Passivation of ring electrodes

摘要

An inkjet device includes: a pumping chamber; a piezoelectric layer disposed above the pumping chamber; a ring electrode having an annular upper portion and an annular lower portion disposed on the piezoelectric layer; and a moisture barrier layer covering a remainder of the piezoelectric layer over the pumping chamber that is not covered by the annular lower portion. The annular upper portion includes an annular inner upper portion and an annular outer upper portion. The annular lower portion includes an annular inner lower portion and an annular outer lower portion. The annular inner upper portion extends inwardly from the annular inner lower portion to cover a portion of the moisture barrier layer surrounded by the annular inner lower portion. The annular outer upper portion extends outwardly from the annular outer lower portion to cover a portion of the moisture barrier layer that surrounds the annular outer lower portion.