US Patent 10336071 Multi-nozzle print head

A print head (1) for depositing a liquid on a substrate comprises a layer structure including a stop layer (5) made of a dielectric material, an electrically conducting device layer (6), and an insulator layer (7) made of a dielectric material. A nozzle (3) is formed in the layer structure. The nozzle has a nozzle opening (34) for ejecting the liquid. A ring trench (31) is formed around the nozzle. The nozzle opening and the ring trench are radially separated by an annular nozzle wall (32). An ejection channel (37) is formed adjacent to the ring trench along the direction of ejection. An extraction electrode (8) is arranged on the insulator layer (7) and surrounds the nozzle.