Fluid ejection device and process for the production thereof

A fluid ejection device comprising;

• a plurality of pressure chambers, and at least one of said plurality of pressure chambers divided independently from others of said plurality of pressure chambers;
• an ink channel communicating with said pressure chamber;
• an ink outlet communicating with said pressure chamber;
• and
• a pressure generating section comprising a laminated body made of a piezoelectric material, an elastic body and a resin layer, said elastic body sandwiched between said piezoelectric material and said resin layer, said section covering one face said pressure chamber;
• wherein said piezoelectric material is divided into a plurality of sections with each section corresponding to a pressure chamber, said resin layer extending continuously over said pressure chambers and between said piezoelectric material where said piezoelectric material is divided into said plurality of sections.

A fluid ejection device comprising:

• at least one pressure chamber divided independently from other pressure chambers:
• an ink channel communicating with said pressure chamber;
• an ink outlet communicating with said pressure chamber;
• and
• a pressure generating section comprising a laminated body made of a piezoelectric material and an elastic body, said section covering one face of said pressure chamber;
• wherein said pressure chamber, said ink channel and said ink outlet are defined by a laminated structure comprising at least:
• a first substrate having a through-hole for the pressure chamber and a through-hole for an ink inlet;
• a second substrate having a tapered through-hole and bonded to one face of said first substrate;
• and
• a third substrate having a through-hole for the ink outlet and bonded to said second substrate;
• wherein the ink channel comprises a groove in the first substrate in communication with the through-hole for the pressure chamber and the through-hole for the ink inlet;
• and
• the tapered through-hole in the second substrate tapers from a wide end in contact with the pressure chamber formed as the though-hole in the first substrate to a narrow end in contact with the ink outlet formed as the through-hole in the third substrate;
• the through-hole in the third substrate for said ink outlet is aligned approximately on center with the narrow end of the tapered through-hole in the second substrate, said through-hole in the third substrate having a diameter smaller than a diameter of the narrow end of the tapered through-hole in the second substrate;
• and
• the third substrate has a thickness of not more than about 50 μm and the second substrate has a thickness of less than about 0.8 mm in a range of thickness comprising about 1.2 to about 1.9 times (rg−rs) where rg is the diameter of the wide end of the tapered though-hole in the second substrate and rs is the diameter of the narrow end of the tapered through-hole in the second substrate.

The fluid ejection device comprising:

• at least one pressure chamber divided independently from other pressure chambers:
• an ink channel communicating with said pressure chamber;
• an ink outlet communicating with said pressure chamber;
• and
• a pressure generating section comprising a laminated body made of a piezoelectric material and an elastic body, said section covering one face of said pressure chamber;
• wherein said pressure chamber, said ink channel and said ink outlet are defined by a laminated structure comprising:
• a first substrate having a through-hole for the pressure chamber and a through-hole for an ink inlet;
• a second substrate having a tapered through-hole and bonded to one face of said first substrate;
• a third substrate having a through-hole for the ink outlet and bonded to said second substrate;
• and
• a fourth substrate bonded to the an other face of the first substrate and having a through-hole therein for the pressure chamber and a through-hole therein for the ink inlet;
• wherein the ink channel comprises a through-hole in the first substrate;
• the second substrate having the tapered through-hole tapering from a wide end in contact with the pressure chamber formed as the through-hole in the first substrate to a narrow end in contact with the ink outlet formed as the through-hole in the third substrate;
• the through-hole in the third substrate for said ink outlet is aligned approximately on center with the narrow end of the tapered through-hole in the second substrate, said through-hole in the third substrate having a diameter smaller than a diameter of the narrow end of the tapered through-hole on the second substrate, and
• the third substrate has a thickness of not more than about 50 μm and the second substrate has a thickness of less than about 0.8 mm in a range of thickness comprising about 1.2 to about 1.9 times (rg−rs), where rg is the diameter of the wide end of the tapering through-hole formed on the second substrate and rs is the diameter of the narrow end of the tapering through-hole in the second substrate.