Patent ID: 8523329

Claim:
An inkjet printhead substrate comprising: a pair of individual conductive layers configured to supply electrical power to a heat generation element which generates thermal energy for discharging ink; a first common conductive layer configured to be connected to one of said pair of individual conductive layers, and supply electrical current to said pair of individual conductive layers; a second common conductive layer configured to be connected to the other of said pair of individual conductive layers, wherein said electrical current flows into said second common conductive layer from said pair of individual conductive layers; and an isolation layer configured to be provided between said one of said pair of individual conductive layers and said first common conductive layer, and between the other of said pair of individual conductive layers and said second common conductive layer, wherein said isolation layer is formed from a conductive material which has a lower solubility in ink than a material used for said pairs of individual conductive layers, said first common conductive layer and said second common conductive layer.