Fault Detection Circuit for CoP Bonding Pad Chains
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Solution Overview
Problem
Existing semiconductor devices with a stacked structure, such as those with a Cell over Peripheral (CoP) structure, face challenges in efficiently detecting faults in bonding pads, which are critical for ensuring proper connectivity and functionality.
Innovation Solution
A semiconductor device with a CoP structure incorporates a test pad chain connected to fault detection circuits that include data input, data path, and data reset circuits to detect and locate faults in bonding pads by analyzing voltage levels and signal transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a stacked structure (CoP) is used to increase integration, then device functionality and capacity are improved, but fault detection capability in bonding pads deteriorates
Solution Approach 1:
The test pad chain is divided into multiple segments with individual fault detection circuits at each stage. Each detection circuit independently monitors a specific segment of the bonding pad chain, allowing localized fault detection without requiring complete chain testing. This segmentation enables precise identification of fault locations while maintaining detection capability in the stacked CoP structure.
2Difficulty of detecting and measuring
If multiple fault detection circuits are added to detect bonding pad faults, then fault detection capability is improved, but device complexity increases
Solution Approach 1:
Multiple fault detection circuits are merged into a unified test pad chain structure where circuits are cascaded together. The output of one detection circuit feeds into the next, creating an integrated detection system that shares common signal paths and control logic. This merging approach enables comprehensive fault detection while minimizing the increase in overall device complexity through资源共享 and structural integration.
3Reliability
If comprehensive fault detection is implemented, then reliability is improved, but testing time increases
Solution Approach 1:
Fault detection circuits are configured to perform preliminary detection of bonding pad connectivity during the stacking process itself, before final device assembly and testing. The test pad chain is activated early in the manufacturing flow to identify and isolate faulty bonds, allowing defective structures to be rejected before committing additional processing time and resources. This preliminary action significantly reduces overall testing time while maintaining high reliability.
Data Source
AI summary
A semiconductor device includes a first structure including first test pads, a second structure disposed on the first structure and including second test pads that respectively correspond to the first test pads and form a test pad chain with the first test pads, a first terminal connected to one end of the test pad chain, a plurality of fault detection circuits connected to the test pad chain to detect a connection status of the test pad chain, and a second terminal connected to the other end of the test pad chain.