Ultrasonic Inspection Device for Semiconductor Packages
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Solution Overview
Problem
Conventional ultrasonic inspection devices face challenges in focusing ultrasonic waves on semiconductor chips within packaged devices, as the chip cannot be visually recognized, making it difficult to adjust the focal point accurately.
Innovation Solution
An ultrasonic inspection device with a stage control unit that adjusts the distance between the ultrasonic transducer and the semiconductor device based on peaks in the time waveform of reflected waves, allowing for precise focusing of ultrasonic waves on the chip surface within the package, even when the chip is layered.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a packaged semiconductor device is inspected, then the inspection can be performed on the device in its final state, but the chip cannot be visually recognized making it difficult to focus ultrasonic waves accurately
Solution Approach 1:
The system uses feedback from detected reflected wave peaks to automatically adjust the ultrasonic transducer position. The stage control unit monitors the time waveform of reflected waves and adjusts the distance between the transducer and semiconductor device to maximize the peak signal, thereby automatically achieving optimal focus on the chip without visual recognition.
Solution Approach 2:
The system performs self-alignment by using the reflected waves from the chip itself as the focusing reference. The chip's own reflection signal serves as the feedback mechanism to automatically position the ultrasonic focus, eliminating the need for external visual guidance or manual adjustment.
2Measurement precision
If the distance between ultrasonic transducer and semiconductor device is manually adjusted, then the operator can try to focus on the chip, but without visual recognition the focusing precision is insufficient
Solution Approach 1:
The patent replaces manual mechanical adjustment with an automated control system. The stage control unit uses electrical signals based on detected peak positions to automatically adjust the mechanical stage position, substituting human operator skill with an automated feedback control mechanism that achieves higher precision.
Solution Approach 2:
The system changes the control parameter from manual position estimation to objective measurement of reflected wave peak amplitude. By using the peak signal strength as the focusing criterion, the system transforms the focusing task into a measurable parameter optimization problem that can be solved automatically.
3Ease of manufacture
If ultrasonic waves are focused on a packaged device, then inspection can be performed without removing the chip, but the focal point cannot be easily positioned on the chip surface
Solution Approach 1:
The system employs feedback control where the detected peak position in the reflected wave time waveform guides the stage movement. The stage control unit continuously monitors the peak signal and adjusts the transducer-chip distance to maximize the reflected wave amplitude, ensuring accurate focusing on the chip surface while maintaining package integrity.
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
Enables easy and accurate adjustment of the focal point of ultrasonic waves to the desired position on a packaged semiconductor device, improving inspection accuracy by maximizing peak detection and utilizing package information for efficient waveform focusing.
Implementation Method 1
a reflection detection unit configured to detect reflected waves of the ultrasonic waves reflected by the semiconductor device
Implementation Method 2
it is possible to easily adjust a focus of the ultrasonic waves to a position of the chip in the package by controlling the distance between the semiconductor device and the ultrasonic transducer on the basis of the peak
Data Source
AI summary
This ultrasonic inspection device, for inspecting a packaged semiconductor device, is provided with: an ultrasonic transducer which outputs ultrasonic waves to a semiconductor device; a receiver (a reflection detection unit) which detects reflected waves of the ultrasonic waves reflected on the semiconductor device; a stage which moves the positions of the semiconductor device relative to the ultrasonic transducer; a stage control unit which controls driving of the stage; and an analysis unit which analyzes the reaction of the semiconductor device to the input of the ultrasonic waves from the ultrasonic transducer. The stage control unit controls the distance between the semiconductor device and the ultrasonic transducer on the basis of a peak occurring in time waveform of the reflected wave detected by the receiver.