Liquid ejection head and manufacturing method thereof

A liquid ejection head, comprising:

• a plurality of ejection ports which eject liquid;
• a plurality of pressure chambers which respectively communicate with the ejection ports;
• a plurality of piezoelectric elements which respectively deform the plurality of pressure chambers and are provided to faces of the pressure chambers opposite to faces on which the ejection ports are formed;
• a common liquid chamber which supplies the liquid to the plurality of pressure chambers and is formed on a side of the piezoelectric element opposite to the pressure chamber;
• a plurality of through-holes which stand from connecting portions of the piezoelectric elements substantially perpendicularly to the faces on which the piezoelectric elements are mounted, the through-holes running through a partition wall of the common liquid chamber;
• and
• a plurality of spherical members which are disposed in each of the through-holes, each of the spherical members having a conductive coating,
• wherein a recess is formed on a side of the piezoelectric element facing the through-hole in each of the connecting portions.

A liquid ejection head, comprising:

• a plurality of ejection ports which eject liquid;
• a plurality of pressure chambers which respectively communicate with the ejection ports;
• a plurality of piezoelectric elements which respectively deform the plurality of pressure chambers and are provided to faces of the pressure chambers opposite to faces on which the ejection ports are formed;
• a common liquid chamber which supplies the liquid to the plurality of pressure chambers and is formed on a side of the piezoelectric element opposite to the pressure chamber;
• a plurality of pressure determination elements which determine pressure in the pressure chambers, respectively;
• a plurality of through-hole wires which stand substantially perpendicular to the faces on which the piezoelectric elements are mounted, the through-hole wires running through a partition wall of the common liquid chamber and being electrically connected to the pressure determination elements in connecting portions, respectively;
• and
• a spherical member which has a conductive coating and is disposed in each of the connecting portions,
• wherein a recess is formed on a side of the pressure determination element facing the through-hole wire in each of the connecting portions.

A liquid ejection head, comprising:

• a plurality of ejection ports which eject liquid;
• a plurality of pressure chambers which respectively communicate with the ejection ports;
• a plurality of piezoelectric elements which respectively deform the plurality of pressure chambers and are provided to faces of the pressure chambers opposite to faces on which the ejection ports are formed;
• a common liquid chamber which supplies the liquid to the plurality of pressure chambers and is formed on a side of the piezoelectric element opposite to the pressure chamber;
• a plurality of pressure determination elements which determine pressure in the pressure chambers, respectively;
• a plurality of through-holes which stand from connecting portions of the pressure determination elements substantially perpendicularly to the faces on which the piezoelectric elements are mounted, the through-holes running through a partition wall of the common liquid chamber;
• and
• a plurality of spherical members which are disposed in each of the through-holes, each of the spherical members having a conductive coating,
• wherein a recess is formed on a side of the pressure determination element facing the through-hole in each of the connecting portions.

A method for manufacturing a liquid ejection head, comprising:

• a step of forming through-holes in portions of a flow channel plate which forms a common liquid chamber for supplying liquid to pressure chambers communicated with ejection ports, the portions facing a partition wall of the common liquid chamber;
• a conductive treatment step of forming conductive material on inner walls of the through-holes;
• a step of applying an electrically conductive agent to at least one of mutually connecting portions between connecting portions of the through-holes, connecting portions of piezoelectric elements for respectively deforming the pressure chambers, and spherical members for respectively connecting between the connecting portions of the through-holes and the connecting portions of the piezoelectric elements;
• a step of bonding a top layer of the liquid ejection head forming the common liquid chamber, and a bottom layer of the liquid ejection head including the pressure chambers;
• a step of inserting the spherical members from the through-holes;
• and
• a step of heating the electrically conductive agent or directing light via the through-holes for melting the electrically conductive agent, curing the electrically conductive agent, and connecting the spherical members between the connecting portions of the through-holes and the connecting portions of the piezoelectric elements.

A method for manufacturing a liquid ejection head, comprising:

• a step of forming through-holes in portions of a flow channel plate which forms a common liquid chamber for supplying liquid to pressure chambers communicated with ejection ports, the portions facing a partition wall of the common liquid chamber;
• a step of bonding a top layer of the liquid ejection head including the common liquid chamber, and a bottom layer of the liquid ejection head including the pressure chambers;
• a step of applying an electrically conductive agent to portions in which the through-holes and connecting portions of piezoelectric elements for respectively deforming the pressure chambers are electrically connected to each other;
• inserting a plurality of spherical members having electrical conductivity from the through-holes;
• and
• curing the electrically conductive agent.