Optoelectronic chip on film (OE‐COF) packaging technology

Abstract

SUMMARYAs a next-generation film carrier packaging technique intended for applications to high-speed large-capacity optical modules, OE-COF (Optoelectronic Chip on Film) packaging is proposed, in which LSIs and optical devices are installed on an optoelectronic compound film (OE film) by means of solder bumps. Its realizability is discussed. A 10-channel VCSEL of the 0.85-µm band with a 250-µm pitch is flip-chip mounted on an OE film by using thirty-six 80% Au-Sn solder bumps with a diameter of 40 µm. In regard to the basic configuration that couples an optical waveguide via a 45° mirror formed on the OE film, a mechanically strong flip-chip mounting of the VCSEL on an OE film and a low-loss optical coupling structure of the VCSEL and the OE film are discussed. As a result, a lowthermal-expansion OE film (11 × 10 -6

An experimental and numerical investigation into the effects of the chip‐on‐film (COF) processing parameters on the Au‐Sn bonding temperature

“…To support the development of next-generation packaging methods, various researchers have attempted to enhance the performance of the COF packaging process or to develop new bonding methods for fine-pitch packages (Kumano et al, 2001;Takahara et al, 2002;Li and Hong, 2005;Jang et al, 2007). Kumano et al (2001) demonstrated the feasibility of extending the stud bump bonding flip-chip technique used for the bonding of chip size packages and multi-chip modules to the COF packaging process.…”

“…Kumano et al (2001) demonstrated the feasibility of extending the stud bump bonding flip-chip technique used for the bonding of chip size packages and multi-chip modules to the COF packaging process. Takahara et al (2002) discussed the application of the opto-electronic COF technique to the packaging of high-speed, large-capacity optical modules and showed that the technique enabled the realization of mechanically robust flip-chip mountings of vertical cavity surface emitting lasers with excellent optical guiding properties. Li and Hong (2005) optimized the processing parameters of the traditional COF packaging process using the Taguchi design method and showed that the optimal design reduced the bonding misalignment and increased the bonding strength.…”