JP2002203889A - Equipment for vacuum holding device to be treated - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide equipment for vacuum holding a device to be treated, capable of sufficiently securing an exhausted flow even with a low capacity battery equipped on the mobiles and surely vacuum holding the device to be treated. SOLUTION: The equipment 38 for vacuum holding the device to be treated is provided with an arm 341 for sucking and holding wafers, an exhaust path 341C formed inside the arm 341 and opened at the sucking surface and a vacuum sucking mechanism 343 connected to the exhaust path 341C via a pipe 344A. The vacuum sucking mechanism comprises a compressor driven by the equipped battery (not shown), an air tank 345 storing air compressed and exhausted from the compressor 344 as compressed air, an air pressure adjusting mechanism adjusting the pressure of the compressed air flow from the air tank 345 and an ejector 347 spouting the compressed air supplied from the air pressure adjustment mechanism 346.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum holding apparatus for a workpiece, and more particularly, to a vacuum holding apparatus for a workpiece mounted on a moving body such as an automatic transport device.

[0002]

2. Description of the Related Art For example, in a semiconductor device inspection process, a prober is widely used as an inspection device for a semiconductor wafer (hereinafter, simply referred to as "wafer"). The prober usually includes a loader chamber and a prober chamber, and performs an electrical characteristic test of the device in a wafer state. The loader chamber includes a carrier mounting portion on which a plurality of (for example, 25) wafers are stored, and a wafer transfer mechanism (hereinafter, “tweezers”) that transfers wafers one by one from the carrier mounting portion. ), And a pre-alignment mechanism (hereinafter, referred to as “sub-chuck”) for performing pre-alignment of the wafer conveyed via the tweezers. The prober chamber has a mounting table (hereinafter, referred to as “main chuck”) on which a wafer is mounted and moves in the X, Y, Z, and θ directions.
An alignment mechanism for aligning a wafer in cooperation with the main chuck, a probe card disposed above the main chuck, and a test head interposed between the probe card and the tester are provided.

Therefore, when inspecting a wafer, first, an operator places a carrier containing a plurality of wafers in lot units on a carrier placement portion in a loader room. Then, when the prober is driven, the tweezers take out the wafers in the carrier one by one, perform pre-alignment via the sub chuck, and deliver the wafer to the main chuck in the prober chamber via the tweezers. In the loader chamber, the main chuck and the alignment mechanism cooperate to perform wafer alignment. While the indexed wafer is fed through the main chuck through the main chuck, the wafer is brought into electrical contact with the probe card to perform a predetermined electrical characteristic test. When the inspection of the wafer is completed, the wafer on the main chuck is received by the tweezers in the loader chamber, returned to the original position in the carrier, and the inspection of the next wafer is repeated as described above. When the inspection of all wafers in the carrier is completed, the operator replaces the next carrier and repeats the above inspection for a new wafer.

However, when the diameter of a wafer is increased, for example, to a 300 mm wafer, the carrier containing a plurality of wafers is extremely heavy, and it is almost impossible for an operator to carry the carrier. Even if it can be carried, it is heavy and dangerous to carry alone. This can be said not only for the prober but also for semiconductor manufacturing equipment in general.

Therefore, Japanese Patent Laid-Open Publication No. Hei 10-303270 proposes a method of transporting carriers in lots using an automatic transport vehicle (hereinafter referred to as "AGV"). With this transfer method, transfer of the wafer can be solved.

[Problems to be solved by the invention]

However, the increase in the diameter of the wafer and the ultra-miniaturization of the device dramatically increase the number of devices formed on one wafer, and it takes a long time to complete the inspection of one wafer. Inspection of wafers on a lot basis means that all inspected wafers remain in the prober (carrier) until inspection of all wafers is completed.
The time required to transfer a wafer in a lot unit to a subsequent process is accordingly delayed, and as a result, it is difficult to reduce the TAT (Turn-Around-Time).

Therefore, the wafers are distributed one by one to a plurality of probers, the wafers are processed in parallel by the plurality of probers, the wafers that have been inspected are sequentially taken out and collected in lots by carrier, and the collected wafers are collected in carrier units. TAT can be shortened by transferring to the next step. In this case, tweezers must be mounted on the AGV in order to transfer the wafers one by one. However, in order to hold the wafers one by one on the arm using tweezers, a vacuum suction mechanism is required. As the vacuum suction mechanism, for example, a mechanism using a compressor and an ejector is simple and preferable, but the power supply capacity of the battery, which is the drive source of the compressor that can be mounted on the AGV, is limited, and a sufficient exhaust flow rate required for vacuum suction is secured There was a problem that it was not possible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to secure a sufficient exhaust flow rate even with a low-capacity power supply mounted on a moving body, and to surely vacuum-adsorb a processing target. It is an object of the present invention to provide a vacuum holding device for an object to be processed.

[0009]

According to a first aspect of the present invention, there is provided a vacuum holding apparatus for an object to be processed, comprising an arm for holding the object by suction, and an arm formed in the arm and having a suction surface of the arm. An exhaust path that opens, and a vacuum suction mechanism that is connected to the exhaust path via a communication pipe, and is a vacuum holding device for a workpiece to be mounted and used on a moving body, wherein the vacuum suction mechanism includes: A compressor driven by an on-board power supply, a container for storing gas compressed from the compressor as compressed gas, gas pressure adjusting means for adjusting the pressure of compressed gas flowing out of the container, and supply from the gas pressure adjusting means. Means for ejecting a pressurized gas to be applied.

According to a second aspect of the present invention, in the vacuum holding apparatus for an object to be processed, the moving object is an automatic transport vehicle in the first aspect of the invention. Things.

According to a third aspect of the present invention, there is provided a vacuum holding apparatus for an object to be processed, according to the first or the second aspect of the present invention, comprising a plurality of the arms.

According to a fourth aspect of the present invention, there is provided a vacuum holding apparatus for an object to be processed according to the first aspect of the present invention, wherein the first opening and closing the communication pipe is opened and closed. An on-off valve is provided between the gas pressure adjusting means and the jetting means.

According to a fifth aspect of the present invention, there is provided a vacuum holding apparatus for an object to be processed according to the first aspect of the present invention, wherein the communication pipe is opened and closed. An on-off valve is provided between the arm and the jetting means.

According to a sixth aspect of the present invention, in the apparatus for maintaining a vacuum of an object to be processed, the pressure in the exhaust passage between the arm and the second on-off valve is reduced. A detection means is provided.

According to a seventh aspect of the present invention, in the vacuum holding apparatus for an object to be processed, in the invention according to the sixth aspect, the pressure detecting means detects the presence or absence of the object to be processed on the arm. And a second pressure detecting means for detecting a pressure leak in the exhaust path.
Wherein the on-off valve opens and closes based on the detection result of the second pressure detecting means.

According to an eighth aspect of the present invention, there is provided a vacuum holding apparatus for an object to be processed according to any one of the first to seventh aspects, wherein the gas pressure adjusting means and the jetting means are provided. And a third pressure detecting means for detecting a pressure in the communication pipe between the first and second communication pipes, and the compressor is driven based on a detection result of the third pressure detecting means. .

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. First, a transfer system for transferring a workpiece (hereinafter, referred to as a “wafer”) to which the vacuum holding device for a workpiece according to the present embodiment is applied will be described. This transport system E is shown in FIG. (B), a host computer 1 for controlling production of the entire factory including a wafer (not shown) inspection process, and a plurality of inspections for inspecting electrical characteristics of the wafer under the control of the host computer 1 Device (for example, a prober) 2, a plurality of automatic transfer devices 3 for automatically transferring wafers one by one to these probers 2 in response to respective requests, and a transfer control device (hereinafter, referred to as a control device) for controlling these AGVs 3. This is referred to as “AGV controller”). Prober 2
And AGV3 have optically coupled parallel I / O (hereinafter, referred to as "PIO") interfaces based on SEMI standards E23 and E84, and receive one wafer W at a time by performing PIO communication between them. I have to pass it. The prober 2 is configured as a single-wafer type prober 2 for receiving wafers W one by one and performing inspection. Hereinafter, the single wafer type prober 2 will be described simply as a prober. The AGV controller 4 is connected to the host computer 1 and an SECS (Semiconductor Equipment Company).
It is connected via a communication line, controls the AGV 3 via wireless communication under the control of the host computer 1, and manages the wafer W in lot units.

As shown in FIG. 1, a plurality of probers 2 are connected to a host computer 1 via a group controller 5 via an SECS communication line, and the host computer 1 is connected to a plurality of probers 2 via a group controller 5. Is managing. The group controller 5
It manages information on inspection of the prober 2, such as recipe data and log data. A tester 6 is connected to each prober 2 via a SECS communication line, and each prober 2 individually executes a predetermined test according to a command from each tester 6. These testers are connected to the host computer 1 via the tester host 7 via the SECS communication line, and the host computer 1 is a tester host computer (hereinafter, referred to as “tester host”) 7.
, A plurality of testers 6 are managed. Further, a marking device 8 for performing a predetermined marking based on the inspection result of the wafer is connected to the host computer 1 via a marking instruction device 9. The marking instruction device 9 instructs the marking device 8 to perform marking based on the data of the tester host 7. Further, the host computer 1 has a stocker 10 for storing a plurality of carriers C.
The stocker 10 is connected via an ECS communication line, and stores and sorts wafers before and after inspection in a carrier unit under the control of the host computer 1 and carries out wafer loading and unloading in a carrier unit.

The prober 2 has a loader chamber 21 and a prober chamber 22 as shown in FIG. The loader chamber 21 has an adapter 23, tweezers 24, and a sub chuck 25, and is configured according to a conventional prober except for the adapter 23. Adapter 23 is AG
It is configured as a first transfer mechanism for transferring wafers W one by one to and from V3. Details of the adapter 23 will be described later. The tweezers 24 have upper and lower arms 241, and each of the arms 241 holds and holds the wafer W by vacuum suction, and releases the vacuum suction to transfer the wafer to and from the adapter 23. The wafer W is transferred to the prober chamber 22. The sub-chuck 25 performs pre-alignment based on the orientation flat while the wafer W is carried by the tweezers 24. The prober chamber 22 has a wafer chuck 26, an alignment mechanism 27, and a probe card 28. The main chuck 26 moves in the X and Y directions via the X and Y tables 261 and moves in the Z and θ directions via an elevating mechanism and a θ rotating mechanism (not shown). The alignment mechanism 27 includes an alignment bridge 271, a CCD camera 272, and the like, as is conventionally known, and performs alignment between the wafer W and the probe card 28 in cooperation with the main chuck 26. Probe card 2
8 has a plurality of probes 28A, and the probes 28A and the wafer on the main chuck 26 are in electrical contact with each other and are connected to the tester 6 via a test head (not shown).
Since the tweezers 24 have upper and lower arms 241, the upper arm is described as an arm 241 </ b> A and the lower arm is described as 241 </ b> B as necessary.

The adapter 23 is a device unique to this embodiment. As shown in FIG. 2B, the adapter 23 includes an adapter body 231 formed in a flat cylindrical shape and having a tapered surface, and a sub chuck 232 that moves up and down at the center of the bottom surface of the adapter body 231. When the wafer W is transferred to or from the tweezers 24, the sub chuck 232 is moved up and down and the wafer W can be sucked and held. The adapter 23 is detachably provided, for example, on a carrier table (not shown), and moves up and down via an indexer (not shown) of the carrier table. The carrier table is configured such that carriers can also be arranged, and has a discrimination sensor (not shown) for discriminating the carrier or the adapter 23. Therefore, when the wafer W is transferred, the adapter 23 moves up through the indexer, and the sub chuck 232 moves up to the transfer position of the wafer W as shown in FIG. Then, the wafer W is lowered to the position shown by the two-dot chain line in FIG.

As shown in FIGS. 1B and 2A and 2B, the AGV 3 is disposed at one end of the apparatus main body 31 and has the carrier C mounted thereon. And a mapping sensor 33 for detecting the storage position of the wafer in the carrier, tweezers 34 for transporting the wafer in the carrier C, and a wafer W
, A pre-alignment sub-chuck 35, an optical pre-alignment sensor 36 (see FIG. 11), an optical character reader (OCR) 37 for reading an ID code (not shown) of the wafer W, and a driving source. And a plurality of probers 2 between the stocker 10 and the prober 2 through wireless communication with the AGV controller 4.
The carrier C is conveyed by self-running, and the wafers 2W of the carrier C are distributed one by one to a plurality of probers 2 via tweezers.

The tweezers 34 is a wafer transfer mechanism mounted on the AGV 3. The tweezers 34 can rotate and move up and down when the wafer W is transferred. That is, as shown in FIGS. 2A and 2B, the tweezers 34 include upper and lower two-stage arms 341 for vacuum-sucking the wafer W.
, A forward / reversely rotatable base 342 for supporting the arms 341 so as to be able to move back and forth, and a drive mechanism (not shown) housed in the base 342. When the wafer W is transferred, the upper and lower arms 341 individually move forward and backward on the base 342 via the driving mechanism, and the base 342 rotates forward and backward in the direction of transferring the wafer W. In the description below, the upper arm will be described as an arm 341A and the lower arm will be described as 341B as necessary.

However, the compressor that can be mounted on the AGV 3 uses the mounted battery as a power source. However, as described above, only a low-capacity battery of, for example, about 25 V can be mounted on the compressor. The air flow rate is insufficient for use. That is, the air is directly ejected from the ejector 347 by the small compressor 344 using the battery mounted with the AGV 3 as a power source.
Even if the air is exhausted from A, the air flow in the compressor 344 is small, so that the air in the exhaust passage 341C of the arm 341 cannot be sufficiently sucked and exhausted, and the wafer W cannot be vacuum-adsorbed on the arm 341. Therefore, the insufficiency of the flow rate is compensated for by applying the following special measures to the vacuum holding device 38 for the object to be processed in the present embodiment.

That is, the vacuum holding device 38 of the present embodiment
As shown in FIGS. 3 and 4, two upper and lower arms 341 for holding the wafer W by suction, and an exhaust path 341C formed in these arms 341 and opened at the suction surface of the wafer W.
And a vacuum suction mechanism 343 connected to the exhaust path 341C via a pipe 344A, and driven under the control of the AGV controller 4. The vacuum suction mechanism 343 includes a compressor 344 driven by an on-board battery, an air tank 345 storing compressed air fed from the compressor 344 at a predetermined pressure (for example, 0.45 MPa), and an air tank 345. A gas pressure adjusting mechanism 346 for adjusting the pressure of the compressed air flowing out of the apparatus, and an ejector 347A for ejecting the compressed air supplied from the gas pressure adjusting mechanism 346.

The compressor 344 sends air under pressure and temporarily stores compressed air in the air tank 345 at a predetermined pressure.
Even if the air flow rate of the small compressor 344 using the battery mounted with the AGV 3 as a power source is small, the wafer W is temporarily stored in the air tank 345 with a predetermined amount of compressed air.
The air flow rate required for vacuum suction of can be secured.
That is, by using the compressed air stored in the air tank 345, an air flow rate necessary for vacuum suction of the wafer W can be secured. The gas pressure adjusting mechanism 346 is configured as shown in FIG.
As shown in the figure, the air filter 346A and the pressure reducing valve 346
B, and has a pressure gauge 346C, stores compressed air in the air tank 345, and exhausts compressed air from the ejector 347A to the outside at a constant flow rate required for vacuum suction of the wafer W. The shaded portion of the pipe 344A in FIG. 3 is a decompression portion.

The vacuum suction mechanism 343 includes a switching valve 347 for opening and closing a pipe 344A provided between the gas pressure adjusting mechanism 346 and the ejector 347A, and a pipe 344A provided between the arm 341 and the ejector 347A. Check valve 348 for opening and closing the valve, and an exhaust passage 34 disposed between the arm 341 and the check valve 348 for the pilot.
A pressure sensor 349 for detecting the pressure in 1C is provided, and the arm 341 holds and releases the wafer W.

The switching valve 347 is constituted by a solenoid valve as shown in FIG. 4. When the solenoid is energized, the gas pressure adjusting mechanism 346 and the arm 341 communicate with each other. It is disconnected from the arm 341. Therefore, air at a constant pressure flows from the gas pressure adjusting mechanism 346 to which the switching valve 347 is energized, and the ejector 347
A and exhaust air from the arm 341
Air is sucked from 1C and exhausted. At this time, the arm 34
1 holds the wafer W, the opening of the exhaust path 341C of the arm 341 is closed by the wafer W. Therefore, the exhaust path 341C (in FIG.
41C) is in a reduced pressure state, and the wafer W is vacuum-sucked on the arm 341. The degree of vacuum at this time is detected by the pressure sensor 349, and the ON / OFF of the solenoid valve 347A is controlled based on the detected value. In addition, since the air in the air tank 345 is consumed, the compressor 3 based on the detection value of the pressure gauge 346C is used.
44 is turned on and off. When the solenoid is energized, the check valve 348 with the pilot
The exhaust path 341C communicates with the ejector 347A side to suck air from the exhaust path 341C, and when the solenoid is no longer in a biased state, the check valve 348 with the pilot
1C is closed to maintain a predetermined degree of reduced pressure. When the vacuum suction by the arm 341 is released, the check valve 34 with the pilot is used.
The solenoid 8 may be energized to make the exhaust path 341C communicate with the ejector 347A to open the exhaust path 341C to the atmosphere.

As shown in FIG. 4, the pressure sensor 349 has a first pressure switch 349A and a second pressure switch 349B, and detects different pressures. The first pressure switch 349A is a sensor for detecting the presence or absence of the wafer W on the arm 341. The first pressure switch 349A detects a pressure in the exhaust path 341C, for example, 25 kPa lower than the atmospheric pressure, and determines whether or not the wafer W exists based on the detected value. To inform. Also,
The second pressure switch 349B is a sensor that detects a pressure leak in the exhaust path 341C. The second pressure switch 349B detects a pressure in the exhaust path 341C that is 40 kPa lower than the atmospheric pressure, for example, and detects a pressure leak when the internal pressure becomes higher than this detection value. That there is. When the second pressure switch 349B detects a pressure leak, that is, when the pressure in the exhaust path 341C increases (when the degree of vacuum decreases), the solenoid valve 347 is energized based on the detection result of the second pressure switch 349B and the pilot When the check valve 348 with the pilot is opened and the compressed air is exhausted from the ejector 347A, the exhaust path 34
When the pressure in 1C is reduced and the pressure of the second pressure switch 349B reaches a pressure lower than the atmospheric pressure by 40 kPa or more, the solenoid valve 347 is turned off and the check valve 348 with pilot is closed to maintain the reduced pressure state. When the value of the pressure gauge 346C falls below a predetermined value, the compressor 344 is driven to activate the air tank 34.
5. Refill compressed air in 5.

Then, the AGV 3 has the wafer W of the prober 2
Is reached, the tweezers 34 are driven in the AGV 3 to take out the wafers W in the carrier C one by one. However, as shown in FIG. 5, 25 steps of grooves C1 are formed in the inner surface of the carrier C, for example, in the vertical direction, and the wafers W are inserted into these grooves C1 and stored horizontally. Therefore, the wafer W is placed in the groove C1 in the carrier C.
After the wafer W is taken out of the carrier C using the tweezers 34, it is necessary to perform centering using, for example, an optical sensor. However, in the present embodiment, the centering of the wafer W is performed using the carrier C.

That is, as shown in FIG.
An inclined surface C2 whose side surface gradually narrows toward the rear surface is formed symmetrically on the rear surface of the carrier C. Therefore, the inclined surface C2 is used when centering the wafer W. For example, the tweezers 34 are driven as shown in FIG.
41 is inserted into the cassette C from below the predetermined wafer W. During this time, the tweezers 34WP slightly lifts and places the wafer W on the arm 341. Arm 3 in this state
41 is inserted further into the carrier C, the arm 34
While the wafer W moves to the back from the position shown by the broken line in FIG. At this time, since the left and right inclined surfaces C2 are symmetrical, the wafer W on the arm 341 is brought into contact with the left and right inclined surfaces C2 and automatically centered while the tweezers 341 pushes the wafer W into the carrier C. It can be performed. After centering, the vacuum suction mechanism 343 is driven to move the wafer W to the arm 3
At 41, it is held by suction. In this state, the arm 341 retreats from inside the carrier C, and takes out the wafer W from the carrier C. When the tweezers 34 takes out one wafer W from the carrier C as described above, the tweezers rotates 90 ° and delivers the wafer W to the adapter 23 of the prober 2.

When the tweezers 34 of the AGV 3 transfer the wafer W to / from the adapter 23 of the prober 2, as described above, the optical coupling PI between the prober 2 and the AGV 3 is used.
O communication is performed. Therefore, AGV3 and prober 2 each have a PIO communication interface,
The transfer of one wafer W is performed accurately using communication. Since the AGV 3 includes the tweezers 34 which have not existed conventionally, the signal line for controlling the vacuum suction mechanism 343 of the tweezers 34 and the signal for controlling the arm 341 in addition to the communication line defined by the conventional SEMI standard. Has a line.

The prober 2 is connected to the wafer W as described above.
One adapter (hereinafter, also referred to as a “load port” as necessary) 23 is provided as a load port for the transfer of the data. However, load port 23
In the case of one, the prober 2 cannot insert the next wafer W until the inspected wafer W is taken out,
There was a limit to throughput improvement. Therefore, in the present embodiment, as shown in FIG. 6, at least one virtual load port 23V is set in the prober 2 separately from an actual load port (hereinafter, referred to as an "actual load port") 23 by software. They are handled as if there are multiple load ports. That is, the AGV 3 performs the PIO communication via the software when performing the PIO communication using the optical signal L even when the inspected wafer W exists in the prober 2 as shown in FIG. The load port number of the signal line of the interface is switched, and a new wafer W can be loaded even if a wafer W exists in the prober 2.

When the virtual load port 23V is specified to the prober 2 via the PIO communication between the AGV 3 and the prober 2, the inspected wafer W is not returned to the actual load port 23, for example, the unload arm 241 or the unload A table (not shown) functions as a virtual load port 23V, which can hold the inspected wafer W, leave the adapter 23 open, and wait for the next wafer W. By providing the virtual load port 23V in this manner, the unload arm 241 and the unload table (not shown) can be fully utilized, the throughput can be improved, and the extra real load port can be achieved. It is not necessary to provide a device, and an increase in footprint and an increase in cost of the apparatus can be prevented.

By the way, the transport system E of this embodiment
Is the tweezers 3 of the AGV 3 as shown in FIGS.
PIO communication interface 1 for accurately transferring wafer W between prober 4 and adapter 23 of prober 2
1A and 11B. As shown in FIG. 7, each of these PIO communication interfaces 11A and 11B is composed of eight bits having eight ports, and signals shown in FIG. 7 are allocated to the first to eighth bits.

Therefore, A using PIO communication using the PIO communication interfaces 11A and 11B shown in FIG.
A method of transferring the wafer W between the GV 3 and the prober 2 will be described with reference to FIGS. 8 to 12
13 shows a method of loading a wafer W from the AGV 3 to the prober 3, FIG. 13 shows a flow of the wafer W in the prober 2, and FIGS. 14 to 16 show a method of unloading the wafer W from the prober 2 to the AGV 3.

First, the wafer W is transferred from the AGV 3 to the prober 2.
A method of loading a transferred wafer will be described. When the host computer 1 transmits a transfer command of the wafer W to the AGV controller 4 via the SECS communication, the AGV 3 moves to the front of the prober 2 (wafer transfer position) under the control of the AGV controller 4 as shown in the flowchart of FIG. Move (step S1). When the AGV 3 reaches the prober 2 as shown in FIG. 10A, the mapping sensor 33 detects the carrier C as shown in FIG.
Side, the tweezers 34 move up and down, and while the tweezers 34 move up and down, the accommodation state of the wafer W in the carrier C is mapped via the mapping sensor 33.
As shown in FIG. 10C, the upper arm 341A of the tweezers 34 advances and enters the carrier C from slightly below a predetermined wafer W. During this time, the centering of the wafer W is performed via the arm 341A and the carrier C as shown in the flowchart of FIG. 8 (step S2). That is, as shown in FIG.
The tweezers 34 rises slightly while the wafer W is placed on the arm 341A, and the arm 341A reaches the innermost portion as it is. During this time, arm 341
A performs centering of the wafer W by bringing the wafer W into contact with the symmetrical inclined surface C2 of the carrier C. Next, after the vacuum suction mechanism 343 (see FIGS. 3 and 4) of the tweezers 34 is driven to vacuum suction the wafer W with the arm 341A,
The arm 341A retreats from the carrier C and takes out the centered wafer W from the carrier C (step S).
2).

When the wafer W is taken out of the carrier C by the arm 341A, as shown in FIG. 10D, the sub chuck 35 moves up to receive the wafer W from the arm 341, and then while the sub chuck 25 rotates. The pre-alignment of the wafer W is performed via the pre-alignment sensor 36. Subsequently, as shown in FIG. 10E, the sub chuck 35 stops rotating and then descends to move the wafer W to the arm 3.
While returning to 41A, the tweezers 34 rise and the ID code attached to the wafer W is read by the OCR 37 to identify the lot of the wafer W. Then, as shown in FIG. Adapter 23 for prober 2
The direction of the arm 341 is adjusted to the state shown in FIG. The ID code of the wafer W identified by the OCR 37 is notified from the AGV 3 to the prober 2 by optical communication described later.

Next, as shown in FIG. 8 and FIG.
The optical coupling PIO communication between the prober 2 and the prober 2 is started. First,
As shown in FIGS. 8 and 9, the AGV 3 transmits a High-level CS_0 signal to the prober 2 and then transmits a High-level VALID signal. CS_0 signal is High
If valid in the h state, the VALID signal maintains the High state, and the adapter (load port) 23 of the prober 2 confirms the receivable state of the wafer W (step S).
3). When the prober 2 receives the VALID signal, as shown in FIG. 9, the L_REQ signal of the prober 2 changes to the high state, and the prober 2 transmits the L_REQ signal to the AGV 3 to instruct the AGV 3 to carry the wafer.

The AGV 3 determines whether an L_REQ signal has been received as shown in FIG. 8 (step S4),
When the prober 3 determines that the L_REQ signal has not been received, the prober 2 transmits the L_REQ signal to the AGV 3 (step S5). When the AGV 3 determines that the L_REQ signal has been received, the TR_REQ signal of the AGV 3 changes to the high state to start the transfer of the wafer W, and transmits the TR_REQ signal to the prober 3 (step S6).
Notifies the prober 2 that the transfer of the wafer W is started. When the prober 2 receives the TR_REQ signal as shown in FIG.
A READY signal is transmitted to the GV3 to notify the AGV3 that the load port 23 is accessible.

The AGV 3 determines whether a READY signal has been received from the prober 2 (step S7).
Determines that no READY signal has been received, the prober 2 transmits a READY signal to the AGV 3 (step S8). When the AGV 3 determines that the READY signal has been received, the BUSY signal goes high in the AGV 3 as shown in FIG. 9 and the signal is transmitted to the prober 3 (step S9), and the transfer of the wafer W to the prober 2 is performed. Notify to start.

Next, AGV3 is set to AE as shown in FIG.
It is determined whether an NB signal has been received (step S1).
0), when the AGV 3 determines that the AENB signal has not been received, the prober 2 sets the AENB signal to a high state as shown in FIG. 9 and starts transmission (step S1).
1). After the BUSY signal from the AGV3 is changed to the High state, the AENB signal is output from the adapter 23 during loading.
When the sub chuck 232 is at the lowered position and does not hold the wafer W, that is, when the wafer W can be loaded, the state becomes a high state. At the time of unloading, the sub chuck 232 is at the raised position and holds the wafer W. After confirming that the wafer W can be unloaded, the wafer W enters the High state. Further, the AENB signal is in a low state when the wafer W is detected by the vacuum suction sensor of the sub chuck 232 in the adapter 23 during loading and cannot be loaded. When the unloading cannot be performed, the wafer W is not detected.
ow state.

Thus, in step S10, AGV3
Determines that the AENB signal has been received in the high state, the transfer (loading) of the wafer W from the AGV 3 is started (step S11), and the upper arm 341A of the tweezers 34 is moved from the prober 2 to the state shown in FIG. , And transports the wafer W to a position directly above the load port 23 as shown in FIG.

Next, AGV3 sends PENB to prober 2.
After transmitting the signal (step S12), the wafer W is detected by the prober 2 and the AENB signal is in the low state and L_
It is determined whether or not the REQ signal is in the low state (step S13). When the prober 2 determines that the signals are in the high state, the sub chuck 232 is in the lowered position, there is no wafer W, and the access is possible, FIG. As shown in (c), the sub chuck 232 is raised and the vacuum suction mechanism 343 of the tweezers 34 releases the vacuum suction. P
The ENB signal turns off the vacuum suction mechanism 343 during loading
It becomes a High state when it makes it. Also, load port 2
The sub chuck 232 in 3 receives the wafer W by performing vacuum suction as shown in FIG. 9 (step S14). Subsequently, as shown in FIG. 9, the prober 2 changes the AENB signal to L level.
The signal is transmitted to the AGV 3 in the ow state to notify that the wafer W is held by the sub chuck 323 (step S15). At the same time, prober 2 has L_R
The EQ signal is set to a low state, and the signal is transmitted to the AGV 3 to notify that the signal is not low (step S16). Accordingly, the AGV 3 recognizes that the next wafer W is not currently loaded by the prober 2.

Thereafter, the flow returns to step S13, and the prober 2 detects the wafer W again to determine whether the AENB signal is in the low state and the L_REQ signal is in the low state, and all the signals are in the low state. When it is determined that the loading has been completed, the arm 341A is returned from the load port 23 to the AGV 3 (step S17). When the arm 341A returns, the AGV 3 sets the TR_REQ signal, the BUSY signal, and the PENB signal to the low state, transmits each signal to the prober 2, and notifies that the loading of the wafer W has been completed (step S18).

Next, as shown in FIG.
After the MPT signal is set to the high state and transmitted to the prober 2 to notify that the transfer operation of the wafer W is completed (step S19), the AGV 3 is switched from the prober 2 to the RE in the low state.
It is determined whether an ADY signal has been received (step S2).
0), if the AGV 3 determines that the READY signal has not been received, the prober 2 sends the READY signal to the Low state and transmits it to the AGV 3 as shown in FIG. S21). AGV
3 determines that the READY signal in the low state has been received, the AGV 3 outputs the CS_0 signal and the VA signal as shown in FIG.
The LID signal is set to the low state, and the respective signals are transmitted to the prober 3 (step S22), the transfer operation of the wafer W is completed, and the tweezers 34 are rotated 90 ° in the reverse direction as shown in FIG. Then, after waiting for an instruction from the host computer 1, the system enters into a delivery state of the next wafer W.

In the prober 2, as shown in FIG. 11 (e), the sub chuck 232 which has received the wafer W in the adapter 23 once descends to perform centering of the wafer W in the adapter 23. As shown in (f), the adapter 23 is lowered to the position where the wafer W is transferred to the tweezers 24, and the sub chuck 232 is raised to rise above the adapter main body 231. In this state, the upper arm 241A of the tweezers 24 advances to the adapter 23 side as shown in FIG. 9G, the sub chuck 231 of the adapter 23 descends, and the arm 241A vacuum-adsorbs and receives the wafer W.

When the wafer W is received by the arm 241A,
The arm 241 is oriented toward the main chuck 26 in the prober chamber 22 as shown in FIG. After that, similarly to the conventional prober, the tweezers 24 and the sub chuck 25 cooperate with each other as shown in FIG.
After performing the pre-alignment, the wafer W is delivered to the main chuck 26 as shown in FIG. Furthermore,
After the alignment is performed via the alignment mechanism 27 as shown in FIG. 4D, the wafer W and the probe 28A of the probe card 28 are moved while the main chuck 26 is being indexed as shown in FIG. The electrical characteristics of the wafer W are inspected by making electrical contact with the wafer W. In FIG. 12B and FIG. 12C, reference numeral 26A denotes an elevating pin for the wafer W.

The above-described AGV 3, which has finished transferring the wafer W while the prober 2 having received the wafer W is performing the inspection, transfers the wafer W of the same lot to another plurality of probers 2 under the control of the host computer 1. According to the request of
After transferring the wafer W to and from the other plurality of probers 2 in the manner described above, the same inspection can be performed in parallel at the prober 2.

When the inspection of the electrical characteristics of the wafer W by the prober 2 is completed, the elevating pins 26A of the main chuck 26 move up to lift the wafer W from the main chuck 26 as shown in FIG. (B) of FIG.
After the lower arm 241B of the tweezers 24 advances to the main chuck 26 to receive the wafer W as shown in FIG. 12, the tweezers 24 are rotated by 90 ° as shown in FIG. When the tweezers 24 advance to the adapter 23 as shown in FIG.
The sub chuck 232 in the adapter 23 rises and receives the wafer W from the arm 241B as shown in FIG. Thereafter, the AGV 3 moves before the prober 2 under the control of the AGV controller 4 as shown in FIG. When AGV3 confronts prober 2, adapter 2
3 rises from the position shown by the two-dot chain line to the solid line position for transferring the wafer W as shown in FIG.

Next, a method of unloading a wafer for transferring the wafer W from the prober 2 to the AGV 3 will be described with reference to FIGS. As shown in FIGS. 14 and 15, when the AGV 3 moves in front of the predetermined prober 2 based on an instruction from the AGV controller 4, (Step 3)
1), PIO communication between the AGV 3 and the prober 2 is started. After transmitting the CS_0 signal to the prober 2, the AGV 3 transmits a VALID signal (step S3).
2). When the prober 2 receives the VALID signal,
As shown in (2), the U_REQ signal of the prober 2 changes to the high state, and the U_REQ signal is transmitted to the AGV 3 to instruct transfer to unload the wafer W.

AGV3 is U_REQ as shown in FIG.
It is determined whether a signal has been received (step S33).
When determining that the GV3 has not received the U_REQ signal, the prober 2 transmits a U_REQ signal to the AGV3 (step S34). Accordingly, when the AGV 3 determines that the U_REQ signal has been received in step S33,
AGV3 sets TR_RE to start transfer of wafer W.
The Q signal is set to the High state, and the signal is transmitted to the prober 3 (step S35).
Is notified to start transporting.

Next, AGV3 receives REA from prober 2.
It is determined whether a DY signal has been received (step S3).
6) If the AGV3 determines that the READY signal has not been received, the prober 2 sends the READY signal to the AGV3 at H level.
The transmission is made in the high state (step S37). AGV
3 receives the READY signal and determines that access to the prober 2 is possible, and as shown in FIG.
The USY signal is set to the High state and the signal is transmitted to the prober 3 (step S38), and the transfer of the wafer W to the prober 2 is started.

Next, the AGV 3 determines whether or not the high state of the AENB signal has been received from the prober 2 as shown in FIG. 14 (step S39).
When judging that no signal has been received, the prober 2 sets the AENB signal to a high state and transmits it, as shown in FIG. (Step S40). In step S39, A
When the GV 3 receives the high-level AENB signal, detects the wafer W in the prober 2 and determines that the sub-chuck 232 in the load port 23 can be unloaded in the raised state, the transfer of the wafer W from the AGV 3 is started. As shown in FIG. 16A, the lower arm 341B of the tweezers 34 is moved to just above the adapter 23 of the prober 2 (step S41).

Next, after the AGV 3 turns on the vacuum suction mechanism 343 and transmits a high-state PENB signal to the prober 2 (step S42), the prober 2 detects that there is no wafer W, and outputs an AENB signal from the prober 2. Low
It is determined whether the U_REQ signal is in the low state and the U_REQ signal is in the low state (step S43). When the prober 2 determines that all the signals are in the high state and the sub chuck 232 is in the accessible state, FIG. As shown, after the adapter 23 is raised and the sub chuck 232 is lowered, the wafer W is held by the lower arm 341B of the tweezers 34.
And the wafer W is delivered from the adapter 23 to the tweezers 34 (step S44). When the prober 2 detects that the wafer W has been removed, the prober 2 sets the U_REQ signal to a low state as shown in FIG.
3 to notify the AGV 3 that the wafer W has been removed (step S45). Subsequently, the prober 2 sets the AENB signal to the low state and transmits the signal to the AGV 3 to notify the adapter 23 that there is no wafer W (step S4).
6).

Thereafter, the flow returns to step S43, where the prober 2 detects that there is no wafer W in the adapter 23 and executes AE.
When it is determined whether the NB signal is in the low state and the U_REQ signal is in the low state, and when it is determined that the unloading of the wafer W by the adapter 23 is completed in any of the low states, the arm 341B is connected to the load port 23. From AG
Return to V3 (step S47). AGV3 is arm 34
When 1B returns, TR_REQ signal, BUSY signal, PEN
After the B signals are all set to the Low state and the respective signals are transmitted to the prober 2 to notify the prober 2 that the unloading operation has been completed (step S48), the AGV 3 changes the COMPT signal to High as shown in FIG. The state is transmitted to the prober 2 to notify the completion of the unloading operation (step S49).

Next, AGV3 is transferred from prober 2 to Low.
It is determined whether the READY signal in the state has been received (step S50), and if the AGV 3 determines that the READY signal has not been received, as shown in FIG.
The EADY signal is transmitted in a low state (step S5).
1). When the AGV 3 determines that the READY signal in the Low state has been received, the AGV 3 performs the CS operation as shown in FIG.
The _0 signal and the VALID signal are set to the low state, and the respective signals are transmitted to the prober 3 (step S52), the transfer of the wafer W is completed, and the tweezers 34 are turned 90 ° in the reverse direction as shown in FIG. After rotation, Figure 1
As shown in FIG. 6 (c), the sub chuck 35 moves up to receive the wafer W from the arm 341B, and the pre-alignment sensor 36 detects the orientation flat. Subsequently, as shown in (d) of the figure, the sub chuck 35 descends to return the wafer W to the arm 341B, and the tweezers 34 rises to read the ID code of the wafer W by the OCR 37. The arm 341B is stored in the original place in the carrier C as shown in FIG.

As described above, according to the present embodiment,
An arm 341 for holding the wafer W by suction;
41, an exhaust path 341C that opens at the suction surface of the wafer W, and a vacuum suction mechanism 343 connected to the exhaust path 341C via a pipe 344A. The vacuum suction mechanism 343 is a mounted battery. A compressor 344 to be driven; an air tank 345 for storing gas compressed from the compressor 344 as compressed gas; a gas pressure adjusting mechanism 346 for adjusting the pressure of compressed gas flowing out of the air tank 345; Ejector 347A for ejecting pressurized gas supplied from mechanism 346
After the air pressure-fed from the compressor 344 driven by the battery mounted on the AGV 3 is stored as compressed air in the air tank 345, the pressure of the compressed air is adjusted via the gas pressure adjusting mechanism 346. The arm 341 is ejected from the ejector 347A.
The wafer W can be reliably sucked by vacuum.

Also, according to the present embodiment, since the upper and lower arms 341A and 341B are provided, the upper arm 3
41A can be used exclusively for loading the wafer, and the lower arm 341B can be used exclusively for unloading the wafer, so that the transfer capability of the wafer W can be increased. The gas pressure adjusting mechanism 346 and the ejector 347
Since the switching valve 347 that opens and closes the pipe 344A is provided between A, the vacuum suction mechanism 343 can be reliably turned on and off via the switching valve 347. Since the check valve with pilot 348 for opening and closing the pipe 344A is provided between the arm 341 and the ejector 347A, the vacuum holding and release of the vacuum of the wafer W can be reliably controlled via the check valve with pilot 348. Since the pressure sensor 349 for detecting the pressure in the exhaust path 341C is provided between the arm 341 and the check valve 348 with the pilot, the degree of vacuum in the exhaust path 341C is detected via the pressure sensor 349 and the wafer on the arm 341 is detected. You can know the holding status of W,
Moreover, based on the detected value, the compressor 344 is turned ON and O
FF control can be performed.

It should be noted that the present invention is not limited to the above embodiment at all, and the design can be appropriately changed as needed. For example, the valves used in the air circuit of the vacuum suction mechanism 343 can be changed as needed. The gist of the present invention is characterized in that the compressor 344 uses the compressor 344 to store compressed air in the air tank 345 to secure the flow rate of air or the like, because of the insufficient flow rate of the vacuum suction mechanism 343 used for vacuum suction.

[0060]

According to the first to eighth aspects of the present invention, a sufficient exhaust gas flow rate can be secured even with a low-capacity power source mounted on a moving body, and the object to be processed can be reliably mounted. A vacuum holding device for an object to be processed which can be vacuum-sucked can be provided.

[Brief description of the drawings]

FIG. 1A is a conceptual diagram illustrating an embodiment of a vacuum holding device for a workpiece according to the present invention, and FIG. 1B is a conceptual diagram illustrating a configuration of an AGV.

2A is a plan view conceptually showing a state of transferring a wafer between a prober and an AGV, and FIG. 2B is a cross-sectional view showing a main part of FIG.

FIG. 3 is a conceptual diagram showing a vacuum suction mechanism of tweezers used in an AGV.

FIG. 4 is a circuit diagram showing a vacuum suction mechanism shown in FIG.

FIG. 5 is an explanatory diagram for explaining a wafer centering method using a carrier.

FIG. 6 is an explanatory diagram for explaining transfer of a wafer when a virtual load port is set in a prober.

FIGS. 7 (a) and 7 (b) are configuration diagrams each showing an interface used for PIO communication of the transport system shown in FIG. 1;

8 is a flowchart showing a wafer loading method applied to the wafer transport method using the transport system shown in FIG.

9 is a timing chart of optical communication applied to the loading method shown in FIG.

FIGS. 10A to 10F are process diagrams showing a loading process corresponding to the flowchart shown in FIG. 8;

FIGS. 11A to 11G are process diagrams showing a loading process corresponding to the flowchart shown in FIG. 8;

FIGS. 12A to 12E are process diagrams showing a flow of a wafer in a prober.

FIGS. 13A to 13F are process diagrams showing a loading process corresponding to the flowchart shown in FIG. 8;

FIG. 14 is a flowchart showing a wafer unloading method in the wafer transfer method using the transfer system shown in FIG. 1;

15 is a timing chart of optical communication applied to the unloading method shown in FIG.

16 (a) to (e) are process diagrams showing an unloading process corresponding to the flowchart shown in FIG.

[Explanation of symbols]

 38 Vacuum holding device 341 Arm 343 Vacuum suction mechanism 344 Compressor 344A Pipe (communication pipe) 345 Air tank (container) 346 Gas pressure adjusting mechanism (Gas pressure adjusting means) 346C Pressure gauge (Third pressure detecting means) 347 Switching valve (first on-off valve) 347A Ejector (ejection unit) 348 Check valve with pilot (second on-off valve) 349 Pressure sensor (pressure detection unit) 349A First pressure switch (first pressure detection unit) 349B Second pressure switch (second pressure detecting means) W Wafer (object to be processed)

Continued on front page F-term (reference) JA15 JA23 JA34 JA47 JA50 KA02 KA06 KA07 KA08 KA10 KA11 KA13 MA33 PA02

Claims (8)

[Claims] 1. An arm for adsorbing and holding an object to be processed, an exhaust passage formed in the arm and opening at an adsorption surface of the arm, and a vacuum adsorption mechanism connected to the exhaust passage via a communication pipe. A vacuum holding device for a workpiece to be mounted and used on a moving body, wherein the vacuum suction mechanism includes a compressor driven by a mounted power supply, and a container for storing gas compressed from the compressor as a compressed gas. Gas pressure adjusting means for adjusting the pressure of the compressed gas flowing out of the container, and means for reducing the pressure in the exhaust path by ejecting the pressure gas supplied from the gas pressure adjusting means. A vacuum holding device for an object to be processed. 2. The apparatus according to claim 1, wherein the moving body is an automatic carrier. 3. The apparatus according to claim 1, wherein the plurality of arms are provided. 4. The apparatus according to claim 1, wherein a first on-off valve for opening and closing the communication pipe is provided between the gas pressure adjusting means and the jetting means. Vacuum holding device for the object to be processed. 5. The processing target according to claim 1, wherein a second on-off valve for opening and closing the communication pipe is provided between the arm and the jetting means. Body vacuum holding device. 6. The apparatus according to claim 5, further comprising pressure means for detecting a pressure in the exhaust passage between the arm and the second on-off valve. 7. The first pressure means for detecting the presence or absence of the object to be processed on the arm,
2. The apparatus according to claim 1, further comprising a second pressure detecting means for detecting a pressure leak in the exhaust passage, wherein the second on-off valve opens and closes based on a detection result of the second pressure detecting means. 7. The vacuum holding device for a workpiece according to 6. 8. A third pressure detecting means for detecting a pressure in the communication pipe is provided between the gas pressure adjusting means and the jetting means, and the compressor is controlled based on a detection result of the third pressure detecting means. 2. The method according to claim 1, wherein the driving is performed.
A vacuum holding device for a workpiece according to any one of claims 1 to 7.