IC Package Isolation Layer for CTE Mismatch at Die Interfaces
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Solution Overview
Problem
The challenge of CTE mismatch between semiconductor dies and gap-fill layers in integrated circuit packages leads to delamination risks, affecting the bonding integrity and reliability of the package.
Innovation Solution
An isolation layer is formed directly over the interfaces between lower integrated circuit dies and the gap-fill layer to mitigate the CTE mismatch, enhancing bonding integrity and reducing delamination risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If semiconductor dies are directly bonded to gap-fill layers, then manufacturing process is simplified, but delamination occurs due to CTE mismatch
Solution Approach 1:
An isolation layer is introduced as an intermediary between the semiconductor die and the gap-fill layer. This isolation layer has a coefficient of thermal expansion that matches the semiconductor die, thereby eliminating CTE mismatch and preventing delamination during thermal cycling while maintaining bonding integrity
2Reliability
If isolation layer is added to prevent delamination, then bonding integrity is improved, but device complexity increases
Solution Approach 1:
The package structure is segmented into distinct functional layers: the semiconductor die, the isolation layer with matched CTE, and the gap-fill layer. This segmentation allows each layer to perform its specific function independently, preventing delamination while maintaining overall structural simplicity
3Ease of manufacture
If CTE mismatch is not addressed, then manufacturing process remains simple, but package reliability deteriorates during operation
Solution Approach 1:
The coefficient of thermal expansion parameter is changed by introducing an isolation layer with CTE matched to the semiconductor die. This parameter modification eliminates thermal stress and prevents delamination during thermal cycling, ensuring long-term package reliability without complicating the manufacturing process
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
This approach improves the reliability of integrated circuit packages by maintaining bonding integrity during manufacturing and operation, thereby ensuring better performance and longevity.
Implementation Method 1
the effect of the coefficient of thermal expansion (CTE) mismatch between the lower integrated circuit dies and the lower gap-fill layer on the bonding integrity
Data Source
AI summary
An integrated circuit package and the method of forming the same are provided. The integrated circuit package may include a first die having a first substrate and a first through via extending through the first substrate, a first gap-fill layer along a sidewall of the first substrate, an isolation layer on a surface of the first substrate and a surface of the first gap-fill layer, a first bonding layer over the isolation layer, and a first bonding pad in the first bonding layer. The isolation layer may overlap an interface between the sidewall of the first substrate and a sidewall of the first gap-fill layer, and may extend on sidewalls of the first through via.