Laser ablation for die separation to reduce laser splash and electronic device

Patent metadata

Field	Value
Publication number	US-12512416-B2
Application number	US-202217826764-A
Country	US
Kind code	B2
Filing date	May 27, 2022
Priority date	May 27, 2022
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

A method includes performing a laser ablation process that removes a portion of a wafer to form a trench in a scribe region between adjacent die regions of the wafer, the trench extending from a first side of the wafer toward an opposite second side of the wafer, the trench extending through a metallization structure and an active circuit portion of the wafer, and a bottom of the trench spaced apart from the second side of the wafer. The method also includes performing a wafer expansion process that separates individual semiconductor dies from the wafer after the laser ablation process.

First claim

What is claimed is:

1 . A method of fabricating an electronic device, the method comprising:
performing a laser ablation process that removes a portion of a wafer to form a trench in a scribe region between adjacent die regions of the wafer, the trench extending from a first side of the wafer toward an opposite second side of the wafer, the trench extending through a metallization structure and an active circuit portion of the wafer, and a bottom of the trench spaced apart from the second side of the wafer; after the laser ablation process, performing a wafer probe test that tests circuitry of the active circuit portion of the wafer; after the wafer probe test, performing a wafer expansion process that separates individual semiconductor dies from the wafer; and packaging one of the semiconductor dies in a package structure to form an electronic device.

2 . The method of claim 1 , further comprising, after the wafer probe test and before the wafer expansion process, performing a grinding process on the second side of the wafer.

3 . The method of claim 2 , wherein the laser ablation process is a multi-pass process that uses multiple passes of an ablation laser to successively increase the depth of the trench and/or a lateral width of the trench.

4 . The method of claim 3 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

5 . The method of claim 2 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

6 . The method of claim 1 , wherein the laser ablation process is a multi-pass process that uses multiple passes of an ablation laser to successively increase the depth of the trench and/or a lateral width of the trench.

7 . The method of claim 6 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

8 . The method of claim 7 , wherein the laser ablation process forms the trench to an average width of 20 μm or more and 40 μm or less between the adjacent die regions of the wafer.

9 . The method of claim 1 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

10 . The method of claim 9 , wherein the laser ablation process forms the trench to an average width of 20 μm or more and 40 μm or less between the adjacent die regions of the wafer.

11 . The method of claim 1 , wherein the laser ablation process forms the trench to an average width of 20 μm or more and 40 μm or less between the adjacent die regions of the wafer.

12 . A method of separating semiconductor dies from a wafer, the method comprising:
performing a laser ablation process that removes a portion of a wafer to form a trench in a scribe region between adjacent die regions of the wafer, the trench extending from a first side of the wafer toward an opposite second side of the wafer, the trench extending through a metallization structure and an active circuit portion of the wafer, and a bottom of the trench spaced apart from the second side of the wafer; and after the laser ablation process, performing a wafer expansion process that separates individual semiconductor dies from the wafer.

13 . The method of claim 12 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

14 . A method of fabricating an electronic device, the method comprising:
performing a laser ablation process that removes a portion of a wafer to form a trench in a scribe region between adjacent die regions of the wafer, the trench extending from a first side of the wafer toward an opposite second side of the wafer, the trench extending through a metallization structure and an active circuit portion of the wafer, and a bottom of the trench spaced apart from the second side of the wafer; after the laser ablation process, performing a wafer probe test that tests circuitry of the active circuit portion of the wafer; and after the wafer probe test, performing a wafer expansion process.

15 . The method of claim 14 , further comprising, after the wafer probe test and before the wafer expansion process, performing a grinding process on the second side of the wafer.

16 . The method of claim 15 , wherein the laser ablation process is a multi-pass process that uses multiple passes of an ablation laser to successively increase the depth of the trench and/or a lateral width of the trench.

17 . The method of claim 16 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

18 . The method of claim 15 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

19 . The method of claim 14 , wherein the laser ablation process is a multi-pass process that uses multiple passes of an ablation laser to successively increase the depth of the trench and/or a lateral width of the trench.

20 . The method of claim 19 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

21 . The method of claim 20 , wherein the laser ablation process forms the trench to an average width of 20 μm or more and 40 μm or less between the adjacent die regions of the wafer.

22 . The method of claim 14 , wherein the laser ablation process forms the trench to an average depth distance of 20 μm or more and 25 μm or less from the first side of the wafer toward the second side of the wafer.

23 . The method of claim 22 , wherein the laser ablation process forms the trench to an average width of 20 μm or more and 40 μm or less between the adjacent die regions of the wafer.

24 . The method of claim 14 , wherein the laser ablation process forms the trench to an average width of 20 μm or more and 40 μm or less between the adjacent die regions of the wafer.

Assignees

• Texas Instruments Inc

Inventors

• Wyant Michael Todd
• Liu Joseph O
• Manack Christopher Daniel

Classifications

• H10W46/401

  for identification or tracking · CPC title

• H10W72/50

  Bond wires · CPC title

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P34/42

  with electromagnetic radiation, e.g. laser annealing (laser cutting H10P54/20) · CPC title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title