Semiconductor Inspection Circuit for Multi-Path Wiring Defect Detection
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Solution Overview
Problem
Existing inspection methods struggle to effectively monitor the connection state of power supply, ground, and signal pins in semiconductor LSI systems, particularly in complex configurations like System in Package (SiP) with high bandwidth memory, due to difficulties in testing multiple paths and ensuring operation reliability.
Innovation Solution
A semiconductor device with a circuit configuration that includes path switching circuits, resistance switchers, and voltage observation circuits to monitor the connection states of power supply and ground pins by applying specific logic inputs and observing power variation waveforms, allowing for the detection of breakages or defects in microbump connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a static current is applied to a wiring portion connecting circuit blocks via an external resistor to monitor connection state, then the breakage state of microbump can be visualized by voltage measurement, but it is difficult to test wiring portions where one pin is connected to multiple target pins through multiple paths such as power supply pins or ground pins
Solution Approach 1:
The patent divides the multi-path wiring inspection problem into multiple single-path inspection tasks by introducing path switching circuits. These circuits selectively connect different wiring paths to the inspection circuit one at a time, allowing each path to be inspected individually using the existing static current method. This segmentation enables the inspection system to handle complex multi-path configurations while maintaining measurement precision.
Solution Approach 2:
The patent employs dynamic path switching circuits that can change connection configurations based on inspection requirements. The switching circuits dynamically redirect the inspection current to different wiring paths, enabling the system to adapt to various wiring topologies including power supply pins and ground pins with multiple connections. This dynamic reconfiguration transforms a static inspection limitation into a versatile multi-path testing capability.
2Adaptability or versatility
If path switching circuits and resistance switchers are added to enable multi-path wiring inspection, then adaptability to test power supply and ground pins is improved, but device complexity increases
Solution Approach 1:
The patent designs the path switching circuits and resistance switchers to serve multiple functions: they enable inspection of signal pins, power supply pins, and ground pins with various connection configurations using a single unified inspection circuit. The resistance switcher, in particular, can operate in different resistance states to accommodate different inspection modes, reducing the need for multiple specialized circuits and thereby managing complexity through multi-functionality.
Solution Approach 2:
The path switching circuits act as intermediaries between the simple static current inspection method and the complex multi-path wiring configurations. Rather than modifying the inspection method itself, the switching circuits mediate by adapting the wiring connections to match the inspection circuit's capabilities, thus enabling versatile inspection without fundamentally complicating the core measurement technique.
3Reliability
If function test is performed on the entire package to detect wiring defects, then wiring defects can be detected, but it is not always easy to clarify a correlation between function defect and wiring defect
Solution Approach 1:
The patent applies segmentation by dividing the entire package wiring into individual inspectable paths using path switching circuits. Instead of performing a blanket function test on all wirings simultaneously, the system segments the wiring into discrete paths that can be individually targeted and inspected. This segmentation enables precise localization of wiring defects by isolating them to specific paths, making it easy to correlate function defects with their underlying wiring causes.
Solution Approach 2:
The inspection circuit with path switching capability serves as an intermediary between the functional test system and the wiring structure. It translates functional test requirements into targeted wiring path inspections, providing a bridge that connects system-level function testing with component-level wiring defect detection and localization.
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 provides reliable monitoring of connection states for power supply, ground, and signal pins, ensuring operation reliability by detecting abnormalities in power impedance and current distribution, applicable to a wide range of semiconductor products, including information devices and in-vehicle systems.
Implementation Method 1
an electrical resistance of the microbump portion increases when the breakage of the microbump portion progresses, it is possible to visualize the breakage condition by decreasing a voltage generated in an external resistor portion when a static current flows
Data Source
AI summary
Provided is a semiconductor inspection circuit which is capable of inspecting connection states of power supply, ground, and signal bumps in a semiconductor package or a printed circuit board equipped with a semiconductor LSI mounted in a product operation state. As a means to solve the problem, a circuit capable of switching a path is provided at an input portion of a driver/receiver, a mechanism capable of transferring an output of a path switching circuit near a receiver circuit to a voltage waveform circuit with an internal variable terminal is provided, and a breakage state of a bump can be observed in the product operation state by observing a DC level at a terminal having a certain DC resistance when a signal bump connection state is observed and receiving a step wave and observing a response waveform thereof when an IO power supply bump connection state is observed.