TANAKA Kikinzoku Kogyo K.K., which develops industrial precious metals products as one of the core companies of TANAKA Precious Metals, announced that it has established a gold particle bonding technology for high-density mounting of semiconductors using AuRoFUSE™ low-temperature fired paste for gold-to-gold bonding.
AuRoFUSE™ is a composition of submicron-sized gold particles and a solvent that creates a bonding material with low electrical resistance and high thermal conductivity to achieve metal bonding at low temperatures. Using AuRoFUSE™ preforms (dried paste forms), this technology can reach 4 μm fine-pitch mounting with 20 μm bumps. Formed through a thermocompression bonding process (20 MPa at 200°C for 10 seconds), AuRoFUSE™ preforms exhibit compression of approximately 10% in the compressive direction while showing minimal deformation in the horizontal direction. This gives them sufficient bonding strength1 for practical applications, making them suitable for use as gold bumps. With the main component being gold, which has a high level of chemical stability, AuRoFUSE™ preforms also provide excellent reliability after mounting.
This technology enables miniaturization of semiconductor wiring and greater integration (higher density) for various types of chips. It is expected to contribute to the high-level technical innovation required of advanced technologies, including optical devices such as light-emitting diodes (LEDs) and semiconductor lasers (LDs), and use in digital devices such as personal computers, smartphones, and in-vehicle components.
TANAKA will actively distribute samples of this technology in the future to promote greater awareness in the marketplace.