US-12623455-B2 - Printing device for high viscous fluids with selective nozzle activation

Abstract

A printing device includes a reservoir accommodating a fluid, a first nozzle disposed on the bottom of the reservoir, the first nozzle including a plurality of nozzle holes through which the fluid is discharged as a droplet, first electrodes disposed on at least a portion of the bottom of the first nozzle, corresponding to the plurality of nozzle holes and a first insulating layer surrounding the first electrodes.

Inventors

• Yong Hwan Kim
• Min Ho BAE
• Hae Wook YANG
• Gil Jun KIM

Assignees

• SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date

20260512

Application Date

20240205

Priority Date

20230711

Claims (20)

1. 1 . A printing device comprising: a reservoir comprising a fluid; a first nozzle disposed on the bottom of the reservoir, the first nozzle including a plurality of nozzle holes through which the fluid is discharged as a droplet; first electrodes directly disposed on at least a portion of a bottom of the first nozzle, corresponding to the plurality of nozzle holes; and a first insulating layer surrounding the first electrodes.
2. 2 . The printing device of claim 1 , wherein, when a distance between the plurality of nozzle holes is smaller than a size of the droplet, the distance between the plurality of nozzle holes is between about 50% to about 90% of the size of the droplet.
3. 3 . The printing device of claim 1 , wherein a size of a particle included in the fluid is about 100 μm or less.
4. 4 . The printing device of claim 1 , wherein an internal diameter of each of the nozzle holes is between about 100 μm to about 500 pmm.
5. 5 . The printing device of claim 1 , wherein the first electrodes overlap with at least a portion of an end of the first nozzle.
6. 6 . The printing device of claim 1 , wherein the first insulating layer is in contact with at least a portion of an end of the first nozzle.
7. 7 . The printing device of claim 1 , further comprising connection electrodes electrically connected to the first electrodes.
8. 8 . The printing device of claim 1 , further comprising a control unit individually controlling each of the plurality of nozzle holes to control whether the droplet is to be discharged through each of the nozzle holes, wherein the control unit selectively applies a discharge voltage to each of the first electrodes.
9. 9 . The printing device of claim 1 , wherein an electric field is formed between the first electrodes and a grounded target such that the fluid is modified to be the droplet that is discharged.
10. 10 . The printing device of claim 1 , wherein, when a distance between the plurality of nozzle holes is greater than a size of the droplet, the printing device is rotated to a selectable angle.
11. 11 . The printing device of claim 10 , wherein the selectable angle is about 45° or less.
12. 12 . The printing device of claim 1 , wherein the plurality of nozzle holes are arranged in one row.
13. 13 . The printing device of claim 1 , wherein the plurality of nozzle holes are arranged in two rows, and wherein the plurality of nozzle holes in each row are arranged to be side by side.
14. 14 . The printing device of claim 1 , wherein the plurality of nozzle holes are arranged in two rows to be arranged in a zigzag pattern.
15. 15 . The printing device of claim 1 , further comprising: a second nozzle disposed on the bottom of the first insulating layer; second electrodes disposed on at least a portion of a bottom of the second nozzle, corresponding to the plurality of nozzle holes; and a second insulating layer surrounding the second electrodes.
16. 16 . The printing device of claim 15 , wherein the second electrodes overlap at least a portion of an end of the second nozzle.
17. 17 . The printing device of claim 15 , wherein the second insulating layer is in contact with at least a portion of an end of the second nozzle.
18. 18 . The printing device of claim 15 , wherein an electric field is formed by a potential difference between the first electrodes and the second electrodes such that the fluid is modified to be the droplet that is discharged.
19. 19 . The printing device of claim 18 , wherein no voltage or a negative voltage is applied to the first electrodes, and a positive voltage is applied to the second electrodes.
20. 20 . The printing device of claim 1 , wherein the printing device forms a pattern on a target through area printing.

Description

This application claims priority to Korean Patent Application No. 10-2023-0089971, filed on Jul. 11, 2023, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which in its entirety is herein incorporated by reference. BACKGROUND 1. Field The invention generally relates to a printing device, and more particularly to a printing device using a high viscous fluid. 2. Description of the Related Art A printing device is a device which prints patterns or forms on a target by discharging a fluid through a nozzle. For example, a printing device to which an electrohydrodynamic printing method is applied may form an electric field between a nozzle and a target and apply an electrostatic force to a fluid, thereby discharging the fluid in the form of a droplet. SUMMARY Embodiments provide a printing device in which discharge of a high viscous fluid is possible, and electric field interference between nozzles (or nozzle holes) is reduced, so that area printing can be readily performed. In accordance with an embodiment, a printing device includes a reservoir accommodating a fluid, a first nozzle disposed on the bottom of the reservoir, the first nozzle including a plurality of nozzle holes through which the fluid is discharged as a droplet, first electrodes disposed on at least a portion of the bottom of the first nozzle, corresponding to the plurality of nozzle holes and a first insulating layer surrounding the first electrodes. In an embodiment, when a distance between the plurality of nozzle holes is smaller than a size of the droplet, the distance between the plurality of nozzle holes may be about 50% to about 90% of the size of the droplet. In an embodiment, a size of a particle included in the fluid may be about 100 μm or less. In an embodiment, an internal diameter of each of the nozzle holes may be about 100 μm to about 500 μm. In an embodiment, the first electrodes may overlap with at least a portion of an end of the first nozzle. In an embodiment, the first insulating layer may be in contact with at least a portion of an end of the first nozzle. In an embodiment, the printing device may further include connection electrodes electrically connected to the first electrodes. In an embodiment, the printing device may further include a control unit individually controlling whether the droplet is to be discharged through each of the nozzle holes, wherein the control unit may selectively apply a discharge voltage to each of the first electrodes. In an embodiment, an electric field may be formed between the first electrodes and a grounded target such that the fluid is modified as the droplet to be discharged. In an embodiment, when a distance between the plurality of nozzle holes is greater than a size of the droplet, the printing device may be rotated to be at a selectable angle. In an embodiment, the selectable angle may be about 45° or less. In an embodiment, the plurality of nozzle holes may be arranged in one row. In an embodiment, the plurality of nozzle holes may be arranged in two rows, and nozzle holes arranged in each row may be arranged side by side. In an embodiment, the plurality of nozzle holes may be arranged in two rows, and may be arranged in a zigzag pattern. In an embodiment, the printing device may further include a second nozzle disposed on the bottom of the first insulating layer, second electrodes disposed on at least a portion of the bottom of the second nozzle, corresponding to the plurality of nozzle holes and a second insulating layer surrounding the second electrodes. In an embodiment, the second electrodes may overlap with at least a portion of an end of the second nozzle. In an embodiment, the second insulating layer may be in contact with at least a portion of an end of the second nozzle. In an embodiment, an electric field may be formed by a potential difference between the first electrodes and the second electrodes such that the fluid is modified as the droplet to be discharged. In an embodiment, a negative voltage or no voltage may be applied to the first electrodes, and a positive voltage may be applied to the second electrodes. In an embodiment, the printing device may form a pattern on a target through area printing. BRIEF DESCRIPTION OF THE DRAWINGS The above and other features of the invention will become more apparent by describing in further detail embodiments thereof with reference to the accompanying drawings, in which: FIG. 1 is a cross-sectional view of a printing device, in accordance with an embodiment. FIG. 2 is a schematic block diagram illustrating an operation method of a control unit of the printing device, in accordance with an embodiment. FIG. 3 is a cross-sectional view of the printing device illustrating area printing, in accordance with an embodiment. FIG. 4 is a cross-sectional view of a printing device illustrating line printing, in accordance with an embodiment. FIG. 5 is a block diagram of a printing device illustrating line printing,