Method and apparatus for screen printing registered images on opposite sides of a web

摘要

A method and machine are disclosed for screen printing acid-resist mirror inversion images in registration on opposite sides of a metal web with a degree of precision sufficient to permit the incorporation of screen printing techniques in the fabrication of lead frames, electromagnetic core laminations, and other metal plate products by chemical milling processes. A matched pair of upright screen stencils supported in spaced relation on opposite sides of the web is provided with a cooperable pair of squeegees for printing through the image areas of the stencils. The directly opposed squeegees are mounted on a common reciprocable carriage for conjoint movement such that printing on opposite sides of the web is effected synchronously. In preferred forms, a web drive is provided for incrementally advancing the web between the stencils and for holding the web under tension during printing. A screen separator mounted on the carriage in offset relation to the squeegees assures release of the stencils from the web after printing.