Method of controlling the height of encapsulant on an inkjet printhead
View Patent ↗A method of controlling a height of an encapsulant material on an inkjet printhead is provided. The method includes dispensing the encapsulant material on an outer portion of the inkjet printhead. The encapsulant material is then depressed to reduce its height on the outer portion of the inkjet printhead. The encapsulant material may be depressed directly after dispensing or before it completely cures. The encapsulant material may be completely cured before reducing its height. The height of the cured encapsulant material may be reduced by removing a top portion of the encapsulant material through machining operation. Reducing the height of the encapsulant material on the inkjet printhead minimizes the distance of the nozzle plate of the inkjet printhead to the printing media, thus improving print quality.
1. A method of controlling a height of an encapsulant material on an inkjet printhead having a heater chip electrically connected to a flexible circuit by way of a connecting wire extending above the heater chip and the flexible circuit, the method comprising:
providing the inkjet printhead having an outer portion;
dispensing to a first height the encapsulant material on the outer portion of the inkjet printhead, the encapsulant material covering a top surface of the heater chip and the flexible circuit and encapsulating the connecting wire, the first height rising above both the top surface of the heater chip and the connecting wire; and
depressing the encapsulant material to a second height lower than the first height while maintaining the encapsulant material over the top surface of the heater chip and the connecting wire.
2. The method of claim 1 , wherein the depressing of the encapsulant material includes depressing the encapsulant material to the second height directly after dispensing the encapsulant material on the outer portion of the inkjet printhead.
3. The method of claim 1 , further including curing the encapsulant material dispensed on the outer portion of the inkjet printhead and depressing the encapsulant material after an initial cure stage.
4. The method of claim 1 , further including curing the encapsulant material dispensed on the outer portion of the inkjet printhead and depressing the encapsulant material before the encapsulant material completely cures.
5. A method of controlling a height of an encapsulant material on an inkjet printhead having a heater chip electrically connected to a flexible circuit by way of a connecting wire extending above the heater chip and the flexible circuit, the method comprising:
providing the inkjet printhead having an outer portion;
dispensing to a first height the encapsulant material on the outer portion of the inkjet printhead, the encapsulant material covering a top surface of the heater chip and the flexible circuit and encapsulating the connecting wire, the first height rising above both the top surface of the heater chip and the connecting wire; and
depressing the encapsulant material with a depressing plate to a second height lower than the first height while maintaining the encapsulant material over the top surface of the heater chip and the connecting wire.
6. The method of claim 5 , wherein the depressing of the encapsulant material includes depressing a top surface of the encapsulant material with a flat bottom surface of the depressing plate.
7. The method of claim 5 , wherein the depressing of the encapsulant material includes depressing a top surface of the encapsulant material with a shaped or patterned bottom surface of the depressing plate.
8. The method of claim 5 , wherein the depressing of the encapsulant material includes depressing the encapsulant material with the depressing plate for a period of at most 1 minute.
9. The method of claim 5 , wherein the depressing of the encapsulant material includes maintaining the depressing plate in contact with the encapsulant material during a curing stage of the encapsulant material.
10. The method of claim 5 , further including chilling the depressing plate before depressing the encapsulant material.
11. The method of claim 5 , further including removing the depressing plate from contact with the encapsulant material in a twisting or a sliding motion.
12. The method of claim 5 , wherein the depressing of the encapsulant material further includes providing a sacrificial layer on the encapsulant material.
13. The method of claim 12 , wherein the providing of the sacrificial layer includes providing a polytetrafluoroethylene film on the encapsulant material.
14. The method of claim 12 , further including removing the sacrificial layer after a curing stage of the encapsulant material.
15. A method of controlling a height of an encapsulant material on an inkjet printhead having a heater chip electrically connected to a flexible circuit by way of a connecting wire extending above the heater chip and the flexible circuit, the method comprising:
providing the inkjet printhead having an outer portion;
dispensing to a first height the encapsulant material on the outer portion of the inkjet printhead, the encapsulant material covering a top surface of the heater chip and the flexible circuit and encapsulating the connecting wire, the first height rising directly above both the top surface of the heater chip and the connecting wire where the connecting wire attaches to the heater chip;
curing the encapsulant material; and
removing a top portion of the cured encapsulant material from an area directly above the top surface of the heater chip where the connecting wire attaches to the heater chip to control the encapsulant material to a second height lower than the first height while maintaining the encapsulant material over the top surface of the heater chip and the connecting wire.
16. The method of claim 15 , wherein the dispensing of the encapsulant material includes dispensing the encapsulant material comprising about 1% to about 5% by weight of filler for increasing a shear strength of the encapsulant material.
17. The method of claim 15 , wherein the dispensing of the encapsulant material includes dispensing the encapsulant material comprising fumed silica, boron nitride, arsenic pentoxide, arsenic trioxide, vanadium pentaoxide, barium oxide, or magnesium oxide as a filler for increasing a shear strength of the encapsulant material.
18. The method of claim 15 , further including grinding the top portion of the cured encapsulant material to control the encapsulant material to the second height.
19. The method of claim 15 , further including milling the top portion of the cured encapsulant material to control the encapsulant material to the second height.
20. The method of claim 15 , further including depressing the encapsulant material directly after dispensing the encapsulant material on the outer portion of the inkjet printhead.
21. The method of claim 15 , further including depressing the encapsulant material during the curing of the encapsulant material.