Preparation method of rare earth polishing powder for rough polishing of glass wafer
By preparing a glass wafer coarse polishing powder with a nested structure of nano-silica and rare earth oxides, the limitations of existing polishing materials in terms of speed and surface quality are overcome, achieving efficient and stable polishing effect and long life, while reducing processing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-22
- Publication Date
- 2026-04-14
AI Technical Summary
Existing glass wafer polishing materials have limitations in terms of polishing rate, surface roughness control, and service life. They are difficult to achieve both high-speed material removal and extremely low surface roughness at the same time, and the slurry stability is poor.
Rare earth carbonates and nano-silica sols are mixed and then heated, dried, calcined and crushed to form a coarse polished powder with a nested structure of nano-silica and rare earth oxides. A dispersant is added to improve stability.
It achieves higher polishing rates (3-4 μm/min) and better surface quality (surface roughness Sa < 0.6 nm), with stable abrasive structure, long service life, good slurry stability, and reduced processing costs.
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Figure CN121851902A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polishing material preparation technology, specifically to a method for preparing rare earth polishing powder for rough polishing of glass wafers. Background Technology
[0002] With the rapid development of high-tech industries such as semiconductors, microelectronics, and optoelectronics, the performance requirements for basic substrate materials are increasing. Glass wafers, as an emerging semiconductor material, possess unique advantages such as excellent light transmittance, tunable thermal expansion coefficient, good chemical stability, and insulation, demonstrating their potential to replace traditional silicon wafers in several cutting-edge fields. Specifically, in the manufacturing of microelectromechanical systems (MEMS), glass wafers can serve as ideal substrates or packaging materials, providing effective physical protection and chemical isolation for sensitive components. In the processing of CMOS image sensors, CCDs, and microwave integrated circuits, their dielectric properties and surface characteristics are of significant value. Especially in the field of optical and laser devices, the high transparency and low dispersion characteristics of glass wafers make them a key material for manufacturing high-performance lenses, optical windows, and lidar components, crucial for improving imaging and signal processing quality.
[0003] The processing of glass wafers typically involves multiple precision steps, including dicing, grinding (rough and fine grinding), and polishing (rough and fine polishing). Grinding aims to quickly remove dicing marks and achieve initial surface planarization; while polishing, especially rough and fine polishing, directly determines the final precision and quality of the wafer surface, making it a core step for subsequent micro / nano-scale patterning or direct use as a functional substrate. The efficiency and effectiveness of the polishing process largely depend on the performance of the polishing materials.
[0004] Currently, traditional glass wafer polishing materials (such as single-component silicon dioxide and cerium oxide) still have limitations in terms of polishing rate, surface roughness control, and service life. For example, although using nano-silica alone can achieve a low roughness, the material removal rate is often insufficient; while rare earth oxides (such as cerium oxide) have high chemical mechanical polishing activity, their particles are prone to agglomeration and sedimentation in the polishing slurry, resulting in poor polishing stability and low material utilization. Moreover, it is sometimes difficult to achieve both high removal rate and ultra-smooth surface when used alone.
[0005] Therefore, the industry urgently needs to develop a new type of polishing material that can achieve high-rate material removal while ensuring extremely low surface roughness, good slurry stability, and polishing consistency, to meet the increasingly stringent processing requirements of glass wafers in the manufacture of high-performance semiconductors and optical devices. In view of this, this invention proposes an innovative method for preparing coarse polishing powder, aiming to overcome the shortcomings of existing technologies. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing rare-earth polishing powder for rough polishing of glass wafers. To achieve the above objectives, the present invention provides the following technical solution: A method for preparing coarse polishing powder for glass wafer polishing, characterized by comprising the following steps: (1) Slurry preparation: Mix rare earth carbonates and deionized water at a weight ratio of 1:1, adjust the slurry and stir thoroughly; (2) Preparation of composite precursor: Based on the weight of rare earth carbonates described in step (1), add 1%-5% nano silica sol to the slurry, heat to 90℃-100℃ and keep warm for at least 2 hours, then continue to keep warm and stir until the slurry evaporates into a paste to obtain the precursor; (3) Drying: The precursor is dried at 150°C; (4) Calcination: The dried material is calcined at 800℃-1000℃ for 18-24 hours; (5) Crushing: The calcined material is crushed to a central particle size of 1.0μm-1.2μm to obtain a coarse polished powder matrix; (6) Dispersion treatment: Based on the weight of the coarse polishing powder matrix, add 0.2% dispersant and mix evenly to obtain the coarse polishing powder for glass wafer polishing.
[0007] Preferably, the rare earth carbonate is one of cerium carbonate or cerium praseodymium carbonate.
[0008] Preferably, the central particle size of the nano-silica sol is 10nm-150nm.
[0009] Preferably, the crushing is carried out using ball milling.
[0010] Preferably, the dispersant is one or a mixture of two of sodium hexametaphosphate and sodium polyacrylate with a molecular weight of 4000.
[0011] Compared with the prior art, the beneficial effects of the present invention are: 1. Significantly improved polishing performance: The prepared glass wafer coarse polishing powder, through a unique nested structure of nano-silica and rare earth oxides, achieves a higher polishing rate (3-4 μm / min) and better surface quality (surface roughness Sa < 0.6 nm).
[0012] 2. Stable abrasive structure and long service life: High-temperature heating causes carbonates and nano-silica to react, resulting in the hydrolysis of carbonates to form basic carbonates, while the nano-silica agglomerates to form a three-dimensional network structure. The two types of particles are intertwined and nested, resulting in a composite oxide abrasive with high agglomeration strength and smaller initial grains, thus significantly enhancing the mechanical stability and wear resistance of the abrasive.
[0013] 3. Good slurry stability and low processing cost: This coarse polishing powder exhibits a small particle size decrease during cyclic polishing, maintains a stable polishing rate, and significantly extends the service life of the polishing slurry. Its application in glass wafer polishing effectively reduces abrasive consumption and slurry replacement frequency, thereby significantly lowering overall processing costs.
[0014] In summary, the coarse polishing powder preparation method provided by this invention not only achieves simultaneous optimization of polishing efficiency and surface quality, but also fundamentally improves product lifespan and process stability by strengthening the abrasive structure, demonstrating outstanding comprehensive technical advantages and economic value. Attached Figure Description
[0015] Figure 1 This is a surface roughness diagram of Embodiment 1 of the present invention.
[0016] Figure 2 This is a surface roughness diagram of Embodiment 2 of the present invention.
[0017] Figure 3 This is a surface roughness diagram of Embodiment 3 of the present invention.
[0018] Figure 4 This is a surface roughness diagram of Embodiment 4 of the present invention.
[0019] Figure 5 This is a surface roughness diagram of Embodiment 5 of the present invention.
[0020] Figure 6 This is a surface roughness diagram of Embodiment 6 of the present invention.
[0021] Figure 7 This is a surface roughness diagram of Embodiment 7 of the present invention.
[0022] Figure 8 This is a surface roughness diagram of Comparative Example 1 of the present invention.
[0023] Figure 9 This is a surface roughness diagram of Comparative Example 2 of the present invention.
[0024] Figure 10 This is a particle size distribution diagram of the sample in Example 1 of the present invention before polishing.
[0025] Figure 11 This is a particle size distribution diagram of the sample after polishing in Example 1 of the present invention.
[0026] Figure 12 This is a particle size distribution diagram of the sample in Example 2 of the present invention before polishing.
[0027] Figure 13 This is a particle size distribution diagram of the sample after polishing in Example 2 of the present invention.
[0028] Figure 14 This is a particle size distribution diagram of the sample in Example 3 of the present invention before polishing.
[0029] Figure 15 This is a particle size distribution diagram of the sample after polishing in Example 3 of the present invention.
[0030] Figure 16 This is a particle size distribution diagram of the sample in Example 4 of the present invention before polishing.
[0031] Figure 17 This is a particle size distribution diagram of the sample after polishing in Example 4 of the present invention.
[0032] Figure 18 This is a particle size distribution diagram of the sample in Example 5 of the present invention before polishing.
[0033] Figure 19 This is a particle size distribution diagram of the sample after polishing in Example 5 of the present invention.
[0034] Figure 20 This is a particle size distribution diagram of the sample in Example 6 of the present invention before polishing.
[0035] Figure 21 This is a particle size distribution diagram of the sample after polishing in Example 6 of the present invention.
[0036] Figure 22 This is a particle size distribution diagram of the sample in Example 7 of the present invention before polishing.
[0037] Figure 23 This is a particle size distribution diagram of the sample after polishing in Example 7 of the present invention.
[0038] Figure 24 This is a particle size distribution diagram of the sample of Comparative Example 1 of the present invention before polishing.
[0039] Figure 25 This is a particle size distribution diagram of the sample of Comparative Example 1 after polishing.
[0040] Figure 26 This is a particle size distribution diagram of the sample of Comparative Example 2 of the present invention before polishing.
[0041] Figure 27 This is a particle size distribution diagram of the sample of Comparative Example 2 after polishing. Detailed Implementation
[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0043] Example 1 A method for preparing coarse polishing powder for glass wafer polishing includes the following steps: (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, add 10g of 10nm silica sol to (1), heat the slurry to 90℃, keep it warm for 2 hours with stirring on, continue stirring, evaporate excess water, and make the slurry into a paste state to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 800℃ and the time to 24h; (5) The calcined material is crushed to a center particle size of 1.03 μm by dry ball milling; (6) Weigh 200g of the powder obtained in (5), add 0.4g of sodium hexametaphosphate, mix evenly, and obtain the coarse polishing powder sample 1.
[0044] Example 2 A method for preparing coarse polishing powder for glass wafer polishing includes the following steps: (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, add 50g of 10nm silica sol to (1), heat the slurry to 90℃, keep it warm for 2 hours while stirring, continue stirring, evaporate excess water, and make the slurry into a paste state to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 800℃ and the time to 24h; (5) The calcined material is crushed to a center particle size of 1.08 μm by dry ball milling; (6) Weigh 200g of the powder obtained in (5), add 0.4g of sodium polyacrylate, mix evenly, and obtain the coarse polishing powder sample 2.
[0045] Example 3 A method for preparing coarse polishing powder for glass wafer polishing includes the following steps: (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, add 50g of 150nm silica sol to (1), heat the slurry to 90℃, keep it warm for 2 hours with stirring on, continue stirring, evaporate excess water, and make the slurry into a paste state to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 800℃ and the time to 24h; (5) The calcined material is crushed to a center particle size of 1.05 μm by dry ball milling; (6) Weigh 200g of the powder obtained from (5), add 0.4g of sodium hexametaphosphate, mix evenly, and obtain the coarse polished powder sample 3.
[0046] Example 4 A method for preparing coarse polishing powder for glass wafer polishing includes the following steps: (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, add 50g of 100nm silica sol to (1), heat the slurry to 90℃, keep it warm for 2 hours with stirring on, continue stirring, evaporate excess water, and make the slurry into a paste state to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 800℃ and the time to 24h; (5) The calcined material is crushed to a center particle size of 1.12 μm by dry ball milling; (6) Weigh 200g of the powder obtained from (5), add 0.4g of sodium polyacrylate, mix evenly, and obtain the coarse polishing powder sample 4.
[0047] Example 5 A method for preparing coarse polishing powder for glass wafer polishing includes the following steps: (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, add 10g of 50nm silica sol to (1), heat the slurry to 93℃, keep it warm for 2 hours with stirring on, continue stirring, evaporate excess water, and make the slurry into a paste state to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 800℃ and the time to 24h; (5) The calcined material is crushed to a center particle size of 1.13 μm by dry ball milling; (6) Weigh 200g of (5) powder, add 0.4g of sodium hexametaphosphate, mix evenly, and obtain the coarse polished powder sample 5.
[0048] Example 6 A method for preparing coarse polishing powder for glass wafer polishing includes the following steps: (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, add 30g of 50nm silica sol to (1), heat the slurry to 96℃, keep it warm for 2 hours while stirring, continue stirring, evaporate excess water, and make the slurry into a paste state to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 880℃ and the time to 18h; (5) The calcined material is crushed to a center particle size of 1.19 μm by dry ball milling; (6) Weigh 200g of the powder obtained from (5), add 0.4g of sodium hexametaphosphate, mix evenly, and obtain the coarse polished powder sample 6.
[0049] Example 7 A method for preparing coarse polishing powder for glass wafer polishing includes the following steps: (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, add 20g of 30nm silica sol to (1), heat the slurry to 98℃, keep it warm for 2h while stirring, continue stirring, evaporate excess water, and make the slurry into paste form to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 960℃ and the time to 20h; (5) The calcined material is crushed to a center particle size of 1.15 μm by dry ball milling; (6) Weigh 200g of the powder obtained from (5), add 0.4g of sodium polyacrylate, mix evenly, and obtain the coarse polishing powder sample 7.
[0050] Comparative Example 1 (1) Take 1000g of cerium carbonate and 1000g of deionized water, and stir well; (2) While stirring, heat the slurry to 95°C. Keep it warm for 2 hours while stirring, and continue stirring to evaporate excess water and make the slurry into a paste state to obtain the precursor. (3) Place the precursor (2) directly into the drying oven and heat and dry the material at a temperature of 150°C; (4) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 960℃ and the time to 20h; (5) The calcined material is crushed to a center particle size of 1.06 μm by dry ball milling; (6) Weigh 200g of powder, add 0.4g of sodium polyacrylate, mix well, and obtain control sample 1.
[0051] Comparative Example 2 (1) Take 1000g of cerium carbonate and 1000g of deionized water, stir evenly, and siphon off the excess water to make the slurry into a paste-like precursor. (2) Place the precursor (1) directly into the drying oven and heat and dry the material at a temperature of 150°C; (3) Transfer the dried material into a programmable muffle furnace for roasting, set the roasting temperature to 800℃ and the time to 18h; (4) The calcined material is crushed to a center particle size of 1.12 μm by dry ball milling; (5) Weigh 200g of powder, add 0.4g of sodium polyacrylate, mix well, and obtain control sample 2.
[0052] The polishing powder prepared in the example was mixed with 1800g of deionized water to form a slurry. The slurry was then used to polish glass wafers according to the conditions in Table 1 below. The polishing rate, surface roughness, and particle size changes after cyclic polishing were compared after polishing.
[0053] Table 1: Polishing conditions Table 2 compares the effects of slurry preparation and polishing of glass wafers in the embodiments and comparative samples of the present invention.
[0054] like Figure 1-9 As shown, these are surface roughness diagrams for Examples 1-7 and Comparative Examples 1-2; Figure 10-27As shown, the particle size changes of the samples before and after polishing in Examples 1-7 and Comparative Examples 1-2 are shown in Table 2. Table 2 shows the comparison of the polishing effects of the glass wafers after the slurry preparation of the examples and comparative examples in this invention. The above polishing effects show that the glass wafer polishing powder prepared in the examples has a fast polishing rate, with an average removal amount of 3.76 μm / min. The surface after polishing can reach Sa < 0.6 nm. After cyclic polishing, the particle size decrease is small and the powder has good wear resistance.
[0055] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A method for preparing coarse polishing powder for glass wafer polishing, characterized in that, Includes the following steps: (1) Slurry preparation: Mix rare earth carbonates and deionized water at a weight ratio of 1:1, adjust the slurry and stir thoroughly; (2) Preparation of composite precursor: Based on the weight of rare earth carbonates described in step (1), add 1%-5% nano silica sol to the slurry, heat to 90℃-100℃ and keep warm for at least 2 hours, then continue to keep warm and stir until the slurry evaporates into a paste to obtain the precursor; (3) Drying: The precursor is dried at 150°C; (4) Calcination: The dried material is calcined at 800℃-1000℃ for 18-24 hours; (5) Crushing: The calcined material is crushed to a central particle size of 1.0μm-1.2μm to obtain a coarse polished powder matrix; (6) Dispersion treatment: Based on the weight of the coarse polishing powder matrix, add 0.2% dispersant and mix evenly to obtain the coarse polishing powder for glass wafer polishing.
2. The method for preparing coarse polishing powder for glass wafer polishing according to claim 1, characterized in that, The rare earth carbonate is either cerium carbonate or cerium praseodymium carbonate.
3. The method for preparing coarse polishing powder for glass wafer polishing according to claim 1, characterized in that, The central particle size of the nano-silica sol is 10nm-150nm.
4. The method for preparing coarse polishing powder for glass wafer polishing according to claim 1, characterized in that, The crushing process is carried out using ball milling.
5. The method for preparing coarse polishing powder for glass wafer polishing according to claim 1, characterized in that, The dispersant is one or a mixture of two of sodium hexametaphosphate and sodium polyacrylate with a molecular weight of 4000.