KR100393195B1 - Method for depositing phosphor screen for field effect electron emitting device by using electrophoretic method - Google Patents

Abstract

PURPOSE: A method is provided to form a phosphor screen in an inexpensive manner by forming external electrodes and forming phosphor screens through an electrophoretic method by applying bias voltages to each of external electrodes. CONSTITUTION: A method comprises a step of preparing Y2O2S:Eu:10% In2O3 as a red phosphor, ZnS:Cu,Al:10% In2O3 as a green phosphor, and ZnS:Ag,Cl,Al:10% In2O3 as a blue phosphor; a step of preparing isopropyl alcohol(IPA) 500cc and 7.5g Al(NO3)3+9H2 charger solution 10cc, preparing glycerin(50%) + IPA(50%) stabilizer solution 100cc, filling a container with phosphor 50g, IPA 500cc, the charger solution, the stabilizer solution 10cc, and CH2O2, and stirring the filled material for 40 minutes; a step of arranging an Al electrode plate and a front substrate(16) in the container, forming external terminals by interconnecting anodes to be deposited with phosphor screens of the same color, and depositing phosphors by applying a bias voltage of 100 to 150V to the external terminals; and a step of drying the front substrate.

Description

Method of applying fluorescent film of field effect electron-emitting device by electrophoresis

The present invention relates to a method of applying a fluorescent film to a field effect electron-emitting device by electrophoresis, and more particularly, to a method of applying a fluorescent film on an anode formed on a front substrate of a field effect electron- To a method of applying a fluorescent film of a field effect electron-emitting device by electrophoresis.

FIG. 1 is a schematic cross-sectional view of a conventional field effect electron emission device. As shown in the drawing, a conventional field effect electron emission device has a plurality of cathodes 2 formed on a rear substrate 1, and a plurality of microtips 2 'are formed in an array on each of the cathodes 2 . These microtips 2 'are provided in the through holes 3a of the insulating layer 3 formed on the cathode 2. On the insulating layer 3, gates 4 having openings 4a corresponding to the through holes 3a are laminated. A plurality of anodes 5 are provided on the front substrate 6 so as to face the micro-tips 2 '. The front substrate 6 is supported on the gates 4 by spacers 8 at regular intervals. And a fluorescent film 7 is formed on the anode 5. Here, the micro-tip array of the rear substrate is a portion corresponding to the cathode of the electron gun of the CRT (refer to the ellipse in the drawing), and the portion of the front substrate on which the fluorescent film is coated is the anode to be. When a microtip array of such a field effect electron-emitting device is grounded and a constant voltage is applied between the gates 4 and the anodes 5, the electrons are emitted into the vacuum to reach the anodes 5, The electrons accelerated by the voltage of the anode 5 collide with the fluorescent film 7 with a constant kinetic energy. Accordingly, the kinetic energy of the electrons is transmitted to the fluorescent film 7, and the fluorescent film 7 receives the kinetic energy of the electrons and is excited to emit light. However, since red, green, and blue fluorescent films 7 are arranged on the anode 5 at regular intervals, as shown in the figure, when the devices are driven by switching the gates 4, The red, green, and blue fluorescent films 7 emit light simultaneously or are turned off (i.e., red, green, and blue fluorescent films are separately emitted) Can not be driven. In addition, such fluorescent films 7 can be manufactured only by using a PVA-slurry or by screen printing, and can not be applied by electrophoretic method. Therefore, the manufacturing cost of the fluorescent film becomes expensive.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an organic electroluminescent device, which is capable of forming an anode so as to emit light of red, And an object of the present invention is to provide a method of applying a fluorescent film of an electron emitting device.

According to an aspect of the present invention, there is provided a method of applying a fluorescent film to a field effect electron emission device,

(A) Y ₂ O ₂ S: Eu: 10% In ₂ O ₃ as a red phosphor, ZnS: Cu and Al: 10% In ₂ O ₃ as a green phosphor, and ZnS: Ag, Cl, and Al: 10% In ₂ O ₃ , respectively;

(B) IPA (IsoPropyl alcohol) 500cc and _{7.5g Al (NO 3) 3 +} 9H 2 O preparing filled 10cc solution and glycerin prepared (50%) + IPA (50 %) solution was stable and then 100cc, phosphor 50g IPA + (500 cc) + the filling solution + the stabilizing solution 10 cc + formic acid (CH ₂ O ₂ ) in an ultrasonic vessel to a predetermined height and then stirring for 40 minutes;

(C) The space between the Al electrode plate and the front substrate is adjusted to 3 to 5 cm in the container, and the positive electrodes formed in a striped pattern on the front substrate are coated with a fluorescent film of the same color of red, Depositing the phosphor for 3 to 8 seconds by applying a bias voltage adjusted to 100 to 150 V to an external terminal to which the positive electrodes to which the one-color fluorescent film is applied are connected to each other to form external terminals;

(D) removing the front substrate coated with the fluorescent film from the container and drying the front substrate;

Wherein the phosphor is changed in the step (b) and the external terminal is changed in the step (c).

In the present invention, in the step (b), it is preferable to fill the liquid in the container to a height of 3 to 3.5 cm,

After step (b), 6 drops of formic acid are added again and stirred for 40 minutes to adjust the conductivity of the plating solution; And stirring the plating solution in an ultrasonic vessel after the step of adjusting the conductivity of the plating solution, and adding 1 to 2 cc of the filling solution when the viscosity is weak.

Hereinafter, a field effect electron-emitting device and a manufacturing method thereof according to the present invention will be described with reference to the drawings.

FIG. 2 is a schematic cross-sectional view of a field effect electron-emitting device according to the present invention. As shown in FIG. 1, the basic structure of the field effect electron emission device according to the present invention is substantially the same as that of the conventional field effect electron emission device as shown in FIG. 1 except that the fluorescent films 17 are formed on the ITO anode 15, On the anode 15 in the same stripe as the cathode 15. The structure in which these anodes are arranged will be described with reference to FIG.

The positive electrodes 15r, 15g, and 15b of the front substrate of the FED according to the present invention include positive electrodes 15r, 15g, and 15b having fluorescent films of red, green, and blue, respectively, Are connected to each other and connected to external terminals 15R, 15G and 15B. The anodes 15r and the anodes 15g are connected to the external terminals 15R and 15G without crossing each other and are connected to the external terminals 15R and 15G. However, the anodes 15b do not cross the anodes 15g, 15B. Therefore, as shown in FIG. 4, the insulating layer 19 is formed on the crossing region so that the connection line of the anodes 15b can be bypassed in the region where the connection line intersects the anode 15g. A metal paste is applied on the insulating layer 19 to form a connection line of the anodes 15b. Thus, red, green, and blue fluorescent films are formed on the connected anode 15r, 15g, and 15b by an electrophoretic method. The method of applying the fluorescent film by the electrophoresis method will be described later.

In the field effect electron emission device of the present invention, the external terminals 15R, 15G and 15B formed on the front substrate 16 are electrically connected to the external terminals 15R 'and 15G ', 15B'). 6, the external terminals 15R, 15G, and 15B of the front substrate 16 and the external terminals 15R, 15G, and 15B of the front substrate 16 are connected by the connection line 20 containing In: Sn of 50:50, 15G ', 15B' are coupled to each other. The thickness of the connection line 20 is appropriately adjusted in accordance with the height of the spacer 18 that maintains the interval between the front substrate 16 and the rear substrate 11. [

A method of manufacturing the field effect electron-emitting device having the above structure is as follows.

First, cathodes 12, micro-tips 12 ', an insulating layer 13 and a gate 14 are formed on a rear substrate 11, as shown in FIG. 2, Thereby forming external terminals 15R ', 15G', and 15B 'as shown (step (a)).

Next, stripe-shaped anodes 15r, 15g and 15b are formed on the front substrate 16, and one side edge of the front substrate 16 is coated with the same color of red, 15G, and 15B connected to each other are formed between the anode and the cathode to be coated with the fluorescent film. The steps (a) and (b) may be reversed.

Next, as shown in FIG. 2, the red, blue and green fluorescent films 17 are applied on the anodes 15 by an electrophoretic method (step (c)).

As shown in FIG. 3, the fluorescent film coating step sequentially forms red, green and blue fluorescent films on the three anodes 15r, 15g, and 15b, respectively. As shown in FIG. 3, Are connected to each other and connected to the external terminals 15R, 15G, and 15B. At this time, an insulating layer (not shown) is formed on the crossing regions of the anodes so that the connection line connecting the anodes 15b to be coated with the blue (arbitrary one color) fluorescent film is bypassed to the anodes 15g to be coated with the fluorescent A metal paste is applied on the insulating layer 19 to form a connecting line 15b as shown in FIG.

Next, the external terminals 15R, 15G, and 15B of the front substrate 16 are placed between the front substrate 16 and the rear substrate 11 with the spacers 18 disposed as shown in Fig. And the external terminals 15R ', 15G', and 15B 'of the back substrate 11 are connected to each other in vacuum so as to be energizable (step (d)). At this time, the connection lines (20 in FIG. 6) connecting the external terminals 15R, 15G and 15B of the front substrate 16 and the external terminals 15R ', 15G' and 15B 'of the rear substrate 11 In: Sn: 50: 50.

Next, the edges of the front substrate 16 and the rear substrate 11 are sealed, and the sealed interior is evacuated to complete the device (step (e)).

In the above manufacturing method, the fluorescent film application method by the electrophoresis method, which is the most important process, will be described with reference to the apparatus of FIG.

3, the external terminal 15R of the front substrate 16 to which the positive electrodes are connected is connected to the cathode of the DC power source 32 as shown in FIG. 7, and the DC power source 32 And the Al electrode plate 30 is connected to the anode of the power source 32 and the red fluorescent film coating process is performed by the electrophoresis method, the phosphor absorbs Al < ⁺ > + ions and is supplied to the anode of the front substrate connected to the cathode of the power source 32 Flowing and attached. Here, reference numeral 33 denotes a magnetic vibrator (for stirring). When the application process of the red fluorescent film is completed, the front substrate is taken out from the container and the red fluorescent film is dried. In this manner, the green fluorescent film coating process and the blue fluorescent film coating process are sequentially performed to complete the fluorescent film coating process. The order of the red, green, and blue fluorescent film coating processes may be any order.

The procedure of the fluorescent film application process is as follows.

First, Y ₂ O ₂ S: Eu: 10% In ₂ O ₃ was used as a red phosphor, ZnS: Cu, Al: 10% In ₂ O ₃ was used as a green phosphor and blue phosphor was used as a red phosphor ZnS: Ag, Cl, Al: 10% In ₂ O ₃ are prepared. In addition, 7.5 g Al (NO ₃ ) ₃ +9H ₂ O (10 cc) was prepared as the IPA (500 cc) + solution "A" (charger) prepared 100cc of glycerin (50%) + IPA (50 %) as (a stabilizer), and then, the phosphor 50g + IPA (500cc) + solution "a" (10cc) + solution "B" (10cc) + formic acid (CH ₂ O ₂ ) Is filled into an ultrasonic wave (400 KHz) container and stirred for 40 minutes. The height of the liquid in the container is preferably 3 to 3.5 cm. Add 1 ml or less (about 6 drops) of formic acid again and stir for 40 minutes to control the conductivity of the solution. Prepare this plating solution as desired.

Next, the plating solution prepared as described above is put into an ultrasonic vessel and stirred before applying the fluorescent film by the electrophoresis method. When the viscosity is weak, 1 to 2 cc of the solution "A" is added as a charger .

Next, as shown in FIG. 7, the distance between the Al electrode plate 30 and the front substrate 31 is adjusted to 3 to 5 cm, and the bias voltage adjusted to 100 to 150 V is applied and deposited for 3 to 8 seconds . In this case, the phosphor absorbs Al ⁺⁺ ions and flows to the positive electrodes of the front substrate 31 connected to the negative electrode of the power source 32, and is attached.

FIG. 1 is a schematic cross-sectional view of a conventional field effect electron emission device,

FIG. 2 is a schematic cross-sectional view of a field effect electron-emitting device according to the present invention,

FIG. 3 is a schematic plan view showing red, green and blue anode patterns of the front substrate of the field-effectable electron-emitting device of FIG. 2;

FIG. 4 is a cross-sectional view taken along line A-A 'of FIG. 3,

FIG. 5 is an electrode perspective plan view for schematically explaining the arrangement relationship of the electrodes formed on the front substrate and the rear substrate of the field effect electron emission device of FIG. 2,

6 is a cross-sectional view taken along line A-A 'of FIG. 5,

And FIG. 7 is a schematic cross-sectional view of an apparatus for applying a fluorescent film of a field-effect electron-emitting device according to the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

11. Rear substrate 15. ITO anode

15r, 15g, 15b. Positive electrodes 15R, 15G, 15B. External terminals of the front substrate

15R ', 15G', 15B '. The external terminals of the rear substrate

16. Front substrate 17. Fluorescent film

18. Spacer 19. Insulating layer

20. Connection line

As described above, according to the electrophoresis method of the present invention, the method of applying the fluorescent film of the field effect electron-emitting device includes the steps of connecting the anode to be coated with the fluorescent film of the same color so as to apply the color fluorescent film to the anode of the front substrate, A clean fluorescent film can be obtained at a low cost by forming an external terminal and successively forming a fluorescent film of each color by electrophoresis while sequentially applying a bias voltage to the external terminals.

Claims (4)

(A) Y ₂ O ₂ S: Eu: 10% In ₂ O ₃ as a red phosphor, ZnS: Cu and Al: 10% In ₂ O ₃ as a green phosphor, and ZnS: Ag, Cl, and Al: 10% In ₂ O ₃ , respectively; (B) 500 cc of IPA (isopropyl alcohol) and 10 cc of a 7.5 g Al (NO ₃ ) ₃ + 9H ₂ O filling solution were prepared and 100 cc of a stable solution of glycerin (50%) + IPA (50% (500 cc) + the filling solution + the stabilizing solution 10 cc + formic acid (CH ₂ O ₂ ) in an ultrasonic vessel to a predetermined height and then stirring for 40 minutes; (C) The space between the Al electrode plate and the front substrate is adjusted to 3 to 5 cm in the container, and the positive electrodes formed in a striped pattern on the front substrate are coated with a fluorescent film of the same color of red, Depositing the phosphor for 3 to 8 seconds by applying a bias voltage adjusted to 100 to 150 V to an external terminal to which the positive electrodes to which the one-color fluorescent film is applied are connected to each other to form external terminals; (D) removing the front substrate coated with the fluorescent film from the container and drying the front substrate; Wherein the phosphor is changed in the step (b), and the step (c) is repeated three times while changing the external terminal in the step (b). The method according to claim 1, The method for applying a fluorescent film of a field effect electron-emitting device according to claim 1, wherein in the step (b), the height of the liquid in the container is 3 to 3.5 cm. The method according to claim 1, The method of claim 1, further comprising, after step (b), adding 1 ml or less of formic acid to the solution, and stirring the solution for 40 minutes to adjust the conductivity of the plating solution. Application method. The method of claim 3, Further comprising the step of adding the plating solution to the plating solution in an ultrasonic vessel followed by stirring, and adding 1 to 2 cc of the filling solution when the viscosity is weak, after the step of adjusting the conductivity of the plating solution. (EN) METHOD FOR APPLYING FLUORESCENT FILM FOR EFFECTIVE ELECTRO -