Wafer Level Package Through Slots for Thermal Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ensuring the reliability of wafer level packaging in semiconductor devices, particularly in ensuring the structural integrity and reducing warpage due to coefficient of thermal expansion mismatch during manufacturing processes.
Innovation Solution
A manufacturing process involving a carrier with a de-bonding layer, where dies are adhered and encapsulated with a polymeric structure and subsequent encapsulant, followed by removal of the polymeric structure to form a through slot in the encapsulant, which alleviates warpage by allowing stress release and enhances structural reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wafer level packaging is used to improve productivity and reduce manufacturing cost, then manufacturing efficiency is improved, but warpage and structural reliability deteriorate due to coefficient of thermal expansion mismatch
Solution Approach 1:
The encapsulant is segmented by forming through slots that divide the continuous encapsulant material into separate regions. This segmentation allows different portions of the encapsulant to independently accommodate thermal expansion stresses, preventing uniform warpage across the entire package structure while maintaining the overall integrity of the wafer level packaging
Solution Approach 2:
The through slots create localized regions within the encapsulant where stress can be relieved. Instead of requiring the entire encapsulant to have uniform stress distribution, the local quality of the encapsulant is modified at specific locations (where through slots are formed) to allow stress release, while other regions maintain their structural function
2Strength
If a continuous encapsulant structure is used to maintain structural integrity, then structural strength is improved, but warpage increases due to inability to release thermal stress
Solution Approach 1:
The continuous encapsulant is divided into separate regions by through slots, creating a segmented structure that can accommodate thermal stress through localized deformation at the slot regions while maintaining overall structural integrity of the package
3Strength
If polymeric structure is used for encapsulation to provide structural support, then structural strength is improved, but manufacturing complexity increases due to additional removal steps
Solution Approach 1:
The polymeric structure is temporarily introduced during manufacturing to provide structural support and define through slot locations, then completely removed to form the through slots in the encapsulant. This temporary extraction of the polymeric material allows for simplified through slot formation without requiring complex direct machining or etching processes
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
The process increases yield and reliability of the package structure by reducing warpage and manufacturing errors, while maintaining structural integrity through stress alleviation and improved adhesion.
Implementation Method 1
removal of the polymeric structure to form a through slot in the encapsulant, which alleviates warpage by allowing stress release
Data Source
AI summary
A package structure includes a plurality of first dies, a first encapsulant, and a first redistribution structure. The first encapsulant encapsulates the first dies. The first redistribution structure is disposed on the first dies and the first encapsulant. The first redistribution structure includes a dielectric layer covering a top surface and sidewalls of the first encapsulant.