ABSTRACT
To meet the demand for small, light, thin, high-performance semiconductor components, there has recently been a great deal of effort in miniaturization. To achieve this, the I/O pin count of the devices must increase and the I/O pin pitch of the devices must decrease. Hence, PWBs (Printed Wiring Boards) with higher wiring densities are essential. It is difficult for conventional PWBs with mechanically drilled plated-through-holes to meet high density interconnection requirement. To
augment the packing efficiency of PWBs, the microvias in PWB dielectric parts are formed by laser drilling. The space created by the drilling is filled with ECAs, and this part provides interconnections between metal layers [1-4].
