KR101307986B1 - Method for cathode electrode in field emission surface light source device - Google Patents

Abstract

PURPOSE: A method of manufacturing a cathode electrode in a field emission surface light source reduces process time and costs by selecting and spreading an electrode unit and/or a non-electrode unit when a carbon nanotube ink layer is formed. CONSTITUTION: An electroless plating layer (120) is formed by electroless-plating a substrate. An electrode pattern (130) divided into an electrode unit and a non-electrode unit is formed on the electroless plating layer. A first metal layer (140) is formed on the electrode unit by performing first electroplating. A second metal layer (150) is formed on the first metal layer through second electroplating. A carbon nanotube ink layer (160) is formed on the electrode unit, or the carbon nanotube ink layer is formed on the electrode unit and the non-electrode unit. The non-electrode unit is removed.

Description

Field emission surface light source cathode electrode manufacturing method {METHOD FOR CATHODE ELECTRODE IN FIELD EMISSION SURFACE LIGHT SOURCE DEVICE}

The present invention relates to a method for producing a cathode electrode, and more particularly to a method for producing a field emission surface light source cathode electrode comprising a carbon nanotube emitter in a field emission surface light source device.

A field emission surface light source device emits electrons from a field emission source of a cathode electrode by applying a voltage between the anode electrode and the cathode electrode to form an electric field, and emits the electrons from the field emission source of the anode electrode. It is an element that emits light by impulse.

At this time, the most researched material to the cathode electrode is carbon nanotubes (carbon nanotube, CNT), which is excellent in conduction and electric field concentration effect of the carbon nanotubes, it is possible to drive low voltage and large area This is because it has many advantages.

BACKGROUND ART In order to manufacture a field emission surface light source device using carbon nanotubes as an emitter (field emission source), a vacuum deposition process, a screen printing process, an emitter inkjet printing process, and the like are known. However, in the case of vacuum deposition process, there is an advantage that precise pattern formation is possible, but there is a disadvantage that not only the process cost increases due to the large material consumption and the multi-step process, and the waste generated in the etching process increases. In addition, the screen printing process can reduce the process cost compared to the vacuum deposition process, but has a disadvantage in that it is difficult to form a precise pattern. On the other hand, the emitter inkjet printing process uses the screen printing method only when forming the emitter, and it is possible to form a pattern more precisely than the screen printing process, but it is accompanied by a post-repair process that requires removing the ejected droplets in unnecessary places. There is this.

Therefore, there is a search for a method for producing a field emission surface light source cathode electrode using carbon nanotubes as an emitter in a precise and simple process.

Embodiments of the present invention are to provide a method for producing a field emission surface light source cathode electrode capable of forming a precise pattern while using a low cost and a simple process.

According to an aspect of the invention, the step of forming an electroless plating layer by electroless plating the substrate; Forming an electrode pattern divided into an electrode part and a non-electrode part on the electroless plating layer; Performing a first electroplating process using electricity applied through the electroless plating layer to form a first metal layer on the electrode unit; Forming a second metal layer on the first metal layer through second electroplating; Forming a carbon nanotube ink layer on the electrode portion or forming a carbon nanotube ink layer on the electrode portion and the non-electrode portion; And a sixth step of removing the non-electrode portion, and a method of manufacturing a field emission surface light source cathode electrode may be provided.

In addition, after the step 6, the step of melting the upper portion of the second metal layer through heat treatment to attach the carbon nanotube ink layer on the upper second metal layer; An eight step of forming a carbon nanotube emitter through an activation process; And removing the electroless plating layer existing in the non-electrode portion.

In this case, the first step may include sandblasting and acid treating the substrate before the electroless plating.

In addition, the electroless plating of the first step may be NiCr electroless plating.

In addition, the first metal layer may be formed of Cu, Al, or Cr, and the second metal layer may be formed of Sn, In, or Al.

On the other hand, step 5 may be a step of applying carbon nanotube ink on the electrode portion and the non-electrode portion through a spray process, or selectively printing the carbon nanotube ink only on the electrode portion through the inkjet process.

On the other hand, the heat treatment of the seven steps may be performed at 150 ℃ to 400 ℃.

According to another aspect of the present invention, a field emission surface light source device including a field emission surface light source cathode electrode manufactured according to the method for manufacturing a field emission surface light source cathode electrode according to an embodiment of the present invention may be provided.

Embodiments of the present invention can reduce the process steps, process time and process costs by using a process of forming an electroless plating layer and electroplating using the electroless plating layer to form an electrode.

In addition, when the carbon nanotube ink layer is formed, the electrode part and / or the non-electrode part may be selected and applied to reduce process steps, process time, and process cost.

1 to 8 are views sequentially showing a method of manufacturing a field emission surface light source cathode electrode according to an embodiment of the present invention.
9 is a schematic view of a field emission surface light source device including a field emission surface light source cathode electrode according to an embodiment of the present invention.

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

The terms "upper "," on ", or "on" in this specification are intended to refer to a relative positional concept based on the attached drawings, wherein the expressions refer to the presence of other elements or layers directly As well as other layers or components therebetween may be interposed or present and the surface of the layer referred to above (particularly the surface having a three-dimensional shape) may be completely It should be noted that it is possible to include not covering. Likewise, the expression "lower," " under, "or" under "may also be understood as a relative concept of the position between a particular layer (component)

1 to 8 are views sequentially showing a method of manufacturing a field emission surface light source cathode electrode according to an embodiment of the present invention.

Referring to FIG. 1, a substrate 110 is first prepared to form a field emission surface light source cathode electrode 100 (hereinafter, referred to as a cathode electrode). The substrate 110 may be, for example, a glass substrate as a substrate having transparency.

Referring to FIG. 2, an electroless plating layer 120 is formed by electroless plating the substrate 110. Electroless plating means plating performed without applying electrical energy to an aqueous solution from the outside, and specifically, the electroless plating layer 120 is formed on the entire surface of the substrate 110 by immersing the substrate 110 in an electroless plating bath. Can be. In this case, the electroless plating may be NiCr electroless plating.

Meanwhile, the substrate 110 may be pretreated before the electroless plating. In this case, the pretreatment method may use sand blasting and acid treatment. The inventors of the present invention have found that electroless plating can proceed more smoothly when sandblasting and acid treating the substrate 110 before electroless plating (step 1 above).

Referring to FIG. 3, an electrode pattern 130 is formed on the electroless plating layer 120. The electrode pattern 130 may be divided into an electrode portion 130a which is a portion where the electrode is formed and a non-electrode portion 130b which is a portion where the electrode is not formed.

The method of forming the electrode pattern 130 is not limited to a specific method. For example, the electrode pattern 130 may be formed through photolithography after laminating a photosensitive film such as a dry film photoresist (DFR film) on the upper surface of the electroless plating layer 120. In this case, the DFR film may function as a mask for forming the electrode pattern 130. On the other hand, the photo process is a well known process in the semiconductor process, etc., so a detailed description thereof will be omitted.

After the electrode pattern 130 is formed, as shown in FIG. 3, the electrode portion 130a has a shape in which the electroless plating layer 120 is exposed, and the non-electrode portion 130b includes the electroless plating layer 120 and the DFR film. It becomes a laminated form (two steps above).

Referring to FIG. 4, a first metal layer 140 is formed on the electrode portion 130a. In this case, electroplating may be used as a method of forming the first metal layer 140. It is necessary to supply electricity to the electrode for the electroplating, in the embodiment of the present invention can use the electroless plating layer 120 as the electrode. That is, electroplating may be performed by applying electricity through the electroless plating layer 120 formed on the substrate 110, and thus, the first metal layer 140 may be formed on the electrode unit 130a.

As described above, according to the exemplary embodiment of the present invention, since the electrode may be formed by electroplating using the electroless plating layer 120, there is an advantage in that process steps, process time, and process costs can be reduced compared to the conventional vacuum deposition process.

The first metal layer 140 may be formed of Cu, Al, or Cr, but is not limited thereto. In addition, the thickness of the first metal layer 140 is not limited and may be, for example, formed in a thickness of 100 nm to 200 nm (three or more steps).

Referring to FIG. 5, a second metal layer 150 is formed on the first metal layer 140. In this case, electroplating may be used as a method of forming the second metal layer 150. Hereinafter, for convenience of description, the electrolytic plating used when the first metal layer 140 is formed is referred to as a first electroplating, and the electroplating used when the second metal layer 150 is formed is referred to as a second electroplating. Let's do it.

Specifically, the first metal layer 140 may be used as an electrode for the second electroplating. That is, the second electroplating may be performed by applying electricity through the first metal layer 140, and thus, the second metal layer 150 may be formed on the first metal layer 140.

The second metal layer 150 may be formed of Sn, In, or Al, but is not limited thereto. In addition, the thickness of the second metal layer 150 is not limited and may be, for example, 100 nm to 200 nm thick. The second metal layer 150 may function as an adhesive layer with the carbon nanotube ink layer 160 (see FIG. 6), which will be described later, and may perform a function of preventing oxidation of the electrode (step 4 above).

Referring to FIG. 6, the carbon nanotube ink layer 160 may be formed on the electrode 130a, or the carbon nanotube ink layer 160 may be formed on the electrode 130a and the non-electrode 130b. That is, the carbon nanotube ink layer 160 may be formed only on the electrode portion 130a, and the carbon nanotube ink layer 160 may be formed on both the electrode portion 130a and the non-electrode portion 130b.

In the former case, the carbon nanotube ink may be selectively printed on only the upper portion of the electrode 130a through an inkjet process. In the latter case, the carbon nanotube ink may be formed on the upper portion of the electrode 130a and the non-electrode 130b. Can be carried out by applying through a spray process. 6 shows that the carbon nanotube ink layer 160 is formed on the electrode 130a and the non-electrode 130b.

In the exemplary embodiment of the present invention, since the carbon nanotube ink may be applied by selecting the electrode 130a or the electrode 130a and the non-electrode 130b when the carbon nanotube ink layer 160 is formed, conventional screen printing may be performed. Process steps, process time and process costs can be reduced compared to the method or emitter inkjet printing process.

The thickness of the carbon nanotube ink layer 160 is not limited. For example, the carbon nanotube ink layer 160 may have a thickness of 40 nm to 60 nm.

The carbon nanotube ink layer 160 is formed of carbon nanotube ink, and the carbon nanotube ink may include carbon nanotubes, a surfactant, a dispersant, an organic binder, and the like which are purified by heat treatment or acid treatment. For example, the carbon nanotube ink may be prepared by using water as a solvent and sodium dodecylsulfate (SDS) as a dispersant, and removing unnecessary bundles by centrifugation after sonication to promote physical stirring. have.

The physical properties of the carbon nanotube ink are not particularly limited, and for example, carbon nanotube inks having lower ink viscosity and less impurities than carbon nanotube pastes used for screen printing may be used. Such carbon nanotube ink may have a viscosity of 5 to 10 cps and a carbon nanotube concentration of 0.05 to 1.0 wt%.

On the other hand, carbon nanotubes generally refer to a material formed in the shape of a hexagonal honeycomb cylinder by combining three different carbon atoms with one carbon atom, and are known to have diameters of several to several hundred nanometers and a length of about 10 μm. have.

The carbon nanotubes are composed of graphite having a hexagonal structure of carbon-bonded graphite, and the single-walled carbon nanotube (SWCNT) depends on whether one graphite (C) layer is one layer or several layers. ) Or multi-walled carbon nanotubes (MWCNTs), and in particular, when the single-walled carbon nanotubes are formed in a bundle, they may be divided into single-walled carbon nanotubes. Since the carbon nanotubes are known materials, detailed descriptions thereof will be omitted.

When the carbon nanotube ink layer 160 is formed, the electrode unit 130a may include a substrate 110, an electroless plating layer 120, a first electrode layer 140, a second electrode layer 150, and a carbon nanotube ink layer ( 160 has a stacked form, and the non-electrode portion 130b has a stacked form of a substrate 110, an electroless plating layer 120, a DFR film, and a carbon nanotube ink layer 160 (more than five steps). ).

Referring to FIG. 7, the non-electrode portion 130b is removed next. In other words, the stack of the DFR film-carbon nanotube ink layer 160 formed on the non-electrode portion 130b is removed. At this time, when the DFR film is removed using acetone, an acid solution, a photoresist stripper, etc., which can remove the DFR film, the carbon nanotube ink layer 160 stacked on the DFR film may also be removed at the same time. (More than six steps).

Referring to FIG. 8, next, the upper part of the second metal layer 150 is melted through heat treatment, and the carbon nanotube ink layer 160 is attached to the upper part of the second metal layer 150. At this time, the heat treatment may be performed at 150 ℃ to 400 ℃. Through such heat treatment, the adhesion degree of the carbon nanotube ink layer 160 may be strengthened (step 7 above).

Next, the carbon nanotubes included in the carbon nanotube ink layer 160 are erected through an activation process to form a carbon nanotube emitter. The carbon nanotube emitter functions as a field emission source. The activation process of the carbon nanotubes is a well-known process so that a detailed description thereof will be omitted. In connection with FIG. 8, it is evident that the carbon nanotubes are shown in an upright shape (step 8 above).

Next, the electroless plating layer 120 existing in the non-electrode portion 130b is removed. Herein, the electroless plating layer 120 present in the non-electrode portion 130b includes an electroless plating layer 120 formed on both side and bottom surfaces thereof, as well as the upper surface of the substrate 110. The method of removing the electroless plating layer 120 may be performed by immersing the cathode electrode 120 in an acid solution capable of selectively removing the electroless plating layer 120 (9 or more steps).

9 is a schematic view of a field emission surface light source device including a field emission surface light source cathode electrode according to an embodiment of the present invention.

The present invention further provides a field emission surface light source device 1000 including a field emission surface light source cathode electrode 100 manufactured according to the method for manufacturing a field emission surface light source cathode electrode according to an embodiment of the present invention.

Referring to FIG. 9, the field emission surface light source device 1000 may include a lower substrate having a cathode electrode 100 and a getter not illustrated in FIG. 9, an upper substrate having an anode fluorescent layer 200, and upper and lower surfaces. The substrate 300 may be manufactured including a spacer 300 spaced apart from each other by a predetermined interval, and a sealing cover 400 sealing the whole. In addition, the internal space of the field emission surface light source element 1000 is sealed with a vacuum.

However, the field emission surface light source device 1000 illustrated in FIG. 9 is just an embodiment, and the field emission surface light source device may be manufactured in various forms including the above-described field emission surface light source cathode electrode 100. Put it.

As described above, embodiments of the present invention can reduce the process steps, process time and process costs by using a process of forming an electroless plating layer and electroplating using the electroless plating layer to form an electrode. In addition, when the carbon nanotube ink layer is formed, the electrode part and / or the non-electrode part may be selected and applied to reduce process steps, process time, and process cost.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, many modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. The present invention can be variously modified and changed by those skilled in the art, and it is also within the scope of the present invention.

100: field emission surface light source cathode electrode 110: substrate
120: electroless plating layer 130: electrode pattern
130a: electrode portion 130b: non-electrode portion
140: first metal layer 150: second metal layer
160: carbon nanotube ink layer 200: fluorescent anode
300: spacer 400: sealing cover
1000: field emission surface light source element

Claims (8)

1 step of electroless plating the substrate to form an electroless plating layer;
Forming an electrode pattern divided into an electrode part and a non-electrode part on the electroless plating layer;
Performing a first electroplating process using electricity applied through the electroless plating layer to form a first metal layer on the electrode unit;
Forming a second metal layer on the first metal layer through second electroplating;
Forming a carbon nanotube ink layer on the electrode portion or forming a carbon nanotube ink layer on the electrode portion and the non-electrode portion; And
The method of manufacturing a field emission surface light source cathode electrode comprising the step of removing the non-electrode portion. The method according to claim 1,
After step 6,
Melting the upper portion of the second metal layer through heat treatment to attach the carbon nanotube ink layer to the upper portion of the second metal layer;
An eight step of forming a carbon nanotube emitter through an activation process; And
And removing the electroless plating layer present in the non-electrode portion. The method according to claim 1,
Wherein the first step comprises sand blasting and acid treating the substrate prior to the electroless plating. The method according to claim 1,
The electroless plating of the first step is NiCr electroless plating method for producing a field emission surface light source cathode electrode. The method according to claim 1,
The first metal layer is formed of Cu, Al or Cr, the second metal layer is Sn, In or Al is a method of manufacturing a field emission surface light source cathode electrode. The method according to claim 1,
The step 5 is a field emission surface light source cathode electrode which is a step of applying carbon nanotube ink on the electrode portion and the non-electrode portion through a spray process, or selectively printing carbon nanotube ink only on the electrode portion through an inkjet process. Manufacturing method. The method according to claim 2,
The heat treatment of step 7 is a method of producing a field emission surface light source cathode electrode is carried out at 150 ℃ to 400 ℃. A field emission surface light source device comprising a field emission surface light source cathode electrode manufactured according to the method for producing a field emission surface light source cathode electrode according to claim 1.

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