KR101162040B1 - Glass composition for sealing of and display panel comprising the same - Google Patents

Abstract

PURPOSE: A sealing glass composition and a display panel including thereof are provided to enhance density, durability, intensity, and reliability, and to enable moment sealing at low temperature less than 450 deg. Celsius. CONSTITUTION: A sealing glass composition comprises glass which has Tc(temperature of crystallization) of 500-580 deg. Celsius and Tdsp(diatometer softening point) of 250-350 deg. Celsius and glass which has Tc of 350-400 deg. Celsius and Tdsp of 270-320 deg. Celsius. Temperature difference of Tc and Tdsp of low solder glass is 180-230 deg. Celsius. Temperature difference of Tc and Tdsp of the glass having Tc of 350-400 deg. is 50-100 deg. Celsius. The two glasses comprise 30-80 weight% of V2O5, 10-40 weight% of TeO2, and 5-40 weight% of BaO. Temperature difference of Ts(softening point) and Tx(crystallization initiating temperature) of the sealing glass composition is 5-30 deg. Celsius. A weight ratio of the two glasses is 9:1-6:4.

Description

Sealing glass composition and a display panel including the same {GLASS COMPOSITION FOR SEALING OF AND DISPLAY PANEL COMPRISING THE SAME}

The present invention relates to a sealing glass composition and a display panel including the same, and more particularly, capable of instantaneous sealing at a low temperature of 450 ° C. or lower, excellent in density, no cracking, and sealing property and durability after sealing. It relates to a sealing glass composition excellent in strength, reliability and the like and a display panel including the same.

In the display field, a flat panel display is composed of a front panel and a rear panel, and the display shape that can be checked by the eyes is displayed by the electric driving between the two panels. In this case, both panels should be bonded to each other while maintaining a constant gap. For this purpose, an encapsulant should be used. It is important to keep the sealing temperature as low as possible because the panel will be thermally damaged if the sealing temperature is too high.

 In addition, when manufacturing a display device or an illumination light source using OLED, encapsulation technologies are needed to protect organic materials, which are vulnerable to moisture and air, from the external environment. The glass frit used for encapsulation is currently Compared to the polymer material, which is mainly used, the water resistance and durability are good, which can prolong the life of the OLED device. In addition, the sealing by the glass frit can be applied to a substrate (Eagle 2000 TM) having a very low thermal expansion rate, and since the glass frit becomes thinner at the time of firing, only the glass frit is used to prevent damage to the organic light emitting material at high temperature. Locally heatable lasers can be used as the heat source. Therefore, the density after the plasticization step, the cracking property due to thermal shock, and the crystallization property after sealing play a very important role in the quality and lifetime of the OLED device. However, PbO-based glass and the like have been widely used as the sealing material until recently.

The PbO-based glass can be sealed even at a low sintering temperature, and has excellent adhesiveness and chemical stability, but is harmful to humans and the environment because it contains toxic substances such as PbO, and its use is limited in many countries. There is a situation.

Japanese Patent Laid-Open No. 2003-041695 and Japanese Patent Laid-Open No. 2004-2520276 disclose a V ₂ O ₅ -ZnO-BaO-based glass composition for sealing processing that does not contain PbO, but the V ₂ O ₅ -ZnO-BaO Since the glass composition has to reduce the amount of refractory filler added in order to remove the binder and secure the density in the plastic step, there is a problem that cracks due to thermal shock will occur, and if the firing temperature is increased to improve the density, the main firing step Previously crystallized, there is a problem that is difficult to attach during the sealing of the laser firing step.

In addition, Korean Patent Publication No. 2010-0035417 and Japanese Patent Publication No. 2010-0105267 disclose a V ₂ O ₅ -ZnO-BaO-P ₂ O ₅ -based glass composition for sealing processing, but the crystallization temperature (Tc) is 470, respectively. It is difficult to crystallize during laser sealing due to high ℃, 600 ℃, the strength is weak due to thermal shock easily crack, there is a problem of poor durability.

In order to solve the problems of the prior art as described above, the present invention is capable of instant sealing at a low temperature of less than 450 ℃, excellent density, no cracking, sealing after sealing, durability, strength and reliability, etc. It is an object of the present invention to provide an excellent sealing glass composition and a display panel including the same.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention provides a sealing glass composition comprising a) low melting glass and b) accelerator.

In addition, the present invention comprises a front panel, a phosphor, a metal electrode and a rear panel, wherein the front panel and the rear panel provides a display sealed by the sealing glass composition.

As described above, according to the present invention, a sealing glass capable of instant sealing at a low temperature of 450 ° C. or less, excellent in density, no cracking, and excellent sealing properties, durability, strength, and reliability after sealing are all excellent. There is an effect of providing a composition and a display panel comprising the same.

In addition, the sealing glass composition of the present invention is excellent in blackness with a high infrared absorption rate, so that the sealing process is possible even under an oxidizing atmosphere, thereby greatly reducing the processing time and process cost, and mixing the low melting point glass and the accelerator, respectively, which are manufactured to seal the OLED. Laser sealing process margins (range from limit output to low output, which can be used for laser sealing process) are improved, and plasticity is achieved when the difference between softening temperature (Ts) and crystallization start temperature (Tx) (Tx-Ts) is within 20 ° C. Thermal stability is improved and cracks are prevented through sufficient plastic margin, densities, and partial crystallization of the resin, and instantaneous crystallization and adhesion are possible during laser sealing, which significantly improves high sealability, durability, strength, and adhesive performance. Has the effect.

For reference, the laser sealing is performed by adjusting the output strength, travel time, and the distance between the spot and the substrate. If the sealing glass composition does not melt well, the laser output must be increased to melt it, thereby causing damage to the body substrate. There is. Therefore, in order to stabilize the process quality, there is an urgent need for a sealing glass composition capable of laser sealing at low power, and the present invention solves this problem.

1 is a glass frit DTA curve of a typical lead-free glass frit by a differential thermal analysis device, and Tm is a melting point (° C.).
2 is a correlation diagram of endothermic heat-temperature of the low melting point glass material prepared in Preparation Example 8. FIG.
3 is a correlation diagram of endotherm-temperature of the accelerator prepared in Preparation Example 12. FIG.
4 is a correlation diagram of endothermic heat-temperature of the sealing glass composition prepared in Example 1.
5 is a schematic diagram for measuring the three-point bending strength of the sealing glass composition prepared in Example 5.
FIG. 6 is a general camera photograph and an optical microscope photograph showing the sealing state after the laser sealing of the sealing glass composition prepared in Example 5. FIG.

Hereinafter, the present invention will be described in detail.

The present inventors manufacture the low melting point glass and the accelerator, respectively, and mix them in a predetermined ratio, so that the crystallization start temperature (Tx) can be adjusted in a wide temperature range, so that the densities are excellent even in plasticity, and partial thermal crystallization is performed, resulting in low thermal expansion. When the refractory filler was added at 40% or less, it was confirmed that no crack was generated due to thermal shock, and thus the present invention was completed.

The sealing glass composition of this invention is characterized by including a) low melting glass and b) accelerator.

Plasticity as used herein refers to a preliminary heat treatment step of degreasing organic materials such as organic vehicles from the sealing or prebaked glass composition to prevent degradation of the sealing properties by residual organic materials upon firing.

In the present specification, the density means the melted level of the cross-sectional microstructure, which can confirm the firing, and the excellent density means that the glass composition is completely melted by heat, and in general, the glass composition for sealing during firing ( Can be quantified by measuring the density of the specimen).

In the present specification, Tdsp means yield point, Tc means crystallization temperature, Tx means crystallization start temperature, and Ts means softening point.

In the present specification, devitrification means losing transparency, and specifically, refers to a case in which unmelting occurs when melting glass bezel, thereby not becoming glass.

Preferably, the a) low melting point glass has a plastic margin (Tc-Tdsp) of 180 to 230 ° C, more preferably 180 to 200 ° C, and the b) accelerator has a plastic margin (Tc-Tdsp) of 50 to It is preferably 100 ℃, more preferably 60 to 80 ℃, within this range without containing lead or bismuth high fluidity and blackness, it is possible to be fired in an oxidizing atmosphere to greatly reduce the process cost It works.

The a) low melting point glass has a crystallization temperature (Tc) of 500 ° C. or higher and a yield point (Tdsp) of 320 ° C. or lower, and the b) accelerator has a yield point (Tdsp) of 320 ° C. or lower and a crystallization temperature (Tc) of 400 Although it is preferable that it is below C, in this range, when the plasticity is excellent in the density, and after the main firing, that is, after the laser sealing is completely crystallized, there is an excellent adhesion effect.

Wherein a) a low melting point glass is preferably made by including _{V 2 O 5, TeO 2,} BaO and ZnO.

The a) low melting glass is preferably made of 30 to 70% by weight of V ₂ O ₅ , 10 to 50% by weight of TeO ₂ , 1 to 40% by weight of BaO and 1 to 30% by weight of ZnO, more preferably 30 to 60% by weight of V ₂ O ₅ , 15 to 40% by weight of TeO ₂ , 10 to 30% by weight of BaO, and 1 to 20% by weight of ZnO, most preferably 30 to 55% by weight of V ₂ O _5. 15 to 35% by weight of TeO ₂ , 10 to 30% by weight of BaO and 1 to 15% by weight of ZnO, having a fluidity suitable for the sealing process within this range, and having a low risk of devitrification, thereby obtaining a uniform composition. And, plasticity has an excellent effect on the density.

The a) low melting point glass is Sb ₂ O ₃ , P ₂ O ₅ , CeO ₂ , CuO, CoO, Nd ₂ O ₃ , Fe ₂ O _{3 ,} Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and It is preferable to further include at least one selected from the group consisting of Cs ₂ O, in which case the flowability and blackness is improved.

The a) low melting point glass is Sb ₂ O ₃ , P ₂ O ₅ , CeO ₂ , CuO, CoO, Nd ₂ O ₃ , Fe ₂ O _{3 ,} Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and It is preferable to include 0.1 to 20% by weight of one or more selected from the group consisting of Cs ₂ O, more preferably 0.5 to 10% by weight, and most preferably 1 to 5% by weight. In this range, the glass becomes more stable and the blackness is remarkably improved, thereby increasing the infrared absorption rate.

The b) accelerator is preferably made of V ₂ O ₅ , TeO ₂ and BaO.

The b) accelerator may contain less than 5% by weight of ZnO, preferably does not include, within this range is the crystallization start temperature (Tx) and crystallization temperature (Tc) is lowered has the effect of promoting the crystallization. .

Wherein b) accelerator is V ₂ O ₅ 30 to 80 wt%, TeO ₂ 10 to 40% by weight and BaO 5 to 40, and preferably comprises a percent by weight, more preferably V ₂ O ₅ 30 to 60% by weight 20 to 40% by weight of TeO ₂ and 5 to 30% by weight of BaO, most preferably 35 to 55% by weight of V ₂ O ₅ , 20 to 35% by weight of TeO ₂ and 10 to 30% by weight of BaO. It is made, including, there is no devitrification of the glass within this range, there is an effect that the crystallization is easy.

B) accelerators ZrO ₂ , TiO ₂ , P ₂ O ₅ , CeO ₂ , CuO, CoO, Nd ₂ O ₃ , Fe ₂ O _{3 ,} Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs It is preferable to further include at least one selected from the group consisting of ₂ O. In this case, blackness is improved and glass crystallization is promoted.

B) accelerators ZrO ₂ , TiO ₂ , P ₂ O ₅ , CeO ₂ , CuO, CoO, Nd ₂ O ₃ , Fe ₂ O _{3 ,} Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs It is preferable to include 0.1 to 20% by weight of one or more selected from the group consisting of ₂ O, more preferably 0.5 to 10% by weight, and most preferably 5 to 10% by weight. In this range, the blackness is greatly improved, and the infrared absorption is excellent, and the crystallization start temperature (Tx) and the crystallization temperature (Tc) are lowered, thereby promoting glass crystallization.

The a) low melting point glass and the b) accelerator may have a weight ratio of 9: 1 to 1: 9, preferably 9: 1 to 3: 7, more preferably 9: 1 to 5: 5 Most preferably, it is 8: 2 to 6: 4, and in this range, partial crystallization occurs during plasticity, and even when the refractory filler is added at 40% or less, the thermal shock resistance is excellent, there is no cracking, the density and the adhesion strength. Has an excellent effect.

The a) low melting point glass has an effect of enabling partial crystallization by promoting crystallization of the b) promoter in a wide temperature range.

When b) is used alone, there is a problem in that the density decreases in the plasticizing section and crystallization progresses too much, so that the sealing material is hardly sealed when the laser is sealed in the firing section.

The sealing glass composition preferably has a difference (Tx-Ts) between the softening point (Ts) and the crystallization start temperature (Tx) of 20 ° C. or less, and has a large crack preventing effect within this range, and easy crystallization after instantaneous adhesion during laser sealing. In this case, the adhesion strength, sealability, strength, durability, reliability and the like are remarkably improved.

By adjusting the content ratio of the a) low melting point glass and the b) promoter, the crystallization start temperature (Tx) and the crystallization temperature (Tc) are adjusted, and the adjusted crystallization start temperature (Tx) and crystallization temperature (Tc) are plasticity steps. Partial crystallization of the glass composition may result in maximizing the crack prevention effect.

However, when the melting point is further lowered by using the a) low melting point glass or the b) accelerator alone, only the crystallization start temperature (Tx) and the crystallization temperature (Tc) are lowered compared to the softening point (Tg) and the yield point (Tdsp). (Tc-Tdsp) is reduced, there is a problem that the adhesion strength is significantly reduced or the adhesion is not at all when the laser sealing.

The sealing glass composition is preferably made of V ₂ O ₅ , TeO ₂ , ZnO, BaO, Sb ₂ O ₃ and ZrO ₂ , in this case laser sealing is possible to replace the sealing Pb-based and Bi-based glass composition It is effective.

Preferably, the sealing glass composition further includes a refractory filler, in which case there is an effect of improving the thermal stability and mechanical strength of the glass composition.

The refractory filler is preferably at least one member selected from the group consisting of cordierite, krypite, mullite, zircon, alumina, silica and aluminum titanate, in which case the effect of improving the thermal stability and mechanical strength of the glass composition is improved. have.

The refractory filler is preferably included in less than 40% by weight, more preferably in 20 to 40% by weight, and most preferably in 30 to 40% by weight relative to the sealing glass composition comprising the same. Within this range, it has excellent plastic density and thermal shock alleviation effect.

The encapsulating glass composition may be partially crystallized by plasticity near the softening point (Ts) and then crystallized near the softening point (Ts) so as to soften within seconds when the laser is sealed, and then adhere to the crystallization initiation temperature (Tx) to complete the crystallization. Do.

The plasticity step improves the density and proceeds to partial crystallization, and thus has a stable effect on thermal shock.

The plasticity is preferably carried out at 420 ° C. or lower, and more preferably at 400 to 420 ° C., which has excellent densities and promotes partial crystallization within this range.

The sealing glass composition is preferably a thermal expansion coefficient of 35 × 10 ^-7 to 80 × 10 ^-7 , more preferably 35 × 10 ^-7 to 45 × 10 ^-7 , which is applied to the OLED within this range It has an effect that harmonizes well with the thermal expansion properties of the panel.

The sealing glass composition may further include an organic vehicle. In this case, the sealing glass composition becomes a paste and has an effect of being easily applied to an object to be sealed.

The organic vehicle is preferably included in 30 to 60% by weight (40 to 70% by weight of the sealing glass composition excluding the organic vehicle) relative to the total weight of the sealing glass composition.

The organic vehicle is preferably a mixture consisting of an organic binder and a dispersion medium.

The organic binder is an organic material that binds the glass powder or the glass mixture, and is not particularly limited in the case of an organic binder that can be used in a sealing glass composition, but is preferably an ethyl cellulose or an acrylate-based organic binder.

The dispersion medium is a solvent for dispersing the organic binder, and is not particularly limited in the case of a dispersion medium that can be generally used in the sealing glass composition, but is at least one member selected from the group consisting of butyl carbitol acetate, butyl carbitol and terpineol. It is preferable.

The sealing glass composition (paste) preferably has a viscosity of 20 to 60 kcps, and may further include an additive as necessary for this purpose, there is an effect of improving the flowability and paste coating workability within the viscosity range. .

The viscosity is a Brookfield, DV-II + VISCOMETER, SPINDLE # 14 using a sample (for example, sealed glass composition paste) in the holder at room temperature (25 ℃) and left for 20 minutes at room temperature for stabilization after spindle rotation speed 30 rpm It is measured by the value appearing after 5 minutes.

The dense and partially crystallized glass composition according to the present invention is stable to thermal shock and is instantaneously crystallized and melted upon main firing (laser sealing) near the crystallization initiation temperature (Tx) to provide sealing, strength, durability, The reliability and the like are remarkably improved.

The sealing glass composition is preferably used for sealing OLED (Organic Light-Emitting Diode).

The display panel of the present invention comprises a front panel, a phosphor, a metal electrode and a rear panel, wherein the front panel and the rear panel are characterized by being sealed by the sealing glass composition.

Preferably, the display panel is an OLED display panel.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

[Example]

Manufacturing example  1 to 8 ( Low melting point  Manufacture of glass)

The components shown in Table 1 are mixed in the proportions (% by weight) indicated, and then melted at 1150 to 1250 ° C., quenched dryly using a twin roll, and then pulverized with a grinder and having an average particle diameter of 1 to 3 μm. A low melting glass powder having was prepared.

A pellet of 5 × 5 × 5 mm size was prepared from the prepared low melting point glass powder, and then fired to measure the thermal expansion coefficient by TMA (Thermo-mechanical Analysis). Then, the temperature was increased by 10 DEG C. per minute, and the differential thermal analysis device (DTA), SDT-Q600 (TA instrument), showed the transition point (Tg), yield point (Tdsp), softening point (Ts), crystallization start temperature (Tx), and crystallization. The temperature (Tc) was measured and the results are shown in Table 1 below.

In addition, 50 to 60% by weight of the prepared low melting glass powder organic vehicle (consisting of 10.78% by weight of ethyl cellulose, 28.05% by weight of dibutyl phthalate, 20.37% by weight of terpineol and 40.80% by weight of butylcarbitol acetate) Mix the weight percent (solid content 50-60 weight percent), 3-roll milling and defoaming to make paste, then apply it to the substrate glass and heat it to 360 ℃ using a common laboratory box as a heat source After 20 minutes of degreasing and plasticizing at 400 to 420 ° C. for 20 to 30 minutes, a thick film having a thickness of 7 μm was prepared. After that, laser sealing was carried out at a speed of 30 mm / 1s to 30 mm / 5s in a spot temperature range of 700 to 800 ° C., and the transmittance of a thick film manufactured using a magnetic spectrophotometer (U-350, Japan) of Hitachi, Ltd. (Infrared absorptivity) was measured and the results are shown in Table 1 below.

In the measurement by the differential thermal analysis device (DTA), the relationship between the endothermic and the exothermic heat of the sample according to the heating temperature is shown in FIG. The differential thermal analysis graph for is shown in Figure 2 below.

division Manufacturing example One 2 3 4 5 6 7 8 Furtherance
(weight%) V2O5 50 45 40 35 45 45 42 45 TeO2 20 30 30 30 30 30 30 30 BaO 20 18 18 18 17.5 17 18 16 ZnO 10 7 7 7 7 7 7 5 ZrO2 P2O5 5 10 TiO2 Li2O Na2O 0.5 1.0 K2O Sb2O3 3 3 CoO 2 CuO 2 Nd2O3 Fe2O3 Transition point Tg (占 폚) 285 286 285 290 286 285 290 292 Yielding point Tdsp (℃) 300 299 297 305 297 299 305 303 Softening point Ts (℃) 390 450 350 350 415 340 455 460 Start of crystallization Tx (℃) 410 490 365 390 440 350 505 490 crystallization Tc (℃) 430 500 395 440 450 370 515 500 Plastic margin Tc-Tdsp (℃) 130 201 98 125 153 71 205 204 Crystallinity (Tx-Ts) (℃) 20 40 15 40 25 10 40 30 Infrared absorption rate (%) 90 80 92 83 88 92 90 93

As shown in Table 1, the low melting point glass having a yield point (Tdsp) of 320 ° C. or less, a crystallization temperature (Tc) of 500 ° C. or more, and a plastic margin (Tc-Tdsp) of 180 ° C. or more are manufactured in Examples 2 and 7 above. And 8;

For reference, the preparation examples 1 and 2 show that there is a big difference in the plasticity margin (Tc-Tdsp) and crystallinity (Tx-Ts) according to the V ₂ O ₅ content and TeO ₂ content, especially Preparation Example 2 As in the example of 40 to 50% by weight of V ₂ O ₅ and 30 wt% or more of TeO ₂ content can be added to increase the plastic margin, in the case of Preparation Examples 3, 4, 5 and 6 additives for improving the fluidity of the base material As a test, when the P ₂ O ₅ content is 5 wt% or less or the alkali metal is 1 wt% or more, the crystallization is accelerated and the plasticity margin is significantly lowered. At least 10 wt% P ₂ O ₅ and 1 wt% or less alkali metal are added. Also it was confirmed that it has a large influence on the plastic margin change of the low melting point glass.

In addition, in Examples 7 and 8, the plasticity margin was wide and the crystallinity was excellent, but a transition metal was added to solve the problem of lowering infrared absorption.

In addition, the substitution of the representative transition metals Sb ₂ O ₃ , CoO and CuO does not affect the plasticity margin and crystallinity, it was confirmed that the blackness is improved to significantly increase the infrared absorption.

Manufacturing example  9 to 12 (preparation of accelerators)

The components shown in Table 2 below were mixed at the indicated ratios (wt%), and then accelerator powders, calcined accelerators and thick films were sequentially prepared in the same manner as in Preparation Examples 1 to 8.

Prepared accelerator powder, calcined accelerator and thick film in the same manner as in Preparation Examples 1 to 8, the transition point (Tg), yield point (Tdsp), softening point (Ts), crystallization start temperature (Tx), crystallization temperature (Tc) And a differential thermal analysis graph for the accelerators measured by measuring the transmittance (infrared absorptivity) and prepared in Preparation Example 12 (see Table 2 below) and fired in FIG. 3.

division Manufacturing example 8 9 10 11 12 Furtherance
(weight%) V2O5 45 40 40 40 40 TeO2 30 27 27 26.5 26.8 BaO 16 18 18 18 16 ZnO 5 7 7 7 5 ZrO2 3 3 3 P2O5 5 5 5 TiO2 3 Li2O Na2O 0.5 0.8 K2O Sb2O3 3 CoO 2 2 CuO 2 2 Nd2O3 Fe2O3 Transition point Tg (占 폚) 292 290 298 287 285 Yielding point Tdsp (℃) 306 305 312 301 299 Softening point Ts (℃) 460 354 365 348 342 Start of crystallization Tx (℃) 490 366 378 355 356 crystallization Tc (℃) 500 394 391 368 378 Plastic margin Tc-Tdsp (℃) 204 89 79 67 79 Crystallinity (Tx-Ts) (℃) 30 12 13 7 14 Infrared absorption rate (%) 93 90 92 94 96

As shown in Table 2, the accelerator having a yield point (Tdsp) 320 or less, a crystallization temperature (Tc) of 380 ° C. or less and a plastic margin (Tc-Tdsp) of 50 to 100 ° C. according to the present invention are prepared in Preparation Examples 9 to 12. Was prepared.

For reference, in the preparation examples 9 to 12, when the P ₂ O ₅ , TiO ₂ , ZrO ₂ , and alkali metals are added, a typical accelerator in which the material has a significantly lower plastic margin (Tc-Tdsp) and crystallinity (Tx-Ts) It was confirmed that the addition of the double P ₂ O ₅ greatly affects the degree of crystallization of the material, but it was confirmed that it is advantageous to introduce the alkali metal due to disadvantages such as water resistance, moisture resistance.

In addition, in Preparation Example 12, the plastic margin (Tc-Tdsp) is between 50 and 100 ° C. without significant change in thermal analysis even when transition metals containing Na ₂ O and ZrO ₂ to increase infrared absorption by 0.5 to 1 wt% are added. It was confirmed that an accelerator having a crystallinity (Tx-Ts) of 20 ° C or less was produced.

Example  1 to 4 (Preparation of Seal Glass Composition)

The low melting glass powder and the accelerator powder prepared in Preparation Example 8 and Preparation Example 12 were mixed in the ratio (weight%) shown in Table 3 below, and then the sealing glass composition fired in the same manner as in Preparation Examples 1 to 8 and Thick films were prepared.

The fired sealing glass composition and the thick film thus prepared were prepared in the same manner as in Preparation Examples 1 to 8 by the transition point (Tg), yield point (Tdsp), softening point (Ts), crystallization start temperature (Tx), crystallization temperature (Tc) and Transmittance (infrared absorptivity) was measured and a glass differential thermal analysis graph for the sealed glass composition prepared and fired in Example 1 (see Table 3 below) is shown in FIG. 4.

division Production Example 8 Production Example 12 Example 1 Example 2 Example 3 Example 4 Content ratio
(Low melting point glass: accelerator) (Low melting point
Glass) (accelerant) 9: 1 7: 3 5: 5 3: 7 Transition point Tg (占 폚) 292 285 294 286 285 287 Yielding point Tdsp (℃) 306 299 306 301 300 302 Softening point Ts (℃) 460 342 458 396 383 361 Start of crystallization Tx (℃) 490 356 487 413 399 375 crystallization Tc (℃) 500 378 494 438 418 393 Plastic margin Tc-Tdsp (℃) 194 79 193 154 118 91 Crystallinity (Tx-Ts) (℃) 30 14 29 17 16 14 Infrared absorption rate (%) 93 96 93 95 95 96

As shown in Table 3, the sealing glass composition of the present invention was prepared in Examples 1 to 4.

For reference, as the accelerator content increases in Examples 1 to 4, the plasticity margin and crystallinity become more suitable for the plasticity temperature range when the OLED panel is encapsulated and the temperature range that can be immediately crystallized after firing. If too much glass needs to be changed to a low temperature decomposition binder, it was confirmed that the content ratio is preferably about 7: 3 under current conditions.

In addition, the low melting point glass of Preparation Example 1 and the sealing glass composition of Example 2 showed similar behaviors in the plasticity margin (Tc-Tdsp) and crystallinity (Tx-Ts) as a result of thermal analysis, but the low melting point glass of Preparation Example 1 Is a single glass, crystallization temperature (Tc) is 450 ℃ or less, the solidity content, elevated temperature conditions, plasticity profile, plasticity in the section where the plasticity is made according to the type and content of the refractory filler is confirmed that the adhesion performance is greatly reduced Could.

Example  5 to 8 (Preparation of Seal Glass Composition)

After adding the eutectic (β-Eucryptite) to the mixed powder of the low melting point glass and the accelerator of Examples 2 and 3 to 30 or 40% by weight relative to the total weight of the glass composition as shown in Table 4 below Then, it was compression molded into a circular mold having a diameter of 5 mm with a force of 1 Mpa to prepare a sealing glass composition specimen.

In order to confirm the high temperature behavior of the prepared sealing glass composition specimens, the temperature was raised to 600 ° C. at a temperature rising rate of 10 ° C. per minute, and then the temperature-specific behavior was measured and the results are shown in Tables 4 a-d.

In addition, the prepared sealing glass composition specimens were heated up to 400 ° C. at a heating rate of 10 ° C. per minute in a box furnace, and then fired at 400 ° C. for 25 minutes, and then visually observed adhesion, color, and plasticity with the substrate. Was measured, and the results are shown in Table 4 below.

Comparative example  1 to 3 (Preparation of Sealing Glass Composition)

In Examples 5 to 8, except that the low melting glass prepared in Preparation Example 1 or 5 was used alone and the refractory filler was used in the amount shown in Table 4 below, in the same manner as in Examples 5 to 8 A sealing glass composition was prepared and its plastic properties were measured, and the results are shown in Table 4 below.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 5 Example 6 Example 7 Example 8 Glass powder Preparation Example 1 Production Example 5 Production Example 5 Example 2 Example 2 Example 3 Example 3 Filler content (%) 30% 30% 40% 30% 40% 30% 40% a Contraction 310 321 334 306 312 305 314 b Shrink complete 370 380 392 352 368 354 368 c Crystallization start 410 445 447 436 446 421 429 d crystallization 440 468 472 456 461 448 456 Plastic section (c-b) 40 65 55 84 78 67 61 Plasticity degree (visual observation) crystallization Firing Unsung Firing Firing Firing Firing Board crack (visual observation) decap fracture decap none none none none Plastic color black black black black black black black Bond strength (visual observation) - - - River River River Chinese medicine Firing state (visual observation) crystallization part
crystallization - part
crystallization part
crystallization part
crystallization part
crystallization

As shown in Table 4, the sealing glass composition (Examples 5 to 8) of the present invention, partial crystallization occurs compared to the case that does not contain an accelerator (Comparative Examples 1 to 3), the plastic properties and adhesion strength Excellent, no crack was found.

 For reference, in Comparative Example 1, the firing section was narrowed to 40 ° C. (low firing margin was low), and crystallization proceeded to an unbaking, resulting in substrate decapsulation, and in case of Preparation Example 5 (Comparative Example 2 and 3) When the refractory filler is added up to 30% by weight or less, it has sufficient density when plasticizing, but even when the refractory filler is added up to 30% by weight or less, cracking due to thermal shock occurs due to incomplete partial crystallization or insufficient content of the refractory filler. Could confirm.

In addition, the sealing glass composition of Examples 5 to 8 has a firing section of at least 60 ° C. or more, so that more compact firing is possible at the time of plasticity, and further, crystallization in the glass composition is promoted to cause partial crystallization at the time of plasticity, resulting in 30 wt% of a refractory filler. Even when the addition of the crack was prevented during the firing, it was confirmed that the adhesion strength is greatly improved.

In addition, through the results of Examples 5 to 8, it is preferable that the refractory filler is contained in an amount of 30 to 40% by weight in order to suppress plasticity density and cracking of the substrate. It was confirmed that the sealing glass composition is preferable.

As shown in FIG. 1 below, the plastic behavior of a typical glass is softened and then crystallization begins, followed by complete crystallization and then melting. Partial crystallization according to the present invention means that the crystallization also partially progresses as the plasticization proceeds, and the glass and crystallization properties coexist so that they are stable to thermal shock, and then complete in a short time when the main body is laser-sealed. Crystallization takes place, excellent adhesion strength.

Example  9 to 11 (Preparation of Seal Glass Composition)

An organic vehicle comprising 10.78 wt% ethyl cellulose, 28.05 wt% dibutyl phthalate, 20.37 wt% terpineol, and 40.80 wt% butylcarbitol acetate was added to the glass mixed powder including the refractory fillers of Examples 5 to 7. The encapsulated glass composition was prepared from a paste having a solid content of 50% by weight.

The prepared sealing glass composition paste was printed on a glass substrate with a width of 100 μm ² and a thickness of 10 μm, and then burned out of the organic vehicle at a temperature rising rate of 10 ° C. per minute so that the thickness of the thick film was 7 μm. In order to increase the temperature to 360 ° C, after maintaining the temperature for 20 minutes and then again to 400 ° C, and finally calcined at 400 ° C for 25 minutes, the degree of organic binder degreasing and firing of the sealing glass composition was visually observed. The thick film was laser-sealed to observe the adhesion characteristics visually, and the results are shown in Table 5 below.

Comparative example  4 (Preparation of Sealed Glass Composition)

Solid content in the same manner as in Examples 9 to 11 except that the low-melting glass prepared in Preparation Example 5 alone in Examples 9 to 11 and including the refractory filler in the amount shown in Table 5 below. 50% of the sealing glass composition paste was prepared, and the organic binder degreasing, the degree of calcination and the adhesion characteristics were measured, and the results are shown in Table 5 below.

division Comparative Example 4 Example 9 Example 10 Example 11 Glass powder Production Example 5 Example 5 Example 6 Example 7 Filler content (%) 30% 30% 40% 30% a Contraction 321 306 312 305 b Shrink complete 380 352 368 354 c Crystallization start 445 436 446 421 d crystallization 468 456 461 448 Plastic section (c-b) 65 84 78 67 Binder degreasing degree Degreasing Degreasing Degreasing Degreasing Plasticity degree (visual observation) Partial crystallization
Unsung Partial Crystallization Firing Partial crystallization
Firing Partial crystallization
Slightly unbaked After sealing the laser
Attachment characteristic Not attached Attach Attach After attachment
Fine crack

As shown in Table 5, it is confirmed that the sealing glass composition (Examples 9 to 11) to which the organic vehicle of the present invention is applied has a complete firing and excellent adhesion characteristics as compared with the case of not including an accelerator (Comparative Example 4). Could.

For reference, the sealing glass composition (Examples 9 to 11) in which the low melting point glass and the accelerator were mixed at 7: 3 and the refractory filler was included at 30 to 40% by weight, the binder degreasing was fully progressed during plasticity, and the surface was partially crystallized. Was generated, it was confirmed that the adhesion is good even when the laser sealing.

In addition, the sealing glass composition (Comparative Example 4) to which the low melting point glass (Production Example 5) is applied alone has undergone organic binder degreasing, but it is partially crystallized in a state in which softening is not completed due to a narrow firing section, and thus does not adhere to the laser sealing. Could confirm.

In addition, Example 11 has a narrow firing section close to Comparative Example 4, but the low melting point glass and the accelerator are mixed, and unlike Comparative Example 4, the comparatively good firing and laser sealing after adhesion, organic decomposition that decomposes at a low temperature below 300 ℃ When the binder was applied, it was confirmed that the main firing temperature could be lowered by using the low crystallization temperature.

In addition, if the plasticity temperature of the sealing glass composition can be lowered as in Examples 9 to 11, the thermal stress can be lowered on the encapsulated object such as a body substrate, a panel, and the like, thereby introducing a low power laser sealing condition. It was confirmed that the stress applied to the to-be-encapsulated object was greatly improved as a result of the process quality.

Example  12 to 14 (Preparation of Seal Glass Composition)

Into the glass mixed powder containing the refractory fillers of Examples 5 and 6 by adding an organic vehicle consisting of 10.78% by weight of ethyl cellulose, 28.05% by weight of dibutyl phthalate, 20.37% by weight of terpineol and 40.80% by weight of butylcarbitol acetate The sealing glass composition was prepared with the paste of 50 weight% of solid content.

The prepared sealing glass composition paste was cut to 30 mm in width and 15 mm in length and printed on a precisely polished glass substrate with a width of 100 μm ² and a thickness of 10 μm. The temperature was raised to 360 ° C., maintained at 360 ° C. for 20 minutes, and then heated up to 390 to 400 ° C., finally calcined at 390 to 400 ° C. for 25 minutes, and then the remaining glass substrates were raised and laser sealed to complete sealing. Bond strength was measured using a three-point bending strength (Three-point bending), the results are shown in Table 6 below.

The schematic diagram of the measuring method of the said 3-point bending strength is shown in FIG.

In Fig. 5, a constant bending moment is applied between the lower surface between the two points supporting the glass plate, which is the test piece, and the load point for transferring the load to the glass plate, so that the load applied from above (in the direction of the arrow in Fig. 5) is constant. In this case, a constant tensile force is applied to the lower surface of the glass between the two supports. In this way, the initial fracture stress at which fracture starts to be obtained can be obtained, and at the same time, the origin of fracture can be identified.

division Example 12 Example 13 Example 14 Glass powder Example 5 Example 5 Example 6 Content ratio
(Low melting point glass: accelerator) 7: 3 7: 3 7: 3 Filler content (%) 30% 30% 40% a Contraction 306 306 312 b Shrink complete 352 352 368 c Crystallization start 436 436 446 d crystallization 456 456 461 Plastic section (c-b) 84 84 78 Firing temperature (℃) 390 400 400 Plasticity state Partial crystallization Partial crystallization Partial crystallization Firing state after laser sealing During crystallization Crystallization Crystallization Attachment state after laser sealing Attach
No crack Attach
No crack Attach
No crack 3-point bending strength 11.9 15.8 17.3

As shown in Table 6, the filler content or the firing temperature of the encapsulation glass composition (Examples 12 to 14) of the present invention was partially crystallized in the plastic state, the firing state after the laser sealing was a sufficient crystallization state, After laser sealing, it was confirmed that the adhesion characteristics (adhesion state and adhesion strength) were excellent and no crack was found.

For reference, from the results of Examples 12 to 14, the adhesion was well after cracking the laser at all conditions, but in the case of Example 12 having a firing temperature of 390 ℃, crystallization does not proceed completely even after the laser sealing proceeds for several seconds As a result, it was confirmed that the adhesion strength was somewhat reduced, and also from the result of Example 14 that the content of the refractory filler was 40 wt%, it was confirmed that the adhesion strength was improved as the refractory filler content increased only in the condition of crystallization after laser sealing.

In addition, the sealing glass composition of the present invention by lowering the crystallization temperature (Tc) to 430 ℃ or less by appropriately adjusting the mixing ratio of the low melting point glass and the accelerator, and reducing the content of the refractory filler, apply a low-temperature binder that decomposes at 300 ℃ or less In this case, the plasticity temperature can be lowered to 400 ° C. or lower, and the output power of the laser sealing process can be lowered, thereby reducing the process cost and shortening the production time. It was proved.

6 shows photographs taken after sealing of the sealing glass compositions prepared in Examples 12 to 14 and OM (Optical Microscope) photographs, respectively.

In the picture taken with the camera of FIG. 6, the black band part corresponds to the sealing part, and it is possible to confirm that the plasticity state is well formed on the substrate, and the part made of dark brown in the OM picture is sealed by the laser. Corresponds to the observation after laser irradiation can be confirmed that the bonding was made good.

Claims (17)

a) glass with Tc at 500-580 ° C. and Tdsp at 250-350 ° C .; And
b) a glass composition for sealing, characterized in that Tc is 350 ~ 400 ℃ and Tdsp is 270 ~ 320 ℃ glass. The method of claim 1,
Said a) low melting glass, the temperature difference of crystallization temperature (Tc) and yield point (Tdsp) is 180-230 degreeC, The sealing glass composition characterized by the above-mentioned. delete The method of claim 1,
The glass composition for sealing of said b) glass whose temperature difference of crystallization temperature (Tc) and yield point (Tdsp) is 50-100 degreeC. delete The method of claim 1,
The a) glass and the b) glass, V ₂ O ₅ 30 to 80% by weight, TeO ₂ 10 to 40% by weight and BaO 5 to 40% by weight comprising a glass composition for sealing. The method of claim 1,
The glass composition for sealing has a difference (Tx-Ts) between the softening point (Ts) and the crystallization start temperature (Tx) of 5 to 30 ° C. The method of claim 1,
The weight ratio of said a) glass and said b) glass is 9: 1-6: 4, The sealing glass composition characterized by the above-mentioned. The method according to claim 6,
Wherein a) free and b) glass, rod wear glass composition according to claim 1, further including ZnO, Sb ₂ O _3, CoO, and ZrO _2. The method of claim 9,
The a) glass and the b) glass, the sealing glass composition, characterized in that it further comprises at least one to more than 1 to 10% by weight of ZnO, Sb ₂ O ₃ , CoO and ZrO ₂ . The method of claim 1,
The sealing glass composition comprises a filler, characterized in that the sealing glass composition. 12. The method of claim 11,
The filler is a glass composition for sealing, characterized in that at least one selected from the group consisting of cordierite, zirconium phosphate, eu cryptite, mullite, zircon, alumina, silica and aluminum titanate. The method of claim 11 or 12,
The filler is contained in a 20 to 40% by weight relative to the sealing glass composition, the sealing glass composition. The sealing glass paste of Claim 1 containing the sealing glass composition and organic vehicle. The method of claim 14,
The organic vehicle, 40-50 Sealing glass paste, characterized in that contained by weight%. The glass for OLED sealing which consists of a sealing glass composition of any one of Claims 1, 2, 4, 6-12, 14 or 15. An OLED display panel comprising the OLED sealing glass of claim 16.

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