Substrate detecting method and device

• US 6,642,533 B2
• Filed: 01/24/2001
• Issued: 11/04/2003
• Est. Priority Date: 01/25/2000
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamamoto, Shigeyuki, Haraguchi, Hideo, Matsuda, Izuru
• Primary Examiner(s): Glick, Edward J.
• Assistant Examiner(s): SONG, HOON K
• Application Number:
  US09/768,065
• Publication Number:
  US 20010009641A1
• Time in Patent Office: 1,014 Days
• Field of Search: 250/559.33, 250/234, 250/551, 250/559.29, 250/559.36, 414/937, 414/936, 414/416.03, 414/217
• US Class Current: 250/559.33
• CPC Class Codes: H01L 21/67265 of substrates stored in a container, a magazine, a carrier, a boat or the like
• CPC Class Codes: H01L 21/67772 involving removal of lid, door, cover
• CPC Class Codes: Y10S 414/136 including wafer orienting means
• CPC Class Codes: Y10S 414/137 including means for charging or discharging wafer cassette

Abstract

A substrate detection sensor is operatively connected to a door moving mechanism for opening/closing a front door with respect to a sealed container accommodating therein a plurality of substrates. The substrate detection sensor enters the sealed container and detects the substrates successively as it is lowered integrally with the front door, and retracts from the sealed container when all of the substrates have been detected.

Claims

1. A substrate detector installed in a sealed container for storing therein and transferring a plurality of substrates, said substrate detector being operatively connected to a door fixing unit for moving a front door of the sealed container in directions to and from the sealed container and in vertical directions so as to open the sealed container and to close the sealed container with the front door, comprising:

a support arm mounted on the door fixing unit;

a sensor mounted at a distal end of the support arm;

a rotation transmitting member mounted rotatably at an upper end of the door fixing unit for supporting a base end of the support arm and for transmitting rotation thereof to the support arm; and

a linkage connected to the rotation transmitting member for rotating the rotation transmitting member at a predetermined angle, said rotation of the rotary transmitting member at the predetermined angle causing the support arm to be inserted into the sealed container and to be located in a predetermined position with respect to the substrates within the sealed container.

2. The substrate detector according to claim 1, wherein the sensor comprises a light transmission unit and a light receiving unit, and the support arm is provided in a pair, with said light transmission unit and said light receiving unit being mounted at respective distal ends of the pair of support arms.

3. The substrate detector according to claim 2, wherein the rotation transmitting member is a pair of spur gears in mutual engagement for synchronous rotation, said pair of spur gears respectively supporting the base ends of each one of said pair of support arms, so that when rotation is transmitted to the pair of spur gears, the pair of support arms are rotated by the synchronous rotation of the spur gears and inserted into the sealed container and located on both sides of the substrates.

4. The substrate detector according to claim 3, wherein the pair of support arms are respectively provided with a biasing member for providing a torque in a direction in which said support arms are accommodated within a recess formed in the door fixing unit.

5. The substrate detector according to claim 1, wherein the linkage comprises a rotary shaft coaxially connected to said rotation transmitting member, a cam member connected to said rotary shaft and rotatably supported on the door fixing unit, a cam groove of predetermined configuration formed in said cam member, and a cam follower for engagement with said cam groove of the cam member, wherein said rotation transmitting member is rotated at said predetermined angle by the engagement of said cam follower with the cam groove of the cam member.

6. The substrate detector according to claim 1, wherein said linkage comprises a rotary shaft coaxially connected to said rotation transmitting member, a cylindrical cam coaxially connected at an upper end thereof to said rotary shaft and rotatably supported at a lower end thereof on the door fixing unit, a cam groove formed on a circumferential surface of said cylindrical cam, and a cam follower located at a position where it engages with said cam groove when the cylindrical cam is lowered integrally with the door fixing unit.

7. The substrate detector according to claim 6, wherein said cam follower is mounted on an actuator which causes the cam follower to move forward and backward so as to engage with and disengage from the cam groove of the cylindrical cam.

8. The substrate detector according to claim 6, wherein said cam groove is formed so as to rotate said cylindrical cam in a forward direction at an angle for causing said sensor at the distal end of the support arm to be positioned on both sides of the substrates within the sealed container at a time point immediately after the door fixing unit has started lowering, and to rotate said cylindrical cam in a reverse direction at same angle at a time point when all of the substrates within the sealed container have been detected by said sensor.

9. The substrate detector according to claim 6, wherein said cam groove of the cylindrical cam comprises a first cam groove formed so as to rotate said cylindrical cam in a forward direction at an angle for causing said sensor at the distal end of the support arm to be positioned on both sides of the substrates within the sealed container at a time point immediately after the door fixing unit has started lowering, and to rotate said cylindrical cam in a reverse direction at same angle at a time point when all of the substrates within the sealed container have been detected by said sensor, and a second cam groove formed linearly so as not to rotate the cylindrical cam during the door fixing unit is lifted.

10. The substrate detector according to claim 9, wherein said first cam groove and said second cam groove are joined at two locations, with restriction plates being rotatably mounted and biased in one direction at said two joint locations so as to switchably change the cam grooves with which the cam follower engages.

11. The substrate detector according to claim 10, wherein said restriction plates switch the cam grooves such that the cam follower tracks the first cam groove during the door fixing unit is lowered and that the cam follower tracks the second cam groove during the door fixing unit is lifted.

12. A method of detecting substrates accommodated within a sealed container having a removable front door, comprising:

positioning the sealed container with respect to a door moving mechanism for opening and closing the front door;

releasing a lock between the front door and the sealed container and moving the front door a fixed distance in a backward direction with respect to the sealed container by the door moving mechanism;

moving the front door in a direction orthogonal to said backward direction with respect to the sealed container by the door moving mechanism;

inserting a sensor into the sealed container and positioning the sensor at a location where the sensor is capable of detecting the substrates within the sealed container at a time point when the front door has been moved a predetermined distance away from the sealed container;

detecting the presence and position of each of the substrates with the sensor successively as the front door is moved away from the sealed container; and

retracting the sensor out of the sealed container when all of the substrates within the sealed container have been detected by the sensor, and

wherein the sensor is operatively connected to the door moving mechanism so that the sensor is inserted into and retracted out of the sealed container with a same drive source for driving the door moving mechanism for opening and closing the front door.

13. A method of detecting substrates accommodated within a sealed container having a removable front door, comprising:

positioning the sealed container with respect to a door moving mechanism for opening and closing the front door;

releasing a lock between the front door and the sealed container and moving the front door a fixed distance in a backward direction with respect to the sealed container by the door moving mechanism;

moving the front door in a direction orthogonal to said backward direction with respect to the sealed container by the door moving mechanism;

inserting a sensor into the sealed container and positioning the sensor at a location where the sensor is capable of detecting the substrates within the sealed container at a time point when the front door has been moved a predetermined distance away from the sealed container;

detecting the presence and position of each of the substrates with the sensor successively as the front door is moved away from the sealed container; and

retracting the sensor out of the sealed container when all of the substrates within the sealed container have been detected by the sensor, and

wherein the sensor is operatively connected to the door moving mechanism through a cam member having a cam groove of predetermined configuration and a cam follower that tracks said cam groove, one of said cam member and the cam follower being movable integrally with the door moving mechanism and the other being stationary.

14. A sealed container for storing therein and transferring a plurality of substrates, comprising:

a container housing;

a removable front door;

a door moving mechanism including a door fixing unit for fixedly holding the front door, a lifting block operatively connected to the door fixing unit for moving the door fixing unit upward and downward so as to open the container housing and to close the container housing with the front door;

a pair of gear wheels rotatably supported in mutual engagement for synchronous rotation and accommodated within a recess in the door fixing unit at a position near an upper end thereof;

a pair of support arms attached to said pair of gear wheels respectively at base ends thereof;

a sensor comprising a light transmission unit and a light receiving unit which are respectively mounted at distal ends of the pair of support arms;

a cam member rotatably mounted on said door fixing unit and connected to one of said pair of gear wheels such as to transmit rotation thereto;

a cam groove formed in said cam member; and

a cam follower mounted on a stationary part of the door moving mechanism at a position where it engages with said cam groove when the cam member is lowered integrally with the door fixing unit.

15. The sealed container according to claim 14, wherein the engagement between said cam follower and said cam groove causes rotation of said gear wheels, whereby the support arms are rotated into the sealed container and located on both sides of an uppermost substrate within the sealed container.

16. The sealed container according to claim 14, wherein the cam follower is attached on an actuator mounted on the stationary part of the door moving mechanism so that the cam follower is advanced forward to engage with the cam groove and retracted backward to disengage therefrom.

17. The sealed container according to claim 14, wherein the cam groove comprises a curved first track and a linear second track, the cam follower being engaged with said first track when the cam member is lowered integrally with the door fixing unit, and engaged with said second track when the cam member is lifted integrally with the door fixing unit.