| Autor: |
Zaeem Baig, Scott Pozder, Sandeep Mallampati, Eng Chye Chua |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
IRPS |
| DOI: |
10.1109/irps.2019.8720597 |
| Popis: |
Thermal expansion mismatches pose significant challenges to the reliability of flip chip-Ball grid array (FC-BGA) package technology. Technology advancement for FC-BGA packages drives towards thinner substrates, smaller bump pitch and high flow underfills. In this work, the risk of corner cracking is studied using two substrate thickness and underfill types. Environmental stressing is performed beyond the JEDEC recommended limits in order to drive the units to failure. It is observed substrates with a thinner core and underfill with higher CTE produced 5⨯ to 10⨯ more number of cracks in the underfill compared to other cases. Finite element modeling is used to compare the corner stresses to the observed cracking as a means to identify conditions with higher cracking risk. In order to understand if a potential material root-cause of cracking exists, nanoindentation is used to measure the hardness and elastic modulus of underfills before and after stressing. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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