Substrate mounted with electronic element thereon and liquid ejection head including the substrate

A substrate mounted with an electronic element thereon, the substrate comprising:

• a metal base;
• a ceramic insulator provided on a first side of the base, the insulator having a heat-generating electronic element mounted on a side thereof opposite to a side thereof facing the first side of the base;
• and
• a fluid passage that is formed within the base to have liquid flowing therethrough, and radiates heat transmitted from the electronic element via the insulator to the base, wherein the first side of the base is inteposed between the fluid passage and the insulator.

A liquid ejection head mounted with an electronic element thereon, the liquid ejection head comprising:

• a passage unit including a plurality of nozzles that eject liquid and pressure chambers that communicate with the respective nozzles;
• an actuator unit that changes the volume of the pressure chambers;
• and
• a ceramic insulator provided on a first side of the passage unit, the insulator having a driver that drives the actuator unit mounted on a side thereof opposite to a side thereof facing the first side of the passage unit;
• a radiator configured to radiate heat transmitted from the electronic element via the insulator to the passage unit,
• wherein:
• the passage unit includes a plurality of metallic plates that are put in layers to constitute a first fluid passage which extends through the pressure chamber to the nozzle;
• the actuator unit includes a metal diaphragm and a ceramic insulator, the diaphragm being disposed on a surface of one of the metallic plates of the passage unit so as to cover the pressure chamber, the insulator being provided on a side of the diaphragm opposite to a side thereof facing the surface of the one metallic plate;
• the driver is mounted on a side of the insulator opposite to a side thereof facing the diaphragm;
• and
• a second fluid passage, as the radiator, having liquid flowing therethrough is formed at a portion within the metallic plates corresponding to the driver with respect to a direction perpendicular to the surface of the one metallic plate.

A substrate mounted with an electronic element thereon, the substrate comprising:

• a metal base;
• a ceramic insulator provided on a first side of the base, the insulator having a heat-generating electronic element mounted on a side thereof opposite to a side thereof facing the first side of the base;
• a radiator configured to radiate heat transmitted from the electronic element via the insulator to the base, wherein the radiator includes a fluid passage that is formed within the base to have liquid flowing therethrough;
• a pressurizer configured to apply pressure to the liquid within the fluid passage, wherein the pressurizer includes:
• a pressurizing chamber that is formed within the fluid passage, and
• a piezoelectric actuator configured to change the volume of the pressurizing chamber;
• and
• a controller configured to control pressure application by the pressurizer to the liquid within the fluid passage, wherein
• the piezoelectric actuator is connected to the controller, and has a first electrode, a piezoelectric layer, and a second electrode, the first electrode being formed on the side of the insulator on which the electronic element is mounted so as to correspond to the pressurizing chamber with respect to a direction perpendicular to the first side, the piezoelectric layer being formed on a side of the first electrode opposite to a side thereof facing the insulator, the second electrode being formed on a side of the piezoelectric layer opposite to a side thereof facing the first electrode.