Addition Of Extra Layer Research Articles

Horizontal processing for metallizing microvias

The demand for higher operating speeds and increasing densification in electronic packages is driving designers to reduce feature sizes in order to accommodate increases in I/O counts. Consequently, printed circuit board manufacturers are turning to new manufacturing techniques and new materials in order to meet these demands from their customers. Sequential build‐up is one such technique and a plethora of new materials is available to support these innovative routes to high‐density interconnect circuitry. The basic concept involves the addition of extra layers of dielectric and copper on to a multi‐layered board. The additional circuitry is then connected to the underlying board using suitably formed microvias. Focuses on the metallization of microvias using a straight‐through horizontal metallization process. Particular emphasis is placed on the importance of equipment design, the chemistry of the solutions used and optimization of fluid exchange to ensure good coverage of these small features.