KR102549376B1 - Printing Ink Dispensing Apparatus with Heatable Cantilever Structured Fluid Channel and Manufacturing Method of the Same - Google Patents

Abstract

An ink dispensing device for printing having a heated cantilever structure flow channel and a manufacturing method thereof are disclosed. The ink flow channel structure extends out of the base in a cantilever structure while being fixed to the base, and a nozzle for ejecting ink is formed at an end of the extended portion. A tubular ink flow channel extending from the inlet communicating with the ink inlet to the nozzle is provided inside the ink flow channel structure. The heater generates heat with electrical energy and heats the channel heating section, which is at least a part of the ink flow channel structure including the nozzle, so that ink droplets are discharged out of the nozzle through control of temperature and viscosity of ink in the ink flow channel and formation of ink bubbles.

Description

Printing Ink Dispensing Apparatus with Heatable Cantilever Structured Fluid Channel and Manufacturing Method of the Same}

The present invention relates to the field of printing technology, and more particularly, to an ink dispensing device configured to eject printed electronic ink and a method for manufacturing the same.

Recently, as the smart device market expands, interest in flexible substrate devices is rapidly increasing. Accordingly, many studies have been conducted on methods for patterning electrodes on flexible substrates. In particular, the nozzle-based patterning technology has the advantage of enabling rapid prototyping regardless of the type of substrate and the variety of designs to be patterned. In addition, since it is suitable for a process using a flexible substrate, it can be applied without significant limitations compared to the semiconductor process in the flexible substrate industry. A representative example of nozzle-based patterning technology is inkjet technology. Likewise, in the inkjet field, researches aimed at simplification of high-resolution conductive element patterning and process technology are being conducted according to the demand for integration of elements and process suitability in various environments in the industry.

However, inkjet technology is not yet actively used in the flexible substrate industry. There are two main reasons for this: The first reason is that conventional inkjet technology cannot achieve high resolution at the level of traditional semiconductor processes using exposure and wafer processes. As a result, there is a limit to the applications in which the inkjet-type printed electronic technology can be used. The reason is that it is difficult to analyze whether the inkjet is ejected well using only the existing high-speed camera imaging method due to optical limitations as the resolution increases.

The second reason is that when examining the principle of inkjet, it is difficult to pattern a highly viscous sample by inkjet. However, in general, the ink used for electrode patterning has electrical conductivity by using a polymer structure or nanoparticles together with a solvent. For high electrical conductivity, the concentration of the polymer and the particle compared to the solvent must be increased, so the viscosity increases. Therefore, it is difficult to use such a highly viscous sample for patterning with conventional inkjet technology.

However, if the resolution of printing element patterning technology using inkjet is improved and the integration of conductive elements becomes possible, a new process paradigm can be presented instead of the conventional semiconductor process, which consumes a lot of time and cost. An inkjet printing technology that enables this is required.

(1) Republic of Korea Patent No. 10-1030152 (published on September 9, 2009)

One object of the present invention is based on a heated cantilever structured flow channel capable of controlling the temperature/viscosity of ink and discharging ink droplets in an on-demand manner by designing a structure in which a cantilever structured ink flow channel is integrated with a heating means. It is to provide an ink dispensing device of

Another object of the present invention is to provide a method for manufacturing the ink dispensing device.

The problem to be solved by the present invention is not limited to the above problems, and can be expanded in various ways without departing from the spirit and scope of the present invention.

A method of manufacturing an ink dispensing device for printing having a heated cantilever structure flow channel according to embodiments for realizing one object of the present invention, (i) a polysilicon layer 64 on at least one surface of an insulated substrate depositing; (ii) forming a heating electrode layer 40' by doping the polysilicon layer 64 with phosphorus at a predetermined concentration; (iii) performing a patterning process of removing the remaining portion of the heating electrode layer 40', leaving only the heating electrode wire 40 having a predetermined shape; (iv) depositing silicon nitride on the surface where the heating electrode line 40 is formed to form an insulating layer 72 insulating the heating electrode line; (v) forming an ink injection hole 22 penetrating the insulating layer 72 vertically; (vi) forming an ink flow channel structure 30 on top of the insulating layer 72 along the heating electrode line 40; (vii) performing a patterning process to make the ink flow channel structure 30 into a cantilever structure; (viii) forming an ink ejection nozzle 34 at an end of the ink flow channel structure 30 having a cantilever structure; (ix) A patterning process of removing the insulating layer 72 of the corresponding region is performed to expose the first and second end portions 40a' and 40b' of the first and second heating electrode lines 40a and 40b, respectively. doing; (x) performing a patterning operation on the other surface of the substrate to complete the ink flow channel structure 30 as a cantilever structure while forming an ink inlet 22 on the other surface of the substrate; and (xi) forming an ink flow channel communicating with the ink inlet 22 by removing the polysilicon sacrificial layer 76 inside the ink flow channel structure 30 .

In example embodiments, in the 'step of performing the patterning process' for forming the heating electrode line 40, photoresist is deposited on a portion of the heating electrode layer 40' where the heating electrode line 40 is to be formed. doing; Exposing the entire surface of the heating electrode layer 40' through a photolithography process; and by performing an etching process on the heating electrode layer 40' using a reactive ion etching (RIE), leaving only the portion where the photoresist is deposited in the heating electrode layer 40' and the rest A step of forming the heating electrode line 40 by removing portions may be included.

In exemplary embodiments, the 'forming the ink flow channel structure 30' may include depositing a polysilicon sacrificial layer 76 to be used as a sacrificial layer on the insulating layer 72; a channel structure patterning step of leaving a portion of the channel through which ink flows on the first and second heating electrode lines 40a and 40b with respect to the polysilicon sacrificial layer 76 and removing the remainder; and forming the ink flow channel structure 30 by depositing silicon nitride so as to completely cover the polysilicon sacrificial layer 76 remaining after the channel structure patterning step.

In exemplary embodiments, the 'step of forming the ink flow channel structure 30' may include depositing the polysilicon sacrificial layer 76 on the insulating layer 72 except for pillar formation points, depositing a polysilicon sacrificial layer 76 having holes for forming pillars; a channel structure patterning step of leaving a portion of a channel through which ink flows on the first and second heating electrode lines 40a and 40b with respect to the polysilicon sacrificial layer 76 in which the holes for forming the pillars are formed and removing the remaining portion; and depositing silicon nitride in a form of filling the holes while completely covering the polysilicon sacrificial layer 76 in which the holes for forming the pillars of the channel structure remaining after the patterning of the channel structure are formed, so that a plurality of pillars for supporting the channel structure are formed. A step of forming the formed ink flow channel structure 30 may be included.

In example embodiments, the ink ejection nozzle 34 may be formed in the form of a hole drilled through the silicon nitride layer forming the ink flow channel structure 30 to the polysilicon sacrificial layer 76. there is.

In exemplary embodiments, the 'step of performing the patterning operation on the other surface of the substrate' leaves the channel heating section 40-1 to be formed into a cantilever structure and removes all components present on both sides of the channel heating section 40-1 to remove the ink. A step of making all or at least a part of the channel heating section 40-1 in the flow channel structure 30 into a cantilever structure may be included.

In example embodiments, in the 'forming the ink flow channel', the polysilicon sacrificial layer 76 inside the ink flow channel structure 30 may be removed by a wet etching process using KOH.

In exemplary embodiments, the fabrication method may further include depositing silicon nitride on both surfaces of the silicon wafer 62 to form the insulated substrate.

In example embodiments, the manufacturing method may include first and second electrode pads 42a and 42b of the first and second heating electrode lines 40a and 40b, respectively, and the first and second end portions 40a'. , 40b') may further include a step of depositing.

In exemplary embodiments, the nozzle may be formed by an etching process using RIE when patterning the ink flow channel structure 30 into a cantilever structure.

In exemplary embodiments, the nozzle may be formed by using focused ion beam milling (FIB) after completing the ink flow channel structure 30 as a cantilever structure.

On the other hand, an ink dispensing device for printing having a heated cantilever structure flow channel according to embodiments for realizing another object of the present invention includes a base 20, a cantilever structure ink flow channel structure 30, and A heating unit may be included. An ink inlet 22 for printing is formed in the base 20 . The cantilever structure of the ink flow channel structure part 30 is fixed to the base part 20 and extends out of the base part in the form of a cantilever structure, and an ink ejection nozzle 34 is formed at the end of the extended part. In addition, a tubular ink flow channel 32 extending from the inlet 36 communicating with the ink inlet to the nozzle for ejecting the ink is provided inside. The heating unit generates heat with electric energy to heat the channel heating section 40-1, which is at least a part of the ink flow channel structure 30 including the nozzle 34, thereby controlling the viscosity of the ink in the ink flow channel 32 and It is configured to cause ink droplets to be ejected out of the nozzle through ink bubble formation.

In exemplary embodiments, the heating unit is a channel heating section (40-1) provided in a form that accompanies at least a portion of the ink flow channel structure part 30 so as to facilitate heat transfer into the ink flow channel 32. ), and a heating electrode line 40 including an electrode pad connection section 40-2 provided in a form extending a predetermined length from one end of the channel heating section 40-1 to provide a pair of lead wires; and first and second electrode pads 42a and 42b deposited on the first and second end portions 40a' and 40b' of the electrode pad connection section 40-2.

In example embodiments, at least a portion of the electrode pad connection section 40 - 2 and the first and second electrode pads 42a and 42b may be fixed to the base 20 .

In exemplary embodiments, the channel heating section 40-1 is provided in a U-shape, and a bent portion at the bottom of the U-shape may be disposed at a portion where the nozzle is located.

In example embodiments, the heating electrode line 40 may include a polysilicon layer and phosphorus (P) doped in a predetermined concentration in the polysilicon layer.

In example embodiments, the heating electrode line 40 may be insulated from an ink solution in the ink flow channel 32 by being covered with an insulating layer 72 made of silicon nitride.

In example embodiments, the ink flow channel structure 30 surrounding the ink flow channel 32 may be made of silicon nitride.

In the exemplary embodiments, the ink flow channel structure 30 includes a plurality of pillars extending from the bottom to the ceiling of the ink flow channel 32 to support the ink flow channel 32 so as not to sag or deform. 80) may be further included.

An ink dispensing apparatus for printing having a heated cantilever structure flow channel according to exemplary embodiments of the present invention implements a small ink ejection nozzle in a cantilever type, enabling high-resolution patterning. In addition, by implementing the inkjet nozzle in a cantilever structure, it is possible to monitor inkjet ejection, which was not possible in the prior art.

An ink dispensing apparatus having a cantilever-type small nozzle according to the present invention can discharge ink droplets on-demand. Therefore, it enables non-contact inkjet type printing.

In particular, according to the present invention, since the heating unit is integrated with the nozzle and the ink flow channel having a cantilever structure, the viscosity can be controlled by using the temperature control of the printing sample. That is, the ink flow channel of the cantilever structure can be heated as desired, and by using such heating, the viscosity of the ink solution in the ink flow channel, that is, the patterning solution, can be lowered through temperature control. Therefore, the present invention makes it possible to use a patterning solution (high-viscosity patterning sample) having a high concentration of polymer and particles relative to the solvent as a printing sample, and thus can be applied to patterning work requiring high electrical conductivity.

An ink dispensing device for printing having a heated cantilever structure flow channel according to the present invention can control the viscosity/temperature of an ink solution for printing with little power loss by quickly heating only the fluid inside the cantilever to a desired temperature without heating the entire printing system. can

According to exemplary embodiments of the present invention, it is possible to print a high-viscosity printing sample having high electrical conductivity, thereby improving the performance of a printed electronic device using inkjet printing. In addition, the viscosity of the printing sample can be controlled as desired. Accordingly, inkjet printing becomes possible in an area smaller than the previously used nozzles having a size of several tens of micrometers. Due to the small size of the printing, high-resolution printed electronic printing is possible.

1 is a perspective view showing the configuration of an ink dispensing device for printing having a heated cantilever structure flow channel according to an exemplary embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA′ in FIG. 1 .
FIG. 3 is a plan view showing the configuration of a printing ink dispensing apparatus having a heated cantilever structure flow channel shown in FIG. 1 .
FIG. 4 is a cross-sectional view taken along the cutting line BB′ in FIG. 3 .
FIG. 5 is a cross-sectional view taken along the line C-C′ in FIG. 3 .
6 to 9 sequentially show processes for manufacturing an ink dispensing device for printing having a heated cantilever structure flow channel shown in FIG. 1 according to an exemplary embodiment of the present invention.
10 are images taken with an optical microscope of an ink dispensing device for printing having a heated cantilever structure flow channel actually manufactured by the process of FIGS. bottom view, and (c) is an enlarged image of a portion of the front end of the heated cantilever-structured flow channel.
11 is an image (A) taken with an optical microscope of a nozzle part of an ink dispensing device for printing having a heated cantilever structure flow channel actually manufactured by the process of FIGS. 6 to 9, a cross-sectional image (B) of the nozzle part, and a non-nozzle part A cross-sectional image (C) is shown.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. The same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

For the embodiments of the present invention disclosed in the text, specific structural or functional descriptions are illustrated only for the purpose of describing the embodiments of the present invention. Embodiments of the present invention may be embodied in various forms, and should not be construed as being limited to the embodiments described herein. That is, since the present invention can have various changes and various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific form disclosed, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded. Also, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

FIG. 1 is a perspective view showing the configuration of a printing ink dispensing apparatus 10 having a heated cantilever structure according to an exemplary embodiment. FIG. 2 is a cross-sectional view taken along the line AA′ in FIG. 1 . FIG. 3 is a plan view showing the configuration of the printing ink dispensing device 10 having the heated cantilever structure flow channel shown in FIG. 1 .

Referring to FIGS. 1 to 3 , the heating ink dispensing apparatus 10 having a cantilever structure may include a base 20, a cantilever structure of an ink flow channel structure 30, and heating units 40, 42a, and 42b. can

An ink inlet 22 into which ink may be injected from an ink tank or an ink chamber (not shown) storing printing ink may be formed in the base 20 . The ink flow channel structure 30 and the heating units 40, 42a, and 42b may be fixed and supported on the base 20 in a cantilever structure. The ink inlet 22 may communicate with the ink flow channel 32 by vertically penetrating the base 20 . The ink inlet 22 may be formed in a funnel shape to facilitate ink injection.

The cantilever structure of the ink flow channel structure 30 may extend out of the base 20 in a cantilever structure while one side thereof is fixed to the base 20 . A nozzle 34 for ejecting ink may be formed at an end of the extended portion. Also, an ink flow channel 32 may be formed inside the ink flow channel structure 30 having a cantilever structure. The ink flow channel 32 may be provided in a tubular shape extending from the inlet 36 communicating with the ink inlet 22 to the ink ejection nozzle 34 . The ink flow channel structure 30 surrounding the ink flow channel 32 may be formed of, for example, silicon nitride. An example of silicon nitride is Si ₃ N ₄ .

In another exemplary embodiment, the ink flow channel structure 30 includes a plurality of pillars 80 extending from the bottom to the ceiling of the ink flow channel 32 to support the ink flow channel 32 so as not to sag or deform. may further include Since the inside of the ink flow channel structure 30 is an empty space in which the ink flow channel 32 is formed, structural deformation or sagging may be weak. The plurality of pillars 80 may be components to compensate for such a structural weakness of the ink flow channel 32 .

The heating unit may include a heating electrode line 40 including a channel heating section 40-1 and an electrode pad connection section 40-2, and first and second electrode pads 42a and 42b. can

The channel heating section 40 - 1 may be provided in a form that accompanies at least part of the section of the ink flow channel structure 30 to facilitate heat transfer into the ink flow channel 32 . The heating electrode line 40 may include two lines of heating electrode lines, that is, a first heating electrode line 40a and a second heating electrode line 40b.

The channel heating section 40-1 of the first heating electrode line 40a and the second heating electrode line 40b may be provided in a U-shape, for example, and the bent portion at the lower end of the U-shape is a nozzle 34 for ejecting ink. It can be placed in the location where it is located. The electrode pad connection section 40-2 may be provided in a form extending a predetermined length from one end of the channel heating section 40-1 to provide a pair of lead wires. The first and second electrode pads 42a and 42b are deposited on the first and second end portions 40a' and 40b' of the electrode pad connection section 40-2 to electrically connect with the heating electrode line 40. can At least a portion of the electrode pad connection section 40 - 2 and the first and second electrode pads 42a and 42b may be fixed to the base 20 .

The heating electrode line 40 may include a polysilicon layer and phosphorus (P) doped in a predetermined concentration in the polysilicon layer. The resistance of the polysilicon layer 66 doped with phosphorus (P) is reduced compared to before doping, so that the amount of current that can flow at a constant voltage can further increase. A doping concentration of phosphorus (P) may be determined according to a desired resistance value of the heating electrode line 40 . Since the heating electrode line 40 is a heating means using Joule heat, it is basically required to be doped with phosphorus to a level where current can flow. In addition, the phosphorus-doped polysilicon layer 66 has physical properties that can withstand high temperatures well, which is a material selection considering that there are high-temperature processes among subsequent processes.

Electric signals (electrical energy) for heating may be applied to the heating units 40, 42a, and 42b through the first and second electrode pads 42a and 42b. The heating electrode line 40 can generate heat by the electric signal for heating. Heating the heating electrode wire 40 may heat the channel heating section 40 - 1 , which is at least a part of the ink flow channel structure 30 including the nozzle 34 . By such heating, the viscosity of the ink in the ink flow channel 32 can be controlled, and the ink droplets can be ejected out of the nozzle 34 while forming ink bubbles. Printing can thereby be made.

4 and 5 are cross-sectional views respectively viewed along the cutting line BB' and the cutting line C-C' in FIG. 3 . Both drawings show the cross-sectional structure of the vicinity of the nozzle 34, and are shown in an inverted form from the upper and lower parts in actual printing (ie, the part where the nozzle 34 is formed is the upper part of the ink flow channel 32 in the figure, but , which is actually the bottom of the ink flow channel 32).

Referring to FIGS. 4 and 5 , the ink flow channel 32 , which is an internal space defined by the ink flow channel structure 30 , may be a substantially rectangular tubular space. The nozzle 34 may be provided in the form of a through hole formed at the bottom of the distal end of the ink flow channel structure 30 . The first and second heating electrode lines 40a and 40b of the channel heating section 40-1 are buried side by side inside the ceiling portion along the ink flow channel 32 and extend from the inlet portion 36 to the nozzle 34, , It may be provided in the form of meeting each other at the point where the nozzle 34 is located. The first and second heating electrode lines 40a and 40b may be covered with an insulating layer 72 made of silicon nitride to insulate them from the ink solution in the ink flow channel 32 . Numerical values representing sizes shown in FIGS. 4 and 5 are illustrative values, and each constituent part may have a different size than the illustrated size, of course.

Meanwhile, FIGS. 6 to 9 sequentially show processes of manufacturing the printing ink dispensing device 10 having a heated cantilever structure flow channel shown in FIG. 1 according to an exemplary embodiment of the present invention. In Figures 6 to 9, the drawings arranged on the left side are cross-sectional views of each process step, and the drawings arranged on the right side are perspective views in a specific process step. If the serial numbers of the cross-sectional and perspective views are the same, it means that they are drawings of the same process step.

Referring first to FIG. 6 , in step (1), a silicon wafer 62 may be used as a substrate. In order to insulate the substrate, an insulating layer 64 may be deposited over at least one surface of the silicon wafer 62 . The insulating layers 60 and 64 may be formed by, for example, depositing silicon nitride (eg, Si ₃ N ₄ ) on the surface of the silicon wafer 62 substrate by low pressure chemical vapor deposition (LPCVD).

In step (2), polysilicon layers 66 and 68 may be deposited primarily on the surfaces of the insulating layers 60 and 64 to form heating electrodes. These polysilicon layers 66 and 68 can also be formed by, for example, an LPCVD process. The polysilicon layer 66 may function as a sacrificial layer in an etching process 4 to be described later.

In step (3), the first polysilicon layer 66 may be doped with phosphorus (P) at a predetermined concentration and then annealed. Through this, the heating electrode layer 40' may be formed. The phosphorus (P)-doped polysilicon layer 66 has a reduced resistance compared to before doping, and thus can flow a larger amount of current at a constant voltage. The polysilicon layer 64 for the heating electrode may be doped with phosphorus (P) at a high concentration so as to have high electrical conductivity. That is, the doping concentration of phosphorus (P) may be determined according to a desired resistance value of the heating electrode line 40 . Since the heating electrode line 40 is a heating means using Joule heat, it is basically required to be doped with phosphorus to a level where current can flow. In addition, the polysilicon layer 66 doped with phosphorus (P) has physical properties that can withstand high temperatures well, which is a material selection considering that there are high-temperature processes among subsequent processes.

In step (4), a patterning process may be performed in which only the heating electrode lines 40 having a predetermined shape are left in the heating electrode layer 40' and the rest are removed. The heating electrode line 40 may have a shape including a first heating electrode line 40a and a second heating electrode line 40b. The first heating electrode line 40a and the second heating electrode line 40b may be connected to each other on the nozzle 34 to form one heating electrode line 40 . The heating electrode line 40 may include a channel heating section 40-1 and an electrode pad connection section 40-2.

In an exemplary embodiment, the 'patterning process' for forming the heating electrode line 40 in step (4) may be performed as follows. First, photoresist may be deposited on a portion of the heating electrode layer 40' where the heating electrode line 40 is to be formed. Exposure treatment is performed on the entire surface of the heating electrode layer 40' through a photolithography process. Then, an etching process may be performed on the heating electrode layer 40' using reactive ion etching (RIE). By the etching process, the heating electrode line 40 may be formed by removing the remaining portion of the heating electrode layer 40 ′ except for the portion where the photoresist is deposited.

Referring to FIG. 7 , in step (5), a silicon nitride layer 72 is formed by depositing silicon nitride (eg, (Si ₃ N ₄ )) on the surface on which the first and second heating electrode lines 40a and 40b are formed. This can also be performed by an LPCVD process The silicon nitride layer 72 can function as an insulating layer 72 that insulates the heating electrode line 40 from the ink fluid.

In step (6), a patterning process may be performed to form the ink inlet 22 into which the ink solution is injected. Formation of the ink inlet 22 may be performed through, for example, a photolithography process and an etching process using RIE. The ink inlet 22 may be formed to penetrate the silicon nitride layer 72 to a predetermined depth in a vertical direction.

In steps (7) to (9), the ink flow channel structure 30 may be formed on the top of the insulating layer 72 along the first and second heating electrode lines 40a and 40b. The ink flow channel structure 30 may be formed of, for example, silicon nitride.

To this end, first, in step (7), a polysilicon sacrificial layer 76 to be used as a sacrificial layer may be deposited on the insulating layer 72 made of a silicon nitride layer. This deposition can be performed using, for example, an LPCVD process.

Then, in step (8), a portion of the channel through which ink flows may be left on the first and second heating electrode lines 40a and 40b with respect to the polysilicon sacrificial layer 76, and the remainder may be removed. Patterning of the channel structure may be performed through, for example, a photolithography process and an etching process using RIE.

Subsequently, in step (9), silicon nitride (eg, Si ₃ N ₄ ) is deposited on the entire upper surface including the polysilicon sacrificial layer 76 of the portion of the channel structure remaining after the channel structure patterning process. Accordingly, the ink flow channel structure 30 in which the polysilicon sacrificial layer 76 is covered with silicon nitride may be primarily formed. That is, the wall structure of the ink flow channel 32 may be formed of silicon nitride.

At this time, as another exemplary embodiment, pillars 80 may be formed in the ink flow channel 32 to prevent the channel from collapsing (see FIG. 10(C)). Although not shown in FIG. 7 , in order to form the pillars 80 , when the polysilicon sacrificial layer 76 is deposited in step (7), it may be deposited except at points where the pillars are to be formed. Accordingly, a polysilicon sacrificial layer 76 having a plurality of holes for forming pillars (not shown) may be deposited. Then, in step (8), with respect to the polysilicon sacrificial layer 76 in which the holes for forming the pillars are formed, a portion of the channel through which the ink flows on the first and second heating electrode lines 40a and 40b is left, and the rest is A channel structure patterning process to remove may be performed. And when the channel structure layer 30 is formed by depositing silicon nitride (Si ₃ N ₄ ) in step (9), a polysilicon sacrificial layer in which holes for forming pillars are formed in the portion of the channel structure remaining after the channel structure patterning step. Silicon nitride may be deposited to completely cover 76 and fill the holes for forming pillars. Accordingly, the ink flow channel structure 30 having a plurality of pillars 80 for supporting the channel structure can be formed.

Referring to FIG. 8, in step (10), a patterning process is performed to form the ink flow channel structure 30 into a cantilever structure and form ink ejection nozzles 34 at the ends of the ink flow channel structure 30. can be performed.

To this end, a patterning process for the nozzle 34 and the cantilever type ink flow channel structure 30 may be performed first. Like the previous patterning processes, this process may be performed through, for example, a photolithography process and an etching process using RIE. A nozzle 34 may be formed at a distal end of the ink flow channel structure 30 . The nozzle 34 may be formed in the form of a hole drilled through the silicon nitride layer forming the ink flow channel structure 30 to the polysilicon sacrificial layer 76 .

As such, the nozzle 34 may be formed using an etching process or the like before removing the polysilicon sacrificial layer 76 (refer to step 13 to be described later). In another embodiment, the nozzle 34 is formed by focused ion beam milling (focused ion beam milling) after completing the ink flow channel structure 30 into a cantilever structure, for example, after fabrication of a printing ink dispensing device having a heated cantilever structure flow channel is completed. It may be formed using beam milling (FIB). If the diameter size of the nozzle 34 is, for example, 1 μm or more, RIE may be used, and if it is 1 μm or less, FIB may be used.

In step (11), a patterning process may be performed to remove a portion of the insulating layer 72 covering the end portions 40a' and 40b' of the first and second heating electrode lines 40a and 40b, respectively. . Patterning may also be performed through, for example, a photolithography process and an etching process using RIE. Through this, the respective end portions 40a' and 40b' of the first and second heating electrode lines 40a and 40b may be exposed. The exposed end portions 40a' and 40b' may be electrically connected to electrode pads 42a and 42b to be formed later.

In step 12, in order to form the ink inlet 22 and complete the ink flow channel structure 30 as a cantilever structure, the opposite surfaces of the substrate portions 60 and 62 may be patterned. This patterning operation may also be performed through, for example, a photolithography process and an etching process using RIE. As an example, in the ink flow channel structure 30, some sections of the channel heating section 40-1 may be made in the form of a cantilever structure. To this end, after the RIE etching process is performed on silicon nitride in the shape of the channel heating section 40-1 to be structured as a cantilever, the cantilever structure 40-1 is left in the subsequent polysilicon sacrificial layer removal process, and the Parts can be removed entirely.

Next, referring to FIG. 9 , in step 13 , the polysilicon sacrificial layer 76 inside the ink flow channel structure 30 may be removed to form the ink flow channel 32 . The polysilicon sacrificial layer 76 inside the ink flow channel structure 30 may be removed by a wet etching process using, for example, potassium hydroxide (KOH). The space where the polysilicon sacrificial layer 76 was removed becomes an empty space and becomes a channel space 32 through which the ink solution can flow. At this time, even the polysilicon sacrificial layer 76 filled in the ink inlet 22 may be removed. Accordingly, the inlet 36 of the channel space 32 may communicate with the ink inlet 22 .

In step 14, first and second electrode pads 42a and 42b may be deposited on the first and second end portions 40a' and 40b' of the first and second heating electrode lines 40a and 40b, respectively. there is. The first and second electrode pads 42a and 42b may be formed of a metal material having excellent conductivity, such as aluminum or copper.

Finally, in step (15), an annealing process is performed on the first and second electrode pads 42a and 42b deposited on the first and second end portions 40a' and 40b' so as to form a strong electrical connection with each other. can do.

In this way, the printing ink dispensing apparatus 10 having a heated cantilever structure flow channel may be manufactured using processes similar to those of manufacturing semiconductor devices.

FIG. 10 illustrates images taken with an optical microscope of a printing ink dispensing device 10 having a heated cantilever structure flow channel that was actually tested and fabricated by performing the processes shown in FIGS. 6 to 9 . (a) is a top view image, (b) is a bottom view image, and (c) is an enlarged image of a portion of the front end of the heated cantilever structure flow channel.

In the image of (a) of FIG. 10 , a red arrow indicates a direction in which current flows in the heating electrode line 40, and a blue arrow indicates a direction in which ink flows toward a nozzle in the ink flow channel structure 30.

11 is an end portion of an ink flow channel structure 30 in which nozzles 34 are formed in a printing ink dispensing device 10 having a heated cantilever structure flow channel actually manufactured by performing the processes shown in FIGS. 6 to 9 shows an image (A) taken with an optical microscope, a cross-sectional image (B) of the nozzle 34 portion, and a cross-sectional image (C) of the non-nozzle portion.

The printing ink dispensing apparatus 10 having a heated cantilever structure flow channel according to an exemplary embodiment of the present invention described above has an ink flow channel 32 and ink ejection inside the cantilever structure ink flow channel structure 30 A nozzle 34 is formed so that ink for printing can be injected, delivered, and discharged through them.

The ink dispensing device 10 having such a structure can be operated by the following ink ejection mechanism. Referring back to FIG. 1 , a driving signal for printing may be applied from the driving power supply unit 15 through the first and second electrode pads 42a and 42b. The driving signal for printing may be, for example, a pulse signal. By the driving signal for printing, the heating electrode line 40 generates Joule heat, and the ink flow channel 32 and especially the nozzle 34 are heated by the heat energy. As a result, the ink in the ink flow channel 32 expands and a predetermined amount of ink droplets are ejected through the nozzle 34, and the ink in the ink flow channel 32 moves toward the nozzle by that amount.

More specifically, a driving signal for printing may be applied through the first and second electrode pads 42a and 42b. The driving signal may be provided in the form of a pulse wave having a desired pulse width and period, for example. In particular, since the heating electrode lines 40 are arranged side by side along the ink flow channel 32, while the pulse wave electric signal flows through the heating electrode line 40, the heating electrode line 40 generates Joule heat to generate the ink flow channel. The structure 30 may be heated. Accordingly, the ink solution present in the ink flow channel 32 can be heated.

Viscosity and temperature of the ink inside the ink flow channel 32 can be controlled by appropriately adjusting the driving signal applied to the heating electrode line 40 using this heating mechanism. In particular, the heating electrode wire 40 in the vicinity of the nozzle 34 is disposed in a bent shape, and generates the highest heat at that portion. Therefore, when a driving signal is applied to the heating electrode line 40, an instantaneous temperature rise may occur in the vicinity of the nozzle 34. As a result, ink droplets may be ejected through the nozzle 34 in a drop-on-demand printing method.

In the above, one printing ink dispensing device 10 having a heated cantilever structure flow channel has been described. Such an ink dispensing device 10 may be used alone or may be used in a set form in which a plurality of ink dispensing devices 10 are arranged in a predetermined shape. If the ink dispensing device is configured in the form of a set in this way, high throughput inkjet patterning required by the printed electronics industry can be easily implemented.

In the printing ink dispensing device 10 having a heated cantilever structure flow channel according to embodiments of the present invention, the heating electrode line 40 is used as a droplet ejection means for controlling the viscosity of ink and for on-demand patterning. can be utilized In the present invention, chemical synthesis is performed inside the ink flow channel 32 of a cantilever structure, and applications for printing synthesis results (eg, metal organic framework, MOF), or samples with a melting point higher than room temperature (eg, low-temperature solder paste) It can also be used for applications such as patterning in a contact method while maintaining a high temperature.

In addition, in the present invention, in a structure in which there is no nozzle 34 at the end of the ink flow channel 32, the liquid sample (or particles contained in the liquid sample) inside the ink flow channel 32 according to the heating temperature is physically It can also be used for research in which the phosphorus characteristics change and analyze the changed material properties using resonance frequency monitoring.

As described above, although the embodiments have been described with limited drawings, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can. For example, the described techniques may be performed in an order different from the method described, and/or components of the described system, structure, device, circuit, etc. may be combined or combined in a different form than the method described, or other components may be used. Or even if it is replaced or substituted by equivalents, appropriate results can be achieved. Therefore, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

10: Ink dispensing device for printing having a heated cantilever structure flow channel
20: base 22: ink inlet
30: cantilever-structured ink flow channel structure
32: ink flow channel 34: nozzle
40: heating electrode wire

Claims (19)

(i) depositing a polysilicon layer on at least one surface of the insulated substrate;
(ii) doping the polysilicon layer with phosphorus at a predetermined concentration to form a heating electrode layer;
(iii) performing a patterning process of removing the remaining portion of the heating electrode layer while leaving only the heating electrode wire having a predetermined shape;
(iv) depositing silicon nitride on the surface where the heating electrode lines are formed to form an insulating layer insulating the heating electrode lines;
(v) forming an ink injection hole vertically penetrating the insulating layer;
(vi) forming a polysilicon sacrificial layer on top of the insulating layer along the heating electrode line;
(vii) forming an ink flow channel structure including silicon nitride by depositing silicon nitride to cover the polysilicon sacrificial layer;
(viii) removing the silicon nitride layer from an end of the ink flow channel structure to form a nozzle for ejecting ink;
(ix) performing a patterning process of removing the insulating layer of a corresponding region to expose the distal end of the heating electrode line;
(x) patterning the other surface of the substrate to complete the ink flow channel structure into a cantilever structure while forming an ink inlet on the other surface of the substrate; and
(xi) forming an ink flow channel communicating with the ink inlet by removing the polysilicon sacrificial layer inside the ink flow channel structure. manufacturing method. The method of claim 1, wherein the 'performing the patterning process' for forming the heating electrode line comprises: depositing a photoresist on a portion of the heating electrode layer where the heating electrode line is to be formed; performing exposure treatment on the entire surface of the heating electrode layer through a photolithography process; and by performing an etching process on the heating electrode layer using a reactive ion etching (RIE), leaving only a portion where the photoresist is deposited on the heating electrode layer and removing the remaining portion to form the heating electrode line. A method of manufacturing an ink dispensing device for printing having a heated cantilever structure flow channel, comprising the step of forming. delete The heated cantilever structure of claim 1 , wherein the polysilicon sacrificial layer includes holes for forming pillars, and the ink flow channel structure includes pillars for support corresponding to the holes for forming pillars. A method of manufacturing an ink dispensing device for printing having a channel. The method of claim 1, wherein the ink ejection nozzle is formed to expose the polysilicon sacrificial layer. The method of claim 1, wherein the 'step of performing the patterning operation on the other surface of the substrate' leaves a channel heating section to be formed into a cantilever structure and removes all elements present on both sides of the cantilever structure to heat the channel in the ink flow channel structure. A method of manufacturing an ink dispensing device for printing having a heated cantilever structure flow channel, comprising the step of making all or at least some of the sections into a cantilever structure. The heated cantilever structure according to claim 1, wherein the removal of the polysilicon sacrificial layer inside the ink flow channel structure in the 'forming the ink flow channel' is performed by a wet etching process using potassium hydroxide (KOH). A method of manufacturing an ink dispensing device for printing having a flow channel. The method of claim 1, further comprising depositing silicon nitride on both surfaces of the silicon wafer to form the insulated substrate. . The method of claim 1, further comprising depositing first and second electrode pads on the first and second end portions of the first and second heating electrode lines, respectively. A method of manufacturing an ink dispensing device for printing. The method of claim 1, wherein the nozzle is formed by an etching process using RIE. The printing ink having a heated cantilever structure flow channel according to claim 1, wherein the nozzle is formed by using focused ion beam milling (FIB) after completing the ink flow channel structure into a cantilever structure. A method for manufacturing a dispensing device. a base having an ink inlet for printing;
It has a cantilever structure extending horizontally out of the base while being fixed to the base, and a nozzle for ejecting ink in a vertical direction is formed at the end of the extended portion, and at an inlet communicating in the vertical direction with the ink inlet. a cantilever-structured ink flow channel structure having a tubular ink flow channel extending to the ink ejection nozzle therein; and
It has a cantilever structure extending horizontally out of the base to extend along the ink flow channel structure, and generates heat with electric energy to heat a channel heating section that is at least a part of the ink flow channel structure including the nozzle, thereby allowing the ink to flow. An ink dispensing device for printing having a heated cantilever structure flow channel, characterized by comprising a heating unit configured to discharge ink droplets out of the nozzle through control of temperature and viscosity of ink in the channel and formation of ink bubbles. 13. The method of claim 12, wherein the heating unit comprises: a channel heating section provided along at least a portion of the ink flow channel structure to facilitate heat transfer into the ink flow channel; and a predetermined length at one end of the channel heating section. a heating electrode line including an electrode pad connection section provided in a form extending to provide a pair of lead wires; and first and second electrode pads deposited on the first and second end portions of the electrode pad connection section. 14. The printing ink dispensing device having a heated cantilever structure flow channel according to claim 13, wherein at least a portion of the electrode pad connection section and the first and second electrode pads are fixed to the base. 14. The printing ink dispensing device of claim 13, wherein the channel heating section is provided in a U shape, and a bent portion at the bottom of the U shape is disposed at a portion where the nozzle is located. 14. The printing ink dispensing device according to claim 13, wherein the heating electrode line comprises a polysilicon layer and phosphorus (P) doped in a predetermined concentration in the polysilicon layer. 14. The printing ink dispensing apparatus according to claim 13, wherein the heating electrode line is insulated from the ink solution in the ink flow channel by being covered with an insulating layer made of silicon nitride. 13. The ink dispensing device for printing having a heated cantilever structure flow channel according to claim 12, wherein the ink flow channel structure surrounding the ink flow channel is made of silicon nitride. 13. The heated cantilever structure of claim 12, wherein the ink flow channel structure further comprises a plurality of pillars extending from the bottom to the ceiling of the ink flow channel to support the ink flow channel so as not to sag or deform. An ink dispensing device for printing having a flow channel.

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