Provided is a method for manufacturing a liquid ejection head substrate and a method for manufacturing a liquid ejection head capable of reducing degradation of the quality of a printed image. To this end, in formation of a liquid ejection head substrate, a part required to have more precise relative positional relation or not required to have high fabrication precision is set as a first part, and for the first part, a single-shot exposure method is employed. Also, a part required to have higher fabrication precision is set as a second part, and for the second part, a split exposure method is employed.

In some examples, a printhead can include a main printer fluid line, a firing chamber in fluid communication with the main printer fluid line to receive printer fluid from the main printer fluid line, and a resistor positioned in the firing chamber. The resistor can, for example, receive an electronic current to cause the resistor to heat up and eject printer fluid droplets from the printhead. The printhead can further include a photolithographically fabricated check valve positioned in the firing chamber. The check valve can, for example, be openable to allow filling of the firing chamber with printer fluid and closeable to at least partially seal the main printer fluid line from printer fluid blowback caused by the resistor.

In some examples, a print bar fabrication method comprises placing printhead dies face down on a carrier, placing a printed circuit board on the carrier, wire bonding each printhead die of the printhead dies to the printed circuit board, and overmolding the printhead dies and the printed circuit board on the carrier, including fully encapsulating the wire bonds.

There is provided a method of manufacturing a liquid ejection head. The liquid ejection head includes a recording device substrate, an electric wiring member configured to be connected to the recording device substrate at an electric connection portion, and a support member including a concave portion and a convex portion. The convex portion includes a first surface and a second surface. The method includes applying an adhesive to the surface of the concave portion on which the recording device substrate is to be placed and to the first surface, pressing the applied adhesive after the recording device substrate is placed on the surface of the concave portion on which the recording device substrate is to be placed, to fill, with the adhesive, a gap between the convex portion and the recording device substrate to a position higher than the first surface, and sealing the electric connection portion.

A liquid ejection head has at least a structure including an ejection orifice forming member having an ejection orifice for ejecting a liquid and a flow path communicating with the ejection orifice and a flow path forming substrate having a liquid introduction flow path communicating with the flow path and supplying the liquid, and includes: a first titanium oxide film with a pure water contact angle of 40° or less; and a second titanium oxide film with a pure water contact angle of 70° or more, wherein the first titanium oxide film covers the structure including inner walls of the flow path and the liquid introduction flow path and is exposed in the flow path and the liquid introduction flow path, and the second titanium oxide film has a portion covering the first titanium oxide film in a vicinity of an opening end.

A liquid discharge head includes a substrate, a pressure chamber through which a first liquid and a second liquid flow while being in contact with each other, a pressure generating element configured to pressurize the first liquid, and a discharge port configured to discharge the second liquid. The substrate has a first channel and a second channel that each extend through the substrate. The first channel is used to supply the first liquid to the pressure chamber. The second channel is used to supply the second liquid to the pressure chamber. A viscosity of the second liquid is greater than a viscosity of the first liquid. An average cross-section area of the second channel is greater than an average cross-section area of the first channel.

A die for a printhead is provided in examples. The die includes a number of fluidic actuator arrays, proximate to a number of fluid feed holes. A number of address lines are disposed proximate to a number of logic circuits on a low-voltage side of the fluid feed holes. An address decoder circuit is coupled to at least a portion of the address lines to select a fluidic actuator in a fluidic actuator array for firing. The address decoder circuit is customized to select a different address for each fluidic actuator in the fluidic actuator array. A logic circuit triggers a driver circuit located in a high-voltage side of the plurality of fluid feed holes opposite the low-voltage side, based, at least in part, on a bit value for the fluidic actuator array, the fluidic actuator selected by the address decoder circuit, and a firing signal.

A liquid discharge head includes: a nozzle plate having a nozzle from which a liquid is to be discharged in a discharge direction, the nozzle having a cylindrical hole having periodical convex portions and concave portions on a sidewall of the nozzle in the discharge direction, a diameter of an outermost portion of the nozzle in the discharge direction being smaller than an average diameter of minimum values and maximum values of diameters of the cylindrical shape. The average diameter is obtained by: Average diameter = (Sum of minimum values + Sum of maximum values) / (Count of minimum values + Count of maximum values).

The present disclosure provides a thermal print head and a method of fabricating the thermal print head. The thermal print head includes a substrate made of a semiconductor material and having a main surface and a convex portion, a resistor layer including a plurality of heat generating portions on the convex portion, and a wiring layer conducted to the plurality of heat generating portions and formed to contact the resistor layer. The convex portion has a top surface, a first inclined surface and a second inclined surface. At least one of two ends of the convex portion in the main scanning direction forms a third inclined surface connected to the main surface and the first inclined surface, and a fourth inclined surface connected to the main surface and the second inclined surface.

A fluid ejection assembly may include a fluid ejection die comprising a back face and a front face through which fluid is ejected. The fluid ejection die may further include a fan-out fluid passages converging towards the back face of the fluid ejection die, the fan-out fluid passages comprising a first fan-out fluid passage and a second fan-out fluid passage and a recirculation channel extending within a polymeric material from the first fan-out fluid passage to the second fan-out fluid passage adjacent the back face of the fluid ejection die.