| Autor: |
Xu, T., Du, Y., Luo, H., Kim, G., Xu, Z., Minary-Jolandan, M., Stark, L., Baughn, T., Lu, H. |
| Předmět: |
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| Zdroj: |
Experimental Mechanics; Sep2017, Vol. 57 Issue 7, p1135-1147, 13p |
| Abstrakt: |
The mechanical properties of a molding compound on a packaged integrated circuit (IC) were measured by spherical nanoindentation using a 50 μm radius diamond tip. The molding compound is a heterogeneous material, consisting of assorted diameters of glass beads embedded in an epoxy. Statistical analysis was conducted to determine the representative volume element (RVE) size for a nanoindentation grid. Nanoindentation was made on the RVE to determine the effective viscoelastic properties. The relaxation functions were converted to temperature-dependent Young's modulus at a given strain rate at several elevated temperatures. The Young's modulus values at a given strain rate from nanoindentation were found to be in a good agreement with the corresponding data obtained from tensile samples at or below 90 °C. However, the values from nanoindentation were significantly lower than the data obtained from tensile samples when the temperature was near or higher than 110 °C, which is near the glass transition. The spatial distribution of the Young's modulus at a given strain rate was determined using nanoindentation with a Berkovich tip. The spatial variation of the Young's modulus at a given strain rate is due to the difference in nanoindentation sites (glass beads, epoxy or the interphase region). A graphical map made from an optical micrograph agrees reasonably well with the nanoindentation results. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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