Kiyotaka Seyama

High performance MCM-D technology

FUJITSU has developed an MCM-D technology which uses bare chips on composite thin films for mounting CMOS chips with high density and low cost. The first use of this technology is for the K6000 Series business server. This MCM technology can be applied to a wide range of computers, from workstations to mainframes to reduce costs and improve performance. This paper focuses on the MCM packaging technology, MCM substrate technology, cooling technology and numerical analysis technique.<<ETX>>

Transcription solder bump technology using the evaporation method

We have developed a new transcription solder bump (TSB) technology using the evaporation method. We use this method in the current production of micro solder area array bump (/spl mu/SAB) formation with 153 /spl mu/m pitch and on chips with over 8000 bumps. In this method, transcription bumps are formed on a dummy wafer by evaporation using a metal mask. Temporary chips are made by dicing the dummy wafer with evaporated bumps, and then the bumps on the temporary chips are transcribed to real chips. This technology has a high accuracy in terms of bump height of less than 2 /spl mu/m, and bumping yield is greater than 99.99999% per bump. Also, we have developed a restoration technique for solder bumps with high yield and low cost.