Method of dicing wafer and die

Abstract

Provided are a method of dicing a wafer, which reduces sectional cracking and chipping, and a die. According to the method, a DAF (die attach film) may be attached on a grinded backside of a wafer, and the DAF and the backside of the wafer may be sawed to a depth. The backside of the wafer may be attached to a ring mount blocked by a tape, and the wafer may be separated into a plurality of dies by applying stress on the wafer through the tape of the ring mount. Each of the dies may include a die adhesive dam formed naturally and may be used together with the DAF when a die is bonded.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. FIGS. 1A-4 represent non-limiting, example embodiments as described herein.

FIGS. 1A-1E are diagrams illustrating a method of dicing a wafer according to example embodiments;

FIG. 2 is an enlarged view of a portion A in FIG. 1E;

FIGS. 3A and 3B are diagrams illustrating a method of applying stress on a wafer; and

FIG. 4 is a diagram illustrating a die according to example embodiments.

Claims

1. A method of dicing a wafer, the method comprising: attaching a DAF (die attach film) on a grinded backside of the wafer;sawing both the DAF and the backside of the wafer to a depth;attaching the backside of wafer to a ring mount blocked by a tape; andseparating the wafer into a plurality of dies by applying stress to the wafer through the tape of the ring mount.

2. The method of claim 1, further comprising: attaching a laminate tape on a top side of the grinded wafer before attaching a DAF.

3. The method of claim 2, further comprising: attaching a ring mount on the laminate tape to support the wafer before attaching a DAF.

4. The method of claim 3, wherein after sawing the DAF, the laminate tape and the ring mount are detached from the wafer.

5. The method of claim 1, wherein the stress is generated by applying tension on the tape of the ring mount.

6. The method of claim 5, wherein the tension applied to the tape is generated by stretching the tape in an outer direction or pulling the tape in a vertical down direction.

7. The method of claim 1, wherein the tape of the ring mount is an UV (ultraviolet) tape removed using an UV illumination process.

8. The method of claim 1, wherein attaching the DAT includes at least one of attaching a single DAF tape and removing a laminate tape through an UV illumination process after attaching a two-layered tape consisting of a DAF tape and the laminate tape.

9. The method of claim 1, wherein the depth in sawing the DAF and the stress applied in separating the wafer are determined by a stress intensity factor KI which is a fracture mechanics factor of the sawn wafer.

10. The method of claim 9, wherein the KI is expressed as KI=σ(π a)1/2 where σ represents stress applied on the wafer through the tape, and a represents the depth, and the σ and the a are determined by applying an intrinsic fracture toughness KIC of the wafer to the KI.

11. The method of claim 1, wherein each of the dies separated during the separating of the wafer includes a die adhesive dam formed on a cut portion due to the sawing.

12. The method of claim 11, wherein the die adhesive dam serves to prevent an adhesive used when a die is bonded from flooding onto a top surface of the die.

13. The method of claim 1, wherein each of the dies separated during the separating of the wafer is used for bonding a die together with the DAT attached on the backside of the die.

14. The method of claim 1, wherein the sawing is performed using a blade or a cutting method.

15. A die fabricated using the method of claim 1, the die including a step difference between an uncut portion and a cut portion formed by the sawing.

16. The die of claim 14, wherein the step difference serves as a die adhesive dam to prevent an adhesive used when the die is bonded from flooding onto a top surface of the die.

17. The die of claim 14, wherein the depth and stress are determined by a stress intensity factor KI which is a fracture mechanics factor of the sawn wafer.

18. The die of claim 16, wherein the KI is expressed as KI=σ(π a)1/2 where σ represents stress applied on the wafer through the tape, a represents the depth, and the σ and the a are determined by applying a fracture toughness KIC of the wafer to the KI.

19. The die of claim 14, wherein the die is used for bonding a die together with the DAF attached on the backside of the die.

20. A die including a step difference between an uncut portion and a cut portion.