Various element technologies are built up through our development projects such as the ultra thin, 0.8 mm 4-die stack package and the 20-die stack package (twenty 30 um thick dies stacked).  We effectively employ and utilize these technologies for mass production and new product development.

Wafer Thinning Technology

Crucial to development and production of thin packages and stacked packages is wafer thinning technology.  At Akita Elpida, wafer back is ground down to thinner than copy paper for mass production.  Furthermore, Akita has established the back-grinding technology to thin down to 25um.  A 25um thick wafer is so thin that it curls or folds like a paper or cloth. As wafer thickness reduces, later production processes such as dicing, die pick-up, wire bonding, and molding become dramatically more difficult.

Wire-Bonding Technology

For development and production of thin packages and stacked packages, advanced wire bonding technology is essential. Making available a broad range of wiring processes such as long wire, chip to chip, overhang wire, low loop wire, and short wire, we offer best-suited wiring processes to achieve desired thin and stacked packages.

Flip Connection Technology

For small, thin, high density packages, flip chip connection is essential. Forming protruding electrodes called "bumps" using metal connection material (Au), 　chips are electrically and directly connected onto a substrate with the circuit side down. 　Also for development of TSV (Through Silicon Via), this bump connection technology is employed to connect inter-chip through silicon electrodes.