IC Package Edge Trace Layout for Die Crack Detection
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Solution Overview
Problem
Existing quality control methods fail to detect small cracks near the edges of silicon wafers during manufacturing, and these cracks can grow over time, leading to logic circuitry failure in integrated circuit dies.
Innovation Solution
A die crack detection system utilizing an elongate conductive trace and test logic within integrated circuit packages, which applies an electrical test pattern and compares it with a response pattern to detect cracks, with optional loopback mode for verification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional automated test equipment is used to detect die cracks at manufacture, then large cracks can be detected, but small cracks near the edges of the die cannot be detected
Solution Approach 1:
The die surface is segmented into multiple regions by dividing it into a grid of segments. Test structures are placed at specific segments (e.g., corner segments) to detect cracks in those regions. This segmentation allows the testing system to focus on critical areas where small edge cracks are most likely to occur, improving detection precision without requiring complex full-surface testing equipment.
Solution Approach 2:
The invention transitions from direct optical inspection of the die surface to an electrical measurement dimension. By placing conductive traces and test structures that convert crack detection into electrical resistance or continuity measurements, the system can detect small cracks through electrical property changes rather than relying on optical resolution limits of conventional testing equipment.
2Productivity
If small cracks are not detected at manufacture, then production efficiency is maintained, but the cracks grow over time and cause logic circuitry failure
Solution Approach 1:
Test structures are incorporated into the die during the manufacturing process itself, before the die is packaged and deployed. This preliminary action allows small cracks to be detected early when they are still detectable, preventing future reliability issues without requiring additional post-manufacturing inspection steps that would reduce productivity.
Solution Approach 2:
The die itself contains the test structures and can perform self-diagnosis for crack detection. The conductive traces and test logic are built into the die architecture, allowing the die to monitor its own integrity through electrical measurements without requiring external specialized equipment, thus maintaining manufacturing throughput while ensuring reliability.
3Measurement precision
If comprehensive testing is performed to detect all potential cracks, then detection accuracy improves, but testing time and cost increase
Solution Approach 1:
Instead of uniformly testing the entire die surface, the invention applies test structures selectively at locations with higher crack probability (e.g., corner segments and edge regions). This local quality approach concentrates testing resources on critical areas, achieving high detection accuracy for small cracks while minimizing overall testing time and cost.
Solution Approach 2:
The invention uses a partial testing approach where only specific segments of the die are tested rather than the entire surface. By focusing on critical segments where small cracks are most likely to occur and cause failure, the system achieves sufficient detection accuracy without the time and cost penalty of comprehensive full-surface testing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively detects die cracks both at the time of manufacture and during the life of a product, ensuring the integrity of integrated circuit dies by preventing logic circuitry failure.
Implementation Method 1
an elongate conductive trace... applies an electrical test pattern... and compares it with a response pattern
Data Source
AI summary
An IC package includes a die and an elongate conductive trace formed adjacent to at least one peripheral edge of the die. Test logic in the package performs a die crack test by applying a test pattern to a first end of the conductive trace and sensing a response pattern at a second end of the conductive trace. The package is configured to operate in at least two distinct modes, including a manufacturing test mode in which a die crack test result is communicated from the package out of a JTAG port, and a field test mode in which the die crack test result is communicated from the package out of a data transfer port. A vehicle computer system may perform a fail safe action based on the die crack test result.