Patent ID: 8371217
Filing Date: 2013-02-12
Classification: B23K,B41F,H05K

Abstract:
1. A screen printing head which, in a printing operation, is displaceable in a first direction over a surface of a workpiece to print deposits of a print medium on the workpiece, the screen printing head comprising: a print head assembly comprising a print unit comprising a main body including a print medium cavity, which in use contains a print medium, and a delivery aperture, which is in fluid communication with the print medium cavity and through which print medium is in use delivered from the print medium cavity to the surface of the workpiece, and a rotatable unit which is disposed in the print medium cavity of the main body and rotatable to displace print medium as contained in the print medium cavity, wherein the rotatable unit comprises a hollow body member which includes an inner cavity and a plurality of transfer apertures which fluidly connect the inner cavity with the print medium cavity; and a drive unit for rotating the rotatable unit such as to displace print medium as contained in the print medium cavity, wherein, during displacement of the screen printing head in the first direction in the printing operation, the drive unit rotates the rotatable unit to apply a force to the print medium at the delivery aperture in the main body in a second direction which is opposite to the first direction of displacement of the screen printing head.