Semiconductor Die Sidewall Protection for Low-K Packaging Stress
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Solution Overview
Problem
Semiconductor packages face challenges in reducing size due to warpage and damage during wafer-level packaging processes, particularly due to CTE mismatch and mechanical stress from encapsulating materials, which affect the integrity of low-k dielectric layers and cause delamination and damage during singulation.
Innovation Solution
Implementing a plasma dicing process to remove dielectric layers and semiconductor substrates in scribe lines, followed by a laser dicing process to handle metallic structures, thereby confining stress to individual die levels and protecting sidewalls with encapsulating material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If encapsulating material is applied to protect semiconductor die, then reliability is improved, but warpage and stress are generated due to CTE mismatch
Solution Approach 1:
The patent removes dielectric layers and semiconductor substrates in scribe line regions to create separations between adjacent semiconductor dies. This segmentation isolates the stress generated by encapsulating material to individual die regions, preventing stress propagation across the entire wafer and reducing overall warpage.
Solution Approach 2:
The patent applies different structural configurations to different regions: scribe line regions have removed dielectric layers and substrates to reduce stress, while active die regions maintain full protective encapsulation. This local differentiation optimizes both protection and stress management.
2Stress or pressure
If plasma dicing process is used to remove dielectric layers in scribe lines, then stress is localized and warpage is reduced, but manufacturing complexity increases
Solution Approach 1:
The dicing process is divided into two distinct stages: plasma dicing to remove dielectric layers and substrates in scribe lines, followed by laser dicing to handle metallic structures. This segmentation allows each process to be optimized for its specific function, achieving stress localization while managing manufacturing complexity through specialized process steps.
3Manufacturing precision
If sidewalls are protected with encapsulating material, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
The plasma dicing process removes dielectric layers and substrates in scribe line regions before the encapsulation step. This preliminary action creates prepared surfaces and structures that enable more effective sidewall protection during subsequent encapsulation, improving manufacturing precision while managing process complexity through proper sequencing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces warpage and damage to semiconductor dies by localizing stress and protecting sidewalls, enhancing the robustness and reliability of semiconductor assemblies.
Implementation Method 1
a plasma dicing process to remove the dielectric layers and the semiconductor substrates in the scribe lines
Implementation Method 2
a laser dicing process to handle metallic structures
Data Source
AI summary
Semiconductor die assemblies with sidewall protection, and associated methods and systems are disclosed. In one embodiment, a semiconductor die assembly includes an interface die with a low-k dielectric layer and a stack of semiconductor dies attached to the interface die. The semiconductor die assembly also includes a molding structure that protects sidewalls of the interface die and sidewalls of the semiconductor dies. In some embodiments, the semiconductor die assembly includes a passivation layer attached to the interface die opposite to the stack of semiconductor dies. Further, the passivation layer may include a sidewall surface coplanar with an outer sidewall surface of the molding structure. The passivation layer may include a ledge underneath the molding structure, which is uncovered by the interface die. The semiconductor die assembly may include a NCF material at the sidewalls of the stack of semiconductor dies, where the molding structure surrounds the NCF material.