Method for making liquid ejection head

A method for making a liquid ejection head comprising a plurality of ejection ports, a liquid passage having a plurality of pressure chambers communicating with the plurality of ejection ports, and a plurality of piezoelectric elements corresponding to the plurality of pressure chambers with isolated pressure-transmitting portions between the corresponding piezoelectric elements and pressure chambers, respectively, the plurality of piezoelectric elements being arranged in a comb shape, the method comprising the steps of:

• (a) filling the spaces between the piezoelectric elements with a filler;
• (b) forming a pressure-transmitting layer for forming the isolated pressure-transmitting portions on a planar surface including ends of the plurality of piezoelectric elements;
• (c) placing a diaphragm on the pressure-transmitting layer and forming a pattern for the liquid passage on the diaphragm;
• (d) forming a coating layer on the pattern for the liquid passage;
• (e) removing the pattern for the liquid passage to form the plurality of pressure chambers;
• and
• (f) removing the pressure-transmitting layer except for the portions corresponding to the plurality of pressure chambers, to form the isolated pressure-transmitting portions.