Offset Backup Bond Pads for Defect-Tolerant Stacked IC Bonding
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Solution Overview
Problem
Bond defect regions between stacked IC chips result in poor electrical coupling, reducing performance and yield, due to processing tool limitations, surface unevenness, and corrosion, leading to open circuits at active and backup bond pads.
Innovation Solution
A stacked IC device with a configuration of active bond pads and backup bond pads, where the backup bond pads are laterally offset by a distance greater than the pitch, providing redundant electrical connections to maintain proper coupling even in the presence of bond defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active bond pads are used for electrical coupling between stacked IC chips, then electrical connection is achieved, but bond defect regions cause poor electrical coupling and open circuits
Solution Approach 1:
The patent introduces backup bond pads positioned at a lateral distance greater than the pitch from active bond pads, creating a cushioning effect against bond defects. The backup bond pads serve as pre-positioned protective elements that can compensate for defects affecting active bond pads, ensuring continuous electrical connection reliability.
Solution Approach 2:
The patent changes the spatial parameter by positioning backup bond pads at a lateral distance greater than the pitch from active bond pads. This parameter change ensures that bond defect regions, which typically affect localized areas, cannot simultaneously impact both active and backup bond pads, thereby maintaining electrical connection reliability.
2Area of stationary object
If backup bond pads are positioned close to active bond pads, then device footprint is reduced, but bond defect regions can affect both active and backup bond pads causing open circuits
Solution Approach 1:
The patent establishes a specific parameter relationship where the lateral distance between backup and active bond pads exceeds the pitch. This parameter change creates optimal spacing that prevents bond defects from affecting both pad types simultaneously while maintaining reasonable device footprint.
Solution Approach 2:
The backup bond pads function as sacrificial or redundant elements that can be 'consumed' or rendered inactive by bond defects without compromising overall system reliability. Their positioning strategy accepts increased area as a trade-off for ensuring that defects do not propagate to both active and backup pads.
3Manufacturing precision
If processing tools and surface quality are improved to eliminate bond defects, then manufacturing precision increases, but processing complexity and cost increase
Solution Approach 1:
Instead of relying solely on improved manufacturing precision to eliminate bond defects, the patent employs backup bond pads as a cushioning measure. This approach accepts the reality of bond defects and creates a compensatory structure, reducing the need for extremely high manufacturing precision while maintaining electrical connection reliability.
Solution Approach 2:
The patent changes the design parameter from attempting to achieve perfect bond interfaces to accepting defect-prone interfaces and compensating through strategic pad positioning. This parameter change reduces processing complexity requirements while maintaining system reliability.
Data Source
AI summary
Various embodiments of the present disclosure are directed towards an integrated circuit (IC) device including a dielectric structure on a semiconductor substrate. A plurality of active bond pads are disposed in the dielectric structure. A plurality of auxiliary bond pads are disposed in the dielectric structure and are laterally offset from the plurality of active bond pads by a first distance greater than a pitch of the plurality of active bond pads. The active bond pads are respectively electrically coupled to a corresponding auxiliary bond pad in the plurality of auxiliary bond pads.