Black backplate glass and its preparation method and LED

Abstract

This invention relates to the field of glass manufacturing technology, specifically to black backplate glass, its preparation method, and LEDs. The black backplate glass comprises a main component and a colorant component. The main component, by mass percentage of oxides, includes: SiO2 65-70%, Al2O3 4-8%, Na2O 4-10%, K2O 0-3%, MgO 3-8%, ZrO2 0-5%, and CaO 6-15%. The colorant component is introduced externally in the form of a mass fraction, including Fe2O3 0-5%, NiO 0-1%, MnO2 0-0.5%, Co3O4 0-0.1%, Cr2O3 0-0.5%, and Fe3O4 0-25%; and Fe2O3, NiO, MnO2, Co3O4, Cr2O3, and Fe3O4 cannot all be 0. It features high flatness, high absorption opacity, low expansion, high thermal conductivity, and good chemical stability, meeting all the requirements for Micro LED backplane glass.

Description

Technical Field

[0001] This invention relates to the field of glass manufacturing technology, and more specifically, to black backplate glass, its preparation method, and LEDs. Background Technology

[0002] With years of technological iteration in display, LED displays have entered an era of "smaller pitch," such as pitches below 0.3 mm, "smaller LED crystals," and 20-micron Micro LED particles. The mature, low-cost, and readily available PCB substrates have gradually lost their advantage. This is because Mini / Micro LED display technology demands increasingly higher precision from circuit boards, and for PCB substrates to become ultra-thin and high-precision, their costs would increase significantly, thus making them less cost-competitive.

[0003] However, Micro LED products ranging from a few inches to tens of inches still require an alternative backplane to simultaneously meet both technical and cost requirements—hence the development of glass substrates. Currently, the automotive, handheld, and IT markets choose glass substrates for several reasons, such as better thermal conductivity, lower thermal stability under heat, and less physical deformation; in particular, their smoothness and flatness effectively reduce the difficulty of mass transfer processes and improve yield; and glass substrates are also easier to make ultra-thin under the same physical and electrical properties, making them more suitable for backlight applications.

[0004] However, there is still a need for a backplate glass that has high flatness, high absorption opacity, low expansion, high thermal conductivity, and good chemical stability, meets all the requirements of Micro LED backplate glass, and is also low in cost and meets market requirements.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a black backplane glass, its preparation method, and an LED. The backplane glass provided by the embodiments of this invention has high flatness, high absorption opacity, low expansion, high thermal conductivity, and good chemical stability, meeting all the requirements of Micro LED backplane glass, and at a lower cost, which meets market demands.

[0007] This invention is implemented as follows:

[0008] In a first aspect, the present invention provides a black backplate glass, the components of which include a main component and a colorant component. The main component, by mass percentage of oxides, includes: SiO2 65-70%, Al2O3 4-8%, Na2O 4-10%, K2O 0-3%, MgO 3-8%, ZrO2 0-5%, CaO 6-15%. The colorant component is introduced externally in the form of mass fraction, including Fe2O3 0-5%, NiO 0-1%, MnO2 0-0.5%, Co3O4 0-0.1%, Cr2O3 0-0.5%, and Fe3O4 0-25%. Moreover, Fe2O3, NiO, MnO2, Co3O4, Cr2O3, and Fe3O4 cannot all be 0.

[0009] In an optional embodiment, the main components, by mass percentage of oxides, include: SiO2 65-70%, Al2O3 4-8%, Na2O 4-10%, K2O 0-3%, MgO 3-8%, ZrO2 0-5%, CaO 6-15%, and the colorant includes Fe2O3 2-5%, NiO 0.3-1%, MnO2 0.1-0.5%, Co3O4 0.02-0.1%, Cr2O3 0.001-0.5%, and Fe3O4 0-25%.

[0010] In an optional implementation, 9 ≤ (Al2O3+SiO2+MgO+CaO) / (Na2O+K2O) ≤ 13.

[0011] In an optional embodiment, the composition of the black back glass satisfies Y≥2.5, Y=2(ZR), where R is the ratio of the total number of oxygen ions to the total number of glass-forming ions, and Z is the coordination number of the glass-forming ions.

[0012] In an optional embodiment, the optical density OD of the black back glass is ≥4, the warpage is ≤0.01%, and the coefficient of thermal expansion is ≤9*10-6K. -1 Thermal conductivity ≥1.2W / mk@90℃, flexural strength without chemical strengthening ≥150Mpa.

[0013] In an optional embodiment, the black back glass has an acid resistance rating of S2, an alkali resistance rating of A2, and a water resistance rating of HGB1.

[0014] In an optional embodiment, the black backplate glass can be used as a Micro LED backplate glass, that is, the black backplate glass provided in the embodiments of the present invention can be a Micro LED black backplate glass.

[0015] In an optional embodiment, the thickness of the black back glass is 0.2-8 mm.

[0016] Secondly, the present invention provides a method for preparing the black back glass described in the foregoing embodiments, comprising mixing raw materials containing metals forming the black back glass, then uniformly melting, homogenizing, shaping, and annealing.

[0017] Thirdly, the present invention provides an LED that includes the black backplate glass described in the foregoing embodiments.

[0018] The present invention has the following beneficial effects: The black backplate glass provided in the embodiments of the present invention has a bright color, is aesthetically pleasing, has high absorption and is opaque, with an optical density OD≥4. It possesses excellent optical, thermal, and mechanical properties, with an expansion coefficient ≤9*10-6K. -1 The warpage rate is ≤0.01%, the thermal conductivity is ≥1.2W / mk@90℃, and the bending strength without chemical strengthening is ≥150Mpa. Furthermore, this black back glass exhibits stable chemical properties, with an acid resistance rating of S2, an alkali resistance rating of A2, and a water resistance rating of HGB1. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an image of the black backplate glass provided in Embodiment 1 of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0022] This invention provides a black backplate glass, the composition of which includes a main component and a colorant component. The main component, by mass percentage of oxides, includes: SiO2 65-70%, Al2O3 4-8%, Na2O 4-10%, K2O 0-3%, MgO 3-8%, ZrO 20-5%, CaO 6-15%. The colorant component is introduced externally in the form of mass fraction, including Fe2O3 0-5%, NiO 0-1%, MnO 20-0.5%, Co3O4 0-0.1%, Cr2O3 0-0.5%, and Fe3O4 0-25%; and Fe2O3, NiO, MnO2, Co3O4, Cr2O3, and Fe3O4 cannot all be 0.

[0023] In other words, in the embodiments of the invention, the total amount of the main components such as SiO2, Al2O3, Na2O, K2O, MgO, ZrO2 and CaO is 100%, and the mass percentage of the colorant is relative to the mass of the above main components.

[0024] The backplane glass possesses high flatness, high absorption and opacity, low expansion, high thermal conductivity, and good chemical stability, meeting all the requirements for Micro LED backplane glass. Furthermore, its lower cost aligns with market demands, making it a suitable candidate for use as a black backplane glass for Micro LEDs. Specifically, SiO2 is the main component forming and connecting silicon-oxygen tetrahedra to constitute the glass network structure, serving as the basic framework of the glass. The SiO2 content is typically 65-70%. When SiO2 < 65%, the glass exhibits poor chemical stability. Additionally, it increases the coefficient of thermal expansion, while decreasing mechanical strength and strain point. When SiO2 > 70%, the high-temperature viscosity of the glass increases, leading to refractory properties and exacerbating the erosion of furnace refractory materials. Therefore, its content needs to be controlled within a suitable range.

[0025] Al₂O₃ readily forms tetrahedral coordination, and [AlO₄] tetrahedral coordination can help build a denser network together with [SiO₄] tetrahedra, making it an important component of glass network structures. Introducing more than 4% Al₂O₃... 3+ It can capture non-bridging oxygen to form aluminum-oxygen tetrahedra that enter the silicon-oxygen network, reconnecting the broken network and making the glass structure more compact. However, when its content is higher than 8%, it can easily lead to poorer chemical stability of the glass, increase high-temperature viscosity, increase melting difficulty, and is not conducive to production.

[0026] Na₂O can reduce glass viscosity and increase its fluidity, making it a good flux in glass components. The addition amount of Na₂O is 4-10%. When the Na₂O content is higher than 10%, it reduces the chemical stability of the glass and increases the coefficient of thermal expansion. When the Na₂O content is lower than 4%, it has no effect and cannot improve the melting effect of the glass. K₂O has the same effect as Na₂O, and its content in the black backing glass of this invention ranges from 0-3%. In addition, K₂O can significantly reduce crystallization, increase glass gloss, and improve the quality of glass products.

[0027] MgO can improve the melting point, strain point, and Young's modulus of glass, reduce the coefficient of thermal expansion of glass, and simultaneously improve thermal conductivity—an important performance indicator of the black glass of this invention. In the embodiments of this invention, the MgO content ranges from 3% to 8%.

[0028] ZrO2 not only has the best resistance to water and acids, but also the best resistance to alkalis. An appropriate amount of ZrO2 helps improve the chemical durability and hardness of glass. However, if the ZrO2 content is too high, on the one hand, the glass's resistance to devitrification decreases, and on the other hand, its melt flow deteriorates, making forming difficult. In the embodiments of this invention, the ZrO2 content ranges from 0% to 5%.

[0029] CaO is one of the main components of glass. It can accelerate the melting and refining process of glass and improve its chemical stability; however, CaO can cause glass to crystallize. At high temperatures, it can reduce the viscosity of molten glass, creating favorable conditions for high-speed glass ribbon drawing. However, the CaO content in glass should not be too high; if it exceeds 15%, it will increase the brittleness of the glass. In the embodiments of this invention, the CaO content ranges from 6% to 15%.

[0030] Fe2O3, NiO, MnO2, Co3O4, Cr2O3, and Fe3O4 are used as colorants; therefore, the above six oxides cannot all be zero simultaneously. Preferably, the amounts of colorants are: Fe2O3 2–5%, NiO 0.3–1%, MnO2 0.1–0.5%, Co3O4 0.02–0.1%, Cr2O3 0.001–0.5%, and Fe3O4 0–25%.

[0031] Furthermore, it is necessary to control the ratio of the sum of SiO2, Al2O3, MgO, and CaO to R2O, i.e., 9 ≤ (Al2O3 + SiO2 + MgO + CaO) / (Na2O + K2O) ≤ 13. At this point, the black backing glass exhibits high glass strength, chemical stability, and thermal conductivity.

[0032] Furthermore, to obtain high-performance glasses, the concept of network bonding degree Y needs to be introduced, which represents the degree of connectivity of the network structure. Y = 2(ZR), where R is the ratio of the total number of oxygen ions to the total number of glass-forming ions, and Z is the coordination number of the glass-forming ions. In this invention, Y ≥ 2.5. If it is less than 2.5, it indicates a low degree of network connectivity, the structure tends to expand freely, the expansion coefficient increases, and the chemical stability also deteriorates.

[0033] The black backplate glass formed using the above formula has the following excellent performance characteristics: optical density OD≥4, warpage ≤0.01%, and expansion coefficient ≤9*10-6K. -1 Thermal conductivity ≥1.2W / mk@90℃, flexural strength without chemical strengthening ≥150Mpa. Furthermore, its acid resistance rating is S2, alkali resistance rating is A2, and water resistance rating is HGB1.

[0034] Furthermore, the thickness of the resulting black back glass can be between 0.2 and 8 mm.

[0035] Furthermore, the method for preparing black backing glass using the above-mentioned raw materials is an existing process, such as any one of the conventional glass preparation processes including casting, float glass, overflow glass, and downdraw glass. The specific conditions of each method will not be listed in detail in the embodiments of this invention.

[0036] This invention is illustrated by only one example. Specifically, it contains Si-containing compounds, Al-containing compounds, Na-containing compounds, Mg-containing compounds, K-containing compounds, Zr-containing compounds, and Ca-containing compounds (such as carbonates, nitrates, sulfates, oxides, etc. containing the aforementioned elements). Under heating conditions, the Si-containing compounds, Al-containing compounds, Na-containing compounds, Mg-containing compounds, K-containing compounds, Zr-containing compounds, and Ca-containing compounds, along with colorants Fe2O3, NiO, MnO2, Co3O4, Cr2O3, and Fe3O4, are mixed evenly and then subjected to high-temperature melting (1500-1600℃), clarification and homogenization, shaping, and annealing to obtain a milky white base glass. Then, according to the required dimensions, it is cut, CNC machined, ground, polished, and processed to obtain the desired black back glass.

[0037] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0038] Examples 1-10

[0039] Examples 1-10 each provide a black backplate glass, the composition and proportions of which are shown in Table 1. The preparation method is as follows:

[0040] The raw materials corresponding to each component are calculated and weighed, and after being thoroughly mixed, they are put into a high-temperature furnace. After processes such as melting, clarifying, forming, annealing, cutting, and polishing, a black back glass with a thickness of 1.1mm is obtained.

[0041] Table 1. Composition of Black Back Panel Glass

[0042]

[0043]

[0044] The black backplate glass prepared in Examples 1-10 exhibits a bright black color, and the color is pure and free of impurities. For example, see the image of the black backplate glass prepared in Example 1. Figure 1 .

[0045] The optical density of the black back glass was measured using an SDR-361T transmission density meter.

[0046] The coefficient of thermal expansion of the black back glass was measured using a DIL (2010STD) coefficient of thermal expansion meter.

[0047] The warpage of the black back glass was measured using a VME432 two-dimensional image measuring instrument.

[0048] The four-point bending strength of the black back glass can be tested using a universal testing machine of model QJ-211S. The test conditions are: upper / lower span 20 / 40cm, downward pressing speed 10mm / min, and rod diameter 6mm.

[0049] The chemical stability of the black back glass was determined according to DIN 12116, ISO 695 and ISO 719 standards.

[0050] Specifically, the DIN 12116 standard measures the resistance of glass to decomposition when placed in an acidic solution. Simply put, the DIN 12116 standard uses a weighed, polished glass sample with a known surface area, followed by contacting the glass sample with a proportional amount of boiling 6 Mo l / L hydrochloric acid for 6 hours. The sample is then removed from the solution, dried, and weighed again. The mass loss of the glass upon exposure to the acidic solution is a measure of the sample's acid durability; a smaller value indicates greater durability. Test results are recorded in units of mass per surface area, specifically mg / dm³. 2 The DIN 12116 standard is divided into four independent levels. Level S1 indicates a maximum weight loss of 0.7 mg / dm³. 2 S2 level refers to a weight loss of 0.7 mg / dm³. 2 Up to 1.5 mg / dm 2 S3 level refers to a weight loss of 1.5 mg / dm³.2 Up to 15 mg / dm 2 And S4 level refers to a weight loss greater than 15 mg / dm³. 2 .

[0051] ISO 695 standard measures the mass loss per unit area of ​​glass when placed in an alkaline solution. Specifically, ISO 695 uses a weighed, polished glass sample, which is placed in a boiling solution of 1 mol / L NaOH + 0.5 mol / L Na₂CO₃ for 3 hours. The sample is then removed from the solution, dried, and weighed again. The mass loss of the glass in the alkaline solution is a measure of the sample's alkali resistance; a smaller value indicates greater alkali resistance. Similar to DIN 12116, the results of ISO 695 are recorded in units of mass per surface area, specifically mg / dm². 2 The ISO 695 standard is divided into three levels. Level A1 indicates a maximum weight loss of 75 mg / dm³. 2 A2 level refers to a weight loss of 75 mg / dm³. 2 Up to 175 mg / dm 2 ; and A3 level refers to a weight loss greater than 175 mg / dm³. 2 .

[0052] ISO 719 standard is the determination of the mass loss per unit area of ​​glass when exposed to pure, CO2-free water. Specifically, the ISO 719 standard protocol uses pulverized glass grains, which are contacted with pure, CO2-free water at 98°C and 1 atmosphere for 30 minutes. The solution is then titrated colorimetrically with dilute HCl to neutralize the pH. The amount of HCl required to titrate to a neutral solution is then converted into an equivalent amount of Na₂O extracted from the glass, and recorded as the mass of Na₂O precipitated per gram of glass; a smaller value indicates greater water resistance. The ISO 719 standard is divided into five levels. HGB1 type refers to the maximum equivalent Na2O extracted, up to 31 μg; HGB2 type refers to the maximum equivalent Na2O extracted, exceeding 31 μg; HGB3 type refers to the maximum equivalent Na2O extracted, exceeding 62 μg; HGB4 type refers to the maximum equivalent Na2O extracted, exceeding 264 μg; and HGB5 type refers to the maximum equivalent Na2O extracted, exceeding 620 μg.

[0053] It should be understood that the above-mentioned testing methods and equipment are common methods for evaluating glass-related performance in this industry. They are only one means of characterizing or evaluating the technical solution and technical effect of this invention. Other testing methods and equipment may also be used, which will not affect the final result.

[0054] The test results are shown in Table 2.

[0055] Table 2 Detection Results

[0056]

[0057] Comparative Examples 1-5

[0058] Comparative Examples 1-5 each provide a black back glass, the composition and proportion of which are shown in Table 3. The preparation method is shown in Example 1. Specifically, the raw materials corresponding to each component are calculated and weighed, and after being thoroughly mixed, they are put into a high-temperature furnace. After melting, clarifying, forming, annealing, cutting, grinding and polishing, a black back glass with a thickness of 1.1 mm is obtained.

[0059] Table 3 Glass composition of comparative examples

[0060]

[0061]

[0062] The black backplate glass prepared in the comparative example was tested according to the above testing method. The test results are shown in Table 4.

[0063] Table 4 Test Results

[0064]

[0065]

[0066] According to Tables 2 and 4:

[0067] 1. The black glass prepared using the technical solution of this invention has a pure color, high absorption and is opaque. However, the glass not prepared according to the technical solution of this invention, such as Comparative Example 1, is transparent and has an optical density of 0. Comparative Example 2 has a higher viscosity, is difficult to melt and clarify, and the cast glass ingot has more unmelted material and dense small air bubbles, which makes it impossible to conduct subsequent tests.

[0068] 2. The black glass prepared using the technical solution of this invention has excellent acid resistance, alkali resistance and water resistance. However, the glass not prepared according to the technical solution of this invention, especially taking Comparative Example 4 as an example, has an abnormally high alkali metal content, which leads to an intensified reaction between Na+ in the glass and H+ in the water, and damages the silicon-oxygen framework of the glass. This causes all four bridging oxygen atoms around the Si atom to become OH, resulting in weight loss and poor chemical stability of the glass.

[0069] 3. Comparative Examples 3, 4, and 5 are not suitable for use as Micro LED backplane glass because (Al2O3+SiO2+MgO+CaO) / (Na2O+K2O) is outside the scope of this technology, resulting in a thermal conductivity of <1.2W / mk.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A black backplane glass, characterized by, Its components include main components and colorant components. The main components, by mass percentage of oxides, include: SiO2 67-70%, Al2O3 5.5-8%, Na2O 4-9%, K2O 1-2.5%, MgO 6-8%, ZrO2 1.5-5%, CaO 9-15%. The colorant components are introduced externally in the form of mass fractions, including Fe2O3 0-5%, NiO 0-1%, MnO2 0-0.5%, Co3O4 0-0.1%, Cr2O3 0-0.5%, and Fe3O4 12-25%.

2. The black backplane glass according to claim 1, characterized by, 9≤(Al2O3+SiO2+MgO+CaO) / (Na2O+K2O)≤13.

3. The black back glass according to claim 1 or 2, characterized in that, The light density OD of the black backplane glass is greater than or equal to 4, the warping rate is less than or equal to 0.01%, and the expansion coefficient is less than or equal to The thermal conductivity at 90 DEG C is greater than or equal to 1.2 W / mk, and the four-point bending strength without chemical strengthening is greater than or equal to 150 Mpa.

4. The black back glass according to claim 1 or 2, characterized in that, The black back glass has an acid resistance rating of S2, an alkali resistance rating of A2, and a water resistance rating of HGB1.

5. The black back glass according to claim 1 or 2, characterized in that, The black backplate glass is a MicroLED black backplate glass.

6. The black back glass according to claim 1 or 2, characterized in that, The thickness of the black back glass is 0.2-8mm.

7. A method for preparing the black backing glass according to claim 1, characterized in that, This includes mixing, melting, homogenizing, shaping, and annealing the raw materials containing the materials forming the black backplate glass.

8. An LED, characterized in that, It includes the black back glass as described in claim 1.

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