KR100800321B1 - Electro-hydrodynamic printing apparatus using lens and method thereof - Google Patents

Abstract

An electro-hydrodynamic printing apparatus using a lens and a method thereof are provided to reduce a position error and realize spray and dropping modes in a single nozzle by changing a shape of the lens based on a type of a desired pattern. An electro-hydrodynamic printing apparatus includes a liquid supply part(1), a hollow electro-hydrodynamic lens(2), a stage part(3), a control part, and a power supply device(4). The liquid supply part has a nozzle(11) to spray conductive liquid in a fixed electro-hydrodynamic pressure. The hollow electro-hydrodynamic lens is placed on an upper part of a substrate to be spaced apart from the nozzle. The stage part is moved with holding the substrate. The control part controls a position and a movement velocity of the stage part. The power supply device applies power to the nozzle and the electro-hydrodynamic lens.

Description

Electro-hydrodynamic printing apparatus using lens and method

1 shows an electrohydraulic printing apparatus for forming a conductive line according to the present invention.

Figure 2 is a photograph of the experimental equipment related to the development of the electrohydraulic lens according to the present invention.

3 shows several forms of electrohydrodynamic lenses according to the invention.

FIG. 4 is a vector analysis of various forms of the electrohydraulic lens of FIG. 3.

5 is a micrograph of a conductive line patterned on a substrate using the electrohydraulic printing device of FIG. 1.

<Explanation of symbols for the main parts of the drawings>

1 ... liquid supply, 11 ... nozzle,

12 ... syringe pump, 2 ... electro-hydraulic lens,

3 ... stage part, 4 ... power supply,

5 ... substrate.

The present invention relates to an electro-hydrodynamic printing apparatus and method for forming a conductive line, and more particularly, to a micro-sized fine conductive line pattern using an electro-hydrodynamic lens. It relates to an electrohydraulic printing apparatus and method that can be formed.

With the rapid development of the electronics industry, electronic components are becoming more and more highly integrated. Accordingly, a small minimum line width is required for printed circuit boards on which various electronic chips are mounted.

Conventional, the pattern printing method of the printed circuit board by chemical etching had problems such as the generation of human hazardous materials and industrial waste, the formation of a limited precision printing pattern, low productivity due to the complexity of the process. As an alternative to the conventional circuit patterning method, direct write technology has recently attracted attention.

As one of such direct writing techniques, a technique using an ink-jet has been disclosed.

The invention disclosed in Korean Laid-Open Patent Publication No. 1998-0014807 relates to a method of printing a printed circuit board, which is improved by spraying ink directly onto a substrate to improve image accuracy and to print even fine images. The spray printing unit sprays ink onto a substrate in the form of droplets through a spray hole by using a phenomenon in which pressure is generated by applying electricity using a piezoelectric body, and performs curing using an ultraviolet lamp.

In addition, U.S. Patent No. 5,132,248 discloses a method of directly patterning a liquid containing a functional material onto a substrate by inkjet. For example, a liquid in which conductive fine particles are dispersed is used as a substrate by an inkjet method. A direct-write inkjet system has been proposed in which a pattern is directly applied to a pattern, followed by heat treatment or laser irradiation to convert it into a conductive film pattern. Later, US Patent Publication Nos. 6,227,658, 6,531,191, 6,599,582 and the like have been proposed. Patterning methods have been proposed.

Further, in Japanese Patent Laid-Open No. 2004-146796 (Korean Laid-Open Patent No. 2004-0028536), in the patterning by the conventional inkjet method, the shape and dimension of a liquid droplet (liquid) on a substrate is not provided unless proper processing is performed on the substrate surface. And a pattern formation method for forming defects such as disconnection or short circuit in the film pattern formed by the inkjet method by recognizing that it is difficult to control the position and the like and making the conductive film pattern having the desired shape difficult. In order to provide an apparatus, a surface treatment step of performing a surface treatment on a substrate before discharging a liquid drop is provided, and a method in which a contact angle with respect to a liquid on a substrate is set by such a surface treatment step is disclosed.

In addition, U.S. Patent No. 6,706,234 proposes a direct write technique for patterning a target shape into a predetermined shape, wherein a material deposited by applying a high voltage to a polarizable material deposited by spraying through a nozzle during a solvent removal process. It is characterized by polarizing.

However, the inkjet or nozzle related technologies described in the above-mentioned publications and the like,

(1) the size of the patterning line, i.e., the interconnection density,

(2) followability of the patterning line, i.e. prevention of disconnection and short-circuit, and

(3) There was a limit to satisfy both the attachment to the desired position, that is, the prevention of position error.

On the other hand, in recent years, a printed circuit board having a small line width and a high density mounting capability is required. Therefore, when a printed circuit board is manufactured by spraying a metal, ceramic, or polymer material through a nozzle, The size should be reduced and the resulting droplets attached to the desired location without error.

However, in the conventional method using the inkjet, the influence of the nozzle size on the droplet size is absolute, and the droplet size generated is about twice the nozzle size. Therefore, in order to spray the fine droplets, the size of the nozzle must be smaller. However, when using a nozzle of too small size, nozzle clogging may occur at the nozzle outlet, and there is a limit to reducing the size of the nozzle.

In addition, in the conventional inkjet method, in order to reduce the line width of the substrate surface, it is necessary to reduce the size of the sprayed droplets. In this case, small droplets cannot be accurately attached to a predetermined position on the substrate surface due to the Brownian motion in the air. There was a problem that an error occurs.

In addition, conventionally, in order to implement a conical liquid injection mode through electro-hydraulic spraying, a ground electrode such as a circle, a pin, and a plate is always needed under the substrate to be patterned in a pin-pin form. Even hundreds to tens of μm had to be satisfied. In addition, the use of the ground electrode may have a positive effect on the line width of the pattern patterned on the substrate, but there are many limitations in various applications, and an unstable portion may be affected by the ground electrode under the substrate. There was also a problem occurring.

The present invention has been made to solve the above-described problems, it is possible to obtain a droplet of finer and more uniform size by using a nozzle of a relatively large particle size, and also to attach a small size droplet to the desired location without error It is an object of the present invention to provide an electrohydraulic printing apparatus and method.

Another object of the present invention is to provide an electro-hydraulic printing apparatus and method that can achieve a stable printing by removing the ground electrode positioned under the substrate to remove the influence of the ground electrode under the substrate when spraying from the liquid column mode For the purpose of

In order to achieve the above object, according to the present invention, an electro-hydraulic printing apparatus using a lens comprising a liquid supply unit having a nozzle for spraying a conductive liquid at a constant hydraulic pressure; A hollow electro-hydraulic lens located at a distance from the nozzle and positioned above the substrate; A stage for moving while holding the substrate; A control unit for controlling the position and the moving speed of the stage unit; And a power supply for applying a voltage to the nozzle and the electrohydraulic lens.

In addition, the electro-hydraulic lens is characterized in that the inner and outer cylindrical.

In addition, the electro-hydraulic lens is characterized in that the outside is cylindrical and the inside is conical.

In addition, the electrohydraulic lens is characterized in that the inner and outer parts are conical and inclined at the same inclination with each other.

In addition, the liquid supply unit is characterized in that for supplying the conductive liquid to the nozzle by a syringe pump (syringe pump).

In addition, the electro-hydraulic printing method using a lens according to the present invention, providing a liquid supply having a nozzle for spraying a conductive liquid at a constant hydraulic pressure, the electro-hydraulic lens at a distance away from the nozzle Positioning, providing a stage for moving while holding the substrate, providing a control for controlling the position and moving speed of the stage, from the power supply when the liquid is sprayed Applying a voltage between the nozzle and the electro-hydraulic lens to convert the spray form into a cone cone jet mode, and a preset pattern of the intact jet when sprayed from the cone cone mode Forming a conductive line by attaching to the substrate according to the shape of the.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the electrohydraulic printing apparatus according to the present invention includes a liquid supply unit 1, an electrohydraulic lens 2, a stage unit 3, a control unit (not shown), and a power supply unit 4. It consists of).

First, the substrate 5 used in this embodiment is a Kapton film made of polyimide and a paper for photographic printing. The substrate 5 has dimensions of 30 mm in width and length and 0.1 mm in thickness. The surface of the substrate 5 was surface treated by using reactive ion etching (RIE) equipment, and the treatment increased the roughness of the surface to between the liquid supplied to the substrate 5 and the substrate 5. Helps the adhesion of

The liquid supply part 1 has a nozzle 11 for spraying a conductive liquid at a constant hydrodynamic pressure. Meanwhile, in the present embodiment, the liquid supply unit 1 is illustrated as supplying a conductive liquid to the nozzle 11 by using a syringe pump 12. The syringe pump 12 may freely adjust the flow rate of a material made of a metal to be sprayed. On the other hand, the nozzle 11 for electrostatic spraying is made of a stainless material and has a dimension of 180㎛ inner diameter, 360㎛ outer diameter.

The electrohydraulic lens 2 is located at a distance away from the nozzle 11. In addition, the electrohydraulic lens 2 has a ring shape, and the inside and the outside thereof are circular in plan view (see FIG. 2). In addition, the electrohydraulic lens 2 has a constant height and may have various shapes as shown in FIG. 3. That is, the electrohydraulic lens 2 may be cylindrical (inner and outer) 22, 21 (Type I), or the outer 21 is cylindrical and the inner 22 may be conical (Type II), Alternatively, the inside and the outside may be formed to be conical and inclined at the same inclination (Type III, IV). Overall, the inner diameter of the upper end of the electrohydrodynamic lens 2 is 6.0 mm, the inlet outside diameter is 7.0 mm to 10 mm depending on the type, and the inner diameter of the lower end of the lens is It is 4.0mm and the outer outside diameter is formed to have a size of 5.0mm ~ 8.0mm depending on the type. On the other hand, the nozzle 11 is located in the upward portion of about 0.5mm ~ 1.5mm from the lower end of the lens. In addition, the electrohydraulic lens 2 is located between the nozzle 11 and the substrate 5 to make the solution sprayed from the nozzle 11 into a conical liquid injection mode.

The stage part 3 is positioned below the substrate 5, and precisely moves the substrate to pattern the conductive lines in the input pattern while maintaining the substrate 5. The stage unit 3 for patterning liquid according to a command of a controller to be described later is composed of a digital control (not shown) and a stage of two axes x-y. The digital control is directly connected to the PC and allows the PC to adjust the drive of the stage. The stage part 3 is positioned to be movable under the nozzle 11.

The control part moves the stage part 3 to a desired position and controls the speed.

The power supply 4 is connected to the nozzle 11 and the electrohydraulic lens 12 to apply a voltage.

Hereinafter, a method of implementing a fine circuit pattern on a substrate by using an electrohydraulic printing apparatus according to the present invention will be described.

In this embodiment, in order to form a conductive line on the substrate 1, a solution containing silver nanoparticles was used as the conductive liquid. The silver nano solution is composed of 20 wt% silver and 80 wt% ethylene glycol, and very small amount of surfactants are added to prevent aggregation between particles. The average particle diameter of silver nanoparticles is 30-50 nm.

First, the solution containing the silver nanoparticles as described above is sprayed with the nozzle 11 in a state of being fixed at a supply flow rate of about 1 to 2 μl / min using the syringe pump 12 of the liquid supply unit 1.

Then, the power supply 4 is used to vary the supply voltage between the nozzle 11 and the electrohydraulic lens 2 so that the spray form is in the conical liquid injection mode. At this time, it is possible to obtain a stable conical liquid column mode that can form an intact jet.

Then, the substrate 5 is moved by controlling the position and the moving speed of the stage 3 using the control unit.

Finally, the patterning is completed by precisely moving the substrate 5 in order to pattern conductive lines on the substrate 5 in the input pattern. 5 shows a photomicrograph of a line patterned on a substrate by a printing apparatus according to the present invention.

On the other hand, in the implementation of the fine circuit pattern by the method described above, the experiment was repeated to confirm the validity of the lens while converting the pattern to a state without applying voltage to the lens through the experiment through the electro-hydraulic lens. Mathematical analysis was also performed to predict the most efficient shape of the electrohydraulic lens and its effect on the distribution of force. The finite element method (FEM) method was used for this mathematical analysis. FIG. 5 shows a vector analysis of various types of electrohydraulic lenses through this method.

As described above, in the embodiment of the present invention, the solution containing silver nanoparticles was sprayed by an electrohydraulic method using only an electrohydraulic lens instead of the ground electrode to form conductive lines on the substrate. In addition, it can contribute to the improvement of the disadvantage that is difficult to use under the substrate, which is a disadvantage in the conventional apparatus using the ground electrode, and using the nozzle larger than the nozzle of the inkjet electro-hydraulic that can realize the inkjet-like pattern even at high viscosity A printing device can be obtained.

According to the present invention having the above-described configuration, since the electrical force is used in addition to the hydraulic force, it is possible to obtain droplets of a finer and more uniform size by using a nozzle having a relatively large particle size, and also a small size. Droplets can be attached wherever they want without position error.

In addition, the shape of the lens can be variously changed according to the desired pattern shape, thereby reducing the positional error. Unlike the inkjet method of implementing only the dropping mode in one nozzle, the shape of the lens is changed to one Various nozzles and spray modes can be implemented in the nozzle.

In particular, the present invention generates a conical liquid injection mode without using a ground electrode, which is further developed in a method of attaching a jet to a desired place using a conventional pin-to-pin type electrode, which is competitive with conventional inkjets. The advantage is that the line width can be realized.

In addition, since there is no ground electrode under the substrate, the lower space of the substrate may be utilized in various ways, and thus, there is an effect in developing printing equipment using an electrohydrodynamic lens in the future.

In addition, by applying the electro-hydraulic lens according to the present invention to remove the ground electrode and further improve the stability, it can be the basis for the development of multi-nozzle and large-area printing technology.

Claims (9)

In electro-hydrodynamic printing apparatus (EHD printing) for forming conductive lines on a substrate, A liquid supply unit having a nozzle for spraying a conductive liquid at a constant hydraulic pressure; A hollow electro-hydraulic lens located at a distance from the nozzle and positioned above the substrate; A stage for moving while holding the substrate; A control unit for controlling the position and the moving speed of the stage unit; And A power supply for applying a voltage to the nozzle and the electrohydraulic lens Characterized in that it includes, electro-hydraulic printing device using a lens. The method of claim 1, The electro-hydraulic lens is characterized in that the inner and outer cylindrical, electro-hydraulic printing device using a lens. The method of claim 1, The electrohydraulic lens is characterized in that the outer cylindrical and the inner conical, electro-hydraulic printing device using the lens. The method of claim 1, The electrohydraulic lens is an electro-hydraulic printing device using a lens, characterized in that the inner and outer conical and inclined at the same inclination with each other. The method of claim 1, The liquid supply unit is characterized in that for supplying a conductive liquid to the nozzle by a syringe pump (syringe pump), electro-hydraulic printing apparatus using a lens. In the electro-hydrodynamic printing (EHD printing) method for forming a conductive line on the substrate, Providing a liquid supply having a nozzle for spraying a conductive liquid at a constant hydraulic pressure; Positioning an electrohydraulic lens above the substrate to be spaced apart from the nozzle; Providing a stage for moving while holding the substrate; Providing a control unit for controlling the position and the moving speed of the stage unit; Converting the spray form into a cone cone jet mode by applying a voltage between the nozzle and the electrohydraulic lens from a power supply when the liquid is sprayed; And Attaching an intact jet when sprayed from the conical liquid jet mode to the substrate according to a shape of a predetermined pattern to form conductive lines; It characterized in that, the electro-hydraulic printing method using a lens. The method of claim 6, The electro-hydraulic lens, characterized in that the inner and outer cylindrical, electro-hydraulic printing method using a lens. The method of claim 6, The electrohydraulic lens, characterized in that the outer cylindrical and the inner conical, electro-hydraulic printing method using a lens. The method of claim 6, The electro-hydraulic lens is characterized in that both inside and outside conical and inclined at the same slope, electro-hydraulic printing method using a lens.

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