THIN FILM PRINT HEAD

PROBLEM TO BE SOLVED: To prevent an ink barrier layer from peeling from a thin film substrate by means of a layer rich in carbon, in a print head. SOLUTION: A thin film substrate 11 of an ink-jet print head includes a silicon substrate 51, a field oxide layer 53, a layer 54 of oxide of phosphorus, a resistance layer 55, and a metal coated layer 57. Complex passivation layers 59, 60 are stacked on the exposed parts of the layer 57 and layer 55 and on the exposed parts of the layer 53. Just above an ink discharge heater resistor 56, a passivation layer 61 of tantalum is stacked on the layers 59, 60. A diamond-shaped carbon(DLC) layer 63 is stacked on a gold layer 62, on the passivation layer 61 of tantalum, and on the exposed parts of the layers 59, 60 to provide a function as an adhesive layer in a region in contact with an ink barrier layer 12.