Stacked Semiconductor Package Pads for Misalignment-Tolerant Bonding
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Solution Overview
Problem
Existing semiconductor packages face challenges in achieving improved electrical properties and increased reliability due to limitations in bonding and test pad configurations.
Innovation Solution
The semiconductor package incorporates a stacked configuration of multiple semiconductor chips with specific bonding pad and test pad designs, including overlapping portions and unique sidewall configurations, to enhance electrical connectivity and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bonding pad configurations are used, then manufacturing is simpler, but electrical properties and reliability are insufficient
Solution Approach 1:
The bonding pad structure is segmented into multiple functional regions: overlapping portions that contact pads on adjacent chips, and non-overlapping portions surrounded by dielectric layers. This segmentation allows different regions to serve different functions, improving electrical connectivity and reliability while maintaining manufacturability through standardized processing steps.
Solution Approach 2:
The patent introduces a vertical stacking dimension by configuring bonding pads to overlap with pads on adjacent chips in the stack. This three-dimensional pad arrangement improves electrical properties and reliability by providing multiple contact paths, while the systematic design of overlapping and non-overlapping portions keeps the complexity manageable.
2Reliability
If test pads are configured without overlapping portions, then manufacturing is easier, but misalignment impact increases
Solution Approach 1:
Test pads are divided into overlapping portions that extend onto adjacent chips and non-overlapping portions remaining on the original chip, surrounded by dielectric layers. This segmentation provides tolerance against misalignment through the overlapping regions while the systematic configuration maintains ease of manufacture through standardized fabrication processes.
Solution Approach 2:
The overlapping portions of test pads act as a cushion against potential misalignment during the bonding process. By extending test pads into overlapping regions before bonding occurs, the design anticipates and compensates for alignment variations, ensuring reliable electrical contact even when minor misalignments occur.
3Reliability
If bonding pads have limited contact area, then device complexity is reduced, but electrical properties deteriorate
Solution Approach 1:
The bonding pad contact area is extended into the vertical dimension by creating overlapping portions that contact pads on adjacent chips in the stack. This three-dimensional configuration increases the effective contact area and improves electrical connectivity without requiring larger lateral pad dimensions, thereby managing device complexity.
Solution Approach 2:
The bonding pad structure merges overlapping portions that contact adjacent chips with non-overlapping portions surrounded by dielectric layers. This unified design improves electrical connectivity through multiple contact paths while maintaining a systematic structure that manages device complexity through consistent fabrication processes.
Data Source
AI summary
Disclosed is a semiconductor package comprising a first semiconductor chip and a second semiconductor chip on the first semiconductor chip. The first semiconductor chip may include an upper bonding pad, an upper test pad, and an upper dielectric layer that surrounds the upper bonding pad and the upper test pad. The second semiconductor chip includes a lower bonding pad in contact with the upper bonding pad, a lower test pad in contact with the upper test pad, and a lower dielectric layer that surrounds the lower bonding pad and the lower test pad.