121st General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for Young Scholars in Physical Chemistry
Room No. Room 402
Time THU 10:24-:
Code PHYS.O-8
Subject Crystalline structure analysis of carbon materials with micro-Raman spectroscopy
Authors Junghwa Lee
Measurement & Analysis group, Samsung Electro-Mechanics, Korea
Abstract MLCC (Multi-Layer Ceramic Capacitor) composed of internal metal electrodes and dielectric ceramic layers is a representative passive component for electronic products. Since the crystallization starts at different temperature for MLCC materials, cracks between electrodes and dielectric layers can be caused during several sintering processes. According to the previous experiments, it is important to control both the amount and the characterization of the residual carbon. In this study we concentrated to clarify the correlation between the structural property of the residual carbon and the crack failure through high sintering temperature. First, Raman spectra are measured by micro-Raman spectroscopy system (Horiba, Ltd. T64000) with He-Ne laser (633 nm). All MLCC samples show carbon D (1350 cm-1) and G (1580 cm-1) bands which are characteristic peaks observed from graphitic lattice vibration. The D band is also known as a defect band. Therefore when the degree of disorder increased, the intensity ratio (ID/IG) increased too. Also the bandwidth (FWHM) of G, D band depends on the structural disorder of carbon materials. Second, we used mathematical fitting process using Marquart algorithm (The MathWorks, Inc. Matlab) to analyze Raman spectra. Raman spectra are well fitted with 5 gaussian functions and 1 linear baseline function. From the amplitude and FWHM of fitted parameters, we could figure out the optimal sintering temperature shows the lowest ID/IG and FWHM which means most ordered structure. We estimate the ordered structure of residual carbon can act as a protection layer of internal metal electrodes and can result in the reduced gap between metal and ceramic crystallization temperature.
E-mail junghwa82.lee@samsung.com