Method of efficiently laser marking singulated semiconductor devices

• US 6,580,957 B2
• Filed: 11/15/1999
• Issued: 06/17/2003
• Est. Priority Date: 01/24/1996
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Canella, Robert L.
• Primary Examiner(s): Voeltz, Emanuel Todd
• Assistant Examiner(s): GAIN, EDWARD F
• Application Number:
  US09/440,820
• Publication Number:
  US 20020107603A1
• Time in Patent Office: 1,310 Days
• Field of Search: 700/121, 700/110, 700/109, 438/15, 438/14
• US Class Current: 700/121
• CPC Class Codes: B23K 26/0838 by using an endless conveyor belt
• CPC Class Codes: G06K 1/126 by photographic or thermographic registration recording apparatus for measuring instruments G01D15/00
• CPC Class Codes: H01L 21/67282 Marking devices
• CPC Class Codes: H01L 2223/54473 for use after dicing
• 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 apparatus and method for marking the surface of a singulated article such as a semiconductor chip are described herein. Semiconductor chips are fed along inclined, parallel tracks to a laser marking field where they are subsequently marked by a laser beam. As the laser beam is marking chips associated with one track, chips associated with other tracks that have already been marked are replaced by unmarked chips. In this manner, the laser is continually being used to mark semiconductor chips without having to wait for unmarked chips to move to the marking location.

Claims

1. A method of producing semiconductor chips wherein the semiconductor chips are fabricated, packaged and characterized, comprising:

characterizing semiconductor chips as suitable for use or not suitable for use; and

marking with identifying indicia only those semiconductor chips which are characterized as suitable for use, by;

positioning at least a first semiconductor chip characterized as suitable for use at a first marking location;

marking the at least a first semiconductor chip characterized as suitable for use at the first marking location while positioning at least a second semiconductor chip characterized as suitable for use at a second marking location; and

marking the at least a second semiconductor chip characterized as suitable for use at the second marking location while removing the at least a first semiconductor chip characterized as suitable for use from the first marking location and positioning at least a third semiconductor chip characterized as suitable for use at the first marking location.

2. The method of claim 1, further comprising marking the chips characterized as suitable for use as the last step in the production process.

3. The method of claim 2, wherein the marking comprises laser marking.

4. The method of claim 2, wherein the marking comprises application of indelible identifying indicia.

5. A method of producing semiconductor chips, the method comprising:

fabricating a plurality of semiconductor chips;

individually packaging the semiconductor chips;

determining whether the individually packaged semiconductor chips are suitable for use;

marking only individually packaged semiconductor chips of the plurality of individually packaged semiconductor chips determined to be suitable for use with identifying indicia by;

positioning at least a first individually packaged semiconductor chip determined to be suitable for use at a first marking location;

marking the first individually packaged semiconductor chip determined to be suitable for use at the first marking location while positioning at least an individually packaged second semiconductor chip determined to be suitable for use at a second marking location; and

marking the at least an individually packaged second semiconductor chip determined to be suitable for use at the second marking location while removing the at least a first individually packaged semiconductor chip determined to be suitable for use from the first marking location and positioning at least a third individually packaged semiconductor chip determined to be suitable for use at the first marking location.

6. The method of claim 5, further comprising marking the individually packaged semiconductor chips determined to be suitable for use as the last step in the production process.

7. The method of claim 5, wherein the marking comprises laser marking.

8. The method of claim 5, wherein the marking comprises application of indelible identifying indicia.

9. A method of producing semiconductor chips, the method comprising:

providing a plurality of packaged semiconductor chips which have been characterized as suitable for use, and at least one packaged semiconductor chip which has been characterized as unsuitable for use;

marking with identifying indicia only the plurality of packaged semiconductor chips which have been characterized as suitable for use by;

positioning at least a first packaged semiconductor chip characterized as suitable for use at a first marking location;

marking the at least a first packaged semiconductor chip characterized as suitable for use at the first marking location while positioning at least a second packaged semiconductor chip characterized as suitable for use at a second marking location; and

marking the at least a second packaged semiconductor chip characterized as suitable for use at the second marking location while removing the at least a first packaged semiconductor chip characterized as suitable for use from the first marking location and positioning at least a third packaged semiconductor chip characterized as suitable for use at the first marking location.

10. The method of claim 9, further comprising marking the plurality of packaged semiconductor chips which have been characterized as suitable for use as the last step in the production process.

11. The method of claim 9, wherein the marking comprises laser marking.

12. The method of claim 9, wherein the marking comprises application of indelible identifying indicia.

13. The method of claim 9, further comprising comparing the identifying indicia to an acceptable identifying indicia model.

14. The method of claim 13, further comprising determining whether the identifying indicia substantially matches the acceptable identifying indicia model.

15. The method of claim 14, further comprising rejecting any packaged semiconductor chip subsequent to marking thereof with identifying indicia if its respective identifying indicia does not substantially match the identifying indicia model.