US Patent 11684988 Prevention of dripping of material for material injection

An injection apparatus for injection material is disclosed. The injection apparatus includes a tank for storing material. The injection apparatus further includes a head body that has a surface for contacting a substrate and an opening part opened at the surface for discharging the material in fluid-communication with the tank. The injection apparatus further includes a member connected to the opening part, in which the member allows gas to flow into and flow out from the opening part.