Abstract
This paper is targeted to investigate the correlation of thermo-mechanical reliability of no-flow flip-chip packages with the mechanical properties of the involved no-flow underfill materials. Our previous research indicates that the no-flow underfill materials alone have significant impact on the collapse-controlled chip connection (C4) joint reliability. This implies that there are some unknown material properties or factors that can play important role in determining the C4 joint reliability. Two possible factors are fracture toughness (KIC) and fatigue property of the cured no-flow underfill materials. Seven no-flow underfill materials are formulated. Each should have at least one material property noticeably different from the others, so that a spectrum of any interested material property can be obtained. The interested material properties include heat distortion temperature (TMA Tg measured by thermo-mechanical analyzer), coefficient of thermal expansion (CTE), modulus, die shear strength, KIC, and fatigue. The experimental procedures for the measurement of TMA Tg, CTE, modulus, die shear strength, and voiding have been described in detail in our former papers. The measurement of KIC is conducted using single edge notch bending (SENB) specimens. The specimens for fatigue testing are in dog-bone shape as described in ASTM D638M. The obtained S-N (Stress-Fatigue Life) curve is used as the measurement of the material fatigue property. The interested responses that we want to collect includes the number of cycles under -55 °C to 125 °C air to air thermal cycling test and -55 °C to 125 °C liquid to liquid thermal shock test, and the failure mode of the C4 joint and cured underfill material. After all these data have been collected, a multi-variable regression and correlation analyses will be performed to extract the close correlation of C4 joint reliability with each material property or the combination of several material properties. With these analyses, a clearer direction will be obtained to improve the key material properties to realize the desired package reliability.
Original language | English |
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Pages | 271-277 |
Number of pages | 7 |
State | Published - 2000 |
Event | International Symposium and Exibition on Materials Processes, Properties and Interfaces - Braselton, USA Duration: 6 Mar 2000 → 8 Mar 2000 |
Conference
Conference | International Symposium and Exibition on Materials Processes, Properties and Interfaces |
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City | Braselton, USA |
Period | 6/03/00 → 8/03/00 |