CN110271288B

CN110271288B - OLED ink-jet printing nozzle and printing device thereof

Info

Publication number: CN110271288B
Application number: CN201910602024.7A
Authority: CN
Inventors: 毕研亮
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2019-07-05
Filing date: 2019-07-05
Publication date: 2020-05-22
Anticipated expiration: 2039-07-05
Also published as: CN110271288A

Abstract

The invention provides an organic light-emitting diode ink-jet printing nozzle, which comprises an ink cavity, a printing head and a printing head, wherein the ink cavity is used for storing ink; an ink supply inlet for delivering ink into the ink chamber; the piezoelectric crystal is connected with the ink cavity and used for generating vibration and deformation so as to extrude the ink cavity; the jet orifice is used for forming ink drops and comprises a conductive structure which is electrically connected to the organic light-emitting diode ink-jet printing nozzle. The conductive structure comprises a conductive body arranged on the surface of the piezoelectric crystal, and a conductive lead connected with the conductive body and the grounding end. And eliminating the electrostatic charge generated in the printing process by the piezoelectric crystal, the conductive structure and the grounding end.

Description

OLED ink-jet printing nozzle and printing device thereof

Technical Field

The invention relates to the technical field of display, in particular to an organic light-emitting diode (OLED) ink-jet printing nozzle and a printing device thereof.

Background

An organic light-emitting diode (OLED) is an autonomous light-emitting device, and the OLED is applied to the technical field of display. Compared with a passive light emitting Liquid Crystal Display (LCD), the OLED display which emits light autonomously has the advantages of high response speed, high contrast, wide viewing angle, and the like, and is easy to realize flexible display. Therefore, the OLED display is very likely to become a mainstream product of the next generation display technology.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a conventional OLED inkjet printing head. The OLED inkjet printing head has ink of organic material entering ink chamber 20 from ink supply inlet 30 of head 100. In the piezoelectric ink-jet printing process, the piezoelectric crystal 50 at the nozzle 100 moves at a high speed to extrude and deform, so that the volume of the ink chamber 20 is reduced, and the ink is extruded to extrude trace ink from the nozzle hole 10 of the nozzle to form an ink droplet 40, so that the droplet can smoothly drop and retract. The functional layer in the OLED device is manufactured, and the excellent performance of the organic material forming the functional layer is a decisive factor of the final luminous performance of the display panel in the production process of OLED ink-jet printing. Factors influencing the performance of the functional layer include water oxygen and heating conditions, and in addition, in the process of high-speed up-and-down deformation of the piezoelectric crystal, static electricity is generated due to corona discharge, and charges carried by the static electricity effect change oxygen remaining in ink into ozone, so that the contact part of organic materials in the ink and the ozone is easy to damage, and the efficiency and the service life of an OLED device are low.

Therefore, how to prevent the generation of static electricity to avoid the generation of ozone, thereby preventing the functional layer organic material from being damaged, and improving the performance and the service life of the OLED device is a technical problem to be solved during mass production.

Disclosure of Invention

In order to solve the problem that an ink material is damaged by ozone in an OLED (organic light-emitting diode) ink-jet printing process, the invention provides an OLED ink-jet printing spray head, so that ozone is prevented from being generated, a functional layer membrane surface is prevented from being damaged, and the luminous efficiency of an OLED device is improved. The OLED ink-jet printing nozzle comprises an ink cavity, a first ink cavity and a second ink cavity, wherein the ink cavity is used for storing ink; an ink supply inlet for delivering ink into the ink chamber; the piezoelectric crystal is connected with the ink cavity and used for generating vibration and deformation so as to extrude the ink cavity; an orifice for forming an ink droplet; the OLED ink-jet printing head is characterized by further comprising a conductive structure, a piezoelectric crystal and a plurality of conductive lines, wherein the conductive structure is electrically connected to the OLED ink-jet printing head and comprises a conductive body arranged on the surface of the piezoelectric crystal; and a conductive lead connected to the conductive body and a ground terminal; and eliminating the electrostatic charge generated in the printing process by the piezoelectric crystal, the conductive structure and the grounding end.

In one embodiment of the present invention, the conductive body is made of a metal material.

In one embodiment of the present invention, the conductive body is embedded in the surface of the piezoelectric crystal.

In one embodiment of the present invention, the piezoelectric element further includes a colloid, and the conductive body is attached to the piezoelectric crystal through the colloid.

In one embodiment of the present invention, the colloid is a conductive adhesive, and the conductive adhesive includes a conductive filler, and the conductive filler is selected from gold, silver, copper, aluminum, zinc, iron, nickel powder, graphite, or some conductive compound.

In one embodiment of the present invention, the conductive body is composed of a plurality of sheet structures, and the sheet structures are attached to the surface of the piezoelectric crystal through the colloid.

In one embodiment of the present invention, the conductive body is composed of a plurality of sheet structures, and the sheet structures are attached to the OLED inkjet printing head through the adhesive.

The invention also provides an OLED ink-jet printing device, which comprises an ink supply device, a printing device and a control device, wherein the ink supply device is used for loading ink materials; the ink-jet printing nozzle is used for printing the ink material on the glass substrate of the OLED panel; the driver is electrically connected to the ink-jet printing nozzle and used for controlling the shape and size of an ink droplet; the ink supply pump is connected between the ink jet printing nozzle and the ink supply device and is used for conveying the ink material of the ink supply device to the ink jet printing nozzle; the OLED ink-jet printing device is characterized in that the ink-jet printing nozzle is the OLED ink-jet printing nozzle.

In one embodiment of the present invention, the ink material is an organic material for forming the organic functional layer.

In one embodiment of the present invention, the organic functional layer is one of a red light emitting organic film layer, a green light emitting organic film layer, a blue light emitting organic film layer, and a thin film encapsulation organic film layer.

Drawings

In order to more clearly illustrate the embodiments or technical solutions in the present disclosure, the drawings needed to be used in the description of the embodiments or the present disclosure will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an OLED (organic light-emitting diode) inkjet printing head in the prior art; and

FIG. 2 is a schematic structural diagram of an OLED inkjet printing head according to an embodiment of the present invention; and

fig. 3 is a schematic structural diagram of an OLED inkjet printing apparatus according to an embodiment of the present invention.

Detailed Description

The following description of the various embodiments refers to the accompanying drawings, which are included to illustrate specific embodiments that can be implemented by the application. Directional phrases used in this application, such as [ upper ], [ lower ], [ front ], [ rear ], [ left ], [ right ], [ inner ], [ outer ], [ side ], etc., refer only to the directions of the attached drawings. Accordingly, the directional terminology is used for purposes of illustration and understanding, and is in no way limiting. In the drawings, elements having similar structures are denoted by the same reference numerals.

In order to solve the problem that organic materials of a functional layer are damaged by ozone in an OLED (organic light-emitting diode) ink-jet printing process, a conductive structure is arranged on a printing nozzle structure. The conductive body with strong conducting charge function is arranged on the surface of the piezoelectric crystal of the printing nozzle, so that static electricity generated in the ink-jet printing process can be guided to the conductive body, and the static electricity is guided to a safe part outside the nozzle through the lead wire to be released. Thereby preventing the generation of ozone, avoiding the damage to the membrane surface of the functional layer and improving the luminous efficiency of the OLED device.

Referring to fig. 2, fig. 2 is a schematic structural diagram of an OLED inkjet printing head according to an embodiment of the present invention. The head 200 includes an ink chamber 20 for storing ink; an ink supply inlet 30 for delivering ink into the ink chamber 20; a piezoelectric crystal 50 connected to the ink chamber 20 for generating vibration and deformation to press the ink chamber 20 to reduce the volume, and the trace ink is extruded from the nozzle hole 10 to form an ink droplet 40 due to the reduction of the volume of the ink chamber 20; the conductive structure is electrically connected to the showerhead 200 for releasing static electricity generated by the showerhead 200; the conductive structure includes a conductive body 60 disposed on the surface of the piezoelectric crystal 50, and a conductive lead 70 connected to the conductive body 60 and the ground 90. And eliminating the electrostatic charge generated in the printing process by the piezoelectric crystal, the conductive structure and the grounding end. In addition, the controller 80 can be further selectively connected between the conductive body 60 and the ground 90 to automatically set the program and select whether to remove the static electricity function, and the static electricity removal function is turned on. Preferably, the conductive body 60 is made of a metal material having a strong conductive charge effect. On the other hand, the conductive body 60 may be made of conductive rubber or conductive plastic.

In one embodiment, the conductive body 60 may be disposed on the surface of the piezoelectric crystal 50 in a damascene manner through a mechanical design.

In one embodiment, the conductive body 60 may be attached to the surface of the piezoelectric crystal 50 by glue or by a print head. Preferably, the colloid is a conductive glue, e.g. a resin matrix with conductive fillers selected from gold, silver, copper, aluminium, zinc, iron, nickel powder, graphite or some conductive compound.

In one embodiment, the conductive body 60 is formed of a plurality of sheet structures. Each sheet structure is attached to the surface of the piezoelectric crystal 50 over its entire surface.

In addition, according to the process requirement and the amount of electrostatic charge that may be generated by the inkjet print head 200, the conductive body 60 may be configured to be entirely attached to most of the surface of the piezoelectric crystal 50, and the conductive body 60 may also be configured to be touched in a segmented manner to maintain electrical connection with the piezoelectric crystal 50. Shown in fig. 2 is a three-segment conductive body 60. The sectional type avoids the problem of unsmooth heat dissipation; the whole surface is attached to the required material and has the characteristic of good heat dissipation.

During the printing production process, the static electricity generating position is usually on the piezoelectric crystal, so the surface of the piezoelectric crystal has electric charge. Since the conductive body 60 for easily conducting charges is added, when charges are generated, the charges tend to flow preferentially to the conductive body 60 above the piezoelectric crystal 50, and then are led out to the ground 90 of the safe area through the conductive lead 70. Since the charges flow preferentially to the conductive body 60 above the piezoelectric crystal 50, the ink side of the ink drop 40 extruded from the orifice 10 will not contact with the charges, and the moisture and oxygen in the ink or the environment will not be changed into ozone to destroy the material structure of the ink due to electrostatic effect.

Through the arrangement of the conductive structure, the contact between ozone and organic materials in ink is avoided, and the performance and quality of a functional layer in an OLED device can be effectively ensured.

An embodiment of the present invention further provides an OLED inkjet printing apparatus, as shown in fig. 3, fig. 3 is a schematic structural diagram of the OLED inkjet printing apparatus provided in the embodiment of the present invention, where the OLED inkjet printing apparatus 1000 includes an ink supply device 700 for loading ink material; an inkjet printing head 200 for printing an ink material on an object, for example, a glass substrate of an OLED panel, to form a desired film structure, for example, an organic functional layer; the driver 300 is electrically connected to the inkjet print head 200 for controlling the shape and size of the ink droplets; the ink supply pump 500 is connected between the inkjet printing head 200 and the ink supply device 700 for delivering the ink material of the ink supply device 700 to the inkjet printing head. The inkjet printing nozzle is the OLED inkjet printing nozzle.

In an embodiment, the ink material is an organic material for forming an organic functional layer, and the organic functional layer is one of a red light emitting organic film layer, a green light emitting organic film layer, a blue light emitting organic film layer, and a thin film encapsulation organic film layer.

In summary, although the present application has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present application, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, so that the scope of the present application shall be determined by the appended claims.

Claims

1. An organic light-emitting diode (OLED) ink-jet printing nozzle comprises an ink chamber for storing ink; an ink supply inlet for delivering ink into the ink chamber; the piezoelectric crystal is connected with the ink cavity and used for generating vibration and deformation so as to extrude the ink cavity; an orifice for forming an ink droplet; it is characterized by also comprising:

the conductive structure is electrically connected to the OLED ink-jet printing nozzle, wherein the conductive structure comprises a conductive body arranged on the surface of the piezoelectric crystal; and

the conductive lead is connected to the conductive body and the grounding end;

and eliminating the electrostatic charge generated in the printing process by the piezoelectric crystal, the conductive structure and the grounding end.

2. The OLED inkjet printing head of claim 1 wherein the conductive body is made of a metallic material.

3. The OLED inkjet printing head of claim 1 wherein the conductive body is mounted on the surface of the piezoelectric crystal.

4. The OLED inkjet printing head of claim 1 further comprising a gel, wherein the conductive body is attached to the piezoelectric crystal through the gel.

5. The OLED inkjet printing head of claim 4 wherein the colloid is a conductive paste comprising a conductive filler selected from a powder of gold or silver or copper or aluminum or zinc or iron or nickel, graphite or a conductive compound.

6. The OLED inkjet printing head of claim 5 wherein the conductive body is comprised of a plurality of sheet structures, the sheet structures being attached to the surface of the piezoelectric crystal by the gel.

7. The OLED inkjet printing head of claim 5, wherein the conductive body is formed by a plurality of sheet structures, and the sheet structures are attached to the OLED inkjet printing head through the adhesive.

8. An OLED inkjet printing device comprising:

the ink supply device is used for loading ink materials;

the ink-jet printing nozzle is used for printing the ink material on the glass substrate of the OLED panel;

the driver is electrically connected to the ink-jet printing nozzle and used for controlling the shape and size of an ink droplet;

the ink supply pump is connected between the ink jet printing nozzle and the ink supply device and is used for conveying the ink material of the ink supply device to the ink jet printing nozzle;

the OLED inkjet printing device is characterized in that the inkjet printing nozzle is the OLED inkjet printing nozzle according to any one of claims 1 to 7.

9. The OLED inkjet printing apparatus according to claim 8 wherein the ink material is an organic material to form an organic functional layer.

10. The OLED inkjet printing apparatus of claim 9 wherein the organic functional layer is one of a red light emitting organic film layer, a green light emitting organic film layer, a blue light emitting organic film layer, and a thin film encapsulation organic film layer.