A Newly Developed System for Small Annular Ring Formation

Fine line circuitry has become much more common in printed wiring board manufacturing during the past decade. Manufacturers are currently producing 4 or 5 conductor lines between circuits. Line definition is 100 μm line and space and high yields in manufacturing must be achieved when small land through‐holes with small annular rings are now being fabricated to meet the requirements of high density circuits by plating, hole filling and so forth. This company has found that a newly developed combination of vacuum lamination and primary imaging dry film which is suitable for small annular ring formation will offer advantages not available with current technologies. It has advantages such as more than 60 μm encapsulation of resist into through‐holes, no ten breakage when incorrect registration of phototool with 130 μm occurs and availability of 2.5 m/min lamination speed. The Hi‐VS System will make it possible to obtain higher yield in very fine line fabrication.