Fumio Echigo

The progress of the ALIVH substrate

The next generation ALIVH substrates were developed named ALIVH G-type for the motherboard use and ALIVH-FB for semiconductor package use. The ALIVH G-type has lower moisture absorption and higher rigidity than the conventional ALIVH. The insulator material of conventional ALIVH is a non-woven aramid-epoxy prepreg. On the other hand, the ALIVH G-type uses glass-epoxy prepreg. We developed the resin flow control technology during the hot press lamination process for hindering the conductive particle in the via paste diffusion. We expect to realize the halogen free ALIVH and liberate the ALIVH from the moisture control, using the glass-epoxy prepreg. The ALIVH-FB has the same structure as the ALIVH. The design rule is minimised for the semiconductor package. The design rule of ALIVH-FB is Line/Space=25/25 /spl mu/m and Via Diameter/Land Diameter=50/150 /spl mu/m. The ALIVH-FB uses three new technologies of: (1) film insulator; (2) YAG THG laser drilling process; and (3) accurate alignment process. The ALIVH-FB is very suitable for semiconductor package use by the fine via on via structure and the properties of the film insulator.

Magnetic recording characteristics of a flexible disk with a non-magnetic underlayer

Abstract We have examined a flexible disk for high recording density (35 kFCI, 542 tpi), and with a maximum transfer rate of 4.5 MBPS. By setting the magnetic layer thickness at less than 0.4 μm, the media coercivity at more than 120 kA/m, and applying it to a non-magnetic underlayer, we have realized useful flexible disk media wear resistance of 2×10 7 passes.