阅读说明：本技术 一种玻璃基板及其作为玻璃衬底的应用 (Glass substrate and application thereof as glass substrate ) 是由 曾召 杨国洪 王答成 兰静 孔令歆 郭静 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种玻璃基板及其作为玻璃衬底的应用,属于光电显示领域。一种玻璃基板,以摩尔百分比计,包括以下组分：67％-69.5％的SiO<Sub>2</Sub>、12％-14％的Al<Sub>2</Sub>O<Sub>3</Sub>、1％-2.5％的B<Sub>2</Sub>O<Sub>3</Sub>、4％-6％的MgO、7％-9％的CaO、1％-2％的SrO、2.1％-4％的BaO和0.1％-0.2％的SnO<Sub>2</Sub>；其中,MgO、CaO、SrO和BaO摩尔百分比之和小于等于18％。一种玻璃基板,具有高杨氏模量、低尺寸变形量和低厚度变化量。(The invention discloses a glass substrate and application thereof as a glass substrate, belonging to the field of photoelectric display. A glass substrate comprising, in mole percent: 67% -69.5% of SiO 2 12 to 14 percent of Al 2 O 3 1% -2.5% of B 2 O 3 4 to 6 percent of MgO, 7 to 9 percent of CaO, 1 to 2 percent of SrO, 2.1 to 4 percent of BaO and 0.1 to 0.2 percent of SnO 2 (ii) a Wherein the sum of the mole percentages of MgO, CaO, SrO and BaO is less than or equal to 18 percent. A glass substrate having a high Young's modulus, a low dimensional deformation, and a low thickness variation.)

1. A glass substrate comprising, in mole percent:

67% -69.5% of SiO₂12 to 14 percent of Al₂O₃1% -2.5% of B₂O₃4 to 6 percent of MgO, 7 to 9 percent of CaO, 1 to 2 percent of SrO, 2.1 to 4 percent of BaO and 0.1 to 0.2 percent of SnO₂。

2. The glass substrate according to claim 1, wherein the sum of the mole percentages of MgO, CaO, SrO, and BaO is 18% or less.

3. The glass substrate according to claim 1, wherein the glass has a strain point temperature of 731-745 ℃.

4. The glass substrate according to claim 3, wherein the glass substrate has a thermal shrinkage of 30ppm or less after being treated at 500 ℃ for 120 min.

5. The glass substrate according to claim 1, wherein the glass has a Young's modulus of 79 to 83 MPa.

6. The glass substrate of claim 1, wherein the liquidus viscosity is greater than 10 kilopoise.

7. Use of a glass substrate according to any one of claims 1 to 6 as a glass substrate for the manufacture of LTPS.

8. Use of a glass substrate according to any one of claims 1 to 6 as a glass substrate for the manufacture of an OLED.

Technical Field

The invention belongs to the field of photoelectric display, and particularly relates to a glass substrate and application thereof as a glass substrate.

Background

With the popularization of mobile interconnection such as intelligent display and tablet personal computers, new requirements on the thickness and weight of intelligent terminal products are provided, the intelligent products develop to be light, thin, flexible and intelligent, particularly the development of electronic wearable devices, bendable smart phones and curved surface display technologies with strong reality sense, and new requirements on the performance of basic materials of electronic display, such as flexibility and good flexibility, are provided.

Meanwhile, the display screen is also developed in the direction of higher resolution, high brightness and low power consumption, and the OLED display has self-luminescence and low power consumption, and compared with the conventional LCD display screen, it can be used on any shape of substrate, so that it becomes the mainstream technology of flexible display. The low-temperature polysilicon thin film transistor (LTPS TFT) can manufacture smaller and faster transistors due to the characteristic of high electron mobility, has the advantages of high brightness, high resolution, low power consumption and the like, and can meet the requirements of high-resolution display of a traditional hard screen and the requirements of flexible high-resolution display by the LTPS-OLED technology. No matter the traditional hard-screen LTPS-OLED display screen or the flexible OLED screen, the LTPS and the OLED need to be manufactured on a glass substrate, and the corresponding manufacturing process requires that the glass substrate has performance requirements of high Young modulus, low dimensional deformation, low thickness variation and the like.

In the Chinese invention with the application number of 201710585934.X, the temperature of the production process of the glass substrate compound is high, and the defects of stones in glass caused by corrosion of refractory materials in a melting furnace are more easily caused in the melting process; the temperature for conveying the molten glass to the overflow groove at the viscosity of 35,000 poises is 1280-1345 ℃, which also causes the increase of internal defects of the glass, and leads to the aggravation of creep deformation of the overflow brick at the high forming temperature, thus seriously affecting the service life.

Disclosure of Invention

The invention aims to overcome the defect of internal defects of a glass substrate caused by high temperature of glass liquid, and provides the glass substrate and application thereof as a glass substrate.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a glass substrate comprising, in mole percent:

67% -69.5% of SiO₂12 to 14 percent of Al₂O₃1% -2.5% of B₂O₃4 to 6 percent of MgO, 7 to 9 percent of CaO and 1 percent of2% of SrO, 2.1% -4% of BaO and 0.1% -0.2% of SnO₂；

Furthermore, the sum of the mole percentages of MgO, CaO, SrO and BaO is less than or equal to 18 percent.

Furthermore, the strain point temperature of the glass is 731-745 ℃.

Furthermore, the thermal shrinkage rate of the glass substrate is less than or equal to 30ppm after the glass substrate is treated at 500 ℃ for 120 min.

Furthermore, the Young modulus of the glass is 79-83 MPa.

Further, the liquidus viscosity is greater than 10 kilopoise.

The glass substrate is used as a glass substrate to manufacture LTPS.

The glass substrate is used as a glass substrate to manufacture OLED.

Compared with the prior art, the invention has the following beneficial effects:

the glass substrate has the advantages that due to the optimization of the components, the strain point temperature is 731-745 ℃, the Young modulus is 79-83 MPa, the thermal shrinkage rate is less than or equal to 30ppm, and the glass substrate has high Young modulus, high strain point temperature, low dimensional deformation and low defect rate; specifically, SiO₂The mol percent of the glass is 67-69.5%, the molding temperature in the molding process is not higher than 1280 ℃, the problem that the corrosion of refractory materials in a melting furnace is caused due to overhigh temperature, so that the defect of stones in the glass is increased is solved, and the production difficulty is reduced; meanwhile, the liquidus viscosity can be ensured to be higher than 10 kilopoises, which is beneficial to overflow pull-down forming and can obtain smaller density; al (Al)₂O₃The mol percentage of the glass is 12 to 14 percent, thereby not only avoiding the conditions that the crystallization temperature of the glass is increased, the crystallization viscosity is reduced and the overflow is not beneficial to downward pulling, but also taking thermal stability, the crystallization viscosity of the glass, and the mechanical strength and the hardness of the glass into consideration; b is₂O₃1 to 2.5 percent, can reduce the viscosity to promote the melting of the glass, reduce the temperature of the glass production process, and also avoid the problem of poor thermal stability caused by the rapid reduction of the strain point temperature of the glass due to the over-high content of the glass.

Furthermore, the sum of the mole percentages of MgO, CaO, SrO and BaO is less than or equal to 18 percent, and the density increase, the strain point temperature decrease and the chemical durability deterioration can be avoided while the temperature of the glass clarification and forming process is optimized.

Furthermore, the strain point temperature of the glass is 731-745 ℃, and the problems of overhigh production process temperature, low yield and short equipment service life caused by a method of increasing the strain point temperature of a material side for reducing the thermal shrinkage of the glass in the prior art are solved.

The glass substrate is used as a glass substrate to manufacture LTPS or OLED, meets the requirements of the preparation process for the glass substrate, and has high Young modulus, low dimensional deformation and low thickness variation.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not a whole embodiment. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terms first, second and the like in the description and in the claims of the present invention are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

According to the invention, through optimized components, the glass substrate with high Young modulus and low dimensional deformation can be obtained, and the display requirement of high resolution can be met. In the present invention, SiO₂Is the main oxide forming the glass, it is silicon oxideTetrahedron [ SiO₄]The structure of (a) forms an irregular continuous network, which becomes the framework of the glass. SiO 2₂Can reduce the thermal expansion coefficient and density of the glass, improve the strain point temperature of the glass, SiO₂When the content is too low, the glass with low expansion, low density and high strain point, SiO, is not easy to obtain₂When the content is too high, the high-temperature viscosity of the glass increases, making the glass difficult to melt and easily causing a stone (cristobalite) defect. Thus, the SiO of the present invention₂The total mole percentage of the glass substrate is controlled to be 67-69.5%, so that the forming temperature of the glass substrate is not higher than 1280 ℃, the service life of an overflow brick and the defects of glass are not affected, the production difficulty is reduced, and simultaneously the total mole percentage of the glass substrate is not lower than 67%, so that the liquidus viscosity can be ensured to be higher than 10 kilopoises, the overflow downdraw forming is facilitated, and a smaller density value can be obtained.

Al₂O₃Also a glass former, Al₂O₃Is an intermediate oxide, when the glass has insufficient O, Al has a coordination number of 6, is in a network gap, and forms [ AlO ] with O₆]An octahedron; when there is excess O in the glass, the coordination number of Al is 4, enters the glass network, and forms [ AlO ] with O₄]Tetrahedron for supplementing network, increasing glass stability, and reducing glass expansion coefficient, and [ AlO ]₄]The tetrahedron has a large volume, which can reduce the density of the glass. Al (Al)₂O₃Can obviously improve the strain point and the elastic modulus of the glass and increase the chemical stability of the glass, but Al₂O₃When the content is too large, the glass is easily devitrified. Al (Al)₂O₃The content of the mole percent is preferably 12-14%, which not only avoids the crystallization temperature rise and crystallization viscosity reduction of the glass, is not beneficial to overflow downdraw forming, but also considers high thermal stability, Young modulus and hardness.

B₂O₃Is a glass forming agent and a flux, which is composed of a boron-oxygen trigonal [ BO ]₃]And boron-oxygen tetrahedron [ BO₄]Is a structural component, and is a silicon-oxygen tetrahedron [ SiO ]₄]Together forming a structural network, B₂O₃Can reduce the density of the glass and improve the BHF resistance of the glass, B₂O₃Lowering the viscosity of the glass at high temperatures and increasing the viscosity at low temperatures, B₂O₃Also acts as a fluxing agent, accelerates the fining of the glass and reduces the crystallization capacity of the glass when B₂O₃When the amount of incorporation is too high, the strain point temperature of the glass decreases, the Young's modulus decreases, and the acid resistance of the glass decreases, so that in the embodiment, B₂O₃The content of (A) is maintained between 1% and 2.5%. If B is present₂O₃If the content of (B) is less than 1%, the effect as a flux is insufficient and B is simply lowered₂O₃The content may in turn cause other problems including deterioration of melting ability and increase of bubbles. On the other hand, higher B₂O₃The content tends to decrease the acid resistance, and at the same time, the strain point of the glass decreases, so that the thermal stability decreases.

The alkaline earth metal oxides CaO, MgO, SrO and BaO belong to the external oxides of the glass network, and the alkaline earth metal cation R²⁺Move relatively freely at high temperature and have O^2-The polarization weakens the effect of silicon-oxygen bonds, and the viscosity of the glass liquid is reduced; but when the temperature is lowered, the cation R²⁺The mobility of the glass is weakened, and the glass is possibly in certain silicon-oxygen tetrahedron groups according to a certain coordination relationship, and the small silicon-oxygen tetrahedron is combined into a large silicon-oxygen tetrahedron group, so that the viscosity of the glass liquid is increased to some extent. Therefore, alkaline earth metal oxides are beneficial to clarifying molten glass at high temperature and beneficial to forming molten glass at low temperature, but too high content of the alkaline earth metal oxides can increase density, lower strain point temperature, lower chemical durability and increase thermal expansion coefficient. The mixed oxide of the alkaline earth metal can reduce the liquidus temperature and increase the liquidus viscosity, thereby being beneficial to overflow pull-down production.

Ca²⁺The coordination number of (A) is generally 6, the mobility of which in the glass network structure is small and which is generally not easily precipitated from the glass, but the mobility is large at high temperatures, Ca²⁺Has the functions of polarizing oxygen and weakening silicon-oxygen bonds, and when the content of CaO in the glass is too large, the material property of the glass is generally shortened, the glass is not favorable for molding, the crystallization tendency of the glass is increased, and the glass is not easy to mold in other casesIn one embodiment, the CaO content is maintained between 7% and 9%. If the content of CaO is more than 9%, the glass has a large tendency to devitrify, and MgO is used to replace part of CaO, whereby the glass is reduced in the tendency to devitrify and the glass is adjusted in the glass behavior,

SrO, which is similarly affected by BaO, is a component that not only improves the chemical resistance of the glass but also its devitrification tendency. In other embodiments, the SrO content is maintained between 1% and 2%. If the SrO content is more than 2%, the density of the glass is undesirably increased; the content of BaO is maintained at 2.1-4%. If the content of BaO is more than 4 percent, the density is greatly increased, and if the content of BaO is less than 2.1 percent, the crystallization viscosity is lower than 10 ten thousand poise, so that the method cannot adapt to overflow down-draw method production.

Tables 1-7 provide examples 1-35 of the present invention, which are specific components of the glass substrate and performance parameters of the resulting glass substrate, respectively.

Table 1 examples 1 to 5 of the present invention

Table 2 example 6-example 10 of the invention

Table 3 examples 11 to 15 of the present invention

Table 4 examples 16 to 20 of the present invention

TABLE 5 examples 21 to 25 of the present invention

TABLE 6 examples 26 to 27 of the present invention

TABLE 7 examples 31 to 35 of the present invention

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.