Separation of workpiece with three material removal stages

• US 20190214299A1
• Filed: 01/07/2018
• Published: 07/11/2019
• Est. Priority Date: 01/07/2018
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Kamseder, Christoph, Mariani, Franco, Bauer, Andreas, Fischer, Thomas
• Granted Patent: US 10,403,506 B2
• Time in Patent Office: Days
• CPC Class Codes: B28D 5/022 by cutting with discs or wheels
• CPC Class Codes: H01L 21/3043 Making grooves, e.g. cutting
• CPC Class Codes: H01L 21/67092 Apparatus for mechanical treatment or grinding or cutting, see the relevant groups in subclasses B24B or B28D
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633

Abstract

A method of manufacturing electronic dies by separating a wafer into electronic dies, wherein the method comprises forming a groove in the wafer with a first material removal tool having a first thickness, enlarging the groove by a second material removal tool having a second thickness larger than the first thickness, and subsequently increasing a depth of the groove by a third material removal tool having a third thickness smaller than the second thickness until the wafer is separated.

Claims

1. A method of manufacturing electronic dies by separating a wafer into the electronic dies, the method comprising:

forming a groove in the wafer with a first material removal tool, the first material removal tool having a first thickness;

enlarging the groove by a second material removal tool, the second material removal tool having a second thickness larger than the first thickness;

subsequently increasing a depth of the groove by a third material removal tool, the third material removal tool having a third thickness smaller than the second thickness until the wafer is separated.

2. The method according to claim 1, the method comprising:

forming a further groove'"'"', extending along a direction being angled with regard to an extension of said groove, in the wafer with the first material removal tool;

enlarging the further groove'"'"' by the second material removal tool;

subsequently increasing a depth of the further groove'"'"' by the third material removal tool until the wafer is separated at the further groove'"'"'.

3. The method according to claim 2, wherein the method comprises carrying out at least one of forming the further groove'"'"', enlarging the further groove'"'"', and separating the wafer at the further groove'"'"' after forming the groove and before separating the wafer at the groove.

4. The method according to claim 1, wherein the third thickness is larger than, smaller than or equal to the first thickness.

5. The method according to claim 1, wherein the method comprises completing removing of at least one test structure, in particular at least one of a process control monitoring test structure and a reliability control monitoring test structure, by the second material removal tool.

6. The method according to claim 1, wherein at least one of the first thickness and the third thickness is in a range between 20 μ

m and 60 μ

m.

7. The method according to claim 1, wherein the second thickness is in a range between 60 μ

m and 150 μ

m.

8. The method according to claim 1, wherein a ratio between the second thickness and one of the first thickness and the third thickness is in a range between 1.1 and 4.

9. The method according to claim 1, wherein a depth of the groove up to which the first material removal tool extends is in a range between 10% and 40% of an entire thickness of the wafer.

10. The method according to claim 1, wherein a depth of the groove up to which the second material removal tool extends is in a range between 60% and 90% of an entire thickness of the wafer.

11. The method according to claim 1, wherein the method comprises attaching a carrier to a main surface of the wafer before separation, wherein in particular, during further increasing the depth of the groove by the third material removal tool, the third material removal tool extends into the carrier.

12. The method according to claim 1, wherein at least one of the first material removal tool, the second material removal tool and the third material removal tool is a saw blade.

13. The method according to claim 1, wherein the wafer is non-encapsulated at the time of separating.

14. The method according to claim 1, wherein the method comprises also using the first material removal tool as the third material removal tool.

15. The method according to claim 1, wherein the method comprises using different tools as the first material removal tool and the third material removal tool.

16. The method according to claim 1, wherein the enlarging comprises widening the groove.

17-20. -20. (canceled)

21. A method for singulating a workpiece into sections, the method comprising:

forming a groove in the workpiece using a first saw blade, the first saw blade having a first thickness;

widening the groove using a second saw blade, the second saw blade having a second thickness, wherein the second thickness is larger than the first thickness;

further deepening the widened groove using a third saw blade, the third saw blade having a third thickness, wherein the third thickness is smaller than the second thickness.

22. The method according to claim 21, wherein the method comprises deepening the groove using the second saw blade.

23. The method according to claim 21, wherein the method comprises further deepening the widened groove in the workpiece using the third saw blade after having formed a further groove'"'"' intersecting the groove, extending perpendicular to the groove and not yet extending completely through the entire workpiece.

24. A method of separating a workpiece into separate sections, the method comprising:

forming a groove in the workpiece up to a first depth and with a first width;

subsequently widening the groove with a second width being larger than the first width;

subsequently further deepening the groove until the workpiece is separated into the separate sections so that a resulting cut-out has a portion with a third width smaller than the second width;

wherein subsequently widening the groove with the second width includes deepening the groove to a second depth.

25. (canceled)

26. A computer program product provided with computer executable code defining a procedure to be carried out by a control unit to cause an apparatus having first, second and third material removal tools for separating a wafer into electronic dies to perform the following steps:

forming a groove in the wafer with the first material removal tool, the first material removal tool having a first thickness;

enlarging the groove by the second material removal tool, the second material removal tool having a second thickness larger than the first thickness; and

subsequently increasing a depth of the groove by the third material removal tool, the third material removal tool having a third thickness smaller than the second thickness until the wafer is separated.