Cross-sectional observation of substrate-mounted components (1) to (6)

In the methods for cross-section preparation in semiconductor structural observation and defect analysis, CP, FIB, and mechanical polishing are mentioned, each having its own advantages and disadvantages, making it necessary to consider which method to use. In recent years, CP and FIB have become more common, and it seems that the use of mechanical polishing, which requires technical skill, is decreasing. However, it is still not to be dismissed. While there are merits and demerits, it is possible to achieve cross-section preparation with mechanical polishing that is comparable to FIB and CP. At our company, based on years of accumulated know-how, we propose the most appropriate processing methods according to the observation purpose and the composition and structure of the samples.

We would like to introduce an example of cross-sectional observation of mounted components conducted by our company. Using commercially available computer circuit boards, we observed the solder joints of mounted components and the internal structures of the components using a metal microscope. The observation modes of the metal microscope include bright field observation, dark field observation, and polarized light observation, among others. Additionally, there are observations using transmitted light, and the observation mode is selected according to the sample. By conducting cross-sectional observations before and after reliability testing, we can evaluate the reliability of the product. When observing, it is important to select an appropriate "observation mode" to clearly capture the condition of the solder joint interface and defects such as cracks.