A low-temperature ceramic binder and a method for preparing diamond grinding wheels using the same.

Abstract

This invention relates to an ultra-low temperature ceramic binder, which is mainly composed of the following raw materials in the indicated mass percentages: Bi₂O₃: 40-80%, B₂O₃: 5-15%, ZnO: 10-35%, SiO₂: 0-5%, Li₂O: 0.5-3%, TiO₂: 0-5%, CaF₂: 2-10%, Y₂O₃: 0-5%. This binder can be fired at a minimum temperature of 400°C and softened at a minimum temperature of 320°C. It enables the ceramic binder to achieve bonding and consolidation before the polymeric pore-forming agent and temporary polymeric binder burn off, maintaining the integrity of the pore structure while achieving a high porosity. Furthermore, using this ceramic binder and a preferred polymeric pore-forming material, it is possible to construct spherical pores with interconnected microscopic gaps, and the pore size can be controlled during preparation.

Description

Technical Field

[0001] This invention belongs to the field of ultra-precision machining and manufacturing technology of hard and brittle materials, specifically relating to a method for preparing a ceramic binder for ultra-low temperature sintering and an ultra-fine particle size ceramic binder diamond for ultra-precision machining of hard and brittle materials. Background Technology

[0002] Ceramic-bonded grinding wheels possess a series of excellent properties, including strong grinding ability, good shape retention, high grinding precision, resistance to clogging, easy dressing, and resistance to high temperatures and acids / alkalis. They can adapt to various coolants and grinding requirements with varying precision, making them the most widely used. Ultrafine-grained grinding wheels (grain size below 5µm) are generally used for ultra-precision machining, especially in integrated circuits, semiconductor power devices, and optoelectronic devices. Due to the use of hard and brittle materials such as single-crystal silicon, sapphire, silicon carbide, lithium tantalate, and gallium nitride, and the extremely high requirements for wafer flatness and surface quality, precision grinding with ultrafine-grained ceramic-bonded diamond grinding wheels is an essential and crucial step, and its processing quality directly determines the product yield.

[0003] The preparation of ceramic-bonded diamond grinding wheels typically involves sintering, where the ceramic binder melts and bonds the diamond, forming a diamond grinding wheel with a certain strength and shape. However, since diamond is a carbonaceous material, sintering in air causes high-temperature oxidation (generally, the oxidation temperature of coarse-grained diamond in air is around 700℃), especially fine-grained diamond, which oxidizes at 600℃ in air, resulting in a decrease in grinding wheel performance. Currently, the sintering temperature of ceramic binders for diamond is generally between 700-800℃, which cannot meet the firing requirements for preparing ultrafine-grained ceramic diamond grinding wheels. Previously, ceramic binders for diamond with sintering temperatures below 600℃ were developed; however, to lower the sintering temperature, a large amount of PbO was added as a melting promoter. But lead, as a heavy metal, seriously threatens the ecological environment and human health, and its use has been restricted or banned by countries worldwide. Therefore, this binder has not been widely adopted. Therefore, there is an urgent need to develop ultra-low temperature (firing temperature ≤600℃) and pollution-free ceramic binders for preparing ultra-fine diamond grinding wheels.

[0004] It is important to note that the firing temperature of ceramic-bonded grinding wheels refers to the temperature range within which the ceramic binder can fully melt and spread on the abrasive surface, forming a bond that satisfies the bonding performance between the abrasive particles. In production, a standard flow block prepared with the binder is generally used, i.e., a cylinder with a diameter and height of 15 mm. Its ability to flow and spread on the abrasive surface is characterized by its deformation at different temperatures. Specifically, the flowability of the binder is characterized by measuring the percentage ratio of the diameter of the flow sample after firing to its initial diameter. Typically, the firing temperature range for the binder is considered to be between 90% and 160% of its flowability. The temperature at which the edges of the sample begin to round out after heating is called the initial melting temperature T1 of the binder, which is the lower limit temperature for the preparation of ceramic binders, and its fluidity is usually about 90%. At temperature T2, the flowing sample becomes hemispherical, with a height of about 2 / 3 of the original sample height. T2 is the melting temperature of the binder, indicating that the binder has melted and is in a viscous flow state, with a fluidity of usually about 120%. When heated to temperature T3, the sample spreads out, with a height of about 1 / 3 of the original sample height. T3 is the flow temperature of the glaze, and its fluidity is usually about 160%. (Specific details are omitted as they are not relevant to the initial melting temperature description.) Figure 1 As shown. The temperature range from T1 to T3 is called the firing temperature range of the binder.

[0005] Furthermore, the finer the abrasive grain size of the grinding wheel, the worse its cutting ability and self-sharpening properties. To ensure continuous cutting ability during wafer planarization and avoid grinding stress on the wafer surface that could cause warping, deformation, and processing damage, in addition to the natural accumulation of abrasive grains to form a certain porosity, it is often necessary to introduce additional pore structures by adding pore-forming materials. This moderately weakens the microstructure and enhances the self-sharpening ability of the grinding wheel. Because traditional pore-forming agents produce irregular internal pore shapes, large differences in pore size, and uncontrollable porosity, the pore structure of ultrafine grinding wheels is difficult to design and control. By adding polymeric spherical pore-forming agents, the particle size and amount of the added polymeric pore-forming material can be controlled to obtain spherical pore structures. The pore size and porosity are positively correlated with the particle size and amount of the added pore-forming agent, effectively reducing the negative impact of pore structure on lifespan reduction. However, this process can only achieve a porosity of less than 50 vol%. This is because obtaining a high-porosity structure requires the addition of a large amount of spherical polymer material. Due to the low friction between the powder particles, spherical polymer materials cannot maintain their structure under conditions of high-temperature burn-off of the polymer pore-forming agent and lack of binder consolidation. Although a temporary polymer binder can be used for compression molding, both the polymer binder and the pore-forming agent completely decompose and burn off at 450°C, failing to provide temporary bonding and skeletal support. Furthermore, at this temperature, all current ceramic binders have not yet reached their initial melting temperature, making it impossible to achieve structural consolidation and causing the molded green body to collapse and become unusable (e.g.). Figure 2 (As shown). Therefore, the preparation of high volume fraction porosity grinding wheel structure is not only determined by the single factor of pore-forming material. The ceramic binder has a coupled effect on the high volume fraction porosity structure. It is necessary to reduce the initial melting temperature of the binder so that after the temporary bonding of polymer and the failure, debonding and burn-off of the pore-forming material at 450℃, the ceramic binder has a suitable bonding and consolidation strength to maintain the macroscopic structure of the green body.

[0006] Therefore, how to scientifically design the composition of ceramic binders to reduce the sintering temperature of the binders and maximize the protection of the strength of the diamond particles themselves; and how to achieve high porosity and pore structure design and control of ultrafine-grained ceramic binder grinding wheels are key technical challenges faced by ultrafine-grained ceramic diamond grinding wheels used in the ultra-precision planarization processing of semiconductor hard and brittle wafer materials.

[0007] To address the above issues, the following patented technologies have undergone related technological development. (1) The composition ratio (by mass) of the low-temperature ceramic binder described in Invention Patent 201711006994.8, "A Low-Temperature Sintering Ceramic Binder and Its Preparation Process," is as follows: 30-35 parts silica sol, 45-50 parts bismuth trioxide, 5-7 parts boric acid, and 12-20 parts additives (3-5 parts zinc oxide, 3-5 parts manganese dioxide, 3-5 parts ferric oxide, and 3-5 parts vanadium pentoxide). This patent mainly emphasizes the low-temperature sintering performance of the ceramic binder, which can effectively prevent the oxidation of diamond during sintering. However, it does not address the strength performance of the binder or its impact on the pore-forming process. (2) Invention patent 202210952515.6, "A Low-Temperature Ceramic Bonded Diamond Grinding Wheel and Its Preparation Method", also uses a bismuth oxide-boron oxide (Bi2O3-B2O3) low-temperature glass system. The composition of the low-temperature ceramic binder is (molar percentage): bismuth oxide 30%-50%, boron oxide 30-50%, silicon oxide 2-10%, and aluminum oxide 2-10%. This patent also mainly emphasizes the low-temperature firing characteristics of the ceramic binder. Although the patent involves using walnut shells as a pore-forming agent, it uses a relatively traditional material selection and does not explain the coupling effect between the binder and the pore-forming process. (3) Invention patent 200510072858.X, "Ceramic Bond Grinding Stone and Its Manufacturing Method," describes a method for preparing a high-porosity ultrafine-grained ceramic bond grinding wheel with a volume fraction porosity of 75-95%. The ceramic bond used is fired at 700℃, which avoids the high-temperature oxidation of conventional coarse-grained diamond. However, for ultrafine-grained diamond, this firing temperature is still too high. It uses 30-100μm polytetrafluoroethylene particles as a pore-forming agent and adds sodium silicate as a medium-temperature binder (approximately...). To maintain the shape of the blank at high temperatures (400-600℃), and to avoid the collapse of the blank after firing due to the failure and debonding of the polymer molding binder at high temperatures (above 450℃); however, because it uses a large amount of sodium silicate (Na2O·nSiO2), it will introduce more Na2O into the binder, which will lead to a decrease and deterioration of the binder strength, which is not conducive to the life of the grinding wheel. At the same time, it will increase the probability of abnormal random shedding of abrasive grains, resulting in occasional scratches in ultra-precision machining, which is unacceptable in practical use.

[0008] Current patent applications for the preparation of ultrafine-grained ceramic diamond grinding wheels, especially high-porosity ultrafine-grained ceramic diamond grinding wheels, only address the problem from the single dimension of low-temperature ceramic binders or pore-forming processes, without considering a comprehensive solution. The resulting grinding wheels fail to achieve a balance between sharpness and durability, and cannot meet the technical requirements of high efficiency, low damage, and long lifespan in the ultra-precision planarization of semiconductor wafers. Based on this, this application was developed. Summary of the Invention

[0009] The purpose of this invention is to overcome the defects of the prior art and provide an ultra-low temperature ceramic binder with a firing temperature as low as 400°C and a softening point temperature as low as 320°C. This binder can achieve bonding and consolidation before the polymeric pore-forming agent and the polymeric temporary binder burn off, maintaining the integrity of the pore structure while achieving a high porosity. At the same time, using this ceramic binder and a preferred polymeric pore-forming material, it is possible to construct spherical pores with interconnected micro-gaps, and the pore size can be controlled.

[0010] The present invention also provides a method for preparing ultrafine-grained ceramic diamond grinding wheels using the above-mentioned ultra-low temperature ceramic binder.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] An ultra-low temperature ceramic binder, which is mainly composed of the following raw materials in the indicated mass percentages:

[0013] Bi2O3: 40-80%, B2O3: 5-15%, ZnO: 10-35%, SiO2: 0-5%, Li2O: 0.5-3%, TiO2: 0-5%, CaF2: 2-10%, Y2O3: 0-5%.

[0014] More preferably, the mass ratio of Bi2O3 to ZnO can be 1.5-5.5:1.

[0015] The Bi2O3 component in the ultra-low temperature ceramic binder of this invention can lower the softening point temperature of the binder, improve its fluidity, and reduce its crystallization temperature. At high temperatures, B2O3 exists as a boron-oxygen trigonal, reducing viscosity and facilitating dissolution; at low temperatures, it forms boron-oxygen tetrahedra, making the structure more compact and improving strength. SiO2 reduces the glass's crystallization tendency, promoting grain refinement. Li2O can reduce the glass's linear thermal expansion coefficient and crystallization tendency. ZnO not only lowers the glass melting temperature of the binder and adjusts the thermal expansion coefficient, but its combination with TiO2 also facilitates the precipitation of small equiaxed grains. CaF2 lowers the glass's melting point and improves its impact resistance. Y2O3, a rare earth oxide, inhibits glass crystallization and achieves grain refinement. The improvement effect of increasing the Bi2O3 / ZnO ratio on the sintering temperature reduction of the binder gradually slows down; therefore, its ratio has an optimal range.

[0016] Specifically, the purity of each raw material can be analytical grade. Furthermore, the raw material B2O3 is selected from analytical grade boric acid, and the raw material Li2O is selected from analytical grade lithium carbonate.

[0017] This invention provides a method for preparing the above-mentioned ultra-low temperature ceramic binder, which includes the following steps:

[0018] 1) Prepare the raw materials according to the proportion and mix them evenly using a three-dimensional mixer to obtain a mixture; Bi2O3, ZnO, SiO2, TiO2, CaF2, and Y2O3 in the components are derived from analytically pure compounds themselves, B2O3 is derived from analytically pure boric acid, and Li2O is derived from analytically pure lithium carbonate.

[0019] 2) Dehydrate the mixture at 350-450℃ (approximately 40-60 minutes), and then melt it in a high-temperature smelting furnace at 900-1100℃ for 40-120 minutes using a quartz crucible to obtain molten glass;

[0020] 3) The glass melt is quenched with water, finely ground by stirring, and dried to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm. The prepared ultra-low temperature ceramic binder has a sintering temperature range of 400-470℃; the softening point temperature of the ceramic binder can be as low as 320℃, which is lower than the decomposition temperature of some polymer pore-forming materials and polymer adhesives; this binder has good wettability with diamond (e.g., Figure 3 As shown in the figure, the flexural strength of diamond-prepared strength test strips can reach 50-65 MPa, and the impact strength is 8-15 KJ / m. 2 .

[0021] In a further preferred embodiment, in step 3), the specific parameters for fine grinding with a stirring mill can be: stirring mill speed 800-900 rpm, wet grinding, water-to-material ratio 1-1.5:1, grinding media is zirconia balls (5-7 mm in diameter), ball-to-material ratio 2-4:1, and ball milling for 0.5-2 hours.

[0022] The present invention also provides an ultrafine-grained ceramic diamond grinding wheel made using the aforementioned ultra-low temperature ceramic binder, which is mainly made of the following raw materials in weight percentage: 15-35% ultra-low temperature ceramic binder, 20-75% diamond abrasive, and 10-55% polymer pore-forming agent.

[0023] Specifically, the polymeric pore-forming agent can be one or two of polyethylene particles, polytetrafluoroethylene particles, etc., and their ratio and particle size can be adjusted according to design requirements. The particle size of the polymeric pore-forming agent can be 20-400 μm.

[0024] Furthermore, the particle size of the diamond abrasive can be 0.5-5 μm.

[0025] The present invention also provides a method for preparing the ultrafine-grained ceramic diamond grinding wheel, the specific method of which is as follows:

[0026] Mix the raw materials evenly according to the proportion to obtain a mixture. Add 5-10% by weight of phenolic resin alcohol solution to the mixture, wherein the mass concentration of phenolic resin alcohol solution is 25%-35%. Wet the mixture, sieve it, granulate it, press the granulated mixture into shape, dry it, and then sinter it in air at a temperature of 400-470℃ for 3.5-5 hours. This will produce an ultrafine-grained ceramic diamond grinding wheel with spherical pore shape, porosity (35-95 vol%), and pore size (20-800 μm) that can be designed and controlled.

[0027] This invention specifically utilizes polytetrafluoroethylene particles with a high decomposition temperature as the substrate for preparing ultrafine diamond ceramic-bonded grinding wheels with a porosity exceeding 75 vol%. The decomposition temperature of these particles (420℃) is higher than the softening point of the binder (320-385℃), effectively preventing the collapse of the ceramic body caused by the loss of polymer materials during burn-off. Furthermore, the preparation of ultra-high porosity grinding wheels requires a temperature profile design with a longer holding time than conventional methods. This invention, using a holding time of 3.5-5 hours, produces ultrafine-grained ceramic-bonded diamond grinding wheels with a porosity reaching up to 95 vol%.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1) The ultra-low temperature ceramic binder of this invention has an ultra-low sintering temperature, ranging from 400 to 470°C; it can not only effectively avoid the high-temperature oxidation of ultrafine diamond during air sintering, but also has a low softening point temperature, as low as 320°C, which is lower than the decomposition temperature of some polymer pore-forming materials and polymer binders; it can enable the ceramic binder to have a bonding and consolidation effect before the polymer pore-forming agent and polymer temporary binder burn off. Using this binder, ultrafine-particle ceramic binder grinding wheels with high porosity and controllable pore size can be prepared.

[0030] 2) The ultra-low temperature ceramic binder in this invention has good wettability with diamond, good bonding strength with diamond, and good impact resistance, and can be applied to grinding under harsh working conditions with impact.

[0031] 3) The ceramic binder in this invention has a low firing temperature and does not contain environmentally friendly heavy metal oxides such as As2O3, PbO, BaO, V2O5, etc., making it green and environmentally friendly.

[0032] 4) This invention uses polytetrafluoroethylene pore-forming agent material with a high decomposition temperature (melting point 327℃, decomposition temperature 420℃), which can match the softening temperature and sintering temperature of the ultra-low temperature binder of this invention. It can prepare ultra-fine particle ceramic diamond grinding wheels with a porosity of more than 75 vol% and easy control of pore size. At the same time, since the binder and diamond are well bonded and the spherical pores are beneficial to the macroscopic structural strength, its application in the ultra-precision planarization of semiconductor wafers can simultaneously obtain high surface processing quality, low processing damage, and good service life. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the changes in ceramic binders at high temperatures.

[0034] Figure 2 Comparison of the blanks before and after firing of conventional high-porosity grinding wheel segments; (a) The blank formed by high-porosity grinding wheel segments has a complete shape; (b) The blank of high-porosity grinding wheel segments collapses after firing.

[0035] Figure 3 This is a micrograph of the ultra-low temperature ceramic binder of the present invention wetted and bonded with diamond.

[0036] Figure 4 This is a photograph of the flow state of the ultra-low temperature ceramic binder in Example 1 of the present invention;

[0037] Figure 5 This is a micrograph of the microstructure of the ultrafine-grained ceramic diamond grinding wheel of Example 1 of the present invention;

[0038] Figure 6 This is a photograph of the flow state of the ultra-low temperature ceramic binder in Embodiment 2 of the present invention;

[0039] Figure 7 This is a micrograph of the microstructure of the ultrafine-grained ceramic diamond grinding wheel of Example 2 of the present invention;

[0040] Figure 8 This is a photograph of the flow state of the ultra-low temperature ceramic binder in Example 3 of the present invention;

[0041] Figure 9 This is a micrograph of the microstructure of the ultrafine-grained ceramic diamond grinding wheel of Example 3 of the present invention;

[0042] Figure 10 Micrograph of the microstructure of the ultrafine-grained ceramic diamond grinding wheel described in Comparative Example 2. Detailed Implementation

[0043] The technical solution of the present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.

[0044] Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products that can be directly purchased or can be prepared using conventional methods in the art (e.g., directly purchasing phenolic resin and then diluting and dissolving it with alcohol to the corresponding concentration to obtain a phenolic resin alcohol solution with a mass concentration of 25%-35%); operations or processes not mentioned in detail (such as granulation) can be carried out using conventional techniques in the art.

[0045] In the examples, the raw materials Bi2O3, ZnO, SiO2, TiO2, CaF2, and Y2O3 used were analytically pure compounds themselves, B2O3 was analytically pure boric acid, and Li2O was analytically pure lithium carbonate.

[0046] Example 1

[0047] 1. Binder preparation steps:

[0048] The raw materials were prepared according to the following weight percentages. The prepared mixture was then mixed uniformly using a three-dimensional mixer, and then dehydrated in a high-temperature oven at 400°C for 60 minutes. Afterwards, the mixture was melted in a high-temperature smelting furnace at 1100°C for 40 minutes using a quartz crucible to obtain molten glass. The molten glass was then water-quenched in water. It was then finely ground using a stirred mill (stirred mill speed 840 rpm, wet grinding, water-to-material ratio 1:1, grinding media being zirconia balls with a diameter of 5-7 mm, ball-to-material ratio 3:1). After ball milling for 1 hour, it was dried at 150°C for 10 hours to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm.

[0049] Element <![CDATA[Bi2O3]]> <![CDATA[B2O3]]> ZnO <![CDATA[SiO2]]> <![CDATA[Li2O]]> <![CDATA[TiO2]]> <![CDATA[CaF2]]> <![CDATA[Y2O3]]> Wt% 50 8.5 25 4 1.5 2 8 1

[0050] The ultra-low temperature ceramic binder prepared in this embodiment has a softening temperature of 385℃ and a firing temperature of 470℃. Its fluidity at 470℃ is as follows: Figure 4 As shown, its fluidity is 130%, reaching the molten state, and its flowability is excellent.

[0051] The ultra-low temperature ceramic binder and diamond strength test strip prepared in this embodiment has a flexural strength of 65 MPa and an impact strength of 15 KJ / m. 2 .

[0052] 2. Steps for preparing ceramic diamond grinding wheels:

[0053] Weigh out the following materials according to weight percentages: 15% of the ultra-low temperature ceramic binder prepared above, 70% of diamond abrasive with a particle size of 2-4 μm, and 15% of polymeric pore-forming agent with a particle size of 20-50 μm (polyethylene particles and polytetrafluoroethylene particles, with a mass ratio of polyethylene particles to polytetrafluoroethylene particles of 1:3). Mix the above materials evenly to obtain the grinding wheel mixture. Add 5% by weight of phenolic resin alcohol solution (concentration 25%) to the mixture and wet for 10 minutes. Pass the mixture through a 60# sieve 5 times to mix and granulate. After granulation, mold the mixture, dry it (12 hours at room temperature, 12 hours in a 50℃ oven, for a total of 24 hours, the same below), and then fire it in an air atmosphere at a sintering temperature of 470℃ for 3.5 hours. This yields an ultra-fine-grained ceramic diamond grinding wheel with spherical pores, a porosity of 45 vol%, and a pore size distribution of 20-50 μm. Figure 5 As shown.

[0054] Example 2

[0055] 1. Binder preparation steps:

[0056] The raw materials were prepared according to the following weight percentages. The prepared mixture was then mixed uniformly using a three-dimensional mixer and dehydrated in a high-temperature oven at 400°C for 60 minutes. Subsequently, the mixture was melted in a high-temperature smelting furnace at 1000°C for 90 minutes using a quartz crucible to obtain molten glass. The molten glass was then water-quenched in water. Afterward, it was finely ground using a stirred mill (stirred mill speed 840 rpm, wet grinding, water-to-material ratio 1:1, grinding media being zirconia balls with a diameter of 5-7 mm, ball-to-material ratio 3:1) for 1 hour. Following this, it was dried at 150°C for 10 hours to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm.

[0057] Element <![CDATA[Bi2O3]]> <![CDATA[B2O3]]> ZnO <![CDATA[SiO2]]> <![CDATA[Li2O]]> <![CDATA[TiO2]]> <![CDATA[CaF2]]> <![CDATA[Y2O3]]> Wt% 60 7.5 20 2 1.5 2 6 1

[0058] The ultra-low temperature ceramic binder prepared in this embodiment has a softening temperature of 340℃ and a firing temperature of 440℃. Its fluidity at 440℃ is as follows: Figure 6 As shown, its fluidity is 130%, reaching the molten state, and its flowability is excellent.

[0059] The ultra-low temperature ceramic binder and diamond strength test strip prepared in this embodiment have a flexural strength of 55 MPa and an impact strength of 12 KJ / m. 2 .

[0060] 2. Grinding wheel preparation steps:

[0061] Weigh out the following materials according to weight percentages: 35% of the ultra-low temperature ceramic binder prepared above, 35% of diamond abrasive with a particle size of 1-2 μm, and 30% of a polymeric pore-forming agent (polyethylene particles and polytetrafluoroethylene particles, with a mass ratio of polyethylene particles to polytetrafluoroethylene particles of 1:2) with a particle size of 20-400 μm. Mix the above materials evenly to obtain the grinding wheel mixture. Add 8% (by weight) of a phenolic resin alcohol solution (30% concentration) to the mixture and wet for 10 minutes. Pass the mixture through a 60# sieve five times for mixing and granulation. After granulation, mold and dry the mixture. Then, sinter it in an air atmosphere at a sintering temperature of 440℃ for 4 hours to obtain an ultrafine-grained ceramic diamond grinding wheel with spherical pores, a porosity of 70 vol%, and a pore size distribution of approximately 35-470 μm. Figure 7 As shown.

[0062] Example 3

[0063] 1. Binder preparation steps:

[0064] The raw materials were prepared according to the following weight percentages. The prepared mixture was mixed uniformly using a three-dimensional mixer. The mixture was then dehydrated in a high-temperature oven at 400°C for 45 minutes. After that, it was melted in a high-temperature smelting furnace at 900°C for 120 minutes using a quartz crucible to obtain glass melt. The molten glass melt was then poured into water for water quenching. After that, it was finely ground using a stirring mill (stirring mill speed 840 rpm, wet grinding, water-to-material ratio 1:1, grinding media is zirconia balls with a diameter of 5-7 mm, ball-to-material ratio 3:1). After ball milling for 1 hour, it was dried at 150°C for 10 hours to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm.

[0065] Element <![CDATA[Bi2O3]]> <![CDATA[B2O3]]> ZnO <![CDATA[SiO2]]> <![CDATA[Li2O]]> <![CDATA[TiO2]]> <![CDATA[CaF2]]> <![CDATA[Y2O3]]> Wt% 70 7.5 14.5 1 1 2 3 1

[0066] The ultra-low temperature ceramic binder prepared in this embodiment has a softening temperature of 320℃ and a firing temperature of 400℃. Its fluidity at 400℃ is as follows: Figure 8 As shown, its fluidity is 110%, which is close to the molten state due to the initial melting state, and the fluidity meets the requirements.

[0067] The ultra-low temperature ceramic binder and diamond strength test strip prepared in this embodiment have a flexural strength of 50 MPa and an impact strength of 8 KJ / m. 2 .

[0068] 2. Grinding wheel preparation steps:

[0069] Weigh out 25% by weight of the ultra-low temperature ceramic binder prepared above, 20% of diamond abrasive with a particle size of 0-0.5 μm, and 55% of polytetrafluoroethylene polymer pore-forming agent with a particle size of 30-300 μm. Mix the above materials evenly to obtain the grinding wheel mixture. Add 10% by weight of the mixture of phenolic resin alcohol solution (concentration 35%) to wet for 10 minutes, and then pass through a 60# sieve 5 times to mix and granulate. After granulation, the mixture is molded, dried, and then fired in an air atmosphere at a sintering temperature of 400℃ for 5 hours to obtain an ultra-fine particle size ceramic diamond grinding wheel with spherical pore shape, a porosity of 95 vol%, and a pore size distribution of approximately 50-350 μm. Figure 9 (As shown).

[0070] Example 4

[0071] 1. Binder preparation steps:

[0072] The raw materials were prepared according to the following weight percentages. The prepared mixture was then mixed uniformly using a three-dimensional mixer, and then dehydrated in a high-temperature oven at 400°C for 60 minutes. Afterwards, the mixture was melted in a high-temperature smelting furnace at 1100°C for 40 minutes using a quartz crucible to obtain molten glass. The molten glass was then water-quenched in water. It was then finely ground using a stirred mill (stirred mill speed 840 rpm, wet grinding, water-to-material ratio 1:1, grinding media being zirconia balls with a diameter of 5-7 mm, ball-to-material ratio 3:1) for 1 hour. After ball milling, it was dried at 150°C for 10 hours to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm.

[0073] Element <![CDATA[Bi2O3]]> <![CDATA[B2O3]]> ZnO <![CDATA[SiO2]]> <![CDATA[Li2O]]> <![CDATA[TiO2]]> <![CDATA[CaF2]]> <![CDATA[Y2O3]]> Wt% 50 8.5 25 4 1.5 3 8 0

[0074] The ultra-low temperature ceramic binder prepared in this embodiment has a softening temperature of 395°C and a firing temperature of 485°C.

[0075] The ultra-low temperature ceramic binder and diamond strength test strip prepared in this embodiment have a flexural strength of 53 MPa and an impact strength of 8 KJ / m. 2 .

[0076] 2. Steps for preparing ceramic diamond grinding wheels:

[0077] Weigh out the following materials according to weight percentages: 15% of the ultra-low temperature ceramic binder prepared above, 70% of diamond abrasive with a particle size of 2-4 μm, and 15% of polymeric pore-forming agent (polyethylene particles and polytetrafluoroethylene particles, with a mass ratio of polyethylene particles to polytetrafluoroethylene particles of 1:3) with a particle size of 20-50 μm. Mix the above materials evenly to obtain the grinding wheel mixture. Add 5% of the mixture weight of phenolic resin alcohol solution (concentration 25%) to wet for 10 minutes, and then pass it through a 60# sieve 5 times to mix and granulate. After granulation, the mixture is molded and dried for 24 hours. Then, it is placed in a furnace and sintered in air atmosphere at a sintering temperature of 470℃ for 3.5 hours to obtain an ultrafine-grained ceramic diamond grinding wheel with spherical pore shape, a porosity of 45 vol%, and a pore size distribution of 20-50 μm.

[0078] Example 5

[0079] 1. Binder preparation steps:

[0080] The raw materials were prepared according to the following weight percentages. The prepared mixture was then mixed uniformly using a three-dimensional mixer, and then dehydrated in a high-temperature oven at 400°C for 60 minutes. Afterwards, the mixture was melted in a high-temperature smelting furnace at 1100°C for 40 minutes using a quartz crucible to obtain molten glass. The molten glass was then water-quenched in water. It was then finely ground using a stirred mill (stirred mill speed 840 rpm, wet grinding, water-to-material ratio 1:1, grinding media being zirconia balls with a diameter of 5-7 mm, ball-to-material ratio 3:1) for 1 hour. After ball milling, it was dried at 150°C for 10 hours to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm.

[0081] Element <![CDATA[Bi2O3]]> <![CDATA[B2O3]]> ZnO <![CDATA[SiO2]]> <![CDATA[Li2O]]> <![CDATA[TiO2]]> <![CDATA[CaF2]]> <![CDATA[Y2O3]]> Wt% 55 7.5 22.5 2.5 1.5 0 8 3

[0082] The ultra-low temperature ceramic binder prepared in this embodiment has a softening temperature of 370°C and a firing temperature of 460°C.

[0083] The ultra-low temperature ceramic binder and diamond strength test strip prepared in this embodiment have a flexural strength of 55 MPa and an impact strength of 7 KJ / m. 2 .

[0084] 2. Steps for preparing ceramic diamond grinding wheels:

[0085] Weigh out the following materials according to weight percentages: 15% of the ultra-low temperature ceramic binder prepared above, 70% of diamond abrasive with a particle size of 2-4 μm, and 15% of polymeric pore-forming agent (polyethylene particles and polytetrafluoroethylene particles, with a mass ratio of polyethylene particles to polytetrafluoroethylene particles of 1:3) with a particle size of 20-50 μm. Mix the above materials evenly to obtain the grinding wheel mixture. Add 5% of the mixture weight of phenolic resin alcohol solution (concentration 25%) to wet for 10 minutes, and then pass it through a 60# sieve 5 times to mix and granulate. After granulation, the mixture is molded and dried for 24 hours. Then, it is placed in a furnace and sintered in air atmosphere at a sintering temperature of 470℃ for 3.5 hours to obtain an ultrafine-grained ceramic diamond grinding wheel with spherical pore shape, a porosity of 45 vol%, and a pore size distribution of 20-50 μm.

[0086] Comparative Example 1

[0087] 1. Binder preparation steps:

[0088] The raw materials were prepared according to the following weight percentages. The prepared mixture was then mixed uniformly using a three-dimensional mixer, and then dehydrated in a high-temperature oven at 400°C for 60 minutes. Afterwards, the mixture was melted in a high-temperature smelting furnace at 1100°C for 40 minutes using a quartz crucible to obtain molten glass. The molten glass was then water-quenched in water. It was then finely ground using a stirred mill (stirred mill speed 840 rpm, wet grinding, water-to-material ratio 1:1, grinding media being zirconia balls with a diameter of 5-7 mm, ball-to-material ratio 3:1) for 1 hour, followed by drying at 150°C for 10 hours to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm.

[0089] Element <![CDATA[SiO2]]> <![CDATA[B2O3]]> ZnO <![CDATA[Li2O]]> <![CDATA[TiO2]]> <![CDATA[Y2O3]]> Wt% 40 30.5 25 1.5 2 1

[0090] The ultra-low temperature ceramic binder prepared in this embodiment has a softening temperature of 610°C and a firing temperature of 720°C.

[0091] The ultra-low temperature ceramic binder and diamond strength test strip prepared in this embodiment have a flexural strength of 40 MPa and an impact strength of 2 KJ / m. 2 .

[0092] 2. Steps for preparing ceramic diamond grinding wheels:

[0093] Weigh out the following materials according to weight percentages: 35% of the ultra-low temperature ceramic binder prepared above, 35% of diamond abrasive with a particle size of 1-2 μm, and 30% of polymeric pore-forming agent with a particle size of 20-400 μm (polyethylene particles and polytetrafluoroethylene particles, with a ratio of 1:2 for polyethylene particles and polytetrafluoroethylene particles). Mix the above materials evenly to obtain the grinding wheel mixture. Add 8% by weight of phenolic resin alcohol solution (30% concentration) to the mixture and wet for 10 minutes. Pass the mixture through a 60# sieve 5 times to mix and granulate. After granulation, mold and dry the mixture. Then, place it in a furnace and fire it in an air atmosphere at a sintering temperature of 720℃ for 3.5 hours. The fired green body is as follows: Figure 2 As shown in (b), the structure collapsed and became unusable.

[0094] Comparative Example 2

[0095] 1. Binder preparation steps:

[0096] The raw materials were prepared according to the following weight percentages, with a Bi2O3 to ZnO mass ratio of 9.56:1. The prepared mixture was mixed uniformly using a three-dimensional mixer and dehydrated in a high-temperature oven at 400°C for 60 minutes. Then, it was melted in a high-temperature smelting furnace at 900°C for 120 minutes using a quartz crucible to obtain glass melt. The molten glass melt was then water-quenched in water. After that, it was finely ground using a stirring mill (stirring mill speed 840 rpm, wet grinding, water-to-material ratio 1:1, grinding media being zirconia balls with a diameter of 5-7 mm, ball-to-material ratio 3:1). After ball milling for 1 hour, it was dried at 150°C for 10 hours to obtain an ultra-low temperature ceramic binder with a particle size of 10-20 μm.

[0097]

[0098]

[0099] The ultra-low temperature ceramic binder prepared in this embodiment has a softening temperature of 340°C and a firing temperature of 430°C. Its fluidity at 430°C is 90%, indicating that it is in the initial melting state and has moderate fluidity.

[0100] The ultra-low temperature ceramic binder and diamond strength test strip prepared in this embodiment have a flexural strength of 45 MPa and an impact strength of 5 KJ / m. 2 .

[0101] 2. Grinding wheel preparation steps:

[0102] Weigh out 25% by weight of the ultra-low temperature ceramic binder prepared above, 20% of diamond abrasive with a particle size of 0-0.5 μm, and 55% of polytetrafluoroethylene polymer pore-forming agent with a particle size of 30-300 μm. Mix the above materials evenly to obtain the grinding wheel mixture. Add 10% by weight of the mixture of phenolic resin alcohol solution (concentration 35%) to wet for 10 minutes, pass through a 60# sieve 5 times to mix and granulate. After granulation, the mixture is molded, dried, and then fired in an air atmosphere at a sintering temperature of 400℃ for 5 hours. The resulting grinding wheel has a porosity of 80 vol% and a generally good pore structure integrity (e.g., ...). Figure 10 As shown in the figure, there is obvious pore fusion and even local pore structure incompleteness. This is because the firing temperature of the binder is higher than the burn-off temperature of the pore-forming agent, which causes the pore-forming agent to burn off and its site structure cannot be maintained.

[0103] Application Test: Grinding Performance of Ultrafine Grained Ceramic-Bonded Diamond Grinding Wheels

[0104] The ultrafine-grained ceramic-bonded diamond grinding wheels prepared in Examples 1, 2, 3, 4, 5 and Comparative Example 2 were subjected to grinding performance tests using a wafer thinning machine. The tests measured the current value, wear, surface roughness, and damage layer under the condition that the grinding wheels were used to grind 8-inch silicon wafers with a grinding allowance of 15 μm. The test results are shown in Table 1 below.

[0105] Table 1. Grinding Test Results of Ultrafine-Grained Ceramic-Bonded Diamond Grinding Wheels

[0106]

[0107] As shown in Table 1, the ultrafine-grained ceramic-bonded diamond grinding wheels prepared by this invention exhibit good grinding performance when grinding silicon wafers due to their spherical pores that are beneficial to the strength of the grinding wheel structure. They also have high feed rates and low processing damage. The feed rate of the M2 / 4 grit grinding wheel in Example 1 can reach 2 μm / s, and its minimum damage layer thickness can reach 2.6 μm; the feed rate of the M1 / 2 grit grinding wheel in Example 2 can reach 0.5 μm / s, and its minimum damage layer thickness can reach 1.2 μm; the feed rate of the M0 / 0.5 grit grinding wheel in Example 3 can reach 0.4 μm / s, and its minimum damage layer thickness can reach 0.6 μm. However, the M0 / 0.5 grit grinding wheel in Comparative Example 2, due to its lower bond strength and higher firing temperature than Example 3, has an unsatisfactory pore structure, with a feed rate of 0.15 μm / s and a damage layer thickness of 1.42 μm, which is significantly different from Example 3.

Claims

1. An ultralow temperature ceramic bond characterized in that, It is mainly made from the following raw materials in the following weight percentages: Bi2O3: 40-80%, B2O3: 5-15%, ZnO: 10-35%, SiO2: 0-5%, Li2O: 0.5-3%, TiO2: 0-5%, CaF2: 2-10%, Y2O3: 0-5%; The sintering temperature of the ultra-low temperature ceramic binder is 400-470℃, and the softening point temperature is 320-385℃. The mass ratio of Bi2O3 to ZnO is 1.5-5.5:

1.

2. The ultra-low temperature ceramic bond of claim 1, wherein, The purity of each raw material is analytical grade.

3. The ultra-low temperature ceramic bonding agent of claim 1, wherein, The raw material B2O3 is selected from analytical grade boric acid, and the raw material Li2O is selected from analytical grade lithium carbonate.

4. The method for preparing the ultra-low temperature ceramic binder according to any one of claims 1 to 3, characterized in that, Includes the following steps: 1) Prepare the raw materials according to the specified proportions and mix them evenly to obtain a mixture; 2) Dehydrate the mixture at 350-450℃, and then melt it at 900-1100℃ for 40-120 minutes to obtain molten glass; 3) The glass melt is quenched with water, finely ground by stirring and drying to obtain an ultra-low temperature ceramic binder with a particle size of 10-20μm.

5. The method for preparing the ultra-low temperature ceramic binder as described in claim 4, characterized in that, In step 3), the specific parameters for fine grinding with a stirring mill are as follows: stirring mill speed 800-900 rpm, wet grinding, water-to-material ratio 1-1.5:1, grinding media is zirconia balls, ball-to-material ratio 2-4:1, ball milling 0.5-2h.

6. A ceramic diamond grinding wheel made using the ultra-low temperature ceramic binder according to any one of claims 1 to 3, characterized in that, It is mainly made of the following raw materials by weight percentage: 15-35% ultra-low temperature ceramic binder, 20-75% diamond abrasive, and 10-55% polymer pore-forming agent.

7. The ceramic diamond grinding wheel as described in claim 6, characterized in that, The polymeric pore-forming agent is one or both of polyethylene particles and polytetrafluoroethylene particles, and the particle size of the polymeric pore-forming agent is 20-400 μm.

8. The ceramic diamond grinding wheel as described in claim 6, characterized in that, The diamond abrasive has a particle size of 0.5-5 μm.

9. A method for preparing the ceramic diamond grinding wheel according to any one of claims 6 to 8, characterized in that, Mix all raw materials evenly according to the proportion, add 5-10% of the weight of the mixture with phenolic resin alcohol solution to wet, sieve, granulate, press the granulated mixture into shape, dry it, and then sinter it in air at a temperature of 400-470℃ for 3.5-5 hours to obtain the final product.

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