Die Integrity Detection Circuit for Chip Scale Packages
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Solution Overview
Problem
Chip scale packages lack mechanical protection, making the silicon die vulnerable to damage during manufacturing, assembly, and end-use, and existing methods like optical inspection are limited in detecting defects once the die is packaged or integrated.
Innovation Solution
A detection circuit and wire loops or circuit traces are used to monitor the integrity of the die's perimeter, detecting mechanical and electrical issues by checking continuity and preventing operation if a fault is detected, and communicating faults via a fault pin or serial interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If chip scale packages are used to reduce size and cost, then manufacturing efficiency and productivity are improved, but the die becomes vulnerable to mechanical damage and reliability deteriorates
Solution Approach 1:
The patent implements preliminary action by incorporating wire loops and detection circuits into the die structure before packaging. These monitoring systems are built in advance to detect mechanical damage, allowing the system to proactively identify and respond to integrity issues before they cause failure, thus maintaining reliability while using compact chip scale packages.
Solution Approach 2:
The patent uses wire loops as intermediary elements that physically follow the perimeter of the die and detection circuits as mediators that translate mechanical damage into detectable electrical signals. These intermediaries enable monitoring of die integrity without adding significant size, resolving the contradiction between compact packaging and mechanical protection.
2Reliability
If traditional encapsulation is used to protect the die, then mechanical strength and reliability are improved, but device size increases and manufacturing complexity worsens
Solution Approach 1:
The patent extracts the protection function from traditional bulky encapsulation and implements it through integrated monitoring circuits and wire loops within the chip scale package structure. This separates the mechanical protection role (handled by the package substrate) from the integrity monitoring role (handled by the detection circuit), reducing overall device complexity while maintaining reliability.
Solution Approach 2:
The detection circuit serves multiple functions: monitoring wire integrity, detecting mechanical damage, and providing fault detection capability. This multi-functionality eliminates the need for separate protection mechanisms, reducing device complexity while maintaining reliable die protection in chip scale packages.
3Measurement precision
If optical inspection is used to detect defects, then measurement capability is improved, but it cannot detect defects once the die is packaged or integrated and device complexity increases
Solution Approach 1:
The patent replaces external optical inspection systems with integrated electrical monitoring circuits that continuously monitor wire loop integrity. This substitution enables defect detection to occur after packaging and integration without requiring complex external inspection equipment, maintaining measurement precision while reducing device complexity.
Solution Approach 2:
The detection circuit provides self-service by continuously monitoring its own operational environment through the wire loops. The system automatically detects mechanical damage and integrity issues without requiring external inspection, enabling ongoing defect detection capability that works after packaging and integration while avoiding additional inspection system complexity.
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
The solution effectively detects and responds to mechanical failures in chip scale packages, reducing the risk of defective units and potentially preventing damage by continuously monitoring the die's integrity during manufacturing, assembly, and operation, eliminating the need for optical inspection.
Implementation Method 1
The detection circuit is electrically coupled to first and second points of each of the one or more wires and is configured to monitor the one or more wires and detect a problem with the integrity of the die
Data Source
AI summary
A detection circuit and one or more wires or circuit traces are included in a die. The combination is used to detect mechanical failure of the substrate, e.g. silicon after singulation of the dice from the wafer. Failures may be detected at different regions or planes within the die, and the tests may be performed during operation of the packaged die and integrated circuit, even after installation and during operation of a larger electronic device in which it is incorporated. This is especially useful for chip scale packages, but may be utilized in any type of IC package.