US-12622207-B2 - Apparatus for separating singulated die from substrate dicing tape and methods of using the same

Abstract

Embodiments herein are generally directed to ejection assemblies for singulated dies and thinned wafers and methods related thereto. Die ejection assemblies may be used to minimize cracking or deformation of dies during post-singulation processing. Thus, the die ejection assemblies and methods described herein reduce the number of dies rejected after singulation and the number of failures during a die bonding process. In one general aspect, an apparatus for removing singulated dies from a dicing tape is provided. The apparatus may include a die ejector assembly, which may include a vacuum plate configured to engage with a portion of the dicing tape. A die ejector may be disposed in an ejector opening of the vacuum plate. One or more actuators may be configured to move at least a portion of the die ejector in a lateral direction relative to the upper surface of the vacuum plate.

Inventors

• Cyprian Emeka Uzoh
• Thomas Workman
• Gabriel Z. Guevara

Assignees

• ADEIA SEMICONDUCTOR BONDING TECHNOLOGIES INC.

Dates

Publication Date

20260505

Application Date

20230829

Claims (18)

1. 1 . An apparatus for removing singulated dies from a dicing tape, the apparatus comprising: a die ejector assembly comprising: a vacuum plate having an ejector opening disposed therethrough; a die ejector disposed in the ejector opening, wherein at least a portion of the die ejector is movable in a lateral direction relative to an upper surface of the vacuum plate; and a flexible barrier disposed over the ejector opening, wherein the die ejector is disposed below the flexible barrier.
2. 2 . The apparatus of claim 1 , further comprising one or more actuators to position at least a portion of the die ejector above the upper surface of the vacuum plate concurrently with moving the die ejector in the lateral direction.
3. 3 . The apparatus of claim 2 , wherein the die ejector comprises a cylinder, and the center axis of the cylinder is substantially parallel to the upper surface of the vacuum plate.
4. 4 . The apparatus of claim 2 , wherein the die ejector comprises a roller having an axis of rotation substantially parallel to the upper surface of the vacuum plate.
5. 5 . The apparatus of claim 2 , wherein: the die ejector comprises a coil spring; and the one or more actuators exert a bending moment on the coil spring concurrently with moving the coil spring in the lateral direction.
6. 6 . The apparatus of claim 1 , wherein the die ejector has a length that is at least twice more than its width, and the length is parallel to the upper surface of the vacuum plate and orthogonal to the lateral direction.
7. 7 . The apparatus of claim 6 , wherein the die ejector comprises a coil spring.
8. 8 . The apparatus of claim 1 , further comprising a non-transitory computer-readable storage medium comprising computer-executable instructions that, when executed by a processor, cause the processor to perform operations comprising: aligning the ejector opening with a singulated die disposed on the dicing tape; engaging the vacuum plate with the dicing tape; and exerting, by use of the die ejector, a lateral force on the portion of the dicing tape having the singulated die disposed thereon.
9. 9 . A non-transitory computer-readable storage medium comprising computer-executable instructions that, when executed by a processor, cause the processor to perform operations comprising: aligning the die ejector assembly according to claim 1 with a portion of the dicing tape having a singulated die disposed thereon; engaging the vacuum plate with the dicing tape by exerting a vacuum therebetween; and exerting, by use of the die ejector, a lateral force on the portion of the dicing tape having the singulated die disposed thereon.
10. 10 . A method for removing a singulated die from a dicing tape, the method comprising: aligning the die ejector assembly according to claim 1 with a portion of the dicing tape having the singulated die disposed thereon; engaging the vacuum plate with the dicing tape by exerting a vacuum therebetween; and exerting, by use of the die ejector, a lateral force on the portion of the dicing tape having the singulated die disposed thereon.
11. 11 . The method of claim 10 , wherein exerting the lateral force on the portion of the dicing tape comprises moving the die ejector from a position proximate to a first edge of the singulated die to a position proximate to an opposite second edge of the singulated die.
12. 12 . The method of claim 10 , further comprising: concurrently with exerting the lateral force on the portion of the dicing tape, engaging the singulated die using an end effector disposed thereabove.
13. 13 . An apparatus for removing singulated dies from a dicing tape, the apparatus comprising: a die ejector assembly comprising: a vacuum plate having an ejector opening disposed therethrough; and a die ejector disposed in the ejector opening, wherein: at least a portion of the die ejector is movable in a lateral direction relative to an upper surface of the vacuum plate; the die ejector comprises a resilient member; and an end of the resilient member is coupled to the vacuum plate.
14. 14 . The apparatus of claim 13 , wherein the resilient member is compressible in the lateral direction.
15. 15 . The apparatus of claim 14 , wherein the die ejector comprises a coil spring.
16. 16 . The apparatus of claim 14 , wherein the die ejector comprises a leaf spring.
17. 17 . The apparatus of claim 13 , wherein: the resilient member includes a first resilient member and a second resilient member; the first resilient member is coupled to the vacuum plate; the second resilient member is coupled to the first resilient member; and the first resilient member has a first spring constant, and the second resilient member has a second spring constant that is less than the first spring constant.
18. 18 . An apparatus for removing singulated dies from a dicing tape, the apparatus comprising: a die ejector assembly comprising: a vacuum plate having an ejector opening disposed therethrough; a die ejector disposed in the ejector opening, wherein: at least a portion of the die ejector is movable in a lateral direction relative to an upper surface of the vacuum plate; and the die ejector comprises a bladder.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit of U.S. Provisional Application No. 63/524,348, filed Jun. 30, 2023, which is incorporated by reference herein. FIELD The present disclosure relates to integrated circuit (IC) packaging, and in particular, to systems and methods for removing a die or thinned wafer from dicing tape. BACKGROUND Integrated circuit (IC) packaging processes may include an operation for dicing a wafer to form singulated dies. The wafer is typically thinned prior to singulation using a combination of backgrind, polishing and etch processes. The wafer may be mounted on a dicing tape before or after thinning operations. The dicing tape secures the wafer and the individual dies during dicing operations. The dicing process may comprise reactive ion etching (RIE), dry etch, wet etch, saw dicing, laser dicing, or combinations thereof. The cleaned singulated dies are then separated from the dicing tape and prepared for packaging in subsequent operations. Unfortunately, as wafer thickness requirements decrease, conventional methods of separating singulated dies from the dicing tape have resulted in increasing defectivity, such as marks or scratches, internal or external cracks, or deformation in the separated die. Typically, the increased defectivity is related to induced pressure points on the dies during the separation process. For example, in some separation processes, ejector pins may be used to push upwardly on the dicing tape to help separate the singulated die therefrom. The pins may have a sharp head that may puncture the dicing tape and contact the die, cracking or plastically deforming the die. The cracked or deformed die may be rejected after separation or may fail during subsequent packaging operations, such as bonding operations, contaminating the bonding surface of the host substrate and ultimately resulting in reduced yield and increased manufacturing costs. Further, if the die shatters during separation, fragments of the shattered die may contaminate surrounding dies, further reducing the yield. Thin dies, such as dies having a thickness of 30 microns or less, are more susceptible to damage during removal because of the stress induced by the small contact area of the pins. Apart from their thickness, thinner dies are more fragile than thicker dies on account of their thermal processing history and the combination of integrating materials having different mechanical properties, such as Young's modulus and coefficient of thermal expansion (CTE). For example, for a silicon device having a copper back end of line (BEOL) with silicon oxide dielectric layers, the CTE of silicon oxide dielectric may be about 0.5 ppm/° C., the CTE of the silicon substrate may be about 2.5 ppm/° C., and the CTE of the integrated copper conductive layer may be about 17 ppm/° C. In practice, the formed host substrate comprises an asymmetric thin laminate, which thins the host substrate from its backside and tends to increase the warpage of the thinned substrate or the singulated substrate. Increasing the warpage may result in higher non-uniform stresses in the thinned substrate or thinned singulated dies. Thus, the thinned substrates or dies require a gentler ejection method. Accordingly, there is a need in the art for an improved apparatus for separating singulated dies from a substrate dicing tape, and methods related thereto. SUMMARY Aspects of the present disclosure are generally directed to apparatus for separating singulated dies from a substrate dicing tape and methods related thereto. The apparatus may be used advantageously to minimize cracking or deformation of dies during post-singulation processing. Thus, the die ejection assemblies and methods described herein reduce the number of dies rejected after singulation and the number of failures during subsequent die packaging operations, such as die to die or die to wafer bonding process. In one general aspect, an apparatus for separating singulated dies from a substrate dicing tape is provided. The apparatus may include a die ejector assembly. The die ejector assembly may include a movable vacuum plate configured to engage with a portion of the substrate dicing tape. The vacuum plate may have an ejector opening disposed therethrough. The die ejector assembly may further include a die ejector disposed in the ejector opening. The die ejector assembly may further include one or more actuators configured to move at least a portion of the die ejector in a lateral direction relative to the upper surface of the vacuum plate. Implementation of the general aspect may include one or more of the following features. The die ejector assembly may include a flexible barrier disposed over the ejector opening, where the die ejector is disposed below the flexible barrier. The die ejector may have a length that is at least 2× greater than its width, and the length is parallel to the upper surface of the vacuum plate and orthogonal to the la