Active-Wafer Redistribution Layers to Reduce Package Warping
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Solution Overview
Problem
Existing semiconductor packages face challenges such as stress-induced warping of the package substrate, leading to issues like solder cold joints and bridging during surface mounting, particularly in high-performance computing applications, which complicate effective interconnection with support substrates.
Innovation Solution
The formation of redistribution layers directly on an active wafer or semiconductor die, eliminating the need for a separate interposer, reduces thermal expansion stresses and simplifies the fabrication process, allowing for a more modular and stress-resistant semiconductor device configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate interposer is used to form redistribution layers, then electrical interconnection is achieved, but thermal expansion stresses cause warping of the package substrate
Solution Approach 1:
The patent extracts and eliminates the separate interposer component from the package structure. By forming redistribution layers directly on the active wafer, the invention removes the interposer that was causing thermal expansion mismatch and substrate warping, while maintaining electrical interconnection functionality through the directly-formed redistribution layers
Solution Approach 2:
The patent merges the functions of the active wafer and interposer into a single integrated structure. The redistribution layers are formed directly on the active wafer surface, combining what were previously separate components (wafer and interposer) into one unified package structure, thereby eliminating thermal expansion stresses between dissimilar materials
2Adaptability or versatility
If a separate interposer is used, then redistribution of electrical connections is enabled, but the fabrication process becomes more complex
Solution Approach 1:
The invention extracts and removes the separate interposer fabrication steps from the manufacturing process. By forming redistribution layers directly on the active wafer using standard semiconductor fabrication techniques, the process eliminates the need for separate interposer manufacturing, handling, and assembly steps, thereby simplifying the overall fabrication workflow
Solution Approach 2:
The patent combines the redistribution layer formation process with the active wafer fabrication process. Instead of manufacturing redistribution layers on a separate interposer and then assembling them, the invention integrates both functions into a single fabrication sequence, reducing process complexity and improving manufacturing efficiency
3Productivity
If multiple chips are stacked to improve integration density, then bandwidth and speed increase, but thermal expansion stresses and assembly difficulties increase
Solution Approach 1:
The patent merges multiple chip functions into a single integrated wafer structure with directly-formed redistribution layers. This approach enables high integration density and bandwidth similar to stacked configurations, but maintains a single-plane assembly that is simpler to manufacture and assemble compared to multi-chip stacking
Data Source
AI summary
An embodiment semiconductor device may include a semiconductor die; one or more redistribution layers formed on a surface of the semiconductor die and electrically coupled to the semiconductor die; and an active or passive electrical device electrically coupled to the one or more redistribution layers. The active or passive electrical device may include a silicon substrate and a through-silicon-via formed in the silicon substrate. The active or passive electrical device may be configured as an integrated passive device including a deep trench capacitor or as a local silicon interconnect. The semiconductor device may further include a molding material matrix formed on a surface of the one or more redistribution layers such that the molding material matrix partially or completely surrounds the active or passive electrical device.