Application of helical calcium carbonate in grinding block and wafer thinning grinding wheel

Abstract

The application relates to the technical field of integrated circuit manufacturing, and discloses application of spiral calcium carbonate in grinding blocks and wafer thinning grinding wheels. The spiral calcium carbonate is applied in the grinding block, wherein the spiral calcium carbonate contains Si-O-Ca structure and is used for dispersing stress during grinding of the grinding block; the crystal form of the spiral calcium carbonate is vaterite type, the spiral calcium carbonate comprises a plurality of flaky crystals, the plurality of flaky crystals are arranged in a spiral shape around the center, and adjacent flaky crystals are partially stacked, so that the spiral calcium carbonate has a chiral characteristic, and the plurality of flaky crystals can disperse stress during grinding; and the spiral calcium carbonate is induced by calcium ions and amino silane aspartic acid. Through the technical scheme, the problem of poor flatness of a wafer after thinning in the related art is solved.

Description

[0001] This application is a divisional application of the invention patent application filed on October 28, 2025, with application number 202511543482X. Technical Field

[0002] This application relates to the field of integrated circuit manufacturing technology, and more specifically, to the application of a spiral calcium carbonate in grinding blocks and wafer thinning wheels. Background Technology

[0003] Three-dimensional integrated circuits (3D ICs) are an important technological path for the semiconductor industry to continue Moore's Law and improve chip performance and integration. The core idea is to stack multiple chips or functional layers vertically and achieve interlayer electrical connections through interconnection technologies such as through-silicon vias (TSVs), thereby achieving higher functional density within a limited space.

[0004] Wafer thinning is a key supporting process in 3D IC manufacturing, its main purpose being to reduce the wafer's thickness from its original level to an ultra-thin state suitable for vertical integration. Ultra-thin wafers are the physical basis for achieving 3D stacking and are crucial for optimizing electrical performance and thermal management. As the number of 3D IC stacking layers increases, the requirements for the thinning thickness of individual wafers become increasingly stringent. Simultaneously, 3D IC technology places extremely high demands on the surface quality of the thinned wafer, including excellent Total Thickness Variation (TTV) and extremely low Roughness Average (Ra), to ensure the accuracy, consistency, and stability of subsequent bonding processes.

[0005] To achieve the aforementioned thinning targets, wafer thinning equipment typically utilizes the physical grinding action of grinding wheels to process ultra-thin wafers. Such equipment must have its grinding structure and grinding process precisely designed and controlled to meet the requirements for ultra-thin wafer processing (such as thickness ≤10 μm, TTV ≤1.5 μm, and Ra ≤5 nm) while also considering manufacturing costs and production efficiency.

[0006] The basic components of a grinding wheel are abrasive, binder, and filler. However, traditional grinding wheel fillers such as feldspar and quartz sand have significant defects: (1) high brittleness; (2) significant stress concentration effect; and (3) insufficient interfacial bonding with the binder. During dynamic grinding, due to the above defects of the filler, the grinding wheel is prone to microcrack propagation and subsurface damage layer. These damages reduce the mechanical properties of the grinding wheel, thereby indirectly affecting the flatness and long-term reliability of the wafer after thinning. Especially in the processing of ultra-thin wafers, the failure of the filler matrix interface not only directly contaminates the wafer surface, but also causes irregular wear on the grinding surface of the grinding wheel, which greatly shortens the service life of the grinding wheel, makes it difficult to maintain stable grinding force control and processing accuracy, and ultimately causes the wafer flatness index to exceed the allowable range of the process. Summary of the Invention

[0007] This application proposes the application of spiral calcium carbonate in grinding blocks and wafer thinning wheels to solve or alleviate at least one of the above-mentioned problems.

[0008] The technical solution of this application is as follows: This application proposes a wafer thinning device, including a grinding device and an adsorption platform, wherein the adsorption platform is used to support the wafer and drive the wafer to rotate. The grinding device is raised and lowered above the adsorption platform. The lower part of the grinding device has a grinding wheel for grinding wafers. The grinding wheel includes a substrate and multiple grinding blocks. The grinding blocks are fixed to the substrate by an adhesive layer. The grinding blocks include helical calcium carbonate with a Si-O-Ca structure to disperse stress during grinding.

[0009] As a further technical solution, the helical calcium carbonate containing the Si-O-Ca structure has the crystal form of aragonite.

[0010] As a further technical solution, the average particle size of the spiral calcium carbonate containing the Si-O-Ca structure is 1~100μm.

[0011] As a further technical solution, the helical calcium carbonate containing the Si-O-Ca structure includes multiple plate-like crystals, which are arranged in a spiral around the center and adjacent plate-like crystals are partially stacked, so that the helical calcium carbonate containing the Si-O-Ca structure has chiral characteristics and the multiple plate-like crystals can disperse the stress during grinding.

[0012] As a further technical solution, the helical calcium carbonate containing the Si-O-Ca structure is formed by calcium ions induced by aminosilanized aspartic acid, and the aminosilanized aspartic acid is prepared by a condensation reaction of aspartic acid-β-methyl ester hydrochloride and an aminosilane coupling agent.

[0013] As a further technical solution, the molar ratio of aminosilylated aspartic acid to calcium ions is 0.8~1.5:1.

[0014] As a further technical solution, the mass-to-volume ratio of the aspartic acid-β-methyl ester hydrochloride and the aminosilane coupling agent is 1~1.2 g:1.8 mL.

[0015] As a further technical solution, the raw materials of the grinding block include the following components in parts by weight: 45 parts of abrasive, 34-46 parts of resin, 4-12 parts of spiral calcium carbonate containing Si-O-Ca structure, and 2-10 parts of pore-forming agent.

[0016] As a further technical solution, the average particle size of the abrasive is 10~100 μm.

[0017] As a further technical solution, the grinding apparatus includes: The feeding assembly is vertically connected above the adsorption platform; A rotating shaft, driven by the feed assembly for lifting, is connected to the lower end of the rotating shaft.

[0018] As a further technical solution, the adsorption platform includes: The worktable has a chuck spindle at the bottom, which drives the worktable to rotate. An adsorption disk, disposed on the worktable, is used to adsorb wafers. The adsorption disk can drive the wafers to rotate synchronously under the action of the worktable.

[0019] This application also proposes a thinning method, which uses the aforementioned wafer thinning equipment to perform a wafer thinning process.

[0020] As a further technical solution, the thinning method includes the following steps: A100. Adsorb and fix the wafer onto the adsorption platform; A200, drives the grinding wheel down to contact the wafer; A300: The grinding wheel and the adsorption platform rotate in the same direction, while the grinding wheel is fed downwards. The rotational speed of the grinding wheel is greater than that of the adsorption platform to grind the wafer. A400: When the wafer is ground to the target thickness, stop the rotation of the grinding wheel and the adsorption platform, and move the grinding wheel upward to separate it from the wafer; A500, removes the adsorption of the wafer and transfers the wafer.

[0021] The beneficial effects of this application are as follows: 1. To ensure precision during the wafer thinning process, this application improves the filler in the grinding wheel block that directly contacts the wafer in the wafer thinning equipment by combining both physical morphology and chemical structure. By adding helical calcium carbonate with a Si-O-Ca structure, the synergistic effect of physical morphology and chemical structure is utilized to improve the mechanical properties of the grinding wheel and solve the problem of poor wafer flatness after thinning. Specifically: (1) The spiral morphology can effectively avoid local stress concentration through stress dispersion, making the grinding force distribution more uniform, suppressing the force fluctuation during the thinning process, avoiding wafer microcracks and subsurface damage, reducing the thickness fluctuation of the wafer surface caused by uneven stress, and improving the stability of the wafer flatness after thinning; on the other hand, the surface of the spiral morphology is not flat, but has a spiral gap, which has a larger contact surface area than the block morphology, which can enhance the mechanical anchoring effect with the substrate, improve the mechanical properties of the grinding wheel, avoid particle shedding, maintain stable grinding force control and processing accuracy, and improve the stability of the wafer flatness after thinning. (2) The Si-O-Ca structure can enhance the interfacial bonding between the spiral calcium carbonate and the resin through chemical structure, improve the mechanical properties of the grinding wheel, maintain the stability of the grinding surface morphology during high-speed grinding, reduce the particle shedding rate, and improve the stability of the flatness of the wafer after thinning.

[0022] 2. The wafer thinning equipment in this application is applicable to wafer thinning of different materials, such as silicon, gallium arsenide and silicon carbide, etc. It is suitable for the high-precision processing requirements of power devices such as power field-effect transistors and insulated gate bipolar transistors and radio frequency chips such as gallium arsenide. It is especially suitable for precision grinding of ultra-thin wafers with a thickness of less than 100 μm, which can avoid the risk of chip stacking failure due to thickness deviation and can meet the requirements of silicon through-hole interconnect technology of three-dimensional integrated chips for the flatness of the thinned wafer. Attached Figure Description

[0023] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] Figure 1 This is a schematic diagram of the structure of a wafer thinning apparatus according to one embodiment of this application; Figure 2 for Figure 1 Side view of the grinding device and adsorption platform of the wafer thinning equipment; Figure 3 A flowchart illustrating the specific steps of the wafer thinning method provided in this application; Figure 4 for Figure 2 A schematic diagram of the structure of the grinding wheel in the diagram; Figure 5 for Figure 4 A schematic diagram of the grinding block of a medium-sized grinding wheel; Figure 6 A schematic diagram of stress buffering for spiral calcium carbonate; Figure 7 SEM image of the helical calcium carbonate with Si-O-Ca structure prepared in Example 3; Figure 8 The XRD pattern of the helical calcium carbonate with a Si-O-Ca structure prepared in Example 3 is shown below. Figure 9 The infrared spectrum of the helical calcium carbonate containing a Si-O-Ca structure prepared in Example 3; Figure 10 SEM image of the helical calcium carbonate with Si-O-Ca structure prepared in Example 4; Figure 11 This is a partial enlarged view of the helical calcium carbonate layer with a Si-O-Ca structure prepared in Example 4; Figure 12 SEM image of the spherical calcium carbonate prepared in Comparative Example 1; Figure 13 SEM image of spherical calcium carbonate I with Si-O-Ca structure prepared in Comparative Example 2; Figure 14 SEM image of spherical calcium carbonate II with Si-O-Ca structure prepared in Comparative Example 3; Figure 15 The image shows a SEM image of the spherical calcium carbonate III containing the Si-O-Ca structure prepared in Comparative Example 4.

[0025] Reference numerals: 1. Equipment base; 2. Grinding device; 22. Rotary shaft; 23. Grinding wheel; 231. Substrate; 232. Grinding block; 2321. Base; 2322. Abrasive grain; 2323. Calcium carbonate particles; 2324. Pores; 3. Adsorption platform; 31. Chuck spindle; 32. Worktable; 33. Adsorption disk; 4. Rotary disk. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] To keep the drawings concise, each drawing only schematically shows the parts relevant to the disclosure; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0028] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0031] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] It should be understood that, unless the context clearly indicates otherwise, the terms “comprising,” “including,” or “having” as used herein refer to the presence of an element, but do not exclude the presence or addition of one or more other elements. Furthermore, as used herein, “comprising” and / or “including” indicate the presence of shapes, numbers, steps, operations, members, elements, and / or combinations thereof, and do not exclude the presence or addition of one or more other shapes, numbers, operations, elements, and / or combinations thereof.

[0033] In this application, the numerical range indicated by "~" refers to the range of values ​​specified as the lower and upper limits, respectively, before or after the term. When multiple values ​​for the upper or lower limit of any numerical range are mentioned, the range disclosed herein can be understood as a range with any one of the mentioned upper limits as its upper limit and any one of the mentioned lower limits as its lower limit.

[0034] In the following text, the average particle size can be measured using a commercially available laser particle size analyzer.

[0035] Reference Figure 1 and Figure 2 , Figure 1 The image shows a wafer thinning device. Figure 2 for Figure 1 The side view of the grinding device 2 and the adsorption platform 3 of the wafer thinning equipment. The wafer thinning equipment includes a device base 1, on which a rotating disk 4 is provided. Above the rotating disk 4, multiple adsorption platforms 3 are arranged at intervals along the circumference. The rotating disk 4 can rotate around its own central axis to change the position of the adsorption platform 3, so that the wafer supported by the adsorption platform 3 can switch between the rough grinding station, the fine grinding station and the loading and unloading station.

[0036] Furthermore, an upright support is provided at the end of the equipment base 1, and a grinding device 2 is provided on the side of the support. There are two grinding devices 2, corresponding to a rough grinding section and a fine grinding section. The two have similar structures and are equipped with a feed assembly (not shown) that drives the grinding wheel 23 to move up and down and a mechanism that drives the grinding wheel to rotate along the rotating shaft 22. The feed assembly includes a lifting motor (not shown), which is slidably connected to the housing of the rotating shaft through a lead screw. The housing is slidably connected to the side of the column so that the vertical movement of the rotating shaft 22 is realized by the rotation of the lifting motor, thereby changing the position of the grinding wheel 23 relative to the adsorption platform 3.

[0037] The adsorption platform 3 is used to support the wafer and drive it to rotate. The grinding device 2 is raised and lowered above the adsorption platform 3. The lower part of the grinding device 2 has a grinding wheel 23 that can rotate circumferentially to grind the wafer. The grinding wheel includes a substrate 231 and a plurality of grinding blocks 232. The grinding blocks 232 include helical calcium carbonate with a Si-O-Ca structure, which is used to disperse the stress during grinding.

[0038] Grinding device 2 includes a feed assembly, a rotary shaft 22, and a grinding wheel 23. The grinding block 232 within the grinding wheel 23 ( Figure 4(Shown) This is used for grinding wafers. The grinding wheel 23 can be a cup-shaped grinding wheel, mounted at the lower end of the rotating shaft 22. The rotating shaft 22 is used to rotate the grinding wheel 23 about its axis of rotation. The feed assembly can drive the rotating shaft 22 and the grinding wheel 23 to move up and down synchronously. When the wafer needs to be ground, the grinding wheel 23 moves under the drive of the feed assembly until its bottom surface contacts the surface of the wafer. At this time, both the grinding wheel 23 and the wafer are rotating in the same direction but at different speeds, and the surface of the wafer is ground using the grinding wheel 23. The feed assembly has a known construction and includes, for example, multiple linear guides that guide the movement direction of the rotating shaft 22 and a ball screw-slider mechanism that moves the rotating shaft 22 up and down.

[0039] Reference Figure 4 , it is Figure 2 The schematic diagram of the grinding wheel shows that the grinding wheel 23 includes a substrate 231 and a plurality of grinding blocks 232 disposed on the surface of the substrate 231 for grinding the wafer. The grinding blocks 232 can be rounded rectangles or fan shapes. At least a portion of the grinding blocks 232 is embedded in an annular groove and spaced apart from each other on the substrate 231. The substrate 231 can be fastened to the lower end of the rotating shaft 22 by bolts.

[0040] The raw materials for grinding block 232 may include the following components in parts by weight: 45 parts abrasive, 34-46 parts resin, 4-12 parts spiral calcium carbonate containing a Si-O-Ca structure, and 2-10 parts pore-forming agent. The composition and dosage settings of the grinding block 232 of this application can effectively improve the grinding quality of wafers. Wherein: The abrasive can continuously grind the wafer to achieve wafer thinning; the resin can fully bind the other components, maintain the structural integrity of the grinding block 232 during the grinding process, and ensure the service life of the grinding wheel 23; the spiral calcium carbonate containing the Si-O-Ca structure can improve the stress distribution of the grinding block 232 under external force, avoid local stress concentration, and make the grinding force distribution more uniform, thereby solving the problem of poor wafer flatness after thinning and significantly improving the service life of the grinding wheel 23; the pore-forming agent can form appropriate pores in the grinding block 232 to effectively achieve heat dissipation and chip removal.

[0041] This application controls the weight percentages of the abrasive to 45 parts, the resin to 34-46 parts, the spiral calcium carbonate containing the Si-O-Ca structure to 4-12 parts, and the pore-forming agent to 2-10 parts, thus achieving a reasonable combination of components and fully leveraging the synergistic effect between them. This improves the overall performance of the grinding block 232 in terms of grinding force control, adhesion, heat dissipation, and chip removal, thereby improving the flatness of the thinned wafer. Furthermore, the amount of abrasive used in this application avoids both insufficient abrasive leading to reduced grinding efficiency and excessive abrasive increasing the rigidity and brittleness of the grinding block 232, making it unable to withstand the impact force during grinding and causing cracking or chipping. Similarly, the amount of resin used avoids both insufficient resin resulting in insufficient strength of the grinding block 232, making it unable to withstand the grinding force during grinding and causing the grinding wheel 23 to malfunction, and excessive resin leading to a decrease in the overall hardness of the grinding block 232, making it difficult to quickly remove wafer thickness during grinding and reducing grinding efficiency. This application contains Si- The amount of O-Ca spiral calcium carbonate used avoids both insufficient dosage, which would not significantly enhance the internal structure of the grinding block 232, and excessive dosage, which would make the grinding block 232 too hard and brittle, thus reducing the service life of the grinding wheel 23. The amount of pore-forming agent used in this application avoids both insufficient dosage, which would lead to difficulties in heat dissipation and chip removal, and the resulting chip accumulation would cause the grinding wheel 23 to become clogged, thus reducing the grinding effect, and excessive dosage, which would lead to too many and too large pores inside the grinding block 232, thereby reducing the strength of the grinding block 232 and causing the grinding block 232 to break and crack during the grinding process.

[0042] In this application, by improving the material of the grinding wheel 23, not only can efficient, high-precision and high-flatness wafer thinning processing be achieved, but it can also meet the needs of various wafer types, such as 3D stacked chips, wafer-level packaged chips or flip chips.

[0043] In one embodiment of this application, the helical calcium carbonate containing the Si-O-Ca structure has the crystal form of spherulite.

[0044] In this application, the helical calcium carbonate containing the Si-O-Ca structure has a spherulitic crystal form. Spherulitic calcium carbonate is an unstable crystal form that will absorb heat during grinding and transform into a stable crystal form, thereby enhancing the thermal stability of the grinding wheel 23 during grinding, ensuring the stability of the ground surface morphology in high-speed grinding, and improving the precision of wafer thinning. The crystal form of the helical calcium carbonate containing the Si-O-Ca structure can be characterized by X-ray diffraction.

[0045] In one embodiment of this application, the average particle size of the helical calcium carbonate containing the Si-O-Ca structure is 1~100 μm, for example, it can be 1 μm, 20 μm, 40 μm, 60 μm, 80 μm, or 100 μm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] In this application, when the average particle size of the spiral calcium carbonate containing the Si-O-Ca structure is 1~100 μm, it can play a role in filling and reinforcing at the microscopic level, and also play a role in the skeleton at the macroscopic level, which is beneficial to further improve the mechanical properties of the grinding block 232 and enhance the stability during the grinding process.

[0047] In one embodiment of this application, such as Figure 7 As shown, the helical calcium carbonate containing the Si-O-Ca structure includes multiple plate-like crystals. These multiple plate-like crystals are arranged in a spiral around the center and adjacent plate-like crystals are partially stacked, so that the helical calcium carbonate containing the Si-O-Ca structure has chiral characteristics and the multiple plate-like crystals can disperse the stress during grinding.

[0048] In this application, the helical calcium carbonate containing a Si-O-Ca structure exhibits chiral characteristics, with the helix direction being either left-handed or right-handed. This chiral helical calcium carbonate containing a Si-O-Ca structure can influence the grinding force distribution between the grinding block 232 and the wafer. Due to its chiral characteristics, the grinding force between the grinding block 232 and the wafer exhibits a certain degree of bias when the grinding wheel 23 rotates. This bias allows the grinding force to be distributed more evenly on the wafer surface, avoiding defects such as wafer microcracks and subsurface damage caused by excessive local grinding force. In the preparation of helical calcium carbonate containing a Si-O-Ca structure using a biomimetic mineral method, the chiral structure can be induced by adjusting the helix direction of the inducing agent.

[0049] In one embodiment of this application, the helical calcium carbonate containing the Si-O-Ca structure is induced by the aminosilanization of aspartic acid from calcium ions. The aminosilanized aspartic acid is prepared by the condensation reaction of aspartic acid-β-methyl ester hydrochloride and an aminosilane coupling agent. The specific method for preparing the helical calcium carbonate containing the Si-O-Ca structure includes the following steps: Aspartic acid-β-methyl ester hydrochloride and an aminosilane coupling agent were condensed together, and the reaction solution was precipitated to obtain aminosilanized aspartic acid. Solution I and solution II were mixed, the pH was adjusted to alkaline, and the reaction was carried out to obtain helical calcium carbonate containing a Si-O-Ca structure; Solution I contains calcium ions, and solution II contains aminosilylated aspartic acid and carbonate ions.

[0050] In this application, aminosilanized aspartic acid was used as an inducer to prepare helical calcium carbonate with a Si-O-Ca structure via a biomimetic mineralization method. The Si-O-Ca structure was characterized by Fourier transform infrared spectroscopy, and the peak of the Si-O-Ca structure was located at 1050 cm⁻¹. -1 ~1100 cm -1 .

[0051] In one embodiment of this application, the preparation method of aspartic acid-β-methyl ester hydrochloride is as follows: aspartic acid is mixed with methanol, thionyl chloride is added dropwise under ice bath, the reaction is carried out, methanol is removed, and aspartic acid-β-methyl ester hydrochloride is obtained.

[0052] In this application, by esterifying and protecting aspartic acid, the interference of carboxyl groups on subsequent condensation reactions can be avoided, thereby effectively improving the purity of the target product, aminosilylated aspartic acid. This provides high-quality raw materials for the preparation of helical calcium carbonate with a Si-O-Ca structure, thus better inducing calcium ions to form helical calcium carbonate with a Si-O-Ca structure in subsequent steps. This fully leverages the synergistic effect of the physical morphology and chemical structure of the helical calcium carbonate with a Si-O-Ca structure, further improving the flatness of the thinned wafer. The aspartic acid can be L-aspartic acid or D-aspartic acid; the mass-to-volume ratio of aspartic acid to methanol is 1~1.2 g:10 mL, for example, 1.1 g:10 mL, 1.15 g:10 mL, or 1.2 g:10 mL; the mass-to-volume ratio of aspartic acid to thionyl chloride is 1~1.2 g:1.5 mL, for example, 1.1 g:1.5 mL, 1.15 g:10 mL, or 1.2 g:1.5 mL; the reaction temperature is 25~30℃, for example, 25℃, 28℃, or 30℃, and the reaction time is 12~14 h, for example, 12 h, 13 h, or 14 h, but it is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0053] In one embodiment of this application, the condensation reaction specifically involves: dissolving aspartic acid-β-methyl ester hydrochloride in N,N-dimethylformamide, adding 1-hydroxybenzotriazole and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, activating the mixture, adding an aminosilane coupling agent and N,N-diisopropylethylamine, and performing a condensation reaction to obtain a reaction solution.

[0054] In this application, by optimizing the amounts of each substance used in the condensation reaction, high-purity and stable aminosilanized aspartic acid can be obtained. This allows for better induction of calcium ions to form helical calcium carbonate with a Si-O-Ca structure in subsequent steps. Furthermore, the synergistic effect of the physical morphology and chemical structure of the helical calcium carbonate with the Si-O-Ca structure is fully utilized to further improve the flatness of the thinned wafer. Within the dosage range of this application, the reaction rate will not be too slow due to low substance concentration, nor will the side reactions increase due to excessively high concentration. The mass-to-volume ratio of aspartic acid-β-methyl ester hydrochloride to N,N-dimethylformamide is 1~1.2 g:15 mL, for example, 1 g:15 mL, 1.1 g:15 mL, or 1.15 g:15 mL; the mass ratio of aspartic acid-β-methyl ester hydrochloride to 1-hydroxybenzotriazole and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1~1.2:1.01:1.44, for example, 1:1.01:1.44, 1.1:1.01:1.44, or 1.2:1.01:1.44; during activation, the mixture is stirred at room temperature for 20~30 min under inert gas protection; the mass-to-volume ratio of aspartic acid-β-methyl ester hydrochloride to aminosilane coupling agent is 1~1.2 g:1.8 mL, for example, 1 g:1.8 mL, 1.1 g:1.8 mL, or 1.15 g:1.44. g: 1.8 mL; the volume ratio of aminosilane coupling agent to N,N-diisopropylethylamine is 1.8~2:1.3, for example, 1.8:1.3, 1.9:1.3, 1.95:1.3, 2:1.3; during the condensation reaction, the reaction is carried out under inert gas protection at room temperature with stirring for 12~14 h, for example, 12 h, 13 h, 14 h, but not limited to the listed values, other unlisted values ​​within the range are also applicable. The aminosilane coupling agent can be any commercially available aminosilane coupling agent, preferably KH-550.

[0055] In one embodiment of this application, the reaction solution, after precipitation, further includes filtration, washing, and reversed-phase high-performance liquid chromatography purification.

[0056] In this application, a series of post-precipitation processing steps ensure the acquisition of high-purity aminosilanized aspartic acid, meeting the stringent requirements of this application for raw materials used in the preparation of helical calcium carbonate containing a Si-O-Ca structure. The specific steps are as follows: the reaction solution after the condensation reaction of aspartic acid-β-methyl ester hydrochloride with an aminosilane coupling agent is added to ice-cold diethyl ether to precipitate the product. The precipitate is filtered, and the solid is collected to obtain the crude product. The crude product is washed with diethyl ether, purified by reversed-phase high-performance liquid chromatography, and the target product is collected, lyophilized, and then obtained as aminosilanized aspartic acid.

[0057] In one embodiment of this application, the molar ratio of aminosilyl aspartic acid to calcium ions is 0.8 to 1.5:1, for example, it can be 0.8:1, 0.9:1, 1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0058] In this application, by controlling the molar ratio of aminosilylaspartic acid to calcium ions to 0.8~1.5:1, calcium carbonate is induced to oriented and form a helical morphology. Through the stress dispersion effect of the helical morphology, the grinding force distribution during grinding is made more uniform, reducing the thickness fluctuation of the wafer surface caused by uneven stress. When the molar ratio of aminosilylaspartic acid to calcium ions is in the range of 0.8~1.5:1, it can avoid the accelerated nucleation rate of calcium carbonate due to excessive calcium ions, which would make it impossible to control the growth orientation and destroy the helical structure due to disordered growth direction. It can also avoid the interference of excessive aminosilylaspartic acid with the orientation growth of calcium carbonate, which would reduce the regularity of the helical structure.

[0059] In one embodiment of this application, the molar ratio of carbonate ions to calcium ions is 2 to 3:3, for example, it can be 2:3, 2.2:1, 2.5:3, 2.8:1, 1:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The calcium ions in solution I can be derived from calcium nitrate or calcium chloride, preferably calcium nitrate. The carbonate ions in solution II can be derived from potassium carbonate or sodium carbonate, preferably potassium carbonate.

[0060] In this application, by adjusting the molar ratio of carbonate ions in solution II to calcium ions in solution I to 2~3:3, the formation rate of calcium carbonate crystals is controlled, thereby obtaining spiral calcium carbonate with a relatively concentrated particle size distribution containing Si-O-Ca structure. This avoids uneven grinding force caused by excessive particle size difference and reduces the flatness deviation of the wafer after thinning.

[0061] In one embodiment of this application, when adjusting the pH value to alkaline, the pH value is adjusted to 8-9, for example, 8, 8.5, or 9, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0062] In this application, adjusting the pH value to 8-9 helps to optimize the formation process of calcium carbonate crystal nuclei, so that the degree of hydrolysis of carbonate ions is moderate. This avoids excessive hydrolysis, which would cause too drastic changes in the ion concentration in the solution and affect the stability of the crystal nuclei, while also preventing insufficient hydrolysis, which would slow down the formation rate of the crystal nuclei.

[0063] In one embodiment of this application, the reaction is carried out by static incubation at room temperature for 4 to 6 hours, for example, 4 hours, 5 hours, or 6 hours, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0064] In this application, the static culture reaction time at room temperature is 4-6 h. Under these conditions, on the one hand, sufficient time is provided for the growth of calcium carbonate crystals, and on the other hand, the template modification effect of aminosilanized aspartic acid is more complete, thereby obtaining a good spiral morphology. Then, the stress dispersion effect of the spiral morphology is fully utilized during the grinding process, improving the flatness of the thinned wafer.

[0065] In one embodiment of this application, the abrasive includes one or more of corundum, silicon carbide, boron carbide, diamond, and boron nitride, preferably diamond. Diamond has extremely high wear resistance and sharpness, enabling it to grind materials rapidly. Furthermore, its high thermal conductivity and good stability allow for rapid heat dissipation, effectively reducing the temperature in the grinding area, and it is less prone to chemical reactions, making it particularly suitable for high-precision wafer thinning processes. The average particle size of the abrasive is 10~100 μm, for example, 10 μm, 40 μm, 70 μm, or 100 μm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0066] In one embodiment of this application, the resin includes one or more of phenolic resin, polyimide resin, and epoxy resin, preferably phenolic resin. Phenolic resin has high heat resistance and bonding properties, can withstand relatively high grinding temperatures without softening or decomposition, and firmly binds the particles together, allowing the grinding block 232 to maintain structural integrity under high-speed rotation and grinding forces, which is beneficial for improving the accuracy of wafer thinning. The flowability of the phenolic resin at 125°C can be 10~20 mm, for example, 10 mm, 15 mm, or 20 mm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The resin is added in powder form, and the average particle size of the resin can be 10~40 μm, for example, 10 μm, 20 μm, 30 μm, or 40 μm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0067] In one embodiment of this application, the pore-forming agent includes one or more of polymer microspheres, carbonates, and metal hydroxides, preferably polymer microspheres, and more preferably polymethyl methacrylate microspheres. Polymer microspheres typically have a regular spherical shape and a relatively uniform particle size distribution, enabling uniform dispersion and relatively stable chemical properties. Due to the uniform particle size and good dispersion of the polymer microspheres, the resulting pores also exhibit high uniformity and regularity. This uniform pore structure facilitates the uniform penetration of coolant into the grinding block 232, ensuring sufficient cooling of all parts of the grinding area, reducing grinding temperature, and minimizing wafer damage caused by thermal stress. The average particle size of the pore-forming agent can be 20~100 μm, for example, 20 μm, 40 μm, 60 μm, 80 μm, or 100 μm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0068] In one embodiment of this application, the grinding apparatus 2 includes: The feeding assembly is lifted and connected above the adsorption platform 3; The rotating shaft 22 is driven by the feed assembly to move up and down, and the grinding wheel 23 is connected to the lower end of the rotating shaft 22.

[0069] In this application, the feed assembly and the rotary axis 22 work together to ensure the flatness of the wafer surface during grinding. The feed assembly provides a stable vertical feed path for the rotary axis 22 to drive the grinding wheel 23; the rotary axis 22 can control the radial runout to a very small range, ensuring that the grinding wheel 23 maintains uniform contact with the wafer surface throughout the rotation process. The coordinated operation of the feed assembly and the rotary axis 22 results in a thinned wafer with good flatness.

[0070] In one embodiment of this application, the adsorption platform 3 includes: The worktable 32 has a chuck spindle 31 at the bottom, which drives the worktable 32 to rotate. The adsorption disk 33 is set on the worktable disk 32 and is used to adsorb the wafer. The adsorption disk 33 can drive the wafer to rotate synchronously under the action of the worktable disk 32.

[0071] In this application, during the actual operation of the wafer thinning equipment, the chuck spindle 31, the worktable 32, and the adsorption disk 33 work together to provide stable adsorption for the grinding wheel 23 to grind the wafer. The chuck spindle 31 controls the rotation speed and direction of the worktable 32, which in turn stably drives the adsorption disk 33 and the wafer to rotate synchronously. The adsorption disk 33 always firmly adsorbs the wafer, ensuring that the wafer maintains a stable position even under high-speed rotation. This synergistic effect prevents poor wafer surface flatness caused by wafer displacement during grinding.

[0072] In another embodiment of this application, the wafer thinning equipment may include multiple adsorption platforms 3, which are used to adsorb different wafers. The multiple adsorption platforms 3 are installed on the same rotating disk 4 and are spaced apart in the circumferential direction of the rotating disk 4. The rotating disk 4 can drive the different adsorption platforms 3 to rotate below the grinding device 2, thereby grinding the corresponding wafers.

[0073] like Figure 1 The wafer thinning equipment shown includes three adsorption platforms 3, which are circumferentially spaced on a rotating disk 4. Simultaneously, two grinding devices 2 are provided: one for rough grinding of the wafer and the other for fine grinding. The rotating disk 4 can drive the adsorption platforms 3 to rotate, allowing for sequential rough and fine grinding of the wafers on the same adsorption platform 3, thus improving the wafer grinding efficiency.

[0074] According to another aspect of this application, this application also proposes a wafer thinning method, which uses the above-mentioned wafer thinning equipment to perform wafer thinning processing.

[0075] In one embodiment of this application, such as Figure 3 As shown, the wafer thinning method may include the following steps: A100. The wafer is adsorbed and fixed on the adsorption platform 3; A200, driving the grinding wheel 23 to move down until it contacts the wafer; A300, the grinding wheel 23 and the adsorption platform 3 rotate in the same direction, while the grinding wheel 23 is fed downward. The rotation speed of the grinding wheel 23 is greater than the rotation speed of the adsorption platform 3, so as to grind the wafer. A400. When the wafer is ground to the target thickness, stop the rotation of the grinding wheel 23 and the adsorption platform 3, and move the grinding wheel 23 upward to separate it from the wafer. A500, removes the adsorption of the wafer and transfers the wafer.

[0076] In this application, the thinning method enables precise wafer thinning. First, the wafer is adsorbed onto the adsorption platform 3 to ensure stable positioning during processing, providing a stable foundation for subsequent processes. Then, the feed assembly drives the grinding wheel 23 downward until it contacts the wafer, achieving precise initiation of the grinding operation. During the grinding stage, the grinding wheel 23 and the adsorption platform 3 rotate in the same direction, with the grinding wheel 23 rotating at a higher speed than the adsorption platform 3. Simultaneously, the grinding wheel 23 continues to feed downward. Through the coordinated control of the speed difference and feed amount, the wafer is ground. When the wafer thickness reaches the target value, the rotation of the grinding wheel 23 and the adsorption platform 3 is immediately stopped, and the feed assembly drives the grinding wheel 23 upward to detach from the wafer, avoiding over-processing. Finally, the adsorption force of the adsorption platform 3 on the wafer is released, and the wafer transfer is completed, forming a closed loop in the entire process.

[0077] The key to the entire process is: First, by positioning the adsorption platform 3 and controlling the feed of the grinding wheel 23, the wafer is ensured to be subjected to uniform force during the thinning process, which effectively improves the flatness and processing accuracy of the wafer; Second, the design of rotation in the same direction and speed difference reduces stress concentration during the grinding process, reduces the risk of wafer damage, and improves product yield; Third, the fully automated operation improves processing efficiency and stability, making it suitable for large-scale production scenarios.

[0078] By using the grinding wheel 23 of this application for wafer thinning, the spiral calcium carbonate structure in the grinding block 232 can evenly distribute the grinding force, avoiding localized damage to the grinding block 232 caused by localized stress concentration, thereby avoiding uneven grinding or scratching of the wafer; in addition, the spiral calcium carbonate containing Si-O-Ca structure in the grinding block 232 can enhance the adhesion and stability of the internal structure of the grinding block 232, reduce the occurrence of breakage and cracking of the grinding block 232, extend the service life of the grinding wheel 23, and improve the wafer grinding efficiency and grinding quality.

[0079] In one embodiment of this application, in step A300, the rotational speed of the grinding wheel 23 is 4000~6000 rpm, and the rotational speed of the adsorption platform 3 is 200~400 rpm. The rotational speed of the grinding wheel 23 can be, for example, 4000 rpm, 5000 rpm, or 6000 rpm; the rotational speed of the adsorption platform 3 can be, for example, 200 rpm, 300 rpm, or 400 rpm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0080] In this application, the high-speed differential rotation of the grinding wheel 23 and the adsorption platform 3, in conjunction with their co-rotation, ensures that the contact trajectory between the grinding wheel 23 and the wafer surface is continuously spirally distributed, avoiding thickness deviations caused by localized repeated grinding and helping to keep the total thickness deviation of the wafer after thinning stable at a low level. On the other hand, it reduces the reverse impact of the grinding wheel 23 on the wafer surface. Combined with the continuous grinding characteristics of high speed, it can reduce the instantaneous grinding force, reduce lattice distortion and microcrack generation, and help to keep the subsurface damage of the wafer after thinning stable at a low level.

[0081] In one embodiment of this application, in step A300, the downward feed rate is 2~6 μm / s, for example, it can be 2 μm / s, 4 μm / s, or 6 μm / s, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0082] In this application, the grinding wheel 23 is fed downwards at a speed of 2~6 μm / s while rotating, which enables uniform grinding layer by layer, effectively controlling the total thickness deviation of the thinned wafer and avoiding local over-grinding or thickness fluctuations caused by excessive feed rate. Furthermore, the relatively low feed rate reduces the amount of grinding per unit time, and combined with co-rotation, it reduces instantaneous grinding stress and impact, decreases lattice defects and microcracks, and helps control the subsurface damage depth at a low level.

[0083] This application also proposes a grinding wheel, including a substrate 231 and a grinding block 232 disposed on the surface of the substrate 231 for grinding wafers, the grinding block 232 comprising: Matrix 2321; Abrasive particles 2322 and calcium carbonate particles 2323 are distributed in the matrix 2321; The calcium carbonate particles 2323 include multiple plate-like crystals, which are arranged in a spiral around the center of the calcium carbonate particles 2323 and adjacent plate-like crystals are partially stacked. The multiple plate-like crystals are used to disperse the stress during grinding. The surface of calcium carbonate particles 2323 contains a Si-O-Ca structure, which is used to enhance the interfacial bonding between calcium carbonate particles 2323 and the matrix 2321.

[0084] In this application, the structural diagram of the grinding wheel is as follows: Figure 4 As shown. The substrate 231 provides a good support base for the grinding block 232, which can withstand the grinding force generated by the grinding block 232 during the grinding process, ensure the stability of the grinding block 232 when rotating at high speed, and ensure that the grinding block 232 will not deform due to the force, so that the grinding wheel 23 can continuously and stably perform wafer grinding.

[0085] The structural schematic diagram of grinding block 232 is as follows: Figure 5 As shown, the internal structure of the grinding block 232 includes a matrix 2321 and abrasive grains 2322 and calcium carbonate particles 2323 distributed therein. The matrix 2321 is a resin matrix with good bonding properties, which can firmly bond the abrasive grains 2322 and calcium carbonate particles 2323 together, so that the grinding block 232 can maintain the integrity of its internal structure and achieve optimal grinding performance during high-speed grinding.

[0086] The abrasive grains 2322 can continuously grind the wafer. Their uniform distribution in the grinding block 232 can ensure the uniformity of the grinding force and guarantee the consistency of the grinding thickness during the wafer thinning process, thereby improving the flatness of the wafer after thinning.

[0087] Calcium carbonate particles 2323 possess a physical helical structure and a chemical Si-O-Ca structure. The helical structure provides stress buffering, as illustrated in Figure 6. The black arrows represent the grinding force transmitted to the calcium carbonate particles 2323, while the gray arrows represent the force dispersed through the helical structure. Figure 6 It can be seen that the spiral structure can uniformly disperse locally concentrated stress. This stress buffering mechanism can dynamically adjust the stress distribution during the grinding process, suppress force fluctuations during grinding, avoid wafer microcracks and subsurface damage, and improve the flatness of the thinned wafer. The Si-O-Ca structure can enhance the interfacial bonding between inorganic calcium carbonate particles 2323 and resin matrix 2321, reduce particle shedding during high-speed grinding, and extend the service life of grinding wheel 23. Figure 6 The diagram is merely a schematic representation of a spiral structure. Each rectangular bar may represent a plate-like crystal. However, it should be understood that in alternative embodiments, calcium carbonate particles 2323 may include more or fewer plate-like crystals, and calcium carbonate particles 2323 may also not have plate-like crystals, but rather have multiple wing-shaped crystals with varying thicknesses, or have a continuous, non-layered or non-plate-like crystal structure.

[0088] In one embodiment of this application, the grinding block 232 further includes pores 2324 distributed in the substrate 2321.

[0089] Figure 5 The pores 2324 shown are obtained by the decomposition or volatilization of a pore-forming agent. Pores 2324 provide a flow channel for the coolant, allowing it to flow rapidly within the grinding block 232 during grinding, effectively removing heat generated during grinding, reducing the impact of thermal stress on wafer grinding, and ensuring the quality of the thinned wafer. Furthermore, pores 2324 allow grinding debris to be discharged from the grinding area, preventing debris accumulation between the grinding block 232 and the wafer, reducing the risk of wheel clogging, and improving grinding efficiency and wheel lifespan.

[0090] In one embodiment of this application, such as Figure 6 and Figure 7 The calcium carbonate particle 2323 comprises multiple plate-like crystals arranged in a spiral around the center of the calcium carbonate particle 2323, with adjacent plate-like crystals partially stacked to form a helical structure with chiral characteristics. In this paper, "chiral characteristics" can be understood as the asymmetric property that the helical structure of the calcium carbonate particle 2323 and its mirror image cannot be completely superimposed through rotation or translation. For example, when there are fewer plate-like crystals, it can be understood as the shape of a fan blade.

[0091] In this application, the multiple lamellar crystal structures of calcium carbonate particles 2323 can disperse the stress during grinding, and the spirally stacked lamellar structures give the calcium carbonate particles 2323 multiple spiral gaps, which can be understood as surface roughness. This can enhance the mechanical anchoring effect with the matrix 2321, further improve the interfacial bonding between the calcium carbonate particles 2323 and the matrix 2321, reduce the risk of particle detachment during high-speed grinding, and extend the service life of the grinding wheel 23.

[0092] In one embodiment of this application, a plurality of grinding blocks 232 are provided on the surface of the substrate 231, and the plurality of grinding blocks 232 are distributed at intervals along the circumferential direction of the substrate 231.

[0093] In this application, the multiple grinding blocks 232 spaced apart circumferentially along the substrate 231 form a chip removal channel. When the grinding wheel 23 rotates at high speed, the spaced areas can quickly guide the grinding debris, preventing debris from accumulating between the grinding blocks 232 and the wafer, thus avoiding secondary scratches or localized compression damage to the wafer. This helps maintain the stability of the subsurface damage depth of the wafer after thinning. At the same time, the spaced areas increase airflow, accelerate the dissipation of grinding heat, reduce wafer thermal deformation caused by localized overheating, and ensure precise control of the total thickness deviation of the wafer after thinning.

[0094] In one embodiment of this application, an annular groove is provided on the surface of the substrate 231, and one end of the grinding block 232 is embedded in the annular groove.

[0095] In this application, an annular groove is provided on the surface of the substrate 231 to provide radial and axial dual constraints for the grinding block 232. This effectively avoids displacement or vibration of the grinding block 232 due to centrifugal force during high-speed rotation, ensuring the consistency of the grinding trajectory of the grinding wheel 23 and helping to reduce the overall thickness deviation of the wafer after thinning. In addition, embedding one end of the grinding block 232 into the annular groove allows for a tighter bond between the grinding block 232 and the substrate 231, reducing stress loss during the grinding process, ensuring that the grinding force is applied evenly to the wafer surface, reducing the risk of local over-grinding, and preventing scratches on the wafer surface due to loosening of the grinding block 232, thus helping to reduce subsurface damage to the wafer after thinning.

[0096] In one embodiment of this application, the shape of the grinding block 232 includes a rounded rectangle or a sector.

[0097] In this application, the shape of the grinding block 232 includes a rounded rectangle or a fan shape. When the shape of the grinding block 232 is a rounded rectangle, the rounded corners can reduce local stress concentration during grinding and avoid scratches or chipping on the wafer surface. When the shape of the grinding block 232 is a fan shape, the arc-shaped edges can make the contact between the abrasive grains 2322 and the wafer gradually transition, reducing the impact on the wafer.

[0098] According to another aspect of this application, this application also proposes a method for preparing the above-mentioned grinding wheel, comprising the following steps: B100: The abrasive, pore-forming agent and spiral calcium carbonate containing Si-O-Ca structure are ball-milled once, then resin is added and ball-milled a second time to obtain a mixture; B200, after being hot-pressed and cured, produces grinding block 232; B300 and grinding block 232 are placed on the surface of substrate 231 to obtain grinding wheel 23.

[0099] The preparation method of this application is simple and easy to industrialize. The two-stage ball milling process can avoid performance fluctuations of the grinding wheel 23 due to uneven composition, promote a more uniform distribution of grinding force during wafer thinning, avoid wafer microcracks and subsurface damage, and improve the stability of wafer flatness after thinning.

[0100] In one embodiment of this application, in step B100, the ball milling time is 2-3 hours, the rotation speed is 250-300 rpm, and the ball-to-material ratio is 3-6:1.

[0101] In this application, by optimizing the time, rotation speed, and ball-to-material ratio of a single ball milling operation, the collisional dispersion effect of the abrasive, pore-forming agent, and helical calcium carbonate containing the Si-O-Ca structure can be ensured. This is beneficial for enhancing the structural stability inside the grinding block 232 during subsequent preparation processes, thereby enabling the wafer thinning process to achieve higher precision. For a single ball milling operation, the time can be 2 h, 2.5 h, or 3 h; the rotation speed can be 250 rpm, 280 rpm, or 300 rpm; and the ball-to-material ratio can be 3:1, 4:1, 5:1, or 6:1, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0102] In one embodiment of this application, during step B100, the secondary ball milling process takes 2-3 hours, rotates at 250-300 rpm, and has a ball-to-material ratio of 3-6:1. In this application, by optimizing the time, rotation speed, and ball-to-particle ratio of the secondary ball milling, the uniform wetting of the resin can be improved, ensuring that the resin gradually penetrates into the tiny gaps between the particles, forming a stable bonding bridge. This uniform wetting strengthens the adhesion between the resin and other components, ensuring the stability of the internal structure of the grinding block 232 during subsequent hot pressing and use, thereby guaranteeing the grinding performance and service life of the grinding wheel 23. During the secondary ball milling, the time can be 2 h, 2.5 h, or 3 h; the rotation speed can be 250 rpm, 280 rpm, or 300 rpm; and the ball-to-particle ratio can be 3:1, 4:1, 5:1, or 6:1, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0103] In one embodiment of this application, during hot pressing in step B200, the temperature is 185~205℃, the pressure is 10~70 MPa, and the holding time is 30~80 min.

[0104] In this application, by optimizing the process parameters of hot pressing, the uniformity of the overall structure and performance of the grinding block 232 is ensured, avoiding differences in density and porosity distribution in different parts, thereby improving the grinding performance and service life of the grinding wheel 23. During hot pressing, the temperature can be 185℃, 190℃, or 205℃; the pressure can be 10 MPa, 40 MPa, or 70 MPa; and the holding time can be 30 min, 60 min, or 80 min, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0105] In one embodiment of this application, during step B200, the curing process involves preheating at 80-100°C for 2-3 hours, followed by raising the temperature to 225-255°C and holding for 4-6 hours.

[0106] In this application, by optimizing the process parameters during curing, the resin can be deeply cross-linked and cured, and the stability of the pore structure can be improved, thereby enhancing the overall performance of the grinding block 232 and ensuring good reliability of the grinding wheel 23 during high-speed rotation and grinding. During curing, the process can involve preheating at 80°C for 3 hours followed by raising the temperature to 225°C and holding for 6 hours, or preheating at 100°C for 2 hours followed by raising the temperature to 255°C and holding for 4 hours. However, this is not limited to the listed cases; other unlisted cases within the range of temperature and time values ​​are also applicable.

[0107] The wafer thinning apparatus and method described below will be presented in detail with reference to examples. The embodiments described below according to this application can be modified in various ways; therefore, the scope of this application should not be construed as limited to the embodiments described in detail below. The embodiments are provided to help those skilled in the art more easily understand this application.

[0108] Unless otherwise specified, in the following examples and comparative examples, the average particle size of diamond micropowder is 50 μm; the phenolic resin powder has a flowability of 15 mm and an average particle size of 40 μm at 125°C; and the average particle size of polymethyl methacrylate microspheres is 50 μm.

[0109] Example 1 like Figure 1 and Figure 2The wafer thinning equipment shown includes a substrate 1, on which a rotating disk 4 is mounted. Above the rotating disk 4 are multiple adsorption platforms 3 spaced apart along the circumference. The rotating disk 4 can rotate around its central axis to change the position of the adsorption platforms 3, so that the wafers supported by the adsorption platforms 3 can switch between rough grinding station, fine grinding station and loading / unloading station.

[0110] The end of the equipment base 1 is equipped with an upright support, and two grinding devices 2 are arranged on the side of the support. One is a rough grinding part and the other is a fine grinding part. The two have similar structures and are equipped with a feed assembly (not shown) that drives the grinding wheel 23 to move up and down and a mechanism that drives the grinding wheel to rotate along the rotating shaft 22. The feed assembly includes a lifting motor (not shown), which is slidably connected to the housing of the rotating shaft through a lead screw. The housing is slidably connected to the side of the column so that the rotation of the lifting motor realizes the vertical movement of the rotating shaft 22, thereby changing the position of the grinding wheel 23 relative to the adsorption platform 3.

[0111] The adsorption platform 3 supports the wafer and drives it to rotate. The grinding device 2 is raised and lowered above the adsorption platform 3. The lower part of the grinding device 2 has a grinding wheel 23 that can rotate circumferentially to grind the wafer. The grinding wheel includes helical calcium carbonate with a Si-O-Ca structure to disperse stress during grinding.

[0112] The grinding apparatus 2 includes a feed assembly, a rotary shaft 22, and a grinding wheel 23. The grinding block 232 in the grinding wheel 23 is used to grind the wafer. The grinding wheel 23 may be a cup-shaped grinding wheel, mounted at the lower end of the rotary shaft 22. The rotary shaft 22 is used to rotate the grinding wheel 23 about its axis of rotation. The feed assembly can drive the rotary shaft 22 and the grinding wheel 23 to move up and down synchronously. When the wafer needs grinding, the grinding wheel 23 moves down to its bottom surface and contacts the wafer under the drive of the feed assembly. At this time, both the grinding wheel 23 and the wafer are rotating in the same direction but at different speeds, and the grinding wheel 23 is used to grind the wafer. The feed assembly has a known structure and includes, for example, multiple linear guides that guide the movement direction of the rotary shaft 22 and a ball screw-slider mechanism that moves the rotary shaft 22 up and down.

[0113] The grinding wheel 23 includes a plurality of grinding blocks 232, which can be rounded rectangles, fan shapes, or other shapes suitable for grinding wafers and facilitating the removal of grinding debris. At least a portion of these grinding blocks 232 are embedded in an annular groove and spaced apart from each other on the substrate 231. The substrate 231 can be fastened to the lower end of the rotating shaft 22 by bolts.

[0114] The adsorption platform 3 has a chuck spindle 31, a worktable 32, and an adsorption disk 33. The chuck spindle 31 moves along the axis of rotation. The adsorption disk 33, made of a porous material such as alumina, is embedded in the upper surface of the worktable 32. The adsorption platform 3 has a conduit that penetrates its interior and extends to its surface. The conduit is connected to a vacuum source, a compressed air source, or a water supply source via a rotary joint. When the vacuum source is activated, the wafer placed on the adsorption platform 3 is adsorbed by the adsorption disk 33. Conversely, when the compressed air source or water supply source is activated, the adsorption between the wafer and the adsorption disk 33 is released. The adsorption platform 3 may be equipped with a tilting device that tilts relative to the grinding wheel 23, or the grinding device 2 may be equipped with a tilting structure that tilts the rotation axis 22. This allows adjustment of the contact between the grinding block 232 and the wafer to grind the wafer into the desired shape.

[0115] The operation of the grinding device 2 is controlled by a control device. The control device controls each component of the grinding device 2. The control device includes, for example, a CPU and a memory. Furthermore, the function of the control device can be implemented through software control or through hardware operation. For example, the control device can control the movement of the feed assembly, the rotary axis 22, and the chuck spindle 31 according to preset grinding process parameters, such as feed rate and rotational speed, to achieve an automated grinding process. Simultaneously, the control device also has fault diagnosis and alarm functions, capable of monitoring the operating status of each part of the equipment in real time, issuing alarms promptly and taking corresponding protective measures when abnormalities occur, ensuring the safety of the equipment and operators.

[0116] Example 2 The wafer thinning method, using the wafer thinning equipment of Example 1, includes the following steps: A100, The wafer is adsorbed and fixed on the adsorption platform 3.

[0117] A110. Preparation: Before performing wafer thinning operation, ensure that the surface of the adsorption platform 3 is clean and free of impurities to avoid impurities affecting the adsorption effect and grinding quality of the wafer. You can use a lint-free cloth dipped in an appropriate amount of alcohol to wipe and clean the surface of the adsorption platform 3.

[0118] A120. Place the wafer: Using a vacuum pen or other precision gripping tool, place the wafer to be thinned on the adsorption platform 3, ensuring that the center of the wafer is aligned with the center of the adsorption platform 3.

[0119] A130. Initiating Vacuum Adsorption: The vacuum source connected to the adsorption platform 3 is activated via the control device. The porous structure inside the adsorption platform 3 creates a negative pressure under vacuum, adsorbing the wafer onto its surface. To ensure strong adsorption, the vacuum level of the adsorption platform 3 can be monitored in real time via the control device. When the vacuum level reaches the preset value, it indicates that the wafer has been stably adsorbed and the next step can be performed.

[0120] A200, driving the grinding wheel 23 down to contact the wafer.

[0121] A210. Parameter setting: Input the target position parameter for the movement of the grinding wheel 23 into the control device. This parameter is determined based on factors such as the thickness of the wafer, the grinding allowance, and the initial position of the grinding wheel 23.

[0122] A220. Start the feed assembly: The control device sends a command to the feed assembly to precisely control its movement direction, ensuring it moves vertically downwards. The feed assembly drives the grinding wheel 23 to move smoothly downwards at a set speed. During the movement, the control device monitors the position information of the feed assembly in real time and compares it with the preset target position. When it approaches the target position, the feed speed is reduced to achieve precise alignment.

[0123] A300, the grinding wheel 23 and the adsorption platform 3 rotate in the same direction, while the grinding wheel 23 is fed downward. The rotation speed of the grinding wheel 23 is greater than the rotation speed of the adsorption platform 3, so as to grind the wafer.

[0124] A310, Rotary Start: The control device simultaneously starts the grinding wheel 23 and the adsorption platform 3. The grinding wheel 23 rotates at a high speed at a set speed, while the adsorption platform 3 and the wafers adsorbed on it rotate in the same direction at a relatively low speed.

[0125] A320. Grinding: After the grinding wheel 23 and the adsorption platform 3 reach a stable rotation state, the control device continues to control the feed assembly, causing the grinding wheel 23 to feed onto the wafer. During the feeding process, a pressure sensor mounted on the grinding wheel 23 monitors the contact pressure between the grinding wheel 23 and the wafer in real time and feeds it back to the control device. When the pressure reaches a preset value, such as 5 N, the control device stops the feeding action of the feed assembly to ensure that the grinding wheel 23 and the wafer maintain a suitable grinding pressure, which ensures the grinding effect while avoiding excessive pressure that could damage the wafer. Once the grinding wheel 23 and the wafer are adjusted to a suitable grinding pressure, the grinding wheel 23 and the adsorption platform 3 continue to rotate, and the grinding block 232 of the grinding wheel 23 grinds the surface of the wafer.

[0126] Grinding Parameter Monitoring and Adjustment: During the grinding process, the control device monitors several key parameters in real time, such as the rotational speed of the grinding wheel 23, the rotational speed of the adsorption platform 3, the grinding pressure, and the grinding time. These parameter information is collected in real time by sensors installed in key parts of the wafer thinning equipment, such as speed sensors, pressure sensors, and thickness sensors, and fed back to the control device. The control device dynamically adjusts the grinding process based on the preset grinding process model and the actual collected parameter data.

[0127] A400. When the wafer is ground to the target thickness, stop the rotation of the grinding wheel 23 and the adsorption platform 3, and move the grinding wheel 23 upward to separate it from the wafer.

[0128] A410. Thickness Detection and Judgment: A non-contact thickness sensor installed near the grinding wheel 23 continuously monitors the thickness changes of the wafer and feeds back the real-time thickness data to the control device. When the control device receives thickness data showing that the wafer has been ground to the target thickness, it determines that the grinding is complete.

[0129] A420. Stopping Rotation and Separating the Grinding Wheel: The control device immediately issues a command to stop the rotation of the grinding wheel 23 and the adsorption platform 3. Subsequently, the control device activates the feed assembly to move the grinding wheel 23 upward at a set speed, so that the grinding wheel 23 is quickly separated from the wafer, avoiding unnecessary damage caused by prolonged contact between the grinding wheel 23 and the wafer surface after it stops rotating.

[0130] A500, removes the adsorption of the wafer and transfers the wafer.

[0131] A510. Gas Source Switching: The control device shuts off the vacuum source and switches to either a compressed air source or a water source, depending on the actual process. Compressed air or water enters the adsorption platform 3, disrupting the negative pressure between the adsorption platform 3 and the wafer, thereby releasing the adsorption force.

[0132] A520. Wafer Removal: Using a vacuum pen or other precision gripping tools, the thinned wafer is removed from the adsorption platform 3, completing the entire wafer thinning process.

[0133] Example 3 The method for preparing a grinding wheel includes the following steps: B000, a method for preparing helical calcium carbonate containing a Si-O-Ca structure, comprising the following steps: 1.2 g of aspartic acid-β-methyl ester hydrochloride was dissolved in 15 mL of anhydrous N,N-dimethylformamide, and 1.01 g of 1-hydroxybenzotriazole and 1.44 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was activated by stirring at room temperature for 30 min under argon protection. Then, 1.8 mL of aminosilane coupling agent (model KH-550) and 1.3 mL of N,N-diisopropylethylamine were added. The mixture was stirred at room temperature for 12 h under argon protection to obtain a reaction solution. The reaction solution was added dropwise to ice-cold diethyl ether, and a precipitate was formed. The precipitate was filtered, and the solid was collected to obtain the crude product. The crude product was washed with diethyl ether to remove residual solvent and reaction byproducts. The product was purified by reversed-phase high-performance liquid chromatography, and the target product was collected and lyophilized to obtain aminosilanized aspartic acid. The preparation method of aspartic acid-β-methyl ester hydrochloride is as follows: 1 g of L-aspartic acid is mixed with 10 mL of anhydrous methanol, 1.5 mL of thionyl chloride is added dropwise under an ice bath at 0 °C, the temperature is raised to 25 °C, the reaction is stirred for 12 h, and methanol is removed by rotary evaporation to obtain aspartic acid-β-methyl ester hydrochloride. According to the molar ratio of aminosilyl aspartic acid in solution II to calcium ions in solution I of solution I being 1:1, 0.1 mol / L calcium nitrate solution I and mixed solution II containing 0.15 mol / L aminosilyl aspartic acid and 0.1 mol / L potassium carbonate were mixed, the pH was adjusted to 8.5, and the reaction was statically incubated at room temperature for 4 h. The precipitate in the reaction solution was filtered, washed with deionized water and anhydrous ethanol in sequence, and dried to obtain helical calcium carbonate containing Si-O-Ca structure. B100, by weight, 45 parts of diamond micro powder, 5 parts of polymethyl methacrylate microspheres and 12 parts of spiral calcium carbonate containing Si-O-Ca structure are sequentially added to a ball mill and ball-milled once (time 2 h, ball-to-material ratio 5:1, speed 300 rpm). Then, 38 parts of phenolic resin powder are added and ball-milled a second time (time 2 h, ball-to-material ratio 5:1, speed 300 rpm). After ball milling and leveling, a mixture is obtained. B200. Place the mixture into a mold and hot press it into shape (hot pressing temperature is 185℃, heating rate is 10℃ / min, pressure is 70 MPa, and holding time is 80 min). Let it cool naturally to room temperature, and then place it in a hardening oven to cure (when curing, preheat at 80℃ for 3 h, then heat to 225℃ at a heating rate of 10℃ / min and hold for 6 h). After natural cooling, take it out to obtain the grinding block. B300 grinding blocks are bonded and assembled onto an aluminum substrate. After end face and outer circle correction and sharpening, as well as dynamic balancing, a grinding wheel is obtained. The helical calcium carbonate containing the Si-O-Ca structure is levorotatory, with a spherulitic crystal form and an average grain size of 20 μm. SEM images are shown below. Figure 7 As shown, the XRD pattern is as follows Figure 8 As shown, the infrared spectrum is as follows Figure 9 As shown in the figure. Infrared spectroscopy reveals that the helical calcium carbonate possesses a Si-O-Ca structure.

[0134] Example 4 The only difference between this embodiment and Example 3 is that in preparing aspartic acid-β-methyl ester hydrochloride, L-aspartic acid is replaced with an equal amount of D-aspartic acid, resulting in right-handed spiral calcium carbonate containing a Si-O-Ca structure. The SEM image is shown below. Figure 10 As shown, a magnified view of a portion of the spiral layer is as follows: Figure 11 As shown, by Figure 11 It can be seen that the surface of the spiral layer has a plate-like crystal structure.

[0135] Example 5 The only difference between this embodiment and Embodiment 3 is that, in this embodiment, the weight of phenolic resin powder is 34 parts and the weight of spiral calcium carbonate containing Si-O-Ca structure is 16 parts when preparing the grinding wheel.

[0136] Example 6 The only difference between this embodiment and embodiment 3 is that, in this embodiment, when preparing the grinding wheel, the weight parts of phenolic resin powder are 42 parts, the weight parts of spiral calcium carbonate containing Si-O-Ca structure are 8 parts, and the weight parts of polymethyl methacrylate microspheres are 2 parts. When preparing helical calcium carbonate with a Si-O-Ca structure, the molar ratio of aminosilylated aspartic acid to calcium ions is 0.8:1.

[0137] Example 7 The only difference between this embodiment and embodiment 3 is that, in this embodiment, when preparing the grinding wheel, the weight parts of phenolic resin powder are 46 parts, the weight parts of spiral calcium carbonate containing Si-O-Ca structure are 4 parts, and the weight parts of polymethyl methacrylate microspheres are 10 parts. When preparing helical calcium carbonate with a Si-O-Ca structure, the molar ratio of aminosilylated aspartic acid to calcium ions is 1.5:1.

[0138] Comparative Example 1 The only difference between Comparative Example 1 and Example 3 is that, in this comparative example, the helical calcium carbonate containing the Si-O-Ca structure is replaced with an equal amount of helical calcium carbonate. The preparation method of helical calcium carbonate is as follows: A 0.1 mol / L calcium nitrate solution I and a mixed solution II containing 0.15 mol / L L-aspartic acid and 0.1 mol / L potassium carbonate were mixed according to a 1:1 molar ratio of L-aspartic acid in solution II to calcium ions in solution I. The pH was adjusted to 8.5, and the mixture was statically incubated at room temperature for 4 h. The precipitate in the reaction solution was filtered, washed successively with deionized water and anhydrous ethanol, and dried to obtain helical calcium carbonate. The SEM image is shown below. Figure 12 As shown.

[0139] Comparative Example 2 The only difference between this comparative example and Example 3 is that, in this comparative example, the helical calcium carbonate containing the Si-O-Ca structure is replaced with an equal amount of spherical calcium carbonate I containing the Si-O-Ca structure; The preparation method of spherical calcium carbonate I containing Si-O-Ca structure includes the following steps: 1.2 g of aspartic acid-β-methyl ester hydrochloride was dissolved in 15 mL of anhydrous N,N-dimethylformamide, and 1.01 g of 1-hydroxybenzotriazole and 1.44 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was activated by stirring at room temperature for 30 min under argon protection. Then, 1.8 mL of aminosilane coupling agent (model KH-550) and 1.3 mL of N,N-diisopropylethylamine were added. The mixture was stirred at room temperature for 12 h under argon protection to obtain a reaction solution. The reaction solution was added dropwise to ice-cold diethyl ether, and a precipitate was formed. The precipitate was filtered, and the solid was collected to obtain the crude product. The crude product was washed with diethyl ether to remove residual solvent and reaction byproducts. The product was purified by reversed-phase high-performance liquid chromatography, and the target product was collected and lyophilized to obtain aminosilanized aspartic acid. The preparation method of aspartic acid-β-methyl ester hydrochloride is as follows: 1 g of L-aspartic acid is mixed with 10 mL of anhydrous methanol, 1.5 mL of thionyl chloride is added dropwise under an ice bath at 0 °C, the temperature is raised to 25 °C, the reaction is stirred for 12 h, and methanol is removed by rotary evaporation to obtain aspartic acid-β-methyl ester hydrochloride. According to a 2:1 molar ratio of aminosilanized aspartic acid in solution II to calcium ions in solution I, 0.1 mol / L calcium nitrate solution I and a mixed solution II containing 0.15 mol / L aminosilanized aspartic acid and 0.1 mol / L potassium carbonate were mixed. The pH was adjusted to 8.5, and the reaction was statically incubated at room temperature for 4 h. The precipitate in the reaction solution was filtered, washed successively with deionized water and anhydrous ethanol, and dried to obtain spherical calcium carbonate I containing Si-O-Ca structure. SEM image is shown below. Figure 13 As shown.

[0140] Comparative Example 3 The only difference between this comparative example and Example 3 is that, in this comparative example, the helical calcium carbonate containing the Si-O-Ca structure is replaced with an equal amount of spherical calcium carbonate II containing the Si-O-Ca structure. The preparation method of spherical calcium carbonate II containing Si-O-Ca structure includes the following steps: 1.2 g of aspartic acid-β-methyl ester hydrochloride was dissolved in 15 mL of anhydrous N,N-dimethylformamide, and 1.01 g of 1-hydroxybenzotriazole and 1.44 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was activated by stirring at room temperature for 30 min under argon protection. Then, 1.8 mL of aminosilane coupling agent (model KH-550) and 1.3 mL of N,N-diisopropylethylamine were added. The mixture was stirred at room temperature for 12 h under argon protection to obtain a reaction solution. The reaction solution was added dropwise to ice-cold diethyl ether, and a precipitate was formed. The precipitate was filtered, and the solid was collected to obtain the crude product. The crude product was washed with diethyl ether to remove residual solvent and reaction byproducts. The product was purified by reversed-phase high-performance liquid chromatography, and the target product was collected and lyophilized to obtain aminosilanized aspartic acid. The preparation method of aspartic acid-β-methyl ester hydrochloride is as follows: 1 g of L-aspartic acid is mixed with 10 mL of anhydrous methanol, 1.5 mL of thionyl chloride is added dropwise under an ice bath at 0 °C, the temperature is raised to 25 °C, the reaction is stirred for 12 h, and methanol is removed by rotary evaporation to obtain aspartic acid-β-methyl ester hydrochloride. According to the molar ratio of aminosilanized aspartic acid in solution II to calcium ions in solution I of 0.25:1, 0.1 mol / L calcium nitrate solution I and mixed solution II containing 0.15 mol / L aminosilanized aspartic acid and 0.1 mol / L potassium carbonate were mixed. The pH was adjusted to 8.5, and the reaction was statically incubated at room temperature for 4 h. The precipitate in the reaction solution was filtered, washed with deionized water and anhydrous ethanol, and dried to obtain spherical calcium carbonate II containing Si-O-Ca structure. SEM image is shown below. Figure 14 As shown.

[0141] Comparative Example 4 The only difference between this comparative example and Example 3 is that, in this comparative example, the helical calcium carbonate containing the Si-O-Ca structure is replaced with an equal amount of spherical calcium carbonate III containing the Si-O-Ca structure. The preparation method of spherical calcium carbonate III containing Si-O-Ca structure includes the following steps: 1.2 g of aspartic acid-β-methyl ester hydrochloride was dissolved in 15 mL of anhydrous N,N-dimethylformamide, and 1.01 g of 1-hydroxybenzotriazole and 1.44 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was activated by stirring at room temperature for 30 min under argon protection. Then, 1.8 mL of aminosilane coupling agent (model KH-550) and 1.3 mL of N,N-diisopropylethylamine were added. The mixture was stirred at room temperature for 12 h under argon protection to obtain a reaction solution. The reaction solution was added dropwise to ice-cold diethyl ether, and a precipitate was formed. The precipitate was filtered, and the solid was collected to obtain the crude product. The crude product was washed with diethyl ether to remove residual solvent and reaction byproducts. The product was purified by reversed-phase high-performance liquid chromatography, and the target product was collected and lyophilized to obtain aminosilanized aspartic acid. The preparation method of aspartic acid-β-methyl ester hydrochloride is as follows: 1 g of L-aspartic acid is mixed with 10 mL of anhydrous methanol, 1.5 mL of thionyl chloride is added dropwise under an ice bath at 0 °C, the temperature is raised to 25 °C, the reaction is stirred for 12 h, and methanol is removed by rotary evaporation to obtain aspartic acid-β-methyl ester hydrochloride. According to the molar ratio of aminosilanized aspartic acid in solution II to calcium ions in solution I of 0.5:1, 0.1 mol / L calcium nitrate solution I and mixed solution II containing 0.15 mol / L aminosilanized aspartic acid and 0.1 mol / L potassium carbonate were mixed. The pH was adjusted to 8.5, and the reaction was statically incubated at room temperature for 4 h. The precipitate in the reaction solution was filtered, washed with deionized water and anhydrous ethanol, and dried to obtain spherical calcium carbonate III containing Si-O-Ca structure. SEM image is shown below. Figure 15 As shown.

[0142] Comparative Example 5 The only difference between this comparative example and Example 3 is that, in preparing the grinding wheel, this comparative example did not add helical calcium carbonate with a Si-O-Ca structure, and the weight of the added phenolic resin powder was 50 parts.

[0143] Comparative Example 6 The only difference between this comparative example and Example 3 is that, in preparing the grinding wheel in this comparative example, the weight parts of diamond micro powder are 40 parts, the weight parts of polymethyl methacrylate microspheres are 5 parts, the weight parts of spiral calcium carbonate containing Si-O-Ca structure are 12 parts, and the weight parts of phenolic resin powder are 43 parts.

[0144] Comparative Example 7 The only difference between this comparative example and Example 3 is that, in preparing the grinding wheel in this comparative example, the weight parts of diamond micro powder are 50 parts, the weight parts of polymethyl methacrylate microspheres are 5 parts, the weight parts of spiral calcium carbonate containing Si-O-Ca structure are 12 parts, and the weight parts of phenolic resin powder are 33 parts.

[0145] Experimental Example 1: Mechanical Property Testing The following performance tests were performed on the grinding blocks in Examples 3-7 and Comparative Examples 1-7: (1) Flexural strength: Prepare a sample strip with a length × width × height of 65 mm × 7 mm × 7 mm, and measure the flexural strength on a single lever flexural strength tester with a load speed of 10 N / S; (2) Compressive strength: Prepare a cylindrical sample block with a diameter of Φ20 mm×20 mm, and measure the compressive strength on a compressive strength testing machine with a support blade diameter of 10 mm and a load speed of 200 N / S; (3) Tensile strength: Prepare an “8” shaped sample block, clamp the sample block on a tensile testing machine, and apply a tensile force at a constant rate of 400 N / s until the sample block breaks.

[0146] The test results are shown in Table 1 below.

[0147] Table 1. Mechanical property test results

[0148] The grinding blocks obtained in Examples 3-7 have high flexural strength, compressive strength and tensile strength, indicating that the grinding wheel of this application has good mechanical properties. Good mechanical properties can enable the grinding wheel to maintain the stability of the grinding surface morphology during high-speed grinding, reduce the particle shedding rate and improve the stability of the flatness of the wafer after thinning.

[0149] The grinding block obtained in Example 3 exhibits higher flexural strength, compressive strength, and tensile strength than Comparative Examples 1-4. This indicates that the helical calcium carbonate containing the Si-O-Ca structure not only disperses stress and avoids local stress concentration through its helical morphology but also enhances the interfacial bonding between the helical calcium carbonate and the resin through its Si-O-Ca structure. By leveraging the synergistic effect of physical morphology and chemical structure, the mechanical properties of the grinding block are improved. The grinding block obtained in Example 3 also exhibits higher flexural strength, compressive strength, and tensile strength than Comparative Example 5. This demonstrates that adding helical calcium carbonate containing the Si-O-Ca structure as a filler can improve the stress distribution of the grinding block under external force, avoid local stress concentration, and improve the mechanical properties of the grinding block. Furthermore, the grinding block obtained in Example 3 exhibits higher flexural strength, compressive strength, and tensile strength than Comparative Examples 6-7. This indicates that the raw material ratio of the grinding block affects its mechanical properties; when the raw material ratio is within the range specified in this application, the mechanical properties of the grinding block can be improved.

[0150] Experiment Example 2: Grinding Performance Test The grinding wheels prepared in Examples 3-7 and Comparative Examples 1-7 were used to grind 12-inch wafers. The total thickness deviation of the wafer after thinning and the service life of the grinding wheels were measured. The specific test method was as follows: The wafer was adsorbed onto the adsorption platform; the grinding wheel with an outer diameter of 300 mm × inner diameter of 237 mm × height of 32 mm was moved down to contact the wafer under the drive of the feed assembly; the grinding wheel and the adsorption platform rotated in the same direction, with the grinding wheel rotating at 4800 rpm and the adsorption platform rotating at 300 rpm; during rough grinding, the grinding wheel was fed downwards at a feed rate of 5 / 4 / 3 μm / s while rotating, and the cooling water flow rate was 4 L / min during the grinding process; after rough grinding, the grinding wheel prepared in this grinding block was used for fine grinding, with the grinding wheel being fed downwards at a feed rate of 0.3 / 0.2 / 0.1 μm / s while rotating, and the cooling water flow rate was 4 L / min during the grinding process, until the wafer thickness was reduced to 765 μm. μm, the grinding wheel and adsorption platform stop rotating, the feed assembly drives the grinding wheel to move upward until it separates from the wafer; the adsorption platform releases the wafer from the wafer, and the wafer is transferred for testing.

[0151] The test results are shown in Table 2 below.

[0152] Table 2 Grinding performance test results

[0153] The grinding wheels obtained in Examples 3-7 have lower total thickness deviation and longer service life after thinning the wafer, indicating that the grinding wheels of this application can provide higher processing flatness and significantly increase the service life, which is conducive to extending the wheel replacement cycle, reducing the risk of production interruption and maintenance frequency, and improving the overall production line utilization rate and cost control capability.

[0154] The grinding wheel obtained in Example 3, after thinning the wafer, showed a lower total thickness deviation and a longer service life than Comparative Examples 1-4. This indicates that the helical calcium carbonate containing the Si-O-Ca structure, on the one hand, utilizes its helical morphology to disperse stress and avoid local stress concentration; on the other hand, it enhances the interfacial bonding between the helical calcium carbonate and the resin through the Si-O-Ca structure. By leveraging the synergistic effect of physical morphology and chemical structure, stable control of the grinding force can be achieved during the thinning process, thereby solving the problem of poor wafer flatness after thinning and improving the service life of the grinding wheel. The grinding wheel obtained in Example 3, after thinning the wafer, showed a lower total thickness deviation and a longer service life than Comparative Example 5. This indicates that by adding helical calcium carbonate containing the Si-O-Ca structure as a filler, the stress distribution of the grinding block under external force can be improved, avoiding local stress concentration and making the grinding force distribution more uniform during the thinning process. This solves the problem of poor wafer flatness after thinning and significantly improves the service life of the grinding wheel. The grinding wheel obtained in Example 3, after thinning the wafer, showed a lower total thickness deviation than Comparative Examples 6-7 and a longer service life than Comparative Examples 6-7. This indicates that the raw material ratio of the grinding block has an impact on the flatness of the thinned wafer and the service life of the grinding wheel. When the raw material ratio of the grinding block is within the range of the application, the problem of poor flatness of the thinned wafer can be solved, and the service life of the grinding wheel can be significantly improved.

[0155] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. The application of a spiral calcium carbonate in grinding blocks, characterized in that, The spiral calcium carbonate contains a Si-O-Ca structure, which is used to disperse the stress of the grinding block during grinding. The spiral calcium carbonate has a spherulite crystal form. The spiral calcium carbonate comprises multiple plate-like crystals, which are arranged in a spiral around a center and adjacent plate-like crystals are partially stacked, so that the spiral calcium carbonate has chiral characteristics and the multiple plate-like crystals can disperse the stress during grinding. The spiral calcium carbonate is formed by the induction of calcium ions with aminosilanized aspartic acid.

2. The application of the spiral calcium carbonate according to claim 1 in grinding blocks, characterized in that, The average particle size of the spiral calcium carbonate is 1~100 μm.

3. The application of the spiral calcium carbonate according to claim 1 in grinding blocks, characterized in that, The aminosilanized aspartic acid is prepared by a condensation reaction of aspartic acid-β-methyl ester hydrochloride and an aminosilane coupling agent.

4. The application of the spiral calcium carbonate according to claim 1 in grinding blocks, characterized in that, The molar ratio of aminosilylated aspartic acid to calcium ions is 0.8~1.5:

1.

5. The application of the spiral calcium carbonate according to claim 3 in grinding blocks, characterized in that, The mass-to-volume ratio of the aspartic acid-β-methyl ester hydrochloride and the aminosilane coupling agent is 1~1.2 g:1.8 mL.

6. The application of the spiral calcium carbonate according to claim 1 in grinding blocks, characterized in that, The method for preparing the spiral calcium carbonate includes the following steps: mixing a solution containing the calcium ions, a solution containing the aminosilylated aspartic acid and carbonate ions to obtain a mixed solution, adjusting the pH to alkaline, and reacting to obtain spiral calcium carbonate.

7. The application of the spiral calcium carbonate according to claim 6 in grinding blocks, characterized in that, In the mixed solution, the molar ratio of carbonate ions to calcium ions is 2~3:

3.

8. The application of the spiral calcium carbonate according to claim 6 in grinding blocks, characterized in that, The process of adjusting the pH value to alkaline specifically involves adjusting the pH value to 8-9.

9. The application of the spiral calcium carbonate according to claim 6 in grinding blocks, characterized in that, The reaction specifically involves static incubation at room temperature for 4-6 hours.

10. The application of the spiral calcium carbonate according to claim 9 in grinding blocks, characterized in that, The raw materials of the grinding block include the following components in parts by weight: 45 parts of abrasive, 34-46 parts of resin, 4-12 parts of spiral calcium carbonate, and 2-10 parts of pore-forming agent.

11. The application of the spiral calcium carbonate according to claim 10 in grinding blocks, characterized in that, The abrasive has an average particle size of 10-100 μm; the pore-forming agent has an average particle size of 20-100 μm.

12. The application of the spiral calcium carbonate according to claim 10 in grinding blocks, characterized in that, The resin includes one or more of phenolic resin, polyimide resin, and epoxy resin; the pore-forming agent includes one or more of polymer microspheres, carbonates, and metal hydroxides; and the abrasive includes one or more of corundum, silicon carbide, boron carbide, diamond, and boron nitride.

13. An application of spiral calcium carbonate in wafer thinning grinding wheels, characterized in that, The grinding wheel includes grinding blocks; The grinding block includes spiral calcium carbonate with a Si-O-Ca structure, which is used to disperse stress during grinding. The helical calcium carbonate containing the Si-O-Ca structure has the crystal form of spherulite. The helical calcium carbonate containing the Si-O-Ca structure comprises multiple plate-like crystals, which are arranged in a spiral around the center and adjacent plate-like crystals are partially stacked, so that the helical calcium carbonate containing the Si-O-Ca structure has chiral characteristics and the multiple plate-like crystals can disperse the stress during grinding. The spiral calcium carbonate is formed by the induction of calcium ions with aminosilanized aspartic acid.

14. The application of the spiral calcium carbonate according to claim 13 in a wafer thinning grinding wheel, characterized in that, The grinding wheel includes a substrate and a plurality of grinding blocks disposed on the surface of the substrate for grinding wafers. The plurality of grinding blocks are shaped as rounded rectangles or fan shapes. The surface of the substrate is provided with an annular groove, and at least a portion of the plurality of grinding blocks is embedded in the annular groove and spaced apart from each other on the substrate.

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