New high-density multilayer technology on PCB

We have developed a new high-density multilayer technology on PCB (Printed Circuit Board), named DSOL (Deposited Substrate On Laminate) technology. The first characteristic of the DSOL technology is the dielectric fabrication, which uses a new photosensitive material, a bulky fluorene unit bonded epoxy acrylate resin. The fluorene based resin has interesting properties such as good electrical properties, low curing temperature (160°C) for a heat-resistant resin (glass transition temperature: 230°C), low coefficient of thermal expansion (40 ppm), and high resolution. In particular, the dielectric formation process has the advantage that fine and high-aspect-ratio via holes are formed on FR-4 laminates through exactly the same process and manufacturing facilities as a conventional photosensitive epoxy resin. The second characteristic is the technology which patterns fine-pitch copper conductors using a semi-additive process with a sputtering method. This technology makes 40 μm pitch lines on large-area laminates possible, as this process consists of flash wet etching of only 0.3 μm thick sputtered thin-films. We have successfully developed a high-density packaging substrate for high-pin-count area array ASIC (Application Specific Integrated Circuit) chips (3828 pins). A high-density substrate based on the DSOL technology is the most suitable for achieving high-density packages (MCMs, CSPs, and BGAs) using fine-pitch and area array interconnection technologies