Method for effectively reducing melting bubbles in LTPS glass substrate

Abstract

A method for effectively reducing melting bubbles in an LTPS glass substrate. The LTPS glass substrate is composed of the following oxides in percentage: 62-65% of SiO2, 18-22% of Al2O3, 3.9-4.85% of CaO, 1.5-2% of B2O3, 4-5% of MgO, 5-6.8% of SrO2, and 0.10-0.15% of SrCl2, wherein the proportion of SiO2 + Al2O3 is 83-84%, and raw materials for introducing SrO are Sr(NO3)2, SrCO3, and SrSO4. The following steps are used for melting: uniformly mixing the raw materials of these components, melting the mixed raw materials at a high temperature of 1690-1720°C for 8-15 hours, pouring clear molten glass into a mold from a platinum crucible for molding, and then placing the mold in a muffle furnace for precise annealing to obtain LTPS glass.

Description

A method for effectively reducing bubbles in LTPS glass substrate melting Technical Field

[0001] The present invention relates to the field of glass manufacturing, and in particular to a method for effectively reducing bubbles in the melting of an LTPS glass substrate. Background Art

[0002] TFT-LCD glass substrates contain no alkali metal compounds and have a high aluminum oxide content, making the glass melting process significantly more challenging than conventional soda-lime silicate glass. The high melting temperature and high viscosity of the glass make it difficult to remove bubbles. LTPS (Low Temperature Poly-Silicon) glass substrates have melting and clarification temperatures approximately 80-100°C higher than those of TFT-LCD glass substrates, making the batch melting even more challenging. The high viscosity of the glass melt also makes it difficult to effectively remove bubbles, making homogenization and clarification processes even more challenging. Bubbles are a common defect in the glass manufacturing process, affecting the appearance, transmittance, mechanical strength, and hardness of glass products. A glass substrate with a significant number of residual microbubbles and poor homogeneity will not meet the requirements for display glass substrates.

[0003] Summary of the Invention

[0004] The object of the present invention is to provide a method for effectively reducing bubbles in the melting of an LTPS glass substrate, and to provide an LPTS glass substrate composition and a preparation method thereof.

[0005] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0006] A method for effectively reducing bubbles in the melting of an LTPS glass substrate, characterized in that the composition consists of the following oxides in percentage by mass: SiO2 62-65%, Al2O3 18-22%, CaO 3.9-4.85%, B2O3 1.5-2%, MgO 4-5%, SrO 5-6.8%, SrCl2 0.20-0.25%, wherein SiO2+Al2O3 accounts for 83-84%;

[0007] Furthermore, a method for effectively reducing bubbles in the melting of LTPS glass substrates is provided, wherein the raw materials for introducing SrO are Sr(NO3)2, SrCO3 and SrSO4, and the mass ratio of the three is Sr(NO3)2:SrCO3=4.5~6; SrSO4:[Sr(NO3)2+SrCO3]=5%~8%.

[0008] A method for effectively reducing bubbles in the melting of an LTPS glass substrate, characterized by taking the following steps for melting:

[0009] (1) Mix the raw materials of each component uniformly according to the above mass percentages, place them in a high temperature furnace and melt them at a high temperature of 1690-1720°C for 8-15 hours;

[0010] (2) The melted and clarified glass liquid is poured from a platinum crucible into a mold to form it;

[0011] (3) Then it enters the muffle furnace for precision annealing to obtain LTPS substrate glass.

[0012] Beneficial effects of the present invention: The present invention provides a method for effectively reducing glass bubbles in LTPS substrates, so that the number of bubbles per unit volume in the melted sample is significantly better than that of a process formula using conventional glass composition, achieving excellent clarification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG1 is a bubble diagram of a melted sample of Example 1;

[0014] FIG2 is a bubble diagram of the melted sample of the comparative example.

[0015] Implementation Method

[0016] A method for effectively reducing bubbles in the melting of LTPS glass substrates, the specific implementation steps are as follows:

[0017] The components and contents of the LTPS glass substrate compositions used to prepare the compositions in Examples 1 to 5 are shown in Table 1:

[0018] The LTPS glass substrate in each embodiment is prepared according to the following steps:

[0019] The raw materials of each component according to Table 1 were mixed evenly, placed in a platinum crucible in a high-temperature furnace and melted at a high temperature of 1690-1720° C. for 8-15 hours; after the glass liquid reached a molten state, it was stirred with a platinum stirring rod to more easily discharge bubbles, thereby achieving the purpose of clarification and homogenization; the melted and clarified glass liquid was poured from the platinum crucible into a mold for forming; then it was placed in a muffle furnace for precision annealing, and the obtained glass was cut and polished to obtain an LTPS glass substrate. The number of bubbles per unit volume in the sample was counted using an optical microscope, and the clarification effect was compared. As shown in Table 1, the method provided by the present invention achieved a significant reduction in the number of bubbles compared with the comparative example, as shown in Figures 1 and 2.

[0020] Examples 1 to 5

[0021] Table 1

[0022] The present invention provides a method for effectively reducing bubbles in LTPS substrate glass, resulting in a significantly better number of bubbles per unit volume in the melted sample than a process recipe using conventional glass compositions, achieving an excellent clarification effect. The key to achieving this goal lies in controlling the mass ratio of Sr(NO3)2, SrCO3, and SrSO4. SrSO4 is a glass clarifier that releases oxygen at high temperatures. Its reaction at high temperatures is: 2SrSO4==2SrO+2SO2↑+O2↑. This release of oxygen at high temperatures, combined with the high-temperature evaporation of SrCl2, achieves the goal of clarifying the glass melt. Furthermore, Sr(NO3)2 is also a high-temperature oxygen supply agent that decomposes to release oxygen at high temperatures. However, the oxygen release temperatures of the two are different. On the one hand, the decomposition product SrO of Sr(NO3)2 and SrCO3 is incorporated into the glass network, significantly affecting the formation of the silicate network structure. Simultaneously, the different oxygen release temperatures of the two are utilized to degas the glass melt in stages, achieving the optimal clarification effect.

[0023] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change, and modification of the above embodiments made in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for effectively reducing bubbles in the melting of LTPS glass substrates, characterized in that: The composition for melting LTPS glass is composed of the following oxides in mass percentage: SiO2 62-65%, Al2O3 18-22%, CaO 3.9-4.85%, B2O3 1.5-2%, MgO 4-5%, SrO 5-6.8%, SrCl2 0.10-0.15%, wherein SiO2+Al2O3 83-84%; The following steps are taken for melting: (1) mixing the raw materials of the above-mentioned mass percentages uniformly, placing them in a high temperature furnace and melting them at a high temperature of 1690-1720° C. for 8-15 hours; (2) The melted and clarified glass liquid is poured from a platinum crucible into a mold to form; (3) Then it enters into a muffle furnace for precision annealing at a temperature of 800-830°C to obtain LTPS substrate glass.

2. A method for effectively reducing bubbles in melting of LTPS glass substrate according to claim 1, characterized in that: In the oxide, the introduced raw materials of SrO are Sr(NO3)2, SrCO3 and SrSO4, and the mass ratio of the three is Sr(NO3)2:SrCO3=4.5~6; SrSO4:[Sr(NO3)2+SrCO3]=5%~8%.

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