Capillary Self-Assembly for 3D Heterogeneous System Integration and Packaging
- PDF / 675,136 Bytes
- 12 Pages / 432 x 648 pts Page_size
- 0 Downloads / 240 Views
Capillary Self-Assembly for 3D Heterogeneous System Integration and Packaging Yuka Ito1, Takafumi Fukushima2, Kang-Wook Lee3, Tetsu Tanaka4, and Mitsumasa Koyanagi3 1
Sumitomo Bakelite Company, Ltd., 5-8 Higashi-Shinagawa 2-chome, Tennoz Parkside Building, Shinagawa-ku, Japan 2 Graduate School of Biomedical Engineering, Tohoku University, 6-6-12 Aza-Aoba, Aramaki, Aoba-Ku, Sendai, Japan 3 New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aza-Aoba, Aramaki, Aoba-Ku, Sendai, Japan 4 Graduate School of Biomedical Engineering, Tohoku University, Tohoku University, 6-6-12 Aza-Aoba, Aramaki, Aoba-Ku, Sendai, Japan ABSTRACT The self-assembly of known good dies (KGDs) on substrates using the liquid capillary method is shown to be a promising technology to achieve three-dimensional (3D) heterogeneous system integration and packaging. Firstly, the effects of the edge structures of self-assembled substrates and chips on alignment accuracies were investigated. When hydrophobic sidewalls with 10-μm-height steps were applied to both chips and assembly sites formed on substrates, the alignment accuracy within 1.0 μm was realized. The alignment accuracies were within 2.0 μm using either substrates or chips having 10-μm-height step structures with hydrophobic sidewalls. Self-assembly of 12-ch vertical-cavity surface-emitting lasers (VCSELs) with a long rectangle shape on glass substrates were also demonstrated. Separation of assembly sites into twelve areas enhanced the resultant force acting on the VCSEL short edge. The enhanced resultant force provided the high alignment accuracies within 2.0 μm. After the self-assembly of the VCSEL and the subsequent thermal compression, the chips successfully exhibited no degradation of their current–voltage (I–V) characteristics and appropriate 850-nm light emission. We demonstrated self-assembly and microbump bonding using non-conductive film (NCF)-covered dies with Cu/Sn microbumps for high-throughput and high-yield multichip-to-wafer 3D integration. The self-assembly of the NCF-covered dies provided high alignment accuracy within 1.1 μm on average. After the self-assembly of NCF-coved dies and thermal compression, microbump chains composed of 7396 bump joints were successfully obtained, resulting in good electrical properties of 32 mΩ/joint without any bridge shorts and failures. The variations of microbump joint resistance were maintained within 5% of the initial value after thermal cycle testing of even 1000 cycles. INTRODUCTION Three-dimensional (3D) heterogeneous system integration and packaging in which different-sized chips and various materials/devices can be highly integrated is increasingly becoming essential for the advent of new societies called IoT (Internet of Things), M2M (Machine-to-Machine), and Trillion sensors. Such 3D heterogeneous systems with through-Si
2355 Downloaded from https://www.cambridge.org/core. Columbia University Libraries, on 15 Aug 2017 at 09:25:12, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/c
Data Loading...
