Translator Disclaimer
10 June 2006 Thermomigration technology for silicon ball grid array package fabrication
Author Affiliations +
Proceedings Volume 6260, Micro- and Nanoelectronics 2005; 62601D (2006)
Event: Micro- and Nanoelectronics 2005, 2005, Zvenigorod, Russian Federation
Single-crystal silicon is an ideal material for packages. Moreover, it has the same temperature coefficient of expansion as a chip. Silicon has high thermal conductivity and low dielectric penetrability. It also has excellent mechanical properties. In addition, recent trends in engineering literature indicate a growing interest in the use of silicon as a mechanical material. We have developed a design and fabrication technology of SBGA packages. The SBGA package consists of silicon substrate with ball leads arranged under the package base in several rows. A main problem with such a package is a formation of feedthroughs in the silicon substrate. The feedthroughs can be fabricated by means of the aluminum thermomigration (temperature gradient zone melting) method. The thermomigration process is due to dissolution of silicon atoms on the hot side of the molten zone, the transport of the atoms across the zone, and their deposition on the cold side of the zone. We fabricated SBGA carrier which has 0.2×0.2 mm sizes of the feedthroughs and 1.27 mm pitch footprint. The SBGA package has peripheral ball array. Package sizes have 25×25 mm and 576 ball leads. A resistance 0.4 mm length of the feedthrough is equal to 0.5 Ω. The parasitic capacitance is also quite small. In the case 1000 Ω-cm silicon, a parasitic capacitance is only 2.0 pF. Taking this values of 0.5 Ω and 2.0 pF, then we see that the RC time constant of a typical feedthrough is on the order of 1.0 ps.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Vatery I. Rudakov, Boris V. Mochalov, and Nikolai I. Plis "Thermomigration technology for silicon ball grid array package fabrication", Proc. SPIE 6260, Micro- and Nanoelectronics 2005, 62601D (10 June 2006);

Back to Top