Height measurement of microbumps using a white-light triangulation method.
Applied Optics
|March 17, 2022
Summary
This study introduces a new method for measuring microbump height using white-light triangulation. This technique ensures reliable chip connections by accurately assessing microbump uniformity, crucial for advanced electronic packaging.
Area of Science:
- Semiconductor manufacturing
- Advanced packaging technologies
- Metrology and measurement science
Background:
- Microbumps are essential for chip interconnects in advanced packaging, enabling higher performance and density.
- Accurate microbump height and coplanarity are critical for connection reliability and preventing chip failure.
- Non-uniform bump height leads to connection issues and reduced manufacturing yield.
Purpose of the Study:
- To develop and validate a novel height measurement method for microbumps.
- To improve the reliability and yield of advanced semiconductor packaging.
- To provide an accurate and efficient metrology solution for microbump characterization.
Main Methods:
- Utilized white-light triangulation combined with the geometrical characteristics of microbumps.
- Developed a measurement system with a linear light projection module and a high-quality imaging module (CCD camera, microscope).
- Analyzed projection and imaging models for microbumps illuminated by a scanning light plane.
Main Results:
- A simple formula was derived to compute microbump height based on system geometry.
- Measurement results demonstrated good agreement with a commercial optical profiler.
- Detailed analysis of measurement uncertainty was performed.
Conclusions:
- The proposed white-light triangulation method offers an accurate approach for microbump height measurement.
- This method contributes to enhancing the reliability and yield of microelectronic devices.
- The technique provides a valuable tool for quality control in advanced packaging processes.
