shown in FIGS. 2 and 3b), it rests on legs 68 which are at a level above the bottom wall 17 of the frame holding chamber 16. You can adjust the position as needed. Further legs and cross members may be provided between the side members as required depending on the length of the workpiece transport device.

In FIGS. 2, 3a and 3b, the device 5
0 upper conveyor 52 is aligned with transfer line 48 . An elevator is provided to raise frame 60 so that lower conveyor 54 is on the transfer line. As shown, the elevator includes four ball screw jacks 70 that extend out of the chamber 16 through a vacuum seal assembly 71 in the bottom wall 17. Each jack has a lubricating section 7 to lubricate the seal assembly.
It is equipped with 5. Alternatively, the elevator may be equipped with hydraulic or pneumatic cylinders.

Vertical movement of the transport device 50 is guided by four lateral guide wheels 72, two of which are mounted on the outer surface of each lower longitudinal member. These wheels roll along upper rod paths 73 and lower rod paths 74 provided on both side walls of the chamber 16. Movement of the device 50 is also guided by a longitudinal guide wheel 76 mounted on an axis 77 perpendicular to one of the lower longitudinal members 64.
The wheel 76 rolls between two upper passages 78 and two lower passages 79 provided on one side wall portion 15 of the chamber 16. The upper and lower passages for guide wheels 72, 76 are aligned so that device 50 is properly aligned in its raised and lowered positions, respectively.

Support blocks 8 aligned along side rails 62
2 is rotatably provided with a number of rollers 80 (block 82 is omitted from FIG. 2).
Two pulleys 84 are provided at one end of the shaft 83 of each roller.
85 is installed. As shown in Figure 3a, the pulleys of adjacent rollers are interconnected by belts 86 which cause the rollers to rotate simultaneously in the same direction.

Whichever conveyor is in the transfer line, the axis of one roller of that conveyor is connected to a magnetic device 90,
92 to a shaft 94 which extends through a rotary seal in side wall 15. This rotating shaft is driven by a reversible motor 95 outside the chamber 16.

FIG. 4 illustrates the method of the invention. The parts of this figure show a processing chamber 100, a holding chamber 16, and a lock chamber 18. Preferably, the processing chamber includes an inlet buffer and an overrun buffer. The processing chamber 100 and the holding chamber 16 are interconnected by a first gate valve 20. The holding chamber 16 and the locking chamber 18 are interconnected by a second gate valve 24. The workpieces enter and exit the lock chamber 18 by means of a third gate valve 28. Processing room 1
00 accommodates a first conveyor 101, a lock chamber 18, and a second conveyor 102. As mentioned above, the holding chamber 16 houses a workpiece transport system 50 having two conveyors, an upper level conveyor 52 and a lower level conveyor 54, and each conveyor connected to a vacuum processing apparatus. It has an elevator aligned with a transfer line 48 passing through.

In Figure 4a, valves 20, 24 are closed. 1
Two workpieces 110 are being processed in chamber 100 and unprocessed workpieces 112 are waiting in holding chamber 16 on conveyor 54 at the lower level of transport device 50 . Since valves 20 and 24 are closed, chamber 16 is evacuated by the diffusion pump and the pressure within process chamber 100 is independently set, if desired. Valve 28 is open and conveys a second green workpiece 114 from conveyor 104 in the unloading area onto conveyor 102 in the lock chamber, as shown in FIG. 4b. Then, the valve 28 is closed and the lock chamber 18 is evacuated by the rough pump.

The conveyor 50 is aligned so that the empty conveyor 52 is in the transfer line. When processing of the workpiece 110 is finished, the valve 20 is opened and the workpiece 110 is conveyed onto the empty upper conveyor 52. The conveying device 50 then moves upwards so that the lower conveyor 54 is located in the transfer line, as shown in FIG. 4c.
The unprocessed piece 112 is transferred to the conveyor 101 in the processing chamber.
Transport on top of. When the valve 20 is closed, the work piece 11
Process 2 proceeds. Valves 24 and 28 remain closed and rough pumping of lock chamber 18 continues.

As shown in FIG. 4d, the valve 24 is opened and the unprocessed workpiece 114 is conveyed into the holding chamber 16 onto the lower conveyor 54 of the apparatus 50. The apparatus 50 is then moved downwardly to align the upper conveyor 52 with the transfer line as shown in FIG. It is conveyed onto the conveyor 102.
Valve 20 remains closed so processing of workpiece 112 continues in chamber 100. Vent the lock chamber 18,
When the gate valve 28 is opened, the processed workpiece 110
can be transferred from lock chamber 18 onto conveyor 104. Close the valves 20 and 24 and open the holding chamber 1.
6 continue pumping and processing in chamber 100. The treated workpiece 110 is removed from the conveyor and replaced with an untreated workpiece, and the cycle continues at step 4a.
Start again with the diagram.

The use of a holding chamber reduces the injection of gas into the process chamber when gate 20 is opened and the workpiece is transported through gate 28 as indicated in FIGS. 4a and 4f. This allows the lock chamber 18 to pump. As indicated in FIGS. 4b and 4c, processing can continue except for the short time required to transport the workpiece between the processing chamber 100 and the holding chamber 16, thereby increasing the efficiency of the processing chamber. It will be used for various purposes.

Explaining this in conjunction with FIG. 4, processed pieces are placed on the lower conveyor 52, and untreated pieces are placed on the lower conveyor 54. If falling debris is a problem,
Preferably, the method is modified so that the treated workpieces are placed on the lower conveyor 54 below the untreated workpieces.

Various other modifications may be made to the method and apparatus without departing from the spirit of the invention.

[Brief explanation of drawings]

1 is a schematic side view of a vacuum coating apparatus incorporating the present invention; FIG. 2 is a partial cross-sectional side view of a holding chamber incorporating a two-level workpiece transport apparatus according to the invention; FIG. FIG. 3b is a partial cross-sectional end view of the holding chamber and workpiece conveyance device shown in FIG. 2; FIG. 4 is a processing chamber and holding chamber illustrating the method according to the invention. 1 is a schematic diagram of a vacuum processing apparatus including a vacuum lock chamber and a vacuum lock chamber. 10... Processing chamber, 16... Holding chamber, 18... Lock chamber, 20, 24, 28... Gate valve, 26,
29... Actuator, 30... Diffusion pump,
42... Roller, 44... Frame, 48... Transfer line, 50... Conveying device, 52, 54... Conveyor, 60... Frame, 72... Wheel,
80... Laura.

Claims (1)

[Claims] 1. A first chamber and a second chamber that can be evacuated, a first gate valve that interconnects the first chamber and the second chamber, and a second gate valve that allows entry and exit into the second chamber. It consists of a 2-gate valve, a first conveyor in the first chamber, a second conveyor outside the first and second chambers, and a workpiece conveyance device in the second chamber, and the workpiece conveyance device is common. a third conveyor and a fourth conveyor supported adjacent to each other on the frame of the first conveyor;
When the gate valve is open, the first and third conveyors
the first conveyor for conveying workpieces between each of the conveyor and the fourth conveyor, and the second conveyor and each of the third conveyor and the fourth conveyor when the second gate valve is open; a device for selectively moving a third conveyor and a fourth conveyor into alignment with a second conveyor for conveying workpieces therebetween. 2. The vacuum processing apparatus according to claim 1, further comprising a third chamber that can be evacuated, and the second gate valve interconnects the second chamber and the third chamber. 3. The vacuum processing apparatus according to claim 1, wherein the third conveyor and the fourth conveyor are parallel. 4. A vacuum processing apparatus according to claim 3, wherein each conveyor comprises a number of parallel, substantially horizontal rollers and means for rotating the rollers simultaneously. 5. The vacuum processing apparatus according to claim 4, wherein the third conveyor and the fourth conveyor are supported above and below each other, and the conveyor moving device is an elevator that moves the frame in the vertical direction. 6. The vacuum processing apparatus according to claim 5, wherein the workpiece conveyance device further includes a wheel provided on the frame to guide movement of the frame. 7. A method for transporting a workpiece into and out of a vacuum processing device, including processing the workpiece and transporting the processed workpiece from a first conveyor in a first chamber to a first level of a multilevel conveyor in a second chamber. moving the multi-level conveyor to align the second level of the multi-level conveyor with the first conveyor, transporting the first unprocessed piece from the second level onto the first conveyor, and then moving the first chamber onto the first conveyor. sealing against the two chambers, conveying the second unprocessed piece from a second conveyor outside the second chamber to the second level, and moving the multilevel conveyor to align the first level with the second conveyor. , transporting the processed workpiece from the first level to a second conveyor, and sealing the second chamber. 8 A second conveyor is in a third sealable chamber, transporting each processed workpiece from the second conveyor out of the apparatus and transporting each unprocessed workpiece from outside the apparatus into the third chamber. 8. The method of claim 7, further comprising transferring onto a conveyor, sealing and evacuating the third chamber.