Laser marking station with enclosure and method of operation

• US 6,262,388 B1
• Filed: 12/21/1998
• Issued: 07/17/2001
• Est. Priority Date: 12/21/1998
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micro Electronics Incorporated
• Inventors: Canella, Robert L., Ibarra, Tony T.
• Primary Examiner(s): Evans, Geoffrey S
• Application Number:
  US09/217,039
• Time in Patent Office: 939 Days
• Field of Search: 219/121.82, 219/121.86, 219/121.68, 219/121.69, 219/121.6, 219/121.83
• US Class Current: 219/121.68
• CPC Class Codes: B23K 2101/007 Marks, e.g. trade marks
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/0342 Observing magnetic fields related to the workpiece
• CPC Class Codes: B23K 26/0838 by using an endless conveyor belt
• CPC Class Codes: B23K 26/12 in a special atmosphere, e.g. in an enclosure
• CPC Class Codes: B23K 26/127 in an enclosure
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A laser marking station housing a laser marking head within a walled, substantially bottomless enclosure defining an opening into which a tray carrier bearing a tray of IC packages to be marked may be raised to place the tray at correct laser focal length and effect complete (laser) light containment within the enclosure using the tray carrier to effect closure of the opening. A lift mechanism for raising the tray carrier into the enclosure is also disclosed.

Claims

1. A laser marking station, comprising:

a substantially bottomless enclosure;

a transport actuator located at least in part below the substantially bottomless enclosure and configured to position a tray transport underneath a downward facing opening into the substantially bottomless enclosure; and

at least one laser marking head housed within the substantially bottomless enclosure.

2. The apparatus of claim 1, further including:

a vertically extendable and retractable lift mechanism located under the laser marking station; and

a tray carrier disposed on the tray transport;

wherein the tray transport is configured and positioned to align the tray carrier with the lift mechanism.

3. The apparatus of claim 2, wherein the lift mechanism is configured to engage and vertically move the tray carrier when located on the tray transport under the laser marking station without contacting the tray transport.

4. The apparatus of claim 3, wherein the lift mechanism includes a horizontally movable drive wedge element having an inclined upper surface and a horizontally constrained slave wedge element having an inclined lower surface of like angle of inclination to the inclined upper surface.

5. The apparatus of claim 4, further including a lift structure secured to the slave wedge element and extending upwardly therefrom.

6. The apparatus of claim 5, wherein the lift structure further includes two substantially parallel side plates laterally spaced a greater distance than a width of the tray transport.

7. The apparatus of claim 6, wherein the tray carrier is substantially sized and shaped to correspond to the downward facing opening into the substantially bottomless enclosure of the laser marking station so as to provide a substantially light-safe closure for the downward facing opening when inserted thereinto.

8. The apparatus of claim 7, wherein the tray carrier includes a portion of reduced width defined by mutually longitudinally coextensive elongated notches in parallel sides thereof, and the substantially parallel side plates include extensions thereon configured to engage the tray carrier at said portion of reduced width, the extensions being sized to substantially prevent light leakage from the substantially bottomless enclosure in a vicinity of the reduced width portion of the tray carrier.

9. The apparatus of claim 8, further including at least one sensor associated with the substantially bottomless enclosure for confirming presence of the tray carrier within the substantially bottomless enclosure in a position effecting the substantially light-safe closure of the downward facing opening therein.

10. The apparatus of claim 9, wherein the at least one sensor is responsive to a magnetic element located on the tray carrier.

11. The apparatus of claim 5, wherein the tray carrier is substantially sized and shaped to correspond to the downward facing opening into the substantially bottomless enclosure of the laser marking station so as to provide a substantially light-safe closure for the downward facing opening when inserted thereinto.

12. The apparatus of claim 4, wherein the slave wedge element is horizontally constrained by a bearing assembly permitting substantially only vertical movement of the slave wedge element.

13. The apparatus of claim 11, wherein the drive wedge element is horizontally movable by an associated dual-action drive mechanism.

14. The apparatus of claim 13, wherein the associated dual-action drive mechanism comprises a dual-action air cylinder.

15. The apparatus of claim 14, wherein the dual-action air cylinder comprises a drive block to which the drive wedge element is mounted, the drive block being slidable on at least one guide shaft.

16. The apparatus of claim 2, wherein the tray carrier is substantially rectangular and includes a substantially planar upper surface having upwardly extending stops at each corner thereof.

17. The apparatus of claim 16, wherein the tray carrier includes a portion of reduced width defined by mutually longitudinally coextensive elongated notches in parallel sides thereof and wherein the lift mechanism includes elements sized and configured to fill the notches.

18. The apparatus of claim 2, wherein the tray carrier is disposed on the tray transport without securement thereto.

19. The apparatus of claim 18, wherein an upper surface of the tray transport and a lower surface of the tray carrier include mutually cooperative physical structures.

20. The apparatus of claim 19, wherein the mutually cooperative physical structures are adapted to align the tray carrier on the tray transport when the tray carrier is disposed thereon.

21. The apparatus of claim 20, wherein the mutually cooperative physical structures comprise a plurality of substantially hemispherical protrusions on one of the tray transport and the tray carrier, and a plurality of substantially hemispherical recesses located and sized to receive at least portions of the plurality of substantially hemispherical protrusions on the other of the tray transport and the tray carrier.

22. The apparatus of claim 21, wherein the substantially hemispherical protrusions extend upwardly from the upper surface of the tray transport and the substantially hemispherical recesses extend into the lower surface of the tray carrier.

23. The apparatus of claim 20, wherein the tray transport is of lesser longitudinal extent than the tray carrier.

24. The apparatus of claim 1, wherein the at least one laser marking head comprises at least two adjacent laser marking heads.

25. The apparatus of claim 1, further including at least one inspection camera located adjacent the substantially bottomless enclosure.

26. The apparatus of claim 25, wherein the at least one inspection camera comprises two inspection cameras adjacent opposing sides of the substantially bottomless enclosure.

27. The apparatus of claim 1, further including a member sized and configured to effect closure of the substantially bottomless enclosure when raised vertically into the downward facing opening.

28. The apparatus of claim 27, wherein the member comprises a carrier disposed on the tray transport adapted to bear a tray in which a plurality of IC packages is disposed.

29. A method of operating a laser marking station, comprising:

providing a substantially bottomless enclosure having at least one laser marking head disposed therein;

providing a carrier on which a tray having a plurality of IC packages therein is disposed;

disposing the carrier below the substantially bottomless enclosure; and

raising the carrier at least partially into the substantially bottomless enclosure.

30. The method of claim 29, further comprising confirming a presence of the carrier within the substantially bottomless enclosure, and activating the at least one laser marking head to mark the plurality of IC packages in the tray at least partially responsive to the carrier presence confirmation.

31. The method of claim 30, further including inspecting at least one IC package marked at an end of a traversal of the at least one laser marking head in marking the plurality of IC packages in the tray.

32. The method of claim 29, further including substantially concurrently marking the IC packages in two portions of the tray.

33. The method of claim 29, further comprising raising the carrier at least partially into the substantially bottomless enclosure to effect a substantially light-safe closure thereof.