About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Electronic Packaging and Interconnection Materials IV
|
| Presentation Title |
Achieving Fluxless Bonding of Pure Indium TIM via Silver Metallization for Heat Dissipation in HPC Packaging |
| Author(s) |
Chih-Yun Chang, Yuan-Han Ku, C. Robert Kao |
| On-Site Speaker (Planned) |
Chih-Yun Chang |
| Abstract Scope |
The use of indium as a thermal interface material (TIM1) in flip chip ball grid array (FCBGA) packages is limited by the post-lid ball mounting reflow process because trapped flux vaporizes and results in severe voiding. To address this issue, a fluxless bonding process utilizing an Ag surface finish on the metal lid was developed. Indium joints with varying Ag thicknesses (0, 0.5, and 1.0 µm) were evaluated for TIM performance by multiple reflow tests (MRT) and high temperature storage (HTS) tests. Scanning acoustic tomography (SAT) confirmed that the 1.0 µm Ag finish effectively suppressed voiding, maintaining 91% TIM coverage after 10 SAC reflow cycles. Microstructural analysis revealed that a stable AgIn₂ intermetallic compound (IMC) facilitated excellent fluxless wetting. Furthermore, thermal resistance, shear strength, fracture behavior, and HTS data are characterized to verify the heat dissipation performance and long-term reliability of the proposed fluxless solution. |
| Proceedings Inclusion? |
Planned: TMS Journal: Journal of Electronic Materials |
| Keywords |
Electronic Materials, Joining, Surface Modification and Coatings |