Method of filling conductive material into through holes of printed

Abstract

To achieve the above object, the invention provides a novel method of filling through holes of a printed wiring board with conductive filler material by initially feeding compressed air to the conductive filler material by initially feeding compressed air to the conductive filler material across mask in the direction of through holes so that pressurized conductive filler material can be filled into through holes from a conductive-material extruding nozzle unit. It is suggested that such silk screen be used for the mask, which is provided with through holes at positions corresponding to the positions of these through holes of the printed wiring board. It is also suggested that such a nozzle assembly unit be used, which incorporates a conductive-material storing chamber and a nozzle tip member at the tip of this chamber, and yet, a conductive-material supply unit is connected to an operating unit of an extrusion valve in the chamber so that the conductive filler material can be delivered to the tip of the nozzle assembly unit. It is also suggested that a dolly unit be used at a position corresponding to the mask composed of silk screen. Furthermore, it is suggested that solvent-free conductive filler material be used.