Oblique Through Silicon Via Chip Backfill Structural Strength
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Solution Overview
Problem
Through silicon via chips with oblique structures are prone to fractures during surface bonding and welding processes due to their step structure, particularly at the hollow lower part of the via, which compromises their structural strength.
Innovation Solution
A backfill structure layer is introduced at the lower part of the oblique via, with insulating layers between the rewiring metal layer and the silicon substrate, and between the rewiring metal layer and the backfill structure layer, to enhance structural support and prevent fractures, facilitating subsequent surface mounting and welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an oblique through silicon via with step structure is used, then manufacturing difficulty and cost are reduced, but the chip is prone to fracture at the step during testing and processing
Solution Approach 1:
The patent applies local quality by filling only the lower portion of the oblique via with a backfill material, creating a region of enhanced structural strength at the critical step area while maintaining the oblique geometry for ease of manufacture. This localized reinforcement prevents fracture at the step without requiring complete via refilling, thus resolving the contradiction between manufacturing ease and structural strength.
Solution Approach 2:
The backfill structure acts as a preventive cushioning element placed beforehand in the via to support the step region and prevent future fractures during testing and processing. This prior reinforcement ensures structural integrity is maintained before any damage can occur, addressing the weakness of the step structure while preserving the manufacturing advantages of the oblique via.
2Strength
If a backfill structure layer is added to enhance structural strength, then fracture resistance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent implements partial action by filling only the necessary lower portion of the via with backfill material rather than the entire via. This partial filling provides sufficient structural reinforcement to prevent fractures at the step while avoiding the excessive complexity of complete via refilling, thus balancing strength enhancement with manufacturing simplicity.
Solution Approach 2:
The patent changes the parameter of via filling from complete refilling to partial backfilling, modifying the structural composition to achieve the necessary strength improvement. This parameter change allows the via to maintain its oblique geometry for easy manufacture while adding just enough material to prevent fracture, resolving the contradiction between strength and manufacturing complexity.
Data Source
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AI summary
A through silicon via chip and manufacturing method thereof are provided, where the through silicon via chip includes a silicon substrate (210), the silicon substrate (210) is provided with a via (220), the via (220) is an oblique via, and a backfill structure layer (230) is disposed in the via (220). According to the through silicon via chip and manufacturing method thereof, a fingerprint identification sensor and a terminal device, a backfill structure is added in an oblique via to play a supportive role when a force is exerted on a surface of the through silicon via chip, which avoids a fracture of the through silicon via chip, thereby enhancing structural strength of the through silicon via chip.