Die-Ring Sequencing Circuit for Fast Semiconductor Defect Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor die defect detection methods are inefficient in detecting cracks and other defects, particularly in high-volume production, as they are either too slow or lack sensitivity, and customers face challenges in reading out test results effectively.
Innovation Solution
A die-ring circuit with a symmetrical semiconductor die layout that employs a resistance comparison technique using a voltage comparator, current mirror, and adjustable resistor to self-compare die-ring segments, enabling both digital and analog testing with automated sequencing and a simple readout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual inspection methods are used to detect die cracks, then detection capability is provided, but production speed becomes prohibitively slow and impractical for volume production
Solution Approach 1:
The patent replaces mechanical visual inspection with an electrical resistance measurement system. A die ring circuit is formed around the periphery of the die, with test structures including resistors and conductors arranged in a ring configuration. By applying a test voltage and measuring resistance changes in the die ring, the system automatically detects cracks and defects without requiring manual visual inspection, thereby maintaining high detection capability while enabling rapid automated testing suitable for volume production.
2Productivity
If automated resistance comparison testing is implemented, then testing efficiency and sensitivity are improved, but device complexity increases due to additional circuit components
Solution Approach 1:
The die ring circuit is designed to serve multiple functions within a single integrated structure. The same ring circuit performs both analog resistance comparison for detecting partial opens and shorts, and digital testing for crack detection. The test structures include resistors, conductors, and comparison circuits that can operate in different modes, eliminating the need for separate testing systems and reducing overall device complexity while maintaining high testing efficiency and sensitivity.
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
Enhances defect detection accuracy and efficiency by allowing simultaneous digital and analog testing with automated sequencing, reducing the need for statistical analysis and improving sensitivity to shorts and partial opens.
Implementation Method 1
employs a resistance comparison technique using a voltage comparator
Implementation Method 2
current mirror
Data Source
AI summary
A semiconductor die defect detection device including a current mirror providing a first current on its first output and a second current on its second output, the first and second currents being identical, a swap circuit having a first terminal connected to the first output of the current mirror, a second terminal connected to the second output of the current mirror, a third terminal and a fourth terminal. The device also includes a die ring circuitry disposed at edges of the semiconductor die including a first plurality of segments disposed on a first leg of the die ring circuitry, and a second plurality of segments disposed on a second leg of the die ring circuitry. The device further includes a voltage comparator including a positive input terminal, a negative input terminal and an output terminal, and an adjustable resistor.