KR0144586B1 - Spacer manufacturing for field emission display - Google Patents

Abstract

In order to maintain an ultra-high vacuum between the upper substrate and the lower substrate in a field emission display to achieve a predetermined electron emission, a hole is formed using polyimide, and then the inside of the hole is nitrided. The polyimide was removed by adhering to the cathode substrate and then attached to the substrate, and then the polyimide was removed. Thus, a spacer which is strong against mechanical strain due to the internal pressure difference, without outgassing, and without plastic deformation can be produced.

Description

Spacer formation method of field emission display

1 is a front sectional view of a field emission display of the present invention.

2 is a plan view of a polyimide made of holes with x-ray lithography.

3A to 3F are cross-sectional views for sequentially showing a process of forming a spacer of a field emission display of the present invention.

* Explanation of symbols for main parts of the drawings

1: upper substrate 2: lower substrate

3: transparent electrode 4: phosphor

5: emitter tip 6: insulating film

7 gate electrode 8 spacer

9: sealant 10: mask

11: polyimide 12: hole

13: silicon night light for spacer

14: frit glass for bonding upper substrate

15: frit glass for lower substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a spacer that serves as a support between pixels when manufacturing a flat panel display device such as a field emission display (FED) or a plasma display panel (PDP). The manufacturing method of this invention relates to the spacer formation method of the field emission display which can manufacture a spacer by predetermined | prescribed shape, width | variety, and length by using polyimide which is manufacturing molding and polymers.

The flat panel display device is largely composed of an anode part and a cathode part. The ultra-vacuum must be maintained between the upper substrate and the lower substrate according to the vacuum microelectronics theory so that a predetermined electron emission can be performed to operate as the flat display device. .

In this case, there should be a spacer serving as a support between the pixel and the pixel of the flat panel display element. The larger the area of the device, the higher the pressure difference between the inside and outside of the spacer may be dynamically deformed, so the need for a good spacer This is more urgently needed. In addition, the material of the spacer should not be outgassing (Outgassing) out of the gas under ultra-high vacuum conditions, and should be a material that should not be plastic deformation at a temperature of 400 to 500 degrees.

As far as the above conditions are met, there is US Patent No. 5,205,770, which attaches a polyimide tape on a wafer and then grooves the groove using a micro saw made of diamond at predetermined intervals. And a technique for depositing silicon nitride (Si ₃ N ₄ ) on top of the groove is shown.

In other words, the process technology forms a groove in the polyimide tape and deposits silicon nitride thereon. The deposited silicon nitride sticks out onto the polyimide tape. The chemical polishing removes the polyimide tape and protruding silicon nitride to form columnar silicon nitride. Next, the pillar-shaped silicon nitride is attached using a resin of the lower substrate or frit glass. Thereafter, silicon was immersed in a mixed solution of boric acid and ammonia acetic acid to remove silicon, and then aligned with the upper substrate to complete the device.

However, the problem of the prior art is that it is very difficult to first make a hole using a micro-saw in silicon, and even if the hole is made up to 100 micrometers deep, it is almost impossible to deposit it in a hole less than 50 microns in diameter by the deposition method. In addition, it is not easy to accurately attach the silicon nitride that does not stick out about 2 microns to the lower substrate with resin, and there is a risk of damage to the tip or electrode when etching silicon into the solution, and it is also very difficult to easily etch into the solution. to be.

Therefore, in order to solve the above problems, the present invention, when manufacturing a spacer serving as a support between the pixel, the pixel is resistant to mechanical strain due to the pressure difference, there is no outgasing in ultra-high vacuum conditions, 400 to 500 degrees It is an object of the present invention to manufacture a spacer with a predetermined width and length using polyimide, which is a material which should not undergo plastic deformation even at the temperature of.

In order to achieve the above object, the present invention comprises the steps of: depositing a transparent electrode on an upper substrate, depositing a low voltage phosphor on the upper substrate, forming an emitter of a silicon tip on the lower substrate, and depositing an insulating film between the tips. Thereafter, forming a gate electrode on the insulating film, placing a mask having a predetermined spacer gap on the molding material for spacer manufacturing, and then forming a hole using lithography, and manufacturing the spacer. Filling the inside of the hole formed in the molding material with an insulator to form a spacer, and polishing the spacer so that the spacer has the same plane as the surface of the molding material, and then screen-printing the frit glass to be coated only on the spacer. And arranging the lower substrate by using a microscope and then firing the residue mole. Immersing the ding material in a developer which can be selectively developed to completely remove the screen material; and screen-printing the frit glass on the upper substrate, and then attaching and firing the spacer material to which the molding material has been removed. It is characterized by a spacer forming method.

Hereinafter, the present invention will be described in detail with the accompanying drawings.

1 is a front view of a field emission display for showing the upper substrate and the lower substrate, and the sealing portion of the diaphragm and the edge.

According to the present invention, a transparent electrode 3 is deposited on the glass of the upper substrate 1 to form a desired pattern, and the low voltage phosphor 4 is deposited again thereon. The lower substrate 2 is made of a silicon tip emitter 5 using a silicon wafer etching process, a photo process, and a deposition process, and then deposits an insulating film 6 between the tips, and then, Deposition of the gate electrode 7 completes the desired triode substrate. At this time, if a small voltage difference is applied from the tip 5 having a low work function, electrons are popped out. In order to excite the phosphor 4 without any scattering or collision, the upper substrate 1 and the lower substrate are emitted. (2) The vacuum is to be high. At this time, if the pressure difference between the internal and atmospheric pressure is large, the substrate may not be tolerated and may be destroyed. To withstand this pressure difference, at least one spacer 8 per inch must be supported. However, the spacer 8 must be able to withstand the mechanical strain sufficiently and there should be no gas at all even if the material itself is ultra-high vacuum.

FIG. 2 is a plan view of a polyimide in which a hole is made of X-ray lithography when fabricating a spacer according to the present invention. As described above, the hole 12 is formed by using a mask 10 having a predetermined interval on the polyimide 11. The state which formed is shown.

3A to 3F are cross-sectional views for sequentially showing a process of forming a spacer of a field emission display of the present invention. Looking at the process, first, as shown in FIG. 3A, a molding material for manufacturing a spacer is shown. After forming the mask 10 on top of the polyimide 11, a step of forming holes 12, for example, 100 microns in diameter and 40 microns in depth, using X-ray lithography at predetermined intervals is shown.

Thereafter, as shown in FIG. 3B, silicon nitride or silicon oxide, which is an insulator 13 for spacers, is filled in the hole 12 by 50 microns on both sides of the hole 12 of polyimide using the deposition method and the sol-gel method. Fill it up.

Next, in order to flatten the silicon nitride or silicon oxide, which is the insulator 13 filled in the hole 12, with the polyimide surface, chemical polishing is performed to form a flat surface, and the fritgrass is insulated by screen printing. The upper substrate bonding frit glass 14 and the lower substrate bonding frit glass 15 are formed on the upper and lower portions as shown in FIG. 3C.

Thereafter, as shown in FIG. 3d, the spacer 8 is aligned with the upper substrate 1 using a microscope and baked, and the element is immersed in a developer solution as shown in FIG. 11) Remove. Finally, as shown in FIG. 3 f, the frit glass is formed on the lower substrate 2 by the screen printing method, and then contacted with an insulator such as silicon nitride to be fired to form a spacer having a predetermined interval and height. Can be formed.

As described above, in the present invention, polyimide 11 having excellent chemical and physical properties while being sufficiently removed in a developer was used as a spacer adjuvant, and X-ray lithography was used for the polyimide 11 at a desired interval and height depth. Holes 12 are formed in both of the holes 12 to form spacers by filling silicon nitride or silicon oxide, which is an insulator 13, by using a deposition method, a sol-gel method, or the like. At this time, the finished spacer is made flat through polishing, and then the frit glass 14 and 15 are raised to a certain height by using the screen printing method on the spacer 8 on both sides, and then the spacer is well aligned with the substrate. After the polyimide is immersed in a selectively etchable developer such as hydrazine etchant, it is melted and removed in an instant. Only the spacer of the desired shape is left, and when aligned with the upper substrate on the opposite side, the perfect spacer is formed.

In the present invention, it is very difficult to make a hole with silicon used as a molding material in manufacturing a conventional spacer, and the etching rate is very slow when etching the molding material by filling a spacer material into the hole, but the present invention uses polyimide. Therefore, it is very easy to make holes with X-ray lithography, and the polyimide, a molding material, can be etched at a very high speed when immersed in the developing solution, which can speed up the process.

In addition, when the hole is filled with the spacer material, the present invention uses the deposition method on both sides, so that the deposition rate is very fast and the hardness is excellent in terms of hardness.

Claims (4)

Depositing a transparent electrode on the upper substrate, depositing a low voltage phosphor on the upper substrate, forming an emitter of a silicon tip on the lower substrate, depositing an insulating film between the tips, and then forming a gate electrode on the insulating film And placing a mask having a predetermined spacer spacing on the molding material for spacer manufacturing, forming a hole using lithography, and then filling the inside of the hole with an insulator to form a spacer, wherein the spacer is a molding material. After chemical polishing to have the same plane as the surface, screen fritting, so that the frit glass is coated only on the spacer, and after aligning the spacer and the lower substrate by using a microscope, firing, remaining Molding material is immersed in a selectively developable suspension and removed; A method of forming a spacer of a field emission display, comprising: screen printing an frit glass, and then attaching the frit glass to a spacer from which the molding material has been removed. The method of forming a spacer of a field emission display according to claim 1, wherein the molding material for manufacturing the spacer comprises polyimide, glasses, and photosensitive glass. The method of claim 1, wherein the forming of the spacer by filling the inside of the hole with an insulator comprises filling the insulator by using a deposition method and a sol-gel method on both sides of the hole. The method of forming a spacer of a field emission display according to claim 1 or 3, wherein the spacer insulator filled in the hole of the spacer molding material is silicon nitride or silicon oxide.